We investigate the cross-sectional buckling of multi-concentric tubular nanomaterials, which are called multiwalled carbon nanotubes (MWNTs), using an analysis based on thin-shell theory. MWNTs under hydrostatic pressure experience radial buckling. As a result of this, different buckling modes are obtained depending on the inter-tube separation d as well as the number of constituent tubes N and...

Myocardial Deformation by Doppler Strain Rate Echocardiography in Humans To the Editor: We have read with interest the recent report of Edvardsen et al1 in which left ventricular regional peak systolic strain values measured by ultrasound were correlated with the corresponding strain data extracted by 3-dimensional tagged MRI. The study showed an overall acceptable agreement between the 2 techn...

To assess the effect of deprivation amblyopia on global shape discrimination, sensitivity to radial deformation of circular patterns was assessed in patients treated for congenital (N=7) or developmental (N=1) cataracts. Elevation in radial deformation threshold was dependent on circular contour frequency and the depth of amblyopia. Analysis of thresholds expressed as Weber fractions indicated ...

the frequency response analysis (fra) test has been recognized as one of the sensitive tools available for detecting electrical and mechanical faults inside power transformers. however, there is still no universally systematic interpretation technique for these tests. many research efforts have employed different statistical criteria in order to aid the interpretative capability of the fra, but...

AIMS Early left ventricular (LV) dysfunction in asymptomatic patients with severe aortic regurgitation (AR) may go undetected due to the lack of a sufficiently sensitive diagnostic tool. Ultrasonic strain/strain rate (S/SR) imaging should now provide such sensitivity in detecting early dysfunction in regional LV systolic deformation. The aim of this study was to understand and define the change...

The present study deals with the elastic analysis of concave thickness rotating disks made of functionally graded materials (FGMs).The analysis is carried out using element based gradation of material properties in radial direction over the discretized domain. The resulting deformation and stresses are evaluated for free-free boundary condition and the effect of grading index on the deformation...

In this paper a semi cylindrical fluid filled hyperelastic finger model for soft contact has been developed from the basic principles of mechanics. The deformation parameters namely contact width and radial deflection were calculated for different applied forces. To validate this analytical model, compression tests were conducted on silicone rubber finger specimens . Contact width and radial de...

We report that defect-free Au nanowires show superplasticity on tensile deformation. Evidences from high-resolution electron microscopes indicated that the plastic deformation proceeds layer-by-layer in an atomically coherent fashion to a long distance. Furthermore, the stress-strain curve provides full interpretation of the deformation. After initial superelastic deformation, the nanowire show...

BACKGROUND Strain and strain rate have been proposed as tools to quantify regional myocardial function. One of the major pitfalls of the current methodology is its angle dependency. To overcome this problem, we have developed a new method for the estimation of strain, independent of angle. The aim of this study was to validate this new methodology in an experimental setting using sonomicrometry...

An aneurysm is a balloon-like bulge in the wall of blood vessels, occurring in major arteries of the heart and brain. Biodegradable polymeric stent-assisted coiling is expected to be the ideal treatment of wide-neck complex aneurysms. This paper presents the development of methods to fabricate and optimally design biodegradable polymeric stents for aneurysms treatment. Firstly, a dispensing-bas...