Calculation of the optical conductivity for the Anderson impurity model using the slave boson technique

The optical conductivity of the Anderson impurity mode l has been calculated by emp l oying the slave boson technique and an expansion in powers of l i N, where N is the d egeneracy o f the f electron level . This method has been used to find the effective mass of the conduction electrons for temperatures above and below the Kondo tempera ture. For low temperatures, the mass enhancement is f ound to be large while a t high t emperatures, the mass enhancement is sma ll. The conductivity i s f ound to be Drude like with frequency dependent effective mass and scattering time for low independent effective mass and temperatures and scattering time f requency for high t emperatures. The behavior of both the effective mass and the conductivity is in qualitative agreement with experimental r esul t s .

Letter - A. Monro Grier to W.B. Rankine, 20 March 1902

A letter from A. M. Grier to W.B. Rankine referencing the purchase of granite for the "Tunnel Portal Lining". Grier discusses the purchase of granite with MacIntosh Granite and Marble Company for Stanstead Granite. Grier also discusses a wire sent to a Mr. Brock in regards to the purchase and supply of granite for the project.

John Edminster letter, July 19, 1850

John Edminster was a Baptist missionary born in Cato, New York, in 1820. He was ordained a Pastor in Birmingham, PA, in 1842. He served as Pastor in White Deer, Clinton, Muncy, Derry, Moreland, and Madison, PA. In 1850, he moved to Oregon, Illinois, and established two churches there. He later served at several churches in Iowa, eventually becoming Pastor at Stillman Valley Church and residing at Hale, Ogle Co., Illinois.

Stelco records, 1951-1989

The Steel Company of Canada (Stelco) was formed in 1910 with the incorporation of the Canada Screw Co. Ltd., the Montreal Rolling Mills Co., the Dominion Wire Manufacturing Co. Ltd., the Hamilton Steel and Iron Co. Ltd., and the Canada Bolt and Nut Co. Ltd. By the 1920s, the company was the largest producer of steel ingots in Canada. The 1930s saw continued success and expansion of the company as Stelco increased its iron and steel capacity by 50 percent. The company continued to prosper throughout the next several decades, with sales revenues exceeding one billion dollars in 1974. In 1980, the company officially changed its name to Stelco, in order to simplify its name in both the French and English language. The company began to experience financial difficulties beginning with the recession in 1982. The troubles persisted for the next 25 years as a result of a decreased demand for steel, labour disputes, and high steel imports. In 2004, Stelco entered bankruptcy protection. By 2007, Stelco had lost $240 million in its first four quarters after emerging from bankruptcy protection. That same year Stelco was purchased by the United States Steel Corp. Despite efforts to restructure the company, bankruptcy was again declared in 2014.

Receipt from T. Baxter

Receipt from T. Baxter regarding payment for strong wire work, May 4, 1876.

Receipt from M.Y. Keating, St. Catharines

Receipt from M.Y. Keating, St. Catharines for picture hooks and wire, March 25, 1887.