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πŸ”— Mills' constant

πŸ”— Mathematics

In number theory, Mills' constant is defined as the smallest positive real number A such that the floor function of the double exponential function

⌊ A 3 n βŒ‹ {\displaystyle \lfloor A^{3^{n}}\rfloor }

is a prime number, for all natural numbers n. This constant is named after William H. Mills who proved in 1947 the existence of A based on results of Guido Hoheisel and Albert Ingham on the prime gaps. Its value is unknown, but if the Riemann hypothesis is true, it is approximately 1.3063778838630806904686144926... (sequence A051021 in the OEIS).

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πŸ”— Hawthorne Effect

πŸ”— Mass surveillance πŸ”— Business πŸ”— Psychology πŸ”— Sociology

The Hawthorne effect is a type of human behavior reactivity in which individuals modify an aspect of their behavior in response to their awareness of being observed. The effect was discovered in the context of research conducted at the Hawthorne Western Electric plant; however, some scholars feel the descriptions are apocryphal.

The original research involved workers who made electrical relays at the Hawthorne Works, a Western Electric plant in Cicero, Illinois. Between 1924 and 1927, the lighting study was conducted. Workers experienced a series of lighting changes in which productivity was said to increase with almost any change in the lighting. This turned out not to be true. In the study that was associated with Elton Mayo, which ran from 1928 to 1932, a series of changes in work structure were implemented (e.g., changes in rest periods) in a group of five women. However, this was a methodologically poor, uncontrolled study that did not permit any firm conclusions to be drawn.

One of the later interpretations by Landsberger suggested that the novelty of being research subjects and the increased attention from such could lead to temporary increases in workers' productivity. This interpretation was dubbed "the Hawthorne effect".

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πŸ”— Movile Cave

πŸ”— Geography πŸ”— Romania πŸ”— Ecology πŸ”— Caves

Movile Cave (Romanian: PeΘ™tera Movile) is a cave near Mangalia, ConstanΘ›a County, Romania discovered in 1986 by Cristian Lascu a few kilometers from the Black Sea coast. It is notable for its unique groundwater ecosystem abundant in hydrogen sulfide and carbon dioxide, but low in oxygen. Life in the cave has been separated from the outside for the past 5.5 million years and it is based completely on chemosynthesis rather than photosynthesis.

πŸ”— A man died yesterday. He had a huge impact on our lives. Fred Shuttlesworth.

πŸ”— United States πŸ”— Biography πŸ”— African diaspora πŸ”— United States/Ohio πŸ”— United States/Cincinnati πŸ”— Civil Rights Movement πŸ”— Alabama

Frederick Lee "Fred" Shuttlesworth (born Fred Lee Robinson, March 18, 1922 – October 5, 2011) was a U.S. civil rights activist who led the fight against segregation and other forms of racism as a minister in Birmingham, Alabama. He was a co-founder of the Southern Christian Leadership Conference, initiated and was instrumental in the 1963 Birmingham Campaign, and continued to work against racism and for alleviation of the problems of the homeless in Cincinnati, Ohio, where he took up a pastorate in 1961. He returned to Birmingham after his retirement in 2007. He helped Martin Luther King Jr. during the civil rights movement.

The Birmingham–Shuttlesworth International Airport was named in his honor in 2008.

The Birmingham Civil Rights Institute Fred L. Shuttlesworth Human Rights Award is bestowed annually in his name.

πŸ”— Micromelo Undatus

πŸ”— Gastropods

Micromelo undatus, common name the miniature melo, is an uncommon species of small sea snail or bubble snail, a marine opisthobranch gastropod mollusk in the family Aplustridae.

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πŸ”— Law of Demeter

πŸ”— Computing

The Law of Demeter (LoD) or principle of least knowledge is a design guideline for developing software, particularly object-oriented programs. In its general form, the LoD is a specific case of loose coupling. The guideline was proposed by Ian Holland at Northeastern University towards the end of 1987, and can be succinctly summarized in each of the following ways:

  • Each unit should have only limited knowledge about other units: only units "closely" related to the current unit.
  • Each unit should only talk to its friends; don't talk to strangers.
  • Only talk to your immediate friends.

The fundamental notion is that a given object should assume as little as possible about the structure or properties of anything else (including its subcomponents), in accordance with the principle of "information hiding". It may be viewed as a corollary to the principle of least privilege, which dictates that a module possess only the information and resources necessary for its legitimate purpose.

It is so named for its origin in the Demeter Project, an adaptive programming and aspect-oriented programming effort. The project was named in honor of Demeter, β€œdistribution-mother” and the Greek goddess of agriculture, to signify a bottom-up philosophy of programming which is also embodied in the law itself.

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πŸ”— List of Games in Game Theory

πŸ”— Game theory

Game theory studies strategic interaction between individuals in situations called games. Classes of these games have been given names. This is a list of the most commonly studied games

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πŸ”— Lie to Children

πŸ”— Human rights πŸ”— Philosophy πŸ”— Freedom of speech πŸ”— Philosophy/Logic πŸ”— Politics πŸ”— Psychology πŸ”— Sociology πŸ”— Education πŸ”— Popular Culture πŸ”— Debating

A lie-to-children is a simplified, and often technically incorrect, explanation of technical or complex subjects employed as a teaching method. Educators who employ lies-to-children do not intend to deceive, but instead seek to 'meet the child/pupil/student where they are', in order to facilitate initial comprehension, which they build upon over time as the learner's intellectual capacity expands. The technique has been incorporated by academics within the fields of biology, evolution, bioinformatics and the social sciences.

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πŸ”— The Origin of Consciousness in the Breakdown of the Bicameral Mind

πŸ”— Biography πŸ”— Psychology πŸ”— Biography/science and academia πŸ”— Anti-war

Julian Jaynes (February 27, 1920 – November 21, 1997) was an American researcher in psychology at Yale and Princeton for nearly 25 years and best known for his 1976 book The Origin of Consciousness in the Breakdown of the Bicameral Mind. His career was dedicated to the problem of consciousness, β€œβ€¦the difference between what others see of us and our sense of our inner selves and the deep feelings that sustain it. … Men have been conscious of the problem of consciousness almost since consciousness began.” Jaynes's solution touches on many disciplines, including neuroscience, linguistics, psychology, archeology, history, religion and analysis of ancient texts.

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πŸ”— Vanadium redox battery

πŸ”— Chemistry

The vanadium redox battery (VRB), also known as the vanadium flow battery (VFB) or vanadium redox flow battery (VRFB), is a type of rechargeable flow battery that employs vanadium ions in different oxidation states to store chemical potential energy. The vanadium redox battery exploits the ability of vanadium to exist in solution in four different oxidation states, and uses this property to make a battery that has just one electroactive element instead of two. For several reasons, including their relative bulkiness, most vanadium batteries are currently used for grid energy storage, i.e., attached to power plants or electrical grids.

The possibility of creating a vanadium flow battery was explored by Pissoort in the 1930s, NASA researchers in the 1970s, and Pellegri and Spaziante in the 1970s, but none of them were successful in demonstrating the technology. The first successful demonstration of the all-vanadium redox flow battery which employed vanadium in a solution of sulfuric acid in each half was by Maria Skyllas-Kazacos at the University of New South Wales in the 1980s. Her design used sulfuric acid electrolytes, and was patented by the University of New South Wales in Australia in 1986.

The main advantages of the vanadium redox battery are that it can offer almost unlimited energy capacity simply by using larger electrolyte storage tanks; it can be left completely discharged for long periods with no ill effects; if the electrolytes are accidentally mixed, the battery suffers no permanent damage; a single state of charge between the two electrolytes avoids the capacity degradation due to a single cell in non-flow batteries; the electrolyte is aqueous and inherently safe and non-flammable; and the generation 3 formulation using a mixed acid solution developed by the Pacific Northwest National Laboratory operates over a wider temperature range allowing for passive cooling. VRFBs can be used at depth of discharge (DOD) around 90% and more, i.e. deeper DODs than solid-state batteries (e.g. lithium-based and sodium-based batteries, which are usually specified with DOD=80%). In addition, VRFBs exhibit very long cycle lives: most producers specify cycle durability in excess of 15,000-20,000 charge/discharge cycles. These values are far beyond the cycle lives of solid-state batteries, which is usually in the order of 4,000-5,000 charge/discharge cycles. Consequently, the levelized cost of energy (LCOE, i.e. the system cost divided by the usable energy, the cycle life, and round-trip efficiency) of present VRFB systems is typically in the order of a few tens of $ cents or € cents, namely much lower than the LCOEs of equivalent solid-state batteries and close to the targets of $0.05 and €0.05, stated by the US Department of Energy and the European Commission Strategic Energy Technology (SET) Plan, respectively.

The main disadvantages with vanadium redox technology are a relatively poor energy-to-volume ratio in comparison with standard storage batteries, and the relatively poor round trip efficiency. Furthermore, the aqueous electrolyte makes the battery heavy and therefore only useful for stationary applications. Another disadvantage is the relatively high toxicity of oxides of vanadium (see vanadium Β§Β Safety).

Numerous companies and organizations involved in funding and developing vanadium redox batteries include Avalon Battery, Vionx (formerly Premium Power), UniEnergy Technologies and Ashlawn Energy in the United States; Renewable Energy Dynamics Technology in Ireland; Enerox GmbH (formerly Gildemeister energy storage) in Austria; Cellennium in Thailand; Rongke Power in China; Prudent Energy in China; Sumitomo in Japan; H2, Inc. in South Korea; redT in Britain., Australian Vanadium in Australia, and the now defunct Imergy (formerly Deeya). Lately, also several smaller size vanadium redox flow batteries were brought to market (for residential applications) mainly from StorEn Technologies (USA), Schmid Group, VoltStorage and Volterion (all three from Germany), VisBlue (Denmark) or Pinflow energy storage (Czechia).

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