Analysis of Dislocation Mechanism for Melting of Elements: Pressure Dependence

In the framework of melting as a dislocation-mediated phase transition we derive an equation for the pressure dependence of the melting temperatures of the elements valid up to pressures of order their ambient bulk moduli. Melting curves are calculated for Al, Mg, Ni, Pb, the iron group (Fe, Ru, Os), the chromium group (Cr, Mo, W), the copper group (Cu, Ag, Au), noble gases (Ne, Ar, Kr, Xe, Rn), and six actinides (Am, Cm, Np, Pa, Th, U). These calculated melting curves are in good agreement with existing data. We also discuss the apparent equivalence of our melting relation and the Lindemann criterion, and the lack of the rigorous proof of their equivalence. We show that the would-be mathematical equivalence of both formulas must manifest itself in a new relation between the Gr\"{u}neisen constant, bulk and shear moduli, and the pressure derivative of the shear modulus.Comment: 19 pages, LaTeX, 9 eps figure

Effects of Activated Sludge on Hydrodynamic Characteristics of a Hollow Fiber Membrane Bioreactor

Abstract A submerged hollow fiber membrane module is a widely accepted wastewater membrane bioreactor. Membrane bioreactor with submerged membrane (HF MBR) is complex multiphase physico-chemico-biological system with internal interactions between process variables and dynamic changes within gas-liquid-solids phases. A study of hydrodynamics in an operating laboratory bioreactor at realistic working conditions is crucial for design and scale up of a bioreactor for wastewater treatment processes. Accumulation of high concentrations of biomass causes the occurrence of heterogeneous regions in a bioreactor. This paper focuses on the effects of activated sludge on average residence time, which is often quite different from the ideally designed hydraulic residence time (HRT) in a submerged hollow fiber membrane bioreactor. In this work, tracer experiments using Dirac δ impulse of the saturated NaCl solution and monitoring electrical conductivity in the outflow with a flow-through conductivity cell were performed. From experiments at liquid flow rate range of 7.2-16.5 L h , and activated sludge concentrations MLSS 4.5-7.4 g L -1 probability density of residence time distribution (RTD) functions for hollow fiber membrane bioreactor and average residence times τ MBR were calculated The relative residence time defined as the ratio of HF MBR τ MBR and CSTR τ id were evaluated as function of MLSS concentration. Proposed is a linear regression model of the relative residence time with MLSS concentration. The model has negative proportionality coefficient k = -0.0814 g/L of MLSS due to decrease of the relative residence time with increase of active sludge concentration. Statistical evaluation of the model gives the correlation coefficient of R 2 = 0.8374. Decrease of the mean residence time with increase of MLSS is discussed in view of non-uniform membrane fouling

An analytic model of the Gruneisen parameter at all densities

We model the density dependence of the Gruneisen parameter as gamma(rho) = 1/2 + gamma_1/rho^{1/3} + gamma_2/rho^{q}, where gamma_1, gamma_2, and q>1 are constants. This form is based on the assumption that gamma is an analytic function of V^{1/3}, and was designed to accurately represent the experimentally determined low-pressure behavior of gamma. The numerical values of the constants are obtained for 20 elemental solids. Using the Lindemann criterion with our model for gamma, we calculate the melting curves for Al, Ar, Ni, Pd, and Pt and compare them to available experimental melt data. We also determine the Z (atomic number) dependence of gamma_1. The high-compression limit of the model is shown to follow from a generalization of the Slater, Dugdale-MacDonald, and Vashchenko-Zubarev forms for the dependence of the Gruneisen parameter.Comment: 14 Pages, LaTeX, 5 eps figues; changes in the tex

Collapsing bubble in metal for high energy density physics study

This paper presents a new idea to produce matter in the high energy density physics (HEDP) regime in the laboratory using an intense ion beam. A gas bubble created inside a solid metal may collapse by driving it with an intense ion beam. The melted metal will compress the gas bubble and supply extra energy to it. Simulations show that the spherical implosion ratio can be about 5 and at the stagnation point, the maximum density, temperature and pressure inside the gas bubble can go up to nearly 2 times solid density, 10 eV and a few megabar (Mbar) respectively. The proposed experiment is the first to permit access into the Mbar regime with existing or near-term ion facilities, and opens up possibilities for new physics gained through careful comparisons of simulations with measurements of quantities like stagnation radius, peak temperature and peak pressure at the metal wall

Cora Dell Woodford

Portrait of Cora Dell Woodford, a friend and Oberlin College classmate of Katharine Wright. This photograph is attributed to Urlin & Pfeifer, Columbus, Ohio.https://corescholar.libraries.wright.edu/special_ms1_photographs/2691/thumbnail.jp

Portrait of Lulu Billheimer Wright

Portrait of Lulu Billheimer Wright, wife of Reuchlin Wright.https://corescholar.libraries.wright.edu/special_ms1_photographs/3288/thumbnail.jp

Lulu Billheimer Wright

Portrait of Lulu Billheimer Wright. Lulu was the wife of Reuchlin Wright. They were married on April 27, 1886. This photograph is attributed to G. C. Urlin, Columbus, Ohiohttps://corescholar.libraries.wright.edu/special_ms1_photographs/2936/thumbnail.jp

The History and Statistics of the Irish Incumbered Estates Court, with Suggestions for a Tribunal with Similar Jurisdiction in England

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The recommendations of the Land Transfer Commission of 1869, considered with especial reference to their applicability to transfer of land in Ireland

One of the last letters written by Richard Cobden contains these remarkable words: ?The Land Question has a wider bearing than has yet been given it in our public discussions; and it will not be seriously entertained by the people until it has been presented in its full significance?. If the lamented writer of these words had lived, and if his friend, Mr. Bright, had enjoyed health and vigour in the interval, the question of ?Free Trade in Land? would have made more rapid progress. It is unnecessary in this Society to explain the true meaning of a phrase, in which some persons profess to see foreshadowed the forcible depriving of one class of the community of some of their property. ?Free Trade in Land? simply means the removal of artificial obstructions to the sale and transfer of land?the rendering of transfers and transmissions of estates and charges as easy as possible?the approximation of dealings with land to dealings with government stock and railway shares

On the dwellings of working men in cities, and the efforts that have been made to improve them

I have undertaken to bring forward this subject, not that I hope to state anything which shall be new, but because the subject appears one which should no longer be overlooked by this Society