Engineering

'Smart' pajamas could monitor and help improve sleep

If you've ever dreamed about getting a good night's sleep, your answer may someday lie in data generated by your sleepwear. Researchers have developed pajamas embedded with self-powered sensors that provide unobtrusive and ...

Consumer & Gadgets

Apple Watch may spot heart problem but more research needed

A huge study suggests the Apple Watch can detect a worrisome irregular heartbeat at least sometimes—but experts say more work is needed to tell if using wearable technology to screen for heart problems really helps.

Energy & Green Tech

Hydrogen car prototype

Researchers at the Institute of Chemical Technology and collaborators have successfully developed and tested a scale car prototype that stores and generates hydrogen safely and is capable of using it as fuel.

Hi Tech & Innovation

Apple has designs on blood pressure management system

Counting calories or how many steps you will need to take to work off a wedding feast are not the only features of fitness monitoring. Patients today may be asked to check their blood pressure at home and will be interested ...

High pressure

High pressure science and engineering is studying the effects of high pressure on materials and the design and construction of devices, such as a diamond anvil cell, which can create high pressure. By high pressure it is usually meant pressures of thousands (kilobars) or millions (megabars) of times atmospheric pressure (about 1 bar).

It was by applying high pressure as well as high temperature to carbon that man-made diamonds were first produced as well as many other interesting discoveries. Almost any material when subjected to high pressure will compact itself into a denser form, for example, quartz, also called silica or silicon dioxide will first adopt a denser form known as coesite, then upon application of more temperature, form stishovite. These two forms of silica were first discovered by high pressure experimenters, but then found in nature at the site of a meteor impact.

Chemical bonding is likely to change under high pressure, when the P*V term in the free energy becomes comparable to the energies of typical chemical bonds - i.e. at around 100 GPa. Among the most striking changes are metallization of oxygen at 96 GPa (rendering oxygen a superconductor), and transition of sodium from a nearly-free-electron metal to a transparent insulator at ~200 GPa. At ultimately high compression, however, all materials will metallize.[citation needed]

High pressure experimentation has led to the discovery of the types of minerals which are believed to exist in the deep mantle of the Earth, such as perovskite which is thought to make up half of the Earth's bulk, and post-perovskite, which occurs at the core-mantle boundary and explains many anomalies inferred for that region.[citation needed]

Pressure "landmarks": pressure exerted by a fingernail scratching is ~0.6 GPa, typical pressures reached by large-volume presses are up to 30-40 GPa, pressures that can be generated inside diamond anvil cells are ~320 GPa, pressure in the center of the Earth is 364 GPa, highest pressures ever achieved in a shock waves are over 100,000 GPa.[citation needed]

This text uses material from Wikipedia, licensed under CC BY-SA