Thesis (Ph. D.)--University of Michigan, 1915. / Cover title. "Reprinted from the Physical review, n.s., vol. VII, no. 4, April, 1916."

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 111-118). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 111-118). Also available on the Internet.

A. <u>Objectives</u>. After a careful consideration of the problems involved, the writer formulated the following objectives: (1) To determine the variation of lamp characteristics with life for various wave forms. (2) To determine the variation of lamp characteristics with voltage for various wave forms. (3) To attempt to correlate the variation of lamp characteristics to the crest factor of the voltage wave employed. B. <u>Equipment</u>. This investigation was performed on 100 watt, type A21 115-volt lamps manufactured by Sylvania Electric Products Inc. The following information obtained from the lamp manufacturer was used as a basis for all calculations. <u>Initial Lumens</u> 1635 <u>Initial Lumens Per Watt</u> 16.35 <u>Rated Average Hrs. Life</u> 750 The wave forms used were produced by means of a General Electric Sine Wave Generator, Model 15A224, consisting of a 10 horsepower, 3600 rpm, direct current motor directly coupled to five alternators. These alternators produced frequencies of 60, 120, 180, 300, and 420 cycles per second respectively. The output of the alternators were connected in series as desired by means of a specially designed switch board. The alternator fields were excited directly from the output of a 3 phase, half wave, 250 volt, 75 ampere, ignitron manufactured by the Westinghouse Electric Corporation. The value of the lamp intensity in foot-candles were read by means of a Western photronic cell. The photronic cell used was equipped with a visual-correction filter so that its response is closely similar to the visibility curve of the human eye. / Master of Science

Thesis (Magister Technologiae - Discipline Electrical Engineering, Faculty of Engineering) -- Vaal University of Technology / Discomfort glare is a topic that has been investigated for many years without any reasonable explanation regarding its effect on the human visual system. Results of previous research concluded that established methods have a lot of similarities in implementation; but a number of differences when comparing the results of observer's evaluations with the mathematically calculated glare ratings. Therefore, an alternative method of evaluating the influence of exposure to an unshielded light source was investigated to establish a more reliable and realistic response from observers. In order to address the discrepancies of previous evaluation systems concerning observer's varying opinions regarding the level of discomfort experienced, it was decided to investigate the feasibility of evaluating the brain activity of the observers exposed to an unshielded incandescent lamp. This was done in order to facilitate the differences in each individual observer's sensitivity to bright light sources and the influence of personal taste therefore, eliminating the effect of personal interpretation. The main purpose of this study was to determine whether it would be possible to get any response regarding brain functions when an observer is exposed to a bare light source. In order to determine the pathway of visual stimuli it was necessary to investigate the operating principles of the human eye in detail. Because the eye is only an instrument that makes seeing possible; it was also important to investigate the brain and all its different functions. The part of the brain where visual interpretation takes place was indicated as the occipital lobe. This is the part of the brain monitored for any change of functional status by taking measurements with an electroencephalogram (EEG). Measurements were indeed possible; it was presented as a suppression of the alpha brain activity. During the testing procedure it was observed that the observers were not equally photosensitive. There was also a difference in the amount of alpha suppression with the observer's eyes open and closed respectively. Because the alpha rhythm has a tendency to increase with closed eyes it was much easier to notice the suppression.