Large changes in stiffness associated with cracking and yielding of reinforced concrete sections may be expected to occur during the dynamic response of reinforced concrete frames to earthquake ground shaking. These changes in stiffness in stories that experience cracking might be expected to cause relatively large peak interstory drift ratios. If so, accounting for such changes would add compl...

BACKGROUND Arterial stiffness has been identified as an important risk factor for cognitive decline. However, its effects on the brain's health are unknown, and there is no animal model available to study the precise impact of arterial stiffness on the brain. Therefore, the objective of the study was to develop and characterize a new model specific to arterial stiffness in order to study its ef...

To date, non-invasive methods to detect kidney malignancies and mild tumors remain a challenge. The purpose of this study was to establish the proper imaging protocol to determine kidney stiffness and its spatial distribution within the various kidney compartments such as the renal sinus, medulla, and cortex. Here, we have used magnetic resonance elastography (MRE) along with coronal oblique ac...

A method of recording a residual limb indentation stiffness map was developed for possible use as an aid in calculating prosthetic socket rectifications. The method was tested to determine the level of repeatability attainable. A hand-held, pencil-like device was used, with an air-driven piston that indented the tissue 10 times per second. The indentor tip contained an electromagnetic digitizer...

Energy-efficient control of bipedal walking robots requires both minimization of mechanical energy losses (often mainly due to impacts) and the use of natural oscillations in a mechanism to minimize actuator torques (as shown by research on passive dynamic walking). In this paper, we discuss how these aspects can be analyzed and optimized using mathematical models of the dynamics, as opposed to...

Architectural layouts of reinforced concrete buildings often require structural walls, with varying dimensions, to be placed in an asymmetric plan configuration. During seismic excitation the asymmetry induces a torsional component of response, which can impact negatively on the performance of the building by increasing demands on both structural and nonstructural elements. Furthermore, the tor...

In order to describe directly interphase properties of composite, force modulation of atomic force microscopy is adopted to study the cross-section of unidirectional carbon fiber/epoxy composites systematically. Research results indicate that in force modulation mode of AFM, relative stiffness of various phases distinct in distribution, which is described by probability histogram of relative st...

A finite element (FE) model of the below-knee residual limb and prosthetic socket was created to investigate the effects of parameter variations on the interface stress distribution during static stance . This model was based upon geometric approximations of anthropometric residual limb geometry . The model was not specific to an individual with amputation, but could be scaled to approximate th...

A closed-chain mechanism having redundancy in force domain can produce an effective spring effect by proper internal load distribution. The so-called antagonistic stiffness is provided by redundant actuation in conjunction with nonlinear geometric constraints. The objective of this study is twofold. The first one is to propose a methodology for optimal kinematic design of antagonistic stiffness...