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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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Coyote Reconnaissance Vehicle
The Light Armoured Vehicle II (LAV II) Coyote (and the related Bison) are armoured cars (or armoured personnel carriers) built by General Dynamics Land Systems Canada for the Canadian Forces. They are a later generation of the LAV-25 and of the same family as the Australian ASLAV, as all are part of the Light Armoured Vehicle family produced by General Dynamics Land Systems - Canada and based on the MOWAG Piranha 8x8.
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  • 03 Nov 2022
Topic Review
BMW 3 Series (E46)
The BMW E46 is the fourth generation of the BMW 3 Series, which was produced from 1997 to 2006. The body styles of the range are: All-wheel drive, last available in the E30 3 Series, was reintroduced for the E46 on the 325xi, 330xi and 330xd models. The E46 was the first 3 Series to be available with an engine using Valvetronic (variable valve lift). Various electronic features were also introduced to the 3 Series in the E46 generation, including satellite navigation, electronic brake-force distribution, rain-sensing wipers and LED tail-lights. Following the introduction of the E90 3 Series sedans in late 2004, the E46 began to be phased out. However the E46 coupé and convertible body styles remained in production until 2006. The E46 M3 is powered by the S54 straight-six engine with either a 6-speed manual or a 6-speed SMG-II transmission. The M3 was introduced in late 2000 and was produced in coupé and convertible body styles only.
  • 62.0K
  • 03 Nov 2022
Topic Review
UCLA-VA Multi-campus PM&R Residency Program
The UCLA-VA Multi-campus PM&R Residency Program is an ACGME-accredited residency program in physical medicine and rehabilitation based in Los Angeles, California. With five clinical fellows in pain medicine and 25 PM&R residents enrolled in the program, it is one of the largest PM&R residency programs in the West Coast and one of a handful of PM&R programs in the U.S. to have its own pain medicine fellowship program.
  • 1.8K
  • 27 Dec 2025
Topic Review
Osmium-165
Osmium (76Os) has seven naturally occurring isotopes, five of which are stable: 187Os, 188Os, 189Os, 190Os, and (most abundant) 192Os. The other natural isotopes, 184Os, and 186Os, have extremely long half-life (1.12×1013 years and 2×1015 years, respectively) and for practical purposes can be considered to be stable as well. 187Os is the daughter of 187Re (half-life 4.56×1010 years) and is most often measured in an 187Os/188Os ratio. This ratio, as well as the 187Re/188Os ratio, have been used extensively in dating terrestrial as well as meteoric rocks. It has also been used to measure the intensity of continental weathering over geologic time and to fix minimum ages for stabilization of the mantle roots of continental cratons. However, the most notable application of Os in dating has been in conjunction with iridium, to analyze the layer of shocked quartz along the Cretaceous–Paleogene boundary that marks the extinction of the dinosaurs 66 million years ago. There are also 30 artificial radioisotopes, the longest-lived of which is 194Os with a half-life of six years; all others have half-lives under 94 days. There are also nine known nuclear isomers, the longest-lived of which is 191mOs with a half-life of 13.10 hours. All isotopes and nuclear isomers of osmium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.
  • 524
  • 03 Nov 2022
Topic Review
Deformable Mirror
Deformable mirrors (DM) are mirrors whose surface can be deformed, in order to achieve wavefront control and correction of optical aberrations. Deformable mirrors are used in combination with wavefront sensors and real-time control systems in adaptive optics. In 2006 they found a new use in femtosecond pulse shaping. The shape of a DM can be controlled with a speed that is appropriate for compensation of dynamic aberrations present in the optical system. In practice the DM shape should be changed much faster than the process to be corrected, as the correction process, even for a static aberration, may take several iterations. A DM usually has many degrees of freedom. Typically, these degrees of freedom are associated with the mechanical actuators and it can be roughly taken that one actuator corresponds to one degree of freedom.
  • 1.1K
  • 03 Nov 2022
Topic Review
History of Measurement
The earliest recorded systems of weights and measures originate in the 3rd or 4th millennium BC. Even the very earliest civilizations needed measurement for purposes of agriculture, construction, and trade. Early standard units might only have applied to a single community or small region, with every area developing its own standards for lengths, areas, volumes and masses. Often such systems were closely tied to one field of use, so that volume measures used, for example, for dry grains were unrelated to those for liquids, with neither bearing any particular relationship to units of length used for measuring cloth or land. With development of manufacturing technologies, and the growing importance of trade between communities and ultimately across the Earth, standardized weights and measures became critical. Starting in the 18th century, modernized, simplified and uniform systems of weights and measures were developed, with the fundamental units defined by ever more precise methods in the science of metrology. The discovery and application of electricity was one factor motivating the development of standardized internationally applicable units.
  • 26.0K
  • 03 Nov 2022
Topic Review
DioneOS
DioneOS (pronounced /djoneos/) is a multitasking preemptive, real-time operating system (RTOS). The system is designed for microcontrollers, originally released on 2 February 2011 for the Texas Instruments TI MSP430x, and then on 29 March 2013 for the ARM Cortex-M3. Target microcontroller platforms have limited resources, i.e., system clock frequency of tens of MHz, and memory amounts of tens to a few hundred kilobytes (KB). The RTOS is adapted to such conditions by providing a compact and efficient image. The efficiency term here means minimizing further central processing unit (CPU) load caused by system use. According to this definition, the system is more effective when it consumes less CPU time to execute its internal parts, e.g., managing threads. The DioneOS system is intended for autonomic devices where user interface has limited functions. The core functions provided by the system is an environment for building multitasking firmware by means of standard, well known concepts (e.g. semaphores, timers, etc.). Because of the target domain of application, the system uses a command-line interface and has no graphical user interface.
  • 488
  • 03 Nov 2022
Topic Review
Kubota Engines
Kubota engines are diesel and spark ignition engines manufactured by Kubota Corporation. Besides gasoline-fueled for spark ignition engines, the company produces dual fuel, LPG-fueled, and natural-gas-fueled engines as well. The engines are widely used in various forms, such as: agricultural equipments, construction equipments, gensets, tractors, and marine propulsion. Beta Marine, an international company providing marine propulsion engines, uses various Kubota engines for fresh water and sea-going boats of various sizes.
  • 9.4K
  • 03 Nov 2022
Topic Review
CNO Cycle
The CNO cycle (for carbon–nitrogen–oxygen; sometimes called Bethe–Weizsäcker cycle after Hans Albrecht Bethe and Carl Friedrich von Weizsäcker) is one of the two known sets of fusion reactions by which stars convert hydrogen to helium, the other being the proton–proton chain reaction (p-p cycle), which is more efficient at the Sun's core temperature. The CNO cycle is hypothesized to be dominant in stars that are more than 1.3 times as massive as the Sun. Unlike the proton-proton reaction, which consumes all its constituents, the CNO cycle is a catalytic cycle. In the CNO cycle, four protons fuse, using carbon, nitrogen, and oxygen isotopes as catalysts, each of which is consumed at one step of the CNO cycle, but re-generated in a later step. The end product is one alpha particle (a stable helium nucleus), two positrons, and two electron neutrinos. There are various alternative paths and catalysts involved in the CNO cycles, all these cycles have the same net result: The positrons will almost instantly annihilate with electrons, releasing energy in the form of gamma rays. The neutrinos escape from the star carrying away some energy. One nucleus goes on to become carbon, nitrogen, and oxygen isotopes through a number of transformations in an endless loop. The proton–proton chain is more prominent in stars the mass of the Sun or less. This difference stems from temperature dependency differences between the two reactions; pp-chain reaction starts at temperatures around 4×106 K (4 megakelvin), making it the dominant energy source in smaller stars. A self-maintaining CNO chain starts at approximately 15×106 K, but its energy output rises much more rapidly with increasing temperatures so that it becomes the dominant source of energy at approximately 17×106 K. The Sun has a core temperature of around 15.7×106 K, and only 1.7% of 4He nuclei produced in the Sun are born in the CNO cycle. The CNO-I process was independently proposed by Carl von Weizsäcker and Hans Bethe in the late 1930s. The first reports of the experimental detection of the neutrinos produced by the CNO cycle in the Sun were published in 2020. This was also the first experimental confirmation that the Sun had a CNO cycle, that the proposed magnitude of the cycle was accurate, and that von Weizsäcker and Bethe were correct.
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  • 03 Nov 2022
Topic Review
Bayesian Model of Computational Anatomy
Computational anatomy (CA) is a discipline within medical imaging focusing on the study of anatomical shape and form at the visible or gross anatomical scale of morphology. The field is broadly defined and includes foundations in anatomy, applied mathematics and pure mathematics, including medical imaging, neuroscience, physics, probability, and statistics. It focuses on the anatomical structures being imaged, rather than the medical imaging devices. The central focus of the sub-field of computational anatomy within medical imaging is mapping information across anatomical coordinate systems most often dense information measured within a magnetic resonance image (MRI). The introduction of flows into CA, which are akin to the equations of motion used in fluid dynamics, exploit the notion that dense coordinates in image analysis follow the Lagrangian and Eulerian equations of motion. In models based on Lagrangian and Eulerian flows of diffeomorphisms, the constraint is associated to topological properties, such as open sets being preserved, coordinates not crossing implying uniqueness and existence of the inverse mapping, and connected sets remaining connected. The use of diffeomorphic methods grew quickly to dominate the field of mapping methods post Christensen's original paper, with fast and symmetric methods becoming available.
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  • 03 Nov 2022
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