In this paper a solar sun tracking system for two axes solar cell is designed and implemented. The system derived by tow motors controlled by micro-controller. To achieve the sun tracking, three types of sun tracking methods is used. The first one is depending on the location of the tracker system this method requires embedded system, GPS system and mathematical calculation equation. The second type use sensor system to scan the horizontal and vertical axis to find out the locations of the sun and send its data to computing system. The third type is just depending on the time that is determined by computing system to drive the tracker. A data acquisition system and graphical user interface (GUI) software is designed to measuring and plotting all the data of the system. The result is compared with international software tracking program.
In this paper a portable parallel gamma tomography scanner is designed and implemented. The system consists of a fixed base with rotation source and detector derived by two steppers motors and controlled by microcontroller. A data acquisition system is designed to transfer signals from the scanner system to the computer, the scanner is configured and controlled by software with graphical user interface, the data is processed by MATLAB software and the reconstructed image is generated by filtered back projection algorithm. A cylindrical phantom is placed on the center of the fixed base and a projection of 50 lines with 180 angles is taken, the processed data is plotted in two and three dimension graph and the reconstructed image is displayed as an image before and after filtering.
X-ray-computed tomography (CT) has become one of the most important investigation procedures worldwide. The study aimed to assess image quality parameters, mainly noise, and radiation doses during abdominal examination. This study examined the diagnostic parameters (kilo voltage, tube current time product, slice thickness, and pitch) and their effects on image quality as well as the radiation doses received from computed tomography scanners using phantom. The study carried out in four CT centers in Sudan. The study applied prospective and experimental methods. The study demonstrated there was a linear correlation between diagnostic parameters and image noise. The reduction in milli-ampere second and peak kilo voltage increased the image noise. Moreover increasing the pitch led to an increase in the image noise, whereas increasing the slice thickness, reduced the image noise. There was also a linear relationship between kilo voltage and radiation dose at Elnileen diagnostic center characterized by an increase kilo voltages values which led to an increase in the radiation dose by 92% and a reduction in the image noise by 83%. However, at Antalya medical center, increasing in kilo voltage values led to an increase in the radiation dose by 35% and a reduction in the image noise by 26%. Also increasing in milli-ampere second values led to an increase in the radiation dose by 49% and a reduction in the image noise by 46% in a phantom compared with an increase in radiation dose by 82% and a reduction in the image noise by 51% in patients .The study found that an optimal protocol for adult abdominal scan at Antalya medical center was 4.22HU for image noise and 10.45 mGy for radiation dose when using 120 kVp, 300 mAs, 5 mm slice thickness and pitch of 0.8. At Elnileen diagnostic center, however, the optimal protocol was 5.4 HU for image noise and 5.4 mGy for radiation dose using 130 kVp, 50 mAs, 10 mm slice thickness and pitch of 2. In addition, the quality control tests for image quality parameters carried out at the two centers were performed by using the Chat Phan phantom and all the tests were within the acceptable limits, according to Sudan Atomic Energy Commission (SAEC) Standardizations. The study concludes with a number of recommendations, such as; the necessity for an extensive collaboration among manufacturers, radiologists, technologists and physicists to find a plan to decrease patient radiation dose (ALARA Principle) from computed tomography scanner.
