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Titanium aluminide (TiAl) alloy is attracting attention in the automobile and aviation industries as a promising lightweight heat-resistant alloy material. Parts used in high-temperature environments must have ductility and toughness at room temperature in addition to high strength at high temperatures, however, some alloys, such as TiAl alloys, are known to be difficult materials for casting and machining. Recently, manufacturing processes using additive manufacturing (AM) have been studied to solve these problems. In the present research, the effect of energy density during the AM process on surface roughness and on the strength of the built parts was studied by changing build parameters. As the energy density increased, the porosity and surface roughness decreased. Additionally, higher energy density tended to increase the fraction of lamellar structure. It was found, however, that an increase in lamellar structure does not necessarily lead to any improvement in tensile or creep strength at 750°C. We found that a constant energy density of 15 J/mm³ showed better tensile and creep properties than those of the standard parameter. Our results suggest that it is important to optimize the parameters according to the required properties of the parts. [ABSTRACT FROM AUTHOR]

Cry toxins from Bacillus thuringiensis (Bt) have been extensively applied in agriculture to substitute the use of chemical insecticides. We have previously reported the use of a coexpression system in which late embryogenesis abundant (LEA) peptides under the control of the lac promoter increase the expression of insecticidal proteins in Bt. The use of lactose to induce the expression of LEA peptides may be a desirable alternative to isopropyl b-D-thiogalactopyranoside, the most frequently used inducer for recombinant protein expression. In this study we investigated the use of lactose as an inducer for optimal protein expression. We observed enhanced insecticidal Cry protein expression by applying a simple technique based on intermittent induction, and then optimized concentration and the point of induction time from the 11th h to the 15th h. Our data suggest that intermittent induction of lactose might be a new technique for the enhancement of bacterial protein expression. [ABSTRACT FROM AUTHOR]