Analytica Chimica Acta

Texto completo: acesso restrito. p. 63–73In this paper, the diffusion of the angina therapeutic agent, nitroglycerin through a skin mimetic is described. The mimetic is a poly(ethylene) glycol loaded microfibre filter to which a transdermal drug patch is attached. The diffusion process is monitored using dynamic scanning Fourier transform infrared (FTIR)-photoacoustic spectrometry in which the IR beam illuminates the filter with the transdermal patch on the underside. Thus, the nitroglycerin diffuses up through the filter. Using different thermal diffusion lengths, as determined by the wavelength dependent modulation frequency of the FTIR spectrometer, the diffusion process is monitored. A convenient model is developed to provide a direct measurement of the diffusion coefficient of nitroglycerin through the poly(ethylene) glycol loaded filter

Journal of Materials Science Letters

Texto completo: acesso restrito. p.19-2

Journal of Fluorescence

Acesso restrito: Texto completo. p. 211-219This report is devoted to the study of the low and room temperature photoluminescence and photoacoustic spectroscopy of the Fe3+ impurity ion in the LiGa5O8–LiGaSiO4–Li5GaSi2O8 system. The sample was obtained by solid-state reaction between β-Ga2O3, Li2CO3, SiO2 and appropriated quantities of Fe2O3. It was investigated by X-ray diffraction to determine the formed phases and through photoluminescence, excitation and photoacoustic spectroscopy measurements. The broad absorption and emission bands in the visible and near-infrared spectral regions presented by that system constitute the motivation for this study. More specifically, the luminescence occurs over a large interval of wavelengths, between 400 nm and 800 nm

Polyhedron

Texto completo: acesso restrito. p.1701–1703Silica gel-immobilized diacetamide is very effective in extracting copper(II) from ethanol or acetone solutions. The complex formed on the surface was studied by means of photoacoustic spectroscope. The IR and visible spectra gave clear evidence that the cation is octahedrally coordinated with a strong tetragonal distortion

Journal of Materials Chemistry

p. 479-482N-(2-Pyridyl)acetamide was covalently immobilized onto silica gel giving 1.57 x mol of this molecule per gram of silica. This new bidentate chelate extracts MCI, (M=Ni, Co, Cu) from ethanol and acetone solutions. The photoacoustic spectra of the solid complexed samples were obtained in the visible and near-infrared spectral regions and were analysed using ligand field theory. The calculated Racah parameters indicate a tetrahedral geometry for nickel and cobalt and a highly distorted octahedral geometry for the copper complex.Salvado

Journal of Applied Physics

p. 1-5In the present work, the Open Photoacoustic Cell Technique was used to find effective thermal diffusivity of human tooth hard tissues, a thermal variable of great interest in the biological science, and inorganic materials. The aging process of the tooth enamel and dentin was analyzed through its effective thermal diffusivity. The study in vitro of these samples showed an increase and posterior decrease with aging of the samples. The values found for the enamel and dentin samples, varied from (36−55)×10−4  cm2 s−1 and (20−32)×10−4  cm2 s−1, respectively