CSHM: Web-based safety and health monitoring system for construction management

INTRODUCTION: This paper describes a web-based system for monitoring and assessing construction safety and health performance, entitled the Construction Safety and Health Monitoring (CSHM) system. METHOD: The design and development of CSHM is an integration of internet and database systems, with the intent to create a total automated safety and health management tool. A list of safety and health performance parameters was devised for the management of safety and health in construction. A conceptual framework of the four key components of CSHM is presented: (a) Web-based Interface (templates); (b) Knowledge Base; (c) Output Data; and (d) Benchmark Group. RESULTS: The combined effect of these components results in a system that enables speedy performance assessment of safety and health activities on construction sites. With the CSHM's built-in functions, important management decisions can theoretically be made and corrective actions can be taken before potential hazards turn into fatal or injurious occupational accidents. IMPACT ON INDUSTRY: As such, the CSHM system will accelerate the monitoring and assessing of performance safety and health management tasks.     

Graduated driver licensing restrictions: awareness, compliance, and enforcement in North Carolina

PROBLEM: This study examined the extent to which critical restrictions in North Carolina's graduated driver licensing (GDL) system are known, adhered to, and enforced. METHOD: Teenagers and their parents were recruited as they applied for either an intermediate or full license at 1 of 23 licensing offices. Telephone interviews were conducted with 900 teenagers and their parents. RESULTS: Awareness of North Carolina's night and passenger restrictions was very high among both parents and teenagers. Ten percent of teenagers reported violating the night restriction without their parents' knowledge, and 15% had done so with their parents' approval. Only 4% of parents reported allowing their teenagers to drive with more than one teenage passenger, but 19% of teenagers reported that they were allowed to do this. Violations of the passenger restriction without parental knowledge were more common than violations of the night restriction (22% vs. 10%, respectively). Among teenagers who violated restrictions without their parents' knowledge, most reported doing so only once or a few times. Teenagers expressed little concern about detection, although a majority reported driving more carefully to avoid police notice. Neither parents nor teenagers knew much about police enforcement of GDL restrictions. To obtain a sense of the views of law enforcement officers, informal interviews were conducted with 20 officers from five diverse communities and the state highway patrol. These officers were highly supportive of GDL but unfamiliar with many of the specific provisions. Moreover, enforcement of GDL restrictions did not appear to be a high priority. IMPACT ON INDUSTRY: There is a need to increase the belief among teens (and parents) that police are enforcing GDL restrictions in their community; law enforcement participation in well-publicized traffic safety enforcement efforts would likely produce this result.     

基于安全流变理论的交通系统事故过程分析

运用事物的安全流变规律分析系统的运行过程 ,指出系统的运行过程符合安全流变规律。通过对交通系统中的不安全因素扰动的分析 ,揭示了交通系统的安全流变特征 ;对传统的事故定义进行了拓展 ,将事故隐患纳入了事故的发展过程 ;提出了交通系统事故安全流变分析方法 ;最后通过一个具体的案例分析了系统事故的安全流变过程。     

通才式安全工程专业课程设置的探讨

根据安全工程专业所处的学科结构体系 ,讨论了通才式安全工程专业高等教育课程设置所考虑的因素。提出了通才式安全工程专业高等教育课程的设置思想、专业基础课和主干课的学时比以及实践与理论相结合的实习方法。     

CFRP用于火灾后钢筋混凝土梁抗弯加固的试验研究及有限元分析

笔者结合对结构火灾损伤的分析 ,采用有限元分析软件ANSYS对火灾后CFRP加固钢筋混凝土梁荷载与应变、挠度的关系进行了数值分析 ,并与试验结果进行了比较 ,吻合良好。加固后的混凝土梁在钢筋屈服后 ,仍然有一定的荷载容量。这种荷载承受能力可一直持续到结构破坏 ,这主要是碳纤维布在后期发挥的作用 ,用碳纤维布加固受火后的混凝土梁 ,能明显地提高梁的极限承载力 ,在钢筋屈服后对梁的刚度有较大幅度的提高。在挠度的计算中 ,在钢筋屈服后 ,有限元模型由于混凝土的裂缝快速发展 ,刚度下降很大 ,所以挠度在相同荷载下 ,稍大于试验值。这与笔者提出的扰度简化计算公式的计算结果与试验数据十分吻合。用ANSYS对CFRP加固梁进行分析能够达到比较精确的理论分析结果。     

热爆炸理论在粉尘爆炸机理研究中的应用

笔者对粉尘爆炸的几种机理进行了简要分析 ,认为粉尘爆炸是由热爆炸引起的。在对粉尘燃烧过程作了较为合理的假设后 ,将热爆炸理论中均温系统的热爆炸判据 ,应用于粉尘爆炸中 ,得出了爆炸下限与粉尘粒径呈线性关系的结论 ,且与实验符合 ,并推导出粉尘的热爆炸判据。结果表明 :用热爆炸理论来解释粉尘爆炸机理是可行的。     

Assessment of sampling and chemical analysis of source-separated organic household waste

The quality of the waste sampling procedure and chemical analysis was evaluated in a research program on characterization of organic waste obtained after disc screening of source-separated organic household waste. The sampling procedures focused on a truckload of waste and involved several steps of subsampling including shredding, mixing, blending, high-speed-blending, drying and milling prior to analysis of the organic waste with respect to ash content, crude fibers, crude fat, crude protein, sugar, starch, enzyme-digestible organic matter, P, N, C, H, S and calorific value. The statistical evaluation of the procedures involved 10 samples of the same truckload of waste obtained by splitting the sample at each level in the procedure according to a staggered, incomplete nested statistical design. Furthermore, one sample was analysed six times over a period of approximately one year. The statistical evaluation showed that no single step in the sampling procedure contributed with excessive variance and that the variance caused by the sampling procedure was approximately the same as the variance in the chemical analysis observed over a year. The variance varied with the analytical parameter but for most parameters the uncertainty was satisfactorily low (of the order of 3-10% expressed as the relative standard deviation, which is considered to be satisfactory for waste characterization).     

Long-term behavior of passively aerated compost methanotrophic biofilter columns

The methane oxidation potential of several types of compost methanotrophic biofilter columns were compared in the laboratory over a period of 220 days. The results indicate an increase in methanotrophic activity over a period of about 100 days, up to a maximum of 400 g m(-2) day(-1), and a gradual decline to about 100 g m(-2) day(-1) within the next 120 days. High methane oxidation rates appear to be restricted to a small area of the column, 10-15 cm thick. Based on the laboratory investigations carried out to determine the cause for the decline in methane oxidation rate, it was concluded that the formation of exopolymeric substances (EPS), at the zones of maximum methane oxidation, was responsible for this decline. In monitoring methane oxidation in a column for up to 600 days, it was observed that mixing of the medium after formation of EPS enabled the column to temporarily recover high performance. The results suggest that stable, homogenous compost, with a low C/N and low ammonium content, mixed on a regular basis, could achieve and maintain high methane oxidation efficiencies.     

Reusability of sewage sludge in clay bricks

Bricks produced from sewage sludge in different compositions were investigated. Results of the tests indicated that the sludge proportion is a key factor in determining the brick quality. Increasing the sludge content results in a decrease in brick shrinkage, bulk density, and compressive strength. Brick weight loss on ignition was mainly due to the contribution of the contained organic matter from the sludge being burnt off during the firing process, as well as inorganic substances found in both clay and sludge. The physical, mechanical, and chemical properties of the bricks that were supplemented with various proportions of dried sludge from 10 to 40wt% and generally complied with the General Specification for Brick as per the Malaysian Standard MS 7.6:1972, which dictates the requirements for clay bricks used in walling in general. A standard leaching test method also showed that the leaching of metals from the bricks is very low.