Application of the EBSD Technique in the Study of Porosity and Permeability in Deformation Bands in Sandstone.

Deformation bands are common constituents of porous clastic fluid reservoirs. Various techniques have been used to study deformation band structure and the associated changes in porosity and permeability. However, the use of electron backscatter diffraction technique is limited. Thus, more information is needed regarding the crystallographic relationships between detrital crystals, which can significantly impact reservoir rock quality. We employ microscopic and microstructural investigation techniques to analyze the influence of cataclastic deformation bands on pore space. Porosity measurements of the Cretaceous Ilhas Group sandstone in NE Brazil, obtained through computerized microtomography, indicate that the undeformed domains exhibit a total porosity of up to 13%. In contrast, this porosity is slightly over 1% in the deformation bands. Scanning electron microscopy analyses revealed the presence of grain fragmentation and dissolution microstructures, along with cement-filling pre-existing pores. The electron backscatter diffraction analyses indicated extensive grain fragmentation and minimal contribution from intracrystalline plasticity as a deformation mechanism. However, the c axes of quartz crystals roughly align parallel to the orientation of the deformation band. In summary, we have confirmed and quantified the internal changes in a deformation band cluster, with grain size reduction and associated compaction as the main mechanism supported by quartz cementation.

Three-Dimensional Characterization of Polyurethane Foams Based on Biopolyols.

Two biopolyol-based foams derived from banana leaves (BL) or stems (BS) were produced, and their compression mechanical behavior and 3D microstructure were characterized. Traditional compression and in situ tests were performed during 3D image acquisition using X-ray microtomography. A methodology of image acquisition, processing, and analysis was developed to discriminate the foam cells and measure their numbers, volumes, and shapes along with the compression steps. The two foams had similar compression behaviors, but the average cell volume was five times larger for the BS foam than the BL foam. It was also shown that the number of cells increased with increasing compression while the average cell volume decreased. Cell shapes were elongated and did not change with compression. A possible explanation for these characteristics was proposed based on the possibility of cell collapse. The developed methodology will facilitate a broader study of biopolyol-based foams intending to verify the possibility of using these foams as green alternatives to the typical petrol-based foams.

Rare variation of the right internal jugular vein: a case study.

This study reports on a rare variation of the right internal jugular vein (IJV) identified during routine anatomic dissection of a male cadaver. The right IJV had a tributary located parallel and medially to the IJV itself. This branch of the IJV emerged between the transverse processes of the 3rd and 4th cervical vertebrae and drained into the junction between the right internal jugular and brachiocephalic veins. The present study described a rare branch of the right IJV, which is important knowledge for surgeons, in order to prevent accidental injury and bleeding during surgical procedures.

O presente estudo demonstrou uma variação rara da veia jugular interna direita (VJI), identificada durante uma dissecção de rotina de um cadáver masculino. A VJI direita apresentou uma tributária localizada paralelamente e medialmente à referida veia. Essa tributária da VJI emergiu entre os processos transversos das 3ª e 4ª vértebras cervicais e drenou para a junção entre as veias jugular interna e braquiocefálica direita. O conhecimento da variação anatômica demonstrado no presente estudo é importante para os cirurgiões, a fim de prevenir lesões acidentais e sangramento durante procedimentos cirúrgicos.