Search

The present paper considers the heterogeneous nucleation of pure Au droplet solidified on a single crystal substrate plate under the influence of lattice misfit and cooling rate. The undercooling of droplet was measured by DSC. The experimental results present that the undercooling of Au droplet is directly proportional to both the lattice misfit and the cooling rate. It means that the heterogeneous nucleation can be significantly driven by lattice misfit and cooling rate. In addition, the related results show that the relationship between the undercooling and the cooling rate of Au droplet is independent on the lattice misfit. The results with respect to the interface of solidified Au and substrate analyzed by HRTEM prove that the orientation relationship between the substrate and the solidified Au matches with the minimum lattice misfit. [ABSTRACT FROM AUTHOR]

An Al0.1CoCrFeNi high-entropy alloy (HEA) with a face-centered cubic structure in the as-cast and the recrystallized states is investigated. The mean grain size of the as-cast HEA is 14 times larger than that of the recrystallized HEA. The tension tests reveal that deformation twinning is the main mechanism dominating the plastic deformation of two HEAs. With a decrease in the grain size, twin spacing increases, and twin thickness decreases, which results in a low twinning activity. The twinning activity of the recrystallized HEA is strongly inhibited by grain refinement, which degrades the promotion of twinning on the strain-hardening ability and the tensile ductility. IMPACT STATEMENT Grain refinement on strain hardening and twinning in a high-entropy alloy (HEA) is investigated, which is associated with the nanotwin substructure. Grain refinement decreases the twin thickness, and increases the twin spacing. [ABSTRACT FROM PUBLISHER]

Anterior Cruciate Ligament (ACL) injuries occur two to eight times more frequently in women than men. However, it remains unclear whether gender differences exist in ACL at the molecular level. Using reverse transcript polymerase chain reaction (RT-PCR) with histological analysis, the gene expressions of collagen types I and III of fibroblasts from ACLs of 17 male and 17 female athletes with acute ACL tears were studied. Female athletes were found to have a significantly lower gene expression of collagen I. No significant difference was found in type III collagen gene expression between male and female athletes. This finding may help us to explain the higher incidence of ACL injury in female athletes from the molecular perspective. [ABSTRACT FROM AUTHOR]

A three-dimensional finite difference model has been formulated, using the commercial code CFX4, to describe the fluid flow and heat transfer in the funnel mould and secondary cooling segment of the compact strip production (CSP) casting process. Through simulation and computation with the established simulation model, influences of the factors such as casting speed, casting superheat, immersion depth of submerged entrance nozzle, amount of cooling water in the secondary cooling segment on flow field and temperature field in the funnel mould and secondary cooling segment of CSP technology were analysed. [ABSTRACT FROM AUTHOR]

Implantation is an essential issue in orthopedic surgery. Bulk metallic glasses (BMGs), as a kind of novel materials, attract lots of attentions in biological field owing to their comprehensive excellent properties. Here, we show that a Zr 61 Ti 2 Cu 25 Al 12 (at. %) BMG (Zr-based BMG) displays the best cytocompatibility, pronounced positive effects on cellular migration, and tube formation from in-vitro tests as compared to those of commercial-pure titanium and poly-ether-ether-ketone. The in-vivo micro-CT and histological evaluation demonstrate the Zr-based BMG can significantly promote a bone formation. Immunofluorescence tests and digital reconstructed radiographs manifest a stimulated effect on early blood vessel formation from the Zr-based BMG. Accordingly, the intimate connection and coupling effect between angiogenesis and osteogenesis must be effective during bone regeneration after implanting Zr-based BMG. Dynamic gait analysis in rats after implanting Zr-based BMG demonstrates a tendency to decrease the pain level during recovery, simultaneously, without abnormal ionic accumulation and inflammatory reactions. Considering suitable mechanical properties, we provide a realistic candidate of the Zr 61 Ti 2 Cu 25 Al 12 BMG for biomedical applications., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors.)

Catastrophic brittle fracture of monolithic metallic glass (MG) hinders engineering application of MGs. Although many techniques has been tried to enhance tensile ductility of metallic glasses, the enhancement is quite limited. Here, we show the effect of electrodeposited Cu coating on tensile plasticity enhancement of Pd 40 Cu 30 Ni 10 P 20 MG wires, with different volume fractions of copper coatings (R), from 0% to 97%. With increasing R, tensile elongation is enhanced to 7.1%. The plasticity enhancement is due to confinement of the Cu coatings, which lead to multiple and secondary shear bands, according to SEM investigations. In addition, the SEM images also show that the patterns on the fracture surface of the Cu-coated MG wires vary with volume fraction of the Cu coatings. The size of shear offset decreases with increasing R. The viscous fingerings on the fracture surface of monolithic MG wire changes into dimples on the fracture surface of Cu coated MG wires with R of 90% and 97%. The electrodeposition technique used in this work provides a useful way to enhance plasticity of monolithic MGs under tensile loading at room temperature.

Nephrogenic adenoma (NA) is a rare benign metaplastic lesion of the urothelial tract that arises as a response to injury and chronic inflammation. Although the most common site for NA is the bladder, it can occur in any part of urinary tract lined by urothelium. NA can mimic minor variants of urothelial cancer, clear cell adenocarcinoma, and prostate adenocarcinoma, making a combination of histologic examination and immunohistochemistry essential for diagnosis. We hereby report a rare case of nephrogenic adenoma arising in a urethral diverticulum., (Copyright © 2012 Elsevier Inc. All rights reserved.)