947 resultados para Mid-IR
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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
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(IR - spectroscopic characterization of biominerals in marattiaceaeus ferns). Frond samples of the eusporangiate ferns Marattiaceae genera Angiopteris, Christensenia, Danaea and Marattia were investigated by infrared spectroscopy, under different experimental conditions. The results confirmed the previously reported accumulation of biogenic silica (SiO2) in tissues of these ferns and also showed, for the first time, the presence of calcium oxalate in this group of plants, probably as weddellite. The ability to biomineralize SiO2, to produce and accumulate biogenic silica, is suggested now to be a general family trait of the Marattiaceae.
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Um método simples e rápido para a preparação da amostra e quantificação simultânea de açúcares e polióis em sorvetes "diet"/"light" por CLAE-IR foi investigado. Os açúcares frutose, glicose, lactose, maltose, sacarose, juntamente com glicerol e sorbitol foram separados. Diferentes variáveis foram testadas na preparação da amostra e nas condições cromatográficas para a separação dos componentes. A melhor condição para a separação dos analitos da matriz foi obtida através de duas extrações consecutivas com água : etanol (1:8 v/v, seguida de 1:4 v/v). Para a separação cromatográfica em uma coluna CLC-NH2 , a fase móvel foi composta de acetonitrila: água (77,5:22,5 v/v) na vazão de 1mL/min, a 30 ºC. O tempo de corrida foi menor do que 20 min. Amostras de sorvetes "diet"/"light" de 3 diferentes marcas, com sabores de morango, chocolate, flocos e baunilha, recolhidas em Campinas-SP, apresentaram valores de açúcares totais entre 9-15%. Somente os sorvetes com sabor morango apresentaram frutose (0,1-0,5%), e somente aqueles sorvetes com sabor de flocos mostraram a presença de sacarose em maiores quantidades. Os maiores valores de açúcares foram encontrados para lactose, independente da marca ou sabor testados (3,5-10%). As quantidades de sorbitol variaram de 3-4%. A mesma análise foi realizada com sorvete normal (controle) que apresentou valor de açúcares totais de aproximadamente 29%, sendo que destes 16,8%, foi sacarose. Não foram detectados polióis. Na amostra de sorvete controle foi realizado teste de recuperação de sorbitol (99,3%). Os valores encontrados foram comparados com os valores permitidos pela legislação.
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ZnF2, CdF2, and CUF2 have been adsorbed onto the surface of montmorillonite K10, and the infrared and 19F, 27 AI, and 29Si MAS NMR spectra of the reagents over a range of loadings have been obtained. CUF2 was observed to attack the Si02 layer and form the complex CuSiF6, Zn F2 tends to attack the aluminium oxide layer, in which Zn isomorphously replaces AI, and forms AIF3 and AIF4 - complexes. All the spectroscopic evidence ruled out the formation of any AI-F and/or Si-F free species as CdF2 is adsorbed on the surface of montmorillonite K10. The reactivity of MF2-K10 reagents towards Friedel-Crafts benzylation of benzene with benzyl chloride varied from one reagent to another. ZnF2-K10 was observed to be the most reactive and CUF2 was the least reactive.
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A system comprised of a Bomem interferometer and a LT3-110 Heli-Tran cryostat was set up to measure the reflectance of materials in the mid-infrared spectral region. Several tests were conducted to ensure the consistency and reliability of the system. Silicon and Chromium, two materials with well known optical properties were measured to test the accuracy of the system, and the results were found to be in good agreement with the literature. Reflectance measurements on pure SnTe and several Pb and Mn-doped alloys were carried out. These materials were chosen because they exhibit a strong plasma edge in the mid infrared region. The optical conductivity and several related optical parameters were calculated from the measured reflectance. Very low temperature measurements were carried out in the far-infrared on Sn9SMn2Te, and the results are indicative of a spin glass phase at 0.8 K. Resistivity measurements were made at room temperature. The resistivity values were found, as expected, to decrease with increasing carrier concentration and to increase with increasing manganese concentration.
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One of the main objectives of the mid-Atlantic transect is to improve dating resolution of sequences and unconfonnity surfaces. Dinoflagellate cysts from two Ocean Drilling Program boreholes, the onshore Leg 174AX Ocean View Site and Leg 174A continental shelf Site 1071, are used to provide age estimates for sequences and unconfonnities fonned on the New Jersey continental margin during the Miocene epoch. Despite the occasional lack of dinocysts in barren and oxidized sections, dinocyst biochronology still offers greater age control than that provided by other microfossils in marginal marine environments. An early Miocene to late Miocene chronology based on ages detennined for the two study sites is presented. In addition, .palynofacies are used to unravel the systems tract character of the Miocene sequences and provide insight into the effects of taphonomy and preservation of palynomorphs in marginal marine and shelf environments under different ~ea level conditions. More precise placement of maximum flooding surfaces is possible through the identification of condensed sections and palynofacies shifts can also reveal subaerially exposed sections and surfaces not apparent in seismic or lithological analyses. The problems with the application of the pollen record in the interpretation of Miocene climate are also discussed. Palynomorphs provide evidence for a second-order lowering of sea level during the Miocene, onto which higher order sea level fluctuations are super-imposed. Correlation of sequences and unconfonnities is attempted between onshore boreholes and from the onshore Ocean View borehole to offshore Site 1071.
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Tesis (Maestría en Ciencias con Especialidad en Lengua y Literatura) UANL, 2012.
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This paper documents and discusses a dramatic change in the cyclical behavior of aggregate hours worked by individuals with a college degree (skilled workers) since the mid-1980’s. Using the CPS outgoing rotation data set for the period 1979:1-2003:4, we find that the volatility of aggregate skilled hours relative to the volatility of GDP has nearly tripled since 1984. In contrast, the cyclical properties of unskilled hours have remained essentially unchanged. We evaluate the extent to which a simple supply/demand model for skilled and unskilled labor with capital-skill complementarity in production can help explain this stylized fact. Within this framework, we identify three effects which would lead to an increase in the relative volatility of skilled hours: (i) a reduction in the degree of capital-skill complementarity, (ii) a reduction in the absolute volatility of GDP (and unskilled hours), and (iii) an increase in the level of capital equipment relative to skilled labor. We provide empirical evidence in support of each of these effects. Our conclusion is that these three mechanisms can jointly explain about sixty percent of the observed increase in the relative volatility of skilled labor. The reduction in the degree of capital-skill complementarity contributes the most to this result.
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Photothermal effect refers to heating of a sample due to the absorption of electromagnetic radiation. Photothermal (PT) heat generation which is an example of energy conversion has in general three kinds of applications. 1. PT material probing 2. PT material processing and 3. PT material destruction. The temperatures involved increases from 1-. 3. Of the above three, PT material probing is the most important in making significant contribution to the field of science and technology. Photothermal material characterization relies on high sensitivity detection techniques to monitor the effects caused by PT material heating of a sample. Photothermal method is a powerful high sensitivity non-contact tool used for non-destructive thermal characterization of materials. The high sensitivity of the photothermal methods has led to its application for analysis of low absorbance samples. Laser calorimetry, photothermal radiometry, pyroelectric technique, photoacoustic technique, photothermal beam deflection technique, etc. come under the broad class ofphotothermal techniques. However the choice of a suitable technique depends upon the nature of the sample, purpose of measurement, nature of light source used, etc. The present investigations are done on polymer thin films employing photothermal beam deflection technique, for the successful determination of their thermal diffusivity. Here the sample is excited by a He-Ne laser (A = 6328...\ ) which acts as the pump beam. Due to the refractive index gradient established in the sample surface and in the adjacent coupling medium, another optical beam called probe beam (diode laser, A= 6500A ) when passed through this region experiences a deflection and is detected using a position sensitive detector and its output is fed to a lock-in amplifier from which the amplitude and phase of the deflection can be directly obtained. The amplitude and phase of the signal is suitably analysed for determining the thermal diffusivity.The production of polymer thin film samples has gained considerable attention for the past few years. Plasma polymerization is an inexpensive tool for fabricating organic thin films. It refers to formation of polymeric materials under the influence of plasma, which is generated by some kind of electric discharge. Here plasma of the monomer vapour is generated by employing radio frequency (MHz) techniques. Plasma polymerization technique results in homogeneous, highly adhesive, thermally stable, pinhole free, dielectric, highly branched and cross-linked polymer films. The possible linkage in the formation of the polymers is suggested by comparing the FTIR spectra of the monomer and the polymer.Near IR overtone investigations on some organic molecules using local mode model are also done. Higher vibrational overtones often provide spectral simplification and greater resolution of peaks corresponding to nonequivalent X-H bonds where X is typically C, N or O. Vibrational overtone spectroscopy of molecules containing X-H oscillators is now a well established tool for molecular investigations. Conformational and steric differences between bonds and structural inequivalence ofCH bonds (methyl, aryl, acetylenic, etc.) are resolvable in the higher overtone spectra. The local mode model in which the X-H oscillators are considered to be loosely coupled anharmonic oscillators has been widely used for the interpretation of overtone spectra. If we are exciting a single local oscillator from the vibrational ground state to the vibrational state v, then the transition energy of the local mode overtone is given by .:lE a......v = A v + B v2 • A plot of .:lE / v versus v will yield A, the local mode frequency as the intercept and B, the local mode diagonal anharmonicity as the slope. Here A - B gives the mechanical frequency XI of the oscillator and B = X2 is the anharmonicity of the bond. The local mode parameters XI and X2 vary for non-equivalent X-H bonds and are sensitive to the inter and intra molecular environment of the X-H oscillator.
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Open access iiiovemerit and open source software movement plays an important role in creation of knowledge, knowledge management and knowledge dissemination. Scholarly communication and publishing are increasingly taking place in the electronic environment. With a growing proportion of the scholarly record now existing only in digital format, serious issues regarding access and preservation are being raised that are central to future scholarship. Institutional Repositories provide access to past. present and future scholarly literature and research documentation; ensures its preservation; assists users in discovery and use; and offers educational programs to enable users to develop lifelong literacy. This paper explores these aspects on how IR of Cochin University of Science & Technology supports scientific community for knowledge creation. knowledge Management, and knowledge dissemination.
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FT-Raman and FT-IR spectra of ASnFe(PO4)3 [A=Na2, Ca, Cd] were recorded and analyzed. The bands were assigned in terms of the vibrational group frequencies of SnO6 octahedral and PO4 tetrahedral. The spectral analysis shows that the symmetry of corner shared octahedral (SnO6) and the tetrahedral (PO4) are lowered from their free ion symmetry state. The presence of Fe3+ ions disrupts the S–N–O–S–N chain in the structure. This causes distortion of SnO6 and PO4 in the structure of all the compounds. Also it is seen that there are two distinct PO4 tetrahedra of different P–O bond lengths. One of these tetrahedra is linearly distorted in all the title compounds. The PO4 frequencies and bond lengths are calculated theoretically and are in agreement with the experimental values. The presence of PO4 polyanion in the structure can reduce the redox energy and hence reduce the metal oxygen covalency strength in the structure
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Resumen tomado de la publicación
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Dorcé es una idea de negocio que responde de manera directa a la necesidad de vestir de las mujeres a través de su innovador sistema operativo Diseño y confección a tu manera el cual tiene como objetivo revolucionar la tradicional forma de adquirir prendas de vestir femeninas en la ciudad de Villavicencio. Desde su creación y ejecución, se ha observado una gran aceptación de dicho sistema operativo por parte de los clientes antiguos generando muy buenos resultados económicos partiendo de sus actividades principales, el diseño, la confección y venta de prendas de vestir femeninas. Es por esto que el desarrollo de este trabajo de grado va dirigido a organizar de una manera más administrativa los diferentes procesos que se llevan a cabo dentro de la organización a fin de conseguir incrementar la producción y llegar así a un grupo más amplio de clientes con base en sus necesidades y a las actuales tendencias de la moda. Esta labor tiene como fin, responder y satisfacer a la mujer villavicense en términos de moda, servicio y confección, agregándole un valor adicional en cuanto a menores tiempos de entrega, altos estándares de calidad y exclusividad. Todo lo anterior, en un solo lugar. El sistema operativo (factor diferenciador) de esta idea de negocio consiste en ofrecer a los clientes, diferentes modelos de las partes (cuello, manga, contorno, falda y panty) que componen las prendas que fabrica Dorcé (Blusa, vestido y traje de baño). Con el fin de que el cliente pueda armar la prenda a su gusto teniendo el plus de ir a la medida. Dicha prenda de carácter exclusivo, es confeccionada y entregada al cabo de un máximo de 3 días dependiendo de la complejidad que tenga para ser elaborada, garantizándole al cliente no solo la originalidad del diseño de su prenda sino también fabricarla en menor tiempo que la competencia. Es un producto y un servicio innovador que va dirigido a mujeres de quince a setenta años de edad de la ciudad de Villavicencio, mujeres de media y alta sociedad que se caracterizan por su gusto por la moda y la calidad. Una vez se satisfacen las necesidades de nuestros clientes se da lugar a nuevas ventas dentro del grupo social de cada una de ellas, una vez nos refieran de manera positiva con sus amigas y conocidas. Este tipo de publicidad (voz a voz) es la que ha llevado a Dorcé a crecer a través de los años sin perder la exclusividad de su mercado; sin embargo, en la actualidad, la idea de negocio carece de estructura empresarial adecuada, de estrategias que garanticen su crecimiento y sostenibilidad, también carece de recursos financieros inmediatos que faciliten la ampliación y adecuación de la planta de producción y del almacén. Es por ello que las actuales empresarias de esta idea de negocio tienen como objetivo, mediante la elaboración de este plan de empresa, desarrollar, organizar y mejorar las estrategias, acciones, objetivos, alianzas, cambios, inversiones, que se tienen y necesitan para el mejoramiento interno y externo de la compañía. Para el desarrollo de dicho plan, Dorcé cuenta con Doris Blanco, una diseñadora de modas de 25 años de experiencia en el sector textil y confección en la ciudad de Villavicencio, quien está a cargo del área de producción de la empresa, dos estudiantes de Administración de Negocios Internacionales, Fernanda Montes y Juliana Villamizar, quienes están a cargo de la parte administrativa, comercial y estratégica de la empresa. De igual forma cuenta con el conocimiento del mercado textil y de confección, así mismo amplias relaciones que se han venido fortaleciendo a través del tiempo con los diferentes proveedores de materia prima en la ciudad, maquinaria y materia prima inicial, cerca de sesenta mujeres que se han vinculado a la empresa como clientes fieles a la idea de negocio promocionándolo de manera positiva día a día, así como también el interés, empuje y compromiso por parte de las involucradas en desarrollar, ejecutar y sostener esta idea de negocio como proyecto de vida.
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El fin de la Guerra Fría supuso no sólo el triunfo del capitalismo y de la democracia liberal, sino un cambio significativo en el Sistema Internacional; siendo menos centralizado y más regionalizado, como consecuencia de la proximidad y relaciones de interdependencia entre sus actores (no sólo Estados) y permitiendo la formación de Complejos Regionales de Seguridad (CRS). Los CRS son una forma efectiva de relacionarse y aproximarse a la arena internacional pues a través de sus procesos de securitización y desecuritización consiguen lograr objetivos específicos. Partiendo de ello, tanto la Unión Europea (UE) como la Comunidad para el Desarrollo de África Austral (SADC) iniciaron varios procesos de securitización relacionados con la integración regional; siendo un ejemplo de ello la eliminación de los controles en sus fronteras interiores o libre circulación de personas; pues consideraron que de no hacerse realidad, ello generaría amenazas políticas (su influencia y capacidad de actuación estaban amenazadas), económicas (en cuanto a su competitividad y niveles básicos de bienestar) y societales (en cuanto a la identidad de la comunidad como indispensable para la integración) que pondrían en riesgo la existencia misma de sus CRS. En esta medida, la UE creó el Espacio Schengen, que fue producto de un proceso de securitización desde inicios de la década de los 80 hasta mediados de la década de los 90; y la SADC se encuentra inmersa en tal proceso de securitización desde 1992 hasta la actualidad y espera la ratificación del Protocolo para la Facilitación del Movimiento de personas como primer paso para lograr la eliminación de controles en sus fronteras interiores. Si bien tanto la UE como la SADC consideraron que de no permitir la libre circulación de personas, su integración y por lo tanto, sus CRS estaban en riesgo; la SADC no lo ha logrado. Ello hace indispensable hacer un análisis más profundo de sus procesos de securitización para así encontrar sus falencias con respecto al éxito de la UE. El análisis está basado en la Teoría de los Complejos de Seguridad de Barry Buzan, plasmada en la obra Security a New Framework for Analysis (1998) de Barry Buzan, Ole Waever y Jaap de Wilde y será dividido en cada una de las etapas del proceso de securitización: la identificación de una amenaza existencial a un objeto referente a través de un acto discursivo, la aceptación de una amenaza por parte de una audiencia relevante y las acciones de emergencia para hacer frente a las amenazas existenciales; reconociendo las diferencias y similitudes de un proceso de securitización exitoso frente a otro que aún no lo ha sido.
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Material bilingüe