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Drainage
Published in Derek Worthing, Nigel Dann, Roger Heath, of Houses, 2021
Derek Worthing, Nigel Dann, Roger Heath
The section of the Building Regulations that deals with drainage is Approved Document Part H: Drainage and Waste Disposal. The overriding concern of the regulations is that the drainage system should be able to carry and discharge its contents quickly and efficiently in such a way as to avoid damage to health. The points made below reflect the guidance given in Part H but it is worth noting that the design can be based on ‘credible’ alternative approaches, for example by being based on British Standards and using appropriate products which are certified by the British Board of Agrément (BBA).
Groundwater Cleanup and Remediation
Published in David H.F. Liu, Béla G. Lipták, Paul A. Bouts, Groundwater and Surface Water Pollution, 2019
David H.F. Liu, Béla G. Lipták, Paul A. Bouts
Subsurface drains require frequent inspection and maintenance during the first year or two of operation. Typical problems that can develop in drainage systems and require maintenance include clogging of the drain or manhole by sediment buildup or buildup of chemical compounds such as iron and manganese. Clogged pipes can be cleaned by hydraulic jetting, mechanical scrapping, or chemical treatment in cases of chemical buildup.
The Influence of Microfluidic Channel Wettability on PEM Carbon Paper Fuel Cell
Published in Sushanta K. Mitra, Suman Chakraborty, Fabrication, Implementation, and Applications, 2016
S. AlShakhshir, X. Li, P. Chen
Lenormand (1988, 1990) classified the drainage that takes place in porous media into three regimes depending on the viscosity ratio (M) and the capillary number (Ca). Drainage is the displacement of a wetting fluid by the injection of a nonwetting fluid. When drainage takes place in a porous media, three types of fluid flow regimes occur depending on M and Ca values: M=µnwµw,Ca=υµnwσ, where µw and μnw are the wetting and nonwetting fluid viscosities, ν is the fluid velocity, and σ is the surface tension.
Importance of surface drainage management to slope performance
Published in HKIE Transactions, 2018
Ryan W H Lee, Rachel H C Law, Dominic O K Lo
Professional input is highly valued in maintenance particularly in identifying obvious deficiencies and areas for improvement. The adequacy of the drainage measures and maintenance access should be reviewed regularly, for example, through Engineer Inspections. Environmental changes should be given due attention in the review as existing drainage measures could consequently be overwhelmed despite the apparently satisfactory performance in the past, for example, substantially greater amount of surface runoff may be conveyed to channels due to increased paved area or modified topography at upslope. Where necessary, drainage improvement measures may be implemented to enhance the flow efficiency. Some typical examples include the construction of baffle walls or elevated channel sidewalls, enlargement of channels and modification of abrupt channel alignments.
Properties of Foamed Gel for Coal Ignition Suppression in Underground Coal Mine
Published in Combustion Science and Technology, 2019
Qing Guo, Wanxing Ren, Lei Bai
The dominated mechanism affecting stability is the drainage. Drainage is a physical separation process in which gas and liquid in a foam system are separated due to gravity. Figure 5 shows comparison of drainages in plateau border in foam and foamed gel systems. In foamed gel, after being adsorbed at the gas and liquid interface, the gel particles are staggered on the foam wall to form a dense shell-like structure, consequently blocking the water flow channel. At the same time, the gel particles can exist between the bubble layer and the Plateau border. The formation of a three-dimensional network structure (gel skeleton) in the continuous phase also increases the resistance to moisture flow and delays the rate of foam thinning.