Browsing by Author "Uddin, Zia"

Now showing 1 - 2 of 2

Determination Of Various Crystallite Parameters For Zno Nanoparticles With Various Compression Temperatures
(Department of Electrical and Electronic Engineering, 2021-05) Uddin, Zia; Uddin, Mohammad Jaber
In this work, ZnO films were made utilizing the standard blade coating procedure at different compression temperatures (50 to 90 °C temperature at 120 MPa compression). The films were characterized using X-ray Diffraction (XRD) techniques. For advanced material characterization, the XRD method is a very powerful state-of-the-art technology. It allows accurate information on crystalline phase structure, crystal orientations (shape and size), and other structural or crystallite parameters such as lattice parameters, stresses, strains, crystallite size, and crystal defects. The XRD data has been analysed using different methods, such as the Modified Scherrer method, Wagner-Agua method (W-A), Halder-Wagner method (H-W), Size-Strain Plot (SSP) method, and the Williamson-Hall (W-H) method. The results were compared to observe the effects of compression temperatures on various crystallite parameters. From the analysis, it is evident that ZnO nanoparticles are crystallite in nature with a hexagonal wurtzite phase. The crystallite size calculated from the SSP and W-A Method matches very well with the crystallite size observed in the Scherrer method and slightly different from the W-H method. The crystallite size is relatively high for the films prepared at 70 °C temperature at 120 MPa pressure for all methods. Moreover, the modified W–H methods were used to determine different elastic parameters. In terms of strain computation, it is significantly lower than the value of other methods. This increase in estimated strain value of the SSP, H-W and W-A methods is actually because of the contribution of low and mid angle XRD data as well as the attribution of lattice dislocations. Among all the methods, the SSP and W-A methods are more accurate and more favoured, since the points fit the linear line much better than in any other techniques. However, changes in various crystallite properties caused by various annealing temperature at 120 MPa pressure are also utilized to explain the performance of the Dye-sensitized solar cells. The photovoltaic performance of the sample at 70 °C temperature compression was shown to be better where the crystallite size was relatively large.
Search and Rescue System for Alive Human Detection by Semi-autonomous Mobile Rescue Robot
(IEEE, 2016-10-28) Uddin, Zia; Islam, Mojaharul
In this modern era, technological development lead the creation of sky scraper buildings and dwellings which increase risks of losing life due to natural and manmade disasters. Many people died by trapping under debris as their presence cannot detect by the rescue team. Sometimes, it is impossible to reach in certain points of the disasters in such calamity hit zones. The situation is worst for developing country like Bangladesh because of low quality design and construction. In this paper, PIR sensor based semi-autonomous mobile rescues robot is developed which can detect live human being from an unreachable point of the disaster area. Joystick and RF technology is used to control the semi-autonomous robot and communicate with control point. Ultrasonic sensor is used for obstacle detection in navigation path of robot and gas sensor is used to detect gas leak inside the building. IP Camera is also integrated to observe and analyze conditions that will facilitate human detection in reliable manner with highest probability of success rate in that kind of situation.