Unimpeded permeation of water through biocidal graphene oxide sheets anchored on to 3D porous polyolefinic membranes

3D porous membranes were developed by etching one of the phases (here PEO, polyethylene oxide) from melt-mixed PE/PEO binary blends. Herein, we have systematically discussed the development of these membranes using X-ray micro-computed tomography. The 3D tomograms of the extruded strands and hot-pressed samples revealed a clear picture as to how the morphology develops and coarsens over a function of time during post-processing operations like compression molding. The coarsening of PE/PEO blends was traced using X-ray micro-computed tomography and scanning electron microscopy (SEM) of annealed blends at different times. It is now understood from X-ray micro-computed tomography that by the addition of a compatibilizer (here lightly maleated PE), a stable morphology can be visualized in 3D. In order to anchor biocidal graphene oxide sheets onto these 3D porous membranes, the PE membranes were chemically modified with acid/ethylene diamine treatment to anchor the GO sheets which were further confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and surface Raman mapping. The transport properties through the membrane clearly reveal unimpeded permeation of water which suggests that anchoring GO on to the membranes does not clog the pores. Antibacterial studies through the direct contact of bacteria with GO anchored PE membranes resulted in 99% of bacterial inactivation. The possible bacterial inactivation through physical disruption of the bacterial cell wall and/or reactive oxygen species (ROS) is discussed herein. Thus this study opens new avenues in designing polyolefin based antibacterial 3D porous membranes for water purification.

Long pulsed laser induced reverse bulging and plugging

A new kind of failure mode is observed in circular brass foils whose peripheries are fixed and whose surfaces are subjected to a long pulsed laser over a central region. The failure is classified into three stages; they are referred to as thermal bulging, localized shear deformation and perforation by plugging. A distinct feature of the failure mode is that bulging and plugging occurred in the direction opposite to the incident laser beam. The failure mode is different from the well-known types of laser induced material damage, such as spallation, melting and/or vaporization.

3D line drawing from point clouds using chromatic stereo and shading

1 PDF document (8 pp., English).-- Contributed to: VSMM'08: 14th International Conference on Virtual Systems and Multimedia (Limassol, Cyprus, Oct 20-25, 2008)

[G_Hondarribia_Muralla] Documentación geométrica de las murallas de Hondarribia

[ES] Al respecto del modelo virtual con texturas fotográficas generado en este proyecto, se puede consultar también el siguiente artículo:

Polilaktida oinarri duten 3D zelula-euskarri (scaffold) polimeriko biodegradagarrien diseinu, fabrikazio eta propietateak

[EU]Hiru dimentsioko inprimaketa etorkizun handiko teknologia bezala azaltzen zaigu gaur egun. Esate baterako, biomedikuntza arloan aukera berritzaileak ekar ditzake, baina baita hezkuntza, heziketa eta ikerketa munduetan ere. Teknologia berri honen abantailarik nagusiena prototipatze azkarrean datza, eta honi esker, mikro- eta makro- egitura definituak dituzten objektuak diseinatu eta fabrikatu daitezke modu lehiakorrean. Lan honen helburua 3D inprimagailu baten bitartez inprimaturiko polimero biobateragarri eta biodegradagarrietan oinarrituriko ereduen garapen eta fabrikazioan datza. Hala ere, lehenik eta behin, lehengaiak bai fisikoki eta bai termikoki karakterizatu behar dira, ondoren, 3D inprimagailuaren parametroen arteko erlazioa ezarri, eta azkenik, produktu finalaren egitura propietateak eta kalitatea aztertu. Aipaturiko lana aurrera eramateko erabili den materiala polilaktida (PLA) izan da, zeinen erabilera oso zabaldua dagoen medikuntza arloan inplante (torloju, iltze, plaka eta abar) moduan eta ehun ingeniaritzaren munduan.