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Sample records for pinturas base solvente

  1. Estudio de las Propiedades Anticorrosivas del Benzoato de Hierro (III en Pinturas Base Solvente Study of Anticorrosive Properties of the Iron (III Benzoate in Solvent Based Paints

    Directory of Open Access Journals (Sweden)

    Guillermo Blustein

    2006-01-01

    Full Text Available La acción inhibidora del benzoato de hierro en electrodos de acero SAE 1010 en contacto con una suspensión acuosa fue estudiada mediante ensayos electroquímicos. Paralelamente, la eficiencia anticorrosiva de este producto incorporado a cubiertas orgánicas base solvente fue evaluada mediante ensayos de envejecimiento acelerado (cámara de niebla salina y de humedad. La evolución del comportamiento protector de la cubierta aplicada sobre paneles de acero pintados e inmersos en una solución 0.5M de NaClO4 fue periódicamente monitoreada por espectroscopía de impedancia electroquímica. Los resultados obtenidos indican que las pinturas formuladas con benzoato férrico presentan una capacidad anticorrosiva comparable a las formuladas con fosfato de cinc.This study investigated the inhibitory action of iron benzoate on SAE 1010 steel electrodes in aqueous suspensions using electrochemical assays. The anticorrosive efficiency of this product added to organic solvent-based coatings was also evaluated by means of accelerated weathering tests (salt spray cabinet and humidity chamber. The evolution of the protective behavior of the coating applied on steel panels and immersed in 0.5M NaClO4 solution was periodically checked by electrochemical impedance spectroscopy. The results obtained showed that paints formulated with ferric benzoate provide anticorrosive protection similar to those formulated with zinc phosphate.

  2. Aplicación de herramientas de producción más limpia para la gestión ambiental de residuos peligrosos: estudio de caso en pinturas y solventes Spratech Ltda municipio de la Estrella (Ant.)

    OpenAIRE

    Moreno Restrepo, Beatriz Elena

    2014-01-01

    Tesis (Maestría en Desarrollo Sostenible y Medio Ambiente). Universidad de Manizales. Facultad de Ciencias Contables, Económicas y Administrativas, 2014 Este artículo presenta el diagnóstico del riesgo ambiental de una pequeña empresa de pinturas y solventes del sur del Valle de Aburra- Antioquia, en la planta de producción, con el fin de establecer las herramientas de producción más limpia que permitan mejorar la gestión de los residuos peligrosos (Respel) en la organización, buscando e...

  3. Solvent

    OpenAIRE

    Hamida Y. Mostafa; Ebaa A. El-Shamy; Amal S. Farag; Nadia G. Kandile

    2013-01-01

    Neat ethylacetoacetate (EAA) and its mixtures with a co-solvent and an anti-solvent have been studied for refining of heavy wax distillate fraction to produce substantially non-carcinogenic base oil. The co-solvent and anti-solvent used are dipropylene glycol (DPG) and ethylene glycol (EG) respectively. The solubility characteristics of the main solvent and its mixed solvent systems were studied. Selection of the optimum solvent mixture and extraction variables has been studied. The effect of...

  4. Revisión de las investigaciones con base en el estudio de las pinturas para moldes en la industria de la fundición

    Directory of Open Access Journals (Sweden)

    Álvaro Morales

    2011-11-01

    Full Text Available Las pinturas para moldes son sustancias de muy diversa naturaleza, utilizadas para recubrir las superficies de los moldes que estarán en íntimo contacto con el metal fundido y que buscan la sanidad completa de la pieza. La presente revisión hace énfasis en el papel que tiene la pintura como regulador térmico en los moldes metálicos y describe los parámetros que deben tenerse en cuenta para la correcta caracterización.

  5. Acids and bases solvent effects on acid-base strenght

    CERN Document Server

    Cox, Brian G

    2013-01-01

    Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

  6. Glycerol based solvents: synthesis, properties and applications

    OpenAIRE

    García, José I.; García-Marín, Héctor; Pires, Elísabet

    2014-01-01

    The most recent advances in the use of glycerol and glycerol derivatives as solvents are reviewed. There are an increasing number of examples of the use of glycerol itself as a reaction medium, solvent-reagent or a dispersive medium for a large variety of applications. In the case of glycerol derivatives, new synthetic methods, physico-chemical properties and application examples as solvents are revised. Recent studies in the field of solvent classification, as well as solvent substitution is...

  7. Estudo de silanos nas linhas de pintura da Caetano Coatings

    OpenAIRE

    2011-01-01

    Tese de mestrado em Química Tecnológica (Química Tecnológica e Qualidade), apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2011 O principal objectivo deste trabalho foi o controlo da concentração de silício no banho à base de silanos, que integra o pré-tratamento efectuado nas linhas de pintura a pó e pintura líquida da Caetano Coatings com a implementação do procedimento interno ME/LAB/Silanos. O banho à base de silanos é preparado com uma concentração de silício i...

  8. Sobre la pintura y su lugar

    Directory of Open Access Journals (Sweden)

    Francisco Javier Buendía Puyo

    2014-04-01

    Full Text Available En esta investigación se pregunta por la puesta en escena de un elemento fundamental, el cualhistóricamente se ha ido dejando de lado, no solo en la pintura, sino en todas las prácticasartísticas en general, a saber, la superficie. La superficie es siempre el primer lugar para cualquierarte, y es una de las pocas certezas para la pintura. Superficie es pensamiento, idea, lenguaje: laobra misma, el lugar del hombre.

  9. Biological Treatment of Solvent-Based Paint

    Science.gov (United States)

    2011-01-01

    solvent. In addition, hydrocarbon mixtures, aromatic hydrocarbon, and Medium Aliphatic Solvent Naphtha are descriptors used by the manufactures to...Enamel Aromatic Hydrocarbon 14 Mineral Spirits 10 Naphtha 10 Ethyl Benzene 0.21 Xylene 1.0 Sherwin Williams Co Enamel Mineral Spirits 49...Solvent Naphtha 31.5 Non-hazardous Ingredients 68 Parker Paints Enamel Mineral Spirits 17 Naphtha 7 Aromatic Hydrocarbons 3 1,2,4

  10. Análisis de pinturas prehistóricas por difracción de rayos-X

    OpenAIRE

    Do Campo, Margarita

    1989-01-01

    Se analizaron dos muestras de pintura arqueológica de Cristóbal, Jujuy. Luego de molidas en mortero de ágata se mezclaron, debido a su escasa cantidad, con etil celulosa, y fueron montadas en un portaobjetos. Evaporado el solvente, el material en estudio quedó adherido permitiendo difractarlo. Sociedad Argentina de Antropología

  11. Análisis de pinturas prehistóricas por difracción de rayos-X

    OpenAIRE

    Do Campo, Margarita

    1989-01-01

    Se analizaron dos muestras de pintura arqueológica de Cristóbal, Jujuy. Luego de molidas en mortero de ágata se mezclaron, debido a su escasa cantidad, con etil celulosa, y fueron montadas en un portaobjetos. Evaporado el solvente, el material en estudio quedó adherido permitiendo difractarlo.

  12. Pinturas reforzadas con hilos cortos de vidrio

    Directory of Open Access Journals (Sweden)

    Hernández Olivares, Francisco

    2003-04-01

    Full Text Available Current research literature on coatings for building applications make evident the existence of important damage both in outdoors and indoors applications when the paint is used without any reinforcement because of several reasons: the low quality of some paint components, coatings extremely thin, and the unskilful of painters.This article studies the behaviour of some industrial paints for indoors and outdoors applications when reinforced with different gravimetric fractions of dispersable short cut glass fibre yarns. Jt is also studied the support influence (cement mortar, plasterboard and laminated plasterboard and the application method (handy or sprayed. A better performance and durability is obtained for the fractions by weight which are determined for each type of paint, support and application method. Neither the paint colour properties nor the brightness and texture get worse when these gravimetric fractions of glass fibre are added to the paint.La presente investigación estudia la viabilidad del empleo de refuerzos de fibra de vidrio para pinturas de interior y exterior con el fin de paliar parte de las patologías observadas en aplicaciones arquitectónicas. Se ha seleccionado un tipo de fibra de refuerzo dispersable y se ha estudiado el comportamiento de tres tipos de pinturas (temple, plástica y de impermeabilización para fracciones gravimétricas crecientes de refuerzo y distintos procesos de aplicación de la pintura.Se ha conseguido mejorar las propiedades de las pinturas industriales que existen en el mercado para aplicaciones interiores y exteriores en edificación elevando las propiedades mecánicas y de durabilidad de dichas pinturas, sin que ello suponga ningún cambio significativo en las cualidades de la pintura, como son la colorimetría, el brillo y el espesor de película.

  13. Optimal (Solvent) Mixture Design through a Decomposition Based CAMD methodology

    DEFF Research Database (Denmark)

    Achenie, L.; Karunanithi, Arunprakash T.; Gani, Rafiqul

    2004-01-01

    Computer Aided Molecular/Mixture design (CAMD) is one of the most promising techniques for solvent design and selection. A decomposition based CAMD methodology has been formulated where the mixture design problem is solved as a series of molecular and mixture design sub-problems. This approach is...... is able to overcome most of the difficulties associated with the solution of mixture design problems. The new methodology has been illustrated with the help of a case study involving the design of solvent-anti solvent binary mixtures for crystallization of Ibuprofen.......Computer Aided Molecular/Mixture design (CAMD) is one of the most promising techniques for solvent design and selection. A decomposition based CAMD methodology has been formulated where the mixture design problem is solved as a series of molecular and mixture design sub-problems. This approach...

  14. Toxicity and hazardous properties of solvent base adhesive wastes.

    Science.gov (United States)

    Sabater, M C; Martínez, M A; Font, R

    2001-10-01

    In this work, the hazardous properties of solvent base adhesive wastes generated in the footwear manufacturing process have been studied. The characterisation procedures and criteria used are those contained in the legal documents European Union Council Decision 94/904/CE and October 13th Spanish Ministerial Order. The properties studied were the following: flash point, reactivity (gas generation), ecotoxicity, main contaminants extracted by the leaching process and main harmful substances contained in wastes. An additional study of the relationship between flash point and solvent concentration in waste was carried out for polyurethane-acetone and neoprene-toluene systems. The wastes considered were metal containers with remains of dry or semi-dry adhesive. The results obtained show that the presence of solvent in wastes confers on them hazardous characteristics (flash point and harmful composition) depending on the solvent type and its concentration.

  15. A knowledge based advisory system for acid/base titrations in non-aqueous solvents

    NARCIS (Netherlands)

    Bos, M.; Linden, van der W.E.

    1996-01-01

    A computer program was developed that could advice on the choice of solvent and titrant for acid/base titrations in nonaqueous media. It is shown that the feasibility of a titration in a given solvent can be calculated from solvent properties and intrinsic acid/base properties of the sample componen

  16. Pinturas del Corral de Morcilla (Las Batuecas

    Directory of Open Access Journals (Sweden)

    Julián BÉCARES PÉREZ

    2009-10-01

    Full Text Available Durante una de las frecuentes visitas que el Departamento de Prehistoria y Arqueología de Salamanca realiza a Las Batuecas tuvo lugar, en noviembre de 1973, el descubrimiento de un nuevo abrigo con pinturas por el Dr. Jordá, quien me brindó su publicación ayudándome en los trabajos de calco y estudio, por lo que le estoy muy agradecido.

  17. Introduccion a la moderna pintura ecuatoriana

    Directory of Open Access Journals (Sweden)

    Boletín Cultural y Bibliográfico Banco de la República

    1959-10-01

    Full Text Available Por decisión común de la razón, la sensibilidad y voluntad de sus creadores, la pintura actual del Ecuador tiende, en primer lugar, a integrarse en las corrientes pictóricas univerales de nuestro tiempo. Sin embargo, ciertos trazos propios, irrenunciables, por estar alimentados con la misma savia que dio vida a las formas que nos legaron nuestros mayores, hacen de ella un hecho aparte, nacional, inconfundible.

  18. Rare earth element enrichment using membrane based solvent extraction

    Science.gov (United States)

    Makertiharta, I. G. B. N.; Dharmawijaya, P. T.; Zunita, M.; Wenten, I. G.

    2017-01-01

    The chemical, catalytic, electrical, magnetic, and optical properties of rare earth elements are required in broad applications. Rare earth elements have similar physical and chemical properties thus it is difficult to separate one from each other. Rare earth element is relatively abundant in earth's crust but rarely occur in high concentrated deposits. Traditionally, ion-exchange and solvent extraction techniques have been developed to separate and purify single rare earth solutions or compounds. Recently, membrane starts to gain attention for rare earth separation by combining membrane and proven technologies such as solvent extraction. Membrane-based process offers selective, reliable, energy efficient and easy to scale up separation. During membrane-based separation process, one phase passes through membrane pores while the other phase is rejected. There is no direct mixing of two phases thus the solvent loss is very low. Membrane can also lower solvent physical properties requirement (viscosity, density) and backmixing, eliminate flooding phenomenon and provide large interfacial area for mass transfer. This paper will summarize research efforts in developing membrane technology for rare earth element separation. Special attention will be given to solvent extraction related process as the commonly used method for rare earth element separation. Furthermore, membrane configuration and its potentials will also be discussed.

  19. Hystricognath rodents from the Pinturas Formation, Early Middle Miocene of Patagonia, biostratigraphic and paleoenvironmental implications

    Science.gov (United States)

    Kramarz, Alejandro G.; Bellosi, Eduardo S.

    2005-01-01

    The Pinturas Formation is a continental succession, characterized by eolian sediments (mainly tuffaceous) and paleosols, originated in an upland setting of west central Patagonia. The main intraformational erosive surfaces and lithological changes define three sequences. The Formation bears a rich mammalian association (Florentino Ameghino's Astrapothericulan fauna), whose age in relation to the Santacrucian SALMA (middle Miocene) is still controversial. Recent collections from the Pinturas Formation, performed with stratigraphic control, allow differentiation of two distinct hystricognath rodent associations. The lower and middle sequences bear a particular combination of Colhuehuapian (early Miocene) and Santacrucian genera, mostly represented by species exclusively known to the Pinturas Formation ('Pinturan' association). The upper sequence bears typical Santacrucian species, more derived than its Pinturan counterparts. According to the rodent record, the lower and middle sequences of the Pinturas Formation are older than the base of the Santa Cruz Formation exposed at Monte Observación and Monte León, and the upper sequence may be correlated with the lowermost levels of the Santa Cruz Formation and deposits exposed at Karaiken that bear Ameghino's 'Notohippidian' fauna. These correlations agree with more recent radiometric dates and other biostratigraphic evidence, supporting Ameghino's original hypothesis. The Pinturan rodent assemblage of the lower and middle sequences suggests the presence of humid forests, in accordance with other faunal components and palynological data. Sedimentologic, paleopedologic, and ichnologic evidence, however, suggest environments dominated by herbaceous vegetation. This seeming contradiction is interpreted as the result of a marked environmental gradient due to the paleotopography and/or climatic fluctuations. The mammal record corresponds to the more humid intervals, which have less representation in the sedimentary record

  20. Solvent extraction of gold using ionic liquid based process

    Science.gov (United States)

    Makertihartha, I. G. B. N.; Zunita, Megawati; Rizki, Z.; Dharmawijaya, P. T.

    2017-01-01

    In decades, many research and mineral processing industries are using solvent extraction technology for metal ions separation. Solvent extraction technique has been used for the purification of precious metals such as Au and Pd, and base metals such as Cu, Zn and Cd. This process uses organic compounds as solvent. Organic solvents have some undesired properties i.e. toxic, volatile, excessive used, flammable, difficult to recycle, low reusability, low Au recovery, together with the problems related to the disposal of spent extractants and diluents, even the costs associated with these processes are relatively expensive. Therefore, a lot of research have boosted into the development of safe and environmentally friendly process for Au separation. Ionic liquids (ILs) are the potential alternative for gold extraction because they possess several desirable properties, such as a the ability to expanse temperature process up to 300°C, good solvent properties for a wide range of metal ions, high selectivity, low vapor pressures, stability up to 200°C, easy preparation, environmentally friendly (commonly called as "green solvent"), and relatively low cost. This review paper is focused in investigate of some ILs that have the potentials as solvent in extraction of Au from mineral/metal alloy at various conditions (pH, temperature, and pressure). Performances of ILs extraction of Au are studied in depth, i.e. structural relationship of ILs with capability to separate Au from metal ions aggregate. Optimal extraction conditon in order to gain high percent of Au in mineral processing is also investigated.

  1. Carbon dioxide-based supercritical fluids as IC manufacturing solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Davenhall, L.B.; Taylor, C.M.V.; Sivils, L.D.; Pierce, T.; Tiefert, K.

    1999-05-11

    The production of integrated circuits (IC's) involves a number of discrete steps which utilize hazardous or regulated solvents and generate large waste streams. ES&H considerations associated with these chemicals have prompted a search for alternative, more environmentally benign solvent systems. An emerging technology for conventional solvent replacement is the use of supercritical fluids based on carbon dioxide (CO{sub 2}). Research work, conducted at Los Alamos in conjunction with the Hewlett-Packard Company, has lead to the development of a CO{sub 2}-based supercritical fluid treatment system for the stripping of hard-baked photoresists. This treatment system, known as Supercritical CO{sub 2} Resist Remover, or CORR, uses a two-component solvent composed of a nonhazardous, non-regulated compound, dissolved in supercritical CO{sub 2}. The solvent/treatment system has been successfully tested on metallized Si wafers coated with negative and positive photoresist, the latter both before and after ion-implantation. A description of the experimental data will be presented. Based on the initial laboratory results, the project has progressed to the design and construction of prototype, single-wafer photoresist-stripping equipment. The integrated system involves a closed-loop, recirculating cycle which continuously cleans and regenerates the CO{sub 2}, recycles the dissolved solvent, and separates and concentrates the spent resist. The status of the current design and implementation strategy of a treatment system to existing IC fabrication facilities will be discussed. Additional remarks will be made on the use of a SCORR-type system for the cleaning of wafers prior to processing.

  2. Effects of temperature and solvent concentration on the solvent crystallization of palm-based dihydroxystearic acid with isopropyl alcohol

    Institute of Scientific and Technical Information of China (English)

    Gregory F.L.Koay; Teong-Guan Chuah; Sumaiya Zainal-Abidin; Salmiah Ahmad; Thomas S.Y.Choong

    2012-01-01

    Palm-based dihydroxystearic acid of 69.55% purity was produced in a 500-kg-per-batch operation pilot plant and purified through solvent crystallization in a custom fabricated simultaneous batch crystallizer unit.The effects of temperature and solvent concentration on yield,particle size distribution and purity were studied.The purity was higher,while the yield and particle size were lower and smaller,respectively,at higher temperature and solvent concentration.The solvent crystallization process efficiency was rated at 66-69% when carried out with 70-80% isopropyl alcohol at 20 ℃.

  3. Control automático del sistema de mezcla de tintes en Pinturas Cóndor

    OpenAIRE

    Estrella Montalvo, David Fabián; Corrales Paucar, Luis; Villacreses Sánchez, Juan Manuel

    2007-01-01

    El objetivo de este proyecto es optimizar el proceso de producción de pintura mediante la automatización del proceso de mezcla de tintes. De esta forma se buscaba reducir los tiempos muertos originados por realizar en forma manual la mezcla. Con este objetivo se empleó un PLC para controlar las bombas que mueven la pasta desde el tanque dispersor, y solventes y resinas desde tanques de almacenamineto. Se desarrolló una HMI utilizando la plataforma INTOUCH 7.0. Pruebas realizadas demostraron q...

  4. Empleo del método electroquímico acelerado AC-DC-AC para la predicción del tiempo de vida útil de pinturas base agua

    Directory of Open Access Journals (Sweden)

    Bethencourt, M.

    2005-12-01

    Full Text Available In this study an accelerated method for the evaluation of painted metals is proposed. Specifically, the proposed method has been applied in a study of the process of degradation of two water-based paints applied to a carbon steel surface. The technique is based on the application of cycles combining measurement of electrochemical impedance spectra, cathodic polarisation steps, and recording of the evolution of the corrosion potential of the system in function of time. The results obtained from this method are compared with those obtained from studying the evolution of the impedance spectra of both systems in function of the time of immersion, for periods of immersion of the order of 200 days.

    En este trabajo se propone un método acelerado de evaluación de metales pintados. Concretamente, el método se ha aplicado al estudio del proceso de degradación de dos pinturas de base agua aplicadas sobre un acero al carbono. El método está basado en la aplicación de ciclos en los que se combinan la medida de espectros de impedancia electroquímica, etapas de polarización catódica y el registro de la evolución del potencial de corrosión del sistema en función del tiempo. Los resultados obtenidos mediante este método se comparan con los obtenidos al estudiar la evolución de los espectros de impedancia de ambos sistemas en función del tiempo de inmersión, para periodos de inmersión del orden de 200 d.

  5. Improving agar electrospinnability with choline-based deep eutectic solvents.

    Science.gov (United States)

    Sousa, Ana M M; Souza, Hiléia K S; Uknalis, Joseph; Liu, Shih-Chuan; Gonçalves, Maria P; Liu, LinShu

    2015-09-01

    Very recently our group has produced novel agar-based fibers by an electrospinning technique using water as solvent and polyvinyl alcohol (PVA) as co-blending polymer. Here, we tested the deep eutectic solvent (DES), (2-hydroxyethyl)trimethylammonium chloride/urea prepared at 1:2 molar ratio, as an alternative solvent medium for agar electrospinning. The electrospun materials were collected with an ethanol bath adapted to a previous electrospinning set-up. One weight percent agar-in-DES showed improved viscoelasticity and hence, spinnability, when compared to 1 wt% agar-in-water and pure agar nanofibers were successfully electrospun if working above the temperature of sol-gel transition (∼80 °C). By changing the solvent medium we decreased the PVA concentration (5 wt% starting solution) and successfully produced composite fibers with high agar contents (50/50 agar/PVA). Best composite fibers were formed with the 50/50 and 30/70 agar/PVA solutions. These fibers were mechanically resistant, showed tailorable surface roughness and diverse size distributions, with most of the diameters falling in the sub-micron range. Both nano and micro forms of agar fibers (used separately or combined) may have potential for the design of new and highly functional agar-based materials.

  6. How polar are choline chloride-based deep eutectic solvents?

    Science.gov (United States)

    Pandey, Ashish; Rai, Rewa; Pal, Mahi; Pandey, Siddharth

    2014-01-28

    Developing and characterizing green solvents with low toxicity and cost is one of the most important issues in chemistry. Deep Eutectic Solvents (DESs), in this regard, have shown tremendous promise. Compared to popular organic solvents, DESs possess negligible VOCs and are non-flammable. Compared to ionic liquids, which share many characteristics but are ionic compounds and not ionic mixtures, DESs are cheaper to make, much less toxic and mostly biodegradable. An estimate of the polarity associated with DESs is essential if they are to be used as green alternatives to common organic solvents in industries and academia. As no one physical parameter can satisfactorily represent solute-solvent interactions within a medium, polarity of DESs is assessed through solvatochromic optical spectroscopic responses of several UV-vis absorbance and molecular fluorescence probes. Information on the local microenvironment (i.e., the cybotactic region) that surrounds several solvatochromic probes [betaine dye, pyrene, pyrene-1-carboxaldehyde, 1-anilino-8-naphthalene sulfonate (ANS), p-toluidinyl-6-naphthalene sulfonate (TNS), 6-propionyl-2-(dimethylaminonaphthalene) (PRODAN), coumarin-153, and Nile Red] for four common and popular DESs formed from choline chloride combined with 1,2-ethanediol, glycerol, urea, and malonic acid, respectively, in 1 : 2 molar ratios termed ethaline, glyceline, reline, and maline is obtained and used to assess the effective polarity afforded by each of these DESs. The four DESs as indicated by these probe responses are found to be fairly dipolar in nature. Absorbance probe betaine dye and fluorescence probes ANS, TNS, PRODAN, coumarin-153, and Nile Red, whose solvatochromic responses are based on photoinduced charge-transfer, imply ethaline and glyceline, DESs formed using alcohol-based H-bond donors, to be relatively more dipolar in nature as compared to reline and maline. The pyrene polarity scale, which is based on polarity-induced changes in

  7. A knowledge based advisory system for acid/base titrations in non-aqueous solvents

    OpenAIRE

    1996-01-01

    A computer program was developed that could advice on the choice of solvent and titrant for acid/base titrations in nonaqueous media. It is shown that the feasibility of a titration in a given solvent can be calculated from solvent properties and intrinsic acid/base properties of the sample components. A consistent set of properties for various solvents and a large number of acidic and basic compounds was calculated from literature data with the use of a genetic algorithm. Test results show t...

  8. O OFÍCIO DA PINTURA EM PORTUGAL E O PROJETO DA ACADEMIA DE PINTURA

    Directory of Open Access Journals (Sweden)

    Raquel Quinet Pifano

    2013-06-01

    Full Text Available O presente artigo aborda o processo de reconhecimento do estatuto teórico das artes visuais e a consequente transformação do estatuto social do artista na Europa a partir do século XV. A formulação inédita de uma teoria da arte fundamentará tal processo e justificará a criação da Academia de Desenho em Florença no século XVI. A partir daí, muitas academias serão fundadas na Europa, consolidando paulatinamente a institucionalização da arte da pintura, escultura e arquitetura como artes liberais. Embora Portugal não se mantenha à margem deste processo, precisou esperar a dissolução do sistema de organização dos ofícios mecânicos em corporações para então fundar uma Academia de Belas Artes. Reflete-se aqui sobre o processo português de liberalização da arte: as relações entre a prática efetiva da pintura, a teoria da arte e o projeto de uma Academia de Pintura proposto pelo pintor Cyrillo Volkmar Machado.

  9. Opportunities for Bio-Based Solvents Created as Petrochemical and Fuel Products Transition towards Renewable Resources.

    Science.gov (United States)

    Clark, James H; Farmer, Thomas J; Hunt, Andrew J; Sherwood, James

    2015-07-28

    The global bio-based chemical market is growing in size and importance. Bio-based solvents such as glycerol and 2-methyltetrahydrofuran are often discussed as important introductions to the conventional repertoire of solvents. However adoption of new innovations by industry is typically slow. Therefore it might be anticipated that neoteric solvent systems (e.g., ionic liquids) will remain niche, while renewable routes to historically established solvents will continue to grow in importance. This review discusses bio-based solvents from the perspective of their production, identifying suitable feedstocks, platform molecules, and relevant product streams for the sustainable manufacturing of conventional solvents.

  10. Opportunities for Bio-Based Solvents Created as Petrochemical and Fuel Products Transition towards Renewable Resources

    Directory of Open Access Journals (Sweden)

    James H. Clark

    2015-07-01

    Full Text Available The global bio-based chemical market is growing in size and importance. Bio-based solvents such as glycerol and 2-methyltetrahydrofuran are often discussed as important introductions to the conventional repertoire of solvents. However adoption of new innovations by industry is typically slow. Therefore it might be anticipated that neoteric solvent systems (e.g., ionic liquids will remain niche, while renewable routes to historically established solvents will continue to grow in importance. This review discusses bio-based solvents from the perspective of their production, identifying suitable feedstocks, platform molecules, and relevant product streams for the sustainable manufacturing of conventional solvents.

  11. Pretreatment of Lignocellulosic Biomass with Ionic Liquids and Ionic Liquid-Based Solvent Systems.

    Science.gov (United States)

    Hou, Qidong; Ju, Meiting; Li, Weizun; Liu, Le; Chen, Yu; Yang, Qian

    2017-03-20

    Pretreatment is very important for the efficient production of value-added products from lignocellulosic biomass. However, traditional pretreatment methods have several disadvantages, including low efficiency and high pollution. This article gives an overview on the applications of ionic liquids (ILs) and IL-based solvent systems in the pretreatment of lignocellulosic biomass. It is divided into three parts: the first deals with the dissolution of biomass in ILs and IL-based solvent systems; the second focuses on the fractionation of biomass using ILs and IL-based solvent systems as solvents; the third emphasizes the enzymatic saccharification of biomass after pretreatment with ILs and IL-based solvent systems.

  12. Evaluación del riesgo ocupacional por exposición a benceno tolueno y xilenos en una industria de pinturas en Bogotá D.C.

    Directory of Open Access Journals (Sweden)

    María Del Pilar Rubiano D.

    2010-09-01

    Full Text Available Se determinaron los niveles de benceno, tolueno y xilenos (BTX en el aire de una industria de pinturas adscrita al Instituto Colombiano de Seguros Sociales, con el propósito de evaluar el riesgo ocupacional ocasionado por el uso de estos solventes; se compararon estos resultados con los valores límite umbral (Threshold Limit Valué , TLV.

  13. Los soportes textiles de pintura de caballete en México, siglos XVII-XIX. Aportaciones históricas tras su restauración

    Directory of Open Access Journals (Sweden)

    Rita Sumano González

    2012-12-01

    Full Text Available El presente artículo aborda la forma en que ciertos lienzos textiles fueron usados como soportes de pintura de caballete en México durante los siglos XVII al XIX. Se llevó a cabo un estudio usando como fuente primaria doscientos informes de trabajo de pinturas que habían sido restauradas por el Seminario Taller de Restauración de Pintura de Caballete de la Escuela Nacional de Conservación, Restauración y Museografía en México (STRPC-ENCRyM-INAH. Los registros de técnica de factura de los soportes se organizaron de acuerdo a una ficha de análisis textil y se vertieron en una base de datos, para después interpretarlos utilizando estadística descriptiva. Los resultados del análisis estadístico orientaron la investigación histórica, que se sirvió de fuentes vivas, materiales, bibliográficas y documentales. De esta investigación se desprendieron datos relevantes sobre la forma en que los lienzos fueron usados como soportes de pintura de caballete lo que puede contribuir a su estudio y a una mejor conservación de las pinturas.

  14. Significado de la Pintura Rupestre Esquemática

    Directory of Open Access Journals (Sweden)

    Pilar ACOSTA

    2009-10-01

    Full Text Available La interpretación global de los esquematismos que ha tenido de siempre más adeptos ha sido indudablemente la relacionada con la religión.Esta causa ha sido la constante repetida infinitas veces cada vez que el tema de la Pintura Rupestre en general ha surgido; con mayor motivo pues, es lógico que se atribuya este significado al arte esquemático dada la "coincidencia extraordinaria" de que los ídolos sean uno de sus temas preferidos.Sin embargo, creemos que hay que tener en cuenta una serie de circunstancias de todo tipo antes de aceptar "a priori" el sentido religioso de esta pintura, sólo por el hecho de ser "pintura" y por desconocer su verdadera finalidad, la cual, estamos seguros, jamás llegará a ser captada y comprendida en su verdadero sentido.

  15. Traços puritanos na pintura de Rembrandt

    Directory of Open Access Journals (Sweden)

    Carolina Pulici

    2007-07-01

    Full Text Available Este texto desenvolve uma pista levantada por Max Weber em A ética protestante e o "espírito" do capitalismo: trata-se da influência da ascese protestante na pintura de Rembrandt. Com base na sociologia da religião de Weber e em algumas análises sobre o pintor holandês e a Holanda do século XVII, argumenta-se ser possível ver numa parte do itinerário artístico rembrandtiano o equivalente pictórico da sensibilidade puritana descrita por Weber.This text develops a clue that was raised by Max Weber in The protestant ethic and the "spirit" of the capitalism: it deals about the protestant ascesis' influence on Rembrandt's painting. Taking Weber's sociology of religion and some analyses of the Dutch painter and the seventeenth century Holland as guidelines, it is argued that it's possible to see in a certain part of Rembrandt's artistic itinerary the pictorial equivalent of the puritan sensibility described by Weber.

  16. Pintura y paisaje: un recorrido por la Alameda Mexicana

    OpenAIRE

    Adrián Hernández Cordero

    2012-01-01

    La Alameda es el paseo más antiguo y emblemático de la Ciudad de México. Desde su creación ha sido uno de los paisajes preferidos para los pintores. Durante sus cuatro siglos de existencia se han generado una gran cantidad de pinturas de diferentes épocas que nos permiten mirar momentos del paseo y de la Ciudad de México. El documento primero sitúa la discusión entre paisaje y pintura con la intención de mostrar convergencias y divergencias en cuanto a sus objetivos y lenguajes. Posteriorment...

  17. Pintura, una materia interdisciplinar. Metodologías docentes.

    Directory of Open Access Journals (Sweden)

    Joaquim Cantalozella i Planas

    2009-07-01

    Full Text Available El grado de Bellas Artes permite revisar las asignaturas vinculadas a los talleres de creación y mejorar las metodologías docentes. Pintura pasará a compartir espacio con las materias de Dibujo, Escultura y más adelante Imagen. Así pues, lo que se impone es un aprendizaje basado en la interdisciplinariedad que puede llegar a proporcionar una mayor flexibilidad del conocimiento. El artículo presenta una serie de reflexiones sobre la docencia en los talleres de Pintura, de los dos primeros cursos del grado, y un conjunto de propuestas metodológicas para mejorarla.

  18. Purification of biodiesel by choline chloride based deep eutectic solvent

    Science.gov (United States)

    Niawanti, Helda; Zullaikah, Siti; Rachimoellah, M.

    2017-05-01

    Purification is a crucial step in biodiesel production to meet the biodiesel standard. This study purified biodiesel using choline chloride based deep eutectic solvent (DES). DES was used to reduce unreacted oil and unsaponifiable matter in rice bran oil based biodiesel. The objective of this work was to study the effect of extraction time using DES on the content and yield of fatty acid methyl ester (FAME). Rice bran used in this work contains 16.49 % of oil with initial free fatty acids (FFA) of 44.75 %. Acid catalyzed methanolysis was employed to convert rice bran oil (RBO) into biodiesel under following operation conditions: T = 60 °C, t = 8 h, molar ratio of oil to methanol = 1/10, H2SO4 = 1% w/w of oil. Rice bran oil based biodiesel obtained contain 89.05 % of FAME with very low FFA content (0.05 %). DES was made from a mixture of choline chloride and ethylene glycol with molar ratio of 1/2. Molar ratio of crude biodiesel to DES were 1/2 and 1/4. Extraction time was varied from 15 minutes to 240 minutes at 30 °C. The highest FAME content was obtained after purification for 240 min. at molar ratio crude biodiesel to DES 1/4 was 96.60 %. This work shows that DES has potential to purify biodiesel from non-edible raw material, such as RBO.

  19. Colorimetric solvent indicators based on Nafion membranes incorporating nickel(II)-chelate complexes.

    Science.gov (United States)

    Hosokawa, Hitoshi; Funasako, Yusuke; Mochida, Tomoyuki

    2014-11-10

    To develop solvent-recognition films, Nafion membranes incorporating cationic nickel-chelate complexes, that is, [Ni(L(1))(L(2))](+) (HL(1) = acetylacetone, 2,2,6,6-tetramethyl-3,5-heptanedione; L(2) = N,N-diethylethylenediamine, N-butyl-N,N',N'-trimethylethylenediamine), were prepared. Immersion of the films in various solvents effected the color changes varying from red to pale blue green depending on the donor number of the solvents. The color change is based on an equilibrium shift between square-planar and solvent-coordinated octahedral geometries of the cations. The degree of the color change depended on the affinity of the incorporated complex to the solvent molecules. The films were robust and exhibited a reversible solvent response. The films exhibited thermochromism when a small amount of appropriate solvents were incorporated and changed from pale blue green at low temperatures to red at high temperatures.

  20. Co-solvents with high coulombic efficiency in propylene carbonate based electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gao; Zhao, Hui; Park, Sang-Jae

    2017-06-27

    A homologous series of cyclic carbonate or propylene carbonate (PC) analogue solvents with increasing length of linear alkyl substitutes were synthesized and used as co-solvents with PC for graphite based lithium ion half cells. A graphite anode reaches a capacity around 310 mAh/g in PC and its analogue co-solvents with 99.95% Coulombic efficiency. Cyclic carbonate co-solvents with longer alkyl chains are able to prevent exfoliation of graphite when used as co-solvents with PC. The cyclic carbonate co-solvents of PC compete for solvation of Li ion with PC solvent, delaying PC co-intercalation. Reduction products of PC on graphite surfaces via single-electron path form a stable Solid Electrolyte Interphase (SEI), which allows the reversible cycling of graphite.

  1. Photonic Crystal Based Sensor for Organic Solvents and for Solvent-Water Mixtures

    Directory of Open Access Journals (Sweden)

    Otto S. Wolfbeis

    2012-12-01

    Full Text Available Monodisperse polystyrene nanoparticles with a diameter of 173 nm were incorporated into a polydimethylsiloxane matrix where they display an iridescent color that can be attributed to the photonic crystal effect. The film is of violet color if placed in plain water, but turns to red in the presence of the non-polar solvent n-hexane. Several solvents were studied in some detail. We show that such films are capable of monitoring the water content of ethanol/water mixtures, where only 1% (v/v of water leads to a shift of the peak wavelength of reflected light by 5 nm. The method also can be applied to determine, both visually and instrumentally, the fraction of methanol in ethanol/methanol mixtures. Here, a fraction of 1% of methanol (v/v results in a wavelength shift of 2 nm. The reflected wavelength is not influenced by temperature changes nor impeded by photobleaching. The signal changes are fully reversible and response times are <1 s.

  2. Arte y ciencia a través de las imágenes de aves en la pintura mural prehispánica

    OpenAIRE

    María de Lourdes Navarijo Ornelas

    2000-01-01

    Lourdes Navarijo examina las modalidades de representación gráfica de las aves en la pintura mural prehispánica. Aun cuando existen numerosos ejemplos en la arquitectura, la cerámica y otros objetos de uso común, lo cual atestigua la importancia de las aves en las culturas precolombinas, este estudio se concentra en la pintura. Tomando como base ejemplos de Teotihuacan y de cinco sitios arqueológicos más de la zona maya, la autora intenta explicar el papel de las aves como signos o metáforas ...

  3. Biodegradación de la materia orgánica presente en las aguas residuales de una empresa de pinturas

    OpenAIRE

    2007-01-01

    Debido a la necesidad de la Compañía Global de Pinturas (CGP) por darle un valor agregado a las aguas efluentes del Proceso de Producción de Pinturas Base Agua, se desarrolló un proyecto para el tratamiento biológico de estas con cepas nativas o consorcios, que permita disminuir su la carga orgánica y darles un posible uso en otros procesos de la planta o en el mismo proceso productivo. El tratamiento biológico realizado se desarrolló en el Laboratorio de Biotecnología de la Universidad EAFIT...

  4. Biodiesel production from ethanolysis of DPO using deep eutectic solvent (DES) based choline chloride - ethylene glycol as co-solvent

    Science.gov (United States)

    Taslim, Indra, Leonardo; Manurung, Renita; Winarta, Agus; Ramadhani, Debbie Aditia

    2017-03-01

    Biodiesel is usually produced from transesterification using methanol or ethanol as alcohol. However, biodiesel produced using methanol has several disadvantages because methanol is toxic and not entirely bio-based as it is generally produced from petroleum, natural gas and coal. On the other hand, ethanol also has several disadvantages such as lower reactivity in transesterification process and formation of stable emulsion between ester and glycerol. To improve ethanolysis process, deep eutectic solvent (DES) was prepared from choline chloride and ethylene glycol to be used as co-solvent in ethanolysis. Deep eutectic solvent was prepared by mixing choline chloride and ethylene glycol at molar ratio of 1:2, temperature of 80 °C, and stirring speed of 300 rpm for 1 hour. The DES was characterized by its density and viscosity. The ethanolysis of DPO / Degummed Palm Oil was performed at 70 °C, ethanol to oil molar ratio of 9:1, catalyst (potassium hydroxide) concentration of 0.75 wt.% concentration, co-solvent (DES) concentration of 1, 2, 3, 4, 5 and 6 wt.%, stirring speed of 600 rpm, and reaction time of 1 hour. The obtained biodiesel was then characterized by its density, viscosity and ester content. The oil - ethanol phase condition was observed in reaction tube. The oil - ethanol phase with DES tends to form meniscus compared to that without DES. Which implied that oil and ethanol become more slightly miscible, which favours the reaction. Using DES as co-solvent in ethanolysis resulted in an increase in yield and easier purification. The esters properties met the international standards ASTM D6751, with highest yield achieved at 81.72 % with 99.35 % ethyl ester contents at 4% DES concentration.

  5. Green solvent-based approaches for synthesis of nanomaterials

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The use of green solvents (including supercritical fluids and ionic liquids) in the synthesis of nanomaterials is highlighted. The methods described can not only reduce or eliminate the use or generation of substances hazardous to health and the environment, but can also be used to efficiently prepare nanomaterials with high performances. The unique characteristics of green solvents are responsible for the green features and unusual advantages of these approaches.

  6. La pintura de Alberto Gutiérrez

    Directory of Open Access Journals (Sweden)

    Clemente Airó

    1961-06-01

    Full Text Available Alberto Gutiérrez, nacido en 1935 y que desde los veinte años practicamente reside fuera del país, es uno de los pintores nuevos de Colombia que no más fidelidad representa el internacionalismo actual de la pintura.

  7. Cellulose solvent- and organic solvent-based lignocellulose fractionation enabled efficient sugar release from a variety of lignocellulosic feedstocks.

    Science.gov (United States)

    Sathitsuksanoh, Noppadon; Zhu, Zhiguang; Zhang, Y-H Percival

    2012-08-01

    Developing feedstock-independent biomass pretreatment would be vital to second generation biorefineries that would fully utilize diverse non-food lignocellulosic biomass resources, decrease transportation costs of low energy density feedstock, and conserve natural biodiversity. Cellulose solvent- and organic solvent-based lignocellulose fractionation (COSLIF) was applied to a variety of feedstocks, including Miscanthus, poplar, their mixture, bagasse, wheat straw, and rice straw. Although non-pretreated biomass samples exhibited a large variation in enzymatic digestibility, the COSLIF-pretreated biomass samples exhibited similar high enzymatic glucan digestibilities and fast hydrolysis rates. Glucan digestibilities of most pretreated feedstocks were ∼93% at five filter paper units per gram of glucan. The overall glucose and xylose yields for the Miscanthus:poplar mixture at a weight ratio of 1:2 were 93% and 85%, respectively. These results suggested that COSLIF could be regarded as a feedstock-independent pretreatment suitable for processing diverse feedstocks by adjusting pretreatment residence time only.

  8. EPR character of gadolinium complexes with noncyclic polyether Schiff bases and its solvent effects

    Institute of Scientific and Technical Information of China (English)

    姚克敏; 陈德余; 王晓南; 邓宁

    1996-01-01

    EPR characters of three new gadolinium complexes with noncydic polyether Schiff bases in powder or organic solvents, including various oxyethylene chain lengths and different substituting groups in ligands, are investigated respectively. Some regularities are summed up. The difference of EPR character in various solvents, particularly at different temperatures, has been examined. The ’single peak effect’ due to THF solvent at low temperature is observed for the first time. This phenomenon is explicated.

  9. Molecular microenvironments: Solvent interactions with nucleic acid bases and ions

    Science.gov (United States)

    Macelroy, R. D.; Pohorille, A.

    1986-01-01

    The possibility of reconstructing plausible sequences of events in prebiotic molecular evolution is limited by the lack of fossil remains. However, with hindsight, one goal of molecular evolution was obvious: the development of molecular systems that became constituents of living systems. By understanding the interactions among molecules that are likely to have been present in the prebiotic environment, and that could have served as components in protobiotic molecular systems, plausible evolutionary sequences can be suggested. When stable aggregations of molecules form, a net decrease in free energy is observed in the system. Such changes occur when solvent molecules interact among themselves, as well as when they interact with organic species. A significant decrease in free energy, in systems of solvent and organic molecules, is due to entropy changes in the solvent. Entropy-driven interactioins played a major role in the organization of prebiotic systems, and understanding the energetics of them is essential to understanding molecular evolution.

  10. Pretreatment of Lignocellulosic Biomass with Ionic Liquids and Ionic Liquid-Based Solvent Systems

    Directory of Open Access Journals (Sweden)

    Qidong Hou

    2017-03-01

    Full Text Available Pretreatment is very important for the efficient production of value-added products from lignocellulosic biomass. However, traditional pretreatment methods have several disadvantages, including low efficiency and high pollution. This article gives an overview on the applications of ionic liquids (ILs and IL-based solvent systems in the pretreatment of lignocellulosic biomass. It is divided into three parts: the first deals with the dissolution of biomass in ILs and IL-based solvent systems; the second focuses on the fractionation of biomass using ILs and IL-based solvent systems as solvents; the third emphasizes the enzymatic saccharification of biomass after pretreatment with ILs and IL-based solvent systems.

  11. An Investigation of the Behavior of Solvent based Polycaprolactone ink for Material Jetting.

    Science.gov (United States)

    He, Yinfeng; Wildman, Ricky D; Tuck, Chris J; Christie, Steven D R; Edmondson, Steven

    2016-02-12

    An initial study of processing bioresorbable polycaprolactone (PCL) through material jetting was conducted using a Fujifilm Dimatix DMP-2830 material printer. The aim of this work was to investigate a potential solvent based method of jetting polycaprolactone. Several solvents were used to prepare a PCL solvent based ink and 1, 4-dioxane was chosen with the consideration of both solubility and safety. The morphology of PCL formed under different substrate temperatures, droplet spacings were investigated. Multi-layer PCL structures were printed and characterized. This work shows that biodegradable polycaprolactone can be processed through material jetting.

  12. Merleau-Ponty: filosofía y pintura

    Directory of Open Access Journals (Sweden)

    Mariana Larison

    2010-07-01

    Full Text Available El presente texto intenta comprender porqué el arte y, particularmente, la pintura, se presentan, dentro de la obra del filósofo francés Maurice Merleau-Ponty, como modos ejemplares del fenómeno expresivo y nos permiten, en este sentido, comprender las características propias de la operación perceptiva.

  13. Literatura y pintura. Jusep Torres Campanals, una novela cubista

    Directory of Open Access Journals (Sweden)

    Vílchez Ruiz, Carmen E

    2007-08-01

    Full Text Available This article presents a study of the relation between the arts of literature and painting, from the interdisciplinary point of view. Focused on the structural analysis of Max Aub’s novel Jusep Torres Campanals, we will see how this work represents the translation of cubist painting’s aesthetics into the literary discourse. Through this analysis we will be able to prove how the narrative discourse’s decompositive technique, as used in a cubist painting, shows Jusep Torres Campanals as a fascinating dialogic dimension between truth and falseness, between painting and writing. Setting the reader again before the reflection of the old dialogue between literature and painting.Este artículo se presenta desde la perspectiva interdisciplinar del estudio de las relaciones entre dos artes, la Literatura y la Pintura, centrándose en el análisis estructural de la novela de Max Aub, Jusep Torres Campanals, tras el que observaremos cómo esta obra supone la traslación de la estética de la pintura cubista al discurso literario. A lo largo del análisis podremos comprobar, pues, cómo la técnica de descomposición del discurso narrativo, a la manera de un cuadro cubista, convierte a Jusep Torres Campanals, en un fascinante espacio de diálogo entre la verdad y la mentira, la pintura y la escritura, situándonos de nuevo ante la reflexión del antiguo diálogo entre la Literatura y la Pintura.

  14. The Rapid Synthesis of Schiff—Base withou Solvent under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    HaiJianYANG; WenHauSUN; 等

    2002-01-01

    A microwave-assisted preparation of a series of Schiff-base via efficient condensation of salicylaldehyde and aryl amines without solvent is described in high yield as well as environmental friendship reaction in organic synthesis.

  15. The Rapid Synthesis of Schiff-Base without Solvent under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A microwave-assisted preparation of a series of Schiff-base via efficient condensation of salicylaldehyde and aryl amines without solvent is described in high yield as well as environmental friendship reaction in organic synthesis.

  16. Pintura y paisaje: un recorrido por la Alameda Mexicana

    Directory of Open Access Journals (Sweden)

    Adrián Hernández Cordero

    2012-01-01

    Full Text Available La Alameda es el paseo más antiguo y emblemático de la Ciudad de México. Desde su creación ha sido uno de los paisajes preferidos para los pintores. Durante sus cuatro siglos de existencia se han generado una gran cantidad de pinturas de diferentes épocas que nos permiten mirar momentos del paseo y de la Ciudad de México. El documento primero sitúa la discusión entre paisaje y pintura con la intención de mostrar convergencias y divergencias en cuanto a sus objetivos y lenguajes. Posteriormente, se hace un recorrido histórico en el cual se presentan, interpretan y analizan varias pinturas de la Alameda mexicana correspondientes a diferentes periodos y a múltiples corrientes artísticas. Finalmente, se muestra cómo en la actualidad la Alameda se ha convertido en un paisaje invisible.

  17. Pretreatment of Lignocellulosic Biomass with Ionic Liquids and Ionic Liquid-Based Solvent Systems

    OpenAIRE

    Qidong Hou; Meiting Ju; Weizun Li; Le Liu; Yu Chen; Qian Yang

    2017-01-01

    Pretreatment is very important for the efficient production of value-added products from lignocellulosic biomass. However, traditional pretreatment methods have several disadvantages, including low efficiency and high pollution. This article gives an overview on the applications of ionic liquids (ILs) and IL-based solvent systems in the pretreatment of lignocellulosic biomass. It is divided into three parts: the first deals with the dissolution of biomass in ILs and IL-based solvent systems; ...

  18. A pintura trágica de Edvard Munch: um ensaio sobre a pintura e as marteladas de Nietzsche

    Directory of Open Access Journals (Sweden)

    PAULO ROBERTO ARRUDA DE MENEZES

    1993-12-01

    Full Text Available As relações entre a filosofia de Nietzsche e a pintura de Munch são instigantes e complexas. Os aforismos, modo de expressão primordial em Nietzsche da mesma maneira que o são as séries em Munch, lhe permitem perseguir uma idéia a partir de várias perspectivas possibilitanto, a ambos, experimentos com o pensar. Cada pintura propõe uma interpretação diferente para um mundo onde não existem mais fatos e onde a separação sujeito-objeto foi definitivamente abolida. Assim , ao pintar a dor, os ciúmes, a doença, o grito, a morte, a solidão, a paixão, as mulheres, Munch não mergulha, como poderia parecer à primeira vista, no pessimismo absoluto mas, pelo contrário, diz sim a tudo o que é problemático, colocando-se na direção da superação da morte na vida, sendo e fazendo uma pintura trágica, dionisíaca.

  19. Evaluación antibacteriana del G-0 en pinturas aplicadas

    Directory of Open Access Journals (Sweden)

    Nidia M. Rojas Hernández

    2005-01-01

    e influir en su actividad antimicrobiana, modificándola. Se demostró que al adicionar el G-0 a las pinturas, las de tipo oleoso tuvieron una acción inhibidora superior que las pinturas acuosas y en general, las de color verde, fueron más activas que las de color rojo.

  20. Synergetic Solvent Engineering of Film Nanomorphology to Enhance Planar Perylene Diimide-Based Organic Photovoltaics.

    Science.gov (United States)

    Wang, Jialin; Liang, Ziqi

    2016-08-31

    Solvent additive has proven as a useful protocol for improving the film nanomorphology of polymer donor (D): fullerene acceptor (A) blends in bulk heterojunction (BHJ) photovoltaic cells. By contrast, the effect of such solvent additive on nonfullerene BHJ cells based on perylene diimide acceptor, for instance, is less effective because of their highly planar structure and strong π-aggregation in solid state. Here we choose N,N'-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxylic diimide (PDI) and thieno[3,4-b]thiophene-alt-benzodithiophene (PTB7) as a model D:A blend system to investigate how solvent engineering strategy synergistically impacts the blend film nanomorphology. Based on the differences of solvent volatility and solubility, various host solvents-chloroform (CF) and chlorobenzene (CB) and solvent additives-chloronaphthalene (CN) and 1,8-diiodooctane (DIO) are selected for comparative studies. It is found that the π-aggregation of PDIs can be largely suppressed by using low-boiling point (Tb) CF solvent, yet enlarged by using high-Tb CB. Moreover, CN additive provides good solubility of PDI molecules and hence reduces large PDI aggregates in CB system, while DIO exhibiting poor solubility works oppositely. By contrast, DIO that presents larger Tb difference with CF prolongs the film-forming, which assists in optimizing the PDI aggregation and increases the intermixed PTB7:PDI phases more significantly than CN in CF system, yielding the finest phase-separation morphology and balanced charge mobility. Consequently, the inverted BHJ cells based on CF-processed PTB7:PDI blend film with 0.4 vol % DIO exhibit the highest PCE of 3.55% with a fill factor of 56%, both of which are among the best performance for such a paradigm PTB7:PDI blend-based BHJ cells.

  1. Santiago Serrano (1970-1980: Hacia una pintura no aprehensible

    Directory of Open Access Journals (Sweden)

    Óscar Muñoz Sánchez

    2014-01-01

    Full Text Available La pintura de Santiago Serrano en los años setenta, quizás la fase más brillante de toda su trayectoria, todavía no había sido estudiada desde un enfoque que conjugara la observación directa de su obra y la lectura de sus escritos inéditos. Este artículo es el resultado de una investigación sobre su trabajo artístico en aquella década, con el objetivo de averiguar las referencias, motivaciones y procedimientos que le llevaron, ya desde finales de 1970, a un grado tan radical de abstracción que entronca con Malevich, Rothko, Newman o Diebenkorn. Por su particular concepción y uso del color y la materia, Serrano se distinguió claramente de otras tendencias abstractas como el informalismo o las geometrías derivadas del minimalismo, el op art o el cinetismo.  Asimismo, se analiza el desarrollo de su obra en el contexto de la Pintura-Pintura, sobre todo con relación a las aportaciones de Supports/Surfaces, el grupo de Trama y los pintores italianos adscritos a la Pittura Analitica y Pittura-Pittura. Finalmente, se advierte cómo la pintura de Serrano en los setenta se ha proyectado sobre determinadas fases de su obra posterior.The painting of Santiago Serrano in the seventies, perhaps the most brilliant part of his whole production, had not yet been studied using an approach that combines the direct observation of his work and the reading of his unknown writings. This article is the result of the study of the development of his artistic work during that decade (in order to find the references, motivations and procedures which led him to such a radical level of abstraction that is connected with the art of Malevich, Rothko, Newman or Diebenkorn. Due to his particular conception and use of colour and material, Serrano´s work was clearly different from other abstract trends like Informalism or Geometric Art derived from Minimalism, Op Art or Kinetic Art. Furthermore, the development of his work is analysed in the context of Painting

  2. El lenguaje geométrico en la pintura

    OpenAIRE

    Nuere Menéndez-Pidal, Silvia

    2002-01-01

    La realización de la presente tesis responde a la necesidad de adecuar los elementos geométricos, así como los sistemas de representación de la geometría descriptiva, al ámbito de la pintura, proponiendo para ello un lenguaje geométrico adecuado a tal fin. Dentro de la comunicación y en particular de la comunicación visual, se han definido distintos lenguajes facilitadores del acto comunicativo. Nuestro interés es seguir profundizando en el lenguaje visual, aplicándolo a la geometría en el a...

  3. Dos pinturas de Denis Calvaert identificadas en los fondos del Museo del Prado

    Directory of Open Access Journals (Sweden)

    Diéguez Rodríguez, Ana

    2010-06-01

    Full Text Available Based on stylistic considerations, this study attributes two unpublished paintings in the Prado Museum to Denis Calvaert. This Flemish artist is not well known in Spain due to the scarcity of his works and because of a strong Italian stylistic influence, which has contributed to the incorrect attribution of his paintings.

    Atendiendo a razones de estilo este estudio da a conocer dos pinturas inéditas de Denis Calvaert entre los fondos del museo del Prado. Pintor flamenco poco conocido en España por la escueta obra que aquí se conserva, y por su fuerte influencia italiana que ha hecho que muchas de sus obras hayan estado atribuidas a esta última escuela.

  4. Pintura y Terror : Jacques-Louis David en 1793-1794

    OpenAIRE

    García Hernández, Miguel Ángel

    2016-01-01

    Entre 1793 y 1794, durante el llamado «Gran Terror», los retratos de los «mártires revolucionarios» de Jacques-Louis David han desarticulado las bases de la pintura de historia al eliminar la narración y el espacio de la perspectiva tal y como habían sido concebidos desde el Renacimiento. Este artículo indaga en este proceso a través del entramado político, social y religioso que se puso en marcha durante la República jacobina. Entre 1793 i 1794, durant l’anomenat «Gran Terror», els retrat...

  5. Steric and Solvent Effect in Dye-Sensitized Solar Cells Utilizing Phenothiazine-Based Dyes

    Directory of Open Access Journals (Sweden)

    Hany Kafafy

    2014-01-01

    Full Text Available Three phenothiazine-based dyes have been prepared and utilized as dye-sensitized solar cells (DSSCs. The effects of dye-adsorption solvent on the performances of dye-sensitized solar cells based on phenothiazine dyes were investigated in this study. The highest conversion efficiency of 3.78% was obtained using ethanol (EtOH and 2.53% for tetrahydrofuran (THF, respectively, as dye-adsorption solvents. Cell performance using EtOH as a dye-adsorption solvent showed relatively higher performance than that using THF. Electrochemical and photochemical tests of phenothiazine dyes in solution and adsorbed on the TiO2 surface showed less dye loading and coverage on the TiO2 surface during adsorption in the case of THF, which decreased the solar cell performance of the DSSC using THF as adsorption solvent compared with using EtOH as adsorption solvent. Meanwhile, the steric effect of phenothiazine-based (PT1–3 dyes was also investigated. Dye with longer and branched aliphatic chain in the order of PT1, PT2, and PT3 showed an increased resistance of the recombination reaction and electron lifetime, thereby increasing Voc and enhancing the overall cell performance because of the sterically hindered conformation of the phenothiazines.

  6. Conceptual design of a novel CO2 capture process based on precipitating amino acid solvents

    NARCIS (Netherlands)

    Sanchez Fernandez, E.; Heffernan, K.; Ham, L.V. van der; Linders, M.J.G.; Eggink, E.; Schrama, F.N.H.; Brilman, D.W.F.; Goetheer, E.L.V.; Vlugt, T.J.H.

    2013-01-01

    Amino acid salt based solvents can be used for CO2 removal from flue gas in a conventional absorption-thermal desorption process. Recently, new process concepts have been developed based on the precipitation of the amino acid zwitterion species during the absorption of CO2. In this work, a new conce

  7. Solvent-dependent enthalpic versus entropic anion binding by biaryl substituted quinoline based anion receptors.

    Science.gov (United States)

    Sun, Zhan-Hu; Albrecht, Markus; Raabe, Gerhard; Pan, Fang-Fang; Räuber, Christoph

    2015-01-08

    Anion receptors based on an 8-thiourea substituted quinoline with pentafluorinated (1a) or nonfluorinated (1b) biarylamide groups in the 2-position show similar binding of halide anions with somewhat higher association constants for the more acidic fluorinated derivative. Surprisingly, binding affinities for the halides in the case of the nonfluorinated 1b are similar in nonpolar chloroform or polar DMSO as solvent. Thorough thermodynamic investigations based on NMR van't Hoff analysis show that anion binding in chloroform is mainly enthalpically driven. In DMSO, entropy is the driving force for the binding of the ions with replacement of attached solvent.

  8. Effective Improvement of the Photovoltaic Performance of Carbon-Based Perovskite Solar Cells by Additional Solvents

    Institute of Scientific and Technical Information of China (English)

    Chenxi Zhang; Yudan Luo; Xiaohong Chen; Yiwei Chen; Zhuo Sun; Sumei Huang

    2016-01-01

    A solvent-assisted methodology has been developed to synthesize CH3NH3PbI3 perovskite absorber layers. It involved the use of a mixed solvent of CH3NH3I, PbI2,γ-butyrolactone, and dimethyl sulfoxide (DMSO) followed by the addition of chlorobenzene (CB). The method produced ultra-flat and dense perovskite capping layers atop mesoporous TiO2 films, enabling a remarkable improvement in the performance of free hole transport material (HTM) carbon elec-trode-based perovskite solar cells (PSCs). Toluene (TO) was also studied as an additional solvent for comparison. At the annealing temperature of 100 °C, the fabricated HTM-free PSCs based on drop-casting CB demonstrated power conversion efficiency (PCE) of 9.73%, which is 36 and 71% higher than those fabricated from the perovskite films using TO or without adding an extra solvent, respectively. The interaction between the PbI2–DMSO–CH3NH3I intermediate phase and the additional solvent was discussed. Furthermore, the influence of the annealing temperature on the absorber film formation, morphology, and crystalline structure was investigated and correlated with the photovoltaic performance. Highly efficient, simple, and stable HTM-free solar cells with a PCE of 11.44% were prepared utilizing the optimum perovskite absorbers annealed at 120 °C.

  9. Nano-structured gemini-based supramolecular solvent for the microextraction of cyhalothrin and fenvalerate.

    Science.gov (United States)

    Feizi, Neda; Yamini, Yadollah; Moradi, Morteza; Ebrahimpour, Behnam

    2016-09-01

    A novel supramolecular solvent-based microextraction followed by high-performance liquid chromatography with ultraviolet detection method has been developed for the extraction and determination of two pyrethroid analytes, cyhalothrin and fenvalerate, in water and soil samples. The liquid-liquid-phase separation of surfactants has been used in analytical extraction. The surfactant-rich phase is a nano-structured liquid, recently named as a supramolecular solvent, generated from the amphiphiles. The alkyl carboxylic acid based supramolecular solvents were introduced before. Coacervates made up of gemini surfactant, consisting of two amphiphilic moieties, were first used as solvent. The effective parameters on extraction (i.e., type of organic solvent, the amount of surfactant and volume of tetrahydrofuran, sample solution pH, salt addition, ultrasonic and centrifugation time) were investigated and optimized. Under the optimum conditions, preconcentration factors of 110 and 145 were obtained for the analytes. The linearity was 0.5-200.0 μg/L with the correlation of determination of (R(2) ) ≥ 0.9984. The limit of detection of the method was (S/N = 3) 0.2 μg/L, and precisions in the range of 6.3-10.3% (RSDs, n = 5) were obtained. This method has been successfully applied to analyze real samples, and good recoveries in the range of 101.2-108.8% were obtained.

  10. Mejora del proceso de fabricación de pintura en polvo

    OpenAIRE

    Folch-Rusiñol, Alberto

    2013-01-01

    El siguiente proyecto se centra en el estudio de una posible mejora de la planta de pintura en polvo de la empresa Industrias TITAN. Inicialmente se realiza un estudio del entorno económico que rodea la compañía. Se analiza el marco macroeconómico mundial y español y seguidamente se estudia el mercado de las pinturas y barnices, las principales compañías, los condicionantes y las perspectivas. Por último se profundiza en el mercado de pintura en polvo. Asimismo se presenta la compañía p...

  11. Grabados europeos y pintura en el Nuevo Reino de Granada

    Directory of Open Access Journals (Sweden)

    Marta Fajardo de Rueda

    2014-05-01

    Full Text Available La recepción de los numerosos grabados europeos que a través de estampas y libros ilustrados llegaron con propósitos evangelizadores y su influencia en la pintura aún no ha sido suficientemente estudiada por nuestra historiografía. No se aceptaba plenamente por temor a desconocer la originalidad de los artistas. Pero la investigación documental confirma muchas correspondencias entre grabados y pinturas que sugieren otra manera de interpretar la creatividad de los pintores. Con el propósito de abrir nuevos caminos para la investigación y reconocer esta importante fuente, se propone estudiar en el contexto de la época la forma en que se recibieron los grabados, cómo se adaptaron, modificaron y a veces enriquecieron, a la vez que contribuyeron a la formación de los artistas. Para ello conviene examinar las condiciones en que se ejecutó la obra; cuál fue su tratamiento y a qué otras fuentes acudió el artista. Precisar las condiciones de apropiación de los grabados por parte de los pintores y de sus comitentes, contribuye muy probablemente a una mejor comprensión de las obras y de su tiempo.

  12. Las pinturas rupestres de la Serreta, Cieza (Murcia

    Directory of Open Access Journals (Sweden)

    Miguel Ángel MATEO SAURA

    2009-11-01

    Full Text Available RESUMEN: Desde que fueran descubiertas en 1973, varios han sido los trabajos publicados sobre las pinturas de la cueva de la Serreta. Su parcialidad y unos criterios distintos a los mantenidos por sus autores, nos ha llevado a la realización de un nuevo estudio conjunto de los dos frisos pintados.La principal aportación de estas pinturas es la puesta de manifiesto de la convivencia de dos de los estilos pictóricos más relevantes de la prehistoria hispana como son el naturalista levantino y el esquemático. Rasgos etnográficos y socioeconómicos como son las armas o las estrategias de caza, son otras cuestiones a resaltar en este conjunto ciezano.ABSTRACT: Since the paintings at La Serreta cave were discovered in 1973, several essays about them haven been published. All these essays refer only to some of the paintings, and our opinion on them differs from that held by their authors; for this reason we have decided to carry out a new study on the two friezes as a whole.These paintings reveal, as their main contribution, that the two most outstanding pictorial styles in Spanish prehistory Levantine Naturalism and Schematism, existed concurrently. Some ethnographical, social and economic characteristics, as weapons and hunting techniques, are the other points to bring out in this Ciezan group of paintings.

  13. Grabados europeos y pintura en el Nuevo Reino de Granada

    Directory of Open Access Journals (Sweden)

    Marta Fajardo de Rueda

    2014-01-01

    Full Text Available La recepción de los numerosos grabados europeos que a través de estampas y libros ilustrados llegaron con propósitos evangelizadores y su inÀuencia en la pintura aún no ha sido su¿cientemente estudiada por nuestra historiografía. No se aceptaba ple - namente por temor a desconocer la originalidad de los artistas. Pero la investigación documental con¿rma muchas correspondencias entre grabados y pinturas que sugie - ren otra manera de interpretar la creatividad de los pintores. Con el propósito de abrir nuevos caminos para la investigación y reconocer esta importante fuente, se propone estudiar en el contexto de la época la forma en que se recibieron los grabados, cómo se adaptaron, modi¿caron y a veces enriquecieron, a la vez que contribuyeron a la for - mación de los artistas. Para ello conviene examinar las condiciones en que se ejecutó la obra; cuál fue su tratamiento y a qué otras fuentes acudió el artista. Precisar las con- diciones de apropiación de los grabados por parte de los pintores y de sus comitentes, contribuye muy probablemente a una mejor comprensión de las obras y de su tiempo.

  14. Estudio de la capacidad para intumescer de dos sistemas de pintura expuestos a ambientes internos agresivos

    Directory of Open Access Journals (Sweden)

    Chico, B.

    2005-12-01

    Full Text Available The influence exerted by temperature on the resistant capacity of structural steel is well known. A highly efficient protection system for steel consists of the application of intumescent paints. In the case of fire, their effectiveness is based on the property that when they come into contact with flames they react by swelling to form an insulating layer, referred to as "intumescence", which impedes the propagation of heat. These paints do not require continuous maintenance though their service behaviour depends on the exposure conditions to which they are exposed. This paper studies the behaviour of two acrylated rubber type intumescent systems exposed to a galvanising plant for 16 months, evaluating the effect of the environment on the capacity to intumesce of the coating when subjected to heating.

    Es conocida la influencia que ejerce la temperatura en la capacidad resistente del acero estructural. Un sistema de protección del acero, altamente efectivo, consiste en la utilización de pinturas intumescentes. Su efectividad se basa en el hecho de que, en el caso eventual de un incendio, al entrar en contacto con la llama reaccionan hinchándose y formando una capa aislante que se denomina "intumescencia" y que impide la propagación del calor. Estas pinturas no precisan de un mantenimiento continuo, aunque su comportamiento en servicio depende de las condiciones de exposición. Este trabajo estudia el comportamiento de dos sistemas intumescentes de tipo caucho acrilado expuestos en una planta de galvanizado durante 16 meses, valorando el efecto del medio ambiente sobre la capacidad para intumescer del recubrimiento cuando es sometido a un calentamiento.

  15. A simple method for determining water content in organic solvents based on cobalt(II) complexes

    Institute of Scientific and Technical Information of China (English)

    Lin Zhou; Xiao Hua Liu; Hai Xin Bai; Hong Juan Wang

    2011-01-01

    A method to determine water content in organic solvents was developed based on the color change of cobalt(II) nitrate in different solvents. The color-change mechanism and optimal conditions for determining the water content were investigated. The results showed that there was a good linear relationships between the absorbance of cobalt(II) complexes in organic solvents and water contents with y in 0.9989~0.9994. This method has the advantages of low cost, good reproducibility, good sensitivity, simple in operation, fast in detection, friendly to the environment and no limitation on linear range for determining water content. It was used to determine water in samples with a satisfactory recovery in 97.81%~101.24%.

  16. SOLVENT-BASED TO WATERBASED ADHESIVE-COATED SUBSTRATE RETROFIT - VOLUME II: PROCESS OVERVIEW

    Science.gov (United States)

    This volume presents initial results of a study to identify the issues and barriers associated with retrofitting existing solvent-based equipment to accept waterbased adhesives as part of an EPA effort to improve equipment cleaning in the coated and laminated substrate manufactur...

  17. Primeiros passos de maturidade a caminho da reintegração cromática diferenciada em pintura de cavalete em Portugal

    Directory of Open Access Journals (Sweden)

    Ana Bailão

    2010-08-01

    Full Text Available El objetivo de este trabajo es analizar y contextualizar la reintegración cromática diferenciada en la pintura de caballete durante el siglo XX en Portugal. Se trata de un estudio de los criterios con base en las actividades de reintegración cromática llevadas a cabo por Abel de Moura y Fernando Mardel en dos paneles de pinturas sobre madera: el tríptico de "Pietá com dois Santos", perteneciente a lo Museu de Artes Decorativas Portuguesas, Fundação Ricardo do Espírito Santo Silva (FRESS y el tríptico de la Iglesia de “Encarnação”, en la actualidad en el Museo de Arte Sacro en Funchal. El área reintegrada es valorada mediante el uso de sistemas de información geográfica.

  18. Otto Dix, Pablo Picasso y la pintura de guerra

    Directory of Open Access Journals (Sweden)

    Ángel Llorente Hernández

    2012-01-01

    Full Text Available La Primera Guerra Mundial provocó desde su desencadenamiento cambios importantes en los países implicados que afectaron a todos los ámbitos de la vida de sus poblaciones. Algunos artistas sintieron especialmente la repercusión moral y la convulsión causadas por la guerra mecanizada en la que un número cada vez mayor de soldados morían en el frente, a la vez que se producían masacres en zonas de la retaguardia. El pintor expresionista alemán Otto Dix recogió en sus dibujos, hechos en primera línea de combate, la dureza de los enfrentamientos y de la vida de los combatientes en las trincheras del frente occidental y reflejó en grabados y pinturas posteriores a la Gran Guerra las penalidades y los horrores sufridas por aquellos. Sus obras son, además de testimonios de las atrocidades de los combates, condena y denuncia de todas las guerras. En el año 1937 el español Pablo Picasso pintó el mural Guernica, cuyo título alude al bombardeo de la localidad vasca del mismo nombre, ocurrido poco tiempo antes de que su autor lo comenzase. Ya desde su creación, el cuadro se convirtió en una de las obras artísticas principales del pasado siglo y en icono de la lucha por la paz. Ambos artistas emplearon lenguajes vanguardistas para crear formas nuevas, alejadas de las maneras tradicionales de representar la guerra en la cultura occidental. Dix se sirvió del expresionismo para mostrar en sus composiciones escenas verosímiles de una dureza difícil de soportar para quienes las contemplan. Picasso se apoyó sobre todo en el cubismo y el surrealismo para aludir a los efectos de la guerra moderna sobre la población indefensa.Countries involved in The Great War experienced dramatic changes in every aspect of their day to day life. Some artists were especially sensitive towards the moral convulsion caused by a mechanized war where an increasing number of soldiers were dying in the frontline and massacres were taking place in the rear. Through

  19. Predicting the acute neurotoxicity of diverse organic solvents using probabilistic neural networks based QSTR modeling approaches.

    Science.gov (United States)

    Basant, Nikita; Gupta, Shikha; Singh, Kunwar P

    2016-03-01

    Organic solvents are widely used chemicals and the neurotoxic properties of some are well established. In this study, we established nonlinear qualitative and quantitative structure-toxicity relationship (STR) models for predicting neurotoxic classes and neurotoxicity of structurally diverse solvents in rodent test species following OECD guideline principles for model development. Probabilistic neural network (PNN) based qualitative and generalized regression neural network (GRNN) based quantitative STR models were constructed using neurotoxicity data from rat and mouse studies. Further, interspecies correlation based quantitative activity-activity relationship (QAAR) and global QSTR models were also developed using the combined data set of both rodent species for predicting the neurotoxicity of solvents. The constructed models were validated through deriving several statistical coefficients for the test data and the prediction and generalization abilities of these models were evaluated. The qualitative STR models (rat and mouse) yielded classification accuracies of 92.86% in the test data sets, whereas, the quantitative STRs yielded correlation (R(2)) of >0.93 between the measured and model predicted toxicity values in both the test data (rat and mouse). The prediction accuracies of the QAAR (R(2) 0.859) and global STR (R(2) 0.945) models were comparable to those of the independent local STR models. The results suggest the ability of the developed QSTR models to reliably predict binary neurotoxicity classes and the endpoint neurotoxicities of the structurally diverse organic solvents.

  20. A pintura “sublime” de Barnett Newman

    Directory of Open Access Journals (Sweden)

    Alice de Carvalho Lino

    2016-07-01

    Full Text Available O presente artigo refere-se à crítica de Lyortard à pintura de Barnett Newman a partir da estética do sublime de Longino, Burke e Kant. Primeiramente, amparando-se em Longino, o crítico estabelece uma relação entre o silêncio sublime, a imagem do indeterminado e as artes nos séculos XIX e XX. Indícios desta indeterminação pictural já seriam perceptíveis desde as telas de Manet e Cézanne, já que eles teriam rompido com os padrões estabelecidos na representação, constituindo outra relação entre a figura e o espaço, mediante as cores com seus valores. No caso das pinturas de Newman, o indeterminado estaria na cor, no próprio quadro, que possibilitaria, nos termos de Lyotard, a ocorrência da obra. Esta ocorrência equivaleria ao “consumo” imediato da imagem, capaz de suscitar o prazer do sentimento sublime. O terror ou o temor sentido estaria na possibilidade da não ocorrência da obra, que é descrita por Lyotard a partir do aspecto da “privação”, presente, especialmente, na estética de Burke. Lyotard descreve as obras de Newman recorrendo também à noção de “inapresentável”, devido à presença do informe e da ausência completa da forma nos quadros. Nesse momento de sua argumentação, ele recorre ao conceito do sentimento do sublime de Kant. Assim, diferentemente da incapacidade da imaginação vivenciar os fenômenos naturais em todo seu poderio e grandeza, a pintura sublime – na caracterização de Lyotard – apresentaria tais potências mesmo que de modo negativo.

  1. Alcohol based-deep eutectic solvent (DES) as an alternative green additive to increase rotenone yield

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Zetty Shafiqa; Hassan, Nur Hasyareeda; Zubairi, Saiful Irwan [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor (Malaysia)

    2015-09-25

    Deep eutectic solvents (DESs) are basically molten salts that interact by forming hydrogen bonds between two added components at a ratio where eutectic point reaches a melting point lower than that of each individual component. Their remarkable physicochemical properties (similar to ionic liquids) with remarkable green properties, low cost and easy handling make them a growing interest in many fields of research. Therefore, the objective of pursuing this study is to analyze the potential of alcohol-based DES as an extraction medium for rotenone extraction from Derris elliptica roots. DES was prepared by a combination of choline chloride, ChCl and 1, 4-butanediol at a ratio of 1/5. The structure of elucidation of DES was analyzed using FTIR, {sup 1}H-NMR and {sup 13}C-NMR. Normal soaking extraction (NSE) method was carried out for 14 hours using seven different types of solvent systems of (1) acetone; (2) methanol; (3) acetonitrile; (4) DES; (5) DES + methanol; (6) DES + acetonitrile; and (7) [BMIM] OTf + acetone. Next, the yield of rotenone, % (w/w), and its concentration (mg/ml) in dried roots were quantitatively determined by means of RP-HPLC. The results showed that a binary solvent system of [BMIM] OTf + acetone and DES + acetonitrile was the best solvent system combination as compared to other solvent systems. It contributed to the highest rotenone content of 0.84 ± 0.05% (w/w) (1.09 ± 0.06 mg/ml) and 0.84 ± 0.02% (w/w) (1.03 ± 0.01 mg/ml) after 14 hours of exhaustive extraction time. In conclusion, a combination of the DES with a selective organic solvent has been proven to have a similar potential and efficiency as of ILs in extracting bioactive constituents in the phytochemical extraction process.

  2. Supramolecular solvent-based vortex-mixed microextraction: determination of glucocorticoids in water samples.

    Science.gov (United States)

    Qin, Hui; Qiu, Xiaoyan; Zhao, Jiao; Liu, Mousheng; Yang, Yaling

    2013-10-11

    Glucocorticoids contamination has become a big environmental issue in China and other developing countries, due to increasing needs in medical prescription and farming. However, no highly sensitive and precise methods have been reported to quantify glucocorticoids so far. In the past several years, supramolecular solvent-based vortex-mixed microextraction (SS-BVMME) has been shown to be effective. However, the mechanism of SS-BVMME is still unknown. In this report, a novel method has been proposed for rapid quantification of trace amount of glucocorticoids, beclomethasone dipropionate (BD), hydrocortisone butyrate (HB) and nandrolone phenylpropionate (NPP) in water samples from the Green Lake. This method is simple, safe and cost effective. It contains two steps: supramolecular solvent-based vortex-mixed microextraction (SS-BVMME) technique and high performance liquid chromatography (HPLC) analysis. First, ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) and n-butanol were mixed to form the supramolecular solvent. After mixing the supramolecular solvent with an aqueous sample to test, a homogenous mixture was formed immediately. BD, HB and NPP were then extracted based on their binding interactions, particularly hydrogen bond formed between their hydroxyl group and the supramolecular solvent. The overall process of sample preparation took only 20min and more than 5 samples could be simultaneously prepared. The minimum detectable concentrations of samples in this method were 0.09925, 0.5429 and 2.428ngmL(-1) for BD, HB and NPP, respectively. Product recoveries ranged from 88% to 103% with relative standard deviations from 0.6% to 4%. For the first time, we report that hydrogen bond plays a key role in SS-BVMME. We also improve the sensitivity significantly to quantify glucocorticoids, which may greatly benefit environmental safety management in China.

  3. A green deep eutectic solvent-based aqueous two-phase system for protein extracting

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Kaijia; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Huang, Yanhua; Li, Na; Wen, Qian

    2015-03-15

    Highlights: • A strategy for the protein purification with a deep eutectic solvent(DES)-based aqueous two-phase system. • Choline chloride-glycerin DES was selected as the extraction solvent. • Bovine serum albumin and trypsin were used as the analytes. • Aggregation phenomenon was detected in the mechanism research. - Abstract: As a new type of green solvent, deep eutectic solvent (DES) has been applied for the extraction of proteins with an aqueous two-phase system (ATPS) in this work. Four kinds of choline chloride (ChCl)-based DESs were synthesized to extract bovine serum albumin (BSA), and ChCl-glycerol was selected as the suitable extraction solvent. Single factor experiments have been done to investigate the effects of the extraction process, including the amount of DES, the concentration of salt, the mass of protein, the shaking time, the temperature and PH value. Experimental results show 98.16% of the BSA could be extracted into the DES-rich phase in a single-step extraction under the optimized conditions. A high extraction efficiency of 94.36% was achieved, while the conditions were applied to the extraction of trypsin (Try). Precision, repeatability and stability experiments were studied and the relative standard deviations (RSD) of the extraction efficiency were 0.4246% (n = 3), 1.6057% (n = 3) and 1.6132% (n = 3), respectively. Conformation of BSA was not changed during the extraction process according to the investigation of UV–vis spectra, FT-IR spectra and CD spectra of BSA. The conductivity, dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to explore the mechanism of the extraction. It turned out that the formation of DES–protein aggregates play a significant role in the separation process. All the results suggest that ChCl-based DES-ATPS are supposed to have the potential to provide new possibilities in the separation of proteins.

  4. Semiologia e pintura segundo René Passeron

    Directory of Open Access Journals (Sweden)

    Wilcon Pereira

    1981-01-01

    Full Text Available Trata-se de uma síntese das principais idéias de René Passeron a propósito da fundamentação de uma análise lingüístico-semiótica das obras pictóricas. Em que medida um quadro pode ser considerado um texto? Quais seriam os elementos básicos de uma pintura? Podemos falar em articulações de unidades no campo visual definido por uma obra dessa natureza? E quais os repertórios e as regras combinatórias? O artigo propõe a discussão destes problemas a partir das rigorosas e oportunas colocações do importante teórico, crítico e historiador da arte, infelizmente quase desconhecido entre nós.

  5. Insights into the effects of solvent properties in graphene based electric double-layer capacitors with organic electrolytes

    Science.gov (United States)

    Zhang, Shuo; Bo, Zheng; Yang, Huachao; Yang, Jinyuan; Duan, Liangping; Yan, Jianhua; Cen, Kefa

    2016-12-01

    Organic electrolytes are widely used in electric double-layer capacitors (EDLCs). In this work, the microstructure of planar graphene-based EDLCs with different organic solvents are investigated with molecular dynamics simulations. Results show that an increase of solvent polarity could weaken the accumulation of counter-ions nearby the electrode surface, due to the screen of electrode charges and relatively lower ionic desolvation. It thus suggests that solvents with low polarity could be preferable to yield high EDL capacitance. Meanwhile, the significant effects of the size and structure of solvent molecules are reflected by non-electrostatic molecule-electrode interactions, further influencing the adsorption of solvent molecules on electrode surface. Compared with dimethyl carbonate, γ-butyrolactone, and propylene carbonate, acetonitrile with relatively small-size and linear structure owns weak non-electrostatic interactions, which favors the easy re-orientation of solvent molecules. Moreover, the shift of solvent orientation in surface layer, from parallel orientation to perpendicular orientation relative to the electrode surface, deciphers the solvent twin-peak behavior near negative electrode. The as-obtained insights into the roles of solvent properties on the interplays among particles and electrodes elucidate the solvent influences on the microstructure and capacitive behavior of EDLCs using organic electrolytes.

  6. Green Printing: Colorimetric and Densitometric Analysis of Solvent-Based and Vegetable Oil-Based Inks of Multicolor Offset Printing

    Science.gov (United States)

    Dharavath, H. Naik; Hahn, Kim

    2009-01-01

    The purpose of this study was to determine the differences in the measurable print attributes (Print Contrast and Dot Gain) and color gamut of solvent-based (SB) inks vs. vegetable oil-based (VO) inks of multicolor offset printing. The literature review revealed a lack of published research on this subject. VO inks tend to perform (color…

  7. CO{sub 2}-based supercritical fluids as environmentally-friendly processing solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Davenhall, L.B.; Taylor, C.M.V.; Pierce, T. [Los Alamos National Lab., NM (United States). Physical Organic Chemistry Group; Tiefert, K. [Hewlett-Packard Co., Inc., Santa Clara, CA (United States)

    1999-03-01

    The production of integrated circuits involves a number of discrete steps that utilize hazardous or regulated solvents. Environmental, safety and health considerations associated with these chemicals have prompted a search for alternative, more environmentally benign, solvent systems. An emerging technology for conventional solvent replacement is the use of supercritical fluids based on carbon dioxide (CO{sub 2}). Supercritical CO{sub 2} (SCCO{sub 2}) is an excellent choice for IC manufacturing processes since it is non-toxic, non-flammable, inexpensive, and is compatible with all substrate and metallizations systems. Also, conditions of temperature and pressure needed to achieve the supercritical state are easily achievable with existing process equipment. The authors first describe the general properties of supercritical fluids, with particular emphasis on their application as alternative solvents. Next, they review some of the work which has been published involving the use of supercritical fluids, and particularly CO{sub 2}, as they may be applied to the various steps of IC manufacture, including wafer cleaning, thin film deposition, etching, photoresist stripping, and waste treatment. Next, they describe the research work conducted at Los Alamos, on behalf of Hewlett-Packard, on the use of SCCO{sub 2} in a specific step of the IC manufacturing process: the stripping of hard-baked photoresist.

  8. Bridge- and Solvent-Mediated Intramolecular Electronic Communications in Ubiquinone-Based Biomolecular Wires

    Science.gov (United States)

    Liu, Xiao-Yuan; Ma, Wei; Zhou, Hao; Cao, Xiao-Ming; Long, Yi-Tao

    2015-05-01

    Intramolecular electronic communications of molecular wires play a crucial role for developing molecular devices. In the present work, we describe different degrees of intramolecular electronic communications in the redox processes of three ubiquinone-based biomolecular wires (Bis-CoQ0s) evaluated by electrochemistry and Density Functional Theory (DFT) methods in different solvents. We found that the bridges linkers have a significant effect on the electronic communications between the two peripheral ubiquinone moieties and solvents effects are limited and mostly depend on the nature of solvents. The DFT calculations for the first time indicate the intensity of the electronic communications during the redox processes rely on the molecular orbital elements VL for electron transfer (half of the energy splitting of the LUMO and LUMO+1), which is could be affected by the bridges linkers. The DFT calculations also demonstrates the effect of solvents on the latter two-electron transfer of Bis-CoQ0s is more significant than the former two electrons transfer as the observed electrochemical behaviors of three Bis-CoQ0s. In addition, the electrochemistry and theoretical calculations reveal the intramolecular electronic communications vary in the four-electron redox processes of three Bis-CoQ0s.

  9. Flexibility and explicit solvent in molecular-dynamics-based docking of protein-glycosaminoglycan systems.

    Science.gov (United States)

    Samsonov, Sergey A; Gehrcke, Jan-Philip; Pisabarro, M Teresa

    2014-02-24

    We present Dynamic Molecular Docking (DMD), a novel targeted molecular dynamics-based protocol developed to address ligand and receptor flexibility as well as the inclusion of explicit solvent in local molecular docking. A class of ligands for which docking performance especially benefits from overcoming these challenges is the glycosaminoglycans (GAGs). GAGs are periodic, highly flexible, and negatively charged polysaccharides playing an important role in the extracellular matrix via interaction with proteins such as growth factors and chemokines. The goal of our work has been to develop a proof of concept for an MD-based docking approach and to analyze its applicability for protein-GAG systems. DMD exploits the electrostatics-driven attraction of a ligand to its receptor, treats both as entirely flexible, and considers solvent explicitly. We show that DMD has high predictive significance for systems dominated by electrostatic attraction and demonstrate its capability to reliably identify the receptor residues contributing most to binding.

  10. [Study on Enhancing Characteristic Vibration of the Molecular Vibration Spectrum for BDE-15 Based on Solvent Effect].

    Science.gov (United States)

    Jiang, Long; Meng, Chong; Li, Yu

    2015-12-01

    the similar change trend with Raman vibrational intensities. The spectra information of BDE-153, BDE-154, BDE-209 were used to authenticate the application on PBDEs of the analysis method above for BDE-15, obtaining the solvent effect index values on vibrational intensities on BDE-153, BDE-154, BDE-209 of alcohols, acetonitrile, dimethyl sulfoxide, nitrobenzene are all greater than 6 or 5, which indicate the enhancing vibrational intensities method can be used to identification research on PBDEs based on molecule vibrational spectra further.

  11. Solvent-based self-healing approaches for fiber-reinforced composites

    Science.gov (United States)

    Jones, Amanda R.

    Damage in composite materials spans many length scales and is often difficult to detect or costly to repair. The incorporation of self-healing functionality in composite materials has the potential to greatly extend material lifetime and reliability. Although there has been remarkable progress in self-healing polymers over the past decade, self-repair in fiber-reinforced composite materials presents significant technical challenges due to stringent manufacturing and performance requirements. For high performance, fiber-reinforced composites, the self-healing components need to survive high temperature processing, reside in matrix interstitial regions to retain a high fiber volume fraction, and have minimal impact on the mechanical properties of the host material. This dissertation explores several microencapsulated solvent-based self-healing approaches for fiber-reinforced composites at the fiber/ matrix interface size scale as well as matrix cracking. Systems are initially developed for room temperature cured epoxies/ glass fiber interfaces and successfully transitioned to carbon fibers and high temperature-cured, thermoplastic-toughened matrices. Full recovery of interfacial bond strength after complete fiber/matrix debonding is achieved with a microencapsulated solvent-based healing chemistry. The surface of a glass fiber is functionalized with microcapsules containing varying concentrations of reactive epoxy resin and ethyl phenyl acetate (EPA) solvent. Microbond specimens consisting of a single fiber and a microdroplet of epoxy are cured at 35°C, tested, and the interfacial shear strengths (IFSS) during the initial (virgin) debonding and subsequent healing events are measured. Debonding of the fiber/matrix interface ruptures the capsules, releasing resin and solvent into the crack plane. The solvent swells the matrix, initiating transport of residual amine functionality for further curing with the epoxy resin delivered to the crack plane. Using a resin-solvent

  12. A Sustainable Redox-Flow Battery with an Aluminum-Based, Deep-Eutectic-Solvent Anolyte.

    Science.gov (United States)

    Zhang, Changkun; Ding, Yu; Zhang, Leyuan; Wang, Xuelan; Zhao, Yu; Zhang, Xiaohong; Yu, Guihua

    2017-06-19

    Nonaqueous redox-flow batteries are an emerging energy storage technology for grid storage systems, but the development of anolytes has lagged far behind that of catholytes due to the major limitations of the redox species, which exhibit relatively low solubility and inadequate redox potentials. Herein, an aluminum-based deep-eutectic-solvent is investigated as an anolyte for redox-flow batteries. The aluminum-based deep-eutectic solvent demonstrated a significantly enhanced concentration of circa 3.2 m in the anolyte and a relatively low redox potential of 2.2 V vs. Li(+) /Li. The electrochemical measurements highlight that a reversible volumetric capacity of 145 Ah L(-1) and an energy density of 189 Wh L(-1) or 165 Wh kg(-1) have been achieved when coupled with a I3(-) /I(-) catholyte. The prototype cell has also been extended to the use of a Br2 -based catholyte, exhibiting a higher cell voltage with a theoretical energy density of over 200 Wh L(-1) . The synergy of highly abundant, dendrite-free, multi-electron-reaction aluminum anodes and environmentally benign deep-eutectic-solvent anolytes reveals great potential towards cost-effective, sustainable redox-flow batteries. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Solution based zinc tin oxide TFTs: the dual role of the organic solvent

    Science.gov (United States)

    Salgueiro, Daniela; Kiazadeh, Asal; Branquinho, Rita; Santos, Lídia; Barquinha, Pedro; Martins, Rodrigo; Fortunato, Elvira

    2017-02-01

    Chemical solution deposition is a low cost, scalable and high performance technique to obtain metal oxide thin films. Recently, solution combustion synthesis has been introduced as a chemical route to reduce the processing temperature. This synthesis method takes advantage of the chemistry of the precursors as a source of energy for localized heating. According to the combustion chemistry some organic solvents can have a dual role in the reaction, acting both as solvent and fuel. In this work, we studied the role of 2-methoxyethanol in solution based synthesis of ZTO thin films and its influence on the performance of ZTO TFTs. The thermal behaviour of ZTO precursor solutions confirmed that 2-methoxyethanol acts simultaneously as a solvent and fuel, replacing the fuel function of urea. The electrical characterization of the solution based ZTO TFTs showed a slightly better performance and lower variability under positive gate bias stress when urea was not used as fuel, confirming that the excess fuel contributes negatively to the device operation and stability. Solution based ZTO TFTs demonstrated a low hysteresis (ΔV  =  -0.3 V) and a saturation mobility of 4-5 cm2 V-1 s-1.

  14. Towards safer sodium-ion batteries via organic solvent/ionic liquid based hybrid electrolytes

    Science.gov (United States)

    Monti, Damien; Ponrouch, Alexandre; Palacín, M. Rosa; Johansson, Patrik

    2016-08-01

    Hybrid electrolytes aimed at application in sodium-ion batteries (SIB) consisting of an organic solvent mixture (EC:PC) and different ionic liquids (ILs); EMImTFSI, BMImTFSI, and Pyr13TFSI, and with the NaTFSI salt providing the Na+ charge carriers have here been extensively studied. The physico-chemical and electrochemical characterisation includes ionic conductivity, viscosity, density, cation coordination and solvation, various safety measures, and electrochemical stability window (ESW). Hybrid electrolytes with 10-50% of IL content were found to have ionic conductivities on par with comparable organic solvent based electrolytes, but with highly enhanced safety properties. A systematic Raman spectroscopy study of the cation coordination and solvation before and after electrolyte safety tests by ignition suggest that IL cations and TFSI remain stable when ignited while organic solvents are consumed. Finally, the solid electrolyte interphase (SEI) formed when using hybrid electrolytes has both better mechanical and electrochemical stability than the SEI derived from pure IL based electrolytes. For a half-cell with a hard carbon (HC) electrode and a hybrid electrolyte with a composition of 0.8 m NaTFSI in EC0.45:PC0.45:Pyr13TFSI0.10 encouraging results were obtained for IL based electrolytes - ca. 182 mAhg-1 at C/10 over 40 cycles.

  15. Effects of solvent and substituent on the electronic absorption spectra of some substituted Schiff bases: a chemometrics study.

    Science.gov (United States)

    Hemmateenejad, Bahram; Yazdani, Mahdieh; Sharghi, Hashem

    2012-06-01

    A series of Schiff bases were studied for their delicate changes in absorption electronic spectra by changing substituents and solvents. UV/vis absorbance spectra of Schiff base derivatives of different substituents ranging from electron withdrawing to electron donating (Br, CF(3), Cl, CN, CO(2)H, F, Me, NO(2), OH, OMe, H) were studied in different solvents (acetonitrile, chloroform, cyclohexane, dioxane, dimethylsulfoxide and methanol). Linear relationships were established to investigate the effect of solute structure and solvatochromic parameters of solvents on the absorbance spectra. Meaningful chemical factors and then regression models were provided utilizing factor analysis (FA) and multiple linear regression (MLR). It was found that the frequency of maximum absorbance was mainly controlled by the solvent's dipolarity/polarizability. The λ(max) of the ortho-nitro derivative represented the largest dependency on solvents' polarity/polarizability so that it can be used as a solvatochromic probe. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Effects of metals on the transformation of hexabromocyclododecane (HBCD) in solvents: implications for solvent-based recycling of brominated flame retardants.

    Science.gov (United States)

    Zhong, Yin; Peng, Ping'an; Yu, Zhiqiang; Deng, Haopeng

    2010-09-01

    The management of electronic wastes (e-wastes) has become a global issue as it may release large quantities of hazardous materials such as heavy metals and brominated flame retardants (BFRs) to the environment. Solvent-based recycling is a newly developed, efficient and environmentally beneficial technology for the removal or recovery of BFRs from e-wastes. However, little is known about the behavior of BFRs in the solvents and to what extent they may be affected by co-existing heavy metals. This study quantified the rates of transformation of hexabromocyclododecane (HBCD), a widely used BFR, in the presence of different solvents (i.e. acetone, methanol or toluene) and metals (i.e. Ni, Cu, Zn, Fe or Al). Our experimental results showed that less than 20% of HBCD was transformed in all pure solvent systems within 24h at 50 degrees C. The presence of Ni greatly increased the transformation of HBCD (45-99%) in these solvent systems, whereas other metals had little or no effect on extraction process. The kinetics study showed that transformation of HBCD in Ni-containing systems followed pseudo-first-order kinetics and that the highest transformation rate constant (1.2+/-0.1h(-1)) of HBCD was recorded in the Ni+acetone system. The formation of HBr and pentabromocyclododecene in the acetone+Ni system suggested that transformation of HBCD proceeded via dehydrobromination. Collectively, these results indicated that acetone should not be applied in the recycling or extraction of HBCD from Ni-rich e-wastes, as debromination of HBCD may occur during these processes, even at mild extraction temperatures.

  17. Safe, high-energy supercapacitors based on solvent-free ionic liquid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Arbizzani, Catia; Biso, Maurizio; Cericola, Dario; Lazzari, Mariachiara; Soavi, Francesca; Mastragostino, Marina [University of Bologna, Dipartimento di Scienza dei Metalli, Elettrochimica e Tecniche Chimiche, via S. Donato 15, 40127 Bologna (Italy)

    2008-12-01

    Safety is the main concern for energy storage-system application in hybrid-electrical vehicles (HEVs) and ionic liquids (ILs) of low vapor pressure and high thermal stability represent a strategy to meet this key requisite. The use of solvent-free ILs in supercapacitors enables the high cell voltages required for increasing supercapacitor energy up to the values for power-assist application in HEVs. In order to exploit the wide electrochemical stability window of ILs, tailored electrode materials and cell configurations have to be used. The performance of asymmetric double-layer carbon supercapacitors (AEDLCs) and carbon/poly(3-methylthiophene) hybrid supercapacitors operating with different pyrrolidinium-based ILs are reported and compared. This study demonstrates that a design-optimized AEDLC operating with safe, solvent-free IL electrolyte meets cycling stability and the energy and power requisites for power-assisted HEVs at the investigated temperatures. (author)

  18. Supercritical CO2-based solvents in next generation micro- electronics processing

    Institute of Scientific and Technical Information of China (English)

    ZHANG XiaoGang; Keith P.JOHNSTON

    2007-01-01

    Large amount of chemicals and highly purified-water are needed in microelectronic manufacture. The ability of solutions to penetrate tiny spaces will become significantly more challenging as the feature size of semiconductor devices decreases to nanoscale dimensions and the functional complexity of integrated circuitries (ICs) ever increases. Supercritical fluids (SCFs) possess a unique combination of properties (no surface tension and gas-like viscosity) that can potentially be exploited for application in microelectronics manufacturing and processing in response to needs for material-compatible cleaning systems, small-dimension developing solvents, and low chemical-use processes. Recent microelectronics processes for cleaning and rinsing of patterned porous low-k dielectrics and drying of photoresist in CO2-based solvents are the main focus of this review. Additional topics in supercritical fluid processing include spin coating of photoresists, development with nanoscale dimensions, metal deposition and silylation.

  19. Noncovalent interactions from electron density topology and solvent effects on spectral properties of Schiff bases

    Science.gov (United States)

    Gandhimathi, S.; Balakrishnan, C.; Theetharappan, M.; Neelakantan, M. A.; Venkataraman, R.

    2017-03-01

    Two Schiff bases were prepared by the condensation of o-allyl substituted 2,4-dihydroxy acetophenone with 1,2-diaminopropane (L1) and ethanediamine (L2) and characterized by elemental analysis, and ESI-MS, IR, UV-Vis, 1H and 13C NMR spectral techniques. The effect of solvents with respect to different polarities on UV-Vis and emission spectra of L1 and L2 was investigated at room temperature show that the compounds exist in keto and enol forms in solution and may be attributed to the intramolecular proton transfer in the ground state. The solute-solvent interactions, change in dipole moment and solvatochromic properties of the compounds were studied based on the solvent polarity parameters. For L1 and L2, the ground and excited state electronic structure calculations were carried out by DFT and TD-DFT at B3LYP/6-311G (d,p) level, respectively. The IR, NMR and electronic absorption spectra computed were compared with the experimental observations. The intramolecular charge transfer within the molecule is evidenced from the HOMO and LUMO energy levels and surface analysis. The noncovalent interactions like hydrogen bonding and van der Waals interactions were identified from the molecular geometry and electron localization function. These interactions in molecules have been studied by using reduced density gradient and graphed by Multiwfn.

  20. Dropwise additive manufacturing of pharmaceutical products for solvent-based dosage forms.

    Science.gov (United States)

    Hirshfield, Laura; Giridhar, Arun; Taylor, Lynne S; Harris, Michael T; Reklaitis, Gintaras V

    2014-02-01

    In recent years, the US Food and Drug Administration has encouraged pharmaceutical companies to develop more innovative and efficient manufacturing methods with improved online monitoring and control. Mini-manufacturing of medicine is one such method enabling the creation of individualized product forms for each patient. This work presents dropwise additive manufacturing of pharmaceutical products (DAMPP), an automated, controlled mini-manufacturing method that deposits active pharmaceutical ingredients (APIs) directly onto edible substrates using drop-on-demand (DoD) inkjet printing technology. The use of DoD technology allows for precise control over the material properties, drug solid state form, drop size, and drop dynamics and can be beneficial in the creation of high-potency drug forms, combination drugs with multiple APIs or individualized medicine products tailored to a specific patient. In this work, DAMPP was used to create dosage forms from solvent-based formulations consisting of API, polymer, and solvent carrier. The forms were then analyzed to determine the reproducibility of creating an on-target dosage form, the morphology of the API of the final form and the dissolution behavior of the drug over time. DAMPP is found to be a viable alternative to traditional mass-manufacturing methods for solvent-based oral dosage forms. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  1. An acetylcholinesterase (AChE) biosensor with enhanced solvent resistance based on chitosan for the detection of pesticides.

    Science.gov (United States)

    Warner, John; Andreescu, Silvana

    2016-01-01

    Solvent tolerance of immobilized enzymes is important for many biosensing and biotechnological applications. In this paper we report an acetylcholinesterase (AChE) biosensor based on chitosan that exhibits high solvent resistance and enables sensitive detection of pesticides in presence of a high content of organic solvents. The solvent effect was established comparatively for the enzyme immobilized in chitosan and covalently cross-linked with glutaraldehyde. The activity of the immobilized AChE was dependent on the immobilization method and solvent type. The enzyme entrapped in chitosan fully conserved its activity in up to 25% methanol, 15% acetonitrile and 100% cyclohexane while the enzyme cross-linked with glutaraldehyde gradually lost its activity starting at 5% acetonitrile and methanol, and showed variable levels in cyclohexane. The detection limits of the biosensor for paraoxon were: 7.5 nM in 25% methanol, 100 nM in 15% acetonitrile and 2.5 μM in 100% cyclohexane. This study demonstrates that chitosan provides an excellent immobilization environment for AChE biosensors designed to operate in environments containing high amounts of organic solvents. It also highlights the effect of the immobilization material and solvent type on enzyme stability. These findings can enable future selection of the immobilization matrix and solvent type for the development of organic phase enzyme based systems.

  2. Solvent Optimization for Efficient Enzymatic Monoacylglycerol Production Based on a Glycerolysis Reaction

    DEFF Research Database (Denmark)

    Damstrup, Marianne; Jensen, Tine; Sparsø, Flemming V.;

    2005-01-01

    This study was aimed at screening solvent systems of varying polarities to identify suitable solvents for efficient and practical enzymatic glycerolysis. Several pure solvents and solvent mixtures were screened in a batch reaction system consisting of glycerol, sunflower oil, and Novozymo (R) 435...

  3. Preferential solvation and solvation shell composition of free base and protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin in aqueous organic mixed solvents.

    Science.gov (United States)

    Farajtabar, Ali; Jaberi, Fatemeh; Gharib, Farrokh

    2011-12-01

    The solvatochromic properties of the free base and the protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) were studied in pure water, methanol, ethanol (protic solvents), dimethylsulfoxide, DMSO, (non-protic solvent), and their corresponding aqueous-organic binary mixed solvents. The correlation of the empirical solvent polarity scale (E(T)) values of TPPS with composition of the solvents was analyzed by the solvent exchange model of Bosch and Roses to clarify the preferential solvation of the probe dyes in the binary mixed solvents. The solvation shell composition and the synergistic effects in preferential solvation of the solute dyes were investigated in terms of both solvent-solvent and solute-solvent interactions and also, the local mole fraction of each solvent composition was calculated in cybotactic region of the probe. The effective mole fraction variation may provide significant physico-chemical insights in the microscopic and molecular level of interactions between TPPS species and the solvent components and therefore, can be used to interpret the solvent effect on kinetics and thermodynamics of TPPS. The obtained results from the preferential solvation and solvent-solvent interactions have been successfully applied to explain the variation of equilibrium behavior of protonation of TPPS occurring in aqueous organic mixed solvents of methanol, ethanol and DMSO.

  4. Preferential solvation and solvation shell composition of free base and protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin in aqueous organic mixed solvents

    Science.gov (United States)

    Farajtabar, Ali; Jaberi, Fatemeh; Gharib, Farrokh

    2011-12-01

    The solvatochromic properties of the free base and the protonated 5, 10, 15, 20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) were studied in pure water, methanol, ethanol (protic solvents), dimethylsulfoxide, DMSO, (non-protic solvent), and their corresponding aqueous-organic binary mixed solvents. The correlation of the empirical solvent polarity scale ( ET) values of TPPS with composition of the solvents was analyzed by the solvent exchange model of Bosch and Roses to clarify the preferential solvation of the probe dyes in the binary mixed solvents. The solvation shell composition and the synergistic effects in preferential solvation of the solute dyes were investigated in terms of both solvent-solvent and solute-solvent interactions and also, the local mole fraction of each solvent composition was calculated in cybotactic region of the probe. The effective mole fraction variation may provide significant physico-chemical insights in the microscopic and molecular level of interactions between TPPS species and the solvent components and therefore, can be used to interpret the solvent effect on kinetics and thermodynamics of TPPS. The obtained results from the preferential solvation and solvent-solvent interactions have been successfully applied to explain the variation of equilibrium behavior of protonation of TPPS occurring in aqueous organic mixed solvents of methanol, ethanol and DMSO.

  5. Interfacial micromorphological differences in hybrid layer formation between water- and solvent-based dentin bonding systems.

    Science.gov (United States)

    Gregoire, Geneviève L; Akon, Bernadette A; Millas, Arlette

    2002-06-01

    Many dentin bonding systems of different compositions, and in particular containing different solvents, have been introduced to the market. Their effect on the quality of the interface requires clarification by means of comparative trials. This study investigated micromorphological differences in hybrid layer formation with a variety of commercially available water- or solvent-based dentin bonding products and their recommended compomers. Five bonding systems were used on groups of 10 teeth each as follows: group I, acetone-based system used with 36% phosphoric acid; group II, a different acetone-based system containing nano-sized particles for filler loading and used with a non-rinsing conditioner containing maleic acid; group III, the acetone-based system of group II used with 36% phosphoric acid (the only difference in the treatment for groups II and III was the acid etching system); group IV, a mixed-solvent-based system (water/ethanol) used with 37% phosphoric acid; and group V, a water-based system used with 37% phosphoric acid. Each bonding system was covered with the recommended compomer. Class I occlusal preparations were made in extracted teeth and restored with one of the above systems. Five specimens of each group were studied with optical microscopy after staining. Scanning electron microscopy was used to examine the interface of the bonding system/dentin of the other 5 teeth in each group. The optical microscopy measurements were made with a 10 x 10 reticle. A micron mark with scale was used for the scanning electron microscope. All measurements were made in microm. The following criteria were used to define a good interface: absence of voids between the different parts of the interface, uniformity of the hybrid layer, good opening of the tubuli orifices, and tag adherence to the tubuli walls. Morphological differences were found at the interface depending on dentin treatment and adhesive composition. The acetone-containing systems were associated

  6. EVALUACIÓN DEL RIESGO OCUPACIONAL POR EXPOSICIÓN A BENCENO, TOLUENO Y XILENOS EN UNA INDUSTRIA DE PINTURAS EN BOGOTÁ, D.C.

    Directory of Open Access Journals (Sweden)

    María del Pilar Rubiano

    2010-11-01

    Full Text Available Se determinaron los niveles de benceno,tolueno y xilenos (BTX en el aire deuna industria de pinturas adscrita al InstitutoColombiano de Seguros Sociales,con el propósito de evaluar el riesgo ocupacional ocasionado por el uso de estos solventes; se compararon estos resultados con los valores límite umbral (Threshold Limit Valué , TLV. Se escogió como estrategia de muestreo la metodología de período parcial con muestras consecutivas y se utilizaron tubos de carbón activado como medio de captación de solventes. La extracciónse hizo con disulfuro de carbono y se utilizó como método de análisis la cromatografía de gases con detector de ionización de llama. Se encontró que el método es altamente selectivo porque aun en presencia de otros 10 solventes utilizados en la industria de pinturas, fue posible encontrar una buena separación para BTX. La precisión, expresada como coeficiente de variación, fue menor al 10%, la exactitud varió entre 85 y 99% para los tres disolventes. Se encontraron concentraciones en aire que variaron entre no detectable y 55,1 mg/m3 para el benceno; entre 18,3 y 253 mg/m3 para tolueno; entre 11,8 y 122,2 mg/m3 para xileno. Los valores TLV de benceno, tolueno y xilenos, corregidos de acuerdo con el modelo de Brief y Scala para una jornada diaria de 10 horas fueron de 1,1, 132 y 304 mg/m3 respectivamente. Se encontró que existe riesgo ocupacional por benceno en algunos puestos de trabajo, lo cual es preocupante si se tiene en cuenta que éste no es utilizado como materia prima en la fabricación de pinturas. El tolueno presenta riesgo ocupacional en menor proporción mientras que la presencia de xilenos no genera riesgo porque las concentraciones encontradas no superaron el valor TLV. Se determinó que existe riesgo ocupacional en la mayoría de los puestos de trabajo de la industria estudiada cuando se considera la mezcla de los tres disolventes.

  7. Da natureza viva à pintura bruta: Cézanne e Merleau-Ponty

    Directory of Open Access Journals (Sweden)

    Bruno O. De Andrade

    2013-07-01

    Full Text Available O que se nota ao ler os textos de Maurice Merleau- Ponty que direta ou indiretamente se relacionam com o problema Cézanne é – para além de uma profunda compreensão das linhas de força da pintura do mestre de Provence, e da pintura de um modo geral, rara entre filósofos – uma verdadeira afinidade entre duas formas de pensamento inaugurais, um filosófico e outro pictórico. Haveria entre o pensamento de Merleau-Ponty e a pintura de Cézanne não somente uma afinidade, mas um verdadeiro imbricamento? Um dos pontos desse trabalho pretende esboçar uma resposta a essa questão; o outro ponto a ser discutido, que de algum modo se relaciona com o primeiro, diz respeito à radicalização da pintura de Cézanne nos últimos anos de sua produção, expressa nas magistrais pinturas da Montanha Santa Vitória. Tal radicalização, nos parece, escapa à análise de Merleau Ponty; no entanto, pode ser análoga à radicalização do pensamento do autor de O olho e o espírito, à sua fenomenologia da percepção ou do corpo, à ontologia do ser bruto, da carne.

  8. Solvent-free Synthesis of Flavanone over New Hybrid Mesoporous Base Catalysts

    Institute of Scientific and Technical Information of China (English)

    WANG Hui; NIU Xiao-di; ZHAO Min; XIAO Xue-bin; WANG Hong-su; WANG Zhong-dong

    2011-01-01

    Benzyl and anthracenemethyl groups were respectively bonded to the N atoms of 3-aminopropyl functionalized mesoporous SBA-15(APS-SBA-15) to obtain two new base catalysts over which the condensation reaction of benzaldehyde and 2′-hydroxyacetophenone was studied.Good catalytic activities and high selectivities for flavanones were obtained in solvent-free reactions,which is attributed to the effect of benzyl and anthracenemetyl groups on the base sites of catalysts and the steric hindrance of futher reaction of flavanone with benzaldehyde.

  9. Efficient inverted organic light-emitting devices by amine-based solvent treatment (Presentation Recording)

    Science.gov (United States)

    Song, Myoung Hoon; Choi, Kyoung-Jin; Jung, Eui Dae

    2015-10-01

    The efficiency of inverted polymer light-emitting diodes (iPLEDs) were remarkably enhanced by introducing spontaneously formed ripple-shaped nanostructure of ZnO (ZnO-R) and amine-based polar solvent treatment using 2-methoxyethanol and ethanolamine (2-ME+EA) co-solvents on ZnO-R. The ripple-shape nanostructure of ZnO layer fabricated by solution process with optimal rate of annealing temperature improves the extraction of wave guide modes inside the device structure, and 2-ME+EA interlayer enhances the electron injection and hole blocking and reduces exciton quenching between polar solvent treated ZnO-R and emissive layer. As a result, our optimized iPLEDs show the luminous efficiency (LE) of 61.6 cd A-1, power efficiency (PE) of 19.4 lm W-1 and external quantum efficiency (EQE) of 17.8 %. This method provides a promising method, and opens new possibilities for not only organic light-emitting diodes (OLEDs) but also other organic optoelectronic devices such as organic photovoltaics, organic thin film transistors, and electrically driven organic diode laser.

  10. Computational prediction of octanol-water partition coefficient based on the extended solvent-contact model.

    Science.gov (United States)

    Kim, Taeho; Park, Hwangseo

    2015-07-01

    The logarithm of 1-octanol/water partition coefficient (LogP) is one of the most important molecular design parameters in drug discovery. Assuming that LogP can be calculated from the difference between the solvation free energy of a molecule in water and that in 1-octanol, we propose a method for predicting the molecular LogP values based on the extended solvent-contact model. To obtain the molecular solvation free energy data for the two solvents, a proper potential energy function was defined for each solvent with respect to atomic distributions and three kinds of atomic parameters. Total 205 atomic parameters were optimized with the standard genetic algorithm using the training set consisting of 139 organic molecules with varying shapes and functional groups. The LogP values estimated with the two optimized solvation free energy functions compared reasonably well with the experimental results with the associated squared correlation coefficient and root mean square error of 0.824 and 0.697, respectively. Besides the prediction accuracy, the present method has the merit in practical applications because molecular LogP values can be computed straightforwardly from the simple potential energy functions without the need to calculate various molecular descriptors. The methods for enhancing the accuracy of the present prediction model are also discussed.

  11. Stability and thermophysical studies on deep eutectic solvent based carbon nanotube nanofluid

    Science.gov (United States)

    Chen, Yan Yao; Walvekar, Rashmi; Khalid, Mohammad; Shahbaz, Kaveh; Gupta, T. C. S. M.

    2017-07-01

    Commercial coolants such as water, ethylene glycol and triethylene glycol possess very low thermal conductivity, high vapor pressure, corrosion issues and low thermal stability thus limiting the thermal enhancement of the nanofluids. Thus, a new type of base fluid known as deep eutectic solvents (DESs) is proposed in this work as a potential substitute for the conventional base fluid due to their unique solvent properties such as low vapor pressure, high thermal stability, biodegradability and non-flammability. In this work, 33 different DESs derived from phosphonium halide salt and ammonium halide salts were synthesised. Carbon nantubes (CNTs) with different concentrations (0.01 wt%-0.08 wt%) were dispersed into DESs with the help of sonication. Stability of the nanofluids were determined using both qualitative (visual observation) and quantitative (UV spectroscopy) approach. In addition, thermo-physical properties such as thermal conductivity, specific heat, viscosity and density were investigated. The stability results indicated that phosphonium based DESs have higher stability (up to 4 d) as compared to ammonium-based DESs (up to 3 d). Thermal enhancement of 30% was observed for ammonium based DES-CNT nanofluid whereas negative thermal enhancement was observed in phosphonium based DES-CNT nanofluid.

  12. SOLVENT-BASED TO WATERBASED ADHESIVE-COATED SUBSTRATE RETROFIT - VOLUME III: LABEL MANUFACTURING CASE STUDY: NASHUA CORPORATION

    Science.gov (United States)

    This volume discusses Nashua Corporation's Omaha facility, a label and label stock manufacturing facility that no longer uses solvent-based adhesives. Information obtained includes issues related to the technical, economic, and environmental barriers and opportunities associated ...

  13. Pinturas murales del I estilo pompeyano en Cartagena

    Directory of Open Access Journals (Sweden)

    Fernández Díaz, Alicia

    1999-12-01

    Full Text Available This study is the result of the discovery of some fragments of mural Roman paintings found in some excavation sites in the town of Cartagena, which can be classified in the first Pompeian style (end of the 2nd century BC. Their ornamental scheme consists of an imitation in stucco of «spun of padded (dressed marble» or more commonly denominated as isodomic apparel, whose purpose is not only functional or destined to cover the several materials employed in the construction, but also ornamental and associated to concepts like gravitas and mos maiorum.Este estudio, presentado a modo de noticia, es el resultado del hallazgo de unos fragmentos de pintura mural romana en unas excavaciones de la ciudad de Cartagena que pueden encuadrarse en el I estilo pompeyano (finales del siglo II a.C.. Su esquema decorativo consiste en una imitación en estuco de hiladas de aparejo de mármol almohadillado o más comúnmente denominado como aparejo isódomo, cuya finalidad no es únicamente funcional o destinada a tapar los diferentes materiales empleados en la construcción, sino también ornamental y asociada a conceptos como gravitas y mos maiorum.

  14. Influencia de distintos medios agresivos en la acción protectora de las pinturas ricas en zinc

    Directory of Open Access Journals (Sweden)

    Abreu, C. M.

    1999-06-01

    Full Text Available The aim of the present work is to determine the influence that different atmospheric agents have in steel protection by zinc rich paints based on inorganic silicate binder. The presence of pollutants in the atmosphere has been simulated by periodical deposition of sulphate and/or chloride solutions on the surface of the samples. With the aim of determining the validity of immersion tests, usually used in these types studies, the samples were kept in a controlled atmosphere at 20°C and 60% RH. These exposition conditions could represent a relative dry atmosphere allowing the zinc corrosion. Electrochemical impedance spectroscopy was employed to follow the time evolution of the studied paints. The corresponding impedance spectra were modeled using an electrical equivalent circuit approach. This methodology allows establishing that pollutants as well as weathering conditions define the protecting mechanism of these zinc rich paints. The results show a fast evolution towards a barrier-type protecting mechanism.

    En este trabajo se pretende determinar la influencia de distintos agentes corrosivos atmosféricos en la protección anticorrosiva que ejercen las pinturas ricas en zinc de base silicato inorgánico. Sobre las muestras pintadas, y una vez han curado, se depositan periódicamente disoluciones de sulfato y de cloruro, tanto de forma independiente como conjunta. Con objeto de determinar la validez de los ensayos de inmersión, habitualmente utilizados en este tipo de estudios, las pinturas se exponen en cámara de humedad a 20°C y 60% de humedad relativa, lo que sería equiparable a ambientes naturales relativamente secos y que, sin embargo, permiten la corrosión del zinc. La evolución de las pinturas se estudia mediante espectroscopia de impedancia electroquímica. Los espectros obtenidos se interpretan en función de modelos de circuitos equivalentes. Esta metodología permite establecer que el mecanismo de protección est

  15. Dimensionamiento del sistema de tratamiento de aguas residuales industriales en la industria de la pintura

    OpenAIRE

    Guevara Gavilanes, Silvia; Parrales Baquerizo, Narcisa; Villamar Bajaña, Franklin

    2009-01-01

    Las aguas residuales en la Industria de la pintura son el conjunto de las aguas que son contaminadas durante su empleo en actividades de limpieza realizadas en el proceso de elaboración de las pinturas acuosas. Para reparar esta alteración a la naturaleza aplicaremos sistemas de tratamientos de aguas donde se realiza distintos procesos necesarios para poder llegar al estado inicial del agua sin contaminación, los sistemas de tratamiento no hacen otra cosa que separar todos los contaminante...

  16. Diego Velázquez y la pintura oblicua de Juan Caramuel

    OpenAIRE

    Marías, Fernando

    2008-01-01

    La recuperación de un texto olvidado de Juan Caramuel de Lobkowitz, sobre el arte de la pintura y el retrato de Inocencio X de Diego Velázquez, permite el análisis de algunas de sus ideas sobre la pintura antigua y moderna, en relación con el debate contemporáneo entre rubensistas y poussinistas, y sobre el arte de Velázquez, en relación con sus propias teorías sobre la arquitectura oblicua y la necesaria adecuación entre la forma y la estructura significante de lo representado ...

  17. Modificaciones en la imagen radiográfica de pinturas reenteladas

    OpenAIRE

    Chaves Castanedo, Mª Pilar

    2016-01-01

    323 p. El examen científico aplicado a la conservación de obras de arte, contribuye sin lugar a dudas, a avanzar en la conservación de nuestro legado histórico artístico y cultural. Sin embargo, en el desarrollo de nuestra actividad profesional venimos apreciando en radiografías de pinturas que han sido restauradas, que dependiendo de las intervenciones realizadas, los registros radiográficos varían. Las radiografías de pinturas reenteladas, proporcionan a veces imágenes más difusas de lo ...

  18. En defensa de la pintura. Ciudad de México, 1753

    OpenAIRE

    Mina Ramírez Montes

    2001-01-01

    Luego de una introducción sobre las academias de pintura en México, previas a la de San Carlos, se plantea el problema de la liberalidad, ingenuidad y nobleza de la pintura, a la vez que se analiza una carta al virrey, suscrita por los principales pintores y grabadores de la capital del virreinato, encabezados por José de Ibarra y Baltasar Troncoso y Sotomayor, en la que hacen un análisis del valor de la obra pictórica y de la calidad étnica de sus ejecutantes, con la finalidad de conseguir d...

  19. Comparative in vitro study of cholinium-based ionic liquids and deep eutectic solvents toward fish cell line.

    Science.gov (United States)

    Radošević, Kristina; Železnjak, Jelena; Cvjetko Bubalo, Marina; Radojčić Redovniković, Ivana; Slivac, Igor; Gaurina Srček, Višnja

    2016-09-01

    With the advent of ionic liquids, much was expected concerning their applicability as an alternative to organic solvents in the chemical technology and biotechnology fields. However, the most studied and commonly used ionic liquids based on imidazolium and pyridinium were found not to be as environmentally friendly as it was first expected. Therefore, a new generation of alternative solvents named natural ionic liquids and deep eutectic solvents, composed of natural and/or renewable compounds, have come into focus in recent years. Since the number of newly synthesized chemicals increases yearly, simple and reliable methods for their ecotoxicological assessment are necessary. Permanent fish cell lines can serve as a test system for the evaluation of a chemical's cytotoxicity. This paper presents research results on the cytotoxic effects on Channel Catfish Ovary (CCO) cell line induced by fifteen cholinium-based ionic liquids and deep eutectic solvents. Based on the decrease in cell viability, the most obvious toxic effect on CCO cells was caused by ionic liquid choline oxalate, while other solvents tested exhibited low cytotoxicity. Therefore, we can conclude that cholinium-based ionic liquids and deep eutectic solvents are comparatively less toxic to CCO cells than conventional ionic liquids.

  20. Gels and lyotropic liquid crystals: using an imidazolium-based catanionic surfactant in binary solvents.

    Science.gov (United States)

    Cheng, Ni; Hu, Qiongzheng; Bi, Yanhui; Xu, Wenwen; Gong, Yanjun; Yu, Li

    2014-08-01

    The self-assembly behavior of an imidazolium-based catanionic surfactant, 1-butyl-3-methylimidazolium dodecylsulfate ([C4mim][C12H25SO4]), was investigated in water-ethylammonium nitrate (EAN) mixed solvents with different volume ratios. It is particular interesting that this simple surfactant could not only form lyotropic liquid crystals (LLC) with multimesophases, i.e., normal hexagonal (H1), lamellar liquid crystal (Lα), and reverse bicontinuous cubic phase (V2), in the water-rich environment but also act as an efficient low-molecular-weight gelator (LMWG) which gelated EAN-abundant binary media in a broad concentration range. The peculiar nanodisk cluster morphology of gels composed of similar bilayer units was first observed. FT-IR spectra and density functional theory (DFT) calculations reveal that strong H bonding and electrostatic interactions between EAN and the headgroups of [C4mim][C12H25SO4] are primarily responsible for gelation. The self-assembled gels displayed excellent mechanical strength and a thermoreversible sol-gel transition. It is for the first time that a rich variety of controllable ordered aggregates could be observed only by simply modulating the concentration of a single imidazolium-based catanionic surfactant or the ratio of mixed solvents. This environmentally friendly system is expected to have broad applications in various fields, such as materials science, drug delivery systems, and supramolecular chemistry.

  1. Solvent stimulated actuation of polyurethane-based shape memory polymer foams using dimethyl sulfoxide and ethanol

    Science.gov (United States)

    Boyle, A. J.; Weems, A. C.; Hasan, S. M.; Nash, L. D.; Monroe, M. B. B.; Maitland, D. J.

    2016-07-01

    Solvent exposure has been investigated to trigger actuation of shape memory polymers (SMPs) as an alternative to direct heating. This study aimed to investigate the feasibility of using dimethyl sulfoxide (DMSO) and ethanol (EtOH) to stimulate polyurethane-based SMP foam actuation and the required solvent concentrations in water for rapid actuation of hydrophobic SMP foams. SMP foams exhibited decreased T g when submerged in DMSO and EtOH when compared to water submersion. Kinetic DMA experiments showed minimal or no relaxation for all SMP foams in water within 30 min, while SMP foams submerged in EtOH exhibited rapid relaxation within 1 min of submersion. SMP foams expanded rapidly in high concentrations of DMSO and EtOH solutions, where complete recovery over 30 min was observed in DMSO concentrations greater than 90% and in EtOH concentrations greater than 20%. This study demonstrates that both DMSO and EtOH are effective at triggering volume recovery of polyurethane-based SMP foams, including in aqueous environments, and provides promise for use of this actuation technique in various applications.

  2. Supramolecular solvent-based hollow fiber liquid phase microextraction of benzodiazepines.

    Science.gov (United States)

    Rezaei, Fatemeh; Yamini, Yadollah; Moradi, Morteza; Daraei, Bahram

    2013-12-04

    A new, efficient, and environmental friendly hollow fiber liquid phase microextraction (HF-LPME) method based on supramolecular solvents was developed for extraction of five benzodiazepine drugs. The supramolecular solvent was produced from coacervation of decanoic acid aqueous vesicles in the presence of tetrabutylammonium (Bu4N(+)). In this work, benzodiazepines were extracted from aqueous samples into a supramolecular solvent impregnated in the wall pores and also filled inside the porous polypropylene hollow fiber membrane. The driving forces for the extraction were hydrophobic, hydrogen bonding, and π-cation interactions between the analytes and the vesicular aggregates. High-performance liquid chromatography with photodiode array detection (HPLC-DAD) was applied for separation and determination of the drugs. Several parameters affecting the extraction efficiency including pH, hollow fiber length, ionic strength, stirring rate, and extraction time were investigated and optimized. Under the optimal conditions, the preconcentration factors were obtained in the range of 112-198. Linearity of the method was determined to be in the range of 1.0-200.0 μg L(-1) for diazepam and 2.0-200.0 μg L(-1) for other analytes with coefficient of determination (R(2)) ranging from 0.9954 to 0.9993. The limits of detection for the target benzodiazepines were in the range of 0.5-0.7 μg L(-1). The method was successfully applied for extraction and determination of the drugs in water, fruit juice, plasma and urine samples and relative recoveries of the compounds studied were in the range of 90.0-98.8%.

  3. Extraction of tetra-oxo anions into a hydrophobic, ionic liquid-based solvent without concomitant ion exchange.

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, D. C.; Vandegrift, G. F.; Shkrob, I. A.; Wishart, J. F.; Kerr, K.; Dietz, M. L.; Qadah, D. T. D.; Garvey, S. L.; BNL; Univ. of Wisconsin at Milwaukee

    2010-06-16

    Hydrophobic ionic liquids (IL) have the potential to simplify certain separations by serving as both an extraction solvent and an electrolyte for subsequent electrochemical reductions. While IL-based solvents are known to be efficient media for metal ion extraction, separations employing these solvents are frequently complicated by the loss of constituent IL ions to the aqueous phase, resulting in deteriorating performance. In this study, we have examined the extraction of pertechnetate and related tetra-oxo anions from aqueous solutions into IL-based solvents incorporating tetraalkylphosphonium bis[(trifluoromethyl)sulfonyl]imide and a crown ether. In contrast to various previously studied IL-based cation extraction systems, facile anion extraction without significant transfer of the IL ions to the aqueous phase has been observed. In addition, the solvents exhibit high distribution ratios (100-500 for pertechnetate), significant electrical conductivity (>100 ?S/cm), and a wide (4 V) electrochemical window. The results suggest that these solvents may provide the basis for improved approaches to the extraction and recovery of a variety of anions.

  4. Extraction of Tetra-oxo Anions into a Hydrophobic, Ionic Liquid-Based Solvent Without Concomitant Ion Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, D.C.; Wishart, J.; Vandegrift, III, G.F.; Shkrob, I.A.; Kerr, K.; Dietz, M.L.; Qadah, D.T.D.; Garvey, S.L.

    2010-06-10

    Hydrophobic ionic liquids (IL) have the potential to simplify certain separations by serving as both an extraction solvent and an electrolyte for subsequent electrochemical reductions. While IL-based solvents are known to be efficient media for metal ion extraction, separations employing these solvents are frequently complicated by the loss of constituent IL ions to the aqueous phase, resulting in deteriorating performance. In this study, we have examined the extraction of pertechnetate and related tetra-oxo anions from aqueous solutions into IL-based solvents incorporating tetraalkylphosphonium bis[(trifluoromethyl)sulfonyl]imide and a crown ether. In contrast to various previously studied IL-based cation extraction systems, facile anion extraction without significant transfer of the IL ions to the aqueous phase has been observed. In addition, the solvents exhibit high distribution ratios (100-500 for pertechnetate), significant electrical conductivity (>100 {micro}S/cm), and a wide ({approx}4 V) electrochemical window. The results suggest that these solvents may provide the basis for improved approaches to the extraction and recovery of a variety of anions.

  5. Response Surface Optimization of Rotenone Using Natural Alcohol-Based Deep Eutectic Solvent as Additive in the Extraction Medium Cocktail

    Directory of Open Access Journals (Sweden)

    Zetty Shafiqa Othman

    2017-01-01

    Full Text Available Rotenone is a biopesticide with an amazing effect on aquatic life and insect pests. In Asia, it can be isolated from Derris species roots (Derris elliptica and Derris malaccensis. The previous study revealed the comparable efficiency of alcohol-based deep eutectic solvent (DES in extracting a high yield of rotenone (isoflavonoid to binary ionic liquid solvent system ([BMIM]OTf and organic solvent (acetone. Therefore, this study intends to analyze the optimum parameters (solvent ratio, extraction time, and agitation rate in extracting the highest yield of rotenone extract at a much lower cost and in a more environmental friendly method by using response surface methodology (RSM based on central composite rotatable design (CCRD. By using RSM, linear polynomial equations were obtained for predicting the concentration and yield of rotenone extracted. The verification experiment confirmed the validity of both of the predicted models. The results revealed that the optimum conditions for solvent ratio, extraction time, and agitation rate were 2 : 8 (DES : acetonitrile, 19.34 hours, and 199.32 rpm, respectively. At the optimum condition of the rotenone extraction process using DES binary solvent system, this resulted in a 3.5-fold increase in a rotenone concentration of 0.49 ± 0.07 mg/ml and yield of 0.35 ± 0.06 (%, w/w as compared to the control extract (acetonitrile only. In fact, the rotenone concentration and yield were significantly influenced by binary solvent ratio and extraction time (P<0.05 but not by means of agitation rate. For that reason, the optimal extraction condition using alcohol-based deep eutectic solvent (DES as a green additive in the extraction medium cocktail has increased the potential of enhancing the rotenone concentration and yield extracted.

  6. Ibiza en la pintura costumbrista de Amadeo Roca

    Directory of Open Access Journals (Sweden)

    Lena Mateu Prats, Mª.

    2013-06-01

    Full Text Available The controversy that aroused in the thirties provoked by the way in which Amadeo Roca represented the traditional costumes of Ibiza in his paintings acts as the structural axis of this article in order to deepen in the appropriate concept of ideal of group and in the evolutionary process that affects it. The clash between established correctness (limited by the loss of historical memory and artistic freedom (not lacking ethnographic documentation and content offers an interesting field of study in which ethnohistorical methodology must take part. Beside this the painter’s convenient stay in a peasant village of the island sketches an anthropological view of the place and the moment, interrelated with the process of achievement and indeed of disappearance of a part of his work.La polémica que en los años treinta suscitó la manera con que se mostraba la indumentaria tradicional ibicenca en la pintura costumbrista de Amadeo Roca sirve de eje estructural al artículo para profundizar en el correspondiente concepto de ideal de grupo y en el proceso evolutivo que le afecta. El enfrentamiento entre la corrección establecida (limitada por la pérdida de memoria histórica y la libertad artística (no exenta de documentación etnográfica y contenido ofrece así un interesante campo de estudio en el que ha de tomar parte la metodología etnohistórica. Junto a ello, la oportuna estancia del pintor en un núcleo de la payesía isleña, esboza una visión antropológica del lugar y el momento, interrelacionada con el proceso de realización, e incluso desaparición, de parte de su obra.

  7. Las Pinturas Rupestres de «Los Guindos»

    Directory of Open Access Journals (Sweden)

    Manuel Gabriel LÓPEZ PAYER

    2009-10-01

    Full Text Available RESUMEN: Las pinturas se encuentran situadas muy cerca de la mina de plomo de «Los Guindos» (La Carolina, Jaén a unos 800 m. de altura sobre el nivel del mar. Fueron descubiertas en el año 1925 cerca de restos arqueológicos de la Edad del- Bronce. Existen dos conjuntos (I y II. El que se estudia aquí es el conjunto I; está formado por dos grupos, el I y el II. El I está a la izquierda de la entrada de la abertura, y el II en el techo. Hay 25 figuras en total. La mayor parte, del tipo «golondrina» así llamados por la profesora P. Acosta. Una sola de entre ellas es un cuadrúpedo. Estas figuras son poco numerosas. Presentan un gran esquematismo. El color de todas las figuras es rojo. Por esta razón, podrían pertenecer a la etapa final del Bronce I o al comienzo del Bronce II.ABSTRACT: These paintings are to be found near the lead mine of «Los Guindos» (La Carolina-Jaén at about 800 meters altitude above sea level. They were discovered in 1925 near archeological remnants belanging to the Bronze Age. There are two sites (I and II. The one we are dealing with is site I, which is camposed of two groups, 1 and 2. Number 1 is on die left of the entrance, and number 2 an the ceiling. Altogether, there are 25 figures. Most of them of the «golondrina» type (swallow so named by Pr. P. Acosta. Only one of the figures is a quadruped. These figures are few and show great schematism - All the figures are of a red colour. For this reason they could belong to the late Bronze I or the biginning of Bronze II.

  8. DFT-based QSAR and QSPR models of several cis-platinum complexes: solvent effect.

    Science.gov (United States)

    Sarmah, Pubalee; Deka, Ramesh C

    2009-06-01

    Cytotoxic activities of cis-platinum complexes against parental and resistant ovarian cancer cell lines were investigated by quantitative structure-activity relationship (QSAR) analysis using density functional theory (DFT) based descriptors. The calculated parameters were found to increase the predictability of each QSAR model with incorporation of solvent effects indicating its importance in studying biological activity. Given the importance of logarithmic n-octanol/water partition coefficient (log P(o/w)) in drug metabolism and cellular uptake, we modeled the log P(o/w) of 24 platinum complexes with different leaving and carrier ligands by the quantitative structure-property relationship (QSPR) analysis against five different concentrations of MeOH using DFT and molecular mechanics derived descriptors. The log P(o/w) values of an additional set of 20 platinum complexes were also modeled with the same descriptors. We investigated the predictability of the model by calculating log P(o/w) of four compounds in the test set and found their predicted values to be in good agreement with the experimental values. The QSPR analyses performed on 24 complexes, combining the training and test sets, also provided significant values for the statistical parameters. The solvent medium played an important role in QSPR analysis by increasing the internal predictive ability of the models.

  9. Enhanced removal of lead from contaminated soil by polyol-based deep eutectic solvents and saponin

    Science.gov (United States)

    Mukhopadhyay, Soumyadeep; Mukherjee, Sumona; Hayyan, Adeeb; Hayyan, Maan; Hashim, Mohd Ali; Sen Gupta, Bhaskar

    2016-11-01

    Deep eutectic solvents (DESs) are a class of green solvents analogous to ionic liquids, but less costly and easier to prepare. The objective of this study is to remove lead (Pb) from a contaminated soil by using polyol based DESs mixed with a natural surfactant saponin for the first time. The DESs used in this study were prepared by mixing a quaternary ammonium salt choline chloride with polyols e.g. glycerol and ethylene glycol. A natural surfactant saponin obtained from soapnut fruit pericarp, was mixed with DESs to boost their efficiency. The DESs on their own did not perform satisfactory due to higher pH; however, they improved the performance of soapnut by up to 100%. Pb removal from contaminated soil using mixture of 40% DES-Gly and 1% saponin and mixture of 10% DES-Gly and 2% saponin were above 72% XRD and SEM studies did not detect any major corrosion in the soil texture. The environmental friendliness of both DESs and saponin and their affordable costs merit thorough investigation of their potential as soil washing agents.

  10. Tannin-based thin-film composite membranes for solvent nanofiltration

    KAUST Repository

    Perez Manriquez, Liliana

    2017-06-28

    The natural oligomer tannic acid was used as a reactant for an interfacial polymerisation on top of a crosslinked polyacrylonitrile (PAN) membrane. The PAN membrane was soaked with the aqueous tannic acid solution and contacted with a dilute solution of teraphtaloylchloride in hexane. Since both layers, the PAN support and the thin tannin-based layer, are highly crosslinked, the resulting thin film composite membrane is stable in harsh solvent environments such as N-Methyl-2-pyrrolidone (NMP). NMP permeances of up to 0.09L/m2 h bar with a molecular weight cut-off of approximately 800g/mol were obtained. The exceptional stability in NMP and the incorporation of natural compounds like tannic acid for the manufacture of organic solvent nanofiltration membranes provides a cost-effective alternative for industrial separations due to the simplicity of the interfacial reaction and the replacement of the commonly applied toxic aromatic amines. The scale up of the manufacturing process is not difficult; the low price of the natural tannic acid is another advantage.

  11. Alternative Single-Solvent Electrolytes Based on Cyanoesters for Safer Lithium-Ion Batteries.

    Science.gov (United States)

    Brox, Sebastian; Röser, Stephan; Husch, Tamara; Hildebrand, Stephan; Fromm, Olga; Korth, Martin; Winter, Martin; Cekic-Laskovic, Isidora

    2016-07-07

    To identify alternative single-solvent-based electrolytes for application in lithium-ion batteries (LIBs), adequate computational methods were applied to screen specified physicochemical and electrochemical properties of new cyanoester-based compounds. Out of 2747 possible target compounds, two promising candidates and two structurally equivalent components were chosen. A constructive selection process including evaluation of basic physicochemical properties as well assessing the compatibility towards graphitic anodes was initiated to identify the most promising candidates. With addition of a film-forming additive in a low concentration, the most promising candidate showed an adequate long-term cycling stability with LiNi1/3 Mn1/3 Co1/3 O2 [NMC(111)] in a full-cell setup using graphite as anode material. The main advantages of the new electrolyte formulation are related to its good thermal behavior, especially with regard to safety in combination with satisfying electrochemical performance.

  12. Las Pinturas Negras de Goya y la Quinta del Sordo. Precisiones sobre las teorías de Juan José Junquera

    Directory of Open Access Journals (Sweden)

    Glendinning, Nigel

    2004-09-01

    Full Text Available In 2003, three publications of Juan José Junquera cast doubt on the authenticity of Goya's Black Paintings. The present article disputes the validity of Professor Junquera's conclusions and re-examines the relevant documents in detail.

    En 2003, tres publicaciones de Juan José Junquera pusieron en tela de juicio la paternidad de las Pinturas Negras de Goya. El presente artículo cuestiona las conclusiones del profesor Junquera, examinando con detalle la base documental de sus teorías.

  13. A análise do discurso diante de estranhos espelhos: visualidade e (interdiscursividade na pintura

    Directory of Open Access Journals (Sweden)

    Renan Belmonte Mazzola

    2013-11-01

    Full Text Available Este artigo intenciona compreender a dimensão discursiva das pinturas por meio da análise do discurso ancorada em Michel Foucault. Recorta-se a figura do espelho em pinturas canônicas com vistas a observar seu funcionamento discursivo enquanto elemento do enunciado artístico visual. Apresenta três partes: a primeira, que determina o lugar ocupado pelo discurso estético nos trabalhos de Michel Pêcheux e de Michel Foucault; a segunda, que se concentra na análise de três pinturas europeias, a saber, As meninas, de Velásquez; Um bar em Folies-Bergère, de Manet; e As ligações perigosas, de Magritte; e a terceira parte, que discute a intersecção entre visualidade e interdiscursividade a partir (a das reflexões de M. Foucault acerca do discurso estético e (b da figura do espelho presente nessas pinturas.

  14. Solvent selection methodology for pharmaceutical processes: Solvent swap

    DEFF Research Database (Denmark)

    Papadakis, Emmanouil; Kumar Tula, Anjan; Gani, Rafiqul

    2016-01-01

    A method for the selection of appropriate solvents for the solvent swap task in pharmaceutical processes has been developed. This solvent swap method is based on the solvent selection method of Gani et al. (2006) and considers additional selection criteria such as boiling point difference, volati...

  15. In Vitro and In Vivo toxicity profiling of ammonium-based deep eutectic solvents.

    Science.gov (United States)

    Hayyan, Maan; Looi, Chung Yeng; Hayyan, Adeeb; Wong, Won Fen; Hashim, Mohd Ali

    2015-01-01

    The cytotoxic potential of ammonium-based deep eutectic solvents (DESs) with four hydrogen bond donors, namely glycerine (Gl), ethylene glycol (EG), triethylene glycol (TEG) and urea (U) were investigated. The toxicity of DESs was examined using In Vitro cell lines and In Vivo animal model. IC50 and selectivity index were determined for the DESs, their individual components and their combinations as aqueous solutions for comparison purposes. The cytotoxicity effect of DESs varied depending on cell lines. The IC50 for the GlDES, EGDES, UDES and TEGDES followed the sequence of TEGDESIn Vivo toxicity profiles of DESs were being demonstrated, raising the toxicity issue of these neoteric mixtures and their potential applicability to be used for therapeutic purposes.

  16. Roles of Poly(propylene Glycol) During Solvent-Based Lamination of Ceramic Green Tapes

    Science.gov (United States)

    Suppakarn, Nitinat; Ishida, Hatsuo; Cawley, James D.; Levine, Stanley R. (Technical Monitor)

    2000-01-01

    Solvent lamination for alumina green tapes is readily accomplished using a mixture of ethanol, toluene and poly(propylene glycol). After lamination, the PPG is clearly present as a discrete film at the interface between the laminated tapes. This condition, however, does not generate delamination during firing. Systematic sets of experiments are undertaken to determine the role of PPG in the lamination process and, specifically, the mechanism by which it is redistributed during subsequent processing. PPG slowly diffuses through the organic binder film at room temperature. The PPG diffusion rapidly increases as temperature is increased to 80 C. The key to the efficiency of adhesives during green-tape lamination is mutual solubility of the nonvolatile component of the glue and the base polymeric binder.

  17. Imidazole-based deep eutectic solvents for starch dissolution and plasticization.

    Science.gov (United States)

    Zdanowicz, Magdalena; Spychaj, Tadeusz; Mąka, Honorata

    2016-04-20

    Potato starch and high-amylose starch were treated with imidazole-based deep eutectic solvents (DESs) as dissolution and plasticization media. Beside imidazole (IM) for two-component DESs preparation choline chloride (CC), glycerol (G) or carboxylic acids (citric or malic) were used. An influence of water content in starch (as well as an extra water in the starch/DES system) on polymer dissolution and plasticization processes was investigated. Dissolution and gelatinization of starch in DESs were followed via DSC and laser scanning microscopy. A rheometric characteristics revealed an influence of starch/DES system storage time on the plasticization process. The tendency to recrystallization of compression-molded-starch films was evaluated using XRD technique. High dissolution and plasticization effectiveness of CC/IM and G/IM and a low tendency to film retrogradation of thermoplasticized starch were noted.

  18. Solvent based hydrogen bonding: impact on poly(3-hexylthiophene) nanoscale morphology and charge transport characteristics.

    Science.gov (United States)

    Chang, Mincheol; Choi, Dalsu; Fu, Boyi; Reichmanis, Elsa

    2013-06-25

    We demonstrate that supramolecular assembly and subsequent enhancement of charge transport characteristics of conjugated polymers can be facilitated simply by adding small amounts of a more volatile poor solvent, which can hydrogen bond with the majority solvent. Addition of up to 2 vol % acetone to a precursor solution of poly(3-hexylthiophene) (P3HT) in chloroform leads to approximately a 4-fold increase in P3HT field-effect mobility. The improvement is associated with hydrogen bonding interactions between acetone and chloroform which decrease the evaporation rate of the mixed solvent. P3HT is less soluble in the binary solvent than in the more readily vaporized chloroform component, and this characteristic enables the supramolecular assembly of P3HT chains at the nanoscale. Two-dimensional molecular ordering of the polymer film was controlled by varying the quantity of poor solvent added to the precursor solution, and the correlation between field-effect mobility and molecular ordering was investigated. Hansen solubility parameters were used to systematically understand how the solvent mixture enhances the alignment and assembly of polymer chains and influences subsequent thin film properties. The value of the relative energy difference (RED) of the solvent with respect to P3HT increased from less than 1 to more than 1 during film formation, which indicates that the solvent characteristics are initially those of a good solvent but transform into those of a poor dissolution medium. A mechanistic illustration of the molecular ordering process during film formation is postulated.

  19. Multiphase enantioselective Kharasch-Sosnovsky allylic oxidation based on neoteric solvents and copper complexes of ditopic ligands.

    Science.gov (United States)

    Aldea, Luis; García, José I; Mayoral, José A

    2012-07-21

    Recoverable multiphase enantioselective catalytic systems for the Kharasch-Sosnovsky oxidation of cycloalkenes with tert-butyl peroxybenzoate are described, based on the use of [BMIM][PF(6)] and a new solvent derived from glycerol as the catalyst reservoir phases, and chiral copper complexes with different ligands from the bis(oxazoline) family. The best results are obtained with the glycerol-derived solvent and a recently described azabisoxazoline-based ditopic ligand, allowing up to four uses of the catalytic phase with good results.

  20. Quick supramolecular solvent-based microextraction for quantification of low curcuminoid content in food.

    Science.gov (United States)

    Caballero-Casero, Noelia; Ocak, Miraç; Ocak, Ümmüham; Rubio, Soledad

    2014-03-01

    There is a need to monitor the consumption of curcuminoids, an EU-permitted natural colour in food, to ensure that acceptable daily intakes are not exceeded, especially by young children. This paper describes a sensitive method able to quantify low contents of curcumin (CUR), demethoxycurcumin (DMC) and bis-demethoxycurcumin (BDMC) in foodstuffs. The method was based on a single-step extraction by use of a supramolecular solvent (SUPRAS) made up of reverse aggregates of decanoic acid, and direct analysis of the extract by use of liquid chromatography-photodiode array (PDA) detection. The extraction involved the stirring of 200 mg foodstuff with 600 μL SUPRAS for 15 min. No cleanup or concentration of the extracts was required. Curcuminoid solubilisation occurred via dispersion and hydrogen bonding. The method was used for the determination of curcuminoids in different types of foodstuff (snack, gelatine, yoghurt, mayonnaise, butter, candy and fish products) that encompassed a wide range of protein, fat, carbohydrate, sugar and water contents (0.85-11.04, 0-81.11, 0.06-75, 0.06-79.48, and 10.08-85.10 g, respectively, in each 100 g of food). Method quantification limits for the foodstuffs analysed were in the ranges 2.9-7.7, 2.8-11.2 and 3.3-9.0 μg kg(-1) for CUR, DMC and BDMC, respectively. The concentrations of curcuminoids detected in the foodstuffs and the recoveries obtained from fortified samples were in the ranges ND-284, ND-201 and ND-61.3 μg kg(-1), and 82-106, 89-106 and 90-102 %, for CUR, DMC and BDMC, respectively. The relative standard deviations were in the range 2-7 %. This method enabled quick and simple microextraction of curcuminoids with minimal solvent consumption, while delivering accurate and precise data.

  1. Sugar-Based Polyamides: Self-Organization in Strong Polar Organic Solvents.

    Science.gov (United States)

    Rosu, Cornelia; Russo, Paul S; Daly, William H; Cueto, Rafael; Pople, John A; Laine, Roger A; Negulescu, Ioan I

    2015-09-14

    Periodic patterns resembling spirals were observed to form spontaneously upon unassisted cooling of d-glucaric acid- and d-galactaric acid-based polyamide solutions in N-methyl-N-morpholine oxide (NMMO) monohydrate. Similar observations were made in d-galactaric acid-based polyamide/ionic liquid (IL) solutions. The morphologies were investigated by optical, polarized light and confocal microscopy assays to reveal pattern details. Differential scanning calorimetry was used to monitor solution thermal behavior. Small- and wide-angle X-ray scattering data reflected the complex and heterogeneous nature of the self-organized patterns. Factors such as concentration and temperature were found to influence spiral dimensions and geometry. The distance between rings followed a first-order exponential decay as a function of polymer concentration. Fourier-Transform Infrared Microspectroscopy analysis of spirals pointed to H-bonding between the solvent and the pendant hydroxyl groups of the glucose units from the polymer backbone. Tests on self-organization into spirals of ketal-protected d-galactaric acid polyamides in NMMO monohydrate confirmed the importance of the monosaccharide's pendant free hydroxyl groups on the formation of these patterns. Rheology performed on d-galactaric-based polyamides at high concentration in NMMO monohydrate solution revealed the optimum conditions necessary to process these materials as fibers by spinning. The self-organization of these sugar-based polyamides mimics certain biological materials.

  2. 1-Butyl-3-Methyl Imidazolium-based Ionic Liquids Explored as Potential Solvents for Lipid Processing

    Science.gov (United States)

    Due to global environmental concerns, there is increasing interest in replacing the volatile solvents currently used to process commodity plant lipids. Room-temperature molten salts are one type of media receiving great attention as a possible replacement of the typical organic solvent. Molten sal...

  3. Develop and test a solvent accessible surface area-based model in conformational entropy calculations.

    Science.gov (United States)

    Wang, Junmei; Hou, Tingjun

    2012-05-25

    It is of great interest in modern drug design to accurately calculate the free energies of protein-ligand or nucleic acid-ligand binding. MM-PBSA (molecular mechanics Poisson-Boltzmann surface area) and MM-GBSA (molecular mechanics generalized Born surface area) have gained popularity in this field. For both methods, the conformational entropy, which is usually calculated through normal-mode analysis (NMA), is needed to calculate the absolute binding free energies. Unfortunately, NMA is computationally demanding and becomes a bottleneck of the MM-PB/GBSA-NMA methods. In this work, we have developed a fast approach to estimate the conformational entropy based upon solvent accessible surface area calculations. In our approach, the conformational entropy of a molecule, S, can be obtained by summing up the contributions of all atoms, no matter they are buried or exposed. Each atom has two types of surface areas, solvent accessible surface area (SAS) and buried SAS (BSAS). The two types of surface areas are weighted to estimate the contribution of an atom to S. Atoms having the same atom type share the same weight and a general parameter k is applied to balance the contributions of the two types of surface areas. This entropy model was parametrized using a large set of small molecules for which their conformational entropies were calculated at the B3LYP/6-31G* level taking the solvent effect into account. The weighted solvent accessible surface area (WSAS) model was extensively evaluated in three tests. For convenience, TS values, the product of temperature T and conformational entropy S, were calculated in those tests. T was always set to 298.15 K through the text. First of all, good correlations were achieved between WSAS TS and NMA TS for 44 protein or nucleic acid systems sampled with molecular dynamics simulations (10 snapshots were collected for postentropy calculations): the mean correlation coefficient squares (R²) was 0.56. As to the 20 complexes, the TS

  4. Characterization of solvents containing CyMe4-BTPhen in selected cyclohexanone-based diluents after irradiation by accelerated electrons

    Directory of Open Access Journals (Sweden)

    Distler Petr

    2015-12-01

    Full Text Available Radiation stability of CyMe4-BTPhen was examined in systems with three selected cyclohexanone-based diluents. Accelerated electrons were used as a source of ionizing radiation. The CyMe4-BTPhen radiation degradation identification and characterization of the degradation products were performed by high performance liquid chromatography (HPLC and mass spectrometry (MS analyses. Residual concentrations of tested ligand were determined. Moreover, extraction properties of the solvents irradiated at two different doses were compared with the extraction properties of non-irradiated solvents to estimate the influence of the presence of degradation products in the organic phase.

  5. Polarizable continuum model study on the solvent effect of polymer matrix in poly(ethylene oxide)-based solid electrolyte.

    Science.gov (United States)

    Eilmes, Andrzej; Kubisiak, Piotr

    2008-09-18

    The Polarizable Continuum Model has been used to study the effect of polymer matrix on Li (+) and Mg (2+) complexation in poly(ethylene oxide)-based solid electrolyte. Structures of complexes, stabilization energies, and vibrational frequencies are compared with corresponding vacuum values. The solvent effect of the polymer decreases with increasing cation coordination number. Optimized complex geometries do not differ significantly compared to vacuum calculations. Calculated shifts in vibrational frequencies depend on the complex structure; for hexacoordinated ion most frequencies are slightly red-shifted. The most important effect is the decrease of differences between relative stabilities of different structures in the solvent.

  6. Process to prepare stable trifluorostyrene containing compounds grafted to base polymers using a solvent/water mixture

    Science.gov (United States)

    Roelofs, Mark Gerrit; Yang, Zhen-Yu; Han, Amy Qi

    2010-06-15

    A fluorinated ion exchange polymer is prepared by grafting at least one grafting monomer derived from trifluorostyrene on to at least one base polymer in a organic solvent/water mixture. These ion exchange polymers are useful in preparing catalyst coated membranes and membrane electrode assemblies used in fuel cells.

  7. Langevin-Poisson-EQT: A dipolar solvent based quasi-continuum approach for electric double layers

    Science.gov (United States)

    Mashayak, S. Y.; Aluru, N. R.

    2017-01-01

    Water is a highly polar solvent. As a result, electrostatic interactions of interfacial water molecules play a dominant role in determining the distribution of ions in electric double layers (EDLs). Near a surface, an inhomogeneous and anisotropic arrangement of water molecules gives rise to pronounced variations in the electrostatic and hydration energies of ions. Therefore, a detailed description of the structural and dielectric properties of water is important to study EDLs. However, most theoretical models ignore the molecular effects of water and treat water as a background continuum with a uniform dielectric permittivity. Explicit consideration of water polarization and hydration of ions is both theoretically and numerically challenging. In this work, we present an empirical potential-based quasi-continuum theory (EQT) for EDL, which incorporates the polarization and hydration effects of water explicitly. In EQT, water molecules are modeled as Langevin point dipoles and a point dipole based coarse-grained model for water is developed systematically. The space dependence of the dielectric permittivity of water is included in the Poisson equation to compute the electrostatic potential. In addition, to reproduce hydration of ions, ion-water coarse-grained potentials are developed. We demonstrate the EQT framework for EDL by simulating NaCl aqueous electrolyte confined inside slit-like capacitor channels at various ion concentrations and surface charge densities. We show that the ion and water density predictions from EQT agree well with the reference molecular dynamics simulations.

  8. Synthesis and thermo-physical properties of deep eutectic solvent-based graphene nanofluids

    Science.gov (United States)

    Fang, Y. K.; Osama, M.; Rashmi, W.; Shahbaz, K.; Khalid, M.; Mjalli, F. S.; Farid, M. M.

    2016-02-01

    This study introduces a new class of heat transfer fluids by dispersing functionalised graphene oxide nanoparticles (GNPs) in ammonium and phosphonium-based deep eutectic solvents (DESs) without the aid of a surfactant. Different molar ratios of salts and hydrogen bond donors (HBD) were used to synthesise DESs for the preparation of different concentrations of graphene nanofluids (GNFs). The concentrations of GNPs were 0.01 wt%, 0.02 wt% and 0.05 wt %. Homogeneous and stable suspensions of nanofluids were obtained by high speed homogenisation and an ultrasonication process. The stability of the GNFs was determined through visual observation for 4 weeks followed by a centrifugal process (5000-20 000 rpm) for 30 min in addition to zeta potential studies. Dispersion of the GNPs in DES was observed using an optical microscope. The synthesised DES-based GNFs showed no particle agglomeration and formation of sediments in the nanofluids. Thermo-physical properties such as thermal conductivity and specific heat of the nanofluids were also investigated in this research. The highest thermal conductivity enhancement of 177% was observed. The findings of this research provide a new class of engineered fluid for heat transfer applications as a function of temperature, type and composition DESs as well as the GNPs concentration.

  9. Synthesis and thermo-physical properties of deep eutectic solvent-based graphene nanofluids.

    Science.gov (United States)

    Fang, Y K; Osama, M; Rashmi, W; Shahbaz, K; Khalid, M; Mjalli, F S; Farid, M M

    2016-02-19

    This study introduces a new class of heat transfer fluids by dispersing functionalised graphene oxide nanoparticles (GNPs) in ammonium and phosphonium-based deep eutectic solvents (DESs) without the aid of a surfactant. Different molar ratios of salts and hydrogen bond donors (HBD) were used to synthesise DESs for the preparation of different concentrations of graphene nanofluids (GNFs). The concentrations of GNPs were 0.01 wt%, 0.02 wt% and 0.05 wt %. Homogeneous and stable suspensions of nanofluids were obtained by high speed homogenisation and an ultrasonication process. The stability of the GNFs was determined through visual observation for 4 weeks followed by a centrifugal process (5000-20,000 rpm) for 30 min in addition to zeta potential studies. Dispersion of the GNPs in DES was observed using an optical microscope. The synthesised DES-based GNFs showed no particle agglomeration and formation of sediments in the nanofluids. Thermo-physical properties such as thermal conductivity and specific heat of the nanofluids were also investigated in this research. The highest thermal conductivity enhancement of 177% was observed. The findings of this research provide a new class of engineered fluid for heat transfer applications as a function of temperature, type and composition DESs as well as the GNPs concentration.

  10. Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

    Energy Technology Data Exchange (ETDEWEB)

    D Banerjee; J Finkelstein; A Smirnov; P Forster; L Borkowski; S Teat; J Parise

    2011-12-31

    Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg{sub 4}(3,5-PDC){sub 4}(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network with a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite

  11. Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Debasis; Finkelstein, Jeffrey; Smirnov, A.; Forster, Paul M.; Borkowski, Lauren A.; Teat, Simon J.; Parise, John B. (LBNL); (UNLV); (Buffalo)

    2015-10-15

    Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg4(3,5-PDC)4(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network with a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing

  12. A novel 9 × 9 map-based solvent selection strategy for targeted counter-current chromatography isolation of natural products.

    Science.gov (United States)

    Liang, Junling; Meng, Jie; Wu, Dingfang; Guo, Mengzhe; Wu, Shihua

    2015-06-26

    Counter-current chromatography (CCC) is an efficient liquid-liquid chromatography technique for separation and purification of complex mixtures like natural products extracts and synthetic chemicals. However, CCC is still a challenging process requiring some special technical knowledge especially in the selection of appropriated solvent systems. In this work, we introduced a new 9 × 9 map-based solvent selection strategy for CCC isolation of targets, which permit more than 60 hexane-ethyl acetate-methanol-water (HEMWat) solvent systems as the start candidates for the selection of solvent systems. Among these solvent systems, there are clear linear correlations between partition coefficient (K) and the system numbers. Thus, an appropriate CCC solvent system (i.e., sweet spot for K = 1) may be hit by measurement of k values of the target only in two random solvent systems. Besides this, surprisingly, we found that through two sweet spots, we could get a line ("Sweet line") where there are infinite sweet solvent systems being suitable for CCC separation. In these sweet solvent systems, the target has the same partition coefficient (K) but different solubilities. Thus, the better sweet solvent system with higher sample solubility can be obtained for high capacity CCC preparation. Furthermore, we found that there is a zone ("Sweet zone") where all solvent systems have their own sweet partition coefficients values for the target in range of 0.4 natural products as standards and further confirmed by isolation of several targets including honokiol and magnolol from the extracts of Magnolia officinalis Rehd. Et Wils and tanshinone IIA from Salvia miltiorrhiza Bunge. In practice, it is much easier to get a suitable solvent system only by making a simple screening two to four HEMWat two-phase solvent systems to obtain the sweet line or sweet zone without special knowledge or comprehensive standards as references. This is an important advancement for solvent system selection

  13. Pintura de historia e identidad nacional en España

    OpenAIRE

    Pérez Vejo, Tomás

    1996-01-01

    Estudio del proceso de creación invención de una identidad nacional de tipo historicista en españa a través de su plasmación en la pintura de historia oficial. Mediante el uso de índices de frecuencia estadística de los temas y tópicos habituales en este tipo de pintura y el análisis iconográfico concreto de aquellos cuadros que se han considerado mas relevantes y significativos se reconstruye el trasfondo ideológico de las grandes series de iconografía histórica impulsadas por el estado espa...

  14. Gitanos en la pintura religiosa de los siglos XVI y XVII

    Directory of Open Access Journals (Sweden)

    Blanca Rodríguez Hernández

    2015-01-01

    Full Text Available El principal objetivo del presente trabajo es reconocer y analizar la presencia tanto de gitanos como de ciertos elementos provenientes de su cultura en la pintura religiosa europea durante los siglos XVI y XVII. Para ello estableceremos previamente un modelo interpretativo de tipo indicial basado en cuatro criterios de identificación (rasgos físicos, indumentaria, acción y ubicación. La interpretación de dichos elementos por parte de la tradición pictórica occidental tenía una doble vertiente: estéti- ca o moral, tal y como comprobaremos a través de una selección de pinturas del Antiguo y Nuevo Testamento.

  15. Choline chloride-based deep eutectic solvents as additives for optimizing chromatographic behavior of caffeic acid

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guizhen; Zhu, Tao; Lei, Yingjie [Tianjin University of Technology, Tianjin (China)

    2015-10-15

    A series of deep eutectic solvents (DESs) were prepared using glycerol and choline chloride (ChCl), and Fourier transform infrared spectrometer (FT-IR) was used to analyze the spectra of glycerol, choline chloride and DESs based on glycerol and choline chloride. Then DESs were used as the additives of mobile phase to optimize chromatographic behavior of caffeic acid in high performance liquid chromatography (HPLC). A 17-run Box-Behnken design (BBD) was employed to evaluate effect of DESs as additives by analyzing the maximum theoretical plate number. Three factors, reaction temperature (60 .deg. C, 80 .deg. C, 100 .deg. C), molar ratio of glycerol and choline chloride (2 : 1, 3 : 1, 4 : 1, n/n), and volume percent of additives (0.05%, 0.10%, 0.15%, v/v), were investigated in BBD. The optimum experiment condition was that of reaction temperature (80 .deg. C), molar ratio of glycerol and ChCl (3 : 1, n/n), and volume percent of additive (0.10%, v/v). The mean chromatographic theoretical plate number of the caffeic acid this condition was 1567.5, and DESs as additives shorten the retention time and modify the chromatogram shape, proving DESs as additives for effective theoretical plate number and column efficiency in HPLC.

  16. Bio-based solvents: an emerging generation of fluids for the design of eco-efficient processes in catalysis and organic chemistry.

    Science.gov (United States)

    Gu, Yanlong; Jérôme, François

    2013-12-21

    Biomass and waste exhibit great potential for replacing fossil resources in the production of chemicals. The search for alternative reaction media to replace petroleum-based solvents commonly used in chemical processes is an important objective of significant environmental consequence. Recently, bio-based derivatives have been either used entirely as green solvents or utilized as pivotal ingredients for the production of innovative solvents potentially less toxic and more bio-compatible. This review presents the background and classification of these new media and highlights recent advances in their use in various areas including organic synthesis, catalysis, biotransformation and separation. The greenness, advantages and limitations of these solvents are also discussed.

  17. RITMO Y ESPACIO EN LA PINTURA BIZANTINA Rhythm and space in byzantine painting

    Directory of Open Access Journals (Sweden)

    Federico José Xamist

    2011-10-01

    Full Text Available Durante el siglo XX se lleva a cabo una revalorización de la pintura del medioevo heleno, ignorada durante todo el clasicismo europeo. AAnte la constatación de que el espacio representado en la pintura bizantina no reproduce el espacio natural se llega a la conclusión de que las operaciones pictóricas aplicadas por los pintores bizantinos tienen como objeto simbolizar un espacio sobrenatural. En las siguientes líneas intentaremos abrir la problemática del espacio en la pintura bizantina a una interpretación plástica, es decir, intentaremos presentar una lectura de las operaciones pictóricas en cuanto tales siguiendo los planteamientos de Georgos Kordis, profesor de la cátedra Eikonografia de la Facultad de Teología de la Universidad de Atenas y destacado pintor griego. Nuestro objetivo es plantear algunas directrices para introducirnos en la problemática pictórica de la representación del espacio en la pintura bizantina.During the twentieth century is carried out a revaluation of the Hellenic medieval painting, ignored during the European classicism. Given the finding that the space represented in Byzantine painting does not reproduce the natural space leads to the conclusion that painting operations implemented by the Byzantine painters are intended to symbolize a supernatural space. The following lines try to open the question of space in painting plastic Byzantine interpretation, ie to try to present a reading of the painting operations as such, following the approach of Georges Kordis, chair professor of the Faculty Eikonografia Theology of the University of Athens and prominent Greek painter. Our goal is to propose some guidelines for introducing us to the problem of pictorial representation of space in the Byzantine painting.

  18. Poesía y pintura en la obra de Leopoldo Panero

    Directory of Open Access Journals (Sweden)

    Martínez, José Enrique

    2012-12-01

    Full Text Available Leopold Panero’s work is widely known in «Las Bienales Hispanoamericanas de Arte» celebrated during the 50’s decade. However, this article studies a theme that has not received much attention: Panero’s writings, prose and verse, on painting. Although they consist on brief narratives and a few poems, painting is deeply considered in his work as an allusion or comparison with continuous correspondences between poetry and painting. Panero was more interested in humanist and spiritual concepts that transcend the physical reality than in form or technique.Es bien conocida la labor de Leopoldo Panero en las Bienales Hispanoamericanas de Arte celebradas durante la década del 50; de ahí que este artículo se ocupe de un aspecto poco estudiado: los escritos en prosa y verso de Panero sobre pintura. En general se trata de textos breves en prosa y de escasos poemas, pero la pintura está muy presente en su obra como alusión o como comparación, con continuas correspondencias entre poesía y pintura. Más que la técnica y la forma, a Panero le interesó lo que en el arte hay de humanismo y de espiritualidad que trasciende la materia.

  19. Extraction of Illegal Dyes from Red Chili Peppers with Cholinium-Based Deep Eutectic Solvents.

    Science.gov (United States)

    Zhu, Shuqiang; Liu, Dongling; Zhu, Xinyue; Su, Along; Zhang, Haixia

    2017-01-01

    Deep eutectic solvents (DESs) as a new kind of green solvents have been used to extract bioactive compounds but there are few applications in extracting chrysoidine dyes. In this study, we developed an ultrasonic-assisted extraction method with choline chloride/hydrogen bond donor (ChCl/HBD) DES for the extraction of chrysoidine G (COG), astrazon orange G (AOG), and astrazon orange R (AOR) in food samples. Some experimental parameters, such as extraction time, raw material/solvent ratio, and temperature, were evaluated and optimized as follows: the ratio of ChCl/HBD, 1 : 2 (v/v); the ratio of sample/DES, 1 : 10 (g/mL); extraction time, 20 min; extraction temperature, 50°C. Under the optimized conditions, the limits of detection (μg/mL) were 0.10 for COG and 0.06 for AOG and AOR. The relative standard deviations were in the range of 1.2-2.1%. The recoveries of the three dyes were in the range of 80.2-105.0%. By comparing with other commonly used solvents for extracting chrysoidine dyes, the advantages of DESs proved them to be potential extraction solvents for chrysoidine G, astrazon orange G, and astrazon orange R in foods.

  20. Extraction of Illegal Dyes from Red Chili Peppers with Cholinium-Based Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Shuqiang Zhu

    2017-01-01

    Full Text Available Deep eutectic solvents (DESs as a new kind of green solvents have been used to extract bioactive compounds but there are few applications in extracting chrysoidine dyes. In this study, we developed an ultrasonic-assisted extraction method with choline chloride/hydrogen bond donor (ChCl/HBD DES for the extraction of chrysoidine G (COG, astrazon orange G (AOG, and astrazon orange R (AOR in food samples. Some experimental parameters, such as extraction time, raw material/solvent ratio, and temperature, were evaluated and optimized as follows: the ratio of ChCl/HBD, 1 : 2 (v/v; the ratio of sample/DES, 1 : 10 (g/mL; extraction time, 20 min; extraction temperature, 50°C. Under the optimized conditions, the limits of detection (μg/mL were 0.10 for COG and 0.06 for AOG and AOR. The relative standard deviations were in the range of 1.2–2.1%. The recoveries of the three dyes were in the range of 80.2–105.0%. By comparing with other commonly used solvents for extracting chrysoidine dyes, the advantages of DESs proved them to be potential extraction solvents for chrysoidine G, astrazon orange G, and astrazon orange R in foods.

  1. Influence of the type of solvent on the development of superhydrophobicity from silane-based solution containing nanoparticles

    Science.gov (United States)

    Pantoja, M.; Abenojar, J.; Martinez, M. A.

    2017-03-01

    Superhydrophobic surfaces are very appealing for numerous industrial applications due to their self-cleaning capacity. Although there are different methods to manufacture superhydrophobic surfaces, some of them do not keep the aesthetic appearance of the neat surface. Sol-gel processes are a valid alternative when transparent coatings are desired. The main goal of this research is to study the viability of this method by making superhydrophobic coatings from silane-based solution containing SiO2 nanoparticles. The effect of using different solvents is investigated, as well as the role played by the different components of the solution (silane, nanoparticles and solvent). Solutions of methyltrimethoxisilane (MTS) and tetraethoxysilane (TEOS) and 1% of SiO2 (%wt) were prepared with different solvents (ethanol, ethanol/water and white spirit). The hydrophobicity of the developed coatings is studied using contact angle measurements, while the aesthetic appearance is evaluated with gloss and color measurements. Also, infrared spectroscopy, dynamic light scattering (DSL), and surface tension measurements are used to study the silane solutions. The results show that the capacity of solvents to promote the dispersion of the nanoparticles is crucial to ensuring superhydrophobicity, since these agglomerates provide the micro- and nano- surface roughness required to get a hierarchical structure. However, the combined use of silanes and nanoparticles is key to make a superhydrophobic surface because physical (the surface roughness provided by nanoparticles) and chemical characteristics (hydrophobicity provided by silanes) are coupled.

  2. LSER-based modeling vapor pressures of (solvent+salt) systems by application of Xiang-Tan equation

    Institute of Scientific and Technical Information of China (English)

    Aynur Senol

    2015-01-01

    The study deals with modeling the vapor pressures of (solvent+salt) systems depending on the linear solvation energy relation (LSER) principles. The LSER-based vapor pressure model clarifies the simultaneous impact of the vapor pressure of a pure solvent estimated by the Xiang-Tan equation, the solubility and solvatochromic parameters of the solvent and the physical properties of the ionic salt. It has been performed independently two structural forms of the generalized solvation model, i.e. the unified solvation model with the integrated properties (USMIP) containing nine physical descriptors and the reduced property-basis solvation model. The vapor pressure data of fourteen (solvent+salt) systems have been processed to analyze statistical y the reliabil-ity of existing models in terms of a log-ratio objective function. The proposed vapor pressure approaches reproduce the observed performance relatively accurately, yielding the overall design factors of 1.0643 and 1.0702 for the integrated property-basis and reduced property-basis solvation models.

  3. Deep Eutectic Solvent-Based Microwave-Assisted Method for Extraction of Hydrophilic and Hydrophobic Components from Radix Salviae miltiorrhizae

    Directory of Open Access Journals (Sweden)

    Jue Chen

    2016-10-01

    Full Text Available Deep eutectic solvents (DESs have attracted significant attention as a promising green media. In this work, twenty-five kinds of benign choline chloride-based DESs with microwave-assisted methods were applied to quickly extract active components from Radix Salviae miltiorrhizae. The extraction factors, including temperature, time, power of microwave, and solid/liquid ratio, were investigated systematically by response surface methodology. The hydrophilic and hydrophobic ingredients were extracted simultaneously under the optimized conditions: 20 vol% of water in choline chloride/1,2-propanediol (1:1, molar ratio as solvent, microwave power of 800 W, temperature at 70 °C, time at 11.11 min, and solid/liquid ratio of 0.007 g·mL−1. The extraction yield was comparable to, or even better than, conventional methods with organic solvents. The microstructure alteration of samples before and after extraction was also investigated. The method validation was tested as the linearity of analytes (r2 > 0.9997 over two orders of magnitude, precision (intra-day relative standard deviation (RSD < 2.49 and inter-day RSD < 2.96, and accuracy (recoveries ranging from 95.04% to 99.93%. The proposed DESs combined with the microwave-assisted method provided a prominent advantage for fast and efficient extraction of active components, and DESs could be extended as solvents to extract and analyze complex environmental and pharmaceutical samples.

  4. Solvent-based dissolution method to sample gas-phase volatile organic compounds for compound-specific isotope analysis.

    Science.gov (United States)

    Bouchard, Daniel; Hunkeler, Daniel

    2014-01-17

    An investigation was carried out to develop a simple and efficient method to collect vapour samples for compound specific isotope analysis (CSIA) by bubbling vapours through an organic solvent (methanol or ethanol). The compounds tested were benzene and trichloroethylene (TCE). The dissolution efficiency was tested for different air volume injections, using flow rates ranging from 25ml/min to 150ml/min and injection periods varying between 10 and 40min. Based on the results, complete mass recovery for benzene and TCE in both solvents was observed for the flow rates of 25 and 50ml/min. However, small mass loss was observed at increased flow rate. At 150ml/min, recovery was on average 80±17% for benzene and 84±10% for TCE, respectively in methanol and ethanol. The δ(13)C data measured for benzene and TCE dissolved in both solvents were reproducible and were stable independently of the volume of air injected (up to 6L) or the flow rate used. The stability of δ(13)C values hence underlines no isotopic fractionation due to compound-solvent interaction or mass loss. The development of a novel and simple field sampling technique undertaken in this study will facilitate the application of CSIA to diverse gas-phase volatile organic compound studies, such as atmospheric emissions, soil gas or vapour intrusion.

  5. Thermodynamically based solvent design for enzymatic saccharide acylation with hydroxycinnamic acids in non-conventional media

    DEFF Research Database (Denmark)

    Zeuner, Birgitte; Kontogeorgis, Georgios; Riisager, Anders

    2012-01-01

    Enzyme-catalyzed synthesis has been widely studied with lipases (EC 3.1.1.3), but feruloyl esterases (FAEs; EC 3.1.1.73) may provide advantages such as higher substrate affinity and regioselectivity in the synthesis of hydroxycinnamate saccharide esters. These compounds are interesting because...... of their amphiphilicity and antioxidative potential. Synthetic reactions using mono- or disaccharides as one of the substrates may moreover direct new routes for biomass upgrading in the biorefinery. The paper reviews the available data for enzymatic hydroxycinnamate saccharide ester synthesis in organic solvent systems...... as well as other enzymatic hydroxycinnamate acylations in ionic liquid systems. The choice of solvent system is highly decisive for enzyme stability, selectivity, and reaction yields in these synthesis reactions. To increase the understanding of the reaction environment and to facilitate solvent screening...

  6. Solvent Debinding of MIM Parts in a Polystyrene-Palm Oil Based Binder System

    Science.gov (United States)

    Asmawi, R.; Ibrahim, M. H. I.; Amin, A. M.; Mustafa, N.

    2016-11-01

    The influence of the leaching temperatures on the solvent debinding process of SS316L stainless steel alloy compact has been investigated. Solvent debinding process of injection moulded SS316L feedstock was conducted to eliminate palm kernel oil by using n- heptane solution at various temperatures of 40, 50 and 60°C and at different time duration up to 9 hours. The samples were prepared by injection molding a mixture of stainless steel SS316L alloy with waste polystyrene polymer and palm kernel oil at powder loading 60% vol. The weight loss percentages of palm kernel were calculated and the pore structure evolution was analyzed by scanning electron micrograph to observe the pores created after solvent extraction process. Results show that a complete diffusion of the palm kernel molecules out of the compact part best at 60°C within 6 hours of extraction time

  7. In Vitro and In Vivo toxicity profiling of ammonium-based deep eutectic solvents.

    Directory of Open Access Journals (Sweden)

    Maan Hayyan

    Full Text Available The cytotoxic potential of ammonium-based deep eutectic solvents (DESs with four hydrogen bond donors, namely glycerine (Gl, ethylene glycol (EG, triethylene glycol (TEG and urea (U were investigated. The toxicity of DESs was examined using In Vitro cell lines and In Vivo animal model. IC50 and selectivity index were determined for the DESs, their individual components and their combinations as aqueous solutions for comparison purposes. The cytotoxicity effect of DESs varied depending on cell lines. The IC50 for the GlDES, EGDES, UDES and TEGDES followed the sequence of TEGDES< GlDES< EGDES< UDES for OKF6, MCF-7, A375, HT29 and H413, respectively. GlDES was selective against MCF-7 and A375, EGDES was selective against MCF-7, PC3, HepG2 and HT29, UDES was selective against MCF-7, PC3, HepG2 and HT29, and TEGDES was selective against MCF-7 and A375. However, acute toxicity studies using ICR mice showed that these DESs were relatively toxic in comparison to their individual components. DES did not cause DNA damage, but it could enhance ROS production and induce apoptosis in treated cancer cells as evidenced by marked LDH release. Furthermore, the examined DESs showed less cytotoxicity compared with ionic liquids. To the best of our knowledge, this is the first time that combined In Vitro and In Vivo toxicity profiles of DESs were being demonstrated, raising the toxicity issue of these neoteric mixtures and their potential applicability to be used for therapeutic purposes.

  8. The potential applications in heavy oil EOR with the nanoparticle and surfactant stabilized solvent-based emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, F. [Texas A and M Univ., College Station, TX (United States)

    2010-07-01

    The main challenges in developing the heavy oil reservoirs in the Alaska North Slope (ANS) include technical challenges regarding thermal recovery; sand control and disposal; high asphaltene content; and low in-situ permeability. A chemical enhanced oil recovery method may be possible for these reservoirs. Solvent based emulsion flooding provides mobility control; oil viscosity reduction; and in-situ emulsification of heavy oil. This study evaluated the potential application of nano-particle-stabilized solvent based emulsion injection to enhance heavy oil recovery in the ANS. The optimized micro-emulsion composition was determined using laboratory tests such as phase behaviour scanning, rheology studies and interfacial tension measurements. The optimized nano-emulsions were used in core flooding experiments to verify the recovery efficiency. The study revealed that the potential use of this kind of emulsion flooding is a promising enhanced oil recovery process for some heavy oil reservoirs in Alaska, Canada and Venezuela. 4 refs., 2 tabs., 10 figs.

  9. A facile approach to prepare a dual functionalized DNA based material in a bio-deep eutectic solvent.

    Science.gov (United States)

    Mondal, Dibyendu; Bhatt, Jitkumar; Sharma, Mukesh; Chatterjee, Shruti; Prasad, Kamalesh

    2014-04-18

    DNA (Salmon testes) was functionalized by Fe3O4 nanoparticles and protonated layered dititanate sheets (H2·Ti2O5·H2O) in a mixture of choline chloride and ethylene glycol (a deep eutectic solvent) to yield a hybrid material having magnetic and antibacterial properties. Ti sheets were found to interact with the phosphate moieties, while Fe interacted with the base pair of DNA in the hybrid material.

  10. CES as an Efficient Natural Catalyst for Synthesis of Schiff Bases under Solvent-Free Conditions: An Innovative Green Approach

    Directory of Open Access Journals (Sweden)

    Suresh Patil

    2012-01-01

    Full Text Available A mild and efficient method has been reported for the preparation of Schiff base ligands through the condensation reaction of various aromatic aldehydes with substituted aromatic amines in the presence of CES (calcined eggshell as a heterogeneous catalyst under solvent-free conditions. The advantages of this ecofriendly, economic method are simplicity of the reaction procedure, moderate to good product yields, and very short reaction times.

  11. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  12. Evaluación de la exposición a solventes orgánicos en pintores de carros de la ciudad de Bogotá

    OpenAIRE

    Palma Parra, Ruth Marien; Briceno-Ayala, Leonardo

    2013-01-01

    Introducción. Los pintores de vehículos automotores están expuestos a solventes puros o mezclas de estos, los cuales se han asociado con efectos neurológicos y mutacarcinogénicos. Materiales y Métodos. Se realizó un estudio descriptivo de corte transversal para caracterizar las condiciones de salud y trabajo de individuos expuestos a solventes orgánicos en talleres de lámina y pintura en Bogotá. Se comparó un grupo de expuestos a solventes orgánicos con un grupo no expuestos...

  13. El uso de la pintura en la publicidad de revistas femeninas en España. Análisis de la publicidad que usa la pintura en la revista Vogue

    OpenAIRE

    Jiménez Marín, Gloria; Gómez Abeja, Domingo

    2006-01-01

    La historia del arte ha influido en la publicidad en todas sus manifestaciones: pintura, escultura, fotografia, cine ... Esta investigación se centra en una de las siete bellas artes: la pintura, y la estudia para comprender qué influencia ha supuesto en la creatividad publicitaria y como sus creativos se valen de ella para acercarse mas a los consumidores y evitar el desprecio de los receptores ante la publicidad comercial. El perfil escogido es el de las revistas femeninas de alta gama p...

  14. Evaluation of solvent system for the enzymatic synthesis of ethanol-based biodiesel from sludge palm oil (SPO).

    Science.gov (United States)

    Nasaruddin, Ricca Rahman; Alam, Md Zahangir; Jami, Mohammed Saedi

    2014-02-01

    A green technology of biodiesel production focuses on the use of enzymes as the catalyst. In enzymatic biodiesel synthesis, suitable solvent system is very essential to reduce the inhibition effects of the solvent to the enzymes. This study produced ethanol-based biodiesel from a low-cost sludge palm oil (SPO) using locally-produced Candida cylindracea lipase from fermentation of palm oil mill effluent (POME) based medium. The optimum levels of ethanol-to-SPO molar ratio and enzyme loading were found to be 4:1 and 10 U/25 g of SPO respectively with 54.4% w/w SPO yield of biodiesel and 21.7% conversion of free fatty acid (FFA) into biodiesel. Addition of tert-butanol at 2:1 tert-butanol-to-SPO molar ratio into the ethanol-solvent system increased the yield of biodiesel to 71.6% w/w SPO and conversion of FFA into biodiesel to 28.8%. The SPO and ethanol have promising potential for the production of renewable biodiesel using enzymatic-catalyzed esterification and transesterification.

  15. Novel shortcut estimation method for regeneration energy of amine solvents in an absorption-based carbon capture process.

    Science.gov (United States)

    Kim, Huiyong; Hwang, Sung June; Lee, Kwang Soon

    2015-02-03

    Among various CO2 capture processes, the aqueous amine-based absorption process is considered the most promising for near-term deployment. However, the performance evaluation of newly developed solvents still requires complex and time-consuming procedures, such as pilot plant tests or the development of a rigorous simulator. Absence of accurate and simple calculation methods for the energy performance at an early stage of process development has lengthened and increased expense of the development of economically feasible CO2 capture processes. In this paper, a novel but simple method to reliably calculate the regeneration energy in a standard amine-based carbon capture process is proposed. Careful examination of stripper behaviors and exploitation of energy balance equations around the stripper allowed for calculation of the regeneration energy using only vapor-liquid equilibrium and caloric data. Reliability of the proposed method was confirmed by comparing to rigorous simulations for two well-known solvents, monoethanolamine (MEA) and piperazine (PZ). The proposed method can predict the regeneration energy at various operating conditions with greater simplicity, greater speed, and higher accuracy than those proposed in previous studies. This enables faster and more precise screening of various solvents and faster optimization of process variables and can eventually accelerate the development of economically deployable CO2 capture processes.

  16. Solvent exposure and malignant lymphoma: a population-based case-control study in Germany

    Directory of Open Access Journals (Sweden)

    Deeg Evelin

    2007-04-01

    Full Text Available Abstract Aims To analyze the relationship between exposure to chlorinated and aromatic organic solvents and malignant lymphoma in a multi-centre, population-based case-control study. Methods Male and female patients with malignant lymphoma (n = 710 between 18 and 80 years of age were prospectively recruited in six study regions in Germany (Ludwigshafen/Upper Palatinate, Heidelberg/Rhine-Neckar-County, Würzburg/Lower Frankonia, Hamburg, Bielefeld/Gütersloh, and Munich. For each newly recruited lymphoma case, a gender, region and age-matched (± 1 year of birth population control was drawn from the population registers. In a structured personal interview, we elicited a complete occupational history, including every occupational period that lasted at least one year. On the basis of job task-specific supplementary questionnaires, a trained occupational physician assessed the exposure to chlorinated hydrocarbons (trichloroethylene, tetrachloroethylene, dichloromethane, carbon tetrachloride and aromatic hydrocarbons (benzene, toluene, xylene, styrene. Odds ratios (OR and 95% confidence intervals (CI were calculated using conditional logistic regression analysis, adjusted for smoking (in pack years and alcohol consumption. To increase the statistical power, patients with specific lymphoma subentities were additionally compared with the entire control group using unconditional logistic regression analysis. Results We observed a statistically significant association between high exposure to chlorinated hydrocarbons and malignant lymphoma (Odds ratio = 2.1; 95% confidence interval 1.1–4.3. In the analysis of lymphoma subentities, a pronounced risk elevation was found for follicular lymphoma and marginal zone lymphoma. When specific substances were considered, the association between trichloroethylene and malignant lymphoma was of borderline statistical significance. Aromatic hydrocarbons were not significantly associated with the lymphoma diagnosis

  17. Solvent-free melting techniques for the preparation of lipid-based solid oral formulations.

    Science.gov (United States)

    Becker, Karin; Salar-Behzadi, Sharareh; Zimmer, Andreas

    2015-05-01

    Lipid excipients are applied for numerous purposes such as taste masking, controlled release, improvement of swallowability and moisture protection. Several melting techniques have evolved in the last decades. Common examples are melt coating, melt granulation and melt extrusion. The required equipment ranges from ordinary glass beakers for lab scale up to large machines such as fluid bed coaters, spray dryers or extruders. This allows for upscaling to pilot or production scale. Solvent free melt processing provides a cost-effective, time-saving and eco-friendly method for the food and pharmaceutical industries. This review intends to give a critical overview of the published literature on experiences, formulations and challenges and to show possibilities for future developments in this promising field. Moreover, it should serve as a guide for selecting the best excipients and manufacturing techniques for the development of a product with specific properties using solvent free melt processing.

  18. Enhanced performance of supercritical fluid foaming of natural-based polymers by deep eutetic solvents

    OpenAIRE

    Martins, Marta; Aroso, Ivo Manuel Ascensão; Reis, R L; Duarte, Ana Rita C.; Craveiro, R.; Paiva, A

    2014-01-01

    Natural deep eutetic solvents (NADES) are defined as a mixture of two or more solid or liquid components, which at a particular composition present a high melting point depression becoming liquids at room temperature. NADES are constituted by natural molecules and fully represent the green chemistry principles. For these reasons, the authors believe that the submit manuscript is a highly valuable contribution to the field of green chemistry and chemical engineering. For the first time, the po...

  19. An efficient phase-selective gelator for aromatic solvents recovery based on a cyanostilbene amide derivative.

    Science.gov (United States)

    Zhang, Yuping; Ma, Yao; Deng, Mengyu; Shang, Hongxing; Liang, Chunshuang; Jiang, Shimei

    2015-07-07

    Two novel low molecular weight organogelators (LMOGs) 1 and 2 composed of a cholesteryl group, an amide group and various terminal cyanostilbene moieties were synthesized. They could form stable gels in p-xylene. In particular, 2 with more extended π-conjugation length showed remarkable gelation ability in many aromatic solvents, chloroform and chloroform-containing mixed solvents at a relatively low concentration. FT-IR and XRD spectra indicated that the difference between 1 and 2 in the gelation properties may result from the deviation of the intermolecular hydrogen bonding and π–π stacking as driving forces for the formation of the gels. Significantly, 2 can function as an efficient room-temperature phase-selective gelator (PSG) for potential application in the separation and recovery of various aromatic solvents from its mixture with water. Meanwhile, the gelator can be easily recovered and reused several times. Furthermore, the phase-selective gelation properties of 2 can provide a simple and feasible approach for the removal of the rhodamine B (RhB) dye from water.

  20. DFT-based simulations of amide I' IR spectra of a small protein in solution using empirical electrostatic map with a continuum solvent model.

    Science.gov (United States)

    Welch, William R W; Kubelka, Jan

    2012-09-01

    A continuum solvent model was tested for simulations of amide I' IR spectra for a 40-residue subdomain of P22 viral coat protein in aqueous solution. Spectra obtained using DFT (BPW91/6-31G**) parameters for a reduced all-Ala representation of the protein were corrected by an electrostatic potential map obtained from the solvent cavity surface and AMBER99 side-chain atom partial charges. Various cavity sizes derived from van der Waals atomic radii with an added effective solvent radius up to 2.0 Å were tested. The interplay of the side-chain and solvent electrostatic effects was investigated by considering the side chains and solvent separately as well as together. The sensitivity to side-chain conformational fluctuations and to the parametrization of C(β) group partial charges was also tested. Simulation results were compared to the experimental amide I' spectra of P22 subdomain, including two (13)C isotopically edited variants, as well as to the previous simulations based on the molecular dynamics trajectory in explicit solvent. For small cavity sizes, between van der Waals and that with added solvent radius of 0.5 Å, better qualitative agreement with experiment was obtained than with the explicit solvent representation, in particular for the (13)C-labeled spectra. Larger protein cavities led to progressively worse predictions due to increasingly stronger electrostatic effects of side chains, which could no longer be well compensated for by the solvent potential. Balance between side-chain and solvent electrostatic effects is important in determining the width and shape of the simulated amide I', which is also virtually unaffected by side-chain-geometry fluctuations. The continuum solvent model combined with the electrostatic map is a computationally efficient and potentially robust approach for the simulations of IR spectra of proteins in solution.

  1. La visión de Marruecos a través de la pintura orientalista española

    OpenAIRE

    Arias Anglés, Enrique

    2010-01-01

    En el presente trabajo se analizan las diversas visiones de Marruecos que aportó la pintura orientalista española a la sociedad en cada momento de su largo desarrollo histórico. Se abarca así un amplio período cronológico que discurre entre 1830 y 1960, aproximadamente. Ya en sus mismos orígenes, la pintura orientalista española comienza a ocuparse de Marruecos, primeramente por lógicas razones de vecindad y, posteriormente, por los intereses coloniales que se despiertan a partir de la llamad...

  2. El pintor José Arpa Perea y la renovación de la pintura sevillana de su tiempo

    OpenAIRE

    Rodríguez Serrano, Carmen

    2015-01-01

    La presente tesis doctoral titulada, El pintor José Arpa y la renovación de la pintura sevillana de su tiempo, pretende analizar, profundizar y poner en valor la figura de un artista, insuficientemente apreciado en el panorama artístico europeo y nacional, a la par que enfatizar en sus innovaciones estilísticas, alejadas en gran medida de la tradicional pintura sevillana de finales del siglo XIX y principios del XX a través de un extenso catálogo. La vida, obra, principios estéticos y pues...

  3. Effect of organic solvents on peroxidases from rice and horseradish: prospects for enzyme based applications.

    Science.gov (United States)

    Singh, Priyanka; Prakash, Rajiv; Shah, Kavita

    2012-08-15

    A feasibility test for rice peroxidase (RP) enzyme as a substitute for horseradish peroxidase (HRP) was carried out. The activity of HRP was maximum at 30 °C with pH 6.0-7.0. The purified rice peroxidase showed optimum activity at 30 °C with pH 7-8 and was thermostable till 68 °C, which is higher than the temperature reported for HRP. RP obeyed Michaelis-Menten kinetics. With increasing substrate concentrations, RP and HRP had V(max) as 8.23 μM min(-1) and 4.21 μM min(-1) and K(m) as 5.585 and 3.662 mM, respectively. In 10% 1,4-dioxane and ethanol, RP exhibited 2 and 1.3 times higher activity, respectively than HRP. Shelf life studies show RP to be significantly stable till 60 h in 20% 1,4-dioxane and till 12 h in ethanol. The activity of RP/HRP increased gradually with 0%-40% ethanol or 0%-30% 1,4-dioxane till 20 h with a sharp decline thereafter. The stability of HRP and RP reduced with increasing storage period. Enzyme efficiencies compared as V(m)/K(m) showed water miscible organic solvents, viz.1,4-dioxane and ethanol, to exhibit a regular decrease in V(m)/K(m) with increase in organic solvent concentration whereas, a reverse trend was observed with water-immiscible solvent like chloroform. The relative activity of RP and HRP enzymes upon immobilization on poly-5-carboxy-indole shows increasing enzyme activity with time and with guaiacol/dopamine hydrochloride as substrates. Immobilized RP had a better relative activity with dopamine as substrate than immobilized HRP, whereas with guaiacol both RP and HRP had a comparable activity upon immobilization. Results suggest rice peroxidase to be a cheaper and convenient enzyme system for immobilization using organic solvents. The high thermal stability, more stability in organic solvents and longer shelf life of RP over the immobilizing matrix suggest conducting polyindole having carboxyl functional groups to be a suitable matrix for the covalent entrapment of rice peroxidase through amide linkage. Good

  4. High-performance dye-sensitized solar cells based on solvent-free electrolytes produced from eutectic melts.

    Science.gov (United States)

    Bai, Yu; Cao, Yiming; Zhang, Jing; Wang, Mingkui; Li, Renzhi; Wang, Peng; Zakeeruddin, Shaik M; Grätzel, Michael

    2008-08-01

    Low-cost excitonic solar cells based on organic optoelectronic materials are receiving an ever-increasing amount of attention as potential alternatives to traditional inorganic photovoltaic devices. In this rapidly developing field, the dye-sensitized solar cell (DSC) has achieved so far the highest validated efficiency of 11.1% (ref. 2) and remarkable stability. However, the cells with the best performance use volatile solvents in their electrolytes, which may be prohibitive for outdoor solar panels in view of the need for robust encapsulation. Solvent-free room-temperature ionic liquids have been pursued as an attractive solution to this dilemma, and device efficiencies of over 7% were achieved by using some low-viscosity formulations containing 1-ethyl-3-methylimidazolium thiocyanate, selenocyanate, tricyanomethide or tetracyanoborate. Unfortunately, apart from tetracyanoborate, all of these low-viscosity melts proved to be unstable under prolonged thermal stress and light soaking. Here, we introduce the concept of using eutectic melts to produce solvent-free liquid redox electrolytes. Using a ternary melt in conjunction with a nanocrystalline titania film and the amphiphilic heteroleptic ruthenium complex Z907Na (ref. 10) as a sensitizer, we reach excellent stability and an unprecedented efficiency of 8.2% under air-mass 1.5 global illumination. Our results are of importance to realize large-scale outdoor applications of mesoscopic DSCs.

  5. Evaluation of alcohol-based deep eutectic solvent in extraction and determination of flavonoids with response surface methodology optimization.

    Science.gov (United States)

    Bi, Wentao; Tian, Minglei; Row, Kyung Ho

    2013-04-12

    Deep eutectic solvents (DESs) are emerging rapidly as a new type of green solvent instead of an ionic liquid (IL), and are typically formed by mixing choline chloride with hydrogen bond donors. Few studies have applied DESs to the extraction and determination of bioactive compounds. Therefore, in the present study, DESs were used to extract flavonoids (myricetin and amentoflavone), which are well known and widely used antioxidants, to extend their applications. A range of alcohol-based DESs with different alcohols to choline chloride (ChCl) mixing ratios were used for extraction using several extraction methods. Other factors, such as temperature, time, water addition and solid/liquid ratio, were examined systematically using a response surface methodology (RSM). A total of 0.031 and 0.518 mg g(-1) of myricetin and amentoflavone were extracted under the optimized conditions: 35 vol% of water in ChCl/1,4-butanediol (1/5) at 70.0 °C for 40.0 min and a solid/liquid ratio of 1/1 (g 10 mL(-1)). Good linearity was obtained from 0.1 × 10(-3) to 0.1 mg mL(-1) (r(2)>0.999). The excellent properties of DESs highlight their potential as promising green solvents for the extraction and determination of a range of bioactive compounds or drugs. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Direct and ultrasensitive optofluidic-based immunosensing assay of aflatoxin M1 in dairy products using organic solvent extraction.

    Science.gov (United States)

    Lou, Xuening; Zhu, Anna; Wang, Hongliang; Wu, Jun; Zhou, Liping; Long, Feng

    2016-10-12

    Aflatoxin M1 (AFM1), a highly toxic secondary metabolite, is present in a wide range of dairy products. In this study, we designed a simple, low-cost, reusable, and easy-to-operate immunosensing method for ultrasensitive detection of AFM1 in dairy products by using a portable evanescent wave-based optofluidic biosensing platform (EOBP). The developed method provides the minimum detection limit of 5 ng/L, which is below the most restrictive standard imposed by the current regulations for AFM1 in dairy products. The effect of several organic solvents, such as methanol, acetone, and acetonitrile, on the binding reaction of antibody-antigen in heterogeneous and homogeneous solutions was evaluated. Although the effect of organic solvents on the homogeneous binding reaction between antibody and antigen is more significant than that of heterogeneous binding reaction between antibody in solution and antigen immobilized onto the sensor surface, the fluorescence signal detected by EOBP is linearly dependent on AFM1 concentration. Therefore, AFM1 can be directly quantified even if the samples contain a certain organic solvent concentration. The robustness and stability of AFM1-ovalbumin conjugate allow the regeneration of modified biosensor surface for more than 200 times, thereby achieving a cost-effective and reliable AFM1 determination. The proposed method provides a rapid, ultrasensitive, and reliable AFM1 determination in dairy products without complicated sample pretreatment process.

  7. Experimental and DFT studies of solvent effects on molecular structure and physical properties of Dipyridylamine pyridine based ligand

    Science.gov (United States)

    Bilkan, Mustafa Tuğfan; Şahin, Onur; Yurdakul, Şenay

    2017-04-01

    The solvent effects on molecular structure, electronic, vibrational and thermochemical properties of 2,2‧-Dipyridylamine were investigated by using experimental and theoretical methods. 2,2‧-Dipyridylamine molecule was selected for this study intentionally because it has two pyridyl rings connected by amine bridge. This allows to change the stable equilibrium geometry, even the slightest effects. Dichloromethane was chosen as solvent. The reason for this selection is to examine whether the chlorine atoms make hydrogen bonds with the ligand atoms. For this purpose, firstly 2,2‧-Dipyridylamine solution was prepared and characterized by FT-IR and FT-Raman spectroscopy. Secondly, crystal structure of 2,2‧-Dipyridylamine was obtained to compare with the calculated geometric parameters. The crystal structure was analyzed by Single Crystal X-Ray diffraction methods. Density Functional Theory calculations were conducted with B3LYP functional and 6-31G(d) basis set. The theoretical vibrational properties of optimized geometric structure were computed in vapor and solvation phases. Two different theoretical approaches were discussed, based on the experimental results. It can be seen from the experimental and theoretical studies that the structural, vibrational, thermochemical and electronic properties are dependent on the solvent effects for selected structure. Furthermore, the chlorine atoms of Dichloromethane do not make hydrogen bonds with the ligand atoms.

  8. Impact of solvents and supercritical CO{sub 2} drying on the morphology and structure of polymer-based biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Causa, Andrea; Acierno, Domenico; Filippone, Giovanni [Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale V. Tecchio, 80, 80125 Napoli (Italy); Salerno, Aurelio; Domingo, Concepción [Instituto de Ciencia de Materiales de Barcelona (ICMAB-CSIC), Campus de la UAB, 08193 Bellaterra (Spain)

    2014-05-15

    In the present work, two-dimensional systems based on biodegradable polymers such as poly(ε-caprolactone) (PCL), poly(ethylene oxide) (PEO) and polylactic acid (PLA) are fabricated by means of a sustainable approach which consists in inducing phase separation in solutions of such polymers and “green” solvents, namely ethyl lactate (EL) and ethyl acetate (EA). The extraction of the solvent is promoted by a controlled drying process, which is performed in either air or supercritical CO{sub 2}. The latter can indeed act as both an antisolvent, which favors the deposition of the polymer by forming a mixture with EL and EA, and a plasticizing agent, whose solvation and transport properties may considerably affect the microstructure and crystallinity of the polymer films. The morphological, topographical and crystalline properties of the films are tailored through a judicial selection of the materials and the processing conditions and assessed by means of thermal analyses, polarized optical microscopy, scanning electron microscopy and confocal interferometric microscopy. The results show that the morphological and crystalline properties of the films are strongly dependent on the choice of both the polymer/solvent system and the operating conditions during the drying step. In particular, the morphological, topographical and thermal properties of films prepared starting from highly crystalline polymers, namely PCL and PEO, are greatly affected by the crystallization of the material. Conversely, the less crystalline PLA forms almost completely amorphous films.

  9. Impact of solvents and supercritical CO2 drying on the morphology and structure of polymer-based biofilms

    Science.gov (United States)

    Causa, Andrea; Salerno, Aurelio; Domingo, Concepción; Acierno, Domenico; Filippone, Giovanni

    2014-05-01

    In the present work, two-dimensional systems based on biodegradable polymers such as poly(ɛ-caprolactone) (PCL), poly(ethylene oxide) (PEO) and polylactic acid (PLA) are fabricated by means of a sustainable approach which consists in inducing phase separation in solutions of such polymers and "green" solvents, namely ethyl lactate (EL) and ethyl acetate (EA). The extraction of the solvent is promoted by a controlled drying process, which is performed in either air or supercritical CO2. The latter can indeed act as both an antisolvent, which favors the deposition of the polymer by forming a mixture with EL and EA, and a plasticizing agent, whose solvation and transport properties may considerably affect the microstructure and crystallinity of the polymer films. The morphological, topographical and crystalline properties of the films are tailored through a judicial selection of the materials and the processing conditions and assessed by means of thermal analyses, polarized optical microscopy, scanning electron microscopy and confocal interferometric microscopy. The results show that the morphological and crystalline properties of the films are strongly dependent on the choice of both the polymer/solvent system and the operating conditions during the drying step. In particular, the morphological, topographical and thermal properties of films prepared starting from highly crystalline polymers, namely PCL and PEO, are greatly affected by the crystallization of the material. Conversely, the less crystalline PLA forms almost completely amorphous films.

  10. Alternative Bio-Based Solvents for Extraction of Fat and Oils: Solubility Prediction, Global Yield, Extraction Kinetics, Chemical Composition and Cost of Manufacturing

    Directory of Open Access Journals (Sweden)

    Anne-Gaëlle Sicaire

    2015-04-01

    Full Text Available The present study was designed to evaluate the performance of alternative bio-based solvents, more especially 2-methyltetrahydrofuran, obtained from crop’s byproducts for the substitution of petroleum solvents such as hexane in the extraction of fat and oils for food (edible oil and non-food (bio fuel applications. First a solvent selection as well as an evaluation of the performance was made with Hansen Solubility Parameters and the COnductor-like Screening MOdel for Realistic Solvation (COSMO-RS simulations. Experiments were performed on rapeseed oil extraction at laboratory and pilot plant scale for the determination of lipid yields, extraction kinetics, diffusion modeling, and complete lipid composition in term of fatty acids and micronutrients (sterols, tocopherols and tocotrienols. Finally, economic and energetic evaluations of the process were conducted to estimate the cost of manufacturing using 2-methyltetrahydrofuran (MeTHF as alternative solvent compared to hexane as petroleum solvent.

  11. Alternative bio-based solvents for extraction of fat and oils: solubility prediction, global yield, extraction kinetics, chemical composition and cost of manufacturing.

    Science.gov (United States)

    Sicaire, Anne-Gaëlle; Vian, Maryline; Fine, Frédéric; Joffre, Florent; Carré, Patrick; Tostain, Sylvain; Chemat, Farid

    2015-04-15

    The present study was designed to evaluate the performance of alternative bio-based solvents, more especially 2-methyltetrahydrofuran, obtained from crop's byproducts for the substitution of petroleum solvents such as hexane in the extraction of fat and oils for food (edible oil) and non-food (bio fuel) applications. First a solvent selection as well as an evaluation of the performance was made with Hansen Solubility Parameters and the COnductor-like Screening MOdel for Realistic Solvation (COSMO-RS) simulations. Experiments were performed on rapeseed oil extraction at laboratory and pilot plant scale for the determination of lipid yields, extraction kinetics, diffusion modeling, and complete lipid composition in term of fatty acids and micronutrients (sterols, tocopherols and tocotrienols). Finally, economic and energetic evaluations of the process were conducted to estimate the cost of manufacturing using 2-methyltetrahydrofuran (MeTHF) as alternative solvent compared to hexane as petroleum solvent.

  12. La pintura como recurso docente en primero de grado en fisioterapia

    OpenAIRE

    Cano de la Cuerda, Roberto; Collado Vázquez, Susana; Muñoz Hellín, Elena

    2011-01-01

    Presentamos un ejemplo de aplicación de la pintura como herramienta docente en la asignatura Fundamentos de Fisioterapia de 1º de Grado en Fisioterapia (URJC), y mediante la cual se ilustran los contenidos de dos temas del programa. Durante los seminarios se explican los conceptos de deficiencia, discapacidad y minusvalía, y mediante la visualización de material pictórico los alumnos determinarán las posibles aplicaciones de dicha terminología, en cada uno de los cuadros emplea...

  13. La pintura como recurso docente en primero de grado en fisioterapia

    OpenAIRE

    Cano de la Cuerda, Roberto; Collado Vázquez, Susana; Muñoz Hellín, Elena

    2011-01-01

    Presentamos un ejemplo de aplicación de la pintura como herramienta docente en la asignatura Fundamentos de Fisioterapia de 1º de Grado en Fisioterapia (URJC), y mediante la cual se ilustran los contenidos de dos temas del programa. Durante los seminarios se explican los conceptos de deficiencia, discapacidad y minusvalía, y mediante la visualización de material pictórico los alumnos determinarán las posibles aplicaciones de dicha terminología, en cada uno de los cuadros emplea...

  14. O 'Grupo Tapir'e a pintura de casarios (1960-1980)

    OpenAIRE

    Martini, Fátima Regina Sans [UNESP

    2004-01-01

    Nos anos 1960 a 1980, alguns artistas seguiram na contramão da chamada arte de vanguarda ou da arte dos ismos, pintando principalmente casarios - seqüências de casas geminadas, freqüente no estilo arquitetônico colonial brasileiro - um assunto empregado em determinadas pinturas de paisagens urbanas. O tema foi amplamente consumido, ainda que possa ter sido considerado ultrapassado no período. Os artistas viveram de sua arte e participavam ativamente das exposições promovidas pelas principais ...

  15. Entre a abstração e a imagem realista: pintura no limite

    Directory of Open Access Journals (Sweden)

    Fátima Junqueira

    Full Text Available RESUMO Este texto pretende fazer uma reflexão sobre a pintura contemporânea, que se destaca por ficar no limite entre dois conceitos clássicos da arte moderna: "figurativo" e "abstrato". O artigo baseia-se em autores da teoria da arte moderna (como Clement Greenberg e Leo Steinberg da filosofia (como Jacques Rancière, da teoria da arte contemporânea (como Anne Cauquelin e nos escritos do pintor alemão Gerhard Richter.

  16. IMITACIÓN ENTRE PINTURA Y CINE EL REQUIEM DE OROZCO RECREADO POR GABRIEL FIGUEROA

    OpenAIRE

    2010-01-01

    El artículo ofrece una exposición desde la historia y teoría del arte acerca de la imitación entre distintas artes, entre artistas y los posibles motivos para que ocurra la copia de la pintura en el cine. El caso que sirve de referencia es la recreación del grabado de José Clemente Orozco, El Réquiem, que el cinefotógrafo Gabriel Figueroa Mateos elaboró en una película.

  17. Arquetipos de la crueldad femenina en la literatura y la pintura de entresiglos, (1870-1930)

    OpenAIRE

    Primo Cano, Carlos

    2016-01-01

    Arquetipos de la crueldad femenina en la literatura y la pintura de entresiglos (1870-1930) analiza el diálogo entre la literatura y las artes plásticas en el marco de las representaciones finiseculares de la figura que se ha dado en llamar femme fatale. La presente tesis doctoral adopta un enfoque comparatista con el objetivo de identificar los arquetipos subyacentes que conforman un corpus textual centrado en tres figuras principales: la bíblica Salomé, responsable de la decapitación de Jua...

  18. El laúd en la pintura española del barroco

    OpenAIRE

    Palmer González, María Soledad

    2015-01-01

    Esta tesis doctoral tiene como objeto de estudio el laúd y su representación en la pintura barroca española, haciendo especial hincapié en las obras de los artistas de las tres escuelas más destacadas dentro del panorama nacional: la escuela madrileña, sevillana y valenciana. Esta investigación sobre el laúd ha resultado un pequeño paso para dar a conocer la importancia de este instrumento en la sociedad y en el arte europeo, pero, sobre todo, dilucidar su papel en el ámbito español barroco. ...

  19. Proyecto de nave para fabricación de pinturas al agua

    OpenAIRE

    2016-01-01

    Se pretende la construcción de una nave industrial con la actividad de fabricación de pinturas al agua, sobre una parcela situada en el polígono industrial de Pelagatos, en Chiclana de la Frontera. La parcela dispone de una superficie de 1000 metros cuadrados, con una fachada de 20 metros y un fondo de 50 metros. La parcela es plana en general. Debe construirse la superficie máxima que permita el Plan General de Ordenación Urbana. Se dispondrán en planta baja las siguientes dep...

  20. Poesia y Pintura: Frank O'Hara y el expresinionismo abstracto

    OpenAIRE

    Alberto Santamaría

    2015-01-01

    El objetivo de este artículo es analizar las relaciones entre poesía y pintura en el seno del expresionismo abstracto. Para ello tomamos tres nombres de referencia: Clement Greenberg (crítico de arte), Frank O'Hara (poeta) y Willem De Kooning (pintor). A través de estos nombres tratamos de señalar la estrecha relación que existía entre poetas y pintores en la llamada Escuela de Nueva York.

  1. Métodos de representación en la pintura figurativa

    OpenAIRE

    2012-01-01

    El conocido secretismo de los talleres y el desinterés de los pintores en dejar constancia escrita de su trabajo dificultan el estudio de la representación en la pintura. Esta situación obliga al pintor a recorrer personalmente paso a paso el mismo camino que sus antecesores. No existe más guía que las obras de los maestros y las máximas que, de taller en taller, se han transmitido hasta nosotros; es cierto que algunas son curiosas y con visos de verdad, pero en el fondo, poco aportan al pint...

  2. Poesia y Pintura: Frank O'Hara y el expresinionismo abstracto

    Directory of Open Access Journals (Sweden)

    Alberto Santamaría

    2015-07-01

    Full Text Available El objetivo de este artículo es analizar las relaciones entre poesía y pintura en el seno del expresionismo abstracto. Para ello tomamos tres nombres de referencia: Clement Greenberg (crítico de arte, Frank O'Hara (poeta y Willem De Kooning (pintor. A través de estos nombres tratamos de señalar la estrecha relación que existía entre poetas y pintores en la llamada Escuela de Nueva York.

  3. Representação do masculino nas artes visuais : performance, pintura, fotografia

    OpenAIRE

    Afrahi, Shahram

    2012-01-01

    Esta tese estuda representações imagéticas do sexo masculino que não se enquadram no modelo tradicional de homem. Este modelo tradicional se consolida pela figura que domina em sua relação com a mulher, estabelecendo desigualdade entre os gêneros. O masculino investigado aqui recusa representação que assinale para o domínio por meio da exposição do próprio corpo. As linguagens artísticas tornam visível um corpo que tende a transformar-se. Performances, pinturas e fotografias das últimas três ...

  4. A new decomposition-based computer-aided molecular/mixture design methodology for the design of optimal solvents and solvent mixtures

    DEFF Research Database (Denmark)

    Karunanithi, A.T.; Achenie, L.E.K.; Gani, Rafiqul

    2005-01-01

    and then the second part is solved to determine the optimal mixture. The decomposition of the CAMD MINLP model into relatively easy to solve subproblems is essentially a partitioning of the constraints from the original set. This approach is illustrated through two case studies. The first case study involves...... the design of an optimal extractant for the separation of acetic acid from water by liquid-liquid extraction. The results suggest that the new extractant would be able to perform better than the extractant being widely used for this separation. The second case study is an industrial problem involving......This paper presents a novel computer-aided molecular/mixture design (CAMD) methodology for the design of optimal solvents and solvent mixtures. The molecular/mixture design problem is formulated as a mixed integer nonlinear programming (MINLP) model in which a performance objective...

  5. A new decomposition-based computer-aided molecular/mixture design methodology for the design of optimal solvents and solvent mixtures

    DEFF Research Database (Denmark)

    Karunanithi, A.T.; Achenie, L.E.K.; Gani, Rafiqul

    2005-01-01

    This paper presents a novel computer-aided molecular/mixture design (CAMD) methodology for the design of optimal solvents and solvent mixtures. The molecular/mixture design problem is formulated as a mixed integer nonlinear programming (MINLP) model in which a performance objective...... is to be optimized subject to structural, property, and process constraints. The general molecular/mixture design problem is divided into two parts. For optimal single-compound design, the first part is solved. For mixture design, the single-compound design is first carried out to identify candidates...... the design of an optimal extractant for the separation of acetic acid from water by liquid-liquid extraction. The results suggest that the new extractant would be able to perform better than the extractant being widely used for this separation. The second case study is an industrial problem involving...

  6. Caracterització de materials en la pintura gòtica sobre taula. Química i tecnologia en l'obra de Jaume Huguet.

    OpenAIRE

    Salvadó Cabré, Nativitat

    2001-01-01

    L'objectiu primordial d'aquest treball és la caracterització i l'estudi de materials i la interpretació del color en la pintura de retaules d'època gòtica.Per aquest estudi s'ha desenvolupat una metodologia en la caracterització dels materials, s'ha creat una base de dades de resultats analítics i de cromaticitat de substàncies de referència i, posteriorment s'han aplicat aquestes tècniques a una selecció d'obres del pintor Jaume Huguet (s.XV).Ha estat necessària la utilització de tècniques ...

  7. Solvent-induced O-H vibration red-shifts of oxygen-acids in hydrogen-bonded O-H···base complexes.

    Science.gov (United States)

    Keinan, Sharon; Pines, Dina; Kiefer, Philip M; Hynes, James T; Pines, Ehud

    2015-01-22

    Infrared spectroscopy has been used to characterize the solvent effect on the OH stretching vibrations νOH of phenol, 1-naphthol, 2-naphthol, 1-hydroxypyrene, and ethanol. We distinguish the dielectric (nonspecific) effect of the solvent on ΔνOH, the observed red-shifts in νOH, from the much larger red-shift caused by direct hydrogen (H)-bonding interactions with the solvents. To isolate the solvent dielectric constant ε effect on νOH, the OH oscillator was also studied when it is already H-bonded with an invariant oxygen base, dimethyl sulfoxide. We find that ΔνOH depends importantly on ΔPA, the difference between the proton affinities of the conjugate base of the proton donor and the proton acceptor. For a given H-bonded complex, νOH tends to vary inversely with ε, exhibiting different slopes for polar and nonpolar solvents, i.e., solvents comprising molecules with and without a permanent dipole moment, respectively. We use a two-state valence-bond-based theory to analyze our experimental data. This demonstrates that the OH oscillator acquires a more ionic-like character in the vibrational excited state, i.e., charge transfer; this results in a stronger H-bond in a more anharmonic potential for the OH vibration. The theory distinguishes between nonpolar and polar solvents and successfully accounts for the observed 1/ε and ΔPA variations.

  8. Aqueous or solvent based surface modification: The influence of the combination solvent - organic functional group on the surface characteristics of titanium dioxide grafted with organophosphonic acids

    Science.gov (United States)

    Roevens, Annelore; Van Dijck, Jeroen G.; Geldof, Davy; Blockhuys, Frank; Prelot, Benedicte; Zajac, Jerzy; Meynen, Vera

    2017-09-01

    To alter the versatility of interactions at its surface, TiO2 is modified with organophosphonic acids (PA). A thorough understanding of the role of all synthesis conditions is necessary to achieve controlled functionalization. This study reports on the effect of using water, toluene and their mixtures when performing the modification of TiO2 with PA. Sorption and calorimetry measurements of surface interactions with various probing species clearly indicate that, by grafting PA in water, clear differences appear in the distribution of organic groups on the surface. Also the functional group of the PA determines the impact of using water as solvent. Modification in toluene results in a higher modification degree for propylphosphonic acid (3PA), as the solvent-solute interaction may hinder the grafting with phenylphosphonic acid (PhPA) in toluene. Water is preferred as solvent for PhPA modification as stabilizing π-OH interactions enhance surface grafting overcoming the competitive interaction of water at the surface as observed with 3PA. By using water in toluene mixtures for the functionalization of TiO2 with 3PA, the degree of functionalization is higher than when only water or toluene is used. Furthermore, adding small amounts of water leads to the formation of titanium propylphosphonates, next to surface grafting.

  9. Comparison of autogenous mucosal grafts and collagen-based, solvent-preserved allografts for vestibuloplasty.

    Science.gov (United States)

    Sezer, Bahar; Selçuk, Ender; Ertürk, Selda; Gomel, Murat

    2004-03-01

    This study was designed to determine whether solvent-preserved dura mater and fascia lata grafts would be as effective as palatal mucosal grafts for vestibuloplasty. All graft systems succeeded in covering the alveolar ridge with firmly attached tissue, which is needed to ensure prosthetic stability. There was no remarkable reduction in area until the stents were removed. However, after 6 months of vestibuloplasty, there was a significant reduction in gained vestibular area in the fascia lata group, whereas no significant difference between dura mater and palatal grafts was observed. These findings suggest that dura mater could serve as a biologic oral dressing for mucosal defects as effectively as palatal grafts in vestibuloplasty.

  10. A Diazonium Salt-Based Ionic Liquid for Solvent-FreeModification of Carbon.

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chengdu [ORNL; Huang, Jing-Fang [ORNL; Li, Zuojiang [ORNL; Luo, Huimin [ORNL; Dai, Sheng [ORNL

    2006-01-01

    A novel ionic liquid that consists of p-butylbenzenediazonium ions and bis(trifluoromethanesulfonyl)amidates (Tf{sub 2}N{sup -}) has been synthesized as a task-specific ionic liquid for the solvent-free modification of carbon materials. The use of anions Tf{sub 2}N{sup =} is the key to rendering the hydrophobicity, low liquidus temperature, and ionicity to this novel molten salt. This diazonium salt has a melting point of 7.2 C and a moderate electric conductivity of 527 {micro} s/cm at 25 C. The thermal stability of this diazonium ionic liquid has been investigated by high-resolution thermogravimetric analysis (HRTGA). The compound is stable up to about 90 C in nitrogen, which is only 10 C less than its solid tetrafluoroborate counterpart. The modification of carbon materials has been carried out through both thermal and electrochemical activations of diazonium ions to generate free radical intermediates without the use of any solvent. The surface-coverage loadings of 3.38 {micro} mol/m{sup 2} and 6.07 {micro} mol/m{sup 2} for covalently attached organic functionalities have been achieved by the thermally induced functionalization and electrochemically assisted reaction, respectively.

  11. Thermodynamic constrains for life based on non-aqueous polar solvents on free-floating planets.

    Science.gov (United States)

    Badescu, Viorel

    2011-02-01

    Free-floating planets (FFPs) might originate either around a star or in solitary fashion. These bodies can retain molecular gases atmospheres which, upon cooling, have basal pressures of tens of bars or more. Pressure-induced opacity of these gases prevents such a body from eliminating its internal radioactive heat and its surface temperature can exceed for a long term the melting temperature of a life-supporting solvent. In this paper two non-aqueous but still polar solvents are considered: hydrogen sulfide and ammonia. Thermodynamic requirements to be fulfilled by a hypothetic gas constituent of a life-supporting FFP's atmosphere are studied. The three gases analyzed here (nitrogen, methane and ethane) are candidates. We show that bodies with ammonia oceans are possible in interstellar space. This may happen on FFPs of (significantly) smaller or larger mass than the Earth. Generally, in case of FFP smaller in size than the Earth, the atmosphere exhibits a convective layer near the surface and a radiative layer at higher altitudes while the atmosphere of FFPs larger in size than Earth does not exhibit a convective layer. The atmosphere mass of a life-hosting FFP of Earth size is two or three orders of magnitude larger than the mass of Earth atmosphere. For FFPs larger than the Earth and specific values of surface pressure and temperature, there are conditions for condensation (in the ethane atmosphere). Some arguments induce the conclusion than the associated surface pressures and temperatures should be treated with caution as appropriate life conditions.

  12. Mechanism of gold solvent extraction from aurocyanide solution by quaternary amines: models of extracting species based on hydrogen bonding

    Institute of Scientific and Technical Information of China (English)

    马刚; 闫文飞; 陈景; 严纯华; 高宏成; 周维金; 施鼐; 吴谨光; 徐光宪; 黄昆; 余建民; 崔宁

    2000-01-01

    The mechanism of gold solvent extraction from KAu(CN)2 solution was investigated by means of FTIR, EXAFS, ICP and radioactive tracer methods. Two extraction systems were studied, namely N263-tributyl phosphate(TBP)-n-dodecane and N263-iso-octanol-n-dodecane. High-resolution FT IR spectroscopy indicated that the CN stretching vibrations of the two extraction systems differred greatly. In order to interpret the significant difference in CN stretching vibrations, twoextracting species models are proposed——supramolecular structures based on the formation ofhydrogen bonds between Au(CN)2- and modifiers such as TBP and iso-octanol.

  13. Mechanism of gold solvent extraction from aurocyanide solution by quaternary amines: models of extracting species based on hydrogen bonding

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The mechanism of gold solvent extraction from KAu(CN)2 solution was investigated by means of FTIR, EXAFS, ICP and radioactive tracer methods. Two extraction systems were studied, namely N263-tributyl phosphate(TBP)-n-dodecane and N263-iso-octanol-n-dodecane. High-reso- lution FT IR spectroscopy indicated that the CN stretching vibrations of the two extraction systems differred greatly. In order to interpret the significant difference in CN stretching vibrations, two extracting species models are proposed supramolecular structures based on the formation of hydrogen bonds between Au(CN)2- and modifiers such as TBP and iso-octanol.

  14. Desarrollo y recorrido de la grisalla en la pintura a través de la colección del MNAC

    OpenAIRE

    2014-01-01

    La presente Tesis Doctoral se centra en la pintura con Grisalla, pero no en su vertiente más conocida -como pintura monocroma-, sino en su empleo más extendido -en tiempos pasados-, donde gran parte de los artífices europeos la utilizaba como el método fundamental para ejecutar sus pinturas. Debido a los diferentes significados que se le atribuyen al termino GRISALLA, empezamos concretando a qué nos referimos con Grisalla, contrastando diversas definiciones, desde las más generalistas -que se...

  15. Los soportes textiles de pintura de caballete en México, siglos XVII-XIX. Aportaciones históricas tras su restauración

    OpenAIRE

    Rita Sumano González

    2012-01-01

    El presente artículo aborda la forma en que ciertos lienzos textiles fueron usados como soportes de pintura de caballete en México durante los siglos XVII al XIX. Se llevó a cabo un estudio usando como fuente primaria doscientos informes de trabajo de pinturas que habían sido restauradas por el Seminario Taller de Restauración de Pintura de Caballete de la Escuela Nacional de Conservación, Restauración y Museografía en México (STRPC-ENCRyM-INAH). Los registros de técnica de factura de los so...

  16. O imaginário ex-votivo na pintura de Frida Kahlo * The “ex-votos” in Frida Kahlo’s painthing imaginary

    OpenAIRE

    Duarte, Ana Helena da Silva Delfino

    2015-01-01

    Elegeu-se para essa reflexão localizar a iconografia ex-votiva presente na obra da pintora mexicana Frida Kahlo (1907-1954), que possui inúmeros trabalhos onde podem ser encontrados resíduos do imaginário popular das pinturas/ex-votos oriundos da arte dos milagres, prática cultural religiosa fortemente encontrada em seu país. Este trabalho objetiva fazer uma análise comparativa de algumas pinturas de Frida Kahlo com pinturas ex-votivas mexicanas e salientar pontos de convergências e divergênc...

  17. Los Reyes Católicos en la pintura española del siglo XIX

    Directory of Open Access Journals (Sweden)

    Rincón García, Wifredo

    2004-05-01

    Full Text Available A lo largo del siglo XIX, uno de los temas históricos más recurrentes de la pintura española será el reinado de los Reyes Católicos y los artistas se sucederán a lo largo del siglo plasmando los más diversos momentos de la vida y el gobierno de Isabel I de Castilla y Fernando II de Aragón que, tras unir sus vidas y sus coronas, unificaron también los reinos hispánicos y juntos culminaron en 1492 la larga tarea de la reconquista iniciada muchos siglos antes. Durante su reinado tuvo lugar también el Descubrimiento de América, sin lugar a dudas, otro de los hitos históricos más importantes de la pintura española y en cuya iconografía estos monarcas juegan también un papel importante.…

  18. Estudio de la Roca Soporte de las Pinturas Rupestres de la Cueva de Altamira

    Directory of Open Access Journals (Sweden)

    F. J. VALLE

    2009-10-01

    Full Text Available RESUMEN: Se describen las características geológicas principales del nivel de calcarenitas donde se encuentra la Cueva de Altamira, así como ciertos caracteres de la superficie de la roca soporte de las pinturas. Se presentan los resultados de los análisis químico, difractométrico y petrográfico de dicha roca, que ponen de manifiesto la presencia de concentraciones de montmorillonita irregularmente distribuidas en la misma. Se señala que las variaciones de volumen de dicho mineral como resultado de los cambios de humedad relativa de la Cueva (producidos por la presencia de visitantes han podido ser la causa de la desescamación de la misma, con el consiguiente desprendimiento de la pintura.ABSTRACT: The main geological features of the site in which the Cave of Altamira is located are described, as well as certain features of the rock surface on which the Palaeolithic paintings were applied. The results of the chemical, X-ray and pétrographie analyses of the rock are given. These analysis show the presence of small, irregularly distributed concentrations of montmorillonite in the rock. It is proposed that the volume changes experienced by the montmorillonite as a result of the variations of relative humidity in the cave, produced by the presence of visitors, have caused certain parts of the rock (and the paint over it to flake off.

  19. Descubrimiento de pinturas rupestres en la Sierra de la Culebra (Zamora

    Directory of Open Access Journals (Sweden)

    Ramón GRANDE DEL BRÍO

    2009-10-01

    Full Text Available En el mes de enero de 1977, un recorrido de prospección arqueológica me llevó hasta Linarejos, aldea situada cabe la falda oriental de la sierra de la Culebra, al noroeste de la provincia de Zamora. Tomé desde allí el antiguo camino que conducía a Villarino de Manzanas, hacia el sur. Un grupo de canchales de naturaleza cuarcítica con orientación noroeste-sureste (armoricana se extendían cabe el paso del Portillón. El reconocimiento por mi parte de varios covachos que se abrían en la canchalera en cuestión me permitió descubrir pinturas rupestres de tipo esquemático en uno de ellos. Las pinturas se presentan distribuidas en un panel interior del covacho, a una altura de un metro setenta centímetros respecto del suelo. Están pintadas en color rojo. Ligeramente desvaídas.

  20. La luz y el color en la pintura de El Greco

    Directory of Open Access Journals (Sweden)

    Company, Ximo

    2015-12-01

    Full Text Available This work reconsiders the extraordinary aesthetic value of light and colour in El Greco’s paintings, both of which are understood as the result of a lengthy and deliberate mental and creative process by the Cretan master. It also looks closely at the urgent need to rebalance art history in Spain to counter the proliferation of literary data with a more direct understanding of the paintings themselves in situ.El presente trabajo reconsidera el extraordinario valor estético de la luz y el color en la pintura de El Greco, entendidas ambas categorías como el resultado de un extenso y meditado proceso mental y creativo del gran maestro cretense. Ahonda, además, en la urgente necesidad de practicar una historia del arte en España que equilibre la excesiva hipertrofia del dato literario en beneficio de un conocimiento de la pintura más en directo y a pie de obra.

  1. Fast environment-friendly ball mill-assisted deep eutectic solvent-based extraction of natural products.

    Science.gov (United States)

    Wang, Man; Wang, Jiaqin; Zhang, Yue; Xia, Qian; Bi, Wentao; Yang, Xiaodi; Chen, David Da Yong

    2016-04-22

    A fast environment-friendly extraction method, ball mill-assisted deep eutectic solvent-based extraction, was used for the extraction of natural products from plants. In this study, tanshinones were selected as target compounds to evaluate the efficiency of the developed extraction method. Under the optimized experimental conditions, cryptotanshinone (0.176 mg/g), tanshinone I (0.181 mg/g), and tanshinone II A (0.421 mg/g) were extracted from Salvia miltiorrhiza Bunge, and the developed method was found to be greener, more efficient, and faster than conventional, environmentally harmful extraction methods such as methanol-based ultrasound-assisted extraction and heat reflux extraction. The analytical performances including recovery, reproducibility (RSD, n=5), correlation of determination (r(2)), and the limit of detection, with the ranges of 96.1-103.9%, 1.6-1.9%, 0.9973-0.9984, and 5-8 ng/mL, were respectively obtained. Application of ball mill-assisted deep eutectic solvent-based extraction may fundamentally shape the future development of extraction methods.

  2. Los críticos, los artistas y la pintura abstracta en la España de postguerra

    Directory of Open Access Journals (Sweden)

    Díaz Sánchez, Julián

    2002-03-01

    Full Text Available This article deals with some attitudes of the artists and criticals of Art in the face of the Abstract Painting in the Spanish postwar.

    El presente trabajo revisa algunas de las actitudes que artistas y críticos de arte adoptaron frente a la pintura informal en la España de la postguerra.

  3. Las primeras manifestaciones artísticas como recurso en educación primaria: Las pinturas de Altamira

    OpenAIRE

    Trejo Malfaz, María Jesús

    2014-01-01

    Propuesta para el aula con el objetivo de acercar el arte rupestre, más concretamente el arte parietal, a los niños/as de educación primaria. Para conseguir este objetivo recurriremos a las pinturas de la cueva de Altamira.

  4. AIE Based Coumarin Chromophore - Evaluation and Correlation Between Solvatochromism and Solvent Polarity Parameters.

    Science.gov (United States)

    Lanke, Sandip K; Sekar, Nagaiyan

    2016-03-01

    A new class of red emitting extensively conjugated donor-π-acceptor type dyes bearing coumarin units have been synthesized by condensation of 7-(diethylamino)-2-oxo-2 H-chromene-3-carbaldehyde with different active methylenes. All the dyes are characterized by (1)H NMR, (13)C NMR and HRMS spectroscopy. The photophysical behaviour and the relation between structure and properties of the coumarin "push-pull" derivatives were investigated experimentally. The dyes exhibited positive solvatochromism and solvatofluorism in solution of varying polarity. These coumarin dyes show aggregation induced emission properties with red emitting fluorescence. They show absorption in the range of 501-528 and emission in the range of 547-630 nm. We evaluated photophysical properties of coumarin dyes using solvotochromism and solvent dependent shift in the emission wavelength. All the synthesized coumarin dyes COS1-COS4 are showing very good solvatochromic properties.

  5. Mutual diffusion coefficient models for polymer-solvent systems based on the Chapman-Enskog theory

    Directory of Open Access Journals (Sweden)

    R. A. Reis

    2004-12-01

    Full Text Available There are numerous examples of the importance of small molecule migration in polymeric materials, such as in drying polymeric packing, controlled drug delivery, formation of films, and membrane separation, etc. The Chapman-Enskog kinetic theory of hard-sphere fluids with the Weeks-Chandler-Andersen effective hard-sphere diameter (Enskog-WCA has been the most fruitful in diffusion studies of simple fluids and mixtures. In this work, the ability of the Enskog-WCA model to describe the temperature and concentration dependence of the mutual diffusion coefficient, D, for a polystyrene-toluene system was evaluated. Using experimental diffusion data, two polymer model approaches and three mixing rules for the effective hard-sphere diameter were tested. Some procedures tested resulted in models that are capable of correlating the experimental data with the refereed system well for a solvent mass fraction greater than 0.3.

  6. Synthesis, Characterization and Printing Application of Solvent Dyes Based on 2-Hydroxy-4-n-octyloxybenzophenone

    Directory of Open Access Journals (Sweden)

    Bharat C. Dixit

    2011-01-01

    Full Text Available Solvent dyes have been prepared by the coupling of diazo solution of different aromatic amines with 2-hydroxy-4-n-octyloxybenzophenone. The resultant dyes were characterized by elemental analysis as well as IR and 1H NMR spectral studies. The UV-Visible spectral data have also been discussed in terms of structure property relationship. The printing of all the dyes on cotton fiber was monitored. The result shows that better hue was obtained on printing on cotton fiber and it is resulted in yellow to reddish brown colorations which showed a good fastness to light, with poor to good fastness to washing, perspiration and sublimation, however it shows poor rubbing fastness.

  7. The Effects of Solvent and Added Bases on the Protection of Benzylamines with Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Amy L. Ethier

    2015-06-01

    Full Text Available The introduction and removal of protecting groups is ubiquitous in multi-step synthetic schemes. From a green chemistry standpoint, however, alternative strategies that employ in situ and reversible protection and deprotection sequences would be attractive. The reversible reactions of CO2 with amines could provide a possible vehicle for realizing this strategy. Herein, we present (1 the products of reaction of benzylamines with CO2 in a variety of solvents with and without the presence of basic additives; (2 new adducts associated with CO2 protected benzylamine in acetonitrile containing 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU; and (3 the intermolecular competitive acylation of benzylamine and benzyl alcohol and the intramolecular competitive acylation of (4-aminomethylphenyl methanol with isopropenyl acetate in acetonitrile containing DBU in the absence and presence of CO2.

  8. Tetrabutylammonium Bromide (TBABr-Based Deep Eutectic Solvents (DESs and Their Physical Properties

    Directory of Open Access Journals (Sweden)

    Rizana Yusof

    2014-06-01

    Full Text Available Density, viscosity and ionic conductivity data sets of deep eutectic solvents (DESs formed by tetrabutylammonium bromide (TBABr paired with ethlyene glycol, 1,3-propanediol, 1,5-pentanediol and glycerol hydrogen bond donors (HBDs are reported. The properties of DES were measured at temperatures between 303 K and 333 K for HBD percentages of 66.7% to 90%. The effects of HBDs under different temperature and percentages are systematically analyzed. As expected, the measured density and viscosity of the studied DESs decreased with an increase in temperature, while ionic conductivity increases with temperature. In general, DESs made of TBABr and glycerol showed the highest density and viscosity and the lowest ionic conductivity when compared to other DESs. The presence of an extra hydroxyl group on glycerol in a DES affected the properties of the DES.

  9. Functionalization of CNTs surface with phosphonuim based deep eutectic solvents for arsenic removal from water

    Science.gov (United States)

    AlOmar, Mohamed Khalid; Alsaadi, Mohammed Abdulhakim; Hayyan, Maan; Akib, Shatirah; Hashim, Mohd Ali

    2016-12-01

    Herein, we present the use of deep eutectic solvent (DES) as functionalization agents for carbon nanotubes (CNTs) to form novel adsorbents for removal of arsenic ions (As3+) from water. Two DESs systems were prepared using methyltriphenylphosphonium bromide (MTPB) and benzyltriphenylphosphonium chloride (BTPC) as salts, in conjugation with glycerol (Gly) as a hydrogen bond donor. The resulting novel adsorbents were characterized using thermogravimetric analysis (TGA), Zeta potential, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, XRD, EDX, FESEM, and BET surface area. Optimization studies were carried out utilizing RSM-CCD experimental design to estimate the optimum removal conditions for each adsorbent. The adsorption experimental data of both adsorbents were found to fit well with pseudo-second-order kinetics model, as well as with Langmuir and Freundlich adsorption isotherm models. The maximum adsorption capacity of a MTPB-DES-functionalized CNTs adsorbent was 23.4 mg/g.

  10. Spectrophotometric Study of Stability Constants of Cr(III, Ni(II and Cu(II Complexes with a Schiff’s Base in Different Solvents

    Directory of Open Access Journals (Sweden)

    Israel Leka Lere

    2013-12-01

    Full Text Available Complexation of Cr(III, Ni(II and Cu(II with para-dimethylaminoanil of ortho-hydroxyphenylglyoxal Schiff’s base in methanol, ethanol and acetone solvents has been studied spectrophotometrically at room temperature (298K. The stoichiometry and stability of the complexes were determined using mole-ratio method. Stability data shows solvent-wise stability order as methanol > ethanol > acetone.

  11. Development of green betaine-based deep eutectic solvent aqueous two-phase system for the extraction of protein.

    Science.gov (United States)

    Li, Na; Wang, Yuzhi; Xu, Kaijia; Huang, Yanhua; Wen, Qian; Ding, Xueqin

    2016-05-15

    Six kinds of new type of green betaine-based deep eutectic solvents (DESs) have been synthesized. Deep eutectic solvent aqueous two-phase systems (DES-ATPS) were established and successfully applied in the extraction of protein. Betaine-urea (Be-U) was selected as the suitable extractant. Single factor experiments were carried out to determine the optimum conditions of the extraction process, such as the salt concentration, the mass of DES, the separation time, the amount of protein, the temperature and the pH value. The extraction efficiency could achieve to 99.82% under the optimum conditions. Mixed sample and practical sample analysis were discussed. The back extraction experiment was implemented and the back extraction efficiency could reach to 32.66%. The precision experiment, repeatability experiment and stability experiment were investigated. UV-vis, FT-IR and circular dichroism (CD) spectra confirmed that the conformation of protein was not changed during the process of extraction. The mechanisms of extraction were researched by dynamic light scattering (DLS), the measurement of the conductivity and transmission electron microscopy (TEM). DES-protein aggregates and embraces phenomenon play considerable roles in the separation process. All of these results indicated that betaine-based DES-ATPS may provide a potential substitute new method for the separation of proteins.

  12. How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends

    KAUST Repository

    Wodo, Olga

    2014-10-13

    © 2014 AIP Publishing LLC. Solvent-based fabrication is a flexible and affordable approach to manufacture polymer thin films. The properties of products made from such films can be tailored by the internal organization (morphology) of the films. However, a precise knowledge of morphology evolution leading to the final film structure remains elusive, thus limiting morphology control to a trial and error approach. In particular, understanding when and where phases are formed, and how they evolve would provide rational guidelines for more rigorous control. Here, we identify four modes of phase formation and subsequent propagation within the thinning film during solvent-based fabrication. We unravel the origin and propagation characteristics of each of these modes. Finally, we construct a mode diagram that maps processing conditions with individual modes. The idea introduced here enables choosing processing conditions to tailor film morphology characteristics and paves the ground for a deeper understanding of morphology control with the ultimate goal of precise, yet affordable, morphology manipulation for a large spectrum of applications.

  13. Advanced solvent based methods for molecular characterization of soil organic matter by high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tfaily, Malak M.; Chu, Rosalie K.; Tolic, Nikola; Roscioli, Kristyn M.; Anderton, Christopher R.; Pasa-Tolic, Ljiljana; Robinson, Errol W.; Hess, Nancy J.

    2015-05-19

    Soil organic matter (SOM) a complex, heterogeneous mixture of above and belowground plant litter and animal and microbial residues at various degrees of decomposition, is a key reservoir for carbon (C) and nutrient biogeochemical cycling in soil based ecosystems. A limited understanding of the molecular composition of SOM limits the ability to routinely decipher chemical processes within soil and predict accurately how terrestrial carbon fluxes will response to changing climatic conditions and land use. To elucidate the molecular-level structure of SOM, we selectively extracted a broad range of intact SOM compounds by a combination of different organic solvents from soils with a wide range of C content. Our use of Electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and a suite of solvents with varying polarity significantly expands the inventory of the types of organic molecules present in soils. Specifically, we found that hexane is selective for lipid-like compounds with very low O:C ratios; water was selective for carbohydrates with high O:C ratios; acetonitrile preferentially extracts lignin, condensed structures, and tannin poly phenolic compounds with O:C > 0.5; methanol has higher selectivity towards compounds characterized with low O:C < 0.5; and hexane, MeOH, ACN and water solvents increase the number and types of organic molecules extracted from soil for a broader range of chemically diverse soil types. Our study of SOM molecules by ESI-FTICR MS revealed new insight into the molecular-level complexity of organics contained in soils.

  14. Effect of lipophilic tail architecture and solvent engineering on the structure of trehalose-based nonionic surfactant reverse micelles.

    Science.gov (United States)

    Shrestha, Lok Kumar; Sato, Takaaki; Dulle, Martin; Glatter, Otto; Aramaki, Kenji

    2010-09-23

    We use small-angle X-ray scattering and dynamic light scattering to investigate the structural and dynamical properties of trehalose polyisostearate, abbreviated as TQ-n (n = 3, 5, and 7), in different organic solvents, where n represents the number of isosterate chains per surfactant molecule. TQ-n spontaneously assembles into reverse micelles without addition of water at 25 °C. We found that for TQ-5 and TQ-7, steric hindrance of the lipophilic surfactant tail causes significant reduction of the aggregation number, whose scheme is clearly distinguished from the modification of the critical packing parameter. Increasing the hydrocarbon chain length of oils from octane to hexadecane favors one-dimensional micellar growth, leading to the formation of rodlike micelles due to different penetration tendencies of oils into the lipophilic shell of the surfactant. Subtle differences in solvent polarity also plays a crucial role in the micellar size, which is decreased when liquid paraffin is replaced with squalene. A further decrease is attained in more polar mixed triglyceride oils. A rising temperature also results in the same direction. The extrapolated structure factor to the zero scattering vector, S(q → 0), for the TQ-3/decane systems almost exactly follows that predicted for hard spheres, demonstrating that osmotic compressibility of the system is well explained if accounting for the excluded volume. However, we found that the effective diffusion coefficient decreases with surfactant concentration, which is an opposite trend to what is expected for hard spheres. This apparent contradiction is likely to be due to the occurrence of transient interdigitation between the lipophilic tails of neighboring reverse micelles at higher concentration. Our data highlight the relevance of the concept of "tunable reverse micellar geometry" in the novel trehalose-based nonionic surfactant binary mixtures, in which lipophilic tail architecture, solvent engineering, concentration

  15. Computer Aided Solvent Selection and Design Framework

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Conte, Elisa; Abildskov, Jens

    , millions of tons solvents have to be wasted every year [2]. Therefore, it becomes important to minimize and optimize the use of organic solvents as much as possible, to satisfy the “Green Chemistry Principles” [3]. Another challenge is that currently solvent selection relies very much on previous...... is to develop a systematic framework and implement it as software for selection and design of solvents for many applications including organic synthesis, complex reaction systems and solvent-based separations. The solvent selection framework is based on a combination of knowledge from industrial practice...... identification of solvent candidates using special software ProCAMD and ProPred, which are the implementations of computer-aided molecular techniques. The second consists of assigning the RS-indices following the reaction–solvent and then consulting the known solvent database and identifying the set of solvents...

  16. A solvent-controlled switch of manganese complex assemblies with a beta-diketonate-based ligand.

    Science.gov (United States)

    Aromí, Guillem; Gamez, Patrick; Roubeau, Olivier; Berzal, Paula Carrero; Kooijman, Huub; Spek, Anthony L; Driessen, Willem L; Reedijk, Jan

    2002-07-15

    The coordination properties of the new polynucleating ligand H(3)L1 (1,3-bis(3-oxo-3-phenylpropionyl)-2-hydroxy-5-methylbenzene) with Mn(II/III) are described. Depending on the solvent used, the reaction of H(3)L1 with Mn(OAc)(2) yields either of the two new multinuclear assemblies [Mn(2)(HL1)(2)(py)(4)] (1) and [Mn(3)(HL1)(3)] (2), as revealed by X-ray crystallography. The structure of 2 is remarkable in that it shows a unique asymmetric triple-stranded helicate. Complexes 1 and 2 can be interconverted by controlling the solvent of the reaction system, and therefore, this ensemble constitutes an interesting externally addressable switch. In the presence of Mn(III)/pyridine, partial degradation of H(3)L1 occurs via oxidative cleavage, and the new complex [Mn(2)(L2)(2)(py)(4)] (3) is formed. The crystal structure of this complex has shown the fully deprotonated form of the new donor H(3)L2 (3-(3-oxo-3-phenylpropionyl)-5-methylsalicylic acid). From the same reaction, the Mn(II) complex 1 is also obtained. A rational synthesis of H(3)L2 is reported, and this has been used to prepare 3 in high yields, directly from its components. Variable-temperature magnetic susceptibility (chi(m)) measurements were performed on complexes 1-3 under a magnetic field of 1 kG. The data for each complex were fit to the appropriate chi(m) vs T theoretical equation, respectively. In 1, the Mn(II) ions are uncoupled, with g = 2.01. The data from 2 were fit by assuming the presence of an exchange coupled Mn(II)...Mn(II) pair next to a magnetically isolated Mn(II) center. The fit gave J = -2.75 cm(-1), g(12) = 1.97, and g(3) = 1.92, respectively. In 3, two models fit the experimental data. In the most satisfactory, the Mn(III) ions are coupled antiferromagnetically with J = -1.48 cm(-1) and g = 1.98 and a term for weak ferromagnetic intermolecular exchange is included with zJ' = 0.39 cm(-1). The other model contemplates the presence of two uncoupled zero field split Mn(III) ions.

  17. Dipole Strength Calculation Based on Two-Level System Approximation to Study Q/B-Band Intensity Ratio of ZnTBP in Solvent

    Science.gov (United States)

    Rusydi, Febdian; Shukri, Ganes; Saputro, Adithya G.; Agusta, Mohammad K.; Dipojono, Hermawan K.; Suprijadi, Suprijadi

    2017-04-01

    We study the Q/B-band dipole strength of zinc tetrabenzoporphyrin (ZnTBP) using density functional theory (DFT) in various solvents. The solvents are modeled using the polarized continuum model (PCM). The dipole strength calculations are approached by a two-level system, where the Q-band is described by the HOMO → LUMO electronic transition and the B-band by the HOMO-1 → LUMO electronic transition. We compare the results with the experimental data of the Q/B-band intensity ratio. We also perform time-dependent DFT coupled with PCM to calculate the Q/B-band oscillator strength ratio of ZnTBP. The results of both methods show a general trend with respect to the experimental Q/B-band intensity ratio in solvents, except for the calculation in the water solvent. Even so, the approximation is a good starting point for studying the UV-vis spectrum based on DFT study alone.

  18. Microstructure of polyacrylonitrile-based activated carbon fibers prepared from solvent-free coagulation process

    Directory of Open Access Journals (Sweden)

    Norhaniza Yusof

    2016-02-01

    Full Text Available Polyacrylonitrile precursor fibers prepared using a solvent-free coagulation process were stabilized, carbonized, and physically activated by carbon dioxide into activated carbon fibers (ACFs. The activation temperature varied from 600 to 900 °C while the activation time was 1 h. Atomic force microscopy was used to observe the surface morphology, as well as the surface roughness of the ACFs. Higher pyrolysis temperature formed rougher surfaces, and increased the pore sizes. Meanwhile, Fourier transform infrared spectroscopy revealed more conversion of oxygen containing functional groups to carbonaceous materials as the activation temperature increased. Moreover, the microstructure properties were thoroughly characterized by the X-ray photoelectron spectroscopy (XPS and X-ray diffraction (XRD studies. XRD analysis showed that the activation of the ACFs shrank the ordered structure, reducing the D-spacing from 0.358 to 0.347 nm for the fibers prepared at activation temperatures of 600 to 900 °C. Meanwhile, XPS analysis concluded that that the oxygen containing functional groups were still retained even at high activation temperatures while the nitrogen containing functional groups were reduced during the high temperature activation in the CO2 atmosphere.

  19. Tuning Microparticle Porosity during Single Needle Electrospraying Synthesis via a Non-Solvent-Based Physicochemical Approach

    Directory of Open Access Journals (Sweden)

    Yuan Gao

    2015-12-01

    Full Text Available Porous materials, especially microparticles (MP, are utilized in almost every field of engineering and science, ranging from healthcare materials (drug delivery to tissue engineering to environmental engineering (biosensing to catalysis. Here, we utilize the single needle electrospraying technique (as opposed to complex systems currently in development to prepare a variety of poly(ε-caprolactone (PCL MPs with diverse surface morphologies (variation in pore size from 220 nm to 1.35 µm and architectural features (e.g., ellipsoidal, surface lamellar, Janus lotus seedpods and spherical. This is achieved by using an unconventional approach (exploiting physicochemical properties of a series of non-solvents as the collection media via a single step. Sub-micron pores presented on MPs were visualized by electron microscopy (demonstrating a mean MP size range of 7–20 μm. The present approach enables modulation in morphology and size requirements for specific applications (e.g., pulmonary delivery, biological scaffolds, multi-stage drug delivery and biomaterial topography enhancement. Differences in static water contact angles were observed between smooth and porous MP-coated surfaces. This reflects the hydrophilic/hydrophobic properties of these materials.

  20. Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives.

    Science.gov (United States)

    Schulz, Gisela L; Urdanpilleta, Marta; Fitzner, Roland; Brier, Eduard; Mena-Osteritz, Elena; Reinold, Egon; Bäuerle, Peter

    2013-01-01

    The optimization of solution-processed organic bulk-heterojunction solar cells with the acceptor-substituted quinquethiophene DCV5T-Bu 4 as donor in conjunction with PC61BM as acceptor is described. Power conversion efficiencies up to 3.0% and external quantum efficiencies up to 40% were obtained through the use of 1-chloronaphthalene as solvent additive in the fabrication of the photovoltaic devices. Furthermore, atomic force microscopy investigations of the photoactive layer gave insight into the distribution of donor and acceptor within the blend. The unique combination of solubility and thermal stability of DCV5T-Bu 4 also allows for fabrication of organic solar cells by vacuum deposition. Thus, we were able to perform a rare comparison of the device characteristics of the solution-processed DCV5T-Bu 4 :PC61BM solar cell with its vacuum-processed DCV5T-Bu 4 :C60 counterpart. Interestingly in this case, the efficiencies of the small-molecule organic solar cells prepared by using solution techniques are approaching those fabricated by using vacuum technology. This result is significant as vacuum-processed devices typically display much better performances in photovoltaic cells.

  1. Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives

    Directory of Open Access Journals (Sweden)

    Gisela L. Schulz

    2013-10-01

    Full Text Available The optimization of solution-processed organic bulk-heterojunction solar cells with the acceptor-substituted quinquethiophene DCV5T-Bu4 as donor in conjunction with PC61BM as acceptor is described. Power conversion efficiencies up to 3.0% and external quantum efficiencies up to 40% were obtained through the use of 1-chloronaphthalene as solvent additive in the fabrication of the photovoltaic devices. Furthermore, atomic force microscopy investigations of the photoactive layer gave insight into the distribution of donor and acceptor within the blend. The unique combination of solubility and thermal stability of DCV5T-Bu4 also allows for fabrication of organic solar cells by vacuum deposition. Thus, we were able to perform a rare comparison of the device characteristics of the solution-processed DCV5T-Bu4:PC61BM solar cell with its vacuum-processed DCV5T-Bu4:C60 counterpart. Interestingly in this case, the efficiencies of the small-molecule organic solar cells prepared by using solution techniques are approaching those fabricated by using vacuum technology. This result is significant as vacuum-processed devices typically display much better performances in photovoltaic cells.

  2. Efficient polymer solar cells based on poly(3-hexylthiophene) and indene-C₆₀ bisadduct fabricated with non-halogenated solvents.

    Science.gov (United States)

    Guo, Xia; Zhang, Maojie; Cui, Chaohua; Hou, Jianhui; Li, Yongfang

    2014-06-11

    The photovoltaic performance of poly(3-hexylthiophene) (P3HT) has been improved greatly by using indene-C60 bisadduct (ICBA) as acceptor instead of phenyl-C61-butyric acid methyl ester (PCBM). However, the solvent of dichlorobenzene (DCB) used in fabricating polymer solar cells (PSCs) limited the application of the PSCs, because of the environmental problem caused by the harmful halogenated solvent. In this work, we fabricated the PSCs based on P3HT/ICBA processed with four low-harmful non-halogenated solvents of toluene, o-xylene, m-xylene, and p-xylene. The PSCs based on P3HT/ICBA (1:1, w/w) with toluene as the solvent exhibit the optimized power conversion efficiency (PCE) of 4.5% with open-circuit voltage (Voc) of 0.84 V, short circuit current density (Jsc) of 7.2 mA/cm(2), and fill factor (FF) of 71%, under the illumination of AM 1.5G at 100 mW/cm(2). Upon using 1% N-methyl pyrrolidone (NMP) as a solvent additive in the toluene solvent, the PCE of the PSCs was greatly improved to 6.6% with a higher Jsc of 10.3 mA/cm(2) and a high FF of 75%, which is even higher than that of the devices fabricated with halogenated DCB solvent. The X-ray diffraction (XRD) measurement shows that the crystallinity of P3HT increased with the NMP additive. The investigations on morphology of the active layers by atomic force microscopy (AFM) and transmission electron microscopy (TEM) indicate that the NMP additive promotes effective phase separation and formation of nanoscaled interpenetrating network structure of the active layer, which is beneficial to the improvement of Jsc and PCE for the PSCs fabricated with toluene as the solvent.

  3. Evaluating the complexation behavior and regeneration of boron selective glucaminium-based ionic liquids when used as extraction solvents

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Manishkumar D.; Steyer, Daniel J. [Department of Chemistry, School of Green Chemistry and Engineering, University of Toledo, Toledo, OH (United States); Anderson, Jared L., E-mail: Jared.Anderson@UToledo.edu [Department of Chemistry, School of Green Chemistry and Engineering, University of Toledo, Toledo, OH (United States)

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer Glucaminium-based ILs exhibit high selectivity for boron species using DLLME. Black-Right-Pointing-Pointer The concentration of glucaminium-based IL affects type of boron complex formed. Black-Right-Pointing-Pointer Use of 0.1 M HCl allows for regeneration of the IL solvent following extraction. Black-Right-Pointing-Pointer Selectivity of the glucaminium-based ILs for boron species in seawater is similar to Milli-Q water. - Abstract: Glucaminium-based ionic liquids are a new class of solvents capable of extracting boron-species from water with high efficiency. The complexation behavior of these ILs with borate was thoroughly studied using {sup 11}B NMR. Two different complexes, namely, monochelate complex and bischelate complex, were observed. {sup 11}B NMR was used extensively to determine the formation constants for monochelate and bischelate complexes. The IL concentration was observed to have a significant effect on the IL-borate complexes. Using an in situ dispersive liquid-liquid microextraction (in situ DLLME) method, the extraction efficiency for boron species was increased dramatically when lithium bis[(trifluoromethyl)sulfonyl]imide (LiNTf{sub 2}) was used as the metathesis salt in an aqueous solution containing 0.1 M sodium chloride. IL regeneration after extraction was achieved using 0.1 M hydrochloric acid. The extraction efficiency of boron species was consistent when the IL was employed after three regeneration cycles. The selectivity of the IL for boron species in synthetic seawater samples was similar to performing the same extraction from Milli-Q water samples.

  4. La pintura mural hispano-musulmana. ¿Tradición o innovación?

    Directory of Open Access Journals (Sweden)

    Rallo Gruss, Carmen

    2003-06-01

    Full Text Available It is generally thought that in Western Europe and at the end of the medieval period, tempera paint with oil as a medium was applied to dry plaster walls because the Roman technique for painting on wet plaster (al fresco had been forgotten. Texts such as the Libro dell'Arte by Cennino Cennini discuss the recovery of the fresco technique by some of the founding painters of the Italian Renaissance, such as Giotto. From Renaissance Italy, it is argued, the technique expanded to the rest of Europe. However, in medieval Hispanic monuments with Islamic iconography there is evidence of painted fresco decoration dated prior to the fifteenth century. This paper studies the sources of this technical tradition by analysing examples of Iberian, Roman, Islamic, Mudéjar and Morisco mural painting.

    El convencimiento de que a finales de la Edad Media las paredes eran decoradas con pintura al seco, realizada con temple, más o menos graso, olvidando la técnica de pintura al fresco utilizada habitualmente por los romanos, es algo admitido para toda la Europa Occidental. Textos como el Libro dell´Arte de Cennino Cennini nos hablan de su recuperación por los iniciadores del Renacimiento italiano como el Giotto; desde allí se expandirá la técnica a todos los países europeos. Sin embargo, en los monumentos hispanos con iconografía de tradición islámica se siguen realizando decoraciones al fresco hasta el siglo XV. En busca de explicaciones a esta excepción, en este artículo se buscan las fuentes de esa tradición técnica, analizando ejemplos de pintura mural ibera, romana, islámica y «de lo morisco» o mudéjar. El estudio se centra en los materiales utilizados, incluso con analítica de laboratorio, en paralelo con los motivos estilísticos que se encuentran en cada época.

  5. A pintura e outras modalidades expressivas, como facilitadoras do desenvolvimento potencial dos educandos

    Directory of Open Access Journals (Sweden)

    Sonia De Fatima Thomasi Facco

    2012-04-01

    Full Text Available Este artigo tem o objetivo de mostrar os resultados de um trabalho realizado com um grupo de crianças o qual buscou o desenvolvimento da criatividade, auto-estima e autoconfiança. Elas estavam todas matriculadas na mesma escola, mas em séries diferentes. Eram crianças que sentiam grandes limitações no ato de criar através do desenho, da pintura, da construção com sucata e do uso de outros materiais, porém no decorrer dos trabalhos passaram a acreditar na sua potencialidade e a elaborar com mais cuidado e interesse os trabalhos que produziam. O referencial básico para a elaboração dos trabalhos plásticos estiveram ligados ao meio sócio-cultural no qual estas crianças estavam inseridas.

  6. Quase pintura: poesia e visualidade em Pau Brasil, de Oswald de Andrade

    Directory of Open Access Journals (Sweden)

    Luciano Cortez

    2005-06-01

    Full Text Available A reconstituição dos dados da paisagem revelam os modos operatórios do discurso poético de Oswald de Andrade para traduzir o mundo em poesia. Essa tradução se fez por meio da transposição de recursos de linguagem próprios às artes plásticas das vanguardas européias de inícios do século XX para o universo da palavra. Seu resultado foi uma poesia capaz de reproduzir no plano verbal o dinamismo do mundo moderno. Em Oswald de Andrade isso implicou a elaboração de uma poesia com sabor primitivista próximo ao que reconhecera na pintura cubista.

  7. Entorno de la creación: la pintura de Diego Arango Ruiz

    Directory of Open Access Journals (Sweden)

    Clemencia Arango

    2006-01-01

    Full Text Available La trayectoria artística del pintor Diego Arango se ha caracterizado por la investigación antropológica, ambiental e histórica. Su formación, marcada por los movimientos estudiantiles y políticos de las décadas de los sesenta y setenta, le ha permitido combinar sus ideas políticas con técnicas artísticas como la fotografía, la serigrafía y la pintura digital. El resultado es un arte revolucionario que le ha dado reconocimiento en varios países de América y Europa.

  8. Entorno de la creación: la pintura de Diego Arango Ruiz

    Directory of Open Access Journals (Sweden)

    Clemencia Arango

    2006-10-01

    Full Text Available La trayectoria artística del pintor Diego Arango se ha caracterizado por la investigación antropológica, ambiental ehistórica. Su formación, marcada por los movimientos estudiantiles y políticos de las décadas de los sesenta y setenta, le ha permitido combinar sus ideas políticas con técnicas artísticas como la fotografía, la serigrafía y la pintura digital. El resultado es un arte revolucionario que le ha dado reconocimiento en varios países de América y Europa.

  9. Sou, então, pintura: em torno de auto-retratos de Iberê Camargo

    Directory of Open Access Journals (Sweden)

    Lucia Teixeira

    2005-06-01

    Full Text Available O artigo analisa auto-retratos de Iberê Camargo, fixando-se especialmente nos auto-retratos de 1943 e de 1984, em que a questão do tempo se manifesta tanto na cronologia que diferencia as duas concepções de pintura quanto na gestualidade que marca o ritmo e o andamento como categorias enunciativas da pintura. Se no auto-retrato de 1943 o ritmo é suave, quase etéreo, criando efeitos de harmonia e integração, no quadro de 1984 a gestualidade brusca acelera e confunde o tempo da pintura, conferindo-lhe um andamento veloz e um efeito de inacabamento e imperfeição. É a inscrição do tempo na matéria pictórica que transforma a representação, alterando assim a relação intersubjetiva entre observador e pintor.Este artículo analiza autorretratos de Iberê Camargo, en particular los autorretratos de 1943 y de 1984. El tema del tiempo se manifiesta tanto en la cronología que diferencia dos concepciones de pintura como en la gestualidad que marca el ritmo y el desarrollo como categorías enunciativas de la pintura. Mientras que en el autorretrato de 1943 el ritmo es suave, casi etéreo, creando efectos de armonía e integración, en el cuadro de 1984 la gestualidad brusca acelera y confunde el tiempo de la pintura, resultando en un desarrollo veloz y en un efecto inacabado de imperfección. La inscripción del tiempo en la matéria prictórica transforma la representación y altera de esta forma la relación intersubjetiva entre observador y pintor.The paper analyses Iberê Camargo's self-portraits, in particular his 1943 and 1984 paintings, in which the issue of time manifests itself both in the chronology which distinguishes the two conceptions of painting and in action which marks the rhythm and pace as enunciative categories of painting. In the self-portrait of 1943 the rhythm is soft, almost ethereal; in the 1984 painting, the abrupt action accelerates and disarrays the time of the painting, resulting in a fast pace and an effect of

  10. Absence of association between organic solvent exposure and risk of chronic renal failure: a nationwide population-based case-control study.

    Science.gov (United States)

    Fored, C Michael; Nise, Gun; Ejerblad, Elisabeth; Fryzek, Jon P; Lindblad, Per; McLaughlin, Joseph K; Elinder, Carl-Gustaf; Nyrén, Olof

    2004-01-01

    Exposure to organic solvents has been suggested to cause or exacerbate renal disease, but methodologic concerns regarding previous studies preclude firm conclusions. We examined the role of organic solvents in a population-based case-control study of early-stage chronic renal failure (CRF). All native Swedish residents aged 18 to 74 yr, living in Sweden between May 1996 and May 1998, formed the source population. Incident cases of CRF in a pre-uremic stage (n = 926) and control subjects (n = 998), randomly selected from the study base, underwent personal interviews that included a detailed occupational history. Expert rating by a certified occupational hygienist was used to assess organic solvent exposure intensity and duration. Relative risks were estimated by odds ratios (OR) in logistic regression models, with adjustment for potentially important covariates. The overall risk for CRF among subjects ever exposed to organic solvents was virtually identical to that among never-exposed (OR, 1.01; 95% confidence interval [CI], 0.81 to 1.25). No dose-response relationships were observed for lifetime cumulative solvent exposure, average dose, or exposure frequency or duration. The absence of association pertained to all subgroups of CRF: glomerulonephritis (OR, 0.96; 95% CI, 0.68 to 1.34), diabetic nephropathy (OR, 1.02; 95% CI, 0.74 to 1.41), renal vascular disease (OR, 1.16; 95% CI, 0.76 to 1.75), and other renal CRF (OR, 0.92; 95% CI, 0.66 to 1.27). The results from a nationwide, population-based study do not support the hypothesis of an adverse effect of organic solvents on CRF development, in general. Detrimental effects from subclasses of solvents or on specific renal diseases cannot be ruled out.

  11. Oxidation of Aliphatic Alcohols by Using Precious Metals Supported on Hydrotalcite under Solvent- and Base-Free Conditions.

    Science.gov (United States)

    He, Yufei; Feng, Junting; Brett, Gemma L; Liu, Yanan; Miedziak, Peter J; Edwards, Jennifer K; Knight, David W; Li, Dianqing; Hutchings, Graham J

    2015-10-12

    Precious metal nanoparticles supported on magnesium-aluminum hydrotalcite (HT), TiO2 , and MgO were prepared by sol immobilization and assessed for the catalytic oxidation of octanol, which is a relatively unreactive aliphatic alcohol, with molecular oxygen as the oxidant under solvent- and base-free conditions. Compared with the TiO2 - and MgO-supported catalysts, platinum HT gave the highest activity and selectivity towards the aldehyde. The turnover number achieved for the platinum HT catalyst was >3700 after 180 min under mild reaction conditions. Moreover, the results for the oxidation of different substrates indicate that a specific interaction of octanal with the platinum HT catalyst could lead to deactivation of the catalyst.

  12. Solvent cleaning system and method for removing contaminants from solvent used in resin recycling

    Science.gov (United States)

    Bohnert, George W.; Hand, Thomas E.; DeLaurentiis, Gary M.

    2009-01-06

    A two step solvent and carbon dioxide based system that produces essentially contaminant-free synthetic resin material and which further includes a solvent cleaning system for periodically removing the contaminants from the solvent so that the solvent can be reused and the contaminants can be collected and safely discarded in an environmentally safe manner.

  13. Para a história do restauro de pintura em Portugal: as antigas intervenções no retrato de José António de Oliveira Machado, da Biblioteca Nacional de Portugal

    Directory of Open Access Journals (Sweden)

    António João Cruz

    2015-06-01

    Full Text Available Uma pintura sobre tela, de finais do século XVIII, aparentemente em bom estado de conservação, mostrou que afinal já sofreu danos muito significativos, possivelmente devido às más condições de acondicionamento em que esteve. Na primeira metade do século XIX encontrava-se num depósito em Lisboa, para onde foram recolhidas as obras retiradas dos conventos, então extintos em Portugal. A pintura foi depois sujeita a numerosas intervenções de restauro, das quais as mais extensas foram tecnicamente bem executadas, provavelmente em finais do século XIX ou princípios do século XX, ainda que seguindo princípios diferentes dos actuais. Com base no estudo efectuado, recorrendo a diversos métodos de exame e análise, são descritas as intervenções detectadas, especialmente as operações de tratamento dos rasgões e de lacunas, algumas das quais executadas de forma pouco comum, assim como são identificados os materiais usados nessas intervenções.

  14. Two-dimensional assembly based on flow supramolecular chemistry: kinetic control of molecular interactions under solvent diffusion.

    Science.gov (United States)

    Numata, Munenori; Kozawa, Tomohiro

    2014-05-19

    Self-assembly of porphyrin molecules can be controlled kinetically to form structures with lengths extending from the nano- to the micrometer scale, through a programmed solvent-diffusion process in designed microflow spaces. Temporal solvent structures generated in the microflow were successfully transcribed into molecular architectures.

  15. O Passeio Público do Rio de Janeiro na Literatura, na Pintura e na Fotografia do Século XIX

    Directory of Open Access Journals (Sweden)

    Solange de Aragão

    2012-06-01

    Full Text Available Este artigo tem como objetivo geral e mais amplo chamar a atenção dos pesquisadores para a importância da literatura, da pintura e da fotografia como fontes documentais para a construção da História do Paisagismo no Brasil por meio de um estudo de caso muito particular: o Passeio Público do Rio de Janeiro no século XIX. São objetivos específicos apresentar e analisar o modo como esse espaço livre público aparece na literatura, na pintura e na fotografia desse período, considerando suas transformações paisagísticas.

  16. Identidad, tradición y renovación: La pintura regionalista. Aragón (1898-1939)

    OpenAIRE

    Castán Chocarro, Alberto; Lomba Serrano, Concepción

    2014-01-01

    La tesis doctoral "Identidad, tradición y renovación: La pintura regionalista. Aragón (1898-1939)" tiene por objeto analizar la naturaleza y características de la pintura regionalista, fenómeno desarrollado en España entre los últimos años del siglo XIX y el final de la Guerra Civil, así como el modo en qué ésta se manifestó en el contexto aragonés. La plástica regionalista vino a encarnar algunas de las preocupaciones fundamentales que caracterizaron a la sociedad española del momento, inme...

  17. Identidad, tradición y renovación: La pintura regionalista. Aragón (1898-1939)

    OpenAIRE

    Castán Chocarro, Alberto; Lomba Serrano, Concepción

    2014-01-01

    La tesis doctoral "Identidad, tradición y renovación: La pintura regionalista. Aragón (1898-1939)" tiene por objeto analizar la naturaleza y características de la pintura regionalista, fenómeno desarrollado en España entre los últimos años del siglo XIX y el final de la Guerra Civil, así como el modo en qué ésta se manifestó en el contexto aragonés. La plástica regionalista vino a encarnar algunas de las preocupaciones fundamentales que caracterizaron a la sociedad española del momento, inme...

  18. A pintura em Schelling e o problema da imagem = The painting in Schelling and the problem of image

    Directory of Open Access Journals (Sweden)

    Barros, Fernando Ribeiro de Moraes

    2010-01-01

    Full Text Available O propósito geral deste artigo consiste em mostrar, a partir de hipóteses globais de interpretação da natureza e da arte, o lugar da pintura na filosofia de F. W. J. v. Schelling. Submetendo a obra pictórica a condições teórico-especulativas inovadoras, a ponderação schellinguiana impele-nos, não raro, a um tratamento diferenciado do visível. Por isso, a título de exercício de reflexão, espera-se igualmente indicar que tal caracterização da pintura ecoa e antecipa, ao longe, questões levantadas pela filosofia contemporânea – em especial, pela fenomenologia – a respeito da imagem

  19. Del Grabado Europeo a la Pintura Americana. La serie El Credo del pintor quiteño Miguel de Santiago

    Directory of Open Access Journals (Sweden)

    Marta Fajardo de Rueda

    2011-06-01

    Full Text Available El hallazgo de dos series de grabados flamencos del siglo XVII sobre el tema El Credo, de los artistas Adrian Collaert (1560-1618 y Johan Sadeler (1550-1600, permiten confirmar la importante presencia de los grabados europeos en los talleres de pintura de la América Hispana y su influencia decisiva en la formación de nuestros artistas. Se analizan entonces bajo esta perspectiva, las once pinturas al óleo que conforman la Serie de los Artículos de El Credo, obra del pintor quiteño Miguel de Santiago (1603-1706 que se encuentran en la Catedral Primada de Bogotá desde la época colonial.

  20. Del Grabado Europeo a la Pintura Americana. La serie El Credo del pintor quiteño Miguel de Santiago

    Directory of Open Access Journals (Sweden)

    Marta Fajardo de Rueda

    2011-01-01

    Full Text Available El hallazgo de dos series de grabados flamencos del siglo XVII sobre el tema El Credo, de los artistas Adrian Collaert (1560-1618 y Johan Sadeler (1550-1600, permiten confirmar la importante presencia de los grabados europeos en los talle - res de pintura de la América Hispana y su influencia decisiva en la formación de nuestros artistas. Se analizan entonces bajo esta perspectiva, las once pinturas al óleo que conforman la Serie de los Artículos de El Credo, obra del pintor quiteño Miguel de Santiago (1603-1706 que se encuentran en la Catedral Primada de Bogotá desde la época colonial.

  1. Application of ultrasound-assisted emulsification microextraction based on applying low-density organic solvent for the determination of organochlorine pesticides in water samples.

    Science.gov (United States)

    Zhang, Yufeng; Lee, Hian Kee

    2012-08-24

    In this study, a polyethylene Pasteur pipette-based ultrasound-assisted emulsification microextraction (USAEME) applying low-density organic solvent was successfully developed for the extraction of trace levels of organochlorine pesticides (OCPs) in water samples and followed by gas chromatography-mass spectrometry (GC-MS) analysis. In this approach, a polyethylene Pasteur squeeze-type pipette was employed as a convenient extraction device and ultrasound radiation was applied to accelerate the emulsification of low-density organic solvent in aqueous solutions to enhance the microextraction efficiency of OCPs in water samples. Thirty microliters of extraction solvent (isooctane), of lower density than water, were injected into the aqueous sample solution held in the pipette. The latter was then immersed in an ultrasound water bath to form an emulsion. After 30s extraction, phase separation was achieved by centrifugation. The upper layer (isooctane) was collected and analyzed by GC-MS. No disperser solvent was required in this procedure. Significantly, fast analysis and high extraction efficiency were achieved. Another feature of the procedure was the use of the pipette as the extraction device, which permitted less dense than water organic solvent to be used as extraction solvent. This method broadens the applicability of USAEME to a wider range of solvent. Additionally, carry-over problems were avoided with the use of the disposable pipette. Parameters affecting the efficiency of polyethylene Pasteur pipette-based USAEME, such as the extraction solvent, extraction solvent volume, extraction and centrifugation time, ionic strength and extraction temperature were investigated. Under the optimum conditions, the proposed method provided good enrichment factors (EFs) in the range of 128 and 328, with relative standard deviations (RSDs) ranging from 2.7% to 12.4%. The limits of detection were in the range of 0.8 and 10ng/L depending on the analytes. The linearities were

  2. Colorimetric Humidity and Solvent Recognition Based on a Cation-Exchange Clay Mineral Incorporating Nickel(II)-Chelate Complexes.

    Science.gov (United States)

    Hosokawa, Hitoshi; Mochida, Tomoyuki

    2015-12-01

    Solvatochromic nickel(II) complexes with diketonato and diamine ligands were incorporated into a saponite clay by ion exchange, and their colorimetric humidity- and solvent-recognition properties were investigated. These powders exhibit color change from red to blue-green depending on humidity, and the detection range can be controlled by modifying the metal complex. The humidity response takes advantage of the humidity-dependent water content in clay and the coordination of water molecules to the metal complex in equilibrium. The addition of organic solvents to the powders causes a color change to occur, varying from red to blue-green depending on the donor number of the solvent, thereby enabling solvent recognition. In the clay, the affinity of less sterically hindered complexes to water or solvent molecules is decreased compared with that in solution because the cationic complexes interact with the anionic layers in the clay. Incorporating diethylene glycol into the materials produced thermochromic powders.

  3. Estética, política y vida cotidiana. El caso de la pintura callejera chilena

    Directory of Open Access Journals (Sweden)

    Patricio Rodriguez-Plaza

    2005-06-01

    Full Text Available Este artículo trata de compartir una reflexión académica con respecto al fenómeno de la pintura callejera chilena, entendiéndola como un hecho estético total, que lo es menos por sus producciones y resultados que por los usos y percepciones que lo entretejen, conforman y desparraman por la ciudad.

  4. Las pinturas rupestres esquemáticas de la Peña del Castellar (Villar del Humo, Cuenca

    Directory of Open Access Journals (Sweden)

    Anna ALONSO

    2009-10-01

    Full Text Available Con motivo de nuestra visita a los importantes yacimientos rupestres de Villar del Humo, y comentando sobre ellos con las gentes del lugar, fuimos informados de la existencia de un abrigo con figuras semejantes a las de los otros conjuntos '. Ante la posibilidad de que se tratase de pinturas, nos desplazamos a la zona donde, efectivamente, existía el grupo de representaciones que dan lugar a esta nota.

  5. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanhua; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

    2015-06-02

    Highlights: • A strategy for extraction of protein based on DES-coated magnetic graphene oxide. • The deep eutectic solvents were based on choline chloride. • Bovine serum albumin was used as the analyte. • The material prepared works for the acidic but not the basic or the neutral proteins. - Abstract: Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe{sub 3}O{sub 4}@GO) to form Fe{sub 3}O{sub 4}@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe{sub 3}O{sub 4}@GO-DES, and the results indicated the successful preparation of Fe{sub 3}O{sub 4}@GO-DES. The UV–vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe{sub 3}O{sub 4}@GO-DES. Comparison of Fe{sub 3}O{sub 4}@GO and Fe{sub 3}O{sub 4}@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe{sub 3}O{sub 4}@GO-DES performs better than Fe{sub 3}O{sub 4}@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L{sup −1} Na{sub 2}HPO{sub 4} contained 1 mol L{sup −1} NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled.

  6. DFT-based simulations of IR amide I' spectra for a small protein in solution. Comparison of explicit and empirical solvent models.

    Science.gov (United States)

    Grahnen, Johan A; Amunson, Krista E; Kubelka, Jan

    2010-10-14

    Infrared (IR) amide I' spectra are widely used for investigations of the structural properties of proteins in aqueous solution. For analysis of the experimental data, it is necessary to separate the spectral features due to the backbone conformation from those arising from other factors, in particular the interaction with solvent. We investigate the effects of solvation on amide I' spectra for a small 40-residue helix-turn-helix protein by theoretical simulations based on density functional theory (DFT). The vibrational force fields and intensity parameters for the protein amide backbone are constructed by transfer from smaller heptaamide fragments; the side chains are neglected in the DFT calculations. Solvent is modeled at two different levels: first as explicit water hydrogen bonded to the surface amide groups, treated at the same DFT level, and, second, using the electrostatic map approach combined with molecular dynamics (MD) simulation. Motional narrowing of the spectral band shapes due to averaging over the fast solvent fluctuation is introduced by use of the time-averaging approximation (TAA). The simulations are compared with the experimental amide I', including two (13)C isotopically edited spectra, corrected for the side-chain signals. Both solvent models are consistent with the asymmetric experimental band shape, which arises from the differential solvation of the amide backbone. However, the effects of (13)C isotopic labeling are best captured by the gas-phase calculations. The limitations of the solvent models and implications for the theoretical simulations of protein amide vibrational spectra are discussed.

  7. Vortex-assisted low density solvent based demulsified dispersive liquid-liquid microextraction and high-performance liquid chromatography for the determination of organophosphorus pesticides in water samples.

    Science.gov (United States)

    Seebunrueng, Ketsarin; Santaladchaiyakit, Yanawath; Srijaranai, Supalax

    2014-05-01

    A simple, rapid, effective and eco-friendly preconcentration method, vortex-assisted low density solvent based solvent demulsified dispersive liquid-liquid microextraction (VLDS-SD-DLLME), followed by high performance liquid chromatography-diode array detector (HPLC-DAD) analysis, has been developed for the first time for the determination of four organophosphorus pesticides (OPPs) (e.g., azinphos-methyl, parathion-methyl, fenitrothion and diazinon) in environmental water samples. In this preconcentration procedure, an emulsion was obtained after the mixture of extraction solvent (1-dodecanol) and dispersive solvent (acetonitrile, ACN) was injected rapidly into 10 mL of the sample solution. The vortex agitator aided the dispersion of the extraction solvent into the sample solution. After the formation of an emulsion, the demulsifier (ACN) was added, resulting in the rapid separation of the mixture into two phases without centrifugation. Under optimal conditions, the proposed method provided high extraction efficiency (90-99%), good linearity range (0.5-500 ng mL(-1)), low limits of detection (0.25-1 ng mL(-1)) and good repeatability and recoveries were obtained.

  8. A toxic organic solvent-free technology for the preparation of PEGylated paclitaxel nanosuspension based on human serum albumin for effective cancer therapy.

    Science.gov (United States)

    Yin, Tingjie; Dong, Lihui; Cui, Bei; Wang, Lei; Yin, Lifang; Zhou, Jianping; Huo, Meirong

    2015-01-01

    Clinically, paclitaxel (PTX) is one of most commonly prescribed therapies against a wide range of solid neoplasms. Despite its success, the clinical applicability of PTX (Taxol) is severely hampered by systemic toxicities induced by Cremophor EL. While attempts to bypass the need for Cremophor EL have been developed through platforms such as Abraxane, nab relies heavily on the use of organic solvents, namely, chloroform. The toxicity introduced by residual chloroform poses a potential risk to patient health. To mitigate the toxicities of toxic organic solvent-based manufacture methods, we have designed a method for the formulation of PTX nanosuspensions (PTX-PEG [polyethylene glycol]-HSA [human serum albumin]) that eliminates the dependence on toxic organic solvents. Coined the solid-dispersion technology, this technique permits the dispersion of PTX into PEG skeleton without the use of organic solvents or Cremophor EL as a solubilizer. Once the PTX-PEG dispersion is complete, the dispersion can be formulated with HSA into nanosuspensions suitable for intravenous administration. Additionally, the incorporation of PEG permits the prolonged circulation through the steric stabilization effect. Finally, HSA-mediated targeting permits active receptor-mediated endocytosis for enhanced tumor uptake and reduced side effects. By eliminating the need for both Cremophor EL and organic solvents while simultaneously increasing antitumor efficacy, this method provides a superior alternative to currently accepted methods for PTX delivery.

  9. Effects of solvents and dosing procedure on chemical toxicity in cell-based in vitro assays.

    NARCIS (Netherlands)

    Tanneberger, K.; Rico Rico, A.; Kramer, N.I.; Busser, F.J.M.; Hermens, J.L.M.; Schirmer, K.

    2010-01-01

    Due to the implementation of new legislation, such as REACh, a dramatic increase of animal use for toxicity testing is expected and the search for alternatives is timely. Cell-based in vitro assays are promising alternatives. However, the behavior of chemicals in these assays is still poorly underst

  10. Pulmonary Toxicity of Perfluorinated Silane-Based Nanofilm Spray Products: Solvent Dependency

    DEFF Research Database (Denmark)

    Nørgaard, Asger Wisti; Hansen, Jitka S.; Sørli, Jorid Birkelund

    2014-01-01

    A number of cases of pulmonary injury by use of aerosolized surface coating products have been reported worldwide. The aerosol from a commercial alcohol-based nanofilm product (NFP) for coating of nonabsorbing surfaces was found to induce severe lung damage in a recent mouse bioassay. The NFP...

  11. Solvent-vapour treatment induced performance enhancement of amplified spontaneous emission based on poly[2-methoxy-5-(2/-ethyl-hexyloxy)-l,4-phenylene vinylene

    Institute of Scientific and Technical Information of China (English)

    Zhang Bo; Hou Yan-Bing; Teng Feng; Lou Zhi-Dong; Liu Xiao-Jun; Hu Bing; Wu Wen-Bin

    2011-01-01

    In this work, performance enhancements of amplified spontaneous emission (ASE) from poly[2-methoxy-5-(2'- ethyl-hexylaxy)-1,4-phenylene vinylene] (MEH-PPV) have been achieved via solvent vapour treatment. Correlations between the morphology of the film and the optical performance of polymer-based ASE are investigated. The active layers are characterised by atomic force microscopy and optical absorption. The results show that the solvent-vapour treatment can induce the MEH-PPV self-organisation into an ordered structure with a smooth surface, leading to enhanced optical gain. Thus the solvent-vapour treatment is a good method for improving the optical properties of the MEH-PPV.

  12. Solvent-Controlled Assembly of ionic Metal-Organic Frameworks Based on Indium and Tetracarboxylate Ligand: Topology Variety and Gas Sorption Properties

    KAUST Repository

    Zheng, Bing

    2016-07-15

    Four Metal-Organic Frameworks (MOFs) based on Indium and tetracarboxylate ligand have been synthesized through regulation of the solvent conditions, the resulted compounds not only exhibited rich structural topologies (pts, soc and unique topologies), but also interesting charge reversal framework features. By regulating the solvent, different building units (indium monomer, trimer) have been generated in situ, and they are connected with the ligand to form ionic frameworks 1-4, respectively. Among the synthesized four ionic frameworks, compounds 3 and 4 could keep their crystallinity upon heating temperature up to 300oC after fully removal of solvent guest molecules, they also exhibit the charge reversal framework features (3 adopts an overall cationic framework, while 4 has an anionic framework). Both compounds 3 and 4 exhibit significant uptake capacity for CO2 and H2, besides that, compounds 3 and 4 also present excellent selective adsorption of CO2 over N2 and CH4.

  13. Reaction Mechanism for Direct Proton Transfer from Carbonic Acid to a Strong Base in Aqueous Solution II: Solvent Coordinate-Dependent Reaction Path.

    Science.gov (United States)

    Daschakraborty, Snehasis; Kiefer, Philip M; Miller, Yifat; Motro, Yair; Pines, Dina; Pines, Ehud; Hynes, James T

    2016-03-10

    The protonation of methylamine base CH3NH2 by carbonic acid H2CO3 within a hydrogen (H)-bonded complex in aqueous solution was studied via Car-Parrinello dynamics in the preceding paper (Daschakraborty, S.; Kiefer, P. M.; Miller, Y.; Motro, Y.; Pines, D.; Pines, E.; Hynes, J. T. J. Phys. Chem. B 2016, DOI: 10.1021/acs.jpcb.5b12742). Here some important further details of the reaction path are presented, with specific emphasis on the water solvent's role. The overall reaction is barrierless and very rapid, on an ∼100 fs time scale, with the proton transfer (PT) event itself being very sudden (water solvent changes little until the actual PT occurrence; this results from the very strong driving force for the reaction, as indicated by the very favorable acid-protonated base ΔpKa difference. Further solvent rearrangement follows immediately the sudden PT's production of an incipient contact ion pair, stabilizing it by establishment of equilibrium solvation. The solvent water's short time scale ∼120 fs response to the incipient ion pair formation is primarily associated with librational modes and H-bond compression of water molecules around the carboxylate anion and the protonated base. This is consistent with this stabilization involving significant increase in H-bonding of hydration shell waters to the negatively charged carboxylate group oxygens' (especially the former H2CO3 donor oxygen) and the nitrogen of the positively charged protonated base's NH3(+).

  14. Solvent effect on H-bond cooperativity factors in ternary complexes of methanol, octan-1-ol, 2,2,2-trifluoroethanol with some bases.

    Science.gov (United States)

    Solomonov, Boris N; Varfolomeev, Mikhail A; Abaidullina, Dilyara I

    2008-03-01

    Cooperative hydrogen bonds in ternary complexes (ROH)(2)...B (ROH-alcohols; B-bases) formed in pure bases (B) and solutions in n-hexane, carbon tetrachloride, benzene and 1,2-dichloroethane were studied by FTIR spectroscopy. Based on the observations, the authors were able to propose an original method of evaluating solvent effects on cooperativity factors in the complexes. Frequencies of cooperative hydrogen bonds OH...B (nu(b)) were determined for ternary complexes of pyridine with aliphatic alcohols (methanol, octan-1-ol) and for 2,2,2-trifluoroethanol with three different bases (acetonitrile, diethyl ether, tetrahydrofuran). The solvent shifts of nu(b) were found to correlate with an empirical thermochemical parameter of the solvent, S(VW). The cooperativity factors were determined for the complexes (ROH)(2)...B in all studied media. It has been found that the cooperativity factors are almost independent of the solvent. In addition, a method was proposed of estimating the frequencies and cooperativity factors for ternary complexes (ROH)(2)...B in the gas phase. It has been found that in gas phase the cooperativity factors are practically the same as in condensed media.

  15. Multiple testing issues in discriminating compound-related peaks and chromatograms from high frequency noise, spikes and solvent-based nois in LC-MS data sets

    NARCIS (Netherlands)

    Nyangoma, S.O.; Van Kampen, A.A.; Reijmers, T.H.; Govorukhina, N.I; van der Zee, A.G.; Billingham, I.J; Bischoff, Rainer; Jansen, R.C.

    2007-01-01

    Multiple testing issues in discriminating compound-related peaks and chromatograms from high frequency noise, spikes and solvent-based noise in LC-MS data sets.Nyangoma SO, van Kampen AA, Reijmers TH, Govorukhina NI, van der Zee AG, Billingham LJ, Bischoff R, Jansen RC. University of Birmingham. Liq

  16. Ionic Liquid Solvent Based on Cyclic Guanidinium Cation for Nucleophilic Displacement Reactions

    Institute of Scientific and Technical Information of China (English)

    LIN Ying-jie; QIU Zhi-ming; DUAN Hai-feng; LI Sheng-hai; ZHANG Suo-bo

    2004-01-01

    The nucleophilic displacement reaction of n-bromooctane and potassium iodide in ionic liquid based on cyclic guanidinium cation(2) was investigated. The kinetic reasult shows that the rate of the reaction is enhanced in ionic liquid (2). The same reaction in [bmim][PF6](1)(where bmim=1-butyl-3-methylimidazolium) was also studied. It was found that as a reaction medium ionic liquid (2) is better than (1) for nucelophilic displacement reactions.

  17. Evaluation of Disposal Concepts for Used Solvents at DoD Bases

    Science.gov (United States)

    1983-02-01

    Occupational Safety and Health Act (OSHA) and Department of Transportation (DOT) regulations also impact the selection of viable 2-4 Table 3. Comercial ...good handling and segregation practices for the used material; and the availability of a comercial organization that can perform the reclamation service...California El Centro Naval Air Facility CaLifornia El Toro Marine Corps Air Station California Fort Ord California George Air Force Base California Hunters

  18. The Effect of Temperature on Kinetics and Diffusion Coefficients of Metallocene Derivatives in Polyol-Based Deep Eutectic Solvents.

    Directory of Open Access Journals (Sweden)

    Laleh Bahadori

    Full Text Available The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs containing ammonium-based salts and hydrogen bond donvnors (polyol type are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden's rule. The oxidation of ferrocene (Fc/Fc+ and reduction of cobaltocenium (Cc+/Cc at different temperatures are studied by cyclic voltammetry and potential-step chronoamperometry in DESs. For most DESs, chronoamperometric transients are demonstrated to fit an Arrhenius-type relation to give activation energies for the diffusion of redox couples at different temperatures. The temperature dependence of the measured conductivities of DES1 and DES2 are better correlated with the Vogel-Tamman-Fulcher equation. The kinetics of the Fc/Fc+ and Cc+/Cc electrochemical systems have been investigated over a temperature range from 298 to 338 K. The heterogeneous electron transfer rate constant is then calculated at different temperatures by means of a logarithmic analysis. The glycerol-based DES (DES5 appears suitable for further testing in electrochemical energy storage devices.

  19. Preparation and pharmaceutical evaluation of acetaminophen nano-fiber tablets: Application of a solvent-based electrospinning method for tableting.

    Science.gov (United States)

    Hamori, Mami; Nagano, Kana; Kakimoto, Sayaka; Naruhashi, Kazumasa; Kiriyama, Akiko; Nishimura, Asako; Shibata, Nobuhito

    2016-03-01

    In this study, we developed nano-fiber-based tablets with acetaminophen (AAP; LogPow=0.51) for controlled-release delivery systems and evaluated in vitro drug dissolution and in vivo pharmacokinetics in rats. Nano-fibers made from methacrylic acid copolymer S (MAC; EUDRAGIT S100) and containing AAP were prepared using a solvent-based electrospinning (ES) method. In vitro dissolution rate profiles of AAP showed tableting pressure-dependent decreases and pH-dependent increases. The results of tablet tracking by X-ray irradiation showed tablets based on MAC nano-fibers did not disintegrate in the upper intestinal lumen and had the properties of a long-term-acting tablet. In addition, the in vitro release profiles of AAP from nano-fiber tablets prepared by dissolving MAC with AAP (NFT), nano-fiber tablets prepared by adsorbing AAP to drug-free MAC nano-fibers (NFTadso), and tablets prepared by adsorbing half the amount of AAP to MAC nano-fibers containing the remaining amount of AAP (NFThalf) showed independent controlled-release aspects of AAP compared with physical mixture tablets (PMT). In vivo pharmacokinetic studies in rats after intraduodenal administration of 14 mg/rat AAP in NFT, NFTadso, and NFThalf demonstrated that all these tablets based on MAC nano-fibers showed sustained-release profiles compared with PMT, and showed ultra-sustained release properties for AAP. These new tablets based on MAC nano-fibers did not disintegrate in the intestine in the lower pH region, and the tablets could regulate the release of AAP in a pH-dependent manner. The ES method is a useful technique to prepare nano-fibers and showed promising results as an oral delivery system for sustained-release regulation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  20. L-proline-based deep eutectic solvents (DESs) for deep catalytic oxidative desulfurization (ODS) of diesel.

    Science.gov (United States)

    Hao, Lingwan; Wang, Meiri; Shan, Wenjuan; Deng, Changliang; Ren, Wanzhong; Shi, Zhouzhou; Lü, Hongying

    2017-10-05

    A series of L-proline-based DESs was prepared through an atom economic reaction between L-proline (L-Pro) and four different kinds of organic acids. The DESs were characterized by Fourier transform infrared spectroscopy (FT-IR), H nuclear magnetic resonance ((1)HNMR), cyclic voltammogram (CV) and the Hammett method. The synthesized DESs were used for the oxidative desulfurization and the L-Pro/p-toluenesultonic acid (L-Pro/p-TsOH) system shows the highest catalytic activity that the removal of dibenzothiophene (DBT) reached 99% at 60°C in 2h, which may involve the dual activation of the L-Pro/p-TsOH. The acidity of four different L-proline-based DESs was measured and the results show that it could not simply conclude that the correlation between the acidity of DESs and desulfurization capability was positive or negative. The electrochemical measurements evidences and recycling experiment indicate a good stability performance of L-Pro/p-TsOH in desulfurization. This work will provide a novel and potential method for the deep oxidation desulfurization. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Electroplated Fe-Co-Ni films prepared from deep-eutectic-solvent-based plating baths

    Directory of Open Access Journals (Sweden)

    Takeshi Yanai

    2016-05-01

    Full Text Available We fabricated soft magnetic films from DES-based plating baths, and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2 ⋅ 4H2O, NiCl2 ⋅ 6H2O and CoCl2 ⋅ 6H2O. The composition of the electroplated film depended on the amount of the reagent in the plating bath, and we consequently obtained the films with various composition. The current efficiency of the plating process shows high values (> 88 % in the wide composition range. The soft magnetic films with low coercivity were obtained at the Fe compositions of ≈ 30 at.% and > 80 at.%, and we found that low coercivity could be realized by the control of the film composition. We also found that the Fe-rich films prepared from DES-based plating bath have some advantages as a soft magnetic phase for a nanocomposite magnet due to their high saturation magnetization and very fine crystal structure.

  2. Stabilization of Li Metal Anode in DMSO-Based Electrolytes via Optimization of Salt-Solvent Coordination for Li-O 2 Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bin [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Xu, Wu [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Yan, Pengfei [Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland WA 99354 USA; Kim, Sun Tai [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798 South Korea; Engelhard, Mark H. [Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland WA 99354 USA; Sun, Xiuliang [Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Mei, Donghai [Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA; Cho, Jaephil [Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798 South Korea; Wang, Chong-Min [Environmental and Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland WA 99354 USA; Zhang, Ji-Guang [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99354 USA

    2017-03-08

    The conventional DMSO-based electrolyte (1 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in DMSO) is unstable against the Li metal anode and therefore cannot be used directly in practical Li-O2 batteries. Here, we demonstrate that a highly concentrated electrolyte based on LiTFSI in DMSO (with a molar ratio of 1:3) can greatly improve the stability of the Li metal anode against DMSO and significantly improve the cycling stability of Li-O2 batteries. This highly concentrated electrolyte contains no free DMSO solvent molecules, but only complexes of (TFSI–)a-Li+-(DMSO)b (where a + b = 4), and thus enhances their stability with Li metal anodes. In addition, such salt-solvent complexes have higher Gibbs activation energy barriers than the free DMSO solvent molecules, indicating improved stability of the electrolyte against the attack of superoxide radical anions. Therefore, the stability of this highly concentrated electrolyte at both Li metal anodes and carbon-based air electrodes has been greatly enhanced, resulting in improved cyclic stability of Li-O2 batteries. The fundamental stability of the electrolyte with free-solvent against the chemical and electrochemical reactions can also be used to enhance the stability of other electrochemical systems.

  3. A Selenium-Based Ionic Liquid as a Recyclable Solvent for the Catalyst-Free Synthesis of 3-Selenylindoles

    Directory of Open Access Journals (Sweden)

    Eder J. Lenardão

    2013-04-01

    Full Text Available The ionic liquid 1-butyl-3-methylimidazolium methylselenite, [bmim][SeO2(OCH3], was successfully used as solvent in the catalyst-free preparation of 3-arylselenylindoles by the reaction of indole with ArSeCl at room temperature. The products were obtained selectively in good yields without the need of any additive and the solvent was easily reused for several cycles with good results.

  4. Nuevas Estaciones de Pintura Rupestre Esquemática en Extremadura

    Directory of Open Access Journals (Sweden)

    María Cleofé RIVERO DE LA HIGUERA

    2009-10-01

    Full Text Available Nos proponemos en este breve artículo dar a conocer una serie de yacimientos, inéditos unos, conocidos otros, que vienen a llenar de alguna manera el vacío de estudios sistemáticos existente en el campo de la pintura esquemática en tierras extremeñas a partir del gran corpus elaborado por el abate H. Breuil en los años 33 al 35. No es que desde esa fecha no se haya descubierto nada sobre el tema, si se ha descubierto, lo que sucede es que ninguno de los hallazgos se han publicado con los calcos y fotografías que era de esperar y la noticia de los mismos no ha rebasado nunca, o muy pocas veces el ámbito local o regional, en cualquier caso no se les ha prestado la atención debida. Por eso queremos hoy traer una muestra de estos descubrimientos, cumpliendo así dos objetivos: en primer lugar dar a conocer con calcos y fotografías recientes las nuevas pinturas y en segundo lugar rendir un sincero homenaje a todas aquellas personas que con entusiasmo, sacrificio y desinterés se han ocupado en buscar y reunir datos tan valiosos para la ciencia prehistórica, labor siempre dura y mal pagada, pero muy útil para quien posteriormente quiera hacer un trabajo de conjunto. Por ello con motivo de la tesis que tenemos en curso de preparación, no tenemos más remedio que reconocer, respetar y agradecer el trabajo realizado por estas personas, unas al brindarme su amistad y acompañarme como D. Jesús Cánovas y D. Graciano Baus, otras al indicarme los lugares de palabra y por escrito, otras finalmente al no haber ocultado la noticia y autorizarme a darla. A ellos y a quienes han colaborado conmigo en los trabajos de calco, fotografía y estudio, amigos y compañeros del Departamento de Prehistoria y Arqueología de Salamanca, especialmente al Dr. Jordá, jefe del mismo y al Dr. Fortea, les damos las gracias porque han hecho posible lo que ahora esbozamos y que desarrollaremos con más amplitud en nuestra tesis doctoral.

  5. Aplicación de la resistencia de ruido al estudio de pinturas ricas en zinc

    Directory of Open Access Journals (Sweden)

    Espada Recarey, Luis

    2001-02-01

    Full Text Available Electrochemical Noise has been one of the more useful analysis methods to the study the corrosion processes due to the fact that it is simple and cheap. The objective of this work is to check the efficiency of this technique when it is applied to the study of Rich Zinc Paints and specifically the Noise Resistance parameter which is very efficiency to study metal-electrolyte systems. Then this technique was applied to Rich Zinc Paints systems of which we have already information by means of electrochemical impedance spectroscopy. The outcomes of this paper show the efficiency of applying Noise Resistance technique to explain the behavior of this kind of systems. REVISION 34 Obtención de la tenacidad de fractura dinámica de iniciación de materiales elásticos y lineales Determination of dynamic fracture initiation toughness of linear elastic materials

    La medida e interpretación del ruido electroquímico, REQ se está consolidando como uno de los métodos de análisis más utilizados para la interpretación del fenómeno de la corrosión, por su sencillez y bajo coste frente a otros tipos de metodologías del estudio. El objeto de este trabajo es comprobar la eficacia de la técnica de ruido electroquímico aplicada al estudio de las pinturas ricas en zinc, concretamente, en lo relativo al parámetro "resistencia de ruido" que tan eficaz se ha mostrado en el estudio de sistemas metal desnudoelectrolito. Para ello, se aplicó esta técnica de análisis a muestras de pinturas ricas en zinc, de las que ya se poseía información sobre su comportamiento, a través de la aplicación a las mismas muestras de la impedancia electroquímica, EIE. Los resultados de este articulo muestran la eficacia de la aplicación de la resistencia de ruido, a la hora de explicar el comportamiento de este tipo de sistemas.

  6. Reactions and Separations in Green Solvents

    NARCIS (Netherlands)

    Van Spronsen, J.

    2010-01-01

    Most chemical processes involve solvents in the reaction and the separation step. These solvents give rise to a heavy environmental and economical burden. Moreover, these solvents are based on non-sustainable resources like petroleum. The aim of this thesis has been to develop a number of alternativ

  7. Reactions and Separations in Green Solvents

    NARCIS (Netherlands)

    Van Spronsen, J.

    2010-01-01

    Most chemical processes involve solvents in the reaction and the separation step. These solvents give rise to a heavy environmental and economical burden. Moreover, these solvents are based on non-sustainable resources like petroleum. The aim of this thesis has been to develop a number of

  8. Solvent control: dinuclear versus tetranuclear complexes of a bis-tetradentate pyrimidine-based ligand.

    Science.gov (United States)

    Gobeze, Worku A; Milway, Victoria A; Moubaraki, Boujemaa; Murray, Keith S; Brooker, Sally

    2012-08-28

    A new bis-tetradentate acyclic amine ligand L(Et) has been synthesized from 4,6-bis(aminomethyl)-2-phenylpyrimidine and 2-vinylpyridine. Dinuclear complexes, Mn(II)(2)L(Et)(MeCN)(H(2)O)(3)(ClO(4))(4) (1), Fe(II)(2)L(Et)(H(2)O)(4)(BF(4))(4) (2), Co(II)(2)L(Et)(H(2)O)(3)(MeCN)(2)(BF(4))(4) (3), Ni(II)(2)L(Et)(H(2)O)(4)(BF(4))(4) (4), Ni(II)(2)L(Et)(H(2)O)(4)(ClO(4))(4)·8H(2)O (4'), Cu(II)(2)L(Et)(BF(4))(4)·MeCN (5), Zn(II)(2)L(Et)(BF(4))(2)(BF(4))(2)·½MeCN (6), were obtained from 1 : 2 reactions of L(Et) and the appropriate metal salts in MeCN, whereas in MeOH tetranuclear complexes, Mn(II)(4)(L(Et))(2)(OH)(4)(ClO(4))(4) (7), Fe(II)(4)(L(Et))(2)(F)(4)(BF(4))(4)·5/2H(2)O (8), Co(II)(4)(L(Et))(2)(F)(4)(BF(4))(4)·3H(2)O (9), Ni(II)(4)(L(Et))(2)(F)(4)(BF(4))(4)·4H(2)O (10), Cu(II)(4)(L(Et))(2)(F)(4)(BF(4))(4)·3H(2)O (11) and Zn(II)(4)(L(Et))(2)(F)(4)(BF(4))(4) (12), result. Six complexes have been structurally characterized: in all cases each L(Et) is bis-tetradentate and provides a pyrimidine bridge between two metal centres. As originally anticipated, complexes 1, 4' and 6 are dinuclear, while 9, 10 and 12 are revealed to be tetranuclear, with two M(2)(L(Et))(4+) moieties bridged by two pairs of fluoride anions. Weak to moderate antiferromagnetic coupling between the metal centres is a feature of complexes 2, 3, 4, 8, 9 and 10. The dinuclear complexes 1-6 undergo multiple, mostly irreversible, redox processes. However, the pyrimidine-based dicopper(II) complex 5 undergoes a two electron quasi-reversible reduction, Cu(II)(2)→ Cu(I)(2), and this occurs at a more positive potential [E(m) = +0.11 V (E(pc) = -0.03 and E(pa) = +0.26 V) vs. 0.01 M AgNO(3)/Ag] than for either of the dicopper(II) complexes of the analogous pyrazine-based ligands.

  9. Reversible structural transformations in a Co(II)-based 2D dynamic metal-organic framework showing selective solvent uptake

    Indian Academy of Sciences (India)

    Sanjog S Nagarkar; Sujit K Ghosh

    2015-04-01

    A Co(II)-based two-dimensional (2D) metal-organic framework (MOF) [Co(pca)(bdc)0.5(H2O)2] (1) {pca = pyrazine carboxylic acid, and bdc = 1,4-benzene dicarboxylic acid} was synthesized solvothermally. The compound loses the coordinated lattice water molecules on heating which is accompanied by solidstate structural transformation to yield dehydrated phase [Co(pca)(bdc)0.5] (1′). The hydrated structure can be regained by exposing 1′ to water vapour (1′′). These reversible solid-state structural transformations are accompanied by a visible colour change in the material. The dehydrated compound also shows highly selective water uptake over other solvents like MeOH, EtOH, THF. This selective water uptake can be ascribed to the high affinity of polar water molecule towards the open metal site created on heating. The present report provides important insights into the reversible structural transformations observed due to variable coordination number of the central metal ion and transformability of the framework. The selective water uptake over alcohols along with visible colour change demonstrates the potential of the present compound in bio-alcohol purification.

  10. Optical sensor based on hybrid FBG/titanium dioxide coated LPFG for monitoring organic solvents in edible oils.

    Science.gov (United States)

    Coelho, Luís; Viegas, Diana; Santos, José Luís; de Almeida, José Manuel Marques Martins

    2016-01-01

    A hybrid optical sensing scheme based on a fiber Bragg grating (FBG) combined with a titanium dioxide coated long period fiber grating (LPFG) for monitoring organic solvents in high refractive index edible oils is reported. In order to investigate and optimize the sensor performance, two different FBG/LPFG interrogation systems were investigated. The readout of the sensor was implemented using either the wavelength shift of the LPFG resonance dip or the variation in the optical power level of the reflected/transmitted light at the FBG wavelength peak, which in turn depends on the wavelength position of the LPFG resonance. Hexane concentrations up to 20%V/V, corresponding to the refractive index range from 1.451 to 1.467, were considered. For the transmission mode of operation, sensitivities of 1.41 nm/%V/V and 0.11 dB/%V/V, with resolutions of 0.58%V/V and 0.29%V/V, were achieved when using the LPFG wavelength shift and the FBG transmitted optical power, respectively. For the FBG reflection mode of operation, a sensitivity of 0.07 dB/%V/V and a resolution better than 0.16%V/V were estimated.

  11. Development of an Analytical Method Based on Temperature Controlled Solid-Liquid Extraction Using an Ionic Liquid as Solid Solvent

    Directory of Open Access Journals (Sweden)

    Zhongwei Pan

    2015-12-01

    Full Text Available At the present paper, an analytical method based on temperature controlled solid-liquid extraction (TC-SLE utilizing a synthesized ionic liquid, (N-butylpyridinium hexafluorophosphate, [BPy]PF6, as solid solvent and phenanthroline (PT as an extractant was developed to determine micro levels of Fe2+ in tea by PT spectrophotometry. TC-SLE was carried out in two continuous steps: Fe2+ can be completely extracted by PT-[BPy]PF6 or back-extracted at 80 °C and the two phases were separated automatically by cooling to room temperature. Fe2+, after back-extraction, needs 2 mol/L HNO3 as stripping agent and the whole process was determined by PT spectrophotometry at room temperature. The extracted species was neutral Fe(PTmCl2 (m = 1 according to slope analysis in the Fe2+-[BPy]PF6-PT TC-SLE system. The calibration curve was Y = 0.20856X − 0.000775 (correlation coefficient = 0.99991. The linear calibration range was 0.10–4.50 μg/mL and the limit of detection for Fe2+ is 7.0 × 10−2 μg/mL. In this method, the contents of Fe2+ in Tieguanyin tea were determined with RSDs (n = 5 3.05% and recoveries in range of 90.6%–108.6%.

  12. Design and synthesis of two luminescent Zn(II)-based coordination polymers with different structures regulated by different solvent system

    Science.gov (United States)

    Wu, Wei-Ping; Wen, Gui-Lin; Liao, Yi; Wang, Jun; Lu, Lu; Wu, Yu; Xie, Bin

    2016-08-01

    Two new coordination polymers (CPs) [Zn(HL)(H2O)]n (1) and [Zn3(L)2(H2O)2]n·(H2O)n (2), based on a multifunctional ligand combined carboxylate groups and a nitrogen donor group 5-(6-carboxypyridin-2-yl)isophthalic acid (H3L), have been synthesized under different solvent media and fully characterized by powder X-ray diffraction (PXRD), infrared (IR) spectra, elemental analyses (EA) and thermogravimetric analyses (TGA). Single-crystal X-ray diffraction analysis reveals that 1 shows 1D dimeric chain structure, while 2 gives a 3D dense packing framework. Topology analysis illustrates that 2 can be simplified as a 3-nodal net (4, 5, 6-connected net) with the point symbol of {44·62}{46·64}2{48·66·8}. In addition, solid state luminescent properties of two complexes have also been studied in detail, which may act as the potential optical materials.

  13. Experimental study of solvent-based emulsion injection to enhance heavy oil recovery in Alaska North Slope area

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, F.; Mamora, D. [Texas A and M Univ., College Station, TX (United States)

    2010-07-01

    This study examined the feasibility of using a chemical enhanced oil recovery method to overcome some of the technical challenges associated with thermal recovery in the Alaska North Slope (ANS). This paper described the second stage research of an experimental study on nano-particle and surfactant-stabilized solvent-based emulsions for the ANS area. Four successful core flood experiments were performed using heavy ANS oil. The runs included water flooding followed by emulsion flooding; and pure emulsion injection core flooding. The injection rate and core flooding temperature remained constant and only 1 PV micro-emulsion was injected after breakthrough under water flooding or emulsion flooding. Oil recovery increased by 26.4 percent from 56.2 percent original oil in place (OOIP) with waterflooding to 82.6 percent OOIP with injection of emulsion following water flooding. Oil recovery was slightly higher with pure emulsion flooding, at 85.8 percent OOIP. The study showed that low permeability generally resulted in a higher shear rate, which is favourable for in-situ emulsification and higher displacement efficiency. 11 refs., 4 tabs., 20 figs.

  14. Non-flammable electrolytes based on trimethyl phosphate solvent for lithium-ion batteries

    Institute of Scientific and Technical Information of China (English)

    HU Chuan-yue; LI Xin-hai

    2005-01-01

    The properties of trimethyl phosphate(TMP)-based nonflammable electrolytes with LiPF6 as solute were investigated using graphite anode and LiCoO2 cathode. The effect of TMP on non-flammability of electrolytes was also evaluated. It is found that the TMP reduction decomposition on graphite electrode at the potential of 1.3V (vs Li/Li+) is suppressed with ethylene carbonate(EC), dimethyl carbonate(DMC) and ethylmethyl carbonate(EMC) cosolvents and vinylene carbonate(VC) additives. The results show that the non-flammable electrolyte of 1mol/L LiPF6 61%(EC1.5-DMC1.0-EMC1.0)-39% TMP has good electrochemical properties. The discharge capacities of half-cells after 20 cycles are 254.8mA·h/g for Li/graphite and 144.1mA·h/g for Li/LiCoO2. The graphite/LiCoO2 prismatic lithium-ion cell delivers a discharge capacity of 131mA·h/g at first cycle. With an addition of 4%VC to this non-flammable electrolyte, a discharge capacity of 134mA·h/g at first cycle and a capacity ratio of 84.3% after 50 cycles are obtained for prismatic lithium-ion batteries. Furthermore, a nail penetration test demonstrates that the safety of prismatic lithium-ion batteries is dramatically improved by using TMP-containing non-flammable electrolytes.

  15. Differentiation of Chemical Components in a Binary Solvent Vapor Mixture Using Carbon/Polymer Composite-Based Chemiresistors

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Sanjay V.; Jenkins, Mark W.; Hughes, Robert C.; Yelton, W. Graham; Ricco, Antonio J.

    1999-07-19

    We demonstrate a ''universal solvent sensor'' constructed from a small array of carbon/polymer composite chemiresistors that respond to solvents spanning a wide range of Hildebrand volubility parameters. Conductive carbon particles provide electrical continuity in these composite films. When the polymer matrix absorbs solvent vapors, the composite film swells, the average separation between carbon particles increases, and an increase in film resistance results, as some of the conduction pathways are broken. The adverse effects of contact resistance at high solvent concentrations are reported. Solvent vapors including isooctane, ethanol, dlisopropyhnethylphosphonate (DIMP), and water are correctly identified (''classified'') using three chemiresistors, their composite coatings chosen to span the full range of volubility parameters. With the same three sensors, binary mixtures of solvent vapor and water vapor are correctly classified, following classification, two sensors suffice to determine the concentrations of both vapor components. Polyethylene vinylacetate and polyvinyl alcohol (PVA) are two such polymers that are used to classify binary mixtures of DIMP with water vapor; the PVA/carbon-particle-composite films are sensitive to less than 0.25{degree}A relative humidity. The Sandia-developed VERI (Visual-Empirical Region of Influence) technique is used as a method of pattern recognition to classify the solvents and mixtures and to distinguish them from water vapor. In many cases, the response of a given composite sensing film to a binary mixture deviates significantly from the sum of the responses to the isolated vapor components at the same concentrations. While these nonlinearities pose significant difficulty for (primarily) linear methods such as principal components analysis, VERI handles both linear and nonlinear data with equal ease. In the present study the maximum speciation accuracy is achieved by an array

  16. Temas homéricos en la pintura española del siglo XIX

    Directory of Open Access Journals (Sweden)

    Arias Anglés, Enrique

    2002-09-01

    Full Text Available A series of themes from nineteenth-century Spanish painting referring to Homer's The Iliad and The Odyssey are brought together and analyzed. Pictorial compositions are confronted with the specific texts that they supposedly illustrate, if identifiable. When they are not, then an attempt is made to relate texts to images, if the titles of the works allow.

    En este estudio se recogen y analizan una serie de temas de la pintura española del siglo XIX referentes a los dos poemas homéricos de la Ilíada y la Odisea, fijando además concretamente los textos literarios de donde fueron extraídos y cotejando con ellos las composiciones pictóricas que pretendieron ilustrarlos, en caso de sernos conocidas, y cuando no nos lo son, tratando de poner las imágenes a través de dichos textos si nos lo permiten los títulos de las obras.

  17. O Corpo Feminino e Seus Enigmas: A Esfinge na Pintura de Franz Stuck

    Directory of Open Access Journals (Sweden)

    Enéias Farias Tavares

    2015-10-01

    Full Text Available http://dx.doi.org/10.5007/2175-8026.2015v68n3p27 Neste ensaio, discutirei o problema da representação do feminino nas artes do final do século 19. Para tanto, partirei da leitura de Bram Dijkstra em Idols of Perversity (1986. Na sequência, refletirei sobre o modo como o imaginário do corpo feminino está associado ao encontro de Édipo e a Esfinge, monstro feminino que oferta enigmas e apresenta uma composição corporal tripartida. O estereotipo desse feminino demonizado, todavia, começa a ser repensado no mesmo século, tornando-se a própria esfinge e sua constituição um enigma a ser desvendado. Minha análise para a leitura dessa alteração de sensibilidade nas artes do 19 se centrará em três diferentes pinturas do artista alemão Franz Stuck para o tema da Esfinge. Para tanto, usarei, além de Dijkstra, as reflexões de Connell, Edmunds, Paglia e Goex.

  18. OSWALD DE ANDRADE E TARSILA DO AMARAL:POESIA E PINTURA MODERNISTAS

    Directory of Open Access Journals (Sweden)

    Prof. Dr. Sérgio Vicente Motta

    2013-02-01

    Full Text Available O objetivo deste texto é estabelecer relações entre a literatura e a pintura, por meio da comparação entre um poema de Oswald de Andrade (“Longo da linha” e uma tela de Tarsila do Amaral (“Palmeiras”, ambos pertencentes à fase “Pau-Brasil” do movimento modernista brasileiro. Para destacar também o passo dado pelos dois artistas, no Modernismo, em relação ao academicismo anterior, será utilizada a teoria semiótica de C. S. Peirce como embasamento analítico para demonstrar, na tela de Tarsila, um percurso rumo à planaridade e à estilização para produzir efeitos de primeiridade, mais próximos da forma e da aventura dos sentidos do que da simbolização, enquanto em Oswald este mesmo percurso conduz à presença da visualização como fator de composição.

  19. Una nueva pintura de Peter Thijs identificada en la Colegiata de Santa Gertrudis de Nivelles (Valonia

    Directory of Open Access Journals (Sweden)

    Sanzsalazar, Jahel

    2009-03-01

    Full Text Available Considered today as anonymous and attributed in a 1925 document to Gaspar de Crayer, the painting at Nivelles reveals the stylistic features of Peter Thijs: composition, models, handling and color are comparable to other works by his hand. As usual, Thijs has recourse to the paintings of Van Dyck, while eluding the more habitual depictions of this episode from the life of Saint Dominic, fervor for whom grew in Antwerp during the first half of the 17th century, due promotion by Dominicans and Jesuits.

    Tenida en la actualidad como anónima, y atribuida a Gaspar de Crayer en documentos de principios del siglo XX, la pintura de la Colegiata de Nivelles es comparable en composición, modelos, factura y sentido del color con otras obras de Peter Thijs. El pintor recurre, como fue su costumbre, a Van Dyck, a la vez que se distancia de las representaciones más frecuentes de este episodio de la vida de Santo Domingo, cuyo fervor creció en Amberes por impulso de dominicos y jesuitas en la primera mitad del siglo XVII.

  20. Solution phase synthesis of aluminum-doped silicon nanoparticles via room-temperature, solvent based chemical reduction of silicon tetrachloride

    Science.gov (United States)

    Mowbray, Andrew James

    We present a method of wet chemical synthesis of aluminum-doped silicon nanoparticles (Al-doped Si NPs), encompassing the solution-phase co-reduction of silicon tetrachloride (SiCl4) and aluminum chloride (AlCl 3) by sodium naphthalide (Na[NAP]) in 1,2-dimethoxyethane (DME). The development of this method was inspired by the work of Baldwin et al. at the University of California, Davis, and was adapted for our research through some noteworthy procedural modifications. Centrifugation and solvent-based extraction techniques were used throughout various stages of the synthesis procedure to achieve efficient and well-controlled separation of the Si NP product from the reaction media. In addition, the development of a non-aqueous, formamide-based wash solution facilitated simultaneous removal of the NaCl byproduct and Si NP surface passivation via attachment of 1-octanol to the particle surface. As synthesized, the Si NPs were typically 3-15 nm in diameter, and were mainly amorphous, as opposed to crystalline, as concluded from SAED and XRD diffraction pattern analysis. Aluminum doping at various concentrations was accomplished via the inclusion of aluminum chloride (AlCl3); which was in small quantities dissolved into the synthesis solution to be reduced alongside the SiCl4 precursor. The introduction of Al into the chemically-reduced Si NP precipitate was not found to adversely affect the formation of the Si NPs, but was found to influence aspects such as particle stability and dispersibility throughout various stages of the procedure. Analytical techniques including transmission electron microscopy (TEM), FTIR spectroscopy, and ICP-optical emission spectroscopy were used to comprehensively characterize the product NPs. These methods confirm both the presence of Al and surface-bound 1-octanol in the newly formed Si NPs.

  1. THz frequency spectrum of protein-solvent interaction energy using a recurrence plot-based Wiener-Khinchin method.

    Science.gov (United States)

    Karain, Wael

    2016-10-01

    The dynamics of a protein and the water surrounding it are coupled via nonbonded energy interactions. This coupling can exhibit a complex, nonlinear, and nonstationary nature. The THz frequency spectrum for this interaction energy characterizes both the vibration spectrum of the water hydrogen bond network, and the frequency range of large amplitude modes of proteins. We use a Recurrence Plot based Wiener-Khinchin method RPWK to calculate this spectrum, and the results are compared to those determined using the classical auto-covariance-based Wiener-Khinchin method WK. The frequency spectra for the total nonbonded interaction energy extracted from molecular dynamics simulations between the β-Lactamase Inhibitory Protein BLIP, and water molecules within a 10 Å distance from the protein surface, are calculated at 150, 200, 250, and 310 K, respectively. Similar calculations are also performed for the nonbonded interaction energy between the residues 49ASP, 53TYR, and 142PHE in BLIP, with water molecules within 10 Å from each residue respectively at 150, 200, 250, and 310 K. A comparison of the results shows that RPWK performs better than WK, and is able to detect some frequency data points that WK fails to detect. This points to the importance of using methods capable of taking the complex nature of the protein-solvent energy landscape into consideration, and not to rely on standard linear methods. In general, RPWK can be a valuable addition to the analysis tools for protein molecular dynamics simulations. Proteins 2016; 84:1549-1557. © 2016 Wiley Periodicals, Inc.

  2. Solvent-resistant organic transistors and thermally stable organic photovoltaics based on cross-linkable conjugated polymers

    KAUST Repository

    Kim, Hyeongjun

    2012-01-10

    Conjugated polymers, in general, are unstable when exposed to air, solvent, or thermal treatment, and these challenges limit their practical applications. Therefore, it is of great importance to develop new materials or methodologies that can enable organic electronics with air stability, solvent resistance, and thermal stability. Herein, we have developed a simple but powerful approach to achieve solvent-resistant and thermally stable organic electronic devices with a remarkably improved air stability, by introducing an azide cross-linkable group into a conjugated polymer. To demonstrate this concept, we have synthesized polythiophene with azide groups attached to end of the alkyl chain (P3HT-azide). Photo-cross-linking of P3HT-azide copolymers dramatically improves the solvent resistance of the active layer without disrupting the molecular ordering and charge transport. This is the first demonstration of solvent-resistant organic transistors. Furthermore, the bulk-heterojunction organic photovoltaics (BHJ OPVs) containing P3HT-azide copolymers show an average efficiency higher than 3.3% after 40 h annealing at an elevated temperature of 150 °C, which represents one of the most thermally stable OPV devices reported to date. This enhanced stability is due to an in situ compatibilizer that forms at the P3HT/PCBM interface and suppresses macrophase separation. Our approach paves a way toward organic electronics with robust and stable operations. © 2011 American Chemical Society.

  3. Aproximación técnica a las tablitas del Instituto Gómez-Moreno. Pintura sobre tabla decimonónica

    OpenAIRE

    HEINZ FERNÁNDEZ, KATHARINA; Pérez Marín, Eva

    2011-01-01

    La tablita, o tableautin, pintura de pequeño formato y motivos costumbristas, alcanzó un éxito sin precedentes a partir de la segunda mitad del siglo XIX hasta principios del XX, codeándose en las Exposiciones Nacionales de Bellas Artes con los grandes formatos de pintura. En el presente artículo se realiza una aproximación a la técnica de ejecución de este tipo de pintura sobre tabla, y a su vinculación con la sociedad decimonónica española. La metodología de trabajo ha consistido en la docu...

  4. Nanostructured alkyl carboxylic acid-based restricted access solvents: Application to the combined microextraction and cleanup of polycyclic aromatic hydrocarbons in mosses.

    Science.gov (United States)

    Caballero-Casero, N; Çabuk, H; Martínez-Sagarra, G; Devesa, J A; Rubio, S

    2015-08-26

    Alkyl carboxylic acid-based nanostructured solvents, synthesized in mixtures of tetrahydrofuran (THF) and water through self-assembly and coacervation, were proved to behave as restricted access liquids. Both physical and chemical mechanisms were found responsible for exclusion of macromolecules such as proteins and polysaccharides. The potential of these solvents for extracting small molecules from complex solid samples, without interference from large biomolecules, was here evaluated. For this purpose, they were applied to the extraction of 14 priority polycyclic aromatic hydrocarbons (PAHs) from mosses prior to their separation by liquid chromatography and fluorescence detection (LC-FLD). Sample treatment involved the vortex shaking of 200 mg of moss with 200 μL of decanoic acid-based solvent for 5 min, subsequent centrifugation for 8 min and analysis of the extract by LC-FLD using external calibration. Proteins precipitated during extraction because of both the decrease of the dielectric constant of the solution caused by THF and the formation of macromolecular complexes with decanoic acid. Polysaccharides were not solubilized in the aqueous cavities of the solvent because of their size exclusion. In-house method validation was performed according to the recommendations of the European Commission Decision 202/657/EC. Method detection and quantification limits for the different PAHs were in the ranges 0.04-0.24 and 0.14-0.80 μg kg(-1), respectively. The method was applied to the determination of different moss species collected in both polluted and unpolluted sites in the South of Spain. Recoveries were within the range 71-110%. The results obtained show that solvents with restricted access properties have the potential to expand the scope of application of restricted access materials to areas other than biological fluids because of their suitability to combine analyte isolation and sample cleanup of solid samples in a single step.

  5. Evaluation of Mercury in Environmental Samples by a Supramolecular SolventBased Dispersive LiquidLiquid Microextraction Method Before Analysis by a Cold Vapor Generation Technique.

    Science.gov (United States)

    Ali, Jamshed; Tuzen, Mustafa; Kazi, Tasneem G

    2017-02-01

    Supramolecular solvent–based dispersive liquid–liquid microextraction was used as a preconcentration method for the determination of trace levels of Hg. This simple method accurately measured oxidized HgII content in claystone and sandstone samples obtained from the Thar Coalfield in Pakistan. Cold vapor atomic absorption spectrometry was used as the detection technique because it is reliable and accurate. The HgII in acidic media forms a complex with dithizone (DTz) in the presence of supramolecular solvent (tetrahydrofuran and 1-undecanol), forming reverse micelles. Formation of the Hg-DTz complex was achieved to increase the interactions with the supramolecular solvent phase at pH 2.5 under the optimized experimental conditions. After addition of the supramolecular solvent to the aqueous solution, the micelles were uniformly mixed using a vortex mixer. The cloudy solution was centrifuged, and the Hg-DTz complex was extracted into the supramolecular solvent phase. Under optimized experimental conditions, the LOD and enrichment factor were found to be 5.61 ng/L and 77.8, respectively. Accuracy of the developed method was checked with Certified Reference Materials. The developed method was successfully applied for the determination of HgII in claystone and sandstone samples from the Block VII and Block VIII areas of the Thar Coalfield on the basis of depth.

  6. Spectroscopic, solvent influence and thermal studies of ternary copper(II) complexes of diester and dinitrogen base ligands.

    Science.gov (United States)

    Emara, Adel A A; Abu-Hussein, Azza A A; Taha, Ahmed A; Mahmoud, Nelly H

    2010-10-15

    New mixed-ligand copper(II) complexes containing the bidentate dinitrogen ligands [N,N,N',N'-tetramethylethylenediamine (tmen), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen)] and the bidentate dioxygen ligands [diethylmalonate (DEM), ethylacetoacetate (EAA) and ethylbenzoylacetate (EBA)] were prepared. The complexes were characterized by elemental analysis, infrared, mass and ESR spectral data, magnetic and molar conductance measurements and thermal gravimetric analysis. From the investigation, the geometries of the complexes are square planar for perchlorate complexes and a square pyramid or octahedral for the nitrate complexes. Solvatochromic behavior of the Cu(II) complexes indicates strong solvatochromism of their solutions in polar and non-polar solvents. The observed solvatochromism is due to the solute-solvent interaction between the chelate cation and the solvent molecules.

  7. Enhancing Low-Temperature and Pressureless Sintering of Micron Silver Paste Based on an Ether-Type Solvent

    Science.gov (United States)

    Zhang, Hao; Li, Wanli; Gao, Yue; Zhang, Hao; Jiu, Jinting; Suganuma, Katsuaki

    2017-08-01

    Micron silver paste enables a low-temperature and pressureless sintering process by using an ether-type solvent CELTOL-IA (C x H y O z , x > 10, boiling point of approximately 200°C) for the die attachment of high-powered devices. The conductive patterns formed by the silver paste had a low electrical resistivity of 8.45 μΩ cm at 180°C. The paste also achieved a high bonding strength above 30 MPa at 180°C without the assistance of pressures. These superior performance indicators result from the favorable removal of the solvent, its thermal behavior, and its good wetting on the silver layer. The results suggest that the micron silver paste with a suitable solvent can promote the further spreading of next-generation power devices owing to its marked cost advantage and excellent performance.

  8. Infrared and vibrational CD spectra of partially solvated alpha-helices: DFT-based simulations with explicit solvent.

    Science.gov (United States)

    Turner, David R; Kubelka, Jan

    2007-02-22

    Theoretical simulations are used to investigate the effects of aqueous solvent on the vibrational spectra of model alpha-helices, which are only partly exposed to solvent to mimic alpha-helices in proteins. Infrared absorption (IR) and vibrational circular dichroism (VCD) amide I' spectra for 15-amide alanine alpha-helices are simulated using density functional theory (DFT) calculations combined with the property transfer method. The solvent is modeled by explicit water molecules hydrogen bonded to the solvated amide groups. Simulated spectra for two partially solvated model alpha-helices, one corresponding to a more exposed and the other to a more buried structure, are compared to the fully solvated and unsolvated (gas phase) simulations. The dependence of the amide I spectra on the orientation of the partially solvated helix with respect to the solvent and effects of solvation on the amide I' of 13C isotopically substituted alpha-helices are also investigated. The partial exposure to solvent causes significant broadening of the amide I' bands due to differences in the vibrational frequencies of the explicitly solvated and unsolvated amide groups. The different degree of partial solvation is reflected primarily in the frequency shifts of the unsolvated (buried) amide group vibrations. Depending on which side of the alpha-helix is exposed to solvent, the simulated IR band-shapes exhibit significant changes, from broad and relatively featureless to distinctly split into two maxima. The simulated amide I' VCD band-shapes for the partially solvated alpha-helices parallel the broadening of the IR and exhibit more sign variation, but generally preserve the sign pattern characteristic of the alpha-helical structures and are much less dependent on the alpha-helix orientation with respect to the solvent. The simulated amide I' IR spectra for the model peptides with explicitly hydrogen-bonded water are consistent with the experimental data for small alpha-helical proteins

  9. Magnetic graphene oxide modified with choline chloride-based deep eutectic solvent for the solid-phase extraction of protein.

    Science.gov (United States)

    Huang, Yanhua; Wang, Yuzhi; Pan, Qi; Wang, Ying; Ding, Xueqin; Xu, Kaijia; Li, Na; Wen, Qian

    2015-06-02

    Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe3O4@GO) to form Fe3O4@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe3O4@GO-DES, and the results indicated the successful preparation of Fe3O4@GO-DES. The UV-vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe3O4@GO-DES. Comparison of Fe3O4@GO and Fe3O4@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe3O4@GO-DES performs better than Fe3O4@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L(-1) Na2HPO4 contained 1 mol L(-1) NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled.

  10. A lição da pintura pela pintura: variações; paráfrases; apropriações; citações The lesson of painting by painting: variations; paraphrases; appropriations; quotations

    Directory of Open Access Journals (Sweden)

    Paula André

    2008-12-01

    Full Text Available O que levará um pintor a interessar-se pela pintura de outro pintor do passado? Como se processa esse uso e abuso? O que revela uma pintura? Analisar as obras-mestras do passado consiste essencialmente em demonstrar o mecanismo da criação e revelar os meios usados. Não se pode criar uma forma original sem se abrir a formas do passado. Quando Harold Bloom diz que Shakespeare lê de um modo mais completo do que pode ser lido, leva-nos a interrogar se um pintor não vê de um modo mais completo do que poder ser visto. Os artistas que inovam estão profundamente ligados à tradição e praticam a lição da pintura pela pintura. As variações ou recriações artísticas são um diálogo íntimo com a obra, são o desvendar de um enigma e uma história da arte feita pelos pintores.What may lead a painter to become interested in the painting of another painter from the past? How does it work, that use and abuse? What does reveal a painting? To analyse master works from the past consists essentially in evidencing the mechanisms of creativity and revealing the means which were used. One can not create an original form without opening oneself to the forms of the past. When Harold Bloom says that Shakespeare reads in a more thoroughly manner than it can ever be read, he makes one wonder if - like wise - a painter does not see in a more thoroughly manner than it can ever be seen. Innovative artists are deeply linked to tradition and practice a lesson of painting by the painting itself. The variations or artistic recreations are an intimate dialogue with the work, they are the revelation of an enigma and an art history made by the painters.

  11. Pintura mural y publicidad exterior. De la función estética a la dimensión pública

    OpenAIRE

    Canales Hidalgo, Juan Antonio

    2008-01-01

    El discurso del presente trabajo se articula desde la premisa que defiende una relación secular entre arte y funcionalidad, ya establecidad por la pintura mural en el Paleolítico Superior. Al analizar una pintura mural de carácter monumental, queremos decir de superficie considerable, ubicada en el espacio público e integrada en el edificio que la sustenta y en la arquitectura del entorno, observamos que coexisten al menos tres tipos de funciones: estética, decorativa y publicitaria.. La arid...

  12. El programa teológico-docente de las pinturas murales de dos conventos franciscanos de época moderna en Mallorca

    OpenAIRE

    Forteza Oliver, Miquela

    2012-01-01

    Una de las particularidades de la iconografía de las órdenes religiosas fue su propensión a representar grandes series o ciclos pictóricos relacionados con la historia o los fundadores de sus órdenes respectivas. En Mallorca, se conservan dos series de pinturas murales en el claustro de los conventos franciscanos de San Buenaventura de Llucmajor y San Bernardino de Petra. Estos dos ejemplos son representativos de un tipo de pintura de carácter popular, realizada mediante la técnica de la gris...

  13. El programa teológico-docente de las pinturas murales de dos conventos franciscanos de época moderna en Mallorca

    OpenAIRE

    Forteza Oliver, Miquela

    2011-01-01

    Una de las particularidades de la iconografía de las órdenes religiosas fue su propensión a representar grandes series o ciclos pictóricos relacionados con la historia o los fundadores de sus órdenes respectivas. En Mallorca, se conservan dos series de pinturas murales en el claustro de los conventos franciscanos de San Buenaventura de Llucmajor y San Bernardino de Petra. Estos dos ejemplos son representativos de un tipo de pintura de carácter popular, realizada mediante la técnica de la gris...

  14. Evaluación de pinturas arquitectónicas de tipo látex con fibras naturales de tagua y cabuya

    OpenAIRE

    2009-01-01

    El presente trabajo se basa en el análisis de pinturas arquitectónicas de tipo látex con fibras de Cabuya, con un 10% y, Tagua, con un 5%; mediante la intervención de dos tratamientos: Alcalinización y Blanqueo, y Alcalinización y Organo Silano. Estas muestras fueron sometidas a rigurosas pruebas de Control de Calidad, dando como resultados la poca compatibilidad de las fibras de Tagua con las pinturas sin influir de manera favorable los tratamientos realizados, y ciertas mejoras en las prueb...

  15. 环保溶剂型氯丁胶的制备%Preparation of environment-friendly solvent-based neoprene adhesive

    Institute of Scientific and Technical Information of China (English)

    赵俊勇; 杨洪记; 刘文涛; 何素芹; 朱诚身

    2012-01-01

    At present,the solvent-based neoprene adhesive was still dominant in rubber-based adhesives. In order to make low-toxicity solvent-based neoprene adhesive, the better proportion of non-benzene mixed solvents for liquefying neoprene was preferred by "solubility parameter+hydrogen bond index" method,then a pre-reaction liquid between tert-butyl phenolic resin and light-MgO was made by pre-chelation reaction. Finally, a environment-friendly solvent-based neoprene adhesive with faster curing speed and 35.5% solid contents was prepared by mixing. The research results showed that the corresponding neoprene adhesive had reversely best combination property because its shear strength and peeling strength were 1.83 Mpa and 17.9 N/25 mm respectively when mass ratio of m(120* solvent oil):m(ethyl acetate):m(acetone) was 4:7:4 in mixed solvent.%目前,溶剂型氯丁胶仍在橡胶基胶粘剂中占主导地位.为制备低毒性溶剂型氯丁胶,可根据"溶度参数+氢键指数"法优选出溶解氯丁橡胶用非苯类混合溶剂的较佳配比;然后使叔丁基酚醛树脂与轻质MgO预先发生螯合反应制得预反应液,再采用混炼法制得固化速率快、固含量高达35.5%的环保溶剂型氯丁胶.研究结果表明:当混合溶剂中m(120#溶剂油):m(乙酸乙酯):m(丙酮):4:7:4时,相应氯丁胶的综合性能相对最好,其剪切强度为1.83 MPa、剥离强度为17.9 N/25 mm.

  16. A toxic organic solvent-free technology for the preparation of PEGylated paclitaxel nanosuspension based on human serum albumin for effective cancer therapy

    Directory of Open Access Journals (Sweden)

    Yin TJ

    2015-12-01

    Full Text Available Tingjie Yin,* Lihui Dong,* Bei Cui, Lei Wang, Lifang Yin, Jianping Zhou, Meirong Huo State Key Laboratory of Natural Medicines, Department of Pharmaceutics, China Pharmaceutical University, Nanjing, People’s Republic of China *These authors contributed equally to this work Abstract: Clinically, paclitaxel (PTX is one of most commonly prescribed therapies against a wide range of solid neoplasms. Despite its success, the clinical applicability of PTX (Taxol® is severely hampered by systemic toxicities induced by Cremophor EL. While attempts to bypass the need for Cremophor EL have been developed through platforms such as Abraxane™, nab™ relies heavily on the use of organic solvents, namely, chloroform. The toxicity introduced by residual chloroform poses a potential risk to patient health. To mitigate the toxicities of toxic organic solvent-based manufacture methods, we have designed a method for the formulation of PTX nanosuspensions (PTX-PEG [polyethylene glycol]-HSA [human serum albumin] that eliminates the dependence on toxic organic solvents. Coined the solid-dispersion technology, this technique permits the dispersion of PTX into PEG skeleton without the use of organic solvents or Cremophor EL as a solubilizer. Once the PTX-PEG dispersion is complete, the dispersion can be formulated with HSA into nanosuspensions suitable for intravenous administration. Additionally, the incorporation of PEG permits the prolonged circulation through the steric stabilization effect. Finally, HSA-mediated targeting permits active receptor-mediated endocytosis for enhanced tumor uptake and reduced side effects. By eliminating the need for both Cremophor EL and organic solvents while simultaneously increasing antitumor efficacy, this method provides a superior alternative to currently accepted methods for PTX delivery. Keywords: human serum albumin, nanosuspension, paclitaxel, polyethylene glycol, solid-dispersion technology

  17. Green oxidation of alkenes in ionic liquid solvent by hydrogen peroxide over high performance Fe(III) Schiff base complexes immobilized on MCM-41

    Indian Academy of Sciences (India)

    Mohammad Taghi Goldani; Ali Mohammadi; Reza Sandaroos

    2014-05-01

    A series of Fe(III) Schiff base complexes immobilized on MCM-41 were prepared and characterized by various physicochemical and spectroscopic methods. The complexes were used for oxidation of cyclohexene by 30% hydrogen peroxide in the presence and absence of ethylmethyl imidazolium chloride (EMIM) ionic liquid as solvent. The immobilized complexes proved to be effective catalysts and generally exhibited much higher catalytic performance than their homogeneous analogue. Catalytic performance of the complexes was also found to be closely related to the Schiff base ligands used. Additionally, ion liquid solvent efficiently improved all the catalytic performances. Finally, the reaction was extended to different alkenes using the heterogeneous complex 2-L4. Among all the alkenes, those containing -electron-withdrawing groups and trans-orientations exhibited lower tendency for oxidation.

  18. Achieving balanced intermixed and pure crystalline phases in PDI-based non-fullerene organic solar cells via selective solvent additives.

    Science.gov (United States)

    Li, Mingguang; Liu, Jiangang; Cao, Xinxiu; Zhou, Ke; Zhao, Qiaoqiao; Yu, Xinhong; Xing, Rubo; Han, Yanchun

    2014-12-28

    Herein, balanced intermixed and pure crystalline phases in N,N'-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxylic diimide (EP-PDI)-based non-fullerene organic solar cells (OSCs) were achieved via selective solvent additives (SAs). Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  19. De la pintura psicopatológica al arte como terapia en España (1917-1986).

    OpenAIRE

    HERNANDEZ MERINO, ANA MARIA

    2011-01-01

    Hemos investigado sobre el interés que ha suscitado tanto para los psiquiatras como para los artistas, la pintura de enfermos mentales y la utilización del arte como terapia en España. También hemos hecho una aproximación comparativa con el desarrollo de la cuestión en el resto de los países europeos y hemos analizado las diferentes orientaciones teóricas. En de la Segunda Guerra Mundial se comenzó a utilizar el "art-therapy" en los países anglosajones, debido a las necesidades de los lar...

  20. El umbral entre la arquitectura, la pintura y la escultura (Las artes plásticas y del espacio)

    OpenAIRE

    Chávez Prado, Pedro Nicolás

    2012-01-01

    El objetivo de esta investigación es demostrar y valorar la existencia del Umbral entre la arquitectura, la pintura y la escultura constituido este por los fundamentos visuales como son la línea, la forma, los volúmenes, la simetría, la textura, los colores, el ritmo, la luz, la sombra y la penumbra. Asimismo, demostrar que el elemento diferenciador entre estas artes son la objetividad y la subjetividad del acto creador. Para ello, en la presente tesis titulada “El umbral entre la arquitectur...

  1. La pintura y la escultura aplicada en la experimentación del penco como soporte plástico

    OpenAIRE

    Faicán Gómez, César

    2000-01-01

    El penco como textura de fibra para el arte, este tema esta tratado desde diferentes puntos de vista, el social, histórico y químico, descubriendo sus características para plasmarla a la escultura y la pintura. También las obras artísticas que se han obtenido tienen como tema principal el expresionismo híbrido [hombre, flora, fauna, etc.] aprovechándose al máximo su textura, su color natural, durabilidad, maleabilidad, grosor y otros.lo que hace posible la creación artística Licenciado en...

  2. PRIMER INTENTO DE DATACIÓN DE PINTURAS MURALES MESOAMERICANAS (First Attempt to Date Mesoamerican Mural Paintings)

    OpenAIRE

    Avto Goguitchaichvili; Juan Morales; Rodrigo Esparza López; Ana María Soler; Jaime Urrutia Fucugauchi; Miguel Cervantes Solano

    2016-01-01

    Se reporta, por vez primera, el intento de datación de cuatro pinturas murales del centro de México: Templo de Venus (Cacaxtla), Templo Rojo (Templo Mayor, Tenochtitlan), Chapulines y Estrellas (Cholula). Estos sitios corresponden al periodo Clásico y Posclásico Temprano de la cronología mesoamericana. Las edades obtenidas para Chapulines (1105-1194 A. D.), Templo de Venus (1002-1308 A. D.) y Estrellas (340-649 A. D.) están dentro de la cronología y contexto arqueológico de los sitios estudia...

  3. PRIMER INTENTO DE DATACIÓN DE PINTURAS MURALES MESOAMERICANAS (First Attempt to Date Mesoamerican Mural Paintings)

    OpenAIRE

    Avto Goguitchaichvili; Juan Morales; Rodrigo Esparza López; Ana María Soler; Jaime Urrutia Fucugauchi; Miguel Cervantes Solano

    2016-01-01

    Se reporta, por vez primera, el intento de datación de cuatro pinturas murales del centro de México: Templo de Venus (Cacaxtla), Templo Rojo (Templo Mayor, Tenochtitlan), Chapulines y Estrellas (Cholula). Estos sitios corresponden al periodo Clásico y Posclásico Temprano de la cronología mesoamericana. Las edades obtenidas para Chapulines (1105-1194 A. D.), Templo de Venus (1002-1308 A. D.) y Estrellas (340-649 A. D.) están dentro de la cronología y contexto arqueológico de los sitios estudia...

  4. Universal solvation model based on solute electron density and on a continuum model of the solvent defined by the bulk dielectric constant and atomic surface tensions.

    Science.gov (United States)

    Marenich, Aleksandr V; Cramer, Christopher J; Truhlar, Donald G

    2009-05-07

    We present a new continuum solvation model based on the quantum mechanical charge density of a solute molecule interacting with a continuum description of the solvent. The model is called SMD, where the "D" stands for "density" to denote that the full solute electron density is used without defining partial atomic charges. "Continuum" denotes that the solvent is not represented explicitly but rather as a dielectric medium with surface tension at the solute-solvent boundary. SMD is a universal solvation model, where "universal" denotes its applicability to any charged or uncharged solute in any solvent or liquid medium for which a few key descriptors are known (in particular, dielectric constant, refractive index, bulk surface tension, and acidity and basicity parameters). The model separates the observable solvation free energy into two main components. The first component is the bulk electrostatic contribution arising from a self-consistent reaction field treatment that involves the solution of the nonhomogeneous Poisson equation for electrostatics in terms of the integral-equation-formalism polarizable continuum model (IEF-PCM). The cavities for the bulk electrostatic calculation are defined by superpositions of nuclear-centered spheres. The second component is called the cavity-dispersion-solvent-structure term and is the contribution arising from short-range interactions between the solute and solvent molecules in the first solvation shell. This contribution is a sum of terms that are proportional (with geometry-dependent proportionality constants called atomic surface tensions) to the solvent-accessible surface areas of the individual atoms of the solute. The SMD model has been parametrized with a training set of 2821 solvation data including 112 aqueous ionic solvation free energies, 220 solvation free energies for 166 ions in acetonitrile, methanol, and dimethyl sulfoxide, 2346 solvation free energies for 318 neutral solutes in 91 solvents (90 nonaqueous

  5. Effects of residual water on microtensile bond strength of one-bottle dentin adhesive systems with different solvent bases

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-xing; HUANG Cui; ZHENG Tie-li; WANG Sa; CHENG Xiang-rong

    2005-01-01

    Background The wet-bonding technique is recommended for the one-bottle dentin adhesive systems, but the moisture concept varies widely among the instructions of manufacturers as well as among investigators. The aim of this study was to evaluate the effects of different dentin surface moisture on the microtensile bond strength(s) of an ethanol/water-based adhesive system and an acetone-based system to dentin. Methods Forty intact human premolars extracted for orthodontic reasons were used. Superficial occlusal flat dentin surfaces of these premolars were exposed, finished with wet 600-grit silicon carbide paper. Under four wet and dry conditions (overwet, blot dry, one-second dry and desiccated), resin composite was bonded to dentin by using Single Bond (SB) or Prime & Bond NT (PB) according to the manufacturers' instructions. The teeth were longitudinally sectioned in the "x" and "y" directions to obtain bonded beams with a cross-sectional area of 0.81 mm2 with a slow-speed diamond saw. The bonded specimens were tested in tension at a crosshead speed of 1 mm/min until failure of the bonds. Failure modes were observed with a scanning electron microscope. The mean bond strengths were analyzed by one-way ANOVA and Turkey's test. Results The bond strength of the overwet/SB, blot dry/SB, one-second dry/SB and desiccated/SB groups was 10.87 Mpa, 22.47 Mpa, 24.91 Mpa and 12.99 Mpa, respectively. The bond strength of the overwet/PB, blot dry/PB, one-second dry/PB and desiccated/PB groups was 10.02 Mpa, 20.67 Mpa, 21.82 Mpa and 10.09 Mpa, respectively. For both SB and PB, the blot dry group and one-second dry group revealed significantly higher bond strengths than the overwet and desiccated groups (P<0.05). Conclusions In order to achieve the highest bond strength to dentin, keeping the dentin surface in an appropriately moist condition is critical for the one-bottle dentin adhesive systems with ethanol/water or acetone solvent.

  6. Caracterización arqueométrica de pigmentos y soportes procedentes de pinturas murales góticas (S. XIII-XV

    Directory of Open Access Journals (Sweden)

    Kriznar, A.

    2007-04-01

    Full Text Available A novel investigation on samples of gothic wall paintings (13-15th Centuries has been carried out. They were found in some Churchs of Slovenia, being not yet studied using technics of materials analysis. One of them is selected: the Church of “Anunciación de María”, city of Crngrob, Slovenia. The scientific investigation of the Gothic wall painting samples was mainly based in the preparation of the so-called stratigraphic sections (cross-sections from the original small samples. This procedure allows to study the different layers of mortar as support and the painting itself. Next, these preparations were examined using several instrumental techniques commonly applied in materials characterization at the ICMSE, for instance, digital photography, optical and electronic microscopies, IR spectroscopy and EDX for chemical analysis. Aditional information concerning pigments and mortars was obtained by IR transmision spectroscopy using KBr pellets, as well as using XRD. Samples studied at the ICMSE can be classified in two groups, which allows to appreciate two procedures or techniques of wall paintings performed at the Church of Crngrob. The first is typical of Gothic Italian paintings: technic of so-called fresco buono over several layers of mortars, using marble powder to get a white and smooth surface. The results of the present study have also allowed to characterize and identify the inorganic pigments and mortars used in these wall paintings. They were found to be the appropiate for this kind of technical work. For instance, they have been applied iron oxides to get the yellow, orange and even green colours, but surprisingly it has not been found neither malachite (copper pigment of green colour nor copper compounds to get a green colour. In older layers of wall paintings, the pigment cinnabar was used to get the red colour. It is a mineral used typically in Italy. As revealed in this research, no aglutinant except the lime coming from the

  7. La primera exposición de esculturas celebrada en el Real Museo de Pinturas

    Directory of Open Access Journals (Sweden)

    Rose-De Viejo, Isadora

    2005-03-01

    Full Text Available Documents preserved in the archives of the Prado Museum and the Madrid Royal Palace, an announcement in the Diario de Madrid and the testimony of a foreign resident, reveal that the first sculptural works exhibited in the then still denominated Royal Painting Museum for a period of fifteen days in January 1827, were two full-length seated portrait statues executed in Rome: Carlos IV (1817 by Ramón Barba and María Luisa de Parma (1816 by José Alvarez Cubero. This must have been a major cultural and political event that until now had not been noted in the literature on the history of the museum.

    Documentos conservados en los archivos del Museo del Prado y del Palacio Real, un anuncio aparecido en el Diario de Madrid y el testimonio de un forastero, revelan que las primeras esculturas expuestas en el entonces todavía denominado Real Museo de Pinturas durante quince días de enero de 1827, fueron dos estatuas sedentes de cuerpo entero ejecutadas en Roma: el Carlos IV (1817 de Ramón Barba y la María Luisa de Parma (1816 de José Alvarez Cubero. Esto debió ser un acontecimiento cultural y político que hasta ahora no se había recogido en la literatura sobre la historia del museo.

  8. Pinturas novohispanas en España: responsables, finalidad y procedimiento

    Directory of Open Access Journals (Sweden)

    Barea Azcón, Patricia

    2007-12-01

    Full Text Available Nowadays a significant amount of mexican colonial painting belonging to XVII and XVIII centuries remains in Spain and they are distributed among museums, religious institutiones and private collections. In the most of the cases they are oils painted over canvas which iconographic theme is the Virgin of Guadalupe. Althought they are located in whatever region, most of them are found in the places close bounder to the viceroyalty, being of particular interest those located in the western part of Andalucía (Spain. One of the most interesting but unknown aspect is that concerning to the paintings arrival process in which several factors are involved and underlie questions like a who were the main figures, b which was their purpuse, c What methodology they used, d where paintings finally arrived, and e which was the background of this process.

    Actualmente se conserva en España un significativo conjunto de pintura virreinal mexicana de los siglos XVII y XVIII distribuido entre museos, instituciones religiosas y colecciones particulares. En la mayoría de los casos se trata de óleos pintados sobre lienzo que tienen como tema iconográfico a la Virgen de Guadalupe. Aunque se localizan en todas las comunidades, encontramos mayor presencia en las que estuvieron más vinculadas con el virreinato, entre las que hay que destacar Andalucía Occidental. Uno de los aspectos más interesantes y desconocidos es el referido al procedimiento de llegada de estas obras, en el que intervinieron factores de diversa índole y en el que subyacen cuestiones como a quiénes fueron los protagonistas, b cuál fue su propósito, c qué método emplearon, d a dónde fueron a parar, y en última instancia, e cuál es el trasfondo del mismo.

  9. Standard Practice for Preparing Aircraft Cleaning Compounds, Liquid-Type, Temperature-Sensitive, or Solvent-Based, for Storage Stability Testing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This practice covers the determination of the stability in storage of liquid enzyme-based, terpene-based, and solvent-based chemical cleaning compounds used to clean the exterior surfaces of aircraft. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  10. Performance evaluation of titanium dioxide based dye-sensitized solar cells under the influence of anodization steps, nanotube length and ionic liquid-free redox electrolyte solvents

    Science.gov (United States)

    Cheong, Y. L.; Beh, K. P.; Yam, F. K.; Hassan, Z.

    2016-06-01

    In this work, highly ordered titanium dioxide (TiO2) nanotube (NT) arrays were synthesized on titanium foil using electrochemical anodization method. The morphological aspects of the nanotubes based on different anodization duration and number of anodization steps (maximum two) have been investigated. The nanotube arrays subsequently used as photoanode in a dye-sensitized solar cell (DSSC) assembly. The studies on the effects of different solvents for triiodide/iodide redox electrolyte and NT length towards the performance of DSSC were conducted. It is known that electrolyte solvent can significantly affect the photovoltaic conversion efficiency. It is noteworthy that longer NT length tends to yield higher efficiency due to better dye adsorption. However, when the NTs exceeded certain length the efficiency decreases instead. Meanwhile, a comparison of DSSC performance based on number of anodization steps on titanium was performed. Highly ordered NT arrays could be obtained using two-steps anodization, which proved to have positive effects on the DSSC performance. The highest photovoltaic conversion efficiency in this work is 2.04%, achieved by two-step anodization. The corresponding average nanotubes length was ˜18 μm, with acetonitrile (ACN) as the redox electrolyte solvent.

  11. Miscellaneous hydrocarbon solvents.

    Science.gov (United States)

    Bebarta, Vikhyat; DeWitt, Christopher

    2004-08-01

    The solvents discussed in this article are common solvents not categorized as halogenated, aromatic, or botanical. The solvents discussed are categorized into two groups: hydrocarbon mixtures and single agents. The hydrocarbon mixtures discussed are Stoddard solvent, naphtha, and kerosene. The remaining solvents described are n-hexane, methyl n-butyl ketone, dimethylformamide, dimethyl sulfoxide, and butyl mercaptans. Effects common to this group of agents and their unique effects are characterized. Treatment of exposures and toxic effects of these solvents is described, and physiochemical properties and occupational exposure levels are listed.

  12. Mdea Based Solvents Used At the Lacq Processing Plant Utilisation de solvants à base de MDEA à l'usine de Lacq

    Directory of Open Access Journals (Sweden)

    Elgue J.

    2006-11-01

    Full Text Available The use of MDEA-based solvents has allowed the processing scheme of the sour natural gases treated at the Lacq plant to be modified, leading to substantial savings in operating costs. Compared to the well known SNPA-DEA process, the new MDEA-based solvents meet the same performance requirements as regards H2S and CO2 removal, but are far more economic in terms of energy consumption. MDEA is used to selectively remove H2S from the gas, while activated MDEA is used when total acid gas removal is necessary. The adequate activator has been selected from among a series of products, according to the actual plant specificity. Optimization of the process has included the selection of the proper contacting device : for this mass transfer enhanced by chemical first order reaction, structured packings have proven to be more efficient than trays. L'utilisation de solvants à base de MDEA a permis de modifier le schéma de désulfuration du gaz de Lacq et de réaliser ainsi de substantielles économies de traitement. Les procédés à base des nouveaux solvants permettent d'atteindre les mêmes performances d'élimination de H2S et du CO2, avec une consommation d'énergie très inférieure à celle du désormais classique procédé SNPA-DEA. La MDEA est utilisée pour l'enlèvement sélectif de l'H2S, alors que la MDEA activée permet l'élimination complète des composés acides. L'activateur le mieux adapté aux conditions de fonctionnement spécifiques des unités de Lacq a été sélectionné parmi une série de produits. Dans le cadre de l'optimisation des unités, les internes du contacteur gaz/liquide ont été changés : les garnissages structurés ont confirmé leur efficacité supérieure à celle des plateaux à clapets pour ce transfert de matière avec réaction chimique.

  13. Development of deep eutectic solvents applied in extraction and separation.

    Science.gov (United States)

    Li, Xiaoxia; Row, Kyung Ho

    2016-09-01

    Deep eutectic solvents, as an alternative to ionic liquids, have greener credentials than ionic liquids, and have attracted considerable attention in related chemical research. Deep eutectic solvents have attracted increasing attention in chemistry for the extraction and separation of various target compounds from natural products. This review highlights the preparation of deep eutectic solvents, unique properties of deep eutectic solvents, and synthesis of deep-eutectic-solvent-based materials. On the other hand, application in the extraction and separation of deep eutectic solvents is also included in this report. In this paper, the available data and references in this field are reviewed to summarize the applications and developments of deep eutectic solvents. Based on the development of deep eutectic solvents, an exploitation of new deep eutectic solvents and deep eutectic solvents-based materials is expected to diversify into extraction and separation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Impact of heating rate and solvent on Ni-based catalysts prepared by solution combustion method for syngas methanation

    Directory of Open Access Journals (Sweden)

    Zeng Yan

    2014-12-01

    Full Text Available Ni-Al2O3 catalysts prepared by solution combustion method for syngas methanation were enhanced by employing various heating rate and different solvent. The catalytic properties were tested in syngas methanation. The result indicates that both of heating rate and solvent remarkably affect Ni particle size, which is a key factor to the catalytic activity of Ni-Al2O3 catalysts for syngas methanation. Moreover, the relationship between Ni particle size and the production rate of methane per unit mass was correlated. The optimal Ni-Al2O3 catalyst prepared in ethanol at 2°C/min, achieves a maximum production rate of methane at the mean size of 20.8 nm.

  15. Substituent and Solvent Effects on Excited State Charge Transfer Behavior of Highly Fluorescent Dyes Containing Thiophenylimidazole-Based Aldehydes

    Science.gov (United States)

    Santos, Javier; Bu, Xiu R.; Mintz, Eric A.

    2001-01-01

    The excited state charge transfer for a series of highly fluorescent dyes containing thiophenylimidazole moiety was investigated. These systems follow the Twisted Intramolecular Charge Transfer (TICT) model. Dual fluorescence was observed for each substituted dye. X-ray structures analysis reveals a twisted ground state geometry for the donor substituted aryl on the 4 and 5 position at the imidazole ring. The excited state charge transfer was modeled by a linear solvation energy relationship using Taft's pi and Dimroth's E(sub T)(30) as solvent parameters. There is linear relation between the energy of the fluorescence transition and solvent polarity. The degree of stabilization of the excited state charge transfer was found to be consistent with the intramolecular molecular charge transfer. Excited dipole moment was studied by utilizing the solvatochromic shift method.

  16. Solvent Effects on the Electrochemical Behavior of TAPD-Based Redox-Responsive Probes for Cadmium(II

    Directory of Open Access Journals (Sweden)

    Rihab Sahli

    2014-01-01

    Full Text Available Two tetralkylated phenylenediamines (TAPD 1 and 2 have been prepared by reductive alkylation of para-dimethylaminoaniline with furfural or thiophene 2-carboxaldehyde, respectively. Their chelation ability has been evaluated as electrochemical guest-responsive chemosensors for Cd(II in acetonitrile (ACN, dimethylformamide (DMF, propylene carbonate (PC, and nitromethane (NM. The voltamperometric studies showed that these compounds are able to bind the Cd(II cation with strong affinities except in DMF. The redox features of the chemosensors changed drastically when they are bounded to Cd(II to undergo important anodic potential peak shifts comprised between ca. 500 and ca. 900 mV depending on the solvent. The addition of ∼4–10% molar triflic acid (TfOH was found to be necessary to achieve rapidly the cation chelation which is slow without the acid. The electrochemical investigations suggested the formation of 1 : 2 stoichiometry complexes [Cd(L2]2+. The results are discussed in terms of solvent effects as a competitive electron donating ligand to the cation. The reaction coupling efficiency (RCE values were determined and were also found to be solvent-dependent.

  17. Enzymatic Synthesis of Glucose-Based Fatty Acid Esters in Bisolvent Systems Containing Ionic Liquids or Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Kai-Hua Zhao

    2016-09-01

    Full Text Available Sugar fatty acid esters (SFAEs are biocompatible nonionic surfactants with broad applications in food, cosmetic, and pharmaceutical industries. They can be synthesized enzymatically with many advantages over their chemical synthesis. In this study, SFAE synthesis was investigated by using two reactions: (1 transesterification of glucose with fatty acid vinyl esters and (2 esterification of methyl glucoside with fatty acids, catalyzed by Lipozyme TLIM and Novozym 435 respectively. Fourteen ionic liquids (ILs and 14 deep eutectic solvents (DESs were screened as solvents, and the bisolvent system composed of 1-hexyl-3-methylimidazolium trifluoromethylsulfonate ([HMIm][TfO] and 2-methyl-2-butanol (2M2B was the best for both reactions, yielding optimal productivities (769.6 and 397.5 µmol/h/g, respectively which are superior to those reported in the literature. Impacts of different reaction conditions were studied for both reactions. Response surface methodology (RSM was employed to optimize the transesterification reaction. Results also demonstrated that as co-substrate, methyl glucoside yielded higher conversions than glucose, and that conversions increased with an increase in the chain length of the fatty acid moieties. DESs were poor solvents for the above reactions presumably due to their high viscosity and high polarity.

  18. Orthogonal protection of saccharide polyols through solvent-free one-pot sequences based on regioselective silylations

    Directory of Open Access Journals (Sweden)

    Serena Traboni

    2016-12-01

    Full Text Available tert-Butyldimethylsilyl (TBDMS and tert-butyldiphenylsilyl (TBDPS are alcohol protecting groups widely employed in organic synthesis in view of their compatibility with a wide range of conditions. Their regioselective installation on polyols generally requires lengthy reactions and the use of high boiling solvents. In the first part of this paper we demonstrate that regioselective silylation of sugar polyols can be conducted in short times with the requisite silyl chloride and a very limited excess of pyridine (2–3 equivalents. Under these conditions, that can be regarded as solvent-free conditions in view of the insolubility of the polyol substrates, the reactions are faster than in most examples reported in the literature, and can even be further accelerated with a catalytic amount of tetrabutylammonium bromide (TBAB. The strategy proved also useful for either the selective TBDMS protection of secondary alcohols or the fast per-O-trimethylsilylation of saccharide polyols. In the second part of the paper the scope of the silylation approach was significantly extended with the development of unprecedented “one-pot” and “solvent-free” sequences allowing the regioselective silylation/alkylation (or the reverse sequence of saccharide polyols in short times. The developed methodologies represent a very useful and experimentally simple tool for the straightforward access to saccharide building-blocks useful in organic synthesis.

  19. A utilização do modelo de simulação computacional para análise e modificação de um sistema de produção de pinturas automotivas

    OpenAIRE

    Soares, Bernardo Bregoli

    2013-01-01

    O presente trabalho descreve a utilização da simulação computacional aplicada ao ambiente da fábrica em uma empresa de pinturas automotivas, visando analisar propostas de modificação futura na fábrica, para o atendimento de um novo patamar de demanda de produção. O processo de pintura ocorre em uma linha de produção intermitente, com movimentação por meio de pontes rolantes automáticas. Tal sistema flow shop é composto principalmente das operações de jateamento, pintura e-coat ...

  20. La presencia de la música en la pintura del cubismo de Pablo Picasso hasta 1914

    Directory of Open Access Journals (Sweden)

    Cecilia García Marco

    2013-01-01

    Full Text Available La presencia de los instrumentos musicales es numerosa y significativa en todas las fases del cubismo. Analizando la evocación musical de la pintura cubista, ésta se desvela como un impulso creativo y un puente de conocimiento en esta revolución artística que transformó el arte del s. XX. En esa ruptura con todo lo anterior en el arte, en la búsqueda de un nuevo espacio pictórico y una exploración sin límites de un nuevo lenguaje pictórico, están siempre presente la música: en los volúmenes, objetos, letras y signos. La búsqueda pictórica de P. Picasso y G. Braque les conduce a querer plasmar la música y transformarla de objeto mental a obra de arte. Estaban rodeados de música, incluso G. Braque sabía tocar instrumentos musicales. Esta nueva mirada musical es necesaria para entender la pintura cubista, y una vez más reverenciar el papel decisivo de la música en otros campos del arte. El enfoque interdisciplinar fecunda las investigaciones y gracias a él se dan profundos avances de otro modo imposibles. Enlazar diversas disciplinas ayuda a tener una visión más profunda, amplia y creativa.

  1. Suicidio en azul con negra mancha. Breve historia de un balazo en la pintura de Pablo Picasso

    Directory of Open Access Journals (Sweden)

    Godoy C., Ivan

    2013-12-01

    Full Text Available Paris 1901: unrequited love drove Carles Casagemas, a close friend of Pablo Picasso’s youth, to commit suicide by shooting himself in the head. This tragic event was a major blow to Picasso, causing him to dwell upon the subject of death and express his “mourning” through his paintings. The “bullet hole” in his friend’s temple symbolically displaced several areas of the young Picasso’s life and became a “deep vacuum” and “melancholy”, permeating various areas in Picasso’s paintings, and marking the start of his famous blue period.París 1901: por el amor de una mujer, se suicida de un balazo en la cabeza Carles Casagemas, amigo íntimo de juventud de Pablo Picasso. Este trágico suceso producirá un gran dolor en el artista, el cual, lo hará internarse en el tema de la muerte y elaborar su “duelo” apoyado en su pintura. El “hoyo a bala” en la sien de su amigo se desplazará simbólicamente a varios espacios de la vida del joven Picasso y devendrá en “vacío profundo” y “melancolía”, permeando diferentes ámbitos dentro de la pintura de Picasso, dando comienzo a su mentado período azul.

  2. A propósito de las interpretaciones eróticas en pinturas de Murillo de asunto popular

    Directory of Open Access Journals (Sweden)

    Valdivieso, Enrique

    2002-12-01

    Full Text Available Over the past few years, certain foreign specialists of seventeenth century Spanish Baroque painting have maintained that in some of Murillo's works of «popular» subjects there exists a clear erotic content. The purpose of this article is to demonstrate that such content is impossible on the grounds both of Murillo's own mentality and the control exerted by the Inquisition. Murillo always complied with the most rigorous moral principles in force during his lifetime, and the Inquisition was permanently vigilant regarding sinful sexual behavior.

    A lo largo de los últimos años algunos especialistas foráneos de la pintura barroca española del S. XVII han venido manteniendo que en algunas pinturas de Murillo de asunto popular existen claros contenidos eróticos. Trata este artículo de evidenciar que tales contenidos no son posibles. Primero a causa de la mentalidad del propio Murillo siempre fiel al cumplimiento de los más rigurosos principios morales vigentes en su época, ni tampoco a causa de la perfecta vigilancia sobre conductas pecaminosas con respecto al sexo que la Inquisición efectuaba en aquella época.

  3. La primera generación de pintores navarros contemporáneos: aportaciones para un catálogo de sus pinturas en el Museo de Navarra

    Directory of Open Access Journals (Sweden)

    Urricelqui Pacho, Ignacio J.

    2002-12-01

    Full Text Available This study contributes to the elaboration of a catalogue of paintings in the Museo de Navarra by examining a series of works from the late nineteenth and early twentieth centuries carried out by a group of artists who constituted the first generation of contemporary painters in this region. On the one hand, inexact data has been corrected, and on the other, new information is brought to light which will contribute to a better understanding of this artistic group. Likewise, an attempt is made to revaluate paintings carried out in Navarre during this transcendental period for Spanish painting.

    Este trabajo desea contribuir a la elaboración de un catálogo de pinturas del Museo de Navarra con el estudio de una serie de obras realizadas a finales del siglo XIX y principios del siglo XX por un grupo de artistas que vienen a constituir la primera generación de pintores contemporáneos de esta región. De un lado ofrecemos la corrección de una serie de datos inexactos detectados en la catalogación de estas pinturas, de otro, aportamos información novedosa que contribuirá a un mejor conocimiento de este interesante conjunto artístico. Igualmente, no escapa a nuestro objetivo, ayudar a una revalorización de la pintura realizada en Navarra durante un período trascendental para la pintura española.

  4. Solvent resistant nanofiltration membranes

    OpenAIRE

    Dutczak, S.M.

    2011-01-01

    This thesis describes preparation and characterization of membranes for organic solvent filtration (OSF). The main aim was developing membranes for solvent resistant nanofiltration (SRNF) with molecular weight cut-off below 500 g mol-1.

  5. Solvents in novolak synthesis

    Science.gov (United States)

    Sobodacha, Chet J.; Lynch, Thomas J.; Durham, Dana L.; Paradis, Valerie R.

    1993-09-01

    Novolac resins may be prepared with or without a solvent present. We have found that solvent power greatly affects the properties of the finished resin and thus gives the resist chemist another variable with which to `fine-tune' resist properties. Using designed experiments, we investigated the effect of solvent power, as measured by Hansen's Solubility Parameters, of a number of solvents and solvent mixtures on the final properties of the novolac resin. We found that the relative molecular weight (RMW) and dissolution rate of a novolac resin can be varied by selection of a solvent or solvent mixture with the appropriate polarity and hydrogen- bonding characteristics. The solvent polarity and hydrogen-bonding characteristics may affect the stability of the cresol/formaldehyde transition state, thus causing the observed changes in RMW and dissolution rate.

  6. A homochiral vanadium-salen based cadmium bpdc MOF with permanent porosity as an asymmetric catalyst in solvent-free cyanosilylation.

    Science.gov (United States)

    Bhunia, Asamanjoy; Dey, Subarna; Moreno, José María; Diaz, Urbano; Concepcion, Patricia; Van Hecke, Kristof; Janiak, Christoph; Van Der Voort, Pascal

    2016-01-25

    A homochiral vanadium-salen based MOF with the pcu topology is constructed via in situ synthesis under solvothermal conditions. The synthesized MOF exhibits BET surface areas of 574 m(2) g(-1), showing the highest H2 adsorption capacity (1.05 wt% at 77 K, 1 bar) and the highest CO2 uptake (51 cm(3) g(-1) at 273 K, 1 bar) for currently known salen-based MOFs. This framework shows excellent performance as an asymmetric catalyst in solvent-free cyanosilylation.

  7. Improving the Performances of Random Copolymer Based Organic Solar Cells by Adjusting the Film Features of Active Layers Using Mixed Solvents

    Directory of Open Access Journals (Sweden)

    Xiangwei Zhu

    2015-12-01

    Full Text Available A novel random copolymer based on donor–acceptor type polymers containing benzodithiophene and dithienosilole as donors and benzothiazole and diketopyrrolopyrrole as acceptors was designed and synthesized by Stille copolymerization, and their optical, electrochemical, charge transport, and photovoltaic properties were investigated. This copolymer with high molecular weight exhibited broad and strong absorption covering the spectra range from 500 to 800 nm with absorption maxima at around 750 nm, which would be very conducive to obtaining large short-circuits current densities. Unlike the general approach using single solvent to prepare the active layer film, mixed solvents were introduced to change the film feature and improve the morphology of the active layer, which lead to a significant improvement of the power conversion efficiency. These results indicate that constructing random copolymer with multiple donor and acceptor monomers and choosing proper mixed solvents to change the characteristics of the film is a very promising way for manufacturing organic solar cells with large current density and high power conversion efficiency.

  8. The effect of macromolecular crowding on the electrostatic component of barnase-barstar binding: a computational, implicit solvent-based study.

    Directory of Open Access Journals (Sweden)

    Helena W Qi

    Full Text Available Macromolecular crowding within the cell can impact both protein folding and binding. Earlier models of cellular crowding focused on the excluded volume, entropic effect of crowding agents, which generally favors compact protein states. Recently, other effects of crowding have been explored, including enthalpically-related crowder-protein interactions and changes in solvation properties. In this work, we explore the effects of macromolecular crowding on the electrostatic desolvation and solvent-screened interaction components of protein-protein binding. Our simple model enables us to focus exclusively on the electrostatic effects of water depletion on protein binding due to crowding, providing us with the ability to systematically analyze and quantify these potentially intuitive effects. We use the barnase-barstar complex as a model system and randomly placed, uncharged spheres within implicit solvent to model crowding in an aqueous environment. On average, we find that the desolvation free energy penalties incurred by partners upon binding are lowered in a crowded environment and solvent-screened interactions are amplified. At a constant crowder density (fraction of total available volume occupied by crowders, this effect generally increases as the radius of model crowders decreases, but the strength and nature of this trend can depend on the water probe radius used to generate the molecular surface in the continuum model. In general, there is huge variation in desolvation penalties as a function of the random crowder positions. Results with explicit model crowders can be qualitatively similar to those using a lowered "effective" solvent dielectric to account for crowding, although the "best" effective dielectric constant will likely depend on multiple system properties. Taken together, this work systematically demonstrates, quantifies, and analyzes qualitative intuition-based insights into the effects of water depletion due to crowding on the

  9. Occupational solvent exposure and adult chronic lymphocytic leukemia: No risk in a population-based case-control study in four Nordic countries.

    Science.gov (United States)

    Talibov, Madar; Auvinen, Anssi; Weiderpass, Elisabete; Hansen, Johnni; Martinsen, Jan-Ivar; Kjaerheim, Kristina; Tryggvadottir, Laufey; Pukkala, Eero

    2017-09-15

    The aim of this study was to assess the effect of occupational solvent exposure on the risk of adult chronic lymphocytic leukemia (CLL). The current case-control study was nested in the Nordic Occupational Cancer Study (NOCCA) cohort. 20,615 CLL cases diagnosed in 1961-2005 in Finland, Iceland, Norway, and Sweden, and 103,075 population-based controls matched by year of birth, sex, and country were included. Occupational histories for cases and controls were obtained from census records in 1960, 1970, 1980/1981, and 1990. Exposure to selected solvents was estimated by using the NOCCA job-exposure matrix (NOCCA-JEM). Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated by using conditional logistic regression models. Overall, nonsignificant CLL risk elevations were observed for methylene chloride, perchloroethylene, and 1,1,1-trichloroethane. Compared to unexposed, significantly increased risks were observed for cumulative perchloroethylene exposure ≤13.3 ppm-years (OR = 1.85, 95% CI 1.16-2.96) and average life-time perchloroethylene exposure ≤2.5 ppm (1.61, 95% CI 1.01-2.56) among women, and cumulative methylene chloride exposure ≤12.5 ppm-years (OR = 1.19, 95% CI 1.01-1.41) and 12.5-74.8 ppm-years (OR = 1.23, 95% CI 1.01-1.51) among men in an analysis with 5 years lag-time, though without dose-response pattern. Decreased CLL risk was observed for aliphatic and alicyclic hydrocarbon solvents and toluene. This study did not support associations for solvent exposure and CLL. Observed weak associations for methylene chloride, perchloroethylene, 1,1,1-trichloroethane exposures, aliphatic and alicyclic hydrocarbons and toluene were not consistent across sexes, and showed no gradient with amount of exposure. © 2017 UICC.

  10. Identifying native-like protein structures with scoring functions based on all-atom ECEPP force fields, implicit solvent models and structure relaxation.

    Science.gov (United States)

    Arnautova, Yelena A; Vorobjev, Yury N; Vila, Jorge A; Scheraga, Harold A

    2009-10-01

    Availability of energy functions which can discriminate native-like from non-native protein conformations is crucial for theoretical protein structure prediction and refinement of low-resolution protein models. This article reports the results of benchmark tests for scoring functions based on two all-atom ECEPP force fields, that is, ECEPP/3 and ECEPP05, and two implicit solvent models for a large set of protein decoys. The following three scoring functions are considered: (i) ECEPP05 plus a solvent-accessible surface area model with the parameters optimized with a set of protein decoys (ECEPP05/SA); (ii) ECEPP/3 plus the solvent-accessible surface area model of Ooi et al. (Proc Natl Acad Sci USA 1987;84:3086-3090) (ECEPP3/OONS); and (iii) ECEPP05 plus an implicit solvent model based on a solution of the Poisson equation with an optimized Fast Adaptive Multigrid Boundary Element (FAMBEpH) method (ECEPP05/FAMBEpH). Short Monte Carlo-with-Minimization (MCM) simulations, following local energy minimization, are used as a scoring method with ECEPP05/SA and ECEPP3/OONS potentials, whereas energy calculation is used with ECEPP05/FAMBEpH. The performance of each scoring function is evaluated by examining its ability to distinguish between native-like and non-native protein structures. The results of the tests show that the new ECEPP05/SA scoring function represents a significant improvement over the earlier ECEPP3/OONS version of the force field. Thus, it is able to rank native-like structures with C(alpha) root-mean-square-deviations below 3.5 A as lowest-energy conformations for 76% and within the top 10 for 87% of the proteins tested, compared with 69 and 80%, respectively, for ECEPP3/OONS. The use of the FAMBEpH solvation model, which provides a more accurate description of the protein-solvent interactions, improves the discriminative ability of the scoring function to 89%. All failed tests in which the native-like structures cannot be discriminated as those with low

  11. Solvent abuse: a review.

    Science.gov (United States)

    Barnes, G E

    1979-01-01

    The literature on solvent abuse is reviewed. Methods of use, symptoms of use, and effects of long-term solvent abuse are discussed. Several surveys on solvent use are summarized. The highest prevalence of solvent abuse seems to occur in native peoples undergoing periods of cultural change. Environmental conditions which are postulated as leading to psychological vulnerability and solvent abuse include: low social assets, parental drug use, peer and sibling influence, and acculturative stress. Solvent abuse seems to provide a pharmacological way out of a stressful environment for people who feel helpless to improve their situation in other ways. Methods of intervention that have been proposed for dealing with solvent abuse are discussed. Methods of intervention thus far employed generally have not been evaluated in any systematic fashion. Suggestions for future research are provided.

  12. Understanding and Modelling the Effect of Dissolved Metals on Solvent Degradation in Post Combustion CO2 Capture Based on Pilot Plant Experience

    Directory of Open Access Journals (Sweden)

    Sanjana Dhingra

    2017-05-01

    Full Text Available Oxidative degradation is a serious concern for upscaling of amine-based carbon capture technology. Different kinetic models have been proposed based on laboratory experiments, however the kinetic parameters included are limited to those relevant for a lab-scale system and not a capture plant. Besides, most of the models fail to recognize the catalytic effect of metals. The objective of this work is to develop a representative kinetic model based on an apparent auto-catalytic reaction mechanism between solvent degradation, corrosion and ammonia emissions. Measurements from four different pilot plants: (i EnBW’s plant at Heilbronn, Germany (ii TNO’s plant at Maasvlakte, The Netherlands; (iii CSIRO’s plants at Loy Yang and Tarong, Australia and (iv DONG Energy’s plant at Esbjerg, Denmark are utilized to propose a degradation kinetic model for 30 wt % ethanolamine (MEA as the capture solvent. The kinetic parameters of the model were regressed based on the pilot plant campaign at EnBW. The kinetic model was validated by comparing it with the measurements at the remaining pilot campaigns. The model predicted the trends of ammonia emissions and metal concentration within the same order of magnitude. This study provides a methodology to establish a quantitative approach for predicting the onset of unacceptable degradation levels which can be further used to devise counter-measure strategies such as reclaiming and metal removal.

  13. Designing Solvent Exchange-Induced In Situ Forming Gel from Aqueous Insoluble Polymers as Matrix Base for Periodontitis Treatment.

    Science.gov (United States)

    Srichan, Tharatree; Phaechamud, Thawatchai

    2017-01-01

    An in situ forming gel is a dosage form which is promised for site-specific therapy such as periodontal pocket of periodontitis treatment. Ethylcellulose, bleached shellac, and Eudragit RS were applied in this study as a polymeric matrix for in situ forming gel employing N-methyl pyrrolidone (NMP) as solvent. Solutions comprising ethylcellulose, bleached shellac, and Eudragit RS in NMP were evaluated for viscosity, rheology, and rate of water penetration. Ease of administration by injection was determined as the force required to expel polymeric solutions through a needle using texture analyzer. In vitro gel formation and in vitro gel degradation were conducted after injection into phosphate buffer solution pH 6.8. Ethylcellulose, bleached shellac, and Eudragit RS could form the in situ gel, in vitro. Gel viscosity and pH value depended on percentage amount of the polymer, whereas the water diffusion at early period likely relied on types of polymer. Furthermore, the solutions containing higher polymer concentration exhibited the lower degree of degradation. All the preparations were acceptable as injectable dosage forms because the applied force was lower than 50 N. All of them inhibited Staphylococcus aureus, Escherichia coli, Candida albicans, Streptococcus mutans, and Porphyrommonas gingivalis growth owing to antimicrobial activity of NMP which exhibited a potential use for periodontitis treatment. Moreover, the developed systems presented as the solvent exchange induced in situ forming gel and showed capability to be incorporated with the suitable antimicrobial active compounds for periodontitis treatment which should be further studied.

  14. Accelerated solvent extraction for GC-based tobacco fingerprinting and its comparison with simultaneous distillation and extraction.

    Science.gov (United States)

    Li, Yong; Pang, Tao; Guo, Ziming; Li, Yanli; Wang, Xiaolin; Deng, Jianhua; Zhong, Kejun; Lu, Xin; Xu, Guowang

    2010-04-15

    An accelerated solvent extraction (ASE) procedure has been developed as a pretreatment method for chemical fingerprinting of volatile and semi-volatile components in cut tobacco. The ASE extraction conditions including temperature, operation pressure and extraction cycles were optimized to maximize extraction yield. The method was validated with repeatability, recovery and linearity. Compared with simultaneous distillation extraction (SDE), ASE provides higher extraction yields, less extraction time, lower solvent consumption and less labor time, and is more suitable for tobacco sample preparation. A typical ASE extract was analyzed by gas chromatography/time-of-flight mass spectrometry (GC-TOFMS). A total of 305 components with signal-to-noise ratio higher than 100 were tentatively identified by NIST05 and Wiley database. Finally, 36 cigarette samples from six cigarette brands were analyzed using the developed chemical fingerprinting method. Partial least squares-discriminant analysis shows good discrimination of different cigarette brands. The results indicate that ASE method can serve as high-throughput sample preparation technique for cigarette chemical fingerprint analysis.

  15. A facile, green, one-pot synthesis of amidoalkyl naphthols under solvent-free conditions catalyzed by a carbon-based solid acid

    Institute of Scientific and Technical Information of China (English)

    Abolghasem Davoodnia; Rahil Mahjoobin; Niloofar Tavakoli-Hoseini

    2014-01-01

    An efficient, environmentally friendly procedure for the synthesis of amidoalkyl naphthols through the one-pot, three-component reaction of β-naphthol, aryl aldehydes, and acetamide in the presence of a carbon-based solid acid under thermal solvent-free conditions is described. The beneficial fea-tures of this new synthetic approach include short reaction time, high yields, clean reaction profiles, and a simple work-up procedure. Furthermore, the catalyst can be readily recycled and reused four times without obvious significant loss of activity. The structure of the catalyst was confirmed by Fourier transform infrared spectroscopy, N2 adsorption/desorption analysis, and X-ray diffraction.

  16. EFFECTS OF SOLVENT, BASE, AND TEMPERATURE IN THE OPTIMISATION OF A NEW CATALYTIC SYSTEM FOR SONOGASHIRA CROSS-COUPLING USING NCP PINCER PALLADACYCLE

    Directory of Open Access Journals (Sweden)

    Diego S. Rosa

    2015-05-01

    Full Text Available The optimisation of a new catalyst system using NCP pincer palladacycle 1 was investigated using the experimental design technique. NCP pincer palladacycle 1 was previously investigated in Suzuki-Miyaura and Heck-Mizoroki cross-couplings and found to be a highly efficient catalyst precursor. In this study, the effects of the type of base (K3PO4 or DABCO, solvent (DMF or dioxane and reaction temperature (130 or 150 ºC in the second step on the reactional yield in Sonogashira cross-coupling were assessed using the two-factor design. The results showed that temperature is statistically significant in relation to the reaction yield.

  17. Synthesis of (E-2-Styrylchromones and Flavones by Base-Catalyzed Cyclodehydration of the Appropriate β-Diketones Using Water as Solvent

    Directory of Open Access Journals (Sweden)

    Joana Pinto

    2015-06-01

    Full Text Available A low cost, safe, clean and environmentally benign base-catalyzed cyclodehydration of appropriate β-diketones affording (E-2-styrylchromones and flavones in good yields is disclosed. Water was used as solvent and the reactions were heated using classical and microwave heating methods, under open and closed vessel conditions. β-Diketones having electron-donating and withdrawing substituents were used to evaluate the reaction scope. The reaction products were isolated in high purity by simple filtration and recrystallization from ethanol, when using 800 mg of the starting diketone under classical reflux heating conditions.

  18. Las pinturas rupestres de la «Cueva Grande de El Puntal» (El Centenillo, Jaén

    Directory of Open Access Journals (Sweden)

    Manuel Gabriel LÓPEZ PAYER

    2009-10-01

    Full Text Available RESUMEN: Las pinturas rupestres esquemáticas de «Cueva Grande» en El Puntal (Baños de la Encina, Jaén, están situadas al Norte de esta provincia, en plena Sierra Morena. «Cueva Grande» es una cueva no muy profunda, cuyas características tipológicas más importantes pueden ser resumidas como sigue:1.° Existencia de dos colores: rojo y negro. 2.° Una gran heterogeneidad en los temas representados. 3.° Se observa cierta influencia del área cultural del Bronce de Extremadura. 4.° No presenta claros paralelismos con el resto de las representaciones pictóricas de Sierra Morena. 5. ° Muy cerca del lugar donde se encuentran las pinturas existen restos arqueológicos correspondientes al Bronce I. Pero creemos que no tienen una relación directa con estas pinturas. En general, parece que es una representación bastante tardía, pudiendo tratarse de una fase cultural del Bronce Final.ABSTRACT: In «Cueva Grande» (El Puntal, Baños de la Encina that is a not very deep cave situated in the North of Jaén, in the center of Sierra Morena, there are some schematic cave paintings whose more important characteristics may be resumed as follows: 1.° The existence of the red and black colours. 2." A great heterogeneity in themes represented. Practically no theme is repeated. 3.° Statistically, at least, there is a great influence of the cultural area of the Bronze's Age of Extremadura. 4. ° Till the moment there haven ' t been found clear typologie parallels with the rest of Sierra Morena's paintings. 5." Nearly to the place where the paintings are, there are archaelogical remains that belong to the Bronze I. Nevertheless we don't believe they have a direct relation with these paintings, but with the ones situated in a place that is very near to the ones studied. In general, it seems to be a very late representation, may be situated in a cultural moment of the Final Bronze Age.

  19. El empleo de la Concha Nácar en la pintura virreinal : estudio radiográfico de la colección de pintura "enconchada" del Museo de América de Madrid

    OpenAIRE

    Estefanía Rivas Díaz

    2002-01-01

    El presente artículo muestra los trabajos realizados sobre una de las más importantes colecciones españolas de pintura colonial: la colección de «enconchados» del Museo de América de Madrid. Hasta ahora tan sólo había sido analizada desde un punto de vista formal; nuestra contribución pretende en cambio un análisis técnico, a partir de estudios radiográficos y estratigráficos, desde el cual ampliar nuestro conocimiento de los artistas y el arte del virreinato de la Nueva España.This paper is ...

  20. Molecular Thermodynamic Modeling of Mixed Solvent Solubility

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O’Connell, John P.

    2010-01-01

    A method based on statistical mechanical fluctuation solution theory for composition derivatives of activity coefficients is employed for estimating dilute solubilities of 11 solid pharmaceutical solutes in nearly 70 mixed aqueous and nonaqueous solvent systems. The solvent mixtures range from...... nearly ideal to strongly nonideal. The database covers a temperature range from 293 to 323 K. Comparisons with available data and other existing solubility methods show that the method successfully describes a variety of observed mixed solvent solubility behaviors using solute−solvent parameters from...

  1. DOE solvent handbook information sheet

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, A.A.

    1992-01-01

    Solvents and cleaners are used in the Department of Defense (DOD) and the Department of Energy-Defense Program (DOE-DP) maintenance facilities for removing wax, grease, oil, carbon, machining fluids, solder fluxes, mold releases, and other contaminants before repairing or electroplating parts. Private industry also uses cleaners and degreasers for surface preparation of various metals. Growing environmental and worker safety concerns have brought attention to these solvents and cleaners, most of which are classified as toxic. Tightening government regulations have already excluded the use of some chemicals, and restrict the use of various halogenated hydrocarbons because of their atmospheric-ozone depleting effects, as well as their cancer-related risks. As a result, a program was established to develop an efficient, easily accessible, electronic solvent utilization handbook. This is being accomplished by: (1) identifying solvents (alternatives) that are not currently restricted by government regulations for use DOE-DP facilities, and private industry, (2) evaluating their cleaning performance, (3) evaluating their corrosivity, (4) evaluating their air emissions, (5) evaluating the possibility of recycling or recovering all or portions of the alternative degreasers, (6) testing substitute solvents compatibility with non-metallic materials, (7) inputting all of the data gathered (including previous biodegradability information) into a database, and (8) developing a methodology for efficient, widespread access to the data base information system.

  2. DOE solvent handbook information sheet

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, A.A.

    1992-05-01

    Solvents and cleaners are used in the Department of Defense (DOD) and the Department of Energy-Defense Program (DOE-DP) maintenance facilities for removing wax, grease, oil, carbon, machining fluids, solder fluxes, mold releases, and other contaminants before repairing or electroplating parts. Private industry also uses cleaners and degreasers for surface preparation of various metals. Growing environmental and worker safety concerns have brought attention to these solvents and cleaners, most of which are classified as toxic. Tightening government regulations have already excluded the use of some chemicals, and restrict the use of various halogenated hydrocarbons because of their atmospheric-ozone depleting effects, as well as their cancer-related risks. As a result, a program was established to develop an efficient, easily accessible, electronic solvent utilization handbook. This is being accomplished by: (1) identifying solvents (alternatives) that are not currently restricted by government regulations for use DOE-DP facilities, and private industry, (2) evaluating their cleaning performance, (3) evaluating their corrosivity, (4) evaluating their air emissions, (5) evaluating the possibility of recycling or recovering all or portions of the alternative degreasers, (6) testing substitute solvents compatibility with non-metallic materials, (7) inputting all of the data gathered (including previous biodegradability information) into a database, and (8) developing a methodology for efficient, widespread access to the data base information system.

  3. In silico study of amphiphilic nanotubes based on cyclic peptides in polar and non-polar solvent

    DEFF Research Database (Denmark)

    Vijayakumar, Vinodhkumar; Vijayaraj, Ramadoss; Peters, Günther H.J.

    2016-01-01

    The stability of cyclic peptide assemblies (CPs) forming a macromolecular nanotube structure was investigated in solvents of different polarity using computational methods. The stability and structure of the complexes were studied using traditional molecular dynamics (MD). Energy of dissociation...... was estimated from steered MD in combination with umbrella sampling simulations. A cyclic peptide nanotube (CPNT) was constructed by stacking of eight cyclo[(d-Trp-l-Gln-d-Trp-l-Glu)2], and hereafter is referred to as (WQWE)8. Its dissociation was studied by pulling 1, 2, or 3 subunits from the nanotube....... The crucial point in the dissociation event of the CP subunit(s) is the breaking of backbone–backbone hydrogen bonds and consecutive annihilation of side chain interactions. Gibbs free energy calculations to estimate the binding affinity of CP subunit(s) reveal that the (WQWE)8 nanotube is significantly more...

  4. Membrane-Based Osmotic Heat Engine with Organic Solvent for Enhanced Power Generation from Low-Grade Heat

    Energy Technology Data Exchange (ETDEWEB)

    Shaulsky, E; Boo, C; Lin, SH; Elimelech, M

    2015-05-05

    We present a hybrid osmotic heat engine (OHE) system that uses draw solutions with an organic solvent for enhanced thermal separation efficiency. The hybrid OHE system produces sustainable energy by combining pressure-retarded osmosis (PRO) as a power generation stage and membrane distillation (MD) utilizing low-grade heat as a separation stage. While previous OHE systems employed aqueous electrolyte draw solutions, using methanol as a solvent is advantageous because methanol is highly volatile and has a lower heat capacity and enthalpy of vaporization than water. Hence, the thermal separation efficiency of a draw solution with methanol would be higher than that of an aqueous draw solution. In this study, we evaluated the performance of LiCl-methanol as a potential draw solution for a PRO-MD hybrid OHE system. The membrane transport properties as well as performance with LiCl methanol draw solution were evaluated using thin-film composite (TFC) PRO membranes and compared to the results obtained with a LiCl water draw solution. Experimental PRO methanol flux and maximum projected power density of 47.1 L m(-2) h(-1) and 72.1 W m(-2), respectively, were achieved with a 3 M LiCl-methanol draw solution. The overall efficiency of the hybrid OHE system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages under conditions with and without heat recovery. The modeling results demonstrate higher ORE energy efficiency with the LiCl methanol draw solution compared to that with the LiCl water draw solution under practical operating conditions (i.e., heat recovery <90%). We discuss the implications of the results for converting low-grade heat to power.

  5. Paraísos artificiales. La imagen drogada en la pintura europea del entresiglos XIX-XX

    OpenAIRE

    2015-01-01

    Paraísos artificiales. La imagen drogada en la pintura europea del entresiglos XIX-XX. La presente investigación recopila y analiza la imagen pictórica drogada en el entresiglos XIX-XX europeo, prestando especial atención al caso español, desde la exposición descriptiva; un trabajo elaborado con voluntad de catálogo. Las conclusiones teóricas dan cuenta no sólo de que el leitmotiv tóxico puede convertirse en una temática cambiosecular en sí misma, también pone de manifiesto como el uso y ...

  6. La presencia de la música en la pintura del cubismo de Pablo Picasso hasta 1914

    OpenAIRE

    2013-01-01

    La presencia de los instrumentos musicales es numerosa y significativa en todas las fases del cubismo. Analizando la evocación musical de la pintura cubista, ésta se desvela como un impulso creativo y un puente de conocimiento en esta revolución artística que transformó el arte del s. XX. En esa ruptura con todo lo anterior en el arte, en la búsqueda de un nuevo espacio pictórico y una exploración sin límites de un nuevo lenguaje pictórico, están siempre presente la música: en los volúmenes, ...

  7. De la pintura española a un semanario argentino: Las portadas de Eugenio Fornells para Con Permiso

    Directory of Open Access Journals (Sweden)

    Lorena Mouguelar

    2015-07-01

    Full Text Available El artículo propone un análisis iconográfico de las portadas que Eugenio Fornells realizó para Con Permiso, semanario crítico editado en la ciudad de Rosario, Argentina, entre febrero y abril de 1919. Pese a la breve existencia de esta publicación, su estudio permite poner a foco los vínculos entre las tradiciones de la pintura occidental y ciertas ilustraciones impresas en Argentina a principios del siglo XX, así como la incidencia de las migraciones trasnacionales de creadores visuales en el tránsito de tendencias estéticas de un continente a otro. Las imágenes del artista catalán muestran un cruce productivo entre elementos de la alta cultura moderna y la prensa satírica masiva.

  8. EL ARTE ES VIDA Y LA VIDA ES ARTE: LA PINTURA DE JOSÉ DEL CARMEN HERNÁNDEZ

    Directory of Open Access Journals (Sweden)

    Bogdan Piotrowski

    2014-01-01

    Full Text Available Se presenta aquí la obra artística de José del Carmen Hernández desde la premisa según la cual, al valorar su pintura podemos hablar del arte de la vida y de la vida artística plena. Se resalta su esforzada trayectoria de vida que lo ha llevado desde un humilde origen campesino hasta la formación artística académica y a través de tertulias de artistas en diferentes partes del mundo. Al destacar su obra pictórica, escultórica, mural y abstracta, se concluye con el vínculo actual del artista con su propia realidad y la esperanza como motor de su obra frente a la constata - ción de las violencias persistentes.

  9. Comparison of contact angle measurement and microbial adhesion to solvents for assaying electron donor-electron acceptor (acid-base) properties of bacterial surface.

    Science.gov (United States)

    Hamadi, Fatima; Latrache, Hassan

    2008-08-01

    The electron donor-electron acceptor (acid-base properties) of cell surfaces of a series of bacteria were determined by two methods, namely, Microbial Adhesion to Solvents (MATS) and Contact Angle Measurements (CAM) combined with equation of Van Oss. The efficiency of these two methods was then compared. Pseudomonas aeruginosa ATCC 27853, Bacillus subtilis ILP 142B, Staphylococcus aureus ATCC 25923 and four Escherichia coli strains including HB101, AL52, O128B12 and ATCC 25922, acid-base properties were examined under the two different conditions mentioned above. The results showed that the correlation between acid-base properties determined by MATS and CAM was very weak. We have also found that when the microbial cell surface was electron donor by CAM method, similar result was found by MATS, but the reverse was not always true. In contrast, a good correlation between the two methods was obtained when the four E. coli strains were examined.

  10. Water based on a molecular model behaves like a hard-sphere solvent for a nonpolar solute when the reference interaction site model and related theories are employed

    Science.gov (United States)

    Hayashi, Tomohiko; Oshima, Hiraku; Harano, Yuichi; Kinoshita, Masahiro

    2016-09-01

    For neutral hard-sphere solutes, we compare the reduced density profile of water around a solute g(r), solvation free energy μ, energy U, and entropy S under the isochoric condition predicted by the two theories: dielectrically consistent reference interaction site model (DRISM) and angle-dependent integral equation (ADIE) theories. A molecular model for water pertinent to each theory is adopted. The hypernetted-chain (HNC) closure is employed in the ADIE theory, and the HNC and Kovalenko-Hirata (K-H) closures are tested in the DRISM theory. We also calculate g(r), U, S, and μ of the same solute in a hard-sphere solvent whose molecular diameter and number density are set at those of water, in which case the radial-symmetric integral equation (RSIE) theory is employed. The dependences of μ, U, and S on the excluded volume and solvent-accessible surface area are analyzed using the morphometric approach (MA). The results from the ADIE theory are in by far better agreement with those from computer simulations available for g(r), U, and μ. For the DRISM theory, g(r) in the vicinity of the solute is quite high and becomes progressively higher as the solute diameter d U increases. By contrast, for the ADIE theory, it is much lower and becomes further lower as d U increases. Due to unphysically positive U and significantly larger |S|, μ from the DRISM theory becomes too high. It is interesting that μ, U, and S from the K-H closure are worse than those from the HNC closure. Overall, the results from the DRISM theory with a molecular model for water are quite similar to those from the RSIE theory with the hard-sphere solvent. Based on the results of the MA analysis, we comparatively discuss the different theoretical methods for cases where they are applied to studies on the solvation of a protein.

  11. Fluorescent derivatization combined with aqueous solvent-based dispersive liquid-liquid microextraction for determination of butyrobetaine, l-carnitine and acetyl-l-carnitine in human plasma.

    Science.gov (United States)

    Chen, Yi-Ching; Tsai, Chia-Ju; Feng, Chia-Hsien

    2016-09-16

    A novel aqueous solvent-based dispersive liquid-liquid microextraction (AS-DLLME) method was combined with narrow-bore liquid chromatography and fluorescence detection for the determination of hydrophilic compounds. A remover (non-polar solvent) and extractant (aqueous solution) were introduced into the derivatization system (acetonitrile) to obtain a water-in-oil emulsion state that increased the mass transfer of analytes. As a proof of concept, three quaternary ammonium substances, including butyrobetaine, l-carnitine and acetyl-l-carnitine, were also used as analytes and determined in pharmaceuticals, personal care products, food and human plasma. The analytes were derivatized with 4-bromomethylbiphenyl for fluorescence detection and improved retention in the column. The linear response was 10-2000nM for l-carnitine and acetyl-l-carnitine with a good determination coefficient (r(2)>0.998) in the standard solution. The detection limit for l-carnitine and acetyl-l-carnitine was 4.5 fmol. The method was also successfully applied to a 1μL sample of human plasma. In the linearity calculations for determining butyrobetaine, l-carnitine and acetyl-l-carnitine in human plasma, the determination coefficients ranged from 0.996 to 0.999. Linear regression exhibited good reproducibility and a relative standard deviation better than 7.50% for the slope and 9.06% for the intercept. To characterize highly hydrophilic compounds in various samples, the proposed method provides good sensitivity for a small sample volume with a low consumption of toxic solvents.

  12. Influence of Solvent-Solvent and Solute-Solvent Interaction Properties on Solvent-Mediated Potential

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Qi

    2005-01-01

    A recently proposed universal calculational recipe for solvent-mediated potential is applied to calculate excess potential of mean force between two large Lennard-Jones (LJ) or hard core attractive Yukawa particles immersed in small LJ solvent bath at supercritical state. Comparison between the present prediction with a hypernetted chain approximation adopted for solute-solute correlation at infinitely dilute limit and existing simulation data shows high accuracy for the region with large separation, and qualitative reliability for the solute particle contact region. The calculational simplicity of the present recipe allows for a detailed investigation on the effect of the solute-solvent and solvent-solvent interaction details on the excess potential of mean force. The resultant conclusion is that gathering of solvent particles near a solute particle leads to repulsive excess PMF, while depletion of solvent particles away from the solute particle leads to attractive excess PMF, and minor change of the solvent-solvent interaction range has large influence on the excess PMF.

  13. Determination of atenolol in human plasma using ionic-liquid-based ultrasound-assisted in situ solvent formation microextraction followed by high-performance liquid chromatography.

    Science.gov (United States)

    Zeeb, Mohsen; Farahani, Hadi; Papan, Mohammad Kazem

    2016-06-01

    An efficient analytical method called ionic-liquid-based ultrasound-assisted in situ solvent formation microextraction followed by high-performance liquid chromatography was developed for the determination of atenolol in human plasma. A hydrophobic ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) was formed by the addition of a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) to a sample solution containing an ion-pairing agent during microextraction. The analyte was extracted into the ionic liquid phase while the microextraction solvent was dispersed throughout the sample by utilizing ultrasound. The sample was then centrifuged, and the extracting phase retracted into the microsyringe and injected to liquid chromatography. After optimization, the calibration curve showed linearity in the range of 2-750 ng/mL with the regression coefficient corresponding to 0.998. The limits of detection (S/N = 3) and quantification (S/N = 10) were 0.5 and 2 ng/mL, respectively. A reasonable relative recovery range of 90-96.7% and satisfactory intra-assay (4.8-5.1%, n = 6) and interassay (5.0-5.6%, n = 9) precision along with a substantial sample clean-up demonstrated good performance of the procedure. It was applied for the determination of atenolol in human plasma after oral administration and some pharmacokinetic data were obtained.

  14. Solvent- and Pressure-Induced Phase Changes in Two 3D Copper Glutarate-Based Metal-Organic Frameworks via Glutarate (+gauche ⇄ -gauche) Conformational Isomerism.

    Science.gov (United States)

    Bezuidenhout, Charl X; Smith, Vincent J; Esterhuysen, Catharine; Barbour, Leonard J

    2017-04-26

    Two isoreticular three-dimensional copper(II) glutarate-based pillared-layered metal-organic frameworks (MOFs) with flexible pillars, [Cu2(glu)2(bpa)] and [Cu2(glu)2(bpp)] (bpa = 1,2-bis(4-pyridyl)ethane; bpp = 1,3-bis(4-pyridyl)propane), undergo spontaneous phase changes upon solvent loss at room temperature. Using single-crystal X-ray diffraction analysis (SCXRD), we show that the phase changes result in new narrow-channel forms that experience a large reduction in solvent-accessible volume. Moreover, the [Cu2(glu)2(bpa)] MOF displays a stepped sorption isotherm for the uptake of CO2 at room temperature. This is indicative of reversion of the framework to the wide-channel form under CO2 pressure. Supercritical CO2 was used to isolate the gas-included structures, and by means of SCXRD we were able to determine the positions of the CO2 molecules in the channels of the frameworks. Finally, we report the use of molecular modeling simulations to elucidate the phase-change mechanism, including the energetic changes involved. Structural limitations in both MOFs allow for only direct gauche-gauche enantiomeric interconversion of the glutarate moieties.

  15. The hybrid MPC-MINLP algorithm for optimal operation of coal-fired power plants with solvent based post-combustion CO2 capture

    Directory of Open Access Journals (Sweden)

    Norhuda Abdul Manaf

    2017-03-01

    Full Text Available This paper presents an algorithm that combines model predictive control (MPC with MINLP optimization and demonstrates its application for coal-fired power plants retrofitted with solvent based post-combustion CO2 capture (PCC plant. The objective function of the optimization algorithm works at a primary level to maximize plant economic revenue while considering an optimal carbon capture profile. At a secondary level, the MPC algorithm is used to control the performance of the PCC plant. Two techno-economic scenarios based on fixed (capture rate is constant and flexible (capture rate is variable operation modes are developed using actual electricity prices (2011 with fixed carbon prices ($AUD 5, 25, 50/tonne-CO2 for 24 h periods. Results show that fixed operation mode can bring about a ratio of net operating revenue deficit at an average of 6% against the superior flexible operation mode.

  16. Alternative Green Solvents Project

    Science.gov (United States)

    Maloney, Phillip R.

    2012-01-01

    Necessary for safe and proper functioning of equipment. Mainly halogenated solvents. Tetrachloride, Trichloroethylene (TCE), CFC-113. No longer used due to regulatory/safety concerns. Precision Cleaning at KSC: Small % of total parts. Used for liquid oxygen (LOX) systems. Dual solvent process. Vertrel MCA (decafluoropentane (DFP) and trons-dichloroethylene) HFE-7100. DFP has long term environmental concerns. Project Goals: a) Identify potential replacements. b) 22 wet chemical processes. c) 3 alternative processes. d) Develop test procedures. e) Contamination and cleaning. f) Analysis. g) Use results to recommend alternative processes. Conclusions: a) No alternative matched Vertrel in this study. b) No clear second place solvent. c) Hydrocarbons- easy; Fluorinated greases- difficult. d) Fluorinated component may be needed in replacement solvent. e) Process may need to make up for shortcoming of the solvent. f) Plasma and SCC02 warrant further testing.

  17. A pintura antifurto de Pedro Victor Brandão. Política como arte no contexto de crise econômica mundial

    Directory of Open Access Journals (Sweden)

    Marcelo Neder Cerqueira

    2014-12-01

    Full Text Available Pintura Antifurto é resultado da apropriação das imagens de anversos e reversos de cédulas manchadas por um dispositivo antifurto em explosões de caixas eletrônicos. A partir de uma autorização emitida pelo Departamento do Meio Circulante do Banco Central, reproduções fotográficas tem sido feitas e distribuídas gratuitamente. O texto que segue foi apresentado por Marcelo Neder Cerqueira no dia 20 de Outubro de 2011, quando a Casa França-Brasil promoveu a mesa redonda sobre a Pintura Antifurto. A mostra foi realizada dentro na Ocupação Cofre, onde artistas mostram seus trabalhos numa sala de 2,40m² sem função definida desde a transformação em centro cultural. Entre 1820 e 1924, a histórica construção da Casa França-Brasil, localizada em frente à Baía de Guanabara, abrigou a primeira praça do comércio da cidade. Abstract: Pintura Antifurto [Anti-theft Painting] results from appropriation of the images of observes and reverses of banknotes marked by an anti-theft device in explosions of ATM’s. After an authorization issued by the Currency Department of the Central Bank, photographic reproductions were made and freely distributed. This text was presented on October 20th 2014, when Casa França-Brasil realized a debate about Pintura Antifurto. The show was realized on the framework of Ocupação Cofre [Vault Occupation], where artists are invited to exhibit in a room of 2.40 m² that has no function since the transformation in cultural center of this construction that from 1820 to 1924 worked as the first commerce square of the city.

  18. A novel poly(deep eutectic solvent)-based magnetic silica composite for solid-phase extraction of trypsin.

    Science.gov (United States)

    Xu, Kaijia; Wang, Yuzhi; Li, Yixue; Lin, Yunxuan; Zhang, Haibao; Zhou, Yigang

    2016-11-23

    Novel poly(deep eutectic solvent) grafted silica-coated magnetic microspheres (Fe3O4@SiO2-MPS@PDES) were prepared by polymerization of choline chloride-itaconic acid (ChCl-IA) and γ-MPS-modified magnetic silica composites, and were characterized by vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectra (XPS), thermal gravimetric analysis (TGA) and transmission electron microscope (TEM). Then the synthetic Fe3O4@SiO2-MPS@PDES microspheres were applied for the magnetic solid-phase extraction (MSPE) of trypsin for the first time. After extraction, the concentration of trypsin in the supernatant was determined by a UV-vis spectrophotometer. Single factor experiments were carried out to investigate the effects of the extraction process, including the concentration of trypsin, the ionic strength, the pH value, the extraction time and the temperature. Experimental results showed the extraction capacity could reach up to 287.5 mg/g under optimized conditions. In comparison with Fe3O4@SiO2-MPS, Fe3O4@SiO2-MPS@PDES displayed higher extraction capacity and selectivity for trypsin. According to the regeneration studies, Fe3O4@SiO2-MPS@PDES microspheres can be recycled six times without significant loss of its extraction capacity, and retained a high extraction capacity of 233 mg/g after eight cycles. Besides, the activity studies also demonstrated that the activity of the extracted trypsin was well retained. Furthermore, the analysis of real sample revealed that the prepared magnetic microspheres can be used to purify trypsin in crude bovine pancreas extract. These results highlight the potential of the proposed Fe3O4@SiO2-MPS@PDES-MSPE method in separation of biomolecules.

  19. Modulation of Electron Injection Dynamics of Ru-Based Dye/TiO2 System in the Presence of Three Different Organic Solvents: Role of Solvent Dipole Moment and Donor Number.

    Science.gov (United States)

    Mahanta, Subrata; Matsuzaki, Hiroyuki; Murakami, Takurou N; Katoh, Ryuzi; Matsumoto, Hajime; Furube, Akihiro

    2015-06-08

    In the present work, femtosecond transient absorption spectroscopy (fs-TAS) has been employed to investigate the electron injection efficiency (EIE) both from the singlet and triplet excited states of a well-known ruthenium dye (N719) to the conduction band (CB) of nanostructured TiO(2) in presence of three different organic solvents [γ-butylactone (GBL), 3-methoxypropionitrile (MPN), and dimethylformamide (DMF)] with different donor numbers (DNs) and dipole moments (DMs). The DM and DN of a solvent modulates the CB edge energy of TiO(2), and this effect reflects well in the fs-TAS results, which shows an EIE trend following the order GBL≥MPN≫DMF, that is, highest in GBL and lowest in DMF solvent environments. Fs-TAS results indicate a lower contribution of electron injection from both the singlet and triplet states in DMF, for which the dominant adsorption of DMF molecules on the TiO(2) surface seems to play an important role in the mechanism.

  20. Temperature-based on-column solute focusing in capillary liquid chromatography reduces peak broadening from pre-column dispersion and volume overload when used alone or with solvent-based focusing.

    Science.gov (United States)

    Groskreutz, Stephen R; Horner, Anthony R; Weber, Stephen G

    2015-07-31

    On-column focusing is essential for satisfactory performance using capillary scale columns. On-column focusing results from generating transient conditions at the head of the column that lead to high solute retention. Solvent-based on-column focusing is a well-known approach to achieve this. Temperature-assisted on-column focusing (TASF) can also be effective. TASF improves focusing by cooling a short segment of the column inlet to a temperature that is lower than the column temperature during the injection and then rapidly heating the focusing segment to the match the column temperature. A troublesome feature of an earlier implementation of TASF was the need to leave the capillary column unpacked in that portion of the column inside the fitting connecting it to the injection valve. We have overcome that problem in this work by packing the head of the column with solid silica spheres. In addition, technical improvements to the TASF instrumentation include: selection of a more powerful thermo-electric cooler to create faster temperature changes and electronic control for easy incorporation into conventional capillary instruments. Used in conjunction with solvent-based focusing and with isocratic elution, volumes of paraben samples (esters of p-hydroxybenzoic acid) up to 4.5-times the column liquid volume can be injected without significant bandspreading due to volume overload. Interestingly, the shapes of the peaks from the lowest volume injections that we can make, 30nL, are improved when using TASF. TASF is very effective at reducing the detrimental effects of pre-column dispersion using isocratic elution. Finally, we show that TASF can be used to focus the neuropeptide galanin in a sample solvent with elution strength stronger than the mobile phase. Here, the stronger solvent is necessitated by the need to prevent peptide adsorption prior to and during analysis.

  1. La Casa Profesa de los Jesuitas en Madrid y una serie de pinturas adquiridas por Carlos III

    Directory of Open Access Journals (Sweden)

    Sánchez López, Andrés

    2007-09-01

    Full Text Available This study deals with the reconstruction -both architectonic and pictorial- of the 17th-century Main House (Casa Profesa and church of the Jesuits in Madrid, unfortunately destroyed during the 19th century due to the urban reforms carried out on the calle Mayor. Thanks to a series of paintings acquired by Carlos III following the expulsion of the Jesuits from Spain (1767, it is possible to have an idea of the important works that once adorned this temple. The author locates and studies these paintings, all of them of artistic interest, since they are by major 17th-century painters such as Luca Giordano, Murillo or Pedro Orrente, as well as 16th-century masters such as Andrea del Sarto or Gerolamo Muziano.

    La Casa Profesa de los Jesuitas en Madrid y una serie de pinturas adquiridas por Carlos III. El estudio supone una reconstrucción de la fundación de la Casa Profesa de los Jesuitas de Madrid así de cómo debía ser el templo. Este edificio, uno de los más importantes de la Capital en el siglo XVII, desapareció desafortunadamente en el s. XIX con el cambio urbanístico que sufrió la calle Mayor. Gracias a una serie de pinturas que Carlos III adquirió tras la expulsión de los Jesuitas podemos hacernos una idea de las importantes obras de arte que ornaban este templo. El estudio sirve también para la localización y estudio de estas obras todas ellas de gran interés artístico pues fueron realizadas por algunos de los más importantes pintores del s. XVII como Luca Giordano, Murillo o Pedro Orrente, así como maestros del siglo XVI italiano tales como Andrea del Sarto o Gerolamo Muziano.

  2. Supercritical solvent coal extraction

    Science.gov (United States)

    Compton, L. E. (Inventor)

    1984-01-01

    Yields of soluble organic extract are increased up to about 50% by the supercritical extraction of particulate coal at a temperature below the polymerization temperature for coal extract fragments (450 C.) and a pressure from 500 psig to 5,000 psig by the conjoint use of a solvent mixture containing a low volatility, high critical temperature coal dissolution catalyst such as phenanthrene and a high volatility, low critical temperature solvent such as toluene.

  3. Comparative study of corn stover pretreated by dilute acid and cellulose solvent-based lignocellulose fractionation: Enzymatic hydrolysis, supramolecular structure, and substrate accessibility.

    Science.gov (United States)

    Zhu, Zhiguang; Sathitsuksanoh, Noppadon; Vinzant, Todd; Schell, Daniel J; McMillan, James D; Zhang, Y-H Percival

    2009-07-01

    Liberation of fermentable sugars from recalcitrant biomass is among the most costly steps for emerging cellulosic ethanol production. Here we compared two pretreatment methods (dilute acid, DA, and cellulose solvent and organic solvent lignocellulose fractionation, COSLIF) for corn stover. At a high cellulase loading [15 filter paper units (FPUs) or 12.3 mg cellulase per gram of glucan], glucan digestibilities of the corn stover pretreated by DA and COSLIF were 84% at hour 72 and 97% at hour 24, respectively. At a low cellulase loading (5 FPUs per gram of glucan), digestibility remained as high as 93% at hour 24 for the COSLIF-pretreated corn stover but reached only approximately 60% for the DA-pretreated biomass. Quantitative determinations of total substrate accessibility to cellulase (TSAC), cellulose accessibility to cellulase (CAC), and non-cellulose accessibility to cellulase (NCAC) based on adsorption of a non-hydrolytic recombinant protein TGC were measured for the first time. The COSLIF-pretreated corn stover had a CAC of 11.57 m(2)/g, nearly twice that of the DA-pretreated biomass (5.89 m(2)/g). These results, along with scanning electron microscopy images showing dramatic structural differences between the DA- and COSLIF-pretreated samples, suggest that COSLIF treatment disrupts microfibrillar structures within biomass while DA treatment mainly removes hemicellulose. Under the tested conditions COSLIF treatment breaks down lignocellulose structure more extensively than DA treatment, producing a more enzymatically reactive material with a higher CAC accompanied by faster hydrolysis rates and higher enzymatic digestibility.

  4. Development of a microfluidic-chip system for liquid-phase microextraction based on two immiscible organic solvents for the extraction and preconcentration of some hormonal drugs.

    Science.gov (United States)

    Asl, Yousef Abdossalami; Yamini, Yadollah; Seidi, Shahram

    2016-11-01

    In the present study, for the first time, an on-chip liquid phase microextraction (LPME) coupled with high performance liquid chromatography was introduced for the analysis of levonorgestrel (Levo), dydrogesterone (Dydo) and medroxyprogesterone (Medo) as the model analytes in biological samples. The chip-based LPME set-up was composed of two polymethyl methacrylate (PMMA) plates with microfabricated channels and a microporous membrane sandwiched between them to separate the sample solution and acceptor phase. These channels were used as a flow path for the sample solution and a thin compartment for the acceptor phase, respectively. In this system, two immiscible organic solvents were used as supported liquid membrane (SLM) and acceptor phase, respectively. During extraction, the model analytes in the sample solution were transported through the SLM (n-dodecane) into the acceptor organic solvent (methanol). The new set-up provided effective and reproducible extractions using low volumes of the sample solution. The effective parameters on the extraction efficiency of the model analytes were optimized using one variable at a time method. Under the optimized conditions, the new set-up provided good linearity in the range of 5.0-500µgL(-1) for the model analytes with the coefficients of determination (r(2)) higher than 0.9909. The relative standard deviations (RSDs%) and limits of detection (LODs) values were less than 6.5% (n=5) and 5.0µgL(-1), respectively. The preconcentration factors (PFs) were obtained using 1.0mL of the sample solution and 20.0µL of the acceptor solution higher than 19.9-fold. Finally, the proposed method was successfully applied for the extraction and determination of the model analytes in urine samples.

  5. Solvent-mediated secondary building units (SBUs) diversification in a series of MnII-based metal-organic frameworks (MOFs)

    Science.gov (United States)

    Niu, Yan-Fei; Cui, Li-Ting; Han, Jie; Zhao, Xiao-Li

    2016-09-01

    The role of auxiliary solvents in the formation of MOFs has been investigated for a series of MnII-based framework systems. Reactions of 4,4‧,4″-nitrilotribenzoic acid (H3L) with MnII through varying auxiliary solvents of the medium resulted in the formation of diversified multinuclear MnII subunits in four new coordination polymers: [Mn3(L)(HCOO)3(DEF)3] (1), [Mn3(L)2(EtOH)2]·DMF (2), [Mn5(L)4(H2O)2]·2(H2NMe2)+·4DMF·2H2O (3), and [Mn3(L)2(py)4(H2O)]·H2O (4) (H3L=4,4‧,4‧-nitrilotribenzoic acid, DMF=dimethylformamide, DEF=N,N-diethylformamide, py=pyridine). These four compounds were fully characterized by single-crystal X-ray diffraction, showing interesting SBUs variations. For compound 1, it displays a (3,6)-connected kgd net with wheel [Mn6] cluster serving as SBU, whereas in 2, the sequence of Mn3(COO)9(EtOH)2 is repeated by inversion centers located between Mn1 and Mn3 to form an infinite Mn-carboxylate chain, which are further interlinked by L3- ligands to form a 3D architecture. In 3, the pentanuclear Mn5(CO2)12 clusters are interlinked to form a layer, which are further pillared by L3- to generate a 3D network. Compound 4 has a (3,6)-connected network in which the SBU is a linear trimeric Mn3(COO)6(py)4(H2O) cluster. In addition, the thermal stabilities, X-ray powder diffraction of all the compounds were studied, photoluminescence behaviors of compounds 1, 3 and 4 are discussed.

  6. Pipette-tip solid-phase extraction based on deep eutectic solvent modified graphene for the determination of sulfamerazine in river water.

    Science.gov (United States)

    Liu, Lingling; Tang, Weiyang; Tang, Baokun; Han, Dandan; Row, Kyung Ho; Zhu, Tao

    2017-05-01

    A green and novel deep eutectic solvent modified graphene was prepared and used as a neutral adsorbent for the rapid determination of sulfamerazine in a river water sample by pipette-tip solid-phase extraction. Compared with conventional graphene, deep eutectic solvent modified graphene can change the surface of graphene with wrinkled structure and higher selective extraction ability. The properties of deep eutectic solvent modified graphene and graphene were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Static adsorption showed deep eutectic solvent modified graphene had a higher adsorption ability (18.62 mg/g) than graphene. Under the optimum conditions, factors such as kinds of washing solvents and elution solvents and volume of elution solvent were evaluated. The limits of detection and quantification were 0.01 and 0.03 μg/mL, respectively. The method recoveries of sulfamerazine were in the range of 91.01-96.82% with associated intraday relative standard deviations ranging from 1.63 to 3.46% and interday relative standard deviations ranging from 0.68 to 3.84%. Deep eutectic solvent modified graphene showed satisfactory results (recovery was 95.38%) and potential for rapid purification of sulfamerazine in river water sample in combination with the pipette-tip solid-phase extraction method. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. The orientation of solvent-dipoles at the surface of the pure solvent

    NARCIS (Netherlands)

    Nedermeijer-Denessen, H.J.M.; Ligny, C.L. de

    1975-01-01

    A method is described for the assessment of the preferential orientation of solvent-dipoles at the surface of the solvent from the surface potential χ and its temperature coefficient, dχ/dT. The method is based on the model of Levine et al. of the Stern inner region at the mercury-water interface in

  8. The orientation of solvent-dipoles at the surface of the pure solvent

    NARCIS (Netherlands)

    Nedermeijer-Denessen, H.J.M.; Ligny, C.L. de

    1975-01-01

    A method is described for the assessment of the preferential orientation of solvent-dipoles at the surface of the solvent from the surface potential χ and its temperature coefficient, dχ/dT. The method is based on the model of Levine et al. of the Stern inner region at the mercury-water interface in

  9. PSE For Solvent Applications: A Generic Computer-aided Solvent Selection and Design Framework

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Sin, Gürkan; Gani, Rafiqul

    Solvents are widely used across a number of industries in many applications such as separation agents, reaction mediums, cleaning agents and product carriers. Selection of optimal solvents in these applications is mostly based on previous experiences and experimental trial and error. A process sy...

  10. Cleaning without chlorinated solvents

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, L.M.; Simandl, R.F.

    1994-12-31

    Because of health and environmental concerns, many regulations have been passed in recent years regarding the use of chlorinated solvents. The Oak Ridge Y-12 Plant has had an active program to find alternatives for these solvents used in cleaning applications for the past 7 years. During this time frame, the quantity of solvents purchased has been reduced by 92%. The program has been a twofold effort. Vapor degreasers used in batch cleaning-operations have been replaced by ultrasonic cleaning with aqueous detergent, and other organic solvents have been identified for use in hand-wiping or specialty operations. In order to qualify these alternatives for use, experimentation was conducted on cleaning ability as well as effects on subsequent operations such as welding, painting and bonding. Cleaning ability was determined using techniques such as X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) which are capable of examining monolayer levels of contamination on a surface. Solvents have been identified for removal of rust preventative oils, lapping oils, machining coolants, lubricants, greases, and mold releases. Solvents have also been evaluated for cleaning urethane foam spray guns, swelling of urethanes and swelling of epoxies.

  11. Uniform Treatment of Solute-Solvent Dispersion in the Ground and Excited Electronic States of the Solute Based on a Solvation Model with State-Specific Polarizability.

    Science.gov (United States)

    Marenich, Aleksandr V; Cramer, Christopher J; Truhlar, Donald G

    2013-08-13

    We present a new kind of treatment of the solute-solvent dispersion contribution to the free energy of solvation using a solvation model with state-specific polarizability (SMSSP). To evaluate the solute-solvent dispersion contribution, the SMSSP model utilizes only two descriptors, namely, the spherically averaged dipole polarizability of the solute molecule (either in its ground or excited electronic state) and the refractive index of the solvent. The model was parametrized over 643 ground-state solvation free energy data for 231 solutes in 14 nonpolar, non-hydrogen-bonding solvents. We show that the SMSSP model is applicable to solutes in both the ground and the excited electronic state. For example, in comparison to available experimental data, the model yields qualitatively accurate predictions of the solvatochromic shifts for a number of systems where solute-solvent dispersion is the dominant contributor to the shift.

  12. Effect of solvents on propylene epoxidation over TS-1 catalyst

    Institute of Scientific and Technical Information of China (English)

    Yulong WU; Qingshan LIU; Xueli SU; Zhentao MI

    2008-01-01

    Solvents have an important effect on the epoxidation of propylene catalyzed by TS-1. The experimental results show that, in different solvents, the catalytic activity of epoxidation is in the following order: methanol > 2-propanol > 2-butanol > acetoni-trile > acetone > tetrahydrofuran. Based on the reaction mechanism, the effects of solvents on the epoxidation were studied from eight aspects, which included the electronic effect, the steric effect, the polarity of solvent, the effect of solvent on sorption and diffusion of reactant, the oxidation of alcohol, the etherification of PO, the deactivation of TS-1 and the solubility of propylene in the solvents. The electronic effect, steric effect and the polarity of solvent were considered to be the main aspects. This work may provide theoretical guidance for choosing solvents for these kinds of reactions and also may serve as basis for further industrialization.

  13. El empleo de la Concha Nácar en la pintura virreinal : estudio radiográfico de la colección de pintura "enconchada" del Museo de América de Madrid

    Directory of Open Access Journals (Sweden)

    Estefanía Rivas Díaz

    2002-01-01

    Full Text Available El presente artículo muestra los trabajos realizados sobre una de las más importantes colecciones españolas de pintura colonial: la colección de «enconchados» del Museo de América de Madrid. Hasta ahora tan sólo había sido analizada desde un punto de vista formal; nuestra contribución pretende en cambio un análisis técnico, a partir de estudios radiográficos y estratigráficos, desde el cual ampliar nuestro conocimiento de los artistas y el arte del virreinato de la Nueva España.This paper is going to show our v/ork on one of the most important Spanish colonial painting collection: the collection of «enconchados» in the American Museum of Madrid. Until now, this collection had been only investigated from a formal point of view: our contribution expose a technical analysis (radiographic and stratigraphic studies, from which is possíble to open the knowledge on New Spain viceroyalty artists and art. We will show the most outstanding elemente discovered.

  14. Solvent-mediated secondary building units (SBUs) diversification in a series of Mn{sup II}-based metal-organic frameworks (MOFs)

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Yan-Fei; Cui, Li-Ting [Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China); Han, Jie, E-mail: chan@ouhk.edu.hk [School of Science & Technology, The Open University of Hong Kong, Kowloon, Hong Kong Special Administrative Region (Hong Kong); Zhao, Xiao-Li, E-mail: xlzhao@chem.ecnu.edu.cn [Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China); State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

    2016-09-15

    The role of auxiliary solvents in the formation of MOFs has been investigated for a series of Mn{sup II}-based framework systems. Reactions of 4,4′,4″-nitrilotribenzoic acid (H{sub 3}L) with Mn{sup II} through varying auxiliary solvents of the medium resulted in the formation of diversified multinuclear Mn{sup II} subunits in four new coordination polymers: [Mn{sub 3}(L)(HCOO){sub 3}(DEF){sub 3}] (1), [Mn{sub 3}(L){sub 2}(EtOH){sub 2}]·DMF (2), [Mn{sub 5}(L){sub 4}(H{sub 2}O){sub 2}]·2(H{sub 2}NMe{sub 2}){sup +}·4DMF·2H{sub 2}O (3), and [Mn{sub 3}(L){sub 2}(py){sub 4}(H{sub 2}O)]·H{sub 2}O (4) (H{sub 3}L=4,4′,4′-nitrilotribenzoic acid, DMF=dimethylformamide, DEF=N,N-diethylformamide, py=pyridine). These four compounds were fully characterized by single-crystal X-ray diffraction, showing interesting SBUs variations. For compound 1, it displays a (3,6)-connected kgd net with wheel [Mn{sub 6}] cluster serving as SBU, whereas in 2, the sequence of Mn{sub 3}(COO){sub 9}(EtOH){sub 2} is repeated by inversion centers located between Mn1 and Mn3 to form an infinite Mn-carboxylate chain, which are further interlinked by L{sup 3−} ligands to form a 3D architecture. In 3, the pentanuclear Mn{sub 5}(CO{sub 2}){sub 12} clusters are interlinked to form a layer, which are further pillared by L{sup 3−} to generate a 3D network. Compound 4 has a (3,6)-connected network in which the SBU is a linear trimeric Mn{sub 3}(COO){sub 6}(py){sub 4}(H{sub 2}O) cluster. In addition, the thermal stabilities, X-ray powder diffraction of all the compounds were studied, photoluminescence behaviors of compounds 1, 3 and 4 are discussed. - Graphical abstract: Supramolecular assembly of C{sub 3}-symmetric ligand 4,4′,4″-nitrilotribenzoic acid (H{sub 3}L) with Mn{sup II} through varying auxiliary solvents of the medium resulted in the formation of diversified multinuclear Mn{sup II} subunits in four new coordination polymers. The results exhibit the structures of Mn-SBUs in these

  15. A solvent/non-solvent system for achieving solution-processed multilayer organic light-emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yue; Wu, Zhaoxin, E-mail: zhaoxinwu@mail.xjtu.edu.cn; He, Lin; Jiao, Bo; Hou, Xun

    2015-08-31

    We developed a solvent/non-solvent system to fabricate the multilayer organic light-emitting devices (OLEDs) based on poly(N-vinylcarbazole) (PVK) by solution-process. This solvent system consists of both the solvent and non-solvent of PVK, in which fluorescent small molecules could be fully dissolved and directly spin-coated on top of the PVK layer; it could effectively avoid the redissolution of PVK during the spin-coating process of small molecules emitting layer. In the further investigation of this system, we also demonstrated the three-component solvent system, and found out that the third component, a less volatile solvent of PVK, was crucial for preparing a smoother interface between PVK and emitting layer. Compared with OLEDs through the vacuum deposition, the devices fabricated by solution-process from the solvent/non-solvent system showed comparable efficiency, which indicate that the solvent/non-solvent system can be used as an alternative process to prepare the polymer and small molecule multilayer devices through all-solution-process. - Highlights: • We fabricate the multilayer OLEDs by solution-process using a novel system. • We develop a solvent/non-solvent system of polymer (PVK) to avoid redissolution. • Small molecules could be fully dissolved and directly spin-coated on PVK layer. • The devices fabricated by the system and vacuum deposition show comparable efficiency.

  16. Chemical reactions in solvents and melts

    CERN Document Server

    Charlot, G

    1969-01-01

    Chemical Reactions in Solvents and Melts discusses the use of organic and inorganic compounds as well as of melts as solvents. This book examines the applications in organic and inorganic chemistry as well as in electrochemistry. Organized into two parts encompassing 15 chapters, this book begins with an overview of the general properties and the different types of reactions, including acid-base reactions, complex formation reactions, and oxidation-reduction reactions. This text then describes the properties of inert and active solvents. Other chapters consider the proton transfer reactions in

  17. Microfluidic White Organic Light-Emitting Diode Based on Integrated Patterns of Greenish-Blue and Yellow Solvent-Free Liquid Emitters

    Science.gov (United States)

    Kobayashi, Naofumi; Kasahara, Takashi; Edura, Tomohiko; Oshima, Juro; Ishimatsu, Ryoichi; Tsuwaki, Miho; Imato, Toshihiko; Shoji, Shuichi; Mizuno, Jun

    2015-01-01

    We demonstrated a novel microfluidic white organic light-emitting diode (microfluidic WOLED) based on integrated sub-100-μm-wide microchannels. Single-μm-thick SU-8-based microchannels, which were sandwiched between indium tin oxide (ITO) anode and cathode pairs, were fabricated by photolithography and heterogeneous bonding technologies. 1-Pyrenebutyric acid 2-ethylhexyl ester (PLQ) was used as a solvent-free greenish-blue liquid emitter, while 2,8-di-tert-butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenyltetracene (TBRb)-doped PLQ was applied as a yellow liquid emitter. In order to form the liquid white light-emitting layer, the greenish-blue and yellow liquid emitters were alternately injected into the integrated microchannels. The fabricated electro-microfluidic device successfully exhibited white electroluminescence (EL) emission via simultaneous greenish-blue and yellow emissions under an applied voltage of 100 V. A white emission with Commission Internationale de l’Declairage (CIE) color coordinates of (0.40, 0.42) was also obtained; the emission corresponds to warm-white light. The proposed device has potential applications in subpixels of liquid-based microdisplays and for lighting. PMID:26439164

  18. Kinetics, reactivity, initial-transition state analysis and thermodynamic parameters of base-catalyzed hydrolysis of coumalic acid in solvents with different polarities

    Directory of Open Access Journals (Sweden)

    Ezz A. Abu-Gharib

    2017-02-01

    Full Text Available Base-catalyzed hydrolysis of coumalic acid (COU in binary aqueous-methanol and aqueous-acetone mixtures has been studied kinetically at a temperature range from 283 to 313 K. Moreover, the change in the activation energy barrier of COU from water to water–methanol and water–acetone mixtures is estimated from the kinetic data. Solvent effects on reactivity trends have been analyzed into initial and transition state components by using transfer chemical potentials of the reactants and kinetic data. The transfer chemical potentials δmμθ for COU− anion are derived from solubility data from its calcium, cerium and lanthanum salts. The decrease in rate constant of the base hydrolysis reaction of COU as the percentage of methanol or acetone increases is dominated by transition state (TS. The base hydrolysis reaction of COU follows a rate law with kobs = k2[OH−] and the reaction mechanism was suggested. The high negative values of entropy of activation support the proposal mechanism, i.e. the investigated reaction takes place via the formation of an intermediate complex. Thus, the ring opening of the intermediate complex would be the rate controlling step.

  19. A molecular dynamics study of intramolecular proton transfer reaction of malonaldehyde in solution based upon a mixed quantum–classical approximation. II. Proton transfer reaction in non-polar solvent

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, H.; Yamada, A.; Okazaki, S., E-mail: okazaki@apchem.nagoya-u.ac.jp [Department of Applied Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2015-05-07

    The intramolecular proton transfer reaction of malonaldehyde in neon solvent has been investigated by mixed quantum–classical molecular dynamics (QCMD) calculations and fully classical molecular dynamics (FCMD) calculations. Comparing these calculated results with those for malonaldehyde in water reported in Part I [A. Yamada, H. Kojima, and S. Okazaki, J. Chem. Phys. 141, 084509 (2014)], the solvent dependence of the reaction rate, the reaction mechanism involved, and the quantum effect therein have been investigated. With FCMD, the reaction rate in weakly interacting neon is lower than that in strongly interacting water. However, with QCMD, the order of the reaction rates is reversed. To investigate the mechanisms in detail, the reactions were categorized into three mechanisms: tunneling, thermal activation, and barrier vanishing. Then, the quantum and solvent effects were analyzed from the viewpoint of the reaction mechanism focusing on the shape of potential energy curve and its fluctuations. The higher reaction rate that was found for neon in QCMD compared with that found for water solvent arises from the tunneling reactions because of the nearly symmetric double-well shape of the potential curve in neon. The thermal activation and barrier vanishing reactions were also accelerated by the zero-point energy. The number of reactions based on these two mechanisms in water was greater than that in neon in both QCMD and FCMD because these reactions are dominated by the strength of solute–solvent interactions.

  20. Aplicação das ferramentas da Qualidade: estudo de caso em pequena empresa de pintura

    Directory of Open Access Journals (Sweden)

    Fabrício Pozzuto de Souza Coelho

    2016-10-01

    Full Text Available As sete ferramentas da qualidade mostram um conjunto de técnicas úteis para a melhoria da qualidade. Apesar do uso disseminado, poucos estudos avaliaram sua implantação no âmbito das pequenas empresas. Este artigo objetivou investigar o impacto da implantação dessas ferramentas em uma pequena empresa de pintura localizada no litoral do Estado de São Paulo. Utilizando o referencial da qualidade e o método do estudo de caso se verificou que a implantação de cinco ferramentas da qualidade: Fluxograma do processo; Folha de verificação; Gráfico de Pareto; Diagrama de causa e efeito e plano de ação; e, Gráfico de controle, apresentou resultados satisfatórios para a gerência da empresa. Partiu-se de um índice de produtos não-conformes de 12,5% para 4% ao final do sexto mês da implantação das ações de melhoria. Verificou-se neste artigo o potencial da implantação das ferramentas da qualidade no âmbito das pequenas empresas.

  1. Consideraciones sobre pintura en Tierra de Campos: nuevas atribuciones a los maestros de Astorga y de Becerril

    Directory of Open Access Journals (Sweden)

    Fiz Fuertes, Irune

    2002-12-01

    Full Text Available La pintura castellano-leonesa del siglo XVI comprende un vasto territorio que dificulta el conocimiento total de la misma, necesario para establecer conexiones entre las distintas escuelas; si a este hecho unimos la falta en mucho casos de la documentación proveniente de los libros de fábrica, el paisaje se complica. Hay que agradecer a todos los estudiosos que nos precedieron el haber dado a conocer la mayoría de las obras cuya autoría es aún hoy objeto de discusión. En este artículo no se pretende presentar nuevas teorías, sino que con la ventaja de más puntos de referencia, aunque se carece de la documentación pertinente en las dos obras tratadas, estilísticamente podemos aportar nuevas atribuciones que ayudarán a matizar más el panorama planteado....

  2. Pedro de Castañeda: su pintura para el refectorio del Colegio Mayor de San Ildefonso (1553

    Directory of Open Access Journals (Sweden)

    González Ramos, Roberto

    2003-09-01

    Full Text Available El pintor Pedro de Castañeda es un artista poco conocido, activo en la zona de Alcalá de Henares en las décadas centrales del siglo XVI. Se sabe que junto a su hijo Juan fue colaborador del entallador y traductor de Vitruvio Miguel de Urrea. Pedro de Castañeda pintó un cirial que había tallado Urrea para la iglesia parroquial de Camarma de Esteruelas, trabajo por el que ambos cobraron cierta cantidad en 1540, y en 1550 colaboró con ese entallador y con Claudio de Arciniega, ayudado por Juan, en la obra de los retablos colaterales de la iglesia de Daganzo de Arriba (perdidos, realizando su pintura. Parece que se trata del mismo artista el Pedro Castañeda que se documenta trabajando en la zona de Segovia, concretamente en dos retablos para la iglesia de Cascajares del Fresno. Falleció en 1557…

  3. Otro enigma de El Greco: ¿un pintor escéptico que realiza pintura religiosa?

    Directory of Open Access Journals (Sweden)

    Rodríguez G. de Ceballos, Alfonso

    2015-12-01

    Full Text Available Contrary to current opinion, El Greco was not only a prolific painter of religious pictures, but also person of entrenched beliefs both as a member of an Orthodox family, and when he converted to the Roman Catholic faith, as is clear from many episodes and events in his life and death. This hypothesis is borne out by the correct and traditional iconography in his religious paintings, and in the ideological, technical and expressive aspects of his work.Frente a la opinión reciente, El Greco no solo fue pintor de amplísima obra religiosa, sino personalmente de arraigadas convicciones religiosas, tanto como miembro de una familia de fe ortodoxa como también después de su paso al catolicismo romano, como lo demuestran muchos episodios y acontecimientos de su vida y muerte. Avalan esta suposición tanto la correcta y tradicional iconografía de su pintura sacra, cuanto muchas de las características ideológicas, técnicas y expresivas de su obra.

  4. Solvent-induced red-shifts for the proton stretch vibrational frequency in a hydrogen-bonded complex. 1. A valence bond-based theoretical approach.

    Science.gov (United States)

    Kiefer, Philip M; Pines, Ehud; Pines, Dina; Hynes, James T

    2014-07-17

    A theory is presented for the proton stretch vibrational frequency νAH for hydrogen (H-) bonded complexes of the acid dissociation type, that is, AH···B ⇔ A(-)···HB(+)(but without complete proton transfer), in both polar and nonpolar solvents, with special attention given to the variation of νAH with the solvent's dielectric constant ε. The theory involves a valence bond (VB) model for the complex's electronic structure, quantization of the complex's proton and H-bond motions, and a solvent coordinate accounting for nonequilibrium solvation. A general prediction is that νAH decreases with increasing ε largely due to increased solvent stabilization of the ionic VB structure A(-)···HB(+) relative to the neutral VB structure AH···B. Theoretical νAH versus 1/ε slope expressions are derived; these differ for polar and nonpolar solvents and allow analysis of the solvent dependence of νAH. The theory predicts that both polar and nonpolar slopes are determined by (i) a structure factor reflecting the complex's size/geometry, (ii) the complex's dipole moment in the ground vibrational state, and (iii) the dipole moment change in the transition, which especially reflects charge transfer and the solution phase proton potential shapes. The experimental proton frequency solvent dependence for several OH···O H-bonded complexes is successfully accounted for and analyzed with the theory.

  5. Purex process solvent: literature review

    Energy Technology Data Exchange (ETDEWEB)

    Geier, R.G.

    1979-10-01

    This document summarizes the data on Purex process solvent presently published in a variety of sources. Extracts from these various sources are presented herein and contain the work done, the salient results obtained, and the original, unaltered conclusions of the author of each paper. Three major areas are addressed: solvent stability, solvent quality testing, and solvent treatment processes. 34 references, 44 tables.

  6. Cost-Benefit Analysis of Nanoparticle Albumin-Bound Paclitaxel versus Solvent-Based Paclitaxel for the Treatment of Metastatic Breast Cancer in the United States

    Science.gov (United States)

    Vichansavakul, Kittaya

    Breast cancer is the second leading cause of death among women in the US. Although early detection and treatment help to increase survival rates, some unfortunate patients develop metastatic breast cancer that has no cure. Palliative treatment is the main objective in this group of patients in order to prolong life and reduce toxicities from interventions. In the advancement of treatment for metastatic breast cancer, solvent-based paclitaxel has been widely used. However, solvent-based paclitaxel often causes adverse reactions. Therefore, researchers have developed a new chemotherapy based on nanotechnology. One of these drugs is the Nanoparticle albumin-bound Paclitaxel. This nanodrug aims to increase therapeutic index by reducing adverse reactions from solvents and to improve efficacy of conventional cytotoxic chemotherapy. Breast cancer is a disease with high epidemiological and economic burden. The treatment of metastatic breast cancer has not only high direct costs but also high indirect costs. Breast cancer affects mass populations, especially women younger than 50 years of age. It relates to high indirect costs due to lost productivity and premature death because the majority of these patients are in the workforce. Because of the high cost of breast cancer therapies and short survival rates, the question is raised whether the costs and benefits are worth paying or not. Due to the rising costs in healthcare and new financing policies that have been developed to address this issue, economic evaluation is an important aspect of the development and use of any new interventions. To guide policy makers on how to allocate limited healthcare resources in the most efficient and effective manner, many economic evaluation methods can be used to measure the costs, benefits, and impacts of healthcare innovations. Currently, economic evaluation and health outcomes studies have focused greatly on cost-effectiveness and cost-utility analysis. However, the previous studies

  7. Temperature-stabilized silicon-based surface-acoustic-wave gas sensors for the detection of solvent vapors

    Science.gov (United States)

    Bender, Stefan; Mokwa, W.

    1998-12-01

    In the current paper a dual-delay-line- and a resonator- device based on CMOS-silicon-technology is presented. As a piezoelectric layer ZnO is used. The layer was deposited at room temperature in a RF magnetron sputter process. Using x- ray diffraction it could be shown that the crystals are mostly oriented with the c-axis (hexagonal structure) perpendicular to the surface which is necessary to conduct surface acoustic waves. Pt electrodes were designed for frequencies between 140 and 600 MHz and were deposited on top using a lift-off-process. A poly-silicon heating resistor was integrated as a sublayer for controlling and changing of the temperature of the SAW-device for studying the influence of temperature on the mass sensitive layer. A Pt thin film resistance served for temperature measurement. The performance of the devices were compared to standard quartz based SAWs.

  8. Development and optimization of a naphthoic acid-based ionic liquid as a "non-organic solvent microextraction" for the determination of tetracycline antibiotics in milk and chicken eggs.

    Science.gov (United States)

    Gao, Jiajia; Wang, Hui; Qu, Jingang; Wang, Huili; Wang, Xuedong

    2017-01-15

    In traditional ionic liquids (ILs)-based microextraction, ILs are often used as extraction and dispersive solvents; however, their functional effects are not fully utilized. Herein, we developed a novel ionic liquid 1-butyl-3-methylimidazolium naphthoic acid salt ([C4MIM][NPA]) with strong acidity. It was used as a mixed dispersive solvent with conventional [C2MIM][BF4] in "functionalized ionic liquid-based non-organic solvent microextraction (FIL-NOSM)" for determination of tetracycline antibiotics (TCs) in milk and eggs. Utilization of [C4MIM][NPA] in FIL-NOSM method increased extraction recoveries (ERs) of TCs by more than 20% and eliminated the pH adjustment step because of its strong acidity. Under optimized conditions based on central composite design, the ERs of four TCs were 94.1-102.1%, and the limitsofdetection were 0.08-1.12μgkg(-1) in milk and egg samples. This proposed method provides high extraction efficiency, less pretreatment time and requires non-organic solvents for determination of trace TC concentrations in complex animal-based food matrices.

  9. Centrifuge-less dispersive liquid-liquid microextraction base on the solidification of switchable solvent for rapid on-site extraction of four pyrethroid insecticides in water samples.

    Science.gov (United States)

    Hu, Lu; Wang, Huazi; Qian, Heng; Liu, Chaoran; Lu, Runhua; Zhang, Sanbing; Zhou, Wenfeng; Gao, Haixiang; Xu, Donghui

    2016-11-11

    An on-site dispersive liquid liquid microextraction base on the solidification of switchable solvent has been developed as a simple, rapid and eco-friendly sample extraction method for the fast determination of pyrethroid insecticides in aqueous samples using high-performance liquid chromatography with ultraviolet detection. In this extraction method, medium-chain saturated fatty acids (n≥10), which can rapidly solidify at low temperatures (insecticides were obtained in the concentration ranges of 1-500μg/L, with coefficients of determination greater than 0.9993. The recoveries of the four pyrethroid insecticides ranged from 84.7 to 95.3%, with relative standard deviations ranging from 1.6 to 4.6%. The limits of detection based on a signal-to-noise ratio of 3 were in the range of 0.24-0.68μg/L, and the enrichment factors were in the range of 121-136. The results demonstrate that this method was successfully applied to determine pyrethroid insecticides in real water samples. No centrifugation or any special apparatus are required, make this a promising method for rapid field-sampling procedures. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. A comparison of chilled DI water/ozone and CO{sub 2}-based supercritical fluids as replacements for photoresist-stripping solvents

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Davenhall, L.B.; Barton, J.; Taylor, C.M.V. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.; Tiefert, K. [Hewlett-Packard Co., Santa Clara, CA (United States)

    1998-12-31

    Part of the Hewlett Packard Components Group`s Product Stewardship program is the ongoing effort to investigate ways to eliminate or reduce as much as possible the use of chemical substances from manufacturing processes. Currently used techniques to remove hard-baked photoresists from semiconductor wafers require the use of inorganic chemicals or organic strippers and associated organic solvents. Environmental, health and safety, as well as cost considerations prompted the search for alternative, more environmentally-benign, and cost-effective solutions. Two promising, emerging technologies were selected for evaluation: the chilled DI water/ozone technique and supercritical fluids based on carbon dioxide (CO{sub 2}). Evaluating chilled DI water/ozone shows this process to be effective for positive photoresist removal, but may not be compatible with all metallization systems. Testing of a closed-loop CO{sub 2}-based supercritical CO{sub 2} Resist Remover, or SCORR, at Los Alamos, on behalf of Hewlett-packard, shows that this treatment process is effective in removing photoresists, and is fully compatible with commonly used metallization systems. In this paper, the authors present details on the testing programs conducted with both the chilled DI H{sub 2}O/ozone and SCORR treatment processes.

  11. Human and environmental impact assessment of postcombustion CO2 capture focusing on emissions from amine-based scrubbing solvents to air.

    Science.gov (United States)

    Veltman, Karin; Singh, Bhawna; Hertwich, Edgar G

    2010-02-15

    Carbon Capture and Storage (CCS) has become a key technology in climate change mitigation programs worldwide. CCS is well-studied in terms of greenhouse gas emission reduction potential and cost of implementation. Impacts on human health and the environment have, however, received considerably less attention. In this work, we present a first assessment of human health and environmental impacts of a postcombustion CO(2) capture facility, focusing on emissions from amine-based scrubbing solvents and their degradation products to air. We develop characterization factors for human toxicity for monoethanolamine (MEA) as these were not yet available. On the basis of the limited information available, our assessment indicates that amine-based scrubbing results in a 10-fold increase in toxic impact on freshwater ecosystems and a minor increase in toxic impacts on terrestrial ecosystems. These increases are attributed to emissions of monoethanolamine. For all other impact categories, i.e., human toxicity, marine ecotoxicity, particulate matter formation, photochemical oxidant formation, and terrestrial acidification, the CO(2) capture facility performs equally well to a conventional NGCC power plant, albeit substantial changes in flue gas composition. The oxidative degradation products of MEA, i.e., formaldehyde, acetaldehyde, and ammonia, do not contribute significantly to total environmental impacts.

  12. Single Stage Contactor Testing Of The Next Generation Solvent Blend

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

    2014-01-06

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

  13. Theoretical investigation on the microstructure of triethylene glycol based deep eutectic solvents: COSMO-RS and TURBOMOLE prediction

    Science.gov (United States)

    Aissaoui, Tayeb; Benguerba, Yacine; AlNashef, Inas M.

    2017-08-01

    The in-silico combination mechanism of triethylene glycol based DESs has been studied. COSMO-RS and graphical user interface TmoleX software were used to predict the interaction mechanism of hydrogen bond donors (HBDs) with hydrogen bond acceptors (HBA) to form DESs. The predicted IR results were compared with the previously reported experimental FT-IR analysis for the same studied DESs. The sigma profiles for the HBD, HBAs and formed DESs were interpreted to identify qualitatively molecular properties like polarity or hydrogen bonding donor and acceptor abilities. The predicted physicochemical properties reported in this study were in good agreement with experimental ones.

  14. Method for Predicting Solubilities of Solids in Mixed Solvents

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O'Connell, J. P.

    2009-01-01

    A method is presented for predicting solubilities of solid solutes in mixed solvents, based on excess Henry's law constants. The basis is statistical mechanical fluctuation solution theory for composition derivatives of solute/solvent infinite dilution activity coefficients. Suitable approximations...... are made for a single parameter characterizing solute/solvent interactions. Comparisons with available data show that the method is successful in describing a variety of observed mixed solvent solubility behavior, including nearly ideal systems with small excess solubilities, systems with solute......-independent excess solubilities, and systems deviating from these simple rules. Successful predictions for new solvent mixtures cat? be made using limited data from other mixtures....

  15. Halogenated solvent remediation

    Science.gov (United States)

    Sorenson, Kent S.

    2004-08-31

    Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. A preferred method includes adding a composition to the ground water wherein the composition is an electron donor for microbe-mediated reductive dehalogenation of the halogenated solvents and enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative compositions effective in these methods include surfactants such as C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof. Especially preferred compositions for use in these methods include lactic acid, salts of lactic acid, such as sodium lactate, lactate esters, and mixtures thereof. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the composition.

  16. Safe battery solvents

    Science.gov (United States)

    Harrup, Mason K.; Delmastro, Joseph R.; Stewart, Frederick F.; Luther, Thomas A.

    2007-10-23

    An ion transporting solvent maintains very low vapor pressure, contains flame retarding elements, and is nontoxic. The solvent in combination with common battery electrolyte salts can be used to replace the current carbonate electrolyte solution, creating a safer battery. It can also be used in combination with polymer gels or solid polymer electrolytes to produce polymer batteries with enhanced conductivity characteristics. The solvents may comprise a class of cyclic and acyclic low molecular weight phosphazenes compounds, comprising repeating phosphorus and nitrogen units forming a core backbone and ion-carrying pendent groups bound to the phosphorus. In preferred embodiments, the cyclic phosphazene comprises at least 3 phosphorus and nitrogen units, and the pendent groups are polyethers, polythioethers, polyether/polythioethers or any combination thereof, and/or other groups preferably comprising other atoms from Group 6B of the periodic table of elements.

  17. Single-stranded DNA detection by solvent-induced assemblies of a metallo-peptide-based complex

    Science.gov (United States)

    Das, Priyadip; Reches, Meital

    2016-05-01

    DNA detection is highly important for the sensitive sensing of different pathogenic bacteria and viruses. The major challenge is to create a sensor that can selectively detect very small concentrations of DNA without the need for amplification or complicated equipment. Different technologies such as optical, electrochemical and microgravimetric approaches can detect DNA fragments. Here we show, for the first time, the use of self-assembled nanostructures generated by a metallo-peptide as an optical sensing platform for DNA detection. The system can selectively detect single stranded DNA fragments by fluorescence measurements as it can discriminate even one base mismatch and can perform in the presence of other interfering proteins. This system may be useful in lab-on-a-chip applications.DNA detection is highly important for the sensitive sensing of different pathogenic bacteria and viruses. The major challenge is to create a sensor that can selectively detect very small concentrations of DNA without the need for amplification or complicated equipment. Different technologies such as optical, electrochemical and microgravimetric approaches can detect DNA fragments. Here we show, for the first time, the use of self-assembled nanostructures generated by a metallo-peptide as an optical sensing platform for DNA detection. The system can selectively detect single stranded DNA fragments by fluorescence measurements as it can discriminate even one base mismatch and can perform in the presence of other interfering proteins. This system may be useful in lab-on-a-chip applications. Electronic supplementary information (ESI) available: Peptide and receptor synthesis, characterization of the final and intermediate products, experimental details and additional figures including SEM, TEM, DLS, XRD, UV analysis and AFM topographic analysis. See DOI: 10.1039/c5nr07714a

  18. Valoración de la mezcla óptima de microesferas y pinturas de señalización para garantizar una mejor retroreflectancia en aplicaciones viales de acuerdo a las normas inen.

    OpenAIRE

    Diana VÉLEZ; Villacís, Javier

    2013-01-01

    Este proyecto tiene como propósito determinar una relación eficiente entre pintura de demarcación vial y microesferas de vidrio, de modo que contribuya a la seguridad vial, bajando el índice de accidentes por una ineficiencia de las demarcaciones e iluminación en las carreteras. Se tiene conocimiento que en el día la visibilidad depende únicamente del color de la pintura, pero durante la noche la visibilidad se dificulta por la deficiente iluminación en zonas rurales y por esta razón se requi...

  19. La influencia de las teorías de la Institución Libre de Enseñanza sobre Estética y Naturaleza en la pintura valenciana de paisaje.

    OpenAIRE

    Hernández Perelló, Mari Carmen

    2015-01-01

    El presente trabajo se apoya en tres pilares fundamentales que son el paisaje, la Institución Libre de Enseñanza y la pintura valenciana de paisaje. Con éste lo que pretendemos es por un lado, demostrar que a finales del siglo XIX y principios del XX, en la zona valenciana se produce un desarrollo de la pintura de paisaje debido, en parte, a la llegada de influencias de la ILE, y por otro, mostrar como estas obras reflejan el entendimiento institucionista de la naturaleza. Las ...

  20. Resumen de tesis. El museo nacional de bellas artes de La Habana y la colección de retratos de la pintura española del siglo XIX

    OpenAIRE

    2013-01-01

    [ES] El Museo Nacional de Bellas Artes de La Habana, fundado en 1913, constituye la máxima institución museística de Cuba. La variedad e importancia de sus colecciones y el volumen de obras reunidas -alrededor de cuarenta y siete mil setecientas piezas, entre pinturas, grabados, esculturas, dibujos, cerámicas, etc.-, lo convierten en el más destacado en el contexto del Caribe insular y uno de los más importantes de Latinoamérica. La colección de pintura española del siglo XIX de la pinacot...

  1. Vía Crucis de pintura e imágenes de bulto en Nueva España: Reflexiones sobre la complementariedad de una devoción.

    OpenAIRE

    Robin, Alena; The University of Western Ontario

    2016-01-01

    Este ensayo analiza cinco series de pintura realizadas en Nueva España en el transcurso del siglo XVIII por diferentes pintores y en diversas regiones del virreinato. Todas representan las estaciones del Vía Crucis, conjugando de diversas maneras dos géneros plásticos: la pintura con la escultura. El propósito de este trabajo es estudiar de qué manera los dos géneros artísticos interactúan en las representaciones de los sucesos del Vía Crucis para ofrecer una reflexión sobre cómo la práctica ...

  2. Análisis de pinturas murales góticas en Eslovenia del maestro Bolfgang y su discípulo maestro de Mače (siglo XV)

    OpenAIRE

    Križnar, Anabelle; Ruíz-Conde, Antonio; Sánchez-Soto, Pedro José

    2014-01-01

    [ES] Dentro del arte gótico Europeo, este estudio trata de explicar la técnica de pintura mural del Maestro Bolfgang y su discípulo Maestro de Mače. Se trata de dos de los más importantes pintores en el territorio de Eslovenia en la segunda mitad del siglo XV. Siguiendo una metodología basada en el examen de materiales pictóricos, se realizó una caracterización de pigmentos y morteros de soporte empleados en una serie de pinturas murales hechas por ambos artistas, en concreto en las que se en...

  3. The use of reflecting paints on building`s roofs for energy saving; Uso de pinturas reflejantes en los techos de las edificaciones para el ahorro de energia electrica

    Energy Technology Data Exchange (ETDEWEB)

    Valera Negrete, Jose Adrian [Programa de Ahorro de Energia del Sector Electrico (PAESE), Comision Federal de Electricidad, Mexico, D. F. (Mexico); Sanchez Soto, Ramon [Facultad de Ingenieria, Departamento de Termoenergia de la UNAM, Mexico, D. F. (Mexico)

    1998-12-31

    This paper shows the effects of the use of reflecting paints in different colors on the buildings roofs and the results in energy saving obtained in a field test carried on in Monterrey, Nuevo Leon State of Mexico using aluminum paint. [Espanol] El presente trabajo muestra los efectos del uso de pinturas reflejantes de diferentes colores en los techos de edificaciones, y los resultados de ahorro de energia electrica obtenidos en una prueba de campo efectuada en Monterrey, Nuevo Leon, Mexico, utilizando pintura de aluminio.

  4. Resumen de tesis. El museo nacional de bellas artes de La Habana y la colección de retratos de la pintura española del siglo XIX

    OpenAIRE

    Laguna Enrique, Martha Elizabeth

    2013-01-01

    [ES] El Museo Nacional de Bellas Artes de La Habana, fundado en 1913, constituye la máxima institución museística de Cuba. La variedad e importancia de sus colecciones y el volumen de obras reunidas -alrededor de cuarenta y siete mil setecientas piezas, entre pinturas, grabados, esculturas, dibujos, cerámicas, etc.-, lo convierten en el más destacado en el contexto del Caribe insular y uno de los más importantes de Latinoamérica. La colección de pintura española del siglo XIX de la pinacot...

  5. 基于化学溶剂的焦油冷凝净化技术试验%EXPERIMENTAL STUDY OF TAR CONDENSING REMOVAL BASED ON CHEMICAL SOLVENTS

    Institute of Scientific and Technical Information of China (English)

    郭飞强; 董玉平; 景元琢; 董磊

    2012-01-01

    利用化学溶剂冷凝捕集的方法,使燃气中的焦油颗粒凝结沉积.通过试验,对3种典型的溶剂净化性能进行对比分析,从中筛选出性能优良的溶剂,并试验研究溶剂流量与净化性能的关系,结果表明燃气流速为70m3/h、溶剂流量约为250L/h时,焦油的去除效率达到90%,溶剂的损失可控制在一个较小范围内.%According to the tar problem in biomass gas,chemical solvent condensate trapping way was used to make tar particles in the gas condense and deposit.Tar problem could be solved mostly in this way.In the experiment,three typical solvents were comparatively analyzed,and the best solvent was chosen.Then,relationship between flow rate of the best solvent and purification performance was studied.The results show that tar removal efficiency can reach up to 90% when the flow rute of the solvent is 250L/h,also solvent loss will be less.

  6. Solvent Extraction Developments in Southern Africa

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The largest solvent-extraction plant in the world at the time, the Nchanga Copper Operation, was in Zambia. The first commercial process using solvent extraction for the refining of the platinum-group metals was in South Africa. More recently, the Southern African region has seen the implementation of solvent extraction for other base metals, precious metals, and specialty metals. These include the world firsts of primary production of zinc at Skorpion Zinc in Namibia and the large-scale refining of gold by Harmony Gold in South Africa. Several other flowsheets that use solvent-extraction technology are currently under commissioning, development, or feasibility study for implementation in this part of the world, including those for the recovery of copper, cobalt, nickel, tantalum, and niobium.

  7. Optical properties of a long dynamic range chemical UV dosimeter based on solvent cast polyvinyl chloride (PVC).

    Science.gov (United States)

    Amar, Abdurazaq; Parisi, Alfio V

    2013-11-01

    The dosimetric properties of the recently introduced UV dosimeter based on 16 μm PVC film have been fully characterised. Drying the thin film in air at 50 °C for at least 28 days was found to be necessary to minimise the temperature effects on the dosimeter response. This research has found that the dosimeter response, previously reported to be mainly to UVB, has no significant dependence on either exposure temperature or dose rate. The dosimeter has negligible dark reaction and responds to the UV radiation with high reproducibility. The dosimeter angular response was found to have a similar pattern as the cosine function but deviates considerably at angles larger than 70°. Dose response curves exhibit monotonically increasing shape and the dosimeter can measure more than 900 SED. This is about 3 weeks of continuous exposure during summer at subtropical sites. Exposures measured by the PVC dosimeter for some anatomical sites exposed to solar radiation for twelve consecutive days were comparable with those concurrently measured by a series of PPO dosimeters and were in line with earlier results reported in similar studies.

  8. A micro-system based on glass-nanoporous silicon for optical sensing of organic solvent vapor.

    Science.gov (United States)

    Kim, Young-You; Kim, Han-Jung; Kim, Ho-Jong; Choi, Dae-Geun; Cheng, Horchhong

    2012-06-01

    We present a recent experimental study on the application of nanoporous silicon (np-Si) to an optical vapor sensor. We fabricated the micro-system based on a glass-nanoporous silicon layer on a p(+)-type silicon wafer. To check the selectivity and sensitivity of the np-Si layer to organic vapors, we prepared three types of np-Si layer samples--a single layer, distributed Bragg reflector (DBR) layer, and microcavity layer--and investigated its reflectance spectra upon exposure to different concentrations of various organic vapors. When the np-Si layer samples were exposed to the organic vapors, a red-shift occurred in the reflectance spectrum, and we determined that this red-shift can be attributed to the changes in the refractive index induced by the capillary condensation of the organic vapor within the pores of the np-Si layer. The np-Si layer samples showed excellent sensing ability to different types and concentrations of organic vapors. After removing the organic vapors, the reflectance spectrum immediately returned to its original state.

  9. Fragment-Based Approach for the Evaluation of NMR Chemical Shifts for Large Biomolecules Incorporating the Effects of the Solvent Environment.

    Science.gov (United States)

    Jose, K V Jovan; Raghavachari, Krishnan

    2017-03-14

    We present an efficient implementation of the molecules-in-molecules (MIM) fragment-based quantum chemical method for the evaluation of NMR chemical shifts of large biomolecules. Density functional techniques have been employed in conjunction with large basis sets and including the effects of the solvent environment in these calculations. The MIM-NMR method is initially benchmarked on a set of (alanine)10 conformers containing strong intramolecular interactions. The incorporation of a second low level of theory to recover the missing long-range interactions in the primary fragmentation scheme is critical to yield reliable chemical shifts, with a mean absolute deviation (MAD) from direct unfragmented calculations of 0.01 ppm for (1)H chemical shifts and 0.07 ppm for (13)C chemical shifts. In addition, the performance of MIM-NMR has been assessed on two large peptides: the helical portion of ubiquitin ( 1UBQ ) containing 12 residues where the X-ray structure is known, and E6-binding protein of papilloma virus ( 1RIJ ) containing 23 residues where the structure has been derived from solution-phase NMR analysis. The solvation environment is incorporated in these MIM-NMR calculations, either through an explicit, implicit, or a combination of both solvation models. Using an explicit treatment of the solvent molecules within the first solvation sphere (3 Å) and an implicit solvation model for the rest of the interactions, the (1)H and (13)C chemical shifts of ubiquitin show excellent agreement with experiment (mean absolute deviation of 0.31 ppm for (1)H and 1.72 ppm for (13)C), while the larger E6-binding protein yields a mean absolute deviation of 0.34 ppm for (1)H chemical shifts. The proposed MIM-NMR method is computationally cost-effective and provides a substantial speedup relative to conventional full calculations, the largest density functional NMR calculation included in this work involving more than 600 atoms and over 10,000 basis functions. The MIM

  10. Molecular structures of (3-aminopropyl)trialkoxysilane on hydroxylated barium titanate nanoparticle surfaces induced by different solvents and their effect on electrical properties of barium titanate based polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Yanyan; Wang, Guanyao; Huang, Xingyi, E-mail: xyhuang@sjtu.edu.cn; Bu, Jing; Sun, Xiaojin; Jiang, Pingkai

    2016-02-28

    Graphical abstract: - Highlights: • The silanization on the surface of hydroxylated barium titanate nanoparticles was introduced by using two kinds of trialkoxysilanes with different solvents (toluene and ethanol), respectively. • Solvents have more remarkable impact on the dielectric properties of the subsequent BT/PVDF nanocomposites than the types of silanes. • The solvents used for BT nanoparticle surface modification exhibit a significant effect on the breakdown strength of the nanocomposites. - Abstract: Surface modification of nanoparticles by grafting silane coupling agents has proven to be a significant approach to improve the interfacial compatibility between inorganic filler and polymer matrix. However, the impact of grafted silane molecular structure after the nanoparticle surface modification, induced by the utilized solvents and the silane alkoxy groups, on the electrical properties of the corresponding nanocomposites, has been seldom investigated. Herein, the silanization on the surface of hydroxylated barium titanate (BT-OH) nanoparticles was introduced by using two kinds of trialkoxysilane, 3-aminopropyltriethoxysilane (AMEO) and 3-aminopropyltrimethoxysilane (AMMO), with different solvents (toluene and ethanol), respectively. Solid-state {sup 13}C, {sup 29}Si nuclear magnetic resonance (NMR) spectroscopy and high-resolution X-ray photoelectron spectroscopy (XPS) were employed to validate the structure differences of alkoxysilane attachment to the nanoparticles. The effect of alkoxysilane structure attached to the nanoparticle surface on the dielectric properties of the BT based poly(vinylidene fluoride) (PVDF) nanocomposites were investigated. The results reveal that the solvents used for BT nanoparticle surface modification exhibit a significant effect on the breakdown strength of the nanocomposites. Nevertheless, the alkoxy groups of silane show a marginal influence on the dielectric properties of the nanocomposites. These research results

  11. Pinturas rupestres y estructuras de piedra en las Sierras de Curicó (extremo noroccidental de Tandilia, Región Pampeana

    Directory of Open Access Journals (Sweden)

    Patricia Madrid

    2000-12-01

    Full Text Available En las Sierras de Curicó (también conocidas como de La China en el Pdo. de Olavarría, se han detectado pinturas rupestres en paredones y reparos de los afloramientos tabulares de cuarcita. Se trata de tres sectores con motivos lineales, geométricos, pintados en rojo. En el faldeo de la misma sierra, se localizaron dos estructuras pequeñas de piedra pircada de forma circular. En la cima de otro afloramiento rocoso, ubicado 500 m al oeste de estas estructuras, se halló una acumulación oval de piedras. En este trabajo se resumen las características del conjunto arqueológico y se presentan los resultados de los sondeos realizados en una de esas estructuras. Se examina la contemporaneidad entre las estructuras y las pinturas rupestres y su posible filiación tehuelche. Se comparan estas pinturas con otras manifestaciones similares de la Región Pampeana. Por último, se exploran aspectos simbólicos y religiosos de las sociedades pampeanas tardías.In the Curicó hills (also known as the La China hill, in the Olavarría district, rock art has been discovered on walls and in shelters in the quartzite tabular outcrops of the Balcarce Formation. The paintings are in three sectors and consist of lineal and geometrical motifs painted in red. On the slope of the hill, two stone circular structures were detected, and on the top of the opposite hill an oval stone structure was also found. In this article, the characteristics of this archaeological material are summarised and the results from test pits, excavated in one of these structures is presented. The contemporaneity among the findings is examined as well as its possible tehuelche affiliation. Finally, the symbolic and religion dimensions of the Late Pampean indigenous societies are explored.

  12. Enabling LiTFSI-based electrolytes for safer lithium-ion batteries by using linear fluorinated carbonates as (Co)solvent.

    Science.gov (United States)

    Kalhoff, Julian; Bresser, Dominic; Bolloli, Marco; Alloin, Fannie; Sanchez, Jean-Yves; Passerini, Stefano

    2014-10-01

    In this Full Paper we show that the use of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as conducting salt in commercial lithium-ion batteries is made possible by introducing fluorinated linear carbonates as electrolyte (co)solvents. Electrolyte compositions based on LiTFSI and fluorinated carbonates were characterized regarding their ionic conductivity and electrochemical stability towards oxidation and with respect to their ability to form a protective film of aluminum fluoride on the aluminum surface. Moreover, the investigation of the electrochemical performance of standard lithium-ion anodes (graphite) and cathodes (Li[Ni1/3 Mn1/3 Co1/3 ]O2 , NMC) in half-cell configuration showed stable cycle life and good rate capability. Finally, an NMC/graphite full-cell confirmed the suitability of such electrolyte compositions for practical lithium-ion cells, thus enabling the complete replacement of LiPF6 and allowing the realization of substantially safer lithium-ion batteries.

  13. Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

    Energy Technology Data Exchange (ETDEWEB)

    Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi [Universiti Teknologi Malaysia, Skudai (Malaysia)

    2015-04-15

    The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity.

  14. Sulfination by using Pd-PEPPSI complexes: studies into precatalyst activation, cationic and solvent effects and the role of butoxide base.

    Science.gov (United States)

    Sayah, Mahmoud; Lough, Alan J; Organ, Michael G

    2013-02-18

    The activation of PEPPSI precatalysts has been systematically studied in Pd-catalysed sulfination. Under the reactions conditions of the sulfide and KOtBu in toluene, the first thing that happens is exchange of the two chlorides on the PEPPSI precatalyst with the corresponding sulfides, creating the first resting state; it is via this complex that all Pd enters the catalytic cycle. However, it is also from this same complex that a tri-Pd complex forms, which is a more persistent resting state. Under standard reaction conditions, this complex is catalytically inactive. However, if additional pyridine or a smaller base (i.e., KOEt) is added, this complex is broken down, presumably initially back to the first resting state and it is again capable of entering the catalytic cycle and completing the sulfination. Of note, once the tri-Pd complex forms, one equivalent of Pd is lost to the transformation. Related to this, the nature of the cation of the sulfide salt and solvent dielectric is very important to the success of this transformation. That is, the less soluble the salt the better the performance, which can be attributed to lowering sulfide concentration to avoid the movement of the Pd-NHC complex into the above described off-cycle sulfinated resting states.

  15. Infrared studies of polyacrylonitrile-based polymer electrolytes incorporated with lithium bis(trifluoromethane)sulfonimide and urea as deep eutectic solvent

    Science.gov (United States)

    Sim, L. N.; Yahya, R.; Arof, A. K.

    2016-06-01

    In this work, urea is introduced into polyacrylonitrile (PAN)-based polymer electrolyte containing lithium bis(trifluoromethane)sulfonimide (LiTFSI) to form a deep eutectic solvent with urea and LiTFSI in the mole ratio of 1:3. The ambient ionic conductivity of the polymer electrolyte film is enhanced from 2.54 × 10-4 S cm-1 to 3.82 × 10-3 S cm-1 with the addition of urea. Infrared studies has revealed that urea interacts with the LiTFSI through coordination of Li+ ions onto the carbonyl (Cdbnd O) group of urea, and hydrogen bonding possibly to the O atoms in the SO2 groups of TFSI- ions. Hydrogen bonding interactions of urea with DMF and PAN are also evident. The enhancement in conductivity is believed to be due to urea being involved in the dissociation of LiTFSI and its role as an additional ion conduction pathway through its carbonyl group.

  16. The QuEChERS analytical method combined with low density solvent based dispersive liquid–liquid microextraction for quantitative extraction of multiclass pesticide residues in cereals

    Directory of Open Access Journals (Sweden)

    T. Bedassa

    2017-07-01

    Full Text Available In this study, a combination QuEChERS and low density solvent based DLLME was developed for extraction and preconcentration of five multiclass pesticide residues including atrazine, ametryn, terbutryn, carbaryl and chlorothalonil, from selected cereals: Teff, barley and maize samples. Liquid chromatography with variable wavelength detector (VWD was used for quantitative determination of the pesticides. Various experimental parameters affecting the extraction and the preconcentration efficiencies were optimized. Calibration curves constructed using Teff samples were linear over wide ranges, 7.1-200 μg kg-1 with R2 ≥ 0.990. LODs of the method were ≤ 8.9 μg kg-1, below the MRLs of EU for maize and barley. The RSDs were in the range of 2.3–9.5%. The method has also been applied to different cereal samples and satisfactory average recoveries ranging 69.0–117% were obtained for the spiked cereal samples at two concentration levels. Therefore, the developed method can be successfully utilized as a simple alternative for the analysis of multiclass pesticide residues in cereals and other related samples.

  17. A NEW CLASS OF IONIC SOLVENTS, ELECTROLYTES AND ENGINEERING FLUIDS BASED ON 1,3-ALKYLMETHYL-1,2,3-BENZOTRIAZOLIUM SALTS

    Directory of Open Access Journals (Sweden)

    Ahmad Mudzakir

    2010-06-01

    Full Text Available A new series of ionic liquids based on 1,3-alkylmethyl-1,2,3-benzotriazolium cation has been prepared. The spectroscopic, physical and electrochemical characteristics of this family of salts have been investigated with respect to potential usage as ionic solvents, electrolytes and engineering fluids. Incorporation of diverse anions including weak coordinating anion and pseudohalide with this benzotriazolium cation produces ionic liquids with advantageously low melting points and good thermal stability. Thermal analyses of these very stable salts included the determination of melting points (-65 to 164 oC and decomposition temperatures (up to 291 oC. The electrochemical windows of representative benzotriazolium species has been investigated by cyclic voltammetry and determined to be ~ 3 V. The X-ray single crystal and spectroscopic studies revealed that weak hydrogen-bonding interactions between the benzotriazolium ring protons and the anions are present both in the solid state as well as in solution.   Keywords: ionic liquids, X-ray single crystal, thermal analysis, electrochemical analysis, benzotriazolium salt

  18. Encuentros entre pintura, escultura y fotografía o la apropiación de Ofelia en el arte argentino

    OpenAIRE

    Rueda, María de los Ángeles de

    2006-01-01

    Este artículo pertenece a una serie en construcción, cuyo origen se remonta a las investigaciones que he llevado a cabo hace una década sobre la parodia en la pintura argentina a lo que se suma la indagación que he comenzado recientemente sobre los desplazamientos discursivos de la fotografía. Asimismo al interior de los debates del grupo de investigación que dirijo Múltiples/mútiples, el interés se fue trasladando desde los problemas de la no auraticidad de las imágenes, a las operaciones de...

  19. La pintura de Velázquez como recurso didáctico en materia de atención a la diversidad

    OpenAIRE

    Marcos Díez, María Araceli

    2014-01-01

    Dentro de los recursos con que se cuenta para la labor didáctica en Educación Primaria, en este trabajo se plantea la exploración de un campo poco tratado como es el del uso de las manifestaciones artísticas y, en concreto, la pintura para motivar y acercar a los alumnos a una mayor comprensión de la diversidad presente en nuestras aulas y en su propio entorno social. El pintor elegido es Diego Rodríguez de Silva y Velázquez; el marco cronológico de partida, el Siglo de Oro español y...

  20. La música en la pintura europea entre los siglos XIV y XX: El ejemplo de la Colección Thyssen-Bornemisza

    OpenAIRE

    García Heredia, Mª Dolores

    2016-01-01

    Con este trabajo se ha pretendido realizar un estudio de la iconografía musical en la pintura europea a lo largo de un período determinado: desde el siglo XIV al siglo XX. La colección Thyssen-Bornemisza nos ha ofrecido la posibilidad de abarcar estos siete siglos. Hemos intentado penetrar en el significado de las escenas sonoras y aproximarnos a su musicalidad a partir del análisis de los instrumentos o elementos musicales reflejados en cuarenta y nueve cuadros. Al mismo tiempo, hemos indaga...

  1. 福禄集团以1500万欧元收购西班牙玻璃涂料制造商Pinturas Benicarl o

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    世界知名新材料商福禄集团近日宣布,在无债务基础上,以1500万欧元的现金形式全权收购西班牙玻璃涂料制造商Pinturas Benicarl o公司。此次收购将为福禄公司的玻璃涂料部门带来新的水性涂层技术,也为福禄公司进入玻璃容器领域打开了大门。

  2. Esa mujer inalcanzable. La psicología de la mujer en la pintura de Félix Rovelló de Toro

    Directory of Open Access Journals (Sweden)

    Porta Tovar, José María

    2001-03-01

    Full Text Available Not available

    Se recoge en este artículo un análisis del perfil de la mujer pintada por el maestro Félix Revello de Toro, desde el punto de vista de la psicología moderna.
    El autor, José M.ª Porta Tovar, psiquiatra de profesión, estudia minuciosamente los detalles de las modelos de su pintura, para descubrir, a partir del conjunto de todos ellos, ese perfil de la mujer ideal, sublimado e inalcanzable, pero presente y sugestivo en el subconsciente colectivo del hombre de nuestros días.

  3. Asignación estratégica de un modelo de logística inversa aplicado a los envases de pintura

    OpenAIRE

    Vargas Barco, Andrés Felipe

    2014-01-01

    El presente proyecto de investigación tuvo como principal objetivo resaltar la importancia de la responsabilidad social empresarial en el marco del desarrollo sostenible, unificando estrategias de logística inversa con modelos que permitirán cerrar el ciclo de vida útil de los envases de las mas prestigiosas compañías colombianas; líderes en el sector químico, mas exactamente de pinturas. Al ver la oportunidad del proyecto, en este se analizaron a grandes rasgos, los procesos inmersos en ...

  4. ESTUDIO TÉCNICO Y DEL ESTADO DE CONSERVACIÓN DE UNA PINTURA AL ÓLEO REALIZADA SOBRE EL TABLERO DE UNA MESA ABATIBLE DECORATIVA

    OpenAIRE

    DURÁN GONZÁLEZ, ALICIA

    2016-01-01

    [ES] El presente trabajo de final de grado desarrolla el estudio de una pintura al óleo sobre soporte lígneo, cuya principal peculiaridad reside en que se trata del tablero de una mesa abatible decorativa de estilo rococó. Se trata de una obra de autoría desconocida, datada en mediados del siglo XVIII, en la que aparece representada una escena béli ca. A través de este trabajo se persiguen diversos objetivos: por una parte, estudiar ciertos aspectos inherentes a la ...

  5. El proceso gráfico de la pintura punteada cantábrica : hacia la identificación de uina cadena operativa artística

    OpenAIRE

    2007-01-01

    La aproximación a la actividad artística en la investigación del arte parietal paleolitico plantea diversas posibilidades. En los últimos años, y sobre todo en lo que se refiere al arte mobiliar, se ha progresado en la recoonstitución de la cadena operativa gráfica. En este caso, nos cetramos en las pinturas punteadas cantábricas para las que se reconoce una homogeneidad estilística excepcional durante un periodo cronológico amplio (Gravetiense-Solutrense). Asimismo, presentan una pautas comu...

  6. Normalização dos postos de trabalho na secção de pintura de uma empresa de mobiliário

    OpenAIRE

    Ribeiro, Luís Pedro Mendes Pereira

    2012-01-01

    Dissertação de mestrado integrado em Engenharia e Gestão Industrial A presente dissertação, inserida no âmbito do 5º ano do Mestrado Integrado em Engenharia e Gestão Industrial, descreve um projeto cujo objetivo principal foi a normalização dos postos de trabalho da área de pintura de uma empresa de mobiliário, a Swedwood Portugal, empresa pertencente ao grupo Swedwood, ramo industrial do IKEA. Na conjetura atual as empresas têm a necessidade de reduzir custos, mantendo a quali...

  7. Nuevos documentos sobre Gabriel José de Ovalle y algunas consideraciones acerca de la apreciación de la pintura novohispana

    OpenAIRE

    Clara Bargellini

    2001-01-01

    El hallazgo de un grupo de documentos acerca del pintor novohispano Gabriel José de Ovalle, activo en Zacatecas y Durango hacia mediados del siglo xviii, proporciona información nueva sobre el artista y el desarrollo de su carrera, pero también sugiere consideraciones acerca de la valoración de la pintura en la historiografía y en la propia época virreinal. Ya que los documentos informan que Ovalle había llegado a Zacatecas desde la ciudad de México, se revisan los juicios hasta ahora vertido...

  8. Actualización del sistema SCADA y de control para los reactores MQ5 y MQ6 de la planta de Pinturas Condor, Sherwin Williams Ecuador

    OpenAIRE

    Jonathan Reinoso

    2015-01-01

    El presente documento describe la actualización del sistema SCADA para los reactores MQ5 y MQ6 de la planta de Pinturas Condor mediante el software Intouch y la actualización del sistema de control del reactor MQ5 implementado en un controlador lógico programable (PLC) de marca SCHNEIDER, además de la arquitectura de control realizada en el proyecto. El sistema SCADA y de control de los reactores permiten la visualización y control de los datos y variables más relevantes durante las diferente...

  9. La calle es nuestra: La pintura mural del colectivo plástico de zaragoza durante la transición.

    Directory of Open Access Journals (Sweden)

    Mª Luisa Grau Tello

    2012-04-01

    Full Text Available Dentro del proceso de transición española hacia un régimen democrático, la pintura mural en el espacio urbano adquirió un papel de primera importancia al convertirse en un medio de expresión con el que partidos políticos y ciudadanos manifestaron sus deseos de cambio. El Colectivo Plástico de Zaragoza protagonizó esta actividad en Zaragoza junto con los barrios de la ciudad, que expresaron a través de estos murales las deficiencias y reivindicaciones que demandaban sus vecinos.

  10. Alteraciones hematológicas en trabajadores expuestos ocupacionalmente a mezcla de Benceno-Tolueno-Xileno (BTX) en una fábrica de pinturas

    OpenAIRE

    Haro García, Luis; Vélez Zamora, Nadia; Aguilar Madrid, Guadalupe; Guerrero Rivera, Susana; Sánchez Escalante, Vanessa; Sergio R Muñoz; Mezones Holguín, Edward; Juárez Pérez, Cuauhtémoc

    2016-01-01

    Objetivos. Evaluar las tres series celulares sanguíneas e identificar la presencia de hipocromía, macrocitosis, leucopenia, linfocitopenia y trombocitopenia en un grupo de trabajadores expuestos a la mezcla de benceno-tolueno-xileno (BTX). Materiales y métodos. Estudio transversal donde se incluyó a 97 trabajadores de una empresa de pinturas de México a los que se les realizó una biometría hemática convencional y les fue estimada la exposición a través de la dosis diaria potencial...

  11. Cuadros en movimiento: la pintura en el cine: Relaciones intermediales en La hora de los valientes [Mercero 1998] y Te doy mis ojos [Bollaín 2003

    Directory of Open Access Journals (Sweden)

    Esther Gimeno Ugalde

    2011-12-01

    Full Text Available The objective of this article is to study the relationship between cinema and painting from an intermedial perspective by analysing two Spanish films: La hora de los valientes (Antonio Mercero 1998 and Te doy mis ojos (Icíar Bollaín 2003. We intend to compare how the respective directors use painting to construct and enrich the cinematographic story and to analyse what narrative and artistic role the paintings play in the filmic text. The study of the two films will serve to illustrate our initial hypothesis, that painting is used not only for artistic and narrative purposes, but also to make the spectator a witness of a twofold drama: the individual and the collective. The exchange of looks which permeates the diegesis places painting to the forefront, whilst determining the interpretation of the filmic textBasándonos en un enfoque teórico intermedial, el presente artículo tiene como objeto estudiar las relaciones entre cine y pintura a partir de dos películas españolas: La hora de los valientes [Antonio Mercero 1998] y Te doy mis ojos [Icíar Bollaín 2003]. Nos proponemos cotejar cómo los respectivos directores introducen la pintura para construir y enriquecer el relato cinematográfico y analizar qué función narrativa y estética cumplen los cuadros en el texto fílmico. El estudio de ambos filmes nos servirá para demostrar nuestra hipótesis inicial: la pintura se emplea no solo con fines estéticos y narrativos, sino también para convertir al espectador en testigo de un doble drama, el individual y el colectivo. El juego de miradas que atraviesa la diégesis sitúa a la pintura en un primer plano, a la vez que determina la lectura del texto fílmico

  12. Organic solvent topical report

    Energy Technology Data Exchange (ETDEWEB)

    COWLEY, W.L.

    1999-05-13

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed.

  13. Organic solvent topical report

    Energy Technology Data Exchange (ETDEWEB)

    Cowley, W.L.

    1998-04-30

    This report is the technical basis for the accident and consequence analyses used in the Hanford Tank Farms Basis for Interim Operation. The report also contains the scientific and engineering information and reference material needed to understand the organic solvent safety issue. This report includes comments received from the Chemical Reactions Subcommittee of the Tank Advisory Panel.

  14. ADME evaluation in drug discovery. 2. Prediction of partition coefficient by atom-additive approach based on atom-weighted solvent accessible surface areas.

    Science.gov (United States)

    Hou, T J; Xu, X J

    2003-01-01

    A novel method for the calculations of 1-octanol/water partition coefficient (log P) of organic molecules has been presented here. The method, SLOGP v1.0, estimates the log P values by summing the contribution of atom-weighted solvent accessible surface areas (SASA) and correction factors. Altogether 100 atom/group types were used to classify atoms with different chemical environments, and two correlation factors were used to consider the intermolecular hydrophobic interactions and intramolecular hydrogen bonds. Coefficient values for 100 atom/group and two correction factors have been derived from a training set of 1850 compounds. The parametrization procedure for different kinds of atoms was performed as follows: first, the atoms in a molecule were defined to different atom/group types based on SMARTS language, and the correction factors were determined by substructure searching; then, SASA for each atom/group type was calculated and added; finally, multivariate linear regression analysis was applied to optimize the hydrophobic parameters for different atom/group types and correction factors in order to reproduce the experimental log P. The correlation based on the training set gives a model with the correlation coefficient (r) of 0.988, the standard deviation (SD) of 0.368 log units, and the absolute unsigned mean error of 0.261. Comparison of various procedures of log P calculations for the external test set of 138 organic compounds demonstrates that our method bears very good accuracy and is comparable or even better than the fragment-based approaches. Moreover, the atom-additive approach based on SASA was compared with the simple atom-additive approach based on the number of atoms. The calculated results show that the atom-additive approach based on SASA gives better predictions than the simple atom-additive one. Due to the connection between the molecular conformation and the molecular surface areas, the atom-additive model based on SASA may be a more

  15. Low-density solvent-based vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction combined with gas chromatography-mass spectrometry for the fast determination of phthalate esters in bottled water.

    Science.gov (United States)

    Zhang, Yufeng; Lee, Hian Kee

    2013-01-25

    For the first time, a novel low-density solvent-based vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction (LDS-VSLLME) was developed for the fast, simple and efficient determination of six phthalate esters (PEs) in bottled water samples followed by gas chromatography-mass spectrometry (GC-MS). In the extraction procedure, the aqueous sample solution was injected into a mixture of extraction solvent (toluene) and surfactant (cetyltrimethyl ammonium bromide), which were placed in a glass tube with conical bottom, to form an emulsion by the assistance of vortex agitation. After extraction and phase separation by centrifugation, and removal of the spent sample, the toluene extract was collected and analyzed by GC-MS. The addition of surfactant enhanced the dispersion of extraction solvent in aqueous sample and was also favorable for the mass transfer of the analytes from the aqueous sample to the extraction solvent. Moreover, using a relatively less toxic surfactant as the emulsifier agent overcame the disadvantages of traditional organic dispersive solvents that are usually highly toxic and expensive and might conceivably decrease extraction efficiency to some extent since they are not as effective as surfactants themselves in generating an emulsion. With the aid of surfactant and vortex agitation to achieve good organic extraction solvent dispersion, extraction equilibrium was achieved within 1 min, indicating it was a fast sample preparation technique. Another prominent feature of the method was the simple procedure to collect a less dense than water solvent by a microsyringe. After extraction and phase separation, the aqueous sample was removed using a 5-mL syringe, thus leaving behind the extract, which was retrieved easily. This novel method simplifies the use of low-density solvents in DLLME. Under the optimized conditions, the proposed method provided good linearity in the range of 0.05-25 μg/L, low limits of detection (8-25 ng

  16. Influence of imidazolium based green solvents on volume phase transition temperature of crosslinked poly(N-isopropylacrylamide-co-acrylic acid) hydrogel.

    Science.gov (United States)

    Chang, Chi-Jung; Reddy, P Madhusudhana; Hsieh, Shih-Rong; Huang, Hsin-Chun

    2015-01-28

    The volume phase transition temperature (VPTT) of crosslinked poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAM-co-AA) hydrogel in water in the presence of five imidazolium based ionic liquids (ILs) was studied. The VPTT of PNIPAM-co-AA hydrogel can be modulated to different extents by the addition of different amounts of ILs. The modulations in VPTT values can be attributed to the IL-induced alterations in hydrophobic, hydrophilic and hydrogen bonding interactions of PNIPAM-co-AA hydrogel with the neighboring solvent and molecular chains. The influence of ILs having a common cation, 1-butyl-3-methylimidazolium cation ([Bmim]) and different anions, such as iodide (I-), tetrafluoroborate (BF4-), chloride (Cl-), acetate (CH3COO-) and hydrogen sulfate (HSO4-), on the phase transition of PNIPAM-co-AA hydrogel was monitored by the aid of differential scanning calorimetry (DSC), dynamic light scattering (DLS) and Fourier transform infrared (FT-IR) spectroscopy. Furthermore, the interfacial properties between aqueous IL and polymer surface were scrutinized with the help of contact angle (CA) measurements. The overall specific ranking of ILs in preserving the hydration layer around the PNIPAM-co-AA hydrogel in water was [Bmim][I]>[Bmim][BF4]>[Bmim][Cl]>[Bmim][Ac]>[Bmim][HSO4]. The trend of these ILs followed the well-known Hofmeister series. Interestingly, the PNIPAM-co-AA hydrogel in water shows abnormal salting-out property in the presence of [Bmim][BF4] at higher concentration and this abnormal behavior can be explained based on the lack of sufficient binding sites on the macromolecule for higher number of [Bmim][BF4] at a higher concentration.

  17. Nuevas noticias sobre las pinturas para el Real Palacio del Buen Retiro realizadas en Italia (1633-1642

    Directory of Open Access Journals (Sweden)

    Simal López, Mercedes

    2011-09-01

    Full Text Available The location of new documents concerning the commissions by the Count-Duke of Olivares of various series of paintings for the decoration of the Buen Retiro Palace from the Marquis of Castel-Rodrigo, Spanish Ambassador to Rome, and the Count of Monterrey, Viceroy of Naples, between 1633 and 1642, have allowed for: the specification of the chronology and the contents of the different shipments; the confirmation of the role of Gaspar de Guzmán as coordinator of the entire commission; the knowledge of the kind of instructions exchanged between Philip IV’s favorite and Spanish diplomats in Italy; and the identification of the emplacement of some of the works, such as the Saint John the Baptist cycle, intended to decorate the Oratory of the Palace.

    La localización de nuevos documentos relativos a los encargos de varias series de pinturas por parte del conde-duque de Olivares para la decoración del palacio del Buen Retiro al marqués de Castel Rodrigo, embajador en Roma, y al conde de Monterrey, virrey de Nápoles, entre 1633 y 1642 han permitido precisar la cronología y el contenido de los distintos envíos que se realizaron, ratificar la identidad de don Gaspar de Guzmán como coordinador de todo el encargo, conocer el tipo de instrucciones que intercambiaron el valido de Felipe IV y los representantes diplomáticos en Italia, e identificar el destino de algunas obras, como las del ciclo de San Juan Bautista, destinadas a decorar el oratorio del palacio.

  18. PRIMER INTENTO DE DATACIÓN DE PINTURAS MURALES MESOAMERICANAS (First Attempt to Date Mesoamerican Mural Paintings

    Directory of Open Access Journals (Sweden)

    Avto Goguitchaichvili

    2016-03-01

    Full Text Available Se reporta, por vez primera, el intento de datación de cuatro pinturas murales del centro de México: Templo de Venus (Cacaxtla, Templo Rojo (Templo Mayor, Tenochtitlan, Chapulines y Estrellas (Cholula. Estos sitios corresponden al periodo Clásico y Posclásico Temprano de la cronología mesoamericana. Las edades obtenidas para Chapulines (1105-1194 A. D., Templo de Venus (1002-1308 A. D. y Estrellas (340-649 A. D. están dentro de la cronología y contexto arqueológico de los sitios estudiados. Sin embargo, la edad de Templo Rojo (1829-1888 A. D. señala a una edad demasiado tardía no compatible con la cronología reportada. Por tanto, cabe la posibilidad de que la magnetización pudiera haber sufrido alguna alteración después de haber sido aplicada. ENGLISH: We report the results of the first attempt to date four mural paintings from sites in Central Mexico: the Temple of Venus (Cacaxtla, the Red Temple (part of the Templo Mayor complex in Tenochtitlan, and the Chapulines and Estrellas temples (Cholula. These sites correspond to the Classic and Early Postclassic period of the Mesoamerican chronology. The ages obtained for the Chapulines (1105-1194 AD, Temple of Venus (1002-1308 AD and Estrellas (340-649 AD murals are within the accepted chronology and archaeological context of their respective sites. However, the date range that we obtained for the Red Temple (1829-1888 AD points to a time period incompatible with Tenochtitlan’s established chronology. It is possible that the mural’s pictorial magnetization suffered some alteration over time.

  19. Operator care and eco-concerned development of a fast, facile and economical assay for basic nitrogenous drugs based on simplified ion-pair mini-scale extraction using safer solvent combined with drop-based spectrophotometry.

    Science.gov (United States)

    Plianwong, Samarwadee; Sripattanaporn, Areerut; Waewsa-nga, Kwanrutai; Buacheen, Parin; Opanasopit, Praneet; Ngawhirunpat, Tanasait; Rojanarata, Theerasak

    2012-08-30

    A fast, facile, and economical assay for basic nitrogenous drugs has been developed based on the mini-scale extraction of the drug-dye ion pair complex combined with the use of safe-for-analyst and eco-friendlier organic extractant and drop-based micro-spectrophotometry. Instead of using large volume devices, the extraction was simply carried out in typical 1.5 mL microcentrifuge tubes along with the use of micropipettes for accurate transfer of liquids, vortex mixer for efficient partitioning of solutes and benchtop centrifuge for rapid phase separation. In the last step, back-extraction was performed by using the microvolume of acidic solution in order to concentrate the colored species into a confined aqueous microdrop and to keep the analyst away from unwanted contact and inhalation of organic solvents during the quantitation step which was achieved by using cuvetteless UV-vis micro-spectrophotometry without any prior dilutions. Using chlorpheniramine maleate as a representative analyte and n-butyl acetate as a less toxic and non-ozone depleting extractant, the miniaturized method was less laborious and much faster. It was accurate, precise and insensitive to the interferences from common excipients. Notably, it gave the assay results of drug in tablets and oral solution comparable to the large-scale pharmacopeial method while the consumption of organic solvents and the release of wastes were lowered by 200-400 folds.

  20. Ab initio study of solvent-dependent one-, two- and three-photon absorption properties of PRODAN-based chemo-sensors

    Indian Academy of Sciences (India)

    Md Mehboob Alam; Mausumi Chattopadhyaya

    2014-07-01

    In this work, we study the solvent-dependent one-, two- and three-photon absorption (1PA, 2PA and 3PA) properties of 2-propionyl-6-dimethylamino naphthalene (PRODAN) and three newly synthesized20 cyclopenta[b]naphthalene derivatives, in gas phase and three different solvents, namely cyclohexane, dichloromethane and ethanol. A comparison between the calculated and the available experimental data shows that the results obtained with B3LYP/cc-pVDZ level of theory matches well with the experimental absorption data for all of these compounds. The 2P and 3P transition probabilities, for all of these systems, are found to be maximum in solvents of intermediate polarity (here, dichloromethane), which is in accordance with the experimental observation for various other systems. All the 1P, 2P and 3P transition probabilities are found to be the maximum for PRODAN as compared to other three molecules in both the gas as well as the different solvent phases (except for 3PA in gas and cyclohexane solvents). We have explained these results by meticulously inspecting the components of different transition moment vectors and the tensor elements involved.

  1. An attempt towards simultaneous biobased solvent based extraction of proteins and enzymatic saccharification of cellulosic materials from distiller's grains and solubles.

    Science.gov (United States)

    Datta, Saurav; Bals, B D; Lin, Yupo J; Negri, M C; Datta, R; Pasieta, L; Ahmad, Sabeen F; Moradia, Akash A; Dale, B E; Snyder, Seth W

    2010-07-01

    Distiller's grains and solubles (DGS) is the major co-product of corn dry mill ethanol production, and is composed of 30% protein and 30-40% polysaccharides. We report a strategy for simultaneous extraction of protein with food-grade biobased solvents (ethyl lactate, d-limonene, and distilled methyl esters) and enzymatic saccharification of glucan in DGS. This approach would produce a high-value animal feed while simultaneously producing additional sugars for ethanol production. Preliminary experiments on protein extraction resulted in recovery of 15-45% of the protein, with hydrophobic biobased solvents obtaining the best results. The integrated hydrolysis and extraction experiments showed that biobased solvent addition did not inhibit hydrolysis of the cellulose. However, only 25-33% of the total protein was extracted from DGS, and the extracted protein largely resided in the aqueous phase, not the solvent phase. We hypothesize that the hydrophobic solvent could not access the proteins surrounded by the aqueous phase inside the fibrous structure of DGS due to poor mass transfer. Further process improvements are needed to overcome this obstacle.

  2. Simultaneous dispersive liquid-liquid microextraction based on a low-density solvent and derivatization followed by gas chromatography for the simultaneous determination of chloroanisoles and the precursor 2,4,6-trichlorophenol in water samples.

    Science.gov (United States)

    Bai, Xiuzhi; Zhang, Ting; Li, Haipu; Yang, Zhaoguang

    2016-06-01

    Chloroanisoles, particularly 2,4,6-trichloroanisole, are commonly identified as major taste and odor compounds in water. In the present study, a simple and efficient method was established for the simultaneous determination of chloroanisoles and the precursor 2,4,6-trichlorophenol in water by using low-density-solvent-based simultaneous dispersive liquid-liquid microextraction and derivatization followed by gas chromatography with electron capture detection. 2,4-Dichloroanisole, 2,6-dichloroanisole, 2,4,6-trichloroanisole, 2,3,4-trichloroanisole, and 2,3,6-trichloroanisole were the chloroanisoles evaluated. Several important parameters of the extraction-derivatization procedures, including the types and volumes of extraction solvent and disperser solvent, concentrations of derivatization agent and base, salt addition, extraction-derivatization time, and temperature were optimized. Under the optimized conditions (80 μL of isooctane as extraction solvent, 500 μL of methanol as disperser solvent, 60 μL of acetic anhydride as derivatization agent, 0.75% of Na2 CO3 addition w/v, extraction-derivatization temperature of 25°C, without salt addition), a good linearity of the calibration curve was observed by the square of correlation coefficients (R(2) ) ranging from 0.9936 to 0.9992. Repeatability and reproducibility of the method were < 4.5% and <7.3%, respectively. Recovery rates ranged from 85.2 to 101.4%, and limits of detection ranged from 3.0 to 8.7 ng/L. The proposed method was applied successfully for the determination of chloroanisoles and 2,4,6-trichlorophenol in water samples.

  3. Vortex-assisted micro-solid-phase extraction followed by low-density solvent based dispersive liquid-liquid microextraction for the fast and efficient determination of phthalate esters in river water samples.

    Science.gov (United States)

    Guo, Liang; Lee, Hian Kee

    2013-07-26

    A simple and efficient two-step method, vortex-assisted micro-solid-phase extraction (VA-μ-SPE) followed by low-density solvent based dispersive liquid-liquid microextraction (LDS-DLLME) combined with analysis by gas chromatography-mass spectrometry (GC-MS), was developed for the determination of trace level phthalate esters in environmental water samples. The analytes were firstly extracted and preconcentrated by vortex-assisted μ-SPE which was faster than conventional μ-SPE (6min compared to 30min), and then desorbed by ultrasonication into acetonitrile. The latter served as the dispersive solvent in the subsequent LDS-DLLME step which further pre-concentrated the analytes. Six phthalate esters were selected as model compounds for developing and evaluating the method. Some key parameters for VA-μ-SPE and LDS-DLLME, such as sorbent selection and amount, vortex time, ultrasonication solvent and time, extraction solvent type and volume for DLLME, the speed and time of centrifugation, were investigated. Under the most favorable conditions, good limits of detection (as low as 0.006μg/L) and repeatability of extraction (RSDs below 9.2%, n=5) were obtained. The developed method was applied to determine phthalate esters in environmental water samples.

  4. Solvent Immersion Imprint Lithography

    Energy Technology Data Exchange (ETDEWEB)

    Vasdekis, Andreas E.; Wilkins, Michael J.; Grate, Jay W.; Kelly, Ryan T.; Konopka, Allan; Xantheas, Sotiris S.; Chang, M. T.

    2014-06-21

    The mechanism of polymer disolution was explored for polymer microsystem prototyping, including microfluidics and optofluidics. Polymer films are immersed in a solvent, imprinted and finally brought into contact with a non-modified surface to permanently bond. The underlying polymer-solvent interactions were experimentally and theoretically investigated, and enabled rapid polymer microsystem prototyping. During imprinting, small molecule integration in the molded surfaces was feasible, a principle applied to oxygen sensing. Polystyrene (PS) was employed for microbiological studies at extreme environmental conditions. The thermophile anaerobe Clostridium Thermocellum was grown in PS pore-scale micromodels, revealing a double mean generation lifetime than under ideal culture conditions. Microsystem prototyping through directed polymer dissolution is simple and accessible, while simultaneous patterning, bonding, and surface/volume functionalization are possible in less than one minute.

  5. Role of solvent/non-solvent ratio on microsphere formation using the solvent removal method.

    Science.gov (United States)

    Godbee, J; Scott, E; Pattamunuch, P; Chen, S; Mathiowitz, E

    2004-03-01

    The importance of good solvent concentration in the non-solvent mixture and the non-solvent viscosity on the ability to form microspheres using solvent removal process was investigated. The higher the viscosity of the polymer solutions, the higher the concentration of good solvent needed in the nonsolvent mixture to produce microspheres. This finding was due to faster precipitation of the polymer phase. Also, the addition of a model drug, fluorescein isothiocyanate conjugated-labelled bovine serum albumin, to the polymer solution (10% poly-L-lactic acid:poly(fumaric-co-sebacic) anhydride in methylene chloride) resulted in an overall lower polymer solution viscosity (15.5 cP with fluorescein isothiocyanate conjugated-labelled bovine serum albumin as compared with 18.25 cP for blank polymer at 25 degrees C). Additionally, the effect of good solvent concentration on non-solvent viscosity was evaluated, and the viscosity decreased as the concentration of good solvent increased. The effect of good solvent concentration on the non-solvent mixture on sphere formation was of great importance. Microspheres would not form when the good polymer solvent (methylene chloride) in the non-solvent phase was too low (below 175 ml for poly-L-lactic acid or 150 ml for poly(D,L-lactidco-glycolid)) or was replaced by another good solvent such as ethyl acetate, even though the same viscosity was achieved. It was shown that the concentration of the good solvent in the non-solvent mixture was more of a controlling factor than the viscosity of the non-solvent mixture in microsphere formation and the findings support the conclusion that diffusion is the main controlling parameter in solvent removal.

  6. "Abnormal" salt and solvent effects on anion/cation electron-transfer reactions: an interpretation based on Marcus-Hush treatment.

    Science.gov (United States)

    Garcia-Fernandez, E; Prado-Gotor, R; Sanchez, F

    2005-08-11

    Salt and solvent effects on the kinetics of the reactions [Fe(CN)6]3- + [Ru(NH3)5pz](2+) right arrow over left arrow [Fe(CN)6]4- + [Ru(NH3)5pz]3+ (pz = pyrazine) have been studied through T-jump measurements. The forward and reverse reactions show different behaviors: "abnormal" salt and solvent effects in the first case and normal effects in the second one. These facts imply an asymmetric behavior of anion/cation reactions depending on the charge of the oxidant. The results can be rationalized by using the Marcus-Hush treatment for electron-transfer reactions.

  7. Cyclohexylamine as extraction solvent and chelating agent in extraction and preconcentration of some heavy metals in aqueous samples based on heat-induced homogeneous liquid-liquid extraction.

    Science.gov (United States)

    Sorouraddin, Saeed Mohammad; Farajzadeh, Mir Ali; Okhravi, Tohid

    2017-12-01

    A new sample preparation method has been developed for extraction and preconcentration of some heavy metal cations in aqueous samples using cyclohexylamine-based homogeneous liquid-liquid microextraction. In the proposed method, cyclohexylamine was used as both the complexing agent and the extraction solvent. For this purpose, cyclohexylamine at µL level was initially added into an aqueous solution containing Co(II), Ni(II), and Cu(II) ions which was placed in a glass test tube. The mixture was shaken for forming a homogeneous solution. Then sodium chloride was added to the solution. After shaking manually again, the test tube was placed in a water bath thermostated at 70°C. Due to lower solubility of cyclohexylamine at the elevated temperature, a cloudy solution was formed. The fine droplets of cyclohexylamine containing cation-cyclohexylamine complexes were collected on the top of the aqueous phase by centrifuging. The enriched analytes in the upper phase were determined by graphite furnace atomic absorption spectrometry. Several variables possibly affecting the extraction efficiency were investigated and optimized. Under the optimum conditions the calibration curves were linear in the ranges of 80-1000, 40-700, and 80-800ngL(-1) for Co(2+), Ni(2+), and Cu(2+), respectively. Repeatability of the proposed method, expressed as relative standard deviation, ranged from 3.3% to 5.2% (n = 6, C = 200ngL(-1)). Moreover, the obtained detection limits of the selected analytes were in the range of 15.3-37.7ngL(-1). The accuracy of the developed procedure was verified by analyzing a certified reference material, namely NRCC-SLRS4 Riverine water. Finally, the proposed method was successfully applied for the simultaneous analysis of the selected analytes in environmental water samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Critical solvent thermodynamic effect on molecular recognition: The case of the complex formation of carboxylates and ammonium-squaramido based receptors

    Energy Technology Data Exchange (ETDEWEB)

    Piña, M. Nieves, E-mail: neus.pinya@uib.es; López, Kenia A.; Costa, Antoni; Morey, Jeroni, E-mail: jeroni.morey@uib.es

    2013-10-10

    Graphical abstract: - Highlights: • The enthalpy–entropy compensation in the complex is independent of the spacer used. • The enthalpy–entropy compensation is dependent on the microscopic nature of the binary mixture. • The enthalpy–entropy compensation is dependent on the proportion of the components of the binary mixture. - Abstract: An isothermal titration microcalorimetry (ITC) study on the supramolecular complex formation between carboxylates and ammonium-squaramido based receptors at different ethanol:water proportions is reported. The results obtained show that the formation enthalpy sign of a supramolecular complex in a water–ethanol binary mixture can be influenced by the proportion of the cosolvent. Moreover there is an enthalpy–entropy compensation process in the supramolecular complex formation; in poor water mixtures the process is endothermic, whilst in reach water mixtures the process is exothermic. This behavior is mostly due to the intrinsic nature of the mixture between water and ethanol, and particularly the process of solvation and desolvation of receptor, substrate and complex. When this study is repeated with binary mixtures of water–methanol and water–DMSO it is observed that the nature of the organic solvent affects the results. While the mixture water–methanol has a behavior similar to water–ethanol mixture, the water–DMSO mixture shows clear differences. In order to check this compensation process, △Cp values are calculated at two different proportions water–ethanol, and they are consistent with an enthalpy–entropy compensation process similar to that described by the inclusion process for certain hydrophilic cyclodextrines. The results obtained show that the enthalpy–entropy compensation detected in the supramolecular complex formation between carboxylates and ammonium-squaramido receptors is independent of the spacer used, and more dependent on the microscopic nature and proportion of the binary mixture.

  9. Sistematización cronológica de la pintura rupestre esquemática en la provincia de Badajoz : los abridos de la Sierra de Magacela

    Directory of Open Access Journals (Sweden)

    Hipólito Collado Giraldo

    1995-01-01

    Full Text Available En los últimos años, bajo la dirección de Prof. Dr. Don Eduardo Ripoll Perelló, se están realizando dos tesis doctorales a cargo de Doña María Isabel Martínez Perelló y el que suscribe, cuya finalidad es la investigación, estudio, divulgación y puesta en valor de la pintura rupestre esquemática de la provincia de Badajoz. Fruto de estos trabajos ha sido el descubrimiento de más de un centenar de nuevos abrigos que no hacen sino confirmar a Badajoz y a Extremadura como uno de los enclaves fundamentales en el desarrollo del fenómeno esquemático peninsular ^ (fig. 1. Entre ellos los nuevos abrigos localizados en la Sierra de Magacela son una mínima parte del gran complejo esquemático extremeño; su importancia radica en las especiales características técnicas y estilísticas que reúnen, así como en el aceptable estado de conservación de las pinturas, lo que nos va a permitir observar de forma fácil una serie de singulares superposiciones de motivos y colores, que permiten establecer tres diferentes períodos cronológicos en la realización de las mismas.

  10. Los mártires de Chateaubriand en la pintura decimonónica española

    Directory of Open Access Journals (Sweden)

    Arias Anglés, Enrique

    2003-03-01

    Full Text Available Muchas y variadas fueron las inspiraciones de que se sirvieron tanto la pintura de historia como su hermana menor la literaria a lo largo de su desarrollo en el siglo XIX. Sin embargo, no deja de ser sorprendente de donde surgieron algunas de ellas, sobre todo de las literarias, que tuvieron su mayor desenvolvimiento en la segunda mitad de esa centuria y principios de la vigésima. Ejemplo de ello son los dos cuadros que aquí traemos inspirados en la novela de Los Mártires del célebre escritor romántico francés François-René de Chateaubriand (Saint Malo, 1768-París, 1848; prueba no sólo de la gran relación que hubo entre la literatura —el vehículo por el que más pronto y mejor se expresó el espíritu romántico— y la pintura, la más literaria de las artes plásticas, sino quizá también de la celebridad de la que gozó esta novela entre la burguesía de la España del ochocientos…

  11. Planteamiento metodológico para la evaluación del desempeño de pinturas antiincrustantes en condiciones estáticas

    Directory of Open Access Journals (Sweden)

    Félix Echeverría

    2006-01-01

    Full Text Available La protección de superficies sumergidas en agua de mar tiene además de los aspectos de corrosividad un aspecto importante que debe considerarse y es evitar la colonización por especies marinas. La colonización de superficies sumergidas, además de deteriorar todo el sistema de protección, genera inconvenientes en cuanto a la operatividad de naves y estructuras, debido al aumento en rugosidad y peso de estas. Como medida preventiva se emplean recubrimientos de pintura denominados antiincrustantes, los cuales evitan la adhesión de organismos a las superficies. Para la formulación y posterior evaluación de una nueva pintura es necesario tener conocimiento del medio ambiente y disponer montajes tanto de laboratorio como de campo, para lograr resultados representativos y de inmediata aplicación. En el presente trabajo se describen los pasos recomendados a seguir en un estudio de este tipo, metodología que se ha desarrollado y aplicado recientemente con resultados muy halagadores.

  12. Una revisión a la interpretación de la Pintura Moderna de Greenberg a través de los textos de la Vanguardia

    Directory of Open Access Journals (Sweden)

    Javier Cuevas del Barrio

    2011-01-01

    Full Text Available El texto Pintura Moderna de Clement Greenberg, publicado en 1960, es una de las interpretaciones clásicas de las Vanguardias Históricas. A través de él, Greenberg desarrolla su teoría formalista que durante mucho tiempo dominó la interpretación de la pintura vanguardista. En este artículo hacemos una revisión de la teoría greenberiana a través de distintos textos de la Vanguardia, como el Manifiesto Suprematista de Malévich, o la opinión de filósofos como Simmel, Ortega y Benjamin.Clement Greenberg’s text Modern Painting, published in 1960, is one of the classical interpretation of the Avant-garde. Through it, Greenberg developed his formalism theory that long dominated the interpretation of the avant-garde painting. In this article we review Greenberg’s theory through different texts of Modernism as Malevich’s Suprematism Manifest, or the opinion of philosophers such as Simmel, Ortega or Benjamin.

  13. Cinatii, Rambois e Pereira Câo e a pintura-decorativa do Palácio Angeje-Palmela no Paço do Lumiar

    Directory of Open Access Journals (Sweden)

    Miguel Leal

    2006-01-01

    Full Text Available Na zona do Paço do Lumiar, outrora fora de Lisboa, encontra-se o Palácio Angeja- Palmela, edifício palaciano do século XVIII, construído no post terramoto de 1755. Nos seus interiores encontramos uma decoração realizada em pintura a fresco e que podemos atribuir à tríade Cinatti, Rambois e Pereira Cão, cenógrafos e pintores-decoradores da Lisboa de Oitocentos. O palácio, os seus jardins e a sua decoração interior respiram uma atmosfera romântica que é visível na pintura decorativa dos seus interiores, encomenda do seu antigo proprietário D. Domingos de Sousa Holstein, segundo duque de Palmela.In the site of Paço do Lumiar, we find the Angeja-Palmela palace, a building of the XVIII century, built after the Lisbon earthquake of 1755. Inside the palace we find a fresh paintings decoration made by Cinatti, Rambois and Pereira Cão, Lisbon´s set designers and decorative painters of the XIX century. The palace, the gardens and it’s interior decoration breath a romantic atmosphere that we perceive in the respective mural paintings, a commission of it’s former owner, D. Domigos de Sousa Holstein, second duke of Palmela.

  14. Next Generation Solvent Performance in the Modular Caustic Side Solvent Extraction Process - 15495

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Tara E. [Savannah River Remediation, LLC., Aiken, SC (United States); Scherman, Carl [Savannah River Remediation, LLC., Aiken, SC (United States); Martin, David [Savannah River Remediation, LLC., Aiken, SC (United States); Suggs, Patricia [Savannah River Site (SRS), Aiken, SC (United States)

    2015-01-14

    Changes to the Modular Caustic Side Solvent Extraction Unit (MCU) flow-sheet were implemented in the facility. Implementation included changing the scrub and strip chemicals and concentrations, modifying the O/A ratios for the strip, scrub, and extraction contactor banks, and blending the current BoBCalixC6 extractant-based solvent in MCU with clean MaxCalix extractant-based solvent. During the successful demonstration period, the MCU process was subject to rigorous oversight to ensure hydraulic stability and chemical/radionuclide analysis of the key process tanks (caustic wash tank, solvent hold tank, strip effluent hold tank, and decontaminated salt solution hold tank) to evaluate solvent carryover to downstream facilities and the effectiveness of cesium removal from the liquid salt waste. Results indicated the extraction of cesium was significantly more effective with an average Decontamination Factor (DF) of 1,129 (range was 107 to 1,824) and that stripping was effective. The contactor hydraulic performance was stable and satisfactory, as indicated by contactor vibration, contactor rotational speed, and flow stability; all of which remained at or near target values. Furthermore, the Solvent Hold Tank (SHT) level and specific gravity was as expected, indicating that solvent integrity and organic hydraulic stability were maintained. The coalescer performances were in the range of processing results under the BOBCalixC6 flow sheet, indicating negligible adverse impact of NGS deployment. After the Demonstration period, MCU began processing via routine operations. Results to date reiterate the enhanced cesium extraction and stripping capability of the Next Generation Solvent (NGS) flow sheet. This paper presents process performance results of the NGS Demonstration and continued operations of MCU utilizing the blended BobCalixC6-MaxCalix solvent under the NGS flowsheet.

  15. Diamex solvent regeneration studies

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, C.; Cames, B.; Margot, L.; Ramain, L. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification, DRRV, 30 - Marcoule (France)

    2000-07-01

    The CEA has undertaken the development of the DIAMEX process as the first step in the strategy aiming at recovering minor actinides which could then be transmuted or separately conditioned. The scientific feasibility of this process was demonstrated during counter current hot tests operated in 1993. Then experimental works were conducted, on one hand to optimise the extractant formula, on the other hand to improve the flowsheet. Reference extractant and flowsheet were then chosen, respectively in 1995 and 1996. The next step, still in progress, is the demonstration of the DIAMEX technical feasibility (in 2002); this means that the flowsheet should include solvent regeneration treatments. In this aim, degradation studies were performed to quantify main degradation products, and identify those which could be disturbing in the process. This paper deals with experimental studies performed with intend to propose a regeneration treatment, included in the flowsheet, so that the solvent could be recycled. It comprises: - Quantification of the main degradation products issued from radiolysis or hydrolysis, which are methyl octyl amine (MOA) and carboxylic acids; - Effects of these products on extracting and hydrodynamics performances of the process; - Study of methods able to remove mainly disturbing degradation products. Acidic scrubbing, which are performed in the scrubbing and stripping sections of the DIAMEX process, should allow the quantitative removal of methyl octyl amine. Then basic scrubbings, which were more especially studied, should eliminate at least 80% of carboxylic acids, and part of the cations remaining in the solvent. (authors)

  16. Advanced integrated solvent extraction systems

    Energy Technology Data Exchange (ETDEWEB)

    Horwitz, E.P.; Dietz, M.L.; Leonard, R.A. [Argonne National Lab., IL (United States)

    1997-10-01

    Advanced integrated solvent extraction systems are a series of novel solvent extraction (SX) processes that will remove and recover all of the major radioisotopes from acidic-dissolved sludge or other acidic high-level wastes. The major focus of this effort during the last 2 years has been the development of a combined cesium-strontium extraction/recovery process, the Combined CSEX-SREX Process. The Combined CSEX-SREX Process relies on a mixture of a strontium-selective macrocyclic polyether and a novel cesium-selective extractant based on dibenzo 18-crown-6. The process offers several potential advantages over possible alternatives in a chemical processing scheme for high-level waste treatment. First, if the process is applied as the first step in chemical pretreatment, the radiation level for all subsequent processing steps (e.g., transuranic extraction/recovery, or TRUEX) will be significantly reduced. Thus, less costly shielding would be required. The second advantage of the Combined CSEX-SREX Process is that the recovered Cs-Sr fraction is non-transuranic, and therefore will decay to low-level waste after only a few hundred years. Finally, combining individual processes into a single process will reduce the amount of equipment required to pretreat the waste and therefore reduce the size and cost of the waste processing facility. In an ongoing collaboration with Lockheed Martin Idaho Technology Company (LMITCO), the authors have successfully tested various segments of the Advanced Integrated Solvent Extraction Systems. Eichrom Industries, Inc. (Darien, IL) synthesizes and markets the Sr extractant and can supply the Cs extractant on a limited basis. Plans are under way to perform a test of the Combined CSEX-SREX Process with real waste at LMITCO in the near future.

  17. 浅析水性聚氨酯与溶剂型聚氨酯合成革加工工艺区别%Discussion on Difference of Waterborne and Solvent based Polyurethane in Leather Industry

    Institute of Scientific and Technical Information of China (English)

    郑兆祥; 吕海宁; 范新妹; 洪军燕

    2011-01-01

    The difference of structure and condition between waterborne polyurethane and solvent - based polyurethane was discussed, which leads to the changes of processing in leather industry.The basis and mechanism of waterborne and solvent -based polyurethane in choosing wet processing and release paper were pointed out, which provide effective theoretical support for the development of waterborne polyurethane.%分析了水性聚氨酯与溶剂型聚氨酯在分子结构上的不同及其存在状态的差异,而导致其在合成革加工工艺上有所区别,指出了水性与溶剂型聚氨酯在湿法加工和离型纸方面选择的依据与作用机理,为以后水性聚氨酯的发展提供有力的理论支撑.

  18. Synthesis of 1-amidoalkyl-2-naphthols based on a three-component reaction catalyzed by boric acid as a solid heterogeneous catalyst under solvent-free conditions

    Directory of Open Access Journals (Sweden)

    Zahed Karimi-Jaberi

    2012-12-01

    Full Text Available An efficient method for the preparation of 1-amidoalkyl-2-naphthols has been described using a multi-component, one-pot condensation reaction of 2-naphthol, aldehydes and amides in the presence of boric acid under solvent-free conditions.DOI: http://dx.doi.org/10.4314/bcse.v26i3.18

  19. Development and validation of an automated extraction method (accelerated solvent extraction) and a reverse-phase HPLC analysis method for assay of ivermectin in a meat-based chewable formulation.

    Science.gov (United States)

    Abend, Andreas M; Chung, Le; McCollum, David G; Wuelfing, W Peter

    2003-04-10

    A new method for monitoring ivermectin content in HEARTGARD CHEWABLES has been developed and validated. The method consists of the automated extraction of ivermectin from the meat-based formulation under conditions of elevated temperature and pressure (accelerated solvent extraction, ASE, and determination of the active by reverse-phase high performance liquid chromatography (HPLC). The method resolves both active species of ivermectin (components H(2)B(1a) and H(2)B(1b)) from the formulation matrix.

  20. Effect of Solvent and Acid-Base on Palladium(ll)-catalyzed Dicarbonylation of Terminal Acetylenes: a General, Efficient andStereoselective Synthesis of Maleic Diesters and Maleic Anhydrides

    Institute of Scientific and Technical Information of China (English)

    JIANG, Huan-Feng; LI, JiN-Heng; CHEN, Ming-Cai

    2001-01-01

    The productions of maleic diesters and maleic anhydrises depend on the effect of solvint and acid-bade of solvent and acid-base in palladium-catalyzed dicarbonylation of terminal acetylenes. For primaryand secondary alcohol in benzene.only maleic diesters wereobtained stereospecifically from the sicabonylation ofacetylenes in the presence of PdCl2,and NaHCO3.For tERTIARy alcohols,maleic anhydrides were synthesized selectively.

  1. Alcohols as hydrogen-donor solvents for treatment of coal

    Science.gov (United States)

    Ross, David S.; Blessing, James E.

    1981-01-01

    A method for the hydroconversion of coal by solvent treatment at elevated temperatures and pressure wherein an alcohol having an .alpha.-hydrogen atom, particularly a secondary alcohol such as isopropanol, is utilized as a hydrogen donor solvent. In a particular embodiment, a base capable of providing a catalytically effective amount of the corresponding alcoholate anion under the solvent treatment conditions is added to catalyze the alcohol-coal reaction.

  2. Electrospinning of Grooved Polystyrene Fibers: Effect of Solvent Systems

    Science.gov (United States)

    Liu, Wanjun; Huang, Chen; Jin, Xiangyu

    2015-05-01

    Secondary surface texture is of great significance to morphological variety and further expands the application areas of electrospun nanofibers. This paper presents the possibility of directly electrospinning grooved polystyrene (PS) fibers using both single and binary solvent systems. Solvents were classified as low boiling point solvent (LBPS): dichloromethane (DCM), acetone (ACE), and tetrahydrofuran (THF); high boiling point solvent (HBPS): N, N-dimethylformamide (DMF) and cyclohexanone (CYCo); and non-solvent (NS): 1-butanol (BuOH). By the systematic selection and combination of these solvents at given parameters, we found that single solvent systems produced non-grooved fibers. LBPS/DMF solvent systems resulted in fibers with different grooved textures, while LBPS/CYCo led to fibers with double grooved texture. Grooved fibers can also be fabricated from LBPS/LBPS, NS/LBPS, and NS/HBPS systems under specific conditions. The results indicated that the difference of evaporation rate (DER) between the two solvents played a key role in the formation of grooved texture. The formation of this unique texture should be attributed to three separate mechanisms, namely void-based elongation, wrinkle-based elongation, and collapsed jet-based elongation. Our findings can serve as guidelines for the preparation of ultrafine fibers with grooved secondary texture.

  3. Occupational solvent exposure and cognition

    Science.gov (United States)

    Sabbath, E.L.; Glymour, M.M.; Berr, C.; Singh-Manoux, A.; Zins, M.; Goldberg, M.

    2012-01-01

    Objective: Chronic occupational solvent exposure is associated with long-term cognitive deficits. Cognitive reserve may protect solvent-exposed workers from cognitive impairment. We tested whether the association between chronic solvent exposure and cognition varied by educational attainment, a proxy for cognitive reserve. Methods: Data were drawn from a prospective cohort of French national gas and electricity (GAZEL) employees (n = 4,134). Lifetime exposure to 4 solvent types (chlorinated solvents, petroleum solvents, benzene, and nonbenzene aromatic solvents) was assessed using a validated job-exposure matrix. Education was dichotomized at less than secondary school or below. Cognitive impairment was defined as scoring below the 25th percentile on the Digit Symbol Substitution Test at mean age 59 (SD 2.8; 88% of participants were retired at testing). Log-binomial regression was used to model risk ratios (RRs) for poor cognition as predicted by solvent exposure, stratified by education and adjusted for sociodemographic and behavioral factors. Results: Solvent exposure rates were higher among less-educated patients. Within this group, there was a dose-response relationship between lifetime exposure to each solvent type and RR for poor cognition (e.g., for high exposure to benzene, RR = 1.24, 95% confidence interval 1.09–1.41), with significant linear trends (p < 0.05) in 3 out of 4 solvent types. Recency of solvent exposure also predicted worse cognition among less-educated patients. Among those with secondary education or higher, there was no significant or near-significant relationship between any quantification of solvent exposure and cognition. Conclusions: Solvent exposure is associated with poor cognition only among less-educated individuals. Higher cognitive reserve in the more-educated group may explain this finding. PMID:22641403

  4. Application of deep eutectic solvents in the extraction and separation of target compounds from various samples.

    Science.gov (United States)

    Tang, Baokun; Zhang, Heng; Row, Kyung Ho

    2015-03-01

    Deep eutectic solvents, as a new type of eco-friendly solvent, have attracted increasing attention in chemistry for the extraction and separation of target compounds from various samples. To summarize the application of deep eutectic solvents, this review highlights some of the unique properties of deep eutectic solvents and deep-eutectic-solvent-based materials, as well as their applications in extraction and separation. In this paper, the available data and references in this field are reviewed to summarize the application developments of deep eutectic solvents. Based on the development of deep eutectic solvents, the exploitation of new deep eutectic solvents and deep-eutectic-solvent-based materials are expected to diversify into extraction and separation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Solvent effects in chemistry

    CERN Document Server

    Buncel, Erwin

    2015-01-01

    This book introduces the concepts, theory and experimental knowledge concerning solvent effects on the rate and equilibrium of chemical reactions of all kinds.  It begins with basic thermodynamics and kinetics, building on this foundation to demonstrate how a more detailed understanding of these effects may be used to aid in determination of reaction mechanisms, and to aid in planning syntheses. Consideration is given to theoretical calculations (quantum chemistry, molecular dynamics, etc.), to statistical methods (chemometrics), and to modern day concerns such as ""green"" chemistry, where ut

  6. A novel digestion method based on a choline chloride–oxalic acid deep eutectic solvent for determining Cu, Fe, and Zn in fish samples

    Energy Technology Data Exchange (ETDEWEB)

    Habibi, Emadaldin [Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, P.O. BOX 669, Khorramshahr (Iran, Islamic Republic of); Ghanemi, Kamal, E-mail: Kamal.ghanemi@kmsu.ac.ir [Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, P.O. BOX 669, Khorramshahr (Iran, Islamic Republic of); Marine Science Research Institute, Khorramshahr University of Marine Science and Technology, Khorramshahr (Iran, Islamic Republic of); Fallah-Mehrjardi, Mehdi [Department of Marine Chemistry, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, P.O. BOX 669, Khorramshahr (Iran, Islamic Republic of); Marine Science Research Institute, Khorramshahr University of Marine Science and Technology, Khorramshahr (Iran, Islamic Republic of); Dadolahi-Sohrab, Ali [Department of Marine Environment, Faculty of marine natural resources, Khorramshahr University of Marine Science and Technology, Khorramshahr (Iran, Islamic Republic of)

    2013-01-31

    Highlights: ► A novel digestion method: lack of concentrated acids or oxidizing reagents. ► First report of using choline chloride–oxalic acid (ChCl–Ox) for digestion. ► Complete dissolution of biological samples in ChCl–Ox for solubilization metals. ► Extraction recoveries greater than 95%: validated by the fish protein CRM. ► Successfully applied in different fish tissues (Muscle, Liver, and Gills). -- Abstract: A novel and efficient digestion method based on choline chloride–oxalic acid (ChCl–Ox) deep eutectic solvent (DES) was developed for flame atomic absorption spectrometry (FAAS) determination of Cu, Zn, and Fe in biological fish samples. Key parameters that influence analyte recovery were investigated and optimized, using the fish protein certified reference material (CRM, DORM-3) throughout the procedure. In this method, 100 mg of the sample was dissolved in ChCl–Ox (1:2, molar ratio) at 100 °C for 45 min. Then, 5.0 mL HNO{sub 3} (1.0 M) was added. After centrifugation, the supernatant solution was filtered, diluted to a known volume, and analyzed by FAAS. Under optimized conditions, an excellent agreement between the obtained results and the certified values was observed, using Student's t-test (P = 0.05); the extraction recovery of the all elements was greater than 95.3%. The proposed method was successfully applied to the determination of analytes in different tissues (muscle, liver, and gills) having a broad concentration range in a marine fish sample. The reproducibility of the method was validated by analyzing all samples by our method in a different laboratory, using inductively coupled plasma optical emission spectrometry (ICP-OES). For comparison, a conventional acid digestion (CAD) method was also used for the determination of analytes in all studied samples. The simplicity of the proposed experimental procedure, high extraction efficiency, short analysis time, lack of concentrated acids and oxidizing agents, and the

  7. Nuevos avances de la investigación en conservación de pintura

    OpenAIRE

    Calvo Manuel, Ana

    2014-01-01

    Se hace una reflexión sobre los avances en las investigaciones sobre conservación de obras pictóricas en Portugal, en base a los artículos publicados en el presente libro. Los artículos del libro corresponden a algunos aspectos de las investigaciones de los proyectos de doctorado en curso en esta materia.

  8. Solvent-free fluidic organic dye lasers.

    Science.gov (United States)

    Choi, Eun Young; Mager, Loic; Cham, Tran Thi; Dorkenoo, Kokou D; Fort, Alain; Wu, Jeong Weon; Barsella, Alberto; Ribierre, Jean-Charles

    2013-05-06

    We report on the demonstration of liquid organic dye lasers based on 9-(2-ethylhexyl)carbazole (EHCz), so-called liquid carbazole, doped with green- and red-emitting laser dyes. Both waveguide and Fabry-Perot type microcavity fluidic organic dye lasers were prepared by capillary action under solvent-free conditions. Cascade Förster-type energy transfer processes from liquid carbazole to laser dyes were employed to achieve color-variable amplified spontaneous emission and lasing. Overall, this study provides the first step towards the development of solvent-free fluidic organic semiconducting lasers and demonstrates a new kind of optoelectronic applications for liquid organic semiconductors.

  9. Solvent effects on optical excitations of poly para phenylene ethynylene studied by QM/MM simulations based on Many-Body Green's Functions Theory

    CERN Document Server

    Bagheri, Behnaz; Baumeier, Björn

    2016-01-01

    Electronic excitations in dilute solutions of poly para phenylene ethynylene (poly-PPE) are studied using a QM/MM approach combining many-body Green's functions theory within the $GW$ approximation and the Bethe-Salpeter equation with polarizable force field models. Oligomers up to a length of 7.5\\,nm (10 repeat units) functionalized with nonyl side chains are solvated in toluene and water, respectively. After equilibration using atomistic molecular dynamics (MD), the system is partitioned into a quantum region (backbone) embedded into a classical (side chains and solvent) environment. Optical absorption properties are calculated solving the coupled QM/MM system self-consistently and special attention is paid to the effects of solvents. The model allows to differentiate the influence of oligomer conformation induced by the solvation from electronic effects related to local electric fields and polarization. It is found that the electronic environment contributions are negligible compared to the conformational ...

  10. Choline chloride (ChCl) and monosodium glutamate (MSG)-based green solvents from optimized cactus malic acid for biomass delignification.

    Science.gov (United States)

    Yiin, Chung Loong; Quitain, Armando T; Yusup, Suzana; Uemura, Yoshimitsu; Sasaki, Mitsuru; Kida, Tetsuya

    2017-08-10

    This work aimed to develop an efficient microwave-hydrothermal (MH) extraction of malic acid from abundant natural cactus as hydrogen bond donor (HBD) whereby the concentration was optimized using response surface methodology. The ideal process conditions were found to be at a solvent-to-feed ratio of 0.008, 120°C and 20min with 1.0g of oxidant, H2O2. Next generation environment-friendly solvents, low transition temperature mixtures (LTTMs) were synthesized from cactus malic acid with choline chloride (ChCl) and monosodium glutamate (MSG) as hydrogen bond acceptors (HBAs). The hydrogen-bonding interactions between the starting materials were determined. The efficiency of the LTTMs in removing lignin from oil palm biomass residues, empty fruit bunch (EFB) was also evaluated. The removal of amorphous hemicellulose and lignin after the pretreatment process resulted in an enhanced digestibility and thermal degradability of biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Low Density Solvent-Based Dispersive Liquid-Liquid Microextraction for the Determination of Synthetic Antioxidants in Beverages by High-Performance Liquid Chromatography

    Science.gov (United States)

    Çabuk, Hasan; Köktürk, Mustafa

    2013-01-01

    A simple and efficient method was established for the determination of synthetic antioxidants in beverages by using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with ultraviolet detection. Butylated hydroxy toluene, butylated hydroxy anisole, and tert-butylhydroquinone were the antioxidants evaluated. Experimental parameters including extraction solvent, dispersive solvent, pH of sample solution, salt concentration, and extraction time were optimized. Under optimal conditions, the extraction recoveries ranged from 53 to 96%. Good linearity was observed by the square of correlation coefficients ranging from 0.9975 to 0.9997. The relative standard deviations ranged from 1.0 to 5.2% for all of the analytes. Limits of detection ranged from 0.85 to 2.73 ng mL−1. The method was successfully applied for determination of synthetic antioxidants in undiluted beverage samples with satisfactory recoveries. PMID:23853535

  12. Low density solvent-based dispersive liquid-liquid microextraction for the determination of synthetic antioxidants in beverages by high-performance liquid chromatography.

    Science.gov (United States)

    Çabuk, Hasan; Köktürk, Mustafa

    2013-01-01

    A simple and efficient method was established for the determination of synthetic antioxidants in beverages by using dispersive liquid-liquid microextraction combined with high-performance liquid chromatography with ultraviolet detection. Butylated hydroxy toluene, butylated hydroxy anisole, and tert-butylhydroquinone were the antioxidants evaluated. Experimental parameters including extraction solvent, dispersive solvent, pH of sample solution, salt concentration, and extraction time were optimized. Under optimal conditions, the extraction recoveries ranged from 53 to 96%. Good linearity was observed by the square of correlation coefficients ranging from 0.9975 to 0.9997. The relative standard deviations ranged from 1.0 to 5.2% for all of the analytes. Limits of detection ranged from 0.85 to 2.73 ng mL(-1). The method was successfully applied for determination of synthetic antioxidants in undiluted beverage samples with satisfactory recoveries.

  13. A combined interfacial and in-situ polymerization strategy to construct well-defined core-shell epoxy-containing SiO2-based microcapsules with high encapsulation loading, super thermal stability and nonpolar solvent tolerance

    Directory of Open Access Journals (Sweden)

    Yin Jia

    2016-10-01

    Full Text Available SiO2-based microcapsules containing hydrophobic molecules exhibited potential applications such as extrinsic self-healing, drug delivery, due to outstanding thermal and chemical stability of SiO2. However, to construct SiO2-based microcapsules with both high encapsulation loading and long-term structural stability is still a troublesome issue, limiting their further utilization. We herein design a single-batch route, a combined interfacial and in-situ polymerization strategy, to fabricate epoxy-containing SiO2-based microcapsules with both high encapsulation loading and long-term structural stability. The final SiO2-based microcapsules preserve high encapsulation loading of 85.7 wt% by controlling exclusively hydrolysis and condensed polymerization at oil/water interface in the initial interfacial polymerization step. In the subsequent in-situ polymerization step, the initial SiO2-based microcapsules as seeds could efficiently harvest SiO2 precursors and primary SiO2 particles to finely tune the SiO2 wall thickness, thereby enhancing long-term structural stability of the final SiO2-based microcapsules including high thermal stability with almost no any weight loss until 250°C, and strong tolerance against nonpolar solvents such as CCl4 with almost unchanged core-shell structure and unchanged core weight after immersing into strong solvents for up to 5 days. These SiO2-based microcapsules are extremely suited for processing them into anticorrosive coating in the presence of nonpolar solvents for self-healing application.

  14. Preparation of Solvent-free & Water-basedλ-Cyhalothrin Liquid Formulations%无溶剂水基性高效氯氟氰菊酯液体剂型的研制

    Institute of Scientific and Technical Information of China (English)

    华乃震; 罗才宏; 曾鑫年

    2011-01-01

    [目的]俘油使用较多有机溶剂,而水基性剂型中微乳剂和可溶液剂使用较多极性溶剂作溶剂或助溶剂,在安全和环保性上受到人们质疑.论述水基性无溶剂液体剂型的提出、开发的依据及其优点.这种液体剂型不使用任何(极性和非极性)溶剂和植物油溶剂,研制出一种全新的水基性无溶剂2.5%高效氯氟氰菊酯透明液体剂型.[结果]经研制,其最佳配方:高效氯氟氰菊酯2.5%,乳化剂(烷基酚聚氧乙烯醚,烷基酚聚氧乙烯醚磷酸酯)12%~15%,助表面活性剂(丁醇)5%,防冻剂(丙二醇)2%,水余最.该配方样品为无色透明液体,经冷贮[(0±1)℃,7 d]和热贮[(54±2)℃,14 d]高效氯氟氰菊酯分解率小于2%.[结论]样品经测定各项指标符合有关要求,毒力测定结果与传统微乳剂相同.原料成本仅为同剂量乳油40%、传统微乳剂的72%、生物柴油作溶剂微乳剂的77%.%[Aims]EC uses much solvent, and water-based ME and SL use much solvent & flux (polar solvent), which receives question in the safety and the environmental protection.The water-based solvent-free liquid formulation proposal,development basis and merit were described in the article.This kind of liquid formulation does not use any (polar and nonpolar) solvent and vegetable oil solvent.One kind of brand-new water-based solvent-free λ-cyhalothrin 2.5% transparent liquid formulation was developed.[Results]The optimum ratio was as follow: λ-cyhalothrin 2.5%, emulsifier(alkylphenol ethoxylates, alkylphenol ethoxylates phosphate)12-15%, cosurfactant(butyl alcohol)5%, antifreeze(propylene glycol)2% and water remainder after research.This formula sample was colourless transparent liquid, after stored coldly [(0±1) ℃,7 d]and stored hotly [(54±2) ℃, 14 d], λ-cyhalothrin dissociation rate was less than 2%.[Conclusions]Each target of the sample meets the related requirement after test, and toxicity determination results showed that the

  15. Structure versus solvent effects on nonlinear optical properties of push-pull systems: a quantum-mechanical study based on a polarizable continuum model.

    Science.gov (United States)

    Corozzi, Alessandro; Mennucci, Benedetta; Cammi, Roberto; Tomasi, Jacopo

    2009-12-31

    A quantum mechanical investigation on the effects of the solvent and the structure on nonlinear optical activity of a class of merocyanine compounds has been conducted. The interplay of the two effects on the first hyperpolarizability, computed at density functional theory and second-order Møller-Plesset level, has been analyzed in combination with ground state properties and geometries and excited state energies and dipoles. A critical analysis of the simplified two-level model has also been presented.

  16. La investigación en el Área de Pintura Flamenca y Escuelas del Norte del Museo del Prado

    Directory of Open Access Journals (Sweden)

    Vergara Sharp, Alejandro

    2006-02-01

    Full Text Available This article describes different research projects undertaken in the Area of Flemish and Northern European Painting at the Prado museum. One was devoted to the Adoration of the Magi, a painting by Rubens which has offers unusual insight into his creative personality. A second project was devoted to the study of a series of tapestries designed by Rubens, which show episodes of the life of Achilles. In this case the project was the result of a collaboration with the Boijmans Van Beuningen Museum in Rotterdam. At present, the Prado is conducting research into the art of Joachim Patinir, an landscape artist active in Antwerp in the early sixteenth century. In all three cases the Prado is responding to its responsibility to study its own collections.El Museo Nacional del Prado posee una de las colecciones de pintura flamenca de los siglos XV, XVI y XVII de mayor calidad y tamaño que existen, y también es depositario de obras de arte de gran importancia de origen alemán (entre ellas varios cuadros de Durero, holandés (Rembrandt y de otros países cuyo arte se engloba dentro del Área de Conservación de Pintura Flamenca y Escuelas del Norte del museo. Al margen de conservar estas obras y de mostrar al público el mayor número de ellas en condiciones idóneas, también dedicamos una parte importante de nuestra actividad a la investigación. La calidad superlativa de la colección del Prado nos confiere una gran responsabilidad: tenemos la obligación de ser líderes, a nivel mundial, en el estudio de las cuestiones que plantea la historia del arte respecto de los artistas y los cuadros de la colección. En las siguientes páginas se explican tres proyectos de investigación desarrollados por el Área de Pintura Flamenca recientemente, que muestran el abanico de proyectos los que trabajamos en el Prado, los criterios que nos guían a la hora de seleccionarlos, y la forma en que se desarrollan.

  17. Ionic liquid-based totally organic solvent-free emulsification microextraction coupled with high performance liquid chromatography for the determination of three acaricides in fruit juice.

    Science.gov (United States)

    Zhang, Jiaheng; Liang, Zhe; Guo, Hao; Gao, Peng; Lu, Runhua; Zhou, Wenfeng; Zhang, Sanbing; Gao, Haixiang

    2013-10-15

    A novel, totally organic solvent-free emulsification microextraction (TEME) technique using ionic liquids (ILs) is proposed in this study. Seven bis(trifluoromethylsulfonyl)imide ionic liquids were synthesized. After comparing the physicochemical properties of the ionic liquids and their application to microextraction experiments, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C6MIM][NTf2]), which has moderate surface tension and viscosity, was selected as the extraction solvent. The dispersion of ILs and mass transfer were accelerated by ultrasound irradiation and temperature control processes. Therefore, no dispersive organic solvent was needed. Several variables, such as ionic liquid volume, duration of the ultrasound extraction, dispersion temperature, ionic strength and centrifugation time were investigated and optimized. Under the optimum conditions, the calibration curve was linear in the range of 0.1-600 μg L(-1) for chlorfenapyr and fenpyroximate and 0.5-600 μg L(-1) for spirodiclofen, with correlation coefficients of 0.9994-0.9999. The enrichment factors were between 261 and 285. The limits of detection (LODs) were 0.02-0.06 μg L(-1). Real fruit juice samples (at fortified levels of 10 μg L(-1) and 30 μg L(-1)) were successfully analyzed using the proposed method. The relative recoveries and enrichment factors were in the range of 92-104%. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Determination of polychlorinated biphenyls in fish: optimisation and validation of a method based on accelerated solvent extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Ottonello, Giuliana; Ferrari, Angelo; Magi, Emanuele

    2014-01-01

    A simple and robust method for the determination of 18 polychlorinated biphenyls (PCBs) in fish was developed and validated. A mixture of acetone/n-hexane (1:1, v/v) was selected for accelerated solvent extraction (ASE). After the digestion of fat, the clean-up was carried out using solid phase extraction silica cartridges. Samples were analysed by GC-MS in selected ion monitoring (SIM) using three fragment ions for each congener (one quantifier and two qualifiers). PCB 155 and PCB 198 were employed as internal standards. The lowest limit of detection was observed for PCB 28 (0.4ng/g lipid weight). The accuracy of the method was verified by means of the Certified Reference Material EDF-2525 and good results in terms of linearity (R(2)>0.994) and recoveries (80-110%) were also achieved. Precision was evaluated by spiking blank samples at 4, 8 and 12ng/g. Relative standard deviation values for repeatability and reproducibility were lower than 8% and 16%, respectively. The method was applied to the determination of PCBs in 80 samples belonging to four Mediterranean fish species. The proposed procedure is particularly effective because it provides good recoveries with lowered extraction time and solvent consumption; in fact, the total time of extraction is about 12min per sample and, for the clean-up step, a total solvent volume of 13ml is required. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Fabrication of porous ethyl cellulose microspheres based on the acetone-glycerin-water ternary system: Controlling porosity via the solvent-removal mode.

    Science.gov (United States)

    Murakami, Masahiro; Matsumoto, Akihiro; Watanabe, Chie; Kurumado, Yu; Takama, Masashi

    2015-08-01

    Porous ethyl cellulose (EC) microspheres were prepared from the acetone-glycerin-water ternary system using an oil/water (O/W)-type emulsion solvent extraction method. The O/ W type emulsion was prepared using acetone dissolved ethyl cellulose as an oil phase and aqueous glycerin as a water phase. The effects of the different solvent extraction modes on the porosity of the microspheres were investigated. The specific surface area of the porous EC microspheres was estimated by the gas adsorption method. When the solvent was extracted rapidly by mixing the emulsion with water instantaneously, porous EC microspheres with a maximum specific surface area of 40.7±2.1 m2/g were obtained. On the other hand, when water was added gradually to the emulsion, the specific surface area of the fabricated microspheres decreased rapidly with an increase in the infusion period, with the area being 25-45% of the maximum value. The results of an analysis of the ternary phase diagram of the system suggested that the penetration of water and glycerin from the continuous phase to the dispersed phase before solidification affected the porosity of the fabricated EC microspheres.

  20. Arte y ciencia en la pintura de paisaje Alexander von Humboldt

    OpenAIRE

    Garrido Moreno, Elisa

    2015-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Filosofía y Letras, Departamento de Historia y Teoría del Arte. Fecha de lectura: 04-12-2015 During the Enlightenment, new discoveries created a new way of looking at Nature. The modern conception of the world had replaced the vision of a harmonious cosmos with a new sense of order based on the scientific method. Some of the most important scientific travels, like those of Cook in the Pacific, were carried out a...