Plasma Enhanced Chemical Vapor Deposition of Fluorinated Amorphous Carbon Thin Films from Tetrafluoroethylene and Tetraisocyanatesilane

Fluorinated amorphous carbon films were prepared from tetrafluoroethylene (TFE; C₂F₄) and tetraisocyanatesilane (TICS; Si(NCO)₄) using an RF plasma enhanced chemical vapor deposition method for the purpose of application to inter layer low permittivity films used in large scale integrated circuits. Structure of the deposited films was investigated by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Adhesion characteristics were examined by a tape-peel method. Permittivity of the films was investigated from capacitance measurement on metal-insulator-semiconductor structure. The structural analysis revealed that the deposited films contained imide-like group in spite of the fact that TICS molecules contained isocyanate group . The films deposited under the flow ratio TICS/(TFE + TICS) = 70% showed permittivity of 2.3, good adhesion on silicon substrates, and higher thermal stability than the films deposited without TICS.     

Formation of Tetrahydrofuran Derivatives and Acetonylation of Alkenes Using Carbon Radicals Derived from Manganese(III) Oxidation of Diketene

Oxidation of a mixture of diketene and a 1,1-diarylethene 1 with manganese(III) acetate dihydrate gave an equilibrium mixture of 5-hydroxy-2-pentanone 2 and a tetrahydrofuran-2-ol, which was subsequently dehydrated in glacial acetic acid to yield 4-penten-2-one 4 in good yield. A similar reaction in the presence of alcohols or amines afforded 2-alkoxy-2-methyltetrahydrofurans 5 or 3-acetyl-2-aminodihydrofurans 9 in moderate yields. Diketene reacted with manganese(III) acetate in the presence of nucleophiles, such as water and alcohols, to give a mixture of unconjugated manganese(III) enolate A and conjugated manganese(III) enolate B. Major products 4 and 5 were formed by the oxidation of the conjugated manganese(III) enolate B. Tetrahydrofurylideneacetates 3 and 7 derived from the unstable unconjugated enolate A were also obtained as minor products. The reaction pathways are discussed.     

Studies on inhibitors of skin tumor promotion. XI. Inhibitory effects of flavonoids from Scutellaria baicalensis on Epstein-Barr virus activation and their anti-tumor-promoting activities.

To search for possible anti-tumor-promoters, fourteen flavones obtained from the root of Scutellaria baicalensis were examined for their inhibitory effects on the Epstein-Barr virus early antigen (EBV-EA) activation by a short-term in vitro assay. Among these flavones, 5,7,2'-trihydroxy- and 5,7,2',3'-tetrahydroxyflavone showed remarkable inhibitory effects on the EBV-EA activation, and the effect of the latter on Raji cell cycle was also examined by flow cytometer. These two flavones exhibited remarkable inhibitory effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test.     

3-D PTV measurement on turbulence modification due to an oil droplet in a plane Couette water flow

Three-dimensional particle tracking velocimetry (3-D PTV) measurements with a two-camera system have been conducted for a turbulent water plane Couette flow with an oil droplet in order to understand the modification of shear-dominant turbulence by the droplet. The parameters of the stereogrammetry, which are crucial for calculating the spatial coordinate of tracer particles from 2-D images of two cameras, have been determined with a careful calibration. The experimental results show that the axial and wall-normal turbulence intensities and the turbulent kinetic energy are enhanced locally in the confluence regions where axial main flow over the interface meets the secondary flow along the interface in the wall-normal direction. The secondary flows were observed only around the equator of the droplet. The wall-normal and transverse turbulence intensities are found to increase in the region above the droplet. This is due to the change in the direction of the primary flow over the top of the droplet. The turbulence in the other region is attenuated mainly because of the attenuation of the generation and evolution of the coherent structure in the neighbourhood of the droplet.     

Effect of primary filter using theoretical intensity of fluorescent X‐rays and scattered X‐rays

A primary filter is often used for low‐concentration analysis by energy‐dispersive X‐ray fluorescence spectrometer. We determined the material and thickness of the primary filter and calculated the theoretical intensities of the fluorescent X‐rays and scattered X‐rays using lead in brass, for which the concentration is known. The filter materials were zirconium, nickel, titanium, aluminum, and molybdenum with a thickness between 20 and 125 µm. For verification, we calculated the lower limits of detection using theoretical intensities for several filters and compared them with values calculated using the measured intensities. For example, both values were similar for a 125 µm zirconium filter: 128.0 ppm using theoretical intensities and 147.7 ppm using measured intensities. The theoretical intensity values are obtained by measurements and calculations, but require no primary filters for the measurements. This method is extremely effective for selecting the optimal filter for multiple samples and elements. Copyright © 2010 John Wiley & Sons, Ltd.