Optimum Preventive Maintenance Policies for a Computer System with Restart

This paper considers a computer system where an operation is restarted when the system stops on some faults. The restart does not succeed every time. Three preventive maintenance (pm) models are considered: A) The pm is made at the scheduled time T. B) The pm is made at the K-th successful restart. C) The pm is made at the next scheduled time if the total number of successes of restart exceeds K. The availabilities of each model are obtained and the optimum pm policies are discussed.     

Determination of critical micelle concentrations of some nonionic surfactants by Keto-Enol tautomerism of benzoylacetoanilide

The absorbances of benzoylacetoanilide, keto-enol tautomer, dissolved in aqueous solution of several concentration ranges below and above the CMC of the incorporating surfactants. Below the CMC, the absorbance of the band at 250 nm due to the ketonic form showed hardly any change and that of the band at 320 nm due to the enolic form could not be observed. In contrast, above the CMC, the spectral band of the enolic form appeared, and the absorbance increased abruptly and that due to the ketonic form decreased gradually. The changes at the CMC in absorbance for these nonionic surfactants were distinctly observed by plotting the absorbance at 250 and 320 nm as a function of the concentration of surfactants. These changes at the CMC were very noticeable with nonionic surfactants as well as with ionic surfactants. The concentrations corresponding to break points for these surfactants were in fairly good agreement with the published data of the CMC of each surfactant. This method of keto-enol tautomerism using benzoylacetoanilide has been confirmed CMC for most anionic, cationic, and nonionic surfactants.     

Mechanism of carbonization of a semianthracite

The carbonization of a semi-anthracite which produced a domain texture of large isochromatic units was studied to elucidate the mechanism for this type of anisotropic development. The observation of a series of its carbonization residues at several temperatures indicated that the anisotropic domains appeared simultaneously and no stepwise growth was observable. However, its co-carbonization with decacyclene or A240 pitch followed the typical mesophase mechanism to give a flow or coarse-mozaic texture which was quite similar to that observed in the coke produced from its quinoline extract. In contrast, the residue after quinoline extraction retained on carbonization the same basic anisotropy as the coal. The structure of the original coal and the coke was studied by topological observation before and after quinoline and gasification etching. The results suggest that during carbonization the preordered structure of the semi-anthracite is slightly rearranged, with the aid of the quinoline-soluble matter, to become more highly ordered giving a domain texture which corresponds to the isochromatic anisotropic regions of its basic anisotropy.     

Inhibitory Effects of Saururus chinensis Extract on Receptor for Advanced Glycation End-Products-Dependent Inflammation and Diabetes-Induced Dysregulation of Vasodilation

Advanced glycation end-products (AGEs) and the receptor for AGEs (RAGE) are implicated in inflammatory reactions and vascular complications in diabetes. Signaling pathways downstream of RAGE are involved in NF-κB activation. In this study, we examined whether ethanol extracts of Saururus chinensis (Lour.) Baill. (SE) could affect RAGE signaling and vascular relaxation in streptozotocin (STZ)-induced diabetic rats. Treatment with SE inhibited AGEs-modified bovine serum albumin (AGEs-BSA)-elicited activation of NF-κB and could compete with AGEs-BSA binding to RAGE in a dose-dependent manner. Tumor necrosis factor-α (TNF-α) secretion induced by lipopolysaccharide (LPS)—a RAGE ligand—was also reduced by SE treatment in wild-type Ager^+/+ mice as well as in cultured peritoneal macrophages from Ager^+/+ mice but not in Ager^−/− mice. SE administration significantly ameliorated diabetes-related dysregulation of acetylcholine-mediated vascular relaxation in STZ-induced diabetic rats. These results suggest that SE would inhibit RAGE signaling and would be useful for the improvement of vascular endothelial dysfunction in diabetes.     

Transient photoinduced 'hidden' phase in a manganite

Photoinduced phase transitions are of special interest in condensed matter physics because they can be used to change complex macroscopic material properties on the ultrafast timescale. Cooperative interactions between microscopic degrees of freedom greatly enhance the number and nature of accessible states, making it possible to switch electronic, magnetic or structural properties in new ways. Photons with high energies, of the order of electron volts, in particular are able to access electronic states that may differ greatly from states produced with stimuli close to equilibrium. In this study we report the photoinduced change in the lattice structure of a charge and orbitally ordered Nd(0.5)Sr(0.5)MnO(3) thin film using picosecond time-resolved X-ray diffraction. The photoinduced state is structurally ordered, homogeneous, metastable and has crystallographic parameters different from any thermodynamically accessible state. A femtosecond time-resolved spectroscopic study shows the formation of an electronic gap in this state. In addition, the threshold-like behaviour and high efficiency in photo-generation yield of this gapped state highlight the important role of cooperative interactions in the formation process. These combined observations point towards a 'hidden insulating phase' distinct from that found in the hitherto known phase diagram.     

Pesticide adsorption by granular activated carbon adsorbers. 2. Effects of pesticide and natural organic matter characteristics on pesticide breakthrough curves

The principal objective of this study was to elucidate mechanisms by which NOM affects the adsorption of a nonpolar (simazine) and a polar (asulam) herbicide on activated carbon. Experiments were carried out in microcolumns that were continuously fed solutions containing NOM with different molecular weight (MW) distributions and intermittently solutions containing the same NOM plus simazine or asulam. The MW distributions of a groundwater NOM were altered by coagulation and ultrafiltration, which resulted in the preferential removal of high-MW, UV260-absorbing NOM. At a given NOM loading, the simazine removal efficiency was higher in the column that was preloaded with raw groundwater than in columns receiving coagulated or ultrafiltered water. In contrast, the asulam removal efficiency was similar for all three NOM solutions at a given NOM loading. Therefore, the results suggested that low-MW, UV260-absorbing NOM molecules competed directly with strongly adsorbing pesticides, such as simazine, for adsorption sites. For more weakly adsorbing pesticides, such as asulam, direct competition for adsorption sites originated not only from the strongly adsorbing, low-MW NOM, but also from more weakly adsorbing, higher-MW NOM. Consequently, the competing NOM fraction increases as the adsorbability of the SOC decreases, a result that was confirmed by adsorption data for additional pesticides of similar size. However, a smaller pesticide competed more effectively for adsorption sites than a larger pesticide of similar polarity, suggesting that the concentration of competing NOM decreases as the MW of the SOC decreases.     

Comparison between old and new methods for detection of allergenic substances (egg and milk)

The old ELISA method for detection of allergenic substances (egg and milk) in Kanagawa prefecture from 2003 to 2007, employed before improvement of the food allergen labeling system, yielded detection rates of 20% for egg and 30% for milk. In 2005, after improvement of the labeling system, the detection rate using the new ELISA in solutions containing 1% SDS and 7% 2-mercaptoethanol increased by about 10% for egg, but decreased by half for milk. There were 4 positive samples (over 10 μg/g) for both egg and milk proteins, on account of contamination by ingredients at the manufacturing line and the lack of proper food labeling. In 2009, the contamination levels of egg and milk proteins in labeled commercial foods were low. In a comparison between the new and old methods with the same samples, both the new ELISA and Western-blot analyses showed an increase in the detection rate of egg protein. In relation to milk protein, the detection rates were decreased with the new ELISA, although the ELISA detection rate and consistency rates with Western-blot analysis were increased. On the other hand, in the case of a protein content below 5 μg/g, it was impossible to determine ovomucoid and casein by Western-blot analysis.     

Numerical study for enhancement of laminar flow mixing using multiple confined jets in a micro-can combustor

To meet demands arising as a result of present trends towards miniaturization, an innovative design for promoting mixing enhancement in a miniature can combustor is investigated using an unstructured finite-volume technique. A multi-holed baffle plate is employed to create a ring of oxidizer jets surrounding a single fuel jet in parallel with the axis of the cylindrical chamber. The baffle plate is found to produce a dramatic improvement to the mixing performance when compared with simpler co-axial jet cases. Relatively small changes in geometry are found to have a major influence on mixing for laminar isothermal flow.     

Combined convection heat transfer in a channel with two ribs attached to one wall

Two-dimensional calculations were performed for combined convection heat transfer in a channel with two ribs attached to one wall, following a previous study on the forced convection case without buoyancy. The flow is heated from the surfaces of both ribs and the present study dealt with the two cases of buoyancy-assisted flow and buoyancy-opposing flow. The effect of Reynolds number, Re_L, and modified Richardson number, Ri^*, was examined keeping the space between ribs, σ, and blockage ratio, τ, constant (σ = 3.0, τ = 0.5). Increasing the magnitude of buoyancy, unsteady flows predicted by the present calculations are stabilized in both cases. Serious deterioration of Nusselt number on the second rib suddenly occurs in a certain range of Ri^* due to the flow stabilization. This is because flow unsteadiness plays an important role for heat transfer enhancement as was described in a previous study. However, in buoyancy-assisted flow, a similar deterioration of Nusselt number also appears on the second rib even if flow remains steady. This is caused by the disappearance of a strong rotating flow which exists in the cavity between both ribs and keeps the fluid in the cavity cooler. © 1999 Scripta Technica, Heat Trans Asian Res, 28(5): 379–394, 1999