PZT thick films by diol chemical solution deposition

Process optimization and properties of lead zirconate titanate (PZT) films for piezoelectric micromachined ultrasonic transducers (pMUTs) for scanning probe devices will be presented. The goal of the work was a replacement of the tetragenic and mutagenic solvent and a decrease of time-consuming PZT 2-methoxy ethanol (2MOE) route. An alternative diol-based solution synthesis process was developed and "Design Of Experiment” (DOE) was used to achieve processing optimization for thick and crack free films. Tight parameter control allowed to develop a highly reproducible PZT diol process. The crystallization behaviour of crack-free PbZr0.53Ti0.47O3 films (1-5μm) with oriented perovskite structure was examined by X-ray diffraction and surface analysis using scanning electron microscopy. Piezoelectric and dielectric properties were examined. The effective transverse piezoelectric coefficient e 31,f of sol-gel processed films was investigated for 4μm thick layers. Best properties were achieved with {1 0 0}-textured films, where a remanent e 31,f value of −7.3C/m2 was measured for 4.1μm thick film

Linfagioma Quístico Mediastínico: Um Caso Clínico

Os autores referem o caso clínico de uma criança de 2 anos, sexo masculino e raça negra, que apresentava estridor desde os 2 meses de idade e na qual foi diagnosticado um linfangioma quístico mediastínico. A remoção cirúrgica levou ao desaparecimento da sintomatologia. É feita uma revisão teórica sobre esta temática abrangendo aspectos epidemiológicos, clínicos e terapêuticos. Salientam a importância dos diferentes exames complementares para o diagnóstico definitivo

Efeito da pré-embebição na germinação de sementes de coentro (Coriandro sativum L.).

Este trabalho foi realizado com o objetivo de avaliar o comportamento fisiológico das sementes de coentro submetidas a diferentes períodos de imersão em água, visando acelerar e uniformizar o processo germinativo