Sharif Digital Repository

Despite ongoing progress in the field of nanophotonics, characterizing and identifying optical interactions in the deep subwavelength dimensions have remained challenging. The inability of conventional optical microscopy in nanoscale imaging, due to diffraction limit, was the main stimulus for research on new characterizing methods with the capability of non-destructive high-resolution imaging in which the sample preparation is not required. To achieve this goal, scanning probe microscopes are introduced to extract valuable high spatial harmonics from near field measurements on the sample. In this thesis, by focusing on the probe-sample interaction, the near field behavior of the plasmonic... 

Cancer is the second leading cause of death among humans as one of the major human concerns. More than 500,000 people die of cancer each year in the United States alone. Cancer mortality is mainly due to cancer metastasis. Metastasis is the escape of cancer cells from a primary tumor, the circulation of cells in the circulatory system (CTSs), the penetration of/from vessel wall, and the formation of a secondary tumor. It is still not clear how the cells survive in the circulatory system, along with the mechanical pressures and stresses that exist in the body's capillary channals. In this study, a microcirculation model for circulating cells with barriers was designed and constructed by the... 

Isolation and characterization of circulating tumor cells (CTCs) found in blood samples of cancer patients have been considered as a reliable source for cancer prognosis and diagnosis. A new continuous microfluidic platform has been designed in this investigation for simultaneous capture and characterization of CTCs based on their deformability. The deformability-based chip (D-Chip) consists of two sections of separation and characterization where slanted weirs with a gap of 7 μm were considered. Although sometimes CTCs and leukocytes have the same size, the deformability differs in such a way that can be exploited for enrichment purposes. MCF7 and MDA-MB-231 cell lines were used for the... 

Today, lots of vulnerabilities are discovered by researchers who are analyzing the software. Some researchers study these discovered vulnerabilities and find new ones that are similar to them. So they need to first characterize each previously discovered vulnerability and extract the vulnerable context of the program, then extract new vulnerabilities based on that. Some vulnerabilities are emerging because of developer mistakes in the implementation phase. Software developers use different function calls to do the goal of the program. Incorrect invocation for functions can lead to critical vulnerabilities. Our investigation shows that the root cause for some vulnerabilities is incorrect... 

In this research, aluminum titanate or tialite with the chemical composition of Al2TiO5 was synthesized as nanostructured form using the sol-gel method with the aim to serve as a chemical source for aluminum and titanium elements within the fabrication of in-situ Al2O3-Al3Ti-reinforced aluminum matrix nanocomposites. Since the aforementioned nanocomposite is produced based on the thermal decomposition of tialite, the thermar decomposition of this material in air atmosphere, under applied mechanical strain, and direct contact with the underlying aluminum was comprehensively evaluated. The empirical results showed that as tialite is exposed to aluminium, the reaction starts from low...