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The trigger action response plans(TARPs) are inherent to managing the multiple hazards such as: high gas content with multiple coal seams, high spontaneous combustion(sponcom) propensity, heat and ventilation. TARPs aim to provide assurance and guidance when the situation deviates from the original plan or there is a change conditions that could be hazardous. Over the years, learnings from various incidents has continuously required the coal operations to re-visit the TARP trigger values that were based on historic data or based on guidance values from the industry. In most cases, the background to the basis of TARP statistical data, viz., average, maximum, hourly, daily for the monitoring or sampling location is also unknown. Introduction of real-time monitoring devices to monitor the gases and airflows has provided greater understanding of the hazard scenarios and their controls. This paper analyses the carbon monoxide data from operating longwall mines and compares these with the historic trigger values to understand the changes and determine improvement opportunities while setting trigger levels in the TARPs.As an example of setting trigger values, those used in during the sealing of a panel are explored in terms of setting values based upon the sampling location and the level of risk. It is envisaged that the learning's shared herein would further enhance the understanding and management of multiple hazards in Australian coal mines. 相似文献
3.
The influence of oxidation reduction potential and water treatment processes on quartz lamp sleeve fouling in ultraviolet disinfection reactors 总被引:1,自引:0,他引:1
Ultraviolet (UV) disinfection systems are incorporated into drinking water production facilities because of their broad-spectrum antimicrobial capabilities, and the minimal disinfection by-product formation that generally accompanies their use. Selection of an optimal location for a UV system within a drinking water treatment facility depends on many factors; a potentially important consideration is the effect of system location on operation and maintenance issues, including the potential for fouling of quartz surfaces. To examine the effect of system location on fouling, experiments were conducted at a groundwater treatment facility, wherein aeration, chlorination, and sand filtration were applied sequentially for treatment. In this facility, access to the water stream was available prior to and following each of the treatment steps. Therefore, it was possible to examine the effects of each of these unit operations on fouling dynamics within a UV system. Results indicated zero-order formation kinetics for the fouling reactions at all locations. Increases in oxidation reduction potential, caused by water treatment steps such as aeration and chlorination, increased the rate of sleeve fouling and the rate of irradiance loss within the reactor. Analysis of metals in the sleeve foulant showed that calcium and iron predominate, and relative comparisons of foulant composition to water chemistry highlighted a high affinity for incorporation into the foulant matrix for both iron and manganese, particularly after oxidizing treatment steps. Fouling behavior was observed to be in qualitative agreement with representations of the degree of saturation, relative to the metal:ligand combinations that are believed to comprise a large fraction of the foulants that accumulate on the surfaces of quartz jackets in UV systems used to treat water. 相似文献
4.
Standard multivariable sampled-data system with generalized hold of arbitrary order is investigated. An algorithm for design
of H
2-optimal digital controller is presented. Some qualitative properties of the H
2-optimal system are described, which are important in applications. 相似文献
5.
B. P. Lampe E. N. Rosenwasser 《Journal of Computer and Systems Sciences International》2013,52(4):542-570
A frequency-polynomial H 2-optimization method for sampled-data systems with generalized hold functions and delay is proposed, which is based on the application of the concept of a parametric transfer matrix. A number of general properties of H 2-optimal systems that must be taken into account in solving practical design problems are established. 相似文献
6.
Stuart Anderson Jennifer S. Shane Cliff Schexnayder 《Canadian Metallurgical Quarterly》2011,137(5):372-381
Departments of transportation in the United States are under increasing pressure to accelerate projects to meet user-defined constraints and reduce the inconvenience to the traveling public. Although there is information about acceleration projects in other industries, there has been little specifically aimed at highway projects. A domestic scan sponsored by the National Cooperative Highway Research Program was tasked with providing information in this area. The objective of this paper is to synthesize the resulting information into fundamentals that support successful planned accelerated highway project delivery. Case studies of how departments of transportation successfully accelerated the construction of four very different projects in California, Florida, and Texas serve as the basis for identifying these fundamentals. The fundamentals include upfront and detailed planning, designs that facilitate accelerated construction, a collaborative environment for project stakeholders, and incentives and disincentives to motivate construction contractors. 相似文献
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Using data from the Pittsburgh Air Quality Study, we find that temperature, relative humidity, their squared terms, and their interactions explain much of the variation in airborne concentrations of PM 2.5 in the city. Factors that do not appreciably influence the concentrations over a full year include wind direction, inverse mixing height, UV radiation, SO 2 , O 3 , and season of the year. Comparison with similar studies of PM 2.5 in other cities suggests that the relative importance of different factors can vary greatly. Temperature and relative humidity are important factors in both Pittsburgh and New York City, and synoptic scale meteorology influencing these two sites can explain much of the pattern in PM 2.5 concentrations which peak in the summer. However, PM 2.5 levels in other cities have different seasonal patterns and are affected by a number of other factors, and thus the results presented here cannot be generalized to other locations without additional study. 相似文献
9.
The influence of operating conditions such as reheat, intercooling, ambient temperature and pressure ratio are analyzed from a second law perspective on the performance of a natural gas‐fired gas turbine cogeneration system. The effect of these operating parameters on carbon dioxide emissions is also discussed. The second law efficiency of gas turbine cogeneration system increases markedly with reheat option. Higher pressure ratios lead to decreased second law cogeneration efficiency but this effect can be reduced with a higher level of reheat option. The effect of intercooling on second law efficiency is strongly related to pressure ratio with higher pressure ratios significantly decreasing efficiency. The second law efficiency is not so sensitive to the environment temperature for levels of reheat or intercooling greater than 50%. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
10.