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HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

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Hearing Protection Device
A hearing protection device, also known as a HPD, is an ear protection device worn in or over the ears while exposed to hazardous noise to help prevent noise-induced hearing loss. HPDs reduce the level of the noise entering the ear. HPDs can also protect against other effects of noise exposure such as tinnitus and hyperacusis. There are many different types of HPDs available for use, including earmuffs, earplugs, electronic hearing protection devices, and semi-insert devices.
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  • 14 Oct 2022
Topic Review
Chasmataspidid
Chasmataspidids, sometime referred to as chasmataspids, are a group of extinct chelicerate arthropods that form the order Chasmataspidida. Chasmataspidids are probably related to horseshoe crabs (Xiphosura) and/or sea scorpions (Eurypterida), with more recent studies suggest that they form a clade (Dekatriata) with Eurypterida and Arachnida. Chasmataspidids are known sporadically in the fossil record through to the mid-Devonian, with possible evidence suggest that they also present during the late Cambrian. Chasmataspidids are most easily recognised by having an abdomen divided into a short forepart (preabdomen or mesosoma) and a longer hindpart (postabdomen or metasoma) each comprising 4 and 9 segments respectively. There is some debate about whether they form a natural (i.e. monophyletic) group.
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  • 14 Oct 2022
Topic Review
Women of the Wall
Women of the Wall (Hebrew: נשות הכותל, Neshot HaKotel) is a multi-denominational feminist organization based in Israel whose goal is to secure the rights of women to pray at the Western Wall, also called the Kotel, in a fashion that includes singing, reading aloud from the Torah and wearing religious garments (tallit, tefillin and kippah). Pew Research Center has identified Israel as one of the countries that place "high" restrictions on religion, and there have been limits placed on non-Orthodox streams of Judaism. One of those restrictions is that the Rabbi of the Western Wall has enforced gender segregation and limitations on religious garb worn by women. When the "Women of the Wall" hold monthly prayer services for women on Rosh Hodesh, they observe gender segregation so that Orthodox members may fully participate. But their use of religious garb, singing and reading from a Torah have upset many members of the Orthodox Jewish community, sparking protests and arrests. In May 2013 a judge ruled that a 2003 Israeli Supreme Court ruling prohibiting women from carrying a Torah or wearing prayer shawls had been misinterpreted and that Women of the Wall prayer gatherings at the wall should not be deemed illegal. In January 2016, the Israeli Cabinet approved a plan to designate a new space at the Kotel that would be available for egalitarian prayer and which would not be controlled by the Rabbinate. Women of the Wall welcomed the decision, but the plan faced opposition from other factions, including some ultra-Orthodox members of Prime Minister Benjamin Netanyahu's governing coalition, who threatened to withdraw over the government's plan to create non-Orthodox prayer space at the Western Wall in deference to the Women of the Wall. In January 2017, the Israeli High Court ruled that if the government of Israel could not find "good cause" to prohibit women reading from the Torah in prayer services at the Kotel within 30 days, women could do so; they also ruled that the Israeli government could no longer argue that the Robinson's Arch area of the plaza is access to the Kotel. The petition for women to read from the Torah at the Kotel had been brought by a group that split off from the Women of the Wall, calling itself the "Original Women of the Wall". In June 2017, it was announced that the plan approved in January 2016 had been suspended. According to Ronit Kampf, the group's struggle has been "the most covered women's issue in the history of the Israeli media."
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  • 14 Oct 2022
Topic Review
History of Neurology and Neurosurgery
The study of neurology and neurosurgery dates back to prehistoric times, but the academic disciplines did not begin until the 16th century. From an observational science they developed a systematic way of approaching the nervous system and possible interventions in neurological disease.
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  • 14 Oct 2022
Topic Review
Comparison of Shopping Cart Software
The following is a comparison of the features of notable shopping cart software packages available. Some such shopping cart software is extensible through third-party software components and applications. As such, the features listed below may not encompass all possible features for a given software package. The software listed here is but a fraction of all such packages on the market.
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  • 14 Oct 2022
Topic Review
Somerset Space Walk
The Somerset Space Walk is a sculpture trail model of the Solar System, located in Somerset, England. The model uses the towpath of the 22-kilometre (14-mile) Bridgwater and Taunton Canal to display a model of the Sun and its planets in their proportionally correct sizes and distances apart. Unusually for a Solar System model, there are two sets of planets, so that the diameter of the orbits is represented. Aware of the inadequacies of printed pictures of the Solar System, the inventor Pip Youngman designed the Space Walk as a way of challenging people's perceptions of space and experiencing the vastness of the Solar System. The model is built to a scale of 1:530,000,000, meaning that one millimetre on the model equates to 530 kilometres. The Sun is sited at Higher Maunsel Lock, and one set of planets is installed in each direction along the canal towards Taunton and Bridgwater; the distance between the Sun and each model of Pluto being 11 kilometres (6.8 mi). For less hardy walkers, the inner planets are within 67 metres (220 ft) of the Sun, and near to the Maunsel Canal Centre (and tea shop) at Lower Maunsel Lock, where a more detailed leaflet about the model is available. The Space Walk was opened on 9 August 1997 by British astronomer Heather Couper. In 2007, a project team from Somerset County Council refurbished some of the models.
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  • 14 Oct 2022
Topic Review
Ordnance Survey
Ordnance Survey (OS) is the national mapping agency for Great Britain. The agency's name indicates its original military purpose (see ordnance and surveying), which was to map Scotland in the wake of the Jacobite rising of 1745. There was also a more general and nationwide need in light of the potential threat of invasion during the Napoleonic Wars. Since 1 April 2015 Ordnance Survey has operated as Ordnance Survey Ltd, a government-owned company, 100% in public ownership. The Ordnance Survey Board remains accountable to the Secretary of State for Business, Energy and Industrial Strategy. It was also a member of the Public Data Group. Paper maps for walkers represent only 5% of OS' annual revenue. They produce digital map data, online route planning and sharing services and mobile apps, plus many other location-based products for business, government and consumers. Ordnance Survey mapping is usually classified as either "large-scale" (in other words, more detailed) or "small-scale". The Survey's large-scale mapping comprises 1:2,500 maps for urban areas and 1:10,000 more generally. (The latter superseded the 1:10,560 "six inches to the mile" scale in the 1950s.) These large scale maps are typically used in professional land-use contexts and were available as sheets until the 1980s, when they were digitised. Small-scale mapping for leisure use includes the 1:25,000 "Explorer" series, the 1:50,000 "Landranger" series and the 1:250,000 road maps. These are still available in traditional sheet form. Ordnance Survey maps remain in copyright for fifty years after their publication. Some of the Copyright Libraries hold complete or near-complete collections of pre-digital OS mapping.
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  • 14 Oct 2022
Topic Review
Steady State
In chemistry, a steady state is a situation in which all state variables are constant in spite of ongoing processes that strive to change them. For an entire system to be at steady state, i.e. for all state variables of a system to be constant, there must be a flow through the system (compare mass balance). A simple example of such a system is the case of a bathtub with the tap running but with the drain unplugged: after a certain time, the water flows in and out at the same rate, so the water level (the state variable Volume) stabilizes and the system is in a steady state. The steady state concept is different from chemical equilibrium. Although both may create a situation where a concentration does not change, in a system at chemical equilibrium, the net reaction rate is zero (products transform into reactants at the same rate as reactants transform into products), while no such limitation exists in the steady state concept. Indeed, there does not have to be a reaction at all for a steady state to develop. The term steady state is also used to describe a situation where some, but not all, of the state variables of a system are constant. For such a steady state to develop, the system does not have to be a flow system. Therefore, such a steady state can develop in a closed system where a series of chemical reactions take place. Literature in chemical kinetics usually refers to this case, calling it steady state approximation. In simple systems the steady state is approached by state variables gradually decreasing or increasing until they reach their steady state value. In more complex systems state variable might fluctuate around the theoretical steady state either forever (a limit cycle) or gradually coming closer and closer. It theoretically takes an infinite time to reach steady state, just as it takes an infinite time to reach chemical equilibrium. Both concepts are, however, frequently used approximations because of the substantial mathematical simplifications these concepts offer. Whether or not these concepts can be used depends on the error the underlying assumptions introduce. So, even though a steady state, from a theoretical point of view, requires constant drivers (e.g. constant inflow rate and constant concentrations in the inflow), the error introduced by assuming steady state for a system with non-constant drivers may be negligible if the steady state is approached fast enough (relatively speaking).
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  • 14 Oct 2022
Topic Review
List of Intel Core 2 Microprocessors
The Core 2 brand refers to Intel's x86 and x86-64 microprocessors with the Core microarchitecture made for the consumer and business markets (except servers) above Pentium. The Core 2 solo branch covered single-core CPUs for notebook computers, Core 2 Duo – dual-core CPUs for desktop and notebook computers, Core 2 Quad – quad-core CPUs for desktop and notebook computers, and Core 2 Extreme – dual-core and quad-core CPUs for desktop and notebook computers.
  • 5.8K
  • 18 Oct 2022
Topic Review
Terminate and Stay Resident Program
A terminate-and-stay-resident program (commonly TSR) is a computer program running under DOS that uses a system call to return control to DOS as though it has finished, but remains in computer memory so it can be reactivated later. This technique partially overcame DOS's limitation of executing only one program, or task, at a time. TSRs are used only in DOS, not in Windows. Some TSRs are utility software that a computer user might call up several times a day, while working in another program, using a hotkey. Borland Sidekick was an early and popular example of this type. Others serve as device drivers for hardware that the operating system does not directly support.
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