Sharif Digital Repository

WO3 have good electrochromic, gas sensor, photocatalyst, phoelectrochemical (PEC) properties. due its properties, tungsten oxide have many application in technology and industry. In this thesis, pure WO3 thin film and MWCNT-WO3 nanocomposite thin films with different weight percent of MWCNT/WO3 utilize for energy domain, particular hydrogen production with phoelectrochemical reactions spiliting water. For this purpose, initially WO3 thin films were deposited on glass and ITO substrates using sol-gel dip-coating method. Optical and surface properties of the films dried at 100ºC and annealed at 400 ºC had been investigated. UV-Visible spectrophotometer, atomic force microscopy (AFM), X-ray... 

World population growth, depletion of fossil fuels resources depletion and increased air pollution resulting from their consumption, human society has had to replace fossil fuels with renewable sources. In this context, the production of hydrogen using solar energy is feasible candidate to replace fossil fuels, which can be produced by water splitting in a photoelectrochemical (PEC) cell using an appropriate photocatalyst. This clean production method has been attended by many researchers in recent years. The most common photocatalyst for the conversion of sunlight to hydrogen by splitting water is Titanium dioxide (TiO2). But high energy gap and fast electron-hole recombination rate in TiO2... 

iN This thesis, Design and implementation of a low voltage, low power Delta-Sigma Modulator (DSM) is presented. System level considerations have been discussed thoroughly. In addition a systematic design flow in the context of continuous time delta sigma modulators is provided. While voltage-domain signal processing becomes more difficult in deep sub-micron processes, a finer time resolution is achievable. Time-domain quantizers can ameliorate the design challenges of flash quantizers which arises from lower supply voltages and higher fraction of comparator metastable region. VCO based quantizer such as voltage to frequency and voltage to phase considered as time domain quantizers can be a... 

This study aims to estimate impact of the energy subsidy reform on households’ head time allocation in rural and urban areas in to 2011 to 2013 by making use of treatment effect particularly dose response function approach. Our main contribution is estimation and calculation of labor supply reaction to the unconditional cash transfer by dose of the subsidy that they received, while the previous works in this literature have used the well know binary variable of being in the exposure of program. To control for the demand determinants which are deriving the labor demand, we include the province level GDP and unemployment rate in the model. Our findings show that the subsidy dose does not have... 

Membrane bioreactors can replace the activated sludge process and the final clarification step in municipal wastewater treatment. The combination of bioreactor and crossflow microfiltration allows for a high chemical oxygen demand (COD) reduction of synthetic wastewater. In this study, experimental data from a laboratory scale membrane bioreactor are presented. In order to investigate the influence of various operating parameters such as hydraulic retention time (HRT), biomass concentration and organic loading rate on organic pollutant removal, the pilot scale submerged membrane bioreactor (SMBR) with a Polyvinylidene Fluoride (PVDF) hollow fiber membrane module was conducted using synthetic... 

Ethernet is among the most popular forms of data networking in the world. It has been widely used for local area networks and recently, it has also become very popular in metro area networks. As the usage of Ethernet grows, security and privacy of data transport using Ethernet becomes more important. As a result, there have been a lot of developments in improving security of Ethernet. In this thesis, we first provide a brief introduction of data security concepts. Then we briefly review important encryption standards. We focus on IEEE MACsec standard to provide the required security for Ethernet data transport. We have implemented the core encryption/decryption algorithms using HDL codes. We... 

When a fire breaks out in a tunnel, due to the enclosure of the interior of the road tunnels, hot and poison smoke quickly spreads in the tunnel. This phenomenon, in addition to destroy the tunnel structure, causes a lot of financial and human losses. In recent years, research into fire control has become more important with the occurrence of numerous accidents in road tunnels and fatalities. Longitudinal ventilation is still the main method for controlling smoke distribution in tunnels due to lower construction costs and acceptable efficiency. Numerous studies have been conducted to investigate the effect of different and effective parameters on fire control and smoke emissions in direct... 

Supersonic impinging jets, similar to the jet flows exhausted from a nozzle, generate high unsteady pressure and acoustic loads on the rocket payload or the VTOL aircraft structure with possible mission failure during the launch/starting phase. In the past, experimental studies were concentrated on characterizing the steady impingement flow and not the initial transient process. It was shown that one of the main characteristics of supersonic impinging jets is the dominance of the feedback loop mechanism. The present investigation is an attempt to examine the flow characteristics of a high temperature supersonic impinging jet through a convergent-divergent nozzle during the transient starting... 

Graphics Processing Units (GPUs) employ a scratch-pad memory (a.k.a., shared memory) in each streaming multiprocessor to accelerate data sharing among the threads in a thread block and provide a software-managed cache for the programmers.However, we observe that about 60% of GPU workloads of several well-known benchmark suites do not use shared memory. Morever, among those workloads that use shared memory, about 42% of shared memory is not utilized, on average. On the other hand, we observe that many general purpose GPU applications suffer from the low hit rate and limited bandwidth of L1 data cache.We aim to use shared memory space and its corrsponding bandwidth for improving L1 data cache,...