Heat transfer, any or all of several kinds of phenomena, considered as mechanisms, that convey energy and entropy from one location to another. The specific mechanisms are usually referred to as convection, thermal radiation, and conduction . Conduction involves transfer of energy and entropy between adjacent molecules, usually a slow process. Convection involves movement of a heated fluid, such as air, usually a fairly rapid process. Radiation refers to the transmission of…
From corvée to toll Through the millennia, responsibility for financing and building roads and highways has been both a local and a national responsibility in the nations of the world. It is notable that this responsibility has changed along with political attitudes toward road building and has not rested easily with any party. Many roads…
Introduction Hydrostatics involves only a few variables: ρ , g, and h, and so the equations developed are relatively simple and experiment and theory closely agree. The study of fluids in motion is not as simple and accurate. The main difficulty is viscosity. By neglecting viscosity (an ideal fluid), we do not account for the…
A straight line is the shortest distance between two points. Projections of the ends of any line can be drawn using the principles developed for projections of points. Top views of the two end points of a line, when joined, give the top view of the line. Front views of the two end points of…
The establishment of two- or three-dimensional control networks is the most fundamental operation in the surveying of large or small areas of land. Control networks comprise a series of points or positions which are spatially located for the purpose of topographic surveying, for the control of supplementary points, or dimensional control on site. The process…
INTRODUCTION Radionuclides are elements (uranium 235, uranium 283, thorium 232, potassium 40, radium 226, carbon 14 etc) with unstable atomic nuclei and on decomposition release ionizing radiations in the form of alpha, beta and gamma rays. Out of the known 45O radioisotopes only some are of environmental concern like strontium 90, tritium, plutonium 239, argon…
Vehicle control during hydroplaning requires special techniques that are different from normal driving on the road. The brakes should not be applied when hydroplaning; otherwise the vehicle may be imbalanced. Steering input should be smooth. Otherwise, control can be completely lost. What Is Hydroplaning Hydroplaning occurs when there is too much water on the surface…
Ceramic spheres of microscopic sizes are a part of thermal insulation paint. These spheres are hollow and thus less conductive, leading to heat insulation. The paints are also lighter and have many other additional properties which give it an advantage over other paints. The Development of Thermal Insulation Paint Ceramic insulation coatings were originally developed…
Types of defects in plaster This post describes 7 different categories of defects most frequently noticed in plaster (as mentioned below) 1. Non-structural cracks 2. Structural cracks 3. Debonding 4. Lack of hardness 5. Grinning 6. Expansion 7. Popping The causes and repair methods for each are discussed below. 1. NON-STRUCTURAL CRACKS Crazing Crazing is a network of fine cracks, usually in a hexagonal…
The process of finding a single vector which will have the same effect as a set of vectors acting on a body is known as composition of vectors. The resolution of vectors is exactly the opposite process of composition i.e., it is the process of finding two or more vectors which will have the same…