The Stone-Wales defect is a type of defect that can occur in graphene and other two-dimensional materials. It involves a local rearrangement of carbon atoms in the hexagonal lattice structure of graphene. The defect is characterized by the rotation of a pair of carbon-carbon bonds, which transforms one hexagonal ring in the lattice into a series of two adjacent pentagonal and heptagonal rings.

The Cottrell atmosphere refers to a specific electrochemical phenomenon that occurs during the mass transport of species in an electrochemical cell, particularly during voltammetric experiments. Named after the scientist who studied it, the Cottrell equation describes the current response of an electrochemical system under conditions of diffusion-controlled mass transport when an electrode is suddenly held at a potential that allows for faradaic reactions. In a Cottrell atmosphere, the current is proportional to the square root of time.

Minerals are classified into various crystal systems based on the symmetry and arrangement of their crystal lattices. There are seven primary crystal systems, each defined by specific geometric parameters such as the lengths of the axes and the angles between them. Here’s an overview of the seven crystal systems: 1. **Cubic (or Isometric)**: - Axes: All three axes are of equal length and intersect at right angles (90 degrees).

Crystallographic defects, also known as crystal defects, refer to imperfections in the regular geometric arrangement of atoms or molecules in a crystalline structure. These defects play a crucial role in determining the physical, chemical, and mechanical properties of materials.

Geometrically Necessary Dislocations (GNDs) are a specific type of dislocation that arise in crystalline materials when there is a gradient in the plastic deformation across the material. Unlike ordinary dislocations, which can move freely in a homogeneously deformed material, GNDs are required to accommodate the non-uniform strain fields that often occur during processes such as bending, stretching, or otherwise non-uniform deformation of materials.

Crystal structure types refer to the organized arrangement of atoms, ions, or molecules within a crystalline solid. The arrangement is characterized by the symmetry and periodicity of the crystal lattice. Here are some common types of crystal structures: 1. **Cubic**: - **Simple Cubic (SC)**: Atoms are located at the corners of a cube. Example: Polonium.

A unit cell is the smallest repeating unit of a crystal lattice that retains the geometric and symmetry characteristics of the entire crystal structure. It serves as the foundational building block from which the entire crystal structure can be constructed through translational repetition in three-dimensional space.

"Horrible Histories" is a British children's television series that first aired in 2009 and has continued in various forms, including a 2015 special series. It is based on the popular book series of the same name by Terry Deary. The show combines comedy, history, and educational content to engage younger audiences with historical events, figures, and everyday life in different eras.

Crystal chemistry is the branch of chemistry that studies the arrangement of atoms within crystalline solids, the relationships between the structure of these crystals and their physical properties, and the chemical interactions that govern their formation. It combines principles from chemistry, physics, materials science, and mineralogy to understand how crystal structures influence the behavior and characteristics of materials. Key aspects of crystal chemistry include: 1. **Crystal Structure**: This refers to the orderly geometric arrangement of atoms or molecules in a crystal.

Water of crystallization refers to the water molecules that are integrally associated with a crystalline solid. These water molecules are part of the structure of the compound and are essential for maintaining the stability and integrity of the crystal lattice. When certain salts and other compounds crystallize, they can incorporate water molecules into their structure. This incorporation of water can significantly affect the physical and chemical properties of the compound, including its solubility, color, and stability.

Boron-rich metal borides are a class of materials that typically have complex crystal structures due to the presence of boron in high concentrations. These compounds often contain transition metals, and their structure is characterized by the presence of various boron polyhedra and metal coordination entities.

Crystallization adjutants are substances that are used to promote or enhance the crystallization process of solid compounds from a solution. These materials can assist in controlling the size, shape, and purity of the resulting crystals, making them particularly important in various fields, including pharmaceuticals, food chemistry, and materials science. Crystallization is a common technique for purifying substances and can be influenced by many factors, including temperature, concentration, and the presence of additives.

Friedel's law is a principle in crystallography that relates to the symmetry of X-ray diffraction patterns. Specifically, it states that the intensity of diffracted X-rays from a crystal will be the same for reflections that are related by a center of symmetry (or inversion center).

Lattice energy refers to the amount of energy that is released when ions in a gas phase come together to form a solid ionic compound. It can also be viewed as the energy required to separate one mole of an ionic solid into its gaseous ions. Lattice energy is a measure of the strength of the forces between the ions in an ionic solid.

In crystallography, the R-factor (or R-value) is a quantitative measure used to assess how well a proposed model of a crystal structure matches the observed X-ray diffraction data. It is crucial for evaluating the quality of the structure determined from X-ray crystallography.

A thermal ellipsoid is a three-dimensional geometric representation used in crystallography and molecular biology to visualize the thermal motion of atoms in a crystal structure. It illustrates the atomic displacement due to thermal vibrations, which are influenced by temperature. Each atom in a crystalline material oscillates around its equilibrium position, and the extent of this motion can be described by an ellipsoid. The shape and orientation of the ellipsoid provide information about the distribution and amplitude of atomic vibrations.

Thermal laser epitaxy (TLE) is a specialized growth technique used in materials science and semiconductor fabrication to create thin films or heterostructures with precise control over their composition and structure. The method typically involves the use of a focused laser beam to locally heat a substrate or a precursor material, thereby enabling the growth of crystalline films on the substrate based on thermally induced reactions.

A puncheon is a unit of measurement that can refer to both a volume and a weight, depending on the context. 1. **Volume**: In terms of volume, a puncheon is typically equivalent to around 120 gallons (approximately 450 liters) in the context of liquids such as wine or beer. Specifically, in the wine industry, a puncheon often refers to a barrel that holds a certain volume of wine or spirits.

"Little Ashes" is a 2008 biographical drama film directed by Paul Morrison. The film is set in the 1920s and explores the relationship between two prominent figures of the Spanish surrealist movement: the painter Salvador Dalí, played by Robert Pattinson, and the poet Federico García Lorca, portrayed by Javier Beltrán.

An anker is a unit of measurement for large quantities of work or energy in electrical systems, specifically in the context of wrought iron rods or bars. It is mainly used in certain industries and regions but is not a standard SI unit.