Tema 21 de l'assignatura Introducció a les estructures. Grup tarda.

Tema 11 de l'assignatura Sistemes estructurals.

Dins del programa d'activitats d'informació i orientació dels estudis, la UPC impulsa el programa ENTER a la UPC, un cicle de converses informals amb professorat dels diferents àmbits de coneixement de la Universitat. L'objectiu d'aquesta activitat d'orientació acadèmica és donar a conèixer els àmbits de coneixement de la UPC i identificar els diferents graus universitaris que en formem part. La iniciativa s'adreça específicament a l'alumnat indecís que ha de triar el seu futur grau universitari.

Tema 9 de l'assignatura Introducció a les estructures. Grup tarda.

El Professor Manuel Ruisanchez autor juntament a Xavier Vendrell del Parc del Poblenou, dialoga amb el Prof. Daniel Navas en una conversa que situa el projecte en la perspectiva d’una relectura del front inacabat de mar a Barcelona i el relaciona amb altres projectes. L’experiència d’un dels espais mes valorats del paisatge de la Barcelona del 1992 serveix per articular una reflexió sobre els inputs que la percepció, la matèria i els rencontres tenen a veure amb els espais i l’aposta de solucions formals.

¿Conoces el grado en Inteligencia Artificial que se imparte en la Facultad de Informática de Barcelona? ¿Quieres saber por qué estudiar este grado? ¡Descúbrelo en el vídeo!

A methodology to retrieve the dielectric function of a nanocomposite from infrared spectroscopy is presented. The use of effective medium theories allows treating the optical response of a multi-phase composite as that of a single phase with an effective response that is a complex function of the components and their spatial arrangement. This methodology has been tested in a case study involving cerium oxide nanoparticles, whose vibrational properties are known to change significantly upon particle size reduction. Accurate values of its dielectric function in the infrared have been retrieved and used to analyse this phenomenon. The main goal of this study is to develop a systematic methodology for the study of the vibrational properties of nanomaterials. It is also intended that the development of effective medium models will be useful for designing new composite nanomaterials with improved optical properties (e.g., solar absorbers).

Red blood cells (RBCs) alterations can cause very severe blood diseases. In thalassemia, the production of hemoglobin polypeptide chains is unbalanced. This causes no symptoms or small blood count alterations in patients with less important genetic mutations, or severe anemia and high morbi-mortality in the most severe cases. Traditional techniques do not perfectly discriminate among different thalassemia degrees and most patients need to undergo genetic studies. Authors have tried alternatives to analyze RBCs, collecting their emission and absorption spectral traits with spectrometers and spectrofluorometers. Multispectral imaging with confocal microscopy allows capturing both tridimensional and spectral information. In this study we are using confocal spectral imaging to analyze RBCs from patients with different degrees of alpha-thalassemia and iron deficiencies. The instrument, a Leica TCS SP8 confocal microscope has high sensitivity hybrid cameras, a diode laser and a white laser combined with an acoustic-optic tunable filter. RBCs exhibited autofluorescence when excited at 405 nm. The mean emission intensities at 502 nm, 628 nm and 649 nm allowed us to discriminate between different etiologies.

En la industria del color es muy importante conocer la gama de colores de un dispositivo. Mediante la comparación de gamas podemos evaluar el efecto que tiene el uso de distintas tintas, papeles, fuentes de iluminación o dispositivos de impresión en el color obtenido. Existen diversos programas que realizan esta comparación, pero tienen inconvenientes. Por ello hemos desarrollado y validado un software para comparar gamas de color generadas por impresoras. El software representa las gamas simultáneamente en el espacio 3D CIELAB, además de calcular su volumen. Para validar nuestro software hemos realizado un doble análisis. Por un lado, hemos comparado los resultados obtenidos a partir de nuestro software y los obtenidos con otros métodos de comparación, como la representación en diferentes espacios de color. Por otro lado, hemos usado el programa ICC3D para comparar las representaciones de las gamas con las de nuestro programa, además del volumen. Con ambos programas las conclusiones fueron similares, aunque nuestro software presenta algunas ventajas, permitiendo distinguir diferencias entre las gamas que mediante otros métodos no se discriminaron. Este nuevo software va a permitir el estudio de la influencia de distintos factores en la reproducción del color, permitiendo conocer las condiciones para conseguir la mejor calidad posible

Imaging through nebulous media encountered in nature – like fog – is one
of the up-to-date research questions in the field of navigation. Among different
approaches to solve this problem, the use of polarimetric imaging has been proposed.
The aim of this research is to present a polarized light propagation model based on
Monte-Carlo simulations and Mie Theory for its use as a tool to study the feasibility and
characteristics of polarized light detection techniques in these kinds of media. Studying
and obtaining the backscattering Mueller matrix for a turbid environment allows to
completely characterize the backscattering characteristics of the media. Thus, it may be
used to select the combination of polarization components more useful for each
situation. On the other hand, it has been seen that when light first interact with fog,
generated backscatter directly blinds the sensor of the imaging device and hides
reflected signals of objects being imaged. Using a time-resolved variant of the model, it
has been possible to characterize the shape and the influence of the temporal response
of a backscattered light pulse, concluding that, apart from the greater light extinction in
a more scattering medium, media-backscattering and reflected-object signals are
independent

Complete characterization of biological samples is of potential interest in different industrial and research areas, as for instance, in biomedical applications, for the recognition of organic structures or for the early detection of some diseases. During the last decades, polarimetric methods are experiencing an increase of attention in the study of biomedical tissues, and they are nowadays used in such framework to provide qualitative (polarimetric imaging) and quantitative (data processing) information for the studied samples. Polarimetric methods are based on the analysis of polarization modifications produced by lightmatter interactions which can be triggered by a number of complex internal processes but can be roughly understood as the result of the combination of three pure polarimetric features of the sample: its diattenuation, retardance and depolarization. To describe the depolarization sample behavior, we use the Indices of Polarimetric Purity (IPP): related with the randomness of the scattering processes, IPPs provide more information of depolarizing systems than the widely used depolarization index, 𝑃∆, which further synthetizes the depolarization content of samples. As a result, IPPs allow the revelation of some structures from tissue samples (animal and vegetal) hidden in regular intensity images of even in the 𝑃∆ channel, leading to better tissue classification results.

The study of tissue optics is relevant for developing innovative non-invasive diagnostic and therapeutic techniques, and optical phantoms that simulate light propagation processes through soft biological tissue are required to evaluate the performance and calibrate different medical imaging modalities. Liquid lipid based low-cost phantoms were prepared, with cow’s milk as scattering material, Red India ink as the absorbing material and demineralized water as the matrix material since it provides a soft medium biologically compatible with the addition of organic molecules. Two experiments were carried out for characterization of this tissue model. First, collimated and diffuse transmittance and reflectance spectra were measured using phantoms with milk of different fat content. From the data, dependence between: total extinction coefficient, Kubelka Munk’s ratio, absorption and scattering coefficients on the wavelength were estimated. Second, using collimated transmittance measurements the effect of the phantom components was observed. The absorption peak, increases as ink was added to phantoms; and when lipid concentration was varied, by fixed ink, the scattering growths. The extinction coefficient’s dependence on the wavelength was determined, and fluorescence was observed. Results confirm the possibility of spectroscopic identification of milk kinds, as well as the feasibility of low-cost controllable phantom for preliminary biophotonic studies.