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21.
Muthu Kumaran Gnanamani Gary Jacobs Wilson D. Shafer Dennis E. Sparks Shelley Hopps Gerald A. Thomas Burtron H. Davis 《Topics in Catalysis》2014,57(6-9):612-618
Low temperature water–gas shift (LT-WGS) was performed over various group I alkali metal (Li, Na, K, Rb, Cs) promoted cobalt carbide (Co2C) catalysts at temperatures ranging from 453 to 573 K and atmospheric pressure. Cobalt carbide (Co2C) was found to be active for the WGS reaction. The stability of the catalyst is related to the stability of the cobalt carbide phases under reaction conditions. Potassium promoted cobalt carbide catalysts exhibited higher activity and stability compared to the other alkali promoted catalysts for LT-WGS. X-ray diffraction analyses of fresh and used catalysts suggest that the origin of deactivation of the catalysts is primarily due to the chemical transition of cobalt from carbide to metal during WGS. 相似文献
22.
During the design of a new building or retrofitting of an existing one, it is important to reliably assess the indoor humidity
levels of the building as it can potentially affect the building envelope durability, occupants’ comfort and health risks
associated with mould growth. Simplistic assumptions of indoor humidity profiles, which ignore the dynamic coupling of the
indoor environment and building enclosure, may lead to inaccurate conclusions about the indoor environment and moisture performance
of the building enclosure. In this paper, a whole-building hygrothermal model called HAMFitPlus, which takes into account
the dynamic interactions between building envelope components, mechanical systems and indoor heat and moisture generation
mechanisms, is used to assess the indoor humidity condition of an existing occupied house. HAMFitPlus is developed on SimuLink
development platform and integrates COMSOL multiphysics with MatLab. The basic input parameters of the model are discussed
in detail, and its simulation results are presented. In general, the HAMFitPlus simulation results are in good agreement with
the measured data. 相似文献
23.
Soundararajan S. Kumaran Kee P. Lim Joe V. Michael Jeffrey L. Tilson Aya Suslensky Assa Lifshitz 《Israel journal of chemistry》1996,36(3):223-232
The isomerization and thermal decomposition of chloromethylacetylene (CMA) has been studied with two shock tube techniques. The first experiment (Jerusalem) utilizes single-pulse shock tube methods to measure the isomerization rate of CMA to chloroallene. In addition, equilibrium constants can be estimated at ∼1200 K. The second experiment (Argonne) monitors Cl-atom formation at temperatures above ∼1150 K. Absolute yield measurements have been performed over the 1200–1700 K range and indicate that two decomposition channels contribute to CMA destruction, namely, Cl fission and HCl elimination. The results show that the branching fraction between processes is temperature dependent. Therefore, direct Cl-atom fission is accompanied by molecular elimination, undoubtedly giving HCl and one or more isomers of C3H2. MP2 6–31G(d,p) ab initio electronic structure calculations have been used to determine vibration frequencies and moments of inertia for three C3H3Cl isomers. Using these quantities, the experimental equilibrium constants required that ΔH00(CH2Cl–C≡CH ⇌ CHCl=C=CH2) = −;0.24 kcal mole−1. A potential energy surface pertinent to the present system has been constructed, and RRKM calculations have been carried out in order to explain the isomerization rates. The isomerization data can be explained with E0 = 52.3 kcal mole−1 and 〈ΔEdown〉 = 225 cm−1. Subsequent semi-empirical Troe and RRKM-Gorin modeling of the Cl atom rate data require E0 = (67.5 ± 0.5) kcal mole−1 with a 〈ΔEdown〉 = (365 ± 90) cm−1. This suggests a heat of formation for propargyl radicals of (79.0 ± 2.5) kcal mole−1. 相似文献
24.
Nathaporn Areerachakul Saravanamuthu Vigneswaran Huu Hao Ngo Jaya Kandasamy 《Korean Journal of Chemical Engineering》2008,25(4):663-669
The performance of both batch and continuous photo-catalytic reactors was studied to evaluate their capabilities in removing
the sulfonyl urea herbicide of metsulfuron methyl (MM). It was found in a batch reactor that the addition of a small amount
of powder activated carbon (PAC) significantly increased the rate of degradation of MM. The continuous photo-catalytic system
resulted in 57% of MM removal. When a small dose of activated carbon was added in the photo-catalytic system, MM removal increased
to 78–86% MM removal for retention times between of 5.25–21 min (corresponding to withdrawal rates of 10–40 mLmin−1). In this study, the pseudo first order rate constants of a continuous photo-catalytic system revealed that shorter retention
times were associated with lower rate constants. Solid phase micro extraction/gas chromatography (SPME/GC) results showed
that high concentrations of MM were broken down to small volatile organic compounds (VOCs) by photo-catalytic oxidation. PAC
adsorbed the photo-products and increased the degradation of MM. 相似文献
25.
26.
The kinetics of diffusion of gaseous halides in an aluminizing pack are analyzed assuming the presence of an activator, as well as an aluminum-depleted zone. The influence of activator concentration on the aluminum transport rate is calculated for a wide range of activator concentrations in an AlF3-activated pack. Theoretical results are compared with experimental data for the aluminization of nickel. 相似文献
27.
Lignin in the form of lignosulfonate containing about 33% moisture was found to be dispersible in natural rubber by dry mixing. Properties such as tear resistance, abrasion resistance, flex crack resistance, and crack growth resistance improved upon addition of lignin, irrespective of the nature of filler added. This lignin was found to have negative effects on modulus, tensile strenght, resilience, heat buildup, and compression set, which showed, however, remarkable improvement upon aging. 相似文献
28.
29.
In this paper, we propose a novel test methodology for the detection of catastrophic and parametric faults present in analog very large scale integration circuits. An automatic test pattern generation algorithm is proposed to generate piece‐wise linear (PWL) stimulus using wavelets and a genetic algorithm. The PWL stimulus generated by the test algorithm is used as a test stimulus to the circuit under test. Faults are injected to the circuit under test and the wavelet coefficients obtained from the output response of the circuit. These coefficients are used to train the neural network for fault detection. The proposed method is validated with two IEEE benchmark circuits, namely, an operational amplifier and a state variable filter. This method gives 100% fault coverage for both catastrophic and parametric faults in these circuits. 相似文献
30.