Thermodynamic design data for double effect absorption heat pump systems using water-lithium chloride—cooling

In this paper, thermodynamic design data are investigated for the water-lithium chloride pair and a comparative study of the water-LiCl pair with the water-LiBr pair is given, for double-effect absorption cooling systems used for the computer simulation. The computer simulation is based on mass, material and heat balance equations for each part of the system. Coefficients of performance and flow ratios for effects of different operating temperatures are investigated. It is found that the cooling COP is higher for the water-LiCl pair than for the water-LiBr pair, and FR is lower for the water-LiCl pair than for the water-LiBr pair.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-sodium thiocyanate—III. Simultaneous cooling and heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamics propertie of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia-sodium thiocyanate absorption systems for simultaneous cooling and heating. The interaction of operating temperatures has been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-sodium thiocyanate—II. Heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia-sodium thiocyanate absorption systems for heating. The interaction of operating temperatures has been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-lithium nitrate—part three. Simultaneous cooling and heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy-based coefficients of performance have been presented for ammonia-lithium nitrate absorption systems for simultaneous cooling and heating. The interactions of operating temperatures have been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-water—Part I. Cooling

The free choice of operating temperature in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia—water absorption systems for cooling. The interaction of operating temperatures have been illustrated graphically.     

Lattice dynamics and debye temperature of AlCu,AlSi and AlGe alloy systems

The lattice dynamics and specific heat at constant volume for AlCu alloy system is studied using our previous treatment based on the microscopic electronic theory. Considering the volume and electron density effect on the dynamical matrix of the pure constituent, we obtain the band and local mode frequencies at the temperature-dependent specific heat in the Al_1−x Cu_x solid solution. Then, using the data about the mean elastic wave and the specific heat extrapolated to the absolute zero temperature, the Debye temperature is presented for the Al_1−xCu_x, Al_1−xSi_x and Al_1−xGe_x alloy systems. The Debye temperature decreases as a function of the Cu atomic fraction x for Al_1−xCu_x alloy, and remarkably for Al_1−xSi_x and Al_1−xGe_x solid solutions.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-sodium thiocyanate—I. Cooling

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia-sodium thiocyanate absorption systems for cooling. The interaction of operating temperatures has been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on ammonia-lithium nitrate—Part two. Heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy-based coefficients of performance have been presented for ammonia-lithium nitrate absorption systems for heating. The interactions of operating temperatures have been illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on water-lithium chloride—Part one. Cooling

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. For a given combination of temperatures, the concentrations in the absorber and the generator are fixed automatically. This determines the flow ratio. Therefore for any particular working pair, the coefficient of performance is related to the flow ratio.Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalphy based coefficients of performance have been presented for a water-lithium chloride absorption system for cooling. The interaction of operating temperatures has been illustrated graphically. The data obtained are also compared with published data for the water-lithium bromide absorption system under identical conditions.     

Thermodynamic design data for absorption heat pump systems operating on water-lithium iodide—part I. Cooling

The operating temperatures in the absorption heat pump system fix the absorber and the generator concentration for a given working pair. Derived thermodynamic design data, including Carnot coefficients of performance and enthalpy-based coefficients of performance, with and without an economizer heat exchanger for possible combinations of operating temperatures, are presented for water-lithium iodide absorption systems for cooling. The effects of operating temperatures as well as economizer heat exchanger on the performance of an absorption cooler are illustrated graphically.     

Thermodynamic design data for absorption heat pump systems operating on water-lithium chloride—Part II. Heating

Derived thermodynamic design data including Carnot coefficients of performance, enthalpy based coefficients of performance and flow ratios for possible combinations of operating temperatures for absorption heat pump systems operating on water-lithium chloride for heating are presented. The variations of the derived data with operating temperatures are illustrated graphically. The data obtained for the water-LiCl pair are compared with published data for the water-LiBr pair for identical conditions of temperatures.     

Thermodynamic design data for absorption heat pump systems operating on water-lithium iodide—part II. Heating

Derived thermodynamic design data, including Carnot coefficients of performance and enthalpy-based coefficients of performance (for heating) with and without an economizer heat exchanger for possible combinations of operating temperatures are calculated for a system in which water is used as a working fluid and aqueous lithium iodide solution as absorbent. The effects of operating temperatures as well as economizer heat exchanger on the performance of an absorption heat pump are illustrated graphically.     

Thermodynamics and phase diagrams of MoPdRu and related systems

During the irradiation of nuclear fuels up to 10% of the original fissile material (uranium and plutonium) is converted into a wide range of fission products. One particular group of fission-product elements, the transition metals Mo, Tc, Ru, Rh and Pd, are not oxidised at the quite low oxygen potentials existing in the fuels, and are precipitated in the fuel in the form of metallic inclusions. The thermodynamic properties and phase diagram of these alloys are of importance, since the precise composition of these alloys, as a function of radial position can provide important information concerning operating conditions inside a fuel pin. For this reason a thorough reassessment of these systems is under way. This paper reports values of the excess-Gibbs energies of mixing in the MoPd, PdRu and MoRu binary systems, and in the MoPdRu ternary. Calculated sections of the MoPdRu system at selected temperatures are presented.     

Thermodynamic design data for absorption heat pump systems operating on ammonia—water—Part II. Heating

The free choice of operating temperatures in absorption systems is limited by the Gibbs phase rule and the thermodynamic properties of the working pair. Tables of possible combinations of operating temperatures and concentrations, including flow ratios, Carnot coefficients of performance and enthalpy based coefficients of performance have been presented for ammonia—water absorption systems for heating. The interaction of operating temperatures has been illustrated graphically.     

On “Universal” correlations in disordered and chaotic systems

Numerical study of the parametric motion of energy levels in a model system built on Random Matrix Theory is presented. The correlation function of levels' slopes (the so called velocity correlation function) is determined numerically and compared with its limiting analytic form when available. A simple analytic form of the velocity correlation function is proposed which very well reproduces numerical data. The results should be directly applicable in studies of chaotic or mesoscopic systems.     

X-ray photoemission studies of PtSn and PtPb bimetallic systems

The Pt(5d) and Pt(4f) in PtSn and PtPb composites produced by sequential vapor deposition have been examined by X-ray photoelectron spectroscopy. At low concentrations of Pt, the Pt(5d) becomes a single, narrow resonance at about 4 eV below the Fermi level. Its density of states at the Fermi level is small. This leads to a large suppression of the Pt(4f) lineshape asymmetry. As the Pt concentration increases, d-d interactions split the Pt(5d) resonance and increase the 5d density of states at the Fermi level by pushing one of the split resonances to the Fermi level. Consequently, the Pt(4f) lineshape asymmetry increases. The evolution of the Pt(4f) and Pt(5d) in PtSn and PtPb are very similar but different from that of small Pt particles supported on carbon. The close similarity of the electronic properties of Pt in PtSn and PtPb suggests that the poisoning of Pt by Pb is not entirely due to electronic effects although there are indications of stronger interaction between Pt and Pb than between Pt and Sn atoms. The strong surface enrichment of Pb on PtPb points to the importance of the physical blockage of Pt atoms by surface Pb in determining the poisoning effect of Pb.     

Conditional entropies and position–momentum correlations in atomic systems

We show via Wigner functions how the sum and difference between Shannon entropies in position and in momentum space are related to conditional entropies, and how these quantities are linked to position–momentum correlations. The connection between Fermi, Coulomb and position–momentum correlations on these quantities is made, and the impact of these are discussed in atomic systems.     

Rotational Spectra of CH3CCH–NH3, NCCCH–NH3, and NCCCH–OH2

Microwave spectra of NCCCH–NH₃, CH₃CCH–NH₃, and NCCCH–OH₂have been recorded using a pulsed-nozzle Fourier-transform microwave spectrometer. The complexes NCCCH–NH₃and CH₃CCH–NH₃are found to have symmetric-top structures with the acetylenic proton hydrogen bonded to the nitrogen of the NH₃. The data for CH₃CCH–NH₃are further consistent with free or nearly free internal rotation of the methyl top against the ammonia top. For NCCCH–OH₂, the acetylenic proton is hydrogen bonded to the oxygen of the water. The complex has a dynamicalC_2vstructure, as evidenced by the presence of two nuclear-spin modifications of the complex. The hydrogen bond lengths and hydrogen-bond stretching force constants are 2.212 Å and 10.8 N/m, 2.322 Å and 6.0 N/m, and 2.125 Å and 9.6 N/m for NCCCH–NH₃, CH₃CCH–NH₃, and NCCCH–OH₂, respectively. For the cyanoacetylene complexes, these bond lengths and force constants lie between the values for the related hydrogen cyanide and acetylene complexes of NH₃and H₂O. The NH₃bending and weak-bond stretching force constants for CH₃CCH–NH₃are less than those found in NCCCH–NH₃, NCH–NH₃, and HCCH–NH₃, suggesting that the hydrogen bonding interaction is particularly weak in CH₃CCH–NH₃. The weakness of this hydrogen bond is partially a consequence of the orientation of the monomer electric dipole moments in the complex. In CH₃CCH–NH₃the antialigned monomer dipole moments lead to a repulsive dipole–dipole interaction energy, while in NCH–NH₃and NCCCH–NH₃the aligned dipoles give an attraction interaction.