introduction: the aim of this study was to demonstrate changes in nature of mucin and production of acidic forms using pas-alcian blue stain at ph=2.5. appearance of non-goblet metaplastic columnar cells of lower esophagus is considered as an early sign of barrette sophagus, simultaneous in conjunction or before the appearance of goblet cells in patients with gastroesophageal reflux disease. ma...

We study the genesis and the selective propagation of complex crack networks induced by thermal shock or drying of brittle materials. We use a quasistatic gradient damage model to perform large-scale numerical simulations showing that the propagation of fully developed cracks follows Griffith criterion and depends only on the fracture toughness, while crack morphogenesis is driven by the materi...

Columnar jointed rock mass (CJRM) formed by intact divided special symmetrical columnar joints is a type of with poor mechanical properties, strong anisotropy, and weak self-supporting ability, severely affecting the excavation safety stability underground tunnels. In this study, taking Baihetan hydropower station as engineering background, CJRM geological numerical models different dip angles ...

Mudeungsan (Mount Mudeung) is an extinct volcano located in the southwestern part of South Korea that was formed Late Cretaceous period. This mountain, 1187 m above sea level, adjacent to Gwangju Metropolitan City, which has a large population (about 1.4 million) and volcanic rocks, including columnar joints, form various types outcrops. Although this mountain listed as national geopark 2014 UN...

Void formation is a critical reliability concern for solder joints in electronic packaging. The control of microstructures and the quantity impurities Cu electroplated films significantly affect void at joint interface, but studies investigating these factors are rare. In this study, three (denoted as A, B, C) fabricated using an electroplating process. A film has faceted grain texture embedded...

As the largest extant terrestrial animals, elephants do not trot or gallop but can move smoothly to faster speeds without markedly changing their kinematics, yet with a shift from vaulting to bouncing kinetics. To understand this unusual mechanism, we quantified the forelimb and hindlimb motions of eight Asian elephants (Elephas maximus) and seven African elephants (Loxodonta africana). We used...

Joining based on transient liquid phase bonding (TLPB) has a great prospect in microelectronic packaging. However, this process is plagued with its low throughput. In work, we designed and utilised preformed Cu-Sn nanocomposite interlayer (Cu-Sn NI) to speed up the TLPB process. Comparing uses of Sn only, NI enabled be accelerated by >20 times. Furthermore, instead columnar Cu6Sn5 grains, inter...

Dissimilar Ti–Al laser weldings are very interesting due to their difficulties in being processed because of the different physical properties alloys and crack formations during cooling solidification. In this study, effect offset defocusing on microstructure, geometry mechanical response 2 mm thick dissimilar AA6061/Ti-6Al-4V welds was analyzed. Moreover, order reduce residual stresses, joints...