Abstract To comprehend the mechanical behavior of a polycrystalline material, an in-depth analysis individual grain boundary (GB) and dislocation interactions is prime importance. In past decade, nanoindentation emerged as powerful tool to study local response in vicinity GB. The improved instrumentation test protocols allow capture various GB–dislocation during form strain bursts on load–displ...

Molecular dynamics deformation studies of nanocrystalline metals suggest a plasticity mechanism where dislocations are nucleated at grain boundaries (GB), travel through the grain being hindered by local GB stress intensities, to be finally absorbed in the surrounding GBs [1][2]. Recent constant strain rate molecular dynamics simulations of nanocrystalline Al demonstrated that dislocations can ...

Grain boundary (GB) segregation was experimentally studied in a bulk high entropy Cantor alloy, which indicated for the first time that Cr strongly segregates to GBs along with weak of Mn, implying co-segregation and Mn GBs. The strong are explained terms driving forces GB segregation, where alloy interaction is favourable stronger case Cr, while elastic strain energy governs segregation.

Glycoproteins synthesized in both human (HeLa and HEp-2) and simian (Vero and BS-C-1) cell lines following infection with two different strains of respiratory syncytial virus (A2 and Long) were analysed by SDS-PAGE following immunoprecipitation with monoclonal antibodies. Minor virus strain-dependent differences in the large glycoprotein, G, and the fusion protein polypeptides F1 and F2 were ob...

Truncated versions of the human cytomegalovirus (CMV) strain Towne glycoprotein B (gB) gene were stably expressed in CHO cell lines. The calcium-specific ionophore A23187 inhibited proteolytic cleavage of C-terminal-truncated gB expressed by cell line 67.77. These inhibition studies also showed that the 93-kilodalton cleavage product most likely represents the N-terminal cleavage fragment of gB...

Material performance is significantly governed by grain boundaries (GBs), a typical crystal defects inside, which often exhibit unique properties due to the structural and chemical inhomogeneity. Here, it is reported direct atomic scale evidence that oxygen vacancies formed in the GBs can modify the local surface oxygen dynamics in CeO2, a key material for fuel cells. The atomic structures and ...

of “Grain Boundary Field Projection Method and Atomic Lattice Interferometer for Nanometrology” by Chien-Kai Wang, Ph.D., Brown University, May 2014. The aim of this thesis is to investigate how grain boundary (GB) strength and separation mechanisms affect strength and ductility of nanocrystalline materials. Such nanoscale materials are highly nonlinear and thus have different energy profiles i...

Bacterial manganese(II) oxidation has a profound impact on the biogeochemical cycling of Mn and the availability of the trace metals adsorbed to the surfaces of solid Mn(III, IV) oxides. The Mn(II) oxidase enzyme was tentatively identified in Pseudomonas putida GB-1 via transposon mutagenesis: the mutant strain GB-1-007, which fails to oxidize Mn(II), harbors a transposon insertion in the gene ...

Grain-boundary (GB) diffusion creep (Coble creep) is the dominant deformation mechanism for the fine-grained materials under low stress and at elevated temperature [1]. From the classical Coble creep formula [1], the strain rate is proportional to the external stress, and inversely proportional to the cube of the grain size: 3 ~ − d σ ε& . During creep deformation the grains become elongated in...