ground

(noun)

In aquatint, the substance applied to the plate to resist the acid.

Related Terms

Examples of ground in the following topics:

  • Safety Precautions in the Household

    • There are three connections to the earth or ground (earth/ground, ).
    • The third earth/ground connection involves the case of the appliance, through the green earth/ground wire, forcing the case to be at zero volts.
    • Grounding the case solves more than one problem, however.
    • If grounded, the case voltage is kept near zero, but if the case is not grounded, a shock can occur.
    • The case of the appliance is also grounded to zero volts.

  • Etching

    • There are two types of ground: hard ground and soft ground.
    • When the plate cools, the ground hardens.
    • The second way to apply hard ground is to apply a liquid hard ground, which comes in a can and is applied with a brush.
    • Once the liquid hard ground is exposed to air, it hardens.
    • Soft ground also comes in liquid form and is allowed to dry.

  • Ceramics in the Greek Early Classical Period

    • All the figures stand and sit on various ground lines.
    • The Achilles Painter, a pupil of the Berlin Painter and creator of both red-figure and white-ground vessels, is one of the most well-known white ground painters.
    • Attic white ground lekythos. c. 440-430 BCE.
    • Attic white-ground black-figure lekythos.
    • Attic white ground lekythos. c. 440-430 BCE.

  • Characteristics of Connective Tissue

    • Together the ground substance and fibers make up the extracellular matrix.
    • Ground substance is a clear, colorless, viscous fluid that fills the space between the cells and fibers.
    • The ground substance functions as a molecular sieve for substances to travel between blood capillaries and cells.
    • Connective tissues consist of three parts: cells suspended in a ground substance or matrix; and most have fibers running through it.

  • The Third Law of Thermodynamics and Absolute Energy

    • The entropy of a system at absolute zero is typically zero, and in all cases is determined only by the number of different ground states it has.
    • Mathematically, the absolute entropy of any system at zero temperature is the natural log of the number of ground states times Boltzmann's constant kB.
    • The entropy of a perfect crystal lattice is zero, provided that its ground state is unique (only one), because ln(1) = 0.
    • An example of a system which does not have a unique ground state is one containing half-integer spins, for which there are two degenerate ground states.
    • Materials that remain paramagnetic at absolute zero, by contrast, may have many nearly-degenerate ground states, as in a spin glass, or may retain dynamic disorder, as is the case in a spin liquid.

  • Is everything recyclable?

    • Substances used in the medical and livestock industries, for example, can be unsuitable (some scientists believe that the mad cow disease outbreaks in the UK began when infected sheep carcasses were ground up and recycled as cattle feed).

  • Electrostatic Shielding

    • The action of a Faraday cage may depend on whether or not it is grounded.
    • If the cage is not grounded, electrons in the cage will redistribute such that the interior wall of the cage takes on a charge opposite the internal charge.
    • If it is grounded, however, excess charges on the exterior of the cage will go to the ground, leaving the exterior wall of neutral charge.

  • Root Modifications

    • Aerial roots grow above the ground, typically providing structural support.
    • Aerial prop roots develop from the branches and eventually reach the ground, providing additional support .
    • Aerating roots, which rise above the ground, especially above water, are commonly seen in mangrove forests that grow along salt water coastlines.
    • Aerial roots extend to the ground, supporting the growing plant, which eventually strangles the host tree.

  • Glow of Space Shuttles

    • The glow observed as a space shuttle re-enters the atmosphere is due to excited NO2 releasing light to return to its ground state.
    • It is the relaxation of these electrons from the excited state back to the ground state that produces the glow that is visible around the space shuttle (see the concept about the emission spectra for more information).
    • When atomic oxygen from the high atmosphere combines with nitric oxide on the surface of the space shuttle, the resulting excited nitrogen dioxide returns to the ground state emitting an apparent glow.

  • Mechanistic Background

    • Overall bonding in an excited state is usually lower than in the ground state.
    • At normal temperatures essentially all molecules will exist in the ground vibrational state (zero level).
    • The excited state may return to the ground state by emitting a photon (light blue line).
    • Molecular oxygen is a rare example of a triplet ground electronic state.
    • Alternatively, an excited state may return to the ground state by emitting a photon (radiative decay).