A new method for the evaluation of the reversible and irreversible fouling propensity of MBR mixed liquor

In this paper, a new fouling measurement method is presented as a pragmatic approach to determine a mixed liquor's fouling propensity. The MBR-VFM (VITO Fouling Measurement) uses a specific measurement protocol consisting of alternating filtration and physical cleaning steps, which enables the calculation of both the reversible and the irreversible fouling resistances. The MBR-VFM principle, set-up and measurement protocol are described as well as the evaluation of the fouling measurement method. Finally, the MBR-VFM was validated by comparing the fouling propensity measured on-line by the MBR-VFM in a lab-scale MBR with the fouling of the MBR membranes themselves. Our experiments indicated that the MBR-VFM can accurately measure fouling and that it can even be detected earlier than can be seen from the on-line filtration data of the lab-scale system itself. Furthermore, the differences measured in reversible and irreversible fouling seemed to be related to the observed impact of physical and chemical cleaning respectively. Therefore, the application of the MBR-VFM as an on-line sensor in an advanced control system, enabling the deployment of the measured fouling data for the control of membrane cleaning, seems feasible and will be tested in the near future.     

化工装置常用流量计原理及选型使用探讨

介绍了电磁式、涡轮式、差压式等几种流量计的原理及选型与安装使用,阐述了各自的特点。     

用等值宽度法测量fs脉冲宽度

本文提出利用等值宽度测量fs光脉冲持续时间的方法.给出了脉冲形状为sech~2 (t/T)、exp(-2t~2/T~2)和exp(-2|t|/T)的干涉相关曲线上包络与相应二阶强度相关曲线半宽度等值的位置,它们分别是3.984、4.875和4.928.定义了两种相关测量的临界延迟速度.理论分析与实验结果符合得很好.所得结果表明,该测量方法可将常规超短脉冲相关测量的时间分辨率提高几倍至几十倍.     

基于视觉的汽车覆盖件塑性主应变测定

基于视觉技术采用方形网格法进行变形区域塑性主应变分布测量.分析了其原理、特点以及根据节点位移计算塑性主应变的相关理论和方法.     

Theory of optimal consumption and portfolio selection under a Capital-at-Risk (CaR) and a Value-at-Risk (VaR) constraint

The solution to the optimal portfolio selection and consumptionrule subject to Capital-at-Risk and Value-at-Risk constraintsis derived via the use of stochastic dynamic programming.     

中子辐照锂化合物溶液产生氚的测量系统设计及实验

本文介绍一个用来测量中子辐照锂化合物产生的氚氢(HT)和氚水(HTO)系统。包括工作原理、操作步骤及初步实验结果。     

Design of optical triangulation devices

This paper presents the derivation of the precise relation between the displacement of a light spot on an object's surface and the displacement of its image on the detector in an optical triangulation device, along with applications of the design of triangulation devices. Based on this relation, improved designs of optical triangulation devices, including devices of adjustable configurations, are proposed and discussed.     

Measurement of rail cross-section with solid-state sensor arrays

The application of light sectioning to the accurate measurement of a rail cross-section, from a train moving at high speed, is described. The intensity distribution through the thickness of the illuminating light sheet is deliberately graded, allowing the shape of the object to be recovered more accurately by interpolation of the sampled image. Rail profiles are extracted with a definition approximately ten-times better than that of the sampled image.     

光学材料热光系数的精确测量——“热光系数仪”

本文介绍用于光学材料系数精确测量的“热光系数仪”。该仪器采用两种干涉仪组合、微机控制和数据采集处理等设计方案,实现了高精度测量。低温区热膨胀系数α、折射率温度系数β热光系数W的测量精度可达±3×10~(-7)°C~(-1)。     

Instantaneous phase shifting arrangement for microsurface profiling of flat surfaces

Phase shifting interferometry is a well-established technique for non-contact surface profile measurement. Though phase shifting technique has many advantages, it is marred by a few inaccuracies due to the vibration and mechanical movement of the phase shifter itself. Significant amount of work is reported to theoretically compensate these error sources. But for a few works, prominent achievements have not been reported in eliminating these error sources in phase shifting interferometry. In this paper, a novel optical layout, in combination with instantaneous phase shifting interferometry is described. Experiments were carried out with this setup on a super mirror with a λ/20 surface roughness, to demonstrate the validity of the principle.