1. Relating to or caused by a physical force: "Mechanical results are produced by a machine or a tool."
2. A reference to, relating to, derived from, or concerned with machinery or tools: "In photolithography, a mechanical process that involves a sheet of stiff paper on which the copy for a given plate has been mounted."

"The mechanical procedure results in a finished copy which usually contains hard lettering, type proofs, and art; especially, positioned and mounted so that a photochemical reproduction can be made on a letterpress, offset, or other printing plate."

In medicine, the aggravation intensifying the unhealthy condition of existing acne lesions by mechanical factors; such as, rubbing, pinching, or pulling on them.

1. The ratio of the force produced by a machine: One example of a mechanical advantage is a lever or pulley that can be used to analyze the performance of a machine."
2. The ratio of the output force to the input force for a machine which transmits mechanical energy: "Mechanical advantage is the work produced by a machine, divided by the force applied to it".

"Actual machines can provide a mechanical advantage that is greater than unity (number or numeral one, oneness); however, the greater the mechanical advantage, the greater the distance which the input force must move in relation to the output force."

Aeration of waste water and industrial discharges by physical means: Mechanical aeration is the agitation of waste material from manufacturing companies by the use of paddle wheels, mixers, or rotating brushes.

1. A process for producing composite metal powders with controlled, extremely fine microstructures, involving balanced repetitive welding, fracturing, and rewelding of a mixture of powder particles in a dry, highly energetic ball charge which is a type of grinder used to grind materials into extremely fine powder for use in mineral dressing processes, paints, pyrotechnics, and ceramics.
2. A materials-processing method for assembling metal constituents with a controlled microstructure by repeated welding, fracturing, and rewelding of a mixture of powder particles, generally in a high-energy ball mill (a pulverizer that consists of a horizontal rotating cylinder, up to three diameters in length, containing a charge of tumbling or cascading steel balls, pebbles, or rods).

A machine aid to computation in which variables are represented as continuously variable displacements or motions of mechanical elements; such as, gears and shafts.

1. A specific compound or mixture which, when administered, which prevents or retards the absorption of a poison: "In the laboratory, the scientist developed a mechanical antidote for the virus that was spreading among the cattle in the area."
2. A remedy to counteract the effects of a poison or toxin: "The ambulance driver administered the mechanical antidote to the snake bite victim to retard the effects of the toxin during the trip to the hospital."

"The mechanical antidote is administered by mouth, intravenously, or sometimes on the skin, and it may work by directly neutralizing the poison."

1. Those areas within a building that include equipment rooms and passages through which air circulates and where piping, communication, hoisting, conveying, and electrical services are installed.
2. The areas in a building that include equipment rooms, shafts, stacks, tunnels, and closets used for heating, ventilating, air conditioning, piping, communication, hoisting, conveying, and electrical services.

1. An arrangement and construction of moving parts in reciprocating or rotating machines to reduce dynamic forces which may result in undesirable vibrations.
2. A balance in which the sample weight is determined by comparison with a calibrated weight.

The mechanical balance consists, essentially, of a rigid beam that oscillates on a horizontal central knife-edge as a fulcrum and has the two end knife-edges parallel and equidistant from the center. The loads to be weighed are supported on pans hung from bearings.

1. In radar, the radial line on a transparent disk that can be rotated to determine bearing or location.
2. A radar set in which the radial line inscribed on a transparent disk can be rotated manually around an axis coincident with the center of the plan position indicator.

It is used for determining bearing or location.

1. The phenomenon by which normally isotropic materials are made birefringent (splitting of a light beam into two components, which travel at different velocities) by the application of mechanical stress.
2. A change in the double refraction of a solid material when it is subjected to stress.

Small-bowel obstructions in pediatric patients are uncommon but should be suspected in any child with persistent vomiting and abdominal pain because delayed diagnosis and treatment can have devastating consequences.

Infants and young children may have intestinal obstruction present with pain, irritability, vomiting, and abdominal distension.

Small-bowel obstructions progress to decreased or even no bowel movements. Undiagnosed or improperly managed, obstructions can lead to vascular compromise, causing bowel ischemia, necrosis, perforation, and death.

A scale drawing of a mechanical or architectural structure done with precision instruments: "Mechanical drawings involve the actions or processes of making scale drawings."

1. The ratio between the brake (useful) horsepower and the indicated horsepower of an engine.
2. The measure of the effectiveness with which a system performs.

It is stated as the ratio of a system's work output to its work input.

In a theoretically frictionless, or ideal, machine, the work input and the work output are equal, and the efficiency would be 1, or 100%.

The sum of the kinetic (motion) energy and the potential energy of an object.

A person who deals with the design, construction, and uses of machines: "James was a mechanical engineer who was involved in modernizing machines."

1. The branch of engineering concerned with the generation, transmission, and utilization of heat and mechanical power, and with the production and operations of tools, machinery, and their products.
2. A division of engineering concerned with the efficient design, operation, and maintenance of machines: "Mechanical engineering involves the design, the production, and the use of machinery and tools, as well as the generation and transmission of heat and mechanical power."

1. Thermodynamics, in which a constant which expresses the number of units of heat in terms of a unit of work, typically expressed as the amount of heat transfer required to raise the temperature of one gram of water from 14.5 to 15.5 degrees centigrade.
2. The amount of mechanical energy equivalent to a unit of heat.
3. The number of units of work or energy equal to one unit of heat; such as, 4.1858 joules, which equals one small calorie.

A pencil with a plastic or metal case and a thin replaceable lead which can be extended when the point is worn away by twisting the outer casing.

1. Any property of a material which influences its behavior when it is exposed to external forces; such as, its hardness or elasticity.
2. A property which involves a relationship between stress and strain or a reaction to an applied force.

1. A standard process of refrigeration, in which a motor-driven compressor drives the circulation of a refrigerant through a closed loop, so that the refrigerant withdraws heat energy from the load (space to be cooled) as it changes from a liquid to a gaseous state.
2. The removal of heat by utilizing a refrigerant subjected to cycles of refrigerating thermodynamics and employing a mechanical compressor.

1. Any hemostatic device, or material, that facilitates coagulation of bleeding vessels.
2. A mechanical styptic which assists the clotting of blood by mechanical means.

The principle of heat which consists of motions of the particles that make up a substance.

1. The erosion, disintegration, or breakdown of rock into smaller fragments by natural physical agents with no chemicals involved; some agents of mechanical weathering are frost, tree roots, etc.
2. A collective term for all of the natural physical processes which break rock into smaller fragments without chemical changes; for example, wind, abrasions, temperature changes, frost actions, and biological effects; such as, plant root extensions or animal burrowing.