|
Cricket Nets
Cricket nets are used by batters and bowlers to practice their cricketing techniques. They consist of a cricket pitch (natural or artificial) enclosed by netting on either side, behind, and optionally above. The bowling end is left open. Nets stop the cricket ball travelling across the field when the batter plays a shot. They save practice time and eliminate the need for fielders or a wicket-keeper. They allow more people to train at once, particularly when they have several lanes. They allow solitary batting practice when used with a bowling machine. Use Nets are fundamental to cricket practice and are used at every level of the game. Professional cricket clubs are likely to have over 10 lanes of nets, and be able to practice both indoors and outdoors. Nets are also very prevalent in educational establishments, as they allow safe and efficient training with a high volume of pupils when there are significant time constraints. Keen cricketers may have nets in their gard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollock In Nets
Pollock or pollack (pronounced ) is the common name used for either of the two species of North Atlantic marine fish in the genus ''Pollachius''. ''Pollachius pollachius'' is referred to as pollock in North America, Ireland and the United Kingdom, while ''Pollachius virens'' is usually known as saithe or coley in Great Britain and Ireland (derived from the older name coalfish). Other names for ''P. pollachius'' include the Atlantic pollock, European pollock, ''lieu jaune'', and lythe; while ''P. virens'' is also known as Boston blue (distinct from bluefish), silver bill, or saithe. Species The recognized species in this genus are: * ''Pollachius pollachius'' (Linnaeus, 1758) (pollack) * ''Pollachius virens'' (Linnaeus, 1758) (coalfish) Description Both species can grow to and can weigh up to . ''P. virens'' has a strongly defined, silvery lateral line running down the sides. Above the lateral line, the colour is a greenish black. The belly is white, while ''P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galvanised Steel
Hot-dip galvanization is a form of galvanization. It is the process of coating iron and steel with zinc, which alloys with the surface of the base metal when immersing the metal in a bath of molten zinc at a temperature of around . When exposed to the atmosphere, the pure zinc (Zn) reacts with oxygen ( O2) to form zinc oxide ( ZnO), which further reacts with carbon dioxide ( CO2) to form zinc carbonate ( ZnCO3), a usually dull grey, fairly strong material that protects the steel underneath from further corrosion in many circumstances. Galvanized steel is widely used in applications where corrosion resistance is needed without the cost of stainless steel, and is considered superior in terms of cost and life-cycle. It can be identified by the crystallization patterning on the surface (often called a "spangle"). Galvanized steel can be welded; however, one must exercise caution around the resulting toxic zinc fumes. Galvanized fumes are released when the galvanized metal reaches ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batting Cage
A batting cage (or tunnel) is an enclosed area for baseball or softball players to practice the skill of batting. The optimal material for batting cages is netting, and they are typically rectangular in shape. Chain-link fence is not required but can be useful to enclose the netting to prevent vandalism. However, this material is not suitable for the primary impact layer because it will warp the fencing and damage balls. The ideal netting for a batting cage is either diamond- or square-shaped. Both types of netting have their advantages and disadvantages. Usage A batter stands at one end of the cage, with a pitching machine (or, less often, a human pitcher) at the opposing end. The pitcher or pitching machine pitches baseballs to the batter, who hits them. It is recommended to use a protective pitcher's L-screen to prevent batted balls from striking the pitcher or machine. The cage is used to keep the loose baseballs within a certain range so that they're easy to pick up and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baseball
Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play generally beginning when a player on the fielding team, called the pitcher, throws a ball that a player on the batting team, called the batter, tries to hit with a bat. The objective of the offensive team (batting team) is to hit the ball into the field of play, away from the other team's players, allowing its players to run the bases, having them advance counter-clockwise around four bases to score what are called " runs". The objective of the defensive team (referred to as the fielding team) is to prevent batters from becoming runners, and to prevent runners' advance around the bases. A run is scored when a runner legally advances around the bases in order and touches home plate (the place where the player started as a batter). The principal objective of the batting team is to hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UV Stabilized
In polymer chemistry photo-oxidation (sometimes: oxidative photodegradation) is the degradation of a polymer surface due to the combined action of light and oxygen. It is the most significant factor in the weathering of plastics. Photo-oxidation causes the polymer chains to break ( chain scission), resulting in the material becoming increasingly brittle. This leads to mechanical failure and, at an advanced stage, the formation of microplastics. In textiles the process is called phototendering. Technologies have been developed to both accelerate and inhibit this process. For example, plastic building components like doors, window frames and gutters are expected to last for decades, requiring the use of advanced UV-polymer stabilizers. Conversely, single-use plastics can be treated with biodegradable additives to accelerate their fragmentation. Many pigments and dyes can similarly have effects due to their ability to absorb UV-energy. Susceptible polymers Susceptibility to ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyethylene
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging ( plastic bags, plastic films, geomembranes and containers including bottles, etc.). , over 100 million tonnes of polyethylene resins are being produced annually, accounting for 34% of the total plastics market. Many kinds of polyethylene are known, with most having the chemical formula (C2H4)''n''. PE is usually a mixture of similar polymers of ethylene, with various values of ''n''. It can be ''low-density'' or ''high-density'': low-density polyethylene is extruded using high pressure () and high temperature (), while high-density polyethylene is extruded using low pressure () and low temperature (). Polyethylene is usually thermoplastic, but it can be modified to become thermosetting instead, for example, in cross-linked polyethylene. History Polyethylene was first synthesized by the German chemis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twine
Twine is a strong thread, light string or cord composed of two or more thinner strands twisted, and then twisted together ( plied). The strands are plied in the opposite direction to that of their twist, which adds torsional strength to the cord and keeps it from unravelling. This process is sometimes called reverse wrap. The same technique used for making twine is also used to make thread, which is thinner, yarn, and rope, which is stronger and thicker, generally with three or more strands. Natural fibres used for making twine include wool, cotton, sisal, jute, hemp, henequen, paper, and coir. A variety of synthetic fibres are also used. Twine is a popular substance used in modern-day crafting. Prehistoric The invention of twine is at least as important as the development of stone tools for early humans. Indeed, Elizabeth Wayland Barber has called the development of twine, which can be made far stronger and longer than its component fibers, "the string revolution." Twi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulley System
A pulley is a wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt, or transfer of power between the shaft and cable or belt. In the case of a pulley supported by a frame or shell that does not transfer power to a shaft, but is used to guide the cable or exert a force, the supporting shell is called a block, and the pulley may be called a sheave. A pulley may have a groove or grooves between flanges around its circumference to locate the cable or belt. The drive element of a pulley system can be a rope, cable, belt, or chain. The earliest evidence of pulleys dates back to Ancient Egypt in the Twelfth Dynasty (1991-1802 BCE) and Mesopotamia in the early 2nd millennium BCE. In Roman Egypt, Hero of Alexandria (c. 10-70 CE) identified the pulley as one of six simple machines used to lift weights. Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sports Hall
The following is a list of indoor arenas. Africa Asia Europe North America Canada United States Oceania South America See also *Arena *Stadium *Sport venue *Lists of stadiums The following are lists of stadiums throughout the world. Note that horse racing and motorsport venues are not included, because those are not stadiums but sports venues. Combined lists * List of sports attendance figures * List of sports venues ... * List of buildings * List of music venues Notes External links Ballparks by Munsey and Suppes– Also info on NBA and NHL indoor arenasHockey arenas in Europe {{DEFAULTSORT:Indoor Arenas [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bowler (cricket)
Bowling, in cricket, is the action of propelling the ball toward the wicket defended by a batter. A player skilled at bowling is called a ''bowler''; a bowler who is also a competent batter is known as an all-rounder. Bowling the ball is distinguished from ''throwing'' the ball by a strictly specified biomechanical definition, which restricts the angle of extension of the elbow. A single act of bowling the ball towards the batsman is called a ''ball'' or a '' delivery''. Bowlers bowl deliveries in sets of six, called an ''over''. Once a bowler has bowled an over, a teammate will bowl an over from the other end of the pitch. The Laws of Cricket govern how a ball must be bowled. If a ball is bowled illegally, an umpire will rule it a '' no-ball''. If a ball is bowled too wide of the striker for the batsman to be able to play at it with a proper cricket shot, the bowler's end umpire will rule it a ''wide''. There are different types of bowlers, from fast bowlers, whose prima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bowling Machine
In cricket a bowling machine is a device which enables a batsman to practise (usually in the nets) and to hone specific skills through repetition of the ball being bowled at a certain length, line and speed. It can also be used when there is no-one available to bowl, or no one of the desired style or standard. There are a number of different types of bowling machine available to cricket coaches, each quite different in the ways they achieve the required delivery, though most allow the use of remote control, so that a coach can be closer to a batsman when the stroke is played. Mechanical bowling machines This type of machine is by far the most common. It is simple, strong and reliable, as well as being able to bowl a useful range of deliveries. How they work The main mechanism of the machine consists of two heavy wheels, between 30 and 50 cm in diameter, fitted with solid or pneumatic rubber tyres, each driven by its own electric motor. These are mounted in a frame suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
