Sun light or artificially generated electromagnetic waves consists of waves of different lengths. The spectrum of an electromagnetic wave Among these waves microwaves, infrared waves and visible light waves are useful for the distance measurement. In EDM instruments these waves are generated, modulated and then propagated. They are reflected at the point up to which…
For curved surfaces the fluid pressure on the infinitesimal areas are not parallel and so must be combined vectorially. It is usual to consider the total horizontal and vertical force components of the resultant. Surface Containing Liquid Consider the surface AB which contains liquid as shown below: Surface Displacing Liquid Consider the surface AB which…
Ardern and Lockett, who invented the activated sludge process, first used the term, activated sludge, in 1914. Their discovery of the value of recycling biological solids in aerobic wastewater treatment led to the activated sludge process, now the most widely used biological treatment process. On April 3, 1914, at a meeting of the Society of Chemical…
CAUSES OF DAMPNESS Dampness may be caused by: (a) Ground water (b) Rainwater and (c) Leakages from pipes. (a) Dampness due to Ground Water: All buildings are founded on soils. Soil holds water for along time. Sometimes water level may rise and come in contact with foundation. Due to capillary action moisture from ground rises into foundation, floor…
A freely suspended and properly balanced magnetic needle is expected to show magnetic meridian.However, local objects like electric wires and objects of steel attract magnetic needle towards themselves.Thus, needle is forced to show slightly different direction. This disturbance is called local attraction. The list of materials which cause local attraction are: (i) magnetic rock or iron ore, (ii) steel structures, iron…
Projection of Solids: A solid is a three dimensional object having length, breadth and thickness. It is Completely bounded by a surface or surfaces, which may be curved or plane. The shape of a solid is described orthographically by drawing its two orthographic projections, usually, on the two principal planes of projection i.e., HP and…
The problem of water leakages Water is a daily necessary resource for life, health, economic development and the ecosystem all over the world. As water is precious to everyone, its availability and quality are essential. Climate change, droughts, water shortages and population growth are increasing the strain on existing water resources, thereby increasing the necessity…
The new complex method of seismic hazard assessment that resulted in creation of the probabilistic maps of seismic microzonation is presented in this chapter. To study seismicity and analyze seismic hazard of the territory the following databases are formed: macroseismic, seismologic databases and the database of possible seismic source zones (or potential seismic sources –…
Tedious hand calculations and slide rules for structural engineering design and analysis has given way to a plethora of low cost or even free structural engineering design software. A few example links are listed for convenience. The Evolution of Structural Engineering Design Software It wasn’t too long ago that structural engineering design calculations were performed…
FLOOR SLABS Treatments for conventional flat slab design are as follows: 1. More attention must be paid to the design and detailing of exterior bays and lower floors, which are the most susceptible to blast loads. 2. In exterior bays/lower floors, drop panels and column capitols are required to shorten the effective slab length and…