Biotransformation of l‐menthol by twelve isolates of soil‐borne plant pathogenic fungi (Rhizoctonia solani) and classification of fungi

The microbial transformation of l‐menthol ( 1 ) was investigated by using 12 isolates of soil‐borne plant pathogenic fungi, Rhizoctonia solani (AG‐1‐IA Rs24, Joichi‐2, RRG97‐1; AG‐1‐IB TR22, R147, 110.4; AG‐1‐IC F‐1, F‐4, P‐1; AG‐1‐ID RCP‐1, RCP‐3, and RCP‐7) as a biocatalyst. Rhizoctonia solani F‐1, F‐4 and P‐1 showed 89.7–99.9% yields of converted product from 1 , RCP‐1, RCP‐3, and RCP‐7 26.0–26.9% and the other isolates 0.1–12.0%. In the cases of F‐1, F‐4 and P‐1, substrate 1 was converted to (?)‐(1S,3R,4S,6S)‐6‐hydroxymenthol ( 2 ), (?)‐(1S,3R,4S)‐1‐hydroxymenthol ( 3 ) and (+)‐(1S,3R,4R,6S)‐6,8‐dihydroxymenthol ( 4 ), which was a new compound. Substrate 1 was converted to 2 and/or 3 by RRG97‐1, 110.4, RCP‐1, RCP‐3 and RCP‐7. The structures of the metabolic products were elucidated on the basis of their spectral data. In addition, metabolic pathways of the biotransformation of 1 by Rhizoctonia solani are discussed. Finally, from the main component analysis and the differences in the yields of converted product from 1 , the 12 isolates of Rhizoctonia solani were divided into three groups based on an analysis of the metabolites. Copyright © 2003 Society of Chemical Industry     

Effect of Milling on Slip Casting of Partially Stabilized Zirconia

Specimens of partially stabilized zirconia were slip cast from aqueous suspensions and sintered at 1500°C for 3 h. The relative density of the cast specimens and the firing shrinkage of the sintered specimens depend on the milling time for the suspension. Vickers hardness and K_IC values of 11.46±s0.07 GN/m² and 6.10 ±0.04 MN.m^3/2, respectively, were obtained for all sintered specimens. The dispersion of the suspension is important in increasing the relative density of the cast specimens.     

Pool boiling on a superhydrophilic surface

Titanium Dioxide, TiO₂, is a photocatalyst with a unique characteristic. A surface coated with TiO₂ exhibits an extremely high affinity for water when exposed to UV light and the contact angle decreases nearly to zero. Inversely, the contact angle increases when the surface is shielded from UV. This superhydrophilic nature gives a self-cleaning effect to the coated surface and has already been applied to some construction materials, car coatings and so on. We applied this property to the enhancement of boiling heat transfer. An experiment involving the pool boiling of pure water has been performed to make clear the effect of high wettability on heat transfer characteristics. The heat transfer surface is a vertical copper cylinder of 17 mm in diameter and the measurement has been done at saturated temperature and in a steady state. Both TiO₂-coated and non-coated surfaces were used for comparison. In the case of the TiO₂-coated surface, it is exposed to UV light for a few hours before experiment and it is found that the maximum heat flux (CHF) is about two times larger than that of the uncoated surface. The temperature at minimum heat flux (MHF) for the superhydrophilic surface is higher by 100 K than that for the normal one. The superhydrophilic surface can be an ideal heat transfer surface. Copyright © 2002 John Wiley & Sons, Ltd.     

二垩英与资源回收-Ⅰ考虑到二垩英生成的资源与能量回收基础研究

目前在日本,存在大量工业垃圾,包括各种塑料制品,ASR(汽车破碎垃圾),含有毒PCB(多氯联苯)的110变压器和PVC(聚氯乙稀)制品等.而来自城市垃圾焚烧炉的废气含有大量能量.因此,在充分考虑环境、避免二垩英生成的同时,安全回收来自工业垃圾、城市和/或工业垃圾焚烧炉的资源和能量是个非常重要的课题,这也将对抑制CO2排放作出贡献.正确地阐明焚烧过程中二垩英的生成机理及详细研究含少量二垩英的焚烧废气在冷却过程中大量形成二垩英的临界温度是项很重要的工作.解决这个问题可有效实现资源和能量的回收.本报告介绍日本在二垩英排放方面目前采取的对策和存在的问题以及大阪大学为阻止二垩英生成所做的基础研究工作.     

Effect of surfactants on phenol removal by the method of polymerization and precipitation catalysed by Coprinus cinereus peroxidase

The removal of phenol by peroxidase‐catalysed polymerization was examined using Coprinus cinereus peroxidase in the presence of surfactants. The non‐ionic surfactants with poly(oxyethene) residues, Triton X‐100, Triton X‐405 and Tween 20, enhanced the phenol removal efficiency at a level similar to high relative molecular mass poly(ethylene glycol) (relative molecular mass 3000). Although the improvement in the removal efficiency was less than that of Triton X‐100, Span 20, sodium lauryl sulfate (SDS) and lauryl trimethylammonium bromide (DTAB) also enhanced the removal efficiency. The requirement of the enzyme for almost 100% removal of 100 mg dm^?3 phenol decreased to one‐fourth by the addition of 30 mg dm^?3 Triton X‐100. Triton X‐100, Triton X‐405, Tween 20 and DTAB could reactivate the enzyme precipitated with the phenol polymer, leading to the restarting of the phenol removal reaction. Copyright © 2003 Society of Chemical Industry     

Persistent caching: an implementation technique for complex objectswith object identity

Many recent complex object database systems support the concepts of object identity and object identifier. Following an object identifier to access the referenced object is called navigation operation and is an essential operation in dealing with complex objects. Navigation operation is a difficult operation to implement efficiently since every navigation operation inherently causes one disk access operation. A scheme to notably accelerate the navigation operation among a sea of complex objects, by increasing the effective number of objects in one disk page is proposed. The main concept of the presented technique is threefold. The first idea is to store a cached value within a complex object that is referencing another complex object. The second is that when the referenced object is to be updated the update propagation is delayed until the time when the cached value is referenced. The third is to utilize a hashed table on main memory to efficiently validate the consistency between the cached values and the original values     

Complexity of the color appearance of objects with nonuniform illumination

An inversion relationship is clarified between lightness and brightness, and also between chroma and colorfulness under nonuniform illumination with different illuminance levels (high and low) within the same visual field. Brightness (or colorfulness) of object color with low lightness (or chroma) under high illuminance level is perceived higher than that of another object color with high lightness (or chroma) under low illuminance level. Two color images are given for showing the inversion phenomena on brightness–lightness and colorfulness–chroma between object colors under different illuminance levels. These color images are useful for making researchers on color understand the differences in concept between brightness and lightness, and also between colorfulness and chroma. In particular, the concept of colorfulness is important, but difficult to understand. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 372–377, 2007