The photoacoustic cell is the heart of the nondestructive photoacoustic method. This article presents a new simple lumped-components CRLC model of the Helmholtz type photoacoustic cell. This model has been compared with the well known literature models describing the Helmholtz type cells for photoacoustic spectroscopy. Experimental amplitude and phase frequency data obtained for the two photoacoustic cells have been presented and interpreted in a series of models. Results of the fitting of theoretical curves, obtained in these models, to the experimental data have been shown and discussed.

The paper presents magnetic fluid as an excellent material platform for producing more complex magnetic drug delivery systems. In addition, the paper discusses the nanoparticle morphological (electron microscopy) and structural (X-ray diffraction) characterizations. M ossbauer spectroscopy and photoacoustic spectroscopy are revisited as key tools in the characterization of the magnetic core and diamagnetic shell of the magnetic nanoparticle, respectively.