4 resultados para Light gauge cold-formed steel members

em Brock University, Canada


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The Second U.S. Regiment of Light Dragoons was formed in January 1812. In March of 1814, it merged with the First U.S. Regiment of Light Dragoons to form the Regiment of Light Dragoons.

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Low temperature (77K) linear dichroism spectroscopy was used to characterize pigment orientation changes accompanying the light state transition in the cyanobacterium, Synechococcus sp. pee 6301, and cold-hardening in winter rye (Secale cereale L. cv. Puma). Samples were oriented for spectroscopy using the gel squeezing method (Abdourakhmanov et aI., 1979) and brought to 77K in liquid nitrogen. The linear dichroism (LD) spectra of Synechococcus 6301 phycobilisome/thylakoid membrane fragments cross-linked in light state 1 and light state 2 with glutaraldehyde showed differences in both chlorophyll a and phycobilin orientation. A decrease in the relative amplitude of the 681nm chlorophyll a positive LD peak was observed in membrane fragments in state 2. Reorientation of the phycobilisome (PBS) during the transition to state 2 resulted in an increase in core allophycocyanin absorption parallel to the membrane, and a decrease in rod phycocyanin parallel absorption. This result supports the "spillover" and "PBS detachment" models of the light state transition in PBS-containing organisms, but not the "mobile PBS" model. A model was proposed for PBS reorientation upon transition to state 2, consisting of a tilt in the antenna complex with respect to the membrane plane. Linear dichroism spectra of PBS/thylakoid fragments from the red alga, Porphyridium cruentum, grown in green light (containing relatively more PSI) and red light (containing relatively more PSll) were compared to identify chlorophyll a absorption bands associated with each photosystem. Spectra from red light - grown samples had a larger positive LD signal on the short wavelength side of the 686nm chlorophyll a peak than those from green light - grown fragments. These results support the identification of the difference in linear dichroism seen at 681nm in Synechococcus spectra as a reorientation of PSll chromophores. Linear dichroism spectra were taken of thylakoid membranes isolated from winter rye grown at 20°C (non-hardened) and 5°C (cold-hardened). Differences were seen in the orientation of chlorophyll b relative to chlorophyll a. An increase in parallel absorption was identified at the long-wavelength chlorophyll a absorption peak, along with a decrease in parallel absorption from chlorophyll b chromophores. The same changes in relative pigment orientation were seen in the LD of isolated hardened and non-hardened light-harvesting antenna complexes (LHCII). It was concluded that orientational differences in LHCII pigments were responsible for thylakoid LD differences. Changes in pigment orientation, along with differences observed in long-wavelength absorption and in the overall magnitude of LD in hardened and non-hardened complexes, could be explained by the higher LHCII monomer:oligomer ratio in hardened rye (Huner et ai., 1987) if differences in this ratio affect differential light scattering properties, or fluctuation of chromophore orientation in the isolated LHCII sample.

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Walter D’Arcy Ryan was born in 1870 in Kentville, Nova Scotia. He became the chief of the department of illumination at the General Electric Company of Schenectady, New York. He was a founder in the field of electrical illumination. He built the electric steam scintillator which had numerous nozzles and valves. The operator would release steam through the valves. The nozzles all had names which included: Niagara, fan, snake, plume, column, pinwheel and sunburst. The steam scintillator was combined with projectors, prismatic reflectors, flashers and filters to produce the desired effects. In 1920 a group of businessmen from Niagara Falls, New York formed a group who called themselves the “generators’. They lobbied the American and Canadian governments to improve the illumination of the Falls. They were able to raise $58, 000 for the purchase and installation of 24 arc lights to illuminate the Falls. On February 24th, 1925 the Niagara Falls Illumination Board was formed. Initially, the board had a budget of $28,000 for management, operation and maintenance of the lights. The power was supplied free by the Ontario Power Company. They had 24 lights installed in a row on the Ontario Power Company surge tank which was next to the Refectory in Victoria Park on the Canadian side. The official opening ceremony took place on June 8th, 1925 and included a light parade in Niagara Falls, New York and an international ceremony held in the middle of the Upper Steel Arch Bridge. Walter D’Arcy Ryan was the illuminating engineer and A.D. Dickerson who was his New York field assistant directed the scintillator. with information from American Technological Sublime by David E. Nye and the Niagara Falls info website Location: Brock University Archives Source Information: Subject Headings: Added Entries: 100 Ryan, W. D’A. |q (Walter D’Arcy), |d 1870-1934 610 General Electric Company 650 Lighting, Architectural and decorative 650 Lighting |z New York (State) |z Niagara Falls 700 Dickerson, A.F. 700 Schaffer, J.W. Related material held at other repositories: The Niagara Falls Museum in Niagara Falls, Ontario has a program (pamphlet) dedicating new lighting in 1958 and it has postcards depicting the illumination of the Falls. Some of Ryan’s accomplishments can be seen at The Virtual Museum of the City of San Francisco. Described by: Anne Adams Date: Sept 26,Upper Steel Arch Bridge. Walter D’Arcy Ryan was the illuminating engineer and A.D. Dickerson who was his New York field assistant directed the scintillator. with information from American Technological Sublime by David E. Nye and the Niagara Falls info website

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Transcription: Encampment Plattsburgh My Dear Uncle Nov. 11th 1812 We are making every possible preparation to invade Canada. I have no doubt but we march in six days. From the best information I can get it is not contemplated to attack the Isle aux Noix – We shall take into the field 2500 infantry between 3 & 4 hundred cavalry 25 light artillery & 150 artillerists; of the malitia I have no accurate knowledge there is more than 1000 of them, the number of regular troops is mentioned you may rely on as being nearly correct I cannot state to a man as I have not had an opportunity of being the consolidated returns of the different corps. It is said that a [corps formed?] of volunteers are to join us from Vermont. I think it doubtful I believe that we shall have no great difficulty in going to Montreal as to the ultimate policy of the [act it is?] not my duty to judge. Confidential our troops are raw particularly in loading and firing they are much deficient. The 6th and 15th will be able to act with some considerable ... of precision and accuracy the remaining infantry—badly disciplined. Should any thing [occur?] with me my fate be unfortunate the [little?] property willed me by my grandfather will secure you the amount I owe you. General Dearborn I understand is at Burlington on his way here. Some of the prisoners that were taken at Queenstown have [arrived?] at Montreal probably. [Ensign Rich?] is among them. Several officers here became acquainted with him soon after he received his [two illegible words] & speak highly of him. [Always?] affectionately yours J. E. A. Masters P.S. I shall write you again before we march excuse this [scrawl?] my hand are too cold to write a fair hand we shall have here near [400?] sick that are not able to march J. E. A. Masters The [Hon.?] Josiah Masters [Schaghticoke?] N.Y. N. B. Nov. 13th We have orders to be prepared to march on the 15th at 12 oclock. Our baggage will be contained as much as possible. The officers carry no baggage except what they carry in their knapsacks. I am in fine health and am able [Hand?] most any [illegible word] My love to all affectionately Your nephew J. E. A. Masters