Carbon composites of controlled morphology dispersed with finely metal or metallic compound particles can be synthesized in high carbon yield by the pressure pyrolysis of organometallic polymers. The size and the morphology of the carbon matrix can be controlled by the selection of the pyrolysis conditions as well as the amounts of coexistent water and the metal concentration in copolymers. Organometallic polymers undergo pressure pyrolysis affording the liquid phase of oligomers, which is responsible for the morphology of carbons through liquid-liquid microphase separation. Supercritical water affected the liquid phase separation during pyrolysis yielding carbon spherulite of about several micrometers dispersed with ferrite particles less than 100 nm. The magnetic properties of metal-dispersed carbon are attributed to the crystallinity and the particle size of the metals, which have been foundto depend strongly on the properties of both the carbon-metal bond of organometallic compounds and the carbon-carbon bond of the polymer matrix. Metal-dispersed carbon composites of controlled morpholgy have potentials of many applications for magnetic materials, catalysts and pigments and so on. This processing affords a novel method for producing carbon nano-composites with controlled microstructure and morphology.
X-ray diffraction studies under high pressure using synchrotron radiation at the Photon Factory are reviewed. In 1983, a system named “MAX80” was constructed, which consists of a cubic anvil type high pressure vessel combined with a 500-ton hydraulic ram and a posi-tioning stage. High quality powder X-ray diffraction studies can be performed using this system in the pressure range up to 12 GPa and in the temperature range from 300 K to 1700 K. Various studies such as precise measurement of the equations of state, phase diagram, and the kinetics of the phase transformations have been carried out using this system.
The important subjects of technology in the 21th century are predicted to be the balance of environmental and resource and/or energy problems. These problems will only come to satisfactory solution by exploitation of resourse in wastes. Nowadays, the hydrothermal reaction has been applied in inorganic fields such as crystal growth, powder synthesis, wet metallurgy, and so on. Some following new processes and technologies which relate the organic waste problems to resource, are presented; 1) Geo-chemical process; a) Application to liquefaction and gasification of organic wastes in geochemical reactor for advanced geothermal energy utilization. b) Hydrothermal degradation of toxic and hazardous materials such as chlorinated organic materials (PCBs, Dioxines, BHC, etc. ). 2) Wet combustion process; Combination of organic waste treatment with wet combustion (application to make a liquid fertilizer for sterile land and ocean and to make a new power plant process).
This paper is concerned with the principle and the mechanism of geothermal power generation, as well as the brief history and the present situation of geothermal energy utilization. The history of geothermal power generation dates from 1904 when a 0. 5 kW unit was operated on geothermal steam in Larderello, Italy. Some 90 years have passed since then, and it can be said that the technology for generating electric power using geothermal energy stably and economically over a long period of time has been established during the past decade. At the present time, geothermal power generation accounts for only less than 1 % of the total electric power consumption in the world but it is conducted in 18 countries of the world including Japan. Geothermal power generation is expected to develop more and more in future as clean, purely domestic energy source acceptable to the environments of the earth.
Some examples of new application of the hydrothermal process to the extraction of rare metals from complex ores are presented. Tungsten can be separated from tin-tailing which contains tungsten and tin oxides under alkaline hydrothermal conditions. Typical rare-earth ores, such as bastnaesite, xenotime, monazite and ionexchange ore, are also extracted with aqueous solution of NaOH to produce a mixture of rare-earth hydroxides under high temperatures and pressures. The possiblity of nickel extraction process by using hydrothermal reaction is discussed.
Very soon after their production was started, Komatsu Diamond Co. recieved, in June 1963, a letter from GE warning of possible infringement on their registered patent rights. This was the kickoff of a years long series of law suits between the two parties. Upon the registration of their “belt” apparatus patent in 1964, GE lodged, unsuccessfully, an application for a provisional court order to prohibit Komatsu's use of the brand-new apparatuses. The definitive proceedings began in late 1965, and legal inspectors came to the plant for the first time in 1966. The point of dispute was based on the difference in interpretation of the function of, particularly, the die lined with the ceramic sleeve.
This paper is concerned with the synthesis of quartz crystal by hydrothermal reaction. The mechanism and control of the crystal growth, and how to evaluate the quality of the synthetic quartz crystal are discussed, as well as the brief historical review of synthetic quartz production. To manufacture synthetic quartz crystal, developers employ the hydrothermal temperature gradientmethod. This manufacturing process remains unchanged from the early days of synthetic quartz crystal development and manufacturers will continue to use it in the future. Since industries began massproducing of synthetic quartz crystal, makers have developed quartz crystal products to meetchanging market demands, including the demand for optical parts. As the demand for quartz resonators continues to expand, users will issue more exacting requirements about size, precision and stability. Makers will have to escalate their quality control and growth control procedures.