Sharif Digital Repository

This study seeks a method for formulating directional strategy of wind turbine industry in Iran. To this end, by initially evaluating various economic viewpoints concerning the development of industries, the necessity of government intervention is recognized. By defining the concepts of national industry policy, firm technology strategy, and national technology strategy, the role of directional industry strategy is then made clear. Furthermore, the six assumptions of emphasis on formulating strategy (rather than on formulating policy), emphasis on formulating directional strategy, model's prescriptivism, emphasis on formulating the strategy at the level of industry, Iran's being a developing... 

Iran, as a developing country, will be confronted with a significant increase in electricity demand in future years. Being a petroleum producing country has resulted in extreme subsidies for energy production from fossilized resources such as oil and gas. This issue is one of the most important factors regarding underdevelopment of renewable energies in Iran. Expansive use of fossil resources in providing the necessary energy has resulted in Iran being among the 20 countries that have a share in the 75% spread of greenhouse gases. This issue has resulted in greater attention on behalf of the energy sectors policy makers regarding renewable energies, especially wind. Awareness regarding the... 

Predicting the effective elastic properties of carbon nanotube-reinforced nanocomposites is of great interest to many structural designers and engineers for improving material and configuration design in recent years. In this paper, a finite element model of a CNT composite has been developed using the Representative volume element (RVE) to evaluate the effective material properties of nanocomposites. Based on this model, the effects of geometrical characteristics such as the aspect ratio, orientation and volume fraction of the CNTs in conjunction with the interphase behavior on the mechanical properties of the nanocomposites are elucidated and the elastic properties of a complex polymeric... 

A series of ZIF-8/OND hybrid nanostructures with different percentages of oxidized nanodiamond (OND) was prepared. Then, the adsorptive removal performance of pristine ZIF-8 and its nanohybrids with OND towards methylene blue (MB) was investigated. The fabricated adsorbents were characterized via thermogravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption, field emission scanning electron microscopy and zeta potential measurements. The maximal adsorption capacity of ZIF-8 (242 mg/g) was found to grow steadily with the increment in OND content and reached an approximate plateau at 343 mg/g for the nanohybrid containing 5 wt% OND, i.e.... 

In nuclear reactor core design, achieving the optimized arrangement of fuel assemblies (FAs) is the most important step towards satisfying safety and economic requirements. In most studies, nuclear fuel optimizations have been performed by using a finite number of different types of FAs. However the effect of FA numbers with different enrichments and the difference between their maximum and minimum enrichment values can be important and should be evaluated in the optimization process. This research is aimed at evaluating the effect of using different enrichment values for FAs. This issue has been investigated by focusing on two parameters, namely, the initially selected enrichment and the... 

Motivated by surface plasmon polariton waveguides in the optical regime, spoof surface plasmon (SSP) waveguides have received a lot of attention in terahertz and millimeter wave frequencies.Most research on these kinds of waveguides is numerical. However, some limited analytical work can be seen in the literature. In this paper, one type of SSP waveguide that is composed of a rectangular corrugation with finite lateral width on the ground is considered, and an analytical method, which is inspired byMarcatili's method, is proposed in order to calculate the dispersion curve of the first mode. The results of this analytical method and a numerical commercial eigenmode solver are compared. The... 

This paper analyzes the second-order mode of the spoof surface plasmon (SSP) waveguide, which consists of PEC pillars (dominos) with finite lateral widths on a PEC ground. The space is first divided into four regions. The electromagnetic fields of each region are then written as TE and TM. The boundary conditions and matching integrals are employed to determine the dispersion relations of the second-order mode of the SSP waveguide consisting of two relations. Inspired by Marcatili's method, the analytical approach is to develop a recently-used method for the first mode of the SSP waveguide. The dispersion relations are then solved; therefore, the dispersion curve is plotted. The analytical... 

Sport video shot classification is a basic step in the sport video processing. For many purposes such as event detection and summarization, shot classification is needed for content filtering. In this paper, we present a new method for soccer video shot classification. At first, in-field and out-of-field frames are separated. In in-field frames three features based on number of connected components and shirt color percent in vertical and horizontal strips are extracted. The features are all new and showed excellent discrimination in the feature space. These features are given to SVM for classifying long, medium and close-up shots. One of the advantages of our method is that, close-ups can be... 

The first example of a heterogeneous catalytically active system for Buchwald–Hartwig and Ullmann homocoupling of unactivated aryl halides (fluorobenzene) is presented. The novel magnetic heterogeneous palladium catalyst was synthesized by immobilization of palladium ions onto an aminopyridine-functionalized Fe3O4. The catalyst was fully characterized by FTIR spectroscopy, temperature-programmed reduction, thermogravimetric analysis, CHN elemental analysis, transmission electron microscopy, field-emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and atomic absorption spectroscopy. By using this catalyst system, various types of primary and... 

Indoor communication systems operating at millimeter wave frequencies are getting increasing attention due to their ability of having wider bandwidth and as a result conveying information at higher bit rates. At these systems, the capacity of channel is very important especially where there is no line of sight due to an obstacle. Here we examine the use of a multiple-input multiple-output (MIMO) system in a 2D room with an obstacle at 60 GHz. We estimate the channel by using the closed-form Green's function of the room and show the ability of MIMO to increase the available capacity of the system in the room chiefly behind the obstacle. © 2016 IEEE  

In this study the ability of artificial neural network (ANN) in forecasting the daily NASDAQ stock exchange rate was investigated. Several feed forward ANNs that were trained by the back propagation algorithm have been assessed. The methodology used in this study considered the short-term historical stock prices as well as the day of week as inputs. Daily stock exchange rates of NASDAQ from January 28, 2015 to 18 June, 2015 are used to develop a robust model. First 70 days (January 28 to March 7) are selected as training dataset and the last 29 days are used for testing the model prediction ability. Networks for NASDAQ index prediction for two type of input dataset (four prior days and nine... 

Systematic management of enterprise knowledge, e.g. new ideas, innovations and patents, has a great impact on business sustainability and growth. Without comprehensive assessment of knowledge assets, agile companies can not design and run knowledge promotion programs required for survival in competitive environments in modern economy. A comprehensive framework for the assessment of as-is situation and development of knowledge promotion plans includes (a) assessing the as-is situation- the quantity and quality of organizational knowledge; (b) developing a situational program based on assessment results, business strategy and knowledge maturity indicators; (c) and working out an action plan in... 

In this article, the propagation of one-dimensional stress waves in a plate made of functionally graded materials excited by a harmonic force is studied. The material properties of the functionally graded material plate are assumed to be graded in the thickness direction according to a power law distribution in terms of the volume fractions of the constituents. The governing equations are based on stress-strain relation and the equation of motion. Keeping generality, the functionally graded material plate is assumed as a multilayer with linear material property in each layer while arbitrary exponential material property through the thickness. A plate made of aluminum and alumina is... 

Deformation modeling of an infinite plate of functionally graded materials (FGMs) loaded by normal force to the plate surface is studied. The material properties of FGM plate are assumed to be graded in the thickness direction according to a simple power-law distribution in terms of the volume fractions of the constituents. The governing equations are based on stress-strain relation and the equilibrium force equation. Keeping generality, FGM plate has been assumed as a multilayer with linear material property in each layer while arbitrary exponential material property through the thickness. A plate made of Aluminum and Alumina is considered as an example to illustrate the effects of the... 

Aryl halides and especially inactive aryl chlorides were coupled to benzenoid aromatic rings in a Suzuki–Miyaura coupling reaction in the absence of organic solvents and toxic phosphine ligands. The reaction was catalysed by a recoverable magnetic nanocatalyst, Pd@Fe3O4, in aqueous media. This method is green, and the catalyst is easily removed from the reaction media using an external magnetic field and can be re-used at least 10 times without any considerable loss in its activity. The catalyst was characterized using scanning and transmission electron microscopies, thermogravimetric analysis, inductively coupled plasma spectroscopy, Fourier transform infrared spectroscopy, CHN analysis,... 

Background: Melittin, a peptide component of honey bee venom, is an appealing candidate for cancer therapy. In the current study, melittin, melittin-loaded niosome, and empty niosome had been optimized and the anticancer effect assessed in vitro on 4T1 and SKBR3 breast cell lines and in vivo on BALB/C inbred mice. "Thin-layer hydration method" was used for preparing the niosomes; different niosomal formulations of melittin were prepared and characterized in terms of morphology, size, polydispersity index, encapsulation efficiency, release kinetics, and stability. A niosome was formulated and loaded with melittin as a promising drug carrier system for chemotherapy of the breast cancer cells.... 

The aim of this study is to develop a non-linear robust controller with adaptive gains in order to prevent malaria epidemic as a positive system with an uncertain model. The malaria outbreak is modelled by seven non-linear coupled differential equations for the population variables: susceptible, exposed, symptomatic infected and recovered humans and the susceptible, exposed and infected mosquitoes. The non-linear robust adaptive integral-sliding-mode controller is developed in order to appropriately adjust the use of treated bednets, treatment rate of infected individuals and the use of insecticide spray to control malaria epidemic. Accordingly, the numbers of exposed and infected humans and... 

The present article describes the synthesis of a new magnetic polyacrylonitrile-based Pd catalyst involving polyacrylonitrile modified via 2-aminopyridine as an efficient support to immobilize Pd nanoparticles. The simple reusability, easy separation and high stability of this Pd complex make it an excellent candidate to generate a C–O bond via Ph-X activation which is a really important subject in achieving biologically active compounds. It is worth to note access to good and high yields as well as broad substrate scope have resulted from superior reactivity of this catalyst complex. Furthermore, the structure of the magnetic polyacrylonitrile-based heterogeneous catalyst was characterized... 

Aryl benzylsulfonates undergo so-called pseudo-thia-Fries rearrangement under microwave irradiation. Benzylated phenolic compounds have been obtained with the loss of 'SO2' from the starting materials  

Accumulative roll bonding is a severe plastic deformation process used for Cu-Al-Mn shape memory alloy. The main purpose of this study is to investigate the possibility of grain refinement of Cu-9.5Al-8.2Mn (in wt.%) shape memory alloy using accumulative roll bonding and post-deformation annealing. The alloy was successfully subjected to 5 passes of accumulative roll bonding at 600 °C. The microstructure, properties as well as post-deformation annealing of this alloy were investigated by optical microscopy, scanning electron microscopy, x-ray diffraction, differential scanning calorimeter, and bend and tensile testing. The results showed that after 5 passes of ARB at 600 °C, specimens...