A kinetic study on the reaction of dicumyl peroxide with some low-olefin rubbers

The viscosity lowering of toluene solutions of isobutylene-isoprene rubber, polyisobutylene, and ethylene-propylene rubber in the reaction with dicumyl peroxide was investigated. By using the kinetic equations for the reaction of rubber with peroxide which had been derived previously by KIRIYAMA et al. the results of the experiments are discussed.     

Energy transfer to water-soluble anionic dyes adsorbed on fluorophore-containing Langmuir-Blodgett films

Langmuir-Blodgett (LB) films composed from chromophore-containing ammonium amphiphiles, water-soluble anionic polymers and anionic fluorescence dyes are prepared. The adsorption behaviour of dye molecules to the LB films is discussed in terms of concentration and chemical structure. Efficient energy transfer from amphiphilic chromophores to the adsorbed dyes is observed.     

Ubiquitous Memories: a memory externalization system using physical objects

In this paper we propose an object-triggered human memory augmentation system named “Ubiquitous Memories” that enables a user to directly associate his/her experience data with physical objects by using a “touching” operation. A user conceptually encloses his/her experiences gathered through sense organs into physical objects by simply touching an object. The user can also disclose and re-experience for himself/herself the experiences accumulated in an object by the same operation. We implemented a prototype system composed basically of a radio frequency identification (RFID) device. Physical objects are also attached to RFID tags. We conducted two experiments. The first experiment confirms a succession of the “encoding specificity principle,” which is well known in the research field of psychology, to the Ubiquitous Memories system. The second experiment aims at a clarification of the system’s characteristics by comparing the system with other memory externalization strategies. The results show the Ubiquitous Memories system is effective for supporting memorization and recollection of contextual events.     

Plasma Confinement Characteristics in Heliotron J--Spontaneous Change of Plasma Confinement State

Spontaneous transition of the plasma confinement mode was observed in the helicalaxis heliotron device “Heliotron J“ for three different plasma heating schemes, i.e. ECHonly, NBI-only and the combination of ECH and NBI. The transition seems to occur above a certain critical density. In addition to the confinement transition, a spontaneous shift of the hitting position of the divertor plasma flux on the wall was observed. This shift could be related with the change of the edge field topology caused by non-inductive toroidal currents.     

Development of a specimen heating holder with an evaporator and gas injector and its application for catalyst

A specimen heating holder equipped with a gas injector and an evaporator has been developed for use with conventional transmission electron microscopes (TEMs). The developed specimen holder allows both synthesis of metal oxide support and deposition of catalyst nano-particles in situ. Since the holder is designed to be used in small gapped high-resolution objective lens pole-piece, all the procedure from the synthesis of support material to the deposition of catalyst as well as the behavior of the catalyst nano-particles on the support can be observed at near atomic resolution. The developed specimen holder was applied to the study of AuPd catalyst. First, air was injected onto heated aluminum particles via a gas injector to synthesize Al(2)O(3) support. Then, nano-particles of AuPd were deposited on the Al(2)O(3) support. After the deposition, the synthesized Al(2)O(3) support was heated and air was injected again to observe behaviors of the deposited AuPd nano-particles at elevated temperatures in the aerial environment. Behaviors of the AuPd nano-particles such as coalescence, segmentation and diffusion to the Al(2)O(3) support were dynamically observed at atomic level high resolution.     

Enhanced radiosensitization by liposome-encapsulated pimonidazole for anticancer effects on human melanoma cells

The nitroimidazole-related hypoxic radiosensitizer, pimonidazole (Pmz) was encapsulated in liposome composed of dipalmitoylphosphatidylcholine, cholesterol and dipalmitoylphosphatidylglycerol (molar ratio = 1:1:0.2; diameter = 112.9 nm), and the radiosensitization was evaluated in human melanoma cells HMV-II. Cell proliferation was examined by WST-8 assay after X-ray irradiation in the presence of liposomal Pmz or free-Pmz under hypoxic conditions. On 7th day after X-ray irradiation of 5 Gy, cell proliferation decreased more markedly in the administration of liposomal Pmz than free-Pmz at equivalent Pmz doses. Chromatin fragmentation or nuclear condensation was observed in liposomal Pmz-treated HMV-II cells. Radiosensitization was enhanced dose-dependently along with Pmz amounts of 250-2000 microM contained in liposomal Pmz. Intracellular uptake was more abundant for liposomal Pmz for 60-240 min than for free-Pmz. Thus liposomal Pmz has a potential to overcome radiation resistance in hypoxia, owing to enhanced intracellular uptake by melanoma cells.     

Development of a high temperature-atmospheric pressure environmental cell for high-resolution TEM

An environmental cell for high-temperature, high-resolution transmission electron microscopy of nanomaterials in near atmospheric pressures is developed. The developed environmental cell is a side-entry type with built-in specimen-heating element and micropressure gauge. The relationship between the cell condition and the quality of the transmission electron microscopic (TEM) image and the diffraction pattern was examined experimentally and theoretically. By using the cell consisting of two electron-transparent silicon nitride thin films as the window material, the gas pressure inside the environmental cell is continuously controlled from 10(-5)?Pa to the atmospheric pressure in a high-vacuum TEM specimen chamber. TEM image resolutions of 0.23 and 0.31?nm were obtained using 15-nm-thick silicon nitride film windows with the pressure inside the cell being around 5?×?10(-5) and 1?×?10(4)?Pa, respectively.     

Noncontact measurement of deep tissue absorption coefficient using Spatially Resolved Near‐Infrared Spectroscopy

We examined the influence of probe‐tissue distance on the relationship between the deep tissue absorption coefficient and the spatial profile of light intensity by Monte Carlo simulation and in vivo experiments, using noncontact spatially resolved near‐infrared spectroscopy (SRS). These results suggest that noncontact SRS can be reliably used for noncontact measurement of the absorption coefficient and oxygen saturation of deep tissues. © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.