Sharif Digital Repository

Interpreting data of infrastructures monitored to detect damage of a structural is one of the most challenging issues of structural health monitoring (SHM). Especially, when environmental factors such as temperature, wind and humidity affect the data and the situation become more complicated. In this study, two methods of analysis free model of moving principal components analysis (MPCA) and robust regression analysis (RRA) have recently been considered for monitoring infrastructures compared with a variety of methods of data interpretation and results are presented. In this study, the performance of different ways in different loading conditions and arrangement of sensors have been... 

The vital and influential role of railways in the socio-economic growth and development of countries, along with the high costs of rehabilitation and maintenance of its infrastructure, has made the existence of a comprehensive maintenance management system a necessity to not only elevate the level of service, reliability, and safety but also to minimize such repair costs. Accurate modeling of track deterioration is essential as one of the components of such systems.In this study, a large database from outputs of EM120, track recording machine, was provided for the years 2009 to 2018 and for all 18 railway zones of Iranian Railways (approximately 13,000 km railway track and 80 GB of data).... 

This research is focused on fabrication of TiO2 layers by electrophoretic deposition (EPD) for application as photoanode in Dye Sensitized Solar Cell (DSC). DSCs are third generation of solar cells, also known as the Grätzel cell, after its inventor Michael Grätzel. A DSC is composed of a porous layer of wide band gap semiconductor such as TiO2 and ZnO, covered with a molecular dye that absorbs sunlight, and a counter electrode contacted by a liquid redox electrolyte. Dye Sensitized semiconductor (photoanode) has important role in conversion of photon to electricity. To achieve higher efficiency, preparation of photoanode with high surface area resulted to enough dye adsorption is necessary.... 

The aim ofthis work is constructing a dye laser pumped in visible spectrum by a second harmonic of aNd:YAG laser.For this purpose, 12mJ of its energy focused by a cylendrical lens into a dye cell. Instead of usual telescope, making aberration in two dimensions, we have used multi prism beam expander to eliminate aberration and also expand beam beyond 10 times. The more magnification resulted in narrowing laser linewidth and it was about 2 nm for two prism beam expander and 0.5 nm for four prism beam expander.
Beam expander configurations were designed in zero dispersioncondition.Therefore,scanning laser spectrum becomes possible. The wavelength was scanned between 565 nm to595 nm, and... 

Morphing has traditionally been referred to geometric changes made to an aircraft parts and components to enhance its performance or stability. Though, the morphing concept has today developed to a broader scale and covers more than pure configuration or geometric changes. Due to importance and increasing role of HALE aircrafts in reconnaissance missions, their morphing has been recently focused by researchers. Of course, aside from its potential benefits, utility of morphing technology will increase aircraft system complexities and weight that need to be studied and compromised in design process. The present work studies optimal morphing of a HALE UAV by simultaneous analysis of... 

The main idea of this investigation is to increase heat transfer rate by increasing flow circulation of working fluid. By placing additional branches in the evaporator section, secondary bubble pumps were created which improved the circulation of fluid inside PHP. This research was implemented in two distinct phases. In the first phase, the novelty was implemented on a single turn PHP and in the second phase, the same procedure was implemented on a 4-turn PHP. In order to investigate the impact of these additional branches, two similar heat pipes were fabricated. One of them was the conventional PHP and the other had additional branches and is named additional branch PHP (AB-PHP). Thermal... 

In this research, we focus on study and fabrication of organic inorganic solar cells. We use and optimize various methods such as one-step spin-coating, two-step sequential deposition and vapor-assisted solution process (VASP), to prepare high quality perovskite films. One-step deposition is simplest method for deposition of perovskite films. Although perovskite deposition by this method is very simple, the control of uniformity and surface film morphology is difficult. Chlorine inclusion, optimization of annealing conditions, and a sequential solution-based deposition method have been demonstrated to increase film coverage and uniformity. Hence, we use sequential deposition method for...