Quantifying adherence of oxide scales on steels exposed to high temperature and pressure steam

Oxide scale exfoliation is a major concern in fossil fuel power generation because it can cause tube blockages and erode valves and steam turbine components downstream. There is still considerable scientific and commercial interest to improve the mechanistic understanding of oxide failures by developing models to predict exfoliation and the extent of tube blockage as a function of operating conditions and component geometries. Tensile testing inside a scanning electron microscope was conducted on ferritic–martensitic and austenitic steel specimens with the steam side (Fe,Cr)-rich oxides grown after exposures for up to 1000 h in steam with ~100 ppb O₂ at 276 bar and 550°C. Multiple oxide layer cracks and delamination events were observed and analyzed in detail during the tests. Results from the testing agreed well with earlier observations that had identified the failure location at the outer–inner oxide layer for all tested materials. Calculated adhesion energies identified the outer–inner oxide interface of alloy 347HFG as the weakest interface.     

石家庄勒泰中心

<正>项目名称:石家庄勒泰中心业主:勒泰商业地产集团建设地点:河北省石家庄市中山东路39号设计单位:捷德国际建筑师事务所业态构成:商业,酒店,办公,公寓用地面积:6hm2建筑面积:62.4万m2材料应用:石材,金属镶板,玻璃,预制混凝土外立面主创设计师:Tammy Mc Kerrow结构/机电/施工图配合:华东建筑设计研究院有限公司(ECADI)景观设计:Earth Asia照明设计:Grenald Waldron Associates(GWA)标识设计:Dutton Bray水景设计:Oase设计时间:2010年建成时间:2012年图纸版权:捷得国际建筑师事务所摄影:Kerunlp     

On-road experiment to assess drivers’ detection of roadside targets as a function of headlight system,target placement,and target reflectance

Adaptive headlights swivel with steering input to keep the beams on the roadway as drivers negotiate curves. To assess the effects of this feature on driver’s visual performance, a field experiment was conducted at night on a rural, unlit, and unlined two-lane road during which 20 adult participant drivers searched a set of 60 targets. High- (n = 30) and low- (n = 30) reflectance targets were evenly distributed on straight road sections and on the inside or outside of curves. Participants completed three target detection trials: once with adaptive high-intensity discharge (HID) headlights, once with fixed HID headlights, and once with fixed halogen headlights. Results indicated the adaptive HID headlights helped drivers detect targets that were most difficult to see (low reflectance) at the points in curves found by other researchers to be most crucial for successful navigation (inside apex). For targets placed on straight stretches of road or on the outside of curves, the adaptive feature provided no significant improvement in target detection. However, the pattern of results indicate that HID lamps whether fixed or adaptive improved target detection somewhat, suggesting that part of the real world crash reduction measured for this adaptive system (Highway Loss Data Institute (HLDI), 2012a) may be due to the differences in the light source (HID vs. halogen). Depending on the scenario, the estimated benefits to driver response time associated with the tested adaptive (swiveling HID) headlights ranged from 200 to 380 ms compared with the fixed headlight systems tested.     

植物与时间：关于慢速植物知识的探讨

风景园林师通常更倾向以季相特征的方式去理解植物 随时间发生的变化。认为从蒂莫西·莫顿(Timothy Morton) 的时间推移(time lapse)概念中汲取灵感,并通过时间性的 概念来思考植物,将有机会改变风景园林师认知和设计植物的 方式。虽然这种种植设计方法不直接指向一种形式(form), 但它确实与当前称为生态主义或自然主义的种植概念有许多相 似之处。调查了2个建成项目——格伦斯通博物馆(Glenstone Museum)和布鲁克林大桥公园(Brooklyn Bridge Park),以 理解时间性是如何影响设计的。最后,提出了通过慢速植物知 识(slow plant knowledge)引导设计的新发展趋势     

Powder interlayer bonding of geometrically complex Ti-6Al-4V parts

The International Journal of Advanced Manufacturing Technology - Powder interlayer bonding (PIB) is a novel joining technique, which has been developed to facilitate high-integrity repairs of...     

Thermal transients during processing of materials by very high power ultrasonic additive manufacturing

Dynamic recrystallisation at interfaces has been suggested as the bonding mechanism in the joining of metallic tapes, during very high power ultrasonic additive manufacturing. To understand the reasons for such occurrence of dynamic recrystallization, thermal transients from the interface regions were recorded during processing of aluminum alloy (3003 and 6061 series) and 11 000 copper tapes under similar conditions. Measurements in 3003 Al were also carried out for different processing parameters. Measured peak temperatures were seen to increase with increase in shear strength of the material and ultrasonic vibration amplitude. The observations have been rationalized based on interfacial heating at asperities due to adiabatic plastic deformation.     

Band-gap tuning of pendant polymers for organic light-emitting devices and photovoltaic applications

The preparation of a series of novel polymers comprising pendant electro-active “push–pull” chromophores and their performance in solution-processed organic electronic devices is described. The design of the electro-active pendant chromophores was based on the well-known motif of cyano-substituted poly(p-phenylenevinylene). Optical band-gap engineering within this series of polymers was achieved by varying the conjugation length and the electron donor/acceptor functionalities of the pendant chromophores. The introduction of a cyanoimine group into the electro-active pendant module resulted in a marked narrowing of the optical band-gap compared with the other electro-active pendant chromophores investigated in this work. Bulk heterojunction solar cell devices comprising these polymers were prepared by solution processing blends of each polymer with [6,6]-phenyl-C₆₁-butyric acid methyl ester, and their performance was evaluated by measuring power conversion efficiencies. The best-performing solar cell in this series exhibited a power conversion efficiency of 0.29% and a maximum incident photon-to-current conversion efficiency of 22% and was produced using the polymer in which the electro-active chromophore comprised the cyanoimine group.