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🔗 Biography 🔗 Video games

Zachtronics LLC is an American indie video game studio, best known for their engineering puzzle games and programming games. Zachtronics was founded by Zach Barth in 2000, who serves as its lead designer. Some of their products include SpaceChem, Infinifactory, TIS-100, and Shenzhen I/O.

🔗 Human rights 🔗 Canada 🔗 Law 🔗 Canada/Canadian law

Section 33 of the Canadian Charter of Rights and Freedoms is part of the Constitution of Canada. It is commonly known as the notwithstanding clause (French: clause dérogatoire or clause nonobstant), sometimes referred to as the override power, and it allows Parliament or provincial legislatures to temporarily override sections 2 and 7–15 of the Charter.

🔗 Electronics

The Williamson amplifier is a four-stage, push-pull, Class A triode-output valve audio power amplifier designed by D. T. N. Williamson during World War II. The original circuit, published in 1947 and addressed to the worldwide do it yourself community, set the standard of high fidelity sound reproduction and served as a benchmark or reference amplifier design throughout the 1950s. The original circuit was copied by hundreds of thousands amateurs worldwide. It was an absolute favourite on the DIY scene of the 1950s, and in the beginning of the decade also dominated British and North American markets for factory-assembled amplifiers.

The Williamson circuit was based on the 1934 Wireless World Quality Amplifier by Walter Cocking, with an additional error amplifier stage and a global negative feedback loop. Deep feedback, triode-connected KT66 power tetrodes, conservative choice of standing currents, and the use of wide-bandwidth output transformer all contributed to the performance of the Williamson. It had a modest output power rating of 15 Watts but surpassed all contemporary designs in having very low harmonic distortion and intermodulation, flat frequency response throughout the audible frequency range, and effective damping of loudspeaker resonances. The 0.1% distortion figure of the Williamson amplifier became the criterion for high fidelity performance that remains valid in the 21st century.

The Williamson amplifier was sensitive to selection and matching of passive components and valves, and prone to unwanted oscillations at infrasonic and ultrasonic frequencies. Enclosing four valve stages and an output transformer in a negative feedback loop was a severe test of design, resulting in a very narrow phase margin or, quite often, no margin at all. Attempts to improve stability of the Williamson could not fix this fundamental flaw. For this reason, and due to high costs of required quality components, manufacturers soon abandoned the Williamson circuit in favour of inherently more stable, cheaper and efficient three-stage, ultralinear or pentode-output designs.

🔗 Biography 🔗 California 🔗 California/San Francisco Bay Area 🔗 Medicine 🔗 Physics 🔗 Women scientists 🔗 Biography/science and academia 🔗 Women's History 🔗 Physics/Biographies 🔗 Medicine/Radiology

Elizabeth Fleischman-Aschheim (née Fleischman 5 March 1867 – 3 August 1905) was an American radiographer who is considered an X-ray pioneer. Fleischman was the first woman to die as a result of X-ray radiation exposure.

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Weaponry 🔗 Italy 🔗 Architecture 🔗 Military history/Early Modern warfare 🔗 Military history/Maritime warfare 🔗 Ships 🔗 Military history/Medieval warfare 🔗 Industrial design 🔗 Military history/Italian military history 🔗 Former countries 🔗 Military history/European military history 🔗 Former countries/Italian historical states

The Venetian Arsenal (Italian: Arsenale di Venezia) is a complex of former shipyards and armories clustered together in the city of Venice in northern Italy. Owned by the state, the Arsenal was responsible for the bulk of the Venetian republic's naval power from the late Middle Ages to the early modern period. It was "one of the earliest large-scale industrial enterprises in history".

🔗 Statistics

In statistics, Halton sequences are sequences used to generate points in space for numerical methods such as Monte Carlo simulations. Although these sequences are deterministic, they are of low discrepancy, that is, appear to be random for many purposes. They were first introduced in 1960 and are an example of a quasi-random number sequence. They generalize the one-dimensional van der Corput sequences.

🔗 Psychology

The Johari window is a technique designed to help people better understand their relationship with themselves and others. It was created by psychologists Joseph Luft (1916–2014) and Harrington Ingham (1916–1995) in 1955, and is used primarily in self-help groups and corporate settings as a heuristic exercise. Luft and Ingham named their model "Johari" using a combination of their first names.

🔗 Computing

A dial box is a computer peripheral for direct 3D manipulation e.g. to interactively input the rotation and torsion angles of a model displayed on a computer screen. Dial boxes were common input tools in the first years of interactive 3D graphics and they were available for Silicon Graphics (SGI) or Sun Microsystems and sold with their workstations. Currently they have been replaced by standard computer mouse interaction techniques.

Standard dial box has 8 dials mounted on a plate. The plate is set upright with the help of a stand and usually located next to the computer screen for convenient access. The connection to a computer is made via the serial port (RS-232).

One of the fields of application for dial boxes was molecular graphics.

🔗 Australia 🔗 Animals 🔗 Australia/Australian biota 🔗 Cephalopods

Octopolis and Octlantis are two separate non-human underwater settlements built by the gloomy octopuses. The first settlement, named Octopolis by biologists, was found in 2009. The individual structures in Octopolis consist of burrows around a piece of scrap metal. In 2016, a second settlement was found, named Octlantis, which instead of burrows, has dens and is built with seashells.

🔗 Visual arts 🔗 Belgium

Children's Games is an oil-on-panel by Flemish Renaissance artist Pieter Bruegel the Elder, painted in 1560. It is currently held and exhibited at the Kunsthistorisches Museum in Vienna. The entire composition is full of children playing a wide variety of games. Over 90 different games that were played by children at the time have been identified.