Enhanced sputtering from the F/Si(100) surface with extraction of the surface bond direction

It was found that slow highly charged ions had a high ability to ionize F atoms on a F/Si(100)-2×1 surface and desorb F+ ions along the local bond direction. Actually, the F+ ion yields were proportional to the incident charge cubed, and the F+ ions were emitted along the Si-F bond directions showing a fourfold symmetry pattern. The trigger process of the F+ formation is discussed based on a charge transfer process of F 2p electrons by extending the classical over barrier model. Further, we found that the kinetic energy of highly charged ion induced F+ ions is lower than that of electron stimulated F+ ions caused by the removal of a F 2s electron.     

A soluble hybrid material combining carbon nanohorns and C60

A soluble hybrid nanomaterial that combines fullerenes and carbon nanohorns (CNHs) has been prepared and fully characterized. Electrochemical investigations revealed that the CNHs modify the electron accepting ability of C(60) in the hybrid material.     

Performance of a non-contact handling device using swirling flow with various gap height

Abstract  

Vortex levitation can achieve non-contact handling by blowing air into a vortex cup through a tangential nozzle to generate a swirling flow. In this paper, we focused on the relationship between the sucking pressure and the flow dynamics when gap distance from the cup to a work piece changes. Then simultaneous measurement of a pressure and a flow field in the cup was performed. As a result, the mean pressure changes and the pressure fluctuation inside the cup enhances with increasing gap height. Especially, periodic pressure perturbation is observed with wide gap height and it synchronizes with an eccentric rotation of the swirling flow. It is also found that the rotation axis of swirling flow steadily inclines against the central axis of the cup for appropriate gap height.     

Melanin Synthesis Inhibition Activity of Compounds Isolated from Bamboo Shoot Skin (Phyllostachys pubescens)

This study targets the evaluation of melanin synthesis inhibition activity of the bamboo shoot skin as agro-waste. The total methanolic extract of bamboo peel extract was evaluated for its skin protective effects via measuring its melanin inhibitory activity and its suppression activity on the expression of tyrosinase mRNA levels. Results showed that bamboo peel extract has a good ability for the inhibition of melanin synthesis so further studies were performed for the isolation of its constituents. Twelve compounds have been isolated from the shoot skin of Phyllostachys pubescens. Their structures were elucidated based on extensive spectroscopic methods. The melanin inhibition potential of the isolates was tested with their collagen-production-promoting activity for the determination of active principles. Results showed that Betulinic acid, tachioside, and 1,2-dilinolenin significantly suppressed melanin production per cell compared to control. Triacontanol, tricin, and (+)-lyoniresinol 9′-O-glucoside also tended to decrease melanin production per cell. These findings indicated that the skin of bamboo shoots, a significant agricultural waste, is a useful natural source for further research on its potential for aging problems such hyperpigmentation and cognitive function impairment.