A New Form of Rolling Contact Damage in Grease-Lubricated,Deep-Groove Ball Bearings

A new form of rolling contact damage was discovered in the fatigue tests of series 6206 deep groove ball bearings under pure radial load with grease lubrication. The appearance of the damage reveals a few cracks at right angles to the rolling direction of the ball, along with the formation of a dent about 20 μ m deep in the raceway surface. This is found to occur only on the stationary outer ring raceway and the ball surface and is distributed widely within the load zone. Furthermore, under the raceway surface several cracks propagating into the substrate at an angle of about 60-80 degrees relative to the raceway surface are observed not only under the damage site but also in other nearby locations. Only the cracks at the damage position open up to the surface. The grease used for the test contained a lithium complex thickener with mineral oil as the base oil with a kinematic viscosity of 141 mm²/s at 40°C. On the test bearings two pure radial load levels of 9.14 and 12.13 kN were applied. In order to prevent the occurrence of seizure at each load, the speed of the inner ring of the test bearing was maintained at 1800-2500 min^{? 1} and 600-800 min^{? 1}, respectively, to keep the outer ring circumference temperature below 65°C. It is suggested that the damage is caused by metal-to-metal contacts due to lubricant starvation under grease lubrication and to a decrease in oil film thickness due to local increases in temperature.     

Optical and electrical properties of indium tin oxide thin films sputter-deposited in working gas containing hydrogen without heat treatments

Polycrystalline thin films of indium tin oxide sputter-deposited in the working gas containing hydrogen of 0.3–1.5% exhibited transmittance of ≥ 80% for visible lights and blue-shift of ≥ 0.1 eV in the optical absorption energy. The film deposited in the gas containing hydrogen of 1% demonstrated almost flat temperature-dependent resistivity and the lowest resistivity of ≈ 1.5 × 10^? 4 Ω cm at room temperature. The carrier density showed an inverse V-shaped behavior with the maximum at the hydrogen concentration of 1%. The mobility stayed at almost constant below the hydrogen concentration of 1% and dropped rather rapidly above 1%.     

多晶YAG陶瓷的制备及力学性能

本实验采用共沉淀方法制备YAG微粉 ,Al和Y元素分布均匀 ,在 90 0℃煅烧 2h即可全部转变为YAG粉体 ,无过渡相 .15 0 0℃热压 1h可获得致密烧结体 ,其抗弯强度为 2 45MPa ,断裂韧性为 2 .0MPa·m1 /2 ,晶粒大小为 3～ 6μm ;14 0 0℃放电等离子烧结 5min可获得相对密度为 93 %的烧结体 ,其抗弯强度为 3 4 8MPa,断裂韧性为 2 .1MPa·m1 /2 ,晶粒大小为 1～ 2 μm .     

Growth and microstructure of Ba β-alumina films by laser chemical vapor deposition

Ba β-alumina films were prepared by laser chemical vapor deposition. Mostly single-phase Ba β-alumina films were obtained at 1125–1200 K and for an Al/Ba molar ratio of 12.4–16.6. BaAl₂O₄ and α-Al₂O₃ were codeposited with Ba β-alumina under Ba- and Al-rich conditions, respectively. The Ba β-alumina films consisted of hexagonal grains, and the (1 1 0)-oriented Ba β-alumina films had a fin-like columnar structure. The highest deposition rate reached 120 μm h^?1 at around 1200 K. A thin layer of Ba-rich superstructure was formed on the surface of the (1 1 0)-oriented columnar grains.     

Dimeric C34 Derivatives Linked through Disulfide Bridges as New HIV-1 Fusion Inhibitors

C34, a 34-mer fragment peptide, is contained in the HIV-1 envelope protein gp41. A dimeric derivative of C34 linked through a disulfide bridge at its C terminus was synthesized and found to display potent anti-HIV activity, comparable with that of a previously reported PEGylated dimer of C34REG. The reduction in the size of the linker moiety for dimerization was thus successful, and this result might shed some light on the mechanism of the suppression of six-helix bundle formation by these C34 dimeric derivatives. Addition of a Gly-Cys(CH₂CONH₂)-Gly-Gly motif at the N-terminal position of a C34 monomeric derivative significantly increased the anti-HIV-1 activity. This moiety functions as a new pharmacophore, and this might provide a useful insight into the design of potent HIV-1 fusion inhibitors.     

Methylcyclohexane production under fluctuating hydrogen flow rate conditions

Energy storage using liquid organic hydrogen carrier (LOHC) is a long-term method to store renewable energy with high hydrogen energy density. This study investigated a simple and low-cost system to produce methylcyclohexane (MCH) from toluene and hydrogen using fluctuating electric power, and developed its control method. In the current system, hydrogen generated by an alkaline water electrolyzer was directly supplied to hydrogenation reactors, where hydrogen purification equipment such as PSA and TSA is not installed to decrease costs. Hydrogen buffer tanks and compressors are not equipped. In order to enable MCH production using fluctuating electricity, a feed-forward toluene supply control method was developed and introduced to the system. The electrolyzer was operated under triangular waves and power generation patterns of photovoltaic cells and produced hydrogen with fluctuating flow rates up to 7.5 Nm³/h. Consequently, relatively high purity of MCH (more than 90% of MCH mole fraction) was successfully produced. Therefore, the simplified system has enough potential to produce MCH using fluctuating renewable electricity.     

Systematic packaging design tools integrating functional and environmental consequences on product life cycle: Case studies on laundry detergent and milk

This study presents systematic packaging design tools integrating functional and environmental consequences on product life cycle. To design packaging for sustainability, the trade-offs between functional and environmental aspects of packaging throughout the product life cycle should be considered. However, it is difficult for packaging designers to understand the overall trade-offs because the extent of the design consequences on the entire life cycle of packaging and its contents is unclear. We developed two tools for packaging design: the Life Cycle Association Matrix (LCAM) and the Function Network Diagram (FND). The following three steps, based on literature reviews and interviews with industrial experts, were applied. Firstly, we listed the product functions and design variables related to the functions as the attributes allocated to the product life cycle. Secondly, the attributes were connected appropriately based on causal relationships. Lastly, we identified the factors to support decision making in the packaging design procedure. As a result, the LCAM depicts the design consequences on the life cycle, and the FND determines the stakeholders affected by the design consequences. Two case studies were demonstrated to analyze the trade-offs by using our tools. In the case studies, a liquid laundry detergent bottle and a milk carton were redesigned. The tools identified the design consequences and stakeholders affected by the redesign of the usability and protective function for the detergent and milk cases, respectively. The results showed the significance of understanding the design consequences on the product life cycle by integrating the functional and environmental aspects.