Removal of chlorophyll and pheophorbide from Chlorella pyrenoidosa by supercritical fluid extraction: potential of protein resource.

This study tried to quantitatively clarify the usefulness of supercritical fluid extraction for removal of chlorophyll and pheophorbide from Chlorella pyrenoidosa. C. pyrenoidosa powder was subjected to supercritical fluid extraction, and chlorophyll a and pheophorbide a in its extracted fractions were measured by HPLC-UV. Chlorophyll a and pheophorbide a in residue after supercritical fluid extraction became below of detection limit.

Correlation between Chemical Dopants and Topological Defects in Catalytically Active Nanoporous Graphene.

The interplay between chemical dopants and topological defects plays a crucial role in electrocatalysis of doped graphene. By systematically tuning the curvatures, thereby the density of topological defects, of 3D nanoporous graphene, the intrinsic correlation of topological defects with chemical doping contents and dopant configurations is revealed, shining lights into the structural and chemical origins of HER activities of graphene.

Electric Properties of Dirac Fermions Captured into 3D Nanoporous Graphene Networks.

Nanoporous graphene- based electric-double-layer transistors (EDLTs) are successfully fabricated. Transport measurements of the EDLTs demonstrate that the ambipolar electronic states of massless Dirac fermions with a high carrier mobility are well preserved in 3D nanoporous graphene along with anomalous nonlinear Hall resistance and exceptional transistor on/off ratio. This study may open a new avenue for device applications of graphene.

Green solvent for green materials: a supercritical hydrothermal method and shape-controlled synthesis of Cr-doped CeO2 nanoparticles.

This paper describes a supercritical hydrothermal synthesis method as a green solvent process, along with products based on this method that can be used as green materials that contribute to solving environmental problems. The first part of this paper summarizes the basics of this method, including the mechanism of the reactions, specific features of the supercritical state for nanoparticle synthesis, the continuous flow-type reactor and applications; this provides a better understanding of the suitability of this method to synthesize green materials. The second part of the paper describes the method used to synthesize Cr-doped CeO(2) nanoparticles, which show an extremely high oxygen storage capacity, suggesting their high potential as an environmental catalyst. Transmission electron microscopy and scanning electron microscope images showed octahedral Cr-doped CeO(2) nanoparticles with sizes of 15-30 nm and cubic Cr-doped CeO(2) nanoparticles with sizes of 5-8 nm. Octahedral Cr-doped CeO(2) nanoparticles exposing (111) facets and cubic Cr-doped CeO(2) nanoparticles exposing (100) facets were determined by high-resolution transmission electron microscopy and selected area electron diffraction. The X-ray diffraction peaks shifted to a high angle because the radius of the Cr ion is smaller than that of the Ce ion.

Relation between volume expansion and hydrogen bond networks for CO2-alcohol mixtures at 40 °C.

We experimentally determined the density and mole fraction of CO(2) (x(CO(2))) for CO(2)-alcohol (methanol, ethanol, propanol, butanol, isopropyl alcohol, and tert-butyl alcohol) mixtures and performed molecular dynamics (MD) simulations to study the mechanisms of volume expansion at 40 °C. The volume as calculated by vapor-liquid equilibrium (VLE) data increased with decreasing alkyl chain length, although there was no effect of branched alkyl groups. Analysis of the hydrogen bond network showed that the average number of hydrogen bonds per alcohol molecule decreased with increasing branched methyl groups. At pure alcohol condition, large size hydrogen bond networks were made. With further addition of CO(2) molecules, it became difficult to contain the large hydrogen bond networks. Furthermore, the hydrogen bond networks changed to a cyclic pentamer or tetramer, and volume expansion occurred.

Laser-Doppler vibrating tube densimeter for measurements at high temperatures and pressures.

A laser-Doppler vibrometer was used to measure the vibration of a vibrating tube densimeter for measuring P-V-T data at high temperatures and pressures. The apparatus developed allowed the control of the residence time of the sample so that decomposition at high temperatures could be minimized. A function generator and piezoelectric crystal was used to excite the U-shaped tube in one of its normal modes of vibration. Densities of methanol-water mixtures are reported for at 673 K and 40 MPa with an uncertainty of 0.009 g/cm3.