Measurement of intrinsic rates for homogeneous gas‐phase reactions at high temperatures

A coiled quartz tubular reactor has been designed to measure the intrinsic reaction kinetics for homogeneous reactions at high temperatures up to 1100°C. Actual gas residence times were less than 100 ms. A simple and well‐studied test reaction (i.e., the decomposition of nitrous oxide, N₂O), with published intrinsic kinetics, was used to verify the operation of the experimental reactor. For this system, Peclet numbers (Pe = uL/DL) computed from experimental conversion data were greater than 1000, indicating that the plug flow assumption could be used with this reactor system to determine intrinsic rate expressions with errors of less than 5% for the conditions studied.     

Nanofiber organic semiconductors: The effects of nanosize on the electrical charge transport and optical properties of bulk polyanilines

The electrical transport, optical, and microstructural properties of bulk polyaniline (PANI) and nano‐PANIs were investigated. A field emission scanning electron microscopy (SEM) image of bulk PANI showed macroscopic and aggregated granular particles. A SEM image of the nanostructured PANI showed the formation of one‐dimensional nano/microstructures. The formation of nanofibers was observed from the transmission electron microscopy image. The electrical conductivities of the bulk and nanostructured PANIs increased with increasing temperature, which indicated semiconductor behavior. The electrical conductivities of the bulk and nanostructured PANIs at room temperature were found to be 2.12 × 10^?5 and 1.80 × 10^?2 S/cm, respectively. The electrical conductivity of the nanostructured PANI was about 850 times higher than that of the bulk PANI. The obtained band gaps of the bulk and nanostructured PANIs were determined from diffuse reflectance measurements and were found to be 3.27 and 2.41 eV, respectively. The refractive index of the PANI samples changed from 1.3 to 1.61. The obtained results indicate that the electrical and optical properties of the PANI were inherently dependent on the nanostructure. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Consideration of Trends in Evaluating Inter-basin Water Transfer Alternatives within a Fuzzy Decision Making Framework

Evaluation of water supply schemes is an essential task for meeting the goals of inter-basin water transfer project system management. In general, water supply operation involves multi-objective and multifactor optimization and decision. In recent years, multicriterion decision making (MCDM) has emerged as an effective methodology due to its ability to combine quantitative and qualitative criteria for selection of the best alternative. This paper presents a new optimization method using fuzzy pattern recognition to appraise the water supply decision schemes in inter-basin diversion systems. The proposed method is capable to incorporate not only the will of the decision-makers but also the future development trend of water resources and water supply demand and makes the optimization results more reasonable and applicable. One case study for the Xi-River-to -Tanghe Reservoir Water Transfer Project System in China is presented to demonstrate the application of this method.     

Measurement of asphaltene agglomeration from cold lake bitumen diluted with n-alkanes

A laser particle analyzer was used to study the formation of asphaltene agglomerates from Cold Lake bitumen due to the introduction of paraffinic diluents. The growth of the particles over time was investigated, and it was found that asphaltene particle growth is essentially an instantaneous process; that is, the final agglomerate size is reached within 5 seconds. The type of diluent used to precipitate the asphaltenes was determined to have a major effect on the size distribution of asphaltene agglomerates. The average particle size of asphaltene agglomerates ranged from 169 ptn for n-hexadecane to 299m for n-pentane. A relationship is shown to exist between the average particle size of asphaltene agglomerates and the carbon number of the diluent used.     

Echocardiographic diagnosis of supravalvular aortic stenosis

The echocardiographic features of supravalvular aortic stenosis seen in a patient with valvular aortic and multiple pulmonary branch stenosis are described. Since patterns of valvular, discrete subvalvular, and supravalvular aortic stenosis can be recognized by echocardiography, it is now possible to screen close relatives of patients having supravalvular aortic stenosis and pulmonary branch stenosis by this non-invasive technic.     

Use of the false discovery rate for evaluating clinical safety data

Clinical adverse experience (AE) data are routinely evaluated using between group P values for every AE encountered within each of several body systems. If the P values are reported and interpreted without multiplicity considerations, there is a potential for an excess of false positive findings. Procedures based on confidence interval estimates of treatment effects have the same potential for false positive findings as P value methods. Excess false positive findings can needlessly complicate the safety profile of a safe drug or vaccine. Accordingly, we propose a novel method for addressing multiplicity in the evaluation of adverse experience data arising in clinical trial settings. The method involves a two-step application of adjusted P values based on the Benjamini and Hochberg false discovery rate (FDR). Data from three moderate to large vaccine trials are used to illustrate our proposed 'Double FDR' approach, and to reinforce the potential impact of failing to account for multiplicity. This work was in collaboration with the late Professor John W. Tukey who coined the term 'Double FDR'.     

Kinetics of pyrolysis of pure and doped cobalt oxalate

The object of the present work was to illustrate the effect of impurities on the kinetics and energetics of the thermal decomposition of pure cobalt oxalate. Cationic impurities like Mg²⁺, Mn²⁺, Fe²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Pb²⁺, Zr⁴⁺ have been introduced into pure cobalt oxalate dihydrate and differential thermal analysis has been used to determine the enthalpy and energy of activation for the decomposition reaction of pure and doped samples.     

Adaptive linkage crossover

Problem-specific knowledge is often implemented in search algorithms using heuristics to determine which search paths are to be explored at any given instant. As in other search methods, utilizing this knowledge will more quickly lead a genetic algorithm (GA) towards better results. In many problems, crucial knowledge is not found in individual components, but in the interrelations between those components. For such problems, we develop an interrelation (linkage) based crossover operator that has the advantage of liberating GAs from the constraints imposed by the fixed representations generally chosen for problems. The strength of linkages between components of a chromosomal structure can be explicitly represented in a linkage matrix and used in the reproduction step to generate new individuals. For some problems, such a linkage matrix is known a priori from the nature of the problem. In other cases, the linkage matrix may be learned by successive minor adaptations during the execution of the evolutionary algorithm. This paper demonstrates the success of such an approach for several problems.