ULTRASOUNDS

Author: RESA LOPEZ PABLO.
Year: 2006.
University: POLITÉCNICA DE MADRID [www.upm.es].
Place of defense: E.T.S. INGENIEROS INDUSTRIALES.
Place of preparation: E.T.S. ING. INDUSTRIALES.

Summary: The methods for measuring ultrasonic features advantageous for the control of biological processes (non-destructive, non-invasive, can be implemented in real time, are accurate, and so on.). In this work, it applies a technique for monitoring transmission line systems fermentativos (lactic fermentation and alcoholic) discontinuous. We have undertaken measures in liquid composition of simple broths in synthetic and natural environments (milk and must). Changes made in the parameters of propagation are interpreted in terms of the catabolism of monosaccharides, hydrolysis of disaccharides, the clotting proteins, gas production and the growth of microorganisms. To that end, we studied separately the influence of each of these effects at high speed. It finds that, with respect to the propagation of ultrasound, simpler means can be appropriately treated as dissolutions ternary water, sugar (glucose / galactose / lactose or glucose / fructose / sucrose) and product (lactic acid or ethanol) where, in the process, the substrates are transformed into metabolites according to the reaction of fermentation. After proving the lack of a theoretical model to accurately determine the speed of sound in liquid solutions based on the thermodynamic properties of the pure components (especially when there are strong polar liquids), it is proposed a theoretical approach based on the concept of volume excess and to the extent the density and speed of binary mixtures to obtain these variables in ternary mixtures. This model is used to calculate the concentrations of solutes majority along fermentations, obtaining a good correlation, especially in the liquid composition simpler. In all the systems studied, as measured by ultrasound enables the tracking of changes arising from the metabolism of microorganisms, proving its viability for monitoring fermentations and biological processes in general.

Author: MATEO DOMINGO CARLOS.
Year: 2006.
University: PONTIFICIA COMILLAS [www.upcomillas.es].
Place of defense: Alberto Aguilera 25.
Place of preparation: ESCUELA TECNICA SUPERIOR DE INGENIERIA.

Summary: This thesis examines the ways of propagation of elastic waves in electrical cables for use in telecommunications. A theoretical model is proposed for the same and are carried out simulations with the model. Electrical wires are modeled as viscoelásticas cylindrical structures, with core copper and covered with plastic. To solve numerically the theoretical model proposes a hybrid algorithm, which aims to increase the robustness. Both the theoretical model such as numerical algorithms are validated in the thesis, in two large blocks: validation of simulation tools and experimental validation. Experimentally, it has been validated with two complementary techniques, with measures electromagnetic from piezoelectric and testing interferometry. Se observa gran similitud entre los resultados de las simulaciones y los ensayos experimentales. Moreover, it has found a curious fact. In electric cables without plastic insulation attenuation increases as usual frequency. However, electric cables with plastic insulation shows that the modes of spread above are least attenuation. To try to explain this phenomenon has arisen a hypothesis: the ways of spreading more frequently tend to spread mainly by the copper, so its attenuation decreases. This seems to confirm the view of the profile of the modes of spread.