Sonar can be used to measure the thickness of the heart by placing small crystal transducers at opposite sides of the heart or blood vessel and exciting one with some pulsed ultrasonic energy.

The frequency used for these experiments is 15 mc. and the transducer is a specially cut crystal with an epoxy lens capable of providing beam diameters smaller than one millimeter.

The measured powder density of the Af used here was about Af, approximately one-third that of the crystal density ( Af ).

There is one test based on " Brazil law twinning " ( a form of quartz twinning where right and left hand quartz structures are combined in a single crystal ) which can be used to identify synthetic amethyst rather easily.

The mathematics of crystal structures developed by Bravais, Federov and others was used to classify crystals by their symmetry group, and tables of crystal structures were the basis for the series International Tables of Crystallography, first published in 1935.

There are multiple technologies that have been used to implement liquid crystal displays ( LCD ).

Sometimes the abbreviation CR for crystal rectifier is used.

Crystal oscillators often use the same circuits as LC oscillators, with the crystal replacing the tuned circuit ; the Pierce oscillator circuit is commonly used.

Surface acoustic wave ( SAW ) devices are another kind of piezoelectric resonator used in crystal oscillators, which can achieve much higher frequencies.

Square-wave relaxation oscillators are used to provide the clock signal for sequential logic circuits such as timers and counters, although crystal oscillators are often preferred for their greater stability.

The last C, crystal is simply used as a synonym that begins with C for transparency or what gemologists call diaphaneity.

Before the 20th century, jewelers used the term water as in " a gem of the finest water " to express the combination of two qualities, color and crystal.

Alloys used for the strongest permanent magnets are " hard " alloys made with many defects in their crystal structure where the domain walls " catch " and stabilize.

Also, gallium metal easily alloys with many metals, and was used in small quantities as a plutonium-gallium alloy in the plutonium cores of the first and third nuclear bombs, to help stabilize the plutonium crystal structure.

In order to make glass from materials with poor glass forming tendencies, novel techniques are used to increase cooling rate, or reduce crystal nucleation triggers.

Glass can also be cut with a diamond saw, or copper wheels embedded with abrasives, and polished to give gleaming facets ; the technique used in creating Waterford crystal.

A few gemstones are used as gems in the crystal or other form in which they are found.

* In crystal optics, lambda is used to represent the period of a lattice.

Unfortunately the para-Azoxyanisole that Williams and Heilmeier used exhibits the nematic liquid crystal state only above 116 ° C, which made it impractical to use in a commercial display product.

However some techniques, such as the use of boundaries or an applied electric field, can be used to enforce a single ordered domain in a macroscopic liquid crystal sample.

A second rank symmetric traceless tensor order parameter is used to describe the orientational order of a nematic liquid crystal, although a scalar order parameter is usually sufficient to describe uniaxial nematic liquid crystals.

A positional order parameter is also used to describe the ordering of a liquid crystal.

McMillan's model, proposed by William McMillan, is an extension of the Maier – Saupe mean field theory used to describe the phase transition of a liquid crystal from a nematic to a smectic A phase.

Special surface treatments can be used in liquid crystal devices to force specific orientations of the director.

Indian scientist Jagadish Chandra Bose was the first to use a crystal for detecting radio waves in 1894.

The crystal detector in these early crystal radio sets consisted of an adjustable wire point-contact ( the so-called " cat's whisker "), which could be manually moved over the face of the crystal in order to obtain optimum signal.

Cat ’ s whisker diodes were also called crystal diodes and found application in crystal radio receivers.

The diode ( originally a crystal diode ) rectifies the AM radio frequency signal, leaving only the positive peaks of the carrier wave.

Armstrong's research and experimentation with the Audion moved radio reception beyond the crystal set and spark-gap transmitters.

He added that several engineers described the invention " as one of the most important radio developments since the first earphone crystal sets were introduced.

Spiderweb-wound coil for crystal radio

Following World War I, Frederick R. Lack, working in radio telephony in the engineering department, developed the “ AT cut ” crystal, a crystal that operated through a wide range of temperatures.

" It noted, in addition to merchants selling radio sets, " others display mostly accessories ... one shopkeeper last week featured a crystal set small enough to fit into a pocket, and another gave prominent position to a bucket of condensers about an inch in side.

The point-contact crystal detector became vital for microwave radio systems, since available vacuum tube devices could not serve as detectors above about 4000 MHz ; advanced radar systems relied on the fast response of crystal detectors.

This greatly improved the crystal set which rectified the radio signal using an early solid-state diode based on a crystal and a so-called cat's whisker.

The young Lipscomb participated in other projects, such as Morse-coded messages over wires and crystal radio sets, with five nearby friends who became physicists, physicians, and an engineer.

He and his older brother experimented with electricity, building a crystal radio and an alarm system for his house.

Early radio receivers, called crystal radios, used a " cat's whisker " of fine wire pressing on a crystal of galena ( lead sulfide ) to serve as a point-contact rectifier or " crystal detector ".

The earliest crystal radio receivers used a crystal diode detector with no amplification.

1 MHz electronic oscillator circuit which uses the vibrations of an internal quartz crystal to control the frequency.

The electron-emitting and collecting leads would both be placed very close together on the top, with the control lead placed on the base of the crystal.

PHGG is used in foods for particulate suspension, emulsification, antistaling, ice crystal control, and reduced fat baked goods.

* Oscilloquartz SA: Produces and designs high precision frequency control products, including Cesium PRS, quartz crystal oscillator, OCXO, BVA & PRC, SSU ( also called SASE, TSG or BITS ), GPS based synchronisation products for the wireless and wired telecommunication infrastructure.

* X: stable frequency ( crystal control )

Professor Fine persuades Clark to take him to the Fortress of Solitude, where he gives Clark a black crystal and instructs him to insert it into the Fortress ' control console, misleadingly saying that it will destroy Jor-El and therefore save Martha.

Eventually, Luke-who, it turns out, is Brand's son-imprisons Merlin in a blue crystal cave so he can attempt to take control of Ghostwheel for himself.

Yablonovitch's main motivation was to engineer the photonic density of states, to control the spontaneous emission of materials embedded within the photonic crystal ; John's idea was to use photonic crystals to affect the localisation and control of light.

Pemalite technology is incredibly advanced --- a single Pemalite crystal, used to program their computers, would be capable of taking control of every computer on Earth.

The graphite feed was soon replaced by diamond grit because that allowed much better control of the shape of the final crystal.

* They have good accuracy for frequency control since the frequency is controlled by a crystal or tank circuit.

High stability crystal oscillator references often place the crystal in an oven and use a voltage input for fine control.

Sophisticated designs may also adjust the control voltage over time to compensate for crystal aging., k is Boltzmann's constant, T is absolute temperature in Kelvins, and P < sub > s </ sub > is the oscillator output power.

He enforces his will with a powerful crystal that can perform amazing feats of both telekinetic and telepathic prowess and even gives him the ability to control minds.

This system gave way to the present digital system in 1984, which uses a built-in crystal oscillator and microprocessor logic control.

Somewhat limited in features, they were designed for AM phone operation only and frequency control was crystal controlled on transmit.

The interior features a remote touchscreen control system linked to two liquid crystal display ( LCD ) screens that measure in width.

Silica gel litter, often referred to as " crystal litter ", is a porous granular form of sodium silicate, has the highest absorbency of any litter, and has excellent moisture control and complete odor elimination for an extended period of time compared to other litters.

The capacitor is charged up until it holds the correct control voltage, slowly leaking this through the crystal to the common ground.

The BMW 750iL Highline was the top-of-the-line model of the E32, with lots of added luxury for the rear passengers like full leather, dual radio controls, dual climate control with coolbox mounted in the center console, electrically heated and adjustable rear seats, walnut veneer folding tables, two crystal glasses neatly placed in the coolbox, legrests, and sun shade all around the rear / side windows.

Cordelia throws Angel a katana ; while Angel and Lindsey sword-fight she removes the crystal from the control panel, causing the fail-safe to descend into the floor.

However, when Terra refuses to aid him and learned to control her powers, Kefka attempts to kill her and ends up being defeated with Terra gaining her crystal.