Sharif Digital Repository

Block shear failure in the parent material is considered as a common potential failure mode in welded connections used in steel structures. However, there is only little research reported on the block shear failure of welded connections under multiaxial loading. Multiaxial loading is defined as loading not parallel or perpendicular to weld lines and in the case of in planar eccentricity results in torsional loads. In this research a nonlinear finite element model is developed to study the effect of connection geometry, weld group configuration, and eccentricity of lap splice connection on block shear capacity. The case studied concerns a 3 milimeter thick structural steel plate (CSA G40.21... 

In this thesis we are going to improve an ultrasonic flowmeter accuracy by considering the influence of different parameters like temperature, pressure, etc. Firstl of all different cases of flow condition in which ultrasonic flowmeter may work are specified, then velocity and temperature profile of pipe flow are determined using Fluent software. In thr next step ultrasonic pulses transmitted are simulated by the use of code written in Matlab to find wave travel time in the flow. Evetually an accurate relation of calibration for flowmeter is determined by the use of travel time and all other flow properties to evaluate the accuracy of flowmeter in diffent cases. Relation extracted can be... 

In this thesis, the value-ladenness or value-neutrality of technology, new social media and as a result Instagram is investigated. It is also discussed whether values can be taken into account during the design process of technical artefacts, including new social media and Instagram, and methods are developed for this purpose. Several methods have been developed for this purpose, some of them and their compatibility with modern social media are explained; including the Value-Sensitive-Design method and the disclosive computer ethics design method. The frameworks of ethical philosophy such as virtue ethics are reviewed and the appropriate ethical framework for the analysis of new social media... 

a graph into specific subgraphs. Specially, decomposing the edges of a complete graph into cycles with determined length draws the main attention. Most of the former works in this area were studied the Alspach conjecture. In another words, Alspach conjecture states that ” Is the obvious necessary conditions for decomposing a graph into cycles (equality of the edges count with sum of cycle lengths) with specified length but not necessarily identical are also sufficient.” Different cases of Alspach conjecture have been studied and proved completely.The decomposition of a complete graph into cycles with the same length k is called k-cycle system. Steiner triple system is a 3-cycle system.... 

Switched systems as a subset of hybrid systems have both discrete and continuous behaviors and have attracted a lot of attention during the past decades. A set of subsystems or modes whose sequence is specified by a switching rule makes the switched system. Another category of systems is the fractional order system in which the order of derivatives is not limited to integers. This feature has provided a significant capacity for this type of system. On the other hand, every real system faces a set of limitations that neglecting them may reduce the quality of control or even lead to system instability. The purpose of this research is to model and control the switched system, whose subsystems... 

Cardiovascular (CV) system is very similar to a wireless communication system in which a common input signal from the heart is fed into different arterial channels throughout different body parts. By putting multiple sensors on different peripheral body sites effects of this circulation from the heart can be recorded and be used as inputs for different multi channel blind system identification (BSI) methods for estimation of arterial channel dynamics. This Thesis is defined in order to investigate different BSI methods capability in CV characterization. To achieve this goal photoplethysmogram signals has been used as primary sensory recorded effect of heart function at three different... 

Supercapacitors are safe and environmentally friendly energy storage devices that have been considered for their diverse applications. One of the most important factors that control supercapacitors' capacity is the electrode material's structure and properties. Adding heteroatoms or composite materials synthesis is one way to improve electrode performance. In this study, a facile, fast, and economical hydrothermal method was used to synthesize N doped, P doped or N/P co-doped 3D reduced graphene oxide (rGO) for high-performance supercapacitor application. Nitrogen and phosphorus elements were replaced by carbon atoms simultaneously during the graphene oxide hydrothermal reduction procedure.... 

Capacitive deionization (CDI) is a suitable method for water desalination with low energy consumption and high efficiency, which does not have secondary pollution and is environmentally friendly. The hybrid capacitive deionization uses a faradaic electrode next to the carbonaceous electrode, taking advantage of both electrodes, and high capacities have also been reported. Titanium carbide Mxene is an important candidate in CDI due to its high electrical conductivity and tunable interlayer distance, but Mxene suffers from low oxidation resistance. Therefore, in this research, molybdenum disulfide (MoS2) that is an essential member of the 2D transition metal dichalcogenides family, was used as... 

In recent years, the Internet of Things has become one of the most popular technologies that has facilitated new interactions between objects and humans to improve their quality of life. With the rapid proliferation of the Internet of Things, an ever-evolving question arises - how to control access and permissions in a space that can contain hundreds of smart devices - which ultimately address security and privacy concerns of technologies and consumers. Today, cloud computing has become an important technology for the Internet of Things and creates a cloud architecture that is used in various fields in this area. A smart city is an urban area that uses a variety of sensors and electronic... 

Cloud Manufacturing is a new paradigm which under development and has been introduced as one of the promising models for providing ubiquitous, convenient, on-demand network access to a shared pool of configurable manufacturing resources (e.g, networks, servers, facilities, applications, robots, machines and services) that can be rapidly provisioned with minimal management effort and service provider’s interaction. Cloud Manufacturing is defined based on Cloud Computing. Like the Cloud Computing, Cloud Manufaturing offers a service-oriented architecture that is based on information technology (IT) in which each manufacturing resources is expressed as a service. For providing a... 

The rapid development of portable and wearable electronic devices has necessitated the creation of micro-sized energy storage devices, including micro-supercapacitors. Micro-supercapacitors are ideal energy storage sources for these devices due to their lifetime and optimal power density. Consequently, selecting the appropriate electrode material and developing a simple, low-cost manufacturing method for micro-supercapacitors present significant challenges. Graphene oxide, a key material for these applications, often underperforms due to its porosity and low specific surface area. However, its performance can be enhanced by integrating it with a new class of highly porous materials with a...