Have a deep view into what people are curious about.

🔗 United States 🔗 Biography

Archie R. McCardell (August 29, 1926 – July 10, 2008) was an American business leader. He was best known for his tenure as chief executive officer, president, and chairman of the board at the International Harvester farm and heavy equipment manufacturing concern from 1977 to 1982. Although Harvester was the nation's fourth-largest company at the time he assumed control, McCardell triggered a strike by unionized employees which ended disastrously for the company and led to its eventual demise.

🔗 Physics 🔗 Energy

A traveling-wave reactor (TWR) is a proposed type of nuclear fission reactor that can convert fertile material into usable fuel through nuclear transmutation, in tandem with the burnup of fissile material. TWRs differ from other kinds of fast-neutron and breeder reactors in their ability to use fuel efficiently without uranium enrichment or reprocessing, instead directly using depleted uranium, natural uranium, thorium, spent fuel removed from light water reactors, or some combination of these materials. The concept is still in the development stage and no TWRs have ever been built.

The name refers to the fact that fission remains confined to a boundary zone in the reactor core that slowly advances over time. TWRs could theoretically run self-sustained for decades without refueling or removing spent fuel.

🔗 Human rights 🔗 Bible 🔗 England

Select Parts of the Holy Bible for the use of the Negro Slaves in the British West-India Islands, sometimes referred to as a slave bible, is an abbreviated version of the Bible specifically made for teaching a pro-slavery version of Christianity to enslaved people in the British West Indies.

🔗 Visual arts 🔗 Belgium

Children's Games is an oil-on-panel by Flemish Renaissance artist Pieter Bruegel the Elder, painted in 1560. It is currently held and exhibited at the Kunsthistorisches Museum in Vienna. The entire composition is full of children playing a wide variety of games. Over 90 different games that were played by children at the time have been identified.

🔗 Physics 🔗 Astronomy 🔗 Geology 🔗 Mythology 🔗 Iceland 🔗 Norse history and culture 🔗 Mythology/Norse mythology

The sunstone (Icelandic: sólarsteinn) is a type of mineral attested in several 13th–14th-century written sources in Iceland, one of which describes its use to locate the Sun in a completely overcast sky. Sunstones are also mentioned in the inventories of several churches and one monastery in 14th–15th-century Iceland and Germany.

A theory exists that the sunstone had polarizing attributes and was used as a navigational instrument by seafarers in the Viking Age. A stone found in 2002 off Alderney, in the wreck of a 16th-century warship, may lend evidence of the existence of sunstones as navigational devices.

🔗 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.

🔗 Physics

🔗 Medicine 🔗 Transhumanism 🔗 Neuroscience 🔗 Pharmacology 🔗 Psychoactive and Recreational Drugs

Modafinil, sold under the brand name Provigil among others, is a medication to treat sleepiness due to narcolepsy, shift work sleep disorder, or obstructive sleep apnea. While it has seen off-label use as a purported cognitive enhancer, the research on its effectiveness for this use is not conclusive. It is taken by mouth.

Common side effects include headache, anxiety, trouble sleeping, and nausea. Serious side effects may include allergic reactions such as anaphylaxis, Stevens–Johnson syndrome, misuse, and hallucinations. It is unclear if use during pregnancy is safe. The amount of medication used may need to be adjusted in those with kidney or liver problems. It is not recommended in those with an arrhythmia, significant hypertension, or left ventricular hypertrophy. How it works is not entirely clear. One possibility is that it may affect the areas of the brain involved with the sleep cycle.

Modafinil was approved for medical use in the United States in 1998. In the United States it is classified as a schedule IV controlled substance. In the United Kingdom it is a prescription only medication. It is available as a generic medication. In the United Kingdom it costs the NHS about £105.21 a month as of 2018. In the United States the wholesale cost per month is about US$34.20 as of 2018. In 2016, it was the 284th most prescribed medication in the United States, with more than a million prescriptions.

🔗 Computing 🔗 Computing/Software

86-DOS is a discontinued operating system developed and marketed by Seattle Computer Products (SCP) for its Intel 8086-based computer kit. Initially known as QDOS (Quick and Dirty Operating System), the name was changed to 86-DOS once SCP started licensing the operating system in 1980.

86-DOS had a command structure and application programming interface that imitated that of Digital Research's CP/M operating system, which made it easy to port programs from the latter. The system was licensed and then purchased by Microsoft and developed further as MS-DOS and PC DOS.

🔗 Computing

Reservoir computing is a framework for computation that may be viewed as an extension of neural networks. Typically an input signal is fed into a fixed (random) dynamical system called a reservoir and the dynamics of the reservoir map the input to a higher dimension. Then a simple readout mechanism is trained to read the state of the reservoir and map it to the desired output. The main benefit is that training is performed only at the readout stage and the reservoir is fixed. Liquid-state machines and echo state networks are two major types of reservoir computing. One important feature of this system is that it can use the computational power of naturally available systems which is different from the neural networks and it reduces the computational cost.