Transient operation of a catalytic liquid-liquid plug flow reactor for kinetics measurements

A centrifugal partition chromatograph (CPC) was used as a liquid-liquid catalytic reactor for the isomerisation of hexen-3-ol into ethylpropylketone with a water soluble rhodium catalyst. Global mass transfer coefficients were measured and shown to depend on both the nature of the solute and the flow rate. Liquid-liquid partition isotherms were also determined with the CPC using elution chromatography. Finally, a reactor model was derived to account for the experimental results obtained both under stationary and transient (pulse) conditions. A parameter sensitivity evaluation is also presented.     

Restoration of masonry facades, renders and final coats in a severe climate

The restoration of relatively old masonry buildings, 1870-1920, represents about 119930 flats and offices in the 4-5 largest cities in Norway. Driving rain and a severe climate are the key factors for deterioration. The paper describes a case study at the city campus of the University of Oslo.     

Kinetic analysis for effect of initial substrate concentration on growth and secondary metabolite production in cultures of Nicotiana tabacum

Suspension cultures of tobacco cells were studied using airlift and rotary-drum bioreactors. The effect of initial concentrations of a major substrate, sucrose, on the growth and production of a secondary metabolite, phenolic compounds, was investigated. The dry weights and total concentrations of the phenolic compounds increased with the initial sucrose concentration in both bioreactors. Both bioreactors were found to have the same tendency for the effect of initial sucrose concentration. The structured model, presented previously was modified by considering that sucrose was hydrolyzed to glucose and fructose by an enzymatic reaction. The previous and the new models were applied to the above two sets of experimental data obtained with two bioreactors, independently. The hydrolysis of sucrose was elucidated to contribute slightly to the overall kinetics of growth and secondary metabolite production in these cultures. Furthermore, the levels of shear damage in each bioreactor were quantitatively compared based on the death rate constant, k_i, which is one of the model constants.     

统计复用信道的数字用户环路复用设备

将信道传输容量动态分配技术应用于数字用户环路复用设备中，可用效地解决复用设备线路复用率和话音传输质量之间的矛盾，从而使复用设备具有最佳的传输效果。本文介绍了一种性能优良的统计复用信道的数字用户环路复用设备。     

Control of the quality of polymer products in continuous reactors: comparison of performance of state estimators with and without updating of parameters

In the paper the control of the product quality in polymerization reactors is analysed in the presence of persistent perturbations (unmodeled disturbances, modeling errors), as met in industrial reactors. The free radical polymerization of methyl-methacrylate in a continuous stirred tank reactor is studied. It is shown that state estimators (Extended Kalman Filters) with constant parameters cannot give offset free performance. Criteria for the selection of a set of parameters to be updated as additional states in the filter and to evaluate their effectiveness in opposing the action of realistic perturbations are given by an analysis of the linearized model of the system. Performance of different types of estimators, including one and two-time scale filters, with and without updating of parameters, is analysed by simulation on the full order process and the predictions made by previous analysis are confirmed. In the most common case of presence of perturbations affecting the energy balance and the concentration of initiator in the reactor, offset free control of the molecular weight of the product can be achieved by means of a filter which is based only on measurements of temperature and conversion and makes an update of two parameters. In the case that also the kinetic model of the polymerization reaction is affected by errors, a two-time scale filter, which makes use also of Molecular Weight values and updates three parameters, becomes necessary to obtain offset free performance.     

Experimental investigations of the effect of new passive safety systems on the temperature state of fuel elements

Results of experiments conducted on a large-scale integral PSB-VVéR bench and directed toward investigation of the performance of new passive safety systems for nuclear plants with a water-cooled power reactor, an additional system for passive flooding of the active zone, and a system for the passive removal of heat from steam generators are presented. __________ Translated from élektricheskie Stantsii, No. 9, September 2007, pp. 7–10.     

Design for a high power-density Astron reactor

A liquid lithium blanket surrounding the plasma volume is described. The liquid lithium flows along magnetic flux tubes at a high speed. There is no vacuum wall between the blanket and the plasma. The E-layer of relativistic particles within which the plasma is confined serves as a vacuum wall protecting the plasma from the lithium vapor, which is continuously produced at the surface of the blanket, by ionizing the lithium atoms and ejecting the same along open magnetic lines. The heat load at the surface of the blanket generated by 14 MeV neutrons can be several hundred MW per square meter.Work performed under the auspices of the U.S. Atomic Energy Commission.Deceased September 24, 1972.     

修正步冷温度曲线试验研究

按修正步冷温度曲线对经步冷脆化的 2 .2 5Cr 1Mo和在加氢反应器内运行 5a的 2 2 5Cr 1Mo试块进行了修正步冷试验 ,评定了材料的回火脆性。结果表明 ,按修正步冷曲线进行修正步冷试验能使已经脆化的材料进一步脆化 ,为加氢反应器材料损伤的研究提供了一条途径。     

西安脉冲堆计算值和实测结果分析

介绍了西安脉冲堆堆芯布置、计算模型和程序以及计算值与实验测量结果分析。西安脉冲堆在满功率（2MW）下连续运行了72小时，证明西安脉冲堆整个系统和设备是良好的、安全可靠的。根据西安脉冲堆计算值与测量值的比较，证明计算程序可靠，具有较高精度。西安脉冲堆理论计算值与实验测量值符合较好，完全满足工程设计要求，实验测量结果达到了设计指标的要求。     

Polarisation behaviour of diode lasers with frequency selective feedback

The paper reviews recent results obtained with diode lasers used in external hybrid cavities with frequency selective feedback. Such cavities attract continuing interest for several reasons. They generate a tunable single laser mode with very low linewidths (usually a few tens of kilohertz). Very wide discrete tunable ranges over 100 nm for Fabry-Perot type and over 200 nm for quantum well lasers are achieved. They can be made to oscillate in a tunable mode having the desired polarization state,TE orTM and, in some cases, simultaneously atTE andTM. This is done by designing a cavity that increases strongly theTM/TE intensity ratio and by using coatings on one laser facet that greatly lower bothTE andTM reflectivities. High-speed polarization switching in the gigahertz range is possible by inserting passive or active polarization selecting elements in the cavity. For all these reasons hybrid external cavities are attractive for applications in optical metrology, spectroscopy and optical communications. Moreover, the external cavity configuration allows the study of physical mechanisms in the laser diode by inducing on purpose phenomena that would have been otherwise impossible to achieve with free-running lasers.