ScreeScree is a collection of broken rock fragments at the base of a cliff or other steep rocky mass that has accumulated through periodic rockfall. Landforms associated with these materials are often called talus deposits. Talus deposits typically have a concave upwards form, where the maximum inclination corresponds to the angle of repose of the mean debris particle size. The exact definition of scree in the primary literature is somewhat relaxed, and it often overlaps with both talus and colluvium.
Chromosome segregationChromosome segregation is the process in eukaryotes by which two sister chromatids formed as a consequence of DNA replication, or paired homologous chromosomes, separate from each other and migrate to opposite poles of the nucleus. This segregation process occurs during both mitosis and meiosis. Chromosome segregation also occurs in prokaryotes. However, in contrast to eukaryotic chromosome segregation, replication and segregation are not temporally separated. Instead segregation occurs progressively following replication.
LandslideLandslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, shallow or deep-seated slope failures, mudflows, and debris flows. Landslides occur in a variety of environments, characterized by either steep or gentle slope gradients, from mountain ranges to coastal cliffs or even underwater, in which case they are called submarine landslides.
Large Electron–Positron ColliderThe Large Electron–Positron Collider (LEP) was one of the largest particle accelerators ever constructed. It was built at CERN, a multi-national centre for research in nuclear and particle physics near Geneva, Switzerland. LEP collided electrons with positrons at energies that reached 209 GeV. It was a circular collider with a circumference of 27 kilometres built in a tunnel roughly 100 m (300 ft) underground and passing through Switzerland and France. LEP was used from 1989 until 2000.
Surface tensionSurface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to float on a water surface without becoming even partly submerged. At liquid–air interfaces, surface tension results from the greater attraction of liquid molecules to each other (due to cohesion) than to the molecules in the air (due to adhesion). There are two primary mechanisms in play.
ExperimentAn experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary greatly in goal and scale but always rely on repeatable procedure and logical analysis of the results. There also exist natural experimental studies.
Submarine landslideSubmarine landslides are marine landslides that transport sediment across the continental shelf and into the deep ocean. A submarine landslide is initiated when the downwards driving stress (gravity and other factors) exceeds the resisting stress of the seafloor slope material, causing movements along one or more concave to planar rupture surfaces. Submarine landslides take place in a variety of different settings, including planes as low as 1°, and can cause significant damage to both life and property.
LaboratoryA laboratory (UKləˈbɒrətəri; USˈlæbrətɔri; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratories are found in a variety of settings such as schools, universities, privately owned research institutions, corporate research and testing facilities, government regulatory and forensic investigation centers, physicians' offices, clinics, hospitals, regional and national referral centers, and even occasionally personal residences.
WallA wall is a structure and a surface that defines an area; carries a load; provides security, shelter, or soundproofing; or, is decorative. There are many kinds of walls, including: Walls in buildings that form a fundamental part of the superstructure or separate interior rooms, sometimes for fire safety Glass walls (a wall in which the primary structure is made of glass; does not include openings within walls that have glass coverings: these are windows) Border barriers between countries Brick walls Defensive walls in fortifications Permanent, solid fences Retaining walls, which hold back dirt, stone, water, or noise sound Stone walls Walls that protect from oceans (seawalls) or rivers (levees) The term wall comes from Latin vallum meaning ".
Cross section (physics)In physics, the cross section is a measure of the probability that a specific process will take place when some kind of radiant excitation (e.g. a particle beam, sound wave, light, or an X-ray) intersects a localized phenomenon (e.g. a particle or density fluctuation). For example, the Rutherford cross-section is a measure of probability that an alpha particle will be deflected by a given angle during an interaction with an atomic nucleus. Cross section is typically denoted σ (sigma) and is expressed in units of area, more specifically in barns.
