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🔗 El Corte Inglés, Europe’s Biggest Department Store
El Corte Inglés S.A. (Spanish pronunciation: [el ˈkoɾte iŋˈɡles]), headquartered in Madrid, is the biggest department store group in Europe and ranks third worldwide. El Corte Inglés is Spain's only remaining department store chain. El Corte Inglés has been a member of the International Association of department stores since 1998.
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- "El Corte Inglés, Europe’s Biggest Department Store" | 2021-12-13 | 13 Upvotes 2 Comments
🔗 Transparent Aluminum
Aluminium oxynitride (marketed under the name ALON by Surmet Corporation) is a transparent ceramic composed of aluminium, oxygen and nitrogen. ALON is optically transparent (≥ 80%) in the near-ultraviolet, visible, and midwave-infrared regions of the electromagnetic spectrum. It is four times as hard as fused silica glass, 85% as hard as sapphire, and nearly 115% as hard as magnesium aluminate spinel. Since it has a cubic spinel structure, it can be fabricated to transparent windows, plates, domes, rods, tubes, and other forms using conventional ceramic powder processing techniques.
ALON is the hardest polycrystalline transparent ceramic available commercially. Because of its relatively low weight, distinctive optical and mechanical properties, and resistance to oxidation or radiation, it shows promise for applications such as bulletproof, blast-resistant, and optoelectronic windows. ALON-based armor has been shown to stop multiple armor-piercing projectiles of up to .50 BMG.
ALON is commercially available in sizes as large as 18-by-35-inch (460 mm × 890 mm; 46 cm × 89 cm) monolithic windows.
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- "Aluminium Oxynitride" | 2024-08-07 | 17 Upvotes 5 Comments
- "Transparent Aluminum" | 2023-02-12 | 76 Upvotes 25 Comments
🔗 Zooko's Triangle
Zooko's triangle is a trilemma of three properties that are generally considered desirable for names of participants in a network protocol:
- Human-meaningful: Meaningful and memorable (low-entropy) names are provided to the users.
- Secure: The amount of damage a malicious entity can inflict on the system should be as low as possible.
- Decentralized: Names correctly resolve to their respective entities without the use of a central authority or service.
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- "Zooko's Triangle" | 2022-08-17 | 79 Upvotes 40 Comments
- "Zooko's Triangle" | 2021-02-17 | 153 Upvotes 54 Comments
- "Zooko's Triangle" | 2010-08-22 | 23 Upvotes 7 Comments
🔗 Island of Stability
In nuclear physics, the island of stability is a predicted set of isotopes of superheavy elements that may have considerably longer half-lives than known isotopes of these elements. It is predicted to appear as an "island" in the chart of nuclides, separated from known stable and long-lived primordial radionuclides. Its theoretical existence is attributed to stabilizing effects of predicted "magic numbers" of protons and neutrons in the superheavy mass region.
Several predictions have been made regarding the exact location of the island of stability, though it is generally thought to center near copernicium and flerovium isotopes in the vicinity of the predicted closed neutron shell at N = 184. These models strongly suggest that the closed shell will confer further stability towards fission and alpha decay. While these effects are expected to be greatest near atomic number Z = 114 and N = 184, the region of increased stability is expected to encompass several neighboring elements, and there may also be additional islands of stability around heavier nuclei that are doubly magic (having magic numbers of both protons and neutrons). Estimates of the stability of the elements on the island are usually around a half-life of minutes or days; some estimates predict half-lives of millions of years.
Although the nuclear shell model predicting magic numbers has existed since the 1940s, the existence of long-lived superheavy nuclides has not been definitively demonstrated. Like the rest of the superheavy elements, the nuclides on the island of stability have never been found in nature; thus, they must be created artificially in a nuclear reaction to be studied. Scientists have not found a way to carry out such a reaction, for it is likely that new types of reactions will be needed to populate nuclei near the center of the island. Nevertheless, the successful synthesis of superheavy elements up to Z = 118 (oganesson) with up to 177 neutrons demonstrates a slight stabilizing effect around elements 110 to 114 that may continue in unknown isotopes, supporting the existence of the island of stability.
🔗 Wabi-sabi
In traditional Japanese aesthetics, wabi-sabi (侘寂) is a world view centered on the acceptance of transience and imperfection. The aesthetic is sometimes described as one of beauty that is "imperfect, impermanent, and incomplete". It is a concept derived from the Buddhist teaching of the three marks of existence (三法印, sanbōin), specifically impermanence (無常, mujō), suffering (苦, ku) and emptiness or absence of self-nature (空, kū).
Characteristics of the wabi-sabi aesthetic include asymmetry, roughness, simplicity, economy, austerity, modesty, intimacy, and appreciation of the ingenuous integrity of natural objects and processes.
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- "Wabi-Sabi" | 2023-07-23 | 26 Upvotes 8 Comments
- "Wabi-Sabi" | 2021-10-11 | 19 Upvotes 3 Comments
- "Wabi-sabi" | 2013-10-16 | 63 Upvotes 33 Comments
🔗 Musicogenic Seizure
Musicogenic seizure, also known as music-induced seizure, is a rare type of seizure, with an estimated prevalence of 1 in 10,000,000 individuals, that arises from disorganized or abnormal brain electrical activity when a person hears or is exposed to a specific type of sound or musical stimuli. There are challenges when diagnosing a music-induced seizure due to the broad scope of triggers, and time delay between a stimulus and seizure. In addition, the causes of musicogenic seizures are not well-established as solely limited cases and research have been discovered and conducted respectively. Nevertheless, the current understanding of the mechanism behind musicogenic seizure is that music triggers the part of the brain that is responsible for evoking an emotion associated with that music. Dysfunction in this system leads to an abnormal release of dopamine, eventually inducing seizure.
Currently, there are diverse intervention strategies that patients can choose from depending on their situations. They can have surgery to remove the region of the brain that generates a seizure. Behavioral therapy is also available; patients are trained to gain emotional control to reduce the frequency of seizure. Medications like carbamazepine and phenytoin (medication for general seizure) also suggest effectiveness to mitigate music-induced seizures.
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- "Musicogenic Seizure" | 2023-06-21 | 32 Upvotes 15 Comments
🔗 Tom Preston-Werner (this page has been deleted)
Thomas Preston-Werner (born October 28, 1979) is an American billionaire software developer and entrepreneur. He is an active contributor within the open-source development community, most prominently in the San Francisco Bay Area, where he lives.
He is best known as the founder and former CEO of GitHub, a Git repository web-based hosting service, which he co-founded in 2008 with Chris Wanstrath and PJ Hyett. He resigned from GitHub in 2014 when an internal investigation concluded that he and his wife harassed an employee. Preston-Werner is also the creator of the avatar service Gravatar, the TOML configuration file format and the Semantic Versioning Specification (SemVer)
Preston-Werner lives in San Francisco with his wife Theresa and their sons.
His wife is a former graduate student in cultural anthropology known for her involvement in historical research and social subjects.
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- "Tom Preston-Werner (this page has been deleted)" | 2012-10-26 | 17 Upvotes 15 Comments
🔗 Purkinje Effect
The Purkinje effect or Purkinje phenomenon (Czech: [ˈpurkɪɲɛ] (listen); sometimes called the Purkinje shift, often incorrectly pronounced ) is the tendency for the peak luminance sensitivity of the eye to shift toward the blue end of the color spectrum at low illumination levels as part of dark adaptation. In consequence, reds will appear darker relative to other colors as light levels decrease. The effect is named after the Czech anatomist Jan Evangelista Purkyně. While the effect is often described from the perspective of the human eye, it is well established in a number of animals under the same name to describe the general shifting of spectral sensitivity due to pooling of rod and cone output signals as a part of dark/light adaptation.
This effect introduces a difference in color contrast under different levels of illumination. For instance, in bright sunlight, geranium flowers appear bright red against the dull green of their leaves, or adjacent blue flowers, but in the same scene viewed at dusk, the contrast is reversed, with the red petals appearing a dark red or black, and the leaves and blue petals appearing relatively bright.
The sensitivity to light in scotopic vision varies with wavelength, though the perception is essentially black-and-white. The Purkinje shift is the relation between the absorption maximum of rhodopsin, reaching a maximum at about 500 nanometres (2.0×10−5 in), and that of the opsins in the longer-wavelength cones that dominate in photopic vision, about 555 nanometres (2.19×10−5 in) (green).
In visual astronomy, the Purkinje shift can affect visual estimates of variable stars when using comparison stars of different colors, especially if one of the stars is red.
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- "Purkinje Effect" | 2023-04-05 | 109 Upvotes 32 Comments
🔗 The first motion picture production studio: Edison’s Black Maria
The Black Maria ( mə-RY-ə) was Thomas Edison's film production studio in West Orange, New Jersey. It was the world's first film studio.
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- "The first motion picture production studio: Edison’s Black Maria" | 2022-07-05 | 21 Upvotes 8 Comments
🔗 Law of Demeter
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, “distribution-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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- "Law of Demeter" | 2019-07-09 | 81 Upvotes 48 Comments