Sharif Digital Repository

As you know, the behavior factor is one of the important parameters and values for calculating earthquake force and base cutting in the building. In this research, the effect of coefficient of behavior (R) on metal structures has been investigated. For this purpose, we selected a metal structure with an average bending frame and dual system with shear wall and examined it. To determining the effect of this coefficient on different structures, we modeled the structures with regular and irregular plans. Considering the structure height effect and also the type of soil on the site of the proposed structure to the factor and refractive coefficient (B) and its direct impact on the magnitude of... 

Accurate classification of chest radiography images and retrieval of relevant medical reports have become significant challenges in the medical field due to the shortage of radiology specialists and the continuous increase in medical image volumes. The importance of this issue is highlighted by the direct impact that delays in diagnosing cardiac and pulmonary diseases have on public health. Key applications of this area include automatic and precise disease classification, accelerated generation of medical reports, and the development of intelligent systems to support clinical decision-making, especially in resource-limited areas. Existing methods primarily utilize either image or text data... 

Opportunistic networks are special ad-hoc networks in which nodes exploit any opportunisty of pairwise contact to forward packets, without requiring any fixed infrastructures. Routing in Opportunistic Networks due to intermittently connected, non-existence an end to end path between source and destination and with a dynamic topology is a challenging issue. There are several different routing approaches in deliver packets from source to destinations. This approaches can be divided into four categories: awareness approaches, Non-Awareness, direct Delivery and coding based. Use of awareness approaches can be more improved routing process. This category consists of two parts: Context-Aware and... 

In the 1950s, Abrikosov predicted the mixed state in superconductors (type II superconductors) which lead to a Noble Prize in 2003 with the experimental verification by shubnikov. Mixed-state is a network of magnetic flux lines with quantized flux (vortices) in superconductors. High-temperature superconductors are of Type II which the existense of vortices in a significant part of the temperature-field phase diagram of them, is an obvious phenomenon. These superconductors provided a proper context for understanding physical phenomena related to vortices and access to experimental data to compare with those provided by statistical mechanics. Vortices can move inside the superconductor by the... 

One of the novel methods of stabilization of nuclear waste is the use of vitrification technology. In order to stabilize high level wastes (HLLW) in glass, it is required that the elements are in their oxide form. Therefore, it is necessary to evaporate the waste and turn it into a solid form so that the elements can be converted into oxide form in the calcination furnace. Hence, one of the challenges of stabilization is the optimization of evaporation and calcination conditions. In this research, the parameters affecting evaporation were first investigated. Using laboratory measurements of application: temperature (110 to 180 °C), presence of nitric acid (0.5 to 4 mol/L), ratio of zirconium... 

This study used the emulsion liquid membrane method to investigate the extraction and separation of thorium from nitrate solution. According to the results obtained from the studies, Cyanex 272 was a suitable option for selectively extracting thorium. For simultaneous extraction and stripping of thorium from dilute aqueous solutions, an emulsion liquid membrane system consisting of Cyanex 272 as an extractant, Span 80 as a surfactant and sulfuric acid solution as a receiving phase (internal phase) was used. Emulsion liquid membrane method has high mass transfer flux due to high surface to volume ratio, which causes high extraction efficiency and fast transfer of thorium ions from its low... 

One of the most common spinal surgeries involves spinal fusion or vertebral fixation, which is used to treat various conditions such as intervertebral disc disease, scoliosis (lateral deviation of the spinal column), fractures, infections, or the presence of tumors in the spinal column. In this surgical procedure, the use of pedicle screws and titanium rods prevents motion and friction between two vertebrae. Screws may enter the vertebrae in the wrong position and angle, causing bone weakening, rupture of nerve roots or blood vessels, weakness or lack of sensation in some parts of the body, spinal cord injury, and in severe cases, paralysis of the patient. For this reason, fusion surgery is... 

Lithium is a soft, silvery-white alkali metal that is recognized as the lightest metal and the least dense solid element. The increasing demand for lithium, driven by the global shift towards electrification and sustainable energy solutions, has transformed this material into a crucial resource in the modern economy. Lithium has applications in various industries, including the nuclear industry. 6Li is used for the production of tritium, and 7Li, in the form of 7LiOH, is used to adjust the pH in light water reactors and as an anti-corrosion compound in fission reactors. In this study, the extraction of lithium from the aqueous phase using a Y-shaped microchannel was carried out, and the mass...