Growth, optical characterization, and laser operation of a stoichiometric crystal KYb(WO4)(2)

We present our recent achievements in the growing and optical characterization of KYb(WO4)2 (hereafter KYbW) crystals and demonstrate laser operation in this stoichiometric material. Single crystals of KYbW with optimal crystalline quality have been grown by the top-seeded-solution growth slow-cooling method. The optical anisotropy of this monoclinic crystal has been characterized, locating the tensor of the optical indicatrix and measuring the dispersion of the principal values of the refractive indices as well as the thermo-optic coefficients. Sellmeier equations have been constructed valid in the visible and near-IR spectral range. Raman scattering has been used to determine the phonon energies of KYbW and a simple physical model is applied for classification of the lattice vibration modes. Spectroscopic studies (absorption and emission measurements at room and low temperature) have been carried out in the spectral region near 1 µm characteristic for the ytterbium transition. Energy positions of the Stark sublevels of the ground and the excited state manifolds have been determined and the vibronic substructure has been identified. The intrinsic lifetime of the upper laser level has been measured taking care to suppress the effect of reabsorption and the intrinsic quantum efficiency has been estimated. Lasing has been demonstrated near 1074 nm with 41% slope efficiency at room temperature using a 0.5 mm thin plate of KYbW. This laser material holds great promise for diode pumped high-power lasers, thin disk and waveguide designs as well as for ultrashort (ps/fs) pulse laser systems.

Terrestrial laser scanning for landslides deformation monitoring

Within last few years a new type of instruments called Terrestrial Laser Scanners (TLS) entered to the commercial market. These devices brought a possibility to obtain completely new type of spatial, three dimensional data describing the object of interest. TLS instruments are generating a type of data that needs a special treatment. Appearance of this technique made possible to monitor deformations of very large objects, like investigated here landslides, with new quality level. This change is visible especially with relation to the size and number of the details that can be observed with this new method. Taking into account this context presented here work is oriented on recognition and characterization of raw data received from the TLS instruments as well as processing phases, tools and techniques to do them. Main objective are definition and recognition of the problems related with usage of the TLS data, characterization of the quality single point generated by TLS, description and investigation of the TLS processing approach for landslides deformation measurements allowing to obtain 3D deformation characteristic and finally validation of the obtained results. The above objectives are based on the bibliography studies and research work followed by several experiments that will prove the conclusions.

Quines són les necessitats espirituals en els adolescents afectats de càncer en situació de malaltia avançada-terminal, en una unitat de cures pal·liatives?

En les cures pal·liatives pediàtriques es contemplen les dimensions essencials de la persona: la física, la psicològica, la social i l’espiritual. Tot i que s’han fet estudis sobre la dimensió espiritual, en la revisió bibliogràfica es mostra que és un àmbit poc desenvolupat. És important conèixer l’aspecte de creences i valors per tal que la infermera oncològica, juntament amb altres professionals, puguin proporcionar una atenció holística. L’objectiu d’aquest estudi és identificar les necessitats espirituals en adolescents (13 a 18 anys) malalts de càncer en situació avançada-terminal. S’utilitza la metodologia qualitativa. La mostra és de vuit adolescents, que són seleccionats d’acord amb els criteris d’inclusió. Aquests seran entrevistats per la infermera, la investigadora, la qual realitzarà entrevistes semiestructurades i un fotomuntatge depenent de la predisposició de l’adolescent. L’àmbit de realització d’aquest estudi és en un hospital de tercer nivell on es proporcioni atenció especialitzada amb pediatria oncològica i, concretament, en una unitat de cures pal·liatives pediàtriques. Per finalitzar, és important tenir en compte que les entrevistes i el fotomuntatge poden tenir les seves limitacions i que no sempre s’obtingui el resultat esperat.