797 resultados para 1110


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Este trabalho tem por objetivos analisar o definido no SNC e no SNC-AP, quanto ao reconhecimento e mensuração dos ativos fixos tangíveis (AFT). Este estudo permite concluir, quanto ao reconhecimento dos AFT, que o SNC-AP aproxima-se do SNC, com algumas particularidades específicas do âmbito público, como o facto de um elemento poder ser reconhecido como ativo mesmo que não produza rendimentos, desde que possua potencial de serviços. Por outro lado, no que respeita à mensuração, o SNC-AP segue de perto, com as devidas adaptações, os normativos internacionais e também o SNC, mas na mensuração subsequente dos AFT, apenas apresenta a revalorização como alternativa ao custo.

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La presente investigación explica las calificaciones finales de los estudiantes del curso de Economía de la Universidad del Pacífico con el objetivo de comparar el impacto de las experiencias y los conocimientos previos del estudiante frente al desempeño de sus profesores. Para ello, se aplicaron modelos de regresión censurados conocidos como Tobit model, los cuales corrigieron los problemas de censura de la variable dependiente. Los modelos desarrollados resultaron libres de sesgo de selección muestral, y sus procesos de estimación consideraron variables académicas, psicológicas, sociofamiliares, de identificación y pedagógicas. A través de ellos, un conjunto de factores asociados a las experiencias y los conocimientos previos del estudiante resultó ser el de mayor impacto sobre el rendimiento académico. Así, dos variables académicas —la calificación escolar promedio en matemáticas alcanzada durante los tres últimos años de educación secundaria y la asistencia a un colegio privado—, estuvieron entre las más importantes para explicar las calificaciones finales de Economía I. Tres factores académicos adicionales también contribuyeron a elevar las calificaciones: haber estudiado en un colegio que no sea preuniversitario, la procedencia de escuelas que diferencian por sexo (no mixtas) y haber sido expuesto a contenidos más amplios de economía durante la etapa escolar. Asimismo, tres docentes impactaron de modo positivo, pero su impacto fue mucho menor que el de los factores académicos. Es decir, el rendimiento previo y el currículo escolar llegan a importar mucho más que el desempeño didáctico del docente para el éxito académico en las asignaturas introductorias de economía. Finalmente, debido a que no se encontró que los docentes mejor evaluados por los estudiantes impactaban sobre el rendimiento de sus alumnos, se evidencia que es importante revisar los sistemas de evaluación docente, para evitar que estos se conviertan en un instrumento mediante el cual los estudiantes penalicen a los profesores exigentes y que, por el contrario, contribuyan a retroalimentar al docente y a mejorar su desempeño.

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Sob a influência da Antígona sofocliana, Mário de Sacramento escreveu uma peça homónima publicada, isoladamente, em 1959, no vol. XIX, nº 186 da “Revista Vértice”, e incluída, no ano seguinte, na tetralogia intitulada Teatro Anatómico. Nesta peça em um ato, a tragédia homónima de Sófocles configura-se um recurso metateatral de carácter crítico-reflexivo, em que o diálogo intertextual com o ancestral texto trágico promove uma leitura dramática do destino infortunado dos sobreviventes de uma família francesa, vítima da ocupação alemão, na Segunda Guerra Mundial, que, como os últimos Labdácidas, confrontam o sofrimento de situações-limite, ditadas por conflitos insolúveis da condição humana. Neste «ensaio dramático de Mário de Sacramento, a protagonista é uma mulher francesa, Ivonne, que no tempo do Maquis, escolhe, como nome de código, “Antígona”. Pretende-se, neste estudo, apresentar uma análise da influência exercida pela Antígona sofocliana neste «ensaio dramático», ao nível da caracterização das dramatis personae e do desenvolvimento da ação, que se sustenta numa reflexão crítica sobre as motivações da filha de Édipo e o sentido trágico das suas ações.

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Research in solar energy conversion and the associated photoactive materials has attracted continuous interest. Due to its proper electronic band structure, high quantum efficiency, and photonic and chemical innerness, TiO2 has been demonstrated as a versatile oxide semiconductor capable of efficiently utilizing sunlight to produce electrical and chemical energy. Its outstanding physicochemical performances have led to an array of advanced photocatalytic and photoelectrochemical applications including environmental photocatalysis, dye/semiconductor-sensitized solar cell, and solar fuel productions.

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The multiwall carbon nanotubes (MWCNTs)/titanium dioxide (P25) composite in different ratios was prepared using simple evaporation and drying process. The composite was characterized by Raman spectroscopy, X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy, and scanning electron microscopy (SEM). The photocatalytic activity of this composite was investigated using degradation of the Bismarck brown R dye (BBR). An optimal MWCNTs/TiO2 ratio of 0.5% (w/w) was found to achieve the maximum rate of BBR degradation. It was observed that the composite exhibits enhanced photocatalytic activity compared with TiO2. The enhancement in photocatalytic activity performance of the MWCNTs/P25 composite is explained in terms of recombination of photogenerated electron-hole pairs. In addition, MWCNTs act as a dispersing support to control the morphology of TiO2 particles in the MWCNTs/TiO2 composite.

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Polycyclic aromatic hydrocarbons (PAHs) represent a large class of persistent organic pollutants in an environment of special concern because they have carcinogenic and mutagenic activity. In this paper, we focus on and discuss the effect of different parameters, for instance, initial concentration of Anthracene, temperature, and light intensity, on the degradation rate. These parameters were adjusted at pH 6.8 in the presence of the semiconductor materials (TiO2) as photocatalysts overUVlight. The main product of Anthracene photodegradation is 9,10-Anthraquinone which isidentified and compared with the standard compound by GC-MS. Our results indicate that the optimum conditions for the best rate of degradation are 25 ppm concentration of Anthracene, regulating the reaction vessel at 308.15 K and 2.5 mW/cm(2) of light intensity at 17 5mg/100 mL of titanium dioxide (P25).

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Titania modified nanoparticles have been prepared by the photodeposition method employing platinum particles on the commercially available titanium dioxide (Hombikat UV 100). The properties of the prepared photocatalysts were investigated by means of the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), and UV-visible diffuse spectrophotometry (UV-Vis). XRD was employed to determine the crystallographic phase and particle size of both bare and platinised titanium dioxide. The results indicated that the particle size was decreased with the increasing of platinum loading. AFM analysis showed that one particle consists of about 9 to 11 crystals. UV-vis absorbance analysis showed that the absorption edge shifted to longer wavelength for 0.5% Pt loading compared with bare titanium dioxide. The photocatalytic activity of pure and Pt-loaded TiO2 was investigated employing the photocatalytic oxidation and dehydrogenation of methanol. The results of the photocatalytic activity indicate that the platinized titanium dioxide samples are always more active than the corresponding bare TiO2 for both methanol oxidation and dehydrogenation processes. The loading with various platinum amounts resulted in a significant improvement of the photocatalytic activity of TiO2. This beneficial effect was attributed to an increased separation of the photogenerated electron-hole charge carriers.

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The stability of Ag-TiO(2) photocatalysts was examined for the photocatalytic degradation of dichloroacetic acid (DCA) as a function of the recycling times. The photocatalytic activity was investigated by measuring the rate of H(+) ions released during the photodegradation of DCA and confirmed by measuring the total organic carbon removal. The photodegradation reactions were studied at pH 3 and pH 10 for a series of Ag-TiO(2) photocatalysts as different with Ag loadings. All the Ag-TiO(2) and bare TiO(2) photocatalysts showed a decrease in photocatalytic activity on recycling for the DCA photodegradation reaction. The decrease in activity can be attributed to poisoning of active sites by Cl(-) anions formed during the photocatalytic DCA degradation. The photocatalytic activity was, however, easily recovered by a simple washing technique. The reversibility of the poisoning is taken as evidence to support the idea that the recycling of Ag-P25 TiO(2) photocatalysts does not have a permanent negative effect on their photocatalytic performance for the degradation of DCA. The choice of the preparation procedure for the Ag-TiO2 photocatalysts is shown to be of significant importance for the observed changes in the photocatalytic activity of the Ag-TiO2 particles. Copyright (C) 2008 Victor M. Menendez-Flores et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Anais da Câmara dos Deputados, 1920.

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Interactions between two endocrine disruptors (ED) and aquatic humic substances (AHS) from tropical rivers were studied using an ultrafiltration system equipped with a 1 kDa cut-off cellulose membrane to separate free ED from the fraction bound in the AHS. Quantification of 17 alpha-ethynylestradiol and bisphenol A was performed using gas chromatography-mass spectrometry (GC-MS). The times required for establishment of equilibrium between the AHS and the ED were ca. 30 min, and complexation capacities for 17 alpha-ethynylestradiol and bisphenol A were 18.53 and 2.07 mg g(-1) TOC, respectively. The greater interaction of AHS with 17 alpha-ethynylestradiol, compared to bisphenol A, was due to the presence of hydrogen in the structure of 17 alpha-ethynylestradiol, which could interact with ionized oxygenated groups of the AHS. The results indicate that AHS can strongly influence the transport and reactivity of endocrine disruptors in aquatic systems.

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La elaboración y ejecución de las políticas monetarias y fiscales restrictivas en las dos últimas décadas en nuestro país, han afectado el correcto funcionamiento del ICE. Las metas que se plantean las autoridades monetarias y hacendarias año tras año, conllevan a una serie de restricciones en el ámbito presupuestario, limitándose el nivel de gastos corrientes, de inversiones y de endeudamiento de dicha institución. Con el argumento de que el ICE es parte del problema (cuando en realidad ha contribuido ha aminorarlo) del desequilibrio en las finanzas públicas, se ha cercenado su autonomía e independencia; sin atacar la verdadera causa de dicho desbalance, tal y como son el déficit del gobierno central y de la autoridad monetaria.A nivel de las finanzas públicas, se incorporan las estadísticas del ICE bajo un formato contable que difiere de manera importante con los principios de la contabilidad que utilizan las empresas del sector privado. Dicha metodología es obsoleta, presentado serias deficiencias que el mismo FMI (quien la elaboró) reconoce. Este mismo organismo ya ha elaborado una nueva metodología que aún no se utiliza en nuestro país. Más aún, existen países que utilizan metodologías diferentes, las cuales están mas acordes con la contabilidad tradicional de empresa privada.Los impactos positivos o negativos que la actuación del ICE pueda tener sobre el equilibrio macroeconómico, el crecimiento y el desarrollo del país, es algo aún no medido, cuyas relaciones de causa y efecto no se han establecido de manera real. En el debate y las discusiones, han prevalecido más bien las posturas políticas e ideológicas (en respuesta a intereses particulares), en detrimento del análisis científico y técnico. Así mismo, las discusiones se han fundamentado en postulados teóricos, sin ser contrarrestados contra la realidad.

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América Latina es considerada la región más desigual del planeta. Es el Continente donde, según múltiples fuentes, las polarizaciones son mayores en diversos campos, y el acceso a las oportunidades es marcadamente disímil para los diferentes sectores sociales. ¿Cómo impacta la inequidad latinoamericana el fundamental campo de la salud? ¿Qué problemas determina en esta área decisiva de la vida de las sociedades, y qué obstáculos y trabas pone al avance de los esfuerzos para mejorar la salud?.A pesar de su clara relevancia, este tema ha sido limitadamente puesto a foco. El objetivo de este trabajo es llamar la atención sobre el mismo, y contribuir a estimular este debate tan necesario. Para ello se subraya, en primer término, el papel central de la salud para el desarrollo, se reseñan las amplias brechas que existen, a pesar de ello, a nivel mundial entre países, y a su interior, se encaran ciertos difundidos mitos sobre cómo superar los problemas en salud, se exploran algunos de los principales impactos de la desigualdad de América Latina sobre aspectos básicos del campo de la salud y, finalmente, se sugieren algunas líneas de la gran tarea por realizar para enfrentar el peso de la inequidad sobre la salud pública.

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Ground-state diffuse reflectance, time resolved laser-induced luminescence, diffuse reflectance laser flash-photolysis transient absorption and chromatographic techniques were used to elucidate the photodegradation processes of pyrene adsorbed onto microcrystalline cellulose and silica. Ground-state diffuse reflectance showed that on both substrates low concentrations display absorption of pyrene monomers. At high concentrations spectral changes attributed to aggregate formation were observed. Laser induced fluorescence showed that pyrene onto microcrystalline cellulose mainly presents fluorescence from monomers, while for silica, excimer-like emission was observed from low surface loadings (greater than or equal to 0.5 mumol g(-1)). Transient absorption and photodegradation studies were performed at concentrations where mainly monomers exist. On silica, pyrene presents transient absorption from its radical cation. On microcrystalline cellulose both radical cation, radical anion and pyrene triplet-triplet absorption were detected. Irradiation followed by chromatographic analysis showed that pyrene decomposes on both substrates. For pyrene on microcrystalline cellulose 1-hydroxypyrene was the main identified photoproduct since in the absence of oxygen further oxidation of 1-hydroxypyrene was very slow. For pyrene on silica photodegradation was very efficient. Almost no 1-hydroxypyrene was detected since in the presence of oxygen it is quickly oxidized to other photooxidation products. On both substrates, pyrene radical cation is the intermediate leading to photoproducts and oxygen it is not involved in its formation.

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Combined media on photographic paper on steel. 39" x 29" Private Collection