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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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Pacific Temperate Rainforests (WWF Ecoregion)
The Pacific temperate rainforests ecoregion of North America is the largest temperate rain forest ecoregion on the planet as defined by the World Wildlife Fund (other definitions exist). The Pacific temperate rain forests lie along the western side of the Pacific Coast Ranges along the Pacific Northwest Coast of North America from the Prince William Sound in Alaska through the British Columbia Coast to Northern California, and are part of the Nearctic ecozone, as also defined by the World Wildlife Fund. The Pacific temperate rain forests are characterized by a high amount of rainfall, in some areas more than 300 cm (10 ft) per year and moderate temperatures in both the summer and winter months (10–24 °C or 50–75 °F). This ecoregion is a subregion of the Cascadia bioregion. These rain forests occur in a number of ecoregions, which vary in their species composition, but are predominantly of conifers, sometimes with an understory of broadleaf trees, ferns and shrubs. In the WWF's system, sub-ecoregions of the Pacific Temperate Rain Forests Ecoregion are the Northern Pacific coastal forests, Haida Gwaii, British Columbia mainland coastal forests, Central Pacific coastal forests, Central and Southern Cascades forests, Klamath-Siskiyou forests, and Northern California coastal forests ecoregions. The forests in the north contain predominantly Sitka spruce and western hemlock, while those in the coastal forests are home as well to coast redwood (Sequoia sempervirens), coast Douglas-fir (Pseudotsuga menziesii), western redcedar and shore pine. Notably, the three tallest species of trees are found here. Dense growths of epiphytes and mosses cover the trees, and lush vegetation is present everywhere. Hardwood trees such as the bigleaf maple and the alder are also common, especially at lower elevations and along stream banks, and are vital to the ecosystem, in part because of their nitrogen fixing.
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  • 03 Nov 2022
Topic Review
Surety Bond
A surety bond or surety is a promise by a surety or guarantor to pay one party (the obligee) a certain amount if a second party (the principal) fails to meet some obligation, such as fulfilling the terms of a contract. The surety bond protects the obligee against losses resulting from the principal's failure to meet the obligation.
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  • 03 Nov 2022
Topic Review
Ray Tracing
In physics, ray tracing is a method for calculating the path of waves or particles through a system with regions of varying propagation velocity, absorption characteristics, and reflecting surfaces. Under these circumstances, wavefronts may bend, change direction, or reflect off surfaces, complicating analysis. Ray tracing solves the problem by repeatedly advancing idealized narrow beams called rays through the medium by discrete amounts. Simple problems can be analyzed by propagating a few rays using simple mathematics. More detailed analysis can be performed by using a computer to propagate many rays. When applied to problems of electromagnetic radiation, ray tracing often relies on approximate solutions to Maxwell's equations that are valid as long as the light waves propagate through and around objects whose dimensions are much greater than the light's wavelength. Ray theory does not describe phenomena such as interference and diffraction, which require wave theory (involving the phase of the wave).
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  • 03 Nov 2022
Topic Review
Northern Light (Spacecraft)
Northern Light was a concept mission for a robotic mission to Mars that would consist of a lander and a rover, being studied by a consortium of Canadian universities, companies and organisations. The primary contractor for the spacecraft was Thoth Technology Inc. The spacecraft would consist of four parts: an apogee kick engine to provide orbital injection for a cruise vehicle that carries the Northern Light lander and the Beaver Rover to a direct rendezvous with Mars using a Hohmann transfer orbit. Atmospheric entry would be achieved by a heat shield, parachute and airbag deployment system. The lander would transfer the rover to the Martian surface. Once deployed on the Martian surface, the lander contacts Earth directly to the 46 m parabolic antenna located at the Algonquin Radio Observatory. The Beaver Rover was proposed to have a maximum range of 1000 metres (0.62 mile) from the landing site. It would have operated under battery, utilizing tools and sensors to investigate surface rocks that may contain the presence of photosynthetic life.
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Topic Review
FO (Complexity)
In descriptive complexity, a branch of computational complexity, FO is a complexity class of structures that can be recognized by formulas of first-order logic, and also equals the complexity class AC0. Descriptive complexity uses the formalism of logic, but does not use several key notions associated with logic such as proof theory or axiomatization. Restricting predicates to be from a set X yields a smaller class FO[X]. For instance, FO[Similarly, extensions of first-order logic formed by the addition of operators give rise to other well-known complexity classes. This allows the complexity of some problems to be established without reference to algorithms.
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Topic Review
Motif (Folkloristics)
Motif is a word used by folklorists who analyze, interpret, and describe the traditional elements found in the lore of particular folk groups and compare the folklore of various regions and cultures of the world based on these motif patterns. Ultimately, folklorists identify motifs in folklore to interpret where, how, and why these motifs are used, so they can understand the values, customs, and ways of life of unique cultures. In cultural anthropology and folkloristics, the meaning of motif encompasses the meanings of motif used in the areas of music, literary criticism, visual arts, and textile arts because folklorists study motifs (i.e., recurring elements) in each of these areas, motifs that create recognizable patterns in folklore and folk-art traditions.
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  • 03 Nov 2022
Topic Review
ITunes LP
iTunes LP (referred to in pre-launch press by the code name Cocktail) is a format for interactive album artwork introduced by Apple Inc. on September 9, 2009. It is similar to the CMX format being developed by the three major record labels, and operates within the iTunes 9 to iTunes 12 software, allowing the user to view multimedia elements alongside the music. This format is also used to bundle extra content (known as iTunes Extras) with selected movies at the iTunes Store. iTunes LP downloads use a proprietary file format with the extension .itlp, which is essentially a WebArchive adhering to special conventions using HTML, CSS, JavaScript, CSS Animations, and plists. This technology is referred to in iTunes LP files as TuneKit. On November 28, 2009, the iTunes LP SDK was released to the public. In 2011, MTV introduced the O Music Awards, intended artists, fans, and innovators at this online awards show. One of the OMAs' inaugural categories was Best iTunes LP. The winner of this category was Pink's Greatest Hits...So Far!!! (Deluxe Edition). Apple stopped accepting new submissions of iTunes LPs after March 2018. Existing LPs will be deprecated from the store during the remainder of 2018. Customers who have previously purchased an album containing an iTunes LP will still be able to download the additional content using iTunes Match.
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  • 03 Nov 2022
Topic Review
Timeline of Yellow Fever
This is a timeline of yellow fever. Major events such as historical epidemics and medical developments are described.
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  • 03 Nov 2022
Topic Review
CANT Z.501
The CANT Z.501 Gabbiano (Italian: Gull) was a high-wing central-hull flying boat, with two outboard floats. It was powered by a single engine installed in the middle of the main-plane and had a crew of 4–5 men. It served with the Italian Regia Aeronautica during World War II, as a reconnaissance aeroplane. During its debut in 1934, it set a world distance record. It was obsolete by 1940, but was still used throughout World War II, suffering many losses. A few remained in service until 1949.
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  • 03 Nov 2022
Topic Review
Terminology of the British Isles
The terminology of the British Isles refers to the various words and phrases that are used to describe the different (and sometimes overlapping) geographical and political areas of the islands of Great Britain, Ireland, and the smaller islands which surround them. The terminology is often a source of confusion, partly owing to the similarity between some of the actual words used, but also because they are often used loosely. In addition, many of the words carry both geographical and political connotations which are affected by the history of the islands. The purpose of this article is to explain the meanings of and relationships among the terms in use; however many of these classifications are contentious and are the subject of disagreement (See the British Isles naming dispute).
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