Boule (crystal)

A boule is a single crystal ingot produced by synthetic means. A boule of silicon is the starting material for most of the integrated circuits used today.

In the semiconductor industry, boules can be made by a number of methods, such as the Bridgman technique and the Czochralski process, which result in a cylindrical rod of material.

In the Czochralski process a seed crystal is required to create a larger crystal, or ingot. This seed crystal is dipped into the pure molten silicon and slowly extracted. The molten silicon grows on the seed crystal in a crystalline fashion. As the seed is extracted the silicon solidifies and eventually a large, cylindrical boule is produced.

A semiconductor crystal boule is normally cut with a diamond saw into circular wafers, and each wafer is polished to provide substrates suitable for the fabrication of semiconductor devices on its surface.

The process is also used to create sapphires, which are used for substrates in the production of blue and white LEDs, optical windows in special applications and as the protective covers for watches.

Crystal (software)

CRYSTAL is a quantum chemistry ab initio program, designed primarily for calculations on crystals (3 dimensions), slabs (2 dimensions) and polymers (1 dimension) using translational symmetry, but it can also be used for single molecules. It is written by V.R. Saunders, R. Dovesi, C. Roetti, R. Orlando, C.M. Zicovich-Wilson, N.M. Harrison, K. Doll, B. Civalleri, I.J. Bush, Ph. D’Arco, and M. Llunell from Theoretical Chemistry Group at the University of Torino and the Computational Materials Science Group at the Daresbury Laboratory near Warrington in Cheshire, England. The current version is CRYSTAL14, released in June 2014. Earlier versions were CRYSTAL88, CRYSTAL92, CRYSTAL95, CRYSTAL98, CRYSTAL03, CRYSTAL06, and CRYSTAL09.

Features

Hamiltonians

List of companions in Doctor Who spin-offs

This is a list of fictional characters who were companions of the Doctor, in various spin-off media based on the long-running British science fiction television series, Doctor Who.

A

ARC

traveled with the 11th doctor

Alex Campbell

Alex is the Doctor's great grandson (the son of Susan Campbell) and features in the Eighth Doctor adventures. He is portrayed by Jake McGann.

He is initially wary of the Doctor due to the xenophobic atmosphere on Earth following the Dalek occupation. Despite this, he eventually accepts the Doctor but while he is impressed by the technology of the TARDIS he chooses not to travel with him as he wants to become an architect.

During the second Dalek invasion in the plays Lucie Miller and To The Death, Alex becomes a leader for the human resistance on Earth. He sacrifices himself to allow Lucie and Susan the opportunity to thwart the Dalek's plan.

Amy

Amy, portrayed by Ciara Janson, is a companion of the Fifth Doctor in the Key 2 Time series, which includes the plays The Judgement of Isskar, The Destroyer of Delights and The Chaos Pool.

Crystal (programming language)

Crystal is a general-purpose, object-oriented programming language designed and developed by Ary Borenszweig and Juan Wajnerman and over one-hundred listed contributors. Crystal is developed as open source and its syntax is inspired by Ruby. The language is statically type-checked but without having to specify the type of variables or method arguments. Its first official release was released in June 2014. While the original Crystal compiler was written in Ruby, in 2013 a new compiler written using the Crystal programming language itself was released. The current release version is 0.11.1 and the language is in an active development phase.

Description

Although resembling the Ruby programming language in syntax, Crystal compiles to much more efficient native code using an LLVM backend, at the cost of disallowing the dynamic aspects of Ruby. Recent benchmarks have demonstrated that Crystal has a performance broadly similar to C for a wide range of computing tasks. The language has automated garbage collection and currently offers a Boehm collector. Crystal possesses a macro system and supports generics and method and operator overloading.

BOLL

Protein boule-like is a protein that in humans is encoded by the BOLL gene.

Function

This gene belongs to the DAZ gene family required for germ cell development. It encodes an RNA-binding protein which is more similar to Drosophila Boule than to human proteins encoded by genes DAZ (deleted in azoospermia) or DAZL (deleted in azoospermia-like). Loss of this gene function results in the absence of sperm in semen (azoospermia). Histological studies demonstrated that the primary defect is at the meiotic G₂ / M transition in fruitfly but in mice the primary defect is postmeiotic at round spermatid stage. Multiple alternatively spliced transcript variants encoding distinct isoforms have been found for this gene.

The boule-like protein appears to be ubiquitously expressed in males of all animal species, except in the most primitive trichoplax.

References

Further reading

Boule (bread)

Boule, from the French for "ball", is a traditional shape of French bread, resembling a squashed ball. It is a rustic loaf shape that can be made of any type of flour. A boule can be leavened with commercial yeast, chemical leavening, or even wild yeast sourdough. The name of this bread is the reason a bread baker is referred to as a "boulanger" in French, and a bread bakery a "boulangerie."

See also

External links

References

Boule (ancient Greece)

In cities of ancient Greece, the boule (Greek: βουλή, boulē; plural βουλαί, boulai) was a council of citizens (βουλευταί, bouleutai) appointed to run daily affairs of the city. Originally a council of nobles advising a king, boulai evolved according to the constitution of the city; in oligarchies boule positions might be hereditary, while in democracies members were typically chosen by lot, and served for one year. Little is known about the workings of many boulai, except in the case of Athens, for which extensive material has survived.

Athenian boule

The original council of Athens was the Areopagus. It consisted of ex-archons and was aristocratic in character.

Solonian boule

The Athenian boule under Solon heard appeals from the most important decisions of the courts. Those in the poorest class could not serve on the boule of 400. The higher governmental posts, archons (magistrates), were reserved for citizens of the top two income groups.

Reforms of Cleisthenes