Slip of fluid molecules on solid surfaces by surface diffusion

The mechanism of fluid slip on a solid surface has been linked to surface diffusion, by which mobile adsorbed fluid molecules perform hops between adsorption sites. However, slip velocity arising from this surface hopping mechanism has been estimated to be significantly lower than that observed experimentally. In this paper, we propose a re-adsorption mechanism for fluid slip. Slip velocity predictions via this mechanism show the improved agreement with experimental measurements

A new model for temperature jump at a fluid-solid interface

The problem presented involves the development of a new analytical model for the general fluid-solid temperature jump. To the best of our knowledge, there are no analytical models that provide the accurate predictions of the temperature jump for both gas and liquid systems. In this paper, a unified model for the fluid-solid temperature jump has been developed based on our adsorption model of the interfacial interactions. Results obtained from this model are validated with available results from the literature

Fluid velocity slip and temperature jump at a solid surface

A comprehensive review of current analytical models, experimental techniques, and influencing factors is carried out to highlight the current challenges in this area. The study of fluid-solid boundary conditions has been ongoing for more than a century, starting from gas-solid interfaces and progressing to that of the more complex liquid-solid case. Breakthroughs have been made on the theoretical and experimental fronts but the mechanism behind the phenomena remains a puzzle. This paper provides a review of the theoretical models, and numerical and experimental investigations that have been carried out till date. Probable mechanisms and factors that affect the interfacial discontinuity are also documented

A new model for fluid velocity slip on a solid surface

A general adsorption model is developed to describe the interactions between near-wall fluid molecules and solid surface. This model serves as a framework for the theoretical modelling of the boundary slip phenomena. Based on this adsorption model, a new general model for the slip velocity of fluids on solid surfaces is introduced. The slip boundary condition at a fluid-solid interface has hitherto been considered separately for gases and liquids. In this paper, we show that the slip velocity in both gases and liquids may originate from dynamical adsorption processes at the interface. A unified analytical model that is valid for both gas-solid and liquid-solid slip boundary conditions is proposed based on surface science theory. The corroboration with experimental data extracted from the literature shows that the proposed model provides an improved prediction compared to existing analytical models for gases at higher shear rates and close agreement for liquid-solid interfaces in general

Azimuthal electric field in a static rotationally symmetric (2+1)-dimensional spacetime

The fundamental metrics, which describe any static three-dimensional Einstein-Maxwell spacetime (depending only on a unique spacelike coordinate), are found. In this case there are only three independent components of the electromagnetic field: two for the vector electric field and one for the scalar magnetic field. It is shown that we can not have any superposition of these components of the electric and magnetic fields in this kind of static gravitational field. One of the electrostatic Einstein-Maxwell solutions is related to the magnetostatic solution by a duality mapping, while the second electrostatic gravitational field must be solved separately. Solutions induced by the more general (2+1)-Maxwell tensor on the static cylindrically symmetric spacetimes are studied and it is shown that all of them are also connected by duality mappings.Comment: 5 pages, Final versio

New Charged Dilaton Solutions in 2+1 Dimensions and Solutions with Cylindrical Symmetry in 3+1 Dimensions

We report a new family of solutions to Einstein-Maxwell-dilaton gravity in 2+1 dimensions and Einstein-Maxwell gravity with cylindrical symmetry in 3+1 dimensions. A set of static charged solutions in 2+1 dimensions are obtained by a compactification of charged solutions in 3+1 dimensions with cylindrical symmetry. These solutions contain naked singularities for certain values of the parameters considered. New rotating charged solutions in 2+1 dimensions and 3+1 dimensions are generated treating the static charged solutions as seed metrics and performing $SL(2;R)$ transformations.Comment: Latex. No figure

A recombineering based approach for high-throughput conditional knockout targeting vector construction

Functional analysis of mammalian genes in vivo is primarily achieved through analysing knockout mice. Now that the sequencing of several mammalian genomes has been completed, understanding functions of all the genes represents the next major challenge in the post-genome era. Generation of knockout mutant mice has currently been achieved by many research groups but only by making individual knockouts, one by one. New technological advances and the refinements of existing technologies are critical for genome-wide targeted mutagenesis in the mouse. We describe here new recombineering reagents and protocols that enable recombineering to be carried out in a 96-well format. Consequently, we are able to construct 96 conditional knockout targeting vectors simultaneously. Our new recombineering system makes it a reality to generate large numbers of precisely engineered DNA constructs for functional genomics studies

Post-heat treatment of electrochemically carburized low-carbon steel

Limited studies are available on post-heat treatment (tempering/annealing) of electro­chemically carburized low-carbon steel, which can relieve internal stresses induced by the quenching process. In this study, the electrochemical carburization was carried out using the electrolyte mixture of sodium carbonate (Na2CO3) and sodium chloride (NaCl) under a CO2 gas environment and 800 °C. The samples were then quenched in either water or oil. The peak hardness of the water-quenched sample (WQ) was higher than the oil-quenched sample (OQ). Comparatively, post-heat treated (tempered and annealed) samples showed lower peak hardness compared to quenched samples. An optical microscope was used to observe microstructural changes, while X-ray diffraction (XRD) was used to examine metal phases within all samples. The full width at half maximum (FWHM) of the martensite peak supported the stress relief in both tempered and annealed samples. Scanning electron microscope (SEM) with energy dispersive X-ray (EDX) was applied to determine the elemental composition of as received and electrochemically carburized and quenched low-carbon steel samples. The carbon content of the WQ sample was relatively higher than the OQ sample, whereas the tempered samples showed higher carbon content compared to the annealed samples, but both were lower than for quenched samples. Electrochemical carburization increased the carbon content and improved the hardness, while the tempering or annealing process relieved internal stresses that resulted in the hardness reduction

A reduced risk of stroke with lithium exposure in bipolar disorder: a population‐based retrospective cohort study

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/115969/1/bdi12336.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/115969/2/bdi12336_am.pd