Abstract
In this work the implementation of an optical fiber interferometric system for differential thermal analysis enabling the identification of chemical species is described. The system is based on a white light Mach-Zehnder configuration using pseudo-heterodyne demodulation to interrogate two identical fiber Bragg gratings (FBG) in a differential scheme. System performance is compared using either standard hardware or low cost virtual instrumentation for operation control and signal processing. The operation with the virtual system enabled temperature measurements with a +/-0.023 degrees C resolution nearly matching the performance of the standard hardware. The system ability to discriminate chemical species by differential thermal analysis was demonstrated. Mixed samples of acetone and methanol could be successfully identified, indicating the suitability of the system for high precision measurements using low cost instrumentation. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4774054]

Abstract
The last years are witnesses of continuous raise in the price of traditional fuels. This fact, joined to environmental concerns and the fears concerning the inevitable oil reserves depletion, has empowered the search for new energetic sources. Organic photovoltaic cells or Gratzel cells are a solution for collecting solar energy. Searching for new materials for this type of solar cells is normally a trial-and-error procedure. Assembling components to make a solar cell in the laboratory is a difficult and expensive task. In this work, the electrochemical behaviour of flavonoids that can be used as sensitizers in solar photovoltaic cells when in contact with a given semiconductor is studied. This procedure can simplify the process of pairing a dye with a semiconductor in order to obtain optimum performance when designing new photovoltaic cells. (c) 2012 American Institute of Chemical Engineers

Abstract
The deterioration of water quality by Cyanobacteria cause outbreaks and epidemics associated with harmful diseases in Humans and animals because of the toxins that they release. Microcystin-LR is one of the hepatotoxins most widely studied and the World Health Organization, recommend a maximum value of 1 mu g L(-1) in drinking water. Highly specific recognition molecules, such as molecular imprinted polymers are developed to quantify microcystins in waters for human use and shown to be of great potential in the analysis of these kinds of samples. The obtained results were auspicious, the detection limit found, 1.5 mu g L(-1), being of the same order of magnitude as the guideline limit recommended by the WHO. This technology is very promising because the sensors are stable and specific, and the technology is inexpensive and allows for rapid on-site monitoring.

Abstract
A new procedure based on an ethanolic solution of the appropriate cations to obtain SrBi2Ta2O9 (SBT) thin films is described, reducing the necessity of toxic organicals. According to X-ray diffraction analysis the desired SBT crystalline phase is obtained after heat treatment at 720 degrees C, in air, for 20 min. The ferroelectric properties of the obtained thin film include a remnant polarization value of 5,0 mu C/cm(2) and a coercive field of 50 kV/cm, which are rather good results for a stoichiometric SBT thin film.

Abstract
The effect of rapid thermal annealing and conventional furnace annealing on the crystallization of SrBi2Ta2O9 is modeled using an Arrhenius-type equation. Based on previous experimental results several authors have suspected that different reaction mechanisms occur depending of the heating rate employed in these two treatment methods. Oppositely, the results here presented and the analysis of reported data suggest two concurrent reaction mechanisms 1) direct transformation of the reagents into the perovskite phase and 2) transformation of an intermediate into the perovskite phase. Another important conclusion here obtained confirms the validity of the Arrhenius equation to predict the behavior of the crystallization process by either of the two heating methods mentioned above.

Abstract
A novel and general chemical solution route for processing high-quality transition metal and rare-earth orthorhombic manganite thin films on Pt(111)/Ti/SiO2/Si substrates was reported. The precursor solutions decomposition process of the manganites was studied by TG and DTA techniques, showing the formation of the phase above 650A degrees C in LaMnO3 and 750A degrees C in both EuMnO3 and DyMnO3 thin films. X-ray diffraction and Raman spectroscopic analysis reveal the formation of a pure orthorhombic structure, with a space group Pbnm, in LaMnO3, EuMnO3 and DyMnO3 thin films annealed at temperatures above the TG phase formation temperature observed. Microstructure and grain morphology of the films were analyzed by SEM and AFM techniques, showing a progressive improvement of the films structures with the increase of the annealing temperature. The temperature dependence of the magnetic response of the LaMnO3, EuMnO3 and DyMnO3 thin films show typical transition temperatures, compared with those reported for lanthanum, europium and dysprosium manganite single crystals and ceramics.