Nonmetal-Metal Transition in Solutions of Metals in Molten Salts

Solutions of metals in molten salts present a rich phenomenology: localisatlon of electrons in disordered ionic media, activated electron transport increasing with metal concentration towards a nonmetal-metal (NM-M) transition, and liquid-liquid phase separation. A brief review of progress in the study of these systems is given in this article, with main focus on the NM-M transition. After recalling the known NM-M behaviour of the component elements in the case of expanded fluid alkali metals and mercury and of solid halogens under pressure, the article focuses on liquid metal-molten salt solutions and traces the different NM-M behaviours of the alkalis in their halides and of metals added to polyvalent metal halides.

Recrystallization of freezable bound water in aqueous solutions of medium concentrations

For aqueous solutions with freezable bound water, vitrification and recrystallization are mingled, which brings difficulty to application and misleads the interpretation of relevant experiments. Here, we report a quantification scheme for the freezable bound water based on the water-content dependence of glass transition temperature, by which also the concentration range for the solutions that may undergo recrystallization finds a clear definition. Furthermore, we find that depending on the amount of the freezable bound water, different temperature protocols should be devised to achieve a complete recrystallization. Our results may be helpful for understanding the dynamics of supercooled aqueous solutions and for improving their manipulation in various industries.

Bending problems of Non-Homogeneous Cylindrical Orthotropic Circular Plate

In this paper ,the bending problem of the non-homogeneous cylindrical orthotropiccircular plate is described.A general solution for the bending of circular plate underuniformly distributed transverse load is solved.and the exact solution of such circularplate with clamped edges is obtained.

Flow, thermal criticality and transition of a reactive third-grade fluid in a pipe with Reynolds' model viscosity

Neglecting the consumption of the material, a steady incompressible flow of an exothermic reacting third-grade fluid with viscous heating in a circular cylindrical pipe is numerically studied for both cases of constant viscosity and Reynolds＇ viscosity model. The coupled ordinary differential equations governing the flow in cylindrical coordinates, are transformed into dimensionless forms using appropriate transformations, and then solved numerically. Solutions using Maple are presented in tabular form and given in terms of dimensionless central fluid velocity and temperature, skin friction and heat transfer rate for three parametric values in the Reynolds＇ case. The numerical results for the velocity and temperature fields are also presented through graphs. Bifurcations are discussed using shooting method. Comparisons are also made between the present results and those of previous work, and thus verify the validity of the provided numerical solutions. Important properties of thermal criticality are provided for variable viscosity parameter and reaction order. Further numerical results are presented in the form of tables and graphs for transition of physical parameters, while varying certain flow and fluid material parameters. Also, the flow behaviour of the reactive fluid of third-grade is compared with those of the Newtonian reactive fluid.

First-principles study of substitutional solute and carbon interactions in tungsten

Interstitial carbon and substitutional transition metal(TM)solutes are common impurities in tungsten and tungsten alloys.Yet,despite its important role in affecting mechanical and irradiation performances of tungsten,the interplay between these impurities remains largely unknown.In this work,we performed systematic first-principles simulations to study the interaction between carbon and TM solutes.By calculating related binding energies,we found that interplay between carbon and TM solutes is dominated by elastic interactions,with carbon generally showing attractions to TM solutes.Further,including vacancies in our calculation,we found that all solute-vacancy-carbon complexes are energetically stable with respect to associated point defects.Additional analysis shows that vacancy-carbon binding is generally weakened by TM solutes,while carbon also in turn reduces the binding energy between vacancy and TM solutes.Based on these binding energy results,we,respectively,evaluated the effect of solute and carbon on each other’s diffusion behaviors.We found that Cr and V slightly decrease the carbon diffusivity while other commonly seen TM solutes show little impacts on carbon diffusion,and we also expect carbon to slow down vacancy-mediated TM solute diffusion in tungsten.