Sharif Digital Repository

Recently, with the expansion of environmental issues and raising of customers' awareness, companies are experiencing huge pressure from shareholders and the government for greater compatibility with their environment. Companies and industry owners must implement green operations in their daily activities to be able to keep up with the competitive atmosphere of the environment. One of the most important operations to be implemented is cooperating with green suppliers. In this study, a multi-objective mathematical model is proposed to select suppliers and allocate optimal orders to them in a two-echelon supply chain, including supply and distribution echelons. The proposed model focuses on the... 

In this study, for the first time, the influence of the nanoporous Zr-based NH2-UiO-66 metal-organic frameworks (MOFs) on the tensile strength and fracture toughness of the epoxy coating was investigated. In addition, the impacts of the UiO particles' functionality (i.e., NH2 or GMA) on the MOFs/epoxy interfacial bonding and nanoparticles dispersion quality in the epoxy resin were examined by the tensile test, dynamic mechanical thermal analysis (DMTA) and field emission-scanning electron microscope (FE-SEM). The NH2-UiO-66 and GMA-UiO-66 MOFs chemical structures were investigated by FT-IR, BET, and FE-SEM approaches. The FE-SEM investigation of the fracture morphology (at the cross-section... 

In order to maintain the production of offshore oil wells, the National Iranian Oil Company periodically services facilities and equipment located in oil wellheads with mobile wellhead servants. It also gives technical supports to oil wellheads and mobile wellhead servants with supporter vessels. Due to supply limitations, there are not enough special vessels (namely supporter vessels and mobile wellhead servants) compared to the number of oil wellheads. The failure of special vessels to service oil wellheads and supporter vessels to technically support mobile wellhead servants based on a predetermined plan, will lead to considerable loss in production performance of oil wells and hence... 

This study explored the conceptualization of socially just teaching in higher education. Participants were English language professors who were studied through a qualitative study. The data collected through interviews and memos were analyzed using inductive thematic analysis. Three themes were extracted: a critical stance, a dialogic and emergent curriculum, and ontological turns. The findings indicated that socially just teaching requires foregrounding the questions of being. Furthermore, the findings revealed that socially just teaching necessitates critiquing othering based on essentialist stereotypes through the contextualized teaching which revolves around cultural recognition,... 

Interacting capillary bundle model has been much attended for modeling of imbibition process, however, how the tube morphology controls the front displacement is not well discussed in the available literature, especially when corner flow of wetting phase is considered. Tubes with non-circular cross-sections were used for simulating imbibition process performed on drained bundle of tubes. Different combinations of the interacting tubes with equilateral triangular, square, and circular cross sections were used in the bundle model to explore the role of capillary morphology. The evolution of displacement front, as well as transient water saturation profiles along the model, were obtained for... 

Designing a novel epoxy composite system with dual self-healing/barrier anti-corrosion functions using graphene oxide (GO) nano-platforms decorated by polypyrrole (PPy) nanoparticles doped with zinc metal ions is the major objective of this research attempt. GO-PPy-Zn nanoplatform was fabricated via one-pot polymerization of pyrrole monomers on GO and two direct/indirect methods of zinc doping. In order to verify the PPy nanoparticles synthesis on GO sheets several analyses such as UV–visible, XPS, HR-TEM and FE-SEM were performed. The epoxy nanocomposite coatings containing GO-PPy and GO-PPy-Zn nanoplatforms were fabricated and applied on carbon steel. The nanocomposite coatings... 

The remediation of nonaqueous phase liquids (NAPLs) enhanced by surfactant and nanoparticles (NP) has been investigated in numerous studies. However, the role of NP-assisted surfactants in the dissolution process is still not well discussed. Besides, there is a lack of empirical dissolution models considering the effects of initial residual saturation Strap, NAPL distribution, and surfactant concentration in NAPL-aqueous phase systems. In this work, micromodel experiments are conducted to quantify mass transfer coefficients for different injected aqueous phases including deionized water, SDS surfactant solutions, and NP-assisted solutions with different levels of concentrations and flow... 

In this study, the Peganum harmala seed extract (PHSE) was used as a green reducing agent of graphene oxide with high deoxygenation capability. PHSE not only acts as a reducing agent of GO due to the high amount of nitrogen-rich compounds but also plays an essential role in the particles' active anti-corrosion performance improvement. In order to add more active inhibition property, the zinc cations were doped successfully on the chemical structure of GO nanosheets, and eventually, the RGO-PHSE-Zn nanocomposite was obtained. The FT-IR results and UV–visible achievements declared that the epoxide (-C-O-C-) functional groups attached to the surface of the GO nanosheets had been successfully... 

For the first time, the UIO-66, NH2-UIO, and NH2-UIO particles covalently functionalized by Glycidyl Methacrylate (GMA@NH2-UIO), were utilized as the novel functional anti-corrosive fillers. The functionality, high surface area, phase composition, excellent thermal properties as well as chemical stability of the Zr-MOFs were proved by FT-IR, BET, XRD, TGA, and water stability tests, respectively. The smart pH-sensitive controlled-release activity of the corrosion inhibitors (i.e., Zr ions and organic compounds) from the prepared Zr-MOFs was proved by the water stability test of the Zr-MOFs particles in the acidic (pH = 2), neutral (pH = 7.5), and alkaline (pH = 12) solutions containing 3.5...