An aid to the development of Botswana's resources: Section on hydrology

The author has identified the following significant results. It is proved that FCC's can be used for a simple estimate of the total evaportranspiring area of the Okavango Delta, sufficiently accurate for preliminary inputs for the development of mathematical model of the surface hydrology of the delta. The color coded matrix has shown as interesting inverse correlation with an array on the same grid prepared by ecologists from air photography study, for percent liable to flood

An aid to the development of Botswana's resources

There are no author-identified significant results in this report

Development of processes for the production of solar grade silicon from halides and alkali metals, phase 1 and phase 2

High temperature reactions of silicon halides with alkali metals for the production of solar grade silicon are described. Product separation and collection processes were evaluated, measure heat release parameters for scaling purposes and effects of reactants and/or products on materials of reactor construction were determined, and preliminary engineering and economic analysis of a scaled up process were made. The feasibility of the basic process to make and collect silicon was demonstrated. The jet impaction/separation process was demonstrated to be a purification process. The rate at which gas phase species from silicon particle precursors, the time required for silane decomposition to produce particles, and the competing rate of growth of silicon seed particles injected into a decomposing silane environment were determined. The extent of silane decomposition as a function of residence time, temperature, and pressure was measured by infrared absorption spectroscopy. A simplistic model is presented to explain the growth of silicon in a decomposing silane enviroment

The Physical and Symbolic Functions of the U.S.-Mexico Border Wall

Nation-states across the world continuously construct thick barriers, wire fences, and inventive fortifications along their borders due to a variety of reasons. In response to this global trend, Reece Jones answers this question in his article “Why Do States Build Walls?” by offering three main reasons states build border walls: the establishment of national sovereignty, the protection of national wealth, and the protection of national culture. This thesis responds to the article by analyzing two distinct functions of modern border walls, the physical and the symbolic functions. I examine each of these functions within the context of the U.S.-Mexico Border Wall using existing research by political theorists and political geographers. When discussing the establishment of national sovereignty through the construction of the U.S.-Mexico Border Wall, I find that the wall does physically and symbolically divide the two states of Mexico and the United States, yet cannot successfully control migration across the border. The U.S.-Mexico Border Wall struggles to control smuggling through its physical function. However, it symbolically protects national wealth by creating a distinction between the global north (United States) and the global south (Mexico). The solely symbolic function of the border wall in protecting the national wealth is intentional as the U.S. economy actually depends on migrant works in order to be successful. Finally, the U.S.-Mexico Border Wall is able to protect the national culture where it divides sister cities physically, but symbolically it defines who is included and excluded in American culture. Overall, I find that while the U.S.-Mexico Border Wall expresses both functions, neither function is substantial enough to warrant the cost of construction and upkeep of the border wall