Sharif Digital Repository

Integrated on-chip inductors with high quality factors are demonstrated using a low loss artificial conductor technology. This concept is based on an artificial layered meta-material comprising a bi-layered Ni 80Fe 20/Cu superlattice. By properly tailoring the thickness ratio between the non-magnetic and magnetic metallic layers, the skin effects can be effectively suppressed within a wide frequency range, and can be tuned to a minimum at the frequency of interest up to 67 GHz. The quality factor has been increased by 41% of a 2nH inductor at 14.5GHz. The bandwidth of skin effect suppression is obtained between 10-18 GHz  

In this paper we address classification of Web content and in particular its application in the detection of pornographic Web pages. Filtering of undesirable Web content is mainly achieved based on blocking a specific Web address via searching it in a reference list of black URLs or doing a plain contextual analysis on the page by searching special keywords in the text. The main problem with current filtering methods is the requirement for instantly update of the URL list and also the high rate of over-blocking the usual pages. In this paper, we propose an intelligent approach which is based on using textual, profile, and visual features in a hierarchical structure classifier. Textual... 

We propose an algorithm to compensate for the refractive index error in the optical coherence tomography (OCT) images of multilayer tissues, such as skin. The performance of the proposed method has been evaluated on one-and two-layer solid phantoms, as well as the skin of rat paw. © 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)  

This paper presents a novel approach for detection and recognition of multi-view faces whose size and location is unknown and the illumination conditions are varying. The illumination is a big problem in face detection and recognition. In this paper, a new pre-processing method is proposed in order to cancel the effect of various illumination conditions on a face. Then, a binary face is obtained that its pixels are 0 or 1. Next, a fuzzy face model is produced from the distribution of zeros in the binary face. The model is used in order to detect faces in images by using a fuzzy approach. Because of the independency of the detection method to the skin color of face, persons with every kind of... 

The formation of condensate banking in the near well-bore region will lead to the reduction in gas relative permeability and loss of well deliverability. This loss is investigated by conducting a series of fine grid numerical compositional simulation with the gas condensate and dry gas reservoir data. Also, a method for calculation of condensate blockage skin factor is introduced in which the skin factor is calculated using dry gas and gas condensate simulation production data. The authors also found that absolute permeability and pressure drawdown of the producing well have significant influence on the well gas deliverability and condensate blockage skin factor  

The analysis of the capture zone of wells is useful to design pumping systems and wellhead protection programs. In this study, an analytical solution for the head distribution of a partially penetrating well, and semi-analytical methods to determine the geometry of the capture surface are presented. The analytical solution is derived based on an infinitesimal radius under a constant pumping rate in a two-zone confined aquifer. Using the developed solution, a sensitivity analysis is performed to study the influence of skin on the drawdown, location of the stagnation point, maximum horizontal and vertical extent of the capture surface. The results show the efficiency of a partially penetrating... 

Here we report on the production of highly directed ion blocks by plasma interaction of ultraviolet wavelength light produced from a KrF laser. This may support the requirement to produce a fast ignition deuterium-tritium fusion at densities not much higher than the solid state by a single shot petawatt-picoseconds ultraviolet laser pulse. Using double Rayleigh initial density profiles, we are studying numerically how the nonlinear force necessary to accelerate plasma blocks may reach the highest possible thickness. Propagation of plasma blocks and the volumetric hot electrons can be shown in detail. Results of computations for wavelengths of two lasers are compared, which show that the... 

Biocompatible porous polymeric scaffolds provide a suitable environment for proliferation of stem cells in human body. In this research work, porous gelatin–poly(ethylene glycol), PEG, based scaffolds were prepared using combination of freeze-gelation and freeze-extraction methods. Effects of various parameters such as freezing temperature, cross-linking agent, concentrations of gelatin and PEG and their blending ratio on physical and mechanical properties, swelling ratio, porosity, pore size, and degradation rate of scaffolds were investigated. Also, proliferation of fibroblast skin cells on the scaffolds was examined by MTS assay to assess the suitability of the scaffolds in wound healing... 

Background and Objectives: Melanoma is a dangerous kind of skin disease with a high death rate, and its prevalence has increased rapidly in recent years. Diagnosis of melanoma in a primary phase can be helpful for its cure. Due to costs for dermatology, we need an automatic system to diagnose melanoma through lesion images. Methods: Here, we propose a sparse representation based method for segmentation and classification of lesion images. The main idea of our framework is based on a kernel sparse representation, which produces discriminative sparse codes to represent features in a high-dimensional feature space. Our novel formulation for discriminative kernel sparse coding jointly learns a... 

The paucity of cellular and molecular signals essential for normal wound healing makes severe dermatological ulcers stubborn to heal. The novel strategies of skin regenerative treatments are focused on the development of biologically responsive scaffolds accompanied by cells and multiple biomolecules resembling structural and biochemical cues of the natural extracellular matrix (ECM). Electrospun nanofibrous scaffolds provide similar architecture to the ECM leading to enhancement of cell adhesion, proliferation, migration and neo tissue formation. This Review surveys the application of biocompatible natural, synthetic and composite polymers to fabricate electrospun scaffolds as skin... 

Porous scaffolds composed of gelatin/poly (vinyl alcohol), (Gel/PVA), were prepared using combination of freeze gelation and freeze drying methods. The effect of polymer concentration, gelatin/PVA ratio, and glutaraldehyde/gelatin ratio (GA/Gel) was investigated on morphology of pores, swelling ratio, biodegradation, and skin cell culture. At optimum preparation conditions the scaffolds had uniform pore size distributions showing high swelling ratio of 23.6. The scaffolds were of biodegradable nature and almost degraded in 28 days. Human dermal fibroblast cells (HDF) were cultured on the scaffolds and MTS assay was conducted to evaluate the influence of PVA on growth and proliferation of the...