Ad
related to: sublimation keyring time and temp table for temperature and pressure range
Search results
Results From The WOW.Com Content Network
In thermodynamics, the enthalpy of sublimation, or heat of sublimation, is the heat required to sublimate (change from solid to gas) one mole of a substance at a given combination of temperature and pressure, usually standard temperature and pressure (STP). It is equal to the cohesive energy of the solid.
The Knudsen cell is used to measure the vapor pressures of a solid with very low vapor pressure. Such a solid forms a vapor at low pressure by sublimation.The vapor slowly effuses through the pinhole, and the loss of mass is proportional to the vapor pressure and can be used to determine this pressure. [1]
Naphthalene is a solid that sublimes gradually at standard temperature and pressure, [9] at a high rate, with the critical sublimation point at around 80 °C (176 °F). [10] At low temperature, its vapour pressure is high enough, 1 mmHg at 53 °C, [11] to make the solid form of naphthalene evaporate into gas. On cool surfaces, the naphthalene ...
The form of the cooled surface often is a so-called cold finger which for very low-temperature sublimation may actually be cryogenically cooled. If the operation is a batch process , then the sublimed material can be collected from the cooled surface once heating ceases and the vacuum is released.
A typical phase diagram.The solid green line applies to most substances; the dashed green line gives the anomalous behavior of water. In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium. [1]
The most common dyes used for sublimation activate at 350 degrees Fahrenheit / 175 degrees Celsius. However, a range of 380 to 420 degrees Fahrenheit / 195 to 215 degrees Celsius is normally recommended for optimal color. The result of the sublimation transfer process is a nearly permanent, high-resolution, full-color print.
The density of dry ice increases with decreasing temperature and ranges between about 1.55 and 1.7 g/cm 3 (97 and 106 lb/cu ft) below 195 K (−78 °C; −109 °F). [3] The low temperature and direct sublimation to a gas makes dry ice an effective coolant, since it is colder than water ice and leaves no residue as it changes state. [4]
Tungsten is often used in high temperature applications as well as for filaments in electron/ion optics. It becomes brittle from work hardening when mechanically deformed, or subjected to very high temperatures. Molybdenum and tantalum are useful for high temperature applications. [3] Titanium and niobium are good materials.