Proof of Concept of Impact Detection in Composites Using Fiber Bragg Grating Arrays

Impact detection in aeronautical structures allows predicting their future reliability and performance. An impact can produce microscopic fissures that could evolve into fractures or even the total collapse of the structure, so it is important to know the location and severity of each impact. For this purpose, optical fibers with Bragg gratings are used to analyze each impact and the vibrations generated by them. In this paper it is proven that optical fibers with Bragg gratings can be used to detect impacts, and also that a high-frequency interrogator is necessary to collect valuable information about the impacts. The use of two interrogators constitutes the main novelty of this paper.

Polilaktida oinarri duten inplante polimeriko biodegradagarrien diseinu, fabrikazio eta propietateak

[EU]3D inprimaketa gaur egun, biomedikuntzaren garapenerako aukera ezberdinak ematen dituen teknologia iraultzaile gisa aurkezten da; bai medikuntza arloan formazio eta ikerkuntzarako erreminta gisa, baita dispositibo berrien diseinu eta fabrikaziorako. Bere abantailarik aipagarriena prototipaketa azkarra da. Gainera, teknologia honek barne egitura eta forma ezberdineko objektuak fabrikatzea ahalbidetzen du koste lehiakor batean. Lan honen helburua 3D inprimagailuen bidezko prototipoen fabrikazioan zentratzen da, horretarako lehengai bezala polimero biodegradagarri eta biobateragarria erabiliz. Horrez gain, metodo tradizionalarekin konparatuz teknologia honek izan ditzakeen abantailak ere aztertu nahi dira, ez bakarrik alde ekonomikoari edo denborari begira, baita fabrikatutako objektuen propietateei begira ere. Dena dela, horrekin hasi aurretik ezaugarritze fisiko eta termikoa burutu beharko zaie lehengaiei, 3D inprimagailuaren parametroen aukeraketa egokia egiteko eta parametro horien eta amaierako produktuaren kalitate, egitura eta propietateen artean erlazio egokia ezartzeko. Lan hau aurrera eramateko poli(L-laktida)-rekin (PLLA) egingo da lan, bai ehun ingeniaritzan baita hezurren apurketen finkapenerako dispositiboetan oso erabilia izan den polimeroa.

Acerca del posible y derivado carácter tecnológico de ciertos tipos óseos debitados: los casos de muescas, «écaillés» y retocadores

[ES] Los análisis efectuados sobre una serie de tipos óseos debitados (muescas, "écaillés" y retocadores) pertenecientes a los niveles musteroides y auriñacoides de los yacimientos de Gatzarria (Pays de Soule, Pyrénées Atlantiques) y Abeilles (Montmaurin, Haute Garonne) posibilitan sugerir hipótesis relativas a su causalidad. En este sentido, una gran parte del efectivo global examinado pudiera relacionarse directamente con determinados tratamientos tecnológicos de fractura, talla y retoque.

Lethal Interpersonal Violence in the Middle Pleistocene

Evidence of interpersonal violence has been documented previously in Pleistocene members of the genus Homo, but only very rarely has this been posited as the possible manner of death. Here we report the earliest evidence of lethal interpersonal violence in the hominin fossil record. Cranium 17 recovered from the Sima de los Huesos Middle Pleistocene site shows two clear perimortem depression fractures on the frontal bone, interpreted as being produced by two episodes of localized blunt force trauma. The type of injuries, their location, the strong similarity of the fractures in shape and size, and the different orientations and implied trajectories of the two fractures suggest they were produced with the same object in face-to-face interpersonal conflict. Given that either of the two traumatic events was likely lethal, the presence of multiple blows implies an intention to kill. This finding shows that the lethal interpersonal violence is an ancient human behavior and has important implications for the accumulation of bodies at the site, supporting an anthropic origin.