Commercially available prosthetic hands are simple grippers with one or two degrees of freedom; these pinch type devices have two rigid fingers in opposition to a rigid thumb. This paper focuses on an innovative approach for the design of a myoelectric prosthetic hand. The new prosthesis features underactuated mechanisms in order to achieve a natural grasping behavior and a good distribution of...

Despite extensive efforts, a definitive picture of the glass transition of ultra-thin polymer films has yet to emerge. The effect of film thickness h on the glass transition temperature T(g) has been widely examined, but this characterization does not account for the fragility of glass-formation, which quantifies how rapidly relaxation times vary with temperature T. Accordingly, we simulate sup...

This report makes a case for the need to examine the methodological foundations of AI. Many aspects of AI have not yet developed to a point of general agreement. The goals of AI work, the methods for acheiving these goals, the presentation of results, and the assessment of claims are all highly contentious issues. All aspects of AI methodology are subject to debate The Workshop on the Foundatio...

Problem 1. Infinite Products and Coproducts in Ab. We have seen that finite products and coproducts agree in Ab. However, the same is not true for infinite products and coproducts. Let I be a set and let {Ai}i∈I be a family of abelian groups, each equal to some fixed group A. (a) Show that the set AI := HomSet(I, A) is an abelian group. Furthermore, show that we can think of this group as the i...

e investigate the concentration dependence of the characteristic relaxation time of dilute polymer olutions in transient uniaxial elongational flow. A series of monodisperse polystyrene solutions of ve different molecular weights 1.8 106 M 8.3 106 g/mol with concentrations spanning ve orders of magnitude were dissolved in two solvents of differing solvent quality diethylphthalate and oligomeric...

This work is devoted to the study of the viscosity and relaxation of flexible polymer chains in dilute solutions. Our aim was to determine the relation between the intrinsic viscosity and the relaxation times of the polymer internal normal modes within the bead-spring approach. In the theoretical part we generalize the Zimm theory of the polymer dynamics by taking into account the permeability ...

An analysis of a novel indentation model has been implemented to obtain master curves describing the optimal experimental parameters necessary to achieve the highest possible accuracy in the determination of viscoelastic properties of soft materials. The indentation model is a rigid indenter driven by a compliant measurement system, such as an atomic force microscope or optical tweezers, into a...

We use molecular dynamics simulations of the Kremer-Grest (KG) bead-spring model of polymer chains of length between 10 and 500, and a closely related analogue that allows for chain crossing, to clearly delineate the effects of entanglements on the length-scale-dependent chain relaxation in polymer melts. We analyze the resulting trajectories using the Rouse modes of the chains and find that en...