High-resolution imaging of zeolite with aberration-corrected transmission electron microscopy

We demonstrated high-resolution imaging of atomic columns in zeolite frameworks with spherical aberration-corrected transmission electron microscopy (AC-HRTEM). An MFI-type zeolite was observed by AC-HRTEM with optimized optical setup. Compared with the conventional imaging mode based on a positive spherical aberration, the negative spherical aberration imaging (NCSI) mode sharpened image contrasts at atomic column positions. The projected atomic columns of zeolite are so complex that sharp image contrast can help to distinguish each atomic column position

Contribution of Pore-Connectivity to Permeation Performance of Silicalite-1 Membrane; Part II, Diffusivity of C₆ Hydrocarbon in Micropore

This study investigated the permeation behaviors of n-hexane and 2-methylpentane through two-types of silicalite-1 membranes that have different pore-connectivity. The permeation mechanisms of these hydrocarbons were able to be explained by the adsorption–diffusion model. In addition, the fluxes through silicalite-1 membranes could be expressed by the modified Fick’s first law. The hydrocarbon fluxes through S-1S with better pore-connectivity were ca. 3–20 times larger than those through S-1M with poor pore-connectivity. For these membranes with different pore-connectivity, the activation energy of diffusion of n-hexane was 17.5 kJ mol−1 for the membrane with better pore-connectivity and 18.0 kJ mol−1 for the membrane with poorer pore-connectivity, whereas for 2-methylpentane it was 17.9 and 33.0 kJ mol−1, respectively. We concluded that the pore-connectivity in silicalite-1 membrane significantly influences the molecular diffusivities

AN APPLICATION OF A PRESSURE INTENSIFIER USING AN OIL HAMMER TO A HYDRAULIC CYLINDER OF A CONSTRUCTION MACHINE

ABSTRACT The active utilization of the pressure rise phenomenon of an oil hammer and a new type of hydraulic pressure intensifier using an oil hammer were proposed and developed. In this research, an application of this intensifier to a hydraulic cylinder of a construction machine is studied through experimentation and simulation. High pressure is generated when the fluid flow through the pipeline is shut quickly by the solenoid operated valve at the downstream end. If the fluid is taken out through the check valve when the pressure is high, much higher-pressure fluid than the supply is obtained. Therefore the pressure is intensified. The purpose of this research is to help apply this device to industrial machinery. The necessary level of increased pressure is thought to be around 30MPa to apply it to an actual machine. We intend to find a suitable pipeline length and diameter, in order that low pressure supplied by a pump may be increased to the necessary high pressure by an oil hammer