Photoacoustic Spectroscopy of Titanium Dioxide, Niobium Pentoxide, Titanium:Niobium, and Ruthenium-Modified Oxides Synthesized Using Sol-Gel Methodology.

The aim of this work was the development and morphological/chemical, spectroscopic, and structural characterization of titanium dioxide, niobium pentoxide, and titanium:niobium (Ti:Nb) oxides, as well as materials modified with ruthenium (Ru) with the purpose of providing improvement in photoactivation capacity with visible sunlight radiation. The new materials synthesized using the sol-gel methodology were characterized using the following techniques: scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), photoacoustic spectroscopy (PAS), and X-ray diffraction (XRD). The SEM-EDS analyses showed the high purity of the bases, and the modified samples showed the adsorption of ruthenium on the surface with the crystals' formation and visible agglomerates for higher calcination temperature.

Sol-gel and Pechini niobium modified: synthesis, characterization and application in the 2,4-D herbicide degradation.

In this work, a comparison was made between the synthesis of niobium-based materials (Nb2O5), both in terms of material characterization and catalytic performance. The methods used were chemical mixtures: modified sol-gel and Pechini. The materials were calcined at different temperatures (753, 873 and 993K) and characterized by the following techniques: photoacousticspectroscopy (PAS), zero charge point (pHPZC), scanning electron microscopy (SEM/EDS), thermogravimetric analysis (TGA/DTG) and X-ray diffraction (XRD).

Pharmaceutical compounds photolysis: pH influence.

The operating parameters of photolytic and photocatalytic reaction processes directly affect the efficiency in the degradation of compounds. In particular, pH is a variable that needs to be considered as it exerts great influence on adsorption, absorption, solubility, among others. This study describes the application of the photolytic process, at different pHs, in the degradation of different pharmaceutical compounds.

Cu/NbO, Fe/NbO and Cu-Fe/NbO applied in salicylic acid degradation: Parameters studies and photocatalytic activity.

This study describes the synthesis of Cu/NbO, Fe/NbO, and Cu-Fe/NbO catalysts obtained by incorporating copper and/or iron metals into niobium pentoxide (NbO). The new materials were characterized by the following techniques: Thermogravimetric Analysis (TA), surface and pore analysis, X-ray diffractometry (XRD), and Fourier Transform Infrared Spectroscopy (FT-IR). The catalyst was applied in the photocatalytic degradation of salicylic acid (SA).

Neural Network Modeling and Dynamic Analysis of Different Types of Engine Mounts for Internal Combustion Engines.

This paper presents the results of studies on reducing the amount of vibrations in different frequency ranges generated by a combustion engine through the use of different types of engine mounts. Three different types of engine supports are experimentally and numerically analyzed, namely an elastomeric engine mount, an elastomeric engine mount with a hydraulic component and standard decoupling, and an elastomeric engine mount with a hydraulic component and a modified decoupler-with this engineering design being a novelty in the literature. Experimental tests that considered different excitation frequencies were performed for the three types of engine mounts.

Functioned catalysts with magnetic core applied in ibuprofen degradation.

In the present work, the performance of Ag/ZnO/CoFeO magnetic photocatalysts in the photocatalytic degradation of ibuprofen (IBP) was evaluated. This study considered the use of pure Ag/ZnO (5% Ag) and also the use of the Ag/ZnO/CoFeO magnetic catalysts containing different amounts (5, 10 and 15% wt) of cobalt ferrite (CoFeO). The catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and photoacoustic spectroscopy.

Paraquat degradation by photocatalysis: experimental desing and optimization.

This study describes the experimental design and optimization of application TiO catalysts doped with 0.5, 1, 1.5, 2.

Continuous process applied to degradation of triclosan and 2.8-dichlorodibenzene-p-dioxin.

This study describes the use of a prototype for the continuous photocatalytic reaction process using Fe/NbO-immobilized catalyst for triclosan and 2.8-dichlorodibenzene-p-dioxin (2.8-DCDD)'s degradation.

Removal of synthetic and industrial effluent color by photocatalytic process.

The present work aimed at evaluating the photocatalytic process as an alternative for color removal from a synthetic solution (methylene blue dye) and of a sample of textile effluent, obtained from the various stages of the process, mainly dyeing. The parameters were evaluated using titanium dioxide (anatase, rutile, commercial and synthetized by the sol-gel method) in order to determine their structural influence in the discoloration of the samples. A synthetic methylene blue dye solution and a real effluent (Brazilian textile industry) were treated.

Comparision of photocatalysis and photolysis processes for arsenic oxidation in water.

The oxidation of As(III) to As(V) in aqueous solution was evaluated using heterogeneous photocatalysis and photolysis. The influence of TiO as catalyst in different crystalline (rutile, anatase) and commercial forms was evaluated in a batch reactor and an insignificant difference was observed between them. The process by photocatalysis reached up to 97% As(III) oxidation and no significant difference was observed comparing to results obtained by photolysis.

Textile dye removal from aqueous solutions by malt bagasse: Isotherm, kinetic and thermodynamic studies.

The biosorption of orange solimax TGL 182% (OS-TGL) textile dye onto new and low cost biossorbent (malt bagasse) in aqueous solutions was investigated. The malt bagasse was characterized by Fourier transform infrared spectroscopy and specific surface area (BET method).Batch biosorption experiments were conducted in order to determine the following parameters: particles size, pH, agitation speed, temperature, contact time, biomass dosage, influence of the ionic strength and, finally, the influence of other textile dye on the OS-TGL biosorption.