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In 5-Axis Machining of impellers, interference problems with tool and neighboring surfaces often take place due to the narrow and deep gap between blades, so the problem of avoiding interference is very important. Also, because the efficiency of turbo machines can be maximized only when fluids smoothly flow due to the characteristics of the impeller, high quality of the machined surface is required. During 5-Axis machining of these impellers, the excessive local interference avoidance, necessary to avoid interference, leads to inconsistency of cutter posture, low quality of machined surface and increase of processing time. Therefore, in order to increase the efficiency of 5-Axis Machining of impellers, it is necessary to minimize the cutter posture changes and create a continuous tool path while avoiding interference. This study, by using an MC-space algorithm for interference avoidance and an MB-spline algorithm for continuous control, is intended to create a 5-Axis machining tool path with excellent surface quality and economic feasibility; finally, this study will verify the effectiveness of the suggested method through verification processing.

Rigid polyurethane foams (PUFs) were prepared from polymeric 4,4'-diphenylmethane diisocyanate (PMDI), polyether polyol, 1,4-butanediol, silicone surfactant, and distilled water. The properties of the synthesized PUF samples were investigated with differential scanning calorimetry, scanning electron microscopy, and a Universal testing machine. The density of the PUF was decreased from 173.7 to 41.7 kg/m³ with an increase in distilled water from 0.5 to 3.0 parts per hundred polyol by weight (php), respectively, with 0 php butanediol. The cell size of the PUF sample increased from 115 to 258 μm with an increase in distilled water from 0.5 to 3.0 php, respectively, with 10 php butanediol. From the results of the thermal analysis of the PUF sample, it was found that the glass-transition temperatures of the PUF samples were increased from 49.5 to 80.8°C with an increase in distilled water from 0.5 to 3.0 php, respectively, with 0 php butanediol. The results of the investigation of the mechanical properties of the PUF samples showed that the mechanical strength of the PUF samples was increased with the distilled water at equal density. The surfactant effect on the properties of the PUF was studied, and it was observed that the cell size of the PUF samples decreased from 360 to 146 μm with an increase in surfactant from 0 to 0.33 php, respectively. However, the cell size did not change significantly when the surfactant exceeded 0.33 php. The increase of the mechanical strength from 0 to 0.33 php surfactant was attributed to the decrease of the cell size of the PUF samples, and the decrease of the mechanical strength with more than 0.33 php surfactant might be due to the plasticized effect of the PUF samples. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 12–21, 2003

Rigid polyurethane foams (PUFs) were prepared from polymeric 4,4'-diphenylmethane diisocyanate, polyester polyol, 1,4-butane diol, silicone surfactant, hydrochlorofluorocarbon (HCFC) 141B, and distilled water. The properties and structure of the PUFs were investigated with differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and a universal testing machine. The density of the PUF blown by distilled water and/or HCFC 141B decreased from 175.7 to 28.2 kg/m³ with an increase of blowing agents. From the SEM results, the average cell size of the PUF blown by distilled water increased from 150 to 290 μm with the distilled water content. From the DSC results, the glass-transition temperature (Tg) of the PUF blown by distilled water increased from 85.7 to 101.7°C with increasing distilled water content, whereas the Tg of the PUF blown by HCFC 141B remained unchanged with HCFC 141B content. The compressive strength and modulus of the PUF blown by a mixture of distilled water and HCFC 141B was increased from 0.13 to 0.25 MPa and from 3.00 to 7.23 MPa, respectively, with the distilled water content at the sample density of about 44.0 kg/m³. The increase of the compressive strength and modulus of the PUF at the same density was related to the increase of the Tg from 86.0 to 100.9°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 486–493, 2001

Polyurethanes were synthesized using the high functional 4,4'-diphenylmethane diisocyanate (MDI), polyester polyol, and 1,4-butane diol. The synthesized polyurethanes were analyzed using differential scanning calorimeter (DSC), dynamic mechanical thermal analysis (DMTA), Fourier transform infrared (FTIR) spectrometer, and swelling measurement using N,N'-dimethylformamide. From the result of thermal analysis by DSC and DMTA, single Tgs were observed in the polyurethane samples at all the formulated compositions. From this result, it is suggested that the polyurethanes synthesized in this study have crosslinked structure rather than the phase-separated segmented structure because of the high functionality (f = 2.9) of the MDI. By annealing the polyurethane samples using DSC, the Tgs were increased by 4.7~16.0°C at the various annealing temperatures. From the results of FTIR and swelling measurement of polyurethanes, it is suggested that the increase of Tg of the polyurethanes by annealing is not due to increase of the hydrogen bond strength but mainly due to the increase of the crosslink density. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 624–630, 2000

It was demonstrated that UVB increases synthesis and expression of IL‐1α and GM‐CSF by keratinocytes. Upregulation of GM‐CSF by UVB is reported to be mediated by IL‐1α. However, regulation of IL‐1α and GM‐CSF by UVA is not well‐known. The purpose of the present study was to evaluate the effects of UVA on IL‐1α and GM‐CSF production. Here we used a competitive RT‐PCR for measuring cytokine gene expression in an epidermal cell line after UVA irradiation. IL‐1α and GM‐CSF mRNA did not show any change at 1 h and 6 h following exposure to UVA. After UVA irradiation, however, IL‐1α mRNA decreased and GM‐CSF mRNA increased at 24 h and the level of GM‐CSF in culture supernatant increased at 24 h and 48 h. Addition of antihuman IL‐1α neutralizing antibody to UVA irradiated cells did not prevent the increase of GM‐CSF mRNA expression. These results suggest that UVA radiation may induce GM‐CSF production through an IL‐1α independent pathway.

The inflammatory reaction in the human gastric mucosa to Helicobacter pylori could be initially triggered by an array of cytokines expressed in infected gastric epithelial cells. The spiral morphology and flagella of these organisms could increase their velocity in a viscous environment such as methylcellulose solution. The goal of this study was to determine whether modification of H. pylori motility could influence the expression of cytokine genes from gastric epithelial cells infected with H. pylori. Adherent human gastric epithelial cells were cultured and overlaid with methylcellulose solutions of varying viscosity. These epithelial cell layers covered with methylcellulose solution were inoculated with H. pylori. RNAs were then extracted from the gastric epithelial cells. Various cytokine gene expressions were assessed and quantified by reverse transcription-polymerase chain reaction (RT-PCR) and standard synthetic RNA. Cytokine proteins were also measured by enzyme-linked immunosorbent assay (ELISA). Expression of mRNA for interleukin(IL)-8 was upregulated in H. pylori-infected gastric epithelial cells overlaid with methylcellulose of 15 centipoise (cp) viscosity. The expression of mRNA for IL-lα, IL-8, monocyte chemotactic protein (MCP)-l and granulocyte macrophage colony-stimulating factor (GM-CSF) was also upregulated in H. pylori-infectedgastric epithelial cells overlaid with methylcellulose solution of the same viscosity. The number of molecules of the expressed cytokine transcripts also paralleled the amounts of protein secreted from gastric epithelial cells infected with H. pylori. These results suggest that methylcellulose solution (simulating the mucus layer in vivo) could increase contact of H. pylori with gastric epithelial cells by increasing its motility. This could result in the upregulation of mRNA for proinflammatory cytokines in gastric epithelial cells, therefore enhancing inflammatory reaction at H. pylori-infected sites.

This study developed a drying method and a dryer that are optimized for shiitake mushrooms. They are mainly being cultivated and consumed as food and medicine in Korea, Japan, China, and Southeast Asia. They generally contain lots of moisture. For this reason, the use of a dryer causes problems such as decomposition and spoilage, and natural dry processing is preferred. To resolve these problems, various drying methods have been proposed (e.g. hot air drying, heat pump vacuum drying) but there has been a difficulty in maintaining a medium-temperature range of 30 to 40degC, the optimal temperature environments for retaining their main components. The study developed a 2-stage decompresses resistive heat pump dryer that can operate also in medium-temperature environments - existing decompresses heat pump dryers have been able to operate only in high-temperature environments. A dryer optimized for shiitake mushrooms that are being produced and distributed in large quantities was proposed, and the utility of the machine was proved through experiments.

NITE-SiC, SiC/SiC qualification of environmental resistance in various conditions is on-going toward early utilization in advanced energy and aero-space systems. Multi-layered SiC/SiC composites for preventing environmental attacks to pyrocarbon interphase was provided. Thermal exposure test in air and liquid metal(Pb and Li-Pb) compatibility test were carried out. It was confirmed the significant loss of PyC interphase in SiC/SiC composites. In case of Li-Pb-layered SiC/SiC composites, an attack of air and liquid metal has been sucessfuly supressed by surface SiC layer

Large volumetric shrinkage (~50 Vol%) occurs during ceramic matrix composites fabrication by hot-pressing due to infiltration and densification process of powder for matrix formation, resulting in unfortunately significant fiber-architecture and -strength damage. This study tries to explore damage-less near-net shaping technique by preform densification before hot-pressing in Nano-Infiltration and Transient Eutectic-phase (NITE) process. In particular, effects of preform densification for the damage-less near-net shaping, important influencing elements such as fiber-architecture, microstructural integrity and homogeneity, and composite's mechanical properties were evaluated using simple shaped (plate) and complex shaped composites. The preform densification demonstrated protective fiber-architecture in complex shaped composites and enhanced composites' density to 2.77/cm3 and ultimate bending strength to [?]200 MPa in simple shaped composites, owing to significantly reduced volumetric shrinkage.

Organization of Advanced Sustainability Initiative for Energy System/Material (OASIS), at Muroran Institute of Technology is now intensively enforcing its efforts for industrialization of advanced SiC/SiC composites and SiC based composites by fabrication system integration of NITE method. This paper provides the brief review of the activities at OASIS, where prototype production line of green sheets and prepreg sheets are under installation. The near-net shaped preforms with the NITE green-sheets and prepreg-sheets are made into near-net shape components for potential applications under consideration by HIP and Pseudo-HIP. Aiming at the near term utilization, SiC/SiC hybrid structures with metallic materials, such as steels and other refractory metals, were fabricated with promising results. Trial to reduce the production cost has been continued.

For nuclear and fusion materials R&D, high dose neutron irradiation at very high temperature is one of the most important and challenging techniques. As the part of Japan/EU Broader Approach (BA) program for fusion, International Fusion Materials Irradiation Facility/Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) project is on-going. Where, High Flux Test Module (HFTM) design aiming up to 1000degC has been intensively investigated. Innovative SiC/SiC and tungsten embedded SiC/SiC (W/SiC/SiC) heaters have been recognized potential and promising candidates. These heaters were fabricated successfully by NITE method and were evaluated. The SiC/SiC heater showed weak temperature dependence up to 1000degC on in-plane electrical conductivity. Irradiation capsule for heater performance evaluation under neutron irradiation in Belgian Reactor 2 (BR2) is also under preparation. The results of heater performance and basic properties evaluation and of underlying microstructure behavior analysis are provided.

Although, SiC/SiC composites are very attractive for applications at high-temperature including advanced nuclear fusion/fission plants, their high material cost has been one of biggest issues to be utilized. In the neutron irradiation environments, high crystallinity of SiC fibers and matrix is essential to stabilize the mechanical properties, but the expensive crystallized SiC fibers may enhance the cost of material. As a potential option from the cost down aspect, utilization of amorphous SiC fibers was planned. This paper concerns about the radiation damage tolerance of SiC/SiC with amorphous SiC fibers as starting reinforcing fibers. The crystallization procedure of amorphous SiC fibers was investigated during thermal treatments, and a new NITE-SiC/SiC, called as IC-NITE (IC stands for "in-situ" crystallized), composite was produced. Its radiation damage behaviour and microstructural stability were examined by a heavy ion irradiation experiment and TEM.