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πŸ”— The aesthetic usability effect / paradox

πŸ”— Medicine πŸ”— Science

The aesthetic–usability effect describes a paradox that people perceive more aesthetic designs as much more intuitive than those considered to be less aesthetically pleasing. The effect has been observed in several experiments and has significant implications regarding the acceptance, use, and performance of a design. Usability and aesthetics are the two most important factors in assessing the overall user experience for an application. Usability and aesthetics are judged by a user's reuse expectations, and then their post-use, or experienced, final judgement. A user's cognitive style can influence how they interact with and perceive an application, which in turn can influence their judgement of the application.

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πŸ”— Steam Cannon

πŸ”— Military history πŸ”— Military history/Military science, technology, and theory πŸ”— Military history/Weaponry πŸ”— Middle Ages πŸ”— Middle Ages/History

A steam cannon is a cannon that launches a projectile using only heat and water, or using a ready supply of high-pressure steam from a boiler. The first steam cannon was designed by Archimedes during the Siege of Syracuse. Leonardo Da Vinci was also known to have designed one (see the Architonnerre).

The early device would consist of a large metal tube, preferably copper due to its high thermal conductivity, which would be placed in a furnace. One end of the tube would be capped and the other loaded with a projectile. Once the tube reached a high enough temperature, a small amount of water would be injected in behind the projectile. In theory, Leonardo da Vinci believed, the water would rapidly expand into vapour, blasting the projectile out the front of the barrel.

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πŸ”— Uno – The β€œUnit” for Dimensionless Quantities

πŸ”— Measurement

In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, 10βˆ’6), parts-per-billion (ppb, 10βˆ’9), parts-per-trillion (ppt, 10βˆ’12) and parts-per-quadrillion (ppq, 10βˆ’15). This notation is not part of the International System of Units (SI) system and its meaning is ambiguous.

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πŸ”— Wolpertinger

πŸ”— Germany πŸ”— Folklore

In German folklore, a wolpertinger (also called wolperdinger or woiperdinger) is an animal said to inhabit the alpine forests of Bavaria and Baden-WΓΌrttemberg in Germany.

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πŸ”— E-Prime: English without the verb 'to be'

πŸ”— Linguistics πŸ”— Linguistics/Applied Linguistics πŸ”— Languages πŸ”— Constructed languages πŸ”— English Language

E-Prime (short for English-Prime or English Prime, sometimes denoted Γ‰ or Eβ€²) is a version of the English language that excludes all forms of the verb to be, including all conjugations, contractions and archaic forms.

Some scholars advocate using E-Prime as a device to clarify thinking and strengthen writing. A number of other scholars have criticized E-Prime's utility.

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πŸ”— Vivian Maier

πŸ”— Biography πŸ”— Biography/arts and entertainment πŸ”— Chicago πŸ”— Photography πŸ”— Photography/History of photography πŸ”— Women artists

Vivian Dorothy Maier (February 1, 1926 – April 21, 2009) was an American street photographer whose work was not discovered and recognized until after her death. She worked for about forty years as a nanny, mostly in Chicago's North Shore, while she pursued her photography. She took more than 150,000 photographs during her lifetime, primarily of the people and architecture of Chicago, New York City, and Los Angeles, although she also traveled and photographed worldwide.

During her lifetime, Maier's photographs were unknown and unpublished; many of her negatives were never printed. A Chicago collector, John Maloof, acquired some of Maier's photos in 2007, while two other Chicago-based collectors, Ron Slattery and Randy Prow, also found some of Maier's prints and negatives in her boxes and suitcases around the same time. Maier's photographs were first published on the Internet in July 2008, by Slattery, but the work received little response. In October 2009, Maloof linked his blog to a selection of Maier's photographs on the image-sharing website Flickr, and the results went viral, with thousands of people expressing interest. Maier's work subsequently attracted critical acclaim, and since then, Maier's photographs have been exhibited around the world.

Her life and work have been the subject of books and documentary films, including the film Finding Vivian Maier (2013), which premiered at the Toronto International Film Festival, and was nominated for the Academy Award for Best Documentary Feature at the 87th Academy Awards.

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πŸ”— Thousandth of an Inch

πŸ”— Metalworking πŸ”— Measurement

A thousandth of an inch is a derived unit of length in a system of units using inches. Equal to 1⁄1000 of an inch, a thousandth is commonly called a thou (used for both singular and plural) or particularly in North America a mil (plural mils).

The words are shortened forms of the English and Latin words for "thousand" (mille in Latin). In international engineering contexts, confusion can arise because mil is a formal unit name in North America but mil or mill is also a common colloquial clipped form of millimetre. The units are considerably different: a millimetre is approximately 39 mils.

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πŸ”— Musth

πŸ”— Mammals

Musth or must (an Urdu word, from Persian, lit. drunk) is a periodic condition in bull (male) elephants characterized by highly aggressive behavior and accompanied by a large rise in reproductive hormones.

Testosterone levels in an elephant in musth can be on average 60 times greater than in the same elephant at other times (in specific individuals these testosterone levels can even reach as much as 140 times the normal). However, whether this hormonal surge is the sole cause of musth, or merely a contributing factor, is unknown.

Scientific investigation of musth is problematic because even the most placid elephants become highly violent toward humans and other elephants during musth.

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  • "Musth" | 2020-04-06 | 77 Upvotes 15 Comments

πŸ”— Relativistic kill vehicle

πŸ”— Physics πŸ”— Firearms

A projectile is any object thrown into space (empty or not) by the exertion of a force. Although any object in motion through space (for example a thrown baseball) may be called a projectile, the term more commonly refers to a ranged weapon. Mathematical equations of motion are used to analyze projectile trajectory. An object projected at an angle to the horizontal has both the vertical and horizontal components of velocity. The vertical component of the velocity on the y-axis given as Vy=USin(teta) while the horizontal component of the velocity Vx=UCos(teta). There are various terms used in projectiles at specific angle teta 1. Time to reach maximum height. It is symbolized as (t), which is the time taken for the projectile to reach the maximum height from the plane of projection. Mathematically, it is given as t=USin(teta)/g Where g=acceleration due to gravity(app 9.81m/sΒ²) U= initial velocity (m/s) teta= angle made by the projectile with the horizontal axis.

2. Time of flight (T): this is the total time taken for the projectile to fall back to the same plane from which it was projected. Mathematically it is given as T=2USin(teta)/g

3. Maximum Height (H): this is the maximum height attained by the projectile OR the maximum displacement on the vertical axis(y-axis) covered by the projectile. It is given as H= UΒ²SinΒ²(teta)/2g

4. Range(R): The Range of a projectile is the horizontal distance covered (on the x-axis) by the projectile. Mathematically, R= UΒ²Sin2(teta)/g. The Range is maximum when angle teta= 45Β° I.e Sin2(teta)=1.

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