András Szabó

Raman microscopic evaluation of technology dependent structural differences in tablets containing imipramine model drug

Raman imaging method was used to characterize the effect of different manufacturing technologies on properties of the produced tablets, such as compound distribution, polymorphism, strength, and estimated active pharmaceutical ingredient (API) content. The obtained chemical maps were evaluated based on their visual appearance and on the statistical properties of the component scores obtained by direct classical least squares (DCLS) modelling. It is demonstrated that changes in the distribution of the API and excipients can be detected with chemical imaging and these differences are in close relationship with the applied granulation method and with the mechanical properties of the analyzed tablet. It is also shown that the chemical images used for characterizing the component distribution can also be processed for obtaining a cautious estimation to the mass fractions of the components.

Controlling the Composition of Nanosize Hexagonal WO3 for Gas Sensing

Hexagonal (h-) WO3 was prepared through heating hexagonal ammonium tungsten bronze (HATB), (NH4)0.07(NH3)0.04(H2O)0.09WO2.95. By adjusting the heating temperature and atmosphere of HATB, we could control the oxidation state of tungsten atoms and the residual NH3/NH4 + content in h-WO3. The as-produced h-WO3 nanoparticles with different composition were tested as gas sensors and the effect of composition on gas sensing properties was studied. Our results showed that oxidized h-WO3 had the best sensitivity to H2S.

Vibrational spectroscopic study on 2-[2-(4-dipropylamino-phenyl)-vinyl]-1, 3,3-trimethyl-3H-indolium chloride

A new styryl dye were prepared, 2-[2-(4-dipropylamino-phenyl)-vinyl]-1,3,3-trimethyl-3H-indolium chloride (DPPTVI) chloride. Its infrared and Raman were measured. Quantum chemical calculations were computed for both the isolated and the solute cation. Optimized geometry, atomic net charges were calculated. The calculated vibrational frequencies were scaled to the experimental ones. Only 12 scale factors were used for the scaling of 174 vibrational modes. Based on these results, normal coordinate analysis were carried out for both the isolated and the solute cations. Infrared and Raman spectra were simulated. The results for the isolated and the solute cations were compared.

Compositional and Stress-Sensitive Factors during the Thermopower Characterization of Single Phase Crystalline and Glassy Alloys

For the study of stress state in engineering alloys, the thermopower (S) measurement could be acceptable method after a suitable calibration (fitting the S value to the change of well known other physical parameters like the magnetic coercive force, hardness or strength increase during various thermomechanical treatments). For this purpose a simple equipment is constructed and built by which the S shift can be measured versus the increasing mechanical tensile load. The first results will be published in this paper, obtained on various metallic glass ribbons.

Chapter 6:Complex Micro-analysis Assisted Design of Fire-Retardant Nanocomposites – Contribution to the Nanomechanism

Advancement of the methods used to produce fire retardancy is hindered by the shortcomings of the current characterization methods and insufficient understanding of the fire retardancy mechanisms. These two factors are connected with each other: better characterization would promote better understan...

Wave front synthesis for comparative measurement in digital holography and TV holography

The analog reconstruction of a wave front and its application in comparative measurement is well known from comparative holography. Thanks to the rapid development of high quality spatial light modulators (SLM), different methods applying the analog reconstruction of digital holograms has been developed in digital holography too. In these methods the recorded wave fronts of an object are generated by the spatial modulator. The SLM is also capable to generate computer calculated wave fronts (not belonging to an existing object), and multiple such projections can be performed during the measurement time. Using this feature an effective adaptive measuring system can be built. The application of such wave front projections is also possible in TV holography. The wave front projection can be virtually too, when the wave front exists only in the computer memory. Methods both for digital holography and TV holography are developed too.