Detonation characteristics of ammonium nitrate and activated carbon mixtures

To better understand the detonation characteristics of ammonium nitrate (AN) and activated carbon (AC) mixtures, steel tube tests were carried out for AN/AC mixtures of various compositions and different forms of AN (powdered, prilled, phase stabilized and granular), and the detonation velocity was measured. The powdered AN/AC mixtures gave higher detonation velocities than the other AN forms. For all the AN/AC mixtures, the experimentally observed detonation velocities at each loading density were far below the theoretically predicted values calculated by the CHEETAH code based on thermohydrodynamics, exhibiting so-called non-ideal detonation. The lowest detonation velocity of powdered AN/AC mixtures was obtained as D=1.25 km/s for an AC content of 0.1 wt%. This was considered to be close to the critical condition for stable detonation.     

330/220kV电磁环网解环前后暂态稳定特性分析

为保证宁夏电网 330/220 kV 电磁环网解环后电网的安全稳定运行,运用电力系统分析综合程序(Power System Analysis Software Package,PSASP),对电磁环网解环前后电网在三级稳定标准涉及的各种故障形式下进行暂态稳定计算,对比分析解环前后系统电压与频率波动以及功角阻尼比的变化。计算结果表明:330/220kV 电磁环网解环对于宁夏电网的暂态稳定特性影响不大,解环后不会增加暂态失稳事故风险,解环条件一旦具备,应该及时实施解环。     

Job Redesign Needs for Aged Workers

The aim of this paper is to explore and present a proposal for redesigning elements of the workplace for agech workers. The method of research was to observe, record, and measure the actions of sitting workers performing assembly operations on electrical products in the Kani Plant Nagoya Works of Mitsubishi Electric Co. (Japan). The evaluation index used in the experiment was obtained by measuring time motion elements, cycle time per product, and motion velocity waves of elderly workers. Those motion characteristics were then compared to the motion characteristics of young workers. The results led to job redesign elements being identified to reduce handling factors of high difficulty for aged workers and to the necessity to consider a coefficient of correction in Method Time Measurement (MTM) according to differences in the manufactured object’s weight.     

Action-Oriented Support for Occupational Safety and Health Programs in Some Developing Countries in Asia

Action-oriented support programs have been increasingly playing vital roles in promoting safety and health in developing countries in Asia. This paper studied achievements of 3 action-oriented support programs: the WISE program for small enterprises, the WIND program for farmers, and the POSITIVE program for workers and trade unions. Special attention was paid to how the programs have strengthened local efforts for sustainable actions in safety and health improvements. The results showed that there were significant achievements in action-oriented support programs in the region, including a large number of improvement examples, integration into government policies, and network support through employers’ and workers’ organizations. Participatory, action-oriented training tools such as action-checklists, local good example photos, and group work methods played key roles in the effective implementation of the programs. It was of note that there were a number of local efforts to extend the coverage of action-oriented support even to hard-to-reach workers such as home-based workers, rural workers, and ethnic minorities. The efforts included the equal participation in the training by female and male farmers, shortened and weekend training programs, photo sheets showing local good examples, and reasonable fee collection for better sustainability. In conclusion, action-oriented support programs provided local people with concrete means to promote safety and health improvements. The successful programs commonly focused on local initiatives and were built on local wisdom and resources.