Negative Pressure

Negative pressure may refer to:

  • negative pressure as opposed to positive pressure
  • stretched liquid
  • vacuum
  • negative gauge pressure, a way of expressing pressure measurements below atmospheric pressure
  • suction
  • transpirational pull

Other articles related to "pressure, negative pressure":

Support Surfaces - Pressure Ulcer Intervention
... Patients with pressure ulcers should not lie or sit on them ... Continued pressure reduces the blood flow to a wound that is trying to heal ... Specific wound care for pressure ulcers includes the following Stage I pressure ulcers ...
Nature of Dark Energy - Effect of Dark Energy: A Small Constant Negative Pressure of Vacuum
... from its actual nature, dark energy would need to have a strong negative pressure (acting repulsively) in order to explain the observed acceleration in the expansion rate of the ... According to General Relativity, the pressure within a substance contributes to its gravitational attraction for other things just as its mass density does ... both the energy (or matter) density of a substance and its pressure and viscosity ...
Dark Energy - Theories of Explanation - Cosmological Constant
... The cosmological constant has negative pressure equal to its energy density and so causes the expansion of the universe to accelerate ... The reason why a cosmological constant has negative pressure can be seen from classical thermodynamics Energy must be lost from inside a container to do work on the container ... done equal to a change of energy −P dV, where P is the pressure ...
Soil Steam Sterilization - Surface Steaming - Depth Steaming With Vacuum - Negative Pressure Technique
... "Negative Pressure technique generates appropriate soil temperature at a 60 cm depth and complete control of nematodes, fungi and weeds is achieved ... under the steaming sheath and forced to enter the soil profile by a negative pressure ... The negative pressure is created by a fan that sucks the air out of the soil through buried perforated polypropylene pipes ...

Famous quotes containing the words pressure and/or negative:

    “We believe that civilization has been created under the pressure of the exigencies of life at the cost of satisfaction of the instincts.”
    —Sigmund Freud (1856–1939)

    “The idealist’s programme of political or economic reform may be impracticable, absurd, demonstrably ridiculous; but it can never be successfully opposed merely by pointing out that this is the case. A negative opposition cannot be wholly effectual: there must be a competing idealism; something must be offered that is not only less objectionable but more desirable.”
    —Charles Horton Cooley (1864–1929)