The failure of an adhesive layer in a 180° peel test is analyzed by the modeling of the peel as an elastica. The adhesive is assumed to fail by a process of cavitation and fibrillation. The resistance of the fibrillated material to deformation gives rise to a rate-dependent peel force F. Governing equations, which take into account the large deformation of the fibrillated materials, are derived...

The impaired left ventricular emptying that characterizes heart failure may result from a variety of cardiac diseases, including myocardial ischaemia or infarction (that alters regional function), cardiomyopathies ( that alter global function), and pressure or overload states (that lead to hypertrophy and dilatation of the chamber). This functional abnormality of the left ventricle is an import...

In this paper, stiffness of planar translational wire-actuated parallel manipulators is studied. The complete form of the stiffness matrix of the two degrees of freedom manipulators is formulated parametrically. The differential form of the static force balance equations is used to incorporate the variation of wire stiffness with wire length and the change in the Jacobian matrix under external ...

Freestanding particle bridges with controlled composition and macroscopic robustness are demonstrated by the use of supramolecular nanoparticle assembly. Self-assembly of nanoparticles, templating, and supramolecular glue infiltration are combined to form stable and ordered three-dimensional polystyrene particle composites on a polydimethylsiloxane stamp. Freestanding hybrid polystyrene nanopar...

We are developing a novel treatment for heart failure by increasing myocardial 2 deoxy-ATP (dATP). Our studies in rodent models have shown that substitution of dATP for adenosine triphosphate (ATP) as the energy substrate in vitro or elevation of dATP in vivo increases myocardial contraction and that small increases in the native dATP pool of heart muscle are sufficient to improve cardiac funct...

The high current properties of a micro spring pressure contact are characterized. The spring has large compliance (>30 μm) compared to other packaging technologies and fits in a 180 μm pitch 2d array. At 250 mA and 65 ̊C, daisy chains of 134 spring contacts in a silicon package show stable resistances and hotspot temperature rises of less than a degree. At 1 amp, failure near the spring tip or ...

Nahar, Nazmun 2013. Effect of ageing and physical activity level on muscle fatigue during isometric contraction of knee extensor muscles. Master’s theses in Biomechanics. Department of Biology of Physical Activity, University of Jyväskylä, Finland. Muscle fatigue is defined as the loss of force or power producing capacity in response to contractile activity and is a fundamental characteristic o...

BACKGROUND Nitric oxide (NO) exerts autocrine/paracrine effects on cardiac function, including alterations of the inotropic state. In vitro studies suggest that NO modulates the myocardial force-frequency relationship. Basal left ventricular (LV) contractility is depressed and the force-frequency relationship is blunted in human heart failure, and it is speculated that an increase in NO product...

Our objective was to investigate the role of creatine kinase in the contractile dysfunction of right ventricular failure caused by pulmonary artery hypertension. Pulmonary artery hypertension and right ventricular failure were induced in rats by monocrotaline and compared to saline-injected control animals. In vivo right ventricular diastolic pressure-volume relationships were measured in anest...