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In additive manufacturing (AM) processes, three dimensional (3D) objects can be produced by using 3D modelling data. Nowadays, a laser powder bed fusion (LPBF) is becoming popular in AM processes for producing metal parts in the industry field. In general, surface irregularities such as spatter and cavity are generated on the surface. These surface irregularities would lead to increase in surface roughness and reduction in surface fatigue strength. Therefore, surface finishing method is required to repair these surface irregularities. Shot blasting, milling and grinding are typically used for the surface finishing of AMed metal parts. However, these methods have some problems such as remaining of shot grain, tool wear and long processing time. On the other hand, in a large-area electron beam (EB) irradiation method developed recently, high energy density of EB can be obtained without focusing the beam. Therefore, the large-area EB with a diameter of about 60 mm can be used for melting and evaporating material surface instantly, and highly efficient surface finishing of metals such as mold steels and biomaterials was possible. It is expected that the spatter and cavity on the AMed metal parts can be removed in short time by the large-area EB irradiation. In this study, the possibility of surface repairing and surface smoothing for AMed metal parts by large-area EB irradiation is investigated. Then, the mechanism of surface repairing and surface smoothing is also discussed by observation of surface and cross-sectional microstructure. Experimental results show that surface irregularities such as spatter and cavity can be completely repaired in a few minutes by the EB irradiation. Furthermore, bead shape on AMed metal surface is removed with high number of EB irradiation, and surface roughness is significantly decreases. Therefore, surface repairing and surface smoothing for AMed metal parts can be efficiently done by large-area EB irradiation.

Citric acid production from xylan and xylan hydrolysate was done by Aspergillus niger Yang no. 2 cultivated in a semi-solid culture using bagasse as a carrier. Yang no. 2 produced 72.4 g/l and 52.6 g/l of citric acid in 5 d from 140 g/l of xylose and arabinose, respectively. Yang no. 2 produced 51.6 g/l of citric acid in 3 d from a concentrated xylan hydrolysate prepared by cellulase treatment, containing 100 g/l of reducing sugars. Moreover, Yang no. 2 directly produced 39.6 g/l of citric acid maximally in 3 d from 140 g/l of xylan.

Nine aborted fetuses and one newborn calf, diagnosed as Chlamydia psittaci (C. psittaci) infection, were pathologically examined. The characteristic lesions in the liver were focal necrosis in 9 aborted fetuses and granulomatous necrotic foci in the newborn calf. Moderate numbers of intranuclear inclusion bodies were found in necrotic foci of the liver, spleen, thymus, lymph nodes, adrenal gland, kidney, lung and forestomach. Immunohistologically, a small number of C. psittaci antigens was demonstrated in necrotic foci of the liver and correlated with distribution of elementary bodies. Moderate numbers of infectious bovine rhinotracheitis (IBR) virus antigens were also detected in degenerating and necrotizing parenchymal cells in various organs and correlated with distribution of intranuclear inclusion bodies. Thus, these aborted bovine fetuses and newborn calf were interpreted as being dually infected with C. psittaci and IBR virus during pregnancy.