2014 It is shown that liquid 4He can usually be overpressurized only 10-2 bars above the melting pressure. This value suggests that the nucleation takes place on the walls of the cell, not in the bulk liquid as calculated previously. Further theoretical effort on this problem is called for. In the presence of carefully degased graphite we confirm that the barrier to the nucleation disappears, a...

Graphite oxide constitutes carbon network with oxygen atoms both on hexagonal arrangement and the edge sites. Structural and electronic properties for graphite-oxygen complexes have been explored using first-principles total-energy calculations within the local density approximation (LDA). Band structures and density of states for the propose carbon 3D models are reported. A finite energy gap and...

We studied NbCl5 and ZnMg alloy intercalated graphite compounds using an optical spectroscopy technique. These intercalated metallic graphite samples were quite challenging to obtain optical reflectance spectra since they were not flat and quite thin. By using both a new method and an in situ gold evaporation technique we were able to obtain reliable reflectance spectra of our samples in the fa...

Graphite ore collected from Hunan province, south China was characterized by chemical analysis, X-ray diffraction, and optical microscopy. Rougher and multi-stage flotation tests using a mechanical flotation cell and a flotation column containing an additional centrifugal force field were carried out to promote its grade and economic value. In rougher flotation, both the mechanical flotation ce...

Introduction: After silicon carbide (SiC), graphite is the best studied presolar mineral. A wealth of information exists on the isotopic compositions of C and of many minor/trace elements in micrometer-sized grains [e.g., 1-5]. Presolar graphite grains exhibit large C-isotopic anomalies with C/C ratios between 2 and 7000. Although this range is compatible with what is observed for SiC [6, 7], t...

In this work, we present a statistical mechanical analysis to elucidate the molecular-level factors responsible for the static and dynamic properties of polymer films. This analysis, which we term conformal sites theory, establishes that three dimensionless parameters play important roles in determining differences from bulk behavior for thin polymer films near to surfaces: a microscopic wettin...

Electrochemical applications of graphene are of very high importance. For electrochemistry, bulk quantities of materials are needed. The most common preparation of bulk quantities of graphene materials is based on oxidation of graphite to graphite oxide and subsequent thermal exfoliation of graphite oxide to thermally reduced graphene oxide (TR-GO). It is important to investigate to which exten...

Over the past decade, some groups have reported that nanofluids, which are liquids containing suspensions of nanoparticles, have substantially higher thermal conductivity than that of the base fluids. However, the reported high thermal conductivity sometimes cannot be reproduced. Theoretically, potential mechanisms leading to this enhancement are still under scrutiny. In this thesis, we present...

The morphology and the distribution of graphite grains are the decisive factors in judging the properties of the material cast iron. There are six classes of graphite grain morphology defined by ISO-945 through reference drawings for cast iron graphite grain classification. These reference drawings are universally accepted for classification of graphite grains. Many shape representations and re...