Sharif Digital Repository

Polymer composites, due to its exclusive properties, has a special place in industry. Epoxy resin with high adhesion property, low density, thermal stability and high chemical resistance has a special place as matrix in fabrication of high technology hybrid composites. Hybrid composites, due to its high strength and long fatigue life, used to reinforcing building structures and manufacturing fuselage. Layer and reactive structure near the firm core and wear-resistant of NDs, used to improvement of epoxy reisn and hybrid NanoComposite interphase properties. In this study, for improvement of the properties of hybrid NanoComposites, used the NDs in 0.25, 0.5 and 1 %wt with amine and carboxyl... 

Recognizing people mentioned in the text of narrations, is of the main importance in validating narrations in narration analysis. The problem naturally reduces to two sub-problems: Firstly, named entities related to narrators in the text should be determined. Secondly, if they are ambigous, the purpose of each should be clearified. In this resaerch, it is tried to apply pre-trained language models in soultion of the first sub-problem. For the purpose of entity linking with entities in a KB, graph-based model is suggested  

Flow characteristics analysis over a wing, is one of the pioneer challenges in super and sub-sonic flow near flying objects. Taking into account of growing rate of low aspect ratio utilization, usually called Delta wings, investigation of vortex behavior over this wings is highly noticeable. In addition, the lack of research in this branch of Aerodynamics inside the country, considering it’s critical application, has doubled the importance of doing research in this filled. Experimental researches on super-sonic flow over a Delta wing is limited and there are not much accurate researches about vortexes in this category of wings. In this work, the main effort is to investigate the phenomena in... 

Outsourcing has considerably increased in number, as evident by the literature. Many activities, once being carried out by the organization itself, are now accomplished by contractors. Nowadays, implementing successful outsourcing projects is an important and challenging deal for outsourcer organizations. Such organizations always aim to finish their projects based on a defined scope of time, budget and quality while accepted by the final customer. Managers are trying to use outsourcing strategy more extensively but are faced with various problems in practice. So it’s advantageous to perform a research to identify these difficulties to be able to employ this strategy more efficiently. Due to... 

In recent years, a series of deep connections have been found between the ideas that used to be in the Algebraic Theory of Quantum Fields and the important problems of High Energy and Fundamental Physics. In the 1960s and later, some people who were mostly closer to mathematicians were trying to formulate the basics and principles of Quantum Field Theory in mathematically precise way. Many and various efforts have been made in this direction. One of these important efforts has been the Algebraic Theory of Quantum Fields. The main motivation in the Algebraic Theory of Quantum Fields is to focus on the operators and observables of the theory and study the algebraic structure between them instead... 

The control and management of social networks’ potentials has been an important research subject for many organizations and researchers in recent years. Social network of an organization includes all the people that at least once have established a social relationship with the organization directly or indirectly. This relationship can be formal or informal, spontaneous or controlled, and deep or shallow. But in any case, the stronger the communication between people’s social relationships (as members of that social network) become and the more increases in the number of members of that social network, the easier path to success the organization could achieve. Hence, the critical success... 

A company's knowledge is one of its most valuable assets. In this regard, project-based companies operating temporarily with constantly changing project members try hard to manage their knowledge, an important asset that also provides them with a competitive advantage. One of the biggest challenges of project-based organizations is how to facilitate the processes of sharing knowledge which enables the organization to capture and implement its knowledge successfully. In this study, the governance mechanisms of innovation ecosystems are used to support the effective use of knowledge-sharing mechanisms across projects and subgroups of the organization.This study analyzes Kayson holding as its... 

A company's knowledge is one of its most valuable assets. In this regard, project-based companies operating temporarily with constantly changing project members try hard to manage their knowledge, an important asset that also provides them with a competitive advantage. One of the biggest challenges of project-based organizations is how to facilitate the processes of sharing knowledge which enables the organization to capture and implement its knowledge successfully. In this study, the governance mechanisms of innovation ecosystems are used to support the effective use of knowledge-sharing mechanisms across projects and subgroups of the organization.This study analyzes Kayson holding as its... 

Increased uncertainty in the business environment as well as becoming modern and complicated have made supply chains more vulnerable to environmental disruptions than ever before. Due to their unpredictability, these disruptions can cause irreparable damage to supply chains and threaten their survival. Considering the novelty of the concept of e-commerce retail businesses in Iran, the importance of meeting customer expectations to boost the growth of these businesses, and the existence of many uncertainties in the business environment of these organizations, their supply chain resilience against disruptions is very important. Also, the importance of the role of logistics in meeting the... 

Additive manufacturing (AM) has gained significant attention in recent years as a novel approach to fabricate three-dimensional parts. Its advantages, including high speed, low-cost production for small-scale batches, and greater design freedom, have made it a competitive alternative to traditional manufacturing methods. However, the application of AM for components subjected to fretting fatigue requires careful evaluation. Fretting fatigue is a major cause of failure in turbines, particularly at the contact interface between turbine blade roots and disk. In this study, the influence of AM and post-processing treatments on the fretting fatigue life of Ti-6Al-4V alloy was investigated. Five... 

The main purpose of this research was functionalizing graphene, in order to achieve higher hydrophobicity, and producing nanocomposite of functionalized graphene and titanium dioxide by hydrothermal method, and sequently invastigation on photocatalytic properties of the powders and corrosion properties of EPD coated samples. Graphene oxide was synthesized by improved Hummers method and reduced and sequently was functionalized through the chemical process with hydrazine and octadecylamine respectively. Then the nanocomposite of functionalized graphene-titania was synthesized by use of titanium isopropoxide precursor and its photocatalytic properties were measured. The analysis of the...