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61.
N. P. Brandon D. Corcoran D. Cummins A. Duckett K. El-Khoury D. Haigh R. Leah G. Lewis N. Maynard T. McColm R. Trezona A. Selcuk M. Schmidt 《Journal of Materials Engineering and Performance》2004,13(3):253-256
A novel metal-supported solid oxide fuel cell has been developed that is capable of operating at temperatures of 500–600 °C.
The rationale behind the materials used to construct this fuel cell type is given, and results are presented from cell testing
on hydrogen and reformed natural gas, including durability trials of some 2500 h duration. This new fuel cell variant is shown
to be tolerant of carbon monoxide, durable, robust to thermal and redox cycling, and capable of delivering technologically
relevant power densities.
This paper was presented at the Fuel Cells: Materials, Processing, and Manufacturing Technologies Symposium sponsored by the
Energy/Utilities Industrial Sector & Ground Transportation Industrial Sector and the Specialty Materials Critical Technologies
Sector at the ASM International Materials Solutions Conference, October 13–15, 2003, in Pittsburgh, PA. The symposium was
organized by P. Singh, Pacific Northwest National Laboratory, S.C. Deevi, Philip Morris USA, T. Armstrong, Oak Ridge National
Laboratory, and T. Dubois, U.S. Army CECOM. 相似文献
62.
63.
Effective supplier selection and allocation of order quantity among multiple suppliers are indispensable to the success of a manufacturing company. While companies have begun to turn into a comprehensive multi-criteria approach, most buyers still consider purchasing cost to be their primary concern in selecting their suppliers. In this paper, we consider the concave cost supply problem where a manufacturer seeks to select the suppliers and simultaneously procure the quantity of material/component required for production at the minimum total cost during a standard production period. We provide and validate an effective and efficient branch-and-bound algorithm that is finite and that finds the global optimal solution of the problem without any restrictions on the cost functions or on the set of input parameters used in the problem. Numerical experiments are conducted to evaluate the performance of the proposed algorithm. 相似文献
64.
Synthesis and characterization of 2‐hydroxyethylmethacrylate/2‐(3‐indol‐yl)ethylmethacrylamide‐based novel hydrogels as drug carrier with in vitro antibacterial properties 下载免费PDF全文
In this study, a new cationic monomer 2‐(3‐indol‐yl)ethylmethacrylamide (IEMA) derived from tryptamine was synthesized in a single step and characterized by Fourier transform infrared (FTIR), 1H‐NMR, and 13C‐NMR. Then, one‐step preparation of novel poly[2‐hydroxyethylmethacrylate‐c‐2‐(3‐indol‐yl)ethylmethacrylamide], or p(HEMA‐c‐IEMA), copolymeric hydrogels has been performed successfully with IEMA and 2‐hydroxyethylmethacrylate (HEMA) as monomers using free radical aqueous polymerization. The hydrogels were characterized with scanning electron microscopy, FTIR, elemental analysis, thermogravimetric analysis, and texture profile analysis instruments. p(HEMA‐c‐IEMA) hydrogels were used for swelling, diffusion, drug release, and antibacterial activity studies. The drug‐release behavior of the hydrogels was determined as a function of time at 37 °C in pH 1.2 and 7.2. The swelling and drug‐release studies showed that an increased IEMA amount caused a higher increase in swelling and drug‐release values. Additionally, zero‐order, first‐order, and Higuchi equation kinetic models were applied to the drug‐release data, and the data fit well in the Higuchi model, and the Peppas power‐law model was applied to the release mechanism. Finally, the antibacterial activities of the hydrogels were screened against Gram‐positive bacteria (Bacillus cereus and Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli and Salmonella typhimurium). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45550. 相似文献
65.
Murat?TasanEmail author Mehmet?Demirci 《Journal of the American Oil Chemists' Society》2003,80(8):825-828
The contents of total trans FA of sunflower oils at different stages of refining processes were determined by capillary GLC. The contents of 18∶1, 18∶2,
and 18∶3 trans acids were 0.22±0.03, 2.31±0.23, and 0.03±0.01%, respectively, in physically refined sunflower oils, and 0.05±0.01, 0.69±0.26,
and 0.02±0.01%, respectively, in chemically refined sunflower oils. The total trans FA contents drastically increased at the end of the physical refining process. The total trans FA contents of chemically refined sunflower oils were <1%. Because of the high temperature applied in the last stage of physical
refining, the content of total trans FA was higher than in chemically refined sunflower oils. The last-stage conditions should be carefully evaluated to reduce
the formation of trans FA during physical refining. 相似文献
66.
H. Selcuk W. Zaltner J.J. Sene M. Bekbolet M.A. Anderson 《Journal of Applied Electrochemistry》2004,34(6):653-658
The degradation of formic acid (HCOOH), FA (a surrogate contaminant) using titanium dioxide (TiO2) and 1% Pt doped TiO2 electrodes, prepared by sol—gel methods, was investigated in a photoelectrocatalytic (PEC) system in order to determine the effect of Pt doping on the oxidation potential of TiO2. Pt doping shifts the position of band edge and therefore the direct and indirect oxidation potentials of TiO2 in PEC systems. As a result, the degradation of formic acid via the generation of hydrogen peroxide production on 1%Pt—TiO2 electrodes was much better than that on non-doped electrodes. The degradation of HCOOH was also examined with respect to the faradaic efficiency of this process. It was found that the 1%Pt—TiO2 photoanode had a 30% higher efficiency than that of non-doped TiO2 photoanodes. 相似文献
67.
Nowadays, gas welding applications on vehicle’s parts with robot manipulators have increased in automobile industry. Therefore, the speed of end-effectors of robot manipulator is affected on each joint during the welding process with complex trajectory. For that reason, it is necessary to analyze the noise and vibration of robot’s joints for predicting faults. This paper presents an experimental investigation on a robot manipulator, using neural network for analyzing the vibration condition on joints. Firstly, robot manipulator’s joints are tested with prescribed of trajectory end-effectors for the different joints speeds. Furthermore, noise and vibration of each joint are measured. And then, the related parameters are tested with neural network predictor to predict servicing period. In order to find robust and adaptive neural network structure, two types of neural predictors are employed in this investigation. The results of two approaches improved that an RBNN type can be employed to predict the vibrations on industrial robots. 相似文献
68.
Modeling the order picking function in supply chain systems: formulation, experimentation, and insights 总被引:1,自引:0,他引:1
Order picking is found at the interface of production and distribution networks within supply chain systems. In this study the order picking function is modeled to explore its role with respect to inventory deployment and centralized distribution planning, in the presence of production economies of scale and deterministic demand. The results of 5400 numerical experiments suggest that, for certain system cost structures, there may exist an inherent tension between commercially independent stages, owed to the consequences of decentralized planning. Increasing total system cost due to pull style planning over centralized planning appeared to be most heavily influenced by the proportion of costs shared by various system stages around the order picker, and this gap averaged over 30% in worst-case scenarios. 相似文献
69.
70.
In this study, first polyacrylamide hydrogels were synthesized by free‐radical crosslinking polymerization of acrylamide monomer with N,N′‐methylenebis(acrylamide) as a crosslinker in an aqueous solution at 22°C. Then, a series of hydrogels at various charge densities were prepared by partial hydrolysis of polyacrylamide precursors in a 0.1M sodium hydroxide solution at 60°C. The hydrolysis time was varied between 20 and 180 min. The chemical structures and internal morphologies of the hydrogels before and after alkaline hydrolysis were characterized with attenuated total reflectance/Fourier transform infrared and scanning electron microscopy measurements. The swelling ratio of the hydrolyzed hydrogels was measured in buffer solutions at various pHs. From differential curves of dQv/dpH versus pH (where Qv is the equilibrium swelling ratio of the hydrogels), the volume phase transition pH of the hydrogels was found to be 4.33 ± 0.05, regardless of the charge density of the hydrogels. In water at 22°C, the hydrogels with greater charge density showed a more rapid swelling rate because of their higher porosity and hydrophilicity. Moreover, in buffer solutions with the pH changing from 9.0 to 2.0 at 22°C, the hydrogels with greater charge density also exhibited a more rapid deswelling rate than the hydrogels with less charge density. In conclusion, the postmodification method is a good way of preparing pH‐sensitive hydrogels with fast responsiveness. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献