BACKGROUND AND PURPOSE Arterial stiffness may indicate early vascular changes that predispose to the development of major vascular disease. The repeatability of a variety of indices of arterial stiffness calculated from a standard carotid arterial M-mode ultrasound image was investigated. METHODS Twenty-six asymptomatic normal subjects were imaged and had blood pressure recordings on each of ...

*Correspondence: Izabela Jurewicz and Alan Brian Dalton, Department of Physics, University of Surrey, Stag Hill, Guildford GU2 7XH, UK e-mail: [email protected]; [email protected] We present a study of the behavior of highly ordered, segregated single-wall carbon nanotube (CNT) networks under applied strain. Polymer latex templates induce self-assembly of CNTs into hexagonal (2D...

Control systems for shakers are necessary to remove both shaker dynamics as well as coupling effects between the shaker and the structure under test. Little attention has been given to shaker control for nonlinear structures. This paper presents the design, implementation and results of a shaker controller for a horizontal, cantilevered beam subjected to a non-uniform magnetic field. The object...

The mechanical behavior of tendons has been well studied in vitro. A noninvasive method to acquire mechanical data would be highly beneficial. Elastography has been a promising method of gathering in vivo tissue mechanical behavior, but it has inherent limitations. This study presents acoustoelasticity as an alternative ultrasound-based method of measuring tendon stress and strain by reporting ...

The research described in this paper focuses on the application of modal strain techniques on a multi-girder bridge superstructure with the objectives of identifying the presence of damage and detecting false damage diagnosis for such structures. The case study is a one-third scale model of a slab-on-girder composite bridge superstructure, comprised of a steel-free concrete deck with FRP rebars...

efficient mode shape extraction of fluid-structure systems is of particular interest in engineering. an efficient modified version of unsymmetric lanczos method is proposed in this paper. the original unsymmetric lanczos method was applied to general form of unsymmetric matrices, while the proposed method is developed particularly for the fluid-structure matrices. the method provides us with si...

Collagen is a key structural component of extracellular matrix and its mechanical properties, particularly its stiffness, have been shown to influence cell function. This study explores the mechanical behavior of type I collagen gels at low rates relevant to that of cell motion. The Young's modulus, E, was obtained for collagen samples of concentrations 1.3, 2 and 3 mg/ml at varying crosshead d...

We study the influence of the contact stiffness and the ration between cantilever and tip lengths on the resonance frequencies and sensitivities of lateral cantilever modes. We derive expressions to determine both the effective resonance frequency and the mode sensitivity of an atomic force microscope (AFM) rectangular cantilever. Once the contact stiffness is given, the resonance frequency and...

Methods for damage localization, based on modal parameters, are validated by means of numerical examples and experiments. In this paper, different load and damage cases are simulated with a Finite-Element model of a prestressed reinforced concrete bridge. Taking nonlinear material behaviour into account, realistic crack propagations and decrease of stiffness can be detected. The damage is local...