Introduction: The hypervelocity impacts of comet particles at 6.1 km/s have left tracks in the Stardust aerogel. The terminal particles are usually coarse grained minerals but abundant material is also present along the track walls as illustrated by synchrotron X-rays fluorescence spectroscopy [1]. This configuration suggests that the Wild 2 particles are made of poorly cohesive assemblages tha...

The development of agriculture and industry and the increase of population in countries with arid to semi-arid climates have led to more harvesting of groundwater resources and as a result land subsidence in different parts of the worlds. Decades of groundwater overexploitation in the Kashmar-Bardaskan plain in the north-east of Iran has resulted substantial land subsidence in this plain. The p...

This paper provides an overview on obtaining low-carbon ultra-fine grained dual-phase steels through rapid intercritical annealing of cold-rolled sheet as improved materials for automotive applications. A laboratory processing route was designed that involves cold-rolling of a tempered martensite structure followed by a second tempering step to produce a fine grained aggregate of ferrite and ca...

1- Introduction The sediment cores BAG, AZD and AM in the Babolsar, Jouybar and Zaghmarz areas are located at the southern Iranian part of the coastal plain of the Caspian Sea. These areas are contained by major mountain ridge, the Alborz in the south (Central Alborz Structural Zone). The Alborz Mountain represent the main source of terrigenous materials in the South basin of the Caspian Sea. ...

In nanocrystalline high entropy alloys (HEAs), the difference in chemistry and density of interfaces play a role microstructure evolution, although their relative importance is not well understood. Here, we compare data published literature regarding dislocation loop damage pure W under ion irradiation to new results on coarse grained HEAs irradiated single dual beams. Dislocation evolution has...

Outside the cognitive psychologist’s laboratory, problem solving is an activity that takes place in a rich web of interactions involving people and artefacts. This interactivity is constituted by fine-grained actions-perception cycles, and it allows a reasoner’s comprehension of the problem to emerge from a coalition of internal and external resources. Taking an ecological approach to problem s...

We performed inelastic neutron scattering measurements on nanophase Fe powders prepared by high-energy ball milling. Neutron energy loss spectra were measured for two states of the material: ~1! as milled, when the material had a characteristic nanocrystallite size of 12 nm; and ~2! annealed, when the material had a characteristic crystallite size of 28 nm. The longitudinal peak in the phonon d...

Al–Mg alloy powder was cryomilled to achieve a nanocrystalline (NC) structure having an average grain size of 50 nm with high thermal stability, and then consolidated by quasi-isostatic forging. The consolidation resulted in a bulk material with ultrafine grains of about 250 nm, and the material exhibited enhanced strength compared to conventionally processed Al–Mg alloy. The hardness of as-cry...

Synthetic DNA is a highly programmable nanoscale material that can be designed to self-assemble into 3D structures that are fully determined by underlying Watson-Crick base pairing. The double crossover (DX) design motif has demonstrated versatility in synthesizing arbitrary DNA nanoparticles on the 5-100 nm scale for diverse applications in biotechnology. Prior computational investigations of ...