Resistivity in warm dense plasmas beyond the average-atom model

The exploration of atomic properties of strongly coupled partially degenerate plasmas, also referred to as warm dense matter, is important in astrophysics, since this thermodynamic regime is encountered for instance in Jovian planets' interior. One of the most important issues is the need for accurate equations of state and transport coefficients. The Ziman formula has been widely used for the computation of the static (DC) electrical resistivity. Usually, the calculations are based on the continuum wavefunctions computed in the temperature and density-dependent self-consistent potential of a fictive atom, representing the average ionization state of the plasma (average-atom model). We present calculations of the electrical resistivity of a plasma based on the superconfiguration (SC) formalism. In this modeling, the contributions of all the electronic configurations are taken into account. It is possible to obtain all the situations between the two limiting cases: detailed configurations (a super-orbital is a single orbital) and detailed ions (all orbitals are gathered in the same super-orbital). The ingredients necessary for the calculation are computed in a self-consistent manner for each SC, using a density-functional description of the electrons. Electron exchange-correlation is handled in the local-density approximation. The momentum transfer cross-sections are calculated by using the phase shifts of the continuum electron wavefunctions computed, in the potential of each SC, by the Schroedinger equation with relativistic corrections (Pauli approximation). Comparisons with experimental data are also presented.Comment: submitted to "Contributions to Plasma Physics

Godey's lady's book

Thesis (M.A.)--Boston University, 1941. This item was digitized by the Internet Archive

Development of a mechanical vapor-compression distiller incorporating concentrated solar power

The demand for a reliable energy supply has promoted the development of the Marcellus Shale gas industry in the past few years. However, the produced water from hydraulic fracturing (also known as fracking) poses a hazard to human and environmental health because of its dissolved solid, hydrocarbon, and heavy metal content. This research proposes to develop a portable solar power assisted water distiller which can process produced water on-site for natural gas wells.;The distillation technology developed is a small scale mechanical vapor-compression (MVC) distillation unit. The thermal energy for the evaporation of the water is provided by the solar energy, while the recirculation pumps and compressor are driven by electrical motors. The research works completed include the in-house and on-site demonstration of the 1st generation design, and the design of the 2nd generation solar aided MVC distillation unit. The main design features of this research include an insulation system, a heat capacity analysis of heat exchangers, a compressor which requires less power input, and options for making the entire system operate on solar power alone. The potential of the insulation system in reducing the heat loss of the system and the demand for thermal energy was examined. The regeneration system developed was able to recover approximately 91% of the thermal energy released during the condensation and cooling process of the distilled water vapor, which dramatically decreased the consumption of thermal energy and the size of solar components needed. Also, the insulation system will reduce the rate of heat loss to the ambient air by approximately 86% compared to an un-insulated system. A theoretical model was developed to examine the performance of the 2nd generation design and has been presented. The on-site demonstration of the 1st generation system confirmed that the proposed system was able to process the high-salt produced water and extract clean water with the potential to recycle the salts for commercial use. The numerical simulation results show the 2nd generation system with redesigned components and insulation was able to process produced water at a rate of 20 gallon/hour with a power consumption of approximately 4.6 kW, which includes 3.2 kW from solar energy for heating purposes and 1.4 kW from electricity to run the compressor and the recirculation pump