Titanium (Ti) is the material of choice for dental and orthopaedic implants due to its highly biocompatible nature. Modification of the implant surface, either topographically (as roughness) or chemically, can promote accelerated osteogenesis in vivo and greatly increase bone-implant contact and bonding strength. In this paper, we sought to characterise the cellular and molecular responses of h...

پس از اختراع خودرو، بشر بزودی به رابطه میان مقاومت هوا و حرکت اتومبیل پی برد. به مرور زمان با بهبود عملکرد خودروها از جهات مختلف و بالارفتن قیمت سوخت، بهبود آیرودینامیکی نیز به مسأله‌ای اساسی تبدیل شد. پژوهشگران دریافتند که توجه به آیرودینامیک نه تنها برای دستیابی به سرعت‌های بالاتر، بلکه به منظور کاهش مصرف سوخت و ایجاد پایداری مناسب در خودرو، امری ضروری است. به همین دلیل تاکنون تحقیقات زیادی د...

There have been a number of attempts to modify the surface of dental implants to improve osseointegration. These modifications include alterations of surface chemistry and roughness. The purpose of this study was to examine the early response of human osteoblast-like cells placed on Ti-6Al-7Nb disks that had a similar grooved surface topography and three different levels of surface roughness (R...

INTRODUCTION Capsular contracture formation is a common complication following breast augmentation surgery. Breast implant shells have either a smooth or a textured surface. Smooth surfaces demonstrate a higher incidence of contracture formation. The 3-dimensional surface of textured implants is thought to disrupt contractile forces and reduce capsular contracture rates. AIM To investigate th...

In this paper we suggest a modification to the Beckmann-Kirchhoff model of rough surface reflectance that can be used for surfaces of intermediate roughness. One of the problems with the existing Beckmann model is that it fails for large angles of incidence. This problem was overcome for rough surfaces by Vernold and Harvey who use a Lambertian form factor. Here we take this work one step furth...

Reflections at rough surfaces change the temporal structure of the reflected signal. This paper shows how to incorporate this temporal behavior in geometric room acoustics modeling. Specifically, a beam tracer is used for calculating the image sources and reflection paths. The roughness of the surfaces is taken into account in post-processing. A single reflection is assumed to distribute the en...

An efficient and accurate spectral method is presented for scattering problems with rough surfaces. A probabilistic framework is adopted by modeling the surface roughness as random process. An improved boundary perturbation technique is employed to transform the original Helmholtz equation in a random domain into a stochastic Helmholtz equation in a fixed domain. The generalized polynomial chao...

The need for numerical methods in studying electromagnetic scattering from rough surfaces is well established. The most commonly used numerical method is the surface integral equation method and its solution by the method of moments (MoM). Conventional implementation of MoM requires O(N^3) operations, where N is the number of surface unknowns. When N is large, as frequently encountered in study...

– We model numerically the partial normal contact of two elastic rough surfaces with highly correlated asperities. Facing surfaces are unmated and described as self-affine with a Hurst exponent H . The numerical algorithm is based on Fourier acceleration and allows efficient simulation of very large systems. The force, F , versus contact area, A, characteristics follows the law F ∼ A in accorda...

This paper is concerned with the analysis of the electromagnetic wave scattering in inhomogeneous medium with infinite rough surfaces. Consider a time-harmonic electromagnetic field generated by either a magnetic dipole or an electric dipole incident on an infinite rough surface. Throughout the dielectric permittivity is assumed to have a positive imaginary part which accounts for the energy ab...