For example, carbon can be found as diamond, which has a tetrahedral structure around each carbon atom ; graphite, which has layers of carbon atoms with a hexagonal structure stacked on top of each other ; graphene, which is a single layer of graphite that is incredibly strong ; fullerenes, which have nearly spherical shapes ; and carbon nanotubes, which are tubes with a hexagonal structure ( even these may differ from each other in electrical properties ).

It consisted of a, graphite cylinder lying on its side, penetrated through its entire length horizontally by 2, 004 aluminum tubes.

Sp²-hybridized carbon structures that – in contrast to sp³-hybridized carbon in diamond – arrange in planar sheets (" graphene " sheets ) are sometimes also included in the class of diamondoid materials for nanotechnology, e. g., graphite, carbon nanotubes consisting of sheets of carbon atoms rolled into tubes, spherical buckyballs and other graphene structures.

The drawbacks of this technology ( electro thermal atomization ) as currently practiced is that it is more expensive ( due mainly to the cost of the graphite tubes ), and takes significantly longer to perform an analysis than with flame atomization ( minutes versus seconds ), and the graphite tubes, which must be replaced relatively frequently, are expensive.

Some high-powered vacuum tubes ( e. g. large transmitter tubes ) have graphite or zirconium coated tantalum plates which are intended to operate at glowing temperatures.

The earliest tubes were simple quartz, followed by quartz with graphite disks.

* Used to coat graphite cuvettes ( tubes ) in graphite furnace atomic absorption furnaces to decrease heat stress, thus increasing cuvette lifetimes.

Diamond and graphite are two allotropes of carbon: pure forms of the same element that differ in crystalline structure.

For example, the allotropes of carbon include diamond ( where the carbon atoms are bonded together in a tetrahedral lattice arrangement ), graphite ( where the carbon atoms are bonded together in sheets of a hexagonal lattice ), graphene ( single sheets of graphite ), and fullerenes ( where the carbon atoms are bonded together in spherical, tubular, or ellipsoidal formations ).

The atomizers most commonly used nowadays are flames and electrothermal ( graphite tube ) atomizers.

The atomizers most commonly used nowadays are ( spectroscopic ) flames and electrothermal ( graphite tube ) atomizers.

Although a wide variety of graphite tube designs have been used over the years, the dimensions nowadays are typically 20 – 25 mm in length and 5 – 6 mm inner diameter.

A measured volume ( typically 10 – 50 μL ) or a weighed mass ( typically around 1 mg ) of a solid sample are introduced into the graphite tube and subject to a temperature program.

* Cleaning – eventual residues in the graphite tube are removed at high temperature.

An alternating magnetic field is applied at the atomizer ( graphite furnace ) to split the absorption line into three components, the π component, which remains at the same position as the original absorption line, and two σ components, which are moved to higher and lower wavelengths, respectively ( see Zeeman Effect ).

They are composed of many different materials ranging from carbon fibre composite ( graphite reinforced plastic ) to solid steel, which may be augmented by a variety of materials.

There are several allotropes of carbon of which the best known are graphite, diamond, and amorphous carbon.

All carbon allotropes are solids under normal conditions with graphite being the most thermodynamically stable form.

Pencil leads for mechanical pencils are made of graphite ( often mixed with a clay or synthetic binder ).

In the Russian Doll model, sheets of graphite are arranged in concentric cylinders, e. g., a ( 0, 8 ) single-walled nanotube ( SWNT ) within a larger ( 0, 17 ) single-walled nanotube.

Among the more common of such " native elements " are copper, silver, gold, carbon ( as coal, graphite, or diamonds ), sulfur, and mercury.

For example, diamond and graphite are two crystalline forms of carbon, while amorphous carbon is a noncrystalline form.

Covalently bonded crystals are also very common, notable examples being diamond, silica, and graphite.

With furnace atomization, a microliter-sized portion of sample is pipette into a small, open-ended graphite cylinder, which is located in the light beam of the instrument, and the cylinder is then heated by applying a high electrical potential across the cylinder.

The synthesis capsule is heated up by a coaxial graphite heater and the temperature is measured with a thermocouple.

The only viable solution was an annealing process, in which the graphite core was heated to 250 ° C by the nuclear fuel to allow the displaced carbon atoms to slip back into place in crystalline structure, gradually releasing their stored energy as heat, and causing a uniform release which spread throughout the core.

In GFAAS, samples are deposited in a small graphite or pyrolytic carbon coated graphite tube, which can then be heated to vaporize and atomize the analyte.

The sample is vaporized in the heated graphite tube ; the amount of light energy absorbed in the vapor is proportional to atomic concentrations.

Nanomanipulation via STM of a Self-assembly | self-assembled organic semiconductor monolayer ( here: PTCDA molecules ) on graphite, in which the logo of the Center for NanoScience ( CeNS ), Ludwig Maximilian University of Munich | LMU has been written.

Some materials that prove difficult to shape with other processes, such as fiber-glass, Kevlar, and graphite, can be shaped and finished neatly via various routing techniques.

* The various allotropes of carbon, including graphite, are capable of accepting foreign atoms or compounds into their structures via substitution, intercalation or doping ( interstitial or intrastitial ) with the resulting materials being referred to as ' carbon alloys '.

The heat from the salts are transferred to a secondary heat transfer fluid via a heat exchanger and then to the storage media, or alternatively, the salts can be used to directly heat graphite.

Large quantities of width controlled GNRs can be produced via graphite nanotomy process.

GQDs can be produced via graphite nanotomy as shown by Berry group or via bottom-up, solution-based routes ( Diels-Alder, cyclotrimerization and / or cyclodehydrogenation reactions ) shown by Mullen group.

The known inorganic chemistry of the allotropes of carbon ( diamond, graphite, and the fullerenes ) blossomed with the discovery of buckminsterfullerene in 1985, as additional fullerenes and their various derivatives were discovered.

Although diamond s ( top left ) and graphite ( top right ) are identical in chemical composition — being both pure carbon — X-ray crystallography revealed the arrangement of their atoms ( bottom ) accounts for their different properties.

All elements in their standard states ( oxygen gas, solid carbon in the form of graphite, etc.

North Korea also had two additional graphite moderated reactors being built, but that have since become unsalvageable since maintenance of their construction sites was not allowed under the Agreed Framework.

Not until 1987 did he finally switch to a graphite racket when he contracted with Slazenger to play their Panther Pro Ceramic.

During launch many gliders withstand 30G or more, far more than any manned aircraft is stressed to and launch speeds of sometimes over 140 km / h which energy is then converted in altitude ; this has only become possible since the advent of composite materials such as carbon ( graphite ), fiberglass, and Kevlar, which are used extensively in many of their structures.

These grains are recognizable from their exotic chemistry which is alien to the solar system ( such as matrixes of graphite, diamond, or silicon carbide ).

Lonsdaleite is a hexagonal allotrope of the carbon allotrope diamond, believed to form from graphite present in meteorites upon their impact to Earth.

Current graphite shafts weigh considerably less than their steel counterparts ( sometimes weighing less than for a driver shaft ), allowing for lighter clubs that can be swung at greater speed.

The voter is then given the ballot ( s ) and enters a voting booth where they must mark their choice by drawing a vertical line over a printed horizontal line next to their candidate of choice by using a previously provided graphite pencil.

Because of known shrinkage of the graphite moderator bricks in the core due to in-service irradiation effects, some of the steel charge pans on top of them had become dislocated from their design position in the interstitial channel and were suspended from the Burst Can Detection ( BCD ) pipework.

The rationale for the overall design was the elimination of unnecessary weight, especially the unbalanced headstock, and the use of modern materials, such as graphite, for their advantages over wood.

This use of his custom made graphite neck, five-string bass is exemplified on the introduction of the song " Omnipotent Phantasies " and on their instrumental epic " Reflections of a Lost Past ".

Zon had elements of their graphite necks made by Modulus Guitars until Modulus ' patent for Graphite neck construction ran out in the early 1990s.

Some molecules, for example, graphite ( C ) and SiC would condense into solid grains in the planetary disk ; but carbon and SiC grains found in meteorites are presolar based on their isotopic compositions, rather than from the planetary disk formation.

His illustrations of the Moon were made in charcoal, graphite pencil, and ink, and were considered superior to any previously produced lunar maps in their accuracy and level of detail, and continue to be considered works of art.