Quantitative dam break analysis on a reservoir earth dam

Mathematical simulations on dam break or failure using Boss Dambrk hydrodynamic flood routing dam break model were carried out to determine the extent of flooding downstream, flood travel times, flood water velocities, and impacts on downstream affected residences, properties and environmental sensitive areas due to floodwaters released by failure of the dam structure. Computer simulations for one of the worse-case scenarios on dam failure using BOSS DAMBRK software accounted for dam failure, storage effects, floodplains, over bank flow and flood wave attenuation. The simulated results reviewed a maximum flow velocity of 2.40 m/s with a discharge [Q] of approximately 242 m[3]/s occurred at 1.00 km downstream. The maximum discharge increased from 244 m[3]/s [flow velocity = 1.74 m/s occurred at 8th km] to 263 m[3]/s [flow velocity = 1.37 m/s occurred at 12th km]; about a 39% drop in flow velocity over a distance of 4.00 km downstream. If the entire dam gives way instantly, some spots stretching from 0.00 km [at dam site] to approximately 3.40 km downstream of the dam may be categorized as "danger zone", while downstream hazard and economic loss beyond 3.40 km downstream can be classified as "low" or "minimal" zones

Composition and characteristics of construction waste generated by residential housing project

The construction industry is a major consumer of new materials. Given that material production for construction work accounts for a significant percentage of all energy consumed nationally in newly developing countries, it becomes vital that the construction industry strives to reduce waste at all stages of construction. However, the importance of these construction wastes in terms of types and sources have yet to be identified. Established systems to record quantitative data for the generation of construction waste have yet to be formally standardised and are still lacking across much of Europe and developing countries. Although categorisation of waste assists segregation of construction waste and increases the potential for reuse and recycling, little progress has been made in Sarawak, the largest state in Malaysia. To address this need, this pilot study is carried out as the logical first step towards construction waste management in Sarawak by categorisation of construction waste at residential construction projects. Through this study, useful information concerning waste assessment data necessary to achieve a better understanding of construction waste is obtained. Case studies involving quantification and classification of construction waste for several on-going residential construction projects in Miri City, Sarawak, Malaysia are presented. A database of information concerning the quantification of local construction waste was developed, in addition to current construction waste management practices

Field tests on a grease trap effluent filter

This study investigates the field performance tests of a commercial grease trap effluent filter for removal of total suspended solids, and oil and grease discharged from the clear zone of full service restaurant grease traps. The grease trap effluent filters were installed on 1,000-gallon, 2,000-gallon and 5,400-gallon full service restaurant grease traps over a period of 8 weeks, and samples were taken at the inlets and outlets. On average, the effluent filters demonstrated to be capable of removing 41% to 57% of TSS, and 43% to 52% of O and G. Field test data also showed that the total amount of TSS removed by the grease trap effluent filter installed on 1,000 gallon, 2,000 gallon and 5,400 gallon grease traps were approximately 2,542 kg, 709 kg, and 2,319 kg, respectively; and the total amount of O and G removed over the same period were approximately 1,104 kg, 271 kg, and 897 kg, respectively

Computer simulated versus observed NO[2] and SO[2] emitted from elevated point source complex

ISC-AERMOD dispersion model was used to predict air dispersion plumes from an diesel power plant complex. Emissions of NO2 and SO2 from stacks [5 numbers] and a waste oil incinerator were studied to evaluate the pollutant dispersion patterns and the risk of nearby population. Emission source strengths from the individual point sources were also evaluated to determine the sources of significant attribution. Results demonstrated the dispersions of pollutants were influenced by the dominant easterly wind direction with the cumulative maximum ground level concentrations of 589.86 micro g/m3 [1 h TWA NO2] and 479.26 micro g/m3 [1 h TWA SO2]. Model performance evaluation by comparing the predicted concentrations with observed values at ten locations for the individual air pollutants using rigorous statistical procedures were found to be in good agreement. Among all the emission sources within the facility complex, SESB-Power [diesel power plant] had been singled out as a significant source of emission that contributed >85% of the total pollutants emitted

comparison of nearby incremental ground level and in plant concentrations of air pollutants emitted from electronics facilities

Air dispersion modeling by was recently conducted to predict the incremental ground level and in-plant concentrations of toxic organic chemicals due to stack and fugitive emissions from Sama Jaya Free Industrial Zone [SJFIZ], Kuching, Sarawak, Malaysia. Simulations of organic air pollutants emitted from industrial facilities in SJFIZ from years 1996 to 2001 were carried out in September 2004 by members of Faculty of Engineering, Universiti Malaysia Sarawak [UNIMAS]. The results indicated that there were negligible amount of maximum incremental ground level concentrations of less than 3x10-2 micro g/m3 for 365-day average, and less than 18x10-2 micro g/m3 for 24 h. average. For in-plant maximum incremental concentrations, it is found that the simulated results were much lower than TWA values, except xylene. The predicted in plant concentration of xylene was 119.21 [parts per million] ppm as compared to ACGIH TLV-TWA of 100 ppm approximately 19% higher than ACGIH recommended values. From this study, it was concluded that both nearby population and in plant workers were not potentially at risk to exposing organic chemicals far lower than the threshold limit levels set by ACGIH