the purpose of this study is to determine the effect of vierendeel panel width and vertical truss spacing ratio in an inelastic behavior of the stf system due to earthquake loads. the stf system is applied to a six-storey building that serves as apartments [2]. the stf system is used in the building in the transverse direction (n-s direction), while in the longitudinal direction (w-e direction)...

the nonlinear static procedures (nsps) proposed by design codes do not lead to reliable results especially for tall buildings. they generally provide inconsistent estimates of inelastic seismic demands, especially for the top floors due to their inabilities in considering the higher modes effects. in this paper, a new enhanced pushover procedure is proposed which is based on the envelope of the...

We consider quasi-static nonlinear poroelastic systems with applications in biomechanics and, particular, tissue perfusion. The permeability is taken to be dependent on solid dilation, and physical types of boundary conditions (Dirichlet, Neumann, mixed) for the fluid pressure are considered. system under consideration represents a nonlinear, implicit, degenerate evolution problem, which falls ...

Implant placement under soft tissues operation is described. In this operation tissues can reach such deformations that nonlinear properties are appeared. A mass-spring model modification for modeling nonlinear tissue operation is developed. A method for creating elasticity module using splines is described. For Poisson ratio different stiffness for different types of springs in cubic grid is u...

The aim of this article is to review the basic principles of two-photon excitation fluorescence (2PEF) microscopy and to compare the advantages and disadvantages of 2PEF imaging to other microscopy methodologies. 2PEF imaging is a nonlinear approach that generates images of optical sections and that is particularly well suited for deep-tissue and in vivo imaging of live animals. The nonlinear e...

Near-infrared laser-based microsurgery is promising for noninvasive cancer treatment. To make it a safe technique, a therapeutic process should be controllable and energy efficient, which requires the cancer cells to be identifiable and observable. In this work, for the first time we use a miniaturized nonlinear optical endomicroscope to achieve microtreatment of cancer cells labeled with gold ...

Nonlinear microscopy, namely multiphoton imaging and second harmonic generation (SHG), is an established noninvasive technique useful for the imaging of extracellular matrix (ECM). Typically, measurements are performed in vivo on freshly excised tissues or biopsies. In this article, we describe the effect of rehydrating paraffin-embedded sections on multiphoton and SHG emission signals and the ...

A new method is proposed for estimation of nonlinear elastic properties of soft tissues. The proposed approach involves a combination of nonlinear finite element methods with a genetic algorithm for estimating tissue stiffness profile. A multipoint scheme is introduced that satisfies the uniqueness condition, improves the estimation performance, and reduces the sensitivity to image noise. The u...

Poly(1,8-octanediol-co-citric acid) (POC) is a synthetic biodegradable elastomer that can be processed into three-dimensional (3D) scaffolds for tissue engineering. We investigated the effect of designed porosity on the mechanical properties, permeability, and degradation profiles of the POC scaffolds. For mechanical properties, scaffold compressive data were fitted to a one-dimensional (1D) no...

A nonlinear mathematical model was developed and experimentally validated to investigate the effects of changes in optical properties during interstitial laser photocoagulation (ILP). The effects of dynamic optical properties were calculated using the Arrhenius damage model, resulting in a nonlinear optothermal response. This response was experimentally validated by measuring the temperature ri...