Fracture of Alumina with Controlled Pores

Fracture from artificial spherical pores, as well as natural defects, in alumina in a grain-size range of 0.8-9.2 µm has been studied experimentally and compared with a fracture-mechanics model. Results from fracture-strength measurements have been combined with detailed fractographic analysis to elucidate the ensuing crack instability. Two existing models of possible crack configurations have been extended and contrasted. The semicircular crack as well as the circumferential crack both are described as flaws in the stress-concentrating field of a spherical pore. Surface correction terms afforded by the presence of the pore have been incorporated. A comparative computation shows that fracture occurs more likely from the semicircular crack configuration than the circumferential crack configuration.     

An adaptive system for autonomous driving

Software Quality Journal - Having systems that can adapt themselves in case of faults or changing environmental conditions is of growing interest for industry and especially for the automotive...     

Accelerating all-pairs shortest path algorithms for bipartite graphs on graphics processing units

Multimedia Tools and Applications - Bipartite graphs are used to model and represent many real-world problems in biological and physical sciences. Finding shortest paths in bipartite graphs is an...     

Characterization of pollen by vibrational spectroscopy

Classification, discrimination, and biochemical assignment of vibrational spectra of pollen samples belonging to 43 different species of the order Pinales has been made using three different vibrational techniques. The comparative study of transmission (KBr pellet) and attenuated total reflection (ATR) Fourier transform infrared (FT-IR) and FT-Raman spectroscopies was based on substantial variability of pollen grain size, shape, and relative biochemical composition. Depending on the penetration depth of the probe light, vibrational techniques acquire predominant information either on pollen grain walls (FT-Raman and ATR-FT-IR) or intracellular material (transmission FT-IR). Compared with the other two methods, transmission FT-IR obtains more comprehensive information and as a result achieves superior spectral identification and discrimination of pollen. The results strongly indicate that biochemical similarities of pollen grains belonging to the same plant genus or family lead to similar features in corresponding vibrational spectra. The exploitation of that property in aerobiological monitoring was demonstrated by simple and rapid pollen identification based on relatively small spectral libraries, with the same (or better) taxonomic resolution as that provided by optical microscopy. Therefore, the clear correlation between vibrational spectra and pollen grain morphology, biochemistry, and taxonomy is obtained, while successful pollen identification illustrates the practicability of such an approach in environmental studies.