Sharif Digital Repository

In this research, different methods of coating polyaniline on the anode electrode and its performance in a microbial fuel cell, and a chemical method for making polyaniline / graphene catalyst on a cathode electrode and its performance in microbial electrolysis cell electrode were investigated. There are two main goals in this study. First, the production of polyaniline and the comparison of the surface morphology of this fiber with other forms of polyaniline on the surface of the electrode and its effect on the performance of the microbial fuel cell and the second, the production of polyaniline / graphene catalyst in the cathode electrode and its comparison with the platinum catalyst in the... 

Taking into account the impact of advertising on the reference price, we propose an optimal pricing strategy for supply chains in competitive industries subject to reference price effect. Most of researches do not consider the competition among supply chains. An industry with two competing supply chains is considered. Each supply chain includes a manufacturer who sells his/her product via a retailer. There are two types of structures: integrated and decentralized (it is assumed that the relation in a chain is Manufacturer– Stackelberg). Each manufacturer offers wholesale price to his/her retailer anticipating the retailer’s order quantity. In addition, the retailers choose their retail... 

Today, the use of controllable swimmer micro-robots has expanded from micro to macro-scale dimensions due to their many applications. These robots, as a result of their small size and dimensions, have the ability to access limited and complex environments. Considering the various applications of such swimmers, it can be said that in addition to the necessity of well designing and implementation, their maneuverability and controllability are among the most important research areas on these swimmers. Regarding the dimensions and technologies needed for these robots, various methods for designing and implementing them are suggested, which are mostly inspired by the nature of microorganisms. In... 

Today, due to the increasing use of fossil fuel-powered vehicles, attention has been paid to advanced societies by the amount of pollutants emitted by these vehicles and the need to control and reduce them. As the number of cars increases, the volume of data for processing increases, which increases the need for data centers and processing infrastructure with more computing power. Therefore, in this research, we intend to implement a program that continuously categorizes cars according to specific criteria in terms of emission levels. For this purpose we used Apache Storm, a data stream processing framework, to implement the program.In this research, we develop a simulation for cars with the... 

It has been about a century since the introduction of the theory of quantum mechanics. This theory is a branch of physics that describes the behavior of nature in very small scales and microscopic systems . Since no quantum system is entirely isolated from its surroundings , it is necessary to study their interactions with the environment to understand them accurately. The theory of open quantum systems provides the theoretical and conceptual framework needed to consider these interactions. Then using the appropriate quantum operations , the evolution of the combined system can be investigated. Moreover , considering the environmental effects, some quantum features such as dissipation... 

Residential satisfaction plays a pivotal role in shaping liveable cities, profoundly influencing individuals' health and well-being. In contrast, dissatisfaction in living environments often triggers relocation intentions, leading to significant vacancy costs for landlords and property managers. While previous studies predominantly relied on traditional methods like surveys and interviews, our research adopts a novel, bottom-up approach, analysing this phenomenon through the lens of residents themselves. Leveraging a custom-developed Python-based web scraper, we meticulously gathered 195,000 online reviews from apartments.com. This comprehensive dataset spans the most populous cities and... 

In this study, a new finite-element-volume (FEV) arbitrary Lagrangian-Eulerian (ALE) method is suitably extended to simulate the three-phases flows air, liquid water droplets and ice in ice accretion, i.e., over flying object surfaces. This methods benefit from the advantages of both finite-volume and finite-element methods. This method is developed for the first time to simulate three phases turbulent flows. Since the ice formation and growth needs grid movement consistant with ice boundary movement, we have used ALE approach to fulfill this requirment. In this regard, we use the linear spring analogy approach to move the hybrid triangular-rectangular mesh suitably. Facing with a chaotic... 

In this work the transesterification reaction of waste cooking oil in the present of solid catalyst as a type of solid-liquid catalytic reaction, has been studied. For this purpose, two types of alkali solid catalysts were synthesized. CaO-ZrO2 and KOH/γ-Al2O3 catalysts were prepared by co-precipitation and impregnation method, respectively. These catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence (XRF), BET surface area, and temperature programmed desorption of CO2 (TPD-CO2). The obtained results for the CaO-ZrO2 catalysts indicate that with increasing Ca/Zr atomic ratio, the activity of catalysts increases, but the stability... 

Today, with advances in technology and communication equipments, supply chain management plays an important role in different industries. Bullwhip effect is the significant factor which can reduce efficiency of supply chain and increases costs and lead time of services and products to the ultimate customer. In this thesis we have investigated on forecasting method and ordering policy in the bullwhip effect. Basic model based on beer game, moving average, Holt and Brown are 4 models which were studied. Also we defined desired stock and desired stock line which the difference between desired and actual stock and also difference between desired and actual stock line in any period, have...