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🔗 Environment 🔗 Biology 🔗 Physics 🔗 Guild of Copy Editors 🔗 Energy 🔗 Chemical and Bio Engineering

Artificial photosynthesis is a chemical process that biomimics the natural process of photosynthesis to convert sunlight, water, and carbon dioxide into carbohydrates and oxygen. The term artificial photosynthesis is commonly used to refer to any scheme for capturing and storing the energy from sunlight in the chemical bonds of a fuel (a solar fuel). Photocatalytic water splitting converts water into hydrogen and oxygen and is a major research topic of artificial photosynthesis. Light-driven carbon dioxide reduction is another process studied that replicates natural carbon fixation.

Research of this topic includes the design and assembly of devices for the direct production of solar fuels, photoelectrochemistry and its application in fuel cells, and the engineering of enzymes and photoautotrophic microorganisms for microbial biofuel and biohydrogen production from sunlight.

🔗 Chemicals

Nitrophenyl pentadienal, nitrophenylpentadienal, NPPD, or METKA (Russian for "mark") colloquially known as "spy dust", is a chemical compound used as a tagging agent by the KGB during the Cold War Soviet Era. Soviet authorities in Moscow tracked Americans by applying an almost invisible powder to their clothing, cars, doorknobs and other objects. Some other variants of "spy dust" may have contained luminol and would glow under ultraviolet light.

🔗 Philosophy 🔗 Psychology

The IKEA effect is a cognitive bias in which consumers place a disproportionately high value on products they partially created. The name derives from the name of Swedish manufacturer and furniture retailer IKEA, which sells many furniture products that require assembly.

The IKEA effect has been described as follows: "The price is low for IKEA products largely because they take labor out of the equation. With a Phillips screwdriver, an Allen wrench and rubber mallet, IKEA customers can very literally build an entire home's worth of furniture on a very tight budget. But what happens when they do?" They "fall in love with their IKEA creations. Even when there are parts missing and the items are incorrectly built, customers in the IKEA study still loved the fruits of their labors."

PechaKucha (Japanese: ぺちゃくちゃ, IPA: [petɕa kɯ̥tɕa], chit-chat) is a storytelling format where a presenter shows 20 slides for 20 seconds of commentary each (6 minutes and 40 seconds total). At a PechaKucha Night, individuals gather at a venue to share personal presentations about their work. The PechaKucha format can be used, for example, in business presentations to clients or staff, as well as in education settings.

Inspired by their desire to "talk less, show more," Astrid Klein and Mark Dytham of Tokyo's Klein-Dytham Architecture (KDa) created PechaKucha in February 2003. It was a way to attract people to SuperDeluxe, their experimental event space in Roppongi, and to enable young designers to meet, show their work, and exchange ideas in 6 minutes 40 seconds.

In 2004, cities in Europe began hosting PK Nights and days, followed over the years by hundreds of others. As of April 2019, PKNs had been held in more than 1,142 cities worldwide. More than 3 million people have attended a PK Night.

PechaKucha is a registered trademark of PechaKucha, Inc.

In January 2018, PK's Astrid Klein, Mark Dytham, and Sean Smyth established PK, Inc. to create software to expand the PK platform.

🔗 Computing 🔗 Computing/Software

This article compares variety of different X window managers. For an introduction to the topic, see X Window System.

🔗 LGBTQ+ studies

“Ur-Fascism” or “Eternal Fascism: Fourteen Ways of Looking at a Blackshirt” (in Italian: Il fascismo eterno, or Ur-Fascismo) is a renowned essay authored by the Italian philosopher, novelist, and semiotician Umberto Eco. First published in 1995, this influential essay provides an analysis of fascism, a definition of fascism, and discusses the fundamental characteristics and traits of fascism. Drawing on Eco's personal experiences growing up in Mussolini's Italy and his extensive research on fascist movements, the essay offers his insights into the nature of fascism and its manifestations.

🔗 United States 🔗 Skepticism 🔗 Anthropology

Nacirema ("American" spelled backwards) is a term used in anthropology and sociology in relation to aspects of the behavior and society of citizens of the United States of America. The neologism attempts to create a deliberate sense of self-distancing in order that American anthropologists might look at their own culture more objectively.

🔗 Philosophy 🔗 Literature 🔗 Philosophy/Logic 🔗 Linguistics 🔗 Linguistics/Etymology

A red herring is something that misleads or distracts from a relevant or important question. It may be either a logical fallacy or a literary device that leads readers or audiences toward a false conclusion. A red herring may be used intentionally, as in mystery fiction or as part of rhetorical strategies (e.g., in politics), or may be used in argumentation inadvertently.

The term was popularized in 1807 by English polemicist William Cobbett, who told a story of having used a strong-smelling smoked fish to divert and distract hounds from chasing a rabbit.

🔗 Mathematics

This is a list of mathematical symbols used in all branches of mathematics to express a formula or to represent a constant.

A mathematical concept is independent of the symbol chosen to represent it. For many of the symbols below, the symbol is usually synonymous with the corresponding concept (ultimately an arbitrary choice made as a result of the cumulative history of mathematics), but in some situations, a different convention may be used. For example, depending on context, the triple bar "≡" may represent congruence or a definition. However, in mathematical logic, numerical equality is sometimes represented by "≡" instead of "=", with the latter representing equality of well-formed formulas. In short, convention dictates the meaning.

Each symbol is shown both in HTML, whose display depends on the browser's access to an appropriate font installed on the particular device, and typeset as an image using TeX.

🔗 Geology 🔗 Michigan 🔗 Gemology and Jewelry/Gemstones 🔗 Gemology and Jewelry

A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized rugose coral, Hexagonaria percarinata. Such stones were formed as a result of glaciation, in which sheets of ice plucked stones from the bedrock, grinding off their rough edges and depositing them in the northwestern (and some in the northeastern) portion of Michigan's lower peninsula. In those same areas of Michigan, complete fossilized coral colony heads can be found in the source rocks for the Petoskey stones.

Petoskey stones are found in the Gravel Point Formation of the Traverse Group. They are fragments of a coral reef that was originally deposited during the Devonian period. When dry, the stone resembles ordinary limestone but when wet or polished using lapidary techniques, the distinctive mottled pattern of the six-sided coral fossils emerges. It is sometimes made into decorative objects. Other forms of fossilized coral are also found in the same location.

In 1965, it was named the state stone of Michigan.