The low-frequency vibrational and low-temperature thermal properties of amorphous solids are markedly different from those of crystalline solids. This situation is counterintuitive because all solid materials are expected to behave as a homogeneous elastic body in the continuum limit, in which vibrational modes are phonons that follow the Debye law. A number of phenomenological explanations for...

Electron emission spectra from thin metal foils with thin layers of water frozen on them (amorphous solid water) after fast proton impact have been measured and have been simulated in liquid water using the event-by-event track structure code PARTRAC. The electron transport model of PARTRAC has been extended to simulate electron transport down to 1 eV by including low-energy phonon, vibrational...

Fe and Ni doped mesoporous Co3O4 (mCo3O4) catalysts were prepared and investigated for electrochemical oxygen evolution. The incorporation of Fe into mCo3O4 (Fe-mCo3O4) results in unusual synergistic effects via destruction of the bulk mesoporous structure and formation of slit-like pores. The Fe-mCo3O4 composite displayed a significantly enhanced catalytic activity for oxygen evolution.

in this study chemical method of dissolution-precipitation was applied to produce amorphous silica nanoparticles from rice straw ash (rsa), the waste material of rice cultivation. the morphology, particle size, structure and area of specific surface of synthesized amorphous silica nanoparticles were evaluated using transmission electron microscopy (tem), x-ray diffraction analysis (xrd) and bet...

The Amorphous Computing project is aimed at developing programming methodologies for systems composed of vast numbers of locallyinteracting, identically-programmed agents. This paper presents some of the building blocks for robust collective behavior that have emerged as part of this effort, and describes how organizing principles from multi-cellular organisms may apply to multi-agent systems.

objectives: the aim of this study was to evaluate and compare the retentive strength of orthodontic bands cemented with amorphous calcium phosphate (acp)-containing and conventional glass ionomer cements (gics). materials and methods: one-hundred-and-twenty mandibular third molars were embedded in acrylic resin blocks with the buccal surface of crowns perpendicular to the base of the mold. the ...

We have studied the compaction of vapor-deposited amorphous solid water by energetic ions at 40 K. The porosity was characterized by ultraviolet-visible spectroscopy, infrared spectroscopy, and methane adsorption/desorption. These three techniques provide different and complementary views of the structural changes in ice resulting from irradiation. We find that the decrease in internal surface ...

By means of a finite elements technique we solve numerically the dynamics of an amorphous solid under deformation in the quasistatic driving limit. We study the noise statistics of the stress-strain signal in the steady-state plastic flow, focusing on systems with low internal dissipation. We analyze the distributions of avalanche sizes and durations and the density of shear transformations whe...