Elastic Modulus Research Papers - Academia.edu (original) (raw)

The technological effect of wheat fibre, as a healthy ingredient in which consumers are interested, was studied in surimi gel products. Three and six per cent wheat fibre with different particle sizes was added. Functional properties of... more

The technological effect of wheat fibre, as a healthy ingredient in which consumers are interested, was studied in surimi gel products. Three and six per cent wheat fibre with different particle sizes was added. Functional properties of wheat fibre, such as water retention capacity (WRC), swelling (SW) and fat adsorption capacity (FAC), were determined. Elastic modulus (G′) of surimi with 6% wheat fibre was lower throughout thermal gelling. Under scanning electronic microscopy (SEM), gel samples with added fibre presented uneven distribution of fibre. This induced the formation of a non-homogeneous protein net associated with lower gel strength, cohesiveness and water binding capacity (WBC). The sensory panel found no differences in appearance but differences in texture among samples containing different proportions and types of fibre. Fibre with large particle sizes protected surimi from loss of gel strength and hardness during freezing. There were very few variations during frozen storage of different samples.

Adhesive organs like arolia of insects allow these animals to climb on different substrates by creating high adhesion forces. According to the Dahlquist criterion, adhesive organs must be very soft, exhibiting an effective Young's... more

Adhesive organs like arolia of insects allow these animals to climb on different substrates by creating high adhesion forces. According to the Dahlquist criterion, adhesive organs must be very soft, exhibiting an effective Young's modulus of below 100 kPa to adhere well to substrates. Such a low effective Young's modulus allows the adhesive organs to make almost direct contact with the substrate and results in van der Waals forces along with capillary forces. In previous studies, the effective Young's moduli of adhesive organs were determined using indentation tests, revealing their structure to be very soft. However, adhesive organs show a layered structure, thus the measured values comprise the effective Young's moduli of several layers of the adhesive organs. In this study, a new approach is illustrated to measure the Young's modulus of the outermost layer of the arolium, i.e. of the epicuticle, of the stick insect Carausius morosus. As a result of the epicuti...

Needles with asymmetric bevel tips naturally bend when they are inserted into soft tissue. In this study, we present an analytical model for the loads developed at the bevel tip during needle-tissue interaction. The model calculates the... more

Needles with asymmetric bevel tips naturally bend when they are inserted into soft tissue. In this study, we present an analytical model for the loads developed at the bevel tip during needle-tissue interaction. The model calculates the loads based on the geometry of the bevel edge and gel material properties. The modeled transverse force developed at the tip is compared to forces measured experimentally. The analytical model explains the trends observed in the experiments. In addition to macroscopic studies, we also present microscopic observations of needle-tissue interactions. These results contribute to a mechanics-based model of robotic needle steering, extending previous work on kinematic models.

The conductance and electrostriction of bilayer lipid membranes (sBLM) supported on stainless steel and on conducting polymer polypyrrole (PPY) were studied. We showed that an increase in ammonia concentration resulted in an increase in... more

The conductance and electrostriction of bilayer lipid membranes (sBLM) supported on stainless steel and on conducting polymer polypyrrole (PPY) were studied. We showed that an increase in ammonia concentration resulted in an increase in d.c. current flow across the PPY layer adjacent to the metal surface and that covered by the lipid bilayer. The elasticity modulus in the direction perpendicular to the sBLM surface (E) and the electrical capacitance (C) were characterized by a complicated dependence on the application of an external d.c. voltage. In the case of sBLM formed on the PPY layer and that modified by avidin-urease, higher values of E were observed and in addition the latter system was characterized by a less expressed hysteresis of E and C than the metal supported sBLM. This is evidence that sBLM formed on PPY layers is smoother and more homogeneous than that formed on a metal support. We developed a urea minisensor based on sBLM supported on a PPY layer. Avidin-biotin tec...

Human lung undergoes breathing-induced deformation in the form of inhalation and exhalation. Modeling the dynamics is numerically complicated by the lack of information on lung elastic behavior and fluid–structure interactions between air... more

Human lung undergoes breathing-induced deformation in the form of inhalation and exhalation. Modeling the dynamics is numerically complicated by the lack of information on lung elastic behavior and fluid–structure interactions between air and the tissue. A mathematical method is developed to integrate deformation results from a deformable image registration (DIR) and physics-based modeling approaches in order to represent consistent volumetric lung dynamics. The computational fluid dynamics (CFD) simulation assumes the lung is a poro-elastic medium with spatially distributed elastic property. Simulation is performed on a 3D lung geometry reconstructed from four-dimensional computed tomography (4DCT) dataset of a human subject. The heterogeneous Young’s modulus (YM) is estimated from a linear elastic deformation model with the same lung geometry and 4D lung DIR. The deformation obtained from the CFD is then coupled with the displacement obtained from the 4D lung DIR by means of the T...

In the prediction of bone remodelling processes after total hip replacement (THR), modelling of the subject-specific geometry is now state-of-the-art. In this study, we demonstrate that inclusion of subject-specific loading conditions... more

In the prediction of bone remodelling processes after total hip replacement (THR), modelling of the subject-specific geometry is now state-of-the-art. In this study, we demonstrate that inclusion of subject-specific loading conditions drastically influences the calculated stress distribution, and hence influences the correlation between calculated stress distributions and changes in bone mineral density (BMD) after THR.For two patients who received cementless THR, personalized finite element (FE) models of the proximal femur were generated representing the pre- and post-operative geometry. FE analyses were performed by imposing subject-specific three-dimensional hip joint contact forces as well as muscle forces calculated based on gait analysis data. Average values of the von Mises stress were calculated for relevant zones of the proximal femur. Subsequently, the load cases were interchanged and the effect on the stress distribution was evaluated. Finally, the subject-specific stress distribution was correlated to the changes in BMD at 3 and 6 months after THR.We found subject-specific differences in the stress distribution induced by specific loading conditions, as interchanging of the loading also interchanged the patterns of the stress distribution. The correlation between the calculated stress distribution and the changes in BMD were affected by the two-dimensional nature of the BMD measurement.Our results confirm the hypothesis that inclusion of subject-specific hip contact forces and muscle forces drastically influences the stress distribution in the proximal femur. In addition to patient-specific geometry, inclusion of patient-specific loading is, therefore, essential to obtain accurate input for the analysis of stress distribution after THR.

The treatment of humeral shaft fractures ranges from conservative modalities to operative fixation, including plate osteosynthesis and intramedullary fixation. Nonunion is a complication of conservative and operative interventions but is... more

The treatment of humeral shaft fractures ranges from conservative modalities to operative fixation, including plate osteosynthesis and intramedullary fixation. Nonunion is a complication of conservative and operative interventions but is more often associated with elastic nailing. This article discusses elucidates the successful outcomes achieved with flexible nailing of humeral shaft fractures.

A simply supported bridge is modelled to investigate the effect of a strain rate dependent modulus of elasticity on the dynamic response of the structure to a moving load. The bridge is modelled as a one-dimensional discretized finite... more

A simply supported bridge is modelled to investigate the effect of a strain rate dependent modulus of elasticity on the dynamic response of the structure to a moving load. The bridge is modelled as a one-dimensional discretized finite element beam and the moving load is represented by a point force. A constant modulus of elasticity is traditionally employed when simulating the dynamic response of structures under moving loads. In this paper, a time-variant modulus is used to calculate strains and displacements and compare them to the traditional approach for different speeds and bridge spans. The time-variant modulus is obtained from the strain rate of the structure which is used in turn to update the strain. The results show significant changes in the modulus and in the resulting load effect as load magnitude and speed increase.

We explore the compliance approach for K I evaluation of a cracked three point beam (TPB) of functionally graded material (FGM). We suggest an equivalent beam of variable height for cracked FGM beams which includes the homogeneous beam... more

We explore the compliance approach for K I evaluation of a cracked three point beam (TPB) of functionally graded material (FGM). We suggest an equivalent beam of variable height for cracked FGM beams which includes the homogeneous beam for the linear, quadratic and cubic variations in elastic modulus along the beam span. The efficacy of equivalent beams is demonstrated numerically on a 250 × 41 × 6 mm FGM beam with modulus varying from 210 – 315 GPa under 5000 N load.