Sharif Digital Repository

The motion of gas bubbles in the bulk of a fluid can be one of the most widely used industrial phenomena. Various factors such as the size and shape of the bubbles, the physical properties of the liquid phase such as density and viscosity, method of gas injection, the presence of impurities, etc. affect this phenomenon. Some of the most important industrial processes that include the motion of bubbles in the liquid phase bulk are gas adsorption, distillation and froth flotation. According to the results of previous studies, the hydrodynamics of bubble motion in the bulk of a liquid fluid depends on the presence of impurities such as surfactants, proteins and colloidal particles. In many... 

Due to population growth, the demand for water supply has increased. This need has drawn attention to the use of consumed and treatable water resources. Organic pollutants are a key source of water pollution. On the other hand, petrochemical oil pollution and frequent oil accidents during oil production or maritime transport have become one of the environmental problems.There are different methods for water and oil separation and water purification that in the present project, selective separation can be achieved by using hydrophobic materials and surface roughness and creating surfaces with two properties: superhydrophobic and ultra-oil friendly. This method is also very effective, cheap... 

Due to the urgent need for early diagnosis of many blood and gastrointestinal diseases, the development and optimization of rapid diagnosis kits is considered important. One of the best ways to make these kits is to use paper microfluidics. The paper platform is inexpensive and compatible with diagnostic processes and can enable rapid and high-sensitivity detection. In the present study, filter paper has been used as the main platform and hydrophobic channels have been created with the help of a hydrophobic marker to guide the fluid on the paper substrate. To perform the detection process, color changes resulting from the aggregation of nanoparticles on the paper are used. In this case, in... 

The advent of nanopore-based sensors based on resitive pulse sensing gave rise to a remarkable breakthrough in the detection and characterization of nanoscale species. The sensors can detect the species’concentration, size, and charge using the resistive pulse characteristics. Some strong correlations have been reported between the resitive pulse characteristics and the particle’s geometrical and physical properties. These correlations are commonly used to obtain information about the particles in commercial devices and research setups. The correlations, however, do not consider the simultaneous effect of influential factors such as particle shape, charge, and off-axis translocation, which... 

In recent years, the effect of the presence of nanoparticles in the tumor in order to increase the benefit of the treatment in radiation therapy has been the focus of many researchers. Although for photon irradiation, a significant dose increase due to the presence of nanoparticles has been observed, in the case of proton irradiation, due to the different nature of the beam and the lower cross-section of protons with metals compared to photons, scattered and in some cases contradictory findings have been published in the articles, and more studies are needed in this field. Due to laboratory limitations, Monte Carlo simulation is an appropriate tool for simulating difficult real-world... 

In this research, it has been tried to use alumina and magnesia nanoparticles to hydroxyapatite nano powder, a three-component coating, with corrosion resistance, adhesion and desirable biocompatibility on the 316 stainless steel substrate, by electrophoretic method. It should be applied at 3 voltages of 10, 30 and 50 volts and for 3 minutes. TEA was used as a dispersing agent and ethanol as a solvent to prepare the suspension. Alumina nano powder was added to nanohydroxyapat in two amounts of 10 and 20% by weight and 20% was optimized as the amount, and magnesia nano powder was added to the composition in three amounts of 1, 3 and 5% by weight, which was 3% by weight of the results Was... 

The World Health Organization's annual statistics show that 83% of wounds are caused by bacterial infections. Diabetic ulcers affect approximately 28 million people worldwide. The use of antibacterial dressings can help control infections. Recent studies have found that electrical stimulation can accelerate wound healing. However, there is still a need for interventions that speed up epithelial tissue formation. New dressings with zinc and silver particles that have electrical activity are being developed, but research on these methods is limited. Zinc oxide nanoparticles have been used as antibacterial agents due to their unique surface properties. This research aims to use these... 

Numerous environmental and industrial applications entail the movement of water and dissolved components like contaminants within aggregated porous media that are characterized by structural, fractured, or macropores in porous media. Over the last few decades, different macroscopic models based on processes have been employed to replicate the transport of contaminants in such environments. A considerable number of these models focus on simulating advective-dispersive transport across relatively extensive inter-aggregate pore domains, with the understanding that interactions within smaller intra-aggregate pores are governed by diffusion. The transfer of nanoparticles between the two domains...