1,040 research outputs found

    The Development of Microreactor Technology for the Study of Multistep Catalytic Systems and Rapid Kinetic Modelling

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    Microreactor technology was applied to the study of catalytic systems because their high rates of heat and mass transport, improved safety and ease of automation makes them particularly effective research tools in this area. A multistep flow system for the synthesis of benzylacetone from benzyl alcohol via oxidation, aldol condensation and reduction reactions was developed by utilising three micropacked bed reactors and a gas liquid membrane separator. This reaction had previously been conducted in batch cascade, however, the multistep flow system enabled the achievement of higher yields with lower catalyst contact times because separating each reaction into its own reactor allowed greater freedom to tailor the operating conditions for each reaction. The multistep system also allowed the catalysts to be studied in a process wide environment, leading to the identification of significant catalyst inhibition due to by and co-products from upstream reactions. An automated closed loop microreactor platform was developed which utilised Model-Based Design of Experiments (MBDoE) algorithms for rapid kinetic modelling of catalytic reactions. The automated platform was first applied to the homogenous esterification of benzoic acid with ethanol using a sulfuric acid catalyst, where a campaign of steady-state experiments designed by online MBDoE led to the estimation of kinetic parameters with much higher precision than a factorial campaign of experiments. This reaction was then conducted with MBDoE designed transient experiments, which dramatically reduced the experimental time required. The same reaction was studied using a heterogeneous Amberlyst-15 catalyst, and by combining factorial designs, practical identifiability tests and MBDoE for model discrimination and parameter precision, a practical kinetic model was identified in just 3 days. The automated platform was applied to the oxidation of 5-hydroxymethylfurfural in a micropacked bed reactor with gas-liquid flow using AuPd/TiO2 catalysts, however due to poor experimental reproducibility, a kinetic model was not identified

    The Integration of Rural Households into Ruminant Livestock Industries in China

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    A major determinant of rural development in China is the way by which rural households integrate with rural industries. Three forms of integration market integration, vertical integration and integration through local groups are investigated. Policy measures that may facilitate household integration, household specialisation and market segmentation are identified. Findings for the ruminant livestock sector are widely applicable to other agricultural industries in China.China, rural development, livestock, markets, vertical integration, Livestock Production/Industries, Q13, Q18, L1,

    Improving the Economic Decision-Making Capability and Viability of Chinese Wool Textile Mills

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    The successful restructuring of Chinese industries is of immense importance not only for the continued development of China but also to the stability of the world economy. The transformation of the Chinese wool textile industry illustrates well the many problems and pressures currently facing most Chinese industries. The Chinese wool textile industry has undergone major upheaval and restructuring in its drive to modernize and take advantage of developments in world textile markets. Macro level ownership and administrative reforms are well advanced as is the uptake of new technology and equipment. However, the changing market and institutional environment also demands an increasing level of sophistication in mill management decisions including product selection, input procurement, product pricing, investment appraisal, cost analysis and proactive identification of new market and growth opportunities. This paper outlines a series of analyses that have been integrated into a decision-making model designed to assist mill managers with these decisions. Features of the model include a whole-of-mill approach, a design based on existing mill structures and information systems, and the capacity for the model to be tailored to individual mills. All of these features facilitate the adoption of the model by time and resource constrained managers seeking to maintain the viability of their enterprises in the face of extremely dynamic market conditions.China, wool textile mills, industry transition, decision-making models, Agribusiness, Livestock Production/Industries,

    A Search for EUV Emission from the O4f Star Zeta Puppis

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    We obtained a 140 ks EUVE observation of the O4f star, zeta Puppis. Because of its low ISM column density and highly ionized stellar wind, a unique EUV window is accessible for viewing between 128 to 140 A, suggesting that this star may he the only O star observable with the EUVE. Although no SW spectrometer wavelength bin had a signal to noise greater than 3, a bin at 136 A had a signal to noise of 2.4. This bin is where models predict the brightest line due to OV emission should occur. We present several EUV line emission models. These models were constrained by fitting the ROSAT PSPC X-ray data and our EUVE data. If the OV emission is real, the best fits to the data suggest that there are discrepancies in our current understanding of EUV/X-ray production mechanisms. In particular, the emission measure of the EUV source is found to be much greater than the total wind emission measure, suggesting that the EUV shock must produce a very large density enhancement. In addition, the location of the EUV and X-ray shocks are found to be separated by approx. 0.3 stellar radii, but the EUV emission region is found to be approx. 400 times larger than the X-ray emission region. We also discuss the implications of a null detection and present relevant upper limits

    Relating Static and Dynamic Measurements for the Java Virtual Machine Instruction Set

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    It has previously been noted that, for conventional machine code, there is a strong relationship between static and dynamic code measurements. One of the goals of this paper is to examine whether this same relationship is true of Java programs at the bytecode level. To this end, the hypothesis of a linear correlation between static and dynamic frequencies was investigated using Pearson’s correlation coefficient. Programs from the Java Grande and SPEC benchmarks suites were used in the analysis
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