Effect of calcination temperature of mesoporous nickel–alumina catalysts on their catalytic performance in hydrogen production by steam reforming of liquefied natural gas (LNG)

Mesoporous nickel–alumina (Ni–A-NS) catalysts prepared by a non-ionic surfactant-templating method were calcined at various temperatures for use in hydrogen production by steam reforming of liquefied natural gas (LNG). The effect of calcination temperature of nickel–alumina catalysts on their physicochemical properties and catalytic activity for steam reforming of LNG was investigated. Nickel oxide species were finely dispersed on the surface of Ni–A-NS catalysts through the formation of nickel aluminate phase. Reducibility, nickel surface area, and nickel dispersion of Ni–A-NS catalysts decreased with increasing calcination temperature. In the steam reforming of LNG, both LNG conversion and hydrogen composition in dry gas decreased with increasing calcination temperature of Ni–A-NS catalysts. Nickel surface area and reducibility of Ni–A-NS catalysts were well correlated with catalytic performance of the catalysts. Among the catalysts tested, Ni–A-NS700 (nickel–alumina catalyst calcined at 700 °C) with the highest nickel surface area and the highest reducibility exhibited the best catalytic performance.     

Production of middle distillate through hydrocracking of paraffin wax over Pd/SiO2–Al2O3 catalysts

Pd/SiO₂–Al₂O₃ catalysts (Pd/SA-X) with different SiO₂ contents (X, wt%) were prepared for use in the production of middle distillate (C₁₀–C₂₀) through hydrocracking of paraffin wax. The effect of SiO₂ content of Pd/SA-X catalysts on their physicochemical properties and catalytic performance in the hydrocracking of paraffin wax was investigated. High surface area and well-developed mesopores of Pd/SA-X catalysts improved the dispersion of Pd species on the SiO₂–Al₂O₃ support. Acidity of Pd/SA-X catalysts determined by NH₃-TPD experiments showed a volcano-shaped trend with respect to SiO₂ content. Conversion of paraffin wax increased with increasing acidity of the catalyst, while selectivity for middle distillate decreased with increasing acidity of the catalyst. Yield for middle distillate showed a volcano-shaped curve with respect to acidity of the catalyst. This indicates that acidity of Pd/SA-X catalysts played an important role in determining the catalytic performance in the hydrocraking of paraffin wax. Among the catalyst tested, Pd/SA-69 with moderate acidity showed the highest yield for middle distillate.     

Removal of PM2.5 entering through the ventilation duct in an automobile using a carbon fiber ionizer-assisted cabin air filter

This study evaluated the charging characteristics of a carbon fiber ionizer for PM2.5 and carried out particle capture laboratory tests after an ionizer was installed upstream of the media of an electret cabin air filter. When the ion concentration per particle (N_i) of the carbon fiber charger was 10⁶ ions/cm³, the average charge numbers for each particle were 1.54, 0.88, and 0.49 at 0.6, 1.2, and 1.8 m/s of face velocity, respectively (the particle charging times, τ, were 167, 83, and 56 ms, respectively). For these face velocities, the PM2.5 removal efficiencies of the filter media were 69.3%, 65.2% and 62.2%, respectively, but increased to 80.4%, 71.2% and 65.5%, respectively, when the ionizer was turned on. The carbon fiber ionizer was then installed in front of an electret cabin filter in the air conditioning system of an automobile, after which field tests were performed at a roadside area. For the same N_iτ used in the lab-scale tests, the effects of the carbon fiber ionizer on increasing PM2.5 %Reduction were mild as 9.4%, 4.0%, and 2.8% when the flow rates were at the second, fourth, and sixth levels, respectively (the face velocities were 0.6, 1.2, and 1.8 m/s, respectively). The PM2.5 %Reduction can be substantially increased by 20–21%, for a higher value of N_iτ (=1.0×10⁸ ions s/cm³), which is realized by increasing the power consumption of the carbon fiber ionizer.     

Maleic anhydride grafted polyethylene powder coated with epoxy resin: A novel reactive hot melt adhesive

A novel reactive hot melt adhesive was prepared by coating an epoxy resin on maleic anhydride grafted polyethylene (MAPE) powder. This adhesive had markedly improved adhesion power compared with pristine MAPE powder, which is normally used as a hot melt adhesive. The generation of an ester linkage by the reaction between the anhydride group of MAPE and the hydroxyl group of epoxy resin, during the bonding operation at 190°C with the pressure of 22 MPa for 30 min, was confirmed from the FTIR spectra. The bond strength was further improved by a small amount of 1‐methylimidazole, which accelerated the esterification reaction. When the epoxy resin was coated on hydrated MAPE, in which the anhydride group of MAPE was converted into carboxylic acid group by the reaction with water, the esterification reaction was much faster than that of pristine MAPE, and consequently, the bond strength of the adhesive was much higher than that of pristine MAPE coated with epoxy resin. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Emotional response to color across media

In this study, the characteristics of emotional responses to color are explored in two empirical studies. In particular, the relationship between color attributes and emotional dimensions—valence, arousal, and dominance—is analyzed. To account for the cognitive quantity of color, 36 color stimuli were selected following hue and tone categorizations and based on the CIELAB LCh system. In one experiment, the colors were presented on A5‐size glossy paper whereas the identical colors were displayed on CRT monitors in the other experiment. In both experiments, the subjects assessed the emotional responses to each color stimulus using a Self‐Assessment‐Manikin (SAM), which consists of three rows of five pictograms illustrating the three dimensions of emotion, respectively. The empirical results provide evidence that the patterns of affective judgment of colors can be profiled in terms of the three dimensions of emotion (Reliability coefficient, Cronbach's alpha > 0.7). All three attributes of colors, i.e. hue, Chroma, and Lightness, influenced the emotional responses (repeated measurement One‐way ANOVA, P < 0.05), and especially, Chroma was always positively correlated with each of the three emotional dimensions (r > 0.60 P < 0.01). Moreover, the results indicate that emotional responses to color vary more strongly with regard to tone than to hue categories. Comparing the SAM ratings between the two experiments, a systemic explanation has yet to be found to conclude that there is a media effect on the emotional responses to colors. Furthermore, the process of affective judgment of colors and the limit of color as an emotion elicitor are discussed. © 2009 Wiley Periodicals, Inc., Col Res Appl, 2010.     

Effect of applied potential on fatigue crack propagation behavior of API X80 steel in seawater

In the present study, the fatigue crack propagation (FCP) tests were conducted on X80 steel in air and artificial seawater (ASW) under various applied potentials to establish optimum and safe working limits of cathodic protection (CP). The slow strain rate test (SSRT) was also conducted on the X80 BM specimens in ASW under CP potential to identify the susceptibility of hydrogen affecting the FCP behavior. The CP potential of ?850 and ?1,050 mV_SCE suppressed the environmental effect of seawater on the FCP behavior of X80 BM and WM specimens, showing almost identical da/dN-ΔK curves for both air and ASW environments. The SSRT in ASW under CP potential of ?1,050 mV_SCE suggested that the X80 BM specimen steel is susceptible to hydrogen embrittlement, but the effect of hydrogen was believed to be marginal in affecting the FCP behavior of the X80 specimens at a loading frequency of 10 Hz. The FCP behavior of high strength X80 steel is discussed based on the fractographic observation to understand the FCP mechanism in seawater under various CP potentials.     

微波辐射辅助柠檬酸络合法制备的Ho3+/Tm3+/Yb3+共掺杂CaWO4的白光性能（英文）

采用微波辐射辅助柠檬酸络合法制备Ho3+/Tm3+/Yb3+共掺杂CaWO4纳米晶升频转换荧光粉。将柠檬酸络合物前驱体在300~700°C热处理3 h。Ho3+/Tm3+/Yb3+共掺杂CaWO4C在400°C时开始结晶,在600°C时结晶完成。经600°C热处理的Ho3+/Tm3+/Yb3+共掺杂CaWO4主要呈球形,且形态均匀。在980 nm的激光激发下,Ho3+/Tm3+/Yb3+共掺杂CaWO4纳米晶出现肉眼可见的明亮的白色升频转换发射,这种现象来自Tm3+的475 nm蓝光发射以及Ho3+的543 nm绿光和651 nm红光发射。通过调整Tm3+和Ho3+的浓度可以控制Ho3+/Tm3+/Yb3+共掺杂CaWO4的CIE色度图从冷到暖白色之间变化。讨论了Tm3+和Ho3+浓度对升频转换光性能的影响以及与激光泵功率相关的影响机制。     

Multi-objective optimization for mixed-flow pump with blade angle of impeller exit and diffuser inlet

During design optimization, the impeller and diffuser of a mixed-flow pump are generally optimized separately. In such cases, the total head can be overdesigned. In this study, the designs of the impeller and diffuser were optimized simultaneously by using computational fluid dynamics and the Response surface method (RSM). Design variables were defined according to the vane plane development of the impeller and diffuser. Three-dimensional Reynolds-averaged Navier–Stokes equations for the shear stress transport turbulence model were discretized by finite volume approximations and solved on hexahedral grids to analyze the flow in the pump. The total head and total efficiency were selected as objective functions, with four design variables related to the impeller outlet angles and diffuser inlet angles used for optimization. The RSM was constructed based on the objective functions with design points generated from the central composite method. The hydraulic performance of the optimum model was analyzed.     

Tribological Performance of Laser-Textured Polyoxymethylene under Boundary Lubricated Sliding Condition

Micro texturing was fabricated on polyoxymethylene surfaces using laser texturing, and the tribological characteristics were studied. Micro texturing was proven to be very effective in lowering the coefficient of friction, regardless of the texturing depth used in this study. Laser texturing was practical and efficient owing to its fast process time with reasonable machined shapes. An optimum aspect ratio and area density of texturing would exist under the conditions used in this study. Wear of polyoxymethylene was negligible.     

Decentralised production-distribution planning system using collaborative agents in supply chain network

With the fast development of information technology and the global market, collaboration between different functional units in a supply chain becomes one of the most critical factors for global companies to respond to rapid changes in customer needs and increase the efficiency of the whole supply chain. This supply chain environment requires a production-distribution planning system to enable the collaboration between production and distribution units more quickly and orderly. Generally, collaboration in a supply chain needs to resolve conflicts between two decentralised functional units, because each unit tries to locally minimise its own costs, not the overall supply chain costs. Also, there exists incomplete information sharing according to the information privacy of each functional unit. This paper proposes a decentralised production-distribution planning system using collaborative agents that can efficiently mediate the planning gaps between two decentralised planning functions: production and distribution. The validity of collaborative-agent model has been shown using some lemmas and numerical examples.