Rate acceleration of Diels–Alder reactions utilizing a fluorous micellar system in water

A fluorous micellar system in water has been created to produce a large interfacial area between these media that retains substrates, effectively facilitating intermolecular Diels–Alder reactions due to repulsion effects from both media. Because LiFOS functioned not only as a surfactant but also as a supporting electrolyte, an electrochemical approach could be introduced to evaluate the rate acceleration effects. The measurement of the particle size distribution of the fluorous micelles clearly supported these evaluations.     

Electroreductive block copolymerization of dichlorosilanes in the presence of disilane additives

The electroreductive polymerization of dichloromethylphenylsilane in the presence of triphenylsilyl group‐containing disilanes such as hexaphenyldisilane followed by the electroreductive termination with chlorotriphenylsilane afforded triphenylsilyl group‐terminated polymethylphenylsilane in 15–32% yield. The isolated polymethylphenylsilane (M_n = 3350 g mol^?1, M_w/M_n = 1.4) was found to react as a macroinitiator to copolymerize with dibutyldichlorosilane under electroreductive conditions producing the corresponding block copolymer (M_n = 4730 g mol^?1, M_w/M_n = 1.2) in 38% yield. The ratio of monomer units (? MeSiPh? to? BuSiBu? ) of the copolymer was determined to be 75:25 using ¹H NMR analysis, which was in good agreement with the calculated ratio (74:26) on the assumption that molecular weight of the macroinitiator was not changed. The block structure of the resulting copolymer, poly(methylphenylsilane)‐block‐poly(dibutylsilane), was also confirmed by comparing its ¹H NMR and UV absorption spectra with those of polymethylphenylsilane, polydibutylsilane and a statistical copolymer prepared by electroreductive polymerization of dichloromethylphenylsilane with dibutyldichlorosilane. This method is applicable to the preparation of other types of macroinitiator such as triphenylsilyl group‐terminated polydibutylsilane, and polydibutylsilane‐block‐polymethylphenylsilane was also obtained using this macroinitiator. Copyright © 2011 Society of Chemical Industry     

Book reviews

Books reviewed in this article:
Travel Demand Management and Public Policy. Erik Ferguson.
Self-Organization and the City. Juval Portugali (in collaboration with A. Alafasi, I. Benenson, H. Haken, I. Omer). Foreword by Herman Haken.
Growth, Employment and Migration in Southeast Asia: Structural Change in the Greater Mekong Countries. Prema-chandra Athukorala, Chris Manning, Piyasiri Wickramasekara. Cheltenham, U.K.     

Carbon Dioxide Inhibition of Escherichia coli and Staphylococcus aureus on a pH-adjusted Surface in a Model System

Growth of Escherichia coli and Staphylococcus aureuson the surface of Trypticase Soy Agar (TSA) packaged with various CO₂ partial pressures (0, 20, 40, 60, 80, 100%, balance N₂) was compared to the control (N₂ 100%) on TSA in which the pH was adjusted to equal that in CO₂ atmospheres at 15°C and 30°C. At 15°C, the biostatic effect was noted with all CO₂ partial pressures for both species. At 30°C, the biostatic effect of CO₂ was almost completely nullified for E. coli, but that for S. aureus was still effective. S. aureus was more sensitive to the inhibitory effects of CO₂ than E. coli at both the temperatures.     

Bulk heterojunction organic solar cells utilizing 1,4,8,11,15,18,22,25-octahexylphthalocyanine

Bulk heterojunction solar cells utilizing soluble phthalocyanine derivative, 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH₂) have been investigated. The active layer was fabricated by spin-coating the mixed solution of C6PcH₂ and 1-(3-methoxy-carbonyl)-propyl-1-1-phenyl-(6,6)C61 (PCBM). The photovoltaic properties of the solar cell with bulk heterojunction of C6PcH₂ and PCBM demonstrated the strong dependence of active layer thickness, and the optimized active layer thickness was clarified to be 120 nm. By inserting MoO₃ hole transport buffer layer between the positive electrode and active layer, the FF and energy conversion efficiency were improved to be 0.50 and 3.2%, respectively. The tandem organic thin-film solar cell has also been studied by utilizing active layer materials of C6PcH₂ and poly(3-hexylthiophene) and the interlayer of LiF/Al/MoO₃ structure, and a high V_oc of 1.27 V has been achieved.     

Prediction of residual strength of corroded tensile steel plates

Recently, the damage due to deterioration of materials in many old steel bridge structures, which causes unavoidable strength reduction, is becoming a serious problem in Japan and all over the world. Therefore the remaining load-carrying capacities must be carefully evaluated in order to understand the feasibility of those steel structures for the current usage and to evaluate the necessity of retrofitting of selected corroded members to strengthen the existing structure. This paper proposes a new method to calculate the remaining yield and tensile strengths by using a concept of representative effective thickness (t_eff) with the correlation of initial thickness (t₀) and the maximum corroded depth (t_c,max), based on the results of many tensile coupon tests of actual corroded plates. Further, the feasibility of establishing of an analytical methodology to predict the residual strength capacities of a corroded steel member with fewer number of measuring points is also discussed.     

Artifact reduction using reliability reasoning for image generation of FTV

In this paper, we present a new view synthesis method in multiview camera configurations of Free viewpoint TV (FTV) where potential depth errors are considered. The emphasis is on the artifacts eliminating for photorealistic synthesis especially near object boundaries. In contrast to conventional techniques which ignore geometry errors, we first categorize the artifact cases and depth modes. Furthermore, this paper infers the complementarity principle of the artifacts from left and right references. This complementarity guarantees the effectiveness of our reliability-based synthesis. The reliability reasoning is crucial for artifacts reduction. The reliable and unreliable areas from different views can be correctly labeled. Then artifacts caused by unreliable pixels from one reference can be replaced by the reliable pixels from the other reference. As a final result, artifacts of novel view are demonstrated to be significantly reduced on different multiview sequences.     

Study of the basic welding characteristics of Mg alloy

Offering the advantages of lightweight and high specific strength, magnesium (Mg) alloys are extensively used in the manufacture of automotive parts and light-gauge box-type products, such as laptop computers, mobile phones, etc, which are expected to see lighter-weight applications in future. Presently available Mg alloy products, however, are manufactured by molten or semi-molten working in diecasting or thixomoulding processes, with applications technology currently at the development stage. Suitable techniques for the further development of Mg alloy manufacturing technology include plastic working of wrought alloys and assembly of products with complex shapes by welding. This study focuses on TIG welding as a widely practised and convenient technique for assembly of general metal products. The article examines the basic welding characteristics of an Mg alloy equivalent to AZ31 as an Mg alloy in widespread practical use together with the deformation properties of the proposed alloy. A suitable welding procedure is then investigated. Also discussed is an assembly method for products in consideration of the working and welding characteristics of the proposed alloy.     

Optical and electrical anisotropies of polydiacetylene derivative film aligned by shear stress

The molecular alignment of polydiacetylene (PDA) derivatives and their optical and electrical properties of thin films based on PDA derivatives have been studied. The PDA derivatives were aligned depending on the direction of applied shear stress in the film. From measurements of the polarized absorption and current–voltage characteristics, the optical and electrical anisotropies have been observed, that was discussed by taking the PDA main chain alignment into consideration.