Physics Commons^™

A Rotating Aperture Mask For Small Telescopes, Edward L. Foley

Master's Theses

Observing the dynamic interaction between stars and their close stellar neighbors is key to establishing the stars’ orbits, masses, and other properties. Our ability to visually discriminate nearby stars is limited by the power of our telescopes, posing a challenge to astronomers at small observatories that contribute to binary star surveys. Masks placed at the telescope aperture promise to augment the resolving power of telescopes of all sizes, but many of these masks must be manually and repetitively reoriented about the optical axis to achieve their full benefits. This paper introduces a design concept for a mask rotation mechanism that …

Point-Spread Function Assessment Of Sg-Dbr Based Swept Source For Oct Imaging, David Wilkey Gilbert

Master's Theses

Swept Source Optical Coherence Tomography (SS-OCT) is a medical imaging technique that requires high repetition rate, widely-tunable coherent laser sources. Sampled grating distributed Bragg reflector (SG-DBR) lasers are proven in telecom applications and are expected to fulfill the requirements for SS-OCT at a significantly lower cost than alternative solutions.

Constructed entirely on a semiconductor substrate, SG-DBR lasers require four synchronized waveforms to modulate the output wavelength and intensity. Because of this unique tuning mechanism, there are a number of systematic and noise sources that can affect the quality of the OCT point-spread function (PSF). Based on these noise sources, software …

An Investigation Of The Thermo- And Action- Electric Properties Of Molybdenite, William Otis Johnson

Master's Theses

Considerable work has been done on various mineral substances and chemical compounds within recent years to ascertain, if possible, whether the substance possessed any degree of photo- or thermos-sensitivity; and, to determine the characteristics of these responses. Among the most prominent substances which have been tested are selenium, bismuth, antimony, hematite, stibnite, and molybdenite. It was the purpose of this investigation to summarize the phenomena that have occurred within samples of molybdenite under a variety of conditions involving heat, light, and e.m.f.

The Three-Point Gap As A Means Of Control In Instantaneous Photography, Elgin Albert Denio

Master's Theses

In 1926, Wynn Williams investigated the theory of the three-point gap, which phenomenon had been known and utilized for some time but until his investigation was not understood theoretically. This investigation has been divided into two distinct parts: First, when the energy was generated by a large Toepler-Holtz station machine; and second when the energy was generated by a one-kilowatt, 25,000 volt transformer.

Actino- And Thermo- Response Of Molybdenite In Vacuo With Various Colored Lights., John H. Fulton

Master's Theses

The purposes of this investigation are to study the reaction of molybdenite cells to light of various colors while in vacuo and at various temperatures. The samples of molybdenite were also subjected to radiant heat in the last part of the experiment, which was undertaken to determine to some extent the amount of thermos-electric effect which was due to thermal radiation in the first part of the investigation.

A Study Of The Striated Spark By The Method Of Instantaneous Photography, Laurence L. Cruise

Master's Theses

In 1867 Toepler found the existence of a pulse spreading from the region around the spark immediately after it had passed. Since the density of the air in the pulse differs from that of the surrounding gas, the pulse is optically different from the rest of the field and so can be made visible by the “Shadowgraph Method.” Topeler’s work was the first of its kind where an instantaneous view, say of the order of several millionths of a second, of the electric spark was obtained. IN 1926 Dr. Zinszer, while studying the life history of the electric spark by …