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For example, water boils at a lower temperature at lower pressures. The equipment used for pressure experiments depends on whether the pressure is to be increased or decreased and by how much. A vacuum pump is used to remove the air out of a vacuum vessel for low-pressure experiments. High-pressures can be created with a piston-cylinder ...
The idea of a Langmuir–Blodgett (LB) film was first proven feasible in 1917 when Irving Langmuir (Langmuir, 1917) showed that single water-surface monolayers could be transferred to solid substrates. 18 years later, Katharine Blodgett made an important scientific advance when she discovered that several of these single monolayer films could be stacked on top of one another to make multilayer ...
For example, oil droplets in a salad dressing are spherical but the interface between water and air in a glass of water is mostly flat. Surface tension is the physical property which rules interface processes involving liquids. For a liquid film on flat surfaces, the liquid-vapor interface keeps flat to minimize interfacial area and system free ...
Once the valve was opened, air rushed in and the hemispheres were easily separated. The Magdeburg hemispheres were invented by German scientist and mayor of Magdeburg, [1] Otto von Guericke, to demonstrate the air pump that he had invented and the concept of atmospheric pressure. Speculation varied about the contents of the sphere.
In his book, New Experiments Physico-Mechanicall, Touching the Spring of the Air, and its Effects, (Made, for the Most Part, in a New Pneumatical Engine), he described 43 separate experiments, some of which were carried out with Robert Hooke, investigating the effect of reducing the air pressure within the bell jar on the objects contained within.
The operation of the diamond anvil cell relies on a simple principle: =, where p is the pressure, F the applied force, and A the area. Typical culet sizes for diamond anvils are 100–250 micrometres (μm), such that a very high pressure is achieved by applying a moderate force on a sample with a small area, rather than applying a large force on a large area.
This validated his belief that air/gas has mass, creating pressure on things around it. The discovery helped bring Torricelli to the following conclusion: We live submerged at the bottom of an ocean of the element air, which by unquestioned experiments is known to have weight. This test was essentially the first documented pressure gauge.
Condensers with forced-circulation cooling usually employ water as the cooling fluid. The flow may be open, from a tap to a sink, and driven only by the water pressure in the tap. Alternatively, a closed system may be used, in which the water is drawn by a pump from a tank, possibly refrigerated, and returned to it. Water-cooled condensers are ...