Preparation of highly dispersed niobium oxide on silica by equilibrium adsorption method

Two series of Nb₂O₅/SiO₂ catalysts are prepared by an equilibrium adsorption method (type A) and a conventional evaporation to dryness method (type E). The loading amounts of type A catalysts were low ( ˜ 0.2 wt% as Nb₂O₅) and those of type E catalysts were varied from 0.1 to 10 wt%. UV/VIS diffuse reflectance spectra of the catalyst samples show that micro particles of Nb₂O₅) are present on the catalysts with high-loading and monomeric or oligomeric niobate species are present on the catalysts with low-loading. By analyzing luminescence spectra of the low-loading samples, we conclude that the type A catalyst contains monomeric NbO₄ tetrahedra and the type E catalyst oligomeric NbO₄ tetrahedra. Propene photo-oxidation on type A catalysts yields propene oxide selectively, formed on monomeric NbO₄, whereas the photo-oxidation on the type E catalyst with low-loading yields propanal selectively. Propanal is the product in decomposition of propene oxide on oligomeric NbO₄ tetrahedra.     

Selective partial oxidation of light alkanes over alkali-ion-modified silica-supported vanadium oxides excited with visible light

Alkali-ion (Na⁺, K⁺, and Rb⁺)-modified V₂O₅/SiO₂ irradiated with visible light catalyzes the partial oxidation of 2-methylpropane to form mainly propanone and 2-methylpropan-2-ol. The addition of alkali ions to V₂O₅/SiO₂ is essential to generate the active site that can be excited with visible light. It is confirmed that there are two types of reaction paths for the formation of 2-methylpropan-2-ol.     

Efficient identification of phosphorylation by mass spectrometric phosphopeptide fingerprinting

We describe a rapid and efficient method for the identification of phosphopeptides, which we term mass spectrometric (MS) phosphopeptide fingerprinting. The method involves quantitative comparison of proteolytic peptides from native versus completely dephosphorylated proteins. Dephosphorylation of serine, threonine, and tyrosine residues is achieved by in-gel treatment of the separated proteins with hydrogen fluoride (HF). This chemical dephosphorylation results in enrichment of those unmodified peptides that correspond to previously phosphorylated peptides. Quantitative comparison of the signal-to-noise ratios of peaks in the treated versus untreated samples are used to identify phosphopeptides, which can be confirmed and further studied by tandem mass spectrometry (MS/MS). We have applied this method to identify eight known phosphorylation sites of Xenopus Aurora A kinase, as well as several novel sites in the Xenopus chromosome passenger complex (CPC).     

Electrodeposition of Inorganic/Organic Hybrid Thin Films

Electrodeposition of inorganic compound thin films in the presence of certain organic molecules results in self‐assembly of various hybrid thin films with new properties. Examples of new discoveries by the authors are reviewed, taking cathodic formation of a ZnO/dye hybrid as the leading example. Hybridization of eosinY leads to the formation of highly oriented porous crystalline ZnO as the consequence of dye loading. The hybrid formation is a highly complicated process involving complex chemistry of many molecular and ionic constituents. However, electrochemical analyses of the relevant phenomena indicate the possibility of reaching a comprehensive understanding of the mechanism, giving us the chance to further develop them into industrial technologies. The porous crystals are ideal for photoelectrodes in dye‐sensitized solar cells. As the process also permits the use of non‐heat‐resistant substrates, the technology can be applied for the development of colorful and light‐weight plastic solar cells.     

A three-stage heuristic combined neural-network algorithm forchannel assignment in cellular mobile systems

A three-stage algorithm of combining sequential heuristic methods into a parallel neural network is presented for the channel assignment problem in cellular mobile communication systems in this paper. The goal of this NP-complete problem is to find a channel assignment to requested calls with the minimum number of channels subject to interference constraints between channels. The three-stage algorithm consists of: (1) the regular interval assignment stage; (2) the greedy assignment stage; and (3) the neural-network assignment stage. In the first stage, the calls in a cell determining the lower bound on the total number of channels are assigned channels at regular intervals. In the second stage, the calls in a cell with the largest degree and its adjacent cells are assigned channels by a greedy heuristic method. In the third stage, the calls in the remaining cells are assigned channels by a binary neural network. The performance is verified through solving well-known benchmark problems. Especially for Sivarajan's benchmark problems, our three-stage algorithm first achieves the lower bound solutions in all of the 13 instances, while the computation time is comparable with existing algorithms     

In-flight thermal treatment of soda-lime-silica glass powders for glass production by argon–oxygen induction thermal plasmas

In order to investigate the plasma–particle energy exchange dynamics and optimize the plasma discharge and particle parameters during in-flight thermal treatment of soda-lime-silica glass powders, a plasma–particle interaction model was developed. This model solved the conservation equations to predict the plasma temperature and flow fields, and then calculated the injected individual particle trajectories and temperature histories, and the particle source terms to take into account the plasma–particle interaction. It was noticed that particle injection significantly reduced the plasma temperature around the centerline of the torch and hence decreased the heat transfer to particles at higher carrier gas flow-rate and powder feed-rate. As a result the size and composition of quenched particles were affected significantly by the above factors. The simulated results were consistent with those of experiment, which provided valuable guidelines in optimizing the plasma discharge and particle parameters for the efficient thermal treatment of soda-lime-silica glass particles.     

Effect of sedimentary facies and geological properties on thermal conductivity of Pleistocene volcanic sediments in Tokyo,central Japan

When ground source heat pump systems are installed underground, an estimate of the thermal conductivity is required to determine the desired total length of the heat exchanger (U-tube). Many large cities in Asia are built on Quaternary sediments, but the thermal conductivity of these sediments is not well understood. To measure the thermal conductivity of Pleistocene volcanic sediments in Tokyo, Japan, we discuss methods of measuring thermal conductivity and factors influencing the thermal conductivity of volcanic sediment, which has low quartz content. The results obtained from experiments using a drill core, borehole data and artificial sediment samples are as follows: (1) values of thermal conductivity predicted using water content, porosity or sand content can be underestimated in volcanic sediment or sediments with large amounts of magnetic minerals; (2) magnetic minerals have a higher thermal conductivity than quartz, so there is a relationship between magnetic susceptibility and thermal conductivity: (3) comparison of thermal conductivity measurements performed using box- and needle-type probes showed that the values measured using the former are comparatively larger. This decrease in thermal conductivity is explained by formation of air-filled cracks when the needle penetrates the sediment, as air has a lower thermal conductivity than sediment.

     

A fuzzy‐based control method for smoothing power fluctuations in substations along high‐speed railways

The use of superconducting magnetic energy storage (SMES) for smoothing power fluctuations in a railway substation has been discussed. This paper proposes a smoothing control method based on fuzzy reasoning for reducing the SMES capacity at substations along high‐speed railways. The proposed smoothing control method comprises three countermeasures for the reduction of the SMES capacity. The first countermeasure involves modification of rule 1 for smoothing out the average electric power to its average values. The other countermeasures involve the modification of the central value of the stored energy control in the SMES and revision of the membership function in rule 2 for the reduction of the SMES capacity. The SMES capacity in the proposed smoothing control method is reduced by 49.5% compared to that in the nonrevised control method. Computer simulations confirm that the proposed control method is suitable for smoothing out power fluctuations in substations along high‐speed railways and for reducing the SMES capacity. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(2): 35–43, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21175     

Effects of dietary methionine and cystine on lipid metabolism in hepatoma-bearing rats with hyperlipidemia

Abnormal lipid metabolism and its restoration by dietary methionine (Met) and cystine (Cys) were studied in Donryu rats subcutaneously implanted with an ascites hepatoma cell line of AH109A. The hepatoma-bearing rats exhibited byperlipidemia characterized by rises in serum triglyceride and cholesterol levels. Decreased lipoprotein lipase (LPL) activities in epididymal adipose tissue, cardiac muscle, and gastrocnemius as well as increased fatty acid mobilization from adipose tissue were considered to be responsible for the hepatoma-induced hypertriglyceridemia, while increased hepatic cholesterogenesis and decreased steroid excretion into feces were thought to be responsible for the hepatoma-induced hypercholesterolemia. Dietary-supplemented Met or Cys reduced the AH109A-induced hypertriglyceridemia with suppression of fatty acid synthesis in the host liver. Met restored the fall of LPL activities, while Cys did not. Dietary Met or Cys also reduced the hypercholesterolemia with restoration of decreased bile acid excretion into feces. These results suggest that dietary Met or Cys is hypolipidemic in the hepatoma-bearing rats with slight differences in their modes of action.