Al-containing MCM-41 type materials prepared by different synthesis methods: hydrothermal stability and catalytic properties

Al-containing MCM-41 type materials were prepared by three different synthesis methods (aluminum grafting on the calcined MCM-41, pH adjustment during the crystallization period and crystallization in the presence of zeolite seeds). The samples were characterized by powder XRD, nitrogen adsorption, 27Al MAS NMR and FTIR with pyridine as probe molecule. All the samples exhibit a high hydrothermal stability at high temperature just with a minor structural degradation. N2 adsorption data obtained for the sample prepared from a gel containing zeolite seeds suggest a higher structural resistance to the hydrothermal treatment in comparison with the samples prepared by other methods. A different type of pyridine adsorbed, probably interacting simultaneously with a Brönsted and a Lewis acid site, is observed upon pyridine adsorption. This type of adsorption is stronger for the sample prepared in the presence of zeolite seeds and is not observed on Al-grafted MCM-41. 2 The catalytic activity towards the isomerization of α-pinene depends mainly on the number of Brönsted acid sites. The data obtained in this study strongly indicate that for this type of materials, the Lewis acid sites do not influence the selectivity for the isomerization products

Sensoriamento remoto e SIG como ferramenta para o planejamento e controle da febre aftosa na fronteira brasileira.

O projeto Aftosa tem como objetivo desenvolver um sistema de informação que visa apoiar o planejamento, monitoramento e ações de controle, combate e erradicação da febre aftosa na faixa de fronteira do Brasil. O projeto abrange os estados do Acre, Mato Grosso, Mato Grosso do Sul e Rondônia. Neste estudo, é apresentado o sistema de informação que é disponibilizado por meio de um webgis. Para composição do webgis, foram utilizadas imagens dos satélites LANDSAT 5 ? TM, LANDSAT 7 ? ETM+ e SPOT 4, o que possibilita abordar vários níveis de detalhes e escalas e uma base cartográfica com temas ou planos de informação. As informações do webgis, disponíveis de forma interativa para usuários autenticados, servem de apoio as ações de gestores, auxiliam o trabalho cooperativo e a elaboração de políticas públicas para combate da febre aftosa

Adequação e atualização do sistema de informação territorial da faixa de fronteira.

O planejamento da atividade agropecuária, dada a sua dinâmica e complexidade, requer o controle e a atualização constante de informações primárias, obtidas mediante o manuseio e a análise de um grande volume de dados, e posterior disponibilização de informações integradas, atualizadas e de fácil interpretação. Nesse cenário, o sensoriamento remoto tornou-se uma importante ferramenta para a tomada de decisões. O objetivo deste projeto é realizar a atualização das imagens de satélite da faixa de fronteira do Brasil, considerando os Estados do Acre, Rondônia, Mato Grosso e Mato Grosso do Sul e, assim, apoiar o planejamento, o monitoramento de ações de controle e o combate às enfermidades animais, fornecendo elementos importantes para a elaboração de medidas preventivas contra a febre aftosa. Foram utilizadas imagens Landsat e Spot, que serviram de base para confecção de mosaico se atualização do Sistema de Informação Territorial da Faixa de Fronteira para Defesa Agropecuária (SIT-Aftosa), disponível via internet, por meio de um WebGIS que garante ao sistema versatilidade e baixo custo, permitindo ao usuário visualização e, segundo critérios e hierarquia de segurança, acesso a toda base de imagens em escalas variadas, e dados vetoriais e numéricos

International financial reporting standards and earnings management in Latin America

This study analyzes the level of earnings management in Latin America after the adoption of the International Financial Reporting Standards (IFRS) and analyzes the role of cross-listing in the United States. The literature on earnings management in less developed countries is still under construction, and few studies focus on this issue, especially with respect to Latin America, despite its relevant role in the global economy. This paper fills this gap in the literature as it analyzes the level of IFRS earnings management regarding the first and main Latin American countries applying IFRS (Brazil and Chile), when compared to the main Anglo-Saxon countries with IFRS tradition (United Kingdom and Australia), and with the main Continental European economies (France and Germany). The results show that Latin American firms present a higher level of earnings management than Continental European and Anglo-Saxon firms, and this opportunistic behavior remains significant when only global players with cross-listing in the United States are analyzed. Thus, even with a unique set of high quality accounting standards (IFRS) and strong reporting incentives, countries' specific characteristics still play an important role in the way IFRS is implemented in each country.info:eu-repo/semantics/publishedVersio

Investigation into the effects of high-Z nano materials in proton therapy

High-Z nano materials have been previously shown to increase the amount of dose deposition within the tumour due to an increase in secondary electrons. This study evaluates the effects of high-Z nano materials in combination with protons, and the impact of proton energy, nanoparticle material and concentration. These effects were studied in silico through Monte Carlo simulation and experimentally through a phantom study, with particular attention to macroscale changes to the Bragg peak in the presence of nanoparticles. Three nanoparticle materials were simulated (gold, silver and platinum) at three concentrations (0.01, 0.1 and 6.5 mg ml(-1)) at two clinical proton energies (60 and 226 MeV). Simulations were verified experimentally using Gafchromic film measurements of gold nanoparticles suspended in water at two available high concentrations (5.5 mg ml(-1) and 1.1 mg ml(-1)). A significant change to Bragg peak features was evident, where at 226 MeV and 6.5 mg ml(-1), simulations of gold showed a 4.7 mm longitudinal shift of the distal edge and experimentally at 5.5 mg ml(-1), a shift of 2.2 mm. Simulations showed this effect to be material dependent, where platinum having the highest physical density caused the greatest shift with increasing concentration. A dose enhancement of 6%  ±  0.05 and 5%  ±  0.15 (60 MeV and 226 MeV, respectively) was evident with gold at 6.5 mg ml(-1) to water alone, compared to the 21%  ±  0.53 observed experimentally as dose to film with 5.5 mg ml(-1) of gold nanoparticles suspended in water at 226 MeV. The introduction of nanoparticles has strong potential to enhance dose in proton therapy, however the changes to the Bragg peak distribution that occur with high concentrations need to be accounted for to ensure tumour coverage