|
Airfield Rubber Removal
Airfield rubber removal, also known as runway rubber removal, is the use of high pressure water, abrasives, chemicals and other mechanical means to remove the rubber from tires that builds up on airport runways. In the United States, the Federal Aviation Administration (FAA) specifies friction levels for safe operation of planes and measures friction coefficients for the evaluation of appropriate friction levels. Individual airports incorporate rubber removal into their maintenance schedules based on the number of take offs and landings that each airport experiences. Source of airfield rubber build-up When a plane lands, the tires are not spinning. The time it takes for the tires to get up to speed is referred to as "spin up time" (Speidel, 2002). During this time the tires are effectively dragging on the runway as well as being put under pressure by the weight of the airplane. This can be seen in the slight puff of smoke that comes from a landing aircraft's tires as they first tou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weight
In science and engineering, the weight of an object is the force acting on the object due to gravity. Some standard textbooks define weight as a Euclidean vector, vector quantity, the gravitational force acting on the object. Others define weight as a scalar quantity, the magnitude of the gravitational force. Yet others define it as the magnitude of the reaction (physics), reaction force exerted on a body by mechanisms that counteract the effects of gravity: the weight is the quantity that is measured by, for example, a spring scale. Thus, in a state of free fall, the weight would be zero. In this sense of weight, terrestrial objects can be weightless: ignoring Drag (physics), air resistance, the famous apple falling from the tree, on its way to meet the ground near Isaac Newton, would be weightless. The unit of measurement for weight is that of force, which in the International System of Units (SI) is the newton (unit), newton. For example, an object with a mass of one kilogram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandblasting
Sandblasting, sometimes known as abrasive blasting, is the operation of forcibly propelling a stream of abrasive material against a surface under high pressure to smooth a rough surface, roughen a smooth surface, shape a surface or remove surface contaminants. A pressurised fluid, typically compressed air, or a centrifugal wheel is used to propel the blasting material (often called the ''media''). The first abrasive blasting process was patented by Benjamin Chew Tilghman on 18 October 1870. There are several variants of the process, using various media; some are highly abrasive, whereas others are milder. The most abrasive are shot blasting (with metal shot) and sandblasting (with sand). Moderately abrasive variants include glass bead blasting (with glass beads) and plastic media blasting (PMB) with ground-up plastic stock or walnut shells and corncobs. Some of these substances can cause anaphylactic shock to individuals allergic to the media. A mild version is sodablasti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocleaning
Pressure washing or power washing is the use of high-pressure water spray to remove loose paint, mold, grime, dust, mud, and dirt from surfaces and objects such as buildings, vehicles and concrete surfaces. The volume of a mechanical pressure washer is expressed in gallons or liters per minute, often designed into the pump and not variable. The pressure, expressed in pounds per square inch, pascals, or bar, is designed into the pump but can be varied by adjusting the unloader valve. Machines that produce pressures from 750 to 30,000 psi (5 to 200 MPa) or more are available. The terms pressure washing and power washing are used interchangeably in many scenarios, and there is some debate as to whether they are actually different processes. A pressure washing surface cleaner is a tool consisting of two to four high-pressure jets on a rotating bar that swivels when water is flowing. This action creates a uniformed cleaning pattern that can clean flat surfaces at a rapid rate. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroplaning (tires)
Aquaplaning or hydroplaning by the tires of a road vehicle, aircraft or other wheeled vehicle occurs when a layer of water builds between the wheels of the vehicle and the road surface, leading to a loss of traction that prevents the vehicle from responding to control inputs. If it occurs to all wheels simultaneously, the vehicle becomes, in effect, an uncontrolled sled. Aquaplaning is a different phenomenon from when water on the surface of the roadway merely acts as a lubricant. Traction is diminished on wet pavement even when aquaplaning is not occurring. Causes Every vehicle function that changes direction or speed relies on friction between the tires and the road surface. The grooves of a rubber tire are designed to disperse water from beneath the tire, providing high friction even in wet conditions. Aquaplaning occurs when a tire encounters more water than it can dissipate. Water pressure in front of the wheel forces a wedge of water under the leading edge of the tire, cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerize
In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many forms of polymerization and different systems exist to categorize them. In chemical compounds, polymerization can occur via a variety of reaction mechanisms that vary in complexity due to the functional groups present in the reactants and their inherent steric effects. In more straightforward polymerizations, alkenes form polymers through relatively simple radical reactions; in contrast, reactions involving substitution at a carbonyl group require more complex synthesis due to the way in which reactants polymerize. Alkanes can also be polymerized, but only with the help of strong acids. As alkenes can polymerize in somewhat straightforward radical reactions, they form useful compounds such as polyethylene and polyvinyl chloride (PVC), whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and even by industry. Further, both spellings are often used ''within'' a particular industry or country. Industries in British English-speaking countries typically use the "gauge" spelling. is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as of this. Manometric u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Pressure Water
Pressure washing or power washing is the use of high-pressure water spray to remove loose paint, mold, grime, dust, mud, and dirt from surfaces and objects such as buildings, vehicles and concrete surfaces. The volume of a mechanical pressure washer is expressed in gallons or liters per minute, often designed into the pump and not variable. The pressure, expressed in pounds per square inch, pascals, or bar, is designed into the pump but can be varied by adjusting the unloader valve. Machines that produce pressures from 750 to 30,000 psi (5 to 200 MPa) or more are available. The terms pressure washing and power washing are used interchangeably in many scenarios, and there is some debate as to whether they are actually different processes. A pressure washing surface cleaner is a tool consisting of two to four high-pressure jets on a rotating bar that swivels when water is flowing. This action creates a uniformed cleaning pattern that can clean flat surfaces at a rapid rate. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preventive Maintenance
The technical meaning of maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure, and supporting utilities in industrial, business, and residential installations. Over time, this has come to include multiple wordings that describe various cost-effective practices to keep equipment operational; these activities occur either before or after a failure. Definitions Maintenance functions can defined as maintenance, repair and overhaul (MRO), and MRO is also used for maintenance, repair and operations. Over time, the terminology of maintenance and MRO has begun to become standardized. The United States Department of Defense uses the following definitions:Federal Standard 1037C and from MIL-STD-188 and from the Department of Defense Dictionary of Military and Associated Terms * Any activity—such as tests, measurements, replacements, adjustments, and repairs—intended to retain or restore a func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into ''static friction'' ("stiction") between non-moving surfaces, and ''kinetic friction'' between moving surfaces. With the exception of atomic or molecular friction, dry friction generally arises from the interaction of surface features, known as asperities (see Figure 1). *Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. *Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. *Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body. *Internal friction is the force resisting motion between the elements making up a so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
