Random Articles (Page 2)

Have a deep view into what people are curious about.

πŸ”— Black Start

πŸ”— Energy

A black start is the process of restoring an electric power station or a part of an electric grid to operation without relying on the external electric power transmission network to recover from a total or partial shutdown.

Normally, the electric power used within the plant is provided from the station's own generators. If all of the plant's main generators are shut down, station service power is provided by drawing power from the grid through the plant's transmission line. However, during a wide-area outage, off-site power from the grid is not available. In the absence of grid power, a so-called black start needs to be performed to bootstrap the power grid into operation.

To provide a black start, some power stations have small diesel generators, normally called the black start diesel generator (BSDG), which can be used to start larger generators (of several megawatts capacity), which in turn can be used to start the main power station generators. Generating plants using steam turbines require station service power of up to 10% of their capacity for boiler feedwater pumps, boiler forced-draft combustion air blowers, and for fuel preparation. It is uneconomical to provide such a large standby capacity at each station, so black-start power must be provided over designated tie lines from another station. Often hydroelectric power plants are designated as the black-start sources to restore network interconnections. A hydroelectric station needs very little initial power for starting purposes (just enough to open the intake gates and provide excitation current to the generator field coils), and can put a large block of power on line very quickly to allow start-up of fossil-fuel or nuclear stations. Certain types of combustion turbine can be configured for black start, providing another option in places without suitable hydroelectric plants. In 2017, a utility in Southern California successfully demonstrated the use of a battery-based energy-storage system to provide a black start, firing up a combined-cycle gas turbine from an idle state.

Discussed on

πŸ”— Bardcore

πŸ”— Music/Music genres

Bardcore (from the Celtic-origin word β€œbard” meaning β€˜poet’ or β€˜storyteller’) or tavernwave is a 2020 internet phenomenon consisting of medievalised remakes of hit pop songs.

Discussed on

πŸ”— The Unreality of Time

πŸ”— Philosophy πŸ”— Philosophy/Philosophical literature πŸ”— Guild of Copy Editors

"The Unreality of Time" is the best-known philosophical work of the Cambridge idealist J.Β M.Β E. McTaggart (1866–1925). In the argument, first published as a journal article in Mind in 1908, McTaggart argues that time is unreal because our descriptions of time are either contradictory, circular, or insufficient. A slightly different version of the argument appeared in 1927 as one of the chapters in the second volume of McTaggart's greatest work, The Nature of Existence.

The argument for the unreality of time is popularly treated as a stand-alone argument that does not depend on any significant metaphysical principles (e.g. as argued by C.Β D. Broad 1933 and L.Β O. Mink 1960). R.Β D. Ingthorsson disputes this, and argues that the argument can only be understood as an attempt to draw out certain consequences of the metaphysical system that McTaggart presents in the first volume of The Nature of Existence (Ingthorsson 1998 & 2016).

It is helpful to consider the argument as consisting of three parts. In the first part, McTaggart offers a phenomenological analysis of the appearance of time, in terms of the now famous A- and B-series (see below for detail). In the second part, he argues that a conception of time as only forming a B-series but not an A-series is an inadequate conception of time because the B-series does not contain any notion of change. The A-series, on the other hand, appears to contain change and is thus more likely to be an adequate conception of time. In the third and final part, he argues that the conception of time forming an A-series is contradictory and thus nothing can be like an A-series. Since the A- and the B- series exhaust possible conceptions of how reality can be temporal, and neither is adequate, the conclusion McTaggart reaches is that reality is not temporal at all.

Discussed on

πŸ”— Zaum

πŸ”— Philosophy πŸ”— Philosophy/Aesthetics πŸ”— Constructed languages

Zaum (Russian: Π·Π°ΜΡƒΠΌΡŒ, lit. 'transrational') are the linguistic experiments in sound symbolism and language creation of Russian Cubo-Futurist poets such as Velimir Khlebnikov and Aleksei Kruchenykh. Zaum is a non-referential phonetic entity with its own ontology. The language consists of neologisms that mean nothing. Zaum is a language organized through phonetic analogy and rhythm. Zaum literature cannot contain any onomatopoeia or psychopathological states.

Discussed on

  • "Zaum" | 2023-08-18 | 160 Upvotes 46 Comments

πŸ”— MONIAC – Monetary National Income Analogue Computer

πŸ”— Computing πŸ”— Economics πŸ”— Computing/Early computers

The MONIAC (Monetary National Income Analogue Computer) also known as the Phillips Hydraulic Computer and the Financephalograph, was created in 1949 by the New Zealand economist Bill Phillips (William Phillips) to model the national economic processes of the United Kingdom, while Phillips was a student at the London School of Economics (LSE). The MONIAC was an analogue computer which used fluidic logic to model the workings of an economy. The MONIAC name may have been suggested by an association of money and ENIAC, an early electronic digital computer.

Discussed on

πŸ”— Diatoms make 20% of Earth's oxygen and can double in population every 24 hours

πŸ”— Geology πŸ”— Marine life πŸ”— Algae

Diatoms (diÑ-tom-os 'cut in half', from diÑ, 'through' or 'apart'; and the root of tém-n-ō, 'I cut'.) are a major group of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of the Earth's biomass: they generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion metric tons of silicon each year from the waters in which they live, and contribute nearly half of the organic material found in the oceans. The shells of dead diatoms can reach as much as a half-mile (800m) deep on the ocean floor, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up a system of fresh-water lakes.

Diatoms are unicellular: they occur either as solitary cells or in colonies, which can take the shape of ribbons, fans, zigzags, or stars. Individual cells range in size from 2 to 200 micrometers. In the presence of adequate nutrients and sunlight, an assemblage of living diatoms doubles approximately every 24 hours by asexual multiple fission; the maximum life span of individual cells is about six days. Diatoms have two distinct shapes: a few (centric diatoms) are radially symmetric, while most (pennate diatoms) are broadly bilaterally symmetric. A unique feature of diatom anatomy is that they are surrounded by a cell wall made of silica (hydrated silicon dioxide), called a frustule. These frustules have structural coloration due to their photonic nanostructure, prompting them to be described as "jewels of the sea" and "living opals". Movement in diatoms primarily occurs passively as a result of both water currents and wind-induced water turbulence; however, male gametes of centric diatoms have flagella, permitting active movement for seeking female gametes. Similar to plants, diatoms convert light energy to chemical energy by photosynthesis, although this shared autotrophy evolved independently in both lineages. Unusually for autotrophic organisms, diatoms possess a urea cycle, a feature that they share with animals, although this cycle is used to different metabolic ends in diatoms. The family Rhopalodiaceae also possess a cyanobacterial endosymbiont called a spheroid body. This endosymbiont has lost its photosynthetic properties, but has kept its ability to perform nitrogen fixation, allowing the diatom to fix atmospheric nitrogen.

The study of diatoms is a branch of phycology. Diatoms are classified as eukaryotes, organisms with a membrane-bound cell nucleus, that separates them from the prokaryotes archaea and bacteria. Diatoms are a type of plankton called phytoplankton, the most common of the plankton types. Diatoms also grow attached to benthic substrates, floating debris, and on macrophytes. They comprise an integral component of the periphyton community. Another classification divides plankton into eight types based on size: in this scheme, diatoms are classed as microalgae. Several systems for classifying the individual diatom species exist. Fossil evidence suggests that diatoms originated during or before the early Jurassic period, which was about 150 to 200 million years ago.

Diatoms are used to monitor past and present environmental conditions, and are commonly used in studies of water quality. Diatomaceous earth (diatomite) is a collection of diatom shells found in the earth's crust. They are soft, silica-containing sedimentary rocks which are easily crumbled into a fine powder and typically have a particle size of 10 to 200 ΞΌm. Diatomaceous earth is used for a variety of purposes including for water filtration, as a mild abrasive, in cat litter, and as a dynamite stabilizer.

πŸ”— WikiProject AI Cleanup

Welcome to WikiProject AI Cleanupβ€”a collaboration to combat the increasing problem of unsourced, poorly written AI-generated content on Wikipedia. If you would like to help, add yourself as a participant in the project, inquire on the talk page, and see the to-do list.

Discussed on

πŸ”— Human Rights Violations by the CIA

πŸ”— United States/U.S. Government πŸ”— United States

This article deals with the activities of the Central Intelligence Agency of the Federal government of the United States, that violate human rights.

Discussed on

πŸ”— A Schelling point is a solution people choose by default in a coordination game

πŸ”— Game theory

In game theory, a focal point (or Schelling point) is a solution that people tend to choose by default in the absence of communication. The concept was introduced by the American economist Thomas Schelling in his book The Strategy of Conflict (1960). Schelling states that "(p)eople can often concert their intentions or expectations with others if each knows that the other is trying to do the same" in a cooperative situation (at page 57), so their action would converge on a focal point which has some kind of prominence compared with the environment. However, the conspicuousness of the focal point depends on time, place and people themselves. It may not be a definite solution.

πŸ”— Fluidics

πŸ”— Technology πŸ”— Physics πŸ”— Physics/Fluid Dynamics

Fluidics, or fluidic logic, is the use of a fluid to perform analog or digital operations similar to those performed with electronics.

The physical basis of fluidics is pneumatics and hydraulics, based on the theoretical foundation of fluid dynamics. The term fluidics is normally used when devices have no moving parts, so ordinary hydraulic components such as hydraulic cylinders and spool valves are not considered or referred to as fluidic devices.

A jet of fluid can be deflected by a weaker jet striking it at the side. This provides nonlinear amplification, similar to the transistor used in electronic digital logic. It is used mostly in environments where electronic digital logic would be unreliable, as in systems exposed to high levels of electromagnetic interference or ionizing radiation.

Nanotechnology considers fluidics as one of its instruments. In this domain, effects such as fluid-solid and fluid-fluid interface forces are often highly significant. Fluidics have also been used for military applications.

Discussed on