Liquid crystals find wide use in liquid crystal displays, which rely on the optical properties of certain liquid crystalline substances in the presence or absence of an electric field.

In 1793 he explained the mode in which the eye accommodates itself to vision at different distances as depending on change of the curvature of the crystalline lens ; in 1801 he was the first to describe astigmatism ; and in his Lectures he presented the hypothesis, afterwards developed by Hermann von Helmholtz, that colour perception depends on the presence in the retina of three kinds of nerve fibres.

The presence of water ice is supported by spectroscopic observations, which have revealed crystalline water ice on the surface of the moon.

The presence of carbon allows steel to assume one of several different crystalline configurations.

A pit-cooked camas bulb looks and tastes something like baked sweet potato, but sweeter, and with more crystalline fibers due to the presence of inulin in the bulbs.

A pit-cooked camas bulb looks and tastes something like baked sweet potato, but sweeter, and with more crystalline fibers due to the presence of inulin in the bulbs.

Bread goes stale through a process of retrogradation, in which the starch transposes to a crystalline form in the presence of the water contained within the bread itself.

The materials used for generation of terahertz radiation by optical rectification can also be used for its detection by using the Pockels effect, where certain crystalline materials become birefringent in the presence of an electric field.

Crystalline nanoparticles are also of interest because they often provide single-domain crystalline systems that can be studied to provide information that can help explain the behaviour of macroscopic samples of similar materials, without the complicating presence of grain boundaries and other defects.

One sample, which had been exposed to the atmosphere after evacuation at 375-degrees-C, showed the presence of adsorbed water ( about 0.3 wt ) ) as evidenced by a weak resonance line which was very narrow at room temperature and which disappeared, due to broadening, at low temperature.

The washing process whereby soils are removed consists basically of applying mechanical action to loosen the dirt particles and dried matter in the presence of water which helps to float off the debris and acts, to some extent, as a dissolving and solvating agent.

The mixture was then extracted with alkali and with water following which the carbon tetrachloride was distilled on a Vigreux column, a 25% center cut being retained which was then degassed under vacuum in the presence of Af.

-- Glycerinated muscle, in the presence of the physiological agent ( ATP ) responsible for delivering energy to the mechanochemically active proteins of muscle, has been shown to undergo a contraction which is highly sensitive both to temperature and to solvent composition in mixtures of alcohols and water.

The decoloration of a solution of bromine in water with dichloromethylene as catalyst is an analytical test for the presence of alkenes:

In the presence of oxygen, alkenes burn with a bright flame to produce carbon dioxide and water.

In the presence of water, sulfur trioxide ( SO < sub > 3 </ sub >) is converted rapidly to sulfuric acid:

* Dry basis, an expression of a calculation in which the presence of water is ignored

Being less reactive than chlorine but more reactive than iodine, bromine reacts vigorously with metals, especially in the presence of water, to give bromide salts.

Key evidence of Baltic language presence in these regions is found in hydronyms ( names of bodies of water ) in the regions that are characteristically Baltic.

Further investigation revealed that the fixture's mounting apparatus had failed, due to galvanic corrosion of incompatible metals, caused by having aluminum in direct contact with stainless steel, in the presence of salt water.

The properties of the water in the solution are not altered, other than the simple osmotic changes that would be caused by the presence of any solute.

The study was the first nationwide analysis measuring the presence of the chemical in U. S. water systems.

This equilibrium between carbonate, bicarbonate, carbon dioxide and carbonic acid in water can, under changing temperature or pressure conditions, and in the presence of metal ions with insoluble carbonates, result in formation of insoluble compounds.

It is generally thought that the presence of carbonates in rock is strong evidence for the presence of liquid water.

To maintain the catenary shape in the presence of wind, a heavy chain is needed, so that only larger ships in deeper water can rely on this effect.

As a result, the presence or absence of trees can change the quantity of water on the surface, in the soil or groundwater, or in the atmosphere.

* 2006 – NASA reveals photographs taken by Mars Global Surveyor suggesting the presence of liquid water on Mars.

Limited agricultural production, the presence of some natural resources, and permanent settlements are found in the other six depressions, all of which have fresh water provided by the Nile or by local groundwater.

The presence of water in a solution of sodium chloride must be examined in respect to its reduction and oxidation in both electrodes.

Explosives considerably differ from one another as to their behavior in the presence of water.

Examples of hurdles in a food system are high temperature during processing, low temperature during storage, increasing the acidity, lowering the water activity or redox potential, or the presence of preservatives or biopreservatives.

* Tonic water fluoresces blue due to the presence of quinine.

In installations where copper pipe has been fitted to replace a section of corroded galvanized pipe, a special dielectric fitting called a " union " must be used to join the two types of pipes ; otherwise the presence of water in contact with differing metals creates an electrical current that can cause " galvanic corrosion ".

It is also affected by the presence of snow, hail and ice and can relate to dew, mist and fog.

Other colors can appear in the presence of light absorbing impurities, where the impurity is dictating the color rather than the ice itself.

Even with the overall warmth, temperature fluctuations should have been sufficient for the presence of polar ice caps and glaciers, but there is no evidence of either.

A competing theory to explain the presence of ice on the equatorial continents was that the Earth's axial tilt was quite high, in the vicinity of 60 °, which would place the Earth's land in high " latitudes ", although supporting evidence is scarce.

:* Species cumulonimbus capillatus ( Cb cap ): Thunderclouds with very high tops that have become fibrous due to the presence of ice crystals ( C < sub > L </ sub > 9 ).

However, the presence or absence of land masses at the poles is not sufficient to guarantee glaciations or exclude polar ice caps.

The presence of snow and ice is a well-understood positive feedback mechanism for climate.

When British scientists in Antarctica performed airborne ice-penetrating radar surveys in the early 1970s, they detected unusual radar readings at the site which suggested the presence of a liquid, freshwater lake below the ice.

Because of the persistent presence of the ice sheet, the island is sometimes taken to be part of Antarctica.

On October 7, 2009, the presence of water ice was confirmed on the surface of this asteroid using NASA ’ s Infrared Telescope Facility.

The presence of ice on 24 Themis supports this theory.

An alternative mechanism to explain the presence of water ice on 24 Themis is similar to the hypothesized formation of water on the surface of the Moon by solar wind.

However, images from Cassini indicate that Phoebe's craters show a considerable variation in brightness, which indicate the presence of large quantities of ice below a relatively thin blanket of dark surface deposits some thick.

Most ice sensors are simple thermal switches, and do not directly sense the presence or absence of ice buildup.

The presence of subfossil bones at Conkling Cave and Shelter Cave in southern New Mexico show that the species was present south of its current range at the end of the last ice age, leading some experts to project that the species could become increasingly vulnerable as global climate change increases the humidity in semiarid regions.

In 1974, when British scientists in Antarctica performed an airborne ice-penetrating radar survey and detected strange radar readings at the site, the presence of a liquid, freshwater lake below the ice did not instantly spring to mind.

There, they are one of the best lines of evidence for the recent presence of liquid water on Mars in the recent geological past, probably resulting from the slight melting of snowpacks on the surface or ice in the shallow subsurface on the warmest days of the Martian year.

Quaoar — a trans-Neptunian object of similar size — has strong water ice absorption features in its spectra but also has a very red color in the visible implying the presence of the ultrared matter on its surface.

Glacial striation and the presence of chalk and flint erratics that originated from the bed of the North Sea demonstrate the influence of ice action on the geomorphology of the islands.

For example, the chemical composition of and the presence of volcanic ash with the specific acidity spikes in the Greenland ice cores presents clear evidence that they are volcanic, not impact, in origin.