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Bicycle Helmet
A bicycle helmet is a type of helmet designed to attenuate impacts to the head of a cyclist in falls while minimizing side effects such as interference with peripheral vision. There is ongoing scientific research into the degree of protection offered by bicycle helmets in the event of an accident, and the effects of helmet wearing on cyclist and motor vehicle driver behaviour. There is active debate over what can be concluded from available studies, and on whether the use of helmets by cyclists should be promoted or mandated, either just for children, or for cyclists of all ages. In particular the debate over bicycle helmet laws has been intense and occasionally bitter, often based not only on differing interpretations of the scientific and other academic literature, but also on differing assumptions and interests of various parties. History History of designs A cycle helmet should generally be light in weight and provide ample ventilation because cycling can be an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Helmet Laws
Some countries and lower jurisdictions have enacted laws or regulations which require cyclists to wear a Bicycle helmet, helmet in certain circumstances, typically when riding on the road or a road-related area (such as a bicycle lane or path). In some places this requirement applies only to children under a certain age, while in others it applies to cyclists of all ages. Research indicates that bicycle helmet laws reduce bicycle fatalities and injuries. Large increases in the rate of helmet wearing usually take place after helmet laws are passed. Evidence is mixed as to whether the helmet laws lead to less cycling. Background Modern varieties of bicycle helmet first became commercially successful from 1975. Industry helmet standards were developed from the 1970s and are still under development. Even before then, there had been calls for riders to wear helmets, based on the assumptions of high risk to cyclists and effectiveness of helmets in preventing serious injury. The Roya ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Types Of Bicycle Helmets
Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Type (Unix), a command in POSIX shells that gives information about commands. * Type safety, the extent to which a programming language discourages or prevents type errors. * Type system, defines a programming language's response to data types. Mathematics * Type (model theory) * Type theory, basis for the study of type systems * Arity or type, the number of operands a function takes * Type, any proposition or set in the intuitionistic type theory * Type, of an entire function ** Exponential type Biology * Type (biology), which fixes a scientific name to a taxon * Dog type, categorization by use or function of domestic dogs Lettering * Type is a design concept for lettering used in typography which helped bring about modern textual printin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycarbonate
Polycarbonates (PC) are a group of thermoplastic polymers containing carbonate groups in their chemical structures. Polycarbonates used in engineering are strong, tough materials, and some grades are optically transparent. They are easily worked, molded, and thermoformed. Because of these properties, polycarbonates find many applications. Polycarbonates do not have a unique resin identification code (RIC) and are identified as "Other", 7 on the RIC list. Products made from polycarbonate can contain the precursor monomer bisphenol A (BPA). Structure Carbonate esters have planar OC(OC)2 cores, which confers rigidity. The unique O=C bond is short (1.173 Å in the depicted example), while the C-O bonds are more ether-like (the bond distances of 1.326 Å for the example depicted). Polycarbonates received their name because they are polymers containing carbonate groups (−O−(C=O)−O−). A balance of useful features, including temperature resistance, impact resistance and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Which?
''Which?'' is a United Kingdom brand name that promotes informed consumer choice in the purchase of goods and services by testing products, highlighting inferior products or services, raising awareness of consumer rights and offering independent advice. The brand name is used by the Consumers' Association, a registered charity and company limited by guarantee that owns several businesses, including ''Which? Financial Services Limited'' (''Which? Mortgage Advisers''), ''Which? Legal Limited'' and ''Which? Limited'', which publishes the ''Which?'' Papers. The vast majority of the association's income comes from the profit it makes on its trading businesses, for instance subscriptions to ''Which?'' magazine, which are donated to the campaigning part of the organisation to fund advocacy activity and inform the public about consumer issues. ''Which?'' magazine maintains its independence by not accepting advertising, and the organisation receives no government funding. The Consumers' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
