TURBULENCE TRANSPORT OF SURFACTANT SOLUTION FLOW DURING DRAG REDUCTION DEGENERATION

Turbulence transport of surfactant solution flow during drag reduction degeneration is investigated experimentally in a two-dimensional channel.Particle Image Velocimetry (P1V) system is used to take t...     

The effect of reducing the number of EMG channel inputs on loading and stiffness estimates from an EMG-driven model of the spine

Electromyography (EMG)-driven models of the spine routinely require between ten and 14 EMG channels to estimate joint load and stiffness variables. This study was designed to determine the sensitivity of common EMG-driven model outputs to the removal of individual EMG channels, and to test two adapted models driven from eight channels. A total of 11 male participants performed a variety of static exertions designed to resist either an applied trunk flexion or right side trunk lateral bend moment. In this study, 14 channels of EMG were recorded and used to drive a biomechanical model of the spine to predict L4-L5 joint load and stiffness values. The model was subsequently re-run after the removal of individual pairs of bilateral EMG channels, and again with eight-channel models in which the rectus abdominus, latissimus dorsi and multifidus EMG-channels were eliminated. Results showed that the eight-channel model provided estimates for the majority of output variables that did not differ substantially from the 14-channel model, except in instances in which muscle force output was ramped to resist flexion moments. Estimates of the output variables were, in general, improved when multifidus fascicles were re-added to the model and driven from the lumbar erector spinae EMG sites.     

Stores clustering using a data mining approach for distributing automotive spare-parts to reduce transportation costs

Clustering of retail stores in a distribution network with specific geographical limits plays an important and effective role in distribution and transportation costs reduction. In this paper, the relevant data and information for an established automotive spare-parts distribution and after-sales services company (ISACO) for a 3-year period have been analyzed. With respect to the diversity and lot size of the available information such as stores location, order, goods, transportation vehicles and road and traffic information, three effecting factors with specific weights have been defined for the similarity function: 1. Euclidean distance, 2. Lot size 3. Order concurrency. Based on these three factors, the similarity function has been examined through 5 steps using the Association Rules principles, where the clustering of the stores is performed using k-means algorithm and similar stores are allocated to the clusters. These steps include: 1. Similarity function based on the Euclidean distances, 2. Similarity function based on the order concurrency, 3. Similarity function based on the combination of the order concurrency and lot size, 4. Similarity function based on the combination of these three factors and 5. Improved similarity function. The above mentioned clustering operation for each 5 cases addressed in data mining have been carried out using R software and the improved combinational function has been chosen as the optimal clustering function. Then, trend of each retail store have been analyzed using the improved combinational function and along with determining the priority of the depot center establishment for every cluster, the appropriate distribution policies have been formulated for every cluster. The obtained results of this study indicate a significant cost reduction (32%) in automotive spare-parts distribution and transportation costs.     

工艺参数对TiO2碳热还原合成Ti（C,N）粉末的影响

本文探讨了ＴｉＯ２碳热还原法合成Ｔｉ（Ｃ，Ｎ）粉末过程中合成温度，保温时间，Ｎ２气流量，Ｃ／Ｔｉ比值等工艺参数的变化对粉末性状的影响，实验表明，Ｎ比Ｃ更易于Ｔｉ结合，改变工艺对数可调整Ｔｉ（Ｃ１－ｘＮｘ）的ｘ值。在１４００～１７００℃间可获得ｘ值的０．６～０．８５的Ｔｉ（Ｃ１－ｘＮｘ）粉末。     

电炉还原熔炼氧化钴矿的生产实践

介绍了刚果(金)钴铜冶炼厂电炉还原熔炼处理钴铜氧化矿工艺的设计特点及生产实践。     

葡醛内酯生产工艺改进研究

在实验研究的基础上，对现有葡醛内酯生产工艺中存在的的问题提出了相应的对策．为了提高产率，减轻污染以降低生产成本，进行了分阶段和全流程工艺实验，确认淀粉氧化工序中硝酸的浓度以70％适宜，氧化温度应控制在50℃或稍低，氧化淀粉水解前用硼氢化钠或氢气对氧化淀粉进行还原是提高葡醛内酯产率的有效手段．通过控制用酸量、改进加料方式和改善吸收可以有效地减轻环境污染．     

一级除盐系统再生酸碱用量调整与探讨

论述了该厂300MW机组火电厂化学水处理一级除盐设备再生的酸碱用量调整试验的基本过程，并对一级除盐设备运行提出了相应的措施，调整试验达到节约酸碱用量、降低生产成本的目的。     

Incremental Feature Selection

Feature selection is a problem of finding relevant features. When the number of features of a dataset is large and its number of patterns is huge, an effective method of feature selection can help in dimensionality reduction. An incremental probabilistic algorithm is designed and implemented as an alternative to the exhaustive and heuristic approaches. Theoretical analysis is given to support the idea of the probabilistic algorithm in finding an optimal or near-optimal subset of features. Experimental results suggest that (1) the probabilistic algorithm is effective in obtaining optimal/suboptimal feature subsets; (2) its incremental version expedites feature selection further when the number of patterns is large and can scale up without sacrificing the quality of selected features.     

微细粒浸染型金矿碱性介质浮选法研究

介绍了微细粒浸染型金矿石浮选富集的一种新方法———以碳酸钠作为pH调整剂的碱性介质浮选法,并研究了这种方法浮选富集矿石过程中各种因素的影响。研究表明,在弱碱性矿浆中(pH值7 5～8 5)能够较好地实现载金矿物与脉石矿物的浮选分离。     

Atmospheric effects of friction,friction noise and wear with silicon and diamond. Part II. SEM tribometry of silicon in vacuum and hydrogen

Scanning electron microscope (SEM) tribometric data on polycrystalline silicon (poly-Si) vs. poly-Si, Si(100) vs. Si(100) and Si(111) vs. Si(111) interfaces, obtained in Torr and in 0.2 Torr partial pressure of hydrogen gas ( ) from room temperature to 850^°C, were performed under standard and much slower thermal ramping rates. The friction data were analyzed per the methodology described in part I of this paper series. The results indicate a highly beneficial friction- and wear-reducing regime within a relatively narrow thermal region. This desirable region coincides with some chemisorption of excited species of molecular hydrogen just before the mass thermal desorption of surface hydrides. These data represent the tribochemical equivalent of a method routinely used in electronics, whereby deep electron traps (dangling Si bonds) are passivated by baking in molecular hydrogen. The also exerts a moderating influence on the size of the friction noise at all test temperatures. However, the general level of friction beyond the beneficial thermal region is high. In parallel, the general wear rate of Si representative of the entire range of standard thermal ramping in both atmospheric environments is in the extremely high 10^-12m³/(N m) range. Operating strictly in the beneficial, low-friction thermal regime resulted in a several orders-of-magnitude reduction in the wear rate over those measured under standard thermal ramping conditions. Although the results confirm previous findings that Si is not a good material of construction for miniaturized moving mechanical assemblies (e.g., microbearings and gears), there seems to be some limited possibility of gas-phase lubrication of Si micromechanisms with rarefied hydrogen at surface temperatures between 100 and 300^°C. This revised version was published online in July 2006 with corrections to the Cover Date.