Sample records for copoliester alifatico aromatico
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Petroleum hydrocarbon assessment in the sediments of the northeastern Havana littoral, Cuba
Energy Technology Data Exchange (ETDEWEB)
Companioni Dams, Eloy Yordad; Nunez Clemente, Ana Catalina; Cora Medina, Miriam Odette [Laboratorio de Quimica Ambiental, Centro de Investigaciones del Petroleo, Habana (Cuba)]. E-mail: elocompa@yahoo.com; Gonzalez Brovo, Luis [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear, Habana, (Cuba); Marbot Ramada, Rolando [Laboratorio de Quimica Analitica, Centro de Investigaciones del Petroleo, Habana (Cuba); Montes de Oca Porto, Rodny [Laboratorio Antidoping, Habana (Cuba); Rosabal Rodriguez, Maikel [Centro de Ingenieria y Manejo Ambiental de Bahias y Costas, Habana (Cuba); Diaz Diaz, Miguel angel [Laboratorio de Quimica Ambiental, Centro de Investigaciones del Petroleo, Habana (Cuba)
2009-02-15
As a part of a geochemical study, aliphatic and aromatic hydrocarbons were determined in surficial sediments, from a Cuban coastal zone located in the Northeastern Havana Littoral. Sediment samples were collected at 15 sites in this area, and then extracted and analyzed by gas chromatography with flame ionization and mass spectrometry detectors. Total concentration of both, aliphatic (AH) and aromatic (ArH) hydrocarbons, varied from 2.4 {+-} 0.2 to 105.1 {+-} 5.9 {mu}g/g (dry weight) and from 1.1 {+-} 0.2 to 38.4 {+-} 7.6 {mu}g/g (dry weight), respectively. The chromatography profile of AH was dominated by an unresolved complex mixture (UCM), and the presence of isoprenoid hydrocarbons, steranes and hopanes, indicated petroleum - related hydrocarbon inputs. The predominant concentration of phytoplanktonic molecular markers (pristane and nC17) in collected sediments, revealed the marine productivity in this sites. The anthropogenic contribution detected showed the impact of the petroleum exploration along this coastal area. [Spanish] Como parte de un estudio geoquimico se determinaron hidrocarburos alifaticos y aromaticos en sedimentos superficiales, de una zona costera situada en el Litoral Nordeste de La Habana. Las muestras de sedimento se colectaron en 15 estaciones de muestreo en esta area, y posteriormente se extrajeron y analizaron mediante cromatografia gaseosa con detectores de ionizacion a la llama y espectrometria de masas. Las concentraciones totales de hidrocarburos alifaticos (HA) e hidrocarburos aromaticos (HAr) variaron desde 2.4 {+-} 0.2 a 105.1 {+-} 5.9 {mu}g/g (peso eco) y desde 1.1 {+-} 0.2 a 38.4 {+-} 7.6 {mu}g/g (peso eco), respectivamente. El perfil cromatografico de los hidrocarburos alifaticos estuvo dominado por una mezcla compleja no resuelta (MCNR), y la presencia de hidrocarburos isoprenoides, esteranos y hopanos, indico el aporte de hidrocarburos derivados del petroleo. La concentracion predominante de marcadores moleculares
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Energy Technology Data Exchange (ETDEWEB)
Poveda, Patricia Negrini Siqueira
2008-07-01
Biodegradable and green plastics are the new tendency in the world. The effect of the electron beam irradiation in aromatic aliphatic copolyester and the blend with corn starch films (Ecoflex{sup R} and Ecobras{sup R}) were studied by tensile strength at break, elongation at break, Scanning Electronic Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), crosslinking degree and biodegradability. The measurements in both, the machine direction and the transverse direction were made for mechanical tests. It was found that, the electron irradiation caused an increase in the strength at break of the blend with corn starch film, when doses of up to 10 kGy were applied. A significant decrease of the elongation at break of the blend with corn starch was observed at doses of 10 kGy and 40 kGy. It was not found important change in tensile properties for aromatic aliphatic copolyester. Structural changes of the samples (crosslinking or degradation) by SEM were not observed. The FT-IR identified the characteristic peaks of each involved functional group (copolyester and corn starch). However, it was not found bands of oxidation of the samples. In the DSC, changes in the melting temperature of the irradiated Ecoflex{sup R} and Ecobras{sup R} samples, was not identified when compared with the samples of reference. However, it was verified a reduction in the melting enthalpy of the Ecobras{sup R} samples after irradiation. The Ecobras{sup R} material presented crosslinking, when submitted to doses of 10 kGy and 40 kGy. The Ecoflex{sup R} material did not present crosslinking when submitted to these doses. The biodegradability of the materials was evaluated by two methods of test: soil simulated and enzymatic. In both methods, the irradiated samples presented faster biodegradation than the references not irradiated. (author)
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Energy Technology Data Exchange (ETDEWEB)
Broadbank, R W.C.; Harhash, A H.E.; Kanchanalai, S [Leicester College of Technology and Commerce, Leicester (United Kingdom)
1962-03-15
. Los autores describen seguidamente la preparacion de ciertos compuestos nitrometoxi- aromaticos marcados con carbono-14 en el grupo metoxilo. Estudiaron reacciones simetricas de intercambio de grupos metoxilo entre estos compuestos e iones metoxilo disueltos en metanol. Despues ele separar los reactivos (en muestras de la meczla tomada a intervalos adecuados) por extraccion con tolueno y agua, recuperaron los compuestos aromaticos y determinaron sus actividades especificas por recuento mediante un fosforo ele plastico. Al analizar los resultados experimentales, dedican particular atencion a la influencia ejercida por la fuerza ionica sobre la velocidad especifica de reaccion. Establecen comparaciones con los efectos ele la fuerza ionica observados en las reacciones simetricas nucleofilicas biomoleculares en un atomo de carbono (alifatico) saturado, y mencionan algunas otras reacciones de sustituciones nucleofilicas en compuestos aromaticos. (author) [Russian] Izotopnye indikatory nezamenimy pri izuchenii kinetiki reaktsij s nukliofil'nosimmetricheskim zameshcheniem pri aromaticheskom atome ugleroda. Obmen joda mezhdu jodo-nitro-aromaticheskimi soedineniyami i ionami jodida v atsetonovom ili metanolovom rastvore izuchalsya kak s kachestvennoj, tak i kolichestvennoj tochek zreniya posredstvom mecheniya ionov jodida jodom-131. U smesi reaktsii pri opredelennykh intervalakh vremeni bralis' obraztsy, dva reaktanta razdelyalis' toluolovodnoj ehkstraktsiej, a khod reaktsii opredelyalsya beta-otschetom zhidkostnogo schetchika Gejgera-Myullera. Izmereniya rasprostranyalis' takzhe na ''svobodnye ot nositelya'' kontsentratsii ionov jodida. Privoditsya opisanie prigotovleniya nekotorykh nitro-metoksi-aromaticheskikh soedinenij, mechennykh uglerodom-14 v metoksinovoj gruppe. Privoditsya issledovanie reaktsij simmetricheskogo metoksinovogo obmena ehtikh soedinenij s metoksidnymi ionami v metanovom rastvore. Posle otdeleniya reaktantov (iz obraztsov smesi reaktsii, vzyatykh cherez
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Volatile aromatic compounds in Mexico City atmosphere: levels and source apportionment
Energy Technology Data Exchange (ETDEWEB)
Mugica, V. [Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D.F. (Mexico); Ruiz, M.E. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Watson, J.; Chow, J. [Desert Research Institute, Reno, Nevada (United States)
2003-01-01
Samples of ambient air were simultaneously collected at three different sites of Mexico City in March of 1997 in order to quantify the most abundant volatile aromatic compounds and estimate the source contributions by application of the chemical mass balance model (CMB). Volatile aromatic compounds were around 20% of the total of non-methane hydrocarbons present in morning air samples. The most abundant volatile aromatic species in urban air were toluene and xylenes followed by 1, 2, 4 trimethylbenzene, benzene, ethylbenzene, metaethyltoluene, 1, 3, 5 trimethylbenzene, styrene, n propylbenzene, and isopropylbenzene. Sampling campaigns were carried out at crossroads, a bus station, a parking place, and areas where solvents and petroleum distillates are used, with the objective of determining people's exposure to volatile aromatic compounds. The CMB was applied for estimating the contribution of different sources to the presence of each one of the most abundant aromatic compounds. Motor vehicle exhaust was the main source of all aromatic compounds, especially gasoline exhaust, although diesel exhausts and asphalt operations also accounted for toluene, xylenes, ethylbenzene, propylbenzenes, and styrene. Graphic arts and paint applications had an important impact on the presence of toluene. [Spanish] Se colectaron simultaneamente muestras de aire ambiente en tres sitios de la Ciudad de Mexico durante el mes de marzo de 1997 con el fin de conocer las concentraciones y el origen de compuestos aromaticos utilizando el modelo de balance de masa de especies quimicas (CMB). Los compuestos aromaticos volatiles representaron alrededor del 20% del total de hidrocarburos no metalicos presentes en las muestras matutinas colectadas. Las especies aromaticas volatiles mas abundantes en el ambiente fueron el tolueno y los xilenos, seguidos por 1, 2, 4 trimetilbenceno, benceno, etilbenceno, metaetiltolueno, nporpilbenceno, isopropilbenceno, 1, 3, 5 trimetilbenceno y estireno. Se
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Energy Technology Data Exchange (ETDEWEB)
Perez, M.; Mendez, J.; Bomboi, M.T.
1988-02-01
Levels of n-alkanes and polycyclic aromatic hydrocarbons have been measured in the air particulate matter during six months, from January to June of 1987, in an urban area of Madrid. The hydrocarbons were collected on glass fiber filter by high volume sampling. The extraction was varried out by sohxlet and ultrasonic techniques. The extracts were clean-up on silica gel fractionation and the chromatographic analysis was performed by capillary coluymn gas chromatographic. Final results are discussed as well as the inmission values related to the possible emission sources.
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Energy Technology Data Exchange (ETDEWEB)
Pindado, O.; Perez, R. M.; Garcia, S.
2014-02-01
Analytical methods to analyze TPH and several aliphatic and aromatic fractions present in soil and groundwater samples contaminated by hydrocarbons are showed. As a part of BIOXISOIL project, analyzing these parameters is fundamental and indispensable to know the initial contamination level, design an adequate method to decontaminate it and eventually assess decontamination accomplished. Analysis of both matrices involve different extraction stages such as microwave radiation, clean up steps based on solid phase extraction and finally a chromatograph analysis with flame ion detector. Analytical procedures have showed satisfactory analytical quality parameters and have been validated against several certified reference materials. (Author)
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Del Terra, Lorenzo
2008-01-01
2006/2007 La bevanda di caffè è bevuta ed apprezzata in tutto il mondo per le sue qualità organolettiche. Queste sono numerose e sfaccettate in molti diversi aspetti, che vanno dal contenuto in caffeina alle proprietà antiossidanti. Inoltre, il caffè presenta un ricchissimo profilo aromatico, composto da circa un migliaio di composti volatili che contribuiscono a dare alla bevanda il suo aroma caratteristico. Questo complesso aroma è fortemente influenzato da numerosi fattori quali l’o...
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A theory of phase separation in asphaltene-micellar solutions
Energy Technology Data Exchange (ETDEWEB)
Pacheco Sanchez, Juan H. [Instituto Mexicano del Petroleo, Mexico D.F. (Mexico)
2001-08-01
A theory of phase separation in micellar solutions of asphaltene in aromatic hydrocarbons was reported in this paper, based on both the approach of the phase behavior of amphiphile/water micelles, and the self-association of asphaltene in aromatic core. Several experimental techniques have been used by different investigators showing the existence of some kind of critical micellar concentration (CMC) on asphaltenes in aromatic solutions. So, at least asphaltene-monomer and asphaltene-micellar phases are experimentally demonstrated facts. These two phases are the main purpose in this report on a theoretical model. Some results show the temperature versus asphaltene concentration phase diagram. The phase diagram is examined against the limited critical micelle concentration data for asphaltenes-in-toluene systems. Such phase diagram is also qualitatively examined against an experimental demonstration of phase separation. The asphaltene-micelle growth depends on the parameter K responsible for the shape and size of it. At the same time, parameter K depends on both the number of asphaltene-monomer associated in the asphaltene-micelle, and the chemical potentials in the interior and in the periphery of the micelle. An expression for getting the number of asphaltene-monomers self-associated in the asphaltene-micelle was obtained. [Spanish] Se reporta una teoria de separacion de fases en soluciones micelares de asfalteno en hidrocarburos aromaticos, basada tanto en la conducta de fase de micelas formadas por anififilos en agua como en la autoasociacion de asfaltenos en nucleos aromaticos. Se han usado diversas tecnicas experimentales por diferentes investigadores que demuestran la existancia de algun tipo de concentracion micelar critica (CMC) de soluciones de asfaltenos en aromaticos. Entonces, al menos las fases de asfalteno-monomerico y de asfalteno-micelar son hechos experimentalmente demostrados. Esta dos fases son el principal proposito de este reporte en un modelo
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Energy Technology Data Exchange (ETDEWEB)
Perez, M.; Gonzalez, D.
1988-07-01
A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons and aliphatic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column in two different polar stationary phases OV-1 and SE-54. The limitation and the advantages of the procedure are discussed in terms of separation, sensitivity and precision. (Author) 20 refs.
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Energy Technology Data Exchange (ETDEWEB)
Perez, M. M.; Perez-Pastor, R. M.; Bea, F. J.; Campos, A.; Gonzalez, D.
1991-07-01
A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled m the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. (Author)
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Energy Technology Data Exchange (ETDEWEB)
Perez, M M; Perez-Pastor, R M; Bea, F J; Campos, A; Gonzalez, D
1991-07-01
A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled m the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. (Author)
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Direct synthesis of metal complexes starting from zero-valent metals
Energy Technology Data Exchange (ETDEWEB)
Gojon-Zorrilla, Gabriel; Kharisov, Boris I. [Universidad Autonoma de Nuevo Leon, Monterrey, Nuevo Leon (Mexico); Garnovskii, Alexander D. [Institute of Physical and Organic Chemistry (Russian Federation)
1996-06-01
The recent (1980-1994) literature on metal-vapor synthesis of coordination and organometallic compounds is reviewed. An account is given of the high-and low-temperature reactions between free metal atoms and a large variety of substrates, mainly alkenes, alkynes, dienes, arenes, funtionalized arenes, alkyl halides {beta}-diketones and simple inorganic molecules. The main experimental methods are described, as well as the results obtained thereby. It is shown that in many instances these methods present significant advantages over conventional synthetic procedures, offering unique access to some metal complexes. [Spanish] Se reviso la literatura reciente (1980-1994) sobre la sintesis de compuestos de coordinacion y compuestos organometalicos a partir de vapores metalicos. Se examinan las reacciones de los atomos metalicos libres con una gran variedad de substratos, principalmente alquenos, alquinos, dienos, hidrocarburos aromaticos y sus derivados, haluros de alquilo y arilo, {beta}-dicetonas y moleculas inorganicas simples. Se presentan los principales metodos experimentales, asi como los resultados obtenidos; se concluye que la crisintesis presenta en muchos casos ventajas significativas sobre los procedimientos sinteticos tradicionales, constituyendo frecuentemente la unica opcion disponible.
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Energy Technology Data Exchange (ETDEWEB)
Santos, Diego K.M., E-mail: diego_keller_1984@yahoo.com.b; Guimaraes, Danilo H.; Medeiros, Marina O. de A.; Jose, Nadia M. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Prado, Luis A.S. de A. [Technische Universitaet Hamburg (TUHH), Harburg (Germany). Inst. of Polymer and Composites
2009-07-01
Aromatic polyesters have been currently used for the production of PET bottles and polymer fibers. Currently, thermodynamic study is necessary for production of polymers with mechanical properties, thermal degradation and satisfactory. Many thermodynamic properties of polymer solutions, such as solubility, swelling, and balance of the properties Colligative can be expressed in terms of interaction parameter of polymer-solvent {chi}. The present work presents the objective synthesize, characterize and assess the degree of swelling of aromatic polyesters. The polyester formed from the reaction of glycerol and terephthalic acid/phthalic, using varying molar ratios to the glycerolterephthalic acid/phthalic acid (1,0-1,0, 1,0-1,5, 1,0 -- 2.0), by mixing with mechanical agitation and by use of tin catalyst. We studied the thermal and structural behavior through techniques: FTIR, TGA, DSC, XRD, SEM and swelling test. (author)
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Energy Technology Data Exchange (ETDEWEB)
Blass Amador, Georgina; Panama Tirado, Luz Angelica [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)
1992-11-01
compatibility of fuel oil mixes. [Espanol] En Mexico, la mayoria de la energia electrica producida proviene del uso de combustibles residuales pesados conocidos como combustoleos los cuales han sufrido disminuciones en la calidad debido a una combinacion de factores, entre los que destaca el de los cambios en el proceso de refinacion. Es necesario desarrollar metodos que sean capaces de indicar la inestabilidad (formacion de sedimento o incremento en viscosidad durante el almacenamiento o calentamiento) o incompatibilidad (formacion de sedimento al mezclar dos o mas) de los combustoleos utilizados en las centrales termoelectricas. El objetivo de este trabajo fue el desarrollar una prueba alternativa para el estudio de la compatibilidad y/o estabilidad de combustoleos mexicanos empleando cromatografia de liquidos de alta resolucion (CLAR) y asi poder determinar aspectos estructurales del combustoleo que determinan su estabilidad. Dado que la formacion de sedimentos ocurre cuando el poder disolvente del combustible es inadecuado para mantener los asfaltenos en solucion, es importante conocer la medida del poder disolvente o aromaticidad del diluyente; asi pues, la primera parte de este trabajo se centro en la determinacion del perfil de compuestos aromaticos de los diluyentes de los combustoleos, la otra parte se dedico a la determinacion del perfil de distribucion de los pesos moleculares de los asfaltenos presentes en los combustoleos. Los perfiles de la fraccion aromatica, asi como los de distribucion de pesos moleculares se determinaron empleando cromatografia de liquidos, en la que se empleo una variedad de columnas y de disolventes. Se efectuo una combinacion de pruebas de rutina tales como contenido de asfaltenos, equivalencia de tolueno, viscosidad, etcetera con el fin de obtener correlaciones con el metodo cromatografico desarrollado. En este articulo se discute solo la seccion correspondiente a la obtencion del perfil de contenidos de aromaticos de los combustoleos. Se
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Energy Technology Data Exchange (ETDEWEB)
Inacio, Erika M.; Dias, Marcos L., E-mail: erika.minacio@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Lima, Maria Celiana P. [Instituto Federal do Rio de Janeiro (IFRJ), Duque de Caxias, RJ (Brazil)
2015-07-01
The addition of plasticizers to poly(lactic acid) (PLA) is one of the known ways of changing its ductility, making possible the modification of its mechanical and thermal properties. In this work, it was synthesized two biodegradable aliphatic oligoesters: oligo(trimethylene sebacate) (OST) and oligo(trimethylene malonate) (OMT), and these oligomers were used as plasticizer in cast films of commercial film grade PLA at concentrations of 1, 5 and 10 wt% of each plasticizer. X-ray diffraction (XRD) was used to investigate the morphology and differential scanning calorimetry (DSC) was also used aiming the evaluation of the thermal properties of these films. The PLA films containing no plasticizer showed an amorphous behavior, and the addition of PMT on the PLA films acted, simultaneously, decreasing the Tg, and rising the material's crystallinity. In contrast, the increased addition of OST to the PLA films did not change the Tg, and equally, did not have a significant changes in the material's crystallinity. Therefore, it was possible to observe the effect of the concentration of oligomers on the crystallinity of the films as well as the no plasticizer effect of the OST. (author)
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Energy Technology Data Exchange (ETDEWEB)
Inacio, Erika M.; Dias, Marcos L., E-mail: erika.minacio@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Lima, Maria Celiana P. [Instituto Federal do Rio de Janeiro (IFRJ), Duque de Caxias, RJ (Brazil)
2013-07-01
The addition of plasticizers to poly(lactic acid) (PLA) is one of the known ways of changing its ductility, making possible the modification of its mechanical and thermal properties. In this work, it was synthesized two biodegradable aliphatic oligoesters: oligo(trimethylene sebacate) (OST) and oligo(trimethylene malonate) (OMT), and these oligomers were used as plasticizer in cast films of commercial film grade PLA at concentrations of 1, 5 and 10 wt% of each plasticizer. X-ray diffraction (XRD) was used to investigate the morphology and differential scanning calorimetry (DSC) was also used aiming the evaluation of the thermal properties of these films. The PLA films containing no plasticizer showed an amorphous behavior, and the addition of PMT on the PLA films acted, simultaneously, decreasing the Tg, and rising the material's crystallinity. In contrast, the increased addition of OST to the PLA films did not change the Tg, and equally, did not have a significant changes in the material's crystallinity. Therefore, it was possible to observe the effect of the concentration of oligomers on the crystallinity of the films as well as the no plasticizer effect of the OST. (author)
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Energy Technology Data Exchange (ETDEWEB)
Lima, Anie Daniela M.; Fontes, Anita Eleonora F.; Figueiredo, Joao Baptista [PETROBRAS, Rio de Janeiro, RJ (Brazil)] (and others)
2008-07-01
This paper presents the development of a substitute product for the aromatic oil used in rubber tires. The new oil must be in according to The European Community Directive 2005/69/EC, which has the start date in January first of 2010. The directive sets limits for specific levels of polyaromatics content in the oils for rubber tires because of the mutagenic and harmful to the reproduction characteristic of some of these substances. The process of aromatics extraction was conducted on several kinds of feedstocks to obtain a product with kinematic viscosity at 100 deg C in the 40-50 cSt range and polycyclics aromatics content until 3% in mass. It is important to know that the current oils have 20% in mass of polyaromatics content. The product developed is in according with the Directive specifications and contributes to the production of tires more suitable to the environment and human health. (author)
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Energy Technology Data Exchange (ETDEWEB)
Cencig, M O; Gomes, J R; Luengo, C A [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica
1985-12-31
A coal hydro pyrolysis process has been built and operated at the Laboratory for Alternative Fuels, University of Campinas, Brazil, to obtain desired liquid and gaseous chemical and valuable liquid fuels. A bench, down flow reactor, processes up to 3 kg per hour of powdered coal in hydrogen atmosphere at high pressures (up to 50 atm). Reactor temperatures reach 800 deg C. Residual solids are quenched from the gaseous mainstream. Immediately afterwards, appropriate condensers remove the liquid products. On line gas chromatography is used for monitoring output gas composition after the reaction chamber. Condensed oils had a heating value of 8000 kCal per minute. Results of systematic testing during the last two years are presented. Hardware developments and future applications to biomass materials are also discussed. (author). 13 refs., 2 figs., 1 tab
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Energy Technology Data Exchange (ETDEWEB)
Marti Ortega, N.; Aguado Garcia, D.; Bouzas Blanco, A.; Segovia Martinez, L.; Albargues Llamas, M.; Sevillano Cabeza, A.; Campins Falco, P.; Seco Torrecillas, A.; Ferrer Polo, J.
2009-07-01
This paper reports the results on alkylphenol and polycyclic aromatic hydrocarbons (PAH) pollution in mussels and cleans from Comunidad Valenciana coastal waters, in 2008. The significant presence of nonylphenol observed in both bivalves reflects an exposure to alkyl phenolic surfactants from the discharges of wastewater treatment plants that treat industrial and urban wastewaters, where the presence of alkylphenol polyethoxylated is common due to its extensive use (detergents, solubilizers...). The presence of low levels of PAH was observed in most of the studied areas. However, it must be highlighted that bivalves consumption does not imply any risk for human health. (Author) 21 refs.
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Energy Technology Data Exchange (ETDEWEB)
Cachorro Sanchez, P.; Gonzalez Garcia, H.; Luna Jara, J.
2000-07-01
The results of this study are part of a project for characterising domestic and industrial waste flowing through the sewer system of Cartagena de Indias (Columbia). Characterisation was carried out in order to establish the contaminating load in the drinking water supply with a view to establishing a framework for compensatory taxes levied by the corresponding environmental agency. (Author)
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Energy Technology Data Exchange (ETDEWEB)
NONE
2011-02-15
The objective of this work was to determine the removal efficiency of polycyclic aromatic hydrocarbons (PAH) and total petroleum hydrocarbons (TPH) from soil contaminated with hydrocarbons using two different types of agricultural residues, filter cake mud and the sugarcane bagasse pith, as amendment and bulking agents. To test these approaches, a microcosms test was applied to soil contaminated with 14 300 mg kg-1 of TPH and 23.14 mg kg-1 of PAH. The soil treatments consisted of the following ratios of soil to residue (%/%): 100:0, 98:2, 98:4 and 98:6, and macronutrient addition was based on a carbon/nitrogen/phosphorus ratio (C:N:P, %/ % / %) of 100:10:1. Statistical analysis indicated that there were significant differences between the filter cake mud and the sugarcane bagasse pith treatments, in which the TPH removal efficiency was 60.1% using sugar cane bagasse pith and 51.4% with filter cake mud. A filter cake mud ratio of 96:4 produced the highest observed removal efficiency of PAH (43%), and a sugarcane bagasse pith ratio of 98:2 resulted in a PAH removal efficiency of 41%. Filter cake mud treatment could be an alternative for use in the bioremediation process of soils polluted with hydrocarbons. [Spanish] El objetivo del presente trabajo fue determinar la eficiencia de remocion de hidrocarburos aromaticos policiclicos (HAP) y de hidrocarburos totales del petroleo (HTP) de un suelo contaminado con petroleo crudo, utilizando dos tipos de residuos agroindustriales, la cachaza y el bagazo de cana de azucar como enmiendas y texturizante. Para ello, se realizaron pruebas en microcosmos de cultivos solidos para la biorremediacion de un suelo contaminado con 14300 mg kg-1 de HTP y 23.14 mg kg-1 de HAP. Las relaciones suelo: residuo utilizadas en las pruebas fueron las siguientes (%): 100:0, 98:2, 96:4 y 94:6, y la adicion de macronutrimentos con base en la relacion carbono/nitrogeno/fosforo (%%%) de 100:10:1. El analisis estadistico indico que hay diferencias
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Energy Technology Data Exchange (ETDEWEB)
Cunha, Silvio; Marques, Monique F.; Rocha, Valeria, E-mail: silviodc@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Instituto de Quimica; Lariucci, Carlito; Vencato, Ivo [Universidade Federal de Goiania (UFG), GO (Brazil). Instituto de Fisica
2013-11-01
This article describes an undergraduate experiment for the synthesis of p-nitrophenyldiazonium chloride and its coupling with acetylacetone and two enaminones, 4-phenylamino-pent-3-en-2-one and 4-amino-pent-3-en-2-one, in an adaptation of a previously reported synthetic protocol. The azo dyes 4-(E)-phenylamino-3-[(E)-2-(4-nitrophenylazo)]-3-penten-2-one and 4-(E)-amino-3-[(E)-2-(4-nitrophenylazo)]-3-penten-2-one were obtained, and the solid state structure of this latter azo compound was characterized by single crystal X-ray diffraction studies. This two-week integrated laboratory approach involves simple synthetic experiments and microwave chemistry in the organic laboratory plus crystallography analysis, suitable for novice students on undergraduate experimental chemistry courses. (author)
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Energy Technology Data Exchange (ETDEWEB)
Machado, J. Carlos V. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Tavares, Tania M. [Universidade Federal da Bahia (UFBA), Salvador (Brazil)
1998-07-01
This work studies the contamination degree of the meso and infra-coastline sediments of the Baia de Todos os Santos, Bahia, the largest of Brazil, by organic compounds, mainly of period origin. The assessment was proceeded through quantification of total polycyclic aromatic hydrocarbons (PAH's), by fluorimetric analysis in continuous flow. The levels of contamination were quantified taking in consideration the levels considered as critical by the published literature. The grading of the target sites with those of the control sites (background) were compared also. The main objective was to define the degree of contamination relative to different areas of the bay, correlating with the different activities, such as oil exploitation, industrial production, mainly of oil processing at the north of the bay, port and urban, specially near the city of Salvador, with 2 million of inhabitants. In some stations, specially in those classified as industrial, urban and heavy boats traffic, sediments showed contamination, resulting in grades up to 2000 times greater than the control sites. Some regions, mainly industrial and urban, showed high PHA's contamination, higher than 200 {mu}g/g. The majority of sediments in areas remaining as recreational until present days showed no contamination, lesser than {mu}g/g. (author)
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Energy Technology Data Exchange (ETDEWEB)
Perez, M M; Gonzalez, D
1987-07-01
A study of the analysis by gas chromatography of aromatic polycyclic hydrocarbons is presented. The separation has been carried out by glass and fused silica capillary column. The limitations and the advantages of the procedure are discussed in terms of separation efficiency, sensitivity and precision. (Author) 17 refs.
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Energy Technology Data Exchange (ETDEWEB)
Garcia, S.; Perez, R. M.
2014-06-01
A study on the comparison and evaluation of a miniaturized extraction method for the determination of selected PACs in sample filters is presented. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the intermediate precision. (Author)
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Energy Technology Data Exchange (ETDEWEB)
Aversa, Thiago M.; Rodrigues, Monique F.; Vieira, Helida V.P.; Queiros, Yure G.C.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro, Instituto de Macromoleculas, Lab. de Macromoleculas e Coloides na Industria do Petroleo, Rio de Janeiro, RJ (Brazil)], e-mail: thiagoaversa@ima.ufrj.br
2011-07-01
The use of chemically modified resins in oily water treatment process is not very developed yet. Because of this, this work suggests to study the styrene and divinylbenzene sulfonation effect on oil and grease, aniline and calcium removal from the water. The aniline, oils and greases belong to a class of toxic organic compounds, with the Brazilian maximum limits established for disposal in CONAMA 393/2007, while the calcium ions belong to the group of cations of alkaline earth metals which improve hardness to the water, may cause fouling as carbonates and sulfates form. By using sulfonated resins in oily water treatment it is possible to remove not only oils and greases but also calcium and aniline. These kinds of polar compounds are removed because of the cation exchange capacity of resin. (author)
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Energy Technology Data Exchange (ETDEWEB)
Garcia, Marina R.D.; Mirlean, Nicolai; Machado, Maria Isabel C.S. [Fundacao Universidade Federal do Rio Grande (FURG), RS (Brazil); Caramao, Elina B. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)
2004-07-01
Contamination often can be related to different activities, especially in areas with multiple uses. In these cases, studies are necessary to correctly evaluate the origin of contaminants. Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that have two main sources: pyrolytic and petrogenic processes. In Rio Grande City, located at the margins of Patos Lagoon estuary, south Brazil, there are several navigation and industrial activities. This work has the objective to determinate the origins of PAHs and to evaluate the contribution of different sources to the aquatic contamination. The sampling stations were classified according to three main types: industrial effluent, sewage and runoff. We collected sediments from the bottom of effluent channels and from the respective estuarine environments. The material was sieved (0,063 mm), dried, extracted in soxhlet apparatus with methylene chloride and GC-MS analyzed. The results showed that pyrolytic compounds were predominant, indicating the contribution of diffuse sources. This type of study was successful in relating PAHs with their sources, confirming the role of urban and other industries activities in this case of contamination, superimposed to the midstream e downstream activities of petroleum industry. (author)
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Energy Technology Data Exchange (ETDEWEB)
Iturbide-Arguelles, R; Flores-Serrano, R. Ma; Torres-Bustillos, L.G [Instituto de Ingenieria, Universidad Autonoma de Mexico (Mexico)]. E-mail: ria@pumas.iingen.unam.mx
2006-01-15
) en concentraciones de ND a 59,000 mg/kg. No se detecto la presencia de benceno, tolueno, etilbenceno y xileno (BTEX), metil terbutil eter (MTBE) ni metil-teramil eter (MTE). De los 16 hidrocarburos aromaticos policiclicos (HAP) analizados, solo se encontro la presencia de naftaleno en un punto, a una concentracion por debajo de 1 mg/kg. Se identifico la presencia de Fe, Pb y Zn en el suelo, pero los indices de geo-acumulacion calculados sugieren que se trata de concentraciones naturales del suelo y no contaminacion alguna. Se encontraron HTP en las aguas subterraneas, solo en un de los 6 pozos por arriba del nivel recomendado de 10mg/l. Tambien se encontro que el Fe excede el valor sugerido de 0.3 mg/l en 5 de los 6 pozos estudiados. Se encontro que el pH de las aguas subterraneas no esta relacionado con el nivel de metales encontrados (Fe y Zn), pero si con el contenido de HTP. El analisis de riesgo a la salud indico que las concentraciones de naftaleno y zinc, presentes en el suelo y agua subterranea, no representan un riesgo para la salud de los habitantes de las colonias aledanas ni para los trabajadores de la TAD. Sin embargo, dados los altos niveles de concentracion de HTP al norte de la TAD, se recomendo el saneamiento de un volumen de aproximadamente 8,000 m{sup 3} mediante el proceso de biopilas.
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Energy Technology Data Exchange (ETDEWEB)
Garcia Alonso, S.; Perez Pastor, R. M.
2013-10-01
A study on the comparison and evaluation of 3 miniaturized extraction methods for the determination of selected PACs in clear waters is presented. Three types of liquid-liquid extraction were used for chromatographic analysis by HPLC with fluorescence detection. The main objective was the optimization and development of simple, rapid and low cost methods, minimizing the use of extracting solvent volume. The work also includes a study on the scope of the methods developed at low and high levels of concentration and intermediate precision. (Author)
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Energy Technology Data Exchange (ETDEWEB)
Rodriguez Barquero, L.; Arcos Merino, J. M. los; Grau Malonda, A.
1992-07-01
Procedures for liquid scintillation sample preparation of manganese dimethylbutirate, decanoate and palmitate, labelled with 54 Mn are described. their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene. HISafe II. PCS, instagel. Dioxane-naphtalene and Toluene-alcohol. For comparison, Inorganic 54 MnCl-2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (Author)
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Energy Technology Data Exchange (ETDEWEB)
Brito, Carlos Fernando de
2009-07-01
The polycyclic aromatic hydrocarbons (PAHs), by being considered persistent contaminants, by their ubiquity in the environment and by the recognition of their genotoxicity, have stimulated research activities in order to determine and evaluate their sources, transport, processing, biological effects and accumulation in compartments of aquatic and terrestrial ecosystems. In this work, the matrix studied was sediment collected at Pedroso Park's dam at Santo Andre, SP. The analytical technique employed was liquid chromatography in reverse phase with a UV/Vis detector. Statistics treatment of the data was established during the process of developing the methodology for which there was reliable results. The steps involved were evaluated using the concept of Validation of Chemical Testing. The parameters selected for the analytical validation were selectivity, linearity, Working Range, Sensitivity, Accuracy, Precision, Limit of Detection, Limit of quantification and robustness. These parameters showed satisfactory results, allowing the application of the methodology, and is a simple method that allows the minimization of contamination and loss of compounds by over-handling. For the PAHs tested were no found positive results, above the limit of detection, in any of the samples collected in the first phase. But, at the second collection, were found small changes mainly acenaphthylene, fluorene and benzo[a]anthracene. Although the area is preserved, it is possible to realize little signs of contamination. (author)
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Energy Technology Data Exchange (ETDEWEB)
Barrado, A. I.; Garcia, S.; Perez, R. M.
2013-06-01
This paper presents an optimized and validated analytical methodology for the determination of various polycyclic aromatic compounds in ambient air using liquid chromatography with fluorescence detection. This analysis method was applied to samples obtained during more than one year in an area of Madrid. Selected compounds have included thirteen polycyclic hydrocarbons considered priorities by the EPA, and hydroxylated derivatives, which have been less investigated in air samples by liquid chromatography with fluorescence detection. We have characterized and compared the concentration ranges of compounds identified and studied seasonal and monthly variations. In addition, the techniques have been applied to study multivariate correlations, factor analysis and cluster analysis to extract as much information as possible for interpretation and more complete and accurate characterization of the results and their relationship with meteorological parameters and physicochemical. (Author) 50 refs.
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Energy Technology Data Exchange (ETDEWEB)
Malachesky, P. A.; Miller, T. A.; Layloff, T.; Adams, R. N. [University of Kansas, Lawrence, KS (United States)
1965-10-15
nitro-aromatique accuse en outre de tres fortes variations de k{sub exc} selon le systeme solvant. On peut rapprocher ces variations des recentes etudes de l'effet de solvatation sur les constantes de couplage hyperfines. Marcus a examine recemment la theorie du transfert chimique et electrochimique d'electrons et a suggere des correlations entre k{sub exc} et k{sub el}. Les auteurs ont mesure k{sub el} notamment pour le nitrobenzene dans des conditions experimentales qui sont aussi proches que possible des etudes par RPE. Pour les recherches electrochimiques, onaapplique une methode a courant continu enregimestationnaire, de maniere a eliminer certaines des incertitudes inherentes aux techniques de relaxation electrochimique. On a utilise des electrodes a disques tournants a basse temperature. Les effets du solvant sur k{sub el} (pour le nitrobenzene) sont identiques a ceux qui ont ete observes pour k{sub exc}- Mais o n releve des ecarts considerables entre les valeurs de k{sub el} observees et celles qui ont ete calculees par la theorie de Marcus, les auteurs discutent plusieurs explications possibles de ces ecarts. (author) [Spanish] Se posee abundante informacion sobre las velocidades y mecanismos de los procesos de intercambio electronico en sustancias inorganicas. En cambio, se ha prestado menor atencion a los sistemas puramente organicos. Las velocidades de intercambio homogeneo de electrones (k{sub exc}) y las constantes de velocidad de intercambio heterogeneo en los electrodos (k{sub el}) solo se han medido en el caso de contados hidrocarburos. Los autores han determinado el valor de k{sub exc} en una serie de sistemas aromaticos que comprende hidrocarburos, quinonas y nitro compuestos. A tal efecto, han medido el ensanchamientode las lfneas por resonancia paramagnetica de los electrones en mezclas de radicales ionicos y de sus precursores. Los autores han podido medir el valor de k{sub exc} con una precision que permite observar ligeras variaciones debidas
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Energy Technology Data Exchange (ETDEWEB)
Adloff, J. -P.; Adloff-Bacher, M. [Departement de Chimie Nucleaire, Centre de Recherches Nucleaires, Strasbourg (France)
1963-03-15
la brusque variation de la charge nucleaire au cours de la desintegration,ainsi que de la conversion interne du rayonnement y succedant l'emission {beta}. L'iode-132 doit se former au sein du systeme a marquer: la forme chimique la plus appropriee du compose parent est le tetrachlorure de tellure-132, soluble dans un certain nombre de liquides organiques. Plusieurs systemes ont ainsi ete etudies (hydrocarbures aromatiques et derives, alcools, etc.). Apres un contactdequelques heures, la solution organique est analysee par chromatographie en phase gazeuse et les differents composes, marques par radiosynthese, sont separes par distillation en presenced'entraineurs. Les produits marques peuvent etre le resultat de reactions d'echanges isotopiques ou de substitution et fragmentation. L'emploi d'un milieu organique convenable permet dans certains cas un marquage pratiquement specifique. (author) [Spanish] El corlo periodo de semidesintegracion del yodo-132 (T{sub 1/2} = 2,30 h), que justifica su interes en biologia, medicina y como indicador radiactivo entrana no obstante un inconveniente grave cuando se trata de sintetizar moleculas marcadas. Los autores demuestran que es posible sacar provecho de la reactividad quimica del yodo 'naciente' formado por desintegracion del teluro-132 para preparar rapidamente moleculas marcadas de elevada actividad especifica. Esta reactividad se debe a la energia de excitacion del yodo, causada por la brusca variacion de la carga nuclear durante la desintegracion, asi como por la conversion interna de las radiaciones y que suceden a la emision {beta}. El yodo-132 tiene que formarse dentro del sistema que se desea marcar; la forma quimica mas adecuada del compuesto madre es el tetracloruro de teluro-132, soluble en algunos liquidos organicos. De este modo se han estudiado varios sistemas (hidrocarburos aromaticos y sus derivados, alcoholes, etc. ...). Despues de un contacto de algunas horas, la solucion organica se analiza por cromatografia
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Energy Technology Data Exchange (ETDEWEB)
Medvedev, S S; Abkin, A D; Khomikovsky, P M [Fiziko-khimicheskij institut im. Karpova, SSSR, Moscow, Union of Soviet Socialist Republics (Russian Federation)
1960-07-15
polymerisation de l'ethylene irradie par une source de cobalt-60, en milieu gazeux, en faisant varier la pression (de 50 a 300 atmospheres), l'intensite d'irradiation (de 20 a 160 roentgens par seconde) et la temperature (de zero a 50{sup o} C). La vitesse du processus, le rendement radiochimique et le poids moleculaire moyen des polymeres accusent une augmentation brusque avec la pression (entre 50 et 200 atmospheres la vitesse de polymerisation est proportionnelle a la concentration de l'ethylene elevee a la quatrieme puissance). La vitesse de polymerisation ne depend que faiblement de l'intensite d'irradiation (elle n'est proportionnelle qu'a l'intensite d'irradiation elevee a la puissance 0,3) alors que le rendement radiochimique et le poids moleculaire moyen des polymeres s'accroissent a mesure que l'intensite d'irradiation diminue. La vitesse du processus et le poids moleculaire accusent une certaine augmentation a mesure que la temperature s'accroit. Les explications possibles des regularites cinetiques observees sont examinees dans le rapport. Le polyethylene obtenu par irradiation se distingue du polyethylene forme sous pression elevee par un accroissement de la densite et du degre de cristallisation. Le polymere qui a une viscosite caracteristique superieure a l'unite (obtenue a une pression de 100 a 200 atmospheres) a les memes proprietes chimiques que le polyethylene forme sous haute pression. (author) [Spanish] Se estudia en este trabajo el proceso de polimerizacion radioinducida del etileno. A fin de acelerar dicho proceso, la reaccion se inicio en soluciones de compuestos organicos: alcoholes, cetonas e hidrocarburos alifaticos. Se demuestra que a una presion constante de 50 atmosferas y a temperatura ambiente, la velocidad de la reaccion en solucion es de diez a quince veces mayor que en fase gaseosa. Los autores han estudiado en detalle la polimerizacion del etileno irradiado con ayuda de una fuente de cobalto-60 en fase gaseosa; para ello, modificaron la
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Energy Technology Data Exchange (ETDEWEB)
Klehr, E H; Voigt, A F [Institute for Atomic Research and Department of Chemistry, Iowa State University, Ames, IA (United States)
1962-03-15
siguientes solventes: tetracloruro de carbono; 2,2,4-trimetilpentano; n-decano; benceno; tolueno; nitrobenceno, clorobenceno y bromobenceno. Las mediciones se efectuaron sea agitando mercurio metalico de actividad especifica conocida con el solvente, sea determinando el coeficiente de distribucion del metal entre el solvente y el agua y combinando esta determinacion con la de la solubilidad del mercurio en agua, sea aplicando los dos metodos sucesivamente. La radiactividad se determino recontando las muestras del precipitado con un contador Geiger-Mueller, o recontando partes alicuotas del liquido con un contador de centelleo del tipo de pozo. Los valores de la solubilidad resultaron del orden de 4,6 a 16 x 10-6 atomos g/l. En el caso del n-decano, del tolueno y del clorobenceno, se determino la relacion de dependencia entre la solubilidad y la temperatura desde 0 hasta 45 {sup o}C. Para comparar los resultados se aplico a estos sistemas la teoria de la solubilidad de Hildebrand-Scott. En el caso de los hidrocarburos alifaticos, los valores de la solubilidad calculados teoricamente no se alejan mas de un 35% de los observados, pero para los otros solventes los valores teoricos son de 4 a 18 veces mayores que los observados. Modificando la teoria se obtiene una concordancia mayor para unos solventes y menor para otros. (author) [Russian] Opredelyalas' rastvorimost' metallicheskoj rtuti pri temperature 25{sup o}C s pomoshch'yu indikatora Hg{sup 203} v rastvoritelyakh chetyrekhkhloristogo ugleroda, 2,2,4-trimetilpentana, i-dekana, benzola, toluola, nitrobenzola, khlorbenzola i brombenzola. Izmereniya osushchestvlyalis' libo putem vzbaltyvaniya metallicheskoj rtuti izvestnoj udel'noj aktivnosti s rastvoritelem, libo izmereniem koehffitsienta raspredeleniya metalla mezhdu rastvoritelem i vodoj i ob{sup e}dineniem ehtogo izmereniya s rastvorimost'yu rtuti v vode ili i tem i drugim metodom. Radioaktivnost' izmeryalas' podschetom osazhdennykh obraztsov schetchikom Gejgera
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Energy Technology Data Exchange (ETDEWEB)
Machurek, J. E.; Stein, M. H. [Division of Isotopes Development, USAEC, Washington, DC (United States)
1963-11-15
autores comunican los resultados de catorce de esas investigaciones, resumiendo algunos en la monografia y dando mas detalles sobre otros en las actas respectivas. Los temas tratados son los siguientes: 1. Preparacion de combinaciones madera-materiales plasticos utilizando las radiaciones gamma para inducir la polimerizacion. 2. Empleo de las radiaciones beta emitidas por los productos de fision para la hidrogenacion del carbono y sus derivados con miras a la produccion de hidrocarburos liquidos combustibles. 3. Preparacion de semiconductores en los cuales las impurezas se distribuyen con arreglo a un esquema espacial predeterminado, con ayuda de transmutaciones neutronicas. 4. Polimerizacion radioinducida del etileno y sus copolimeroe. 5. Estudios basicos de los mecanismos y la cinetica de las reacciones radioinducidas. 6. Aspectos radioquimicos de la fluoracion de diversos compuestos aromaticos. 7. Empleo de monomeros polifuncionales para acrecentar la radiorreticulacion en el polietileno, el polipropileno, el poliisobutileno y el acetato de celulosa. 8. Efectos de la turgencia, tension y temperatura sobre las propiedades fisicas y quimicas de los polimeros producidos con ayuda de las radiaciones. 9. Influencia de los factores estructurales sobre las modificaciones radioinducidas en polimeros que conducen a la copolimerizacion por injerto. 10. Utilizacion de las radiaciones nucleares para modificar las propiedades de los materiales textiles. 11. Reacciones radioinducidas en las que se utiliza el cripton-85. 12. Preparacion de un ''Manual de Radiaciones''. 13. Empleo de enlaces organometalicos en la dosimetria de radiaciones gamma de elevada intensidad. 14. Preparacion de un dosimetro de celula solar. (author) [Russian] V sootvetstvii s programmoj issledovanij radiatsionnykh protsessov Komissii po atomnoj ehnergii SSHA byli provedeny obshirnye izyskaniya. Glavnaya tsel' ehtikh issledovanij sostoit v sodejstvii razrabotke tekhnologii, kotoraya obespechila by ehffektivnoe
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Energy Technology Data Exchange (ETDEWEB)
Anbar, M. [Weizmann Institute of Science (Israel); IAEC Soreq Research Establishment, Rehovot (Israel)
1963-03-15
4} estimula la accion inhibidora que ejercen sobre la captacion de yodo los iones hierro, cobre, cinc, cadmio, fluoruro, tiocianiato y otros, demostrando que en ella interviene la funcion de captacion. En una serie analoga de experimentos, se encontro que los compuestos sulfhidrilicos y las azidas incrementan la captacion de fluoroborato, aunque disminuyen la captacion total de yodo. Seguidamente, se demostro que la funcion de captacion es menos radiosensible que las funciones de formacion y liberacion de tiroxina. Otra aplicacion muy distinta de los iones fluoroborato marcados con {sup 18}F fue la localizacion de tumores cerebrales por exploracion direccional de coincidencias en la que se aprovecha la baja permeabilidad para estos iones de la barrera sangre- cerebro intacta. Se prepararon agentes de quelacion fluoroaromaticos marcados con {sup 18}F y se aplicaron a problemas de fisiologia de tejido oseo. Para estudiar la permeabilidad a traves de membranas biologicas, se emplearon colorantes aromaticos vitales marcados con {sup 18}F. Se han preparado antimeiabolitos que contienen fluor, marcados con {sup 18}F, entre otros, el 5-fluorouracilo y el acido fluoroorotico y se han aplicado al estudio de problemas fisiologicos e investigaciones sobre el cancer. (author) [Russian] V techenie poslednih treh let ftor-18 primenjaetsja v nashej laboratorii dlja razlichnyh biologicheskih i medicinskih issledovanij. Razrabotany metody poluchenija ftora v rezul'tate reakcij s O{sup 16} (p, n), O{sup 15} (H{sup 3}, p), i F{sup 18} (n, 2 ,). Soedinenija, mechennye radioaktivnym ftorom, byli poducheny metodom izotopnogo obmena sinteza, mechenija otdachej i uderzhivaniem ftora vo ftoroorganicheskih soedinenijah v rezul'tate reakcii (p,2 p). Razrabotana special'naja tehnika scheta nizkogo urovnja aktivnosti dlja raboty s malymi aktivnostjami indikatornyh kolichestv organicheskih ftoristyh soedinenij. Iony ftora-18 byli ispol'zovany pri izuchenii fiziologii kostej. Bylo obnaruzheno