In this article, we present a quantitative stiffness imaging technique and demonstrate its use to directly map the dynamic mechanical properties of materials with nanometer-scale lateral resolution. For the experiments, we use a ‘‘hybrid’’ nanoindenter, coupling depth-sensing nanoindentation with scanning probe imaging capabilities. Force modulation electronics have been added, enhancing instru...

The objective of this study was to measure the mechanical properties of individual, native wood fibers using the continuous nanoindentation measurement technique. The indentation depth profile exhibited a small length-scale effect, which was confirmed using the size-effect index derived from the indentation loading curve. The hardness (Hu) or stiffness (Eu) values determined from indentation un...

v Outline of Thesis vii Author contribution of papers ix Contribution of Thesis xi

Acute rheumatic fever (ARF) is associated with systemic inflammation and arterial stiffness during the acute stage. It has not been reported if arterial stiffness remains after recovery. The aim of this study was to determine the arterial stiffness during acute stage and 6 months after recovery from ARF. Arterial stiffness was assessed by carotid femoral pulse wave velocity (PWV) in 23 ARF pati...

Fourteen patients with rheumatoid arthritis (RA) self rated their pain and stiffness on separate 10 cm visual analogue scales and performed bead intubation coordinometry (BIC) on six occasions each day for seven consecutive days. In addition, 14 healthy controls matched for age and sex also performed BIC measurements according to the same schedule. Data were analysed using least squares and cos...

The biomechanical properties of the extracellular matrix (ECM) play an important role in cell migration, gene expression, and differentiation. Biomechanics measurements of ECM are usually performed on cryotomed tissue sections. However, studies on cell/matrix interplay are impossible to perform due to disruptions in cell viability and tissue architecture from freeze-thaw cycling. We developed a...

In the assessment of fracture healing by monitoring stiffness with vibrational analysis or instrumented external fixators, it has been assumed that there is a workable correlation between stiffness and strength. We used four-point bending tests to study time-related changes in stiffness and strength in healing tibial fractures in sheep. We aimed to test the validity of the measurement of stiffn...

This paper focuses on the performance evaluation of the parallel manipulators for milling of composite materials. For this application the most significant performance measurements, which denote the ability of the manipulator for the machining are defined. In this case, optimal synthesis task is solved as a multicriterion optimization problem with respect to the geometric, kinematic, kinetostat...

1. The stiffness (flexural rigidity) of some echinoderm sperm flagella was measured, using a flexible glass microneedle. 2. Values of 0-3-1 -5 x io a i N m were obtained for the stiffness of live flagella which were immobilized with COg-saturated sea water. 3. The immobilized live flagellum was uniform in stiffness along its entire length, except in a particular plane of imposed bending in whic...