Poesia digital e a nova linguagem

A chegada do computador e da era cibernética estão mudando comportamentos e linguagens do homem contemporâneo. Era da virtualidade, vida digital, hipertexto, poesia digital, e-book, homem semiótico, etc., são realidades que mudam a língua, a linguagem, a literatura e o próprio livro.The arrival of the computer and the cybernetics era are changing contemporary man’s behavior and language. Virtual era, digital life, hypertext, digital poetry, e - book, semiotic man, etc., are realities that cause changes in language, in literature and in the book itself

Oscilações térmicas do nervo facial in vitro em mastoidectomias descompressivas

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2013.Introdução: Há diversas situações médicas que exigem a descompressão aguda do nervo facial (NF), inclusive lesões traumáticas ou neoplásicas. No entanto, o NF é altamente vulnerável às oscilações térmicas e/ou mecânicas, as quais podem vir a ocorrer durante procedimentos cirúrgicos que requerem a utilização de brocas. Objetivos: Avaliar possíveis lesões térmicas ocasionadas por brocas de alta e baixa rotação, bem como comparar suas peculiaridades durante a mastoidectomia radical para descompressão do NF. Método: Oito espécimes de osso temporal obtidos de cadáveres foram submetidos à descompressão do NF pela técnica de mastoidectomia radical, usando brocas de alta rotação e baixa rotação, com irrigação contínua ou sob demanda. As oscilações de temperatura transoperatórias foram medidas através de sensores térmicos ligados ao osso temporal. Estes sensores seguiam o trajeto do NF, à distâncias de 10, 5 e 2mm, utilizando-se ponteiras cortantes de 2,4 milímetros ou ponteiras rombas diamantadas de 2,1mm. Resultados: O uso de brocas de alta velocidade com irrigação sob demanda provocou uma oscilação significativa de temperatura no NF quando comparadas às brocas de baixa velocidade sob irrigação contínua (p < 0,05). As temperaturas mais elevadas foram diretamente proporcionais a suas distâncias do NF. No entanto, nenhuma das brocas apresentou níveis de temperaturas altas o suficiente para causar dano ao NF. Conclusões: As oscilações térmicas secundárias ao uso de brocas em mastoidectomias radicais são consideradas um fator de risco potencial ao NF. Porém, as brocas de alta e de baixa velocidade atualmente disponíveis, sob condições adequadas, usando irrigação contínua e à uma distância limitada do NF, mostraram oscilações térmicas transoperatórias seguras. ______________________________________________________________________________________ ABSTRACTIntroduction: There are many medical situations that demand facial nerve decompression, including traumatic or neoplastic lesions. However, the facial nerve is highly vulnerable to thermal oscillations, which can be observed during surgical procedures that demand the use of drills. Objectives: To assess potential thermal injuries caused by drills of high and low speed, and compare their peculiarities during radical mastoidectomy for facial nerve decompression. Methods: Eight temporal bone flaps obtained from cadavers were submitted to facial nerve decompression by the radical mastoidectomy technique, using both high- and low-speed drills with continuous irrigation or irrigation on demand. The temperature oscillations during all of the procedures were measured using thermal sensors attached to the temporal bone, following the path of the facial nerve, at distances of 10, 5, and 2mm, using cutting burrs of 2.4mm or diamond ball burrs of 2.1mm. Results: High-speed drilling with irrigation on demand generated a higher temperature rise in the facial nerve when compared to low-speed drilling under continuous irrigation (p < 0.05). The closer the burrs were to the facial nerves, the higher the temperatures measured. Neither the high-powered drill nor the low-powered drill presented levels of temperatures high enough to cause facial nerve damage. Conclusions: Thermal oscillations secondary to the use of drills in radical mastoidectomies should be considered a potential risk factor in surgical procedures for facial nerve decompression. However, the recently developed disposable devices, high- or lowpowered drills were safely used in these procedures under adequate conditions, by using continuous irrigation and a limited distance from the facial nerve

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The Oil Shale Transformation in the Presence of an Acidic BEA Zeolite under Microwave Irradiation

The transformation of an oil shale sample from the Autun Basin in the Massif Central, France, was studied using two different heating strategies: microwave irradiation and conventional heating. Microwave heating was performed using a single-mode cavity operating at a frequency of 2.45 GHz under an inert atmosphere. Heating of the sample generated liquid products of similar composition using either microwave or conventional heating. The yields of liquid products were similar in the two cases, while the overall energy requirements were much lower using microwave irradiation. The influence of water vapor on the oil shale decomposition was also studied under microwave energy. In order to simulate conversion of the organic fraction of the oil shale in the presence of an acidic zeolite catalyst, the oil shale sample was mixed with 5 wt % BEA zeolite and heated under microwave irradiation. It was found that the liquid products yield decreased along with an increase in the amount of coke produced. Gaseous and liquid products recovered showed a tendency for the production of lighter components in the presence of zeolite. The aromatic character of the oils was more important when microwaves were used, especially in the presence of zeolite