Abstract: The available studies in the literature which dealt with the scale effects of strip footings on different sand packing systematically still remain scarce. In this research, the variation of ultimate bearing capacity and deformation pattern of soil beneath strip footings of different widths under plane-strain condition on the surface of loose, medium-dense and dense sand have been systematically studied using experimental and noninvasive methods for measuring microscopic deformations. The presented analyses are based on model scale compression test analysed using Particle Image Velocimetry (PIV) technique. Upper bound analysis of the current study shows that the maximum vertical displacement of the sand under the ultimate load increases for an increase in the width of footing, but at a decreasing rate with relative density of sand, whereas the relative vertical displacement in the sand decreases for an increase in the width of the footing. A well agreement is observed between experimental results for different footing widths and relative densities. The experimental analyses have shown that there exists pronounced scale effect for strip surface footing. The bearing capacity factors Nγ rapidly decrease up to footing widths B=0.25 m, 0.35 m, and 0.65 m for loose, medium-dense and dense sand respectively, after that there is no significant decrease in Nγ. The deformation modes of the soil as well as the ultimate bearing capacity values have been affected by the footing widths. The obtained results could be used to improve settlement calculation of the foundation interacting with granular soil.
Abstract: Optical Coherence Tomography (OCT) combined
with the Confocal Microscopy, as a noninvasive method, permits the
determinations of materials defects in the ceramic layers depth. For
this study 256 anterior and posterior metal and integral ceramic fixed
partial dentures were used, made with Empress (Ivoclar), Wollceram
and CAD/CAM (Wieland) technology. For each investigate area 350
slices were obtain and a 3D reconstruction was perform from each
stuck. The Optical Coherent Tomography, as a noninvasive method,
can be used as a control technique in integral ceramic technology,
before placing those fixed partial dentures in the oral cavity. The
purpose of this study is to evaluate the capability of En face Optical
Coherence Tomography (OCT) combined with a fluorescent method
in detection and analysis of possible material defects in metalceramic
and integral ceramic fixed partial dentures. As a conclusion,
it is important to have a non invasive method to investigate fixed
partial prostheses before their insertion in the oral cavity in order to
satisfy the high stress requirements and the esthetic function.
Abstract: This paper presents a novel method for prediction of
the mechanical behavior of proximal femur using the general
framework of the quantitative computed tomography (QCT)-based
finite element Analysis (FEA). A systematic imaging and modeling
procedure was developed for reliable correspondence between the
QCT-based FEA and the in-vitro mechanical testing. A speciallydesigned
holding frame was used to define and maintain a unique
geometrical reference system during the analysis and testing. The
QCT images were directly converted into voxel-based 3D finite
element models for linear and nonlinear analyses. The equivalent
plastic strain and the strain energy density measures were used to
identify the critical elements and predict the failure patterns. The
samples were destructively tested using a specially-designed gripping
fixture (with five degrees of freedom) mounted within a universal
mechanical testing machine. Very good agreements were found
between the experimental and the predicted failure patterns and the
associated load levels.
Abstract: A method and apparatus for noninvasive measurement
of blood glucose concentration based on transilluminated laser beam
via the Index Finger has been reported in this paper. This method
depends on atomic gas (He-Ne) laser operating at 632.8nm
wavelength. During measurement, the index finger is inserted into the
glucose sensing unit, the transilluminated optical signal is converted
into an electrical signal, compared with the reference electrical
signal, and the obtained difference signal is processed by signal
processing unit which presents the results in the form of blood
glucose concentration. This method would enable the monitoring
blood glucose level of the diabetic patient continuously, safely and
noninvasively.