Organometallic materials have become subject of intensive research on distinct technological applications. The Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) techniques have proven to be suitable to address challenges inherent to organic devices, in which the film properties can be tuned at molecular level. Here, we report on the supramolecular arrangement of zinc(II)-protoporphyrin(IX) dimethyl ester (ZnPPIX-DME) using the Langmuir, LB and LS techniques, leading to nanostructured films. The π-A isotherms showed that π-π stacking interaction among ZnPPIX-DME molecules takes place at the air/water interface, favoring the formation of Langmuir films closely packed. The controlled growth of the LB and LS films was monitored via UV-Vis absorption spectroscopy, with the thickness per monolayer within 1.3 and 1.7 nm. The homogeneous topography found at microscale is no longer preserved at nanoscale, which is found rougher according to AFM data. The FTIR indicated that the ZnPPIX-DME is isotropically arranged on both LB and LS films.

Neste trabalho investigou-se o sistema nanométrico CeO2-ZnO preparado pelo método Pechini. As caracterizações estrutural e morfológica foram realizadas para o sistema CeO2-ZnO assim como para CeO2 e ZnO separadamente, o que demonstrou que o método empregado resulta em pós com partículas de tamanho entre 30 a 200 nm. A presença do ZnO nas misturas dos óxidos preparados aumenta a distribuição no tamanho das partículas e também influencia o arranjo das mesmas após a dispersão dos pós.

This work reports on the investigation of nanosized CeO2-ZnO systems prepared by Pechini's method. The structural and morphological characterization of CeO2-ZnO systems as well as the characterization of CeO2 and ZnO separately, showed that the employed method result in powders with spheroidal particles whose size are in the range 30 - 200 nm, which is appropriate to provide homogeneous suspensions. The ZnO present in the prepared mixed oxides seems to increase particle size distribution and to influence the arrangement of the particles after powder dispersion.

A capacidade de um determinado ecossistema natural proporcionar bens e serviços que satisfaçam as necessidades humanas depende de suas características ambientais (processos e componentes naturais). Foi descrita a disponibilidade desses bens e serviços (funções ambientais), controlados e mantidos pelos processos ecológicos operantes na Estação Ecológica de Jataí (Luiz Antônio, SP). As funções ambientais identificadas foram agrupadas em quatro categorias. Foi determinado o valor sócio-econômico das funções ambientais, em termos quali e quantitativos, quando possível, na perspectiva de integrar os valores ambientais nos processos de planejamento e tomada de decisão. O retorno sócio-econômico anual para as funções ambientais identificadas da Estação Ecológica de Jataí é de aproximadamente US$ 708,83/ha/ano. Em comparação com estimativas realizadas para outros ecossistemas naturais, esse valor é bastante moderado. A Estação Ecológica de Jataí demonstra ser pouco protegida, com sua manutenção comprometida por atividades humanas (agricultura) e muitos planos de desenvolvimento. Embora o mercado econômico não reconheça o valor monetário da maioria das funções ambientais, essas estimativas não revelam a grandeza da importância sócio-econômica da Estação Ecológica de Jataí. Um interesse maior com esses valores pode proporcionar um incentivo importante para sua preservação e uso sustentado.

The capacity of a given natural ecosystem to provide certain goods and services that satisfy human needs depends on its environmental characteristics (natural processes and components). It was described the availability of these goods and services (environmental functions) controlled and sustained by ecological processes operating in Ecological Station of Jataí (Luiz Antônio, SP). The environmental functions identified were grouped in four main categories. To make environmental values an integrated factor in planning and decision making it was assessed their socio-economic importance in qualitative terms and, if possible their monetary value. The combined potential annual return from identified functions of Ecological Station of Jataí is at least US$ 708.83/ha/year. In comparison to calculations made for other natural ecosystems this is a rather moderate estimate. The Ecological Station of Jataí is poorly protected and managed, it too is still threatened by human activity (agriculture) and many development plans. Although present day market economics do not recognize the monetary value of most environmental functions, such calculations do provide a revealing insight into the great socio-economic importance of Ecological Station of Jataí. More awareness of these values may provide an important incentive for their preservation and sustainable use.