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T g is directly proportional to bond strength, e.g. it depends on quasi-equilibrium thermodynamic parameters of the bonds e.g. on the enthalpy H d and entropy S d of configurons – broken bonds: T g = H d / [S d + R ln[(1 − f c)/ f c] where R is the gas constant and f c is the percolation threshold.
The SC, or shading coefficient, is used widely in the evaluation of heat gain through glass and windows. [1] [5] Finally, the SCL, or solar cooling load factor, accounts for the variables associated with solar heat load. These include the global coordinates of the site and the size of the structure. [1] [5]
The result of a DSC experiment is a curve of heat flux versus temperature or versus time. There are two different conventions: exothermic reactions in the sample shown with a positive or negative peak, depending on the kind of technology used in the experiment. This curve can be used to calculate enthalpies of transitions. This is done by ...
For many substances, the formation reaction may be considered as the sum of a number of simpler reactions, either real or fictitious. The enthalpy of reaction can then be analyzed by applying Hess' law, which states that the sum of the enthalpy changes for a number of individual reaction steps equals the enthalpy change of the overall reaction.
The physical origin of the non-Arrhenius behavior of fragile glass formers is an area of active investigation in glass physics. Advances over the last decade have linked this phenomenon with the presence of locally heterogeneous dynamics in fragile glass formers; i.e. the presence of distinct (if transient) slow and fast regions within the material.
ZBLAN glass has a broad optical transmission window extending from 0.22 micrometers in the UV to 7 micrometers in the infrared. ZBLAN has low refractive index (about 1.5), a relatively low glass transition temperature (T g) of 260–300 °C, low dispersion and a low and negative temperature dependence of refractive index dn/dT. [1]
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).
In chemistry and thermodynamics, the enthalpy of neutralization (ΔH n) is the change in enthalpy that occurs when one equivalent of an acid and a base undergo a neutralization reaction to form water and a salt. It is a special case of the enthalpy of reaction. It is defined as the energy released with the formation of 1 mole of water.