Effect of oil supply on fretting wear

Fretting wear of lubricated flat steel surfaces (100 mm × 100 mm) was studied using a specially prepared test rig. The amplitudes of reciprocating sliding and the apparent contact pressure were 0.1–0.75 mm and 10 MPa respectively. The specimen surfaces were given various heat treatments and were mesh grooved for oil supply. Gear oil was fed to the sliding surfaces. Ungrooved surfaces gave severe fretting wear under the experimental sliding conditions used. However, significant reduction in fretting wear was obtained by grooving the surface. The effect could be obtained only when the spacing between the grooves was small, presumably because the oil was fed to the whole contact region owing to the smaller spacing.     

Time averaged distribution of a discrete-time quantum walk on the path

The discrete time quantum walk which is a quantum counterpart of random walk plays important roles in the theory of quantum information theory. In the present paper, we focus on discrete time quantum walks viewed as quantization of random walks on the path. We obtain a weak limit theorem for the time averaged distribution of our quantum walks.     

Intracerebroventricular Treatment with 2-Hydroxypropyl-β-Cyclodextrin Decreased Cerebellar and Hepatic Glycoprotein Nonmetastatic Melanoma Protein B (GPNMB) Expression in Niemann–Pick Disease Type C Model Mice

Niemann–Pick disease type C (NPC) is a recessive hereditary disease caused by mutation of the NPC1 or NPC2 gene. It is characterized by abnormality of cellular cholesterol trafficking with severe neuronal and hepatic injury. In this study, we investigated the potential of glycoprotein nonmetastatic melanoma protein B (GPNMB) to act as a biomarker reflecting the therapeutic effect of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) in an NPC mouse model. We measured serum, brain, and liver expression levels of GPNMB, and evaluated their therapeutic effects on NPC manifestations in the brain and liver after the intracerebroventricular administration of HP-β-CD in Npc1 gene-deficient (Npc1^−/−) mice. Intracerebroventricular HP-β-CD inhibited cerebellar Purkinje cell damage in Npc1^−/− mice and significantly reduced serum and cerebellar GPNMB levels. Interestingly, we also observed that the intracerebral administration significantly reduced hepatic GPNMB expression and elevated serum ALT in Npc1^−/− mice. Repeated doses of intracerebroventricular HP-β-CD (30 mg/kg, started at 4 weeks of age and repeated every 2 weeks) drastically extended the lifespan of Npc1^−/− mice compared with saline treatment. In summary, our results suggest that GPNMB level in serum is a potential biomarker for evaluating the attenuation of NPC pathophysiology by intracerebroventricular HP-β-CD treatment.     

Measurement of in-plane deformation by surface inclusion (proposed measuring method and some experimental results)

A new measuring technique is proposed for measuring the in-plane deformation of soft metal surfaces when indented by a hard indenter, using the displacement of inclusions on the soft metal surface as sensors. In in-plane deformation, the soft metal surface flows along the hard indenter surface. In this paper, the principle of this new measuring technique is explained and some example measurements obtained from the experiments with aluminum and copper beryllium alloy plates, are presented.     

Direct imaging of native passive film on stainless steel by aberration corrected STEM

A cross-section of a native passive film on a commercial type 304 stainless steel was directly imaged and characterized using an aberration corrected STEM-EDS in combination with FIB sectioning. The technique demonstrated an enrichment of Cr in the lower part of the passive film, and a depletion of Cr and an enrichment of Ni in the matrix side closest to the passive film/matrix interface in accordance with previous studies, further proving the advantage of this technique with respect to spatial resolution. That is, the STEM-EDS showed a compositional profile with higher spatial resolution compared to AES which has been mainly used for this type of investigation. The technique will be applicable to the investigation of nm to sub-nm compositional fluctuation of passive films, steel surfaces adjacent to inclusions and grain boundaries postulated as an initiating site of pitting corrosion or stress corrosion cracking (SCC).     

Evaluation of biological activities of a groundnut (Apios americana Medik) extract containing a novel isoflavone

Groundnut (Apios americana Medik) contains a novel isoflavone, genistein-7-O-gentiobioside. In the present study, we examined the biological activities of an alcohol extract of groundnut containing genistein-7-O-gentiobioside as the main component. Although the groundnut extract by itself did not show antioxidative activity, it drove the antioxidative system in cells. Pretreatment of human breast carcinoma MCF-7 cells for 24 h with the groundnut extract and soybean isoflavone increased gene expression of heme oxygenase-1 (HO-1), a major antioxidative stress enzyme. These groundnut extract-treated cells showed antioxidative activity against free radicals derived from a radical initiator. Pretreatment of cells with 100 μg/mL groundnut extract prevented the depletion of glutathione by the radical initiator; however, treatment with 100 μg/mL of soybean isoflavone injured the cell membrane, indicating that glutathione might be released to the extracellular environment. These results suggest that the groundnut extract had isoflavone-like activity. Like soybean, groundnuts are a good source of isoflavones.     

Microstructure of organic–inorganic composite coatings studied by TEM and XANES

Chromate coatings on Zn or Zn alloy coated steel sheets often include silica for the aim to improve corrosion resistance. In the case of dry-in-place chromate coatings containing acrylic resin (hereafter referred to as an organic–inorganic composite coating), an addition of silica, however, did not show an improvement in corrosion resistance. The microstructures of the organic–inorganic composite coatings were observed by transmission electron microscopy (TEM) and the chemical states of Cr were investigated by the total electron yield X-ray absorption near edge structure (TEY-XANES) method. TEM samples were successfully prepared by dry ultramicrotomy preventing water-soluble components in the coatings fromdissolving out. TEY-XANES revealed the chemical states of components even in the organic matrix. Using these methods, it was found that the addition of silica changed just the morphology of the chromium compound in the organic–inorganic composite coating but not the chemical state of Cr. This is a reason for the addition of silica being not effective at improving corrosion resistance. The combination of dry ultramicrotomy-TEM and TEY-XANES spectroscopy was proven to be a powerful tool for characterizing organic–inorganic composite coatings.     

Spatio-temporal distribution of rice phenology and cropping systems in the Mekong Delta with special reference to the seasonal water flow of the Mekong and Bassac rivers

Multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS) data was used to estimate the spatial distribution of heading date and rice-cropping system employed in the Mekong Delta relative to seasonal changes in water resources in 2002 and 2003. We improved a Wavelet-based Filter for determining Crop Phenology (WFCP) and developed a Wavelet-based Filter for evaluating the spatial distribution of Cropping Systems (WFCS) to the interpretation of MODIS time-series data to determine the spatial distribution of rice phenology and various rice-cropping systems from the seasonal Enhanced Vegetation Index (EVI) data. The findings correspond well the physical characteristics of the cropping system in the Mekong Delta, which have changed over time in response to localized and seasonal changes in water resources. One such example is the double-irrigated rice-cropping system commonly employed in the upper Mekong Delta in the dry season to avoid damage due to the subsequent floods. The shortage of suitable irrigation water and intrusion of saline water in the coastal regions during the dry season has constrained the practice dry-season cropping and has meant that the double- and single-rainfed rice-cropping systems are employed in the rainy season. A triple-irrigated rice-cropping system is used in the central part of the Mekong Delta which is located midway between the flood-prone and salinity intrusion areas. Analysis of annual changes in the rice cropping systems between 2002 and 2003 showed that the triple-cropped rice expanded to the flood- and salinity-intrusion areas. This expansion indicates that the implementation of measures to limit the extent of flooding and salinity intrusion by improved farming technologies and improvements in land management. The heading dates in the upper Mekong Delta in 2003 were earlier than in 2002 by approximately 20 to 30 days. The reasons for this would be due to decreased flood runoff in 2002 compared to 2001, and implementation of government policies regarding early sowing of dry-season crops. Subsequent analysis of the MODIS data confirmed that the spatial distribution of rice-cropping systems was closely related to seasonal changes in river runoff regime in the Mekong Delta.     

Complexation of pepsin poly(ethylene glycol)

Summary Complexation of porcine pepsin (or pepsin A) (EC.3.4.23.1) with poly(ethylene glycol) (PEG) in an aqueous solution was studied as a function of pH and PEG concentration. The addition of PEG increased the reduced viscosity of the enzyme solution at pH 3 but not at pH 4.5. An increase in pH was observed by mixing both PEG and enzyme solutions which were previously adjusted to pH 3. Under conditions of pH 2.5–3 and 50°C, PEG contributed to an increase in the hydrolyzing activity of pepsin towardN-acetyl-l-phenylalanyl-3,5-diiodo-l-tyrosine. These results indicate that pepsin forms a water-soluble complex with PEG mainly through hydrogen bonds between the carboxyl groups in the enzyme and the ether groups in PEG.     

Performance evaluation of solar-powered air conditioner

With present-day global environmental and energy problems, high expectations exist for solar power generation to reduce carbon dioxide generated by the consumption of fossil fuels. On the other hand, power consumption in residential homes is increasing every year. Among the many household appliances, the power demand for air conditioners increases dramatically during the summer, particularly in the afternoons. Since this pattern closely matches the output pattern of solar cells, it should be possible to combine a photovoltaic array with an air conditioner to decrease the energy consumption within the home. In this paper a residential solar-powered air conditioner is developed that operates through a combination of photovoltaic array and commercial power. Also, the configuration and specification of the solar-powered air conditioner are described, and its performance characteristics are examined by analysis of the characteristics of the solar cell.