Multinuclear MR and MRI study of lithium-ion cells using a variable field magnet and a fixed frequency RF probe

An exploratory multinuclear magnetic resonance(MR)and magnetic resonance imaging(MRI)study was performed on lithium-ion battery cells with ^(7)Li,^(19)F,and ^(1)H measurements.A variable field superconducting magnet with a fixed frequency parallel-plate radiofrequency(RF)probe was employed in the study.The magnetic field was changed to set the resonance frequency of each nucleus to the fixed RF probe frequency of 33.7 MHz.Two cartridge-like lithium-ion cells,with graphite anodes and LiNi_(0.5)Mn_(0.3)Co_(0.2)O_(2)(NMC)cathodes,were interrogated.One cell was pristine,and one was charged to a cell voltage of 4.2 V.The results presented demonstrate the great potential of the variable field magnet approach in multinuclear measurement of lithium-ion batteries.These methods open the door for developing faster and simpler methods for detecting,quantifying,and interpreting MR and MRI data from lithium-ion and other batteries.

Unsteady Hydromagnetic Non-Newtonian Nanofluid Flow Past a Porous Stretching Sheet in the Presence of Variable Magnetic Field and Chemical Reaction

The aim of this study is to examine the unsteady hydromagnetic flow of non-Newtonian nanofluid past a stretching sheet in the presence of variable magnetic field and chemical reaction. The system of non-linear partial differential equations governing the flow was solved using finite difference numerical approximation method. The resulting numerical schemes were simulated in MATLAB software. Furthermore, the skin-friction coefficient, Sherwood number, and Nusselt number have been presented in tabular form and discussed. The findings demonstrated that increasing Reynolds number increases velocity profiles while increasing permeability parameter, suction parameter and angle of inclination for the applied magnetic field reduces the velocity profiles of the fluid flow. Temperature of the fluid increases as the angle of inclination, magnetic number, Reynolds number and Eckert number increase but decreases as Prandtl number increases. Induced magnetic field profiles decrease as magnetic Prandtl number and suction parameter increase. Concentration profiles decrease as the chemical reaction parameter and Schmidt number increase but increase as the Soret number increases. The study is significant because fluid flow and heat transfer mechanisms with the variable magnetic considerations play an important role in magnetohydrodynamic generator or dynamo and magnetohydrodynamic pumps, nuclear reactors, vehicle thermal control, heat exchangers, cancer therapy, wound treatment and hyperthermia.

Some Limit Theorems for Weighted Sums of Random Variable Fields

Let{Xn^-,n^-∈N^d}be a field of Banach space valued random variables, 0 〈r〈p≤2 and{an^-,k^-, （n^-,k^-） ∈ N^d × N^d ,k^-≤n^-} a triangular array of real numhers, where N^d is the d-dimensional lattice （d≥1 ）. Under the minimal condition that {｜｜Xn^-｜｜ r,n^- ∈N^d} is {｜an^-,k^-｜^r,（n^-,k^-）} ∈ N^d ×N^d,k^-≤n^-}-uniformly integrable, we show that ∑（k^-≤n^-）an^-,k^-,Xk^-^（L^r（or a,s,）→0 as ｜n^-｜→∞ In the above, if 0〈r〈1, the random variables are not needed to be independent. If 1≤r〈p≤2, and Banach space valued random variables are independent with mean zero we assume the Banaeh space is of type p. If 1≤r≤p≤2 and Banach space valued random variables are not independent we assume the Banach space is p-smoothable.

Hydromagnetic Squeezing Nanofluid Flow between Two Vertical Plates in Presence of a Chemical Reaction

In this study, Hydromagnetic Squeezing Nanofluid flow between two vertical plates in presence of a chemical reaction has been investigated. The governing equations were transformed by similarity transformation and the resulting ordinary differential equations were solved by collocation method. The velocity, temperature, concentration and magnetic induction profiles were determined with help of various flow parameters. The numerical scheme was simulated with aid of MATLAB. The results showed that increasing the squeeze number only boosts velocity and concentration while lowering temperature. Conversely, increasing the Hartmann number, Reynold’s magnetic number, Eckert number and Thermal Grashof number generally increases temperature but decreases both velocity and concentration. Chemical reaction rate and Soret number solely elevate concentration while Schmidt number only reduces it. The results of this study will be useful in the fields of oil and gas industry, plastic processing industries, filtration, food processing, lubrication system in machinery, Microfluidics devices for drug delivery and other related fields of nanotechnology.

Moving Least Squares Interpolation Based A-Posteriori Error Technique in Finite Element Elastic Analysis

The performance of a-posteriori error methodology based on moving least squares(MLS)interpolation is explored in this paper by varying the finite element error recovery parameters,namely recovery points and field variable derivatives recovery.The MLS interpolation based recovery technique uses the weighted least squares method on top of the finite element method’s field variable derivatives solution to build a continuous field variable derivatives approximation.The boundary of the node support(mesh free patch of influenced nodes within a determined distance)is taken as circular,i.e.,circular support domain constructed using radial weights is considered.The field variable derivatives(stress and strains)are recovered at two kinds of points in the support domain,i.e.,Gauss points(super-convergent stress locations)and nodal points.The errors are computed as the difference between the stress from the finite element results and projected stress from the post-processed energy norm at both elemental and global levels.The benchmark numerical tests using quadrilateral and triangular meshes measure the finite element errors in strain and stress fields.The numerical examples showed the support domain-based recovery technique’s capabilities for effective and efficient error estimation in the finite element analysis of elastic problems.The MLS interpolation based recovery technique performs better for stress extraction at Gauss points with the quadrilateral discretization of the problem domain.It is also shown that the behavior of the MLS interpolation based a-posteriori error technique in stress extraction is comparable to classical Zienkiewicz-Zhu(ZZ)a-posteriori error technique.

Anomalous reactivity of thermo-bioconvective nanofluid towards oxytactic microorganisms

The peristaltic flow of a non-Newtonian nanofluid with swimming oxytactic microorganisms through a space between two infinite coaxial conduits is investigated. A variable magnetic field is applied on the flow. The bioconvection flow and heat transfer in the porous annulus are formulated, and appropriate transformations are used, leading to the non-dimensionalized ruling partial differential equation model. The model is then solved by using the homotopy perturbation scheme. The effects of the germane parameters on the velocity profile, temperature distribution, concentration distribution, motile microorganism profile, oxytactic profile, pressure rise, and outer and inner tube friction forces for the blood clot and endoscopic effects are analyzed and presented graphically.It is noticed that the pressure rise and friction forces attain smaller values for the endoscopic model than for the blood clot model. The present analysis is believed to aid applications constituting hemodynamic structures playing indispensable roles inside the human body since some blood clotting disorders, e.g., haemophilia, occur when some blood constituents on the artery wall get confined away from the wall joining the circulation system.

Anti-plane analysis of semi-infinite crack in piezoelectric strip

Using the complex variable function method and the technique of the conformal mapping, the fracture problem of a semi-infinite crack in a piezoelectric strip is studied under the anti-plane shear stress and the in-plane electric load. The analytic solutions of the field intensity factors and the mechanical strain energy release rate are presented under the assumption that the surface of the crack is electrically impermeable. When the height of the strip tends to infinity, the analytic solutions of an infinitely large piezoelectric solid with a semi-infinite crack are obtained. Moreover, the present results can be reduced to the well-known solutions for a purely elastic material in the absence of the electric loading. In addition, numerical examples are given to show the influences of the loaded crack length, the height of the strip, and the applied mechanical/electric loads on the mechanical strain energy release rate.

Heterogeneous and homogeneous reactive flow of magnetite-water nanofluid over a magnetized moving plate

This model is dedicated to visualizing the nature of magnetite-water nanoliquid induced by a permeable plate having variable magnetic effect,non-linear radiation,heterogeneous and homogeneous chemically reactive species.The system of momentum,thermal and concentration expressions is formulated and transformed from the partial to ordinary differential systems by using the adequate transforms.This highly non-linear system is solved through RKF(Runge-Kutta-Fehlberg)numerical method.Important parameters such as suction/injection,magnetic,and radiation effects as well as other relevant parameters are investigated.The graphs show that the rise in radiation parameter numerically improves the thermal distribution,implying a faster heat transfer rate.Non-linear radiation has greater effect on temperature than the linear radiation.While the volume concentration effect reveals that the friction factor increase with the enhancement of nanoparticle concentration.It is also observed that,plate velocity decreases the skin-friction but increases the wall heat transfer for both suction and blowing cases.The results indicate that the current research has a strong agreement with the relevant data in a limiting approach.