علیرضا رنجبران

The Chemiluminescence method is considered as one of the most widely spread optical methods which is used for identifying combustion systems. In this study, the CH* and OH* Chemiluminescence signals were measured with the use of PMT detector and other optical equipments for a bunsen burner. Also the effect of equivalence ratio and flow rate on these signals have been investigated. The results show that with increasing flow rate, CH* and OH* signals increase linearly. By changing the equivalence ratio, Chemiluminescence signals were maximized near stoichiometric condition. Therefore, these two types signals can be considered as an the heat release rate indicator and can be used to find the optimal working conditions for any desired burner. It was also shown that OH*/CH* is independent of mass flow rate and only affected by the equivalence ratio.Then, the calibration relationship between equivalene ratio and OH*/CH* signal has been extracted for a certain range of equivalence ratio, which is also true in other combustion condition. Finally, the application of this method has been evaluated to identify the dynamics of combustion systems. The results show that the premixed flames have a dominant peak frequency due to the Kelvin-Helmholtz vortices. In premixed flames, the peak frequency is decreased by increasing the equivalence ratio and the corresponding amplitude increases. Also, with increasing flow rate, the peak frequency is linearly increased and its amplitude decreases linearly. This work shows the potential of using the Chemiluminescence method as an effective tool in the field of experimental identification of combustion systems, as well as for controlling and manitoring the lean of fuel combustion chamber and identifying dynamic combustion phenomena.

The reduction of primary resources and the advancement of technology in the world, tempt the people around the world to share their unused assets through online platforms. Internet has provided an opportunity for users to share their experiences of using these platforms in the form of comments that create brand image in the minds of other users. The purpose of this study is to investigate the effect of user experience on their tendency to create online content and the impact of this content on creating a brand image of the shared economy platform. In terms of purpose, this study is applied and survey in terms of method. In order to do confirmatory factor analysis, structural equation modeling with Amous 22 software is used. Accordingly, 394 people who used the SNAP platform and have shared their experiences on Instagram were selected randomly and standard questionnaire distributed among them. Research shows that customer experience is an important motivating factor for producing content on Instagram, which leads to creating brand image about a sharing-economy platform.