Influence of the rubber blend ratio on blowout behaviors of carbon black‐reinforced natural rubber/styrene‐butadiene rubber

Blowout behaviors of NR/SBR blend composites reinforced with carbon black were studied using a microwave oven and variation of the blowout time and temperature with the blend ratio was investigated. Morphology of the interior of the sample before exploding was observed and change of the crosslink density was measured. The blowout time became slower and the blowout temperature became higher as the SBR content of the specimen increased. The specimen with higher NR content had more cavities in the interior just before explosion. The crosslink density became lower by coming close to the blowout and crosslink density of the inner part was more reduced than that of the outer part. New organic materials were found in the burst region after blowout and they might be decomposed products of the polymer chains. The SBR specimen showed better blowout properties than the NR one. Principal sources to cause the blowout were found to be formation of the cavities in a rubber article, reduction of the crosslink density, and dissociation of the rubber chains. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Development of a new automatic system for fault tree analysis for chemical process industries

The main purpose of this study was to develop a computer automated tool for fault tree analysis (FTA) in order to minimize the flaws of manual FTA. The automated FTA system developed in this study consists of two steps: 1) automatic fault tree conversion from a digraph, and 2) calculation of the probability of the occurrence of the top event and finding a minimal cut set of the top event. For the first step, we propose a new algorithm for automatic conversion of a digraph to a fault tree. The new digraph-FT conversion algorithm has eight FT generation rules to transform node information that is based on the node characteristics. Failures and faults are classified into three types to easily synthesize fault trees and analyze fault trees precisely. The automatic FTA system was then applied the analysis of real chemical processes to illustrate the effectiveness of the system.     

Sintering behavior and mechanical properties of WC–10Co,WC–10Ni and WC–10Fe hard materials produced by high-frequency induction heated sintering

The comparison of sintering behavior and mechanical properties of WC–10 wt.%Co, WC–10 wt.%Ni and WC–10 wt.%Fe hard materials produced by high-frequency induction heated sintering (HFIHS) method was accomplished using ultra-fine powder of WC and binders (Co, Ni, Fe). The advantage of this process allows very quick densification to near theoretical density and prohibition of grain growth in nano-structured materials. Highly dense WC–10Co, WC–10Ni and WC–10Fe with a relative density of up to 99% could be obtained with simultaneous application of 60 MPa pressure and induced current within 1 min without significant change in grain size. The hardness and fracture toughness of the dense WC–10Co, WC–10Ni and WC–10Fe composites produced by HFIHS were investigated.     

电镀及表面处理工业的目标、趋势及远景

可持续发展、产品稳定性及各种新的环保法律法规使电镀业面临新的挑战.本文介绍了几种新的环保技术--包括生物除油剂、电解除油自动添加系统、先进的离子交换系统及长效珍珠镍工艺等--的应用状况,探讨了电镀行业可持续发展策略.指出建立技术中心、开发新技术、发展绿色工艺是电镀业未来的发展方向.     

Conditions required for the stimulation of bioluminescence activity of the genetically engineered bacteria, P. putida mt-2 KG1206, preserved by deep-freezing

Herein the conditions required for the stimulation of bioluminescence activity in a genetically engineered strain of Pseudomonas putida mt-2 KG1206, containing the intact TOL plasmid and a constructed plasmid with the P_m-lux gene, are reported upon. Both sodium lactate (SL) and potassium nitrate (KNO₃) were able to stimulate the bioluminescence activity, but a greater increase was observed with nitrogen amendment. This selected stimulant was then tested on reconstituted cells that had been preserved by deep-freezing and mixed with pure inducer solution or groundwater samples. The stimulation of bioluminescence activities for deep-frozen strain was in the range of 101-238% of the control. The effect of KNO₃ was found to be dependent on the type of inducers used and the cell conditions. In general, high bioluminescence activity was observed with groundwater samples, contaminated with high inducer compounds. However, no significant correlation was observed between the bioluminescence intensity and the total inducer concentration in the environmental samples contaminated with complex mixtures with inducers.These results should be useful when other recombinant bioluminescence strains are to be used for environmental monitoring. Overall, the results of this study demonstrate the stimulant conditions for the bioluminescence activity of genetically engineered bacteria, and suggest the potential for preliminary application of this deep-frozen engineered strain in a field-ready bioassay to conveniently detect or monitor a specific group of environmental contaminants.     

Two-dimensional X-shaped organic dyes bearing two anchoring groups to TiO2 photoanode for efficient dye-sensitized solar cells

Novel two-dimensional X-shaped donor–π–acceptor (D–π–A)-type dyes were designed and successfully synthesized for use in a dye-sensitized solar cell (DSSC). Two triphenylamine units in these dyes act as electron donor units, while two cyanoacrylic acid groups act as electron acceptor units and anchoring groups to the TiO₂ photoanode. The photovoltaic properties of the newly synthesized dye-containing DSSCs were investigated to identify the effects of conjugation length between the electron donors and acceptors, and the molecular energy levels of the dyes. Among the three dyes we synthesized, (2E,2′E)-3,3′-(5′,5″-(4,5-bis(4-(bis(4-tert-butylphenyl)amino)styryl)-1,2-phenylene)bis(2,2′-bithiophene-5′,5-diyl))bis(2-cyanoacrylic acid) (11) showed the highest power conversion efficiency of 3.14% (η_max = 4.06% with TiCl₄ treatment) under AM 1.5G illumination (100 mW cm⁻²) in a photoactive area of 0.418 cm² with short circuit current density of 7.27 mA cm⁻², open circuit photovoltage of 612 mV, and a fill factor of 70.6%.     

Combustion characteristics of the heat pellet prepared from the Fe powders obtained by spray pyrolysis

Fe powders for thermal batteries were prepared by reduction of iron oxide powders obtained by spray pyrolysis. The iron oxide powders prepared by spray pyrolysis had fine size, spherical shape and high surface area. The morphologies of the Fe powders were affected by the preparation temperatures of the iron oxide powders. The Fe powders obtained from the iron oxide powders prepared by spray pyrolysis at 900 and 1000 °C had slightly aggregated structure of the primary powders with several microns sizes. The powders had pure Fe phases at reducing temperatures between 600 and 800 °C. The heat pellets with diameter of 18.2 mm were prepared using Fe powders and potassium perchlorate (KClO₄). The porosity of the prepared heat pellet was about 40%. The break strength of the heat pellet was 0.9 kgf. The ignition sensitivity of the heat pellet was 4 W. The maximum burn rate of the heat pellet obtained from the Fe powders were 8.6 cm s^?1.     

Development of fibroblast culture in three-dimensional activated carbon fiber-based scaffold for wound healing

This work developed a novel bi-layer wound dressing composed of 3D activated carbon fibers that allows facilitates fibroblast cell growth and migration to a wound site for tissue reconstruction, and the gentamicin is incorporated into a poly(γ-glutamic acid)/gelatin membrane to prevent bacterial infection. In an in vitro, field emission scanning electron microscopy shows that rat skin fibroblasts appeared and spread on the surface of activated carbon fibers, and penetrated the interior and exterior of the 3D activated carbon fiber construct to a depth of roughly 200 μm. An in vivo analysis shows that fibroblast cells containing the proposed 3D scaffold had the potential of a biologically functionalized dressing to accelerate wound closure. Additionally, fibroblasts migrated to the wound site in a bi-layer wound dressing containing fibroblasts, enhancing fibronectin and type I collagen expression, resulting in faster skin regeneration than that achieved with a Tegaderm? hydrocolloid dressing or gauze.     

A simple drug anchoring microfiber scaffold for chondrocyte seeding and proliferation

The structural properties of microfiber meshes made from poly(2-hydroxyethyl methacrylate) (PHEMA) were found to significantly depend on the chemical composition and subsequent cross-linking and nebulization processes. PHEMA microfibres showed promise as scaffolds for chondrocyte seeding and proliferation. Moreover, the peak liposome adhesion to PHEMA microfiber scaffolds observed in our study resulted in the development of a simple drug anchoring system. Attached foetal bovine serum-loaded liposomes significantly improved both chondrocyte adhesion and proliferation. In conclusion, fibrous scaffolds from PHEMA are promising materials for tissue engineering and, in combination with liposomes, can serve as a simple drug delivery tool.