Engineering Commons^™

A Feasibility Analysis Of A Directly Sun-Pumped Carbon Dioxide Laser In Space, Seiichi Morimoto

Dissertations and Theses

The possibility of using sunlight to pump a CW carbon dioxide laser has been analyzed. Such a laser could be of interest for such applications as space communication and power transmission. In order to optically pump CO₂ using sunlight, the intense vibrational-rotational absorption bands of CO₂ in the 4.3 micron spectral region would have to be utilized. The total pumping power from sunlight can be calculated from the known data of the solar spectral irradiance outside the atmosphere and the infrared absorption by carbon dioxide at 4.3 microns. The pumping power is proportional to the collector area of …

The Design And Construction Of A Flashlamp-Pumped Frequency-Doubled Dye Laser Applicable To Long Path Monitoring Of Air Pollutants, Joel Craig Johnson

Dissertations and Theses

The subject of this thesis is the development of a laser light source which could be used in an air pollution monitor to measure the average concentration of sulfur dioxide gas over long paths (>1 km). Many of the problems encountered in designing a long-path pollutant monitor such as instrument cost and reliability, the selection of an optimum spectral region for making the measurement, and light losses due to scattering and turbulence, are considered. The result of these considerations together with a survey of available laser light sources suggested that a frequency-doubled dye laser possessed several advantages over other …

Photogrammetric Digitizing System, Frank Richard Gorshe

Dissertations and Theses

The acquisition of terrain data from aerial photography using digital photogrammetric methods gives the engineer and planner an economical alternative to conventional ground surveys. This paper describes a complete photogrammetric digitizing system developed for the Portland District Army Corps of Engineers. The hardware of the system consists of a

Wild AlO first order stereoplotter interfaced to an Altec AC-74 coordinate digitizer which is interfaced to both a Hewlett Packard 9810A programmable calculator and a Digi-Data nine-track magnetic tape recorder. The software of the system consists of photogrammetric routines developed for online computation by the programmable calculator and a sophisticated FORTRAN …

A Study Of The Effect Of Vibration On The Residual Stresses In A Welded Fabricated Tube, Shantini Ratnathicam

Dissertations and Theses

In many instances the predominant factor contributing to structural failure in welded parts is the residual stress which exists before the part is put into service. In this investigation an attempt is made to study the changes in residual stresses caused by vibrational stress relief (VSR). VSR is a fairly new idea in stress relief and there is no substantial evidence of its success in reducing residual stresses. This thesis documents the residual stress distributions found in 5/16 inch thick, 22 inch diameter welded fabricated tubes after VSR.

Performance Theorems For The Resource Scheduling Functions Of A Multiprocessing System, George Arthur Nicol

Dissertations and Theses

In this dissertation, a multiprocess scheduling model is developed and a set of performance theorems is constructed for the set of scheduling functions associated with the model. Each theorem describes the conditions under which a scheduling function exhibits a particular type of performance.