Oil Palm Trunk as a Raw Material for Activated Carbon Production

Oil palm trunk is a major lignocellulosic-rich, solid waste material generated from palm-oil upstream industry. The activated carbons prepared from oil palm trunk pretreated with phosphoric acid with the ratio of the acid to the precursor of 0.9, followed by carbonization and activation by carbon dioxide resulted in a high surface area of more than 1800 m²/g with 90% content of micropore surface area. The surface area and the nature of the porosity of the resulting activated carbons were found to be dependent on the amount of the activator used for a fixed quantity of the precursor. Pretreatment of the precursor at low ratio of the phosphoric acid has added advantage, due to the tremendous increase in the apparent surface area of the resulting activated carbon and at the same time enriching its micropore nature. This could result in the conservation of the micropore fraction. On the other hand, using too high a ratio of the phosphoric acid to the precursor did not increase the apparent surface area very much, but instead destroyed the micropore component, and thus increasing the mesopore fraction of the resulting activated carbon. This study also shows that oil palm trunk, a by-product of oil palm industry has a great potential as a raw material for activated carbon production.     

嵌入式微处理器浮点执行部件的CPLD实现

该文重点论述了基于MIL-STD-1750A标准的嵌入式微处理器浮点执行部件EMFPU(EmbeddedFloatingPointUnit)的CPLD实现。详细介绍了FLEX10KE器件的结构特点,EMFPU的设计,以及在AlteraCPLD可编程器件上的实现,并给出了实现的结果。     

关于全国跨大区联网目标网架的设想

本文就当前我国跨大区联网的战略提出尽快研究和规划全国跨大区联网总体目标网架的重要性,建议考虑全国国在跨大区干肉架与周边集资联网存在的形式,并具体采用大容量高架网的结构。文中讨论了防止发生大面积停电事故的基本措施,最后建议尽快研究制定有关联网政策,准则,开发联网软件及关键技术手段,加强宣传及培训,以促进全国联网的早日实现。     

数字程控交换机的开局及维护

以JSU2000—16交换机为模型,就交换机在开局过程中遇到的一些实际问题进行深入分析并提出具体解决方案,对交换机的运行维护提出一些建议。     

利用三层交换机实现vlan间通信

随着社会的发展,企事业单位的网络规模变得越来越大要求也越来越高,为了提高网络性能避免广播风暴,加强网络的安全性,以及组织结构上的考虑,在实际工程中需要考虑将网络划分vlan,而vlan的划分同样也阻断了不同vlan间的网络的互相访问,对实际工作带来不便,通过三层交换机的技术可以解决不同vlan间的通信问题。     

VLAN裁剪技术在高校校园网中的应用

本文结合徐州师范大学校园网实例,分析了VLAN的组播/广播流量泛洪形成的原因,提出大规模校园网VLAN管理中存在的问题,并针对问题给出了VLAN裁剪的解决方案。这种方案对于高校和政府机关的网络管理工作,具有一般性、推广性。     

Effects of handicraft sitting postures on lower trunk muscle fatigue

Fifteen male subjects were exposed to a primary tracking task and a variety of subsidiary tasks for a total of 15 hours. Tracking performance was assessed through the use of two error measures, amount of time off the target track, and number of times off target. Subsidiary performance tasks included: a vigilance task requiring subjects to respond to the deflection of the noodle of a small meter; two reaction time tasks requiring response to the onset of one or the other of two lights; mental multiplication, which required the solution of simple multiplication problems; and digit span, in which the subject was required to repeat as rapidly and as accurately as possible a sot of digits of either five, six or seven numbers in length. In addition, three physiological measures were obtained.

A significant decrement in trucking performance was obtained for both measures utilized. This decrement was not particularly abrupt in its occurrence but rather took place cumulatively over the entire course of the experiment. There was no clearly established performance decrement on the subsidiary tasks utilized in this investigation. A marked variability in performance over the course of the experimental session was characteristic of performance on these tasks. Performance on the vigilance task, and one of the reaction time tasks improved during the 15-hour test session.

The 17-Kotosteroid and 17-Hydroxyeortieoid values increased during the session but only in the case of the latter was the increase significant. The eosinophil count of subjects exposed to the test conditions decreased steadily throughout the experimental session. However, eosinophil measures obtained from control subjects increased during a similar time period.     

Characterisation of trunk muscle activation amplitude patterns during a simulated checkstand operation with continuously changing flexor and lateral moment demands

While the typical physical exposure to modern-day workers has changed from heavy to low level repetitive demands, there is limited research that examines light occupations. This study examined trunk muscle recruitment strategies in response to a simulated checkout operation. Surface electromyography and kinematic variables were recorded from 29 healthy subjects. Four principal patterns accounted for 95.3% of the variation. Significant differences in scores captured different strategies in response to reach conditions and external moment directions. Synergistic co-activation of ipsilateral back sites and differential activation among external oblique and erector spinae sites suggests that the central nervous system may control different regions of the trunk musculature to optimally account for asymmetrical demands. The strategy between the internal oblique and back extensor sites suggests that a specific co-activation strategy may be needed during lighter work. During low-load occupational tasks, several recruitment strategies were required to maintain spinal stability and account for changing external moments.

Statement of Relevance: Different recruitment strategies found in response to changing external moments offer new insights into neuromuscular control for lighter work. Specifically, multiple trunk muscle sites interact in a complex manner, taking into account task specificity and individual variation that are valuable in workstation design, evaluating injury risk and estimating spinal loads.     

基于大数据与线路画像的干线断线故障自适应判别方法

针对干线断线故障特征无序化、整体判别过程自适应系数不稳定、判别误差增大的问题,引入大数据与线路画像两种算法,提出了一种干线断线故障自适应判别方法。分析干线断线故障点特征,构建线路画像,结合干线运行大数据,生成干线断线画像,改善判别方法自适应能力。分析低压位置的侧方位相电压关系,在现有画像结构中干线空闲位置上引入一组参量,判别通过变压器母线电压是否大于额定电压,二次利用大数据算法优化判别函数,自适应判别整体干线断线故障。仿真测试结果表明,该方法能够有效解决判别误差偏大问题,且整体适应性良好,满足实际应用要求。     

Solving problems in the welding of large structures made of molybdenum alloys

This article describes the determination of the stress state of cylindrical couplings, couplings with unloading rings used for restoring the load-carrying capacity of sections of transmission pipelines with metal losses of different origin, and also of sheltering branch pipes, branch pipes with a ring-shape strap and a split T-branch, used as repair jackets preventing unsealing of fittings.