A method for flexibility analysis of continuous processing plants

A methodology has been developed for the analysis of operational flexibility of a continuous processing plant. An application has been demonstrated for a multipurpose plant with uncertain operating conditions. A practical flexibility analysis procedure using a direct search optimization algorithm is proposed to solve the problem. The method provides a heuristic screening technique that makes it possible to avoid the exhaustive enumeration of every constraint vertex, while the direct search optimization offers a simple and effective means to identify bottlenecks. A refinery multiperiod plant problem has been investigated in order to highlight the procedures which lead to the construction of flexibility indices for each operating mode.     

纳米光触媒降解低浓度氨气效能检测方法开发

开发了一种低成本快速创新的检测方法,主要装置为紫外线/可见光分光光度计及石英比色槽,较以往使用气相层析/质谱仪、傅立叶转换红外线光谱仪检测光触媒材料对气体降解效能简单又快速.实验时先将特定浓度气体注入一个密闭的石英比色槽中,再将比色槽置入紫外线/可见光分光光度计内进行检测,以获得特定浓度气体吸收光谱图及制备检量线,氨气检量线浓度范围为1×10-6～4×10-5.在光触媒材料进行异相光催化降解氨气效能分析检测时,将两种TiO2纳米触媒材料定量在石英基板上,置入比色槽内并注入氨气.同时将比色槽用UV光照射,进行降解实验,随后再将比色槽用紫外线/可见光分光光谱仪进行测试,由吸收光谱图中吸收强度,比对检量线,获得气体浓度变化以及光触媒材料对气体的降解效率.实验结果显示,真空潜弧合成系统自制的SANSS-TiO2光触媒,可将氨气的浓度降至原有的10.18%,商用纳米TiO2,仅能降至原有的49.7%.本研究已成功的建立简单,快速可靠的解低浓度氨气效能检测技术.     

Soil testing for available phosphorus in soils where phosphate rock-based fertilizers are used

Traditional soil tests for phosphorus (P) were developed to arrive at fertilizer recommendations when water-soluble P fertilizers have been used. When slowly water-soluble fertilizers such as phosphate rock (PR) have been used, soil tests using acidic extractants overestimate bioavailability of P, whereas alkaline extractants underestimate it. Therefore, separate calibration curves are needed for soluble and PR-based fertilizers. There are two soil tests that show promise as suitable tests in soils fertilized with soluble as well as PR-based fertilizers. These are the iron oxide impregnated paper (P _i ) test and the ion exchange resin paper test. In both cases, the strips act as a sink for P mobilized in a soil solution, and P measured depends only on the concentration of P mobilized in the solution and not on the source of P or properties of the soil. Both tests somewhat simulate the sorption of P by plant roots without disturbing the chemical equilibrium, unlike other tests that extract P by the destructive dissolution of specific soil P compounds. In both cases, P measured from soils fertilized with PR-based fertilizers has shown very good correlation with plant response. Field calibration with crops under different pedological and agroecological regimes is needed for using these soil tests in developing fertilizer recommendations.     

Posterior superior impingement of the rotator cuff on the glenoid rim as a cause of shoulder pain in the overhead athlete

A case of impingement of the deep surface of the supraspinatus tendon on the posterior superior rim of the glenoid and mild anterior laxity has been presented. The partial-thickness tear of the undersurface rotator cuff tendon, degenerative tear of the posterior superior labrum, and osteochondral impression fracture of the humeral head have been documented. The purpose of this case report is to present the pathological findings associated with posterior superior glenoid rim impingement and emphasize its role as a cause of shoulder pain in the overhead athlete. In addition it is important to stress the fact that shoulder pain in the overhead athlete may be multifactorial.     

A C-terminal fragment of Agouti-related protein increases feeding and antagonizes the effect of alpha-melanocyte stimulating hormone in vivo

Agouti-related protein (Agrp) is present in rat and human hypothalamus and is structurally related to agouti protein. Overexpression of either of these proteins results in obesity. However the effect of exogenous Agrp and its in vivo interaction with alpha-melanocyte stimulating hormone (alphaMSH), the likely endogenous melanocortin 3 and 4 receptor (MC3-R and MC4-R) agonist, have not been demonstrated. We report that 1 nmol of Agrp(83-132), a C-terminal fragment of Agrp, when administered intracerebroventricularly (ICV) into rats, increased food intake over a 24-h period (23.0+/-1.4 g saline vs 32.9+/-2.3 g Agrp, p<0.05). The hyperphagia was similar to that seen when 1 nmol of the synthetic MC3-R and MC4-R antagonist SHU9119 was given i.c.v. (19.6+/-1.8 g saline vs 32.5+/-1.7 g SHU9119, p<0.001). Both Agrp(83-132) and SHU9119 blocked the reduction in 1-h food intake of i.c.v. alphaMSH at the beginning of the dark phase. This effect occurred independently of whether the antagonists were administered simultaneously, or nine hours prior, to the alphaMSH. We have also shown Agrp(83-132) is an antagonist at the MC3-R and MC4-R, with similar inhibition of cAMP activation to that previously reported for the full length peptide. In conclusion, Agrp(83-132) administered i.c.v. increases feeding with long lasting effects and is able to inhibit the action of alphaMSH. This interaction may be mediated by the MC3-R and/or MC4-R.     

The contact stress analysis of plate and shell structures in pressure vessels

This study introduces the concept of contact stresses into an analysis of the local stresses in calculations relating to plate and shell structures in pressure vessels. A new computational method for local stresses is proposed in the light of the contact between pad and shell and the compatibility at the pad edges due to the fillet weld. Using the developed program of the contact stress analysis of plates and shells, which is based on the flexibility mixed FEM, the authors have studied the contact features of a pad structure under a concentrated load. Contact stress analyses of a saddle support model and a suspended tower structure have been made, which could not have been achieved with previous methods. The theoretical calculations showed reasonable agreement with the experimental results.     

Multilevel multisensory-based security system for an intelligent home

This article describes a multilevel multisensor-based security system that has multiple interfaces to be applied in an intelligent home. The security system contains four levels. There is a passive detection level, an active detection level, a system supervising level, and a remote supervising level. The control unit of these passive modules is a HOLTEK microchip. Each passive module has two different interfaces (wireless RF and voice). These modules can use a voice to alarm users than an event has occurred, and can transmit the real-time status and image signal to the active detection level and the system’s supervising level via the wireless RF interface. The active detection level can communicate with other levels via the wireless RF interface or the wireless Internet. The remote supervising level, the supervising level, and the active detection level can communicate with other levels via the wireless Internet. The status of these modules can also be displayed on the monitor of the supervising computer. Finally, we present some experimental results using passive and active detection modules in the security system.     

单源双能量X射线物质辨别方法研究

利用X射线双能量进行物质属性的判别,是机场、车站行李安全检查的一项基本技术.未经滤波的单个140KV的X射线源,发射的是连续能谱的X射线,采用两种不同能谱响应的探测器分别得到高低能量的透射信号.综合考虑连续能谱效应和探测器效率的影响,推导出高低能量的线性衰减系数比值的逼近多项式,对于固定的射线源和探测器这个多项式的各个系数是不变的.利用这种方法对物质属性进行判别,并给出了实验结果.     

Analysis of 3D Hand Trajectory Gestures Using Stroke-Based Composite Hidden Markov Models

We present a glove-based hand gesture recognition system using hidden Markov models (HMMs) for recognizing the unconstrained 3D trajectory gestures of operators in a remote work environment. A Polhemus sensor attached to a PinchGlove is employed to obtain a sequence of 3D positions of a hand trajectory. The direct use of 3D data provides more naturalness in generating gestures, thereby avoiding some of the constraints usually imposed to prevent performance degradation when trajectory data are projected into a specific 2D plane. We use two kinds of HMMs according to the basic units to be modeled: gesture-based HMM and stroke-based HMM. The decomposition of gestures into more primitive strokes is quite attractive, since reversely concatenating stroke-based HMMs makes it possible to construct a new set of gesture-based HMMs. Any deterioration in performance and reliability arising from decomposition can be remedied by a fine-tuned relearning process for such composite HMMs. We also propose an efficient method of estimating a variable threshold of reliability for an HMM, which is found to be useful in rejecting unreliable patterns. In recognition experiments on 16 types of gestures defined for remote work, the fine-tuned composite HMM achieves the best performance of 96.88% recognition rate and also the highest reliability.     

Silicon carbide MEMS for harsh environments

Silicon carbide (SiC) is a promising material for the development of high-temperature solid-state electronics and transducers, owing to its excellent electrical, mechanical, and chemical properties. This paper is a review of silicon carbide for microelectromechanical systems (SiC MEMS). Current efforts in developing SiC MEMS to extend the silicon-based MEMS technology to applications in harsh environments are discussed. A summary is presented of the material properties that make SiC an attractive material for use in such environments. Challenges faced in the development of processing techniques are also outlined. Last, a review of the current stare of SiC MEMS devices and issues facing future progress are presented