Estimating discharge in gravel‐bed river using non‐contact ground‐penetrating and surface‐velocity radars

Discharge measurement is a critical task for gravel‐bed channels. Under high‐flow conditions, the elevation of the riverbed changes significantly by intensive torrential flow. The stage–discharge relations commonly used for stream discharge estimation may no longer be adequate. The contact‐type velocity measuring is also subject to measurement errors and/or instrument failures by the high‐flow velocities, driftwood, stumps, and debris. This study developed a new real‐time method to estimate river discharge in gravel‐bed channels. A systematic measuring technology combining ground‐penetrating radar and surface‐velocity radar was employed. The rating curves representing the relations of water surface velocity to the channel cross‐sectional mean velocity and flow area were established. Stream discharge was then deduced from the resulting mean velocity and flow area. The proposed method was examined in a steep gravel‐bed reach of the Cho‐Shui River in central Taiwan. The estimated stream discharge during three flood events were compared to the prediction by using the stage–discharge relation and the index‐velocity method. The proposed method of this study is capable of computing reasonable values of discharge for an entire flood hydrograph, whereas the other two methods tend to produce large extrapolation errors. Moreover, when the computed discharge is used in 2D flood flow simulation, the proposed method demonstrates better performance than the commonly used stage–discharge and index‐velocity methods.     

Cocurrent downflow circulating fluidized bed (downer) reactors — A state of the art review

In the last decade, cocurrent downflow circulating fluidized bed reactors, called “downer” reactors, have been proposed as an alternative to upflow circulating fluidized bed, or “riser”, reactors. In this paper, published results on downer studies are summarized and future directions of research are recommended. Downer reactors are shown to have several distinct advantages over upflow circulating fluidized bed reactors and can potentially be used in many industrial processes, mainly due to a more uniform gas and solids flow structure compared with risers.     

Design of a slave arm of a surgical robot system to estimate the contact force at the tip of the employed instruments

Acquisition of the contact force at the instrument tip can enable better performance, e.g. transparency of the haptic feedback in the surgical robot systems. It is, however, difficult to measure the contact force directly due to technical limitations in attaching sensors to the tip of the instruments. This paper proposes a method to estimate the forces by installing the sensors away from the instrument tip. The proposed method employs specially designed mechanical parts of the slave robot, i.e. a slider cover plate for the z-axis translational force along the insertion direction, and docking clamps for the rotational pivot torques around the fulcrum point. Strain gauges are attached to specially designed places with enhancing shapes. The simulation results of the force estimation are presented to confirm the strain concentration area. The proposed method is validated with quantitative experimental results. Calibrated weights are determined upon the comparison of the strain value with a calibrated 6-axis force/torque sensor. The percentage error in the force calibration is about 5~8% calculated by the root mean square error (RMSE) of force-sensing performance. In addition, it can be computed by considering only the bending phase of each sensor although the hysteresis is observed from the calibration graph.     

Chemical properties of femoral gland secretions in the desert iguana,Dipsosaurus dorsalis

This study investigates the chemistry of femoral gland secretions in the desert iguana,Dipsosaurus dorsalis (Lacertilia: Iguanidae), and discusses their possible functional significance. Electrophoretic and proton NMR studies indicated that the secretions are composed of approximately 80 % protein and 20% lipid material. Individual differences in polyacrylamide gel banding patterns of femoral gland proteins were found. Reflectance spectroscopy revealed that the secretions strongly absorb longwave ultraviolet light, a feature that may be important in the localization of secretion deposits in the environment.     

膜生物反应器技术处理洗浴废水的工程应用

根据洗浴废水的水质水量，设计了生物接触氧化和膜生物反应器相结合的处理工艺(水量为120m^3／d)。通过对工艺相关设计参数的选取和调试运行结果表明，该工艺具有处理效果稳定、抗冲击负荷强以及操作简便等优点。     

水解酸化-接触氧化工艺处理松脂加工废水

通过中和-气浮-水解酸化-接触氧化工艺对松脂加工废水进行处理,废水的CODCr由2 368 mg/L降至93 mg/L,去除率达到95%以上,其余指标均达到污水一级排放标准.试验结果表明,采用厌氧折流板反应器(ABR)能够很好地控制废水水解酸化的进程;接触氧化段较高的溶解氧对难降解的松脂加工废水有较好的处理效果.     

Contributions to the Ohmic Drop in the Electrolysis of ZnCl2 in a Molten Chloride Electrolyte

The electrowinning of zinc from zinc chloride with a molten chloride electrolyte was investigated. The electrolysis of zinc chloride shows ohmic limitations. The energy consumption is to a large extent determined by the anodic reaction, the evolution of chlorine. The chlorine gas plume was visualised in a see-through furnace and images were analysed to determine the plume angle. This parameter serves as an input parameter for a model to determine the ohmic contributions of the electrolyte, the plume and a layer of chlorine bubbles sticking to the anode, as well as the plume velocity. The results indicate that the major contribution (60%) to the ohmic drop is due to a stagnant layer of bubbles growing and sticking to the anode, thereby decreasing the effective anode area by coverage. The plume velocity influences coverage characteristics to some extent, which influences the ohmic drop.     

低氟含量低表面能自清洁氟碳涂料的研究

以氟单体和丙烯酸酯类单体通过聚合物的分子结构设计，合成了一类总氟含量不超过12％的低氟含量的含氟丙烯酸树脂，所制备的氟碳涂料的涂层的表面能低，具有自清洁功能。分析了该涂层中极性与非极性官能团的分子取向机理，测定了纯水水珠在不同含氟单体均聚物和共聚物清漆漆膜上以及在含氟丙烯酸树脂涂层上的接触角，探明了含氟丙烯酸树脂涂层的总氟含量与表面能的关系、含氟官能团在涂层中的分布，探讨了低氟含量的含氟丙烯酸树脂涂料的涂层自清洁机理。     

一种高灵敏度液面探测系统的设计及其临床应用

介绍了一种高灵敏度液面探测(LLD)系统的设计方法及其在全自动生化分析仪中的应用。系统以接触式电容法原理为核心,采用强绝缘金属双套管采样针作为探测传感器,配以基于锁相环相位比较器的电容检测电路,并结合自适应有效脉冲识别算法,实现了生化分析仪样品交叉污染率不大于0.3%和最小2μL样品时加样误差不大于±3%的性能指标。全自动生化分析仪的临床应用表明:系统具有探测灵敏度高、可靠性强和运行稳定等特点。     

Peel Adhesion of Poly(Vinyl Chloride) to Nitrile Rubbers

In addition to molecular interaction and physical entanglement of the molecular chains across the interface in poly (vinyl chloride)-nitrile rubber joints, at high temperatures and long contact times interfacial chemical bonds may be formed which seem to couple the two adherends thereby resulting in cohesive failure of the rubber matrix on peeling. This is verified by performing the peel tests at high temperatures, low peel rates and under swollen conditions. Infrared spectroscopic studies of the PVC/NBR blend reveal the formation of chemical bonds at the contact temperatures studied. The peel fracture energy is found to depend on the acrylonitrile content and presence of carboxylic content in the NBR, and the presence of stabilizer and plasticizer in the PVC phase, in addition to the molding and testing conditions.