Ammonia present in the product gas from coal gasification may increase NOx emissions from IGCC systems. A fixed bed reactor was used to study the effect of calcined limestone (CaO) on NH3 decomposition and reaction of NH3 and NO. Reactions at temperatures to 900°C in helium and in gas compositions typical of air‐blown gasifiers were studied. Although CaO enhanced ammonia decomposition in helium, reaction in the gasification atmosphere resulted in the loss of this catalytic activity. Increasing the total pressure further reduced the rate of NH3 decomposition. CaO enhanced conversion of NO to NH3 in gasification atmospheres.

In this paper, a high rigidity and high speed rotating mechanism using a new concept hydrodynamic bearing in X-ray tube for high speed computed tomography is proposed. In order to obtain both the stability and the high load carrying capacity, the hydrodynamic bearing lubricated by liquid metal (Gallium alloy), named as the hybrid hydrodynamic bearing generates the lubricating film by wedge effect on the plane region between the spiral grooves under high loading condition. The parallelism between the bearing and the rotating body can be secured by optimizing the rigidity distribution of stationary shaft in the proposed rotating mechanism. By carrying out the fundamental design by numerical analyses, it has been made clear that the hybrid hydrodynamic bearing and the rotating mechanism are suitable for the X-ray tube used in the CT with ever-increasingly scanning speed.

Even though solid lubricants or low-volatile greases are used for lubrication of mechanical equipments in space satellites, the life of grease is longer than that of solid lubricants because of the hydrodynamic effects and replenishment. New grease using multiply alkylated cyclopentane (MAC) as base oil was developed for space applications. In this paper, the lubrication characteristics of the new grease have been investigated by experiments using the basic friction tester under high vacuum condition. The results clearly show that the difference of thickener influences the lubrication characteristics even if the greases consist of the same base oil, and MAC grease used with non-soap urea thickener was superior to the others.

Omika-cho, Hitachi-shi, Japan Results from a custom-built experimental volatilisation apparatus are presented. The apparatus consists of a tubular furnace to volatilise and then entrain the volatilised species into a cooled segment to reprecipitate for collection. This design allows for meticulous collection of the volatilised species, which are then analysed with atomic absorption spectroscopy. This paper includes an evaluation of the apparatus and a comparative study of the temperature dependence of Cs volatilisation from two commercial adsorbents. The Cs volatilisation from A-51 JHP and IE-96 was examined from 600 • C to 1000 • C. At 1000 • C the relative volatilisation is found to be 1.67% for A-51 JHP and 0.097% for IE-96. As the adsorbents require immobilisation contain volatile Cs species, the temperature dependence of this behaviour is important as it will affect Cs retention during the immobilisation process. The evaluation of the volatilisation apparatus showed it to be a reliable method to measure volatisation behaviour from adsorbents.

Sealing devices are needed to prevent dust and water invading the positioning mechanisms of outdoor equipment. The frictional resistance generated by the seal frequently obstructs the smooth motion of the mechanism. The friction properties for high-speed and precision control mechanisms are required to be low and stable without lowering the sealing performance. In this study, the influence of the surface conditions of seal gland for PTFE sliding seal on friction properties was investigated experimentally. As a result, it has been found that the suitable surface condition of the seal gland for a high-speed and precision control mechanism is the electroless-nickel-plated surface of 0.1 μm Ra.