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Sample records for rmn calculos teoricos

  1. Magnetic structure analyses of multiferroics RMnO3 and RMn2O5

    International Nuclear Information System (INIS)

    Arima, Taka-hisa; Kimura, Hiroyuki

    2010-01-01

    Magnetic structure of typical multiferroic materials RMnO 3 and RMn 2 O 5 (R:rare earth) has been investigated by neutron diffraction. Magnetic structure analysis using single crystal revealed that both the materials have a cycloidal magnetic structure, where ferroelectricity arises. Polarized neutron diffraction under electric field found the one-to-one correspondence between the direction of cycloidal rotation (spin chirality) and the direction of the electric polarization, evincing that the electric polarization is directly induced by the cycloidal magnetic order. (author)

  2. INTERVALOS DE INTEGRACIÓN UNIFICADOS PARA LA CARACTERIZACIÓN ESTRUCTURAL DE PETRÓLEOS, CARBONES O SUS FRACCIONES POR RMN 1H Y RMN 13C

    Directory of Open Access Journals (Sweden)

    Avella Eliseo

    2010-09-01

    Full Text Available Con base en la revisión de publicaciones, hechas entre 1972 y 2006, se evidenció que hay imprecisiones en los límites de los intervalos de integración que los autores asignan a las señales en resonancia magnética nuclear (RMN para hacer la caracterización estructural de petróleos, carbones o sus fracciones derivadas, a partir de sus espectros de hidrógeno (RMN 1H o de carbono (RMN 13C. En consecuencia, se determinaron límites unificados para la integración de los espectros RMN 1H y RMN 13C de tales muestras mediante un tratamiento estadístico aplicado a los límites de los intervalos de integración ya publicados. Con esos límites unificados se elaboraron cartas de correlación en RMN útiles para la asignación de la integral en esos intervalos, y aun en otros de menor extensión definidos en función de la intersección entre asignaciones diferentes. Además se plantearon ecuaciones necesarias para establecer la integral atribuible a fragmentos más específicos en un intento por hacer una caracterización estructural más exacta a partir de los espectros RMN de petróleos, carbones o sus fracciones derivadas.

  3. Intervalos de integración unificados para la caracterización estructural de petróleos, carbones o sus fracciones por rmn 1h y rmn 13c

    OpenAIRE

    Eliseo, Avella; Fierro, Ricardo

    2010-01-01

    Con base en la revisión de publicaciones, hechas entre 1972 y 2006, se evidenció que hay imprecisiones en los límites de los intervalos de integración que los autores asignan a las señales en resonancia magnética nuclear (RMN) para hacer la caracterización estructural de petróleos, carbones o sus fracciones derivadas, a partir de sus espectros de hidrógeno (RMN 1H) o de carbono (RMN 13C). En consecuencia, se determinaron límites unificados para la integración de los espectros RMN 1H y RMN 13C...

  4. RA-0 reactor. New neutronic calculations; Reactor RA-0. Nuevos calculos neutronicos

    Energy Technology Data Exchange (ETDEWEB)

    Rumis, D; Leszczynski, F

    1991-12-31

    An updating of the neutronic calculations performed at the RA-0 reactor, located at the Natural, Physical and Exact Sciences Faculty of Cordoba National University, are herein described. The techniques used for the calculation of a reactor like the RA-0 allows prediction in detail of the flux behaviour in the core`s interior and in the reflector, which will be helpful for experiments design. In particular, the use of WIMSD4 code to make calculations on the reactor implies a novelty in the possible applications of this code to solve the problems that arise in practice. (Author). [Espanol] En este trabajo se actualizan los calculos neutronicos realizados para el reactor RA-0, instalado en la Facultad de Ciencias Exactas, Fisicas y Naturales de la Universidad Nacional de Cordoba. Se describen los calculos realizados hasta la fecha y los resultados obtenidos. Las tecnicas incorporadas al calculo de un reactor como el RA-0 permiten predecir en detalle el comportamiento del flujo en el interior del nucleo y en el reflector, lo que sera una importante ayuda en el diseno de experimentos. En particular, el empleo del codigo WIMSD4 para calculos del reactor completo constituye una novedad en las posibles aplicaciones de ese codigo para resolver problemas que se presentan en la practica. (Autor).

  5. Reinvestigación de la formación de alquinilciclopropanocarbonitrilos a partir de complejos carbeno de Fischer: Diastereoselectividad y Mecanismo

    OpenAIRE

    Solis Moreno, Guillermo

    2015-01-01

    La reinvestigación de la síntesis de los alquinilciclopropanocarbonitrilos ha permitido corregir la configuración asignada al diastereoisómero mayoritario de la reacción, en la publicación original a través de experimentos de RMN de NOE y NOESY. Adicionalmente, aparece detallado el mecanismo de la reacción estudiado a través de calculos computacionales.

  6. Analysis of the Anisotropic Magnetocaloric Effect in RMn2O5 Single Crystals

    Directory of Open Access Journals (Sweden)

    Mohamed Balli

    2017-11-01

    Full Text Available Thanks to the strong magnetic anisotropy shown by the multiferroic RMn2O5 (R = magnetic rare earth compounds, a large adiabatic temperature change can be induced (around 10 K by rotating them in constant magnetic fields instead of the standard magnetization-demagnetization method. Particularly, the TbMn2O5 single crystal reveals a giant rotating magnetocaloric effect (RMCE under relatively low constant magnetic fields reachable by permanent magnets. On the other hand, the nature of R3+ ions strongly affects their RMCEs. For example, the maximum rotating adiabatic temperature change exhibited by TbMn2O5 is more than five times larger than that presented by HoMn2O5 in a constant magnetic field of 2 T. In this paper, we mainly focus on the physics behind the RMCE shown by RMn2O5 multiferroics. We particularly demonstrate that the rare earth size could play a crucial role in determining the magnetic order, and accordingly, the rotating magnetocaloric properties of RMn2O5 compounds through the modulation of exchange interactions via lattice distortions. This is a scenario that seems to be supported by Raman scattering measurements.

  7. Difusão de spins nucleares em meios porosos - uma abordagem computacional da RMN

    OpenAIRE

    Éverton Lucas-Oliveira

    2015-01-01

    A Ressonância Magnética Nuclear (RMN) é uma importante técnica empregada nas principais áreas de conhecimento, tais como, Física, Química e Medicina. Importantes trabalhos da RMN aplicada ao estudo da dinâmica de moléculas em fluidos presentes em meios porosos permitiram que esta técnica ganhasse também notoriedade na indústria do petróleo. O presente projeto é fundamentado em alguns destes trabalhos seminais, reproduzindo, através de modelos físico-computacionais, os principais efeitos físic...

  8. Ferrielectricity in DyMn2O5: A golden touchstone for multiferroicity of RMn2O5 family

    Directory of Open Access Journals (Sweden)

    J.-M. Liu

    2015-06-01

    Full Text Available The RMn2O5 manganite compounds represent one class of multiferroic family with magnetic origins, which has been receiving continuous attention in the past decade. So far, our understanding of the magnetic origins for ferroelectricity in RMn2O5 is associated with the nearly collinear antiferromagnetic structure of Mn ions, while the exchange striction induced ionic displacements are the consequence of the spin frustration competitions. While this scenario may be applied to almost all RMn2O5 members, its limitation is either clear: the temperature-dependent behaviors of electric polarization and its responses to external stimuli are seriously materials dependent. These inconsistences raise substantial concern with the state-of-the-art physics of ferroelectricity in RMn2O5. In this mini-review, we present our recent experimental results on the roles of the 4f moments from R ions which are intimately coupled with the 3d moments from Mn ions. DyMn2O5 is a golden figure for illustrating these roles. It is demonstrated that the spin structure accommodates two nearly collinear sublattices which generate respectively two ferroelectric (FE sublattices, enabling DyMn2O5 an emergent ferrielectric (FIE system rarely identified in magnetically induced FEs. The evidence is presented from several aspects, including FIE-like phenomena and magnetoelectric responses, proposed structural model, and experimental check by nonmagnetic substitutions of the 3d and 4f moments. Additional perspectives regarding possible challenges in understanding the multiferroicity of RMn2O5 as a generalized scenario are discussed.

  9. Specific heat and magnetization of RMn2(H,D)2

    International Nuclear Information System (INIS)

    Tarnawski, Z.; Kolwicz-Chodak, L.; Figiel, H.; Kim-Ngan, N.-T.H.; Havela, L.; Miliyanchuk, K.; Sechovsky, V.; Santava, E.; Sebek, J.

    2007-01-01

    The effect of hydrogen absorption on magnetic and thermodynamic properties of hydrides compounds RMn 2 (H,D) 2 (R = Y, Nd, Tb, Ho, and Er) have been investigated by performing specific heat and magnetization measurements in the temperature range of 2-320 K and in magnetic fields up to 9 T. The phase transition to the antiferromagnetic order accompanying a crystal structure transformation have been revealed by complicated-structure anomalies in specific heat and weak anomalies in magnetization

  10. Effect of ionic size on the orbital ordering transition in RMnO3+δ

    NARCIS (Netherlands)

    Maris, G.; Volotchaev, V.; Palstra, T.T.M.

    2004-01-01

    We present high-temperature powder x-ray diffraction data of the orbital-order-induced structural distortion of RMnO3, with R a rare earth element. The associated phase transition takes place in a temperature interval of ≈200K in which the orbitally ordered phase and the orbitally disordered phase

  11. Algorithm for the calculation of a steam generator efficiency; Algoritmo para el calculo de la eficiencia de un generador de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Franco, David; Ambriz, Juan Jose; Romero Paredes, Hernando [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1994-12-31

    The efficiency calculation of steam generators is not always simple. The purpose of this paper is to propose an algorithm for the calculation of steam generators efficiency, easy to understand and carry out, in the form of a series of steps to be followed. It takes as starting point that the person in charge of applying these calculations has knowledge of the combustion processes and thermodynamic principles that rule such processes. [Espanol] El calculo de la eficiencia de los generadores de vapor no siempre es sencillo, el presente trabajo tiene como objetivo el de proponer un algoritmo de calculo de eficiencia de generadores de vapor, el cual sea facil de entender y de llevar a cabo, en forma de una serie de pasos a seguir. Se toma como punto de partida, que la persona encargada de aplicar estos calculos tenga el conocimiento de los procesos de combustion y principios termodinamicos que rigen tales procesos.

  12. The pseudogap and anisotropic thermal expansion in RMn{sub 4}Al{sub 8} (R = La,Y,Lu and Sc)

    Energy Technology Data Exchange (ETDEWEB)

    Muro, Y; Nakamura, H; Kohara, T [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan)

    2006-04-26

    The temperature dependence of the magnetic susceptibility shows a broad maximum at {approx}550 and 630 K for LuMn{sub 4}Al{sub 8} and ScMn{sub 4}Al{sub 8}, respectively, which can be interpreted as due to the presence of a pseudogap in the effective bands as in LaMn{sub 4}Al{sub 8} and YMn{sub 4}Al{sub 8}. The anisotropic thermal expansion observed for RMn{sub 4}Al{sub 8} (R = La, Y, Lu and Sc) and the sensitive volume dependence of the gap width throughout the RMn{sub 4}Al{sub 8} system suggest dominant magnetic coupling in Mn spin chains along the c axis.

  13. Calculo de la Barra Antivuelco de un Vehículo Automotor.

    Directory of Open Access Journals (Sweden)

    Javier García de la Figal

    2005-09-01

    Full Text Available El presente trabajo trata acerca del calculo de la barra antivuelco del FORD modelo A, desarrollado por elInstituto de Desarrollo Automotriz, IDA, teniendo en cuenta las fuerzas que la cinta de seguridad de losautomovilistas, ejerce sobre la citada barra, ante un choque que provoca una aceleración de 20 g en elvehículo. El calculo se hace mediante la confección de un modelo de elementos finitos de la barra y lacarrocería, para lo cual se hace uso de un programa profesional de elementos finitos.Se determinan los esfuerzos máximos y los equivalentes, tanto de las partes metálicas del sistema, queson fundamentalmente tubos de acero, como de las partes de material compuesto (poliéster con fibras devidrio E, propios de la carrocería del vehículo. Todo lo cual permite hacer los cálculos y comprobacionesa resistencia de todo el conjunto. Así mismo, se determinan los desplazamientos en todos los sentidos detodos las partes del sistema, para poder realizar los correspondientes análisis de rigidez.El objetivo final de todos los análisis es determinar lo adecuado o no de las soluciones y materialespropuestos para el sistema, bajo la acción de la citada carga de impacto.

  14. 13 Facile application de la RMN du carbone-13 à l'identification et à ...

    African Journals Online (AJOL)

    AKA BOKO

    de bois [13] en utilisant l'analyse directe avec RMN du carbone-13 assistée par ordinateur sans séparation préalable ont démontré la facilité et fiabilité de cette méthode éminemment non invasive. Dans une étude antérieure, nous avons appliqué cette méthodologie dans l'analyse qualitative et quantitative des sucres.

  15. Relation between ferroelectric and antiferromagnetic order in RMn2O5

    International Nuclear Information System (INIS)

    Noda, Yukio; Kimura, Hiroyuki; Kamada, Youichi; Osawa, Toshihiro; Fukuda, Yosikazu; Ishikawa, Yoshihisa; Kobayashi, Satoru; Wakabayashi, Yusuke; Sawa, Hiroshi; Ikeda, Naoshi; Kohn, Kay

    2006-01-01

    RMn 2 O 5 (R=Y and rare earth) shows successive magnetic and ferroelectric phase transitions at about 45, 40, 39, 20 and 10K. We have reinvestigated the magnetic structure of YMn 2 O 5 at the commensurate phase (T=25K) using a single crystal four-circle diffractometer in order to discuss the mechanism of magnetoelectric interaction and the origin of ferroelectricity. We also observed the lattice modulation vectors (q L ) to compare the magnetic propagation vectors (q M ) by synchrotron X-ray diffraction. Improved magnetic structure data are compared with the theory recently proposed

  16. Synthesis RMn{sub 2}O{sub 5} (R = Gd and Sm) nano- and microstructures by a simple hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Gangqiang, E-mail: zgq2006@snnu.edu.cn [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Liu Peng [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Hojamberdiev, Mirabbos [Shaanxi Key Laboratory of Nano-materials and Technology, Xi' an University of Architecture and Technology, Xi' an 710055 (China); Ge Bao [School of Physics and Information Technology, Shaanxi Normal University, Xi' an 710062 (China); Liu Yun; Miao Hongyan; Tan Guoqiang [College of Materials Science and Engineering, Shaanxi University of Science and Technology, Xi' an 710021 (China)

    2009-12-15

    Single-phase RMn{sub 2}O{sub 5} (R = Gd and Sm) nano- and microstructures have been successfully synthesized via a simple hydrothermal process at 250 deg. C for 24 h using NaOH as mineralizer. X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and selective area electron diffraction patterns (SAED) were used to characterize the as-synthesized GdMn{sub 2}O{sub 5} and SmMn{sub 2}O{sub 5} samples. The effect of NaOH concentration and the molar ratio of Mn{sup 2+}/Mn{sup 7+} on the morphology and size of the final products was studied, and a possible formation mechanism of RMn{sub 2}O{sub 5} (R = Gd and Sm) nanoplates and nanorods under hydrothermal conditions was proposed.

  17. Development of applications in Internet for the calculation of solar control devices; Desarrollo de una aplicacion en Internet para el calculo de dispositivos de control solar

    Energy Technology Data Exchange (ETDEWEB)

    Perez V, Jesus B; Robles G, Saul; Villa M, Hector A; Cabanillas L, Rafael E [Universidad de Sonora, Hermosillo, Sonora (Mexico)

    2000-07-01

    In this work the development of an interactive software, visible over the World Wide Web, is presented to support the basic calculation required to control the solar gain inside buildings and houses. The site has two main parts: one part describes in a very required parameters to design devices for the control of the illumination inside the buildings, like overhangs and wingwalls for shading. The other part has the routines and procedures to calculate the sun position for any date and position over the earth, and the horizontal and vertical protection angles. The part to implement the calculations has been developed as a Java applet which can run on any platform and let the users, in an interactive way, to get the results. This software makes possible that any Internet user can run the application from his/her own computer without having to compile of use sophisticated procedures as it happens with traditional languages. With this web site it is intended to cover the necessity of having simple and reliable means for architects and civil engineers to support the use of solar energy and the saving of energy in bioclimatic design of buildings. [Spanish] En este trabajo se presenta el desarrollo de un sitio interactivo visible en el World Wide Web (WWW) que pretende servir de apoyo para los calculos basicos de control de asoleamiento en viviendas y edificios. El sitio esta conformado por dos partes principales: una parte cubre el aspecto informativo, donde en forma sencilla y clara, se explican los conceptos y parametros necesarios para disenar los dispositivos de control, alerones y parteluces. La otra parte contiene los procedimientos y las rutinas de calculo para la determinacion de la posicion solar para cualquier fecha del ano desde cualquier punto sobre la tierra, asi como los angulos de sombreado vertical y horizontal. Para la realizacion de los calculos se ha construido un applet de Java, el cual puede ejecutarse desde cualquier plataforma de computacion y

  18. Desarrollo de una interfaz gráfica de usuario en entorno MATLAB para el manejo de software de segmentación de imágenes RMN

    OpenAIRE

    Cancio del Busto, Javier

    2011-01-01

    Cancio Del Busto, J. (2010). Desarrollo de una interfaz gráfica de usuario en entorno MATLAB para el manejo de software de segmentación de imágenes RMN. http://hdl.handle.net/10251/10184. Archivo delegado

  19. Ab initio study of the structural, electronic, elastic and thermal properties of RMn{sub 2}Ge{sub 2} (R = Ca, Nd and Y) intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Miloud Abid, O.; Yakoubi, A. [Laboratoire d’Etudes des Matériaux et Instrumentations Expérimentales, Université Djilali Liabes de Sidi Bel-Abbes, 22000 (Algeria); Tadjer, A. [Modeling and Simulation in Materials Science Laboratory, Physics Department, University of Sidi Bel-Abbes, Sidi Bel-Abbes (Algeria); Khenata, R., E-mail: khenata_rabah@yahoo.fr [Laboratoire de Physique Quantique de la Modélisation Mathématique (LPQ3M), Université de Mascara, 29000 (Algeria); Ahmed, R. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor (Malaysia); Murtaza, G. [Materials Modeling Laboratory, Department of Physics, Islamia College University, Peshawar (Pakistan); Bin Omran, S. [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Azam, Sikander [New Technologies – Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen (Czech Republic)

    2014-12-15

    Highlights: • The calculated structural parameters of RMn{sub 2}Ge{sub 2} (R = Ca, Nd and Y) compounds are found in good agreement with the experimental data. • The structural and band structure calculation reveals that these compounds are ferromagnetic brittle metals. • The elastic and thermodynamic properties for the herein studied compounds are investigated for the first time. - Abstract: Intermetallic RMn{sub 2}Ge{sub 2} ternary compounds have attracted considerable attention from researchers in recent years because they show strong indications for novel magnetic characteristics and they have the potential to reveal the mechanism of superlattices. The study of the paramagnetic, ferromagnetic and antiferromagnetic phases affirms the strong dependence to the distance between atomic species in these compounds. In this study, we investigated the structural, elastic, electronic and thermodynamic properties of the intermetallic RMn{sub 2}Ge{sub 2} (R = Ca, Nd and Y) compounds. To carry out this study, we used the full potential (FP) linearized (L) augmented plane wave plus local orbitals (APW + lo), a scheme of calculations developed within the frame work of density functional theory (DFT). To incorporate the exchange correlation (XC) energy and corresponding potential into the total energy calculations, local density approximation (LDA) parameterized by Perdew and Wang is taken into account. Analysis of the density of states (DOS) profile illustrates the conducting nature of these intermetallic compounds; with a predominantly contribution from the R and Mn-d states. At ambient conditions, calculations for elastic constants (C{sub 11}, C{sub 12}, C{sub 13}, C{sub 44}, C{sub 33} and C{sub 66}) are also performed, which point to their brittle character. In addition, the quasi harmonic Debye model was used to predict the thermal properties, together with relative expansion coefficients and heat capacity.

  20. Control para un equipo de análisis químico por RMN basado en un microprocesador de 32 bits

    OpenAIRE

    Palacio Tárrega, Víctor Manuel

    2009-01-01

    El objetivo del PFC es desarrollar el sistema de control de un equipo de análisis quimico por RMN. Las especificacions del sistema de control implican que este integre los ortos dos componentes del equipo de análisis ( procesado de señal y sistema de raiofrecuencia ) con una interfaz gráfica para el usuario.Se desarrollan dos componentes para el sistema de control, hardware y software, El hardware de control incrustado está basado en un procesador ARM de 32 bits,, y se completado con todos lo...

  1. Evidencias espectroscópicas de RMN de ¹H y 13C en la formación inusual de un "carbonilo inorgánico", derivado de la lactona costunólida

    OpenAIRE

    Díaz, Eduardo; Barrios, Héctor; Fuentes, Aydeé; Corona, David; Guzmán, Ángel

    2002-01-01

    El uso de la RMN de ¹H y 13C permitió determinar la estructura inusual de un "carbonilo inorgánico" derivado de la lactona dehidrocostus. 1H and 13C NMR of an unusual "inorganic carbonyl" derived from costunolide lactone are described.

  2. Double-flat-spiral magnetic structures: Theory and application to the RMn6X6 compounds

    International Nuclear Information System (INIS)

    Rosenfeld, E.V.; Mushnikov, N.V.

    2008-01-01

    We studied magnetic structure of a layered magnetic material, the lattice of which consists of magnetic layers separated by alternating non-magnetic layers (slabs) of two different types. For such structure, the exchange integrals between the nearest magnetic layers separated by different slabs may have different values, while the next-nearest neighbor exchange integral is the same for all magnetic layers. We developed a model based on three different interlayer exchange integrals. In the framework of this model we analyzed conditions of the appearance of a magnetic structure of the double-flat-spiral type and its distortion in external magnetic field. The results are most obtained in the analytical form. The model was applied to analyze the magnetic structure and magnetization process of the RMn 6 X 6 (R=Y, Sc, Lu; X=Sn, Ge) compounds with the layered crystal structure

  3. Estimation of hydraulic conductivity on clay content in soil determined from resistivity data

    Energy Technology Data Exchange (ETDEWEB)

    Shevnin, Vladimir; Delgado-Rodriguez, Omar; Mousatov, Aleksandr [Mexican Petroleum Institute, Mexico, D.F. (Mexico); Ryjov, Albert [Moscow State Geological Prospecting Academy, Geophysical Faculty, Moscow (Russian Federation)

    2006-07-15

    The influence of clay content in sandy and clayey soils on hydraulic conductivity (filtration coefficient) is considered. A review of published experimental data on the relationship of hydraulic conductivity with soil lithology and grain size, as dependent on clay content is presented. Theoretical calculations include clay content. Experimental and calculated data agree, and several approximation formulas for filtration coefficient vs clay content are presented. Clay content in soil is estimated from electric resistivity data obtained from 2D VES interpretation. A two-step method is proposed, the first step including clay content calculating from soil resistivity and groundwater salinity, and the second step including filtration coefficient estimating from clay content. Two applications are presented. [Spanish] El contenido de arcilla en suelos areno-arcillosos influye sobre la permeabilidad hidraulica (coeficiente de filtracion). Se presenta una revision de datos experimentales publicados que relacionan el coeficiente de filtracion con el tipo litologico del suelo y el tamano de las particulas. A partir de calculos teoricos, se modifican las conocidas formulas que relacionan el coeficiente de filtracion con el contenido de arcilla. Se estima el contenido de arcilla a partir de los datos interpretados por el metodo SEV, y se propone un procedimiento para la estimacion del coeficiente de filtracion: (a) calculo del contenido de arcilla a partir de la resistividad del suelo y de la salinidad del agua subterranea, (b) estimacion del coeficiente de filtracion a partir del contenido de arcilla. Se presentan algunos ejemplos de la aplicacion de esta metodologia.

  4. Conceptuaciones de los estudiantes de las facultades de educacion y ciencias naturales de la Universidad de Puerto Rico, recinto de Rio Piedras, acerca de la ciencia y la pseudociencia

    Science.gov (United States)

    Reyes Medina, Hector A.

    Esta investigacion describe las conceptuaciones de los estudiantes de tercer ano o mas a nivel de bachillerato de los programas de Educacion en Ciencia y Ciencias Naturales de la Universidad de Puerto Rico, Recinto de Rio Piedras, acerca de lo establecido en la literatura para distinguir el conocimiento cientifico de las creencias pseudocientificas. Este estudio se guio por un diseno tipo encuesta transversal que permitio conocer de manera consistente las conceptuaciones de los estudiantes encuestados acerca de la Ciencia y la Pseudociencia. Ademas, permitio desarrollar inferencias estadisticas relacionadas a la poblacion de estudio, sus conceptuaciones y su inclinacion teorica en torno al Realismo y al Racionalismo cientifico moderados. El instrumento utilizado fue el Cuestionario acerca de las concepciones de la ciencia y la pseudocienca en estudiantes universitarios, Reyes (2015). Este cuestionario fue validado mediante la recopilacion de diversas fuentes de evidencias, entre estas se encuentran las evidencias basadas en el contenido, el proceso de respuesta, la estructura interna y de constructo. Tambien, se calculo el Alfa de Crombach para la escala total y para cada componente y se realizo un analisis de factores que demostro la presencia de seis componentes claramente definidos de acuerdo a lo esperado sobre las caracteristicas originales del instrumento. Las estadisticas utilizadas fueron descriptivas. Participaron 302 alumnos, de las facultades de educacion y ciencias naturales. Se encontro que las conceptuaciones de los estudiantes de ambas facultades se inclinan en un 66.2% a favor con lo establecido en el modelo teorico en torno al Realismo y al Racionalismo cientifico moderados. Sin embargo, aun hay un 33.8% de los estudiantes de ambas facultades que poseen conceptuaciones distintas al modelo teorico propuesto.

  5. La formación del directivo empresarial como variable estratégica de cambio

    Directory of Open Access Journals (Sweden)

    FRANCISCO PARRA LUNA

    1997-01-01

    Full Text Available desde una perspectiva critica, se pretende señalar que relevantes teorias organizacionales no han sido todavia incorporadas a los curricula basicos de los directivos empresariales, asi como la pervivencia de la tradicional desconexion universidad-empresa. entre los enfoques teoricos que formarian parte de esta "distancia conceptual" se encontrarian el concepto axiologico de empresa (productora, exclusivante, de sistemas de valores ; el calculo de la eficiencia empresarial (o relacion entre los valores producidos y medios empleados ; el concepto de entorno al que debe adaptarse la empresa (analisis de los cambios sociales, economicos, culturales y otros ; la concepcion de la empresa como "sistema suma no cero" (lo que potenciaria o daria lugar a procesos de negociacion sinergicos versus homeostaticos y, por ultimo, el diseño de un concepto de formacion como correlato del plan estrategico de la empresa en respuesta a los desarios del entorno. se apunta finalmente un proceso formativo al nivel global de empresa, que consta de ocho fases, llamado "plan estrategico-participativo de formacion".

  6. Measurement and calculation of dynamic coefficients in hydrodynamic bearings of gas films; Medicion y calculo de coeficientes dinamicos en cojinetes hidrodinamicos de peliculas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Rafael O.; Di Liscia, Marcelo H.; Diaz, Sergio E. [Universidad Simon Bolivar, Sartendejas, Baruta (Venezuela)

    2007-11-15

    dynamic coefficients. [Spanish] La identificacion de los coeficientes dinamicos en cojinetes de aire es fundamental para un adecuado analisis rotodinamico. El presente trabajo muestra el desarrollo de un algoritmo que permite la obtencion directa de los coeficientes dinamicos en cojinetes hidrodinamicos de aire tanto de forma numerica como experimental. El banco de pruebas utilizado consta de dos cojinetes magneticos, los cuales soportan al rotor en sus extremos y a su vez funcionan como actuadores permitiendo inducir orbitas controladas en el rotor. El cojinete de prueba se encuentra ubicado entre los cojinetes magneticos. Las fuerzas dinamicas generadas en el cojinete de aire se registran a partir de tres celdas de carga. El algoritmo fue desarrollado en un codigo comercial de programacion grafica, a traves del cual se pueden colectar, controlar y procesar las senales. El comportamiento no lineal de este tipo de cojinetes dificulta el calculo de los coeficientes dinamicos, por esta razon el procesamiento de las senales en espacio frecuencial facilita de cierta manera su manejo. Por otra parte, el modelo numerico se comparo con los resultados experimentales obteniendo aproximaciones aceptables tanto en magnitud como en comportamiento. El calculo de los coeficientes dinamicos numericos se realizo resolviendo la ecuacion diferencial de Reynolds para un fluido compresible en el espesor de la pelicula de gas, tomando en consideracion el flujo masico del fluido que se introduce, asi como la perdida de presion que sufre el mismo al pasar a traves de los orificios de alimentacion. Los metodos numericos utilizados incluyen la resolucion de la ecuacion diferencial de Reynolds por diferencias finitas, el calculo del perfil de presiones realizando iteraciones sucesivas y el calculo de las fuerzas hidrodinamicas a traves de una integracion numerica de Simpson. Los coeficientes dinamicos numericos fueron hallados aplicando una tecnica de minimos cuadrados a las fuerzas hidrodinamicas

  7. Thickness calculation software of the thermal insulation in facilities using thermal solar energy; Software para el calculo de espesores del aislante termico en instalaciones de aprovechamiento de energia solar termica

    Energy Technology Data Exchange (ETDEWEB)

    Portillo Jimenez, Canek [Universidad Autonoma de Sinaloa, Culiacan, Sinaloa (Mexico)]. E-mail: cnk@uas.uasnet.mx

    2010-11-15

    It is presented a software application for calculating the thickness of the thermal insulation used in various facilities where there are thermal systems using solar energy. The software facilitates the calculation of the thermal cover thickness over components such as pipes (flat or round), storage and other devices that require thermal protection, installed in outdoors or indoors. The software was programmed in Visual Basic by following the technical specifications of the current regulations in the field. Application examples are performed, obtaining certain results that are discussed briefly. [Spanish] Se presenta un software de aplicacion para el calculo de los espesores de los aislantes termicos, utilizados en diferentes instalaciones donde existen sistemas de aprovechamiento termico de energia solar. El software facilita el calculo del grosor del recubrimiento termico en componentes tales como: tuberias (planas o circulares), depositos acumuladores y otros aparatos que necesiten proteccion termica, instalados en exteriores o en interiores. El software fue programado en Visual Basic siguiendo las especificaciones tecnicas de la normatividad vigente en la materia. Se realizan ejemplos de aplicacion, donde se obtienen ciertos resultados de los cuales se hace una breve discusion.

  8. IDENTIFICAÇÃO DE PRODUTOS DA OXIDAÇÃO DE ÓLEOS COMESTÍVEIS ATRAVÉS DA ESPECTROSCOPIA DE RMN DE 1H / IDENTIFICATION OF OXIDATION PRODUCTS IN EDIBLE OIL BY MEANS OF 1H NMR SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    MARINA COLZATO

    2009-11-01

    Full Text Available A espectroscopia por ressonância magnética nuclear de 1H de alta resolução (RMN de 1H é uma ferramenta útil para monitorar os produtos de oxidação em óleos comestíveis. O método é rápido, relativamente simples e preciso, permitindo o acompanhamento e a caracterização da formação de produtos primários de oxidação, como os hidroperóxidos e os dienos conjugados. Neste trabalho, óleos de canola, azeite de oliva e de macadâmia foram objetos de oxidação acelerada por 30 dias e os produtos de oxidação avaliados por RMN de 1H. Os resultados indicaram uma maior estabilidade (resistência ao estresse térmico, para o óleo de oliva > macadâmia > canola, respectivamente.

  9. DETERMINACIÓN RÁPIDA Y PRECISA DEL CONTENIDO DE HIDRÓGENO EN MEZCLAS DE HIDROCARBUROS POR RMN 1H

    Directory of Open Access Journals (Sweden)

    Eliseo Avella

    2011-12-01

    Full Text Available Se presentan y discuten resultados de ladeterminación de hidrógeno en mezclasde hidrocarburos y de fracciones pesadasde petróleo por integración de las señalesen sus espectros RMN 1H de alta resolución.Los resultados muestran la posibilidadde cuantificar de manera rápida yprecisa el hidrógeno en 37 fragmentosestructurales, además del hidrógeno totalen la muestra, mediante aplicación deintervalos de integración unificados. Adiferencia de los métodos publicados enla literatura, la determinación de hidrógenoes posible con menor cantidad demuestra en disolución, con corto tiempode reciclado, d1, sin ajustes estrictos detemperatura ni adición de agente de relajacióno uso de algún estándar de cuantificaciónexterno.

  10. Les écoulements par RMN à gradient pulsé Pulsed Gradient Nmr Techniques for Studying Flows

    Directory of Open Access Journals (Sweden)

    Lebon L.

    2006-12-01

    Full Text Available Nous présentons ici les techniques de RMN à gradient pulsé qui permettent d'étudier les écoulements multiphasiques en canalisation ou en milieu poreux. Les principaux avantages sont de pouvoir travailler sur des milieux non transparents et d'accéder à des échelles de longueurs faibles. On montre qu'il est possible d'obtenir des informations locales sur l'écoulement, telles que le profil de vitesse et ses fluctuations dans les écoulements diphasiques, ou les cartes de distribution des probabilités de déplacement dans des échantillons poreux hétérogènes. Pulsed gradient NMR techniques are presented here. They allow the study of multiphase flow in pipes as well as porous media. The main advantages are the possibilities of studying non transparent media at small length scales. We show that it is possible to obtain local information on the fluid flow, such as velocity profiles in two phase systems, or maps of distribution of displacement probabilities in heterogeneous porous media.

  11. Symmetry, incommensurate magnetism and ferroelectricity: The case of the rare-earth manganites RMnO3

    International Nuclear Information System (INIS)

    Ribeiro, J L

    2010-01-01

    The complete irreducible co-representations of the paramagnetic space group provide a simple and direct path to explore the symmetry restrictions of magnetically driven ferroelectricity. The method consists of a straightforward generalization of the method commonly used in the case of displacive modulated systems and allows us to determine, in a simple manner, the full magnetic symmetry of a given phase originated from a given magnetic order parameter. The potential ferroic and magneto-electric properties of that phase can then be established and the exact Landau free energy expansions can be derived from general symmetry considerations. In this work, this method is applied to the case of the orthorhombic rare-earth manganites RMnO 3 . This example will allow us to stress some specific points, such as the differences between commensurate or incommensurate magnetic phases regarding the ferroic and magnetoelectric properties, the possible stabilization of ferroelectricity by a single irreducible order parameter or the possible onset of a polarization oriented parallel to the magnetic modulation. The specific example of TbMnO 3 will be considered in more detail, in order to characterize the role played by the magneto-electric effect in the mechanism for the polarization rotation induced by an external magnetic field.

  12. Valence and magnetic state of transition-metal and rare-earth ions in single-crystal multiferroics RMn{sub 2}O{sub 5} (R = Y, Bi, Eu, Gd) from X-ray photoelectron spectroscopy data

    Energy Technology Data Exchange (ETDEWEB)

    Kozakov, A.T. [Scientific-Research Institute of Physics at Southern Federal University, 194 Stachki, Rostov-na-Donu 344194 (Russian Federation); Kochur, A.G., E-mail: agk@rgups.ru [Rostov State University of Transport Communication, 2 Narodnogo Opolcheniya, Rostov-na-Donu 344038 (Russian Federation); Nikolsky, A.V.; Googlev, K.A.; Smotrakov, V.G.; Eremkin, V.V. [Scientific-Research Institute of Physics at Southern Federal University, 194 Stachki, Rostov-na-Donu 344194 (Russian Federation)

    2011-11-15

    Highlights: {yields} Single crystals RMn{sub 2}O{sub 5} (R = Y, Bi, Eu, Gd) and YMnO{sub 3} are grown. {yields} Core level XPS are measured and calculated with inclusion of temperature effect. {yields} Mn2p, Mn3s, R4s, and R4d (R = Eu, Gd) XPS are sensitive to valence and spin state. {yields} Paramagnetic moments per structural cell are estimated. - Abstract: Single crystals of orthorhombic multiferroics RMn{sub 2}O{sub 5} (R = Y, Bi, Eu, Gd), and of hexagonal manganite YMnO{sub 3} are grown. X-ray photoelectron spectra of the core levels of the Mn, Y, Bi, Eu, Gd, and O atoms in multiferroics are obtained at room temperature with the ESCALAB 250 microprobe system with monochromatization of the exciting X-ray radiation. X-ray photoelectron spectra of Mn2p, Mn3s, R4s, and R4d (R = Eu, Gd) levels are assigned based on one-configuration isolated-ion approximation calculations with taking the temperature effect into account. It is shown using the photoelectron spectroscopy methods that both Mn{sup 3+} and Mn{sup 4+} ions are present in orthorhombic multiferroics, while Eu and Gd are in trivalent state. Paramagnetic moments per structural unit are calculated and compared with those determined from our spectroscopic data and with the data from other authors.

  13. Power factor correction at the Miguel Hidalgo refinery; Correccion del factor de potencia en la refineria Miguel Hidalgo

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez Gonzalez, Gustavo [Petroleos Mexicanos, Refineria Miguel Hidalgo, Tula de Allende (Mexico)

    1993-12-31

    In this paper the theoretical fundament and formulae of the power factor are analyzed and a relationship among kilowatts, kilovars and power factor, is shown; also it deals with power factor in combination with load groups, as well as the numerical calculation of the required kvar for the desired improvement of the power factor. Additionally the technical and economical aspects of the capacitors and synchronous motors are contemplated, as well as their location in the electric system in order to achieve the maximum benefits. Finally, the savings obtained with the installation of capacitors in the electric power system of the Miguel Hidalgo refinery, are explained. [Espanol] En el presente trabajo se analizan los fundamentos teoricos y formulas del factor de potencia y se muestra la relacion entre kilowatts, kilovars y factor de potencia; tambien trata al factor de potencia combinado de grupos de cargas, asi como el calculo numerico de los KVAR necesarios para la mejora deseada del factor de potencia. Ademas se contemplan aspectos tecnicos y economicos de los capacitores y los motores sincronos, asi como la ubicacion de los mismos en el sistema electrico para lograr los maximos beneficios. Finalmente se explican las ganancias economicas que se obtuvieron al instalarse capacitores en el sistema electrico de potencia de la refineria Miguel Hidalgo.

  14. Power factor correction at the Miguel Hidalgo refinery; Correccion del factor de potencia en la refineria Miguel Hidalgo

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez Gonzalez, Gustavo [Petroleos Mexicanos, Refineria Miguel Hidalgo, Tula de Allende (Mexico)

    1992-12-31

    In this paper the theoretical fundament and formulae of the power factor are analyzed and a relationship among kilowatts, kilovars and power factor, is shown; also it deals with power factor in combination with load groups, as well as the numerical calculation of the required kvar for the desired improvement of the power factor. Additionally the technical and economical aspects of the capacitors and synchronous motors are contemplated, as well as their location in the electric system in order to achieve the maximum benefits. Finally, the savings obtained with the installation of capacitors in the electric power system of the Miguel Hidalgo refinery, are explained. [Espanol] En el presente trabajo se analizan los fundamentos teoricos y formulas del factor de potencia y se muestra la relacion entre kilowatts, kilovars y factor de potencia; tambien trata al factor de potencia combinado de grupos de cargas, asi como el calculo numerico de los KVAR necesarios para la mejora deseada del factor de potencia. Ademas se contemplan aspectos tecnicos y economicos de los capacitores y los motores sincronos, asi como la ubicacion de los mismos en el sistema electrico para lograr los maximos beneficios. Finalmente se explican las ganancias economicas que se obtuvieron al instalarse capacitores en el sistema electrico de potencia de la refineria Miguel Hidalgo.

  15. Cannabinoid antagonist in nanostructured lipid carriers (NLCs): design, characterization and in vivo study

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, Elisabetta; Ravani, Laura [Department of Life Sciences and Biotechnology, University of Ferrara, I-44121 Ferrara (Italy); Drechsler, Markus [BIMF/Soft Matter Electron Microscopy, University of Bayreuth (Germany); Mariani, Paolo [Department of Life and Environmental Sciences and CNISM, Università Politecnica delle Marche, I-60100 Ancona (Italy); Contado, Catia [Department of Chemical and Pharmaceutical Sciences, University of Ferrara, I-44121 Ferrara (Italy); Ruokolainen, Janne [Department of Applied Physics, Aalto University, 00076 Aalto (Finland); Ratano, Patrizia; Campolongo, Patrizia [Department of Physiology and Pharmacology, Sapienza University of Rome, 00185 Roma (Italy); Trezza, Viviana [Department of Science, Roma Tre University, 00146 Roma (Italy); Nastruzzi, Claudio, E-mail: nas@unife.it [Department of Life Sciences and Biotechnology, University of Ferrara, I-44121 Ferrara (Italy); Cortesi, Rita [Department of Life Sciences and Biotechnology, University of Ferrara, I-44121 Ferrara (Italy)

    2015-03-01

    This study describes the preparation, characterization, and in vivo evaluation in rats of nanostructured lipid carriers (NLCs) encapsulating rimonabant (RMN) as prototypical cannabinoid antagonist. A study was conducted in order to optimize NLC production by melt and ultrasonication method. NLCs were prepared by alternatively adding the lipid phase into the aqueous one (direct protocol) or the aqueous phase into the lipid one (reverse protocol). RMN-NLCs have been characterized by cryogenic transmission electron microscopy (cryo-TEM), X-ray, photon correlation spectroscopy (PCS) and sedimentation field flow fractionation (SdFFF). Reverse NLCs were treated with polysorbate 80. RMN release kinetics have been determined in vitro by dialysis method. In vivo RMN biodistribution in rats was evaluated after intranasal (i.n.) administration of reverse RMN-NLC. The reverse protocol enabled to prevent the lost of lipid phase and to achieve higher RMN encapsulation efficacy (EE) with respect to the direct protocol (98% w/w versus 67% w/w). The use of different protocols did not affect NLC morphology and dimensional distribution. An in vitro dissolutive release rate of RMN was calculated. The in vivo data indicate that i.n. administration of RMN by reverse NLC treated with polysorbate 80 increased RMN concentration in the brain with respect to the drug in solution. The nanoencapsulation protocol presented here appears as an optimal strategy to improve the low solubility of cannabinoid compounds in an aqueous system suitable for in vivo administration. - Highlights: • Rimonabant (RMN) can be encapsulated in nanostructured lipid carriers (NLCs). • Nanoencapsulation improves RMN solubility in a stable physiologic aqueous formulation. • RMN is released in vitro from NLC by a controlled dissolutive release modality. • I.n. administration leads to higher RMN concentration in the brain with respect to plasma. • NLC increases RMN concentration in the brain with respect to

  16. Caracterização de nanocompósitos de poliuretano/montmorilonita organofílica por RMN de baixo campo Characterization of polyurethane/organophilic montmorilonite nanocomposites by low field NMR

    Directory of Open Access Journals (Sweden)

    Marcos Anacleto da Silva

    2012-01-01

    Full Text Available Poliuretanos são materiais poliméricos importantes e versáteis, principalmente devido a algumas de suas propriedades, como alta resistência à abrasão, resistência ao rasgo, excelente absorção de choques mecânicos, boa flexibilidade e elasticidade. No entanto, existem também algumas desvantagens, como a baixa estabilidade térmica e propriedade de barreira. Para superar essas desvantagens, têm sido produzidos nanocompósitos de poliuretano/montmorilonita organofílica. A investigação da estrutura dos nanocompósitos de poliuretano/argila tem sido realizada principalmente por difração de raios X (DRX e microscopia eletrônica de transmissão (TEM. Neste trabalho, foram estudados filmes de nanocompósitos de PU/argila organofílica obtidos por intercalação por solução. Os nanocompósitos foram caracterizados por DRX e, principalmente, por ressonância magnética nuclear de baixo campo (RMN-BC. As medidas de RMN-BC, com a determinação do tempo de relaxação spin-rede do núcleo de hidrogênio, forneceram informações ímpares e importantes sobre a dinâmica molecular desses nanocompósitos. Para validar esse estudo foram realizadas análises de difração de raios X, que confirmaram os resultados de RMN. A estabilidade térmica dos materiais também foi determinada por análise termogravimétrica em atmosfera de gás inerte, observando-se pequena melhora na estabilidade do nanocompósito quando comparado com o poliuretano.Polyurethanes are important and versatile materials, mainly due to some of their properties, such as high resistance to abrasion and tearing, excellent absorption of mechanical shocks and good flexibility and elasticity. However, they have some drawbacks as well, such as low thermal stability and barrier properties. To overcome these disadvantages, various studies have been conducted involving organophilic polyurethane/montmorillonite nanocomposites. The investigation of the structure of polyurethane

  17. Theoretical Aspects of Phonon Dispersion Curves for Metals; Aspects Theoriques des Courbes de Dispersion des Phonons pour les Metaux; Teoreticheskie aspekty fononnykh dispersionnykh krivykh dlya metallov; Aspectos Teoricos de las Curvas de Dispersion Fononica en Metales

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, W. [Department of Natural Philosophy, University of Edinburgh, Scotland (United Kingdom)

    1965-04-15

    , manifiestan la presencia de fuerzas de alcance relativamente grande, que se extienden a varios espacios interatomicos. Los resultados relativos al plomo son particularmente interesantes; no fue posible ajustarlos a un modelo de constantes de fuerza, pero las curvas de dispersion de los vectores de onda en las direcciones de simetria, analizadas en funcion de las constantes de fuerza entre planos atomicos, revelan la existencia de un potencial interatomico de caracter oscilatorio que se extiende a distancias superiores a 20A. La memoria trata de trabajos teoricos recientes, relacionados con el calculo de las curvas de dispersion fononica en metales y con la explicacion del largo alcance del potencial interatomico. En la actualidad, el metodo mas prometedor para abordar con criterio general la interaccion atomica en los metales parece ser el de los 'pseudoatomos neutros ', denominacion recientemente acunada por Ziman. Se exponen los principios de esta teoria de Aproximacion y se examina su relacion con las anomalias de Kohn en las curvas de dispersion fononica. En el caso del sodio, los valores experimentales concuerdan con los datos teoricos, y el potencial interatomico varia periodicamente en la distancia {pi}/k{sub F}, donde hk{sub F} es el momento de Fermi, como ha demostrado Koenig por un procedimiento diferente. Toya y Sham han realizado calculos mas exactos para el sodio; se examinan las relaciones existentes entre los diferentes metodos y otros trabajos de indole mas general, tales como los de Harrison. (author) [Russian] V nastojashhee vremja v rezul'tate jeksperimentov po neuprugomu rassejaniju nejtronov dovol'no polno izucheny fononnye dispersionnye krivye po krajnej mere dlja djuzhiny metallicheskih jelementov i intermetallicheskih soedinenij. Rezul'taty imejut odnu obshhuju oso- oennost': analiz ih s tochki zrenija konstant mezhatomnyh sil pokazyvaet nalichie dovol'no dal'nodejstvujushhih sil, prostirajushhihsja na neskol'ko mezhatomnyh rasstojanij. Osobyj interes

  18. Calculation of uncertainties; Calculo de incertidumbres

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Asencio, Misael [Centro de Estudios Ambientales de Cienfuegos (Cuba)

    2012-07-01

    metodologico para la obtencion de informacion (mesurando) de un sistema material (poblacion). Ello supone la necesidad de la definicion del problema, la eleccion de los metodos de muestreo y medicion adecuados y la ejecucion de estas actividades para la obtencion de la informacion. El resultado de una medicion solo es una aproximacion o estimacion del valor del mesurando, el cual se completa solo cuando va acompanado por una estimacion de la incertidumbre del proceso analitico. Segun el 'Vocabulario de Terminos Basicos y Generales de Metrologia' la incertidumbre de medicion 'es el parametro asociado con el resultado de la medicion que caracteriza la dispersion de los valores que razonablemente pudiera ser atribuida al mensurando (o magnitud). Este parametro podria ser una desviacion estandar o un intervalo de confianza'. La evaluacion de la incertidumbre exige que observemos detalladamente todas sus posibles fuentes, pero no de forma desproporcionada. Podemos realizar una buena estimacion de la incertidumbre concentrando el esfuerzo en las mayores contribuciones. Los pasos fundamentales del proceso de determinacion de la incertidumbre en las mediciones son: - la especificacion del mesurando; - la identificacion de las fuentes de incertidumbre; - la cuantificacion de las componentes individuales de la incertidumbre; - el calculo de la incertidumbre estandar combinada; - informe de la incertidumbre.

  19. Competing exchange interactions and their relevance for the magnetisation process in RMn6-xCrxSn6 powders (R=Y, Gd, Tb, Dy, Ho, Er)

    International Nuclear Information System (INIS)

    Brabers, J.H.V.J.; Zhou, G.F.; Colpa, J.H.P.; Buschow, K.H.J.; De Boer, F.R.

    1994-01-01

    The free-powder magnetisation of RMn 6-x Cr x Sn 6 compounds has been measured for compounds with R=Y, Gd, Tb, Dy, Ho, Er in fields up to 38 T, and interpreted in terms of a simple model, which is also outlined in this paper. From the measurements, estimates for the R-3d mean-field coupling constant (n RT ) could be derived for the cases where R=Gd, Tb, Dy, Ho, Er. In turn, the n RT values can be related to the microscopic spin-coupling constant (J RT ). In the case of YMn 6 Sn 6 the high-field measurement presents evidence for a very weak antiferromagnetic coupling between the Mn layers. Furthermore, values for the Mn moments (μ Mn ) were also derived from the magnetisation measurements. The estimated μ Mn values are of the order of 2.0 μ B . ((orig.))

  20. A review of calculation methods for fast and intermediate reactors; Expose des methodes pour le calcul de reacteurs a neutrons rapides et intermediaires; Obzor metodov rascheta reaktorov na promezhutochnykh i bystrykh nejtronakh; Estudio panoramico de los metodos de calculo de los reactores rapidos e intermedios

    Energy Technology Data Exchange (ETDEWEB)

    Marchuk, G I [Akademiya Nauk, Moskva, Union of Soviet Socialist Republics (Russian Federation)

    1962-03-15

    This paper discusses the development of methods for calculating intermediate and fast reactors. It deals with various approaches to the problems of physical calculation. The calculation of resonance effects is discussed. Consideration is given to multi-group systems of fundamental and conjugate equations, various applications of perturbation theory to the problems of physical reactor calculation, and numerical methods of solving fundamental and conjugate reactor equations, which approximate the method of spherical harmonics. The paper describes an application of the response method to the solution of critical-mass problems, and methods of calculating reactors with hydrogeneous moderators. The fundamental features of an effective one-group reactor model are described. (author) [French] L'auteur examine la mise au point de methodes pour le calcul de reacteurs a neutrons rapides et intermediaires . Il decrit diverses manieres d'aborder les problemes des calculs sur la physique des reacteurs, notamment le calcul des effets de resonance. Il s'attache particulierement aux points suivants: systemes d'equations fondamentales et conjuguees a plusieurs groupes; diverses applications de la theorie des perturbations aux problemes de calculs sur la physique des reacteurs; methodes numeriques pour resoudre les equations fondamentales et conjuguees, voisines de la methode des harmoniques spheriques. L'auteur decrit ensuite une maniere d'appliquer la methode de la reponse aux problemes de la masse critique ainsi que des methodes pour le calcul de reacteurs ralentis a l'hydrogene. Il decrit les caracteristique s fondamentale s d'un modele de reacteur a un groupe effectif. (author) [Spanish] El autor analiza el desarrollo de los metodos de calculo de los reactores nucleares que trabajan con neutrones rapidos y con neutrones intermedios. Examina diversos planteos de los problemas del calculo fisico. Indica la forma de tomar en cuenta los efectos de resonancia y menciona los sistemas

  1. Aplicación de Resonancia Magnética Nuclear para la caracterización de fracciones pesadas del petróleo en el proceso de desasfaltado por extracción (DEMEX)

    OpenAIRE

    Avella Moreno, Eliseo

    2011-01-01

    En la literatura, se encontró una gran variedad de criterios para la preparación de muestras y para la adquisición y el procesamiento de los espectros de resonancia magnética nuclear de hidrógeno-1 (RMN 1H) o de carbono-13 (RMN 13C) de petróleos, carbones y sus fracciones. Se definieron 33 nuevos intervalos de integración en los espectros de RMN 1H y 47, en los espectros de RMN 13C. Se unificaron sus límites inferior y superior mediante un tratamiento estadístico realizado con ...

  2. Theoretical model to determine the energy behavior of test modules at scale of constructions for the efficient use of energy; Modelo teorico para determinar el comportamiento energetico de modulos de prueba a escala de edificaciones para el uso eficiente de la energia

    Energy Technology Data Exchange (ETDEWEB)

    Acoltzi, Higinio; Alvarez, Gabriela [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    In this work a theoretical model of the energy behavior of test modules and its experimental verification is presented. The model determines the history of electrical energy consumption to maintain the comfort conditions in the interior of the modules, with respect to the variation of the materials of ceilings and windows with the purpose of establishing criteria of application of these materials in the construction industry. The measured results of the consumption of the accumulated energy are presented. [Spanish] En este trabajo se presenta un modelo teorico del comportamiento energetico de modulos de prueba y su verificacion experimental. El modelo determina la historia del consumo de energia electrica para mantener las condiciones de confort al interior de los modulos, respecto a la variacion de los materiales de los techos y ventanas, con el objeto de establecer criterios de aplicacion de dichos materiales en la industria de la edificacion. Se presentan los resultados medidos del consumo de energia acumulada.

  3. 19th International Seapower Symposium

    Science.gov (United States)

    2010-07-01

    mentioning about the newly feder- ated T-RMN. RMN stands for Royal Malaysian Navy, that’s where I come from; but actually in this regard, T-RMN stands for...customs offices, with the taxation departments, with organizations that do the ac- tual invoicing, and with the maritime authorities, which in the case...collaborations have also been proposed. Chief of the Royal Malaysian Navy Admiral Abdul Aziz, for example, has mooted the idea of the Maritime

  4. Initiation au Lambda-Calcul (An Initiation into Lambda Calculus)

    Science.gov (United States)

    1989-07-15

    6tmnt donn6 M, V et D, calculo N et W: let rec: trace (M,V) = function D1 - (MYV) f u::D -*let N = rduit M uand W = Rsidus M u V itace(NW)D;; Example...calculer lapproximation do c, par I’ex~cution do, f10). La proc6dure approx ci-dessous calculo I’approximation d’un ).-torme par r6duction normale...rente avec ce r6gime d𔄀valuation. Par contre, la rbgle 4 nWest pas utilis", c’est A dire qu’on ne, calculo pas A I’int6rieur des abstractions. Los tormes

  5. Structure par RMN d'un complexe AlcR(1-60)-ADN: Reconnaissance du petit sillon par la partie N-terminale

    Science.gov (United States)

    Cahuzac, B.; Félenbok, B.; Guittet, E.

    1999-10-01

    Aspergillus nidulans is a filamentous fungus able to use ethanol as sole energy source. The activation of the ethanol regulon genes expression is mediated by the AlcR protein. Its DNA-binding domain is located in the N-terminus (residues 1 to 60), and its NMR solution structure shows a global zinc binuclear cluster fold, with two helices in addition to the basic binuclear motif. A small number of crystallographic structures of DNA complexes of binuclear cluster proteins is yet known, and points out the major groove and the first helix as the principal sites of interaction on the DNA and the protein respectively. In this article we show evidences that the N-terminus of the protein is involved in binding to the minor groove. Aspergillus nidulans est un champignon filamenteux capable d'utiliser l'éthanol comme source unique d'énergie. La protéine AlcR est responsable de l'activation de l'expression des gènes du régulon éthanol. Le domaine de liaison à l'ADN est situé dans la partie N-terminale de la protéine (a.a. 1 à 60), et sa structure déterminée par RMN en solution montre un repliement global en bouquet binucléaire à zinc, avec deux hélices supplémentaires par rapport au motif de base. Alors que les structures déjà connues de complexes ADN - bouquets binucléaires permettent de situer dans le grand sillon la quasi-totalité des interactions, nous montrons dans la présente étude l'implication du début de la séquence dans la reconnaissance du petit sillon de l'ADN (a.a. 5 et 6).

  6. Multicenter, randomized comparison between magnetically navigated and manually guided radiofrequency ablation of atrioventricular nodal reentrant tachycardia (the MagMa-AVNRT-trial).

    Science.gov (United States)

    Reents, Tilko; Jilek, Clemens; Schuster, Peter; Nölker, Georg; Koch-Büttner, Katharina; Ammar-Busch, Sonia; Semmler, Verena; Bourier, Felix; Kottmaier, Marc; Kornmayer, Marie; Brooks, Stephanie; Fichtner, Stephanie; Kolb, Christof; Deisenhofer, Isabel; Hessling, Gabriele

    2017-12-01

    Remote magnetic navigation (RMN) is attributed to diminish radiation exposure for both patient and operator performing catheter ablation for different arrhythmia substrates. The purpose of this prospective, randomized study was to compare RMN with manually guided catheter ablation for AV nodal reentrant tachycardia (AVNRT) regarding fluoroscopy time/dosage, acute and long-term efficacy as well as safety. A total of 218 patients with AVNRT undergoing catheter ablation at three centers (male 34%, mean age 50 ± 17 years) were randomized to a manual approach (n = 113) or RMN (n = 105) using the Niobe ® magnetic navigation system. The primary study endpoint was total fluoroscopy time/dosage for patient and operator at the end of the procedure. Secondary endpoints included acute success, procedure duration, complications and success rate after 6 months. Fluoroscopy time and dosage for the patient were significantly reduced in the RMN group compared to the manual group (6 ± 6 vs. 11 ± 10 min; p < 0.001 and 425 ± 558 vs. 751 ± 900 cGycm 2 , p = 0.002). A reduction in fluoroscopy time/dose also applied to the operator (3 ± 5 vs. 7 ± 9 min 209 ± 444 vs. 482 ± 689 cGycm 2 , p < 0.001). Procedure duration was significantly longer in the RMN group (88 ± 29 vs. 79 ± 29 min; p = 0.03) and crossover from the RMN group to manual ablation occurred in 7.6% of patients (7.6 vs. 0.1%; p = 0.02). Acute success was achieved in 100% of patients in both groups. Midterm success after 6 months was 97 vs. 98% (p = 0.67). No complications occurred in both groups. The use of RMN for catheter ablation of AVNRT compared to a manual approach results in a reduction of fluoroscopy time and dosage of about 50% for both patients and physicians. Acute and midterm success and safety are comparable. RMN is a good alternative to a manual approach for AVNRT ablation.

  7. The Norm NOM-008-ENER-2001 offers an important saving option; La Norma NOM-008-ENER-2001 ofrece una importante opcion de ahorro

    Energy Technology Data Exchange (ETDEWEB)

    Lalana, Emiliano Ramiro [Fideicomiso para el Ahorro de la Energia Electrica (Mexico)

    2006-01-15

    The Norm NOM-008-ENER-2001 no longer commands the efficient handling of energy from functional equipment or apparatuses but from a well planned architectural design that allows diminishing the energy use for cooling purposes, consequently this Norm refers to the conduction and radiation principles regulating the heat gain through the cover portions of a building. The Norm defines a reference theoretical building that will dictate the propitious heat gain for the projected buildings. Here the functioning logic of the Norm in respect to both principles is mathematically explained as well as an application example is developed considering the calculations made for the Norm's reference building and for the projected one, the final revision of the fulfillment of the norm, proposals of solutions and the conclusions. [Spanish] La Norma NOM-008-ENER-2001 comanda el manejo eficiente de energia electrica ya no a partir de equipos o aparatos funcionales sino a partir de un bien planeado diseno arquitectonico que permita disminuir el uso de energia para fines de enfriamiento. Por ende, esta norma se refiere a los principios de conduccion y radiacion regulando la ganancia de calor a traves de la envolvente y porciones de un edificio. La Norma define un edificio teorico de referencia que dictara la ganancia de calor propicia para los edificios proyectados. Aqui se explica matematicamente la logica de funcionamiento de la Norma respecto a ambos principios asi como se desarrolla un ejemplo de aplicacion que considera los calculos realizados para el edificio de referencia de la Norma y para el proyectado, la revision final del cumplimiento de la Norma, propuestas de solucion y conclusiones.

  8. Thermal efficiency of Duovent array glassing; Eficiencia termica de arreglos de vidrios Duovent

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez Garcia G; Cortina Leyva, C; Flores Prieto, Jose J [Centro Nacional de Investigacion y Tecnologico, DGIT SEP, Cuernavaca, Morelos (Mexico)

    2000-07-01

    This paper presents an experimental study of the thermal performance of duovent glazing with different solar control coatings. The thermal efficiency, {eta}, was determined. The duovent array consists of 6 mm glass+solar coating+air layer+6 mm glass. The width of the air layer between the two glasses is 12 mm. The experimental work was carried out using a calorimeter setup calling DEMETEV. The DEMETEV was specially designed to measure the heat gains through sample glassings. The heat flux, the shading coefficients and the thermal efficiency curve as a function of the temperature difference and incident radiative flux are presented. Comparing the results for duovent with clear glasses with the ones reported by Dubrous show a difference of 2.2%. Also this study verifies the theoretical model reported. [Spanish] En este trabajo se presenta un estudio experimental del comportamiento termico de vidrios Duovent con diferentes filtros solares mediante el calculo de la eficiencia termica, {eta}. El arreglo lo comprende vidrio+filtro+aire+vidrio de 6 mm de espesor con un espacio con aire entre vidrios de 12 mm. El trabajo experimental se llevo a cabo haciendo uso del dispositivo calorimetrico experimental, denominado DEMETEV, que fue disenado especialmente para medir las ganancias de calor a traves de vidrios. Se presentan los flujos de calor, los coeficientes de sombreado y la curva de eficiencia termica como funcion de la diferencia de temperaturas y del flujo radioactivo incidente. Los resultados obtenidos para vidrios claros fueron comparados con los que se obtuvieron en el trabajo reportado por Dubrous obteniendo una diferencia del 2.2%. Tambien se presenta la validacion de los datos experimentales con un modelo teorico reportado.

  9. Efficacy and Safety of Atrial Fibrillation Ablation Using Remote Magnetic Navigation

    DEFF Research Database (Denmark)

    Jin, Q I; Pehrson, Steen; Jacobsen, Peter Karl

    2016-01-01

    .0 minutes, PerAF, P = 0.17). The overall complication rate was 0.6%. One PAF patient experienced cardiac tamponade. AF repeat ablations by RMN significantly reduced the procedural and ablation times when compared with their first ablation times. CONCLUSIONS: AF ablation guided by RMN is safe as evidenced...

  10. Impact of catheter ablation with remote magnetic navigation on procedural outcomes in patients with persistent and long-standing persistent atrial fibrillation

    DEFF Research Database (Denmark)

    Jin, Qi; Pehrson, Steen; Jacobsen, Peter Karl

    2015-01-01

    with RMN. METHODS: A total of 313 patients (275 male, age 59 ± 9.5 years) with PsAF (187/313) or L-PsAF (126/313) undergoing ablation using RMN were included. Patients' disease history, pulmonary venous anatomy, left atrial (LA) volume, procedure time, mapping plus ablation time, radiofrequency (RF...

  11. I concetti di "materia", "forma" e "ordine" nel pensiero teorico musicale medievale e contemporaneo

    Directory of Open Access Journals (Sweden)

    Cecilia Panti

    2011-01-01

    Full Text Available La dimensione teorica della musica occidentale, nella sua evoluzione storica, ha inevitabilmente fatto uso di concetti essenziali alla definizione di come il suono è musicalmente organizzato o organizzabile. Fra questi, risultano imprescindibili le nozioni di materia, forma e ordine, che implicano rispettivamente, nei pur diversi ambiti linguistici e contesti storico-filosofici di riferimento, ciò di cui è fatta la musica, ciò a cui la materia sonora tende, e come tale tensione è realizzata. Scopo di questo contributo è una valutazione d’insieme sulla valenza filosofica e l’uso di tali concetti nel pensiero musicale occidentale altomedievale e in quello del Novecento, che nonostante la distanza cronologica presentano convergenze significative. Nel Medioevo, un lungo processo di elaborazione teorico-pratica permise la matematizzazione dello spazio (e, più tardi, anche del tempo musicale, attraverso l’adattamento di moduli melodici, trasmessi oralmente, alle strutture scalari desunte dalla teoria greco-boeziana. La forma e l’ordo musicali furono quindi riferiti ai criteri fisico-matematici atti a distinguere nella materia sonora, in sé disorganica e indefinita, ciò che è musicale da ciò che non lo è. Tale concezione sparisce con l’affermarsi del sistema tonale, ove il suono fisico è concepito come “pre-formato” e “pre-ordinato” nella gamma scalare e nei vincoli attrattivi “naturali” degli armonici. In conseguenza, i concetti di forma e ordine abbandonano il contesto acustico, andando a definire i criteri teorici della composizione artistica, in linea con l’idea filosofica del loro esprimere la coerenza logico-sintattica dell’“insieme organico” (la Formenlehre teorizzata da Widmann. Nell’ambito del pensiero musicale del Novecento, la crisi del sistema tonale e la messa a punto di nuove modalità e tecniche di produzione del suono hanno riorientato la valenza significante e l’uso di questi tre concetti

  12. Fósforo num Cambissolo cultivado com cana-de-açúcar por longo tempo: II - análise de ácidos húmicos por RMN 31P Phosphorus in an Inceptsoil under long-term sugarcane: II - humic acid analysis by NMR 31P

    Directory of Open Access Journals (Sweden)

    Jader Galba Busato

    2005-12-01

    Full Text Available Sistemas de manejo da lavoura de cana-de-açúcar que favoreçam a matéria orgânica do solo podem aumentar o conteúdo de nutrientes disponíveis e diminuir a necessidade de aplicação de fertilizantes industriais. Apesar da importância dos componentes orgânicos no fornecimento de P, pouco se conhece sobre a sua dinâmica em ambientes tropicais. O objetivo deste trabalho foi identificar, por meio da ressonância magnética nuclear (RMN 31P, as espécies de P nos ácidos húmicos de um Cambissolo Háplico Ta eutrófico vértico, localizado no Município de Campos dos Goytacazes, norte do Estado do Rio de Janeiro, e cultivado com cana-de-açúcar com preservação do palhiço e adição de vinhaça por longo tempo. Por meio da análise de RMN 31P foi possível observar acúmulo de P orgânico em formas mais facilmente mineralizadas nas áreas com preservação de matéria orgânica, tal como P em ligações diésteres. Nas áreas de cana queimada, houve maior participação de espécies orgânicas mais estáveis, como o ortofosfato em ligações monoésteres. Os resultados da espectroscopia de RMN 31P mostram que, nas áreas com maior aporte de resíduo orgânico (i.e., cana crua e cana queimada com adição de vinhaça, os ácidos húmicos constituem uma reserva importante de P orgânico prontamente disponível. Já, nas áreas de cana queimada, o acúmulo de P orgânico recalcitrante nos ácidos húmicos indica utilização do P-lábil das substâncias húmicas como fonte importante para nutrição das plantas.Crop management systems that favor soil organic matter can improve the available nutrient content for plants and reduce the use of industrial fertilizer. Despite the importance of organic compounds as a P source, little is known about its dynamics in tropical environments. The objective of this study was to identify organic P species present in humic acids by NMR 31P analysis in a fine clay Fluventic Eutrochrepts in Campos dos

  13. Radiation monitoring network of the Czech Republic

    International Nuclear Information System (INIS)

    Kuca, P.; Novak, L.; Rulik, P.; Tecl, J.

    2003-01-01

    The Radiation Monitoring Network (RMN) of the Czech Republic was established after the Chernobyl accident in 1986 and it is developed all the time. It is co-ordinated by the State Office for Nuclear Safety in co-operation with the National Radiation Protection Institute. Czech RMN consists of the several sub-networks, which include selected or all permanent parts of RMN. The sub-networks are following: the Early Warning Network (EWN), the TLD Territorial Network, the Network of the Measuring Sites of Air Contamination, the Network of Laboratories Equipped with Gamma-spectrometric and Radiochemical Analytical Instrumentation, the Ground and Airborne Mobile Groups. The Laboratory of Monitoring of Internal Contamination and the information system (IS) are a significant part of RMN, too. The data of RMN resulting from monitoring are transferred to the central database of CRMN, processed by the information system (IS). They are used in normal and emergency situations for an evaluation of radiation situation and for preparation of recommendations for protection of the public and the environment. In 2002 any extraordinary radioactivity in the environment was not detected and also none of the measuring points recorded any exceeding of established investigation levels. In components of environment and also in human beings a very low activity of 137 Cs was still measurable, that had been released into environment after the Chernobyl accident and by the nuclear weapon tests in sixties of the last century. (authors)

  14. Radiation monitoring network of the Czech Republic

    International Nuclear Information System (INIS)

    Drabova, D.; Prouza, Z.; Malatova, I.; Bucina, I.

    1996-01-01

    Radiation Monitoring Network of the Czech Republic (RMN) was established after the Chernobyl accident. It consists of technical centers, laboratories and monitoring groups of State Office for Nuclear Safety, National Radiation Protection Institute, nuclear power plants, hydrometeorological service, army and Civil Defense, research institutes and other institutions. The structure of RMN, its basic components and responsible institutions are described. (author)

  15. Ramsey numbers and adiabatic quantum computing.

    Science.gov (United States)

    Gaitan, Frank; Clark, Lane

    2012-01-06

    The graph-theoretic Ramsey numbers are notoriously difficult to calculate. In fact, for the two-color Ramsey numbers R(m,n) with m, n≥3, only nine are currently known. We present a quantum algorithm for the computation of the Ramsey numbers R(m,n). We show how the computation of R(m,n) can be mapped to a combinatorial optimization problem whose solution can be found using adiabatic quantum evolution. We numerically simulate this adiabatic quantum algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(2,s) for 5≤s≤7. We then discuss the algorithm's experimental implementation, and close by showing that Ramsey number computation belongs to the quantum complexity class quantum Merlin Arthur.

  16. Excange interactions and induced Eu3+ magnetic order in RMnO3 investigated using resonant X-ray diffraction

    International Nuclear Information System (INIS)

    Skaugen, Arvid

    2015-03-01

    The so-called multiferroics, materials that concomitantly exhibit more than one ferroic order, have in recent years attracted much attention owing to their possible applications in high density data storage, high sensitivity ac magnetic field sensors and novel spintronic devices. In particular, multiferroics with strong magnetoelectric coupling are more attractive. Among such multiferroics, an interesting special class is the orthorhombic manganites with perovskite structure. In these compounds, frustration serves to destabilize ordinary ferromagnetic or antiferromagnetic ordering, giving rise to rich phase diagrams due to several competing magnetic interactions. Interactions between strong rare earth magnetic moments and weaker transition metal moments add another level of complexity, as well as interest. The current dissertation presents results obtained investigating the magnetic structure responsible for ferroelectricity in a few selected multiferroic compounds, using x-ray resonant magnetic scattering (XRMS). In particular, single crystals of Eu 1-x Y x MnO 3 have been studied at low temperatures and in high magnetic fields. This series of compounds is similar in structure to the heavily studied RMnO 3 (R=Tb,Gd,Dy), only without rare earth magnetism. The novel technique of full polarization analysis has been used to determine the complicated cycloidal Mn magnetic ordering, and additional components due to the Dzyaloshinskii-Moriya interactions have been identified. In the compound Eu 0.8 Y 0.2 MnO 3 , two coexisting multiferroic phases were observed, and a magnetoelectric coupling between the two was established. Moreover, magnetic order of the formally non-magnetic rare earth ion Eu 3+ was observed in the same compound. It has been concluded to result from a Van Vleck type excitation of the J = 0 ground state due to the symmetry-breaking internal exchange field from the Mn magnetic moments. In addition, this dissertation reports on high field investigations

  17. Seguridad del paciente en Radioterapia Intraoperatoria: Impacto de los elementos controlados por el Radiofisico

    Science.gov (United States)

    Tarjuelo, Juan Lopez

    tambien se uso para estudiar la estabilidad de las camaras de ionizacion mencionadas. Se realizo la dosimetria in vivo en 45 pacientes con MOSFET reforzados mobile TN-502RDM-H, pelicula radiocromica Gafchromic MD-55-2, y se elaboro un modelo teorico para explicar los datos. Por ultimo, al precisarse el uso en RIO de la simulacion virtual y del calculo de la dosis absorbida en el paciente virtual, se ha ilustrado este apartado con la aceptacion y el estado de referencia inicial del planificador de tratamientos modulados con calculo de Monte Carlo Elekta Monaco. Para ello se utilizaron la camara de ionizacion TW31016-0104 y la matriz seven29 de PTW-Freiburg, pelicula radiocromica Gafchromic EBT-2, y diferentes maniquies. Resultados: El FMEA identifico 57 modos de fallo y efectos potenciales. No se experimentaron sucesos relativos a una administracion inadecuada de la dosis absorbida. Se identificaron las revisiones dobles y por un par como claves para reducir los riesgos asociados al equipo de profesionales involucrado en la RIO. Se identificaron tambien oportunidades de mejora con el uso de la automatizacion y el enclavamiento. En cuanto al SPC, los indices de capacidad del proceso abarcaron de 1,6 a 9,3 para un nivel de especificaciones del +/-2%. Las intervenciones simuladas alcanzaron del 2% al 34% de las sesiones de medida. Las camaras de ionizacion Farmer derivaron en direcciones opuestas en un periodo de 6 anos; aunque ello no se aprecio en los informes de calibracion del laboratorio acreditado. No derivo la camara PPC-40. En la dosimetria in vivo, las medidas de los MOSFET no se desviaron significativamente de las medidas con pelicula. Los valores centrales de las dosis absorbidas quedaron entre la dosis absorbida prescrita y la maxima, con lo que indicaron un tratamiento correcto del lecho tumoral. Las anchuras de los intervalos de confianza de las dosis absorbidas esperadas segun el modelo teorico al nivel del 95% abarcaron del 8,6% al 14,7%. Las verificaciones de

  18. Transfer of extensor digiti minimi and extensor carpi ulnaris nerve branches to the intrinsic motor nerve branches: A histological study on cadaver.

    Science.gov (United States)

    Namazi, H; Haji Vandi, S

    2017-06-01

    In cases of high ulnar and median nerve palsy, result of nerve repair in term of intrinsic muscle recovery is unsatisfactory. Distal nerve transfer can alleviate the regeneration time and improve the results. Transfer of the extensor digiti minimi (EDM) and extensor carpi ulnaris (ECU) nerve branches to the deep branch of ulnar nerve (DBUN)/recurrent branch of median nerve (RMN) at wrist had been used to restore intrinsic hand function but, incomplete recovery occurred. The axon count at the donor nerve has a strong influence on the final results. This cadaveric study aims to analyses the histology of this nerve transfer to evaluate whether these donor nerves are suitable for this transfer or another donor nerve may be considered. Ten cadaveric upper limbs dissected to identify the location of the EDM, ECU, RMN and DBUN. Surface area, fascicle count, and axon number was determined by histological methods. The mean of axon number in the EDM, ECU, RMN and DBUN branches was 5931, 7355, 30960 and 35426, respectively. In this study, the number of axons in the EDM and ECU branches was 37% (13281/35426) of that in the DBUN. Also, the number of axons in the EDM and ECU branches was 42% (13281/30960) of that in the RMN. The axon count data showed an unfavorable match between the EDM, ECU and DBUN/RMN. Therefore, it is suggested that another donor nerve with higher axon number to be considered. Cadaver study (histological study). Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  19. Computer program for the calculation of stresses in rotary equipment discs; Programas de computo para el calculo de esfuerzos en discos de equipo rotatorio

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez Delgado, Wilson; Kubiak, Janusz; Serrano Romero, Luis Enrique [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    In the preliminary design and diagnosis of rotary machines is very common to utilize simple calculation methods for the mechanical and thermal stresses, dynamic and thermodynamic analysis and flow of fluids in this machines (Gutierrez et al., 1989). The analysis with these methods provides the necessary results for the project initial stage of the machine. Later on, more complex tools are employed to refine the design of some machine components. In the Gutierrez report et al., (1989) 34 programs were developed for the preliminary design and diagnosis of rotating equipment; in this article, one of them is presented in which a method for the analysis of mechanical and thermal stresses is applied in discs of uniform or variable thickness that are normally found in turbomachines and rotary equipment. [Espanol] En el diseno preliminar y diagnostico de maquinas rotatorias es muy comun emplear metodos de calculo sencillos para el analisis de esfuerzos mecanicos y termicos, analisis dinamico y termodinamico y de flujo de fluidos en estas maquinas (Gutierrez et al., 1989). El analisis con estos metodos proporcionan los resultados necesarios para la etapa del proyecto inicial de la maquina. Posteriormente, para refinar el diseno de algunos componentes de la maquina, se aplican las herramientas mas complejas. En el informe de Gutierrez et al., (1989) se desarrollan 34 programas para el diseno preliminar y diagnostico de equipo rotatorio; en este articulo, se presenta uno de ellos, en el que se emplea un metodo para el analisis de esfuerzos mecanicos y termicos en discos de espesor constante o variable que se encuentran comunmente en turbomaquinas y en equipos rotatorios.

  20. Computer program for the calculation of stresses in rotary equipment discs; Programas de computo para el calculo de esfuerzos en discos de equipo rotatorio

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez Delgado, Wilson; Kubiak, Janusz; Serrano Romero, Luis Enrique [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    In the preliminary design and diagnosis of rotary machines is very common to utilize simple calculation methods for the mechanical and thermal stresses, dynamic and thermodynamic analysis and flow of fluids in this machines (Gutierrez et al., 1989). The analysis with these methods provides the necessary results for the project initial stage of the machine. Later on, more complex tools are employed to refine the design of some machine components. In the Gutierrez report et al., (1989) 34 programs were developed for the preliminary design and diagnosis of rotating equipment; in this article, one of them is presented in which a method for the analysis of mechanical and thermal stresses is applied in discs of uniform or variable thickness that are normally found in turbomachines and rotary equipment. [Espanol] En el diseno preliminar y diagnostico de maquinas rotatorias es muy comun emplear metodos de calculo sencillos para el analisis de esfuerzos mecanicos y termicos, analisis dinamico y termodinamico y de flujo de fluidos en estas maquinas (Gutierrez et al., 1989). El analisis con estos metodos proporcionan los resultados necesarios para la etapa del proyecto inicial de la maquina. Posteriormente, para refinar el diseno de algunos componentes de la maquina, se aplican las herramientas mas complejas. En el informe de Gutierrez et al., (1989) se desarrollan 34 programas para el diseno preliminar y diagnostico de equipo rotatorio; en este articulo, se presenta uno de ellos, en el que se emplea un metodo para el analisis de esfuerzos mecanicos y termicos en discos de espesor constante o variable que se encuentran comunmente en turbomaquinas y en equipos rotatorios.

  1. PCRELAP5: data calculation program for RELAP 5 code; PCRELAP5: programa de calculo dos dados de entrada para o codigo RELAP5

    Energy Technology Data Exchange (ETDEWEB)

    Silvestre, Larissa Jacome Barros

    2016-07-01

    Nuclear accidents in the world led to the establishment of rigorous criteria and requirements for nuclear power plant operations by the international regulatory bodies. By using specific computer programs, simulations of various accidents and transients likely to occur at any nuclear power plant are required for certifying and licensing a nuclear power plant. Based on this scenario, some sophisticated computational tools have been used such as the Reactor Excursion and Leak Analysis Program (RELAP5), which is the most widely used code for the thermo-hydraulic analysis of accidents and transients in nuclear reactors in Brazil and worldwide. A major difficulty in the simulation by using RELAP5 code is the amount of information required for the simulation of thermal-hydraulic accidents or transients. The preparation of the input data requires a great number of mathematical operations to calculate the geometry of the components. Thus, for those calculations performance and preparation of RELAP5 input data, a friendly mathematical preprocessor was designed. The Visual Basic for Application (VBA) for Microsoft Excel demonstrated to be an effective tool to perform a number of tasks in the development of the program. In order to meet the needs of RELAP5 users, the RELAP5 Calculation Program (Programa de Calculo do RELAP5 - PCRELAP5) was designed. The components of the code were codified; all entry cards including the optional cards of each one have been programmed. In addition, an English version for PCRELAP5 was provided. Furthermore, a friendly design was developed in order to minimize the time of preparation of input data and errors committed by users. In this work, the final version of this preprocessor was successfully applied for Safety Injection System (SIS) of Angra 2. (author)

  2. Acute and long term outcomes of catheter ablation using remote magnetic navigation for the treatment of electrical storm in patients with severe ischemic heart failure

    DEFF Research Database (Denmark)

    Jin, Qi; Jacobsen, Peter Karl; Pehrson, Steen

    2015-01-01

    BACKGROUND: Catheter ablation with remote magnetic navigation (RMN) can offer some advantages compared to manual techniques. However, the relevant clinical evidence for how RMN-guided ablation affects electrical storm (ES) due to ventricular tachycardia (VT) in patients with severe ischemic heart......-guided catheter ablation can prevent VT recurrence and significantly reduce ICD shocks, suggesting that this strategy can be used as an alternative therapy for VT storm in SIHF patients with ICDs....

  3. Clays as green catalysts in the cholesterol esterification: spectroscopic characterization and polymorphs identification by thermal analysis methods. An interdisciplinary laboratorial proposal for the undergraduate level

    International Nuclear Information System (INIS)

    Maria, Teresa M R.; Nunes, Rui M. D.; Pereira, Mariette M.; Eusebio, M. Ermelinda S.

    2009-01-01

    A laboratory experiment that enables the professor to introduce the problematic of sustainable development in pharmaceutical chemistry to undergraduate students is proposed, using a simple synthetic procedure. Cholesteryl acetate is prepared by the esterification of cholesterol using Montmorillonite K10 as heterogeneous catalyst. Cholesterol and cholesteryl acetate are characterized by spectroscopic ( 1 H RMN, 13 C RMN, FTIR) and thermal analysis techniques. The thermal methods are used to introduce the concepts of polymorphism and the nature of mesophases. (author)

  4. Comparison of Generated Parallel Capillary Arrays to Three-Dimensional Reconstructed Capillary Networks in Modeling Oxygen Transport in Discrete Microvascular Volumes

    Science.gov (United States)

    Fraser, Graham M.; Goldman, Daniel; Ellis, Christopher G.

    2013-01-01

    Objective We compare Reconstructed Microvascular Networks (RMN) to Parallel Capillary Arrays (PCA) under several simulated physiological conditions to determine how the use of different vascular geometry affects oxygen transport solutions. Methods Three discrete networks were reconstructed from intravital video microscopy of rat skeletal muscle (84×168×342 μm, 70×157×268 μm and 65×240×571 μm) and hemodynamic measurements were made in individual capillaries. PCAs were created based on statistical measurements from RMNs. Blood flow and O2 transport models were applied and the resulting solutions for RMN and PCA models were compared under 4 conditions (rest, exercise, ischemia and hypoxia). Results Predicted tissue PO2 was consistently lower in all RMN simulations compared to the paired PCA. PO2 for 3D reconstructions at rest were 28.2±4.8, 28.1±3.5, and 33.0±4.5 mmHg for networks I, II, and III compared to the PCA mean values of 31.2±4.5, 30.6±3.4, and 33.8±4.6 mmHg. Simulated exercise yielded mean tissue PO2 in the RMN of 10.1±5.4, 12.6±5.7, and 19.7±5.7 mmHg compared to 15.3±7.3, 18.8±5.3, and 21.7±6.0 in PCA. Conclusions These findings suggest that volume matched PCA yield different results compared to reconstructed microvascular geometries when applied to O2 transport modeling; the predominant characteristic of this difference being an over estimate of mean tissue PO2. Despite this limitation, PCA models remain important for theoretical studies as they produce PO2 distributions with similar shape and parameter dependence as RMN. PMID:23841679

  5. Mathematical and numerical modeling of the turbulent dispersion of reactive pollutant plumes; Modelacion matematica y numerica de la dispersion turbulenta de plumas de contaminantes reactivos

    Energy Technology Data Exchange (ETDEWEB)

    Rodas Grapain, Arturo

    1999-07-01

    One of the main problems involved in air quality models to calculate the pollutant concentration in a single point in the space and time, is the complexity of the numerical method. Even though the numerical methods are based on sophisticated and elaborated mathematics. They present two important and inevitable drawbacks: the stability of the numerical method. This means that its capacity to obtain reliable convergency in relation to the calculated values and real values is limited. The time and memory consumption. The high machine memory used to perform the numerical procedures and the time needed to prepare such procedures. Another problem is the mathematical basis of the structure of the air quality model. Commonly, simple models can perform quick estimations; however they are not exact contrary to the complex and elaborated models. In order to employ these complex models a high speed computer (workstations or Cray computer) is required. For this reason, this work presents a model approach with a relatively simple theoretical structure. The structure of this model named MOTTQUIP (modelo de transporte turbulento y quimica de plumas) can provide good results in point concentration operations. These results are compared with those obtained by two moderately complex mathematical models (Georgopoulos-Seinfeld and Lipphardt reactive plume models). The model developed in this work, shows a special feature where the solution of the differential equations are not involved explicitly. Therefore, it does not present the typical difficult in solving this kind of equations with the traditional numerical methods. [Spanish] Uno de los principales problemas que se presentan en los modelos de calidad del aire para el calculo de la concentracion de un cierto contaminante, para un punto dado en el espacio y en el tiempo, es la complejidad del metodo numerico involucrado para este fin, debido a que dichos metodos de calculo estan basados en matematicas sofisticadas y muy

  6. Movilidad de litio en conductores iónicos rápidos analizada mediante espectroscopia RMN

    Directory of Open Access Journals (Sweden)

    Sanz, J.

    2010-02-01

    -red (T1 y spin-spin (T2 con la temperatura, ha permitido deducir los tiempos de residencia de los iones Li en los sitios estructurales. La comparación de estos valores con los deducidos a partir de las conductividades ac y dc, hace posible describir de un modo más preciso la dinámica de los iones. A temperaturas crecientes, los movimientos se vuelven menos correlacionados, produciéndose una disminución de la energía de activación. El análisis de los movimientos a larga distancia requiere medidas a baja frecuencia (medidas de T2 y conductividad-dc. Desviaciones de la conductividad del comportamiento Arrhenius, a menudo observadas en conductores iónicos rápidos, han sido adscritas a transiciones de orden-desorden en las que el movimiento de los iones se hace menos correlacionado. Una medida directa de los coeficientes de difusión ha sido obtenida con la técnica RMN de gradiente de campo pulsado (PFG. Finalmente se analiza la importancia de los fenómenos de percolación de vacantes en los procesos de conducción.

  7. Argilas como catalisadores verdes na esterificação do colesterol: caracterização espectroscópica e identificação de polimorfos por métodos de análise térmica. Uma proposta laboratorial interdisciplinar para o 1º ciclo universitário Clays as green catalysts in the cholesterol esterification: spectroscopic characterization and polymorphs identification by thermal analysis methods. An interdisciplinary laboratorial proposal for the undergraduate level

    Directory of Open Access Journals (Sweden)

    Teresa M. R. Maria

    2009-01-01

    Full Text Available A laboratory experiment that enables the professor to introduce the problematic of sustainable development in pharmaceutical chemistry to undergraduate students is proposed, using a simple synthetic procedure. Cholesteryl acetate is prepared by the esterification of cholesterol using Montmorillonite K10 as heterogeneous catalyst. Cholesterol and cholesteryl acetate are characterized by spectroscopic (¹H RMN, 13C RMN, FTIR and thermal analysis techniques. The thermal methods are used to introduce the concepts of polymorphism and the nature of mesophases.

  8. Clays as green catalysts in the cholesterol esterification: spectroscopic characterization and polymorphs identification by thermal analysis methods. An interdisciplinary laboratorial proposal for the undergraduate level; Argilas como catalisadores verdes na esterificacao do colesterol: caracterizacao espectroscopica e identificacao de polimorfos por metodos de analise termica. Uma proposta laboratorial interdisciplinar para o primeiro ciclo universitario

    Energy Technology Data Exchange (ETDEWEB)

    Maria, Teresa M R.; Nunes, Rui M. D.; Pereira, Mariette M.; Eusebio, M. Ermelinda S. [Universidade de Coimbra, Coimbra (Portugal). Dept. de Quimica], e-mail: troseiro@ci.uc.pt

    2009-07-01

    A laboratory experiment that enables the professor to introduce the problematic of sustainable development in pharmaceutical chemistry to undergraduate students is proposed, using a simple synthetic procedure. Cholesteryl acetate is prepared by the esterification of cholesterol using Montmorillonite K10 as heterogeneous catalyst. Cholesterol and cholesteryl acetate are characterized by spectroscopic ({sup 1}H RMN, {sup 13}C RMN, FTIR) and thermal analysis techniques. The thermal methods are used to introduce the concepts of polymorphism and the nature of mesophases. (author)

  9. SÍNTESIS Y CARACTERIZACIÓN DE UN CUADRADO SUPRAMOLECULARA PARTIR DEL AUTO-ENSAMBLAJE DEL COMPLEJO[1,2-BIS(DIFENILFOSFINOETANO] BISTRIFLUOROMETANOSULFONATOPALADIO (II Y 4,4´-BIPIRIDINA

    Directory of Open Access Journals (Sweden)

    Julian Posada

    2011-11-01

    Full Text Available Por primera vez se desarrolló la síntesisy caracterización (IR, UV, RMN-1H,31P, 19F de un nuevo cuadrado supramolecular[3] mediante el auto-ensamblajedel complejo [Pd(CF3SO32(Dppe] [1] yel ligando orgánico 4,4´-Bipiridina [2].Se evidenció la obtención de [3] en mezclacon otra especie supramolecular [4],asignada como un macrociclo triangular.Las estructuras de [3] y [4] se elucidaroncon base en los desplazamientos químicos,la proporcionalidad entre sus integralesy en los patrones de acoplamientode las señales en los espectros RMN-1H yCOSY 1H-1H. Mediante la relación entrelas integrales de las señales correspondientesa las especies supramolecularescoexistentes en los espectros RMN-1Hy 31P se determinó la composición de lamezcla al final de la reacción conteniendo70 % de [3] y 30 % de [4].

  10. SUSTENTABILIDAD URBANA PLANTEAMIENTOS TEORICOS Y CONCEPTUALES

    OpenAIRE

    Verónica Miranda Rosales

    2011-01-01

    El estudio del fenómeno ambiental en nuestras ciudades es fundamental para alcanzar una mejor calidad de vida de nuestra sociedad; el desarrollo sostenible busca aminorar los estragos de la urbanización acelerada y del modo de producción predominante. A pesar de que han surgido alternativas teóricas y conceptuales para caracterizar el fenómeno, como es el desarrollo sustentable, Ecodesarrollo, la Globalización y el Comercio Internacional y desarrollo urbano sustentable, éstas se consideran in...

  11. Fast screening of turkish olive oil by NMR spectroscopy for geographical determination and discrimination purposes

    Directory of Open Access Journals (Sweden)

    Ok, S.

    2014-06-01

    Full Text Available The main goal of this study is to rapidly screen olive oil contents by acquiring one dimensional (1D 1H NMR spectra of 38 samples from Turkey, The Middle East, and Libya. The quantitative analysis of the 1H NMR helped in distinguishing the geographical origin of the olive oil samples. The intensity of 1H NMR variables was submitted to the statistical method, analysis of variance (ANOVA. As a result of combining the NMR data and ANOVA, olive oils were discriminated based on regional origin rather than province. This less time consuming discriminative screening by 1H NMR does not require any further analysis of the olive oil, including oxidative stability measurements or gas chromatography. The possibility of determining authenticity, even in an olive growing area of a small village was also shown. The two-dimensional (2D non-invasive 1H DOSY NMR experiment, known as “NMR chromatography”, was used to determine the olive oil sub-fraction.El objetivo es conocer de manera rápida el contenido de aceite de oliva mediante la adquisición de espectros de 1H RMN de una dimensión (1D. El estudio se ha realizado con 38 muestras procedentes de Turquía, Oriente Medio y Libia. El análisis cuantitativo de 1H RMN ayudó a distinguir el origen geográfico de las muestras de aceites de oliva. La intensidad de las señales de 1H RMN se sometió a estudio estadístico mediante análisis de varianza (ANOVA. Como resultado de la combinación de los datos de RMN y ANOVA, los aceites de oliva fueron discriminados por origen regional antes que por provincia. Esta técnica de discriminación rápida por 1H RMN no requiere ningún análisis adicional de los aceites de oliva mediante estudios de estabilidad a la oxidación o cromatografía de gases. También se demostró la posibilidad de determinar la autenticidad, incluso en el área de cultivo del olivo de una pequeña aldea. Los experimentos de RMN bi-dimensionales (2D no invasiva 1H DOSY, conocido como

  12. Aplicaciones de los registros de resonancia magnética nuclear (nmrl) en la evaluación de yacimientos

    OpenAIRE

    Landi Torres, Richard Paúl

    2008-01-01

    La extraordinaria tecnología de adquisición de registros o perfilaje de resonancia magnética nuclear (RMN) ha estado en continua evolución durante los últimos 10 años. Las compañías petroleras utilizan las mediciones de RMN en una variedad de aplicaciones cada vez más numerosa; por ejemplo, para caracterizar los fluidos de las formaciones durante la evolución de los yacimientos y determinar la producibilidad de la formación. Hoy en día, las mediciones obtenidas con estas herramien...

  13. Computerized dosimetry of I-125 sources model 6711; Dosimetria computarizada de las fuentes de I-125 modelo 6711

    Energy Technology Data Exchange (ETDEWEB)

    Isturiz, J [Centre de Radiotherapie du Parc, Dijon (France)

    2001-07-01

    It tries on: physical presentation of the sources; radiation protection; mathematical model of I-125 source model 6711; data considered for the calculation program; experimental com probation of the dose distribution; exposure rate and apparent activity; techniques of the use given to the sources I-125; and the calculation planning systems. [Spanish] Trata sobre presentacion fisica de las fuentes, radioproteccion, modelo matematico de las fuentes I-125 modelo 6711, datos considerados en el programa de calculo, comprobacion experimental de la distribucion de dosis, tasa de exposicion y actividad aparente, tecnicas de utilizacion de las fuentes I-125; y los sistemas de planificacion del calculo de las dosis.

  14. PERCHÉ LEGGERE MICHELSTAEDTER?

    African Journals Online (AJOL)

    User

    It does so through an investigation concerning ... sinteticamente presentato a livello teorico le nozioni di “lettore implicito”, “lettore modello” e “lettore ... principalmente per la Persuasione, ha vissuto una stagione di rinascita. ...... Cerruti, Marco.

  15. Anthraquinones from the bark of Senna macranthera

    Directory of Open Access Journals (Sweden)

    Alexsandro Branco

    2011-12-01

    Full Text Available 2-acetyl physcion (2-acetyl-1,8-dihydroxy-6-methoxy-3-methyl-9,10-anthraquinone, 2, a rare anthraquinone, was isolated from Senna macranthera var. nervosa (Vogel H.S. Irwin & Barneby (Fabaceae. The chemical structure was elucidated and all ¹H and 13C NMR chemical shifts were assigned by NMR one- (¹HNMR, {¹H}-13CNMR, and APT-13CNMR and two (COSY, NOESY, HMQC and HMBC dimensional of this natural compound. Furthermore, the minor anthraquinones chrysophanol (3, chrysophanol-8-methyl ether (4 and physcion (5 were characterized by GC-MS analysis. The occurrence of the anthraquinones 3-5 confirms that S. macranthera is a typical representative of the genus Senna.2-acetil-fisciona (2-acetil-1, 8-di-hidróxi-6-metóxi-3-metil-9, 10-antraquinona, 2, uma antraquinona rara, foi isolada de Senna acranthera var. nervosa (Vogel H.S. Irwin & Barneby (Fabaceae. estrutura química foi elucidada e todos os deslocamentos químicos de RMN ¹H e 13C foram atribuídos através de RMN uni- (RMN¹H, {¹H}-RMN-13C e APT-RMN13C e bi- (COSY, NOESY, HMQC e HMBC dimensional deste composto natural. Adicionalmente, as antraquinonas minoritárias crisofanol (3, crisofanol-8-metil éter (4 e fisciona (5 foram caraterizadas pela análise de CG-EM. A ocorrência das antraquinonas 3-5 confirma que S. macranthera é uma típica representante do gênero Senna.

  16. Caracterización espectroscópica del D-003 obtenido de la cera de caña de azúcar (Saccharum officinarum L.

    Directory of Open Access Journals (Sweden)

    David Marrero Delange

    Full Text Available Introducción: el D-003 es un ingrediente farmacéutico activo purificado a partir de la cera de caña de azúcar (Saccharum officinarum L. con efectos como reductor del colesterol y antioxidante, el cual está compuesto por una mezcla de ácidos grasos libres saturados de elevado peso molecular, cada uno dentro de un intervalo de concentración específica determinada por cromatografía de gases (CG. La caracterización espectroscópica del D-003, sin embargo, no ha sido previamente informada. Objetivo: caracterizar el ingrediente farmacéutico activo nombrado D-003 de acuerdo con sus espectros ultravioleta (UV, infrarrojo (FTIR, resonancia magnética nuclear (RMN y de masas (EM. Métodos: se evaluaron muestras de seis lotes de D-003 (CNIC, Cuba mediante las técnicas de UV, FTIR, RMN-¹H, RMN-13C y CG-EM. Para obtener los espectros de masas de los ácidos del D-003, estos se derivaron como ésteres metílicos y trimetilsilil. La cuantificación de los ácidos grasos libres saturados de elevado peso molecular, analizados como ésteres metílicos, se llevó a cabo por CG con detector de ionización por llama (DILL. Resultados: los espectros UV, IR, RMN-¹H y RMN-13C mostraron que el ingrediente farmacéutico activo D00-3 está constituido por una mezcla de ácidos grasos libres saturados de elevado peso molecular, mientras las técnicas de CG-EM y CG-DILL permitieron asegurar la presencia de 13 ácidos grasos libres saturados de elevado peso molecular en proporciones definidas: C24:0 (0,2-0,6 %, C25:0 (0,4-0,9 %, C26:0 (2,0-3,1 %, C27:0 (2,1-2,7 %, C28:0 (30,0-37,5 %, C29:0 (1,5-1,7 %, C30:0 (17,0-18,6 %, C31:0 (0,9-1,2 %, C32:0 (6,9-8,9 %, C33:0 (0,9-1,3 %, C34:0 (7,2-11,1 %, C35:0 (0,3-0,6 % y C36:0 (2,2-3,8 %. Conclusiones: a partir de las técnicas espectroscópicas de UV, FTIR, RMN, y CG-EM se demuestra que el D00-3 está compuesto por 13 ácidos grasos saturados de elevado peso molecular, entre los cuales el ácido octacosanoico es el

  17. Marketing político: preceitos teóricos x práticas eleitorais

    OpenAIRE

    Campagnone, Zilda Maria Matheus

    2010-01-01

    Correlações entre preceitos teoricos ditados pelos especialistas em Marketing Político e as práticas eleitorais adotadas pelos candidatos a Presidência da República, que disputam o 2 turno das eleições presidenciais- Brasil/ 1989

  18. Crystallography of refractory metal nuggets in carbonaceous chondrites: A transmission Kikuchi diffraction approach

    Science.gov (United States)

    Daly, Luke; Bland, Phil A.; Dyl, Kathryn A.; Forman, Lucy V.; Saxey, David W.; Reddy, Steven M.; Fougerouse, Denis; Rickard, William D. A.; Trimby, Patrick W.; Moody, Steve; Yang, Limei; Liu, Hongwei; Ringer, Simon P.; Saunders, Martin; Piazolo, Sandra

    2017-11-01

    Transmission Kikuchi diffraction (TKD) is a relatively new technique that is currently being developed for geological sample analysis. This technique utilises the transmission capabilities of a scanning electron microscope (SEM) to rapidly and accurately map the crystallographic and geochemical features of an electron transparent sample. TKD uses a similar methodology to traditional electron backscatter diffraction (EBSD), but is capable of achieving a much higher spatial resolution (5-10 nm) (Trimby, 2012; Trimby et al., 2014). Here we apply TKD to refractory metal nuggets (RMNs) which are micrometre to sub-micrometre metal alloys composed of highly siderophile elements (HSEs) found in primitive carbonaceous chondrite meteorites. TKD allows us to analyse RMNs in situ, enabling the characterisation of nanometre-scale variations in chemistry and crystallography, whilst preserving their spatial and crystallographic context. This provides a complete representation of each RMN, permitting detailed interpretation of their formation history. We present TKD analysis of five transmission electron microscopy (TEM) lamellae containing RMNs coupled with EBSD and TEM analyses. These analyses revealed textures and relationships not previously observed in RMNs. These textures indicate some RMNs experienced annealing, forming twins. Some RMNs also acted as nucleation centres, and formed immiscible metal-silicate fluids. In fact, each RMN analysed in this study had different crystallographic textures. These RMNs also had heterogeneous compositions, even between RMNs contained within the same inclusion, host phase and even separated by only a few nanometres. Some RMNs are also affected by secondary processes at low temperature causing exsolution of molybdenite. However, most RMNs had crystallographic textures indicating that the RMN formed prior to their host inclusion. TKD analyses reveal most RMNs have been affected by processing in the protoplanetary disk. Despite this

  19. Manifestations of spine infections for RMN; Manifestaciones de infecciones de columna por RMN

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, Mauricio; Valencia, Alexandra

    1998-12-01

    Instead of demonstrate the utility and benefits of MRI imaging in infectious processes of the spine, 8 patients with lumbar pain affected by spondilodiscitis were studied. T1 SE, T2, SE with and without fat sat and proton density imaging was performed, axial; sagittal and coronal views were obtained. Contrast media was used in 1 Patient. hypointense lesions in T1 and hyperintense lesions in T2 compatible with esponsilodiscitis were observed in every patient. Images with great anatomic detail of bone and soft tissue structures were obtained. MRI is an alternative diagnostic method with multiplanar images and excellent contrast that permits a precise diagnosis in any of the stages of infectious processes of the spine.

  20. Fukugetina y fukogisida, biflavonoides de clusia guaviarensis cuatr. (clusiaceae

    Directory of Open Access Journals (Sweden)

    Eduardo Martínez O.

    2010-09-01

    Full Text Available De los frutos de la especie nativa Clusia guaviarensis (Cuatr. se aislaron e identificaron los bifiavonoides fukugetina i y fukugisida 2. Este es el primer estudio fitoquímico de esta especie así como el primer reporte de bifiavonoides en el género Clusia. La identificación se realizó por técnicas espectroscópicas tales como IR, UV Y RMN de 'H y "C así como por comparación con muestras auténticas. Se reporta además la presencia de dos atropoisómeros la cual es evidente en el espectro de "C-RMN a temperatura ambiente.

  1. Monika Fludernik, Verso una narratologia ‘naturale’

    Directory of Open Access Journals (Sweden)

    Filippo Pennacchio

    2013-06-01

    La traduzione del saggio è fatta precedere da un’introduzione in cui viene presentato, più in generale, il pensiero di Monika Fludernik, e insieme valutato il suo ruolo nell’ambito del dibattito teorico sviluppatosi in seno alla comunità scientifica a partire dai primi anni Duemila.

  2. Reti strategiche come evoluzione delle reti emergenti

    DEFF Research Database (Denmark)

    Brunetta, Federica; Censi, Anna; Rullani, Francesco

    2015-01-01

    che ne fanno parte in un segmento a più alto valore aggiunto della catena delvalore.Metodologia: Questo lavoro analizza il contratto di rete come fenomeno empiricoche cattura il concetto teorico di rete strategica, approfondendo il caso di due contrattidi rete stipulati nella provincia di Brescia...

  3. Phytochemical research of leaves and flowers of Smallanthus pyramidalis (Triana) H. Rob. (Arboloco) and its use in the recovery of wetlands in Bogota

    International Nuclear Information System (INIS)

    Guzman Avendano, Antonio J; Barrera Adame, Diana A.

    2011-01-01

    This research focused on the phytochemical characterization of the species Smallanthus pyramidalis (Triana) H. Rob. in order to identify the secondary metabolites of flowers and leaves. This is due to the importance these trees on the sustainable development of the wetlands in the Sabana de Bogota, and its possible application as a promising species in the use and conservation of these ecosystems. We performed preliminary chemical tests, fractionation using conventional techniques, identification of physical and chemical properties, and structural analysis using spectroscopic and spectrometric techniques, such as UV, 1H-RMN, 13C-RMN and GC-MS. We identified alkane-type compounds, steroids, terpenoids and flavonoids mainly, and their role in the plant and the ecosystem.

  4. Torque calculation in the induction motor with the finite element method; Calculo del par en el motor de induccion con el metodo del elemento finito

    Energy Technology Data Exchange (ETDEWEB)

    Castillo Diaz, Ramon

    2002-06-15

    In this work the method of the finite element is applied to the bi-dimensional analysis of the induction motor in operation in steady state, excited by sine sources of laminar currents and sine sources of voltage. The analysis is focused mainly in the calculation of the electromagnetic torque. The topics of electromagnetic theory are covered and in an idealized model of the induction motor, analytically and numerically with the method of the finite element, in the variant method of Galerkin, the vectorial potential and the torque are calculated. The results obtained with the analytical and numerical methods are compared. Three formulations are developed to calculate the torque with the method of the finite element, using triangular elements of first order, based in the equation of force of Lorentz, the Maxwell tensor and the principle of the virtual work. Finally, a motor of induction of real characteristics is simulated, assuming it is connected to a three-phase voltage source. In this motor it is analyzed the convergence and the evolution in the results obtained of the torque with different discretions, and the torque-velocity performance curve is calculated. [Spanish] En este trabajo se aplica el metodo del elemento finito al analisis bidimensional del motor de induccion en operacion en estado estable, excitado por fuentes de corriente laminar senoidales y fuentes de voltaje senoidales. El analisis se enfoca principalmente en el calculo del par electromagnetico. Se tratan los topicos de teoria electromagnetica involucrados y en un modelo idealizado del motor de induccion, se calculan analitica y numericamente con el metodo del elemento finito, en la variante metodo de Galerkin, el potencial vectorial y el par. Se comparan resultados obtenidos con los metodos analiticos y numericos. Se desarrollan tres formulaciones para calcular el par con el metodo del elemento finito, utilizando elementos triangulares de primer orden, basadas en la ecuacion de fuerza de

  5. Superconductivity in the lanthanum-yttrium-manganese alloy system

    International Nuclear Information System (INIS)

    Stierman, R.J.

    1980-03-01

    An empirical approach involving lattice instabilities was investigated in the search for new superconducting materials. Pseudo-lanthanide compounds using La and Y were prepared for the system La/sub 1-x/Y/sub x/Mn 2 by arc melting and subsequent heat treatment. Low temperature magnetic susceptibility and low temperature heat capacity measurements were made. The unit cell lattice parameters were determined from x-ray powder patterns taken on most samples and metallographic examination was carried out on selected samples. Alloys with low La concentrations (x greater than or equal to 0.6) showed RMn 2 in the cubic C15 Laves phase as the major component with second phase material present. The magnetic susceptibility and x-ray data indicated a superconducting phase which seemed to be the RMn 2 phase, but heat capacity measurements showed the second phase material was the superconductor, while the RMn 2 was not. Failure to form compounds with higher La content was experienced and may be due to the lattice instability expected at x = 0.56. This indicates that perhaps more stingent conditions are required to form pseudo-lanthanide compounds than were previously considered. More systems should be investigated to see if this is true, and to determine the possibilities of this approach

  6. RESONANCIA MAGNÉTICA NUCLEAR DEL PRODUCTO GELIFICADO DE LA REACCIÓN DE CANNIZZARO

    Directory of Open Access Journals (Sweden)

    Lilia Fernández Sánchez

    2015-01-01

    Full Text Available Se presenta n los espectros de resonancia magnética nuclear ( RMN de protón 1 H, de carbón 13 C y bidimensionales , del produc to de una síntesis orgánica verde de óxido - reducción en la r eacción de Cannizzaro. El producto fue reportado como un gel triboquímico y elucidado por análisis de infrarrojo IR , ray os X y micrografía de barrido ( SEM . Los resultados en este artículo confirman su estructura a través de diversas técnicas de RMN y evalúan el contenido de benzoato de sodio y alcohol bencílico en la muestra e mpleada en la espectroscopia a través del examen de los valores de las integrales en la s señales de RMN de 1 H. El resultado del estudio indica que el alcohol bencílico se encuentra en un 33.44% mol (fase dispersa con respecto al cont enido de benzoato de sodio (fase continua . Estos resultado s confirma n la estruct ura de gel que con el tiempo pierde a la fase dispersa el alcohol produciendo un xerogel

  7. Calculation of economic viability of alternative energy sources considering its environmental costs for small communities of Northeast Brazil; Calculo de viabilidade economica de fontes alternativas de energia considerando seus custos ambientais para pequenas comuidades da regiao nordeste brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Stecher, Luiza Chourkalo

    2014-09-01

    There has been an increasing concern about current environmental issues caused by human activity, as the world searches for development. The production of electricity is an extremely relevant factor in this scenario since it is responsible for a large portion of the emissions that cause the greenhouse effect. Due to this fact, a sustainable development with alternative energy sources, which are attractive for such purpose, must be proposed, especially in places that are not supplied by the conventional electricity grid such as many communities in the Northeast Brazil. This work aims to calculate the environmental cost for the alternative sources of energy - solar, wind and biomass - during electricity generation, and to estimate the economic feasibility of those sources in small communities of Northeast Brazil, considering the avoided costs. The externalities must be properly identified and valued so the costs or benefits can be internalized and reflect accurately the economic feasibility or infeasibility of those sources. For this, the method of avoided costs was adopted for the calculation of externalities. This variable was included in the equation developed for all considered alternative energy sources. The calculations of economic feasibility were performed taking the new configurations in consideration, and the new equation was reprogrammed in the Programa de Calculo de Custos de Energias Alternativas, Solar, Eolica e Biomassa (PEASEB). The results demonstrated that the solar photovoltaic energy in isolated systems is the most feasible and broadly applicable source for small communities of Northeast Brazil. (author)

  8. Costruire e programmare robot

    Directory of Open Access Journals (Sweden)

    Barbara Caci

    2002-01-01

    Full Text Available Negli scenari riguardanti le nuove tecnologie didattiche sta progressivamente acquistando un posto di rilievo la robotica educativa. Tale termine designa una varieta' di esperienze formative, ispirate ai principi teorico metodologici del costruttivismo e della embodied cognition, e basate sull'impiego di Robotic Construction Kits come strumenti di apprendimento.

  9. Determination of the Effectiveness of Control Rods in the VVER Reactor Fuel Assemblies; Determination de l'Efficacite des Barres de Reglage dans les Ensembles Combustibles du reacteur VVER; Opredelenie ehffektivnosti reguliruyushchikh sterzhnej v sborkakh reaktora VVEHR; Determinacion de la Eficacia de las Barras de Control en los Conjuntos de Elementos Combustibles del Reactor VVER

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, V. N.; Lunin, G. L.; Komissarov, L. V.; Kamyshan, A. N.; Halizev, V. I.; Andrianov, G. Ja.; Voznesenskij, V. A.; Kuz' micheva, V. A.; Lebedev, V. I. [Ordena Lenina Institut Atomnoj Energii Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

    1964-06-15

    The paper describes experiments done in homogeneous mock-ups of the fuel assemblies from the VVER Reactor (at one level of enrichment) to determine the effectiveness of absorbing systems comprising shim fuel assemblies or water cavities and of absorbing rods clad in jackets made of differing materials. The paper also gives data on some experiments that have been done in mock-ups of assemblies with differing levels of enrichment. These experiments make it possible to verify the methods used in calculation and to evaluate the prospects of using them for heterogeneous reactors. (author) [French] Le memoire decrit les experiences qui ont ete faites pour determiner l 'efficacite des absorbants contenus dans les barres de compensation, l'effet cavitaire et l 'efficacite des absorbants gaines de materiaux divers, au moyen d'assemblages homogenes de cartouches de combustible du reacteur VVER (reacteur de puissance ralenti et refroidi a l 'eau ayant le meme taux d'enrichissement. On y trouve en outre des donnees sur certaines experiences executees a l 'aide d'assemblages de cartouches de combustible taux d'enrichissement differents. Ces travaux permettent de verifier la methode de calcul et d'evaluer ses possibilites d'application aux reacteurs non homogenes. (author) [Spanish] Se describen en la memoria experimentos para determinar la eficacia de los materiales absorbentes contenidos en las barras de compensacion, el efecto de cavitacion y la eficacia de los materiales absorbentes revestidos de diversos materiales, realizados con ayuda de los conjuntos homogeneos de elementos combustibles del reactor VVER (reactor de potencia moderado y refrigerado por agua) con un solo grado de enriquecimiento. Ademas, se exponen datos sobre los experimentos efectuados con ayuda de conjuntos de grados de enriquecimientos; variados. Tales experimentos permiten verificar el metodo de calculo teorico, utilizad o y evaluar la posibilidad de aplicarlo a los reactores no homogeneos. (author

  10. RENTA.NB. Una experiencia sobre aplicación de Mathematica a las Matemáticas Financieras.

    Directory of Open Access Journals (Sweden)

    Seijas Macías, J. A.

    1999-01-01

    Full Text Available Este articulo se enmarca dentro del trabajo que los autores realizan para la progresiva introducción del programa de calculo simbólico Mathematica, dentro de la asignatura de Análisis y Cálculo de las Operaciones Financieras. En esta comunicación presentamos el archivo de Mathematica "Renta.nb", diseñado para su aplicación en el entorno del Mathematica 3.0, y que pretende servir de ayuda en la introducción al calculo y gestión de operaciones de rentas financieras. Mediante dicho programa los alumnos disponen de una herramienta que les permite realizar todos los cálculos sobre rentas y al mismo tiempo, puede utilizarse en los problemas sobre otras operaciones financieras que se diseñan como rentas (caso de operaciones de amortización y constitución.

  11. COMUNICACIÓN EN SALUD: CONCEPTOS Y MODELOS TEORICOS

    Directory of Open Access Journals (Sweden)

    Iván Ríos Hernández

    2011-01-01

    Full Text Available A través de este artículo de revisión de tema se analiza el concepto comunicación en salud y algunas de las definiciones esbozadas hasta el momento por organismos internacionales y expertos del tema. Se presenta una mirada crítica y reflexiva sobre algunos de los principales modelos teóricos desarrollados en el campo de la comunicación en salud. Se esboza un análisis del paradigma de la Comunicación para el Cambio Social y se compara con las otras teorías y modelos de comunicación en salud discutidos en el escrito. Luego del análisis reflexivo se concluye que el apoderamiento de las comunidades en las estrategias de prevención de enfermedades, representa un reto para los estudios concernientes a las teorías y modelos que tratan de explicar de forma simplificada los elementos inmersos en un proceso de comunicación en salud.

  12. Evaluación con resonancia magnética de artroplastias totales de rodilla sintomáticas. [MRI evaluation of symptomatic total knee arthroplasties ].

    Directory of Open Access Journals (Sweden)

    Francisco Jose Nally

    2016-08-01

    Full Text Available Introducción  Las artroplastías totales de rodilla (ATR sintomáticas con estudios normales resultan un desafío para el ortopedista. La resonancia magnética nuclear (RMN podría ser una alternativa para arribar al diagnóstico.  Objetivo Evaluar la utilidad de la RMN con secuencias optimizadas en ATR sintomática. Además, realizar un estudio interobservador  para determinar que estructuras anatómicas son evaluables. Material y métodos   Se evaluaron  retrospectivamente 15 casos de ATR operados entre 2007-2012 con dolor periprotésico, con radiografía, centellograma y laboratorio normales, sometidos a una RMN. Se realizó un análisis interobservador utilizando el Coeficiente de correlación intercalase (CCIC y Kappa entre 4 profesionales, un residente de diagnóstico por imágenes y otro de Ortopedia; y 2 médicos con 20 años de experiencia, uno en diagnóstico por imágenes y el otro en rodilla. Resultados  Se hayó líquido articular aumentado en 14 pacientes; sinovitis en 4; un osículo infrapatelar y en ningún caso osteólisis. En 7 casos los ligamentos colaterales pudieron ser evaluados correctamente. Los gemelos, el tejido celular subcutáneo y el aparato extensor  se evaluaron sin dificultad. La RMN encontró causas de dolor en 12 casos. El CCIC mostró concordancia para el ligamento colateral medial, el aparato extensor, gemelos y tejido celular subcutáneo.   Conclusión Nuestro estudio demuestra la utilidad del método en la toma de decisiones.  La concordancia interobservador fue estadísticamente significativa para el análisis del ligamento colateral medial, gemelos y tejido celular subcutáneo.   Nivel de evidencia: III , Estudio diagnóstico

  13. Magnetic resonance studies of solid polymers; Etude des polymeres solides par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Lenk, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    This paper is a review of the application of nuclear magnetic resonance (NMR) to solid polymers. In the first, theoretical part, the elements of the theory of NMR, which are necessary for the study of the properties of solid polymers are discussed: the moments method, nuclear relaxation and the distribution of correlation times. In the second part the experimental results are presented. (author) [French] Cette etude est une recherche bibliographique sur l'application de la resonance magnetique nucleaire (RMN) aux polymeres solides. Dans la premiere partie theorique on discute les elements de la theorie de RMN, necessaires pour l'etude des proprietes des polymeres solides: la methode des moments, la relaxation nucleaire et la distribution des temps de correlation. La deuxieme partie presente les resultats des experiences. (auteur)

  14. CARACTERIZACIÓN ESTRUCTURAL Y TEXTURAL DE UNA BENTONITA COLOMBIANA

    Directory of Open Access Journals (Sweden)

    José Carriazo

    2008-04-01

    Full Text Available En el presente trabajo se caracteriza una arcilla-bentonita colombiana (Valle del Cauca, mediante difracción de rayos X, técnicas espectroscópicas (IR, RMN y EPR y análisis textural. Los resultados indican que el componente principal en este material natural es una esmectita dioctaédrica (aluminosa. Igualmente, los resultados de RMN de 29Si y de 27Al revelan la substitución isomórfica de Al3+ por Si4+ en la capa tetraédrica. El estudio de EPR evidencia la presencia de hierro (III ocupando posiciones en la capa octaédrica del mineral de arcilla y formando nanoclusters, posiblemente de óxidos u oxihidróxidos. El análisis textural indica que el material es predominantemente mesoporoso.

  15. Análise comparativa dos efeitos alelopáticos das substâncias químicas titonina e titonina acetilada Comparative analysis of the allelopathic effects of the chemical compounds tithonine and acetylated tithonine

    Directory of Open Access Journals (Sweden)

    A.P.S. Souza Filho

    2006-06-01

    Full Text Available Este trabalho teve por objetivo estabelecer as variações na atividade alelopática da substância química titonina, em função da acetilação de sua molécula. Bioensaios de germinação (25 ºC de temperatura constante e fotoperíodo de 12 horas e de desenvolvimento da radícula e do hipocótilo (25 ºC de temperatura constante e fotoperíodo de 24 horas foram desenvolvidos. Como planta receptora, utilizou-se a planta daninha Mimosa pudica (malícia. Análise de espectros RMN ¹H e 13C e técnicas de RMN bidimensionais foram realizadas na molécula acetilada. O processo de acetilação produziu a molécula 3'-acetil-7,4'-dimetoxiflavona, que diferiu da molécula original, identificada como 3'-hidroxi-7,4'-dimetoxiflavona. A estrutura da titonina-Ac foi confirmada pelos espectros de RMN ¹H, 13C, DEPT, COSY e HETCOR. A titonina foi acetilada com anidrido acético em piridina. A análise comparativa da atividade alelopática das duas substâncias revelou que titonina-Ac apresentou maior potencial para inibir tanto a germinação das sementes como o desenvolvimento da radícula e do hipocótilo da planta daninha malícia. A intensidade dos efeitos alelopáticos das duas substâncias esteve positivamente associada à concentração. O conjunto das informações obtidas permite sugerir a possibilidade de se aumentar a atividade alelopática de uma substância química sem comprometer suas peculiaridades biológicas desejáveis à natureza e aos interesses da sociedade.The objective of this paper was to establish the variations in the allelopathic activity of the chemical substance tithonine, in function of the acetylation of its molecule. Germination bioassays, under 25 ºC of constant temperature and 12-hour photoperiod, and radicle and hypocotyl development bioassays under 25ºC of constant temperature and 24-hour photoperiod were developed. The receiving plant used was the weed Mimosa pudica. Spectral analysis RMN ¹H and 13C and

  16. Thermodynamic and neutron diffraction studies on multiferroic NdMn{sub 2}O{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, S.; Balédent, V.; Auban-Senzier, P.; Pasquier, C.; Doubrovsky, C. [Laboratoire de Physique des Solides, Université Paris-Sud, CNRS-UMR 8502, 91405 Orsay (France); Greenblatt, M. [Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Foury-Leylekian, P., E-mail: pascale.foury@u-psud.fr [Laboratoire de Physique des Solides, Université Paris-Sud, CNRS-UMR 8502, 91405 Orsay (France)

    2015-03-01

    Magnetically frustrated RMn{sub 2}O{sub 5} oxides have attracted considerable attention in recent years, because most of the members of this family show spin ordering induced dielectric polarization along with strong magneto-electric coupling. Although the true origin of the ferroelectricity is still a matter of debate, it has been observed that the magneto-electric phase diagram can be substantially tuned with the variation of rare earth elements. In this work, we have chosen NdMn{sub 2}O{sub 5} as the compound of our interest since it lies exactly in between the ferroelectric and non-ferroelectric members of this family and also, because there are few investigations performed on RMn{sub 2}O{sub 5} systems with large rare earth atoms . With the combination of heat capacity, magnetic susceptibility, dielectric permittivity, powder X-ray diffraction, and powder neutron diffraction measurements, it has been found that NdMn{sub 2}O{sub 5} undergoes an incommensurate magnetic ordering around 30 K followed by a possible ferroelectric-like transition at ∼26 K. Another lock-in kind of magnetic transition appears when the temperature is decreased to ∼15 K. With further lowering of temperature, an antiferromagnetic ordering, which is presumably associated with the Nd{sup 3+}, is achieved near 4 K. This study thus sheds light on a new compound of the RMn{sub 2}O{sub 5} series presenting different multiferroic properties.

  17. BOOK REVIEWS / RECENSIONI

    African Journals Online (AJOL)

    User

    armi da fuoco, Campanella risponde: “È la poesia l'arma che colpisce a distanza” e questa, lui dice d'aver perfezionato come Dante. Dopo il convegno del 1990 su “Poesia e Filosofia”, il romanziere ha messo in rilievo la titanica figura del suo corregionale sia come filosofo, sia come teorico in “Poetica”, sia come autore di ...

  18. Guides for flow sensors selection; Guias para la seleccion de sensores de flujo

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Garcia, Gustavo; Guzman Flores, Roberto; Rodriguez Martinez, Arnulfo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1995-12-31

    In this paper a system is presented that allows the selection and calculation on instruments for flow measurement, based on practical experiences, standards an taking into consideration the process operational characteristics such as fluid type, maximum flow rate, piping diameter, etc. The system is composed of a knowledge base and a software for the selection, calculation and de adequate recommendation of flow sensing elements for the different services needed in the power plants. [Espanol] En este trabajo se presenta un sistema que permite realizar la seleccion y calculo de instrumentos para la medicion de flujo con base en experiencias practicas, normas y tomando en cuenta las caracteristicas de operacion del proceso como el tipo de fluido, flujo maximo, diametro de tuberia, etcetera. El sistema esta compuesto por una base de conocimiento y un software para la seleccion, calculo y la recomendacion adecuada de elementos sensores de flujo para los diferentes servicios que se tienen en centrales generadoras.

  19. Guides for flow sensors selection; Guias para la seleccion de sensores de flujo

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Garcia, Gustavo; Guzman Flores, Roberto; Rodriguez Martinez, Arnulfo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    In this paper a system is presented that allows the selection and calculation on instruments for flow measurement, based on practical experiences, standards an taking into consideration the process operational characteristics such as fluid type, maximum flow rate, piping diameter, etc. The system is composed of a knowledge base and a software for the selection, calculation and de adequate recommendation of flow sensing elements for the different services needed in the power plants. [Espanol] En este trabajo se presenta un sistema que permite realizar la seleccion y calculo de instrumentos para la medicion de flujo con base en experiencias practicas, normas y tomando en cuenta las caracteristicas de operacion del proceso como el tipo de fluido, flujo maximo, diametro de tuberia, etcetera. El sistema esta compuesto por una base de conocimiento y un software para la seleccion, calculo y la recomendacion adecuada de elementos sensores de flujo para los diferentes servicios que se tienen en centrales generadoras.

  20. das publicações em periódicos nacionais

    Directory of Open Access Journals (Sweden)

    Marléa Chagas Moreira

    2006-01-01

    Full Text Available Estudio de clasificación sobre la producción del conocimiento en la enfermería en oncología. Los objetivos son: identificar las publicaciones en la enfermería en oncología en el período entre 1994 y 2004 y, analizar en las publicaciones, los aspectos epistemológicos señalados en las tematicas focalizadas y en el encuadramiento teorico-metodológico adoptado en los estudios. El referencial teorico-metodológico conjuntamente a una metodología epistemológica para la investigación en la enfermería. Fueram utilizados como fuentes de datos tres periódicos: la Revista Brasileña de Enfermería, la Revista Latinoamericana de Enfermería y la Revista Brasileña de Cancerología . De acuerdo con los resultados, las autoras consideran que el conocimiento producido en el área de la enfermería oncológica éstos son consistentes con la complejidad y las tentativas de explicación sobre el arte de cuidar de los clientes y con los esfuerzos de ampliar los criterios y los patrones asistenciales.

  1. Transactions of the Second All-Union Conference on Charged Particle Accelerators (Moscow, 11-18 November 1970). Volume 2

    Science.gov (United States)

    1980-10-09

    vectorial addition of dipola and quadruDole the component of field in ouerating regicn, whicn leads to the relatively smaller values of induction in...hetarogenaity of impuises/momenta/pulses is assumed to be equal to 6=+-1O-3. In the calculo -..ions were utilized the geometric and magnetic parameters of

  2. Lo sport nelle scienze sociali: da chimera a realtà

    Directory of Open Access Journals (Sweden)

    Marco Pasini

    2013-04-01

    Full Text Available Lo sport per la sua trama profonda, le implicazioni che cristallizza, le emozioni che condensa, è fonte di interpretazione e osservatorio straordinariamente ricco per la ricerca sociale. L'obiettivo di questo numero della rivista, grazie ai contributi qualificati, trasversali, multidisciplinari ed empirici, è proprio quello di affrontare le questioni fondamentali sopra indicate attraverso differenti percorsi di senso e approcci teorico-metodologici specifici.

  3. Comunità virtuali per l'apprendimento e nuove tecnologie

    Directory of Open Access Journals (Sweden)

    Stefania Manca

    2002-01-01

    Full Text Available Le comunita' virtuali per l'apprendimento rivestono oggi particolare interesse in ambito formativo in quanto sembrano sancire definitivamente un cambiamento di paradigma teorico e metodologico. L'idea costruttivista ha, infatti, progressivamente sostituito il modello tradizionale del trasferimento di conoscenza, secondo cui apprendere significa essere in grado di esibire conoscenze e capacita' oggettivamente misurabili, decontestualizzate e aventi valore di verita' oggettive, universalmente confrontabili.

  4. Refurbishment of the power supply and NMR systems

    International Nuclear Information System (INIS)

    Dugay, G.

    1998-01-01

    This paper summarises some of the first renovation performed on GANIL power converters, their control system and on magnetic field measurements. Among numerous actions undertaken the most important four, mentioned in the report are: remote control interfaces; current catchers; pulsed supplies; RMN system renovation

  5. Caracterização de acetato de celulose obtido a partir do bagaço de cana-de-açúcar por ¹H-RMN 1H-NMR characterization of cellulose acetate obtained from sugarcane bagasse

    Directory of Open Access Journals (Sweden)

    Daniel A. Cerqueira

    2010-06-01

    Full Text Available A celulose do bagaço de cana-de-açúcar foi usada para sintetizar acetato de celulose com diferentes graus de substituição, os quais foram caracterizados por ¹H-RMN através da relação entre as áreas dos picos dos átomos de hidrogênio presentes nos grupos acetato (-(C=OOCH3 e os picos dos hidrogênios ligados aos átomos de carbono dos anéis glicosídicos. A supressão de alguns sinais foi feita para remover sinais de ressonância da água residual nos materiais e também para remover sinais de impurezas no triacetato de celulose. Um método de deconvolução para o cálculo computacional do grau de substituição foi proposto. Os graus de substituição das amostras de acetato de celulose foram 2,94 e 2,60, o que está de acordo com os resultados por determinação química através de uma titulação ácido base.Cellulose from sugarcane bagasse was used for synthesizing cellulose acetate with different degrees of substitution, which were characterized by ¹H-NMR through the relationship between the peak areas of the hydrogen atoms of the acetate groups (-(C=OOCH3 and the peaks of the hydrogen bonded to the carbon atoms of the glucosidic rings. Suppression of some signals was carried out in order to remove the residual water resonance in the materials and those related to impurities in cellulose triacetate as well. A deconvolution method for the computation of the degree of substitution of acetylation is proposed. The degrees of substitution for the cellulose samples were 2.94 and 2.60, in good agreement with those obtained by chemical determination through an acid-base titration.

  6. Caracterização dos constituintes poliméricos da Maytenus ilicifolia por relaxação nuclear de ¹H por RMN no estado sólido Characterization of Maytenus ilicifolia Samples by ¹H NMR relaxation in the solid state

    Directory of Open Access Journals (Sweden)

    Mônica S. de M. Preto

    2011-01-01

    Full Text Available A Maytenus ilicifolia, conhecida como espinheira-santa, é uma planta popular de uso diverso, como chá é empregada no combate a problemas de doenças gástricas e da diabetes, por exemplo. As plantas possuem em sua constituição polímeros naturais como polissacarídeos, politerpenoides, celulose e fibras. O estudo dos constituintes poliméricos nesse tipo de material tem importância fundamental tanto na identificação, ou seja, qualificação quanto na adulteração da planta. É sabido que podem ser encontrados diversos produtos rotulados como sendo originário da mesma planta, entretanto, muitas das vezes a origem da planta é similar, mas não a mesma, o que pode gerar algum desconforto ou não atividade biológica dos chás quando da ingestão destes. Na literatura não são encontrados muitos trabalhos que envolvam a caracterização comparativa dos constituintes poliméricos, como polissacarídeos e fibras presentes em amostras de origens distintas, para comprovação de adulteração destes produtos. Uma técnica que pode ser promissora para este tipo de estudo é a Ressonância Magnética Nuclear (RMN em estado sólido, já que permite analisar a amostra in natura não sendo um método destrutivo ou invasivo. Esta espectroscopia analisa amostras em campos magnéticos de diferentes potências ou forças. Neste trabalho é apresentado um estudo de caracterização dos constituintes poliméricos majoritários presentes na M. ilicifolia. Três amostras foram estudadas: uma amostra denominada controle e duas comerciais. O estudo envolveu a determinação dos tempos de relaxação spin-rede (T1 do ¹H utilizando a técnica de campo cíclico rápido (FFC, numa gama de frequências que variou de 100 kHz a 10 MHz. Assim, o principal objetivo deste trabalho foi estudar a possibilidade de utilização da RMN de baixo campo magnético na elaboração de um método expedito de análise que permita realizar a caracterização estrutural

  7. Critical experiments and nuclear calculations - LAMPRE-I; Experiences critiques et calculs nucleaires concernant le LAMPRE-I; Kriticheskie opyty i yadernye raschety - LAMPRE-I; Experimentos criticos u calculos nucleares relativos al LAMPRE-I

    Energy Technology Data Exchange (ETDEWEB)

    Battat, M E [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

    1962-03-15

    utilise la methode S{sub n} pour resoudre le probleme du transport neutronique. La comparaison entre les valeurs calculees et les valeurs mesurees des parametres, tels que le coefficient thermique, l'efficacite des barres de controle et la masse critique, presente aussi de l'interet pour evaluer le degre de confiance que l'on peut accorder aux calculs des bureaux d'etudes. (author) [Spanish] Como parte de un programa de ensayos de combustibles de plutonio para reactores reproductores de neutrones rapidos, se ha construido y puesto en marcha en el Los Alamos Scientific Laboratory un reactor experimental de 1 MW refrigerado por sodio, cuyo cuerpo contiene una aleacion fundida de plutonio y hierro (90 atomos por ciento de Pu y 10 atomos por ciento de Fe; punto de fusion: 410 deg. C). La reactividad se regula por medio de un reflector de acero inoxidable y de cuatro barras de control de niquel situadas fuera del nucleo. Se han llevado a cabo experimentos a temperaturas (isotermicas) de 80, 160 y 480 deg. C en el cuerpo, a fin de determinar la masa critica y la eficacia del reflector a cada una de esas temperaturas. Tambien se midio la eficacia de las barras de control, por registro de los periodos y del coeficiente termico de la reactividad. Aplicando el metodo S{sub n} de resolucion del problema del transporte neutronico, se efectuaron calculos para determinar los parametros nucleares basicos del reactor. La comparacion entre los valores calculados y los valores medidos de parametros tales como el coeficiente termico, la eficacia de las barras de control y la masa critica, presenta tambien interes en lo que se refiere a la evaluacion del grado de confianza que puede atribuirse a los calculos del proyectista. (author) [Russian] V kachestve chasti programmy po razvitiyu plutonievogo topliva dlya reaktorov-razmnozhitele j na bystrykh nejtronakh Los-Alamosskaya nauchnaya laboratoriya skonstruirovala i ehkspluatiruet ispytatel'nyj reaktor s natrievym okhlazhdeniem moshchnost'yu v

  8. Identificação de δ tocotrienol e de ácidos graxos no óleo fixo de urucum (Bixa orellana Linné

    Directory of Open Access Journals (Sweden)

    C.K. Costa

    2013-01-01

    Full Text Available Bixa orellana é uma planta nativa do Brasil, conhecida popularmente como urucum. O objetivo desse estudo foi extrair o óleo das sementes de B. orellana e, a partir dele, isolar e identificar o tocotrienol e quantificar seus ácidos graxos. A extração do óleo realizou-se em aparelho Soxhlet utilizando hexano como solvente extrator. O tocotrienol foi isolado por meio de métodos cromatográficos e identificado por espectrometria de ressonância magnética nuclear RMN ¹H e RMN 13C. Os ácidos graxos foram quantificados por cromatografia gasosa acoplada ao espectrômetro de massa. Os resultados demonstraram a presença de δ -tocotrienol e, dentre os ácidos graxos, a ocorrência do ácido aracdônico, que até o presente momento não havia sido relatada na espécie em estudo.

  9. Hydrogenation of heteroaromatics by high pressure DTA techniques. 3; Koatsu DTA ho ni yoru hokozoku kagobutsu no suisoka (rutenium tanji shokubai ni yoru kakusuisoka datsu hetero hanno)

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, M.; Yoshida, T. [Hokkaido National Industrial Research Institute, Sapporo (Japan); Kotanigawa, T. [Japan International Cooperation Agency, Tokyo (Japan)

    1996-10-28

    Ring-opening of heteroaromatics and heteroatom-removal reaction were studied experimentally using the acidic catalyst containing phosphoric acid for improvement of an upgrading method of coal derived oils. In experiment, some Ru-carrying metal oxide catalysts such as RMZ, RML and RMN catalyst, and MNP catalyst containing phosphoric acid were used as specimens. Nuclear hydrogenation reaction and hydro-denitrogenation reaction of dibenzothiophene and carbazole were compared with each other. The experimental results are as follows. Both RMN and RMNP catalysts offer a superior selectivity in nuclear hydrogenation reaction and hydro-denitrogenation reaction of carbazole. Although both catalysts offer an extremely high nuclear hydrogenation activity at 360{degree}C, these offer the high selectivity of denitrogenation products at 430{degree}C. In comparison of the activities of MN and MNP catalysts with the same Mn2O3:NiO ratio, MNP catalyst offers the higher denitrogenation activity than MN catalyst at 430{degree}C. 1 ref., 3 tabs.

  10. ESTRUCTURA TRIDIMENSIONAL DEL a-CICLOPROPIL- (p-METOXIFENIL-5-PIRIMIDINMETANOL (ANCIMIDOL UTILIZANDO EL MÉTODO DE RESONANCIA MAGNÉTICA NUCLEAR

    Directory of Open Access Journals (Sweden)

    O. Ospina

    2005-12-01

    Full Text Available El Ancimidol, α-ciclopropil-(p-metoxifenil-5-pirimidinmetanol, (C15H16N2O2 es un regulador de crecimiento vegetal sintético, que hace parte del grupo de compuestos heterocíclicos que contienen nitrógeno que inhiben la síntesis de las giberelinas. La estructura de esta molécula se determinó por resonancia magnética nuclear, partiendo de una solución en cloroformo deuterado (CDCl3, utilizando un espectrómetro de 500MHz (campo de 11.7Teslas. Se tomaron espectros unidimensionales RMN 1H, RMN 13C, pruebas DEPT 45, 90 y 135 y espectros bidimensionales HMBC y HMQC. En la estructura obtenida para el Ancimidol, se observaron tres ciclos como son la pirimidina, el metoxifenilo y el ciclopropilo, identi-ficados por la asignación de los átomos de hidrógeno y de carbono y por las relaciones de conectividad dadas por los espectros bidimensionales HMBC y HMQC.

  11. Pulsation, Mass Loss and the Upper Mass Limit

    Science.gov (United States)

    Klapp, J.; Corona-Galindo, M. G.

    1990-11-01

    RESUMEN. La existencia de estrellas con masas en exceso de 100 M0 ha sido cuestionada por mucho tiempo. Lfmites superiores para la masa de 100 M0 han sido obtenidos de teorfas de pulsaci6n y formaci6n estelar. En este trabajo nosotros primero investigamos la estabilidad radial de estrellas masivas utilizando la aproximaci6n clasica cuasiadiabatica de Ledoux, la aproximaci6n cuasiadiabatica de Castor y un calculo completamente no-adiabatico. Hemos encontrado que los tres metodos de calculo dan resultados similares siempre y cuando una pequefia regi6n de las capas externas de la estrella sea despreciada para la aproximaci6n clasica. La masa crftica para estabilidad de estrellas masivas ha sido encontrada en acuerdo a trabajos anteriores. Explicamos Ia discrepancia entre este y trabajos anteriores por uno de los autores. Discunmos calculos no-lineales y perdida de masa con respecto a) lfmite superior de masa. The existence of stars with masses in excess of 100 M0 has been questioned for a very long time. Upper mass limits of 100 Me have been obtained from pulsation and star formation theories. In this work we first investigate the radial stability of massive stars using the classical Ledoux's quasiadiabatic approximation. the Castor quasiadiabatic approximation and a fully nonadiabatic calculation. We have found that the three methods of calculation give similar results provided that a small region in outer layers of the star be neglected for the classical approximation. The critical mass for stability of massive stars is found to be in agreement with previous work. We explain the reason for the discrepancy between this and previous work by one of the authors. We discuss non-linear calculations and mass loss with regard to the upper mass limit. Key words: STARS-MASS FUNCTION - STARS-MASS LOSS - STARS-PULSATION

  12. Sistema de información automatizado de recursos humanos para una institución de educación superior

    Directory of Open Access Journals (Sweden)

    Milagros Gómez de Gómez

    2004-01-01

    Full Text Available La presente propuesta es el diseño de un sistema de informacion para la direccion de recursos humanos de la Universidad Dr. Rafael Belloso Chacin, basado en los modelos teoricos planteados por sen, chiavenato, montilva, kendall y kendall. se contruyo sobre un diagnostico previo de la institucion en el cual participaron dos grupos: el primero construido por el personal directivo y el segundo por el personal administrativo.

  13. Smart movie tourism: la nuova frontiera del cineturismo / Smart movie tourism: the new frontier of cine-tourism

    OpenAIRE

    Teresa Graziano

    2016-01-01

    Inserito nel quadro teorico della letteratura sulla Smart City, il presente lavoro mira ad analizzare le implicazioni derivanti dall’utilizzo delle nuove tecnologie intelligenti per la valorizzazione turistica delle location cinematografiche. Dal punto di vista metodologico, l’articolo si fonda su un’analisi quali-quantitativa di alcuni casi di smart movie tourism, al fine di indagare le caratteristiche delle applicazioni per smartphone e tablet (apps) che consentono la riproduzione virtuale ...

  14. La valutazione di dimensioni dello stress, risorse adattive e disagio emozionale in coppie infertili

    OpenAIRE

    Ambrosino, Anna

    2011-01-01

    Il lavoro si inserisce nel filone degli studi sullo stress e coping e assume come riferimento teorico il modello transazionale dello stress di Lazarus (Lazarus, 1966, 1999; Lazarus e Folkman, 1984, 1987). Inserendosi in questo orizzonte, la ricerca si propone di: - esplorare le risorse adattive e il vissuto emotivo percepito dai membri delle coppie infertili che intraprendono un percorso di Procreazione Medicalmente Assistita (PMA), evidenziando l’effetto protettivo e moderatore rispe...

  15. Investigation of Y6Mn23 and YMn12 intermetallic alloys under high hydrogen pressure

    Science.gov (United States)

    Filipek, S. M.; Sato, R.; Kuriyama, N.; Tanaka, H.; Takeichi, N.

    2010-03-01

    Among three intermetallic compounds existing in Y-Mn system the YMn2 and Y6Mn23 can easily form interstitial hydrides while for YMn12 existence of hydride has never been reported. At moderate hydrogen pressure YMn2 and Y6Mn23 transform into YMn2H4.5 and Y6Mn23H25 respectively. At high hydrogen pressure the YMn2 (C15 or C14 parent structure) forms a unique YMn2H6 (s.g. Fm3m) complex hydride of fluorite structure in which one Mn atom Mn(1) and Y randomly occupy the 8c sites while second manganese (Mn2) in position 4a forms complex anion with 6 hydrogen atoms located in positions 24e. Formation of YMn2H6 independently of the structure of parent phase (C14 or C15) as well as occupation of the same site (8c) by Y and Mn(1) atoms suggested that also Y6Mn23 and YMn12 could transform into YMn2H6 - type hydride in which suitable number of Y atoms will be substituted by Mn(1) in the 8c positions. This assumption was confirmed by exposing R6Mn23 and RMn12 to 1 GPa of hydrogen pressure at 1000C. Formation of (RxMn2-x)MnH6 (where x = 18/29 or 3/13 for R6Mn23 and RMn12 hydrides respectively) was confirmed by XRD. Hydrogen concentration in both R6Mn23 and RMn12 based hydrides reached H/Me = 2 thus value two times higher than in R6Mn23H25.

  16. Síntesis y actividad citotóxica de conjugados de la uridina con triterpenos en células de cáncer de mama

    Directory of Open Access Journals (Sweden)

    Jhon Fernando Berrío Escobar

    Full Text Available Objetivos: Sintetizar conjugados del acetónido de la uridina con triterpenos (colesterol y 3β-5α,8α-endoperoxido-colest-6-en-3-ol y ácido succínico como puente. Métodos: Se preparó el acetónido de la uridina en acetona mediante catálisis ácida. Se prepararon los succinatos de los esteroles con anhídrido succínico y catalizador nucleofílico 4-N,N-dimetilamino-piridina (DMAP. Los conjugados 1 y 2 se sintetizaron mediante la esterificación de Steglich, con agente de acoplamiento N,N'-diciclohexilcarbodiimida (DCCy DMAP. Los compuestos se caracterizaron por espectroscopia de RMN (¹H RMN y 13C RMN y espectrometría de masas. Los derivados se evaluaron sobre líneas celulares de ovario de hámster chino (CHO-K1 y de cáncer de mamá (MCF-7. Resultados: Se obtuvieron derivados conjugados del acetónido de la uridina con dos triterpenos con rendimientos superiores al 80%. Los conjugados de uridina con triterpenos no presentaron inhibición significativa de la viabilidad celular sobre las líneas celulares MCF-7 y CHO-K1, tampoco se evidenció una relación dosis-respuesta para los compuestos evaluados. Conclusiones: El método de esterificación con agentes de acoplamiento permitió obtener conjugados de la uridina con triterpenos empleando el ácido succínico como puente. Sin embargo los derivados de uridina obtenidos no presentaron actividad citotóxica significativa (p<0,05 sobre las líneas celulares evaluadas.

  17. Prediction and prognosis of ventricular tachycardia recurrence after catheter ablation with remote magnetic navigation for electrical storm in patients with ischemic cardiomyopathy.

    Science.gov (United States)

    Jin, Qi; Jacobsen, Peter Karl; Pehrson, Steen; Chen, Xu

    2017-11-01

    Ventricular tachycardia (VT) recurrence after catheter ablation for electrical storm is commonly seen in patients with ischemic cardiomyopathy (ICM). We hypothesized that VT recurrence can be predicted and be related to the all-cause death after VT storm ablation guided by remote magnetic navigation (RMN) in patients with ICM. A total of 54 ICM patients (87% male; mean age, 65 ± 7.1 years) presenting with VT storm undergoing acute ablation using RMN were enrolled. Acute complete ablation success was defined as noninducibility of any sustained monomorphic VT at the end of the procedure. Early VT recurrence was defined as the occurrence of sustained VT within 1 month after the first ablation. After a mean follow-up of 17.1 months, 27 patients (50%) had freedom from VT recurrence. Sustained VT recurred in 12 patients (22%) within 1 month following the first ablation. In univariate analysis, VT recurrence was associated with incomplete procedural success (hazard ratio [HR]: 6.25, 95% confidence interval [CI]: 1.20-32.47, P = 0.029), lack of amiodarone usage before ablation (HR: 4.71, 95% CI: 1.12-19.7, P = 0.034), and a longer procedural time (HR: 1.023, 95% CI: 1.00-1.05, P = 0.05). The mortality of patients with early VT recurrence was higher than that of patients without recurrence (P storm guided by RMN is the strongest predictor of VT recurrence. ICM patients who have early recurrences after VT storm ablation are at high risk of all-cause death. © 2017 Wiley Periodicals, Inc.

  18. T. A. Sebeok e i congegni di modellazione del mondo: strumenti teorici al servizio delle pratiche professionali

    Directory of Open Access Journals (Sweden)

    Giorgio Maggi

    2005-06-01

    Full Text Available L'elaborato si compone di una parte che comprende l'illustrazione delle linee generali del pensiero teorico di T. A. Sebeok e nello specif ico della sua teoria dei "sistemi di modellazione", e l'altra che include le riflessioni circa la possibilità di adoperare l'approccio biosemiotico alla realtà sociale e costruire, in tale direzione, un professionalismo ideal-tipico che sia capace di rispondere alle esigenze pratiche della vita quotidiana.

  19. L'esperienza della Grande Guerra nell'autobiografia femminile in Gran Bretagna

    OpenAIRE

    Porzio, Barbara

    2009-01-01

    Il presente lavoro è incentrato sull’analisi delle autobiografie femminili della prima guerra mondiale pubblicate in Gran Bretagna negli anni Trenta del secolo scorso. Nell’introduzione, dopo una breve riflessione di carattere teorico e metodologico sul genere autobiografico ed alcune considerazioni sul contesto storico-culturale in cui nacquero tali opere, viene rintracciata una griglia di argomentazioni retoriche ricorrenti che se da un lato non consentono di ipotizzare l’esistenza di un so...

  20. Trimethylphosphide isomerization in lanthanum ions presence

    International Nuclear Information System (INIS)

    Zacharias, M.A.; Massabni, A.M.G.

    1984-01-01

    The integration between the trimethilphosphide and the lanthanum ions carry to the formation of solid complexes in a relation of 6:1 where the ligand is the phosphonate what is resultant of the isomerization of trimetylphosphite. By the RMN -1 H and infra-red spectra the products were characterized. (L.M.J.) [pt

  1. Effects of geometry in itinerant electron magnets

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, H [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan); Muro, Y [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan); Kohara, T [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan); Shiga, M [Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan)

    2007-04-11

    The magnetism of quasi-one-dimensional itinerant electron magnets RMn{sub 4}Al{sub 8} is compared with that of the typical frustrated itinerant electron magnet YMn{sub 2}. The possible formation and observation of the spin pseudogap are discussed in connection with the spin-liquid state in strongly correlated itinerant electron systems.

  2. Emergency response exercise of laboratories equipped with gammaspectrometry

    International Nuclear Information System (INIS)

    Mala, H.; Jezkova, T.; Rulik, P.; Beckova, V.

    2014-01-01

    Seven laboratories equipped with semiconductor gamma spectrometry (HPGe detectors) are currently included in the Radiation Monitoring Network (RMN) in the Czech Republic. These laboratories have more than 30 spectrometric chains and approximately 20 'experts' and 70 'users' who would guarantee measurements during the radiological emergency (RE). The emergency exercise was carried out in 5 of them in 2014 (in 4 of them also in 2013). The aim was to test repeatedly their capacity in existing technical facilities and with current staff in the event of a RE and identify problems (bottlenecks) in the whole process from receipt of samples to entering the results into the central database of RMN. Duration of the exercise was 12 hours, due to the shortage of staff; work in one 12-hour shift is presumed during a RE, which the laboratories should be able to provide for 14 days. These exercise samples covered a wide range of commodities that would probably come to the laboratories during the RE (aerosol filters, sorbents for sorption of gaseous forms of iodine, fallout, surface and drinking waters, food chain components and soils). Some of the samples were previously spiked with 85 Sr, 88 Y and 40 K (in the exercise these nuclides represented actual contamination that would occur in RE); liquid samples were spiked with 85 Sr and 88 Y and bulk materials with 40 K.During the exercise almost 800 samples were analysed; in addition, the automatic gamma counter (GA) in Prague laboratory measured other 90 samples automatically during the night (samples were prepared during the day-shift). On the basis of the results the total measuring capacity of the laboratories of RMN CR was estimated at about 1300 samples per day. (authors)

  3. Investigation of Y6Mn23 and YMn12 intermetallic alloys under high hydrogen pressure

    International Nuclear Information System (INIS)

    Filipek, S M; Sato, R; Kuriyama, N; Tanaka, H; Takeichi, N

    2010-01-01

    Among three intermetallic compounds existing in Y-Mn system the YMn 2 and Y 6 Mn 23 can easily form interstitial hydrides while for YMn 12 existence of hydride has never been reported. At moderate hydrogen pressure YMn 2 and Y 6 Mn 23 transform into YMn 2 H 4.5 and Y 6 Mn 23 H 25 respectively. At high hydrogen pressure the YMn 2 (C15 or C14 parent structure) forms a unique YMn 2 H 6 (s.g. Fm3m) complex hydride of fluorite structure in which one Mn atom Mn(1) and Y randomly occupy the 8c sites while second manganese (Mn2) in position 4a forms complex anion with 6 hydrogen atoms located in positions 24e. Formation of YMn 2 H 6 independently of the structure of parent phase (C14 or C15) as well as occupation of the same site (8c) by Y and Mn(1) atoms suggested that also Y 6 Mn 23 and YMn 12 could transform into YMn 2 H 6 - type hydride in which suitable number of Y atoms will be substituted by Mn(1) in the 8c positions. This assumption was confirmed by exposing R 6 Mn 23 and RMn 12 to 1 GPa of hydrogen pressure at 100 0 C. Formation of (R x Mn 2-x )MnH 6 (where x = 18/29 or 3/13 for R 6 Mn 23 and RMn 12 hydrides respectively) was confirmed by XRD. Hydrogen concentration in both R 6 Mn 23 and RMn 12 based hydrides reached H/Me = 2 thus value two times higher than in R 6 Mn 23 H 25 .

  4. Emergency response exercise of laboratories equipped with gamma spectrometry

    International Nuclear Information System (INIS)

    Mala, H.; Jezkova, T.; Rulik, P.; Beckova, V. et al.

    2014-01-01

    Seven laboratories equipped with semiconductor gamma spectrometry (HPGe detectors) are currently included in the Radiation Monitoring Network (RMN) in the Czech Republic. These laboratories have more than 30 spectrometric chains and approximately 20 'experts' and 70 'users' who would guarantee measurements during the radiological emergency (RE). The emergency exercise was carried out in 5 of them in 2014 (in 4 of them also in 2013). The aim was to test repeatedly their capacity in existing technical facilities and with current staff in the event of a RE and identify problems (bottlenecks) in the whole process from receipt of samples to entering the results into the central database of RMN. Duration of the exercise was 12 hours, due to the shortage of staff; work in one 12-hour shift is presumed during a RE, which the laboratories should be able to provide for 14 days. These exercise samples covered a wide range of commodities that would probably come to the laboratories during the RE (aerosol filters, sorbents for sorption of gaseous forms of iodine, fallout, surface and drinking waters, food chain components and soils). Some of the samples were previously spiked with 85 Sr, 88 Y and 40 K (in the exercise these nuclides represented actual contamination that would occur in RE); liquid samples were spiked with 85 Sr and 88 Y and bulk materials with 40 K.During the exercise almost 800 samples were analysed; in addition, the automatic gamma counter (GA) in Prague laboratory measured other 90 samples automatically during the night (samples were prepared during the day-shift). On the basis of the results the total measuring capacity of the laboratories of RMN CR was estimated at about 1300 samples per day. (authors)

  5. Calculation of the temperature distribution and thermal stresses in a gas turbine nozzle cooled by air film; Calculo de la distribucion de temperaturas y esfuerzos termicos en una tobera de turbina de gas enfriada por pelicula de aire

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez R, Alejandro; Garcia I, Rafael; Mazur C, Zdislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    temperaturas. Con las temperaturas correctamente importadas, se realizaron las simulaciones para el calculo de los esfuerzos termicos en la tobera.

  6. Magnetic structure and physical properties of the multiferroic compound PrMn{sub 2}O{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Doubrovsky, C. [Laboratoire de Physique des Solides, Universite Paris-Sud, CNRS-UMR 8502, 91405 Orsay Cedex (France); Andre, G. [Laboratoire Leon Brillouin, CEA-CNRS UMR 12, 91191 Gif-sur-Yvette Cedex (France); Bouquet, F. [Laboratoire de Physique des Solides, Universite Paris-Sud, CNRS-UMR 8502, 91405 Orsay Cedex (France); Elkaim, E. [Soleil Synchrotron, 91191 Gif-sur-Yvette Cedex (France); Li, M.; Greenblatt, M. [Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States); Foury-Leylekian, P., E-mail: pascale.foury@u-psud.fr [Laboratoire de Physique des Solides, Universite Paris-Sud, CNRS-UMR 8502, 91405 Orsay Cedex (France)

    2012-06-01

    RMn{sub 2}O{sub 5} (R=lanthanide, Bi, Y) multiferroic compounds are intensively studied for their potential application in the spintronic field. In these systems, the key issue is to understand the origin of the strong coupling between the ferroelectric and magnetic orders and to investigate the influence of the nature of the R ions in this coupling. While the phase diagram of RMn{sub 2}O{sub 5} compounds with small R size is well established, this of large R size compounds is missing due to the lack of samples originating with difficulties of synthesis. We present in this paper the first investigation of the thermodynamic, structural and magnetic properties of high quality polycrystalline PrMn{sub 2}O{sub 5} samples. Our work shows that PrMn{sub 2}O{sub 5} presents two magnetic transitions corresponding to commensurate magnetic orderings. We also evidence a weak lattice effect coupled to the magnetic order. Our results point out that the physical properties of PrMn{sub 2}O{sub 5} differ from those of the parent compounds with magnetic R ions.

  7. Nuclear magnetic resonance at 310 MHz in a superconducting solenoid; Resonance magnetique nucleaire a 310 MHz dans un solenoide supra-conducteur

    Energy Technology Data Exchange (ETDEWEB)

    Dunand, J J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    The realisation of an NMR spectrometer with a superconducting magnet is presented in the first section. The methods to attain the best possible homogeneity of the magnetic field and to minimize the error in the spectrometer are described. The second section is devoted to the study of elastomers and nitr-oxides free radicals. A shift of the transition temperature with the magnetic field appears for the elastomers. The increasing paramagnetic shift has allowed a complete study by NMR of piperidinic and pyrrolidinic nitroxide free radicals. (author) [French] Dans la premiere partie est exposee la realisation d'un spectrometre de RMN utilisant un solenoide supraconducteur. Des solutions sont donnees pour obtenir la meilleure homogeneite possible du champ magnetique et pour minimiser les sources d'erreur apportees par le spectrometre. La deuxieme partie est consacree a l'etude d'elastomeres et de radicaux libres nitroxydes. Une variation de la temperature de transition avec le champ magnetique est mise en evidence pour les elastomeres. L'accroissement du deplacement paramagnetique a permis une etude complete par RMN des radicaux libres nitroxydes piperidiniques et pyrrolidiniques. (auteur)

  8. Magnetic resonance in zero-field: construction of a spectrometer, evaluation of a method for structure studies

    International Nuclear Information System (INIS)

    Llor, M.

    1987-01-01

    The method known as Nuclear Resonance in the zero-field, applied to the spectral analysis of powders, is discussed. In the method, the anisotropy due to the preferential direction of the magnetic field is suppressed, but a high sensitivity is keeped. For powders spectra, the process allows the obtention resolutions, of dipolar and quadrupolar couplings, in the range of those only obtained on monocrystals under strong fields. By suitable magnetic field oscillations, and by the effect of the high field on the RMN signal, the transient evolutions of the spins are obtained. Concerning the absence of a preferred direction in the zero-field, a powder or the monocrystals show nearly the same behavior. In such conditions, a much more interesting spectra than those from a powder in a strong field, can be obtained. The RMN spectrometer is described. The possibilities, the experimental and theoretical limits of the proposed method, are analyzed. Applications on dipolar (proton and phosphor) and quadrupolar (deuterium) interactions, on hydrated salts and on cyclophasphazenes are carried out [fr

  9. Spin reorientation behavior in Yb doped YMnO3

    International Nuclear Information System (INIS)

    Sharma, Neetika; Das, A.

    2014-01-01

    RMnO 3 with smaller rare-earths ions (R = Ho to Lu and Y) crystallize in the non-centrosymmetric hexagonal space group P6 3 cm. The magnetic structure of RMnO 3 compounds with (R=Er,Yb.Lu) are described by irreducible representations (IR) Γ 2,4 and Γ 1,3 for those with higher ionic radii (R=Ho,Y,Y-Er). Of recent the magnetic structure of YMnO 3 has been found to be better described by Γ 3 + Γ 4 IR. YbMnO 3 is another hexagonal manganite, with almost similar transition temperature, and basically shares all the physical properties of YMnO 3 , except for the magnetic structure. The magnetic structure of YbMnO 3 can be explained by Γ 2 or Γ 4 . The non collinear nature of magnetic ordering in these compounds arises due to the frustration inherent in these compounds. In this study we have probed the effect of a magnetic ion (Yb) on the magnetic structure of these frustrated isostructural compounds

  10. The band gap of II-Vi ternary alloys in a tight-binding description

    Energy Technology Data Exchange (ETDEWEB)

    Olguin, Daniel; Blanquero, Rafael [Instituto Politecnico Nacional, Mexico, D.F (Mexico); De Coss, Romeo [Instituto Politecnico Nacional, Yucatan (Mexico)

    2001-02-01

    We present tight-binding calculations for the band gap of II-Vi pseudobinary ternary alloys. We use an sp{sup 3} s* tight-binding Hamiltonian which include spin-orbit coupling. The band gap composition dependence is calculated using a extended version of the virtual crystal approximation, which introduce an empirical correction factor that takes into account the non-linear dependence of the band gap with the composition. The results compare quite well with the experimental data, both for the ternary alloys with wide band gap and for the narrow band gap ones. [Spanish] Presentamos el calculo de la banda de energia prohibida de aleaciones ternarias de compuestos II-VI. El calculo, que incluye interaccion espin-orbita, se hace con el metodo de enlace fuerte, utilizando una base ortogonal de cinco orbitales atomicos por atomo (sp{sup 3} s*), en conjunto con la aproximacion del cristal virtual. En la aproximacion del cristal virtual, incluimos un factor de correccion que toma en cuenta la no linealidad de la banda de energia prohibida como funcion de la concentracion. Con esta correccion nuestros resultados reproducen aceptablemente los datos experimentales hallados en la literatura.

  11. Author Details

    African Journals Online (AJOL)

    Tianansoa, RM. Vol 10, No 3 (2014) - Articles Analyse directe des sucres dans des mélanges complexes miels de Madagascar par 13C RMN assistée par ordinateur avec première détection et quantification du D-glucitol. Abstract PDF. ISSN: 1813-548X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers ...

  12. Origini della vita

    CERN Document Server

    Dyson, Freeman

    1987-01-01

    Spirito, irrequieto, eccezionalmente colto, Freeman Dyson è lontanissimo dallo stereotipo dello scienziato chiuso nella torre d'avorio della propria specializzazione. In questo saggio egli prende la parola, lui fisico teorico ed esperto di problemi degli armamenti, nel dibattito sull'origine della vita. Un tema che, fino a ieri oggetto di esercitazioni teoriche a sfondo filosofico, comincia ad acquistare una dimensione concreta grazie alle possibilità di verifica sperimentale consentite dai progressi della biologia molecolare e dalle tecniche di simulazione al calcolatore.

  13. La cura della professionalità nei servizi per l’infanzia.

    Directory of Open Access Journals (Sweden)

    Vanna Gherardi

    2007-07-01

    Full Text Available Il presente contributo riporta fasi e risultati di un’indagine empirica sulla percezione di cura di insegnanti di scuola dell’infanzia considerando il loro lavoro di cura, ossia in rapporto alla propria professionalità in istituzioni pubbliche rivolte alla cura dell’infanzia. Il principio teorico di riferimento sta nella reciprocità della cura all’interno di una istituzione educativa in una società democratica. I teorici di riferimento sono: Dewey (1937; Lewin (1948; Bernstein (1975; Bronfenbrenner (1979; Bruner (2002.

  14. Substâncias isoladas das folhas de Bauhinia microstachya (Raddi Macbr. (Caesalpiniaceae

    Directory of Open Access Journals (Sweden)

    E.M. Bianco

    Full Text Available Neste trabalho é relatado o isolamento de três substâncias das folhas de Bauhinia microstachya (Raddi Macbr., Caesalpiniaceae, incluindo dois constituintes isolados pela primeira vez nesta espécie, a vitexina e o hidrocarboneto hexatriacontano. As estruturas desses compostos foram estabelecidas através de estudos de RMN- 1H 1D, 2D e EM.

  15. 2018-02-22T15:11:52Z https://www.ajol.info/index.php/all/oai oai:ojs ...

    African Journals Online (AJOL)

    En RMN 13C, la tributyrine presente deux types de carbone ester a d = 172.32 ppm et 172.69 ppm alors que la tributyrine transesterifiee presente cinq atomes de carbone ester a d = 172.53 ppm,172.89 ppm, 172.98 ppm, 173.21 ppm et 175.57 ppm, dus a la presence des esters intermediaires (deux dibutyrines et deux ...

  16. Encefalomielite aguda disseminada - série de casos

    Directory of Open Access Journals (Sweden)

    Maria Miguel Gomes

    2017-07-01

    Conclusões: A análise desta série de casos sugere que a presença de infeção esteja associada à etiologia da ADEM. A RMN foi o estudo de escolha para diagnóstico e seguimento. O prognóstico foi excelente. A distinção entre ADEM e EM permanece um desafio.

  17. Criticality Studies in a Pilot Plant for Processing MTR-Type Irradiated Fuels; Estudios de Criticidad de una Planta Piloto para el Tratamiento de Combustibles Irradiados Tipo ' MTR '

    Energy Technology Data Exchange (ETDEWEB)

    Pereira Sanchez, G.; Uriarte Hueda, A. [Junta de Energia Nuclear, Division de Materiales Madrid (Spain)

    1966-05-15

    A number of theoretical studies on nuclear safety have been carried out in a pilot plant being constructed at the Junta de Energia Nuclear in Madrid for processing irradiated fuels from the MTR-type experimental reactor JEN-1. The study was carried out working with aqueous and organic solutions at two levels of {sup 235}U enrichment - 20% and 93%. The paper is divided into two main parts: the first deals with the individual items of equipment, and the interactions between these are studied in the second part. The calculations in this second part have been made using three different methods to make it more certain that the system as a whole can never be critical. The first method employed is based on the solid angle concept and makes it possible to fix the maximum {sup 235}U concentrations within the system. The second method, based on the albedo, supplies the value of the multiplication factor K of the whole assembly as a function of the concentration of {sup 235}U. In the last part, the distribution of the equipment is compared with other similar systems and experimental tests from other sources. Finally, the paper specifies the conditions for working the installation which ensure that a nuclear accident can never occur. (author) [Spanish] Se ha efectuado una serie de estudios teoricos sobre la seguridad nuclear de una planta piloto, que se encuentra en construccion en la Junta de Energfa Nuclear situada en Madrid, para el tratamiento de combustibles irradiados procedentes del reactor experimental JEN-1 del tipo MTR. El estudio se ha realizado utilizando disoluciones, tanto acuosas como organicas, con dos grados de enriquecimiento, 20% y 93% en {sup 235}U. Este trabajo comprende dos partes principales: en la primera se han considerado las distintas unidades del equipo individualmente y en la segunda se han estudiado las interacciones entre ellas. El calculo de esta segunda parte se ha hecho por tres metodos diferentes para tener una mayor seguridad de que el

  18. Acceso a la tierra de los ex huasipungueros en la hacienda "Carpuela", en el valle del Chota.

    OpenAIRE

    Villa Zura, Marco Patricio

    2015-01-01

    El propo?sito del presente estudio de investigacio?n es abordar como fue el acceso a la tierra de los ex huasipungueros en la hacienda Carpuela en el Valle del Chota, parroquia Ambuqui?, canto?n Ibarra, Provincia de Imbabura, quienes fortalecieron la organizacio?n comunitaria, apoya?ndose en la Ley de Reforma Agraria, ejecutada por el Instituto Ecuatoriano de Reforma Agraria y Colonizacio?n de 1964 y la de 1973 que continuo. Adema?s autores teo?ricos reflejan la historia de los jesuitas qu...

  19. Elettrodinamica classica teoria e applicazioni

    CERN Document Server

    Lechner, Kurt

    2014-01-01

    Il libro è un testo di Elettrodinamica classica avanzata e comprende anche le basi della Teoria dei campi classici. Come tale è rivolto a qualsiasi studente o ricercatore di Fisica Teorica. Una caratteristica fondamentale del testo è rappresentata da una derivazione rigorosa dei fenomeni ettromagnetici dalle fondamenta teorico-matematiche della teoria, che mette bene in evidenze le inconsistenze e i limiti interni della teoria. Il testo contiene anche un certo numero di argomenti recenti o speculativi che nei libri di testo vengono affrontati solo superficialmente.

  20. Modelo de gestión de talento humano para instituciones privadas de educación media

    OpenAIRE

    Viera Pérez, Diego Sebastián

    2017-01-01

    1. Introduccion. -- 2. Planteamiento de la propuesta del trabajo. --3. Marco Teorico. --4. Metodologia. --5. Analisis e Interpretacion de resultados. --6. Propuesta El presente trabajo de investigación tiene como finalidad mejorar el manejo del personal en las instituciones privadas de educación media al presentar razones del porque es necesario que estas cuenten con un modelo de gestión de talento humano ya que a través de esto se podrá mejorar el servicio que prestan, aprovechando al máx...

  1. Síntese e caracterização do copolímero poli(3-hidroxibutirato-co-ε-caprolactona a partir de poli (3-hidroxibutirato e poli(ε-caprolactona

    Directory of Open Access Journals (Sweden)

    Juan P. B. Roa

    2010-09-01

    Full Text Available O copolímero poli(3-hidroxibutirato-co-ε-caprolactona foi sintetizado por transesterificação, a partir dos homopolímeros PHB e PCL, usando acetilacetonato de zircônio(IV, como catalisador, nas concentrações de 20, 50 e 80% de PHB em massa. Os copolímeros foram caracterizados por GPC, métodos espectroscópicos (RMN-¹H, RMN-13C e IV-FT e métodos térmicos (TG e DSC. A rota de síntese utilizada mostrou-se eficaz na síntese dos copolímeros P(HB-co-CL, os quais mostraram diminuição das cadeias poliméricas, apresentando Mw inferior a 24.000Daltons. Todos os copolímeros obtidos são termicamente mais estáveis que o PHB e com menor cristalinidade que os homopolímeros de partida. Esses materiais são bons candidatos para utilização como biomateriais em matrizes para liberação controlada de fármacos ou mesmo como compatibilizante em blendas PHB/PCL.

  2. Nuclear magnetic resonance at 310 MHz in a superconducting solenoid; Resonance magnetique nucleaire a 310 MHz dans un solenoide supra-conducteur

    Energy Technology Data Exchange (ETDEWEB)

    Dunand, J.J. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    The realisation of an NMR spectrometer with a superconducting magnet is presented in the first section. The methods to attain the best possible homogeneity of the magnetic field and to minimize the error in the spectrometer are described. The second section is devoted to the study of elastomers and nitr-oxides free radicals. A shift of the transition temperature with the magnetic field appears for the elastomers. The increasing paramagnetic shift has allowed a complete study by NMR of piperidinic and pyrrolidinic nitroxide free radicals. (author) [French] Dans la premiere partie est exposee la realisation d'un spectrometre de RMN utilisant un solenoide supraconducteur. Des solutions sont donnees pour obtenir la meilleure homogeneite possible du champ magnetique et pour minimiser les sources d'erreur apportees par le spectrometre. La deuxieme partie est consacree a l'etude d'elastomeres et de radicaux libres nitroxydes. Une variation de la temperature de transition avec le champ magnetique est mise en evidence pour les elastomeres. L'accroissement du deplacement paramagnetique a permis une etude complete par RMN des radicaux libres nitroxydes piperidiniques et pyrrolidiniques. (auteur)

  3. Electromagnetic fields originated by transmission power lines and the electromagnetic compatibility in shared rights of way; Campos electromagneticos producidos por lineas de transmision y la compatibilidad electromagnetica en derechos de via compartidos

    Energy Technology Data Exchange (ETDEWEB)

    Perez Rebolledo, Hugo; Zavala Silva, Moises; Galvan Diego, Arturo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1999-12-31

    This article describes the different types of electromagnetic interference by power lines in rights of way areas. The calculations of the electromagnetic fields obtained under a power line with the purpose of establishing acceptable interference limits, are shown. These calculations were conducted for different transmission power lines configurations. A good correlation was obtained among the measured magnetic fields and the calculated one under a power transmission line. For cases of fault currents to ground the ground potentials were estimated in order to obtain the minimum distance where buried pipes can be installed to operate in a safe way. [Espanol] Este articulo describe los diferentes tipos de interferencia electromagnetica producida por lineas de potencia en derechos de via. Se muestran los calculos de los campos electromagneticos obtenidos bajo una linea de potencia, con la intencion de establecer los limites aceptables de interferencia. Estos calculos se efectuaron para diferentes configuraciones de lineas de transmision. Se obtuvo una buena correlacion entre los campos magneticos medidos y el calculado bajo una linea de transmision. Para casos de corriente de falla a tierra se determinaron los potenciales a tierra, a fin de obtener la distancia minima en donde se pueden instalar las tuberias enterradas para operar de manera segura.

  4. Electromagnetic fields originated by transmission power lines and the electromagnetic compatibility in shared rights of way; Campos electromagneticos producidos por lineas de transmision y la compatibilidad electromagnetica en derechos de via compartidos

    Energy Technology Data Exchange (ETDEWEB)

    Perez Rebolledo, Hugo; Zavala Silva, Moises; Galvan Diego, Arturo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    This article describes the different types of electromagnetic interference by power lines in rights of way areas. The calculations of the electromagnetic fields obtained under a power line with the purpose of establishing acceptable interference limits, are shown. These calculations were conducted for different transmission power lines configurations. A good correlation was obtained among the measured magnetic fields and the calculated one under a power transmission line. For cases of fault currents to ground the ground potentials were estimated in order to obtain the minimum distance where buried pipes can be installed to operate in a safe way. [Espanol] Este articulo describe los diferentes tipos de interferencia electromagnetica producida por lineas de potencia en derechos de via. Se muestran los calculos de los campos electromagneticos obtenidos bajo una linea de potencia, con la intencion de establecer los limites aceptables de interferencia. Estos calculos se efectuaron para diferentes configuraciones de lineas de transmision. Se obtuvo una buena correlacion entre los campos magneticos medidos y el calculado bajo una linea de transmision. Para casos de corriente de falla a tierra se determinaron los potenciales a tierra, a fin de obtener la distancia minima en donde se pueden instalar las tuberias enterradas para operar de manera segura.

  5. Little River Inlet Navigation Project, Brunswick County, North Carolina and Horry County, South Carolina. Revision.

    Science.gov (United States)

    1977-06-01

    to gr(ater physiological stress than the Adjacent waterways. In addition to the nine stations in I1,, inner channel, eight others were occupied in...rmn’, u t I,,’ i on. U. S. G, t. Print in Offic , Washington, D.C. 3 . . Cumin rc Nat i una I i i c i\\ tiospher i c Adri ii st , r , . ) 0 . Tidt d , i

  6. ETUDE DE LA DISTRIBUTION DES CATIONS ECHANGEABLES

    African Journals Online (AJOL)

    SEI Joseph

    En considérant alors le cas numérique, où l'observation du signal x (t) se résume à N valeurs échantillonnées à la période Te, la densité spectrale de puissance peut ...... "ANAFOR, une stratégie efficace d'acquisition et de traitement du signal pour la. RMN du solide", Méthodes, Applications, Perspectives, Evreux (2000).

  7. Steroids produced by Penicillium herquei, an endophytic fungus isolated from the fruits of Melia azedarach (Meliaceae); Esteroides produzidos por Penicillium herquei, um fungo endofitico isolado dos frutos de Melia azedarach (Meliaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Marinho, Andrey Moacir do Rosario [Universidade do Estado do Para, Belem, PA (Brazil). Dept. de Ciencias Naturais], e-mail: andreymoacir@yahoo.com.br; Marinho, Patricia Santana Barbosa; Rodrigues Filho, Edson [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2009-07-01

    Six compounds comprising the groups of steroids, the ergosterol, the ergosterol peroxide, the cerevisterol, the neociclocitrinols, the ergosta-4,6,8(14),22-tetraen-3-one, the 25-hydroxy-ergosta-4,6,8(14),22-tetraen-3-one, were isolated from Penicillium herquei fungus obtained from Melia azedarach. The structures were identified by spectral methods of RMN 1D and 2D and MS. (author)

  8. Validation of Hiriart equation to compute steam production by the lip pressure method; Validacion de la ecuacion de Hiriart para calculo de gasto de vapor por el metodo de presion de labio

    Energy Technology Data Exchange (ETDEWEB)

    Flores Armenta, Magaly [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

    1996-09-01

    Mainly in new geothermal wells, it is necessary to evaluate the production in a very fast, simple and not expensive way, to know the convenience to install surface equipment, such as silencers and separators, to drive the steam to the commercial gathering system. In practice, one of the most known methods is the lip pressure one, which requires a simple set of installations. The objective of this paper is to validate the steam flow rate calculated by the lip pressure method, with respect to the ASME method. The ASME method is known for its accuracy, and is done by measuring the steam and liquid after a high pressure separator, by an orifice plate of known diameter and a triangular weir. Results of the validation show up the feasibility of application of the lip pressure method by using a simple adjustment equation. Percentage of mistake results less than 1%, without any notable influence of the production enthalpy. That equation to be applied in a general case, is as follows: Q{nu} =(20642)(F*P*D{sup 2}/{radical}h-2000). For the particular case of the Los Azufres geothermal field, the equation is: Q{nu}= 810*P*D{sup 2} [Espanol] En los pozos geotermicos, principalmente en los nuevos, es necesario evaluar su produccion de manera rapida, sencilla y economica, para determinar la conveniencia de instalar equipo superficial, como separadores, silenciadores, etc., que permita la integracion del vapor al sistema comercial de generacion electrica. Para fines practicos uno de los metodos mas conocidos es el de presion de labio, que solo requiere un arreglo sencillo de instalaciones superficiales. En este documento se validan y ajustan los calculos de produccion de vapor por ese metodo de presion de labio, con respecto a las mediciones exactas efectuadas con el metodo ASME. Este ultimo es reconocido internacionalmente por su precision, y se lleva a cabo separando la mezcla obtenida en superficie en un recipiente a presion para medir el vapor a traves de una placa de orificio

  9. Cost-Effective Optimization of Rubble-Mound Breakwater Cross Sections.

    Science.gov (United States)

    1986-02-01

    of a Conference Held in London, London, England, p 20. Iribarren, Cavanilles R. 1938. "Una formula para el calculo de los diques de escollera," M...NAME AND ADDRESS 10. PROGRAM ELEMENT PROJECT, TASK" AREA & WORK UNIT NUMBERS US Army Engineer Waterways Experiment Station Civil Works Research...purpose as a wave barrier. A breakwater protecting a harbor entrance and mooring area from wave attack might serve q 6 to divert currents and longshore

  10. Long Period Seismic Waves

    Science.gov (United States)

    1976-08-01

    Geoffsica, TPHM. No. 5 , p. 161. Vargas, Freddy (To he published in 1976) 1 .-DTSCRP1TNACTON DE EVENTO«; NATHDALE«; Y ARTTFTCT ALES. 2.- CALCULO DEL...seismic risk, bv de - fininn relative weiqht of maximum MM intensity at a pivon distance ponulation density, area feolupy and attenuation of intensity wit...Population densitv, area peolopv and attenuation of intensitv with distance, is presented topether with a map anplvinp theorv to Bo- livia. ^«^a

  11. Cálculo termodinámico de los diagramas de fases

    OpenAIRE

    Pena, Pilar; Aza Pendas, Salvador de

    1980-01-01

    Partiendo del concepto de energía libre de Gibbs como criterio de equilibrio^e hace una breve introducción sobre las posibilidades de los métodos termodinámicos para el calculo de los diagramas de equilibrio de fases. A continuación se presentan varias aplicaciones concretas para la constmcción de diagramas binarios del tipo de solubilidad sólida completa y del tipo eutéctico.

  12. Investigation of Y{sub 6}Mn{sub 23} and YMn{sub 12} intermetallic alloys under high hydrogen pressure

    Energy Technology Data Exchange (ETDEWEB)

    Filipek, S M; Sato, R [Inst. of Phys. Chem. PAS, ul. Kasprzaka 44, 01-224 Warsaw (Poland); Kuriyama, N; Tanaka, H; Takeichi, N, E-mail: smf@ichf.edu.p [National Institute of Adv. Ind. Science and Techn. 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)

    2010-03-01

    Among three intermetallic compounds existing in Y-Mn system the YMn{sub 2} and Y{sub 6}Mn{sub 23} can easily form interstitial hydrides while for YMn{sub 12} existence of hydride has never been reported. At moderate hydrogen pressure YMn{sub 2} and Y{sub 6}Mn{sub 23} transform into YMn{sub 2}H{sub 4.5} and Y{sub 6}Mn{sub 23}H{sub 25} respectively. At high hydrogen pressure the YMn{sub 2} (C15 or C14 parent structure) forms a unique YMn{sub 2}H{sub 6} (s.g. Fm3m) complex hydride of fluorite structure in which one Mn atom Mn(1) and Y randomly occupy the 8c sites while second manganese (Mn2) in position 4a forms complex anion with 6 hydrogen atoms located in positions 24e. Formation of YMn{sub 2}H{sub 6} independently of the structure of parent phase (C14 or C15) as well as occupation of the same site (8c) by Y and Mn(1) atoms suggested that also Y{sub 6}Mn{sub 23} and YMn{sub 12} could transform into YMn{sub 2}H{sub 6} - type hydride in which suitable number of Y atoms will be substituted by Mn(1) in the 8c positions. This assumption was confirmed by exposing R{sub 6}Mn{sub 23} and RMn{sub 12} to 1 GPa of hydrogen pressure at 100{sup 0}C. Formation of (R{sub x}Mn{sub 2-x})MnH{sub 6} (where x = 18/29 or 3/13 for R{sub 6}Mn{sub 23} and RMn{sub 12} hydrides respectively) was confirmed by XRD. Hydrogen concentration in both R{sub 6}Mn{sub 23} and RMn{sub 12} based hydrides reached H/Me = 2 thus value two times higher than in R{sub 6}Mn{sub 23}H{sub 25}.

  13. Estudo da reação entre polietileno glicol e resina epoxídica na presença de N,N-dimetilbenzilamina Study of the reaction between polyethylene glycol and epoxy resins Using N,N-dimethylbenzylamine as catalyst

    Directory of Open Access Journals (Sweden)

    Mario Zacharuk

    2011-01-01

    Full Text Available Neste trabalho foi estudada a reação entre polietileno glicol (PEG e uma resina epoxídica à base de diglicidil éter de bisfenol A (DGEBA, na presença de N,N-dimetilbenzilamina (DMBA, sendo os produtos desta reação avaliados por espectroscopia no infravermelho (FTIR, espectroscopia de ressonância magnética nuclear de próton (RMN-1H e medidas de viscosidade cone-prato. Amostras curadas com um endurecedor à base de poliamina foram também submetidas a ensaios de tração e calorimetria exploratória diferencial (DSC. Os resultados das análises de viscosidade, FTIR e RMN (1H confirmaram a ocorrência da reação entre grupos epóxi do DGEBA e grupos hidroxila do PEG na presença de DMBA, a 100 ºC. As análises de DSC e os ensaios de tração dos sistemas curados mostram que a reação de DGEBA com PEG gera um material com temperatura de transição vítrea (Tg significativamente menor, em conjunto com o aumento da deformação na ruptura e decréscimo do modulo de elasticidade, quando comparados ao sistema epoxídico de referência (DGEBA.In this work the reaction of polyethylene glycol (PEG and epoxy resin (BADGE in the presence of N,N-dimethylbenzylamine (DMBA was studied. The reaction products were evaluated by infrared spectroscopy (FTIR, nuclear magnetic resonance spectroscopy (NMR and viscosity measurements. Samples cured with a polyamine-based hardener were also submitted to tensile tests and differential scanning calorimetry (DSC. The results of the viscosity analyses, FTIR and RMN (¹H confirmed the reaction between DGEBA epoxy groups and PEG hydroxyl groups in the presence of DMBA, at 100 ºC. DSC analyses and tensile tests of cured systems showed that the reaction of DGEBA with PEG leads to a reduction of Tg, generating a more flexible material.

  14. Realizar mapa de competencias de los representantes técnicos, como herramienta de evaluación de desempeño

    OpenAIRE

    Nasute Molina, Osvaldo Victor

    2015-01-01

    I. RESUMEN - II. MARCO TEORICO - II. METODOLOGIA - IV. OBJETIVOS DEL TRABAJO - V. LIMITES O ALCANCES DEL TRABAJO - VI. INTRODUCCION - VII. CAPITULO 1 – ADMINISTRACIÓN DE LOS RECURSOS HUMANOS - 1.1 ¿QUÉ ES LA ADMINISTRACIÓN DE LOS RECURSOS HUMANOS? - 1.2 PROPÓSITO DE LA ADMINISTRACIÓN DE LOS RECURSOS HUMANOS - 1.3 LA NUEVA VISIÓN DEL RECURSO HUMANO - VIII. CAPITULO 2 - CARACTERÍSTICAS Y TIPOS DE COMPETENCIAS - 2.1 ¿QUÉ SON LAS COMPETENCIAS? - 2.2 CLASIFICACIÓN DE COMPETENCIAS - 2.3 TIPOS DE ...

  15. La pedagogia cattolica e la Bildung: annotazioni…minime

    Directory of Open Access Journals (Sweden)

    FRANCO CAMBI

    2011-12-01

    Full Text Available Il saggio discute le ripercussioni della teoria della Bildung nellapedagogia cattolica italiana. Le figure esemplari di riferimento recepite in Italia sono Förster e Hessen, teorico del personalismo il primo, maestro del neoumanesimo il secondo. Viene poi esaminato il dialogo tra la pedagogia cattolica e la pedagogia della Bildung negli anni cinquanta ed in seguito vengono discusse quattro figure-chiave della pedagogia cattolica italiana (Laeng, Flores, Manno, Ducci e le loro posizioni postmoderne. Nell’ultima parte del lavoro, infine, sono messi in rilievo alcuni nodi fondamentali dei modelli pedagogici piùrecenti.

  16. Análisis morfométrico de poblaciones : un estudio cuantitativo de las neuronas del NGLD del talamo del conejo (Oryctolagus cuniculus L.)

    OpenAIRE

    Carmona Martos, Ramón

    2013-01-01

    La determinacion del numero forma y distribucion de los elementos que forman parte de una estructura resulta para la histología y la estereologia uno de los problemas mas difíciles de resolver al entender de reconocidos autores tales como weibel y cruz-orive. el estudio que se realiza en esta tesis doctoral sienta las bases para la resolución practica de tal problema mediante un sistemaoperativo conseguido a partir de la conjunción de los aspectos teoricos del temay de una serie de procedi...

  17. El comercio electrónico en los cibermedios

    Directory of Open Access Journals (Sweden)

    Moisés Hernández

    2004-01-01

    Full Text Available En el estudio se analiza la aplicacion de los diferentes recursos y posibilidades que ofrece el comercio electronico a los cibermedios venezolanos.en cuanto al enfoque teorico manejado, se tomaron los aportes de Timmers (1998, en lo que se respecta al comercio electronico, Castells (2001 en la conceptualizacion de la era de la informacional y okot-uma (2002 en lo referente a la nueva economia y el e-business. El tipo de investigacion es exploratoria y descriptiva, con un diseño no experimental de tipo transeccional descriptivo.

  18. Techniques and methods of characterization of admixtures for the concrete

    Directory of Open Access Journals (Sweden)

    Palacios, M.

    2003-03-01

    Full Text Available Admixtures are defined as those products that are incorporated in the moment of the process of mixture of the concrete in a quantity not bigger than 5 by mass of the cement %, with relationship to the cement content in the concrete, with object of modifying the properties of the mixture in .state fresh and/or hardened. The behaviour of the admixtures depends on its chemical and ionic composition, the organic functional groups present, and the structure of the polymer and the distribution of molecular weight of the different polymers. In the present work the techniques and methods of characterization physical-chemistry, chemistry and ionic, structural, as well as of the polymers that constitute this admixtures, are described. A lot of techniques have been employed like: ionic chromatography, ultraviolet-visible spectroscopy (UV-VIS, Fourier transform infrared spectroscopy (FTIR, Fourier transform Raman spectroscopy (FT-Raman, nuclear magnetic resonance spectroscopy (1H-RMN and 13C-RMN, gel permeation chromatography (GPC. Two commercial admixtures have been selected to carry out this characterization, a superplastificant based on policarboxilates, and a reducer of the shrinkage based on polipropilenglycol.

    RESUMEN Se definen los aditivos como aquellos productos que son incorporados en el momento del amasado del hormigón en una cantidad no mayor del 5% en masa, con relación al contenido de cemento en el hormigón, con objeto de modificar las propiedades de la mezcla en estado fresco y/o endurecido. El comportamiento de los aditivos depende de su composición química e iónica, de los grupos funcionales orgánicos presentes, de la estructura del polímero y de la distribución de pesos moleculares de los diferentes polímeros que lo constituyen. En el presente trabajo se describen diferentes técnicas y métodos de caracterización físico-química, química e iónica, estructural, así como de los polímeros que

  19. Reflective memory recorder upgrade: an opportunity to benchmark PowerPC and Intel architectures for real time

    Science.gov (United States)

    Abuter, Roberto; Tischer, Helmut; Frahm, Robert

    2014-07-01

    Several high frequency loops are required to run the VLTI (Very Large Telescope Interferometer) 2, e.g. for fringe tracking11, 5, angle tracking, vibration cancellation, data capture. All these loops rely on low latency real time computers based on the VME bus, Motorola PowerPC14 hardware architecture. In this context, one highly demanding application in terms of cycle time, latency and data transfer volume is the VLTI centralized recording facility, so called, RMN recorder1 (Reflective Memory Recorder). This application captures and transfers data flowing through the distributed memory of the system in real time. Some of the VLTI data producers are running with frequencies up to 8 KHz. With the evolution from first generation instruments like MIDI3, PRIMA5, and AMBER4 which use one or two baselines, to second generation instruments like MATISSE10 and GRAVITY9 which will use all six baselines simultaneously, the quantity of signals has increased by, at least, a factor of six. This has led to a significant overload of the RMN recorder1 which has reached the natural limits imposed by the underlying hardware. At the same time, new, more powerful computers, based on the Intel multicore families of CPUs and PCI buses have become available. With the purpose of improving the performance of the RMN recorder1 application and in order to make it capable of coping with the demands of the new generation instruments, a slightly modified implementation has been developed and integrated into an Intel based multicore computer15 running the VxWorks17 real time operating system. The core of the application is based on the standard VLT software framework for instruments13. The real time task reads from the reflective memory using the onboard DMA access12 and captured data is transferred to the outside world via a TCP socket on a dedicated Ethernet connection. The diversity of the software and hardware that are involved makes this application suitable as a benchmarking platform. A

  20. Development of a human body RMN imaging device

    International Nuclear Information System (INIS)

    Saint-Jalmes, H.

    1984-03-01

    Imaging device for human body is studied in this thesis. The section images presented are got by a projection-reconstruction method associated to a section plane selection by an oscillating gradient application. Different stages of the machine development are presented: - design and calculation of a resistive magnet for very homogeneous field imaging - design of gradient coils for imaging magnets - realization of control and acquisition interfaces - realization of imaging software in real time [fr

  1. Metrolab a saisi l'opportunite de l'imagerie medicale

    CERN Multimedia

    Peclet, J C

    2003-01-01

    "Le Prix Nobel de medecine a ete decerne lundi a Paul Lauterbur et Peter Mansfield, dont les recherches ont abouti au developpement de l'imagerie par resonance magnetique nucleaire (IRM).... Ces appareils ne fonctionnent correctement que si leur champ magnetique est absolument homogene. Et c'est ici qu'intervient une petite societe genevoise, Metrolab, leader mondial dans la fabrication de magnetometres RMN, qui mesurent tres exactement cette homogeneite" (1/2 page).

  2. Calculation of Viscous Effects on Ship Wave Resistance Using Axisymmetric Boundary Layer Approaches

    Science.gov (United States)

    1985-05-13

    Layers in Pressure Gradients," NSRDC Report 3308, April 1970. 38. Garcia, J.M. and Zazurca, J.A.A., " Calculo de la Resistencia Viscosa de un Buque a...none USERS 21 ABSTRACT SECURITY CLASSIFICATION UNCLASSIFIED 22a NAME OF RESPONSIBLE INDIVIDUAL Henry T. Wang 22b TELEPHONE (Include Area Code...theory. Since then, calculation of the resistance due to the waves generated by a surface ship advancing at constant forward speed has been an area of

  3. Systems for the calculation of electrical parameters and energy efficiency for high-capacity hydroelectric generators; Sistemas para el calculo de parametros electricos y eficiencia energetica para generadores hidroelectricos de gran capacidad

    Energy Technology Data Exchange (ETDEWEB)

    Reyes Martinez, Oscar Alfonso; Pascacio de los Santos, Alberth; Perez Abad, Carlos Alberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Leon Rivera, Nicolas [CFE-LAPEM, Irapuato, Guanajuato (Mexico)

    2012-07-01

    construccion es la Central Hidroelectrica La Yesca, el cual concluira a finales de 2012 y consiste en dos generadores electricos de 375 MW, 17 kV. Sera el segundo en potencia y el tercero en generacion electrica en el sistema. De acuerdo con las normas nacionales e internacionales, debe efectuarse un conjunto de pruebas estaticas y dinamicas en estos generadores antes de la puesta en servicio, para asegurar su operacion apropiada. La prueba de resistencia de alto voltaje del devanado del estator, la prueba de corto circuito subito trifasico y el calculo de eficiencia energetica son algunas de las pruebas mas importantes por realizar en un nuevo generador electrico. Estas pruebas son dificiles de efectuar en sitio debido a la capacidad del equipo requerido, por lo que muy pocas companias en el mundo pueden conducirlas.

  4. Nuclear Calculations of Light-Water Moderated Reactors and Experimental Correlations; Calculs de Riacteurs Ralentis a l'Eau Ordinaire et Comparaison avec les Risultats Expirimentaux; Raschet reaktorov s zamedlitelem iz obychnoj vody i sravnenie s ehksperimental'nymi rezul'tatami; Calculos Nucleares de Reactores Moderados por Agua Ligera y Correlacion Experimental

    Energy Technology Data Exchange (ETDEWEB)

    Solanilla, R. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina)

    1964-02-15

    nombreuses geometries - faite par comparaison avec certains des principaux parametres d'un reseau y/o de multiplication effective, est satisfaisante, l'ecart entre la reactivite obtenue par le calcul et le chiffre donne par l'experience,n'etant pas, en general, superieur a 2%. (author) [Spanish] Con el empleo de la teoria de dos grupos modificados por fisiones epitermales, se ha analizado un conjunto de sistemas criticos dotados de reflector y moderador de agiia liviana y variado enriquecimiento en {sup 235}U del combustible nuclear. Las secciones eficaces del grupo termal empleadas son las consignadas en las Tablas de Amster para mezclas hidrogenadas a diferentes temperaturas; concentraciones de {sup 235}U y absorbedores en 1/v. El efecto de heterogeneidad en las secciones eficaces ha sido tratado aproximadamente modificando las concentraciones de los absorbedores por variacion espacial del flujo termico en la celda elemental. El factor de desventaja ha sido calculado empleando la formula de Amouyal-Benoist. El coeficiente de difusion termal ha sido definido como la inversa del triple de la seccion eficaz macroscopica de transporte homogeneizada sobre el volumen de la celda elemental. Las constantes del grupo rapido han sido calculadas'de acuerdo al esquema de Ombrellaro de tres grupos rapidos de difusion (10 MeV a 0,821 MeV; 0,821 MeV a 5,5 keV; 5,5 keV a 0,625 eV) con secciones eficacesmicroscopicas ajustadas para cada grupo. La definicion de Ombrellaro de las constantes neutionicas de los tres,grupos rapidos en funcion de las secciones eficaces ajustadas ha sido modificada para el tercer grupo de acuerdo al tratamiento de Hick de la absorcion efectiva de resonancia del {sup 238}U, basada en el computo de la integral de resonancia efectiva. Los calculos han sido realizadas computando la integral de resonancia efectiva del: {sup 238}U por la formula obtenida, por el autor, del calculo teorico, con reduccion de la relacion S/M de acuerdo a la aproximacion del Bell del

  5. 43Ca NMR in solid state

    Science.gov (United States)

    Bellot, P.-V.; Trokiner, A.; Zhdanov, Yu.; Yakubovskii, A.

    1998-02-01

    In this paper we show that 43Ca is a suitable NMR probe to study the properties of high-Tc superconducting oxides. In the normal state, we report the temperature and doping dependencies of the spin susceptibility measured by 43Ca NMR. In the superconducting state and more exactly in the mixed state, by analysing 43Ca NMR linewidth, we have studied the magnetic induction distribution due to the presence of vortices and deduced λ, the penetration depth. Dans cet article, on montre que l'isotope 43 du calcium est une bonne sonde RMN pour l'étude des propriétés des oxydes supraconducteurs à haute température. Dans l'état normal, par la détermination du déplacement de la raie, en fonction de la température, on accède à la variation thermique de la susceptibilité de spin. Dans l'état supraconducteur et plus particulièrement dans l'état mixte, la largeur de raie RMN permet d'étudier la distribution d'induction magnétique due à la présence des vortex et de déterminer λ, la longueur de pénétration.

  6. Investigação da influência do processamento na dinâmica molecular de nanocompósitos de policarbonato e argila organofílica obtidos via intercalação por fusão

    Directory of Open Access Journals (Sweden)

    Elton J. da R. Rodrigues

    Full Text Available Nanocompósitos baseados em policarbonato e argila organofílica foram obtidos pelo método de intercalação por fusão em câmara de mistura sob diferentes valores de torque e temperatura. A influência desses parâmetros na qualidade da dispersão da argila na matriz polimérica foi investigada por ressonância magnética nuclear (RMN de baixo campo, empregando o tempo de relaxação longitudinal, T1H, e por difração de raios X. As diferenças nos tempos de relaxação longitudinal e nos padrões de difração de raios X foram correlacionadas com a formação de domínios com mobilidades distintas. O nanomaterial formado apresentou morfologia intercalada com afastamento crescente das camadas de argila, conforme as condições de processamento se tornavam mais severas. A RMN ¹H mostrou que tanto o cisalhamento quanto a temperatura afetaram a mobilidade das cadeias poliméricas, explicitando a homogeneidade crescente da distribuição dos domínios de relaxação, de acordo com o aumento do torque e da temperatura.

  7. Síndrome de Joubert

    Directory of Open Access Journals (Sweden)

    Andreia Vilas-Boas

    2014-03-01

    Full Text Available Mulher de 30 anos, com antecedentes de atraso do desenvolvimento psicomotor inicial. Observada em consulta por crises tónico-clónicas generalizadas. Ao exame objectivo apresentava, apraxia oculomotora subtil, estrabismo divergente do olho esquerdo e marcha de base alargada com instabilidade. Durante o estudo etiológico da epilepsia realizada ressonância magnética encefálica (RMN que revelou a hipoplasia do vérmis do cerebelo, formando “sinal do dente molar”, sugestivo de síndrome de Joubert. O Síndrome de Joubert é uma doença autossómica recessiva caracterizada por um largo espectro de malformações do rombencéfalo. O síndrome clássico define-se pela presença do “sinal do dente molar” em RMN, na dependência do alargamento das vias de circulação de líquor por hipoplasia de tecido cerebral; défice cognitivo/atraso do desenvolvimento; hipotonia na infância e anomalias dos movimentos oculares. Esta doente apresenta três destes critérios. O tratamento consiste sobretudo na resolução de condições associadas, sendo o prognóstico dependente da gravidade da malformação.

  8. DESARROLLO DE REACCIONES DE CONDENSACIÓN ALDÓLICA SOBRE SOPORTE DE CELULOSA

    Directory of Open Access Journals (Sweden)

    Liliana E. Luna

    2011-01-01

    Full Text Available En este trabajo se desarrollan algunas reacciones sobre soporte sólido de celulosa para alumnos de Química Orgánica del segundo año de las carreras de Bioquímica, Farmacia, Lic. en Química y Lic. en Biotecnología. Las reacciones analizadas fueron la de Claisen-Schmidt entre ciclohexanona y benzaldehído en medio básico para la síntesis de 2,6-dibenciliden-ciclohexanona y la reacción aldólica de acetona con benzaldehído en medio básico para preparar la 4-fenil-4-hidroxi-butanona. Los productos se aíslan permitiendo su identificación por cromatografía en capa delgada, espectroscopía de RMN de protones y se comparan con los productos obtenidos por el método tradicional en solución. Esta metodología simple y eficiente que se experimentó en grupos de alumnos de segundo año de esta Facultad permite la integración de los temas aldehídos, cetonas y enolatos aprendidos anteriormente, en consonancia con espectroscopía IR y RMN-1H en una dada transformación química.

  9. Outros constituintes isolados de Licania arianeae (Chrysobalanaceae

    Directory of Open Access Journals (Sweden)

    Mário G. de Carvalho

    Full Text Available O ácido flavona-6-sulfônico, 4'-O-metil-5,7-diidroxi-flavona-6-sulfonato, conhecido como niruriflavona, e a saponina, ácido 3-O-[6'-O-4-hidroxibenzoil]-²-D-galactopiranosil-ursa-12-en-28-óico, foram isolados, respectivamente, de madeira e folhas de Licania arianeae. As estruturas foram estabelecidas através da análise de espectros de massas e RMN incluindo experimentos bidimensionais.

  10. UN MODELLO TEORICO PER LA VALORIZZAZIONE DEL PAESAGGIO CULTURALE DELLA DIETA MEDITERRANEA

    Directory of Open Access Journals (Sweden)

    Tiziana Meduri

    2015-12-01

    Full Text Available The study aims to identify guidelines for defining a model of cultural planning oriented to the development of the emerging sector of the territory of Reggio Calabria’s metropolitan city, specifically rural areas, to provide an integrated plan of development of cultural identity. The methodology consisted of a preliminary fact-finding investigation. This has lead to, in theory, an operating model where it is proved that the first action to be performed is the accurate identification of an effective tool that can be applied to the province towed to the emergence and local development: the Mediterranean diet. The second step involved the selection of municipalities able to apply the best practices in the area for the promotion of the Mediterranean Diet. Through a checklist, formulated ad hoc, is checked for quality valorization plans that each municipality must prepare. What you intend to prove is that a careful and participatory cultural program could be the possible way out from the narrow vision of culture as a marginal aspect of economic life and in fact placed in the policies of socio-economic development of the territory.

  11. Sullo statuto teorico dell'offerta di moneta: un dibattito con Augusto Graziani

    OpenAIRE

    Cavalieri, Duccio

    1996-01-01

    In this article the debate between Prof. Augusto Graziani and the author on the monetary theory of production is carried further on. The main purpose of the paper is to delineate - along Keynesian lines and in opposition to the theory of the credit money circuit - a consistent and realistic view of the nature of the supply of money, general enough to embrace as limit-cases both a strictly endogenous and a strictly exogenous money supply. The interdependence of the supply and demand for money ...

  12. Experimental hydraulic analysis in conduction tunnels at the trunk section working as a channel considering compound roughness; Analisis hidraulico experimental en tuneles de conduccion en seccion baul trabajando como canal, considerando rugosidades compuestas

    Energy Technology Data Exchange (ETDEWEB)

    Marengo-Mogollon, Humberto; Cortes-Cortes, Carlos [Comision Federal de Electricidad (Mexico); Arreguin-Cortes, Felipe I [Comision Nacional del Agua (Mexico)

    2008-01-15

    This paper presents the roughness coefficients of a conduction tunnel at the trunk section working as a channel obtained experimentally using a hydraulic model of the diversion tunnel of the Hydroelectric Project called El Cajon (Mexico). A comparative analysis between experimental and theoretical coefficients obtained in the literature is shown. [Spanish] Se presentan los coeficientes de rugosidad compuesta de un tunel de conduccion en seccion baul trabajando como canal obtenidos en forma experimental en un modelo hidraulico del tunel de desvio del Proyecto Hidroelectrico El Cajon (Mexico). Se muestra un analisis comparativo entre los coeficientes experimentales y los teoricos obtenidos en la literatura.

  13. Políticas para la igualdad de oportunidades de la mujer: educación, formación y empleo

    Directory of Open Access Journals (Sweden)

    Juana María Madrid Izquierdo

    1996-01-01

    Full Text Available Tras describir el marco teorico en el que se encuadran las políticas de igualdad de oportunidades para la mujer en la Union Europea, los autores realizan un recorrido historico que relata el origen y la evolucion de dichas politicas. A partir de ahí, se describen las acciones y programas diseriados desde la UE para su puesta en practica recurriendo como Fuente primaria a la normativa comunitaria a este respecto. La ultima parte del artículo se dedica al analisis de la situacion laboral de la mujer en el contexto de Murcia

  14. Un tótem frágil: aproximación a la estructura teórica de El Suicidio

    Directory of Open Access Journals (Sweden)

    RAMÓN RAMOS TORRE

    1998-01-01

    Full Text Available el suicidio puede ser considerado como uno de los totems de la sociologia actual. gran parte de su poder resulta de su densidad teorica. pero su entramado teorico es complejo y esta sometido a disputas interpretativas. se propone reconstruir su logica teorica como el resultado de un trayecto circular que inicialmente descompone analiticamente el objeto para despues volver a el y hacerlo inteligible. es en este trayecto de vuelta cuando aparecen serias aporias que enfrentan al principio de explicacion causal con el principio de inteligibilidad de las practicas analizadas. de ahi la fragilidad teorica de el suicidio.

  15. Rapporto impegni/depositi ed incidenza del massimale di crescita. (The effect of growth limits on the loan/deposit ratio

    Directory of Open Access Journals (Sweden)

    A. NICCOLI

    2013-12-01

    Full Text Available Una breve nota sulla Marullo Reedtz ' Gli effetti di "limiti di crescita " sul sistema bancario e sulla distribuzione del credito , in cui l'autore chiarisce alcuni punti di disaccordo che esistono a livello teorico e cita alcune evidenze empiriche a loro sostegno .A brief note on Marullo Reedtz’ The effects of “growth limits” on the banking system and on the distribution of credit, in which the author clarifies some points of disagreement that exist at the theoretical level and cites some empirical evidence to support them.JEL: E51, E52, G21

  16. Desarrollo de una propuesta de capacitación para el área de controller de una automotriz en Córdoba - Argentina

    OpenAIRE

    Del Corro, Margarita Alicia

    2015-01-01

    A. PRESENTACION DEL PROYECTO PAG. - I. Resumen - II. Marco Teórico - III. Metodología - IV. Objetivos del Trabajo - V. Limites o Alcance del Trabajo - VI. Organización del trabajo - B. DESARROLLO DEL PROYECTO - I. Capítulo I. INTRODUCCION - II. Capítulo II: MARCO TEORICO - II.1. Qué es la administración de recursos - Humanos - II.2. Importancia Estratégica de los RRHH - II.3. Historia de la administración de Recursos - Humanos - II.4. Funciones de las Áreas de RRHH - II.5. Capacitación - II....

  17. Analisi dei cicli del mercato immobiliare: un applicazione sui dati italiani

    Directory of Open Access Journals (Sweden)

    Maurizio Festa!

    2012-06-01

    Full Text Available Utilizzando i dati italiani, sulla base dell'approccio teorico del ciclo "a nido d'ape" proposto da Janssen, Kruijt e Needham nel 1994, questo articolo propone un ulteriore contributo allo studio delle dinamiche del mercato immobiliare italiano. Utilizzando alcuni indicatori del mercato, si presentano i grafici del ciclo a nido d'ape per tutte le regioni e per le principali città. Tecniche di cluster analysis sono utilizzate per raggruppare le regioni che mostrano andamenti simili. L'obiettivo finale dell'analisi è quindi quello di esaminare il territorio nazionale in termini di sviluppo ed evoluzione del mercato delle abitazioni.

  18. Evasión y cultura tributaria en los comerciantes del centro Comercial Cooperativa Pro Los Olivos, 2015

    OpenAIRE

    Salazar Reyna, Oscar Manuel

    2016-01-01

    El estudio tiene un fundamento teorico según Bravo, F. (2012) en el libro de Cultura Tributaria. (2a.ed.). Lima: IATA-SUNAT. El cual sirvió de guía para el desarrollo de la presente investigación. El método empleado en la investigación fue el hipotéticodeductivo. Esta investigación utilizó para su propósito el diseño no experimental de nivel correlacional de corte transversal, que recogió la información en un período específico, utilizando como técnica la encuesta que se desarroll...

  19. Thermoregulatory responses and blood parameters of locally adapted ewes under natural weather conditions of Brazilian semiarid region

    Directory of Open Access Journals (Sweden)

    Wirton Peixoto Costa

    2015-12-01

    Full Text Available The effect of the natural weather conditions on respiratory rate, rectal temperature and hematologic parameters such as glucose, total cholesterol, triacylglycerol, total protein, albumin, globulin, red blood cells, microhematocrit, mean corpuscular volume, serum triiodothyronine (T3 and thyroxine (T4 levels was evaluated in red (RMN and white (WMN coat colored Morada Nova ewes, of different class of body condition score (CBCS, during the dry (from july to december and wet (from january to june seasons, which exhibited different (P<0.05 air temperature, relative humidity and radiant thermal load averages. Tukey’s test was used and the difference considered was to P<0.05. Significant greater averages of respiratory rate were observed in the dry period compared to the rainy period (42.26±8.96 and 36.89±8.20 breaths min-1, respectively, mainly in the RMN (45.54±8.23 breaths min-1 compared with the WMN (39.27±8.57 breaths min-1. No differences were observed in rectal temperature measurements between the dry and the wet periods (38.59±0.58 and 38.60±0.56 oC, respectively, but the WMN had higher values than the RMN (38.77±0.54 and 38.40±0.54 oC, respectively. The glucose and total cholesterol were higher in the wet season, with no variation due to breed variety and CBCS. The triacylglycerol did not change between breed varieties and seasons. The albumin was similar between varieties and in different seasons, being different in CBCS. Total protein and globulin serum were higher during the wet season, but total protein was higher and globulin was lower in better CBCS. T3 and T4 levels were higher in the rainy season (0.25±0.07 and 6.74±11.37 ?g dL-1, for T3 and T4, respectively than in the dry season (0.18±0.08 and 6.31±1.64 ?g dL-1, for T3 and T4, respectively. The red blood cells showed no difference, but microhematocrit was higher in WMN and in the better CBCS and mean corpuscular volume was higher in the dry season. The concentration

  20. 19F NMR method for the determination of quality of virgin olive oil

    Directory of Open Access Journals (Sweden)

    Zhou, L. L.

    2015-12-01

    Full Text Available This paper reported a potential analytical technique based on NMR spectroscopy for the determination of quality of olive oil. The model compounds with active hydrogen, including free sterols, free aliphatic alcohols, phenolics, and free fatty acids were determined by 19F NMR upon derivation with 4-fluorobenzoyl chloride. Integration of the appropriate signals of the derivatives of the compounds in the corresponding 19F NMR spectrum allows for the quantification of these compounds. 37 Samples of commercial olive oil and 5 samples of other plant oils were determined by 19F NMR. The amount of diglycerides and the ratio of 1,2-diglycerides to the total amount of diglycerides were analyzed to monitor whether extra virgin olive oil was adulterated with low price olive oil and other plant oils or not. The results showed that the total diglyceride content should not be higher than 2.5% and the ratio (D of 1,2-diglycerides to total diglycerides should be higher than 0.35 for extra virgin olive oil. This method is an easier, simpler, safer, faster and more reliable technique for the determination of the quality of olive oil and can also be extended to monitoring the quality of ordinary edible oils.En este trabajo se describe una técnica analítica basada en la espectroscopía de RMN para determinar la calidad del aceite de oliva. Los compuestos modelo con hidrógeno activo, incluyendo esteroles libres, alcoholes alifáticos libres, compuestos fenólicos, ácidos grasos libres se determinaron por 19F RMN derivatizados con cloruro de 4-fluorobenzoilo. La integración de las señales apropiadas de los derivados de los compuestos en el correspondiente espectro de 19F RMN permite la cuantificación de estos compuestos. 37 muestras de aceites de oliva comerciales y 5 muestras de otros aceites vegetales se determinaron por 19F RMN. La cantidad de diglicéridos y la proporción de los 1,2-diglicéridos a la cantidad total de diglicéridos se analizaron para

  1. Application of scale test modules for model the electrothermal performance in buildings for the efficient use of energy; Aplicacion de modulos de prueba a escala para modelar el funcionamiento electrotermico de edificios para el uso eficiente de la energia

    Energy Technology Data Exchange (ETDEWEB)

    Acoltzi Acoltzi, Higinio

    2000-10-01

    and small vault pottery with glass sun reflector (34% in the experimental model and 37% in the theoretical model). [Spanish] La investigacion para acondicionamiento de espacios por enfriamiento en edificios de tamano real tiene un costo elevado por la cantidad de materiales y la variedad de parametros que intervienen. Por lo anterior, en este trabajo se utilizan modulos de prueba a escala acoplados a sistemas de aire acondicionado para obtener su respuesta electrotermica; es decir, cuantificar la cantidad de energia electrica que consumira un modulo en funcion de los materiales de prueba. Se analiza un modelo termico teorico transitorio y las pruebas experimentales del comportamiento termico de modulos de prueba a escala por la variacion de los materiales de los techos y ventanas, desarrollado con el objeto de establecer criterios de aplicacion de dichos materiales en las industrias de la edificacion. Adicionalmente se presenta el desarrollo de un modelo electrotermico teorico en estado permanente, que define el comportamiento del consumo de energia electrica, para mantener las condiciones de confort al interior de los modulos de prueba respecto a la variacion de los materiales mencionados. Se presenta tambien el diseno y el desarrollo de las pruebas experimentales utilizando los modulos de prueba a escala para validar el modelo electrotermico. La experimentacion se desarrolla exponiendo los modulos de prueba a escala, acoplados a los equipos de aire acondicionado, a la radiacion solar directa, registrando el consumo de energia electrica de los equipos de aire acondicionado, la radiacion solar sobre techo y ventanas de prueba, la temperatura interior de los modulos, la temperatura interior y exterior en la superficie de los techos de prueba, la temperatura ambiente, y la velocidad del viento. Los resultados obtenidos comparando las mediciones en campo y el modelo electrotermico teorico desarrollado, presentan diferencias promedio de 16%. Los ahorros de energia

  2. Measurements and Calculations of the Slowing-Down and Migration Time; Mesures et Calcul du Temps de Ralentissement et de Migration; Izmereniya i raschety vremeni zamedleniya i migratsii; Medicion y Calculo del Tiempo de Moderacion y de Migracion

    Energy Technology Data Exchange (ETDEWEB)

    Profio, A. E.; Koppel, J. U. [General Atomic Division of General Dynamics Corporation, John Jay Hopkins Laboratory for Pure and Applied Science, San Diego, CA (United States); Adamantiades, A. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1965-08-15

    transcurre hasta que la velocidad de los neutrones pulsados disminuya en la medida necesaria para que estos alcancen la energia, el angulo y la posicion de observacion apetecidas. El tiempo medio es una correccion de las mediciones de espectros neutronicos en la masa hechas segun el metodo del tiempo de vuelo, y la variacion impone limites al poder de resolucion efectivo de tales experimentos. Estos parametros son igualmente importantes en los detectores cuyo funcionamiento se base en la moderacion, en los experimentos con el metodo de tiempo de vuelo en los que un moderador situado cerca de la fuente de neutrones pulsados proporciona neutrones de baja energia, y en la espectrometria del tiempo de moderacion. Se han ideado diversos metodos analfticos y numericos para calcular la distribucion espacio-energia angulo-tiempo o sus integrales. Ha podido demostrarse que los momentos temporales Empty-Set {sup (n)} (r, {Omega}, v, t) = {integral}{sub 0}{sup {infinity}}t{sup n} Empty-Set (r, {Omega}, v, t)dt, pueden calcularse aplicando repetidamente una clave de transporte en regimen estacionario. El termino de la fuente para el calculo del momento 'n'es igual a nv{sup -1} Empty-Set {sup (n-1)}. Los autores presentan los resultados correspondientes a maquetas del reactor TRIGA en las que se emplean medios multiplicadores y no multiplicadores. Otro valioso metodo de calculo consiste en emplear una clave de Monte Cario en funcion del tiempo. Los autores exponen los resultados del calculo de un flujo que escapa de una delgada placa de plomo. Se han hecho mediciones del tiempo de moderacion hasta la energia de corte del Cd y hasta la resonancia de 1,46 eV del In en agua y en tolueno. Los rayos gamma de captura se detectaron con un contador de centelleo. Esta tecnica exige disponer de una fuente de suficiente intensidad y de un detector eficaz debido a la brevedad del ciclo de trabajo (escasa anchura de las rafagas para la resolucion del tiempo de moderacion y amplio intervalo entre los

  3. Atribuição dos deslocamentos químicos dos átomos de ¹H e 13C do acetato de acantoaustralida

    Directory of Open Access Journals (Sweden)

    Lúcia R. Rocha Martins

    Full Text Available Do extrato hidroetanólico das partes aéreas de Acanthospermum australe (Asteraceae foram identificados uma lactona diterpênica, o acetato de acantoaustralida (1 e dois flavonoides: quercetina (2 e crisosplenol D (3. As estruturas foram identificadas através de técnicas espectroscópicas de RMN de ¹H e 13C, gHSQC, gHMBC, TOCSY, gNOESY, EM e pela comparação com dados da literatura.

  4. The Coast Artillery Journal. Volume 59, Number 6, December 1923

    Science.gov (United States)

    1923-12-01

    Remarques sur Ie tir Fusant.-F-12, January, 1923. RegIa de Calculo Para Muelles Cilindricos.-Spa-2, June, 1923. Terrain Reduit pour Exercices de tir Fictif au...I to V, on a front Brussels-Metz, pivoting on the fortified area Metz- Thionville. The inner flank of the wheel was to be covered by the VI and VII...rapidly on the fron t Beauraing-Gedinne- Paliseul- Fay- des -Veneurs-Cuignon (5th Army) and Tetaigne-Margut-Quincy (4th Army)." Fearing the German advance

  5. Energy efficiency study of the domestic refrigerators inside of a controlled environment laboratory; Estudio de la eficiencia energetica de refrigeradores domesticos dentro de un laboratorio de ambiente controlado

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo Cabanas, Fernando Gabriel

    2004-04-15

    The evaluation of the energy saving potential is looked for that exists in the park of domestic refrigerators of the country when replacing them by refrigerators of higher power efficiency, through a comparative analysis of the results obtained in experimental tests applied to domestic refrigerators, in agreement with Official Norm NOM 015-2002 and with the theoretical values reported by the manufacturers. Initially the park of domestic refrigerators used in Mexico (brand names, efficiency and electrical consumption) was studied with the objective of evaluating the electric energy consumption in the refrigerators at national level. Once with the consumption determined, a governmental program for the accelerated substitution of the park of domestic refrigerators of greater antiquity is proposed, for models of better power efficiency. Next, the characterization of the Laboratorio de Ambiente Controlado is made (preliminary tests of thermal stability and heat losses) to obtain the thermal conditions marked by Norm NOM-015-2002. Also relevant points for the experimental energy analysis are established in domestic refrigerators according to norm NOM-015-2002. Finally, a test protocol for domestic refrigerators applied in the LAC with base in this norm will be proposed and a validation of this by means of the necessary experimental tests and the required calculations will be carried out. Finally the obtained results of the tests of power efficiency applied to different models from domestic refrigerators, as well as conclusions are presented. [Spanish] Se busca evaluar el potencial de ahorro de energia que existe en el parque de refrigeradores domesticos del pais al sustituirlos por refrigeradores de mayor eficiencia energetica, a traves de un analisis comparativo de los resultados obtenidos de pruebas experimentales aplicadas a refrigeradores domesticos, de acuerdo con la Norma Oficial NOM.015-2002 y con los valores teoricos reportados por los fabricantes. Primeramente

  6. AISLAMIENTO Y ELUCIDACIÓN ESTRUCTURAL DE ALGUNOS METABOLITOS MAYORITARIOS DEL EXTRACTO ETANÓLICO DE Solanum cornifolium. SECCIÓN GEMINATA

    Directory of Open Access Journals (Sweden)

    Luis Enrique Cuca

    2008-02-01

    Full Text Available Del extracto etanólico de la parte aérea de Solanum cornifolium, utilizando técnicas cromatográficas para la separación y purificaciónde cada uno de los compuestos, fueron aislados dos esteroles, B-sitosterol y Estigmasterol, un triterpeno pentacíclico,Lupeol, y un nuevo alcaloide esteroidal 2-(-metil-tetrahirofurano-Solanidina.Sus estructuras fueron elucidadas por RMN, incluyendo técnicas 2D y por comparación con datos de la literatura.

  7. Pago y sostenibilidad de la deuda pública: ejercicios de simulación para algunas economías latino americanas

    Directory of Open Access Journals (Sweden)

    Andrés Ramírez Hassan

    2006-10-01

    Full Text Available Se desarrolla el marco teorico implicito en la restricción presupuestaria intertemporal del gobierno. A partir de este se realizan una serie de simulaciones sobre el problema de sostenibilidad de la deuda publica, y los sacrificios fiscales necesarios para juzgar el actual nivel de endeudamiento sostenible. Se observa que Colombia ubicada en el contexto analizado se encuentra en un lugar intermedio con respecto al esfuerzo fiscal necesario para sostener la deuda publica, concretamente se requiere un superavit primario promedio equivalente al 2.51% del PIB. Esta magnitud es inferior a la requerida por Argentina y Brasil, pero superior a los requerimientos de Venezuela, Chile y Mexico

  8. The serpent and the Madonna: Senses, practices and soundscapes in a vodou site: Saut d’Eau, Haiti

    Directory of Open Access Journals (Sweden)

    Francesco Ronzon

    2017-12-01

    Full Text Available L’articolo analizza la relazione tra sensi, pratiche e paesaggi sonori in relazione a Sodo, sede di un pellegrinaggio vodou su scala nazionale ad Haiti. Partendo dagli studi sui soundscapes (Schafer 1977 come punto di vista teorico per analizzare l’interazione tra suono e persone in un luogo specifico, l’articolo mostra l’interazione tra suoni ambientali, musica registrata e performance dal vivo. In particolare, questa ricerca vuole investigare il micro livello dell’ascolto situato, ovvero i modi con i quali gli attori sociali indirizzano la loro attenzione verso i suoni dell’ambiente in relazione alle loro pratiche sociali, culturali e religiose.

  9. Mejora de procesos en la producción de rollos de alfalfa en los sistemas lecheros argentinos

    OpenAIRE

    Urrets Zavalía, Gastón

    2014-01-01

    RESUMEN - CAPITULO 1: INTRODUCCIÓN - 1.1. Motivación - 1.2. Introducción a la problemática - 1.3. Objetivos - 1.4. Marco Teórico - 1.5. Alcance - 1.6. Metodología - CAPITULO 2: MARCO TEORICO - 2.1. ADMINISTRACIÓN DE OPERACIONES - 2.1.1. Diferencia entre Bienes y Servicios - 2.1.2. Evolución histórica de la Administración de Operaciones - 2.2. GESTIÓN POR PROCESOS - 2.2.1. Concepto de proceso - 2.2.2. Elementos de un Proceso - 2.2.3. Gestión por Procesos vs Enfoque Funcional - 2.3. MEJORA DE P...

  10. Correlation between magnetocapacitance effect and polarization flop direction in a slanted magnetic field in multiferroic helimagnets

    International Nuclear Information System (INIS)

    Abe, Nobuyuki; Sagayama, Hajime; Arima, Taka-hisa; Taniguchi, Kouji

    2011-01-01

    The relationship between the magnetocapacitance effect and rotation direction of electric polarization (P) in a canted magnetic field has been investigated for multiferroic RMnO 3 (R = Tb 1-x Dy x and Eu 0.6 Y 0.4 ). We observed a clear correlation between the enhancement of the magnetocapacitance effect and the rotation direction of P in a P-flop transition. These results indicate that the mobility and the stability of the 90 deg. domain wall in a P-flop transition are dominated by its thickness.

  11. Geochemical model of a geothermal system: an approach on the analytical uncertainty; Modelo geoquimico de sistema geotermico: un enfoque sobre la incertidumbre analitica

    Energy Technology Data Exchange (ETDEWEB)

    Pal Verma, Mahendra [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2008-07-01

    A procedure was developed to consider the analytical uncertainty in each parameter of geochemical analysis of geothermal fluid. The estimation of the uncertainty is based on the results of the geochemical analyses of geothermal fluids (numbered from the 0 to the 14), obtained within the framework of the comparisons program among the geochemical laboratories in the last 30 years. Also the propagation of the analytical uncertainty was realized in the calculation of the parameters of the geothermal fluid in the reservoir, through the methods of interval of uncertainty and GUM (Guide to the expression of Uncertainty of Measurement). The application of the methods is illustrated in the pH calculation of the geothermal fluid in the reservoir, considering samples 10 and 11 as separated waters at atmospheric conditions. [Spanish] Se desarrollo un procedimiento para estimar la incertidumbre analitica en cada parametro de analisis geoquimico de fluido geotermico. La estimacion de la incertidumbre esta basada en los resultados de los analisis geoquimicos de fluidos geotermicos (numerados del 0 al 14), obtenidos en el marco del programa de comparaciones entre los laboratorios geoquimicos en los ultimos 30 anos. Tambien se realizo la propagacion de la incertidumbre analitica en el calculo de los parametros del fluido geotermico en el yacimiento, a traves de los metodos de intervalo de incertidumbre y GUM (Guide to the expression of Uncertainty of Measurement). La aplicacion de los metodos se ilustra en el calculo de pH del fluido geotermico en el yacimiento, considerando las muestras 10 y 11 como aguas separadas a las condiciones atmosfericas.

  12. O Programa Minha Casa, Minha Vida na Região Metropolitana de Natal: uma análise espacial dos padrões de segregação e desterritorialização

    Directory of Open Access Journals (Sweden)

    Jéssica Morais de Moura

    2014-09-01

    Full Text Available Essa pesquisa propõe uma análise sobre as formas de produção da moradia e seus impactos na reconfiguração espacial das metrópoles, concentrando-se no estudo dos empreendimentos do Programa Minha Casa, Minha Vida destinados à população de faixa de renda de zero a três salários mínimos (faixa 1, construídos na Região Metropolitana de Natal. A partir da evidência de que os empreendimentos do PMCMV destinados à população de baixa renda implantados no território da RMN, em sua maioria, estão sendo construídos em localidades distantes do tecido urbano, com pouca ou nenhuma oferta de transporte público e equipamentos sociais, essa pesquisa buscou investigar se a construção dessas moradias tem promovido a segregação social dessa população, impactando diretamente no cotidiano dos moradores, da forma como Haesbaert define a desterritorialização. Foram visitados 32 empreendimentos, distribuídos em 8 municípios da RMN, caracterizando sua localização e inserção urbana, refletindo e verificando se a carência de serviços e infraes¬trutura determinam uma segregação da população residente, implicando em consequências marcantes no seu cotidiano e promovendo o processo social de desterritorialização.

  13. Peculiarity of component interaction in {l_brace}Y, Dy{r_brace}-Mn-Sn ternary systems

    Energy Technology Data Exchange (ETDEWEB)

    Romaka, V.V. [Department of Materials Engineering and Applied Physics, Lviv Polytechnic National University, Ustyyanovycha Str. 5, 79013 Lviv (Ukraine); Konyk, M. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Romaka, L., E-mail: romakal@franko.lviv.ua [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Pavlyuk, V. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine); Jan Dlugosz University, Institute of Chemistry, Environmental Protection and Biotechnology, al. Armii Krajowej 13/15, 42200 Czestochowa (Poland); Ehrenberg, H. [Institute for Complex Materials, IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden (Germany); Tkachuk, A. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mefodiya Str. 6, 79005 Lviv (Ukraine)

    2011-07-14

    Highlights: > {l_brace}Y, Dy{r_brace}-Mn-Sn ternary systems at 770 K are characterized by formation of stannides with general compositions RMn{sub 6}Sn{sub 6} and R{sub 4}Mn{sub 4}Sn{sub 7}. > The crystal structure of YMn{sub 6}Sn{sub 6} was determined by single crystal and powder diffraction methods. > Structural analysis showed that Dy{sub 4}Mn{sub 4}Sn{sub 7} compound is disordered. > Isostructural R{sub 4}Mn{sub 4}Sn{sub 7} compounds were also found with Gd, Tb, Ho, Er, Tm(confirmed), Yb, and Lu. - Abstract: The phase equilibria in the Y-Mn-Sn and Dy-Mn-Sn ternary systems were studied at 770 K by means of X-ray and metallographic analyses in the whole concentration range. Both Y-Mn-Sn and Dy-Mn-Sn systems are characterized by formation of two ternary compounds RMn{sub 6}Sn{sub 6} (MgFe{sub 6}Ge{sub 6}-type, space group P6/mmm) and R{sub 4}Mn{sub 4}Sn{sub 7} (Zr{sub 4}Co{sub 4}Ge{sub 7}-type, space group I4/mmm). The disorder in Dy{sub 4}Mn{sub 4}Sn{sub 7} compound was found by single crystal method. Compounds with the same type of structure were also found with Gd, Tb, Ho, Er, Tm (confirmed), Yb, and Lu and their lattice parameters were determined.

  14. Urbanização dispersa e mobilidade no contexto metropolitano de Natal: a dinâmica da população e a ampliação do espaço de vida

    Directory of Open Access Journals (Sweden)

    Ricardo Ojima

    2014-01-01

    Full Text Available Embora ainda coexistam no espaço urbano o modelo concêntrico e o disperso de urbanização, considerasse aqui que esse fenômeno reflete mais a cristalização e materialidade dos processos anteriores do que a perpetuação da mesma dinâmica urbana que os fizeram existir. A hipótese perseguida é a de que há um novo padrão de urbanização disperso e fragmentado que tem tornado o tecido urbano socialmente mais heterogêneo e que tal característica coloca novos desafios tanto para a esfera social quanto para a escala individual. Assim, apresenta-se o processo de expansão urbano da Região Metropolitana de Natal (RMN, a partir de uma abordagem espacial e demográfica, em direção ao eixo sul de desenvolvimento urbano. Nesse sentido, observar as transformações ocorridas ao longo da década de 2000 nos permite compreender a dimensão do fenômeno e do processo de dispersão urbana na região e ainda analisar o seu impacto. Os resultados permitem confirmar a ampliação dos espaços de vida associados a uma tendência para a dispersão urbana no sentido sul da RMN, indicando que tais processos também estão por ocorrer em regiões metropolitanas nordestinas.

  15. Giuseppe E. Sansone traduttore di lirica romanza medievale. Contributo per una storia della traduzione poetica in Italia

    Directory of Open Access Journals (Sweden)

    Speranza Cerullo

    2013-07-01

    Full Text Available La traduzione di poesia medievale in Italia ha avuto notevole sviluppo negli ultimi venti anni, attraverso l’incremento dell’attività dei traduttori e la promozione di un confronto su questioni di ordine teorico o metodologico, strettamente legate al tema dell’attualizzazione del testo medievale. In questo quadro, il contributo di Giuseppe Sansone ha svolto un ruolo di primo rilievo, attraverso un’attività ininterrotta che conta la pubblicazione di scritti di indirizzo critico-teorico e di cinque antologie di lirica medievale di diversi ambiti linguistici – occitano, spagnolo, catalano, galego e, in misura minore, francese –, offrendo modelli e appunti di metodo nei quali competenze scientifiche e filologiche si coniugano con una sensibilità estetica d’autore, guidata dall’obiettivo primario di una rifondazione del testo poetico nella sua letterarietà, dove la traduzione in versi si propone come testo dotato di una propria autonomia estetica.Over the last twenty years the translation of medieval poetry in Italy has had considerable development due to the increased activity of the translators; besides, a debate on theoretical or methodological issues closely related to the theme of updating medieval texts has been promoted. In this context, the contribution of Giuseppe Sansone and his continuous activity has played a key role: he published critical-theoretical essays and five anthologies of medieval lyrics from different linguistic areas – Provençal, Spanish, Catalan, Galician and, to a lesser extent, French – thus offering models and methodological suggestions in which scientific and philological skills combine with aesthetic sensibility, driven from the primary method of re-founding the poetic text in its literary property, in which the verse translation is proposed as a text with its own aesthetic autonomy.

  16. Calculation of attenuation by rain using the DAH model and diameter of antennas for the Ka Band in Mexico; Calculo de atenuacion por lluvia usando el modelo DAH y diametro de antena para Banda Ka en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Landeros-Ayala, S.; Neri-Vela, R; Cruz-Sanchez, H.; Hernandez-Bautista, H. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2002-03-01

    Fatim Haidara), combinado con los mapas globales de distribucion de lluvia de Crane, para el calculo de la atencion por lluvia en sistema de comunicacion por satelite que operen en la Banda Ka. Ademas, se proponen diametros de antena para los sistemas de comunicaciones en Banda Ka en diferentes localidades de la Republica Mexicana, empleando para ello, los margenes de atencion por lluvia obtenidos a trav del Modelo DAH, y usando como referencia las caracteristicas del satelite de comunicaciones ANIK F2 y de una estacion terrena VSAT.Se muestra una fig. de la atenuacion por lluvia a 27.5 gHz y de los diametros de antena para banda Ka en Mexico. Se da una tabla de la atenuacion por lluvia a 29.5 GHz y a 20.2 GHz.

  17. Estudio teorico de las interacciones de dos modelos de ácidos húmicos con los cationes Al3+, Ca2+, Mg2+, Zn2+, K+ y NH4+ a un nivel de calculo DFT y un modelo de solvatación PCM

    Directory of Open Access Journals (Sweden)

    Eduardo Espinosa-Fuentes

    Full Text Available In this paper, two models of humic acids, the Temple-Northeastern-Birmingham (TNB and Kolla models, were studied. Also, the complexation reaction of the structures formed by the interaction of the TNB and Kolla models with Al3+, Ca2+, Mg2+, Zn2+, K+ and NH4+ cations, common in agricultural soils, was studied. These calculations were made for the complexes, at PM6 and DFT / LANL2DZ level of theory, both in vacuum and in aqueous medium. We found a strong affinity between Kolla and TNB models, and Al3+, Ca2+, Mg2+, Zn2+, K+ and NH4+ cations, influenced by the solvent that affected the interaction sites; the solvent increased the rate of reactivity and affinity for the cations in nucleophilic regions and decreased it in electrophilic regions of the structures. Calculations of molecular electronic potential, MEP and atomic charges, the local smoothness, Fukui functions and the HSAB principle adequately described the HA/cations interactions which were affected by the number of hydrogen bonds. The most reactive sites were the hydroxyl, phenolic, carbonyls oxygens and nitrogens at both vacuum and aqueous medium, especially carbonyl oxygens. These results are consistent with the properties of HA that make them attractive as components of agricultural soils.

  18. Iteración de funciones e introducción al caos con Mathematica

    OpenAIRE

    Rojas, Ángela

    2000-01-01

    En este trabajo se estudio la iteración de punto fijo muy habitual en todos los programas de calculo numérico y su aplicación en un caso particularmente interesante: la función logística. De esta forma se pueden introducir elementos característicos de la teoría del caos: efecto mariposa o exponente de Lyaponuv, bifurcaciones por duplicación de periodo. Esta experiencia se ha realizado en la escuela de ingeniería técnica de Córdoba, usando Mathematica por la potencia y verticalidad que posee e...

  19. La importancia del ciclo de caja y cálculo del capital de trabajo en la gerencia PYME

    OpenAIRE

    Jorge Iván Jiménez Sánchez; Farley Saray Rojas Restrepo; Heidy Julieth Ospina Galvis

    2014-01-01

     El artículo aborda las finanzas en la pyme moderna, la cual necesita de un gerente dinámico y hábil en la gestión administrativa, la información contable y las finanzas, con conocimiento de los días necesarios para cubrir el ciclo de caja y el capital que se requiere para operar a corto plazo, calculo necesario para determinar si va a alcanzar el dinero o si va a necesitar financiación y su valor exacto. Las cifras de fracaso de las pymes en América Latina son abrumadoras, ochenta por ciento...

  20. Proteste ed emancipazione alla frontiera europea. Il caso di Lampedusa

    Directory of Open Access Journals (Sweden)

    Annalisa Lendaro

    Full Text Available Riassunto Questo articolo si propone di approfondire a livello teorico i legami tra proteste ed emancipazione dei migranti senza status legale, che si trovano in situazione di detenzione amministrativa sull’isola italiana di Lampedusa. Il presente contributo mette in evidenza il fatto che l’agency dei migranti, seppur privi di libertà e di uno status legale, è determinante per sbloccare una situazione di crisi in un contesto simile allo stato di eccezione descritto da Agamben. Più precisamente, la protesta dei migranti di Lampedusa mostra in che modo la sospensione dello stato di diritto apra degli spiragli per, non solo denunciare l’ingiustizia di alcune norme, ma anche per agire.

  1. Sviluppo e crisi. Per una prospettiva della compresenza

    Directory of Open Access Journals (Sweden)

    Andrea Pirni

    2011-02-01

    Full Text Available Il paradigma della modernità, adottando il concetto di sviluppo come tema chiave, ha elaborato moltissime teorie del mutamento: qui sviluppo e crisi risultano necessariamente contrapposti sia sotto il profilo teorico che empirico. La complessità crescente delle società europee contemporanee mette in discussione la capacità interpretativa del mutamento che le coinvolge attualmente e suggerisce l’elaborazione di nuove prospettive che focalizzino il processo di trasformazione in corso piuttosto che soffermarsi sul risultato. Dopo aver sinteticamente inquadrato il concetto di sviluppo nell’ambito del paradigma della modernità l’articolo intende sostenere l’utilità di una prospettiva che considera congiuntamente crisi e sviluppo per analizzare il mutamento delle democrazie contemporanee.

  2. Estudo da interação entre borrachas comerciais e misturas de biodiesel/diesel por espectroscopia de ressonância magnética nuclear

    OpenAIRE

    Lorena Mara Alexandre e Silva

    2014-01-01

    Hoje em dia o biodiesel tem se consolidado como uma matriz energética importante em muitos países. Os elastômeros integram uma classe importante de materiais, com aplicação em diversas áreas e principalmente, são vastamente utilizados em motores automobilísticos. Assim, a compatibilidade dos elastômeros com biodiesel é uma preocupação crescente. Para obter e correlacionar informações importantes das fases compartimentadas no sistema borracha/combustível, foram empregados a RMN em baixo, alto ...

  3. "Efecto ancla" en la hidrogenación estereoselectiva de dihidro-mahuba-lactonas

    Directory of Open Access Journals (Sweden)

    Juan C. Martinez V.

    2009-07-01

    Full Text Available En la hidrogenación catalítica de (3R, 48, 2E-2—(hexadec—15-inilideno— 3—hidroxl—4—metllbutanolido (una dihidro—mahuba—lactona, utilizando H2/Pd— C en metanol, se obtuvo un producto con un rendimiento del 86% , ocurriendo una hidrogenación estereoselectiva. Haciendo uso del espectro de RMN H del acetato del producto de hidrogenación y de la ecuación de Karplus, se muestra que el hidroxilo alílico actúa como un "ancla" en el catalizador.

  4. NUEVA BENZOIL LACTONA Y OTROS COSTITUYENTES DE Pilocarpus alvaradoii (Rutaceae

    Directory of Open Access Journals (Sweden)

    Luis E. Cuca

    2008-04-01

    Full Text Available Del extracto etanólico de hojas de Pilocarpus alvaradoii fue aislada e identificada la nueva lactona α-Benzoil-γ-valerolactona (1, junto con los triterpenos pentacíclicos conocidos lupeol (2, epibetulina (3; y las furanocumarinas bergapteno (4, psoraleno (5, y xantotoxina (6.  El aislamiento y la purificación fueron realizados por técnicas cromatográficas convencionales.   La elucidación estructural de estos compuestos se determinó mediante técnicas espectroscópicas (IR, RMN 1H, 13C, EM.

  5. NUEVA BENZOIL LACTONA Y OTROS CONSTITUYENTES DE Pilocarpus alvaradoii (Rutaceae)

    OpenAIRE

    Cuca, Luis E.; Ávila, Mónica C.

    2007-01-01

    Del extracto etanólico de hojas de Pilocarpus alvaradoii fue aislada e identificada la nueva lactona α-Benzoil-γ-valerolactona 1, junto con los triterpenos pentacíclicos conocidos lupeol 2, y epibetulina 3; y las furanocumarinas bergapteno 4, psoraleno 5, y xantotoxina 6. El aislamiento y la purificación fueron realizados por técnicas cromatográficas convencionales. La elucidación estructural de estos compuestos se determinó mediante técnicas espectroscópicas (IR, RMN 1H, 13C, EM). From th...

  6. Epoxidation of polybutadiene rubber in non polar solvent

    International Nuclear Information System (INIS)

    Schneider, Luciane K. de A.; Jacobi, Marly A.M.

    2005-01-01

    The epoxidation of polybutadiene rubber in cyclohexane, at 50 deg C, by the method of performic acid generated in situ, at different reagent concentration was investigated. The epoxy degree was determined by 1 H-RMN, and because of the gelation and coagulation of modified rubber during the reaction, only a maximum of 30 mol % of epoxy degree could be achieved. The reaction followed a first order kinetic in relation to hydrogen peroxide and acid concentration showing a rate constant of 4,0 (± 0,5) x 10 -5 L.mol-1.seg -1 . (author)

  7. Síndrome MAPE, heavy eye y esclerodermia

    OpenAIRE

    Brugnoli de Pagano, Ofelia; Pagano, Gabriela

    2009-01-01

    Paciente de 60 años de edad y sexo femenino con esclerodermia y miopía alta bilateral que consulta por estrabismo y ptosis palpebral. El estrabismo consiste en esotropía progresiva con hipotropía de ojo derecho (OD) asociado a miopía alta axial con gran tamaño del globo ocular medido por ecometría ultrasónica que conjuntamente con imágenes de Resonancia Magnética Nuclear (RMN) llevan al diagnóstico de Síndrome MAPE (Miopic Acquired Progressive...

  8. Buffer layers and articles for electronic devices

    Science.gov (United States)

    Paranthaman, Mariappan P.; Aytug, Tolga; Christen, David K.; Feenstra, Roeland; Goyal, Amit

    2004-07-20

    Materials for depositing buffer layers on biaxially textured and untextured metallic and metal oxide substrates for use in the manufacture of superconducting and other electronic articles comprise RMnO.sub.3, R.sub.1-x A.sub.x MnO.sub.3, and combinations thereof; wherein R includes an element selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y, and A includes an element selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Ra.

  9. Nuclear magnetic resonance in the neonatal period and prediction of the neuro development evolution in premature newborns

    International Nuclear Information System (INIS)

    Oreiro, Vilma

    2007-01-01

    The nuclear magnetic resonance (RMN) is outlined as a progressively more accessible study. The new technology allows, even to omit the sedation of children. In the last 10 years, we have had access to the knowledge of the modifications shown by the brain of the premature newborn in growth as well as in cerebral structures. In 2003, a detailed description was published concerning the technology used to evaluate the images of premature newborns and the evolution of these images according to the own modifications of the progress during the post-conception age [es

  10. Sistema de medición, control y compensación activa para ciclado de campo magnético en aplicaciones de resonancia magnética nuclear

    OpenAIRE

    Forte, Guillermo Omar

    2013-01-01

    Tesis (DCI)--FCEFN-UNC, 2013 Analiza aspectos de la instrumentación asociada a la técnica de Resonancia Magnética Nuclear (RMN) con Ciclado Rápido de Campo Magnético (FFC, por sus siglas en inglés), los que afectan directamente la calidad de las mediciones realizadas. Se implementó un método para la corrección estática de la dependencia espacial del campo magnético generado por el electroimán principal del sistema, dentro de un volúmen determinado.

  11. A note on the weighted Khintchine-Groshev Theorem

    DEFF Research Database (Denmark)

    Hussain, Mumtaz; Yusupova, Tatiana

    Let W(m,n;ψ−−) denote the set of ψ1,…,ψn-approximable points in Rmn. The classical Khintchine-Groshev theorem assumes a monotonicity condition on the approximating functions ψ−−. Removing monotonicity from the Khintchine-Groshev theorem is attributed to different authors for different cases of m...... and n. It can not be removed for m=n=1 as Duffin-Shcaeffer provided the counter example. We deal with the only remaining case m=2 and thereby remove all unnecessary conditions from the Khintchine-Groshev theorem....

  12. Unfolding of Vortices into Topological Stripes in a Multiferroic Material

    Science.gov (United States)

    Wang, X.; Mostovoy, M.; Han, M. G.; Horibe, Y.; Aoki, T.; Zhu, Y.; Cheong, S.-W.

    2014-06-01

    Multiferroic hexagonal RMnO3 (R =rare earths) crystals exhibit dense networks of vortex lines at which six domain walls merge. While the domain walls can be readily moved with an applied electric field, the vortex cores so far have been impossible to control. Our experiments demonstrate that shear strain induces a Magnus-type force pulling vortices and antivortices in opposite directions and unfolding them into a topological stripe domain state. We discuss the analogy between this effect and the current-driven dynamics of vortices in superconductors and superfluids.

  13. Anthraquinones and naphtoquinones from the bark of Tectona grandis (Verbenaceae) reforestation specimen

    OpenAIRE

    Moreira, Rafael Y.O.; Arruda, Mara S.P.; Arruda, Alberto C.; Santos, Lourivaldo S.; Müller, Adolfo H.; Guilhon, Giselle M.S.P.; Santos, Alberdan S.; Terezo, Evaristo

    2006-01-01

    O fracionamento do extrato hexânico do caule de um espécime de reflorestamento de Tectona grandis (Verbenaceae), através de procedimentos fitoquímicos clássicos, levou ao isolamento das naftoquinonas lapachol e desidro-a-lapachona e das antraquinonas tectoquinona e obtusifolina. As estruturas das substâncias foram caracterizadas através da análise de métodos espectrométricos de RMN. Este é o primeiro estudo fitoquímico de um espécime de reflorestamento de Tectona grandis, no Brasil, sendo o o...

  14. Antraquinonas e naftoquinonas do caule de um espécime de reflorestamento de Tectona grandi (Verbenaceae)

    OpenAIRE

    Moreira,Rafael Y.O.; Arruda,Mara S.P.; Arruda,Alberto C.; Santos,Lourivaldo S.; Müller,Adolfo H.; Guilhon,Giselle M.S.P.; Santos,Alberdan S.; Terezo,Evaristo

    2006-01-01

    O fracionamento do extrato hexânico do caule de um espécime de reflorestamento de Tectona grandis (Verbenaceae), através de procedimentos fitoquímicos clássicos, levou ao isolamento das naftoquinonas lapachol e desidro-a-lapachona e das antraquinonas tectoquinona e obtusifolina. As estruturas das substâncias foram caracterizadas através da análise de métodos espectrométricos de RMN. Este é o primeiro estudo fitoquímico de um espécime de reflorestamento de Tectona grandis, no Brasil, sendo o o...

  15. Estudo fitoquímico e avaliação da toxicidade frente a Artemia salina e da atividade antimicrobiana de Calycorectes psidiiflorus (O. Berg) Sobral, Myrtaceae

    OpenAIRE

    Domingues, Elaine A.; Nakamura, Celso V.; de Souza, Maria C.; Teixeira, Tatiane S.; Peixoto, Juliana L. B.; Sarragiotto, Maria H.; Vidotti, Gentil J.

    2010-01-01

    O estudo fitoquímico das folhas de Calycorectes psidiiflorus (O. Berg) Sobral, Myrtaceae, resultou no isolamento e identificação de: sesquiterpeno [8-hidroxicalameneno (1)], triterpenos [α-amirina (2a) e β-amirina (2b)], flavonóide [3-O-α-ramnopiranosil-7-O-bglucopiranosil canferol (3)], e alcalóide [1,2,3,4-tetraidro-1-metil-β-carbolina (4)]. As estruturas das substâncias isoladas foram elucidadas com base nos seus dados de RMN em comparação com os da literatura. A substância 8-hydroxicalame...

  16. Transformée de Fourier applications en RMN et IRM

    CERN Document Server

    Verdun, Francis R

    1995-01-01

    Les méthodes spectroscopiques de Résonance Magnétique Nucléaire et l'Imagerie par Résonance Magnétique ont aujourd'hui largement dépassé le seul cadre du laboratoire. Un nombre croissant de personnes est confronté à leur utilisation ou à l'interprétation des résultats délivrés. Or les interfaces entre l'appareil et l'utilisateur font appel à un traitement mathématique sophistiqué qu'il est souhaitable de comprendre.

  17. Natural terrestrial radiation exposure in Hong Kong. A survey on environmental gamma absorbed dose rate in air

    International Nuclear Information System (INIS)

    Wong, M.C.; Poon, H.T.; Chan, Y.K.; So, C.K.

    2000-01-01

    Hong Kong is a metropolitan city located on the southern coast of China with a population of some six million. About 90% of the population is concentrated in heavily built-up residential and commercial areas, which accounts for less than 50% of the total area in the territory. Hong Kong Observatory, 134A Nathan Road, Kowloon, Hong Kong, China. In order to understand the spatial variations in the environmental radiation levels in Hong Kong, the Hong Kong Observatory (HKO) in early 1999 conducted a study of the environmental gamma absorbed dose rate in air. The study combined data collected by the HKO radiation monitoring network (RMN) and data from a comprehensive territory-wide radiological survey conducted in January and February 1999. The RMN of ten stations each equipped with a Reuter-Stokes Model RSS-1013 HPIC has been in operation since 1987 to continuously monitor the environmental radiation levels over the territory as part of the emergency monitoring programme for response to nuclear accidents at a nearby nuclear power station. The terrestrial component of the environmental radiation field was estimated by subtracting from the measurements the cosmic contribution, which is determined to be about 39 nGy/h from measurements conducted over two large fresh water reservoirs. The RMN data with the long history was analysed to derive the seasonal variations in the environmental radiation levels. On average the environmental gamma absorbed dose rate in air in January and February is 1.03 times of the annual figure. This seasonal correction was applied to the results of the year 1999 survey. As the radiation field in the heavily built-up areas is enhanced by contribution from buildings, in the territory-wide survey measurements were made both in the open field and built-up areas. The territory of Hong Kong was divided into 42 grid boxes of 5 km x 5 km for open field and 61 grid boxes of 2.5 km x 2.5 km for built-up areas according to the population and land use. A

  18. Current shaper: a new topology; Conformador de corriente: una nueva topologia

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Salcedo, Josue

    2003-03-15

    el puente rectificador -en lugar de tener una conexion en serie con el puente-, denominado Conformadores de Corriente Tipo Paralelo. Se describe la teoria de la operacion y el analisis matematico de las formas de onda de la topologia de este nuevo conformador de corriente junto con el analisis teorico que determina la eficacia del sistema y las consideraciones en el diseno de la topologia. En lo referente al diseno de la etapa de potencia se presenta el filtro EMI empleado, el calculo del capacitor voluminoso, el convertidor flyback y del transformador, asi como el tipo de compensador utilizado en la parte de la etapa de control. Para corroborar el analisis de la forma de onda de la corriente de entrada se implemento un prototipo a una potencia de salida de 50W, cuyos resultados experimentales se muestran a la par del contenido armonico de la corriente de entrada necesaria para cumplir con la norma de calidad y los resultados a la respuesta dinamica del convertidor.

  19. Characterization of the billow applied to Tuxpan, Veracruz; Caracterizacion del oleaje aplicada a Tuxpan, Veracruz

    Energy Technology Data Exchange (ETDEWEB)

    Rosales Sierra, Victor

    1999-07-01

    In this work, the criteria for the wave temporal and spectral statistical analysis were reviewed. These analysis are applied to the site Tuxpan, Veracruz, in the Mexican Gulf coast. In the temporal statistic analysis, the high (Rayleigh, Tayfun and Carter) and period (Bretchneider, Cavanie and Longuet-Higgins) theoretic probability distributions are compared with field data from Tuxpan. In the other hand, in the frequency domain analysis, the theoretic spectrums (Bretchneider-Mitsuyasu, Jonswap-Hasselmann, Pierson-Moscowitz, Neumann, ITTC, ISSC, TMA and Ochi-Hubble) are compared with the one obtained from Tuxpan measurements, then changes are made to some spectrums in order to better couple to field data. Finally, some recommendations are made to improve the wave data acquisition and analysis methods. From the study results, it's important to mention that the Tayfun high probability distribution and the Cavanie period probability distribution better fit Tuxpan field data. In the spectral analysis, the Bretchneider spectrum, modified by Mitsuyasu, better coupled to the spectrum obtained from Tuxpan field data. In the temporal statistical analysis, correct the mean level using the parabolic approximation, in order to eliminate the tidal and long period wave effects, it is recommended. For the registered individual wave calculus the zero up cross method was used. [Spanish] En este trabajo se revisan los criterios para el analisis estadisticos temporal y espectral del oleaje, mismos que son aplicados para la caracterizacion del oleaje en Tuxpan, Veracruz. En cuanto al analisis estadistico temporal, se comparan las distribuciones teoricas de probabilidad de altura de Rayleigh, Tayfun y Carter; y las de periodo de Bretchneider, Cavanie y Longuet-Higgins contra las resultantes de las mediciones en campo. Por otro lado y concerniente al analisis en el dominio de la frecuencia, se comparan los espectros teoricos de Bretchneider- Mitsuyasu, Jonswap-Hasselmann, Pierson

  20. ESTUDIO CONFORMACIONAL EN ALGUNAS 1,3-OXAZINAS Y 1,3-BENZOXAZINAS EMPLEANDO METODOS TEORICOS.

    OpenAIRE

    HURTADO OCAMPO, SANDRA MARCELA; HURTADO OCAMPO, SANDRA MARCELA

    2007-01-01

    En la década del cincuenta, resultados experimentales entregados por Urbanski y colaboradores [1] pusieron en evidencia propiedades antituberculósicas y antitumorales en compuestos del tipo 5-nitro-R-N-1 ,3- oxazínicos. Como resultado de un proceso relati 187p.

  1. Do traditional sheep breeders perform conscious selection? An example from a participatory breeding program of Morada Nova sheep.

    Science.gov (United States)

    Arandas, Janaina Kelli Gomes; Alves, Ângelo Giuseppe Chaves; Facó, Olivardo; Belchior, Ernandes Barboza; Shiotsuki, Luciana; de Arruda Leite, Paulo Márcio Barbosa; Ribeiro, Maria Norma

    2017-10-01

    The implementation of sustainable breeding programs requires genetic breeding strategies that are appropriate for the reality production systems. It is also essential that the choice of animal selection criteria be based on breeders' knowledge and objectives. This work is an ethno-zootechnical study of the Morada Nova sheep breed and its crossbreeds. The goals of this study were to register and analyze indigenous breeders' knowledge and practices regarding animal selection criteria and to generate technical information to support a participatory breeding program of the breed. This study was conducted in the Morada Nova municipality in the state of Ceará, Brazil. Semi-structured interviews were evaluated using two groups of individuals, purebred Morada Nova sheep breeders (RMN, n = 13) and breeders of Morada Nova crossbreeds (MMN, n = 48). Interview questions were used to identify local selection criteria adopted by each group in the choice of animals for breeding. Data from the interviews were submitted to frequency distribution analysis and the Shapiro-Wilk test to verify their distribution. Later, the Kruskal-Wallis test was used to compare the two groups of farmers based on that information, in addition to multivariate statistical analysis and evaluation of Smith salience index. Breeders in the RMN group used selection criteria related to breed standards, such as pelage color. In contrast, breeders of the MMN group used criteria related to productivity, such as body conformation and milk production. Breeders should be engaged in the development of breeding programs, and it is important to consider their preferences and objectives when evaluating breeding animals.

  2. The Burnside problem and related topics

    International Nuclear Information System (INIS)

    Adian, Sergei I

    2011-01-01

    This paper gives a survey of results related to the famous Burnside problem on periodic groups. A negative solution of this problem was first published in joint papers of P.S. Novikov and the author in 1968. The theory of transformations of words in free periodic groups that was created in these papers and its various modifications give a very productive approach to the investigation of hard problems in group theory. In 1950 the Burnside problem gave rise to another problem on finite periodic groups, formulated by Magnus and called by him the restricted Burnside problem. Here it is called the Burnside-Magnus problem. In the Burnside problem the question of local finiteness of periodic groups of a given exponent was posed, but the Burnside-Magnus problem is the question of the existence of a maximal finite periodic group R(m,n) of a fixed period n with a given number m of generators. These problems complement each other. The publication in a joint paper by the author and Razborov in 1987 of the first effective proof of the well-known result of Kostrikin on the existence of a maximal group R(m,n) for any prime n, together with an indication of primitive recursive upper bounds for the orders of these groups, stimulated investigations of the Burnside-Magnus problem as well. Very soon other effective proofs appeared, and then Zel'manov extended Kostrikin's result to the case when n is any power of a prime number. These results are discussed in the last section of this paper. Bibliography: 105 titles.

  3. Ressonância magnética do envolvimento cerebral na hemiatrofia facial progressiva (doença de Romberg reconsideração de uma síndrome

    Directory of Open Access Journals (Sweden)

    K. Terstegge

    1995-03-01

    Full Text Available A hemiatrofia facial progressiva (HFP é doença esporádica de etiologia não esclarecida, caracterizada por progressiva atrofia e deformação de um dos lados da face. Os relatos e interpretações de comprometimento do sistema nervoso central na HFP, conforme deduzido pela ocorrência de crises epilépticas em alguns pacientes e pela documentação por pneumencefalografia e CT em pequenas séries de pacientes, são contraditórios. Examinamos três pacientes do sexo feminino com HFP, uma com epilepsia, com o objetivo de obter mais informações sobre a patogênese da doença. MÉTODOS: Realizamos exames de ressonância magnética nuclear (RMN de rotina da cabeça e face. RESULTADOS:Apenas a paciente com epilepsia apresentou achados patológicos no cérebro. Estes eram confinados ao hemisfério homolateral à hemiatrofia facial: dilatação monoventricular, dismorfismo meningo-cortical e alterações na substância branca. CONCLUSÕES: As alterações morfológicas verificadas à RMN assim como os achados neurorradiológicos e histopatológicos mostrados em revisão da literatura indicaram que a hemiatrofia homolateral é achado típico para um subgrupo de pacientes com HFP, mas não indica um modelo de simples processo atrófico. Reconsideramos a possibilidade de uma meningoencefalite crônica com acometimento vascular como possível causa do ocasional envolvimento cerebral na HFP.

  4. Efeito do extrato bruto hidroalcoólico e de frações de folhas da Averrhoa carambola L. (Oxalidaceae no metabolismo glicêmico de ratos Wistar = Effect of Hydroalcoholic extract and fractions of Averrhoa carambola L. (Oxalidaceae leaves on the glycemic metabolism of Wistar rats

    Directory of Open Access Journals (Sweden)

    Marilene Provasi

    2005-01-01

    Full Text Available As folhas de carambola (Averrhoa carambola L. são utilizadas na fabricação do fitoterápico Glico-Vitae., indicado no tratamento do diabetes melittus tipo 2. Em nossos estudos, ratos machos Wistar que receberam, por via intragástrica, o extrato bruto liofilizado (EC e as frações de EC (20 mg/kg, durante duas semanas, apresentaram redução da glicemia. Mas, diferentemente da insulina, o EC e suas frações não estimularam a síntese de glicogênio e a produção de lactato em músculo sóleo isolado. Da fração mais ativa, empregando métodos espectroscópicos de EM, RMN1H e RMN13C, foram isoladas trêsfrações semipurificadas majoritárias e, por comparação com os dados da literatura, foram identificadas como misturas complexas de açúcares.Carambola (Averrhoa carambola L. leaves have been used for the production of Glico-Vitae., a phytotherapic medicine indicated for type 2 diabetes mellitus. Male Wistar rats, which received intragastric administration of the liophyliled extract (EC and fractions of EC (20 mg/kg during 2 weeks, showed decreased (p < 0.05 blood glucose levels. However, in contrast to insulin, EC and its fractions neither increased the glycogen synthesis or thelactate production in isolated soleus muscle. In addition, by using spectroscopic methods (MS, NMR1H and NMR13C a mixture of complex sugars were obtained from the fraction with the highest activity.

  5. Stefano Jacoviello, "La rivincita di Orfeo. Esperienza estetica e semiotica del discorso musicale", Mimesis Edizioni, Milano – Udine, 2012

    Directory of Open Access Journals (Sweden)

    Luca Marconi

    2014-11-01

    Full Text Available A partire dagli scritti di Roman Jakobson, Nicolas Ruwet, Jean-Jacques Nattiez e Gino Stefani, la relazione tra la semiotica e la musica è stata spesso affrontata da numerosi studiosi che anche oggi praticano, specie in Canada, in Finlandia e in Italia, la disciplina chiamata “semiotica (o semiologia della musica”. Negli ultimi anni, in questo ambito spesso si è preferito realizzare studi su alcuni problemi specifici piuttosto che concentrarsi su una teorizzazione generale. Al contrario, Stefano Jacoviello, dopo aver pubblicato brevi saggi di carattere prevalentemente analitico, in questo volume, di ampio respiro teorico, presenta una sorta di manifesto teso a rilanciare, specie in Italia, il ruolo della “semiotica del discorso musicale” come disciplina particolarmente adatta ad affrontare questioni teoriche generali.

  6. Ética, organización y formación

    Directory of Open Access Journals (Sweden)

    MIGUEL ÁNGEL SÁNCHEZ

    1997-01-01

    Full Text Available se reaiza un breve recorrido por el concepto de "etica en los negocios", que aparece con frecuencia en los medios de los estados unidos desde los años setenta. se consideran tambien los fenomenos de corrupcion en españa en 1994 y 1995, con las consiguientes incertidumbres que se crean en la sociedad española. asimismo, se realiza un breve analisis historico retrospectivo, comenzando con la "etica protestante", en los siglos xvii y xviii, siguiento con el liberalismo y la economia social de mercado. se analiza luego la etica empresarial desde un punto de vista teorico y empirico, asi como las consecuencias de la corrupcion (la no etica. por ultimo se considera, brevemente, la importancia de la etica en la formacion.

  7. Computação algébrica no cálculo das variações: determinação de simetrias e leis de conservação

    OpenAIRE

    Gouveia, Paulo D.F.; Torres, Delfim F.M.

    2005-01-01

    Os problemas de optimização dinâmica (em espaços de funções) tratados pelo calculo das variações, são normalmente resolvidos por recurso às condições necessárias de Euler-Lagrange, que são equações diferenciais de segunda ordem (ou de ordem superior, quando os problemas variacionais envolvem derivadas de ordem superior a um). Estas equações são, em geral, não lineares e de difícil resolução. Uma forma de as simplificar consiste em obter leis de conservação: primeiros integrais ...

  8. Síntesis y caracterización de un cuadrado supramoleculara partir del auto-ensamblaje del complejo[1,2-bis(difenilfosfino)etano] bistrifluorometanosulfonatopaladio (ii) y 4,4´-bipiridina

    OpenAIRE

    Posada, Julian; Avella, Eliseo; Duarte, Alvaro; Echegoyen, Luis

    2011-01-01

    Por primera vez se desarrolló la síntesisy caracterización (IR, UV, RMN-1H,31P, 19F) de un nuevo cuadrado supramolecular[3] mediante el auto-ensamblajedel complejo [Pd(CF3SO3)2(Dppe)] [1] yel ligando orgánico 4,4´-Bipiridina [2].Se evidenció la obtención de [3] en mezclacon otra especie supramolecular [4],asignada como un macrociclo triangular.Las estructuras de [3] y [4] se elucidaroncon base en los desplazamientos químicos,la proporcionalidad entre sus integralesy en los patrones de acoplam...

  9. SÍNTESIS Y CARACTERIZACIÓN DE UN CUADRADO SUPRAMOLECULARA PARTIR DEL AUTO-ENSAMBLAJE DEL COMPLEJO[1,2-BIS(DIFENILFOSFINO)ETANO] BISTRIFLUOROMETANOSULFONATOPALADIO (II) Y 4,4´-BIPIRIDINA

    OpenAIRE

    Julian Posada; Eliseo Avella; Alvaro Duarte; Luis Echegoyen

    2011-01-01

    Por primera vez se desarrolló la síntesisy caracterización (IR, UV, RMN-1H,31P, 19F) de un nuevo cuadrado supramolecular[3] mediante el auto-ensamblajedel complejo [Pd(CF3SO3)2(Dppe)] [1] yel ligando orgánico 4,4´-Bipiridina [2].Se evidenció la obtención de [3] en mezclacon otra especie supramolecular [4],asignada como un macrociclo triangular.Las estructuras de [3] y [4] se elucidaroncon base en los desplazamientos químicos,la proporcionalidad entre sus integralesy en los patrones de acoplam...

  10. Resultados de la resonancia magnética nuclear de cerebro en niños con cefalea

    OpenAIRE

    Gurkas, Esra; Karalok, Zeynep S; Taskm, Birce D; Aydogmus, Ummu; Yilmaz, Cahide; Bayram, Gulsah

    2017-01-01

    Introducción: El objetivo fue describir los resultados de la resonancia magnética nuclear (RMN) en niños con cefalea. Población y métodos: Revisión retrospectiva de las historias clínicas de los pacientes ingresados a los consultorios externos de neurología pediátrica con síntomas de cefalea entre enero de 2013 y diciembre de 2014. Resultados: Se ingresaron 478 pacientes (273 mujeres, 205 varones) con síntomas de cefalea. Los tipos de cefalea fueron migraña en 218 pacientes (45, 6%), cefalea ...

  11. Queratosis plantar sifilítica. Neuritis óptica

    Directory of Open Access Journals (Sweden)

    RICARDO FERNANDEZ RODRIGUEZ

    2012-03-01

    Full Text Available Paciente de 45 años que acude a Urgencias por pérdida aguda de visión en el ojo izquierdo. En la exploración se aprecia pupila aferente de Marcus Gunn en el ojo afecto y enla fundoscopia borramiento del borde temporal de la papila.Ingresa en Neurología con el diagnóstico de neuritis óptica. Se confirma una amplitud disminuida de los potencialesevocados visuales en el OI. La RMN cerebral fue normal. Seadministró 1 gr de metilprednisolona iv/d/ 3días, sin mejoríaen la visión.

  12. Estructura electrónica y reactividad de nitrosilos en complejos de metales de transición

    OpenAIRE

    Roncaroli, Federico

    2004-01-01

    El trabajo comprende la preparación de compuestos nitrosilados mono- y dinucleares con metales del grupo 8, conteniendo diversos ligandos auxiliares, y focaliza su atención en diferentes modos de reactividad del grupo nitrosilo coordinado, sea como nitrosonio (NO+) o como monóxido de nitrógeno (NO). Se sintetizó el nuevo compuesto trans-[NCRu(py)4(CN)Ru(py)4NO](PF6)3, el cual se caracterizó por espectroscopías UV-vis, IR, Raman y RMN. Se estudió la reactividad frente a nucleófilos como OH- y ...

  13. Constituintes químicos das folhas e do caule de Coccoloba mollisCasaretto (Polygonaceae)

    OpenAIRE

    Oliveira,Patrícia Emanuella S.; Santos,Wagner S. dos; Conserva,Lucia M.; Lemos,Rosangela P. de Lyra

    2008-01-01

    O estudo químico das frações neutra em hexano das folhas e em diclorometano do caule de Coccoloba mollis resultou no isolamento de um triterpeno pentacíclico (simiarenol), que pela primeira vez ocorre em Polygonaceae, dois fitoesteróides (sitostenona e sitosterol), um diterpeno (trans-fitol) e de um benzenóide (ácido vanílico) que está sendo descrito pela vez neste gênero. A identificação estrutural destes compostos foi feita com base na análise dos dados espectrais (IV, EM e RMN, incluindo D...

  14. Fukugetina y fukogisida, biflavonoides de clusia guaviarensis cuatr. (clusiaceae)

    OpenAIRE

    Martínez O., Eduardo; Moreno-Murillo, Bárbara; Delle Monache, Franco

    2010-01-01

    De los frutos de la especie nativa Clusia guaviarensis (Cuatr.) se aislaron e identificaron los bifiavonoides fukugetina i y fukugisida 2. Este es el primer estudio fitoquímico de esta especie así como el primer reporte de bifiavonoides en el género Clusia. La identificación se realizó por técnicas espectroscópicas tales como IR, UV Y RMN de 'H y "C así como por comparación con muestras auténticas. Se reporta además la presencia de dos atropoisómeros la cual es evidente en el espectro de "...

  15. Green chemistry and nuclear magnetic resonance applications to the valorisation of vegetable oils and l/gnocellulosic biomass residues

    OpenAIRE

    Lucas-Torres Pérez, Covadonga

    2016-01-01

    La alta demanda de materias primas de origen fósil plantea un reto: evitar la pérdida total de recursos del planeta. En este sentido, este trabajo está basado en las novedosas aportaciones de la Química Sostenible en la revalorización de residuos agroalimentarios, estableciéndolos como novedosas materias primas renovables. Así mismo, a lo largo de los capítulos, se han estudiado las aplicaciones que una técnica analítica tan versátil como la Resonancia Magnética Nuclear (RMN), presenta en est...

  16. Use of Pulsed Nmr Spectroscopy to Measure the Amount of Solid Deposits As a Function of Temperature in Waxy Crudes Utilisation de la spectroscopie RMN pulsée pour mesurer la quantité de dépôts solides en fonction de la température dans les bruts paraffiniques

    Directory of Open Access Journals (Sweden)

    Ruffier-Meray V.

    2006-12-01

    Full Text Available Paraffin crystallization in crude oils and in gas condensates is a major problem for petroleum exploitation. Thermodynamic models are used to evaluate the risk. With them, one calculates the Wax Appearance Temperature (WAT as well as the crystallized fraction as a function of temperature, for temperatures below the WAT. During development, these models are tested against experimental data. Although different methods for measuring the WAT are available in the literature and at petroleum companies, such methods unfortunately do not exist for measuring the crystallized fraction as a function of temperature. In this work, we have developed a low resolution NMR method for measuring the crystallized fraction as a function of temperature. The method was first evaluated using pure samples and was then applied to crude oils. The results were compared to those obtained both from differential calorimetry and from the model. La cristallisation des paraffines dans les pétroles bruts et même dans les gaz à condensat est un problème majeur dans le domaine de l'exploitation pétrolière. Afin d'évaluer ce risque, on utilise des modèles thermodynamiques. Ils permettent de calculer la température de cristallisation commençante (TCC ou Wax Appearance Temperature (WAT ainsi que la fraction cristallisée en fonction de la température (pour des températures inférieures à la TCC. Lors de leur développement, ces modèles doivent être évalués sur des données expérimentales. Il existe dans la littérature et chez les pétroliers différentes méthodes pour mesurer la TCC, malheureusement il n'en est pas de même pour la fraction cristallisée en fonction de la température. Dans cet article, nous avons développé une méthode de RMN basse résolution afin de mesurer la fraction cristallisée en fonction de la température. Elle a d'abord été évaluée sur des mélanges de corps purs puis elle a été appliquée à des pétroles bruts. Les r

  17. A FORTRAN program for the use of digital terrain elevation models of the Instituto Nacional de Estadistica, Geografia e Informatica of Mexico (INEGI); Programa en FORTRAN para el manejo de modelos digitales de elevacion del terreno del Instituto Nacional de Estadistica, Geografia e Informatica de Mexico (INEGI)

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Estrada, Gerardo [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

    1996-09-01

    producir un mapa en coordenadas planas rectangulares en metros. Durante la delimitacion de la ventana se hace un filtrado simple para disminuir los errores numericos que existen en el archivo y si se desea puede elegirse un submuestreo de los datos para preparar mapas menos detallados pero de gran cobertura. El programa ha sido desarrollado y probado extensamente en la Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad (CFE) de Mexico, en donde se utiliza en estudios regionales para la elaboracion de mapas base, el trazo automatico de perfiles topograficos y el calculo de condiciones de frontera para modelos termicos. Otros usos directos son el calculo de las correcciones por rugosidad o la estimacion de efectos isostaticos en estudios gravimetricos, la estimacion de cotas topograficas para puntos de coordenadas horizontales conocidas, el modelado termico de efectos climaticos en funcion de la topografia, el calculo automatico de volumenes de material y muchos otros.

  18. Dosimetry in intravascular brachytherapy; Calculos dosimetricos em braquiterapia intravascular

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Laelia Pumilla Botelho

    2000-03-01

    Among the cardiovascular diseases responsible for deaths in the adult population in almost all countries of the world, the most common is acute myocardial infarction, which generally occurs because of the occlusion of one or more coronary arteries. Several diagnostic techniques and therapies are being tested for the treatment of coronary artery disease. Balloon angioplasty has been a popular treatment which is less invasive than traditional surgeries involving revascularization of the myocardium, thus promising a better quality of life for patients. Unfortunately, the rate of restenosis (re-closing of the vessel) after balloon angioplasty is high (approximately 30-50% within the first year after treatment).Recently, the idea of delivering high radiation doses to coronary arteries to avoid or delay restenosis has been suggested. Known as intravascular brachytherapy, the technique has been used with several radiation sources, and researchers have obtained success in decreasing the rate of restenosis in some patient populations. In order to study the radiation dosimetry in the patient and radiological protection for the attending staff for this therapy, radiation dose distributions for monoenergetic electrons and photons (at nine discrete energies) were calculated for blood vessels of diameter 0.15, o,30 and 0.45 cm with balloon and wire sources using the radiation transport code MCNP4B. Specific calculations were carried out for several candidate radionuclides as well. Two s tent sources (metallic prosthesis that put inside of patient's artery through angioplasty) employing {sup 32} P are also simulated. Advantages and disadvantages of the various radionuclides and source geometries are discussed. The dosimetry developed here will aid in the realization of the benefits obtained in patients for this promising new technology. (author)

  19. Dosimetry in intravascular brachytherapy; Calculos dosimetricos em braquiterapia intravascular

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Laelia Pumilla Botelho

    2000-03-01

    Among the cardiovascular diseases responsible for deaths in the adult population in almost all countries of the world, the most common is acute myocardial infarction, which generally occurs because of the occlusion of one or more coronary arteries. Several diagnostic techniques and therapies are being tested for the treatment of coronary artery disease. Balloon angioplasty has been a popular treatment which is less invasive than traditional surgeries involving revascularization of the myocardium, thus promising a better quality of life for patients. Unfortunately, the rate of restenosis (re-closing of the vessel) after balloon angioplasty is high (approximately 30-50% within the first year after treatment).Recently, the idea of delivering high radiation doses to coronary arteries to avoid or delay restenosis has been suggested. Known as intravascular brachytherapy, the technique has been used with several radiation sources, and researchers have obtained success in decreasing the rate of restenosis in some patient populations. In order to study the radiation dosimetry in the patient and radiological protection for the attending staff for this therapy, radiation dose distributions for monoenergetic electrons and photons (at nine discrete energies) were calculated for blood vessels of diameter 0.15, o,30 and 0.45 cm with balloon and wire sources using the radiation transport code MCNP4B. Specific calculations were carried out for several candidate radionuclides as well. Two s tent sources (metallic prosthesis that put inside of patient's artery through angioplasty) employing {sup 32} P are also simulated. Advantages and disadvantages of the various radionuclides and source geometries are discussed. The dosimetry developed here will aid in the realization of the benefits obtained in patients for this promising new technology. (author)

  20. A NMR spectrometer for educational purposes; Espectrometro de RMN para ensino

    Energy Technology Data Exchange (ETDEWEB)

    Colnago, Luiz A; Torre Neto, Andre [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Nucleo de Pesquisa e Desenvolvimento de Instrumentacao Agropecuaria; Villar, Jose D.F.; Seidl, Peter R [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

    1992-12-31

    A NMR spectrometer has been constructed for educational purposes, such as teaching of the technique basic principles and instrumentation. The spectrometer has been designed with a minimum number of components so that the students may have acquittance with both the spectrometer, through block diagrams, and the small numbers of existent components . The device was based on a 0.t Tesla magnet from the continuous wave spectrometer (E M 300 - Varian) existent at the Instituto Militar de Engenharia, and it is expected to facilitate the comprehension of the commercial spectrometers 1 ref., 3 figs.

  1. Cálculo de patana especializada construida de PRFV. // Calculation of specialized shalow water vessels designed and manufactured with PRFV.

    Directory of Open Access Journals (Sweden)

    J. García de la Figal

    2003-05-01

    Full Text Available Se trata del cálculo de resistencia y rigidez de una patana especializada para el tratamiento de aguas residuales en la zonapantanosa de la Ciénaga de Zapata, Cuba, por lo que se recurre a materiales altamente duraderos y resistentes a la acción deun medio tan agresivo. Se trata de plásticos y fibra de vidrio. Por los altos pesos en la cubierta, su calculo no estaestablecido en los Registros de Buques, haciéndose necesario el calculo completo de la patana con este material ortotrópico.Para ello se recurrió al Método de los Elementos Finitos, a través del empleo de un programa de computación. Se llega aldiseño completo de las diferentes partes de la patana con este complejo material. Ya ha sido construida y está en operación.Palabras claves: Elementos finitos, embarcaciones, tratamiento de aguas,PRFV._______________________________________________________________________________AbstractThis paper deals with the calculations of resistance and rigidity of a specialized shalow water vessel for the treatment ofwaste waters. It will be located in the marshy area of Cienaga de Zapata, Cuba, for this reason highly durable and resistantmaterials to the action of such aggressive environment are used. We are dealing with plastics and glass fiber due to the highweight in the cover the calculation is not established by Ships Registrations and therefore became necessary to carried outthe complete vessel calculation with this orthotropic material. It was neccesary applied the Finite Elements Method bymeans of a computation program. We arrived to the complete design of different parts of the vessel with this complexmaterial. It has already been built and it is in operation.Key words: Finite element, vessel, water treatment, PRFV.

  2. Cálculo de patana especializada construida de PRFV. // Calculation of specialized shalow water vessels designed and manufactured with PRFV.

    Directory of Open Access Journals (Sweden)

    J. García de la Figal

    2006-09-01

    Full Text Available Se trata del cálculo de resistencia y rigidez de una patana especializada para el tratamiento de aguas residuales en la zonapantanosa de la Ciénaga de Zapata, Cuba, por lo que se recurre a materiales altamente duraderos y resistentes a la acción deun medio tan agresivo. Se trata de plásticos y fibra de vidrio. Por los altos pesos en la cubierta, su calculo no estaestablecido en los Registros de Buques, haciéndose necesario el calculo completo de la patana con este material ortotrópico.Para ello se recurrió al Método de los Elementos Finitos, a través del empleo de un programa de computación. Se llega aldiseño completo de las diferentes partes de la patana con este complejo material. Ya ha sido construida y está en operación.Palabras claves: Elementos finitos, embarcaciones, tratamiento de aguas,PRFV.___________________________________________________________________________________AbstractThis paper deals with the calculations of resistance and rigidity of a specialized shalow water vessel for the treatment ofwaste waters. It will be located in the marshy area of Cienaga de Zapata, Cuba, for this reason highly durable and resistantmaterials to the action of such aggressive environment are used. We are dealing with plastics and glass fiber due to the highweight in the cover the calculation is not established by Ships Registrations and therefore became necessary to carried outthe complete vessel calculation with this orthotropic material. It was neccesary applied the Finite Elements Method bymeans of a computation program. We arrived to the complete design of different parts of the vessel with this complexmaterial. It has already been built and it is in operation.Key words: Finite element, vessel, water treatment, PRFV.

  3. Estimation of charges for services of transmission of electrical energy between regions of the national electrical system; Estimacion de cargos por servicios de transmision de energia electrica entre regiones del sistema electrico nacional

    Energy Technology Data Exchange (ETDEWEB)

    Inda Ruiz, Adrian; Flores Alba, Dora Elia [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Escobar Lopez, Akihito [Comision Federal de Electricidad (Mexico)

    2002-07-01

    In order to facilitate the answer of the Comision Federal de Electricidad (CFE) to the requests of services of transmission of authorized or potential licensees, this organism devised the construction of matrices of charges that allow in a fast and direct way for specific transactions, to know the charges in which different types of transmission services incur classified by transport levels and by tension levels in which the service is asked for. These tables could be published in the media that might be judged advisable, in order that the applicant licensees have access to a preliminary estimation of the charges for the required services, without the need of going, for one first estimation, directly to the CFE for their calculation. This article presents the results of the development of a calculation tool that allows estimating, in a fast and efficient way, charges for transmission services between regions of the national electrical system. [Spanish] Para facilitar la respuesta de la Comision Federal de Electricidad (CFE) a las solicitudes de servicios de transmision de permisionarios autorizados o potenciales, esta ideo la construccion de matrices de cargos que permitan de manera rapida y directa para transacciones especificas, conocer los cargos en que incurren diferentes tipos de servicios de transmision clasificados por niveles de transporte y por niveles de tension en los que se solicita el servicio. Dichas tablas podran ser publicadas en los medios que se juzguen convenientes, con el fin de que los permisionarios solicitantes tengan acceso a una estimacion preliminar de los cargos por los servicios requeridos, sin necesidad de acudir, para una primera estimacion, directamente a la CFE para su calculo. Este articulo presenta los resultados del desarrollo de una herramienta de calculo que permite estimar, de manera rapida y eficiente, matrices de cargos por servicios de transmision entre regiones del sistema electrico nacional.

  4. MAGNETIC VT study: a prospective, multicenter, post-market randomized controlled trial comparing VT ablation outcomes using remote magnetic navigation-guided substrate mapping and ablation versus manual approach in a low LVEF population.

    Science.gov (United States)

    Di Biase, Luigi; Tung, Roderick; Szili-Torok, Tamás; Burkhardt, J David; Weiss, Peter; Tavernier, Rene; Berman, Adam E; Wissner, Erik; Spear, William; Chen, Xu; Neužil, Petr; Skoda, Jan; Lakkireddy, Dhanunjaya; Schwagten, Bruno; Lock, Ken; Natale, Andrea

    2017-04-01

    Patients with ischemic cardiomyopathy (ICM) are prone to scar-related ventricular tachycardia (VT). The success of VT ablation depends on accurate arrhythmogenic substrate localization, followed by optimal delivery of energy provided by constant electrode-tissue contact. Current manual and remote magnetic navigation (RMN)-guided ablation strategies aim to identify a reentry circuit and to target a critical isthmus through activation and entrainment mapping during ongoing tachycardia. The MAGNETIC VT trial will assess if VT ablation using the Niobe™ ES magnetic navigation system results in superior outcomes compared to a manual approach in subjects with ischemic scar VT and low ejection fraction. This is a randomized, single-blind, prospective, multicenter post-market study. A total of 386 subjects (193 per group) will be enrolled and randomized 1:1 between treatment with the Niobe ES system and treatment via a manual procedure at up to 20 sites. The study population will consist of patients with ischemic cardiomyopathy with left ventricular ejection fraction (LVEF) of ≤35% and implantable cardioverter defibrillator (ICD) who have sustained monomorphic VT. The primary study endpoint is freedom from any recurrence of VT through 12 months. The secondary endpoints are acute success; freedom from any VT at 1 year in a large-scar subpopulation; procedure-related major adverse events; and mortality rate through 12-month follow-up. Follow-up will consist of visits at 3, 6, 9, and 12 months, all of which will include ICD interrogation. The MAGNETIC VT trial will help determine whether substrate-based ablation of VT with RMN has clinical advantages over manual catheter manipulation. Clinicaltrials.gov identifier: NCT02637947.

  5. Obtenção de nanocompósito de EVA/sílica e caracterização por ressonância magnética nuclear no estado sólido Preparation of EVA/silica nanocomposites characterized with solid state nuclear magnetic resonance

    Directory of Open Access Journals (Sweden)

    Adriano A. Passos

    2011-01-01

    Full Text Available Nanocompósitos a base de poli(etileno-co-acetato de vinila (EVA e óxido de sílica (SiO2, com tamanho nanométrico da ordem de 40 nm, foram preparados via intercalação por solução, empregando clorofórmio como solvente. Os nanocompósitos foram caracterizados principalmente pela espectroscopia de ressonância magnética nuclear (RMN, empregando a análise dos núcleos de carbono-13 (matriz polimérica; silício-29 (nanopartícula e pela determinação do tempo de relaxação spin-rede do núcleo de hidrogênio no eixo rotatório (T1rH (matriz polimérica. Pelos dados de RMN foi observado que até cerca de 5% de sílica em massa obteve-se um nanocompósito polimérico com boa dispersão da sílica devido a uma forte interação entre a sílica e matriz de EVA.Nanocomposites of poly(ethylene-co-vinyl acetate/silica (SiO2 with dimensions of ca. 40 nm were prepared via solution intercalation employing chloroform as a solvent. They were mainly characterized with nuclear magnetic resonance spectroscopy (NMR employing carbon-13 (polymeric matrix, silicon-29 (nanoparticles and through the determination of the proton spin-lattice relaxation time in the rotating frame (T1rH (polymer matrix. From the NMR results it was inferred that up to 5% of silica in mass a well dispersed nanocomposite was obtained, owing to a strong interaction between silica and the EVA matrix.

  6. Caracterización espectroscópica de enmiendas orgánicas

    Directory of Open Access Journals (Sweden)

    A. J. Zambrano

    2011-01-01

    Full Text Available Las características estructurales de los ácidos húmicos (ahs dependen, fundamentalmente, del origen y las condiciones en las cuales se desarrollan estos compuestos. Cada vez se busca discernir, con mayor precisión, sobre la estructura y reactividad de los AHs, así como sobre los grupos funcionales que contienen. En esta investigación se utilizó -en conjunto- ir, 1h-rmn, uv-Vis para el estudio estructural de los AHs, de una serie de enmiendas usadas en los Andes Venezolanos y su relación entre sí. Los resultados de la relación E4/E6 señalan menor polimerización para el lodo, estiércol de caprino y las vermicompostas ula y Zea, y mayor para la cachaza y el estiércol de vacuno. Los espectros de infrarrojo de dichos ahs mostraron similitud, especialmente en bandas específicas a algunos grupos funcionales, tales como, alcoholes, aminas, amidas, ácidos carboxílicos, grupos cetónicos e insaturaciones alifáticas y aromáticas. Los análisis de 1H-rmn no permitieron un mayor esclarecimiento de la estructura de los ahs es-tudiados; sin embargo, se confirmó la presencia de grupos funcionales alifáticos y metilénicos, ácidos, alcoholes y amidas. Además de la presencia de estructuras aromáticas en algunos ahs. Estos resultados son congruentes con los obtenidos por irft, expresan que existen diferencias en las estructuras químicas de los ahs de las enmiendas evaluadas vinculadas a su origen y estabilidad química.

  7. Laboratory operation during radiation emergency

    International Nuclear Information System (INIS)

    Bunata, M.; Prouza, Z.; Tecl, J.

    2009-01-01

    During radiation emergency, a special operation mode of laboratories of the Radiation Monitoring Network (hereinafter RMN) is expected. The principal factors differing the emergency mode from the normal one are the following: - significantly higher amount of analyzed samples; - high activities of the majority of the samples; - higher risk of personal and equipment contamination; - higher working and psychological demands on laboratory staff. The assuring of the radiation protection requirements of laboratory staff has to be the primary objective, nevertheless the risk of equipment contamination and of samples cross- contamination of course have to be as well taken into consideration. The presentation describes the experience of the RMN Central Laboratory of the National Radiation Protection Institute in Prague (SURO) which was obtained during realization of field tests, in which a radioactive matter was released. These tests allow us to evaluate the source term or radioactivity dispersal balance based on various detection methods with the aim to estimate exposure of the afflicted persons. Tests provided to simulate emergency working conditions in Central Laboratory - high number of contaminated samples, which have to be analyzed in a short time (short half-time of used radionuclide 99m Tc) using sophisticated laboratory techniques (gamma spectrometers, aerosols collectors, etc.). The testing shows the availability of the SURO laboratory to work during the radiation emergency and to participate on its determination. The suitable settings and the ideal number of staff have been found. The average analysis time was approximately 1 minute per sample and the sample results were available just a few minutes after the counting. Moreover, the settings avoided any danger and kept both the crew and the samples safe and secure from contamination. (authors)

  8. Rifampicin reduces advanced glycation end products and activates DAF-16 to increase lifespan in Caenorhabditis elegans.

    Science.gov (United States)

    Golegaonkar, Sandeep; Tabrez, Syed S; Pandit, Awadhesh; Sethurathinam, Shalini; Jagadeeshaprasad, Mashanipalya G; Bansode, Sneha; Sampathkumar, Srinivasa-Gopalan; Kulkarni, Mahesh J; Mukhopadhyay, Arnab

    2015-06-01

    Advanced glycation end products (AGEs) are formed when glucose reacts nonenzymatically with proteins; these modifications are implicated in aging and pathogenesis of many age-related diseases including type II diabetes, atherosclerosis, and neurodegenerative disorders. Thus, pharmaceutical interventions that can reduce AGEs may delay age-onset diseases and extend lifespan. Using LC-MS(E), we show that rifampicin (RIF) reduces glycation of important cellular proteins in vivo and consequently increases lifespan in Caenorhabditis elegans by up to 60%. RIF analog rifamycin SV (RSV) possesses similar properties, while rifaximin (RMN) lacks antiglycation activity and therefore fails to affect lifespan positively. The efficacy of RIF and RSV as potent antiglycating agents may be attributed to the presence of a p-dihydroxyl moiety that can potentially undergo spontaneous oxidation to yield highly reactive p-quinone structures, a feature absent in RMN. We also show that supplementing rifampicin late in adulthood is sufficient to increase lifespan. For its effect on longevity, rifampicin requires DAF-18 (nematode PTEN) as well as JNK-1 and activates DAF-16, the FOXO homolog. Interestingly, the drug treatment modulates transcription of a different subset of DAF-16 target genes, those not controlled by the conserved Insulin-IGF-1-like signaling pathway. RIF failed to increase the lifespan of daf-16 null mutant despite reducing glycation, showing thereby that DAF-16 may not directly affect AGE formation. Together, our data suggest that the dual ability to reduce glycation in vivo and activate prolongevity processes through DAF-16 makes RIF and RSV effective lifespan-extending interventions. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  9. Laboratory operation during radiation emergency

    International Nuclear Information System (INIS)

    Bunata, M.; Tecl, J.; Prouza, Z.

    2008-01-01

    During radiation emergency, a special operation mode of laboratories of the Radiation Monitoring Network (hereinafter RMN) is expected. The principal factors differing the emergency mode from the normal one are the following: - significantly higher amount of analyzed samples; - high activities of the majority of the samples; - higher risk of personal and equipment contamination; - higher working and psychological demands on laboratory staff. The assuring of the radiation protection requirements of laboratory staff has to be the primary objective, nevertheless the risk of equipment contamination and of samples cross- contamination of course have to be as well taken into consideration. The presentation describes the experience of the RMN Central Laboratory of the National Radiation Protection Institute in Prague (SURO) which was obtained during realization of field tests, in which a radioactive matter was released. These tests allow us to evaluate the source term or radioactivity dispersal balance based on various detection methods with the aim to estimate exposure of the afflicted persons. Tests provided to simulate emergency working conditions in Central Laboratory -high number of contaminated samples, which have to be analyzed in a short time (short half-time of used radionuclide 99m Tc) using sophisticated laboratory techniques (gamma spectrometers, aerosols collectors, etc.). The testing shows the availability of the SURO laboratory to work during the radiation emergency and to participate on its determination. The suitable settings and the ideal number of staff have been found. The average analysis time was approximately 1 minute per sample and the sample results were available just a few minutes after the counting. Moreover, the settings avoided any danger and kept both the crew and the samples safe and secure from contamination. (authors)

  10. Il primato della libertà politica

    Directory of Open Access Journals (Sweden)

    Brunella Casalini

    2012-11-01

    Full Text Available Casalini ripercorre Politics out of History di Wendy Brown soffermandosi in particolare sul dialogo che Brown intrattiene con il pensiero di Marx, Nietzsche e Freud. L’accento posto sul nesso tra libertà individuale e libertà politica e sulla distinzione tra “moralismo” e “moralità” apre alla problematizzazione del nodo teoria-politica. Alla luce della crisi contemporanea della sinistra americana il ruolo del teorico è quindi quello di introdurre tratti di discontinuità in quel discorso di senso comune che la politica tende invece a cristallizzare. In conclusione, secondo Brown, questo scarto deve essere recepito anche dai Women Studies che, restando ancorati a identità statiche, rischiano di non riuscire a svolgere una necessaria «funzione omeopatica» all’interno dei regimi democratici.

  11. Use of Semantic Wikis to support collaborative learning

    Directory of Open Access Journals (Sweden)

    Mauro Coccoli

    2012-08-01

    Full Text Available Semantic Wiki consentono, tramite un linguaggio comprensibile agli elaboratori e formalmente definito, l’annotazione semantica dei contenuti delle pagine Wiki e la rappresentazione esplicita delle relazioni di significato tra essi presenti. Essi offrono la possibilità di sfruttare sia i vantaggi delle tecnologie basate su ontologie sia i meccanismi collaborativi propri dei Wiki. L’articolo descrive un progetto, denominato Semantic WikiSUN, avviato per indagare le prospettive didattiche di tali sistemi. Esso è basato su un quadro teorico complesso che integra evidenze neurocognitive, teorie dell’apprendimento e modelli costruttivisti-sociali della conoscenza. Obiettivo del contributo è, sulla base della esperienza intrapresa, discutere potenzialità e criticità didattiche dei Semantic Wiki, estendendo talvolta la riflessione a considerazioni più generali sui processi di apprendimento mediati da tecnologie semantiche.

  12. Introduzione

    Directory of Open Access Journals (Sweden)

    Alessandro Roncaglia

    2010-03-01

    Full Text Available Con questo numero, Moneta e Credito riprende la sua regolare cadenza trimestrale dopo l'interruzione connessa al passaggio di proprietà dalla Banca Nazionale del Lavoro alla Associazione Paolo Sylos Labini. Abbiamo tentato di colmare tale interruzione con i numeri speciali per il 2008 e per il 2009 usciti nei mesi scorsi: nel primo caso con gli indici dei primi sessant'anni di vita delle riviste e due articoli introduttivi di ricostruzione del loro percorso (Roncaglia, 2008a e 2008b, nel secondo caso con una raccolta di articoli pubblicati negli ultimi anni su temi connessi alla crisi finanziaria ed economica che sarebbe poi esplosa e una breve introduzione per inquadrare questi contributi nel dibattito teorico più recente.   JEL Codes:  E44, G01 

  13. L’adattamento in evoluzione. Percorsi teorici dal 2005 a oggi

    Directory of Open Access Journals (Sweden)

    Claudia Cao

    2012-12-01

    Full Text Available

    In questa sezione apparirà presto un articolo di aggiornamento bibliografico che  completerà il numero monografico di Between sull’adattamento con una ricognizione su quelli che ci sono sembrati i saggi più importanti sul tema apparsi negli ultimi anni.

    Senza pretendere un’impossibile completezza, stiamo prendendo in considerazione le monografie, uscite dal 2005 ad oggi a livello internazionale, che si siano occupate dell’adattamento da un punto di vista teorico, anche nello specifico di un numero limitato di codici/generi (ad es. letteratura e cinema, teatro, televisione, fumetto, videogiochi, etc..

    Chiunque volesse inviare segnalazioni su opere di rilievo può farlo all’indirizzo: g.rossini@gmal.com

  14. Bases para um referencial teorico sobre o fenômeno da cognição

    OpenAIRE

    Moreira, Adelson Fernandes; Borges, Oto

    2008-01-01

    Apresentamos um referencial teórico para investigar a sala de aula, que articulamos a partir das seguintes matrizes teórico-metodológicas: cognição situada, etnometodologia, fundamentos biológicos da cognição, cognição distribuída e fenomenologia. Discutimos as contribuições que extraímos dessas matrizes ao longo de uma investigação que comparouas práticas de interpretação de alunos em diferentes ambientes de aprendizagem. Com base nessa discussão propomos direções para olhar a sala de aula, ...

  15. Definizione, modellazione teorico – sperimentale ed energy management di sistemi termo – fotovoltaici a concentrazione

    OpenAIRE

    Petito, Fabio

    2017-01-01

    2015 - 2016 The evolution in the renewable energies field led to search for solutions that allow the combined achievement of heterogeneous energy vectors. This theme introduces multiple levels of analysis, from the definition of new systems and the environmental impact analysis to the overall economic performances, in the traditional cost – benefit paradigm. In this context, the Green Renewable Technologies redefines the concept of innovative solution, as they represent a choice based o...

  16. PRUEBAS DE CARGA NO DESTRUCTIVAS EN PILOTES

    Directory of Open Access Journals (Sweden)

    LUIS IBAÑEZ MORA

    2008-01-01

    Full Text Available En el presente trabajo se abordan las experiencias en la utilización de la modelación matemática y la realización de pruebas de carga no destructivas en cimentaciones sobre pilotes para evaluar su capacidad de carga. Para ello se exponen los resultados obtenidos en pruebas de carga de más de 200 Toneladas, y la distribución de cargas en una estructura portuaria, evaluando su capacidad resistente. Se establecen comparaciones entre los métodos teóricos de calculo de la capacidad de carga del pilote aislado y modelos matemáticos, así como los resultados de la pruebas de carga a escala real.

  17. e-Science initiatives in Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, J. L.; Diaz, G.; Hamar, V.; Isea, R.; Rojas, F.; Ruiz, N.; Torrens, R.; Uzcategui, M.; Florez-Lopez, J.; Hoeger, H.; Mendoza, C.; Nunez, L. A.

    2007-07-01

    Within the context of the nascent e-Science infrastructure in Venezuela, we describe several webbased scientific applications developed at the Centro Nacional de Calculo Cientifico Universidad de Los Andes (CECALCULA), Merida, and at the Instituto Venezolano de Investigaciones Cientificas (IVIC), Caracas. The different strategies that have been followed for implementing quantum chemistry and atomic physics applications are presented. We also briefly discuss a damage portal based on dynamic, nonlinear, finite elements of lumped damage mechanics and a biomedical portal developed within the framework of the E-Infrastructure shared between Europe and Latin America (EELA) initiative for searching common sequences and inferring their functions in parasitic diseases such as leishmaniasis, chagas and malaria. (Author)

  18. Ideología y matemáticas: Algunos problemas metodológicos

    Directory of Open Access Journals (Sweden)

    Emilio Costa Reparaz

    2004-01-01

    Full Text Available Con este trabajo pretendemos poner de manifiesto los usos y abusos del lenguaje matemático y del intento de convertir un texto vulgar en otro científico mediante la utilización de la jerga matemática. En este trabajo se pretende, por una parte señalar determinados problemas metodológicos a la vez que unificar el leguaje. Conceptos como conocer, saber, verdad, realidad, racionalidad,... son conceptos teoréticos que debemos matizar y acotar su significado y utilización. Otro aspecto que es preciso destacar es el de la matematización frente al cientifismo. Tratamos de separar la Matemática del calculo y esta del lenguaje

  19. Analysis methodology for economic technical feasibility studies in offshore electrical generation systems; Metodologia de analisis para estudios de factibilidad tecnica economica en sistemas de generacion electrica costa fuera

    Energy Technology Data Exchange (ETDEWEB)

    Fiscal Escalante, Raul [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-07-01

    An analysis methodology followed in the development of technique-economic feasibility studies of systems of electrical generation in offshore electrical installations is presented, including the obtaining of the curves of the turbine and generator performance, the technical considerations for the formulation of the operation scenes and the calculations of the economic evaluation of a real scenario. [Spanish] Se muestra una metodologia de analisis seguida en el desarrollo de estudios de factibilidad tecnica-economica de sistemas de generacion electrica en instalaciones electricas costa fuera, incluyendo la obtencion de las curvas de comportamiento de la turbina y el generador, las consideraciones tecnicas para la formulacion de los escenarios de operacion y los calculos de la evaluacion economica de un escenario real.

  20. Cálculos neutrônicos, termo-hidráulicos e de segurança de um dispositivo para irradiação de miniplacas (DIM) de elementos conbustíveis tipo dispersão

    OpenAIRE

    Douglas Borges Domingos

    2010-01-01

    Neste trabalho foram desenvolvidos calculos neutrônicos, termo-hidráulicos e de segurança para avaliar a seguranca operacional de um dispositivo de irradiação a ser colocado no núcleo do reator IEA-R1 do IPEN-CNEN/SP. Este dispositivo de irradiação é utilizado para alojar miniplacas de combustvel do tipo dispers~ao de U3O8-Al e U3Si2-Al, com 19,75% em peso de 235U e densidades, respectivamente, de ate 3,2 gU/cm3 e 4,8 gU/cm3. Estas miniplacas serão irradiadas a queimas acima de 50% do 235U, d...

  1. Preparação regiosseletiva de derivados acilados da D-ribono-1,4-lactona empregando catálise enzimática

    OpenAIRE

    Sebrão, Damianni

    2011-01-01

    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Química, Florianópolis, 2011 Nesta tese foram desenvolvidas metodologias enzimáticas para a preparação regiosseletiva de derivados acilados da D-ribono-1,4-lactona. Os produtos foram identificados e quantificados por RMN-1H, UV-Vis ou titulação volumétrica com solução aquosa de KOH. Várias lipases, uma protease e dois micélios isolados de fungos da região amazôn...

  2. Spectroscopy study on structural elucidation of flavonoids from Solanum jabrense Agra and Nee and S. paludosum Moric; Estudo espectroscopico em elucidacao estrutural de flavonoides de Solanum jabrense Agra and Nee e S. paludosum Moric

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Tania Maria Sarmento da [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Quimica], e-mail: sarmento@pesquisador.cnpq.br; Carvalho, Mario Geraldo de [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Inst. de Ciencias Exatas. Dept. de Quimica; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacazes, RJ (Brazil). Setor de Quimica de Produtos Naturais

    2009-07-01

    The NMR (RMN{sup 1}H, {sup 13}C, COSY, HMQC, HMBC, NOE-DIFF, NOESY) and mass spectra data analysis of sixteen flavonoids, including nine natural, 7-O-methylkanferol (rhamnocitrin), 3,7-di-O-methylkanferol (kumatakenin), 3-O-methylquercetin, 3,7,3',4'-tetra-O-methylquercetin (retusin), 3,7,8,4'-tetra-O-methylgossipetin, 3,7,8,3',4'-penta-O-methylgossipetin, 7-O-methylapigenin (genkwanin), 3,7,8-tri-O-methylherbacetin, 7,4'- di-O-methylquercetin (ombuine), isolated from Solanum paludosum and S. jabrense, and seven prepared methyl and acetyl derivatives, are discussed according the substitution on the rings A, B and C. (author)

  3. Síntesis y caracterización de nuevas nanopartículas de derivados de PBLG para su uso en nanomedicina

    OpenAIRE

    María Elisa Martínez Barbosa; An Young S. Taylor Castillo; Heriberto Acuña Campa; ian Arely Carrasco Cota

    2014-01-01

    En este trabajo se describe la realización de la síntesis y caracterización de cinco derivados de poli-L-glutamato de gamma-bencilo (PBLG) por polimerización aniónica de apertura de anillo utilizando iniciadores de interés biomédico, así como la preparación y caracterización de nanopartículas poliméricas preparadas usando los polímeros sintetizados. Los polímeros fueron caracterizados por resonancia magnética nuclear (RMN 1H) y cromatografía de exclusión de tamaño (GPC/SEC). Las nanopartícula...

  4. Study of the fibrinogen - fibrin transformation kinetics and modifications caused to this reaction by irradiation (X rays) of the fibrinogen solution

    International Nuclear Information System (INIS)

    Hollard, D.; Suscillon, M.; Marcille, G.; Rambaud, F.; Baloyan, M.

    1966-01-01

    The authors present a spectrophotometric method for studying the transformation fibrinogen - fibrin. This method has the advantage of drawing immediately in graph form the three, phases of this transformation: proteolysis or monomerization; polymerisation; clot stabilization. It is a simple, faithful and easily reproductive technic. Owing to this method, they studied modifications of this transformation due to irradiation of fibrinogen solution. Low doses (90 000 R/mn) prevent transverse polymerisation. To upper doses (180 000 R and more), the action of thrombin on fibrinogen does not give an organised clot but a lacteous and fragile gel. There is not here a coagulation in the physiological understanding. (author) [fr

  5. Emergency response exercise of laboratories equipped with gamma spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mala, Helena; Rulik, Petr; Jezkova, Tereza; Beckova, Vera [National Radiation Protection Institute (SURO), 140 00 Praha 28 (Czech Republic)

    2014-07-01

    At present 7 laboratories equipped with semiconductor gamma spectrometry (HPGe detectors) are included in the Radiation Monitoring Network (RMN) in the Czech Republic. These laboratories have 31 spectrometric chains and approximately 20 'experts' and 70 'users' who would guarantee measurements during a radiological emergency (RE). The stress exercise (a load test) was carried out in 4 of them. The aim was to test their measuring capacity in existing technical facilities and staff in the event of a RE and identify problems (bottlenecks) in the whole process from receipt of samples to entering the results into the central database of RMN. Duration of the exercise was 8 to 14 hours. Due to lack of staff, work in one 12-hour shift during a RE is presumed, which the laboratories should be able to provide for 14 days. Exercise samples covered a wide range of commodities that would probably come to the laboratories during RE (aerosol filters, adsorbed gaseous forms of iodine, fallout, surface and drinking waters, food chain components and soils). Some of the samples were previously spiked with {sup 85}Sr, {sup 88}Y and {sup 40}K (these nuclides represented actual nuclides that would occur in RE); soil samples contained higher values of {sup 137}Cs activity originating from the Chernobyl accident. Almost 40 employees took part in the exercise and measurements were carried out at 18 spectrometric chains. An automatic gamma counter which allows automatic operation of two HPGe detectors including the analysis of the spectra with a storage for up to 180 sample containers was operating in one of the laboratories involved in the exercise. The procedures in individual laboratories varied slightly depending on the staff and laboratory space available. During the exercise about 700 samples were evaluated; in addition, gamma-automat measured other 80 samples in the 'night shift'. 700 samples, this means 40 samples per a spectrometric chain or, from

  6. Thermal Neutron Spectral and Spatial Distributions in Light-Water-Moderated Uranium Lattices; Distributions Spectrale et Spatiale des Neutrons Thermiques dans des Reseaux a Uranium et a Eau Leger; Spektral'noe i prostranstvennoe raspredelenie teplovykh nejtronov v uranovykh reshetkakh s vodnym zamedlitelem; Distribuciones Espectral y Espacial de los Neutrones Termicos en los Reticulados de Uranio Moderados por Agua Ligera

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, J.; Volpe, J. J.; Klein, D.; Schmidt, E.; Gelbard, E. [Bettis Atomic Power Laboratory, Pittsburgh, PA (United States)

    1964-02-15

    realizados acerca del comportamiento de los neutrones termicos en los reticulados de uranio moderados por agua ligera. Los experimentos pertenecen a dos tipos principales: mediciones del grado de utilizacion termica y mediciones, por activacion, de la distribucion espacial de los neutrones termicos en un medio acuoso uniformemente envenenado. Esos experimentos se concibieron con miras a comprobar la validez de los actuales modelos teoricos, distinguiendo los efectos espectrales de los espaciales en el interior de un reactor. Se han efectuado eomparaciones con modelos teoricos que entraflan distintas aproximaciones relacionadas con la teoria del transporte y el nucleo de dispercion de los neutrones termicos. La primera serie de experimentos consistio en medir por el procedimiento de activacion los factores de desventaja termica en distintas celdas de reticulados del conjunto TRX, que constituye un reactor de uranio ligeramente enriquecido, moderado por H{sub 2}O, con barras de combustible cilindricas dispuestas en haces hexagonales. Los autores han comparado los resultados de las mediciones del grado de utilizacion termica con los datos de calculos efectuados con arreglo al metodo de Montecarlo. Utilizaron dos nucleos, el de Radkowsky y el de N elk in. El nucleo de Radkowsky constituye una aproximacion de primer orden que se viene utilizando umversalmente en el disello de los reactores. El nucleo de Nelkin, por su parte, representa una descripcion mas reciente y mas detallada del nucleo de dispersion. Dado que los indices de absorcion calculados para los neutrones termicos dependen de la eleccion del nucleo de dispersion, especialmente si el espectro del flujo neutronico no es maxwelliano, se ideo otra serie de experimentos de activacion con ayuda del conjunto TRX para verificar de un modo mas directo la utilidad del nucleo de dispersion. Los experimentos se realizaron en condiciones tales que la deformacion espectral se debia esencialmente a un envenenamiento uniforme. Las

  7. Walter Gieseler, Komposition im 20. Jahrhundert. Details – Zusammenhänge, Celle, Moeck, 1975, pp. 228

    Directory of Open Access Journals (Sweden)

    Wilma D'Ambrosio

    2014-10-01

    Full Text Available Stupisce molto che un libro come Komposition im 20. Jahrhundert. Details - Zusammenhänge [Composizione nel 20° secolo. Particolari – Connessioni] di Walter Gieseler, pubblicato in Germania quasi venticinque anni fa, non abbia mai ricevuto un'attenzione maggiore. Strano destino, per un libro così ricco e innovativo, scritto da un autore cui andrebbe per lo meno tributato il merito di essere stato uno dei primi a realizzare una descrizione sistematica delle tecniche compositive novecentesche. Le ragioni vanno forse cercate nel fatto di non avere mai beneficiato di traduzioni in una lingua più ‘internazionale’ e di non appartenere, in senso convenzionale, né al settore propriamente analitico, né teorico-compositivo, né storico-musicale. Di fatto, il libro riassume tutti questi aspetti, nonché argomenti di materia estetica, esecutiva, psicologico-percettiva, notazionale, ecc.

  8. Jovens negros em conflito com a lei: escola e trajetórias

    Directory of Open Access Journals (Sweden)

    Vilma Aparecida de Pinho Pinho

    2011-12-01

    Full Text Available O trabalho busca investigar as trajetórias de vida e de escolarização de jovens negros em processo de “ressocializacao", visando averiguar os fatores sociais que os levaram a ser considerados em conflito com alei. As analises foram realizadas a luz doaporte teórico das relações etnico-raciais,com ênfase nos enfoques teorico-metodologicos da dialética e da fenomenologia. Os resultados indicam que as condições de pobreza material e não material herdadas de gerações anteriores e o contexto escolar contribuem fortemente para a construção da situação atual desses jovens, que enfrentam a naturalização do racismo, evidenciada em diferentes momentos das narrativas produzidas pelos componentes do universo empírico desta pesquisa.

  9. Introduzione

    Directory of Open Access Journals (Sweden)

    Alessandro Roncaglia

    2010-07-01

    Full Text Available Con questo numero, Moneta e Credito prosegue la sua nuova vita dopo l’interruzione connessa al passaggio di proprietà dalla Banca Nazionale del Lavoro all’Associazione Paolo Sylos Labini. Tale interruzione è stata colmata con i numeri speciali per il 2008 e per il 2009 usciti negli ultimi mesi dell’anno scorso. Il numero speciale per il 2008 contiene gli indici dei primi sessant’anni di vita delle riviste e due articoli introduttivi di ricostruzione del loro percorso (Roncaglia, 2008a e 2008b; quello per il 2009 presenta una selezione di articoli pubblicati negli ultimi anni su temi connessi alla crisi finanziaria ed economica che sarebbe poi esplosa, con una breve introduzione per inquadrare questi contributi nel dibattito teorico più recente.  JEL Codes:  F3, G1, N1,  B5

  10. Leiomioma perianal. Reporte de un caso

    Directory of Open Access Journals (Sweden)

    Yorlenis C Uzcátegui R

    2014-09-01

    Full Text Available Los leiomiomas perianales son tumoraciones derivadas de células mesenquimales distribuidas por todo el cuerpo. Histológicamente se han clasificado en tres subtipos: vascular, no vascular y epiteloide. El subtipo vascular puede ser sólido, cavernoso o venoso. Los leiomiomas son raros en adultos, con incidencia de 0,1 %, generalmente se presentan entre la cuarta a sexta década de la vida con predominio en mujeres en caso de ser benignos. La forma de presentación más frecuente es un nódulo palpable, próximo al ano e indoloro. El diagnóstico se realiza según criterios histológicos e inmunohistoquímicos, además son útiles la ecografía endoanal y RMN. La exéresis es la primera opción terapéutica. Se presenta caso de paciente femenino de 41 años de edad, quien consulta por presentar nódulo palpable perianal derecho, con dolor a la palpación, de ocho meses de evolución, con valores normales de marcadores tumorales, el ultrasonido revela a nivel perianal derecho imagen sólida, hipocrómica (con tejido lineal fibroso, mide 4.82x 6.7x 6.87cm, la RMN muestra lesión ocupante de espacio en la misma ubicación, Doppler Color sin vascularización. Se efectuó exéresis de leiomioma en fosa isquiorectal derecha de 4x6 cm. El estudio anatomopatológico reportó leiomioma perianal subtipo epitelial. En el presente estudio se reporta un caso muy poco frecuente de leiomioma perianal doloroso, exponiendo las características clínicas e histológicas del mismo

  11. Theory of a metrology for the earths magnetic field based on the resonance of polarised atomic nuclei (1962); Theorie d'une metrologie du champ magnetique terrestre basee sur la resonance de noyaux atomiques polarises (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1961-06-15

    The problems presented by the metrology of the earths field are studied from two points of view. a. The first, purely physical, concerns the study of NMR transducers in their role for the transformation of the magnetic field into a frequency. The possibilities and limitations are outlined. The use of an equivalent model is introduced systematically in the considerations of NMR phenomena, this makes it possible to treat all problems of interaction between a spin system and an electric detection system in a unified form. b. The other point of view concerns the restitution of the nuclear signal frequency in the form of a directly perceptible observable. The treatment of information is considered from a statistical angle, which leads to the study of an optimisation process concerning the linearization of the measurement as well as the minimisation of noise effects. (author) [French] Les problemes que pose la metrologie du champ terrestre sont etudies sous un double aspect: a. L'un, purement physique, concerne l'etude des traducteurs a RMN dans leur role de transformation du champ magnetique en une frequence. On en degage les possibilites et les limitations. L'emploi d'un modele equivalent est introduit de maniere systematique pour rendre compte des phenomenes de RMN, ce qui permet de traiter sous forme unifiee tous les problemes d'interaction entre un systeme de spins et un systeme electrique de detection. b. L'autre aspect concerne la restitution de la frequence du signal nucleaire sous la forme d'une observable directement perceptible. On considere le traitement de l'information sous l'aspect statistique, ce qui amene a etudier un processus d'optimisation concernant la linearisation de la mesure aussi bien que la minimisation des effets des bruits. (auteur)

  12. Nuclear magnetic relaxation and origins of RMN signals from GdAl2

    International Nuclear Information System (INIS)

    Santos Oliveira Junior, I. dos.

    1988-12-01

    The intermetallic compound GdAl 2 crystallizes in the cubic Laves phase C15. It is a simple ferromagnet below 176K. The easy direction of magnetization in this compound is such that the Al ions are distributed among two magnetically inequivalent sites. The pulsed NMR technique was used to study the origin of the signals from these two sites and the nuclear magnetic relaxation. (author) [pt

  13. Reliability of hydroelectric generation components, systems and units; Confiabilidad de componentes, sistemas y unidades de generacion hidroelectrica

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Sanchez, Ramon; Torres Toledano, Gerardo; Franco Nava, Jose Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    This article presents a methodology for the calculation of the reliability of components, systems and hydroelectric generating units, as well as the scope of a computational system for the evaluation of such reliability. In the case of the reliability calculation of components and systems, the computer programs is not limited to hydro stations and can be used in other type of systems. [Espanol] En este articulo se presenta una metodologia para calcular la confiabilidad de componentes, sistemas y unidades de generacion hidroelectrica, asi como el alcance de un sistema computacional para evaluar dicha confiabilidad. En el caso del calculo de confiabilidad de componentes y sistemas, el programa de computo no se limita a centrales hidroelectricas y puede utilizarse en otro tipo de sistemas.

  14. Reliability of hydroelectric generation components, systems and units; Confiabilidad de componentes, sistemas y unidades de generacion hidroelectrica

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Sanchez, Ramon; Torres Toledano, Gerardo; Franco Nava, Jose Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    This article presents a methodology for the calculation of the reliability of components, systems and hydroelectric generating units, as well as the scope of a computational system for the evaluation of such reliability. In the case of the reliability calculation of components and systems, the computer programs is not limited to hydro stations and can be used in other type of systems. [Espanol] En este articulo se presenta una metodologia para calcular la confiabilidad de componentes, sistemas y unidades de generacion hidroelectrica, asi como el alcance de un sistema computacional para evaluar dicha confiabilidad. En el caso del calculo de confiabilidad de componentes y sistemas, el programa de computo no se limita a centrales hidroelectricas y puede utilizarse en otro tipo de sistemas.

  15. Analisis del rendimiento y consumo de programas orientados al calculo

    OpenAIRE

    Ruiz Ramírez, Marcos

    2016-01-01

    Estudio que pretende crear una implementación de computación paralela/vectorial a las funciones y rutinas de cálculo del primer nivel del BLAS, recogida en una librería (estática o dinámica), analizando su impacto energético.

  16. Calculo de volúmenes en modelos remallados de elementos finitos

    Directory of Open Access Journals (Sweden)

    Andrés Lapuebla-Ferri

    2011-06-01

    Full Text Available El Método de los Elementos Finitos asistido por ordenador es una herramienta muy extendida en ingeniería. En ciertas aplicaciones, se precisa modificar la malla del modelo a lo largo del proceso de simulación, lo que se conoce como remallado. En estos casos, además, suele ser necesario realizar mediciones en el modelo de elementos finitos, como por ejemplo calcular el volumen de ciertas regiones del mismo. Los paquetes comerciales disponibles en la actualidad permiten satisfacer algunas de estas necesidades, aunque adolecen de ciertas limitaciones. En este trabajo se presenta una aplicación desarrollada en el código propio de MatlabQc, que permite el cálculo aproximado del volumen de una región del espacio comprendida entre una malla de elementos finitos cuadriláteros lineales y otra malla topológicamente equivalente a la anterior, esta última obtenida a través de un proceso de remallado.

  17. Drug targeting and the carriers. Application to chemoembolization and medical imaging

    International Nuclear Information System (INIS)

    Puisieux, F.; Benoit, J.P.; Roblot-Treupel, L.

    1987-01-01

    The last fifteen years have seen an increased interest in drug targeting which can be considered as a new way to control the body distribution of drugs when associated with an appropriate carrier. The systems currently studied possess different structures (macromolecular, vesicular and particular) and can be classified into carriers of first, second and third generation. After a brief review of the three types of carriers, this paper focuses on their respective interest in the different fields of radiology: carriers of first generation (microcapsules, microspheres) in chemoembolization, carriers of second generation (liposomes, nanocapsules, nanospheres) in conventional radiology, in computerized tomography, in scintigraphy, in RMN; carriers of third generation (monoclonal antibodies...) in immunoscintigraphy of tumors [fr

  18. Colloque « Gertrude Stein et les Arts »

    Directory of Open Access Journals (Sweden)

    Emöke Simon

    2012-06-01

    Full Text Available Ce colloque a été organisé par Isabelle Alfandary et Vincent Broqua dans le cadre de l’exposition « Matisse, Cézanne, Picasso… L’aventure des Stein » (présentée au Grand Palais du 5 octobre 2011 au 16 janvier 2012 et avec le concours de la RMN (Réunion des musées nationaux, du Grand Palais, de la Terra Foundation for American Art et de l’Université Paris-Est Créteil. Le colloque a également bénéficié du soutien des services culturels de l’Ambassade des États-Unis d’Amérique.L’œuvre énigmati...

  19. Sesquiterpenos e hidrocarbonetos dos frutos de Xylopia emarginata (Annonaceae

    Directory of Open Access Journals (Sweden)

    Isabel C. Moreira

    Full Text Available O extrato hexânico dos frutos de Xylopia emarginata foi particionado entre hexano e MeOH/H2O. A fase hidroalcoólica foi submetida à separação cromatográfica fornecendo quatro sesquiterpenos: óxido de cariofileno, espatulenol, 1beta,6alfa-diidroxi-4(15-eudesmeno e 4-hidroxi-1,15-peróxieudesmano. A fase hexânica foi fracionada através de cromatografia em coluna fornecendo dois hidrocarbonetos (nonadecano e 1-nonadeceno e uma cetona alifática (hentriacontan-16-ona. As estruturas dos compostos isolados foram estabelecidas através de análise espectroscópica, principalmente RMN e EM.

  20. Antraquinonas e naftoquinonas do caule de um espécime de reflorestamento de Tectona grandi (Verbenaceae

    Directory of Open Access Journals (Sweden)

    Rafael Y.O. Moreira

    Full Text Available O fracionamento do extrato hexânico do caule de um espécime de reflorestamento de Tectona grandis (Verbenaceae, através de procedimentos fitoquímicos clássicos, levou ao isolamento das naftoquinonas lapachol e desidro-a-lapachona e das antraquinonas tectoquinona e obtusifolina. As estruturas das substâncias foram caracterizadas através da análise de métodos espectrométricos de RMN. Este é o primeiro estudo fitoquímico de um espécime de reflorestamento de Tectona grandis, no Brasil, sendo o objetivo principal deste trabalho a comprovação da presença de tectoquinona em espécimes cultivados.

  1. Estudo fitoquímico e avaliação da toxicidade frente a Artemia salina e da atividade antimicrobiana de Calycorectes psidiiflorus (O. Berg Sobral, Myrtaceae

    Directory of Open Access Journals (Sweden)

    Elaine A. Domingues

    Full Text Available O estudo fitoquímico das folhas de Calycorectes psidiiflorus (O. Berg Sobral, Myrtaceae, resultou no isolamento e identificação de: sesquiterpeno [8-hidroxicalameneno (1], triterpenos [α-amirina (2a e β-amirina (2b], flavonóide [3-O-α-ramnopiranosil-7-O-bglucopiranosil canferol (3], e alcalóide [1,2,3,4-tetraidro-1-metil-β-carbolina (4]. As estruturas das substâncias isoladas foram elucidadas com base nos seus dados de RMN em comparação com os da literatura. A substância 8-hydroxicalameneno apresentou atividade antibacteriana (MIC = 7,8 µg/mL e antifúngica (MIC = 15,6 µg/mL.

  2. Analisi teorico-sperimentale di collegamenti dissipativi a parziale ripristino di resistenza in strutture intelaiate in acciaio

    OpenAIRE

    Latour, Massimo

    2011-01-01

    2009 - 2010 Before seismic events of Northridge (Los Angeles, 17 January 1994) and Hyogoken-Nanbu (Kobe, 17 January 1995) MRFs were supposed to be the most reliable seismic resistant systems due to the high number of dissipative zones that are able to develop Before these earthquakes, especially in United States, MRFs were realized, generally, by adopting fully welded connections, which, at the time, were retained to perform better compared to other joint typologies. In a...

  3. Reacting fluids analysis and polluting emissions; Analisis de fluidos reactivos y emisiones contaminantes

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Ledo, Ramon; Ley Koo, Marcos [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Varela Ham, Ruben [Universidad Autonoma Metropolitana, Mexico, D. F. (Mexico)

    1993-12-31

    A problem is set up of a reacting flow which occurs in a gas exhausting duct, which is boiled down to a problem of initial conditions (temperature, pressure and concentration of species) freeing the selection of reaction mechanisms. Through some pre-established algorithms calculation routines can be programmed in specific problems of chemistry kinetics. With the calculation routines set forth in base of the selected mechanism, the temperature, pressure, etc., conditions, a general program is obtained containing the differential equations for the mechanisms, and with its solution, with a certain degree of uncertainty, the gases at a duct outlet can be predicted. The exhaust gases will carry unburned particles and products that can be polluting or not. If we vary the working conditions, we can find the optimum values to work with equipment that produces exhaust gases, anticipating with it the more efficient utilization of the equipment and the energy with the least possible pollution. [Espanol] Se plantea un problema de un flujo reactivo que se lleva a cabo en un ducto de salida de gases de escape, para lo cual se reduce a un problema de condiciones iniciales (temperatura, presion y concentracion de especies), y dejando en libertad la seleccion de mecanismos de reaccion. Mediante algunos algoritmos preestablecidos se pueden programar las rutinas de calculo en problemas especificos de cinetica quimica. Con las rutinas de calculo planteadas en base al mecanismo seleccionado, las condiciones de temperatura, presion, etc. se obtiene un programa general que contiene las ecuaciones diferenciales para el mecanismo y con su solucion se puede predecir con cierto grado de incertidumbre los gases a la salida de un ducto, los gases de salida llevaran particulas inquemadas y productos que pueden ser contaminantes o no, si hacemos variacion en las condiciones de trabajo podemos encontrar los valores optimos para trabajar con equipos que producen gases de escape, previendo con ello

  4. Brote de gastroenteritis por virus Norwalk en una residencia de ancianos de Granada

    Directory of Open Access Journals (Sweden)

    Almagro Nievas Diego

    2003-01-01

    Full Text Available Fundamento: Los brotes de gastroenteritis aguda de origen vírico son actualmente uno de los problemas de salud que más están afectando a las personas residentes en instituciones de la tercera edad. El objetivo del estudio es investigar las causas del origen y transmisión de un brote de gastroenteritis aguda por virus Norwal-Like. Método: En una residencia de ancianos con 141 residentes y 71 trabajadores expuestos, se investigó la relación entre un brote de gastroenteritis aguda y distintas variables: características personales, de lugar, fecha de inicio de los síntomas, clínica de la enfermedad y factores causales (alimentos y agua de consumo. Se realizó un estudio descriptivo, tabla de contingencia y test de hipótesis 2, diseño de casos y controles con el calculo de Odds Ratio cruda y posteriormente ajustada (IC al 95% utilizando regresión logística. Resultados: No se observaron diferencias significativas en las variables de características personales y de lugar. La tasa de ataque en los residentes fue del 30,1% y en trabajadores fue del 21,12%. En el calculo de la Odds Ratio ajustada sólo tuvo valores de relación causal la mousse de nata (Odds Ratio ajustada=4,66; IC-95% 1,15-18,91; p=0,031. Se remitieron 10 muestras de heces de enfermos para su análisis, no detectándose ninguna bacteria patógena, pero si se aisló en 3 de ellas virus Norwal-Like. Conclusiones: El hallazgo de la mousse de nata como posible responsable del brote supone una primicia en la presencia de virus Norwalk, pero este resultado está sujeto a limitaciones, como el posible sesgo de clasificación por no recuerdo de consumo de alimentos. Aún así, supone un elemento a tener en cuenta en el control de gastroenteritis agudas por virus.

  5. BROTE DE GASTROENTERITIS POR VIRUS NORWALK EN UNA RESIDENCIA DE ANCIANOS DE GRANADA

    Directory of Open Access Journals (Sweden)

    Diego Almagro Nievas

    2003-01-01

    Full Text Available vírico son actualmente uno de los problemas de salud que más están afectando a las personas residentes en instituciones de la tercera edad. El objetivo del estudio es investigar las causas del origen y transmisión de un brote de gastroenteritis aguda por virus Norwal- Like. Método: En una residencia de ancianos con 141 residentes y 71 trabajadores expuestos, se investigó la relación entre un brote de gastroenteritis aguda y distintas variables: características personales, de lugar, fecha de inicio de los síntomas, clínica de la enfermedad y factores causales (alimentos y agua de consumo. Se realizó un estudio descriptivo, tabla de contingencia y test de hipótesis 2, diseño de casos y controles con el calculo de Odds Ratio cruda y posteriormente ajustada (IC al 95% utilizando regresión logística. Resultados: No se observaron diferencias significativas en las variables de características personales y de lugar. La tasa de ataque en los residentes fue del 30,1% y en trabajadores fue del 21,12%. En el calculo de la Odds Ratio ajustada sólo tuvo valores de relación causal la mousse de nata (Odds Ratio ajustada=4,66; IC-95% 1,15- 18,91; p=0,031. Se remitieron 10 muestras de heces de enfermos para su análisis, no detectándose ninguna bacteria patógena, pero si se aisló en 3 de ellas virus Norwal-Like. Conclusiones: El hallazgo de la mousse de nata como posible responsable del brote supone una primicia en la presencia de virus Norwalk, pero este resultado está sujeto a limitaciones, como el posible sesgo de clasificación por no recuerdo de consumo de alimentos. Aún así, supone un elemento a tener en cuenta en el control de gastroenteritis agudas por virus.

  6. Reacting fluids analysis and polluting emissions; Analisis de fluidos reactivos y emisiones contaminantes

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Ledo, Ramon; Ley Koo, Marcos [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Varela Ham, Ruben [Universidad Autonoma Metropolitana, Mexico, D. F. (Mexico)

    1992-12-31

    A problem is set up of a reacting flow which occurs in a gas exhausting duct, which is boiled down to a problem of initial conditions (temperature, pressure and concentration of species) freeing the selection of reaction mechanisms. Through some pre-established algorithms calculation routines can be programmed in specific problems of chemistry kinetics. With the calculation routines set forth in base of the selected mechanism, the temperature, pressure, etc., conditions, a general program is obtained containing the differential equations for the mechanisms, and with its solution, with a certain degree of uncertainty, the gases at a duct outlet can be predicted. The exhaust gases will carry unburned particles and products that can be polluting or not. If we vary the working conditions, we can find the optimum values to work with equipment that produces exhaust gases, anticipating with it the more efficient utilization of the equipment and the energy with the least possible pollution. [Espanol] Se plantea un problema de un flujo reactivo que se lleva a cabo en un ducto de salida de gases de escape, para lo cual se reduce a un problema de condiciones iniciales (temperatura, presion y concentracion de especies), y dejando en libertad la seleccion de mecanismos de reaccion. Mediante algunos algoritmos preestablecidos se pueden programar las rutinas de calculo en problemas especificos de cinetica quimica. Con las rutinas de calculo planteadas en base al mecanismo seleccionado, las condiciones de temperatura, presion, etc. se obtiene un programa general que contiene las ecuaciones diferenciales para el mecanismo y con su solucion se puede predecir con cierto grado de incertidumbre los gases a la salida de un ducto, los gases de salida llevaran particulas inquemadas y productos que pueden ser contaminantes o no, si hacemos variacion en las condiciones de trabajo podemos encontrar los valores optimos para trabajar con equipos que producen gases de escape, previendo con ello

  7. The potential flow in presence of a magnetic field; El flujo potencial en presencia de un campo magnetico

    Energy Technology Data Exchange (ETDEWEB)

    Fierros Palacios, Angel [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2001-02-01

    From the Lagrangian formalism as in classical field theory, the partial differential field equations for the propagation of a small perturbation in a continuous and homogeneous conducting media in a magnetic field is obtained. The specific Lagrangian is calculated and it is shown that the equation of motion is the wave equation. Finally, the law of energy conservation is obtained. [Spanish] A partir de un formalismo lagrangiano, como el de la teoria clasica de campos, se obtienen las ecuaciones diferenciales de campo para la propagacion de un pequeno disturbio en un medio conductor continuo y homogeneo que se mueve en presencia de un campo magnetico uniforme. Usando el mismo marco teorico se obtiene la ecuacion de balance de energia. Se calcula la lagrangiana especifica y se demuestra que la ecuacion de movimiento es la ecuacion en onda. Ademas, se obtiene la correspondiente ley de la conservacion de la energia.

  8. Danza e pantomima: modelli interpretativi e chiavi di lettura

    Directory of Open Access Journals (Sweden)

    Stefania Onesti

    2015-03-01

    Full Text Available One of the most ambiguous question in the studying of pantomime ballet is its staging. The combination between dance and pantomime, true novelty of theatrical dance reform, is for us an enigma difficult to solve.The aim of this paper is to outline how dance and pantomime can combine in the eighteenth Century ballet. We will examine, among others, the following sources: the John Weaver’s libretto of The Loves of Mars and Venus (1717, the report of the Mercure de France on the staging of Maria Sallé’s Pygmalion (1734, Gennaro Magri’s Trattato teorico-prattico (1779 and Ferrère manuscript (written in the 1782. These documents are a sort of “interpretative models” and allow to identify an international common stage practice which, most likely, regards also choreographers active in Italy in the second half of Eighteenth Century.

  9. Cervantes, Twain e Lobato: reflexões sobre direito, literatura e censura

    Directory of Open Access Journals (Sweden)

    André Karam Trindade

    2013-06-01

    Full Text Available El objetivo del presente trabajo, que tiene como marco teorico la tradición del movimiento Derecho y Literatura, es hacer un analisis de la censura perpetrada contra la literatura en las democracias constitucionales. Son utilizados tres ejemplos ilustrativos del peligro que representa la prática de perseguicion a los libros en los sistemas democráticos: (a la censura del cuento La Gitanilla, de Miguel de Cervantes, en España; (b la reciente reedición didáctica de Las Aventuras de Tom Sawyer y Huckleberry Finn; (c y la también reciente contestación en el Supremo Tribunal Federal de Brasil de parte de la obra del escritor brasileño Monteiro Lobato. En síntesis, es intentado hacer una crítica al desarollo de nuevas formas de censura en las democracias contemporáneas.

  10. Identità visiva e narrazione in un percorso MOOC per docenti

    Directory of Open Access Journals (Sweden)

    Letizia Cinganotto

    2015-09-01

    Full Text Available Il contributo mira a illustrare un esempio di MOOC per docenti realizzato in un contesto internazionale. In particolare, il focus è rappresentato dalla documentazione e riflessione sul percorso formativo dei docenti attraverso l’uso del diario, componente essenziale per la rielaborazione e reinterpretazione dell’esperienza ai fini dell’arricchimento e della crescita personale e professionale. Le tecnologie multimediali e multimodali offrono la possibilità di costruire varie tipologie di diari all’interno di percorsi di formazione online. In particolare, verranno presi in considerazione alcuni esempi di diari e ne saranno illustrate le caratteristiche principali, dettagliando l’uso di alcuni tool per la rappresentazione narrativa e visiva. L’articolo prende le mosse da un breve quadro di riferimento teorico sulla funzione dei MOOC nella formazione dei docenti e sull’importanza della meta-riflessione ai fini della costruzione del profilo del “professionista riflessivo”.

  11. Idraulica dei sistemi fognari dalla teoria alla pratica

    CERN Document Server

    Gisonni, Corrado

    2012-01-01

    La progettazione dei sistemi fognari e dei manufatti in essi presenti richiede un’attenta conoscenza delle leggi che regolano i fenomeni idraulici, con particolare riferimento alle correnti idriche a superficie libera. Partendo dalle nozioni fondamentali dell’Idraulica, il testo intende colmare alcune importanti lacune che ancora caratterizzano la letteratura italiana nel settore e che spesso sono alla base di errori progettuali, con ovvie conseguenze sulla sicurezza dei centri abitati (come testimoniato dai frequenti fenomeni di allagamento che sono stati registrati negli ultimi anni). Il libro è rivolto agli allievi dei corsi di studio nel settore dell’ingegneria Civile ed Ambientale. Particolare interesse è rivolto ai professionisti operanti nel settore della ingegneria idraulica e della pianificazione urbana, per i quali è forte l’esigenza di testi che contengano indicazioni di carattere sia teorico sia pratico, finalizzate alla progettazione di sistemi di drenaggio nei centri abitati.

  12. Jeanne Hersch: una filosofia dei contorni

    Directory of Open Access Journals (Sweden)

    Roberta De Monticelli

    2013-07-01

    Full Text Available A Si tracciano le linee fondamentali del pensiero di Jeanne Hersch (Ginevra, 1910-2000, che concepisce la filosofia come servizio anti-idolatrico nei confronti della trascendenza da un lato, e dall’altro come continua presa di coscienza dei gesti della libertà che fanno irriducibile al dato e insieme profondamente individuata, qui ed ora, la nostra vita. Si mostra come l’ontologia di questa pensatrice sia indissociabile dalla sua estetica, o piuttosto dalla sua teoria del fare umano quale partecipazione finita e incarnata alla creazione. Si mostra il nesso da lei particolarmente sottolineato fra consistenza morale personale e responsabilità del pensiero teorico, sulla base dell’esempio negativo di Heidegger, sostenitore del nazismo. Si discute la netta presa di posizione che Jeanne Hersch assume contro le seduzioni e le liturgie verbali del suo pensiero incantatorio, irresponsabile nei confronti della verità e “radicato nel disprezzo”.

  13. Preparação, caracterização e degradação de blendas PS/TPS usando glicerol e óleo de buriti como plastificantes Preparation, characterization and degradation of PS/TPS blends using glycerol and buriti oil as plastiscizers

    Directory of Open Access Journals (Sweden)

    Daniela Schlemmer

    2010-01-01

    Full Text Available Poliestireno (PS é um dos materiais descartáveis mais usados no nosso cotidiano, mas ele não se decompõe facilmente. A adição de amido de mandioca ao PS pode melhorar a sua degradabilidade, tendo em vista ser o amido um polímero biodegradável. O objetivo deste trabalho foi desenvolver blendas de PS e (amido termoplástico TPS usando dois diferentes plastificantes: glicerol e óleo de buriti, sendo esse óleo um plastificante natural e original para o amido. As blendas PS/TPS foram preparadas em diversas composições por casting e em seguida caracterizadas por termogravimetria (TG, calorimetria exploratória diferencial (DSC, análise termomecânica (TMA e ressonância magnética nuclear (RMN 13C. As blendas PS/TPS com óleo de buriti apresentaram uma contínua redução em suas Tg e Ta. Nas blendas com glicerol esses parâmetros permaneceram praticamente constantes. As blendas também foram submetidas a testes de degradação no solo e depois analisadas por TG e RMN. A análise das blendas PS/TPS com óleo de buriti mostrou que houve um aumento da perda de massa nas curvas TG. Nos espectros de RMN 13C, todos os picos referentes ao amido desapareceram, depois do teste de aterro, sugerindo que houve consumo do amido das blendas por microorganismos. De acordo com as análises realizadas, a adição do TPS produzido com óleo de buriti pode melhorar a degradabilidade do PS.Polystyrene (PS is one of the most used disposable materials in our daily life, but it does not decompose easily. The addition of cassava starch to PS can improve its degradability since starch is a biodegradable polymer. The aim of this work was to develop blends of PS and thermoplastic starch (TPS using two different plasticizers: buriti glycerol and buriti oil, a novel and natural plasticizer for starch. PS/TPS blends were prepared in various contents with the casting technique and analyzed by thermogravimetry (TG, differential scanning calorimetry (DSC

  14. Preparando um ambiente de desenvolvimento para a plataforma android

    Directory of Open Access Journals (Sweden)

    Felipe Pires de Oliveira

    2015-11-01

    Full Text Available Este artigo descreve as etapas para a criação de um ambiente de desenvolvimento para a plataforma Android. O artigo foi dividido em quatro partes: Primeiro uma introdução sobre o assunto. Na segunda seção são mostrados os passos necessários para a configuração do ambiente de desenvolvimento. Na terceira seção, é demonstrado como criar uma aplicação para dispositivo Android que calculo Índice de Massa Corporal (IMC. A quarta seção apresenta as considerações finais. A solução abordada tem como base a IDE Eclipse e o SDK do Android, bem como o Kit de Desenvolvimento Java da Oracle (JDK.

  15. Preparando um ambiente de desenvolvimento para a plataforma android

    Directory of Open Access Journals (Sweden)

    Felipe Pires de Oliveira

    2015-12-01

    Full Text Available Este artigo descreve as etapas para a criação de um ambiente de desenvolvimento para a plataforma Android. O artigo foi dividido em quatro partes: Primeiro uma introdução sobre o assunto. Na segunda seção são mostrados os passos necessários para a configuração do ambiente de desenvolvimento. Na terceira seção, é demonstrado como criar uma aplicação para dispositivo Android que calculo Índice de Massa Corporal (IMC. A quarta seção apresenta as considerações finais. A solução abordada tem como base a IDE Eclipse e o SDK do Android, bem como o Kit de Desenvolvimento Java da Oracle (JDK.

  16. System for the design of electrical distribution substations; Sistema para el diseno de subestaciones electricas de distribucion

    Energy Technology Data Exchange (ETDEWEB)

    Zayas Perez, Benjamin Eddie; Islas Perez, Eduardo; Bahena Rada, Jessica Liliana; Romero Lima, Jesus [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Sierra Rodriguez, Benjamin; Moreno Diaz, Humberto [Comision Federal de Electricidad (Mexico)

    2011-07-01

    llevan a cabo en las Divisiones de Distribucion de la Comision Federal de Electricidad (CFE) en dos procesos por separado: elaboracion de planos de ingenieria con software para diseno asistido por computadora (CAD, Computer-Aided Design) y calculo de la volumetria para la elaboracion del presupuesto base, con hojas de calculo convencionales. Los documentos se elaboran manualmente y de forma individual, sin existir alguna funcionalidad que permita actualizar automaticamente las modificaciones del diseno en todos los planos, y el correspondiente presupuesto base, resultando un proceso tardado, laborioso y factible de inconsistencia entre los documentos. Con la finalidad de optimizar el proceso de diseno de la obra civil y electromecanica de subestaciones electricas (SE) en un ambiente grafico tridimensional (3D), la Gerencia de Supervision de Proceso del Instituto de Investigaciones Electricas (IIE), en coordinacion con la Subdireccion de Distribucion de la CFE, desarrollo el Sistema para el Diseno de Subestaciones Electricas de Distribucion (DiDSED), el cual aprovecha las ventajas de la tecnologia CAD3D para el desarrollo de la ingenieria de detalle, ingenieria de costos para el calculo del presupuesto base y realidad virtual para navegacion tridimensional interactiva. Cabe destacar que actualmente, este sistema se encuentra en la etapa de implantacion en la Subdireccion de Distribucion de la CFE. En este articulo se describen brevemente las etapas principales del desarrollo del proyecto, asi como la funcionalidad y los componentes principales del sistema.

  17. ESTUDIO QUÍMICO DE LA CORTEZA DE Remijia peruviana “Cascarilla”

    Directory of Open Access Journals (Sweden)

    Gabriel Vargas Arana

    2011-07-01

    Full Text Available En el presente trabajo se realizó el análisis cualitativo de los metabolitos secundarios  y la cuantificación e identificación de los alcaloides presentes en la corteza de Remijia peruviana, la cual forma parte de la familia Rubiaceae, caracterizada por sintetizar  mayoritariamente alcaloides. Se ha aislado y determinado la estructura química de cinco alcaloides quinolínicos: tres nuevos derivados, Quinina acetato (1, Quinina alcohol (2 y N-Etil Quinina (3; y dos reportados anteriormente en la literatura: Quinina (4 y Cinchonina (5. La estructura de los nuevos alcaloides fueron elucidados por análisis básicos de espectroscopía RMN, incluyendo correlaciones homonuclear y heteronuclear (COSY, NOESY, HMBC y HSQC.

  18. Magnetic structures of Er6Mn23 and Dy6Mn23

    International Nuclear Information System (INIS)

    Ouladdiaf, B.; Deportes, J.; Rodriguez-Carvajal, J.

    1995-01-01

    The R 6 Mn 23 (R=rare earth) compounds crystallize in the cubic Th 6 Mn 23 -type structure with space group Fm3m. Powder neutron-diffraction experiments were performed on Dy 6 Mn 23 and Er 6 Mn 23 . The magnetic unit cell coincides with the chemical one. The R moments have a ferromagnetic non-collinear arrangement, whereas the Mn moments are parallel to the [1 1 1] direction. The magnetic structures belong to the three-dimensional Γ 5g irreducible representation of Fm3m associated with the wave vector K=[0 0 0]. The spin configurations in both compounds result from the competition between the R-R, R-Mn magnetic interactions and the crystal electric field on the R ions. (orig.)

  19. In vivo NMR spectroscopy of the liver. Spectroscopie RMN du foie in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Jehenson, P.; Cuenod, C.A.; Syrota, A. (CEA, 91 - Orsay (FR). Service Hospitalier Frederic Joliot)

    1989-01-01

    The application of in vivo MR spectroscopy to the study of the liver is currently an expanding field of research. Owing to technical difficulties, the results obtained thus far were mainly those of animal observations. Several nuclei have been considered: hydrogen, phosphorus, carbon or fluorine. This non-traumatic method allows following and quantifying the various metabolic pathways, especially during hepatic diseases. The major metabolic pathways, i.e. neoglycogenesis, glycogenolysis, Krebs' cycle, etc., are studied, as well as their alterations during diseases such as ischemia, diabetes or alcoholism. The development of this promising technique requires the cooperation of various clinical and fundamental disciplines.

  20. Construction of a NMR permanent magnet; Construcao de um ima permanente para RMN

    Energy Technology Data Exchange (ETDEWEB)

    Colnago, Luiz Alberto; Martins Neto, Ladislau; Oste, Rene de [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Nucleo de Pesquisa e Desenvolvimento de Instrumentacao Agropecuaria

    1992-12-31

    Viewing the development of the pulsed, low resolution NMR spectrometers for quantitative analysis, the electronic part of a NMR spectrometer has first been constructed, based on a 1.4 Tesla magnet of a 60 MHz Varian device, with a gap increased to 23 mm, therefore reducing the field to .66 Tesla (28 MHz for the hydrogen). For the complete construction of the spectrometer in Brazil, a permanent magnet for NMR has also been constructed 9 refs., 3 figs.

  1. Interface card for NMR data acquisition; Cartao de aquisicao de dados para RMN

    Energy Technology Data Exchange (ETDEWEB)

    Torre Neto, Andre; Colnago, Luiz Alberto [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Nucleo de Pesquisa e Desenvolvimento de Instrumentacao Agropecuaria

    1992-12-31

    A NMR spectrometer constructed by NPDIA is being used for analysis of seed oil contents in projects of oil seeds improvement. Some improvements have been introduced in this spectrometer, and this work presents an IBM-Pc compatible interface card. This interface has some characteristics which are exclusive for NMR 6 refs., 3 figs.

  2. FILOSOFIA DE LA MENTE; APORTES TEORICOS Y EXPERIMENTALES A LA VISIÓN EMERGENTISTA DEL VINCULO MENTE-CEREBRO.

    Directory of Open Access Journals (Sweden)

    Paul Ruiz Santos

    2011-01-01

    Full Text Available El presente trabajo intenta sumar alprograma emergentista dentro del mapa teórico referido a la Filosofía de la Mente, tomando como referentes a disciplinas y teorías naturalizadas. Algunos puentes vinculantes desde la naturalización pueden ser por ejemplo el neuro-psicoanálisis, las neuronas espejo, la psicosomática, entre otros. Dichos puentes son posibles de ser tendidos a través de la naturalización de los procesos psicológicos vinculándolos a diferentes procesos biológicos. El objetivo del trabajo no pretende obturar los procesos psicológicos a través de la simplificación y reduccionismo de los mismos, ni biologizar la psicología a través de planteos cartesianos. Sino, de la mano de la neuro-fenomenología, acceder a más y nuevas evidencias sobre el vínculo mente-cerebro y sus implicancias aportando a una visión interaccionista y emergentista del vínculo.

  3. Las multiples violencias de la "violencia" en la escuela: desarrollo de un enfoque teorico y metodologico integrativo

    Directory of Open Access Journals (Sweden)

    María Inés Bringiotti

    2004-12-01

    Full Text Available Foram investigados diversos tipos de violência, no âmbito escolar, que ocasionam aumento do risco para a ocorrência de maltrato infantil. Na primeira etapa a amostra ficou composta por quatro escolas de Buenos Aires, duas de educação inicial e duas primárias, selecionadas ao acaso, em dois distritos predominantemente com classes sociais diferentes (média e baixa. Foram encontradas correlações entre o potencial de maltrato, a História da Educação, nível sócio econômico e educacional da mãe, problemas comportamentais e emocionais da criança. Mediante a análise de regressão foram obtidos modelos específicos para os dois grupos da amostra e encontrados aspectos de violência social, institucional e na interação com os pares (infantil. Na segunda etapa foram encontradas correlações entre o potencial de maltrato, depressão, apoio social. Foram implementados programas de intervenção para pais e, para docentes e autoridades de um jardim da infância, analisando as variáveis de cambio e as que resistiram a uma modificação.

  4. Marxismo como referencial teorico-metodologico em saude coletiva: implicacoes para a revisao sistematica e sintese de evidencias

    Directory of Open Access Journals (Sweden)

    Cassia Baldini Soares

    2013-12-01

    Full Text Available O objeto deste estudo é a incorporação em revisões sistemáticas de resultados de pesquisas desenvolvidas na vertente marxista de produção do conhecimento, como evidências em saúde. Os objetivos são: rever os pressupostos do materialismo histórico e dialético (MHD e discutir as implicações da dialética para a revisão da literatura e síntese de evidências. O MHD constitui um referencial potente para geração de conhecimento e transformação das políticas e práticas em saúde, a partir da explicação de que as contradições sociais estão na base do processo saúde-doença, construção teórica fundamental no campo da saúde coletiva. Atualmente observa-se considerável influência do paradigma crítico, de origem marxista, na construção do conhecimento em saúde. Pesquisas no paradigma crítico apresentam métodos complexos de apreensão do objeto, inerentes às diretrizes da dialética, oferecendo resultados que constituem evidências em saúde. Revisões sistemáticas devem enfrentar a dificuldade metodológica de integrar esses resultados plenamente ao cuidado em saúde.

  5. Methods in nuclear reactors calculations; Metodos de calculo en reactores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Velarde, G

    1966-07-01

    Studies are made of the neutron transport equation corresponding to the the real and virtual reactors, as well as the starting hypotheses. Methods are developed to solve the transport equation in slab geometry, and P{sub l}; B{sub l}; M{sub l}; S{sub n} and discrete ordinates approximations. (Author)

  6. Shield calculations, optimization vs. paradigm; Calculos de blindajes, optimizacion vs. paradigma

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo D, N.; Hernandez S, A.; Martinez G, A. [Centro de Proteccion e Higiene de las Radiaciones, Calle 20 No. 4113 e/41 y 47 Playa C.P. 11300 LaHabana (Cuba)]. e-mail: nestor@cphr.edu.cu

    2006-07-01

    Many shieldings have been designed under the criteria of 'Maximum dose rates of project'. It has created the paradigm of those 'low dose rates', for the one which not few specialists would consider unacceptable levels of dose rate superior to the units of {mu}Sv.h{sup -1}, independently of the exposure times. At the present time numerous shieldings are being designed considering dose restrictions in real times of exposure. After these new shieldings, the dose rates could be notably superior to those after traditional shieldings, without it implies inadequate designs or constructive errors. In the work significant differences in levels of dose rates and thickness of shieldings estimated by both methods for some typical facilities. It was concluded that the use of real times of exposure is more adequate for the optimization of the Radiological Protection, although this method demands bigger care in its application. (Author)

  7. N.M.R. study of organo-phosphorus compounds: non equivalence of methylenic protons in the {alpha} position of an asymmetric phosphorus atom. Application to study of coupling constants J{sub P,H} and J{sub H,H}; R.M.N. de composes organo-phosphores: non equivalence de protons methyleniques en {alpha} d'un phosphore asymetrique. Application a l'etude des constantes de couplage J{sub P,H} et J{sub H,H}

    Energy Technology Data Exchange (ETDEWEB)

    Albrand, J P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    Non-equivalent methylenic protons, with respect to an asymmetric center, have been observed in the n.m.r. spectra of some three- and tetra-coordinated phosphorus compounds. The analysis of these spectra yield the following results: in the studied secondary phosphines, the inversion rate at the phosphorus atom is slow on the n.m.r. time scale; the geminal coupling constant, for a free-rotating methylene group attached to a phosphorus atom, is negative; in phosphines the non equivalence of methylenic protons reveals two {sup 2}J{sub P-C-H} coupling constants which differ by about 5 Hz. This result is in agreement with previous studies on cyclic phosphines. In phosphine oxides, the {sup 2}J{sub P-C-H} values are negative. The {sup 3}J{sub H-P-C-H} coupling constant is positive in both phosphines and phosphine oxides. In phosphines, the non-equivalent methylenic protons exhibit two nearly equal values for this coupling constant. (author) [French] La non-equivalence de protons methyleniques observee dans quelques composes phosphores tricoordines et tetracoordines a apporte les resultats suivants, concernant la stereochimie et les constantes de couplage dans ces composes: dans les phosphines secondaires, la structure pyramidale des liaisons issues du phosphore est fixe a l'echelle de temps de mesure de la R.M.N.; la constante de couplage {sup 2}J{sub H-C-H}, pour un methylene en libre rotation en {alpha} d'un atome de phosphore, est negative; dans les phosphines etudiees, la non-equivalence. observee pour les protons methyleniques s'accompagne d'une difference importante (5 Hz) entre les deux constantes de couplage {sup 2}J{sub P-C-H} determinees par l'analyse; ce resultat est en accord avec la stereospecificite deja observee pour ce couplage dans les phosphines cycliques. Les valeurs observees pour {sup 2}J{sub P-C-H} dans les oxydes de phosphines sont negatives. Les valeurs de la constante de couplage {sup 3}J{sub H-P-C-H}, dans les phosphines et oxydes de phosphine

  8. Contro la tirannia del Progresso. DeLillo e Sebald, alcuni esercizi di resistenza

    Directory of Open Access Journals (Sweden)

    Arturo Mazzarella

    2015-11-01

    Full Text Available Il saggio si propone di contribuire a un’ulteriore revisione critica della categoria di “progresso”: termine decisivo nel lessico teorico-politico della modernità, il quale ancor oggi conserva interamente il proprio valore. Troppo spesso si dimentica, però – come ha messo in luce Nietzsche nel corso di tutta la sua opera –, la profonda radice nichilistica su cui si innesta la categoria di progresso: proiettata in un orizzonte temporale che, in vista di un interminabile perfezionamento individuale e collettivo, finisce per svuotare, annullare, la dimensione del presente. In questo senso resistere (proprio nell’accezione adoperata da Foucault alle tentazioni del progresso significa impegnarsi nella costruzione di un immaginario che individui nel presente, appunto, nelle sue imprevedibili metamorfosi, l’unico tempo storico in grado di generare un reale mutamento. Proprio come dimostrano esemplarmente i due romanzi – di rilevante spessore concettuale – su cui si sofferma il saggio: Austerlitz, di Sebald e Punto omega, di DeLillo.

  9. LUCI ED OMBRE NELL’ATTUAZIONE DEL SISTEMA DI RISOLUZIONE ALTERNATIVA DELLE CONTROVERSIE NEL CONTENZIOSO TRIBUTARIO ITALIANO ED IN QUELLO CROATO

    Directory of Open Access Journals (Sweden)

    Marco Greggi

    2017-01-01

    Full Text Available Nel lavoro gli autori esaminano il sistema della risoluzione alternativa delle controversie (ADR - Alternative Dispute Resolution nelle questioni fi scali in un’ottica comparatistica, ovvero alla luce delle legislazioni e delle dottrine italiana e croata. Nella prima parte del lavoro l’attenzione è rivolta all’esperienza italiana di attuazione del sistema ADR; mentre la seconda parte del lavoro è dedicata all’evoluzione del quadro normativo croato nei tentativi di costruzione di meccanismi di ADR. Il lavoro in entrambe le sue parti contiene una rassegna degli orientamenti dottrinali e attraverso i vari capitoli si sottolinea l’aspetto storico e teorico della questione esaminata. Gli autori dibattono ed espongono sul piano comparatistico anche le implicazioni dell’attuazione del sistema in esame; mentre l’infl uenza della dottrina di diritto pubblico sulla comparsa e lo sviluppo del sistema ADR viene evidenziata mediante l’esposizione della recente prassi italiana e croata del sistema di risoluzione dei contenziosi tributari.

  10. Smart movie tourism: la nuova frontiera del cineturismo / Smart movie tourism: the new frontier of cine-tourism

    Directory of Open Access Journals (Sweden)

    Teresa Graziano

    2016-05-01

    Full Text Available Inserito nel quadro teorico della letteratura sulla Smart City, il presente lavoro mira ad analizzare le implicazioni derivanti dall’utilizzo delle nuove tecnologie intelligenti per la valorizzazione turistica delle location cinematografiche. Dal punto di vista metodologico, l’articolo si fonda su un’analisi quali-quantitativa di alcuni casi di smart movie tourism, al fine di indagare le caratteristiche delle applicazioni per smartphone e tablet (apps che consentono la riproduzione virtuale degli itinerari cinematografici in alcune regioni italiane, evidenziandone potenzialità, risultati e criticità.  Inserted in the theoretical frame of Smart city literature, this paper aims at analysing the impacts of smart technologies for the tourist enhancement of movie locations. From the methodological standpoint, the work is based on a qualitative and quantitative analysis of different cases of smart movie tourism in Italy, in particular some selected applications for smartphones and tablet (apps focused on Italian movie locations, in order to underline their potentialities, results and critical aspects.

  11. La «Cortegiania» e la «Cortesana Filosofia»: B. Castiglione e B. Gracián

    Directory of Open Access Journals (Sweden)

    Maria Teresa Ricci

    2013-06-01

    Full Text Available L’articolo stabilisce un confronto fra la cortigiania, ovvero la filosofia del comportamento raffinato dell’uomo cortese proposta dal testo Il cortigiano di Baldassare Castiglione, e la cortesana filosofia presente in tutta l’opera di Gracián. Questi due autori, che hanno vissuto in paesi e luoghi differenti, hanno dei principi filosofici, antropologici e religiosi molto diversi. Si distinguono dunque sia dal punto di vista letterario sia per il loro approccio teorico. Il primo offre un nuovo modello sociale di comportamento legato alla struttura particolare della corte all’inizio dell’epoca moderna; il secondo si propone esplicitamente di creare un «prodigio», un uomo «artificiale» che sappia far fronte alla realtà ingannevole, che sappia sopravvivere in un mondo ostile. Egli annuncia in un certo senso il passaggio dalla tradizionale società d’ordini, in cui ognuno ha sin dalla nascita il suo posto assicurato nella società, al mondo dell’«individualità astratta»

  12. Lombalgia ocupacional Occupational low back pain

    Directory of Open Access Journals (Sweden)

    Milton Helfenstein Junior

    2010-01-01

    Full Text Available A lombalgia ocupacional apresenta etiologia multifatorial, elevada prevalência e incidência. Caracterizada por quadro de dor de variada duração e intensidade, a dor lombar pode levar à incapacidade laborativa e à invalidez. A lombalgia acarreta sofrimento aos trabalhadores, custos às empresas, aos sistemas previdenciário e assistencial de saúde. Os autores, pela relevância do tema, elaboraram este artigo de revisão bibliográfica dando ênfase ao embasamento teorico-conceitual e à experiência de especialistas.The occupational low back pain presents multifactorial aetiology, important prevalence and incidence. Characterized by pain of varying duration and intensity, low back pain may lead to disability. Low back pain causes suffering to workers, implies costs to companies, to the social security and health assistance system. Because of the theme's relevance, the authors have elaborated this review of literature with emphasis on a theoretical and conceptual basis, as well as experience of experts.

  13. Identità di genere in adolescenza: Lo sguardo di Tiresia sul maschio e la femmina

    Directory of Open Access Journals (Sweden)

    Arturo Casoni

    2015-12-01

    Full Text Available Nell’articolo la riflessione sul genere parte da Tiresia, l’indovino del ciclo mitologico di Edipo che ha attraversato sia la condizione di maschio sia di femmina, e che viene identificato come supposto sapiente al riguardo. Quindi si propone un panorama di ciò che è stato detto di innovativo sul tema negli ultimi cento anni, da Freud alla Queer Theory, passando per Simone de Beauvoir, il ‘femminismo psicoanalitico’, Lacan. Ciò che emerge è che, se molto è cambiato nella percezione del gender, ancora molto rimane insoluto riguardo agli stereotipi maschio/femmina, alle “gabbie” del genere e ai drammi da esse prodotti. Un cardine per riattivare la riflessione innovativa è - a proposito di ‘complesso di Edipo, momento di costruzione dell’identità di genere specialmente in età adolescenziale - trovare uno spazio teorico a ciò che possiamo definire l’originaria bisessualità dei ruoli genitoriali.

  14. Introduzione al laboratorio di fisica misure e teoria delle incertezze

    CERN Document Server

    Ciullo, Giuseppe

    2014-01-01

    Frutto dell'esperienza decennale come supporto per la didattica di laboratori di fisica sia a livello di corsi triennali che di corsi di laurea magistrale, il libro si è concretizzato nella "responsabilità" di tali corsi di laboratorio per fornire un opera di utilizzo dei vari strumenti, che un approccio sperimentale alla fisica richiede. Si parte dalla descrizione delle problematiche delle incertezze in modo operativo e si introducono i concetti fondamentali per l'analisi dei dati e la misura. Invece di una serie dispersiva di testi, con approcci, convenzioni e simbolismi differenti, poco fruibili per l'applicazione diretta ad un laboratorio dei primi anni, il libro fornisce le indicazioni utili per affrontare lo studio dei fenomeni fisici in modo immediato, fornendo anche indicazioni rigorose e giustificazioni teoriche. Lo stimolo teorico-pratico, che uno sperimentale-scienziato deve percepire, non esula dal comprendere problematiche di maggiore approfondimento. L'opera rende fruibili concetti e strumenti...

  15. Lezioni di Cosmologia Teorica

    CERN Document Server

    Gasperini, Maurizio

    2012-01-01

    Il libro è basato sulle lezioni attualmente tenute dall'autore presso l’Università di Bari, ed è progettato in modo da rappresentare un testo di riferimento il più possibile moderno, completo e autosufficiente per i corsi semestrale di Cosmologia, Astrofisica o Fisica Astroparticellare che compaiono nel piano di studi della Laurea Magistrale in Fisica e in Astronomia. Contiene gli elementi di base della cosmologia relativistica, del modello cosmologico standard e del suo completamento inflazionario. E' organizzato per servire da traccia ad un corso di cosmologia di stampo teorico, ma cerca di non perdere mai di vista il confronto con i principali risultati osservativi: molta attenzione viene infatti dedicata alla fenomenologia dei fondi cosmici, e in particolare alla  radiazione gravitazionale fossile perché la sua rivelazione, diretta o indiretta, potrebbe dare indicazioni  cruciali sulla scelta del corretto modello per l'Universo primordiale. Non mancano infine alcuni accenni ad argomenti di inter...

  16. Estudo químico de duas plantas medicinais da amazônia: Philodendron scabrum k. Krause (araceae e Vatairea guianensis aubl. (fabaceae Chemical study of two Amazonian medicinal plants: Philodendron scabrum K. Krause (Araceae and Vatairea guianensis Aubl. (Fabaceae

    Directory of Open Access Journals (Sweden)

    Ivonei Ottobelli

    2011-01-01

    Full Text Available Este trabalho relata o estudo químico de duas plantas medicinais da Amazônia: Philodendron scabrum K. krause (Araceae e Vatairea guianensis Aubl. (Fabaceae. As composições dos óleos essenciais dos cipós de P. scabrum e dos frutos de V. guianensis, respectivamente, foram analisadas em CG-DIC e CG-EM. Os constituintes majoritários dos cipós de P. scabrum foram óxido de cariofileno (19,42%, α-copaeno (16,08% e β-bisaboleno (10,01%; e nos frutos de V. guianensis foram o ácido (9Z-octadecenoico (24,95% e o ácido docosahexaenoico (24,17%. β-sitosterol e o alquilresorcinol 1-hexadecanoil-2,6-dihidroxibenzeno foram isolados do extrato etanólico dos cipós de P. scabrum; e do extrato etanólico dos frutos de V. guianensis, foram isoladas as antraquinonas crisofanol e fisciona. As determinações estruturais foram baseadas em dados de RMN de ¹H e 13C. RMN, uni e bidimensional e comparação com dados da literatura.This work describes the chemical study of two medicinal plants of the Amazon Philodendron scabrum K. Krause (Araceae and Vatairea guianensis Aubl. (Fabaceae. Essential oils composition from stems of Philodendron scabrum K. Krause (Araceae and fruits of Vatairea guianensis Aubl. (Fabaceae, respectively were analyzed in GC-FID and GC-MS. The major constituents from stems of P. scarabum were caryophyllene oxide (22.42%, α-copaene (16.08% and β-bisabolene (12.01% and from fruits of V. guianensis were (9Z-octadecenoic acid (24.95% and docosahexenoic acid (24.17%. β-sitosterol and alkylresorcinol 1-hexadecanoyl-2,6-dihydroxybenzene were isolated from ethanolic extracts from stems of P. scabrum and from ethanolic extracts from fruits of V. guianensis, the athraquinones chrysophanol and physcion were isolated. The structure of isolated compounds we determinate wered based on data from ¹H and 13C NMR, including two dimensional analyses and comparison with literature data.

  17. Does a patent foramen ovale matter when using a remote-controlled magnetic system for pulmonary vein isolation?

    Science.gov (United States)

    Gate-Martinet, Alexie; Da Costa, Antoine; Romeyer-Bouchard, Cécile; Bisch, Laurence; Levallois, Marie; Isaaz, Karl

    2014-02-01

    Pulmonary vein isolation (PVI) takes longer when using a patent foramen ovale (PFO) compared with a transseptal puncture in paroxysmal atrial fibrillation (AF) with manual catheter ablation. To our knowledge, no data exist concerning the impact of a PFO on AF ablation procedure variables when using a remote magnetic navigation (RMN) system. To assess the impact of a PFO when using an RMN system in patients requiring AF ablation. Between December 2011 and December 2012, catheter ablation was performed remotely using the CARTO(®) 3 system in 167 consecutive patients who underwent PVI for symptomatic drug-refractory AF. The radiofrequency generator was set to a fixed power ≤ 35 W. The primary endpoint was wide-area circumferential PVI confirmed by spiral catheter recording during ablation for all patients and including additional lesion lines (left atrial roof) or complex fractionated atrial electrograms for persistent AF. Secondary endpoints included procedural data. Mean age 58±10 years; 18% women; 107 (64%) patients with symptomatic paroxysmal AF; 60 (36%) with persistent AF; CHA2DS2-VASc score 1.2 ± 1. The PFO presence was evidenced in 49/167 (29.3%) patients during the procedure but in only 26/167 (16%) by transoesophageal echocardiography. Median procedure time 2.5 ± 1 hours; median total X-ray exposure time 14 ± 7 minutes; transseptal puncture and catheter positioning time 7.5 ± 5 minutes; left atrium electroanatomical reconstruction time 3 ± 2.3 minutes; catheter ablation time 3 ± 3 minutes. No procedure time or X-ray exposure differences were observed between patients with or without a PFO during magnetic navigation catheter ablation. X-ray exposure time was significantly reduced using a PFO compared with double transseptal puncture access. A PFO does not affect magnetic navigation during AF ablation; procedure times and X-ray exposure were similar. Septal catheter probing is mandatory to limit X-ray exposure and prevent potential complications

  18. Estudio y optimización de los parámetros de reacción para la obtención de material geopolimérico

    Directory of Open Access Journals (Sweden)

    Beleña, I.

    2004-04-01

    Full Text Available The alkali activation of some bulk clays at room pressure and temperature leads to high strength cementitious materials called geopolymers. These inorganic polymers consist of 3D polysialate framework.. Literature concerning this kind of materials is mainly based on patents because of their industrial interest. Influence of several composition parameters (SiO2/Al2O3, Na2O/Al2O3 y H2O/Na2O in the structure and properties of geopolymeric materials, synthesised from metakaolinite and sodium silicate in a highly alkaline environment, has been studied by XRD, 27Al y 29Si-NMR and MES. Process for the obtention of geopolymeric pieces has been optimised varying the cured and drying conditions, obtaining likeceramic products. The different geopolymerization reaction periods have been followed by 27Al y 29Si-NMR.

    La activación alcalina en condiciones de presión y temperatura próximas a las ambientales de algunas arcillas calcinadas da lugar a materiales cementantes de altas prestaciones mecánicas constituidos por redes 3D polisialato-siloxo, también denominados geopolímeros. En el presente trabajo se ha analizado la influencia de diferentes parámetros de composición (SiO2/Al2O3, Na2O/Al2O3 y H2O/Na2O, sobre la naturaleza de los materiales formados a partir de metacaolinita y silicato sódico en medio fuertemente alcalino (NaOH mediante DRX, 27Al y 29Si-RMN y MEB. Se ha optimizado el proceso de obtención de piezas geopoliméricas variando las condiciones de curado y secado, obteniéndose materiales de características comparables a los cerámicos. El seguimiento de la reacción con el tiempo mediante 27Al y 29Si-RMN mostró tres etapas bien diferenciadas de disolución, nucleación y polimerización.

  19. Diseño de rotor para un aerogenerador de bajas velocidades

    Directory of Open Access Journals (Sweden)

    Hugo A. Arevalo

    2009-01-01

    Full Text Available En los ultimos afios ha existido un creciente interes en el disefio y el estudio de turbinas eólicas de baja velocidad debido a la mayor cantidad de lugares donde este potencial eólico esta presente. Usando elementos de Ia teoría de momentum del alabe (BEM y la teoría de la circulación, este articulo describe un metodo basado en el analisis del cambio de circulación y momentum a traves de cada estación del alabe, permitiendo calculos mas precisos y optimizando así el rendimiento del rotor en turbinas eólicas de eje horizontal, baja velocidad de viento y paso fijo. La comparaci6n de los resultados obtenidos con datos provenientes de turbinas eólicas reales muestra una alta similitud.

  20. Gradually varied flow in compound open channels; Flujo gradualmente variado en canales de seccion compuesta

    Energy Technology Data Exchange (ETDEWEB)

    Sotela Avila, Gilberto [Universidad Nacional Autonoma de Mexico (Mexico)

    2001-03-01

    The author shows that the computation of gradually-varied-flow profiles in prismatic compound channels involves the solution of the dynamic equation, but using the compound channel Froude number defined by Blalock and Sturm. The same equation is used for non-prismatic channels by dividing the channel into short reaches and carrying the computation step by step through an iterative process. [Spanish] El autor demuestra que los perfiles del flujo gradualmente variado en canales prismaticos de seccion compuesta se pueden determinar mediante la integracion de la llamada ecuacion dinamica, pero usando el numero de Froude definido por Blalock y Sturm para este tipo de canales. Cuando no son prismaticos, tambien se aplica la ecuacion de la energia por tramos y el calculo sigue un proceso iterativo una vez definidos los tirantes criticos multiples y la zona en que se desarrolla el perfil.

  1. Experimental determination of Ramsey numbers.

    Science.gov (United States)

    Bian, Zhengbing; Chudak, Fabian; Macready, William G; Clark, Lane; Gaitan, Frank

    2013-09-27

    Ramsey theory is a highly active research area in mathematics that studies the emergence of order in large disordered structures. Ramsey numbers mark the threshold at which order first appears and are extremely difficult to calculate due to their explosive rate of growth. Recently, an algorithm that can be implemented using adiabatic quantum evolution has been proposed that calculates the two-color Ramsey numbers R(m,n). Here we present results of an experimental implementation of this algorithm and show that it correctly determines the Ramsey numbers R(3,3) and R(m,2) for 4≤m≤8. The R(8,2) computation used 84 qubits of which 28 were computational qubits. This computation is the largest experimental implementation of a scientifically meaningful adiabatic evolution algorithm that has been done to date.

  2. Magnetic structures of Er{sub 6}Mn{sub 23} and Dy{sub 6}Mn{sub 23}

    Energy Technology Data Exchange (ETDEWEB)

    Ouladdiaf, B. [Institut Max von Laue - Paul Langevin, 38 - Grenoble (France); Deportes, J. [Laboratoire de Magnetisme L. Neel, C.N.R.S., BP 166, 38042 Grenoble Cedex 9 (France); Rodriguez-Carvajal, J. [Institut Max von Laue - Paul Langevin, 38 - Grenoble (France)]|[Laboratoire Leon Brillouin (CEA-CNRS), Centre d`Etudes de Saclay, Gif sur Yvette (France)

    1995-08-01

    The R{sub 6}Mn{sub 23} (R=rare earth) compounds crystallize in the cubic Th{sub 6}Mn{sub 23}-type structure with space group Fm3m. Powder neutron-diffraction experiments were performed on Dy{sub 6}Mn{sub 23} and Er{sub 6}Mn{sub 23}. The magnetic unit cell coincides with the chemical one. The R moments have a ferromagnetic non-collinear arrangement, whereas the Mn moments are parallel to the [1 1 1] direction. The magnetic structures belong to the three-dimensional {Gamma}{sub 5g} irreducible representation of Fm3m associated with the wave vector K=[0 0 0]. The spin configurations in both compounds result from the competition between the R-R, R-Mn magnetic interactions and the crystal electric field on the R ions. (orig.).

  3. Upgrade programs. Status and prospective

    International Nuclear Information System (INIS)

    Loyer, F.

    1998-01-01

    Arguments for launching a renovation program for GANIL system, taking into account aging and wear, are analyzed. A statistics of failures related to vacuum systems, power supplies, electronics, cooling systems, beam dumps and other equipment is given. The renovation program is targeted to: replacement of obsolete components, introduction of advanced systems of failure diagnosis, augmentation of performances of the new regulating and control system and improvement in the performance characteristics of certain fundamental equipment. The first results and to date status of the program development is reported. Mentioned are the works related to control of HF cavities and the associated amplifiers, electronics, the system of cavity synchronization, power supply, RMN, system commutation grid, pumping equipment, etc. Also, improvements concerning the machine data acquisition and online processing are referred to as well as program cost estimations

  4. Isolamento biomonitorado de alcalóides tóxicos de Prosopis juliflora (algaroba

    Directory of Open Access Journals (Sweden)

    I.M. Tabosa

    Full Text Available Uma investigação fitoquímica das vagens de Prosopis juliflora cultivada na região semi-árida do Estado da Paraíba e monitorada através de testes farmacológicos levou ao isolamento, purificação e identificação do alcalóide principal juliprosopina. A presença de outros constituintes químicos em mistura, tais como juliprosina e juliprosineno, foi verificada na fração dos alcalóides totais através de uma análise do espectro de RMN de 13C. Este trabalho sugere que a toxicidade, observada em animais de laboratório, está quimicamente relacionada com os alcalóides piperidínicos presentes nas vagens desta leguminosa.

  5. Study of the reaction between polyethylene glycol and epoxy resins using N,N-dimethylbenzylamine as catalyst

    International Nuclear Information System (INIS)

    Zacharuk, Mario; Coelho, Luiz A.F.; Pezzin, Sergio H.; Becker, Daniela

    2009-01-01

    In this work the use of N,N-dimethylbenzylamine as a catalyst of the reaction of polyethylene glycol (PEG) and epoxy resin (DGEBA) was studied. The reaction products were evaluated by infra-red spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR) and viscosity measurements. Samples cured with a polyamine-based hardener were also submitted to tensile tests and differential scanning calorimetry (DSC). The results of the viscosity analyses, FTIR and RMN ( 1 H) had confirmed the occurrence of the reaction between DGEBA epoxy groups and PEG hydroxyl groups in the presence of N, N-dimethylbenzylamine as catalyst, at 100 deg C. DSC analyses and tensile tests of cured systems showed that the reaction of DGEBA with PEG leads to a reduction of the Tg, generating a more flexible material. (author)

  6. Geothermal potential in Mexico; Potencial geotermico de la republica mexicana

    Energy Technology Data Exchange (ETDEWEB)

    Ordaz Mendez, Christian Arturo; Flores Armenta, Magaly; Ramirez Silva, German [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)]. E-mail: christian.ordaz@cfe.gob.mx

    2011-01-15

    parte de la estrategia de la CFE para incrementar la generacion de energia electrica mediante fuentes no convencionales llevo a cabo un calculo del potencial geotermico del pais. Este calculo se efectuo a traves del inventario nacional de manifestaciones termales con que cuenta la GPG, el cual ha permitido identificar 1380 manifestaciones termales distribuidas en todo el pais, con informacion de las temperaturas tomadas superficialmente y las temperaturas obtenidas por medio de geotermometros. El calculo del potencial geotermico se hizo con base en la clasificacion de estas manifestaciones por rangos de temperatura geotermometrica, obteniendose asi recursos de alta, media y baja entalpia. Posteriormente se utilizo el metodo volumetrico para obtener el potencial geotermico nacional. Los resultados indican que para las Reservas Posibles los recursos de alta entalpia ascienden a 5691 MWe, para los de moderada entalpia son de 881 MWe y los de baja entalpia de 849 MWe dando un total de 7422 MWe. Por otra parte, las Reservas Probables para el recurso de alta entalpia son de 1643 MWe, para los de moderada entalpia de 220 MWe y para los de baja entalpia de 212 MWe dando un total de 2077 MWe. Por ultimo las Reservas Probadas se tomaron como la capacidad adicional que puede instalarse en cada uno de los campos geotermicos conocidos, dando un total de 186 MWe. La informacion se proceso y se integro por medio del Sistema de Informacion Geografica (SIG) ArcGis 9.2 (c), dando como resultado la publicacion via Intranet del Mapa del Potencial Geotermico de la Republica Mexicana.

  7. AnGel System for the diagnosis of generators in operation; Sistema AnGeL para el diagnostico de generadores en operacion

    Energy Technology Data Exchange (ETDEWEB)

    De la Torre V, H. Octavio; Ramirez N, J. Tomas; Pascacio de los S, Alberth; Reyes M, Oscar A; Carrillo C, Jaime; Iturbe F, Marlene [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Ponce de Leon V, Eugenio [Comision Federal de Electricidad (Mexico)

    2005-07-01

    The continuous monitoring of the electrical variables of a generator allows the knowing of the operating status of the main components of the equipment, which is helpful at the time of emitting a diagnosis of the same one. System of diagnosis for generators of operation, denominated AnGel System (acronym of Analysis of Generators in Line). The system was developed by the Management of Electrical equipment of the Instituto de Investigaciones Electricas (IIE) and implemented in the six units of generation of the Manzanillo Thermoelectric Unit. The present article includes a description of the main components and functions. The world-wide tendency in monitoring systems of the fault statistics, were key elements in defining the variable to be monitored: Partial discharges (PD), Shaft current (SC), Neutral current (NC), Tangential Magnetic (TM) flux, Voltages and currents of line (as reference to the operation point). The main processes of deterioration that are intended to be observed with each one of these variables are described with greater thoroughness in the article Sistema AnGel: Aspectos teorico-practicos para el diagnostico de generadores en operacion (AnGel System: Theoretical-practical aspects for the diagnosis of generators in operation), contained in the section of Research Activities in this same issue of the IIE bulletin. [Spanish] La monitorizacion continua de las variables electricas de un generador permite conocer el estado operativo de los principales componentes del equipo, lo que es de ayuda a la hora de emitir un diagnostico del mismo. Sistema de diagnostico para generadores de operacion, denominado Sistema AnGeL (acronimo de Analisis de Generadores en Linea). El sistema fue desarrollado por la Gerencia de Equipos Electricos del IIE e implementado en las seis unidades de generacion del Complejo Termoelectrico Manzanillo. El presente articulo incluye una descripcion de los principales componentes y funciones. La tendencia mundial en sistemas de

  8. Particularidades del cálculo de engranajes plásticos. // Particularities of plastic gear calculation.

    Directory of Open Access Journals (Sweden)

    J. L. Moya Rodríguez

    2003-05-01

    Full Text Available En los últimos tiempos los materiales plásticos han tenido una proliferación en todos los campos de la Industria Mecánica,debido esencialmente a su bajo costo y a las mejoras de las propiedades mecánicas que se han ido logrando. En el casoparticular de las transmisiones por engranajes existe una gran cantidad de estos materiales que pueden ser usados y dehecho se utilizan para la fabricación de ruedas dentadas de características muy disímiles. En la literatura científica existemuy poca información disponible sobre las fallas de engranajes plásticos, métodos de calculo a resistencia y posiblesmateriales a emplear con sus respectivas propiedades mecánicas. Inclusive este tema no se aborda en los currículos deestudio tradicionales en Ibero-América. Queda mucho por discutir aun acerca del empleo de las correcciones del dentado enestas ruedas dentadas plásticas. En el presente trabajo se hace un análisis de los materiales, características, estudio de lasfallas principales, métodos de calculo y ejemplos de aplicación de los engranajes plásticos.Palabras claves: Plásticos, engranes, perfil dentado.__________________________________________________________________________Abstract.Recently the use of plastic materials has been growing up due to their low cost and the improvements achieved on theirmechanical properties. In the particular case of gear transmissions there are great quantities of polymers that can be usedfor gears. Plastic gears are powerful means of cutting drive cost, weight, noise, and wear. Plastic gears also open newopportunities for smaller and more efficient transmissions. There is few information in Scientific literature about plasticgears failures, designing methods and materials. Most engineering reference books are desicated to steel gears but there areremarkably silent about plastic gears. Design methods for plastic gears and gear trains must be modernized, because muchof the information available is derived

  9. EL PAPEL DE LOS MUNICIPIOS COLOMBIANOS EN LA PLANEACION Y GESTION DEL DESARROLLO LOCAL: SUS FUNDAMENTOS TEORICO-CONCEPTUALES

    Directory of Open Access Journals (Sweden)

    Oscar Hernan Muñoz

    2001-07-01

    Full Text Available A partir de la crisis de los paradigmas del desarrollo y el neoliberalismo se dio un cambio en el tratamiento del desarrollo, visto como “un desarrollo a escala humana”, que acepta lo global, lo regional y lo local. Este nuevo enfoque del Desarrollo Local Endógeno permite reforzar la capacidad de la localidad para buscar formas autónomas de Desarrollo económico, social, político, etc., con base en la utilización plena de sus recursos. Dentro de este contexto se identifican seis condiciones básicas, que permiten potenciar el Desarrollo Local Endógeno: existencia de un tejido humano dinámico; identidad social; existencia de centros sociales dinámicos; densidad y diversidad de redes de información; capacidad social para asimilar cambios y el grado de diversificación del mercado de trabajo. Al mismo tiempo, se presentan factores que pueden obstaculizar el desarrollo como: bajos niveles de formación del recurso humano; carencias en el acopio y procesamiento de información; escaso desarrollo de la planificación y de gestión pública y privada, entre otros. Para abordar el estudio del Desarrollo Local Endógeno es necesario analizar la dinámica interna y sus interrelaciones con otros espacios. A escala interna se analizan aspectos locales relacionados con los recursos materiales y humanos, el poder y la organización social local y las relaciones económicas. A escala externa, el análisis del Desarrollo Local abarca elementos relacionados con vías de acceso; control y manejo del transporte y aprovechamiento de productos y personas; capacidad de liderazgo político y económico; sistemas locales de información y políticas de apoyo al desarrollo social. Un factor básico de la planeación y gestión del Desarrollo Local es el relacionado con la construcción de procesos de comunicación entre los actores locales, públicos, privados y comunitarios. La nueva lógica de la planeación tiene como objetivo la estructuración de “formas de autopedagogía colectiva” que lleven a los agentes a desarrollar una conciencia colectiva de su territorio y de su porvenir. En Colombia, el ordenamiento constitucional y el enfoque del Desarrollo Local Endógeno, les confieren a los municipios un papel preponderante en la planeación y gestión del desarrollo local; es decir, que el municipio debe ser, por excelencia, el espacio propicio para la formulación y ejecución de una verdadera política social, que brinde respuestas oportunas y concretas a las necesidades y expectativas de la comunidad local. Dentro de este contexto, las administraciones locales deben articular de una manera clara y coherente todas las acciones dirigidas específicamente a la promoción del desarrollo social del municipio, concertando con las entidades privadas locales las políticas, programas e instrumentos de empleo.

  10. Theoretical fundamentals for the new regulation of the electric power sector; Fundamentos teoricos de la nueva regulacion electrica

    Energy Technology Data Exchange (ETDEWEB)

    Perez Arriaga, J.I.

    1998-12-01

    Regulatory models for the electric power industry throughout the world are experiencing significative changes at a umprecedented pace. It is then justified to speak of a new regulation of the electric power sector, with features of its own. This paper presents the theoretical background for this new regulation, focusing on the identification characterization and analysis of the several activities comprised in electricity supply, as well as the most suitable regulatory approach for each one of them. (Author)

  11. Pressure induced magneto-structural phase transitions in layered RMn2X2 compounds (invited)

    International Nuclear Information System (INIS)

    Kennedy, Shane; Wang, Jianli; Campbell, Stewart; Hofmann, Michael; Dou, Shixue

    2014-01-01

    We have studied a range of pseudo-ternaries derived from the parent compound PrMn 2 Ge 2 , substituting for each constituent element with a smaller one to contract the lattice. This enables us to observe the magneto-elastic transitions that occur as the Mn-Mn nearest neighbour distance is reduced and to assess the role of Pr on the magnetism. Here, we report on the PrMn 2 Ge 2−x Si x , Pr 1−x Y x Mn 2 Ge 2 , and PrMn 2−x Fe x Ge 2 systems. The pressure produced by chemical substitution in these pseudo-ternaries is inherently non-uniform, with local pressure variations dependent on the local atomic distribution. We find that concentrated chemical substitution on the R or X site (e.g., in Pr 0.5 Y 0.5 Mn 2 Ge 2 and PrMn 2 Ge 0.8 Si 1.2 ) can produce a separation into two distinct magnetic phases, canted ferromagnetic and canted antiferromagnetic, with a commensurate phase gap in the crystalline lattice. This phase gap is a consequence of the combination of phase separation and spontaneous magnetostriction, which is positive on transition to the canted ferromagnetic phase and negative on transition to the canted antiferromagnetic phase. Our results show that co-existence of canted ferromagnetic and antiferromagnetic phases depends on chemical pressure from the rare earth and metalloid sites, on local lattice strain distributions and on applied magnetic field. We demonstrate that the effects of chemical pressure bear close resemblance to those of mechanical pressure on the parent compound

  12. Custo de capital próprio em mercados emergentes: uma abordagem empírica no Brasil com o downside risk

    Directory of Open Access Journals (Sweden)

    Graziela Xavier Fortunato

    2010-02-01

    Full Text Available Este artigo visa testar empiricamente a proposta de Estrada (2000 para as empresas que compoem o Ibovespa, avaliando se para mercados emergentes existem outras medidas de risco sistematico diferentes do beta do capital asset pricing model (CAPM. Dessa forma, testou-se o downside risk que capta a parte negativa do retorno. Alem de dados em cross section, utilizaram-se dados em painel, como uma contribuição adicional ao trabalho de Estrada (2000. Os resultados encontrados não confirmam que o downside risk seja uma medida apropriada ao mercado brasileiro. Outras medidas de risco apresentaram melhor correlacao com o retorno, permitindo o calculo do custo de capital com valor diferente daquele obtido pela aplicacao do beta. De acordo com Estrada (2000, os resultados sugerem que os mercados emergentes estao em posicao intermediaria entre os mercados integrados e segmentados, tal como confirmado para o mercado brasileiro.

  13. Diagnosis of the policy for agricultural finance support in the State of Paraná during the 80's values, credit liberation and financial costs Diagnóstico da política de crédito de custeio agrícola no Paraná na década de 80: valores, liberações e encargos financeiros

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Moretto

    1990-08-01

    Full Text Available This paper is meant to analyze the development of the credit policy for small producers of six major cultures in the state of Paraná during the 80's. A comparative analysis official/ norms for the basic cost value in relation to the real financial obligations established by OCEPA R IOCB along with the agricultural seasonal plan of the State was made in this work. Este artigo se propõe a analisar o desempenho da pol/tica de crédito de Custeio para os pequenos produtores das seis principais culturas do Estado do Paraná, na década de 80, baseando-se na análise comparativa das normas oficiais para o Valor Básico de Custeio (VBC com as planilhas de calculo do Desembolso Real do Agricultor (ORA elaboradas pela OCEPAR/OCB e com o calendário agrícola do Estado.

  14. Probabilistic fracture mechanics in the integrity evaluation of components; Mecanica de fractura probabilista en la evaluacion de la integridad de componentes

    Energy Technology Data Exchange (ETDEWEB)

    Franco Nava, Jose Manuel; Torres Toledano, Jose Gerardo; Sanchez Sanchez, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    Because of the importance of fracture mechanics in applications to pressure vessels, piping and other components used in thermal power plants, the Mechanical Engineering Unit of the Instituto de Investigaciones Electricas (IIE) has been developing activities in this field since some years ago. In this paper, the process for the analysis of probabilistic fracture mechanics is described. As an example, an application to the calculation of fault probability in piping systems, is presented. [Espanol] Dada la importancia de la mecanica de fractura en aplicaciones de recipientes a presion, tuberias y otros componentes utilizados en centrales termicas, la Unidad de Ingenieria Mecanica del Instituto de Investigaciones Electricas (IIE) ha venido desarrollando actividades en este campo desde hace algunos anos. En el presente trabajo, se describe el proceso para el analisis de mecanica de fractura probabilista. Como ejemplo se presenta una aplicacion al calculo de probabilidad de falla en tuberias.

  15. Local IgG synthesis in three pediatric patients with cuban epidemic neuropathy Sintesis local de IgG en tres pacientes pediátricos com neuropatía epidêmica cubana

    Directory of Open Access Journals (Sweden)

    Alberto Dorta-Contreras

    1996-03-01

    Full Text Available Three pediatric patients with Cuban epidemic neuropathy were studied. Cerebrospinal fluid and sera were simultaneously obtained. Albumin and IgG were quantified by immunodifusion. Albumin quotient and local synthesis of IgG were calculated by Reiber/Felgenhauer formula. A patient with optic neuritis had a dysfunction of the blood-cerebrospinal fluid barrier. All the group had local synthesis of IgG.Se estudiaron tres pacientes pediátricos con neuropatia epidêmica cubana. Se obtuvieron suero y liquido cefalorraquídeo simultaneamente. Se cuantificaran los niveles de albúmina e IgG por inmunodifusion radial. Se calculo la razón albúmina y la fórmula de Reiber/Felgenhauer. Un paciente con neuritis óptica tuvo una disfunción de la barrera sangre-líquido cefaloraquídeo. Todo el grupo tuvo síntesis local de IgG.

  16. Probabilistic fracture mechanics in the integrity evaluation of components; Mecanica de fractura probabilista en la evaluacion de la integridad de componentes

    Energy Technology Data Exchange (ETDEWEB)

    Franco Nava, Jose Manuel; Torres Toledano, Jose Gerardo; Sanchez Sanchez, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    Because of the importance of fracture mechanics in applications to pressure vessels, piping and other components used in thermal power plants, the Mechanical Engineering Unit of the Instituto de Investigaciones Electricas (IIE) has been developing activities in this field since some years ago. In this paper, the process for the analysis of probabilistic fracture mechanics is described. As an example, an application to the calculation of fault probability in piping systems, is presented. [Espanol] Dada la importancia de la mecanica de fractura en aplicaciones de recipientes a presion, tuberias y otros componentes utilizados en centrales termicas, la Unidad de Ingenieria Mecanica del Instituto de Investigaciones Electricas (IIE) ha venido desarrollando actividades en este campo desde hace algunos anos. En el presente trabajo, se describe el proceso para el analisis de mecanica de fractura probabilista. Como ejemplo se presenta una aplicacion al calculo de probabilidad de falla en tuberias.

  17. ESTUDIO TEÓRICO DE LA MOLÉCULA DE HIDROGENO CALCULO AB-INITIO

    Directory of Open Access Journals (Sweden)

    N. Quitián

    2010-09-01

    Full Text Available Utilizando la técnica LCGO-SCF-MO (Combinación Lineal de los Orbitales Moleculares en Orbitales Gausianos, en el método del Campo Auto-Coherente, se determinaron las energías de orbital, la energía electrónica total, la energía de repulsión nuclear y la energía de Hartree-Fock de la molécula de hidrógeno en su estado fundamental, mediante un cálculo ab initio y utilizando una base de funciones gausianas. Los orbitales moleculares fueron desarrollados en términos de una función Is contraída por átomo de hidrógeno, obtenida por la minimización de los coeficientes y de los exponentes de los orbitales gausianos para el átomo aislado. Los resultados obtenidos nos permiten afirmar que la base molecular mejora sensiblemente los resultados, acercándose más al límite de Hartree-Fock.

  18. Sugarcane exergy calculation; Calculo de la exergia de la cana de azucar

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez P, Maria I.; Nebra P, Silvia A. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mails: mariai@fem.unicamp.br.; sanebra@fem.unicamp.br; Martinez R, Arnaldo [Universidade de Oriente, Santiago de Cuba (Cuba). Facultad de Ingenieria Mecanica. Centro de Estudios de Refrigeracion Luis Fernando Brossard Perez]. E-mail: arnaldo@fim.ceefe.uo.edu.cu

    2000-07-01

    This paper presents a sugarcane exergy calculation, carried out considering the material as constituted by dry fiber and juice, being the last one that includes all the sucrose and water present in sugarcane. The variation intervals of sugarcane chemical composition and consequently the chemical composition of fibre and juice were obtained from a bibliography research. the finals results show that, the fibre exergy, as was considered totally dry and without sucrose, is a function of it chemical composition only. The quotient between the exergy and low calorific value has a middle value of 1,14 and the middle value of it exergy was 2329 kJ/kg of cane. Based on the environmental reference proposed by Szargut for the sugarcane juice exergy determination, it was obtained that the mixture component of the juice exergy has no piratical influence in the total exergy juice value, being the value of the reactive exergy component the determining of a middle value of sugarcane juice exergy of 2814,25 kJ/kg of juice and 2380Kj/Kg of cane. The sugarcane exergy value obtained for 8-18% of fiber, 75-82% of water and 14.5-22% of sucrose was 4709Kj/kg of cane. (author)

  19. Calculo de Parámetros Electrónicos Para el Grafito Bernal

    Directory of Open Access Journals (Sweden)

    Claudia Villaquirán

    2002-06-01

    Full Text Available Using ab-initio calculation, we have computed different electronic parameters associated with the transport coefficients of graphite Bernal. Software CRYSTAL¹ was used with a Pople standard STO- 21G* basis set. Different hamiltonians were tested, choosing a restricted Hartree-Fock one, because it generated the best qualitative results. All graphites studied present a valence bandwidth near 0.60 a.u., in agreement with the literature. In hexagonal Bernal graphite the splitting of the valence P band was accentuated, and E F = -0.00140 a.u. The surface Fermi is located around the HKH edge of the first Brillouin zone. In general such surfaces present a central electron orbit of maximal size in the plane, which diminish in size when the z component of the vector moves in KH direction. Integrating on the surface Fermi calculates the time relaxation parallel and the time relaxation perpendicular and finally we evaluate the parallel and perpendicular resistivity.

  20. Shielding calculations using computer techniques; Calculo de blindajes mediante tecnicas de computacion

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Portilla, M. I.; Marquez, J.

    2011-07-01

    Radiological protection aims to limit the ionizing radiation received by people and equipment, which in numerous occasions requires of protection shields. Although, for certain configurations, there are analytical formulas, to characterize these shields, the design setup may be very intensive in numerical calculations, therefore the most efficient from to design the shields is by means of computer programs to calculate dose and dose rates. In the present article we review the codes most frequently used to perform these calculations, and the techniques used by such codes. (Author) 13 refs.

  1. SYNTHESIS AND CHARACTERIZATION OF NEW HALOGENATED CURCUMINOIDS

    Directory of Open Access Journals (Sweden)

    Eugenio Torres

    2013-12-01

    Full Text Available In this work a novel procedure of synthesis of compounds analogues to curcumin with halogens atoms in its structure is described, which can increase its solubility and biological activity. Four halogenated curcuminoids were obtained with great pharmacological interest, none of them reported in literature before. Synthesis was carried out by means of the aldol condensation assisted by microwaves of halogenated aromatic aldehydes and acetylacetona, using morpholine as basic catalyst, in absence of solvent, and the reaction just needed 1 min. The products were purified by treatment of the reaction mixture with methanol under ultrasound irradiation, followed by chromatographic column. All obtained compounds were characterized by infrared spectroscopy, nuclear magnetic resonance, quantitative elementary analysis and high resolution mass spectrometry. The RMN-1H data demonstrate in all structures of synthesized curcuminoids the enol form is the most favored.

  2. Virtualization Shares: Feasibility and Implementation in the USNA Computer Science Department

    Science.gov (United States)

    2010-03-10

    td by ",ing ’"" """" . .. IiI< .rur. for ImŜ"’. ’ ’’’’’’ rm ..... Inta rnot’t . dvn::r d om,lt",t"", provtd«f by vS;>h< "’. ’Ill...rn rr4lO ", d rr. 32 (1 ..... T<irn> would con!oi" 01 4 Pf<lIlIo, 0< oown-t<" many ." . t on. ",bl,. 5<,.". t..ti𔃻l lo< [II< """"" o"","" td 01...ult of ttl< r.mn ə th< lab or " "",I.." Sirxr two oot oj _. oj tb<w ~i llJ

  3. Síntesis y análisis espectroscópico de algunas borazocinas y su polimerización

    Directory of Open Access Journals (Sweden)

    C. D. Albornoz

    2009-06-01

    Full Text Available Se sintetizan una serie de borazocinas haciéndose un estudio químico y espectroscópico enRMN 1 H, infrarrojo, ultravioleta y espectroscopia de masas, mostrándose la gran estabilidad de estos compuestos y su estructura de anillo de ocho miembros. Se presenta la síntesis de un alto polímero lineal de heterocadena boro —nitrógeno, por efecto de catalizadores sobre la B-tetracloro, N-tetraterbutil borazocina. Su linealidad se explica en base a solubilidades y en los espectros vibracional y de transiciones electrónicas. Este polímero demuestra ser estable térmica y químicamente, excepto al ataque de ciertos oxidantes. Por último, se explica la estabilidad de estos compuestos, por el efecto sustituyente, tanto sobre el núcleo como sobre la cadena.

  4. Sciwora na população pediátrica após traumatismo cervical Sciwora en la población pediátrica después de traumatismo cervical Sciwora in the paediatric population after cervical trauma

    Directory of Open Access Journals (Sweden)

    Vítor Duarte Gonçalves Vidinha

    2011-01-01

    Full Text Available OBJETIVO: Avaliar a incidência e as características das lesões tipo SCIWORA nos indivíduos até os 16 anos, da área de um hospital central entre 1989 e 2009, após traumatismo cervical. MÉTODOS: Estudo retrospectivo de consulta processual. RESULTADOS: Nove (10,5% de 86 crianças apresentavam achados clínicos e radiológicos compatíveis com o diagnóstico de SCIWORA. A média de idades foi de 10,7 anos. A causa mais frequente foi o acidente de trânsito. Seis indivíduos eram classificáveis como Frankel D. Os restantes três casos eram Frankel C. Em três doentes a RMN mostrou imagem de lesão. Sete efetuaram metilprednisolona endovenosa e todos mantiveram imobilização com colar cervical até a primeira consulta de seguimento, às 2 semanas. Na alta, os seis doentes que apresentavam Frankel D à entrada melhoraram para um grau E. Dos doentes com Frankel C à entrada, um melhorou até Frankel D e os restantes dois mantiveram-se inalterados em Frankel C. CONCLUSÃO: Em um hospital de referência traumatológica, SCIWORA representa cerca de 10% das lesões cervicais pediátricas. Os défices neurológicos à entrada e a RMN têm valor prognóstico de recuperação. A corticoterapia em dose elevada não está formalmente indicada e não é consensual o tempo de utilização de imobilização ou a sua indicação em todos os SCIWORA.OBJETIVO: Evaluar la incidencia y las características de las lesiones tipo SCIWORA en los individuos de hasta 16 años de edad, del área de un hospital central, entre 1989 y 2009, después de traumatismo cervical. MÉTODOS: Estudio retrospectivo de consulta procesal. RESULTADOS: nueve (10,5% de 86 niños presentaban hallazgos clínicos y radiológicos compatibles con el diagnóstico de SCIWORA. El promedio de edades fue 10,7 años. La causa más frecuente fue el accidente de tránsito. Seis individuos eran clasificables como Frankel D. Los restantes tres casos eran Frankel C. En tres pacientes, la RMn mostr

  5. Potencial alelopático de duas neolignanas isoladas de folhas de Virola surinamensis (Myristicaceae Allelopathy potential of two neolignans isolated from Virola surinamensis (Myristicaceae leaves

    Directory of Open Access Journals (Sweden)

    F.C. Borges

    2007-03-01

    Full Text Available Este trabalho teve por objetivos isolar, identificar e caracterizar a atividade alelopática de substâncias químicas presentes nas folhas de Virola surinamensis. O processo de isolamento e identificação das substâncias químicas envolveu o uso de solventes orgânicos e de Ressonância Magnética Nuclear (RMN ¹H, RMN 13C e RMN 13C-DEPT, espectro de COSY e de HETCOR. A avaliação da atividade alelopática foi realizada em bioensaios de germinação de sementes, em condições de 25 ºC de temperatura constante e fotoperíodo de 12 horas, e de desenvolvimento da radícula e do hipocótilo, com 25 ºC de temperatura constante e fotoperíodo de 24 horas, empregando-se concentrações variando de 1,0 a 8,0 mg L-1. Como plantas receptoras, foram utilizadas as espécies daninhas Mimosa pudica, Senna obtusifolia e Senna occidentalis. Foram isoladas e identificadas duas neolignanas: a surinamensina e a virolina. A tendência geral observada nos resultados foi de aumento da intensidade dos efeitos alelopáticos inibitórios em função do aumento da concentração, com inibições máximas obtidas, sempre, na concentração de 8,0 mg L-1. A surinamensina apresentou maior potencial para inibir a germinação e o desenvolvimento da radícula e do hipocótilo do que a virolina, independentemente da espécie receptora e do fator da planta analisado. Considerando-se as intensidades dos efeitos promovidos sobre os três fatores das plantas, o desenvolvimento da radícula e o do hipocótilo foram mais intensamente inibidos pelas duas substâncias do que a germinação das sementes. À exceção dos efeitos verificados sobre o desenvolvimento do hipocótilo, malícia foi a espécie de maior sensibilidade aos efeitos alelopáticos das duas neolignanas, enquanto mata-pasto foi aquela que evidenciou inibições de menor magnitude.The objective of this research was to isolate, identify and characterize the allelopathic activity of chemical compounds in Virola

  6. cultural

    Directory of Open Access Journals (Sweden)

    Irene Kreutz

    2006-01-01

    Full Text Available Es un estudio cualitativo que adoptó como referencial teorico-motodológico la antropología y la etnografía. Presenta las experiencias vivenciadas por mujeres de una comunidad en el proceso salud-enfermedad, con el objetivo de comprender los determinantes sócio-culturales e históricos de las prácticas de prevención y tratamiento adoptados por el grupo cultural por medio de la entrevista semi-estructurada. Los temas que emergieron fueron: la relación entre la alimentación y lo proceso salud-enfermedad, las relaciones con el sistema de salud oficial y el proceso salud-enfermedad y lo sobrenatural. Los dados revelaron que los moradores de la comunidad investigada tienen un modo particular de explicar sus procedimientos terapéuticos. Consideramos que es papel de los profesionales de la salud en sus prácticas, la adopción de abordajes o enfoques que consideren al individuo en su dimensión sócio-cultural e histórica, considerando la enorme diversidad cultural en nuestro país.

  7. A IMPORTÂNCIA DA AFETIVIDADE NA RELAÇÃO ENTRE PROFESSOR E ALUNO DURANTE O PROCESSO DE ALFABETIZAÇÃO NA EDUCAÇÃO INFANTIL

    Directory of Open Access Journals (Sweden)

    Giovana Filomena dos Santos

    2017-03-01

    Full Text Available O presente trabalho tem a função de focar a interação entre professor e aluno e o papel da afetividade no desenvolvimento no processo de alfabetização. A partir do referencial teorico abordaremos a formação docente, formação cognitiva da criança, sua vivência social durante a alfabetização.Quando a acriança entra na alfabetização, deve levar em consideração os aspectos  e procedimentos anteriores, que são tão necessarios e que pode contribuir  muito para uma alfabetização mais tranquila e positiva. Para Emília Ferreiro, a construção a construção do conhecimento da escrita tem uma conexão com o individual e também com a interação social na escola, ou fora dela. A construção desse conhecimento ocorre por meio das sequências de hipóteses.

  8. Adultità e crisi dell’autorevolezza tra continuità e cambiamento

    Directory of Open Access Journals (Sweden)

    Laura Cavana

    2010-02-01

    Full Text Available In questo primo report relativo al mio segmento di ricerca, ho inteso costruire l’impianto teorico e concettuale che caratterizzerà l’orizzonte interpretativo privilegiato dei dati empirici raccolti già in questa fase, ma che verranno analizzati in un successivo resoconto. A tal fine ho cercato di muovermi su due direzioni principali: da un lato ho voluto fare emergere esplicitamente la centralità dell’adulto e della sua funzione educativa nel rapporto adulto-bambino, poiché il bambino, per il suo essere piccolo, debole, grazioso e privo di parola, è impensabile senza l’adulto, principio di guida e di organizzazione del suo sviluppo e delle sue condotte. Dall’altro lato ho individuato nella sintesi dialettica o dinamica dell’antinomia “autonomia-dipendenza” l’elemento spia, o variabile significativa, degli stili educativi adulti (agiti, nella fattispecie, dai genitori, dalle insegnanti, dalle educatrici rilevati empiricamente in alcuni servizi per l’infanzia del Nord e del Sud d’Italia, mediante la somministrazione di interviste semistrutturate alle insegnanti e alle educatrici.

  9. Per una didattica del melodramma. Idee e percorsi

    Directory of Open Access Journals (Sweden)

    Giorgio Pagannone

    2011-04-01

    Full Text Available Il presente intervento ha lo scopo di mettere a fuoco alcune questioni di fondo sulla didattica del melodramma e di formulare alcune ipotesi metodologiche approfondite nel volume Insegnare il melodramma: saperi essenziali, proposte didattiche, finanziato dall’Università della Valle d’Aosta e destinato ad insegnanti della scuola di base, dalla scuola dell’infanzia alla secondaria superiore. Il libro è suddiviso in due parti: la prima di riflessione teorica e metodologica; la seconda più operativa, e contenente alcuni percorsi didattici divisi per fasce scolastiche. Esso dunque intende fornire a chi opera nella scuola una riflessione articolata e almeno un po’ approfondita sull’opera lirica, e nel contempo degli strumenti di lavoro concreti. Si può constatare infatti che alcune recenti pubblicazioni sulla didattica dell’opera puntano sull’immediata operatività (anche ai livelli più precoci d’istruzione, ma difettano, a nostro avviso, di un’adeguata cornice teorico-metodologico-concettuale: il che si ripercuote anche sul livello e sulla qualità dei percorsi didattici stessi.

  10. Educational software tool for protection system engineers: distance relay; Herramienta educativa para la formacion de ingenieros en protecciones electricas: relevador de distancia

    Energy Technology Data Exchange (ETDEWEB)

    Trujillo-Guajardo, L.A.; Conde-Enriquez, A. [Universidad Autonoma de Nuevo Leon, Nuevo Leon (Mexico)]. E-mail: luistrujillo84@gmail.com; con_de@yahoo.com

    2012-04-15

    In this article, a graphical software tool is presented; this tool is based on the education of protection system engineers. The theoretical fundaments used for the design of operation characteristics of distance relays and their algorithms are presented. The software allows the evaluation and analysis of real time events or simulated ones of every stage of design of the distance relay. Some example cases are presented to illustrate the activities that could be done with the graphical software tool developed. [Spanish] En este articulo se presenta una herramienta computacional grafica para apoyar la formacion de ingenieros en protecciones electricas. Los fundamentos teoricos para el diseno de caracteristicas de operacion de relevadores de distancia, asi como las rutinas de programacion de un relevador de distancia son presentados. La herramienta desarrollada permite la evaluacion de las etapas de diseno de relevadores y el analisis de la operacion ante eventos reales o simulados. Se presentan algunos casos de ejemplo para ilustrar las actividades didacticas que son posibles de realizar con la herramienta presentada.

  11. Evaluation of socio-economic impact of drought events: the case of Po river basin

    Directory of Open Access Journals (Sweden)

    Musolino Dario

    2017-03-01

    Full Text Available Il paper si focalizza sugli impatti socioeconomici degli eventi siccitosi. Obiettivo del paper è in particolare quello di analizzare gli effetti distributivi degli eventi siccitosi nell’agricoltura, studiando il caso del bacino del Po, l’area agricola più grande ed estesa in Italia. L’approccio teorico e metodologico utilizzato si basa sulla teoria del surplus del consumatore. I risultati più rilevanti delle analisi svolte mostrano che gli effetti delle siccità sono socialmente differenziati. Nel settore agricolo si osserva infatti come l’impatto economico sugli agricoltori è diverso da quello che si registra sui consumatori. Gli agricoltori possono perfino guadagnare dalle siccità, a causa del cosiddetto “effetto prezzo”, causato dalla scarsità di beni agricoli in periodi siccitosi; mentre i consumatori perdono sempre, a causa del sommarsi dell’ “effetto prezzo” e dell’ “effetto quantità”. Impatti di segno e magnitudine diversa sono stati anche stimati tra gli stessi agricoltori, quando distinti per tipologia di coltivazione e per sub-area geografica.

  12. Strontium-90 in milk and mixed diet in the Czech Republic

    International Nuclear Information System (INIS)

    Bartuskova, M.; Schlesingerova, E.

    2014-01-01

    Among various activities of National Radiation Protection Institute (SURO) monitoring of radionuclides in environment and food chain plays an important role. The monitoring takes place in frame of Czech Radiation Monitoring Network (RMN). Determinations of 90 Sr are performed according to the monitoring schedule of RMN. Strontium-90 was released into environment during the tests of nuclear weapons in the fifties and sixties of XX. century and to some extent in 1986 owing to the Chernobyl accident. Strontium is a chemical analogue of calcium and accordingly when entering a mammal body, it behaves very much like calcium. A large portion of the strontium will accumulate in bone and like calcium it transfers to milk. Since the Sr uptake by the human body from milk is an important pathway for radiostrontium incorporation, milk and milk powder are good indicators of 90 Sr content in human diet. Along with milk and milk powder, mixed diet samples composed of representative locally purchased food items according to food consumption statistics are also analysed for 90 Sr.The analyses are made using oxalate precipitation method, when interfering radionuclides are removed by precipitation scavenging and after its ingrowth 90 Y is separated and repeatedly measured by gas flow proportional counter. Strontium-90 activity is calculated as equal to 90 Y activity in equilibrium. Time evolution of 90 Sr activities in milk in Northern Moravia region (1988 present) and in Prague (1965 - present), in milk powder from the regions of the Czech Republic and in the mixed diet samples from the whole republic is presented on the poster. A very small increase due to the Chernobyl accident can be seen in milk. After the ban of atmospheric tests the level of 90 Sr has steadily been falling. The decrease is caused by radioactive decay and migration of the radionuclide in the environment. Due to this decrease activity concentrations in many samples have recently fallen under minimum significant

  13. Investigação da influência do processamento na dinâmica molecular de nanocompósitos de policarbonato e argila organofílica obtidos via intercalação por fusão On the influence of processing parameters on the molecular dynamics of melt intercalated polycarbonate-clay nanocomposites

    Directory of Open Access Journals (Sweden)

    Elton J. da R. Rodrigues

    2012-01-01

    Full Text Available Nanocompósitos baseados em policarbonato e argila organofílica foram obtidos pelo método de intercalação por fusão em câmara de mistura sob diferentes valores de torque e temperatura. A influência desses parâmetros na qualidade da dispersão da argila na matriz polimérica foi investigada por ressonância magnética nuclear (RMN de baixo campo, empregando o tempo de relaxação longitudinal, T1H, e por difração de raios X. As diferenças nos tempos de relaxação longitudinal e nos padrões de difração de raios X foram correlacionadas com a formação de domínios com mobilidades distintas. O nanomaterial formado apresentou morfologia intercalada com afastamento crescente das camadas de argila, conforme as condições de processamento se tornavam mais severas. A RMN ¹H mostrou que tanto o cisalhamento quanto a temperatura afetaram a mobilidade das cadeias poliméricas, explicitando a homogeneidade crescente da distribuição dos domínios de relaxação, de acordo com o aumento do torque e da temperatura.Polycarbonate-organofilic clay nanocomposites were obtained via the melt intercalation method in the blending chamber of a torque rheometer, under distinct values of shear and temperature. The influence of those processing parameters on the clay dispersion in the polymer matrix was probed by low-field nuclear magnetic resonance (NMR, using the T1H measurement technique and by wide angle X-ray scattering (WAXS. The differences in longitudinal relaxation times and in the X-ray reflection patterns were correlated with the formation of relaxation domains with particular molecular mobility, as progressively larger intercalated morphologies were found in the nanocomposites due to the increase of shear stress and temperature. ¹H NMR has shown that both shearing and temperature have played a fundamental part on the polymer chains mobility, which explains the increase in the domain´s homogeneity following the increment of those processing

  14. Chemical constituents from the stem of Brosimum potabile (Moraceae Constituintes químicos do cerne de Brosimum potabile (Moraceae

    Directory of Open Access Journals (Sweden)

    Viviane Gomes da Costa Abreu

    2010-12-01

    Full Text Available Three coumarins, 5-methoxypsoralene, xanthyletin, and (--marmesin, have been isolated from the ethanolic extract of the stem of the Amazonian plant Brosimum potabile. The structures were determined on the basis of NMR analyses and by comparison with spectroscopic data in the literature. The analysis of the hexane fractions by GC-MS in EIMS mode suggested the presence of (1-methylpentyl-benzene; α,α-dimethyl-4-(1-methylethyl-benzenemethanol; 1-methyl-3,5-bis(1-methylethyl-benzene; urs-12-ene; chola-5,22-dien-3β-ol; cholesta-4,6-dien-3β-ol; sitosteryl 9(Z-octadecenoate; cholesta-5,22-dien-3β-ol; cholesta-4,6,22-trien-3-one; and cholesta-4,22-dien-3-one. NMR data of other hexane fractions indicated the presence of 3β-acetoxy-lup-12,20(29-diene; 3β-acetoxy-olean-12-ene; 3β-acetoxy-urs-12-ene; and adian-5-ene. All these compounds are first described in B. potabile.Três cumarinas, 5-metoxipsoraleno, xantiletina e (--marmesina, foram isoladas no extrato etanólico do cerne da planta amazônica Brosimum potabile. Suas estruturas foram determinadas a partir das análises por RMN e por comparação com dados espectroscópicos da literatura. As análises das frações hexânicas por CG/EM sugeriram a presença de (1-metilpentil-benzeno; α,α-dimetil-4-(1-metiletil-benzenometanol; 1-metil-3,5-bis(1-metiletil-benzeno; urs-12-eno; cola-5,22-dien-3β-ol; colesta-4,6-dien-3β-ol; (9Z-octadecenoato de sitosterila; colesta-5,22-dien-3β-ol; colesta-4,6,22-trien-3-ona e colesta-4,22-dien-3-ona. Dados de RMN de outras frações hexânicas indicaram a presença de 3β-acetóxi-lup-12,20(29-dieno; 3β-acetóxi-olean-12-eno; 3β-acetóxi-urs-12-eno e adian-5-eno. Todos esses compostos foram identificados pela primeira vez em B. potabile.

  15. Electronic spreadsheet to acquire the reflectance from the TM and ETM+ Landsat images

    Directory of Open Access Journals (Sweden)

    Antonio R. Formaggio

    2005-08-01

    Full Text Available The reflectance of agricultural cultures and other terrestrial surface "targets" is an intrinsic parameter of these targets, so in many situations, it must be used instead of the values of "gray levels" that is found in the satellite images. In order to get reflectance values, it is necessary to eliminate the atmospheric interference and to make a set of calculations that uses sensor parameters and information regarding the original image. The automation of this procedure has the advantage to speed up the process and to reduce the possibility of errors during calculations. The objective of this paper is to present an electronic spreadsheet that simplifies and automatizes the transformation of the digital numbers of the TM/Landsat-5 and ETM+/Landsat-7 images into reflectance. The method employed for atmospheric correction was the dark object subtraction (DOS. The electronic spreadsheet described here is freely available to users and can be downloaded at the following website: http://www.dsr.inpe.br/Calculo_Reflectancia.xls.

  16. Terrestrial Carbon Fluxes from Deforestation in the Brazilian Amazon and Cerrado Regions Predicted from MODIS Satellite Data and Ecosystem Modeling

    Science.gov (United States)

    Klooster, S.; Potter, C.; Genovese, V.

    2008-12-01

    The NASA-CASA (Carnegie Ames Stanford Approach) simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate tropical forest and savanna (Cerrado) carbon pools for the Brazilian Amazon region over the period 2000-2004. Adjustments for mean age of forest stands were carried out across the region, resulting in a new mapping of aboveground biomass pools based on MODIS satellite data. Yearly maps of newly deforested lands from the Brazilian PRODES (Programa de calculo do desflorestamento da Amazonia ) project were combined with these NASA-CASA biomass predictions to generate seasonal budgets of potential carbon and nitrogen trace gas losses from biomass burning events. Simulations of plant residue and soil carbon decomposition were conducted in the NASA-CASA model during and following deforestation events to track the fate of aboveground biomass pools that were cut and burned each year across the region.

  17. Problems Associated with the Monochromatisation of Slow Neutrons; Quelques aspects de la monochromatisation des neutrons thermiques; Nekotorye voprosy monokhromatizatsii medlennykh nejtronov; Algunos problemas de la monocromatizacion de neutrones lentos

    Energy Technology Data Exchange (ETDEWEB)

    Vertebnyj, V P; Kolotyj, V V; Majstrenko, A N

    1963-01-15

    The paper sets out the result of calculations to determine the shape of the spectral line of twin-rotor, pulsing, slow-neutron monochromators, as a function of the shifts in the phases between the rotors. Consideration is also given to die possibility of using certain light elements as slow-neutron filters. (author) [French] Les auteurs exposent les resultats de leurs calculs relatifs a la forme du spectre des monochromateurs a impulsions et a deux rotors pour neutrons thermiques en fonction de la distance et du dephasage entre les rotors. Ils examinent egalement la possibilite d*utiliser certains elements legers comme filtres a neutrons lents. (author) [Spanish] Los autores exponen ios resultadas de sus calculos relativos a la forma de la linea espectral de los monocromadores pulsantes de dos rotores para neutrones lentos en funcion de la distancia y del desias amiento de los rotores. Examinan asimismo la posibilidad de utilizar algunos elementos ligeros como filtros de neutrones lentos. (author)

  18. Operation of industrial electrical substations. Part II: practical applications

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Jimenez, Juan J; Zerquera Izquierdo, Mariano D; Beltran Leon, Jose S; Garcia Martinez, Juan M; Alvarez Urena, Maria V; Meza Diaz, Guillermo [Universidad de Guadalajara (Mexico)]. E-mails: cheosj@yahoo.com; mdzi@hotmail.com; beltran5601@yahoo.com.mx; jmargarmtz@yahoo.com; victory_alvarez@telmexmail.com; depmec@cucei.udg.mx

    2013-03-15

    The practical application of the methodology explained in Part 1 in a Cuban industry is the principal objective of this paper. The calculus of the economical operation of the principal transformers of the industrial plant is shown of the one very easy form, as well as the determination of the equations of the losses when the transformers operate under a given load diagram. It is calculated the state load which will be passed to the operation in parallel. [Spanish] El objetivo principal de este trabajo es la aplicacion practica de la metodologia, en una industria cubana, que se explico en la Parte 1. El calculo de la operacion economica de los principales transformadores de la planta industrial se muestra de una forma muy facil, asi como la determinacion de las ecuaciones de las perdidas cuando los transformadores operan bajo un diagrama de carga dado. Se calcula la carga de estado que se pasa a la operacion en paralelo.

  19. Cuestionarios Interactivos para Autoevaluación

    Directory of Open Access Journals (Sweden)

    Sánchez García, Juan Francisco

    2007-01-01

    Full Text Available La autoevaluación es un instrumento valioso para que el propio alumno pueda medir el grado de conocimientos adquiridos de la materia en cuestión, al tiempo sirve para adiestrarlo en el tipo de prueba que se utilizará posteriormente en el examen. Por otro lado, dado que en la adaptación al Espacio Europeo de Educación Superior (E3S tiene particular importancia la labor realizada por el propio alumno, los pruebas de autoevalución adquieren, si cabe, una mayor relevancia. Por todo ello, hemos elaborado unos test interactivos con hoja de calculo, para cubrir el doble propósito de evaluar los conocimientos alcanzados por nuestros alumnos, relativos tanto a la materia, como al manejo en sí de la propia herramienta informática de la hoja de cálculo. Se muestran ejemplos concretos relacionados con las matemáticas y la hoja de cálculo Excel.

  20. Theoretical study of excitonic complexes in semiconductors quantum wells; Estudo teorico de complexos excitonicos em pocos quanticos de semicondutores

    Energy Technology Data Exchange (ETDEWEB)

    Dacal, Luis Carlos Ogando

    2001-08-01

    A physical system where indistinguishable particles interact with each other creates the possibility of studying correlation and exchange effect. The simplest system is that one with only two indistinguishable particles. In condensed matter physics, these complexes are represented by charged excitons, donors and acceptors. In quantum wells, the valence band is not parabolic, therefore, the negatively charged excitons and donors are theoretically described in a simpler way. Despite the fact that the stability of charged excitons (trions) is known since the late 50s, the first experimental observation occurred only at the early 90s in quantum well samples, where their binding energies are one order of magnitude larger due to the one dimensional carriers confinement. After this, these complexes became the subject of an intense research because the intrinsic screening of electrical interactions in semiconductor materials allows that magnetic fields that are usual in laboratories have strong effects on the trion binding energy. Another rich possibility is the study of trions as an intermediate state between the neutral exciton and the Fermi edge singularity when the excess of doping carriers is increased. In this thesis, we present a theoretical study of charged excitons and negatively charged donors in GaAs/Al{sub 0.3}Ga{sub 0.7}As quantum wells considering the effects of external electric and magnetic fields. We use a simple, accurate and physically clear method to describe these systems in contrast with the few and complex treatments s available in the literature. Our results show that the QW interface defects have an important role in the trion dynamics. This is in agreement with some experimental works, but it disagrees with other ones. (author)

  1. Synthesis and characterization of poly(styrene-co-methyl methacrylate)

    International Nuclear Information System (INIS)

    Augustinho, Tiago R.; Abarca, Silvia A.C.; Machado, Ricardo A.F.

    2011-01-01

    Polystyrene (PS) is nowadays commonly used due its advantages over competitors. PS presents a lower cost when compared with Acrylonitrile Butadiene Styrene (ABS) and with Polyethylene Tere-phthalate (PET), and can be easier processed than polypropylene (PP). At expandable form (EPS), can be used as projective equipment, thermal insulation, floating boards, refrigerators, isothermal, and low cost applications such as packaging and disposable material. Searching for more resistant materials and with a low cost, researches with copolymers materials are being developed. In this study, copolymerization reactions were carried out by suspension polymerization using monomers styrene and methyl methacrylate (MMA) with styrene. Styrene was in the highest percentage in relation to the MMA. The MMA was selected because is a monomer that presents a higher resistance than PS. The copolymerization was confirmed by performing infrared spectroscopy (IR), nuclear magnetic resonance of hydrogen (RMN 1 H), differential scanning calorimetry (DSC) and thermogravimetry (TGA). (author)

  2. Estudo fitoquímico de Davilla rugosa: flavonóides e terpenóides

    Directory of Open Access Journals (Sweden)

    Jorge M. David

    Full Text Available Este trabalho descreve o isolamento e caracterização de alguns metabólitos presentes nos caules de Davilla rugosa (Dilleniaceae, conhecida vulgarmente como cipó-caboclo e utilizada pela população na medicina tradicional brasileira para diversas enfermidades. O extrato hidrometanólico foi particionado entre hexano, clorofórmio e acetato de etila. Da fase hexânica foram obtidos a friedelina, sitostenona e ácido betulínico. Da fase clorofórmica foram isolados através de técnicas cromatográficas o ácido betulínico e a narigenina. Enquanto que do extrato acetato de etila foram obtidos dois outros flavonóides, quercetina e 4’-O-metil taxifolina. As substâncias tiveram suas estruturas elucidadas através da análise de dados no UV e de RMN.

  3. Penis cancer: a case report

    Directory of Open Access Journals (Sweden)

    Gregorio Sampalmieri

    2014-06-01

    Full Text Available Penis cancer appears as a small lesion that extends gradually to affect the whole of the glans and the shaft of the penis. Its peak incidence is in men aged 40 to 70 years. The most frequent malignant penis tumour is squamous cell carcinoma, which occurrence is probably favoured by smegma accumulation, HPV16 and 18 infection, smoke, and balanitis xerotica obliterans. Here we discuss the case of a 74-year-old man with sovrapubic pain and swelling. Physical examination reveals swollen glans with purulent secretions and oedema. The final diagnosis of squamous cell carcinoma is established by means of RMN and biopsy. Partial penectomy surgery follows. Histopathological examination shows poorly differentiated endophytic infiltrative growth. The tumour infiltrates corpus spongiosum, corpora cavernosa, and urethra. The proximal uretheral stump is free from infiltration (pT3.http://dx.doi.org/10.7175/cmi.v8i2.906 

  4. Investigation of TbMn2O5 by polarized neutron diffraction.

    Science.gov (United States)

    Zobkalo, I A; Gavrilov, S V; Sazonov, A; Hutanu, V

    2018-05-23

    In order to make a new approach to the elucidation of the microscopic mechanisms of multiferroicity in the RMn 2 O 5 family, experiments with different methods of polarized neutrons scattering were performed on a TbMn 2 O 5 single crystal. We employed three different techniques of polarized neutron diffraction without the analysis after scattering, the XYZ-polarization analysis, and technique of spherical neutron polarimetry (SNP). Measurements with SNP were undertaken both with and without external electric field. A characteristic difference in the population of 'right' and 'left' helix domains in all magnetically ordered phases of TbMn 2 O 5 , was observed. This difference can be controlled by an external electric field in the field-cooled mode. The analysis of the results gives an evidence that antisymmetric Dzyaloshinsky-Moria exchange is effective in all the magnetic phases in TbMn 2 O 5 .

  5. Oil accumulation kinetic along ripening in four olive cultivars varying for fruit size

    Directory of Open Access Journals (Sweden)

    Breton Catherine

    2009-01-01

    Full Text Available To determine whether oil accumulation pattern is parallel to drupe olive (Olea europaea L growth and if common climatic parameters may influence oil content we conducted an experiment in rainfed orchards with four olive cultivars, Amygdalolia, Arbequina, Lucques, and Olivière, differing by fruit size at maturity. Fruits were harvested weekly from July to November. They were counted and weighted before being crushed. Fat content was determined on dry matter using a Minispec RMN. Common climatic parameters were recorded. Variance analyses showed stage effects highly significant. Results showed three different patterns for fruit growth. Dry matter accumulated broadly similarly and the weekly rates were positively correlated with fruit size. Oil accumulation is mostly independent of climatic variation and probably depends on genetic programmes for each cultivar. We defined the main steps and events for olive fruit ripening according to recent knowledge on fruit development.

  6. Investigation of TbMn2O5 by polarized neutron diffraction

    Science.gov (United States)

    Zobkalo, I. A.; Gavrilov, S. V.; Sazonov, A.; Hutanu, V.

    2018-05-01

    In order to make a new approach to the elucidation of the microscopic mechanisms of multiferroicity in the RMn2O5 family, experiments with different methods of polarized neutrons scattering were performed on a TbMn2O5 single crystal. We employed three different techniques of polarized neutron diffraction without the analysis after scattering, the XYZ-polarization analysis, and technique of spherical neutron polarimetry (SNP). Measurements with SNP were undertaken both with and without external electric field. A characteristic difference in the population of ‘right’ and ‘left’ helix domains in all magnetically ordered phases of TbMn2O5, was observed. This difference can be controlled by an external electric field in the field-cooled mode. The analysis of the results gives an evidence that antisymmetric Dzyaloshinsky-Moria exchange is effective in all the magnetic phases in TbMn2O5.

  7. [mu]SR magnetic response in frustrated antiferromagnets of type RMn[sub 2] (R = rare earth)

    Energy Technology Data Exchange (ETDEWEB)

    Weber, M. (Physics Dept., TU Munich, Garching (Germany)); Asch, L. (Physics Dept., TU Munich, Garching (Germany)); Kratzer, A. (Physics Dept., TU Munich, Garching (Germany)); Kalvius, G.M. (Physics Dept., TU Munich, Garching (Germany)); Muench, K.H. (Physics Dept., TU Munich, Garching (Germany)); Ballou, R. (Lab. Louis Neel, CNRS, 38 Grenoble (France)); Deportes, J. (Lab. Louis Neel, CNRS, 38 Grenoble (France)); Waeppling, R. (Dept. of Physics, Univ. of Uppsala (Sweden)); Litterst, F.J. (Inst. for Metal Physics, TU Braunschweig (Germany)); Klauss, H.H. (Inst. for Metal Physics, TU Braunschweig (Germany)); Niedermayer, C. (Faculty for Physics, Univ. Konstanz (Germany)); Chappert, J. (CEA/DRFMC, CEN Grenoble, 38 (France))

    1994-07-01

    Zero, longitudinal and transverse field [mu]SR was carried out in the antiferromagnets YMn[sub 2], Y[sub 0.95] Tb[sub 0.15] Mn[sub 2], Y[sub 0.9]Tb[sub 0.1]Mn[sub 2], Y[sub 0.99] Sc[sub 0.01] Mn[sub 2], Y[sub 0.98]Sc[sub 0.02]Mn[sub 2] and TbMn[sub 2]. The dynamics of Mn magnetic moments above T[sub N] is typical for an itinerant antiferromagnet. Within a certain temperature range above T[sub N] part of the material enters a randomly ordered (spin glass like) magnetic state as an out-come of frustration. At temperatures above [approx] 150 K the muon spin relaxation rate indicates that the muon has become mobile. (orig.)

  8. Evidencias de hidrógenos metilénicos gemínales no equivalentes en RMN

    Directory of Open Access Journals (Sweden)

    Jaime Bernal Castillo

    2009-07-01

    Full Text Available Se estudian los espectros de RMP para compuestos del tipo PcSi [OCH(CH2Y2]2 en donde Y = NME2, QEt, NH2 y SH. En cuatro de estas ftalocianinas los protrones metilénicos no son equivalentes. Se demuestra que la agrupación YCH2 CH en los primeros dos derivados constituyen nítidamente un sistema de acoplamiento de espines AMX.

  9. Strong CO+ and {{\\rm{N}}}_{2}^{+} Emission in Comet C/2016 R2 (Pan-STARRS)

    Science.gov (United States)

    Cochran, Anita L.; McKay, Adam J.

    2018-02-01

    We report on imaging and spectroscopic observations of comet C/2016 R2 (Pan-STARRS) obtained with the 0.8 m and 2.7 m telescopes of McDonald Observatory in 2017 November and December, respectively. The comet was at a heliocentric distance greater than 3 au during both sets of observations. The images showed a well-developed tail with properties that suggested it was an ion tail. The spectra confirmed that we were observing well-developed bands of CO+ and {{{N}}}2+. The {{{N}}}2+ detection was unequivocally cometary and was one of the strongest bands of {{{N}}}2+ detected in a comet spectrum. We derived the ratio of these two ions and from that we were able to derive that N2/CO = 0.15. This is the highest such ratio reported for a comet. This Letter includes data taken at The McDonald Observatory of The University of Texas at Austin.

  10. Un error en los calculos matematicos destroza el acelerador de particulas del CERN

    CERN Multimedia

    Cernuda, Olalla

    2007-01-01

    The most famous particle accelerator in the world, who is at CERN, has suffered a catastrophic damage after a great explosion took place in its depths. This explosion has an absolutely scientific explanation: a mathematical mistake in the design of the anchorages of great magnets. (1 page)

  11. La Vision que tienen del Calculo los Diplomados en Empresariales: Un Test Final

    Directory of Open Access Journals (Sweden)

    Seijas Macías, J. Antonio

    2008-01-01

    Full Text Available Como docentes de Matemáticas Aplicadas a la Economía y Empresa somos conscientes de las a veces difíciles relaciones entre ambas disciplinas. ¿En qué sentido se diluyen las matemáticas en la economía? ¿Qué queda de ellas en los alumnos de empresa al acabar la carrera? ¿El lenguaje matemático sigue teniendo significado para ellos? Este trabajo pretende responder a estas preguntas tomando como referencia un test pasado a los alumnos del último año de la diplomatura de Ciencias Empresariales de la Universidad de A Coruña.

  12. Equilibrio liquido-liquido-vapor de misturas ternarias : algoritimo de calculo e aspectos termodinamicos

    OpenAIRE

    Maria Helena Cano de Andrade

    1991-01-01

    Resumo: Este trabalho é uma contribuição ao estudo de processos de separação envolvendo fases em equilibrio liquido-liquido-vapor. Os seguintes aspectos são abordados: (1) desenvolvimento de um algoritmo eficiente de cálculo de flash liquido-liquido-vapor e sua aplicação para gerar diagramas de fases e em cálculos de destilação; (2) avaliação da utilização de parâmetros binários do modelo UNIQUAC obtidos de dados bifásicos em cálculos trifásicos de misturas ternárias; (3) medidas experimentai...

  13. Integrated radiation information system in the Czech Republic

    International Nuclear Information System (INIS)

    Drabova, D.; Prouza, Z.; Malatova, I.; Kuca, P.; Bucina, I.

    1998-01-01

    Outline and organizational structure of radiation monitoring network (RMN) in the Czech Republic is conformable with similar networks abroad integrated system of a number of components serve for continuous monitoring of radiation situation on the territory of the Czech Republic, detecting an abnormal radiological situation due to domestic source, detecting a non notified accident abroad with consequences on the territory of the Czech Republic, monitoring the evolution, determining the components of any radioactivity discharge, first estimation of accident extent, forecasting of accident development and of dispersion of radionuclides in the vicinity of source, acquisition of base for decision upon evaluation and other countermeasures and remedial actions, assessment and forecast of contamination for regulation of food and water consumption, review of enforced countermeasures based on actual monitoring data and refined forecast. For model calculations and decision making in case of a nuclear accident an integrated comprehensive computer based information system is now being set up in Czech Republic. (R.P.)

  14. High pressure {mu}SR studies: rare earths and related materials

    Energy Technology Data Exchange (ETDEWEB)

    Kalvius, G.M., E-mail: kalvius@ph.tum.de; Schreier, E. [Technical University Munich, Physics Department (Germany)], E-mail: kalvius@ph.tum.de; Ekstroem, M.; Hartmann, O. [Uppsala University, Physics Department (Sweden); Henneberger, S., E-mail: kalvius@ph.tum.de; Kratzer, A. [Technical University Munich, Physics Department (Germany)], E-mail: kalvius@ph.tum.de; Waeppling, R. [Uppsala University, Physics Department (Sweden); Martin, E., E-mail: kalvius@ph.tum.de; Burghart, F.J. [Technical University Munich, Physics Department (Germany)], E-mail: kalvius@ph.tum.de; Ballou, R.; Deportes, J. [CNRS, Laboratoire Louis Neel (France); Niedermayer, Ch. [University of Constance, Faculty of Physics (Germany)

    2000-11-15

    After a short introduction to {mu}SR with respect to the study of magnetic properties, followed by a brief outline of the principle of the high pressure-low temperature {mu}SR spectrometer installed at the Paul Scherrer Institute, we discuss some measurements on rare earth materials employing this instrument. They are concerned with: (1) The pressure dependence of the spin turning process in ferromagnetic Gd. (2) The volume dependence of the internal magnetic field in the heavy rare earth metals Gd, Dy, and Ho in their ordered magnetic states. (3) The response of the (first order) magnetic transition in the frustrated antiferromagnets of type RMn{sub 2} (R = Y,Gd) to pressure. (4) The variation of magnetic parameters with pressure in La{sub 2}CuO{sub 4} (powder sample), the antiferromagnetic parent compound of the high T{sub C} superconductors of type La{sub 2-x}(Sr, Ba){sub x}CuO{sub 4}. In conclusion a short outlook on further developments is given.

  15. Triterpenos das folhas de Minquartia guianensis Aubl. (Olacaceae Triterpenes from the leaves of Minquartia guianensis Aubl. (Olacaceae

    Directory of Open Access Journals (Sweden)

    Lorena Mayara de Carvalho Cursino

    2009-03-01

    Full Text Available Este artigo descreve o isolamento dos triterpenos lupeol, taraxerol, lupen-3-ona e esqualeno obtido do extrato diclorometânico das folhas da espécie Minquartia guianensis Aubl., pertencente à família Olacaceae. Estes terpenóides foram isolados através de técnicas cromatográficas e identificados utilizando Ressonância Magnética Nuclear (RMN de ¹H e de 13C. Na literatura disponível, este é o primeiro relato destes triterpenos em M. guianensis.This article describes the isolation of the triterpenes lupeol, taraxerol, lupen-3-one and squalene from the dichloromethane extract of the leaves of Minquartia guianensis Aubl. belonging to the Olacaceae family. These terpenoids were isolated through chromatographic techniques and identified using ¹H and 13C Nuclear Magnetic Resonance (NMR. At the best of our knowledge, this is the first report of these triterpenes in M. guianensis.

  16. Tournaments, oriented graphs and football sequences

    Directory of Open Access Journals (Sweden)

    Pirzada S.

    2017-08-01

    Full Text Available Consider the result of a soccer league competition where n teams play each other exactly once. A team gets three points for each win and one point for each draw. The total score obtained by each team vi is called the f-score of vi and is denoted by fi. The sequences of all f-scores [fi]i=1n$\\left[ {{\\rm{f}}_{\\rm{i}} } \\right]_{{\\rm{i}} = 1}^{\\rm{n}} $ arranged in non-decreasing order is called the f-score sequence of the competition. We raise the following problem: Which sequences of non-negative integers in non-decreasing order is a football sequence, that is the outcome of a soccer league competition. We model such a competition by an oriented graph with teams represented by vertices in which the teams play each other once, with an arc from team u to team v if and only if u defeats v. We obtain some necessary conditions for football sequences and some characterizations under restrictions.

  17. Biodegradation of phenol-formaldehyde resins modified with commercial lignins

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, M.; Nicolau, V. V. [Universidad Tecnologica Nacional (UTN), Cordoba (Argentina); Sponon, M.; Estenoz, D.A. [Instituto de Desarrollo Tecnologico para la Industria Quimica (INTEC/UNL/CONICET), Santa Fe (Argentina)

    2014-07-01

    Full text: In this work the biodegradation of partially-modified resols with 10% w/w of sodium lignosulfonate and 10 and 20 % w/w of Kraft lignin type is studied. The experimental work involved preliminary studies of biodegradation in Petri dish (clear zones), the degradation of resols by enzymatic attack of Pseudomonas aeruginosa under aerobic conditions for a period of 200 days and the characterization of the polymers before and after biodegradation by FT-IR and RMN spectroscopy, gas chromatography (GC) and scanning electron microscopy (SEM). The number of viable cells showed a significant increase during the process. However, the gravimetric analysis was not sufficient to check the biodegradation. The results indicated that endocellular enzymes could be involved. It was observed that the presence of low concentrations of toxic substances released during degradation of the material may have inhibitory effects. Resoles were synthesized in Centro S. A. San Francisco Cordoba, Argentina. (author)

  18. Polímeros como modificadores asfálticos

    Directory of Open Access Journals (Sweden)

    Letícia SocaI da Silva

    2009-12-01

    Full Text Available

    Neste trabalho foram preparadas diferentes misturas de ligante asfáltico modificado com polímeros. Foram utilizadas quatro amostras de polímeros, sendo duas de SBS, uma de SEBS e uma de Polietileno Modificado, as quais foram caracterizadas quanto a sua estrutura e propriedades térmicas através de técnicas de Ressonância Magnética Nuclear (RMN, Cromatografia por Permeação a Gel (GPC, Análise Termogravimétrica (TGA e Calorimetria Diferencial de Varredura (DSC. O ligante modificado foi avaliado quanto a sua viscosidade, retorno elástico, comportamento reológico e estabilidade à estocagem. Foram correlacionadas a estrutura química e as transições térmicas dos polímeros com as características do ligante modificado. Os polímeros do tipo SBS foram os melhores modificadores de asfalto, quando comparado com os demais polímeros avaliados.

  19. Origin of the magnetic-field controlled polarization reversal in multiferroic TbMn2 O 5

    Science.gov (United States)

    Leo, N.; Meier, D.; Pisarev, R. V.; Park, S.; Cheong, S.-W.; Fiebig, M.

    2011-03-01

    The interplay of multi-dimensional complex magnetic order parameters leads to interesting effects like magnetically induced ferroelectricity. A particular interesting example is TbMn 2 O5 because of the associated magnetic-field controllable electric polarization. By optical second harmonic generation we show that the gigantic magnetoelectric effect originates in three independent ferroelectric contributions. Two of these are manganese-generated. The third contribution is related to the magnetism of the Tb 3+ sublattice and has not been identified so far. It mediates the remarkable magnetic-field induced polarization reversal. This model is verified by experiments on the isostructural YMn 2 O5 where Y3+ ions are nonmagnetic and only two polarization contributions are present and no magnetoelectric coupling is observed. These results underline the importance of the 3 d - 4 f -interaction for the intricate magnetoelectric coupling in the class of isostructural RMn 2 O5 compounds. This work was supported by the DFG through SFB 608.

  20. Synthesis and characterization of poly(styrene-co-methyl methacrylate); Sintese e caracterizacao do poli(estireno-co-metacrilato de metila)

    Energy Technology Data Exchange (ETDEWEB)

    Augustinho, Tiago R.; Abarca, Silvia A.C.; Machado, Ricardo A.F. [Departamento de Engenharia Quimica e Alimentos - Universidade Federal de Santa Catarina - UFSC, Florianopolis, SC (Brazil)

    2011-07-01

    Polystyrene (PS) is nowadays commonly used due its advantages over competitors. PS presents a lower cost when compared with Acrylonitrile Butadiene Styrene (ABS) and with Polyethylene Tere-phthalate (PET), and can be easier processed than polypropylene (PP). At expandable form (EPS), can be used as projective equipment, thermal insulation, floating boards, refrigerators, isothermal, and low cost applications such as packaging and disposable material. Searching for more resistant materials and with a low cost, researches with copolymers materials are being developed. In this study, copolymerization reactions were carried out by suspension polymerization using monomers styrene and methyl methacrylate (MMA) with styrene. Styrene was in the highest percentage in relation to the MMA. The MMA was selected because is a monomer that presents a higher resistance than PS. The copolymerization was confirmed by performing infrared spectroscopy (IR), nuclear magnetic resonance of hydrogen (RMN{sup 1}H), differential scanning calorimetry (DSC) and thermogravimetry (TGA). (author)

  1. Artefatos cumarínicos isolados de Polygala paniculata L. (Polygalaceae

    Directory of Open Access Journals (Sweden)

    M. G Pizzolatti

    Full Text Available A partir do fracionamento em coluna de gel de sílica do extrato clorofórmico de Polygala paniculata (Polygalaceae, foram isolados 7-metóxi-8-(1',2'-epóxi-3'-metil-3'-butenil-cumarina (1 e dois artefatos cumarínicos (2a-2b, formados a partir da abertura do anel epóxido de 1 durante o processo de isolamento. O tratamento de 1 com EtOH/SiO2, sob agitação e à temperatura ambiente durante 24 horas, resultou na formação dos respectivos artefatos: 7-metóxi-8-(1'-hidróxi-2-etóxi-3'-metil-3'-butenil-cumarina (2a e 7-metóxi-8-(1'-etóxi-2-hidróxi-3'-metil-3'-butenil-cumarina (2b. As estruturas químicas desses compostos foram determinadas através da análise de seus dados espectrais, incluindo RMN bidimensional.

  2. Constituintes químicos voláteis e não-voláteis de Moringa oleifera Lam., Moringaceae

    Directory of Open Access Journals (Sweden)

    Milena B. Barreto

    Full Text Available O estudo fitoquímico do extrato etanólico das folhas de Moringa oleifera Lam., Moringaceae, resultou no isolamento dos derivados benzilnitrilas niazirina, niazirinina e 4-hidroxifenil-acetonitrila, enquanto que das cascas dos frutos somente o octacosano foi obtido. Os óleos essenciais das folhas, flores e frutos foram analisados por cromatografia gasosa acoplada a espectrometria de massa. Os constituintes principais identificados foram: fitol (21,6% e timol (9,6% nas folhas, octadecano (27,4% e ácido hexadecanóico (18,4% nas flores e docosano (32,7% e tetracosano (24,0% nos frutos. As estruturas dos compostos isolados foram identificadas a partir de técnicas espectroscópicas (RMN, IV e EM. A 4-hidroxifenil-acetonitrila está sendo citada pela primeira vez para o gênero Moringa e os óleos essenciais das flores e frutos estão sendo citados pela primeira vez para a espécie M. oleifera.

  3. Análisis quimico de la semilia de bactris gasipaes HBK (Chontaduro

    Directory of Open Access Journals (Sweden)

    Fabio Zuluaga

    2009-06-01

    Full Text Available Se encontró que la semilla de chontaduro contenía 28% de grasa y 12.5% de carbohidratos. La grasa estaba constituida de 90% de trigllcéridos y de 0.1% de esteróles, además de ácidos grasos libres y otras sustancias no identificadas. Después de la transesterlficaclón del aceite, se identificaron los ásteres etílicos de los ácidos caprlllco, cáprlco, láurico, mirlstlco, paimftico, esteárico, olelco y llnolelco. La mayor parte de la fracción esferoidal estaba constituida por g -sltosterol (90%, campesterol (~9% y colestorol (~ 1 %. La fracción de los carbohidratos fue casi en su totalidad sacarosa. La separación e identificación de los compuestos fueron hechos por cromatografía (capa delgada, columna, gas-llquIdo y por métodos espectroscópicos (IR, UV, RMN y Masas.

  4. Indium-Gallium Radiation Contour of the IRT Nuclear Reactor; Circuit d'activation d'indium-gallium dans le reacteur nucleaire IRT; Indij-gallievyj radiatsionnyj kontur yadernogo reaktora IRT; Circuito de radiaciones de indio-galio del reactor IRT

    Energy Technology Data Exchange (ETDEWEB)

    Breger, A K; Ryabukin, Y S; Tulkes, S G; Volkov, E N

    1960-07-15

    -industrielles. (author) [Spanish] Basandose en un trabajo teorico ya publicado, se preparo en el reactor IRT un circuito de radiaciones de indio-galio que constituye una nueva fuente de rayos gamma de elevada intensidad. El primer circuito de este tipo ''RK-1'' se construyo para el reactor IRT en el Instituto de Fisica de la Academia de Ciencias de la Republica Socialista Sovietica de Georgia. Este trabajo estudia los puntos siguientes: calculo de la activacion de la desintegracion del conjunto indio-galio; estructura del circuito RK-1 y su disposicion en el tanque del reactor y en la camara activa; dispositivo de admision de las sustancias liquidas y gaseosas en la zona de la irradiacion; transportador de las sustancias solidas sometidas a irradiacion. En el reactor IRT, cuya potencia es de 2 000 kW, la intensidad de irradiacion del circuito es igual a la de una fuente de radiacion gamma equivalente a 20 000 g de radio. En el trabajo se estudian las posibilidades de utilizacion de este circuito con fines semi-industriales y de investigacion. (author) [Russian] Osnovyvayas' na uzhe opublikovannoj teoreticheskoj rabote, byl podgotovlen indij-gallievyj radiatsionnyj kontur yadernogo reaktora IRT, kotoryj yavlyaetsya novym moshchnym istochnikom gamma-oblucheniya . Pervyj kontur ehtogo tipa RK-1 byl podgotovlen na reaktore IRT v Institute fiziki Akademii nauk Gruzinskoj SSR. V doklade dayutsya raschety aktivizatsij dlya indij-gallievogo splava, strukturnye kompanovki RK-1 i ikh raspolozhenie v bake reaktora i goryachej kamere, ustrojstvo podachi zhidkikh i gazoobraznykh veshchestv v zonu oblucheniya i konvejer dlya tverdykh veshchestv, kotorye podlezhat oblucheniyu. V reaktore IRT moshchnost'yu 2000 kW moshchnost' oblucheniya kontura ehkvivalentna moshchnosti oblucheniya gamma-izluchatelya, obladayushchego aktivnost'yu v 20000 g ehkv. radiya. V doklade obsuzhdayutsya perspektivy ispol'zovaniya indij-gallievogo radiatsionnogo kontura dlya issledovatel'skikh i polupromyshlennykh tselej

  5. Fundamentos teoricos de la creacion de un modelo de adquisicion corporativa internacional: Caso de las principales empresas de Nuevo Leon

    Directory of Open Access Journals (Sweden)

    Cabeza, L.

    2008-07-01

    Full Text Available The importance to propose a success Model in the international corporate acquisitions consists of offering to the important Mexican firms the factors that will allow having greater success with the international investments. In this research we selected four of the most important firms of Nuevo Leon that have important experience with international acquisitions and present them the questionnaire that was designed to validate the variables of the Model. In this paper we present the theories that give the theoretical foundations to the variables of the proposed Model that consist of 6 variables or key success factors that need to be considered for an international acquisitions, which are: Country Knowledge, Industry Knowledge, Customer relationship, Supplier relationship, Technology and Market.

  6. Teorizando acerca del Conocimiento Productivo para Entender la Educacion Teorico Profesional (Theorizing about Productive Knowledge To Understand Professional Technical Education).

    Science.gov (United States)

    Hidalgo, Abelardo Castro; Carrasco, Decler Martinez

    2000-01-01

    States that, internationally, Professional Technical Education emerges as a method of providing educational solutions for poor sectors of the population. Cites University of Chalmer (Sweden) and University of Bio-Bio (Chile) as institutions transformed into technological universities. Discusses what is productive knowledge and conditions under…

  7. Dispositivi formativi e forme di vita

    Directory of Open Access Journals (Sweden)

    Francesco Cappa

    2016-02-01

    Full Text Available Il dibattito pedagogico che ha caratterizzato gli ultimi anni ha spesso insistito sull’importanza del nesso tra sviluppo tecnologico e modelli formativi. Questa relazione, però, troppo spesso non valorizza i modi in cui l’esperienza educativa e formativa dovrebbe essere sempre più accuratamente pensata, progettata e predisposta se vista dalla prospettiva delle buone pratiche tecnologiche. Tale valorizzazione dell’istanza formativa deve prendere avvio da una riflessione critica e approfondita sui modelli impliciti ed espliciti che caratterizzano le pratiche educative e formative, valorizzando l’uso e l’interpretazione che i soggetti rendono attuali.Per consentire tale riflessione è necessario pensare un dispositivo pedagogico che non perda di vista la complessità delle dimensioni che agiscono nell’accadere educativo, capace di creare nuovi percorsi di sperimentazione delle conoscenze e nuove ipotesi di formazione di sé e degli altri. La formazione interpretata alla luce dei dispositivi pedagogici può offrire un valido strumento teorico e pratico per immaginare, progettare e valutare gli effetti che ogni azione formativa produce legati alla trasformazione dei saperi, alla vita delle forme e alle forme di vita contemporanee.

  8. LA DIAGNOSI DELLE COMPETENZE LINGUISTICHE IN UN CONTESTO MULTILINGUE: UN PROCESSO CONTINUO CHE FAVORISCE L’INSEGNAMENTO E L’APPRENDIMENTO INDIVIDUALIZZATO

    Directory of Open Access Journals (Sweden)

    Drorit Lengyel

    2011-07-01

    Full Text Available Il presente studio affronta il problema della valutazione diagnostica delle competenze linguistiche in contesti educativi multilingui, con particolare attenzione ai bisogni dei bambini e degli adolescenti immigrati. Vengono brevemente esposti gli obiettivi, le funzioni e i principi della valutazione diagnostica e della valutazione formativa considerate parte integrante di una educazione linguistica continua che prevede un insegnamento-apprendimento individualizzato. Sul piano teorico le procedure della valutazione diagnostica delle competenze linguistiche in contesti multilingui fanno riferimento all’apprendimento delle lingue inteso come attività socio-culturale.     Language diagnostics in multilingual settings with respect to continuous procedures as accompaniment of individualized learning and teaching   This study provides an introduction to language diagnostics in multilingual educational settings, with particular reference to the needs of children and adolescents from migrant backgrounds. It summarises the objectives and functions of language diagnostics and the principles that govern diagnostics including formative assessment, considered to be an integral part of continuous language education that emphasises individualised teaching and learning. From a theoretical perspective, diagnostic procedures in multilingual settings treat language learning as a socio-cultural activity.  

  9. La rappresentazione del sogno, due modelli a confronto: la metapsicologia di Sigmund Freud e la teoria del Codice Multiplo di Wilma Bucci

    Directory of Open Access Journals (Sweden)

    Ilaria Bellavia

    2007-09-01

    Full Text Available Obiettivo di questo lavoro è quello di fornire le principali linee di orientamento teorico dell’approccio psicodinamico relative alla funzione del sogno. In tal senso ci si avvarrà della metapsicologia Freudiana, ma anche dei prestigiosi contributi sul carattere del sogno portati da Wilma Bucci. In particolare, si proporrà un parallelismo tra la metapsicologia e la teoria del Codice Multiplo. La teoria energetica di derivazione psicoanalitica mette in risalto alcuni punti cardine sul ruolo del sogno: 1 il sogno deriva dall’energia di un desiderio inconscio; 2 i sogni hanno la funzione di preservare il sonno; 3 la nozione di un censore che si attiva per distorcere e mascherare i contenuti latenti; 4 i contenuti manifesti hanno la funzione di nascondere il reale significato del sogno. Secondo la teoria del codice multiplo, il sogno ha un valore là dove fornisce l’accesso al significato emotivo che è stato dissociato, ma la funzione dell’elaborazione dell’informazione emotiva nel sogno è sovrapponibile a quella dell’elaborazione dell’informazione emotiva durante la veglia, in particolare per quanto riguarda il sonno REM.

  10. Photoacoustic investigation of the effective diffusivity of two-layer semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Medina, J; Gurevich, Yu. G; Logvinov G, N; Rodriguez, P; Gonzalez de la Cruz, G. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    2001-08-01

    In this work, the problem of the effective thermal diffusivity of two-layer systems is investigated using the photoacoustic spectroscopy. The experimental results are examined in terms of the effective thermal parameters of the composite system determined from an homogeneous material which produces the same physical response under an external perturbation in the detector device. It is shown, that the effective thermal conductivity is not symmetric under exchange of the two layers of the composite; i.e., the effective thermal parameters depend upon which layer is illuminated in the photoacoustic experiments. Particular emphasis is given to the characterization of the interface thermal conductivity between the layer-system. [Spanish] En el presente trabajo se utiliza la espectroscopia fotoacustica para medir la difusividad termica de un sistema de dos capas. Los resultados experimentales son analizados en terminos de los parametros termicos efectivos determinados a partir de un material homogeneo, el cual produce la misma respuesta fisica bajo una perturbacion externa. Se puso particular enfasis en la caracterizacion de los efectos de interfase en el flujo de calor en el sistema de dos capas. Los resultados experimentales se comparan con el modelo teorico propuesto en este trabajo.

  11. La gestión comercial y su influencia en el crecimiento de las PYME hoteleras de Manabí

    Directory of Open Access Journals (Sweden)

    Johnny Edison Ponce Andrade

    2017-12-01

    Full Text Available La gestión comercial y el crecimiento empresarial son dos variables que deben estar intimamente relacionadas para lograr el éxito de las organizaciones, sobre ello muchos teoricos han generado sus aportes. Identificados los problemas de las pequeñas y medianas empresas hoteleras de Manabi-Ecuador en esta investigacion, se planteo el objetivo de establecer que la gestión comercial tiene influencia en el crecimiento de las PYME del sector estudiado. Se aplicaron 246 encuestas a los gerentes/administradores de estas empresas. El metodo de investigación es lógico inductivo completo, a través de la validación de una hipótesis general y tres específicas, utilizando el software estadístico SPSS 21. La prueba de Alfa de Cronbach para validar el instrumento arrojo un 0.994, significando que existe un alto nivel de confiabilidad en los datos recabados; el Rho de Spearman en la hipótesis general es de 0,966 evidenciando un nivel de correlación positiva significativa, con confiabilidad cercana a 1. Palabras clave: gestión comercial, crecimiento empresarial, PYME, marketing, turismo.

  12. Las quiebras de la identidad: La doble faz del espacio público

    Directory of Open Access Journals (Sweden)

    GABRIEL GATTI CASAL DE REY

    1997-01-01

    Full Text Available en el pais vasco, tanto las coordenadas que orientan los discursos sobre la identidad colectiva como los escenarios en los que estos discursos se producen y reelaboran han pasado y pasan, tras el proceso de institucionalizacion politica, por una seria redefinicion. la emergencia de estas nuevas formas de construir identidad hace necesaria la reelaboracion del modelo teorico-metodologico que la sociologia ha aplicado a su estudio. dos momentos estructuran nuestro recorrido: 1 identificar los postulados que soportan este modelo (la socializacion entendida como continuidad, los espacios de interaccion entendidos como lugares antropologicos, la identidad entendida como actualizacion de un codigo que preexiste al sujeto ; 2 edificar una optica alternativa, que encuentra en la imagen de la ruptura su centro orientador (la ruptura de los trayectos de socializacion, la crisis que esconde el acceso a los espacios publicos, las quiebras de la identidad. estos desarrollos se apoyan en el estudio de un caso de especial relevancia sociologica: la gestion que de su entrada a uno de estos escenarios institucionales -el de la universidad del pais vasco en sus ramas de euskera- hacen sujetos socializados en el posfranquismo.

  13. DADOS ESPECTROSCÓPICOS DE DITERPENOS LABDÂNICOS: UMA ANÁLISE TEÓRICA VIA RMN E DFT

    Directory of Open Access Journals (Sweden)

    Fabrine S. de Souza

    2015-05-01

    Full Text Available Labdane diterpenes exhibit important bioactivities such as cardiovascular effects in rats as well as effects in the treatment of autoimmune diseases and Alzheimer syndrome. Recently, the labdane diterpenes ent-13-epi-manoil oxide, ribenone and ribenol were isolated from Croton palanostigma. The computational method DFT/B3LYP/cc-pVDZ was used to optimize the structures of these diterpenes and to calculate infrared data. Chemical shifts (δH and δC of the minimum energy structures (local minimum were calculated and compared with the experimental data. Comparison of the NMR data by simple linear regression (SLR showed satisfactory statistical results with a correlation coefficient (R2 and predictive ability (Q2 of over 98%. The predicted NMR data were used to confirm the δH values that have not been published.

  14. X-ray resonant magnetic scattering investigations of hexagonal multiferroics RMnO3 (R = Dy, Ho, Er)

    International Nuclear Information System (INIS)

    Nandi, Shibabrata

    2009-01-01

    Electricity and magnetism were unified into a common subject by James Clerk Maxwell in the nineteenth century yielding the electromagnetic theory. Four equations govern the dynamics of electric charges and magnetic fields, commonly known as Maxwell's equations. Maxwell's equations demonstrate that an accelerated charged particle can produce magnetic fields and a time varying magnetic field can induce a voltage - thereby linking the two phenomena. However, in solids, electric and magnetic ordering are most often considered separately and usually with good reason: the electric charges of electrons and ions are responsible for the charge effects, whereas the electron spin governs magnetic properties.

  15. Characterization of derivates of carbo-anhydride by NMR; Caracterizacao de derivados do anidrido carbico por RMN

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Marcos Pery Amaral [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Bergter, Lothar [Cia. Souza Cruz, Rio de Janeiro, RJ (Brazil); Seidl, Peter Rudolf [Centro de Tecnologia Mineral, Rio de Janeiro, RJ (Brazil)

    1994-12-31

    The term molecular recognition may be applied to several phenomena of different complexities. The compounds which work as blockers or acceptors in this process are generally complexes with functional groups positioned in specific positions. This work presents the NMR characterization of carbo-anhydride derivates which are important in the preparation of synthetic acceptors 2 figs.

  16. A digital method for period measurements in a nuclear reactor

    International Nuclear Information System (INIS)

    Mundim, Sergio Gorretta

    1971-02-01

    The present paper begins by giving a theoretical treatment for the nuclear reactor period. The conventional method of measuring the period is analysed and some previously developed digital methods are described. The paper criticises the latter, pointing out some deficiencies which the proposed process is able to eliminate. All errors connected with this process are also analysed. The paper presents suitable solutions to reduce them to a minimum. The total error is found to he less than the error presented by the other methods described. A digital period meter is designed with memory resources and an automatic scaler changer. Integrated circuits specifications are used in it. Real time experiments with nuclear reactors were made in order to check te validity of the method. The data acquired were applied to a simulated digital period meter implemented in a general purpose computer. The nuclear part of the work was developed at the 'Comissao Nacional de Energia Nuclear' and the simulation work was dane at the 'Departamento de Calculo Cientifico' of COPPE, which also advised the author in the completion of this thesis. (author)

  17. ESFER computer tool for the evaluation of photovoltaic systems used in rural electrification; ESFER herramienta de computadora para evaluar sistemas fotovoltaicos utilizados en electrificacion rural

    Energy Technology Data Exchange (ETDEWEB)

    Villasenor, Francisco; Perez, Miguel; Huacuz, Jorge M [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    ESFER (Evaluacion de Sistemas Fotovoltaicos para Electrificacion Rural) Photovoltaic Systems Evaluation for Rural Electrification is a computerized calculation tool for the analysis of information and evaluation of photovoltaic systems for rural electrification. This article describes such a tool, as well as the parameters that are taken into account for analyzing the systems, the methodology to qualify and the computer program operation. The graphic results of a typical case are presented. ESFER pretends to be a program of general use for the evaluation of photovoltaic systems for rural electrification. [Espanol] ESFER, Evaluacion de Sistemas Fotovoltaicos para Electrificacion Rural, es una herramienta de calculo computarizada para el analisis de informacion y evaluacion de sistemas fotovoltaicos para electrificacion rural. En el presente articulo se describe dicha herramienta, asi como los parametros que se toman en cuenta para analizar los sistemas, la metodologia de calificacion y la operacion del programa de computadora. Se presentan los resultados graficos de un caso tipico. ESFER pretende ser un programa de uso generalizado para la evaluacion de sistemas fotovoltaicos de electrificacion rural.

  18. Proceedings of the 7 Annual conference of the Mexican association for the energy economy. The energy sector in Mexico: challenges and solutions. [Selected papers]; 7. Conferencia anual de la asociacion mexicana para la economia energetica. El sector energia en Mexico: retos y soluciones

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The Mexican Association for the Energy Economy (AMEE) had its VII annual conference, The energy sector in Mexico: challenges and solutions, in October, 2004. Some of the expounded topics are: technical and environmental aspects of the combined cycle power stations; analysis of the generation of electric power across biogas from sanitary landfills in Mexico; cogeneration in large power plants; methodologies for the calculation of relative efficiency: description and application of natural gas distributors in Latin American and others. [Spanish] La Asociacion Mexicana para la Economia Energetica A. C. (AMEE), llevo acabo su VII conferencia anual El sector energia en Mexico: retos y soluciones, en octubre del 2004. Algunos de los temas tratados son: Aspectos tecnicos y medioambientales de las centrales de ciclo combinado con gasificacion integrada; Analisis de la generacion de energia electrica a traves de biogas procedente de rellenos sanitarios en Mexico; Cogeneracion en grandes centrales de proceso; Metodologias para el calculo de eficiencia relativa: descripcion y aplicacion para distribuidores de gas natural en Latinoamerica y otros.

  19. Development of a therapeutic radiopharmaceutical {sup 177}Lu-DOTA- Minigastrin for potential use in PRRT; Desarrollo de un radiofarmaco terapeutico {sup 177}Lu-DOTA-Minigastrina para su potencial uso en PRRT

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Bularte, A. C.; Nevares, N. N.; Zapata, A. M.; Perez, J. H.; Crudo, J. L. [Comision Nacional de Energia Atomica (Argentina); Puerta Yepes, N.; Rojo, A. M. [Autoridad Regulatoria Nuclear (Argentina)

    2010-07-01

    The aim of this work is to obtain {sup 177}Lu-DOTA-Minigastrin with high radiochemical purity (RP) and the highest specific activity (Ae) as possible, using a locally produced (Nuclear Reactor RA-3, Ezeiza Atomic Center) {sup 177}LuCl{sub 3} of an intermediate level of Ae (between 6.36 to 17.95 Ci/mg of {sup 176}Lu) ) and also to perform in vitro and in vivo stability tests, dose calculation in normal mice and its extrapolation to a human model. (authors) [Spanish] El objetivo de este trabajo consistio en obtener {sup 177}Lu-DOTA-Minigastrina con una alta pureza radioquimica (PR) y la mayor actividad especifica (Ae) posible, empleando {sup 177}LuCl{sub 3} de media Ae (entre 6,36-17,95 Ci/mg de {sup 176}Lu) de produccion local (Reactor Nuclear RA-3, Centro Atomico Ezeiza), y realizar los ensayos de estabilidad in vitro e in vivo, el calculo de dosis en ratones normales y su extrapolacion a un modelo humano. (autores)

  20. A digital method for period measurements in a nuclear reactor; Um metodo digital para medidas de periodo em um reator nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Mundim, Sergio Gorretta

    1971-02-15

    The present paper begins by giving a theoretical treatment for the nuclear reactor period. The conventional method of measuring the period is analysed and some previously developed digital methods are described. The paper criticises the latter, pointing out some deficiencies which the proposed process is able to eliminate. All errors connected with this process are also analysed. The paper presents suitable solutions to reduce them to a minimum. The total error is found to he less than the error presented by the other methods described. A digital period meter is designed with memory resources and an automatic scaler changer. Integrated circuits specifications are used in it. Real time experiments with nuclear reactors were made in order to check te validity of the method. The data acquired were applied to a simulated digital period meter implemented in a general purpose computer. The nuclear part of the work was developed at the 'Comissao Nacional de Energia Nuclear' and the simulation work was dane at the 'Departamento de Calculo Cientifico' of COPPE, which also advised the author in the completion of this thesis. (author)

  1. ESFER computer tool for the evaluation of photovoltaic systems used in rural electrification; ESFER herramienta de computadora para evaluar sistemas fotovoltaicos utilizados en electrificacion rural

    Energy Technology Data Exchange (ETDEWEB)

    Villasenor, Francisco; Perez, Miguel; Huacuz, Jorge M. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1995-12-31

    ESFER (Evaluacion de Sistemas Fotovoltaicos para Electrificacion Rural) Photovoltaic Systems Evaluation for Rural Electrification is a computerized calculation tool for the analysis of information and evaluation of photovoltaic systems for rural electrification. This article describes such a tool, as well as the parameters that are taken into account for analyzing the systems, the methodology to qualify and the computer program operation. The graphic results of a typical case are presented. ESFER pretends to be a program of general use for the evaluation of photovoltaic systems for rural electrification. [Espanol] ESFER, Evaluacion de Sistemas Fotovoltaicos para Electrificacion Rural, es una herramienta de calculo computarizada para el analisis de informacion y evaluacion de sistemas fotovoltaicos para electrificacion rural. En el presente articulo se describe dicha herramienta, asi como los parametros que se toman en cuenta para analizar los sistemas, la metodologia de calificacion y la operacion del programa de computadora. Se presentan los resultados graficos de un caso tipico. ESFER pretende ser un programa de uso generalizado para la evaluacion de sistemas fotovoltaicos de electrificacion rural.

  2. Herramienta de Análisis y Diseño de Sistemas de Control Basada en Hojas de Cálculo Excel

    Directory of Open Access Journals (Sweden)

    Nourdine Aliane

    2009-10-01

    Full Text Available Resumen: Este artículo presenta una herramienta para el análisis y diseño de sistemas de control basada en hojas de cálculo Excel. Esta herramienta es un conjunto de subrutinas y funciones desarrolladas con el lenguaje VBA. En la actualidad, esta herramienta se limita al manejo de sistemas lineales representados mediante la función de transferencia. El usuario puede especificar modelos, obtener sus respuestas transitorias y en frecuencia, simular un sistema realimentado a través de un controlador, o ajustar los parámetros de un controlador de forma interactiva. Además, la herramienta permite al usuario mantener varias simulaciones en una misma hoja de cálculo, y su carácter interactivo hace posible observar el efecto de varios parámetros sobre el comportamiento de los sistemas de forma inmediata. Para ilustrar el alcance y algunas características de esta herramienta, se han incluido varios ejemplos. Palabras clave: Control, Sistemas lineales, Simulación, Hojas de Calculo

  3. Muerte súbita por conmoción cardíaca (Commotio cordis asociada a miocardio no compactado Sudden death due to commotio cordis associated to non compacted myocardium

    Directory of Open Access Journals (Sweden)

    Analía Aquieri

    2011-12-01

    Full Text Available El miocardio no compactado es una rara miocardiopatía congénita caracterizada por la presencia de múltiples y prominentes trabeculaciones profundas en la pared ventricular que definen hendiduras comunicantes con el compartimiento ventricular principal. Es una entidad de baja incidencia y prevalencia que se diagnostica mediante estudios de imágenes como el ecocardiograma Doppler (ED, la tomografía computarizada multicorte (TCM y la resonancia magnética cardíaca (RMC. Puede ser asintomática o manifestarse mediante arritmias, insuficiencia cardíaca o eventos tromboembólicos. Se presenta el caso de un hombre de 33 años, asintomático, que durante la práctica deportiva sufre una conmoción cardíaca (commotio cordis que le produce un paro cardiorrespiratorio. El electrocardiograma mostró un ritmo de aleteo ventricular que requirió cardiodesfibrilación eléctrica. En un ED efectuado inicialmente no se observaron anormalidades significativas, pero otro ED, una TCM y una RMN obtenidos luego del alta, certificaron el hallazgo de miocardio no compactado aislado, descartando coronariopatía. Recibió tratamiento beta bloqueante y antiagregante y se discutió la colocación del cardiodesfibrilador implantable. Se plantea la fisiopatología de la asociación de estas dos infrecuentes y potencialmente letales afecciones.Non compact of the left ventricular myocardium is a rare congenital cardiomyopathy characterized by the presence of multiple and prominent deep trabeculations in the ventricular wall, that define recesses communicated with the main ventricular chamber. This is a condition with low incidence and prevalence, diagnosed through imaging techniques such as Doppler echocardiogram (DE, multi-slice computed tomography (MSCT or magnetic resonance imaging (MRI. Clinically, it may be asymptomatic or manifested by cardiac arrhythmias, heart failure or thromboembolism. This is a report on a 33 year old asymptomatic man who suffered a blow on

  4. Strontium-90 in milk and mixed diet in the Czech Republic

    International Nuclear Information System (INIS)

    Bartuskova, M.; Schlesingerova, E.

    2014-01-01

    Among various activities of National Radiation Protection Institute (SURO) monitoring of radionuclides in environment and food chain plays an important role. The monitoring takes place in frame of Czech Radiation Monitoring Network (RMN). Determinations of 90 Sr are performed according to the monitoring schedule of RMN. Strontium-90 was released into environment during the tests of nuclear weapons in the fifties and sixties of XX. century and to some extent in 1986 owing to the Chernobyl accident. Strontium is a chemical analogue of calcium and accordingly when entering a mammal body, it behaves very much like calcium. A large portion of the strontium will accumulate in bone and like calcium it transfers to milk. Since the Sr uptake by the human body from milk is an important pathway for radiostrontium incorporation, milk and milk powder are good indicators of 90 Sr content in human diet. Along with milk and milk powder, mixed diet samples composed of representative locally purchased food items according to food consumption statistics are also analysed for 90 Sr.The analyses are made using oxalate precipitation method, when interfering radionuclides are removed by precipitation scavenging and after its ingrowth 90 Y is separated and repeatedly measured by gas flow proportional counter. Strontium-90 activity is calculated as equal to 90 Y activity in equilibrium. Time evolution of 90 Sr activities in milk in Northern Moravia region (1988 present) and in Prague (1965 - present), in milk powder from the regions of the Czech Republic and in the mixed diet samples from the whole republic is presented on the poster. A very small increase due to the Chernobyl accident can be seen in milk. After the ban of atmospheric tests the level of 90 Sr has steadily been falling. The decrease is caused by radioactive decay and migration of the radionuclide in the environment. Due to this decrease activity concentrations in many samples have recently fallen under minimum significant

  5. Contribution to the study of the structure and properties of silica gel (1962); Contribution a l'etude de la structure et des proprietes des gels de silice (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Fraissard, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-04-15

    The study of the texture of two types of silica gels, xerogels and aerogels, shows that the latter evolve differently on heating. By I.R. spectrography it has been possible to establish that this is due to the existence, in these solids, of a microstructure undetectable by X-rays and which depends on the preparation conditions initially. By using both chemical (thermogravimetry, hydrolysis of diborane) and physical (I.R. spectrography and wide-band N.M.R.) methods we have been able to determine the state of the water of constitution of these gels (water molecules and hydroxyls) and to show that the density, the distribution and the mobility of the protons of this water are very different. For example, the relaxation time T{sub 1} of the protons of a xerogel is about 1 second whilst that of the protons in an aerogel is of the order of a microsecond. Finally, it has been possible by using high resolution N.M.R. to propose a mechanism for the adsorption of formic acid on two types of gel thereby explaining, with the help of previous results, the differences in specificity of these two solids in the decomposition reaction of this acid. (author) [French] L'etude de la texture de deux types de gels de silice, les xerogels et les aerogels, montre que ceux-ci evoluent differemment en fonction de la temperature. La spectrographie I.R a permis de preciser que ceci est du a l'existence, dans ces solides, d'une microstructure indecelable aux rayons X, et fonction des conditions initiales de preparation. Par des methodes chimiques (thermogravimetrie, hydrolyse du diborane) et physiques (spectrographie I.R et R.M.N. large bande), nous avons pu determiner l'etat de l'eau de constitution de ces gels (molecules d'eau et hydroxyles) et montrer que la densite, la repartition et la mobilite des protons de cette eau sont tres differentes. Ainsi le temps de relaxation T{sub 1} des protons d'un xerogel est de l'ordre de la seconde, celui des protons d'un aerogel de l'ordre de la

  6. Estudio de la grasa de teobroma ozonizada usando la Resonancia Magnética

    Directory of Open Access Journals (Sweden)

    Fernández Torres, Irán

    2007-03-01

    Full Text Available Ozonation of theobroma fat at different applied ozone dosages was carried out and peroxide indexes along with antimicrobial activity were determined. The reaction products were identified using Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR. The principal signal intensity values were used for following the reaction course between ozone and theobroma fat. The reaction was followed up to peroxide index values of 544 mmol-equiv/kg. The intensities of olefinic proton signals decreased with the gradual increase in ozone concentration until disappearing completely. The Criegee ozonides obtained at 87.4 mg/g of ozone doses were approximately 3.7 times higher than at the beginning of the reaction. The highest action spectrum of antimicrobial activity was obtained with the higher peroxide index. These results suggest that the 1H NMR spectroscopic technique provides valuable information about of the ozonization grade of theobroma fat which produces an affective antimicrobial activity against Candida albicansSe realizó un estudio de la ozonización de la grasa de teobroma el cual fue seguido a diferentes dosis de ozono y fueron determinados los índices de peróxidos y su actividad antimicrobiana. Los productos de reacción fueron identificado por la espectroscopia de Resonancia Magnética Nuclear Protónica (RMN 1H. Los principales valores de intensidad de las señales fueron usados para el seguimiento de la reacción entre el ozono y la grasa de teobroma. La reacción fue seguida hasta un valor de índice de peróxidos de 1 544 mmolequiv/kg. Las intensidades de las señales de los protones olefínicos desaparecen con un gradual incremento de la concentración de ozono. Los ozónidos de Criegee obtenidos a dosis de ozono de 87,4 mg/g fueron 3,7 veces mayores que los obtenidos al inicio de la reacción. El mayor espectro de acción de la actividad antimicrobiana fue obtenido a mayor índice de peróxidos. Estos resultados sugieren que la t

  7. Design, construction and characterization of a rural solar furnace; Diseno, construccion y caracterizacion de un horno solar rural

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Luna, Gabriela

    2001-06-15

    , Jaramillo et al., 1999) del Centro de Investigacion en Energia (CIE) de la Universidad Nacional Autonoma de Mexico (UNAM). El contenido de la tesis incluye la sistematizacion del trabajo previamente realizado por dichos autores: el diseno y la optimizacion de la geometria, la evaluacion experimental de la misma, asi como tambien un modelo teorico del comportamiento termico del horno solar basado en un balance global de energia que supone estados de cuasi-equilibrio termico de los componentes internos del horno. En esta tesis se desarrolla un modelo teorico de la concentracion de energia solar por los reflectores del horno basado en el modelo de Peres y Karsson (1993). Las predicciones de este modelo se comparan satisfactoriamente con los resultados experimentales de Jaramillo et al. (1999). Contando con el diseno opto-geometrico del horno, se concluye el diseno seleccionando los materiales a utilizar en las distintas partes del mismo, asi como definiendo detalles constructivos. El material seleccionado para las cajas interiores y exteriores y los reflectores es acero inoxidable acabado espejo. Como aislante se usa lana mineral. La parte superior del horno se encuentra protegida por un vidrio que permite la entrada de energia solar y disminuye las perdidas de energia convectivas y radiativas. Para la evaluacion termica del horno se sigue una metodologia experimental basada en los procedimientos internacionales estandarizados para pruebas de hornos y estufas solares (Funk, 2000). Se realizaron tres pruebas para cada una de las siguientes condiciones de operacion: sin carga, con aceite y con agua. La maxima temperatura registrada en el aire interior del horno, para la primera condicion fue de 150 grados centigrados, seguida de la condicion utilizando 6 litros de aceite, en la que se obtuvo una temperatura maxima de 115 grados centigrados y en las pruebas con 6 litros de agua como carga se registro una temperatura maxima de 95 grados centigrados. En estas pruebas la temperatura

  8. Calculation of reactivity without Lagrange interpolation; Calculo de la reactividad sin interpolacion de Lagrange

    Energy Technology Data Exchange (ETDEWEB)

    Suescun D, D.; Figueroa J, J. H. [Pontificia Universidad Javeriana Cali, Departamento de Ciencias Naturales y Matematicas, Calle 18 No. 118-250, Cali, Valle del Cauca (Colombia); Rodriguez R, K. C.; Villada P, J. P., E-mail: dsuescun@javerianacali.edu.co [Universidad del Valle, Departamento de Fisica, Calle 13 No. 100-00, Cali, Valle del Cauca (Colombia)

    2015-09-15

    A new method to solve numerically the inverse equation of punctual kinetics without using Lagrange interpolating polynomial is formulated; this method uses a polynomial approximation with N points based on a process of recurrence for simulating different forms of nuclear power. The results show a reliable accuracy. Furthermore, the method proposed here is suitable for real-time measurements of reactivity, with step sizes of calculations greater that Δt = 0.3 s; due to its precision can be used to implement a digital meter of reactivity in real time. (Author)

  9. Principle and Potential of Nuclear Magnetic Resonance Applied to the Study of Fluids in Porous Media Principe et potentialité de la résonance magnétique nucléaire appliquée à l'étude des fluides en milieux poreux

    Directory of Open Access Journals (Sweden)

    Chardaire-Riviere C.

    2006-11-01

    Full Text Available Nuclear magnetic resonance (NMR and magnetic resonance imaging (MRI have been used in recent years in many fields, including the chemical and petroleum industries, and medicine. Following a review of the basic principles of these two techniques, their applications concerning the study of fluids in porous media are presented. The use of NMR in petrophysics is limited to the study of porosity, permeability, wettability, and the determination of the pore size distribution and saturation in a sample. MRI is an extremely useful technique, not only as a tomographic approach but, above all, because, it helps today to identify certain properties, such as velocity images. This article also presents the results obtained at Institut Français du Pétrole (IFP concerning the study of wettability by NMR and the use of a high magnetic field to visualize fluids in porous media. In the future, a major potential use of NMR for the study of fluids in porous media resides in the extrapolation of the results obtained by spectroscopy to wireline logs, and to imaging. L'évaluation du taux de récupération optimale d'un gisement d'hydrocarbures repose sur l'utilisation des lois d'écoulements polyphasiques en milieu poreux : les lois de Darcy généralisées. Celles-ci permettent d'interpréter des mesures de laboratoire sur des échantillons de gisement, afin de les introduire dans les modèles numériques de simulation à l'échelle du réservoir. Pour envisager une étude approfondie de ce qui se passe en matière d'écoulement à l'intérieur des milieux poreux, il faut évaluer de manière très précise la distribution des fluides. Pour cette raison, les études tomographiques apportent une contribution importante à la connaissance des écoulements en milieu poreux. Dans cet article la méthode tomographique envisagée est l'imagerie par résonance magnétique (IRM qui est une extension de la résonance magnétique nucléaire (RMN. Les principes de ces deux m

  10. Propriedad intelectual en el marco del acuerdo Mercosur – Union Europea de 1995: apuntes teoricos para las negociaciones intercontinentales (1999-2002

    Directory of Open Access Journals (Sweden)

    Astrid Uzcátegui

    2002-09-01

    Full Text Available El presente artículo buscapresentar consideraciones científicas sobrela propiedad intelectual que pueden ser utilizadaspor los negociadores intercontinentalesdel Mercado Común del Sur convistas a alcanzar mejores resultados en elcomplejo proceso de negociación con laUnión Europea que resultará en la primeraZona de Libre Comercio entre dos unionesaduaneras a escala intercontinental. En estesentido, la superación de las eventualestrabas por los dos bloques regionales daráal mundo una verdadera prueba de lavalidez de un regionalismo abierto.Abstract: The present article presentsscientific considerations on intellectualproperty which may be used by intercontinentalnegotiators of the Mercosur, with theaim of accomplishing better results in thecomplex negotiation process whose resultwill be the first Free Trade Zone betweentwo customs unions in an intercontinentalscale. In this sense, overcoming eventualobstacles between these two regional blockswill offer the world a true evidence of thevalidity of an open regionalism.

  11. NMR study of hydrated calcium silicates; Etude par RMN de la structure des silicates de calcium hydrates

    Energy Technology Data Exchange (ETDEWEB)

    Klur, I

    1996-02-26

    Radioactive wastes storage methods are developed by the CEA. As cements are important materials as well for hours living radioisotopes than for years living radioisotopes, a better knowledge of this material will allow to anticipate its behaviour and to obtain safer storage methods. The structure of calcium silicates (C-S-H) (main constituent of cements) have then been determined in this thesis by nuclear magnetic resonance. This method has allow to explain in structural terms, the different calcium rates that can be measured in the C-S-H too. (O.M.) 101 refs.

  12. Estudio cinético de la interconversión de Astilbina mediante espectroscopia de 1H-rmn

    Directory of Open Access Journals (Sweden)

    Omar Estrada

    2012-12-01

    Full Text Available The interconversion kinetics of astilbin to a mixture of their respective diasteroisomers was studied by nuclear magnetic resonance spectroscopy using selective irradiation experiments (TOCSY in dimethylsulfoxide. It is proposed a model which allowed establishing a trend to equilibrium for H-3 (astilbin interconversion to neoisoastilbin

  13. Camphor: a good model for illustrating NMR techniques; Canfora: um bom modelo para ilustrar tecnicas de RMN

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, Julliane Diniz; Leal, Katia Zaccur [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Fisico-Quimica]. E-mail: kzl@rmn.uff.br; Seidl, Peter Rudolf [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica. Dept. de Processos Organicos; Azeredo, Rodrigo Bagueira de V. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Quimica. Dept. de Quimica Organica; Kleinpeter, Erich [Universitaet Potsdam (Germany). Chemisches Institut

    2007-07-01

    The use of Nuclear Magnetic Resonance spectroscopy to establish the three-dimensional structures of molecules is an important component of modern Chemistry courses. The combination of techniques that can be used for this purpose is conveniently illustrated by their application to the camphor molecule. This paper presents applications of several techniques used in NMR spectral interpretation in an increasing order of complexity. The result of individual experiments is illustrated in order to familiarize the user with the way connectivity through bonds and through space is established from 1D/2D-NMR spectra and molecular stereochemistry is determined from different NMR experiments. (author)

  14. Constituintes químicos do caule de Protium hebetatuml (Burseraceae Chemical constituents from the stem of Protium hebetatuml (Burseraceae

    Directory of Open Access Journals (Sweden)

    Túlio de Orleans Gadelha Costa

    2012-01-01

    Full Text Available Protium é um gênero que se destaca na família Burceraceae, compreende cerca de 146 espécies, das quais um pequeno número tem sido estudada do ponto de vista fitoquímico. Neste trabalho, foram isolados os terpenoides α- e β-amirina, os esteroides campesterol, estigmasterol e sitosterol e a cumarina escopoletina, a partir do tronco de Protium hebetatuml. As estruturas destas substâncias foram identificadas por RMN, MS, IV e por comparação com dados espectrais obtidos naa literatura e com amostras autênticas.Protium is the largest genus in the Burceraceae family, which comprises about 146 species, of which a small number has been studied from the phytochemical point of view. In this work the terpenoids α- and β-amyrin, the steroids campesterol, stigmasterol and sitosterol and the coumarin scopoletin were isolated from the stem of Protium hebetatuml. The structures of these substances were identified by NMR, MS, IV and comparison with spectral data from the literature and with authentic samples.

  15. Initial experience of a novel mapping system combined with remote magnetic navigation in the catheter ablation of atrial fibrillation

    DEFF Research Database (Denmark)

    Lin, Changjian; Pehrson, Steen; Jacobsen, Peter Karl

    2017-01-01

    the novel mapping system, LA mapping time was fast (308 ± 60 seconds) with detailed anatomy points (178,831 ± 70,897) collected and magnetic points throughout LA. At the end of the procedures in Group A, the LA model was confirmed to be stable and its location was within the distance threshold (1 mm......). Procedure time (117.9 ± 29.6 minutes vs. 119.2 ± 29.7 minutes, P = 0.89), fluoroscopy time (6.1 ± 2.4 minutes vs. 4.8 ± 2.2 minutes, P = 0.07), and ablation time (28.0 ± 12.9 minutes vs. 27.9 ± 15.8 minutes, P = 0.98) were similar in Group A versus Group B, respectively. No complications occurred in either...... of a novel 3D mapping system (EnSite Precision mapping system) combined with RMN (Niobe ES, Stereotaxis, Inc., St. Louis, MO, USA) for atrial fibrillation (AF) ablation. METHODS: In this prospective nonrandomized study, two groups of patients were treated in our center for drug refractory AF. Patients were...

  16. Borazinas fluorinadas

    Directory of Open Access Journals (Sweden)

    O. Obando

    2009-07-01

    Full Text Available Se estandarizan las condiciones para la elaboración del eterato de trifluoruro de boro, BF3. Et20(l. A partir de (I se obtienen los diferentes aducios, de trifluoruro de boro con aminas primarias y terciarias, empleados en la síntesisde B,B',B" - t r i f l u o r o - N , N ' , N " - t r i a r i l (o trialquil borazinas, ( - B F - N R - 3 (II, donde R = Fenil, o - t o l u i l , p—toluil, terbutil. La reacción de obtención de (II consiste en la deshidrofluoración del aducto BFo—amina primaria por el aducto de impedimento BF3—Amina terciaria, teniendo en cuenta su relación estequiométrica dentro del sistema. Las B—trifluoro borazinas se analizan por espectroscopias IR, UV, y RMN H, análisis elemental y crioscopia.Mediante el empleo del mismo tipo de reacción, se intenta la obtención de polímeros entrecruzados (III por enlazamiento con diaminas.

  17. Monitoring around the secret nuclear facilities of naval ports; Surveillance autour des INBS des ports militaires

    Energy Technology Data Exchange (ETDEWEB)

    Jaskierowicz, D. [Marine Nationale, pharmacien en chef, conseiller scientifique et technique, etat-major de la marine, 83 - Toulon (France); Quere, St. [Marine Nationale, capitaine de corvette, adjoint charge de la prise en compte des installations nucleaires sur l' environnement et le personnel, 83 - Toulon (France)

    2010-06-15

    Based within large industrial cities (Brest, Toulon, Cherbourg) or more rural areas like Crozon (Ile Longue), French navy exploits nuclear facilities where are built, maintained and decommissioned nuclear power submarines and aircraft-carrier. The safety and the security of these installations as well as the non-impact on people and environment are continuously monitored. The DSND, a governmental regulatory body dedicated to the Defense, applies the same regulations enforced by the ASN for civilian nuclear activities. Concerning environmental monitoring, the navy answers to the DSND or the ASN, depending on the type of survey. In every nuclear site, an automatic nuclear monitoring sensor system (2SNM) runs 24/7, with the supervision of specialized personnel in radioprotection. Each year, more than 7000 samples are collected in the ecosystem and thousands of measurements are carried out in four laboratories (LASEM in Cherbourg, Brest and Toulon) - SPRS ILO) of the navy. These results are sent to the DSND and have been integrated since February 2010 to the brand-new public web site of the national monitoring network of radioactivity in the environment (RMN). (author)

  18. Monitoring around the secret nuclear facilities of naval ports

    International Nuclear Information System (INIS)

    Jaskierowicz, D.; Quere, St.

    2010-01-01

    Based within large industrial cities (Brest, Toulon, Cherbourg) or more rural areas like Crozon (Ile Longue), French navy exploits nuclear facilities where are built, maintained and decommissioned nuclear power submarines and aircraft-carrier. The safety and the security of these installations as well as the non-impact on people and environment are continuously monitored. The DSND, a governmental regulatory body dedicated to the Defense, applies the same regulations enforced by the ASN for civilian nuclear activities. Concerning environmental monitoring, the navy answers to the DSND or the ASN, depending on the type of survey. In every nuclear site, an automatic nuclear monitoring sensor system (2SNM) runs 24/7, with the supervision of specialized personnel in radioprotection. Each year, more than 7000 samples are collected in the ecosystem and thousands of measurements are carried out in four laboratories (LASEM in Cherbourg, Brest and Toulon) - SPRS ILO) of the navy. These results are sent to the DSND and have been integrated since February 2010 to the brand-new public web site of the national monitoring network of radioactivity in the environment (RMN). (author)

  19. ALCALOIDES BENCILISOQUINOLÍNICOS DEL TALLO DE Piper augustum Rudge

    Directory of Open Access Journals (Sweden)

    Wilman Delgado A.

    2010-10-01

    Full Text Available Del extracto etanólico del tallo de P. augustum Rudge se aislaron: 3beta-hidroxi- 24-etil-delta5.22colestadieno (estigmasterol I ; l,2-metilendioxi-6-metil-4H-dibenzo(deg quinolina-4,5(6Hdiona (Cepharadione A II; lactama del ácido lO-amino-3,4- dimetoxifenantreno-1-carboxílico (Cepharanone B n i y el nuevo compuesto natural: lactama del ácido N-metil-lO-amino- 4-hidroxi-2,3-dimetoxifenantreno-1 –carboxílico IV, Todos los compuestos fueron identificados mediante técnicas espectroscópicas (EM, RMN 'H y "C, IR y UV y comparación con datos reportados en la literatura; adicionalmente I y II fueron identificados por comparación con muestras auténticas (CCF, pf, y pf, mixto. El extracto etanólico del tallo de Piper augustum Rudge presentó una moderada actividad biológica (DL50 = 350 ppm según el ensayo de mortalidad de Artemia salina Leach (Brine Shrimp Lethality.

  20. Factores Determinantes de la Relación entre el Crecimiento Económico, la Equidad y la Competitividad

    Directory of Open Access Journals (Sweden)

    José Vicente Cadavid H.

    2006-10-01

    Full Text Available En este articulo se describen y analizan distintos enfoques que explican la relación entre las variables agregadas: el crecimiento economico, la productividad y la competitividad de la economia. Se senalan y agrupan las controversias sobre la causalidad desigualdad – crecimiento, y ademas de mostrar un modelo propuesto por Ros (2004 apoyado en el enfoque de la contabilidad del crecimiento (Residuo de Solow, se analizan otros resultados de evidencias econometricas, para finalmente enumerar las deficiencias de la investigacion teorica y de los estudios estadísticos y econometricos de tales interrelaciones y sus determinantes. Igualmente, el escrito es prolijo en la descripcion y analisis de los distintos enfoques y modelos sobre la competitividad de las naciones, desagregando el conjunto de variables que son consideradas por las instituciones de mayor reconocimiento en el tratamiento del tema -CEPAL, FORO ECONOMICO MUNDIAL- para evaluar la evolucion de la competitividad estructural, sistemica y global de las economias. Luego de trasegar por una gama de posturas que le son inherentes al tema, se concluye la falta de contundencia de los enfoques teoricos y las pocas evidencias empiricas sobre las relaciones entre el crecimiento economico, la desigualdad, la pobreza y la competitividad

  1. Lo Gnomone Clementino Astronomia Meridiana in Basilica

    Science.gov (United States)

    Sigismondi, Costantino

    2014-05-01

    Costruito per chiara volontà del papa 70 anni dopo il caso Galileo, lo Gnomone Clementino è un grande telescopio solare che non fa uso di lenti a 92 anni dall’invenzione del cannocchiale. Queste due caratteristiche basterebbero da sole a giustificare l’interesse verso questo strumento. L’astronomia meridiana è alla base dell’astrometria e dell’astrofisica moderna. Lo Gnomone Clementino sta oggi all’astronomia, come il veliero “Amerigo Vespucci” sta alla Marina Italiana. E’ possibile svolgere ogni genere di osservazione e studio su questo strumento, e dal 2002 vi tengo lezioni teorico-pratiche del corso di Storia dell’Astronomia e La Terra nel Sistema Solare della Sapienza, Università di Roma, Facoltà di Lettere e Filosofia. Questo testo aggiunge alcuni tasselli alla ricerca storica sulla meridiana, appoggiandosi, com’è naturale, sulle spalle di giganti che mi hanno preceduto in questi studi. In particolare la misura dell’azimut della meridiana, ed il suo inquadramento tra gli strumenti simili ed alcuni studi di astrometria sui dati del 1701-1703 di Bianchini, che sono apparsi fin’ora soltanto su riviste specializzate ed in Inglese vengono qui proposti in Italiano e semplificati, per valorizzare sempre più questa straordinaria opera d’arte e di scienza.

  2. Soil pro consolidation load and settlement computation; Preconsolidacion de los suelos y calculo de asentamiento

    Energy Technology Data Exchange (ETDEWEB)

    Delgado Martinez, D. E.

    2009-07-01

    It is estimated that cohesive soils are present in about in about 80% of the Cuban territory. Most of these soils are pre consolidated as a result of the country's geo-environmental conditions. That's why it is important, in the Cuban context, to determine accurately the soil pre consolidation load, correct the oedometric curve and apply these concepts to settlement computation. In this paper, a study is presented to define how to estimate the pre consolidation pressure by using several methods. A database was created. It consisted of 102 pre consolidated soils, which are typical from the central region of Cuban. These soil we analyzed by several Cuban geotechnical research centers. (Author) 12 refs.

  3. Characteristic parameters of drift chambers calculation; Calculo de los parametros caracteristicos de camaras de deriva

    Energy Technology Data Exchange (ETDEWEB)

    Duran, I; Martinez-Laso, L

    1989-07-01

    We present here the methods we used to analyse the characteristic parameters of drift chambers. The algorithms to calculate the electric potential in any point for any drift chamber geometry are presented. We include the description of the programs used to calculate the electric field, the drift paths, the drift velocity and the drift time. The results and the errors are discussed. (Author) 7 refs.

  4. Calculos de estabilidade e divisão de fases por meio de redes neurais artificiais

    OpenAIRE

    Jones Erni Schmitz

    2006-01-01

    Resumo: A simulação de processos é um componente fundamental de uma grande variedade de atividades de Engenharia de Processos, tais como a Otimização Online, o controle em Tempo Real, a Identificação, etc. O cálculo de Equilíbrio de Fases é uma atividade fundamental em qualquer simulação de processos de separação. O elevado tempo computacional deste cálculo provocado pela sua natureza iterativa pode criar incompatibilidades entre a atividade de simulação e as aplicações em tempo real que ela ...

  5. Los salarios dentro del sistema del repartimiento forzoso en el Valle de México, 1549-1632

    Directory of Open Access Journals (Sweden)

    Spanoghe, Sander

    1997-06-01

    Full Text Available Not available.

    Este artículo contiene un análisis del salario dentro del repartimiento forzoso, principal sistema de reclutamiento de mano de obra indígena en el Valle de México desde aproximadamente 1550 hasta 1632. Primeramente establezco el valor nominal de los salarios, basándome en fuentes secundarias. En segundo lugar diferencio los salarios según los sectores económicos, consultando fuentes primarias. Después calculo el valor real de estos salarios a base de los precios de maíz y del mínimo socio-vital. Una comparación de los salarios pagados dentro con los dados fuera del repartimiento constituye un tercer método para valorar dichos salarios, mientras el cuarto consiste en una investigación de la relación entre tributo y salario. Siguen las conclusiones, que consideran el salario dentro de su contexto histórico y geográfico, concluyendo que este salario no fue una realidad “real” sino una realidad legal, instituido para callar la conciencia y la crítica de la política laboral colonial.

  6. VARIABILIDADE ESPACIAL DOS ÍNDICES DRIS DO NITROGÊNIO E DO POTÁSSIO NA CULTURA DO MAMOEIRO

    Directory of Open Access Journals (Sweden)

    Mariana Lima de Jesus

    2017-01-01

    Full Text Available Tendo em vista a importância do N e do K no fomento do crescimento vegetativo e do estádio de florescimento do mamoeiro e de sua influencia no equilíbrio nutricional da lavoura  objetivou-se com esse estudo quantificar a variabilidade espacial dos índices DRIS do N e do K de mamoeiro produzido no norte capixaba e correlacionar linearmente e espacialmente seus valores com a produtividade e o índice de balanço nutricional da lavoura. O estudo foi realizado com dados de produtividade e de teores foliares (macronutrientes: N, P, K, Ca, Mg, S; e micronutrientes: Zn e Mn. do pecíolo do mamoeiro de 129 pontos georreferenciados, de uma lavoura comercial de mamão, no município de São Mateus-ES. Esse teores foliares foram utilizados para calculo dos Índice DRIS e do índice de balanço nutricional (IBN. Os índices DRIS do N e do K apresentaram dependência espacial, ajustando-se aos modelos exponencial e esférico, respectivamente. Apenas o IDK apresentou correlação linear com a produtividade.

  7. Studies for the elaboration of standards of energy efficiency in constructions; Estudios para la elaboracion de normas de eficiencia energetica en edificaciones

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Niembro, Gaudencio; Heard, Christopher [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Hernandez Pensado, Fernando [Comision Nacional para el Ahorro de Energia (Mexico)

    1999-07-01

    The obtaining of the first drafts of standard of energy efficiency implicate diverse research work previous to its elaboration, which include the justification and the analysis of the reason of the variables to consider, the corresponding cost-benefit study that gives viability to the standard and a procedure of calculation for its fulfillment. The present paper relates the diverse aspects that were analyzed for the justification, the revision and the obtaining of the first drafts of the first standards of energy efficiency in nonresidential constructions that are hoped to be implemented in Mexico. [Spanish] La obtencion de los anteproyectos de norma de eficiencia energetica implica diversos trabajos de investigacion previos a su elaboracion, los cuales incluyen la justificacion y el analisis del porque de las variables a considerar, el estudio costo- beneficio correspondiente, que da viabilidad a la norma y un procedimiento de calculo para su cumplimiento. El presente trabajo relata los diversos aspectos que se analizaron para la justificacion, la revision y la obtencion de los anteproyectos de las primeras normas de eficiencia energetica en edificaciones no residenciales que se esperan implantar en Mexico.

  8. Educando el alma psicológica

    Directory of Open Access Journals (Sweden)

    Matthew Curtis

    2007-01-01

    Full Text Available Este trabajo retoma aspectos de una exploración de los trabajos de cuatro importantes psicólogos educativos estadounidenses –Granville Stanley Hall, William James, John Dewey y Edward Thorndike– para concentrarse en los principios rectores del desarrollo de los niños. Los trabajos de estos autores están considerados como funciones que psicologizan al niño como un proceso de llegar a ser humano, que deba ser educado con fines éticos e inteligentes. Dos puntos de partida históricos se abordan en este artículo: (1 explorar la psicología como una formación de la moral del niño y (2 la clasificación y el orden del ser de forma razonada a partir de una psicología que abre el interior del niño a la supervisión y al calculo. Este enfoque explora la psicología educativa como una maquinaria de prácticas discusivas, intelectuales y materiales que invitan al estudiante a ver /ser visto y formar/ser formado de formas particulares. Educar al yo autónomo requería métodos modernos

  9. A digital method for period measurements in a nuclear reactor; Um metodo digital para medidas de periodo em um reator nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Mundim, Sergio Gorretta

    1971-02-15

    The present paper begins by giving a theoretical treatment for the nuclear reactor period. The conventional method of measuring the period is analysed and some previously developed digital methods are described. The paper criticises the latter, pointing out some deficiencies which the proposed process is able to eliminate. All errors connected with this process are also analysed. The paper presents suitable solutions to reduce them to a minimum. The total error is found to he less than the error presented by the other methods described. A digital period meter is designed with memory resources and an automatic scaler changer. Integrated circuits specifications are used in it. Real time experiments with nuclear reactors were made in order to check te validity of the method. The data acquired were applied to a simulated digital period meter implemented in a general purpose computer. The nuclear part of the work was developed at the 'Comissao Nacional de Energia Nuclear' and the simulation work was dane at the 'Departamento de Calculo Cientifico' of COPPE, which also advised the author in the completion of this thesis. (author)

  10. Development of a dose database in the refuelling scenario of a nuclear power plant for a virtual reality application

    International Nuclear Information System (INIS)

    Rodenas, J.; Zarza, I.; Pascual, A.; Felipe, A.; Sanchez-Mayoral, M.L.

    2002-01-01

    Operators in Nuclear Power Plants can receive high doses during refuelling operation. A training program simulating refuelling operations will be useful to reduce doses received by workers as well as to minimise operation time. With this goal in mind a Virtual Reality application is developed in the frame of CIPRES Project (Calculos Interactivos de Proteccion Radiologica en un Entorno de Simulacion - Interactive Calculations of Radiological Protection in a Simulation Environment), a RD project sponsored by IBERINCO and developed jointly by IBERINCO and the Nuclear Engineering Department of the Polytechnic University of Valencia. The Virtual Reality application requires the possibility of displaying doses, both instantaneous and accumulated, at all times during the operator training. Therefore, it is necessary to elaborate a database containing dose rates at every point of the refuelling plant. This database is elaborated from Radiological Protection Surveillance data measured throughout the plant during refuelling operation. To estimate doses throughout the refuelling plant some interpolation routines have been used. Different assumptions have been adopted in order to perform the interpolation and obtain consistent data. In this paper, procedures developed to elaborate the dose database for the Virtual Reality application are presented and analysed

  11. Environmental measures for Escuintla No. 3 unit thermal power project

    Energy Technology Data Exchange (ETDEWEB)

    Quisquinay, Carlos; Fabian Rosales, Alejandro [Instituto Nacional de Electrificacion, (Guatemala)

    1997-12-31

    The environmental measures in relation to the project implementation was studied with reference to the Japanese Standards and incorporated in the Implementation Program. This report is prepared however, to review the environmental measures for the project in more detail as to the allowable standards and regulations concerning the measures for the environmental pollution. The authors present the environmental conditions around the Escuintla Power Station in Guatemala; the measures for environmental pollution and evaluation; the measures for prevention of air pollution and diffusion calculations (estimation and assessment of environmental impacts) [Espanol] Las medidas ambientales con relacion a la consolidacion del proyecto, se estudiaron con referencia a los Estandares Japoneses e incorporados en el Programa de Consolidacion. Sin embargo, este reporte ha sido preparado para revisar las medidas ambientales para el proyecto mas detalladamente, con relacion a los estandares y reglamentaciones admisibles concernientes a las medidas de contaminacion ambiental. Los autores presentan las condiciones ambientales en los alrededores de la Central Termoelectrica de Escuintla de Guatemala; las medidas para la prevencion de la contaminacion del aire y los calculos de difusion (estimacion y evaluacion del impacto ambiental)

  12. Environmental measures for Escuintla No. 3 unit thermal power project

    Energy Technology Data Exchange (ETDEWEB)

    Quisquinay, Carlos; Fabian Rosales, Alejandro [Instituto Nacional de Electrificacion, (Guatemala)

    1996-12-31

    The environmental measures in relation to the project implementation was studied with reference to the Japanese Standards and incorporated in the Implementation Program. This report is prepared however, to review the environmental measures for the project in more detail as to the allowable standards and regulations concerning the measures for the environmental pollution. The authors present the environmental conditions around the Escuintla Power Station in Guatemala; the measures for environmental pollution and evaluation; the measures for prevention of air pollution and diffusion calculations (estimation and assessment of environmental impacts) [Espanol] Las medidas ambientales con relacion a la consolidacion del proyecto, se estudiaron con referencia a los Estandares Japoneses e incorporados en el Programa de Consolidacion. Sin embargo, este reporte ha sido preparado para revisar las medidas ambientales para el proyecto mas detalladamente, con relacion a los estandares y reglamentaciones admisibles concernientes a las medidas de contaminacion ambiental. Los autores presentan las condiciones ambientales en los alrededores de la Central Termoelectrica de Escuintla de Guatemala; las medidas para la prevencion de la contaminacion del aire y los calculos de difusion (estimacion y evaluacion del impacto ambiental)

  13. Preparación y caracterización de materiales de oxicarburo de silicio mixtos

    Directory of Open Access Journals (Sweden)

    Rubio, J.

    2010-04-01

    Full Text Available In this work different mixed Silicon oxicarbide materials have been prepared. Si, Si-Ti, Si-Zr and Si-Al oxicarbide materials have been obtained from pyrolisis at 1000 ºC and 1300 ºC of the respective preceramic materials. After pyrolisis X, D and T units of the oxycarbide structure have been observed in such materials. They show the presence of Si-C and Si-O bonds in a given material. The characterization has been carried out by means of FT-IR, Raman NMR 29Si, NMR 13C and XRD. The formation of Si-Ti, Si-Zr and Si-Al bonds has been estimated in accordance with the decrease of the Si-O-Si wave number observed in the FT-IR spectra. Si and Si-Ti oxycarbide materials do not lead to crystallisation after pyrolisis at highest temperatures, however for Si-Zr and Si-Al oxycarbide materials different crystalline phases have been observed. All pyrolised materials present free and carbidic carbon. After pyrolisis at 1300 ºC the free carbon reacts with Si-O bonds to form SiC4 groups which must be assigned to nucleus of the β-SiC crystals.

    Se han preparado materiales del tipo de oxicarburo de silicio mixtos de Si-Ti, Si-Zr y Si-Al por pirólisis de materiales precerámicos obtenidos a partir de alcóxidos de Si, Ti, Zr y Al y PDMS. La pirólisis se ha llevado a cabo a 1000 ºC y 1300 ºC, habiéndose observado la formación de unidades X, D y T de la estructura del oxicarburo en donde existen enlaces Si-C y Si-O. Los estudios se han llevado a cabo mediante FT-IR, Raman, RMN 29Si, RMN 13C y DRX. La formación de enlaces Si-Ti, Si-Zr y Si-Al se ha estimado por el descenso de la posición del enlace Si-O-Si en los respectivos materiales. Mientras que los materiales de Si y Si-Ti no cristalizan cuando son pirolizados a 1000 ºC ó a 1300 ºC, los de Si-Zr y Si-Al cristalizan en diferentes fases embebidas en una matriz vítrea de oxicarburo. En todos los materiales pirolizados se ha observado la presencia de

  14. Nuclear magnetic resonance analysis of freeze-thaw damage in natural pumice concrete

    Directory of Open Access Journals (Sweden)

    Wang, Xiaoxiao

    2016-06-01

    Full Text Available This paper presents an analysis of the damage propagation features of the pore structure of natural pumice lightweight aggregate concrete (LWC under freeze-thaw cyclic action. After freeze-thaw cycling, we conducted nuclear magnetic resonance (NMR tests on the concrete and acquired the porosity, distribution of transverse relaxation time T2, and magnetic resonance imaging (MRI results. The results showed the following. The T2 distribution of the LWC prior to freeze-thaw cycling presented four peaks representative of a preponderance of small pores. After 50, 100, 150, and 200 freeze-thaw cycles, the total area of the T2 spectrum and the porosity increased significantly. The MRI presented the changing spatial distribution of pores within the LWC during freeze-thaw cycling. Ultrasonic testing technology was applied simultaneously to analyze the NMR results, which verified that the new NMR technology demonstrated high accuracy and practicability for research regarding freeze-thaw concrete damage.En este trabajo se analiza la propagación de los daños que se producen en la estructura porosa de hormigón aligerado a base de piedra pómez natural sometido a la acción cíclica de hielo-deshielo. Después de realizarse los ensayos de hielo-deshielo, el hormigón se analizó mediante resonancia magnética nuclear (RMN, determinándose la porosidad y la distribución del tiempo de relajación transversal, T2, y registrándose las imágenes captadas por resonancia magnética. De acuerdo con los resultados obtenidos, antes de los ciclos de hielo-deshielo la distribución de T2 del hormigón aligerado presentaba cuatro picos, indicativos de un predominio de poros pequeños. Después de que se sometiera a 50, 100, 150, y 200 ciclos, se observó un aumento importante tanto de la porosidad como de la superficie total del espectro de T2. Las imágenes captadas por resonancia magnética evidenciaron la modificación de la distribución espacial de los poros del

  15. Espectros de duas formas de lignina obtidos por ressonância magnética nuclear Nuclear magnetic resonance spectra of two types of lignin

    Directory of Open Access Journals (Sweden)

    Romualdo Shigueo Fukushima

    2003-04-01

    Full Text Available O conteúdo de lignina pode ser útil na estimativa da digestão da fibra de plantas forrageiras. A determinação quantitativa da lignina pelo método espectrofotométrico pressupõe a existência de um padrão de referência satisfatório. O objetivo deste trabalho foi avaliar, por meio da ressonância magnética nuclear (RMN, duas ligninas, uma extraída com brometo de acetila (LBrAc e outra com solução ácida de dioxano (LDiox, para utilização como padrão de referência em análises espectrofotométricas. A ressonância de próton acusou altos teores de carboidratos contaminantes nas amostras de LBrAc. Como a cromatografia líquida já havia indicado menor presença de carboidratos contaminantes na LDiox, os espectros por ressonância de carbono, mais rica em detalhes do que a espectroscopia anterior, porém mais demorada, foram realizados somente nas ligninas LDiox. Este espectro revelou picos típicos, comuns à maioria das ligninas. Os achados da RMN foram condizentes com a análise química, a qual identificou que o carboidrato da parede celular que acompanha a LBrAc seria possivelmente a celulose, ao passo que a pequena contaminação da LDiox teria origem nas pentosanas. A LDiox pode ser considerada melhor padrão de referência para as análises espectrofotométricas do que a LBrAc.Lignin content can be useful to estimate fiber digestion of forage plants. Quantitative determination of lignin by the spectrophotometric method presumes an efficient standard. The objective of this work was to evaluate, by the nuclear magnetic resonance (NMR, two lignins, one extracted with acetyl bromide (AcBrL and another with acidic dioxane solution (DL, as standards in spectrophotometric analysis. Proton resonance revealed high presence of carbohydrates in the AcBrL residues. Because liquid chromatograph had already shown low contamination with carbohydrates in the DL samples, only carbon resonance, which is lengthier, but richer in details than

  16. Interaction and transport of cysteamine (MEA) through membrane models. {sup 15}N-NMR et {sup 1}H-NMR; Interaction et transport de la cysteamine (MEA) a travers des membranes modeles. Etude par {sup 15}N-RMN et {sup 1}H-RMN

    Energy Technology Data Exchange (ETDEWEB)

    Lagoueyte, C.; Subra, G.; Bonnet, P.A.; Chapat, J.P.; Debouzy, J.C.; Fauvelle, F.; Berleur, F.; Roman, V.; Fatome, M.; Fernandez, J.P.

    1995-12-31

    We investigated by {sup 15}N-NMR the interactions of [{sup 15}N]-MEA, a radio-protecting aminothiol, with model membranes (SUVs and LUVs) of egg yolk phosphatidylcholine and phosphatidic acid. We prepared LUVs with a pH gradient between the intravesicular space and the bulk medium. Even though the external pH was low, MEA penetrates into the vesicles. With SUVs, {sup 1}H-NMR revealed that the interactions of unlabeled MEA within the hydrophobic core of the bilayer vary with external pH value. (author). 5 refs.

  17. Use of the Neutron Die-Away Technique to Test Control Rod Effectiveness Theories; Emploi de la Methode d'Absorption des Neutrons pour Verifier les Theories sur l'Efficacite des Barres de Commande; Ispol'zovanie metoda spada potoka nejtronov dlya proverki teorij ehffektivnosti reguliruyushchikh sterzhnej; Aplicacion de la Tecnica de Extincion Neutronica a la Verificacion de las Teorias sobre la Eficacia de las Barras de Control

    Energy Technology Data Exchange (ETDEWEB)

    Perez, R. B. [University of Florida, Gainesville, FL (United States); De Saussure, G.; Silver, E. G. [University of Florida, Gainesville, FL (United States); Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1964-04-15

    . Les theories, qui ont ete verifiees sont celles de: 1. Nordheim-Scalettar, 2. Hurwitz-Roe, 3. et celle du code de diffusion numerique. Les auteurs ont calcule l'effet des barres cruciformes a l'aide de la methode de transformation conforme de Hurwitz-Roe et ont trouve pour le laplacien la valeur de 0,0188 cm{sup -2} qui est voisine du resultat de l'experience, 0,0187 {+-} 0,0006 cm-2. Pour les barres epaisses, les previsions de la theorie de Nordheim-Scallettar et de la theorie du code de diffusion depassent les resultats experimentaux d'environ lOyeo. Les deux methodes ont toutefois etabli des previsions correctes en ce qui concerne l'interaction entre les barres epaisses. Pour les barres minces, la methode Nordheim-Scalettar est extremement precise. On peut s'attendre a trouver l'ecart constate pour les barres epaisses, lorsqu'on utilise la theorie de diffusion pour calculer l'effet des barres ayant une section de dimensions comparables a celle du libre parcours moyen des neutrons dans le ralentisseur. On procede actuellement a des mesures avec des banes de dimensions intermediaires pour determiner le point a partir duquel la theorie de la diffusion n'est plus valable. (author) [Spanish] El calculo de la eficacia de las barras de control se complica por el hecho de que esta depende a la vez de la distribucion de las energias neutronicas y de la geometria del conjunto. Cuando se trata de comparar los datos teoricos con los resultados experimentales obtenidos en otros reactores o en sistemas subcriticos, surgen dificultades derivadas de la complejidad intrinseca de tales sistemas. La tecnica de la extincion neutronica brinda la posibilidad de establecer un modelo neutronico integramente termico, en el cual el efecto de la distribucion de energias neutronicas se puede separar de los efectos espaciales. Por lo tanto, es dable estudiar el factor geometrico de la eficacia de las barras de control sin reparar en las caracteristicas del espectro neutronico y luego es

  18. Integral physics data for fast-reactor design; Donnees de physique integrale intervenant dans les etudes de reacteur a neutrons rapides; Integral'nye fizicheskie dannye dlya raschetov reaktorov na bystrykh nejtronakh; Datos fisicos integrales para el diseno de reactores rapidos

    Energy Technology Data Exchange (ETDEWEB)

    Loewenstein, W B; Meneghetti, D [Argonne National Laboratory, Argonne, IL (United States)

    1962-03-15

    examinent ces donnees et decrivent leurs domaines d'application. Ils montrent que dans certaines analyses de spectre et d'etat critique, les resultats experimentaux et analytiques sont limites. Ils font des suggestions sur l'orientation des recherches experimentales et analytiques a venir. Elles combleraient le fosse entre la theorie et l'experience qui existe dans les systemes 'connus'. Ces propositions comprennent egalement des suggestions en vue de 'consolider' la physique de modeles theoriques de grands reacteurs surgenerateurs a neutrons rapides. (author) [Spanish] La preparacion del capitulo dedicado a la fisica de los reactores rapidos, en la segunda edicion de la publicacion 'Reactor Physics Constants' que aparecera en breve, exigio la recopilacion de los datos disponibles sobre experimentos integrales. La eleccion de los datos integrales de fisica de los reactores rapidos que se ha de incluir en esa seccion se baso en los dos criterios siguientes: a) que los datos provengan de sistemas relativamente simples que se presten para un analisis teorico sencillo; y b) que se trate de sistemas complejos que representan prototipos o maquetas que ofrecen interes general para el estudio de los reactores de potencia rapidos. Se fijo el primer criterio con la intencion de registrar los datos integrales de aquellos sistemas que tienen una utilidad mas general en la verificacion de los parametros y los procedimientos de calculo de las secciones eficaces. El segundo criterio se basa en la presentacion de los datos corrientes sobre sistemas reales de reactores de potencia reproductores rapidos. Estos son demasiado complicados para permitir un analisis teorico sencillo. Constituyen una demostracion de la complejidad del reactor real si se compara con la instalacion critica de experimentacio n mas esquematica y mas facil de analizar. Los datos fisicos integrales que intrevienen en el diseno de reactores constituyen el resultado de mediciones efectuadas en conjuntos criticos o

  19. Possible sources for hydrogen production in Mexico; Posibles fuentes de produccion de hidrogeno en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Esparza Mata, Esther; Perez Garcia, Edgar C. [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2004-06-15

    In agreement with the Secretaria de Energia, Mexico consumed daily in year 2000, 1.7 millions of oil barrels and according to numbers of PEMEX the proven reserves to December 31 of that year, ascended to 12,312 million barrels, obviously the consumption and the reserves will change through the time, but making a calculation these reserves will be sufficient only for 20 years, on the other hand according to PEMEX Gas y Petroquimica Basica numbers, the present natural gas reserves are sufficient to supply the demand during 22 years, with these data we can have an approximate calculation of 20 years of fossil fuel supply, to this stage we can name it the period of power transition, when this time interval is over we will have an eminent power crisis and it will be necessary to count already on new power alternatives, which have a sustainable development and which will have to be ready at by the end of the next 20 years. One of the most viable alternatives is obtaining energy from hydrogen, this is the most abundant element in the universe, near 75% is constituted by it, but it is not found in pure state in nature. In order to determine certain state it is necessary to investigate about the processes for the hydrogen obtaining, the reforming of natural gas, the natural gas reserves, the natural gas distribution and the integrated gasification. [Spanish] De acuerdo con la Secretaria de Energia, Mexico consumio en el ano 2000, 1.7 millones de barriles diarios de petroleo y segun cifras de PEMEX las reservas probadas al 31 de diciembre de ese ano ascienden a 12,312 millones de barriles, obviamente el consumo y las reservas cambiaran a traves del tiempo, pero haciendo un calculo estas reservas seran suficientes unicamente para 20 anos, por otro lado segun cifras de PEMEX Gas y Petroquimica basica las reservas de gas natural actuales son suficientes para abastecer la demanda durante 22 anos, con estos datos podemos tener un calculo aproximado de 20 anos de abastecimiento de

  20. Temperature Distribution in Radioactive Solid Wastes. Part I - Beta-Active Solids; Repartition des Temperatures dans les Dechets Radioactifs Solides. Partie I - Solides Radioactifs Beta; 0420 0410 0421 041f 0420 0415 0414 ; Distribucion de la Temperatura en los Desechos Radiactivos Solidos. Parte I - Desechos Solidos Emisores de Radiaciones Beta

    Energy Technology Data Exchange (ETDEWEB)

    Kotewale, D. A.; Ganguly, A. K. [Atomic Energy Establishment, Trombay (India)

    1960-07-01

    The paper deals with the calculations for temperature distribution over time in a radioactive sphere and in a finite radioactive cylinder buried in a medium having the same thermal properties. Formulae are given for such calculations. Numerical results on temperature build-up are presented graphically for the cases where the activity is due to beta-emitters such as P{sup 32}, Sr{sup 89}, Cs{sup 135} and Sr{sup 90} + (Y{sup 90}). General graphs for calculation of temperature build-up for any long-lived beta-emitter at certain points of interest in a sphere and in a cylinder of particular dimensions and diffusivity are presented. (author) [French] Ce memoire a trait aux calculs servant a evaluer la variation des temperatures en fonction du temps dans une sphere radioactive et dans un cylindre radioactif limite enfouis dans un milieue ayant les memes proprietes thermiques. Les formules utilisees dans ces calculs sont indiquees. Les resultats numeriques concernant la formation des temperatures sont representes graphiquement pour les cas ou l'activite est due a des emetteurs beta tels que {sup 32}P, {sup 89}Sr, {sup 135}Cs et {sup 90}Sr + ({sup 90}Y). Le memoire contient des abaques pour le calcul de la formation des temperatures dans les emetteurs gamma de longue periode a certains points interessants des spheres et des cylindres ayant des dimensions et une capacite de diffusion particulieres. (author) [Spanish] En la memoria se estudia el calculo de la distribucion de temperaturas en funcion del tiempo en una esfera radiactiva y en un cilindro radiactivo finito enterrados en un medio de identicas propiedades termicas. Se dan formulas para efectuar dicho calculo. En el caso en que la actividad se deba a emisores beta, tales como {sup 32}P, {sup 89}Sr, {sup 135}Cs y {sup 90}Sr + ({sup 90}Y), se representan graficamente los resultados numericos relativos al incremento de ]a temperatura. Asimismo, se proporcionan graficos generales para calcular el incremento de la

  1. MODIFICACIONES DE LAS PROPIEDADES TEXTURALES Y ESTRUCTURALES DE UNA ZEOLITA USY Y DE SUS MEZCLAS CON "CAOLÍN CLAY" Y CLORHIDROL COMO CONSECUENCIA DEL TRATAMIENTO HIDROTÉRMICO

    Directory of Open Access Journals (Sweden)

    Yazmin Yaneth Agamez Pertuz

    2008-03-01

    Full Text Available El catalizador de FCC está constituido por partículas de composición compleja donde el componente activo es una zeolita Y. En este trabajo se presentan los resultados texturales y estructurales de una zeolita USY comercial lixiviada, de una serie de catalizadores con 7, 15, 25, 35 y 45% de material activo y los de estos materiales desactivados hidrotérmicamente. Las muestras se caracterizaron por fluorescencia de rayos X (FRX, difracción de rayos X (DRX, resonancia magnética nuclear de silicio (29Si RMN y fisiadsorción de nitrógeno a 77 K. A partir de estos resultados se hallaron correlaciones entre el volumen de microporo y el contenido de zeolita y entre el grado de cristalinidad y el porcentaje de zeolita. Además, se encontró que un tratamiento con sólo 20% de vapor de agua a 1033 K durante 16 horas destruye los grupos estructurales Si(2Al y Si(3Al como reflejo de la dealuminización drástica que sufre el material. 

  2. Isolation and structural elucidation of secondary metabolites of plants of the families asteraceae and urticaceae

    International Nuclear Information System (INIS)

    Villagra Quesada, E.

    2002-01-01

    A phytochemistry study of plant's species of the Asteraceae and Urticaceae family is proposed in order to isolate and to elucidate the structure of active principles; due to the fact that several studies have found that some of these families have compounds with anti-inflammatory activity, mainly lactonas sesquiterpenicas . The phytochemistry study was carried out through the application of chromatography techniques, for the separation and purification of the compounds. Includes chromatography of column, fine and liquid layer of high resolution. On the other hand, spectroscopic techniques were used for the elucidation, mainly of nuclear magnetic resonance (RMN) as much of one as of two dimensions. In this way, it was possible to isolate 14 compounds in Decachaeta thieleana and 10 in Phenax mexicanus, from which 6 correspond compounds of innovative structure. The comparison of the results obtained in Decachaeta thieleana (with previous studies) evidences that specimens, orphologically identical (the same species, but different locations), possess totally different compounds. This suggests that the studied specimens do not correspond to the same species. However, the determination of such a cause not only evade the objectives of this work but also the area of study of Chemistry [es

  3. Rheumatoid arthritis: Clinical, SPECT and MRI investigations

    International Nuclear Information System (INIS)

    Ascoli, G.; Cinti, P.; Nonni, M.; Rossi, B.

    2002-01-01

    Aim: To demonstrate psychometric test and neuroimaging technic capacity in subclinical conditions of cerebral affection in patients with rheumatoid arthritis; to demonstrate agreement between topographic cerebral site and morphological signs in neuroimaging study; to evaluate agreement between cognitive deficits and rheumatoid severity. Material and Method: We have enrolled 20 patients, 17 pts. (85%) showed low score evocative for executive function limitation; 6 pts. (33%) showed attention anomaly, movement organization and verbal fluency. SPECT acquisition shows frontal lobe uptake in 95% (19/20 pts.) extended to parietal lobs in 42% (8/19pts.); 1 pt. Shows normal uptake and very high score. RMN study shows a specific sign of leukoencephalopaty in 35% (7/20pts.) and liquoral spaces increased in 25% (5/20 pts.). Conclusions: Frequent cognitive functions alteration during rheumatoid arthritis; very high topographic agreement between cognitive deficits and cerebral perfusion uptake showed by SPECT study; significant correlation between severity index and disease activity and cognitive deterioration; necessity of further longitudinal study for greater number of patient; pathogenetic disconnect mechanism cortical-subcortical by vasculitic reason or deafferentation jointed to negative interaction between motor limit and cognitive deficit

  4. Reactivity of the biphasic trichloroacetonitrile-CH2Cl2/H2O2 system in the epoxidation of soybean oil

    Directory of Open Access Journals (Sweden)

    Martinelli, Márcia

    2002-06-01

    Full Text Available In this work we report on the epoxidation of soybean oil by the trichloroacetonitrile -CH2Cl2/H2O2 byphasic system. The reaction was carried out at room temperature and, most importantly, in non acid conditions which prevent the opening of the oxirane ring. The epoxidized soybean oil was characterized by infrared, 1H and 13C NMR. A maximum conversion of 81 % was achieved in two hours with 86% of selectivity in epoxy groupsEn el presente trabajo informamos sobre la epoxidación de aceite de soja mediante el sistema bifásico tricloroacetonitrilo-CH2Cl2/H2O2. La reacción fue realizada bajo condiciones de temperatura ambiente y, lo más importante, en condición no ácida, lo que evita la apertura del anillo oxirano. El aceite de soja fue caracterizado por infrarrojo y RMN de 1H and 13C. En dos horas se alcanzó una conversión máxima del 81 % obteniéndose una selectividad del 86 % en grupos epóxidos

  5. Towards high resolution ^1H NMR spectra of tannin colloidal aggregates

    Science.gov (United States)

    Mirabel, M.; Glories, Y.; Pianet, I.; Dufourc, E. J.

    1999-10-01

    The time dependent colloidal formation of tannins in hydro-alcoholic medium has been studied by 1H-NMR. Line broadening observed with time can be cancelled by making use of magic angle sample spinning (MASS) thus yielding sharp lines that allow structural studies. We used as an example catechin, a constitutive monomer of Bordeaux young red wine tannins. Chemical shift variations of polyphenol protons allow monitoring the time course of aggregation. La formation de tanins colloïdaux au cours du temps, en milieu hydroalcoolique, a été suivie par RMN-^1H. Un élargissement marqué des résonances est observé et peut être supprimé par la rotation de l'échantillon à l'angle magique ce qui ouvre tout un champ d'études structurales sur ces composés colloïdaux. L'exemple proposé est celui de la catéchine, monomère constitutif de tannins présents en grande quantité dans les vins rouges jeunes de Bordeaux. Des variations du déplacement chimique de certains protons polyphénoliques permettent de suivre l'évolution temporelle de l'agrégation.

  6. PHOTOCATALYTIC DISINFECTION TREATMENTS: VIABILITY, CULTIVABILITY AND METABOLIC CHANGES OF E. coli USING DIFERENT MESUREMENTS METHODS

    Directory of Open Access Journals (Sweden)

    JANETH SANABRIA

    2011-01-01

    Full Text Available En este trabajo, el estrés oxidativo producido con radiación en presencia TiO2 fi jo o suspendido TiO2, y la relación entre cultivabilidad y viabilidad se han realizado, utilizando recuento directo de células viables (CDV y fl uorescencia de hibridación in situ (FISH. Se encontró que cuando el tratamiento es incompleto, las células viables que habían perdido su cultivabilidad pueden recuperar todas sus funciones fi siológicas, cuando son transferidas a un nuevo medio nutritivo. Por otra parte, las alteraciones en los procesos de asimilación de nutrientes fueron estudiados por 1H-RMN durante y después del tratamiento fotocatalítico. Esto permitió tener indicios sobre cómo se propaga la cadena de daños durante el tratamiento. Se demostró que el recuento en placa comúnmente usado para estimar la población de E coli en los procesos de desinfección no sería confi able, mientras que el método combinado FISH-DVC ofrece una alternativa fiable.

  7. Efecto de la concentracion de hidrogeno en la red de hierro bcc por calculos ab-initio

    OpenAIRE

    Sánchez, Javier; Andrés, Pedro L. de; Fullea, J.; Andrade, C.

    2008-01-01

    Utilizando cálculos mecano-cuánticos de primeros principios hemos estudiado la interacción del hidrógeno con la red cúbica centrada en el cuerpo del hierro. El hidrógeno intersticial puede ocupar dos posiciones de alta simetría en la red: el hueco octaédrico y el tetraédrico. Nuestros cálculos nos proporcionan barreras de difusión entre ambos huecos, que analizamos para entender la propagación del hidrogeno a través de la red de hierro. Se ha estudiado el efecto de la concentración de hidróge...

  8. Validation in life for dosimetric calculations in PET; Validacion de vida para calculos dosimetricos en PET

    Energy Technology Data Exchange (ETDEWEB)

    Ocampo ramos, J. C.; Petoussi-Henss, N.; Zankl, M.

    2015-07-01

    The LIFE program (VOXEL-PHANTOM-BASED SOFTWARE FOR INTERNAL DOSE ASSESSMENT) is developing new software for dose assessment in patients undergoing nuclear medicine examinations. This paper shows some of the validation and comparison tests that have been carried out for the case of the F-18 FDG. Unlike current programs (eg. OLINDA) using phantoms stylized size reference, the new developed software uses the pre calculated library Specific Absorption Fractions (SAF) of photons and electrons based on different anthropomorphic phantoms voxelized and the SAF new computational phantoms of the ICRP for photons, electrons, neutrons and alphas. In addition, the software uses the latest information from nuclear decay of the ICRP 107 (2008). The software is being widely put on trial and comparison with other methods of calculation available. (Author)

  9. Calculo del valor en riesgo del futuro de energia e internacionalizacion del sector energetico en Colombia

    OpenAIRE

    Esquivel Fonseca, Leidy Gioanna

    2013-01-01

    El presente trabajo de grado busca definir cuál es el mejor método para determinar el valor en riesgo del contrato de futuro de energía eléctrica que se transa en Colombia, para cumplir con este objetivo se toma como referencia el marco histórico del VaR y de los futuros seguido de las características de la fijación de precios, la estructura del contrato, que políticas y métodos hay para cubrirse del riesgo y como se realiza en otros países, realizando algunos cálculos de los modelos más trad...

  10. Test de Actitudes Alimentarias: Evidencias de Validez de una Nueva Versión Reducida

    Directory of Open Access Journals (Sweden)

    Valdiney Veloso Gouveia

    2010-01-01

    Full Text Available El objetivo de este estudio ha sido presentar una version reducida del Eating Attitudes Test (EAT-26 para su utilizacion en el contexto espanol. Se busco especificamente conocer su fiabilidad y estructura factorial para, finalmente, comprobar el modelo teorico propuesto. Para ello, contamos con una muestra de 212 estudiantes universitarios con una edad media de 19.4 anos, la mayoria mujeres (61.8%. Estos respondieron al EAT-26 y a preguntas sociodemograficas. Inicialmente, a traves de un analisis paralelo se observo la coherencia de la estructura factorial. A continuacion se seleccionaron, a partir del poder discriminativo (p < 0.05, cuatro items para cada factor. Mediante el analisis de Escalamiento Multidimensional, se observo que los 12 items resultantes se distribuian segun las dimensiones teoricas esperadas (S-Stress = 0.07; RSQ = 0.97, aspecto corroborado a traves del analisis factorial confirmatorio (x2 / g.l = 2.08; GFI = 0.92; AGFI = 0.88; CFI = 0.94; e RMSEA = 0.071. Los Alfas de Cronbach para los tres factores pueden ser considerados satisfactorios: Hacer dieta (0.87, Bulimia y preocupacion por la alimentacion (0.60 y Control oral (0.52. Se concluye que la version propuesta presenta parametros psicometricos satisfactorios, pudiendo ser utilizada como medida de screening en la deteccion precoz de casos de anorexia nerviosa en la poblacion general.

  11. Planning and institutionalist thought La planeación y el pensamiento institucionalista

    Directory of Open Access Journals (Sweden)

    Gruchy Allan G.

    1999-06-01

    Full Text Available The institutionalists of the 1930s and 1940s, with their concern for reducing uncertainty about the future, proposed the use of indicative and democratic national economic planning to provide public orientation at the macroeconomic level, while leaving industry in private hands. This article presents the basic elements of national planning: 1 deciding objectives and goals, 2 delimiting the levels and extent of planning and analyzing its interrelations in a holistic form, and 3 receiving feedback and using i t in an appropria te way. It then analyzes the differences
    between the institutionalists and systems analysis theorists.
    It ends with some criticisms of the vision of the contemporary institutionalists.Los institucionalistas del los años treinta y cuarenta, en su preocupacion por reducir la incertidumbre del futuro, propusieron usar la planeacion economica nacional indicativa democratica para dar orientacion publica a nivel macroeconomico, y dejar la industria en manos privadas. Este articulo se exponen los elementos fundamentales de la planeacion nacional: 1 decidir los objetivos y las metas; 2 delimitar los niveles y el alcance de la planeacion y analizar sus interrelaciones en forma holistica; y 3 recibir retroalimentacion y utilizarla de forma adecuada. Luego analiza las diferencias entre los institucionalistas y los teoricos del analisis de sistemas. Finaliza con algunas criticas a la vision de los institucionalistas contemporaneos.

  12. SPERIMENTAZIONE DI UNA PROVA INVALSI: PER COSTRUIRE UN CURRICOLO DI LETTURA

    Directory of Open Access Journals (Sweden)

    Augusto Campagnolo

    2013-01-01

    Full Text Available Che cosa sono le prove INVALSI? Che cosa valutano e a che cosa servono? E ancora, quale contributo possono offrire alla didattica della lettura? Mentre la scuola italiana è investita da una fase di grandi cambiamenti, docenti e dirigenti devono confrontarsi anche con un nuovo sistema di valutazione che, attraverso le prove Invalsi, sta delineando la scuola del futuro. L’articolo offre un contributo di riflessione sul modello di valutazione proposto dalle prove e aiuta a chiarire il quadro teorico della lettura e comprensione del testo; analizza, infine, una prova di lettura e propone un possibile utilizzo delle prove somministrate di italiano nel curricolo scolastico. New INVALSI testing: building a curriculum for reading  What are INVALSI tests? What do they assess and what are they for? And again, what can they contribute to the teaching of reading? Italian schools are undergoing great change, and teachers and administrators are faced with a new evaluation system, the INVALSI tests, which are shaping the future of the school system. The article offers a reflection on the evaluation model proposed by the tests, helping to clarify the theoretical framework for reading and understanding texts and also analyzes a reading test.  Suggestions for a possible way to use the Italian language tests administered as part of the school curriculum are made.

  13. Modos de produccion cientifica: Culturas y metodologias de investigacion en la Universidad de Cadiz

    Science.gov (United States)

    Gonzalez Ramos, Ana M.

    2004-12-01

    Este trabajo de investigacion supone un modelo teorico de caracter aplicado, que proporciona la oportunidad de evaluar la produccion cientifica de los investigadores. Se encuadra dentro de la tradiccion de la estadistica aplicada y la sociologia del conocimiento. Atiende especialmente a dos conjuntos de temas de interes, por una parte, las caracteristicas principales que determinan el nivel y tipo de produccion academica producida por las unidades de investigacion y por los propios investigadores; por otra, la utilizacion que se hace de los metodos y tecnicas de investigacion puesto que de ello tambien depende el modo de produccion cientifica. Los puntos novedosos de esta tesis son: la medicion cuantitativa del objeto de estudio, la suma de los productos y las condiciones externas a la produccion del conocimiento mas otros elementos internos como las caracteristicas de los investigadores y la metodologia utilizada para desarrollar sus trabajos; y, finalmente, el uso de las nuevas tecnologias. El aprovechamiento de los recursos estadisticos y las fuentes de informacion secundarias se complementan con el diseno propio de una encuesta donde se implementa las caracteristicas descritas en un capitulo anterior sobre los metodos cientificos mas idoneos descritos en los principales manuales y articulos cientificos desde distintas disciplinas de conocimiento. Dicha encuesta ha sido desarrollada como un programa propio y en base a los mas innovadores usos de la tecnologia en la metodologia de encuestas.

  14. Angerona: Fatos e ficções sobre a fazenda de café de Cornelio Souchay e Ursula Lambert em Cuba

    Directory of Open Access Journals (Sweden)

    Guenther Roth

    2012-11-01

    Full Text Available O artigo conta a história de Cornelio Souchay, um imigrante alemão que chega a Havana em 1807, vive uma relação amorosa com Ursula Lambert, uma mulata haitiana livre e se torna proprietário de uma fazenda de café exemplar, à qual dá o nome de Angerona, deusa do silêncio. O texto baseia-se em relatos, documentos, cartas de viajantes, filme e romances de autoria de homens ou mulheres, que visitaram Angerona em épocas diferentes. Ao contrário do filme “Roble de Olor” (2003 que festeja a relação amorosa de Cornelio com Ursula, o autor se interessa pela reconstrução da vida do imigrante e da fazenda, cujas ruínas transformadas em monumento nacional pelo Patrimônio Histórico cubano. Com efeito, a descrição minuciosa de diversos aspectos da fazenda, da casa do senhor e de sua relação com os escravos, não tem outro objetivo senão evidenciar o quanto o humanismo rígido de Cornélio e seu calculo racional contribuíram para a maior eficiência do sistema de dominação da fazenda.

  15. Efecto neutralizador del extracto acuoso de Dracontium loretense (JERGÓN SACHA sobre la actividad letal del veneno de Bothrops atrox

    Directory of Open Access Journals (Sweden)

    Amanda Lovera

    2006-07-01

    Full Text Available Objetivo: Determinar la capacidad del extracto acuoso D. loretense (jergon sacha para neutralizar la actividad letal del veneno de la serpiente B. atrox. Materiales y metodos: Se realizo el screening fitoquimico del extracto acuoso del bulbo desecado de D. loretense, se calculo la dosis letal 50(DL50 para el extracto y el veneno de B. atrox. Luego se realizaron enfrentamientos de diferentes dosis de extracto y veneno inyectadas intraperitonealmente en ratones, previa incubacion, para calcular la dosis eficaz 50% (DE50 del extracto para neutralizar el efecto letal del veneno por el metodo de Probits. Resultados: El analisis fitoquimico del extracto permitio identificar compuestos fenolicos, taninos, saponinas, proteinas, terpenoides y esteroides. No sobrevivio ningun raton que recibio el veneno sin D. loretense, y no fallecio ninguno al que se le dio solo el extracto acuoso de D. loretense. Se determino la DE50 en 91,15 µg/raton del extracto para neutralizar 2DL50 del veneno. Se encontro que a mayor dosis del veneno de B.atrox se necesito menores dosis del extracto acuoso de D. loretense. Conclusiones: el extracto acuoso de D. loretense neutraliza la actividad letal de veneno de B. atrox. Es necesario realizar estudios que permitan identificar los metabolitos del extracto que tienen esta accion.

  16. Avaliação da orientação motivacional de metas na modalidade do futebol

    Directory of Open Access Journals (Sweden)

    Vinicius Barroso Hirota

    2013-07-01

    O presente trabalho objetivou avaliar e comparar a orientação motivacional de meta para tarefa e ego de alunos pertencentes a dois ambientes esportivos distintos de futebol, uma Escola de Esporte Privada e uma Organização Não Governamental (ONG, ambos localizados na Cidade de Osasco - SP. Através de uma pesquisa descritiva aplicamos a escala TEOSQ, a uma amostra de 196 sujeitos de ambos os sexos de idade entre 7 e 17 anos (média 11,16+2,09 e os dados foram tratados com o calculo do Coeficiente Alfa, média, desvio padrão, mediana e comparadas as médias com o teste de Mann Whitney. Os resultados mostraram estabilidade no instrumento com Alfa de 0,78 para tarefa e 0,68 de ego na escola de esporte com média de 4,28 de tarefa e 2,40 de ego, já a ONG o Alfa de tarefa foi 0,60 e 0,74 de ego com média de tarefa de 4,40 e ego 2,75. Concluímos a tendência de orientação para tarefa com alunos predispostos a se superarem constantemente, e a fidedignidade do instrumento

  17. ¿Cuál es el problema con el cálculo de utilidad?

    Directory of Open Access Journals (Sweden)

    Carlos Molina Velásquez

    2010-03-01

    Full Text Available Un problema de la ética del bien común, planteado por Franz Hinkelammert es el que representa el “calculo de utilidad”. En el articulo se valora positivamente el carácter consecuencialista de este planteamiento, a la vez que se señalan las virtudes de ciertas versiones del utilitarismo, así como las dificultades con expresiones como “utilidad” o “bienestar para todos”. También se propone recurrir a las ideas de Hinkelammert en el orden del reconocimiento de los limites de factibilidad, lo cual permitiría realizar una crítica original y constructiva a las corrientes utilitaristas y consecuencialistas predominantes. Abstract One problem of the common good ethics posed by Franz J. Hinkelammert is the “calculation of utility”. In this article the consequentialist character of this exposition is positively valued and at the same time it is pointed out the virtues of certain versions of utilitarism as well as, the difficulties posed by expressions as “utility” and “well-being”. It is proposed also to resort to Hinkelammert’s ideas in the orden of recognition of the feasibility limits which would allow us to make a original and constructive critic to the prevailing utilitarian and consequentialist currents.

  18. Análise por RMN de produtos de degradação forçada em fármacos

    OpenAIRE

    Ana Cristina Isler

    2014-01-01

    Resumo: A degradação forçada ou teste de estresse é uma boa estratégia para demonstrar as rotas de degradação e os produtos formados durante a estocagem do fármaco ou do produto formulado. O principal objetivo desse teste é demonstrar a especificidade dos métodos indicativos de estabilidade. Tratam-se de ensaios que visam desafiar e confirmar a especificidade e seletividade da metodologia analítica empregada na quantificação do princípio ativo presente no medicamento e na manutenção dessas ca...

  19. A espectroscopia de RMN como ferramenta elucidativa: estruturas moleculares, mecanismos de reação e metabonômica

    OpenAIRE

    SILVA, Ricardo Oliveira da

    2010-01-01

    A espectroscopia de ressonância magnética nuclear é uma poderosa ferramenta para a elucidação estrutural e para o estudo de transformações químicas, intensamente utilizada na área de química orgânica. Recentemente, a fronteira de suas aplicações tem se expandido para incluir a análise de biofluidos com o fim de tentar identificar padrões associados às mais variadas condições fisiopatológicas que, ao afetarem o metabolismo, deixam sua marca de forma reconhecível nos espectros...

  20. NMR and molecular modeling: application to wine ageing

    Science.gov (United States)

    Saucier, C.; Pianet, I.; Laguerre, M.; Glories, Y.

    1998-02-01

    Red wine contains polyphenols called tannins which are very important for its taste and longevity. These polymers consist in repeating units of catechin and its epimer epicatechin. During ageing, slow condensation reactions take place which lead to new chemical structures. Among the possible reactions, we have focused our attention on acetaldehyde cross-linking. Catechin was used as a model for the production of polymers with acetaldehyde. Two reaction product fractions have been isolated by liquid chromatography. Mass measurement indicated that these fractions contain dimers. NMR (1D and 2D) and molecular modelling were then used to study the structure and conformations of these products. The first product consist in a pure dimer with the two catechin moieties connected with an ethyl bridge on the carbon 6 and 8. The second fraction was a mixture of two dimers (50/50). NMR measurements showed that it could be two symmetrical dimers involving the same carbon for each catechin moiety (6 or8). Le vin rouge contient des polyphénols appelés tanins qui sont très importants pour son goût et sa longévité. Il s'agit principalement de polymères de catéchine et d'épicatéchine. Durant le vieillissement du vin, des réactions de condensation interviennent lentement et conduisent à de nouvelles structures. Parmi les réactions possibles, nous avons plus spécialement étudié la polymérisation par pontage avec l'éthanal. La catéchine a été utilisée comme modèle de tannin et mise en présence d'éthanal en milieu acide proche du vin. Deux fractions de produits de réaction ont été isolées par chromatographie liquide. La spectrométrie de masse a révélé la présence de dimères. La RMN (1D et 2D) et la modélisation moléculaire ont ensuite été utilisées pour déterminer la structure et la conformation de ces produits. La première fraction a été identifiée comme étant un dimère de deux unités catéchines reliées par un pont éthyle par leur

  1. Caracterização de diferentes amostras de mandioca por espectroscopia de ressonância magnética nuclear Characterization of different cassava samples by nuclear magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Gisele C. V Iulianelli

    2011-01-01

    Full Text Available A raiz de mandioca (Manihot esculenta crantz é cultivada nas mais diversas regiões do Brasil e desempenha importante papel na dieta alimentar dos brasileiros, representando para muitas famílias do Norte e Nordeste a principal fonte energética. A farinha de mandioca constitui-se num alimento com alto teor de amido, além de conter fibras, lipídeos e alguns minerais, entretanto apresenta grande variabilidade genética, o que resulta em diferenciação na sua constituição química e estrutural. Frente à importância econômica, nutricional e farmacológica deste produto, o presente trabalho objetivou caracterizar seis diferentes amostras de farinha de mandioca por meio da espectroscopia de RMN. Além de estabelecer o assinalamento dos principais grupamentos químicos, os resultados confirmaram diferenças no aspecto químico e estrutural das amostras de mandioca. Foi visto que a amostra F1 é mais rica em carboidratos, a amostra F4 é mais rica em glicolipídeos, a amostra F2 apresenta alto teor de amilose, e a amostra F6 apresenta maior diversidade de glicolipídeos. Em relação à estrutura molecular, os espectros de RMN indicaram que a amostra F1 apresenta maior organização molecular e que as amostras F3 e F5 apresentam similaridade na amorficidade e também no arranjo e empacotamento molecular.Cassava root (Manihot esculenta crantz is grown in all Brazilian states, being an important product in the diet of Brazilians. For many families of the North and Northeast states, it may represent the main energy source. The cassava root flour has high levels of starch, in addition to containing fiber, lipids and some minerals. There is, however, great genetic variability, which results in differentiation in its chemical composition and structural aspect. Motivated by the economic, nutritional and pharmacological importance of this product, this work is aimed at characterizing six cassava flour samples by NMR spectroscopy. The spectra revealed

  2. Electrical limitations to energy resolution in semiconductor particle detectors; Limitations electriques du pouvoir de resolution en energie des detecteurs a semi-conducteurs; Ehlektricheskie ogranicheniya razreshayushchej sposobnosti po ehnergii v poluprovodnikovykh detektorakh chastits; Limitaciones electricas en la resolucion energetica de detectores de particulas a base de semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, W L; Goulding, F S [Lawrence Radiation Laboratory, University of California, Berkeley, CA (United States)

    1962-04-15

    electrode avec anneau de garde qui fait partie integrante de l'instrument et qui a pour effet d'eliminer dans une large mesure le bruit du aux fuites en surface. Le memoire fournit des donnees experimentales relatives aux fuites et au pouvoir de resolution en energie qui concordent parfaitement avec la theorie. La limite theorique du bruit, exprimee en largeur totale a mi-hauteur du maximum, est de l'ordre de 7 a 10keV pour les detecteurs au silicium type p de 1 cm{sup 2}, a une temperature de 25{sup o}C. (author) [Spanish] Los autores parten de la suposicion de que el ruido de fondo de un detector basado en un semiconductor se debe unicamente a este ultimo, y presentan ecuaciones que indican los limites teoricos del ruido en las combinaciones detector-amplificador. Estas ecuaciones demuestran la existencia de valores optimos en las constantes de tiempo del amplificador y en la polarizacion del detector, para los que el ruido minimo es independiente de la resistividad del semiconductor. Los autores demuestran que el funcionamiento optimo de un sistema detectoramplificador depende unicamente del area del detector, de la capacidad de entrada (menos la capacidad del detector), de la vida media de los portadores minoritarios del semiconductor, y de la transconductancia de la valvula de entrada del amplificador. La memoria describe la estructura de un nuevo detector que incluye como parte integral un electrodo de anillo de guarda cuyo efecto es eliminar en gran parte el ruido que ocasionan las fugas superficiales. Presentan los resultados obtenidos experimentalmente para las perdidas en el detector y la resolucion energetica, que concuerdan satisfactoriamente con los valores teoricos. El limite teorico del ruido expresado como anchura del pico a la mitad de su amplitud esta comprendido entre 7 y 10keV para detectores de silicio del tipo p, de 1 cm{sup 2} a 25{sup o}C. (author) [Russian] Iskhodya iz gipotezy, chto proizvodimyj poluprovodnikovym detektorom shum vyzyvaetsya

  3. Biomass gasification in fixed bed type down draft: theoretical and experimental aspects; Gasificacao de biomassa em leito fixo tipo concorrente: aspectos teoricos e experimentais

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Juan Daniel; Andrade, Rubenildo Vieira; Lora, Electo Eduardo Silva [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Inst. de Engenharia Mecanica. Nucleo de Excelencia em Geracao Termeletrica e Distribuida

    2008-07-01

    Actually are recognizing the advantages of biomass in reducing dependence on fossil fuels and significant reduction in emissions of greenhouse effect gases such as Co2. Also are known the different conversion of biomass routes for their use or exploitation, such as thermochemical process (gasification, pyrolysis and combustion), the biological process (fermentation and transesterification) and the physical process (densification, reducing grain and mechanical pressing). In this sense, the gasification is regarded as the most promising mechanism to obtain a homogeneous gaseous fuel with sufficient quality in the small scale distributed generation. This work presents some aspects of biomass gasification in fixed bed, as well as some preliminary results in the evaluation and operation of fixed bed down draft gasifier with double stage air supply of the NEST, identifying the adequate air supply quantity (equivalence ratio in the range of 0,35 to 0,45) for obtaining a fuel gas with lower heating value around 4 MJ/N m3. (author)

  4. Quantitative Evaluation of Nuclear Power Station Siting from the Point of View of Safety; Evaluacion Cuantitativa del Emplazamiento de Centrales Nucleoelectricas desde el Punto de Vista de la Seguridad

    Energy Technology Data Exchange (ETDEWEB)

    Serment Cabrero, V. [Comision Nacional de Energia Nuclear y Universidad Nacional Autonomia de Mexico (Mexico); Velez, C. [Instituto Politecnico Nacional y Comision Federal de Electricidad (Mexico)

    1967-09-15

    Apart from the minimum operational and safety requirements for the siting of nuclear power stations, the paper proposes introducing the total mean dose to the general population as an additional criterion. Although the calculation of this dose presupposes a detailed knowledge of the main pathways by which the population may be irradiated in case of an accident, the present state of power reactor technology makes it possible to tackle the problem already. An estimate of the total mean dose per unit time involves the safety aspects of the reactor, the features of the site considered, and the way in which these features affect safety. The authors derive the general formula expressing the total mean dose as a function of all the parameters concerned. It is pointed out that in the case of accidents in which the release of fission products is independent of the mechanisms of irradiation, this formula is considerably simplified and makes it possible to establish a classification of the relative suitability, from the safety point of view, of the sites proposed, without touching upon the difficult problem of the definition of accidents and their probabilities of occurrence. A further simplification accrues when there exist predominant mechanisms governing the accidental irradiation of the population. The approach adopted is particularly well suited to calculations with digital computers, and helps to identify the areas in which information is lacking and to direct research intended to remove these deficiencies. (author) [Spanish] Ademas de los requisitos mfnimos opecacionales y de seguridad para el emplazamiento de centrales nucleoelectricas, se sugiere utilizar como criterio adicional la dosis total promedio a la poblacion. Aunque el calculo de esa dosis implica el conocimiento detallado de los caminos principales por los cuales la poblacion puede ser irradiada en el caso de un accidente, el estado actual de la tecnologia de los reactores nucleares de potencia permite ya

  5. Calculation of reactivity for safety in nuclear reactors; Calculo de la reactividad para seguridad en reactores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Suescun D, D. [Universidad Surcolombiana, Av. Pastrana Borrero - Carrera 1, Neiva, Huila (Colombia); Rojas A, O., E-mail: daniel.suescun@usco.edu.co [Universidad Popular Autonoma del Estado de Puebla, Av. 9 Pte 1908, Barrio de Santiago, 72410 Puebla (Mexico)

    2017-09-15

    The measurement of reactivity is a function of time and its calculation results from the variation in nuclear power from the inverse equation of punctual kinetics. This equation is a differential integral, where the term of the integral conserves the historical power and the differential part is directly related to the period of the reactor. In practice, in a nuclear plant, sensors are required to record the signals. For example, the movements of the control rods that cause the fluctuations of nuclear power over time commonly generate signals with noise, an event that makes difficult to estimate the reactivity. Thus is necessary and very useful to build digital reactivity meters in real time, since allows a reactor to be operated with greater security. The calculation of the reactivity is carried out using punctual kinetics, especially the concentration of delayed neutron precursors. In this work we present a new way to reduce the fluctuations in the calculation of the reactivity, for the high precision we propose the generalization of the predictor and corrector of the Adams-Bashforth-Moulton (ABM) method of order 4 to solve numerically the equations of the point kinetics for the calculation of the reactivity, without using the power history, due to the nature of the equations of the punctual kinetics, the modifiers of the different predictors are used to increase the accuracy in the approximation obtained accompanied by the filter known as Savitzky-Golay (Sg), allow to reduce the fluctuations of reactivity. It is known that the Sg filter softens and does not attenuate the nuclear power regardless of its shape, guarantees to reduce noise levels up to σ = 0.01, with a calculation time step of σ = 0.01, s. This formulation uses a polynomial approximation of Gram, with a degree d = 2, to calculate the convolution coefficients by means of an analytical formula that is implemented computationally and avoids problems of bad conditioning, caused by the inversion of a linear system. This formulation uses a polynomial approximation of Gram, with a degree d = 2, to calculate the convolution coefficients by means of an analytical formula that is implemented computationally and avoids problems of bad conditioning, caused by the inversion of a linear system. In addition, this article presents a hybrid method that allows simulating the Gaussian random noise, which is distributed around the medium power and the fluctuations of the reactivity are reduced. The results show better values in the maximum difference and in the average absolute error of the reactivity compared to that reported in the literature. (Author)

  6. Calculo Preliminar de la Tasa de Meteorización del Batolito Antioqueño, Cordillera Central, Colombia

    OpenAIRE

    Carolina Garcia; Michel Hermelin

    2004-01-01

    Este trabajo es una estimación preliminar del tiempo necesario para generar la espesa capa de saprolito que caracteriza el perfil de meteorización actual de un batolito cuarzodiorítico cretácico que aflora en altiplanos de la Cordillera Central de Colombia, entre 5º50' y 7º00' de latitud Norte y 74º50' y 75º35' de longitud Oeste y a alturas entre 750 y 2700 m.Se utilizan datos obtenidos previamente mediante el análisis de la composición química de las aguas superficiales d...

  7. Consideraciones respecto al calculo de empalmes atornillados de perfiles estructurales de GFRP sometidos a flexión

    Directory of Open Access Journals (Sweden)

    Serna, Eduardo

    2003-06-01

    Full Text Available A composite material can be defined as the combination of two or more materials with the aim of obtaining a new product with improved properties. Composite materials, composed of a polymer matrix reinforced with fibers, are currently used as structural elements, in spite of the uncertainties on strength, deformability and durability. The use of pultruded profiles in shapes similar to those used in metallic construction, results in an interesting solution for this material when high resistance. protection against chemical attacks and lightness are required. The structural key point of those materials are the joints. The present paper is focused on joints composed of bolted plates on the wings of IPN pultruded profiles. Different tests conducted in LABEIN are described. Likewise, this paper deals with tests carried out with the purpose of analysing the feasibility of joints with high resistance bolts.Se entiende como material compuesto la combinación de dos o más materiales para obtener un nuevo producto que mejore las propiedades individuales de cada uno ellos. Se está comenzando a emplear el material compuesto. formado por una matriz de tipo polimérico o resina reforzada con fibras. como elementos estructurales. pero con reticencias originadas por las incertidumbres existentes en la actualidad relativas a su resistencia, deformabilidad y durabilidad. Este material aporta un importante interés cuando se quieren obtener elementos estructurales de alta resistencia . protección frente a ataques químicos y ligereza. utilizando perfiles a la manera de la estructura metálica. fabricados por pultrusión, Debido a que el punto crítico estructural se encuentra en las uniones. el presente artículo se centrará en los empalmes atornillados con cubrejuntas de alas de perfiles pultruídos IPN, describiendo los ensayos de diferente naturaleza realizados en las instalaciones del Centro Tecnológico LABEIN. A su vez se recogen los ensayos previos desarrollados para analizar la viabilidad de ejecutar uniones por rozamiento con tornillos de alta resistencia.

  8. Description of the CAREM Reactor Neutronic Calculation Codes; Descripcion de la Linea de Calculo Neutronica del CAREM

    Energy Technology Data Exchange (ETDEWEB)

    Villarino, Eduardo; Hergenreder, Daniel [Investigacion Aplicada, INVAP, San Carlos de Bariloche (Argentina)

    2000-07-01

    In this work is described the neutronic calculation line used to design the CAREM reactor.A description of the codes used and the interfaces between the different programs are presented.Both, the normal calculation line and the alternative or verification calculation line are included.The calculation line used to obtain the kinetics parameters (effective delayed-neutron fraction and prompt-neutron lifetime) is also included.

  9. Calculo Preliminar de la Tasa de Meteorización del Batolito Antioqueño, Cordillera Central, Colombia

    Directory of Open Access Journals (Sweden)

    Carolina Garcia

    2004-12-01

    Full Text Available Este trabajo es una estimación preliminar del tiempo necesario para generar la espesa capa de saprolito que caracteriza el perfil de meteorización actual de un batolito cuarzodiorítico cretácico que aflora en altiplanos de la Cordillera Central de Colombia, entre 5º50' y 7º00' de latitud Norte y 74º50' y 75º35' de longitud Oeste y a alturas entre 750 y 2700 m.Se utilizan datos obtenidos previamente mediante el análisis de la composición química de las aguas superficiales de cuatro cuencas con áreas diferentes, ubicadas sobre el Batolito Antioqueño, al este de Medellín. Los cáculos se hicieron con el método basado en la pérdida de componentes en solución utilizando diferentes valores de solutos. Al utilizar la pérdida de sílice se obtiene un tiempo de meteorización de unos 6 x 10 6 años, comparable con el obtenido mediante la datación de las cenizas volcánicas mas antiguas que recubren la topografía actual y que indican la fecha mínima de configuración de la superficie de erosión.A pesar de resultar de una serie de suposiciones simplificadoras, este resultado es interesante y justifica la realización de determinaciones mas detalladas. Confirma la larga preservación de superficies de erosión antiguas conformadas sobre un saprolito que desde hace varios millones de años no ha sido sometido a una erosión profunda, fenómeno poco común en una zona tectónicamente activa como la estudiada.

  10. RAMA Methodology for the Calculation of Neutron Fluence; Metodologia RAMA para el Calculo de la Fluencia Neutronica

    Energy Technology Data Exchange (ETDEWEB)

    Villescas, G.; Corchon, F.

    2013-07-01

    he neutron fluence plays an important role in the study of the structural integrity of the reactor vessel after a certain time of neutron irradiation. The NRC defined in the Regulatory Guide 1.190, the way must be estimated neutron fluence, including uncertainty analysis of the validation process (creep uncertainty is ? 20%). TRANSWARE Enterprises Inc. developed a methodology for calculating the neutron flux, 1,190 based guide, known as RAMA. Uncertainty values obtained with this methodology, for about 18 vessels, are less than 10%.

  11. Treatment calculation program for reverse osmosis facilities; Programa de calculo de tratamiento para instalaciones de osmosis inversa

    Energy Technology Data Exchange (ETDEWEB)

    Adroer, M.; Bodas, J.; Coma, J.

    2001-07-01

    Reverse osmosis if a technique used ever more frequently for the desalination of water. it is very important to maintain the permeability of the membrane as much as possible throughout its life, and in order to do this, is necessary to know the incrustations properties of the water in contact with the membrane. The Adicro program has been developed to calculate the characteristics of this water from the analysis of the intake water, the type of membrane used, and the recovery percentage. It also calculates the necessary inhibitor doses and, finally, whether the supply water is apt for use in the plant under the predicted conditions or whether it should be modified. (Author) 2 refs.

  12. Obtaining a sulfoaluminate belite cement by industrial waste

    Directory of Open Access Journals (Sweden)

    Elkhadiri, L.

    2003-06-01

    Full Text Available Sulfoaluminate belite clinkers by burning raw at moderate temperatures near 1250 °C were synthesized. The used mixtures were made by calcium carbonate blended to two industrial wastes: low calcium fly ash and phosphogypsum. The clinkers were characterised by X-Ray Diffraction (XRD, Infrared Spectroscopy (FTIR and free lime. The hydraulic behaviour of the obtained cements, by adequate clinkers with 7% of added gypsum, was followed by XRD, scaning electronic microscopy (SEM, FTIR and NMR.

    Los clínkeres belíticos de sulfoaluminatos se obtienen por cocción de crudos a temperaturas moderadas, hacia 1.250 ºC. Esos crudos se componen de carbonato de calcio mezclados con dos subproductos industriales: cenizas volantes pobres en óxido de calcio y fosfoyeso. Los clínkeres obtenidos se caracterizaron a través de Difracción de Rayos X (DRX, Espectroscopia Infrarroja por Transformada de Fourier (FTIR y por la determinación de CaO libre. El comportamiento hidráulico de los cementos elaborados de los clínkeres con el 7% de yeso se estudió por DRX, Microscopía Electrónica de Barrido (SEM, FTIR y Resonancia Magnética Nuclear (RMN

  13. Biosurfactants produced by Microbacterium sp., isolated from aquatic macrophytes in hydrocarbon-contaminated area in the Rio Negro, Manaus, Amazonas

    Directory of Open Access Journals (Sweden)

    João Marcelo Silva Lima

    2017-05-01

    Full Text Available Endophytic bacteria isolated from Eichhornia crassipes (Mart Solms., collected in oil contaminated wastewater of effluent generated by Petrobras refinery in Manaus were investigated to determine their potential for producing biosurfactants. Assay with 2.6-dichlorophenol indophenol (DCPIP indicator to verify hydrocarbon biodegradation activity; oil emulsification test; drop-collapse method; surface tension and growth curve of biosurfactant production. The M87 Microbacterium sp. strain chosen for this work was identified by the sequencing of the rDNA region and the chemical characterization was performed by FTIR, UFLC/MS and 1H RMN techniques. The selected bacterial isolate provided 3g L-1 of biosurfactant, using diesel oil as sole carbon source, being efficient in biodegrading oil as demonstrated by the DCPIP test. Fractions obtained by column chromatography were efficient in reducing water surface tension around 40 mN m-1, especially fraction 1, which reduced it to 34.17 mN m-1. The different techniques of chemical analysis used for the identification of the biosurfactant isolate indicated that this is probably a long - chain fatty acid lipid type, which may be used in the future as both biosurfactant in decontamination processes of hydrocarbon-polluted areas or as bioemulsifier in countless processes, since it exhibited no toxicity as determined by Alamar Blue assay.

  14. Formación y estructura secundaria del 2,3 -bis-(3,4 -dimetoxibenzoíl propionitrilo

    Directory of Open Access Journals (Sweden)

    Francisco Sánchez Viesca

    2004-01-01

    Full Text Available El 3,4-dimetoxibenzoílacetonitrilo y el 2,4,5-trimetoxibenzoílacetonitrilo, requeridos en la síntesis de derivados isoxazólicos, se obtuvieron a partir de las α-halocetonas, la α-bromoacetoveratrona y el cloruro de 2,4,5-trimetoxifenacilo. En el primer caso se aisló un subproducto inesperado cuya estructura se dedujo de su espectroscopía (IR, RMN de 1H y EM y de su análisis elemental cuantitativo. Se identificó como 2,3-bis-(3,4-dimetoxibenzoílpropionitrilo. Del estudio cuidadoso de su espectro de resonancia magnética protónica se dedujo la existencia de 2 puentes de hidrógeno débiles, intramoleculares, del tipo C−H---O=C, debido a los desplazamientos químicos a mayor frecuencia que presentan los hidrógenos involucrados en dichas interacciones, así como, variaciones significativas en las constantes de acoplamiento de estos hidrógenos. Se observaron corrimientos, ∆δ, de 0.5 y de 1 ppm, como se discute en el texto. Esto se confirmó con modelos moleculares y mediante un estudio teórico empleando la teoría de funcionales de la densidad.

  15. EFECTO DEL ULTRASONIDO EN LA SÍNTESIS DE ARCILLA PILARIZADA CON ALUMINIO EN MEDIO CONCENTRADO

    Directory of Open Access Journals (Sweden)

    Sonia Moreno

    2009-04-01

    Full Text Available En este trabajo se realizó la síntesis de bentonita pilarizada con aluminio en medio concentrado, empleando ultrasonido en la etapa de intercalación. El agente pilarizante fue preparado por hidrólisis del AlCl3 con NaOH, seguido de precipitación con disolución de Na2SO4 y redisolución en Ba(NO32, y fue caracterizado por fluorescencia de rayos X (FRX, difracción de rayos X (DRX, microscopía electrónica de barrido (SEM y resonancia magnética nuclear de aluminio (27Al-RMN. La arcilla pilarizada fue caracterizada por FRX, DRX y fisiadsorción de N2 a 77 K, revelando propiedades estructurales y texturales comparables a la modificada siguiendo la metodología convencional: suspensiones diluidas y tiempos de intercalación elevados. El empleo de suspensiones concentradas de arcilla-agente pilarizante y la aplicación de ultrasonido en la etapa de intercalación, permiten una disminución en el volumen de agua entre el 90-95 % y una reducción en el tiempo de intercalación entre el 70–93 % respecto al método convencional de pilarización.

  16. Alcaloides en la especie cubana Croton micradenus Urb

    Directory of Open Access Journals (Sweden)

    Armando Payo Hill

    2001-04-01

    Full Text Available Se emprendió el estudio del contenido de alcaloides en las hojas y tallos de la especie endémica cubana, potencialmente medicinal, Crotón micradenus Urb. Para la extracción y purificación de dichos metabolitos se utilizaron solventes orgánicos y métodos cromatográficos de separación por columna y placa. Mediante métodos espectroscópicos de UV, IR, Masa y RMN ¹H y 13C, así como por la medición de sus constantes físicas, se caracterizaron 4 de los 6 alcaloides aislados, de ellos 3 morfinandienonas: ocobotrina, sinoacutina y 8,14 dihidrosalutaridina y una aporfina: isoboldina.The study of the content of alkaloids in the leaves and stems of the Croton micradenus Urb Cuban endemic species, which is potentially medicinal, was conducted. Organic solvents and chromatographic methods of separation by column and plate were used for the extraction and purification of these metabolites. 4 of the 6 isolated alkaloids, 3 of them morphinandienones: ocobotrine, sinoacutine and 8,14-dihydrosalutaridine and an aporphine (Isobol-dine were characterized by spectroscopic methods of UV, IR, Mass and NMR ¹H and 13C, as well as by the measurement of their physical constants.

  17. Polymerization and curing kinetics of furan resins under conventional and microwave heating

    International Nuclear Information System (INIS)

    Lopez de Vergara, Unai; Sarrionandia, Mariasun; Gondra, Koldo; Aurrekoetxea, Jon

    2014-01-01

    Graphical abstract: - Highlights: • The furan resin structure was investigated using IR and RMN techniques. • The polymerization of furan resins was developed based on multistage kinetics. • Vyazovkin numerical analysis was found the most accurate kinetic method. • Microwave curing of furan resins was much faster than thermal curing. - Abstract: The challenge of this work is the microwave curing study of low free-furfuryl alcohol content furan resins. The chemical characterization of the furan resins has been made by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The chemical composition of the resin and its reactions with p-toluensulfonic acid are proposed, with the aim of understanding the mechanism responsible for the main reactions. The results show the presence of methyl and ether bridges between the furan rings, and the formation of ketone and conjugated structures. Furthermore, the curing kinetics of the furan resins has been characterized by differential scanning calorimetry. Different methods have been applied in order to obtain and compare the activation energy of the process. Vyazovkin numerical analysis was found the most accurate method. Finally, microwave and conventional curing processes has been compared. The analysis showed that microwave curing of furan resins was twice faster than thermal curing

  18. Polymerization and curing kinetics of furan resins under conventional and microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Lopez de Vergara, Unai, E-mail: bergara@gaiker.es [Plastics and Composites Department, Gaiker IK4 Research Centre, Parque Tecnológico, Ed. 202, 48170 Zamudio Spain (Spain); Mechanical Engineering and Industrial Manufacturing Department, Mondragón Unibertsitatea, Loramendi 4, 20500 Mondragón Spain (Spain); Sarrionandia, Mariasun [Mechanical Engineering and Industrial Manufacturing Department, Mondragón Unibertsitatea, Loramendi 4, 20500 Mondragón Spain (Spain); Gondra, Koldo [Plastics and Composites Department, Gaiker IK4 Research Centre, Parque Tecnológico, Ed. 202, 48170 Zamudio Spain (Spain); Aurrekoetxea, Jon [Mechanical Engineering and Industrial Manufacturing Department, Mondragón Unibertsitatea, Loramendi 4, 20500 Mondragón Spain (Spain)

    2014-04-01

    Graphical abstract: - Highlights: • The furan resin structure was investigated using IR and RMN techniques. • The polymerization of furan resins was developed based on multistage kinetics. • Vyazovkin numerical analysis was found the most accurate kinetic method. • Microwave curing of furan resins was much faster than thermal curing. - Abstract: The challenge of this work is the microwave curing study of low free-furfuryl alcohol content furan resins. The chemical characterization of the furan resins has been made by infrared spectroscopy and nuclear magnetic resonance spectroscopy. The chemical composition of the resin and its reactions with p-toluensulfonic acid are proposed, with the aim of understanding the mechanism responsible for the main reactions. The results show the presence of methyl and ether bridges between the furan rings, and the formation of ketone and conjugated structures. Furthermore, the curing kinetics of the furan resins has been characterized by differential scanning calorimetry. Different methods have been applied in order to obtain and compare the activation energy of the process. Vyazovkin numerical analysis was found the most accurate method. Finally, microwave and conventional curing processes has been compared. The analysis showed that microwave curing of furan resins was twice faster than thermal curing.

  19. Voludensitometry. Three dimensional display of medical objects

    International Nuclear Information System (INIS)

    Darier, P.; Garderet, P.; Grangeat, P.; Matte, P.; Tournier, E.; Villafana, R.

    1984-05-01

    In order to study the volumic cartography of material density (X-rays imaging), of proton density (RMN imaging) or of specific activity of a marker (γ or β + imaging) a set of calculation results (called voxels) is reconstructed from sensor data collection. Voxels are identified by a triplet of space coordinates and they represent a local estimation of the parameter to be studied. The concepts for representation there upon developed can be extended for any parameter for which additivity is meaningful. The operator has to govern a software in order to work out the documents leading himself to a mental representation of the object. On a display these documents will be either graphics, images or image sequences. The elementary process for elaboration of one image includes: - conditionning the volume: definition of absolute coordinates (geometrical transformations), interactive extraction (surgery) or automation extraction (segmentation) of sub-volumes, contextual organization (sub-volumes ordering, dissolution); - reduction to two dimensions of the information either by spatial integration (radiography), or by surface representation (morphoscopy). This contribution introduces these different concepts showing the way to the design of an interactive display console. Video recorded sequences that have been realised using an experimental software will illustrate the preliminary results [fr

  20. Síntesis y caracterización de nuevas nanopartículas de derivados de PBLG para su uso en nanomedicina

    Directory of Open Access Journals (Sweden)

    María Elisa Martínez Barbosa

    2014-06-01

    Full Text Available En este trabajo se describe la realización de la síntesis y caracterización de cinco derivados de poli-L-glutamato de gamma-bencilo (PBLG por polimerización aniónica de apertura de anillo utilizando iniciadores de interés biomédico, así como la preparación y caracterización de nanopartículas poliméricas preparadas usando los polímeros sintetizados. Los polímeros fueron caracterizados por resonancia magnética nuclear (RMN 1H y cromatografía de exclusión de tamaño (GPC/SEC. Las nanopartículas fueron preparadas por nanoprecipitación y caracterizadas por microscopía electrónica de transmisión (MET y dispersión de luz (DLS/DDLS. Como se requiere para aplicaciones en nanomedicina, nanopartículas en el intervalo de 20 a 50 nm fueron obtenidas. Por otro lado, se presenta la técnica de dispersión de luz depolarizada (DDLS, como una técnica interesante para la caracterización morfológica y comportamiento dinámico de las nanopartículas poliméricas, en suspensión acuosa.

  1. Syntheses of therapeutically active labelled molecules for metabolic and pharmacokinetic studies. Synthesis, preservation and radiochemical purity problems

    International Nuclear Information System (INIS)

    Pichat, L.

    1977-01-01

    Molecules labelled with radioactive isotopes are without question an essential tool for metabolic and pharmacokinetic studies. Carbon 14 is often preferred to tritium since it allows better observation of the fate of carbonated structures. The fact that 14 CO 2 alone is used as basic material is the distinguishing feature of syntheses with isotopic carbon. In many cases the synthesis schemes of labelled drugs diverge considerably or entirely from those normally adopted for the unlabelled product. It is usually necessary to work on micro-quantities in order to maintain high specific activities, which implies the use of special synthesis techniques and of chromatographic separation and purification methods. Radiochemical purity tests are carried out by thin layer, column and gas phase chromatography, purity and identity checks by mass spectrometry and by 13 C and proton RMN. Labelled products are radiolysed by interaction of excited species with the molecules of the compound, a phenomenon much faster with tritiated than with 14 C-labelled molecules. The radiolysis rates may be reduced by molecule dilution. For ethical reasons it is not convenient to use 14 C molecules in human experiments, but molecular labelled with stable isotopes ( 13 C, 15 N, D) can serve instead [fr

  2. Alex Woloch, Caratterizzazione e distribuzione

    Directory of Open Access Journals (Sweden)

    Sostene Massimo Zangari

    2012-12-01

    Full Text Available Le opere narrative mostrano un’innata consapevolezza della tensione che deriva dalla necessità di distribuire l’attenzione su diversi personaggi in quantità disomogenee. L’autore si propone di creare un modello teorico per affrontare una serie di questioni legate alle scelte distribuzionali nel romanzo dell’Ottocento. Vengono introdotte le categorie di spazio-personaggio – l’incontro/scontro tra individuo rappresentato e spazio narrativo – e sistema-personaggi – la disposizione di personaggi multipli in una struttura narrativa. Le categorie intendono ovviare alla scissione che ha dominato la critica sul personaggio, divisa tra due posizioni antitetiche: da un lato chi ha ridotto il personaggio a mero accorgimento formale, dall’altro coloro i quali ne hanno enfatizzato l’aspetto referenziale e umano. L’intento delle categorie qui proposte è invece quello di recuperare la dialettica che lega questi due aspetti del personaggio finzionale. In particolare, mettere in evidenza come gli esiti strutturali del romanzo dipendano dal problema di rappresentare personaggi minori ridotti ai due principali paradigmi del bizzaro e del lavoratore. I meccanismi del romanzo e i disequilibri strutturali che derivano dall’incorporazione dei personaggi sono interpretati dall’autore come rispechiamento del difficile rapporto tra diseguaglianza e democrazia, che ha contrassegnato un secolo, l’Ottocento, dove alla mobilità sociale della borghesia faceva da contraltare la marginalizzazione delle classi subalterne. L’intervento si conclude con cenni al trattamento del personaggio nei lavori di Jane Austen, Dickens e Balzac.

  3. Il difficile rapporto tra cultura e mercato in Italia. Note a margine della ricerca "Le attività culturali e lo sviluppo economico: un esame a livello territoriale" / The difficult relationship between culture and market in Italy. Notes on the research “Le attività culturali e lo sviluppo economico: un esame a livello territoriale” (Non industrial cultural activities and economic growth: a territorial study

    Directory of Open Access Journals (Sweden)

    Ginevra Domenichini

    2013-01-01

    Full Text Available Il contributo presenta gli esiti della ricerca condotta da Enrico Beretta e Andrea Migliardi sulle interdipendenze tra il settore culturale italiano e il sistema produttivo del Paese; oggetto di analisi sono, in particolare, le attività culturali a contenuto non industriale – arti visive, spettacolo dal vivo, patrimonio artistico-culturale. Partendo dal presupposto che tali risorse possono in vari modi concorrere allo sviluppo, gli Autori propongono una analisi delle dimensioni e caratteristiche del settore da un punto di vista economico e gestionale-amministrativo. Le considerazioni avanzate in merito allo sfruttamento di tale risorsa e gli interventi di policy proposti per una sua corretta valorizzazione offrono un significativo contributo sotto il profilo teorico-conoscitivo e applicativo al dibattito, estremamente attuale, sul valore e le potenzialità di sviluppo, anche economico, del settore.   The paper presents the output of the research conducted by Enrico Beretta and Andrea Migliardi on the connections between the Italian cultural sector and the Country’s economy; the study focuses, in particular, on non industrial cultural activities which include the visual and performing arts and the heritage. Acknowledging their contribution to development, the Authors analyse the dimensions and characteristics of the sector both from an economic and administrative/managerial perspective. Their remarks on the current level of exploitation of such resource and the suggested policy recommendations for its enhancement represent a valuable contribution to the current debate on the value and development potentials of the sector.

  4. "A chiare lettere" Editoriale gennaio 2007

    Directory of Open Access Journals (Sweden)

    Giuseppe Casuscelli

    2011-02-01

    Full Text Available Ad onta delle crisi ricorrenti che investono il diritto ecclesiastico, nell’anno appena iniziato la nostra disciplina raccoglie il testimone inatteso della speranza. Il 2006 ci ha offerto la pubblicazione di tre manuali1 che, con un taglio ed un’impostazione nuovi, si rivolgono ad un’utenza che non è fatta soltanto degli studenti delle nostre Università; la pubblicazione del primo numero della nuova rivista semestrale “Diritto e Religioni”2, che intende trattare il fattore religioso da molteplici punti di vista aprendosi ad una molteplicità di scienze affini (antropologia, sociologia, storia, filosofia; la nascita di questa rivista telematica che non vuole avere un proprio indirizzo o orientamento, ma si prefigge lo scopo di essere strumento e manifesto della pluralità e del pluralismo delle scuole, delle sensibilità, dei metodi che alimentano il patrimonio comune del sapere teorico perché in esso trovi a sua volta alimento il concreto, quotidiano farsi dell’esperienza giuridica. Due ricorrenze di particolare rilievo segnano, ancora, questa fase: i cinquanta anni della Corte costituzionale, alla cui attività molto è legato il rinnovamento del “diritto ecclesiastico”, che ha partecipato alla celebrazione corale offrendo uno specifico contributo di analisi della sua giurisprudenza 3; i dodici lustri della Costituzione repubblicana, un’età “matura” che offre l’occasione per un bilancio della sua vitalità, delle compiute attuazioni, delle attese non ancora realizzate.

  5. Reactor Physics Development for Advanced Gas-Cooled Reactors; Recherches en Physique des Reacteurs, pour des Reacteurs Perfectionnes Refroidis par un Gaz; Razrabotka metodov v oblasti reaktornoj fiziki dlya usovershenstvovannogo reaktora s gazovym okhlazhdeniem; Progresos de la Fisica de los Reactores de Tipo Avanzado Refrigerados por Gas

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J. [United Kingdom Atomic Energy Authority (United Kingdom)

    1964-04-15

    verifier les methodes theoriques elaborees pour etudier des coeurs de reacteurs heterogenes. Ces methodes theoriques, utilisees jusqu'a ce jour, sont connues sous les noms dr 'hetrecontrol' et de 'FTD2'. Les experiences avaient pour but de verifier dans le detail les caracteristiques de ces methodes; on a analyse les mesures faites sur plusieurs coeurs de 'reacteur' de differentes dimensions dans les installations APEX et HERO pour determiner une serie coherente de constantes de reseau concordant avec les resultats des experiences. A ces constantes purement empiriques, on a applique ensuite les methodes <> et 'FTD2' pour preparer la mise en service sans accord d'AGR et le choix du regime de chargement de ce reacteur. Le memoire enumere les techniques experimentales qui ont ete essayees et celles qui ont ete elaborees pour resoudre certains problemes qui se presentaient. Particulierement interessantes sont les methodes ayant pour but de mesurer les effets sur la reactivite dans les installations APEX, HERO et AGR, et de determiner les donnees relatives a la structure fine ainsi que la repartition de la puissance dans les assemblages complexes. Les recherches theoriques actuelles et futures sont axees principalement sur la mise au point d'une methode capable de remplacer 'hetrecontrol' et 'FTD2' pour les etudes sur des coeurs de reacteur apres qu'une bonne partie du combustible a 'brule'. Le programme d'experiences avec l'installation HERO a pour but de verifier ces methodes au moyen de coeurs complexes contenant du plutonium. On compte obtenir des renseignements supplementaires sur l'effet du plutonium au cours du fonctionnement d'AGR et a la suite de mesures de physique sur le combustible irradie. (author) [Spanish] La memoria describe los trabajos experimentales y teoricos que se han ejecutado durante el diseno, el desarrollo y la puesta en marcha del reactor AGR de Windscale y para facilitar el desarrollo de nuevos tipos de reactores refrigerados por gas

  6. Cânfora: um bom modelo para ilustrar técnicas de RMN Camphor: a good model for illustrating NMR techniques

    Directory of Open Access Journals (Sweden)

    Julliane Diniz Yoneda

    2007-01-01

    Full Text Available The use of Nuclear Magnetic Resonance spectroscopy to establish the three-dimensional structures of molecules is an important component of modern Chemistry courses. The combination of techniques that can be used for this purpose is conveniently illustrated by their application to the camphor molecule. This paper presents applications of several techniques used in NMR spectral interpretation in an increasing order of complexity. The result of individual experiments is illustrated in order to familiarize the user with the way connectivity through bonds and through space is established from 1D/2D-NMR spectra and molecular stereochemistry is determined from different NMR experiments.

  7. Time domain NMR study of Agar-gelatin blends; Estudo por RMN no dominio do tempo de blendas de Agar- gelatina

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Ritamara; Pericini, H.A.; Tambelli, Caio E., E-mail: tambelli@usp.br [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos; Raphael, Ellen [Universidade Federal de Sao Joao del Rei (UFSJ), MG (Brazil). Departamento de Ciencias Naturais; Magon, Claudio J.; Donoso, P. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Instituto de Fisica

    2015-07-01

    This communication presents results of {sup 1}H time domain nuclear magnetic resonance of Agar-Gelatin blends plasticised with glycerol, cross-linked with formaldehyde and containing acetic acid. The spin-spin relaxation decay curves of samples obtained from CPMG experiments were inverted into corresponding distributions of relaxation times using NNLS (Non Negative Least Square) algorithm. The continuous distributions reveals up to four components of spin-spin relaxation times (T{sub 2}). The two components at short T{sub 2} were associated with protons in different environments of Agar and gelatin polymer chain. The two components at longer T{sub 2} can be associated with the glycerol that is the responsible to promote the proton conduction in the blend. (author)

  8. NMR study of quasi-one-dimensional itinerant-electron magnets RMn{sub 4}Al{sub 8} (R=Y, Lu and Sc)

    Energy Technology Data Exchange (ETDEWEB)

    Muro, Y. [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan)], E-mail: rk04j052@yahoo.co.jp; Nakamura, H.; Kohara, T. [Graduate School of Material Science, University of Hyogo, Kamigori, Ako-gun, Hyogo 678-1297 (Japan)

    2008-04-01

    {sup 55}Mn-NMR measurements, which revealed previously the presence of spin pseudogap in YMn{sub 4}Al{sub 8}, have been extended to LuMn{sub 4}Al{sub 8} and ScMn{sub 4}Al{sub 8}. Temperature (T) dependences of the Knight shift, K, and the nuclear spin-lattice relaxation rate, 1/T{sub 1}, are well explained by the same pseudogap model used to explain a broad maximum observed in the T-dependence of the susceptibility, indicating common nature in the spin excitation spectrum in the quasi-one-dimensional itinerant-electron compounds.

  9. Use of NMR as an online sensor in industrial processes; Uso da RMN como um sensor online em processos industriais

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Fabiana Diuk de [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil). Inst. de Quimica; Colnago, Luiz Alberto, E-mail: colnago@cnpdia.embrapa.br [Embrapa Instrumentacao, Sao Carlos, SP (Brazil)

    2012-07-01

    Nuclear magnetic resonance (NMR) is one of the most versatile analytical techniques for chemical, biochemical and medical applications. Despite this great success, NMR is seldom used as a tool in industrial applications. The first application of NMR in flowing samples was published in 1951. However, only in the last ten years Flow NMR has gained momentum and new and potential applications have been proposed. In this review we present the historical evolution of flow or online NMR spectroscopy and imaging, and current developments for use in the automation of industrial processes. (author)

  10. Contribution to the study of the {sup 31}P, {sup 1}H spin spin coupling constant N. M. R. in three co-ordinated phosphorus compounds. Influence of the bond orientation and of the nature of the substituent around the phosphorus atom; Contribution a l'etude des constantes de couplage {sup 31}P, {sup 1}H en R.M.N. dans les composes organo-phosphores tricoordines. Influence des facteurs geometriques et de la nature des substituants au niveau du phosphore

    Energy Technology Data Exchange (ETDEWEB)

    Robert, J B [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    niveau du phosphore. Les constantes de couplage sont du type {sup 3}J{sub PH} au travers des fragments P-C-C-H et P-O-C-H, et {sup 2}J{sub PH} au travers du fragment P-CH. Les resultats montrent que, pour les temps d'observation de la RMN, la disposition des liaisons au niveau du phosphore dans l'ensemble des composes etudies (dioxaphospholanes-1,3,2, dioxaphosphorinanes-1,3,2, phosphacyclopentenes-3, phosphorinanones-4) qui portent des substituants varies au niveau du phosphore, est pyramidale et fixe. Ce resultat s'applique egalement aux phosphines secondaires. Le couplage depend tres peu des substituants fixes sur le phosphore sauf dans le cas d'un azote. Pour les couplages {sup 3}J, les resultats montrent que la dependance attendue, basee uniquement sur l'angle diedre de type ''Karplus'', ne suffit pas. La direction du doublet libre donne lieu a une variation supplementaire sur J. Dans le cas des couplages {sup 2}J{sub P-C-H} cette influence est le facteur principal, les variations de J allant de + 25 cps a -6 cps: les valeurs peuvent etre traduites par une loi J = f({alpha}) (0 {<=} {alpha} {<=} 180) {alpha} etant l'angle diedre des plans H-C-P et C-P-X, X representant la direction du doublet libre (axe ternaire de la pyramide passant par le phosphore). (auteur)

  11. Development of a monoenergetic neutron beam (Theoretical aspects, experimental developments and applications); Desarrollo de un haz de neutrones monoenergeticos (Aspectos teoricos, desarrollos experimentales y aplicaciones)

    Energy Technology Data Exchange (ETDEWEB)

    Varela G, A

    2003-07-01

    By the use of a neutron time of flight system at the Tandem Accelerator of the National Nuclear Research Institute; with neutrons provided by means of the {sup 2} H(d, n) {sup 3} He we intend to use the associated particle technique in order to have monoenergetic neutrons. This neutron beam will be used both in basic and applied research. (Author)

  12. ESTUDIO TEORICO-EXPERIMENTAL DE LA REACCION DE AMINAS CON METILGLIOXAL; HACIA LA COMPRENSION DE LOS PROCESOS CAUSANTES DE LA CATARATA Y A SU POSIBLE PREVENCION

    OpenAIRE

    FLORES MORALES ; PATRICIO; FLORES MORALES ; PATRICIO

    2009-01-01

    Esta tesis se sitúa en el contexto de la reacción de glicación, también conocida como la reacción de Maillard (formación de una base de Schiff y posterior reordenamiento de Amidori), que sufren las proteínas del lente ocular humano y ocasiona la opalecencia y su posterior derivación en catarata. El estudio comenzó con el entendimiento del mecanismo de la reacción de Maillard visto desde un punto de vista teórico-computacion al analizado para un sistema modelo que permitió identificar las inte...

  13. Evaluación de la prueba de la moneda peruana en el tamizaje de trastorno cognitivo en adultos mayores

    Directory of Open Access Journals (Sweden)

    Teodoro J Oscanoa

    2016-01-01

    Full Text Available Objetivos. Adaptación peruana del test de la moneda en el tamizaje de trastorno cognitivo en adultos mayores (>60 años. Materiales y métodos. El presente es un estudio de fase I de evaluación de prueba diagnóstica con muestreo de conveniencia y calculo de sensibilidad y especificidad, con una prevalencia pretest de 50%. Para la definición operacional de pacientes con trastorno cognitivo se utilizó los criterios de la DSM IV (The Diagnostic and Statistical Manual of Mental Disorders y el Global Deterioration Scale (GDS (controles: GDS 1 y 2; casos: mayor de 2. Para encontrar el punto de corte se utilizó la curva ROC (Receiver Operating Characteristic. Resultados. Los pacientes estudiados fueron 42 casos y 42 controles, no hubo diferencia significativa entre la edad (77,88 + 6,01 y 76,14 + 6,49 años y años de educación (13,69 + 3,70 y 8,17 + 4,71. La versión peruana del "eurotest" denominada "prueba de la moneda peruana" tiene una sensibilidad de 90,5% y especificidad de 83,3 % con punto de corte de 24. Conclusiones. La versión peruana adaptada del "eurotest", denominada "prueba de la moneda peruana" podría ser útil en el tamizaje de trastorno cognitivo de adultos mayores.

  14. The meaning of the Impact Factor

    Directory of Open Access Journals (Sweden)

    Eugene Garfield

    2003-01-01

    Full Text Available El factor de impacto y otros índices bibliométricos son utilizados en la actualidad, en la mayoría de los países, para evaluar la investigación científica: proyectos de investigación, revistas, artículos, investigadores e instituciones. En el presente artículo se responden a las preguntas mas frecuentes sobre qué es el factor de impacto y cómo debe ser utilizado. En concreto, se habla de su origen, de los criterios que debe cumplir una revista, del factor de impacto como criterio de evaluación, de la relación entre la calidad de las revistas y el factor de impacto, de la evaluación de la calidad de las publicaciones, del período de evaluación para el cálculo del índice de impacto, del calculo del índice de impacto, de la comparación entre revistas de diferentes campos científicos, de la generalización del factor de impacto de una revista a cada uno de los artículos publicados en ella, de la relación entre el factor de impacto y la dificultad de publicar, del idioma en que publican las revistas y de cómo mejorar el factor de impacto de una revista.

  15. Estimación de la prevalencia de trastornos bipolares tipo I en España a través del consumo de carbonato de litio (1996-1998

    Directory of Open Access Journals (Sweden)

    Juan J Criado Álvarez

    2000-01-01

    Full Text Available Fundamento: Los estudios sobre la prevalencia de Trastornos Bipolares Tipo 1 son escasos y están realizados con metodologías diferentes, lo que impide conocer el impacto de los mismos como problema de salud pública en España. Se determina la prevalencia de Trastornos Bipolares tipo 1 en España a través del consumo de carbonato de litio. Métodos: Se estima la prevalencia a través del calculo de las dosis diarias definidas por 100.000 habitantes y día de carbonato de litio (Grupo terapéutico, NOSAN, durante los anos 19961998, para cada una de las provincias españolas. Se ha dispuesto de los datos de las prescripciones indicadas por la Subdirección General de Planifrcaci6n Farmacéutica del Ministerio de Sanidad y Consumo. Resultados: Se estima una prevalencia de 70 casos por 100.000 habitantes y día para el conjunto de la población española. Conclusiones: El consumo de carbonato de litio por provincias y años permite estimar la distribución de los Trastornos Bipolares tipo 1 en España. Las cifras obtenidas sitúan a España en una prevalencia baja- media; aunque las diferencias metodológicas no permiten conclusiones definitivas.

  16. Algoritmo para generar formulas de características geométricas de las secciones planas, su implementación en DERIVE // Algorithm for the calculation of the geometric characteristics of the plane sections defined for polygonal, their implementation in DERI

    Directory of Open Access Journals (Sweden)

    Rolando Rivero-Galán

    2010-01-01

    Full Text Available ResumenEn la esfera del diseno de estructuras y de elementos de maquinas, se presenta con relativafrecuencia el calculo de determinadas caracteristicas o propiedades geometricas de seccionesplanas, como son entre otras: el area de una seccion transversal, el centro de gravedad, unmomento de inercia o mas general la determinacion de alguna caracteristica geometrica definidapor una integral doble extendida en la region del plano que ocupa la seccion, pieza o elemento.El presente trabajo tiene como objetivo la confeccion de un programa para computadora,utilizando el asistente matematico DERIVE, para la determinacion de las caracteristicas geometricasde secciones planas cuyo contorno este constituido por segmentos de rectas.Palabras claves: Algoritmo, seccion plana, DERIVE, momentos, centro de gravedad.______________________________________________________________AbstractIn the sphere of the design of structures, is relative frequency the calculation of certaincharacteristic or geometric properties of plane sections, like: the area of a traverse section, thecenter of gravity, a moment of inertia or more general the determination of some geometriccharacteristic defined by a double integral extended in the region of the plane that occupies thesection, piece or element.The present work has as objective the making of a program for computer, using the mathematicalassistant DERIVE, for the determination of the geometric characteristics of plane sections whosecontour this constituted by segments of right.Key words: Algorithm, plane section, DERIVE, moments, center of gravity

  17. Salud bucal de un grupo de cazadores recolectores prehistóricos

    Directory of Open Access Journals (Sweden)

    Solomita Banfi, Fátima

    2001-01-01

    Full Text Available La patología dental es particularmente interesante por su asociación con la ingesta de alimentos, brinda valiosa información para la reconstrucción de dietas, modos de preparación de alimentos y la utilización de la boca como instrumento. Como parte de las investigaciones realizadas sobre la colección esqueletal procedente del sitio Isla Barranquita I (Dpto. Garay, Santa Fe se relevaron macroscópicamente las patologías dentales más frecuentes: perdida de piezas dentales antemortem, absceso dental, caries, periodontitis, hipoplasia y cálculo. La muestra está compuesta por los restos de 17 individuos de entre 0 y 55 años de edad que fueron exhumados de un enterratorio de tipo secundario. Se observó un elevado índice de caries por boca, especialmente entre individuos juveniles, y calculo dental en grado medio a avanzado entre juveniles y adultos. No se detectó la presencia de periodontitis ni abscesos. La presencia de hipoplasia no fue relevante para la muestra analizada. Se puede concluir un estado de salud bucal regular por la presencia de caries, sin embargo no se hallaron enfermedades infecciosas ni nutricionales para el grupo de cazadores recolectores que habitó el sitio hace unos 1200 años.

  18. O modelo da vigilância à saúde: um estudo exploratório no extremo sul do Brasil

    Directory of Open Access Journals (Sweden)

    Sibele da Rocha Martins

    2008-01-01

    Full Text Available El objetivo de esto estudio fue analizar el modelo de organización tecnológica de la Vigilancia a la Salud, en los 22 municipios que componen la 3ª Coordinadoría Regional de Salud/RS, analisando los elementos de su proceso de trabajo, el perfil dos trabajadores atuantes en los diferentes servicios/ambientes de la Vigilancia a la Salud. Refierese a un estudio contitativo que utilisó un abordaje exploratório, descriptivo y analítico. Los datos fueron obtenidos através de una encuesta estructurada con 82 trabajadores y analisados estatísticamente, através del calculo de media, desvío padrón, siendo utilizado el teste de post hoc de la Diferencia Media Significativa. La Vigilancia a la Salud posee trabajadores em las mas diversas areas del saber, 66% del sexo femenino con idades entre 31 y 50 anõs, atuando em su maioria en el ambiente de la Vigilância Epidemiológica. Con su organización tecnológica pautada em la promoción de la salud la Vigilancia a la Salud busca la construcción de un nuevo modelo de atención que reoriente las práticas de salud en el Sistema Único de la Salud.

  19. La gestión comunicacional basada en la cultura organizacional e identidad corporativa de la Universidad Nacional Abierta (UNA

    Directory of Open Access Journals (Sweden)

    Graciela Perozo de Jiménez

    2006-01-01

    Full Text Available El presente estudio tuvo como propósito determinar la cultura organizacional e identidad corporativa como instrumentos de gestión comunicacional en la Universidad Nacional Abierta, de los Centros Locales del occidente del país. La investigación siguió la modalidad de trabajo de campo de tipo descriptiva, dentro del enfoque cuantitativo. La población estuvo constituida por 138 sujetos miembros del personal académico de los centros locales del occidente del país, quedando la muestra conformada por 103 miembros del personal académico. Como instrumento de recolección de datos se utilizó un (1 cuestionario con la finalidad de obtener información sobre la comunicación corporativa en la UNA, a través de dos dimensiones para su estudio: Cultura organizacional e Identidad corporativa. El cual se sometió a validez de contenido por parte de 10 expertos y se calculo la confiabilidad obteniendo un coeficiente de 0,90. Como técnica de análisis de datos se utilizó la estadística descriptiva, mediante distribución de frecuencias y medias aritméticas. Como resultados se obtuvo las principales características del comportamiento organizacional e identidad corporativa del personal académico de los Centros Locales del occidente del país de la UNA.

  20. DOSEFU: Computer application for dose calculation and effluent management in normal operation

    International Nuclear Information System (INIS)

    Martin Garcia, J. E.; Gonzalvo Manovel, A.; Revuelta Garcia, L.

    2002-01-01

    DOSEFU is a computer application on Windows that develops the methodology of nuclear power plant Exterior Dose Calculation Manuals (Manuals de Calculo de Dosis al Exterior-MACADE) for calculating doses in normal operation caused by radioactive liquid and gaseous effluents, for the purpose of enforcing the new Spanish Regulation on Health Protection against Ionizing Radiations, Royal Decree 783/2001 resulting from transposition of Directive 96/29/Euratom whereby the basic rules regarding health protection of workers and the population against risks resulting from ionizing radiations are established. In addition to making dose calculations, DOSEFU generates, on a magnetic support, the information regarding radioactive liquid and gaseous effluents that plants must periodically send to the CSN (ELGA format). The computer application has been developed for the specific case of Jose Cabrera NPP, which is called DOEZOR. This application can be easily implemented in any other nuclear or radioactive facility. The application is user-friendly, as the end user inputs data and executes the different modules through keys and dialogue boxes that are enabled by clicking on the mouse (see figures 2, 3, 4 and 5 ), The application runs under Windows 95. Digital Visual Fortran has been used as the development program, as this does not require additional libraries (DLLs), it can be installed in any computer without affecting other programs that are already installed. (Author)