OBJECTIVE The purpose of this study is to find the optimal stiffness and volume of bone cement and their biomechanical effects on the adjacent vertebrae to determine a better strategy for conducting vertebroplasty. METHODS A three-dimensional finite-element model of a functional spinal unit was developed using computed tomography scans of a normal motion segment, comprising the T11, T12 and L...

Irregular buildings make up a large portion of  urban infrastructure. Presence of irregularities can be due to architectural and  user changes in building stories. Main objective of this article is evaluate seismic performance of structures with vertical irregularities. Seismic responses are obtained by enveloping peak inelastic responses resulting from pushover analyses according to provided p...

in this article, vibration analysis of an euler-bernoulli beam resting on a pasternak-type foundation is studied. the governing equation is solved by using a spectral finite element model (sfem). the solution involves calculating wave and time responses of the beam. the fast fourier transform function is used for temporal discretization of the governing partial differential equation into a set ...

This study explored the free vibration problem in relation to glass fiber reinforced polymer (GFRP) plates with central cutouts and free boundaries using theoretical, experimental, and numerical methods. The theoretical formulations were derived from the classical lamination plate theory. The rectangular cutout was mathematically modeled into the stiffness matrix of the plate by multiplying Hea...

This study tested the hypothesis that with hypertrophy, the proportion, distribution, and structural alignment of fibrillar collagen are important determinants of myocardial stiffness. Toward this end, the collagen volume fraction (morphometry), the transmural or subendocardial distribution of collagen, and the structural arrangement of fibrillar collagens (picrosirius red) were examined in the...

Beams, made of brittle materials like concrete or cement, show increasing crack development during their service life due to mechanical and environmental loadings. This local damage can be translated into a reduction of the local bending stiffness. Stiffness modifications, while assuming constant mass distribution, can be observed by monitoring the vibrational behavior of the beam. In this pape...

It is shown that excitation spectra of generalized Gibbs ensembles of one-dimensional integrable models with isotopic symmetry contain universal features insensitive to details of the distribution. Namely, the low energy limit of the subsystem of isotopic (for instance, spin) excitations is described by the effective action of a ferromagnet at thermodynamic equilibrium with a single temperature...

INTRODUCTION Osteoarthritis (OA) is a painful, debilitating joint disease marked by cartilage degeneration and underlying subchondral bone changes [1]. To date, the exact mechanism of OA initiation and progression is unclear [2]. One predominant theory indicates that observed increased quantity and stiffness of bone near the subchondral surface results in an overall stiffer subchondral bone, wh...

Molecular alteration in type I collagen, i.e., substituting the α2 chain with α1 chain in tropocollagen molecule, can cause osteogenesis imperfecta (OI), a brittle bone disease, which can be represented by a mouse model (oim/oim). In this work, we use dual-frequency Atomic Force Microscopy (AFM) and incorporated with molecular modeling to quantify the ultrastructure and stiffness of the individ...

Selective Laser Melting (SLM) was used to fabricate scaffolds using the titanium alloy Ti6Al-4V. Two types of high porosity open-cell structures were manufactured: the first built from topology optimised designs with maximised stiffness, and the second from gyroid labyrinths. In mechanical compression tests the scaffolds demonstrate exceptional strengthand stiffness-to-weight ratios. In particu...