Hole, heat capacity

Borehole depth 10,000 ft, deviated hole Drill pipe rotation rate 10 rpm Mud heat capacity 0.77 cal/g Hole diameter 12 in. 

One of the first attempts to calculate the thermodynamic properties of an atomic solid assumed that the solid consists of an array of spheres occupying the lattice points in the crystal. Each atom is rattling around in a hole at the lattice site. Adding energy (usually as heat) increases the motion of the atom, giving it more kinetic energy. The heat capacity, which we know is a measure of the ability of the solid to absorb this heat, varies with temperature and with the substance.8 Figure 10.11, for example, shows how the heat capacity Cy.m for the atomic solids Ag and C(diamond) vary with temperature.dd ee The heat capacity starts at a value of zero at zero Kelvin, then increases rapidly with temperature, and levels out at a value of 3R (24.94 J-K -mol-1). The... 

The HEM is a thermal model which represents a doped semiconductor thermistor (e.g. Ge NTD) as made up of two subsystems carriers (electrons or holes) and phonons. Each subsystem has its own heat capacity and is thermally linked to the other one through a thermal conductance which takes into account for the electron-phonon decoupling (see Fig. 15.2). 

Study of hydrated kaolinites shows that water molecules adsorbed on a phyllosilicate surface occupy two different structural sites. One type of water, "hole" water, is keyed into the ditrigonal holes of the silicate layer, while the other type of water, "associated" water, is situated between and is hydrogen bonded to the hole water molecules. In contrast, hole water is hydrogen bonded to the silicate layer and is less mobile than associated water. At low temperatures, all water molecules form an ordered structure reminiscent of ice as the temperature increases, the associated water disorders progressively, culminating in a rapid change in heat capacity near 270 K. To the extent that the kao-linite surfaces resemble other silicate surfaces, hydrated kaolinites are useful models for water adsorbed on silicate minerals. 

ZT Y r A A A A A AC dimensionless thermoelectric figure of merit electronic coefficient of heat capacity (1+ZT)F2 crystal field singlet non-Kramers doublet (crystal field state) crystal field triplet crystal field triplet hybridization gap jump in heat capacity at Tc K KL -min P 6>d X JCO total thermal conductivity of solid thermal conductivity of electrons or holes thermal conductivity of lattice minimum lattice thermal conductivity electrical resistivity Debye temperature magnetic susceptibility magnetic susceptibility at T = 0... 

Heat capacity and thermal expansion jumps are suitable parameters for comparison of glassy networks with linear polymers in terms of the hole model46,47). 

Phonon frequency, E. (cm ), defined as energy difference between the zero-phonon hole and the pseudophone sidehole and the energy for the low-energy excitation mode obtained from heat capacity measurements, E. (cm ... 

Although the lattice heat capacity in a metal is much larger than its electronic contribution, the Fermi velocity of electrons (typically 106 m/s) is much larger than the speed of sound (about 103 m/s). Due to the higher energy carrier speed, the electronic contribution to the thermal conductivity turns out to be more dominant than the lattice contribution. For a semiconductor, however, the velocity is not the Fermi velocity but equal to the thermal velocity of the electrons or holes in the conduction or valence bands, respectively. This can be approximated as v /3kBT/m, where m is the effective electron mass in the conduction band or hole mass in the valence band. This is on the order of 105 m/s at room temperature. In addition, the number density of conduction band electrons in a semiconductor is much less than... 

Also plotted in Fig. 1.2 is the experimental heat capacity of the liquid (at omi-stant pressure) In simple cases, such as polyethylene, the heat capacity of the liquid state could be understood by introducing a heat capacity contribution for the excess volume (hole theory) and by assuming that the torsional skeletal vibration can be treated as a hindered rotator A more general treatment makes use of a separation of the partition function into the vibrational part (approximated for heat capacity by the spectrum of the solid), a conformational part (approximated by the usual conformational statistics) and an external or configurational part. 

Negative heat capacities have been discussed in context of cosmology and with black holes [17, 27]. Since the late nineteenth century astronomers realized that by adding energy to a star, it would expand and cool down. However, this was not... 

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