A Study about the Effect of Space Size on the Individual Distance

This study is the design guidelines for the living space with robots. The study can be applied to the architectural planning and focused on the basic environmental primary factor. The authors focused on space size, specifical distance from the wall in the front direction, position, and distance between an individual as factors affecting individual distance. The authors research the distances a small mobile robot moves to a six mats space compared with that toward a distances 5 m or more （space less physical factors）. The following three results were obtained： （1） The individual distance is smaller than 30 cm in both the approach angle in the experiment space of six mats; （2） The distance from the wall in the front increased, and the individual distance between a participant and a robot also increased; （3） In terms of body position, the upright positioning was clarified and the individual distance was small.     

Rapid and continuous hydrothermal synthesis of metal and metal oxide nanoparticles with a microtube-reactor at 523 K and 30 MPa

A flow-through apparatus with a microtube-reactor has been developed for rapid and continuous hydrothermal synthesis. Heat-up time of starting solution to 523 K is within 0.08 s and this promises rapid nucleation of nanoparticles compared with conventional batch reactor. Continuous production of Ag, Fe₂O₃, TiO₂, and ZrO₂ particles from metal salts aqueous solution was performed at 523 K and 30 MPa with the reactor. Nanoparticles having an average particle size and a coefficient of variation less than 5.4 nm and 0.22 could be continuously obtained.     

Microstructural evolution and superplasticity of rolled Mg-9Al-1Zn

Microstructural evolution and superplasticity of a Mg-9Al-1Zn alloy rolled at 673 K were investigated at 573 K and 1.5×10⁻³ s⁻¹. The grain size of the as-rolled Mg alloy was 39.5 μm. However, the grain size of the specimen deformed to a true strain of 0.6 was 9.1 μm. The grain refinement was attributed to dynamically continuous recrystallization during an initial stage of tensile test. Stabilization of subgrain boundaries by fine particles and stimulation of continuous recrystallization by prior warm-deformation were not needed to attain dynamically continuous recrystallization in the Mg alloy. As a result of the grain refinement, the rolled Mg alloy exhibited superplastic behavior.     

Electroconductive ceramic tooling for dry deep drawing

Large use and waste of lubricating oil has become a very serious environmental issue. Hence, oil-free metal forming is one of the most promising solutions to this issue. Among them, ceramic tooling is proposed because of its good tribological properties. Its feasibility for dry deep drawing has been studied in laboratory; ceramic tooling is thought to be applicable to dry deep drawing. However, the workability of ceramics in tooling preparation is inferior to that of alloy tool steel. In the present paper, electroconductive ceramics are proposed as an alternative tool material. The electroconductive ceramic tooling is shaped by electric discharge machining such as wire electric discharge machining, die sinking electric discharge, and so forth; any shape of tools can be easily accommodated by these methods. The workability of electroconductive ceramics by electric discharge machining as well as the deep drawability with electroconductive ceramics tooling is experimentally evaluated. Selection of electric conditions for electric discharge machining influences the surface finish quality of electroconductive ceramics. Zirconia-based electroconductive ceramic die has an equivalent deep drawability in dry to conventional SKD11 die with lubricant.