摘要：Recirculation is prohibited in many coal mining countries because of the fear that the re-use of return air would allow the build-up of air contaminants at the workings. The incorrect design and location of a booster fan in any ventilation network can create unsafe condition due to recirculation. The current approach to investigating recirculation using simulation software requires manual effort which becomes tedious in a complex and a large network. An algorithm-based C++ program was designed to detect the recirculation in a booster fan ventilation networks. This program needed an input file prepared from output file generated by any ventilation simulator. This program created an output file for recirculation. This program demonstrated the strong capability to detect the recirculation in a sample network and a coal mine ventilation network. The outcomes of this program were documented in this paper.

摘要：Diesel particulate matter （DPM） is considered to be carcinogenic after prolonged exposure. With more diesel- powered equipment used in underground mines, miners＇ exposure to DPM has become an increasing concern. This paper used computational fluid dynamics method to study the DPM dispersion in a dead-end entry with loading operation. The effects of different push-pull ventilation systems on DPM distribution were evaluated to improve the working conditions for underground miners. The four push-pull systems considered include： long push and short pull tubing; short push and long pull tubing, long push and curved pull tubing, and short push and curved pull tubing. A species transport model with buoyancy effect was used to examine the DPM dispersion pattern with unsteady state analysis. During the 200 s of loading operation, high DPM levels were identified in the face and dead-end entry regions. This study can be used for mining engineer as guidance to design and setup local ventilation, select DPM control strategies and for DPM annual training for underground miners.

摘要：Uniformity of air flow in extraction openings in exhaust air channels for manure gas exhaustion is determined by the distribution of pressure. The areas required in extraction vents and in extraction ducts are determined by the uniformity of air flow desired along the duct and by the loss of pressure that can be accepted. The area ratio between the vents and the cross section of the exhaust air duct will have a strong influence on both uniformity of flow and loss of pressure. The following ventilation properties were studied： Uniformity of air flow; Variations in static pressure along a duct; Air velocity at different distances from the vents. The area ratio should be about 1 for uniform exhaustion. The studies showed that the relative variation in air velocity is independent of the level of the ventilation rate. The uniformity of the exhaust distance is influenced in about the same way by the area ratio as the air velocity in the exhaust vents. Thus, it is important that the area ratio is not too high if a good exhaust function should be guaranteed. The studies also demonstrated that the uniformity of the exhaust distance is independent of the ventilation flow rate. The exhaust ventilation range is, maximally 0.3 m from the vents. The static friction coefficient was on average 0.80.

摘要：Design Concept:Y Lego Designed around three key ideas,the concept proposes a modular unit that maximises cross ventilation through a design that avoids corridors and always gives double orientation to every ***"Y"lego units can be adjusted to suit different site conditions in a range of different configurations. The structural approach highlights steel’s credentials of lightness and high performance under tension.设计理念:Y Lego Y lego围绕着三个关键的概念,设计提出了一个单元要尽量交叉通风,尽量避免走廊并始终给予每个空间以两个朝向。几何的"Y"型可以调整,以适应不同地理条件下的各种不同配置。结构突出了钢材的轻巧及高性能,见图1。

摘要：目的:对于无需机械通气的轻中度呼吸窘迫综合征(RDS)的早产儿选择性地使用表面活性剂,从而研究其疗效和安全性。试验设计:试验对象是132例患有RDS的婴儿,其出生体重≥1250g,胎龄≤36周,出生后4-24h接受治疗,FIO2≥40%的持续时间≥1h,并且没有立即插管的需要。

摘要：目的:比较围拔管期应用两种剂量枸橼酸咖啡因在早产儿(胎龄<30周)拔管中的利弊。设计:采用多中心、随机、双盲临床试验。机构:选用澳洲4个3级新生儿单位。患者:胎龄<30周的早产儿,通气时间超过48h。