Edit Thesis A study of mass transfer into a liquid falling film in spiral tubes using CO2- water system.

Sarmad Safaa Salim
Dr. Jabir S. Aziz

Abstract: Microwave link is one of several transmission media in modern telecommunications networks; it provides reliable data transfer in a wide variety of systems such as GSM, WLL, televisions and many other applications that need data transfer with reliable transfer rate and bandwidth. This thesis studies the point-to-point, line-of-sight microwave links design and the effective parameters on link performance. It presents the diffraction losses due to obstacles within the first Fresnel zone of a link. Normally, point to point microwave links are running through the low atmosphere where terrain varies such that it could obstruct the link. So, one of the important parts in microwave link design is where to locate the transmitter and receiver endpoints such that the line of sight exists and first Fresnel zone is clear. To meet this condition without site survey, this thesis presents another testing method based on making use of Digital Elevation Model (DEM) database. DEM files are digital maps produced by United State Geographical Survey (USGS). In DEM, elevation data are given for a specific sector of earth surface in standard form enabling automation of extracting these data. Thus, proposed application software had been built to extract elevation data from DEM for the proposed link line and determine the path profile. This software, given a name of Radio Link Performance Analysis (RLPA), was designed to be applicable by wide range of users by supporting it with visual, simple and easy-to-use windows. Using RLPA software doesn’t need prior wide knowledge of radio propagation concepts as it is testing, then telling about the existence of LOS and the clearance of first Fresnel zone. A design case study example is also presented and the results are tested by comparing it to Orbit Design copyrighted software named “RadioLink V5.0” that’s capable of opening and processing the DEM files for the same targets. The comparison shows an acceptable matching between the results of both softwares. RLPA was built in Visual Basic V.7 which provides suitable environments to design application and user interface.