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  • Continuously variable transmission


    A continuously variable transmission (CVT), also known as a shiftless transmission, single-speed transmission, stepless transmission, pulley transmission, or, in case of motorcycles, a 'twist-and-go', is an automatic transmission that can change seamlessly through a continuous range of effective gear ratios. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios. The flexibility of a CVT with suitable control may allow the input shaft to maintain a constant angular velocity even as the output speed varies. A belt-driven design offers approximately 88% efficiency, which, while lower than that of a manual transmission, can be offset by lower production cost and by enabling the engine to run at its most efficient speed for a range of output speeds. When power is more important than economy, the ratio of the CVT can be changed to allow the engine to turn at the RPM at which it produces greatest power. This is typically higher than the RPM that achieves peak efficiency. In low-mass low-torque applications (such as motor scooters) a belt-driven CVT also offers ease of use and mechanical simplicity.

  • Homemaking


    Good Housekeeping is one of several periodicals related to homemaking Title page of Our Home Cyclopedia: Cookery and Housekeeping, published in Detroit, Michigan, in 1889Homemaking is a mainly American term for the management of a home, otherwise known as housework, housekeeping, or household management. It is the act of overseeing the organizational, day-to-day operations of a house or estate, and the managing of other domestic concerns. A person in charge of the homemaking, who is not employed outside the home, is in the U.S. called a homemaker, a term for a housewife or a househusband. The term "homemaker", however, may also refer to a social worker who manages a household during the incapacity of the housewife or househusband. Housework is not always a lifetime commitment; many, for economic or personal reasons, return to the workplace. In previous decades, there were many mandatory courses for the young to learn the skills of homemaking. In high school, courses included cooking, nutrition, home economics, family and consumer science (FACS), and food and cooking hygiene. This last one may underlie the tradition that a homemaker is portrayed wearing an apron. More recently, most of these courses have been abolished, and many youths in high school and college would be more likely to study child development and the management of children's behavior.

  • Lawn mower


    A typical modern gasoline/petrol powered rotary "push mower" (or grass cutter) which has self-powered cutting blades, but still requires human power to move across the ground. "Walk-behind" mowers can be self-propelled, only requiring a human to walk behind and guide the mower. Mowers of the type displayed usually vary in width from 20 to 24 inches. "ride-on" mower. A battery-powered robotic lawn mower. A non-motorized multiple blade reel push mower. A lawn mower (also named as mower or lawnmower) is a machine utilizing one or more revolving blades to cut a grass surface to an even height. The height of the cut grass may be fixed by the design of the mower, but generally is adjustable by the operator, typically by a single master lever, or by a lever or nut and bolt on each of the machine's wheels. The blades may be powered by muscle, with wheels mechanically connected to the cutting blades so that when the mower is pushed forward, the blades spin, or the machine may have a battery-powered or plug-in electric motor. The most common self-contained power source for lawn mowers is a small (typically one cylinder) internal combustion engine. Smaller mowers often lack any form of propulsion, requiring human power to move over a surface; "walk-behind" mowers are self-propelled, requiring a human only to walk behind and guide them. Larger lawn mowers are usually either self-propelled "walk-behind" types, or more often, are "ride-on" mowers, equipped so the operator can ride on the mower and control it. A robotic lawn mower ("lawn-mowing bot", "mowbot", etc.) is designed to operate either entirely on its own, or less commonly by an operator by remote control. Two main styles of blades are used in lawn mowers. Lawn mowers employing a single blade that rotates about a single vertical axis are known as rotary mowers, while those employing a cutting bar and multiple blade assembly that rotates about a single horizontal axis are known as cylinder or reel mowers (although in some versions, the cutting bar is the only blade, and the rotating assembly consists of flat metal pieces which force the blades of grass against the sharp cutting bar). There are several types of mowers, each suited to a particular scale and purpose. The smallest types, non-powered push mowers, are suitable for small residential lawns and gardens. Electrical or piston engine-powered push-mowers are used for larger residential lawns (although there is some overlap). Riding mowers, which sometimes resemble small tractors, are larger than push mowers and are suitable for large lawns, although commercial riding lawn mowers (such as zero-turn mowers) can be "stand-on" types, and often bear little resemblance to residential lawn tractors, being designed to mow large areas at high speed in the shortest time possible. The largest multi-gang (multi-blade) mowers are mounted on tractors and are designed for large expanses of grass such as golf courses and municipal parks, although they are ill-suited for complex terrain.

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