Development of Li-ion Battery Bulk Force and Expansion Displacement Test-bench

In order to test the bulk force and expansion displacement of lithium-ion batteries, it is planned to develop a corresponding test-bench, which is mainly composed of a measurement-control system and a mechanical system. To improve the accuracy of the test data, the coupled thermal-structure simulation of the test system in the mechanical system of the test-bench is carried out to select an optimal mechanical structure of the test system. At the same time, for safe and convenient testing, a monitoring-testing system software was developed to ensure the reliability and safety of data collection. Finally, through the test-bench, the battery expansion displacement-SOC curve and the battery bulk force-SOC curve under different discharge rates were tested, providing a basis for the development of a battery management system coupling temperature-current-voltage-displacement-force.

On Improving Battery State of Charge Estimation Using Bulk Force Measurements

Lithium-ion (Li-ion) batteries undergo physical deformation as their state-of-charge (SOC) changes. The physical deformation causes changes in the pressure (equivalently, force) applied at the end-plates of a constrained battery pack or module. This paper proposes the fusion of bulk force and battery voltage measurements to estimate the SOC in Li-ion battery packs. In this paper, using discrete Linear Quadratic Estimators (dLQEs), the advantage of using force measurements in addition to voltage measurement to improve SOC estimates is quantitatively studied through simulations. It is observed that including force measurements can decrease the mean and standard deviation of SOC estimation error by 50% in some SOC intervals.

Modeling the impairment of airway smooth muscle force by stretch

Imposed length changes of only a small percent produce transient reductions in active force in strips of airway smooth muscle (ASM) due to the temporary detachment of bound cross-bridges caused by the relative motion of the actin and myosin fibers. More dramatic and sustained reductions in active force occur following large changes in length. The Huxley two-state model of skeletal muscle originally proposed in 1957 and later adapted to include a four-state description of cross-bridge kinetics has been widely used to model the former phenomenon, but is unable to account for the latter unless modified to include mechanisms by which the contractile machinery in the ASM cell becomes appropriately rearranged. Even so, the Huxley model itself is based on the assumption that the contractile proteins are all aligned precisely in the direction of bulk force generation, which is not true for ASM. The present study derives a coarse-grained version of the Huxley model that is free of inherent assumptions about cross-bridge orientation. This simplified model recapitulates the key features observed in the force-length behavior of activated strips of ASM and, in addition, provides a mechanistically based way of accounting for the sustained force reductions that occur following large stretch.

Modifying Charge Input Optimization in Arc Surfacing with the Controlling Magnetic Influence

The hydrodynamic processes modelling in the weld pool under the influence of the electromagnetic bulk force was carried out. For the approximation of the model equations the finite difference method was used. The resulting system of linear algebraic equations was solved by simple iteration. The finding served the basis for determining the optimal scheme supply of powder material adding for the modification and alloying of the weld (build-up) metal in the presence of an external magnetic field.

OPTICALLY INDUCED ELECTROSTRICTION MODES IN A NANOPARTICLE OF A UNIFORMLY CHARGED ELECTRET

The electromagnetic response of a nanoparticle of an ion-doped polymeric elastic insulator, commonly called an electret, is considered in the continuum model of a uniformly charged elastic sphere. The spectral formulae for the frequency of optically induced spheroidal and torsional shear oscillations driven by bulk force of elastic and dielectric stresses are obtained in analytic form. Particular attention is given to the relaxation dielectric mode of the electrostriction response and its stability in the lowest quadrupole mode. The practical usefulness of ultrafine particles of electrets as biolabels capable of accumulating like-charged inclusions uniformly dispersed over the spherical volume of an elastic matrix is briefly discussed.

Mechanics of Multi-Walled Carbon Nanotubes Under Uniaxial Compression

We report shell buckling instabilities observed experimentally in multi-walled carbon nanotubes subjected to uniaxial compression and interpret the results using insights from elasticity theory and molecular dynamics simulations. Uniform hexagonal arrays of vertically-oriented, freestanding multi-walled carbon nanotubes were grown in a self-assembled, highly-ordered nanoporous alumina matrix and then placed under uniaxial compression using a nanoindenter. Both flat and spherical nanoindenter tips were used to compress many nanotubes at once, and individual nanotube behavior could be deduced from the bulk force-vs.-displacement data by using the uniformity of the nanotube arrays and the geometry of the tips. Buckling instabilities are evident in the measured force-vs.-displacement behavior. A consideration of thin shell elasticity theory and molecular dynamics models provides guidelines for interpreting the experimental results. Excellent agreement is found between the experimentally measured critical buckling loads and those predicted by theory.

2. On the Place and Power of Accent in Language

Professor Blackie then read a paper on “The Place and Power of Accent in Language.” On the subject of accent and quantity, he remarked, especially in relation to the learned languages, the greatest confusion had prevailed, and the existing practice was altogether unreasonable and anomalous. In articulate sound four things had to be distinguished—volume or bulk, force or emphasis, elevation and depression, and prolongation or duration.