Air Ducts

Air duct running along the utilities tunnel.

Surface effect ferromagnetism in pure and reduced strontium titanate

A room temperature ferromagnetic hysteresis is observed in single crystal strontium titanate substrates as purchased from several manufacturers. It was found that polishing all sides of the substrates removed this observed hysteresis, suggesting that the origin of the ferromagnetic behavior resides on the surface of the substrates. X-ray diffraction and energy dispersive x-ray spectra were measured however they were unable to detect any impurity phases. In similar semiconducting oxides it was previously suggested that ferromagnetism could originate in oxygen vacancies or from disorder within the single crystal. To this end substrates were annealed in both air and vacuum in a range of temperatures (600°C to 1100°G) to both create bulk oxygen vacancies and to heal surface damage. Annealing in vacuum was found to create a measureable number of oxygen vacancies however their creation could not be correlated to the ferromagnetic signal of the substrate. Annealing in air was found to effect the remnant moment of the substrate as well as the width of the x-ray diffraction peaks on the unpolished face, weakly suggesting a relation between surface based disorder and ferromagnetism. Argon ion bombardment was employed to create a layer of surface disorder in the polished crystal, however it was not found to induce ferromagnetism. It was found that acid etching was sufficient to remove the ferromagnetism from as purchased samples and similarly simulated handling with stainless steel tweezers was sufficient to re-create the ferromagnetism. It is suggested that the origin of this ferromagnetism in SrTi03 is surface contaminants (mainly iron).

The use of lichens as indicators of ambient air quality in Southern Ontario

The inverse relationship between arboreal lichen species richness and sulphur dioxide in ambient air has been thoroughly documented in the literature. Previous work in southern Ontario has shown that lichen bioindication can identify areas of potential concern regarding air quality. The EMAN suite of l i chens was applied in the City of Samia by surveying 458 Sugar Maple trees, in order to test the applicability of lichen bioindication under conditions of high mean S02 levels and high species richness values. The results of the survey were explored using Geographic Information Systems. A spatial relationship between lichen community variables, the Bluewater Bridge and the highway was identified. Lichen species richness, lichen percent cover and Index of Atmospheric Purity values were higher along the bridge and highway. No strong gradients were found between other known pollution sources and no lichen deserts were identified. The most common community grouping consisted of Physcia millegrana Degel, Candelaria concolor (Dicks) B. Stein, Physcia aipolia (Ehrh ex Humb.) Furnrohr; all of which are known nitrophytes. The relationship between substrate pH and lichen species richness was examined. Sites with a known source of anthropogenic chemical contamination were found to have a correlation of l=0.8 between lichen species richness and pH. The inverse was found for sites with no known source of contamination with a correlation of r 2 =-0.72. The findings suggest that species richness may be influenced by altering substrate pH which promotes the growth of nitrophytic species capable of tolerating high S02 levels.

The Effects of Annealing URu2Si2 on the Resistivity and Meissner Effect

The enigmatic heavy fermion URu2Si2, which is the subject of this thesis, has attracted intensive theoretical and experimental research since 1984 when it was firstly reported by Schlabitz et al. at a conference [1]. The previous bulk property measurements clearly showed that one second order phase transition occurs at the Hidden Order temperature THO ≈ 17.5 K and another second order phase transition, the superconducting transition, occurs at Tc ≈ 1 K. Though twenty eight years have passed, the mechanisms behind these two phase transitions are still not clear to researchers. Perfect crystals do not exist. Different kinds of crystal defects can have considerable effects on the crystalline properties. Some of these defects can be eliminated, and hence the crystalline quality improved, by annealing. Previous publications showed that some bulk properties of URu2Si2 exhibited significant differences between as-grown samples and annealed samples. The present study shows that the annealing of URu2Si2 has some considerable effects on the resistivity and the DC magnetization. The effects of annealing on the resistivity are characterized by examining how the Residual Resistivity Ratio (RRR), the fitting parameters to an expression for the temperature dependence of the resistivity, the temperatures of the local maximum and local minimum of the resistivity at the Hidden Order phase transition and the Hidden Order Transition Width ∆THO change after annealing. The plots of one key fitting parameter, the onset temperature of the Hidden Order transition and ∆THO vs RRR are compared with those of Matsuda et al. [2]. Different media used to mount samples have some impact on how effectively the samples are cooled because the media have different thermal conductivity. The DC magnetization around the superconducting transition is presented for one unannealed sample under fields of 25 Oe and 50 Oe and one annealed sample under fields of 0 Oe and 25 Oe. The DC field dependent magnetization of the annealed Sample1-1 shows a typical field dependence of a Type-II superconductor. The lower critical field Hc1 is relatively high, which may be due to flux pinning by the crystal defects.

"Flying High" - Air Canada and Inniskillin

A media release announcing Air Canada's use of "Inniskillin's 1978 Chardonnay on all first class domestic flights". The announcement describes the process of making the wine and the flavour. Also included is a 1978 Chardonnay label.

Cuban Tourist Commission Air Certificate, 1955

A certificate from the Cuban Tourist Commission "in recognition of his success in crossing the Channel to Cuba from the United States in the Sixth Annual All Women International Air Race". The certificate was awarded to Dorothy Rungeling on July 11, 1955.

9th Annual All Woman Transcontinental Air Race Program, 1955

An official program from the 9th Annual All Woman Transcontinental Air Race, July 2-6 1955, Long Beach, California - Springfield, Massachusetts. Mrs. Dorothy Rungeling is number 36 in the program. Many of the female pilots have signed their profiles in the program for Mrs. Rungeling.

Article - "Dorothy Rungeling Enters "Powder Puff" Air Derby, 1958

An article about Dorothy Rungeling in her third Derby competition in 1958. She will be co-piloted by Miss Susan Koch and the route will take them from San Diego, California to Charleston, South Carolina.

The Confederate Air Corps Certificate, 1958

A certificate from The Confederate Air Corps that reads, "To all who shall see these presents, greeting: Know yes, that in recognition of his having manifested an unusually high regard for black-eyed peas, turnip greens, hog jowl, sow belly, pot likkers, grits, chittlins, and good old corn squeezins, Dorothy Rungeling is, as of this date, hereby appointed to the rank of Colonel in the Confederate Air Corps. This officer will, by virtue of this appointment, therefore, be obliged to carefully and diligently discharge the duties of the office to which appointed by doing and performing all manner of things thereunto belonging. As evidence of his good faith in accepting this commission, the officer named herein will continue to praise the glories of the Deep South, consume a true gentleman's share of the fares mentioned above, pay respectful homage to our lovely Southern Belles, save his Confederate money, harass the carpetbaggers, and always remember that damnyankee is one word. As Secretary of this Corps, I strictly charge and require all officers of the air militia of the South to render such obedience and courtesies as are due an Officer of this distinguished rank and honored position. Done at the City of Montgomery, Alabama, the Cradle of the Confederacy, this Seventh day of July in the year One Thousand Nine Hundred and Fifty Eight." It is stamped with the name Thadeus P. Throckmorton - Secretary, Confederate Air Corps.

1963 Annual All Women's International Air Race Program

A program for the 1963 Annual All Women's International Air Race from Welland, Ontario, Canada to Hollywood-by-the-Sea, Florida. The race took place May 28-29-30 and was sponsored by the Hollywood-By-The-Sea, Florida, Chamber of Commerce and the Florida Women Pilots Association, Inc.

Article - "Canadians in Air Race", 1951

An article clipping discussing the four Canadian women entered in the third annual All Women's International Air Race in 1951.

Third Annual All-Women's International Air Race Flight Log, 1951

A chart of Dorothy Rungeling's flight landings and departures during the Third Annual All-Women's International Air Race in 1951.