3,223 research outputs found

    Studies related to daucic acid

    Get PDF
    Imperial Users onl

    The 2007 Provincial Election and Electoral System Referendum in Ontario

    Get PDF
    Ontario’s general election in Oct. 10, 2007, was unprecedented for several reasons. The election was held on a date fixed by legislation and not one set by the premier or his caucus, something new to Ontario and relatively new to Canadian politics. Turnout declined to 53%, the lowest ever in Ontario history. The incumbent Liberals won a second consecutive majority government, something the party had not achieved since 1937. And finally, the election featured a referendum question that asked voters in Ontario to approve reforms to the electoral system, a proposal that was overwhelmingly rejected. This article explores each of the above-stated elements as they unfolded in the election

    Exit Polling in Canada: An Experiment

    Get PDF
    Although exit polling has not been used to study Canadian elections before, such polls have methodological features that make them a potentially useful complement to data collected through more conventional designs. This paper reports on an experiment with exit polling in one constituency in the 2003 Ontario provincial election. Using student volunteers, a research team at Wilfrid Laurier University conducted an exit poll in the bellwether constituency of Kitchener Centre to assess the feasibility of mounting this kind of study on a broader scale. The experiment was successful in a number of respects. It produced a sample of 653 voters that broadly reflected the partisan character of the constituency, and which can hence be used to shed light on patterns of vote-switching and voter motivations in that constituency. It also yielded insights about best practices in mounting an exit poll in the Ontario context, as well as about the potential for using wireless communication devices to transmit respondent data from the field. The researchers conclude that exit polling on a limited basis (selected constituencies) is feasible, but the costs and logistics associated with this methodology make a province-wide or country-wide study unsupportable at present

    Pt/SnO2-based CO-oxidation catalysts for long-life closed-cycle CO2 lasers

    Get PDF
    Noble-metal/tin-oxide based catalysts such as Pt/SnO2 have been shown to be good catalysts for the efficient oxidation of CO at or near room temperature. These catalysts require a reductive pretreatment and traces of hydrogen or water to exhibit their full activity. Addition of Palladium enhances the activity of these catalysts with about 15 to 20 percent Pt, 4 percent Pd, and the balance SnO2 being an optimum composition. Unfortunately, these catalysts presently exhibit significant decay due in part to CO2 retention, probably as a bicarbonate. Research on minimizing the decay in activity of these catalysts is currently in progress. A proposed mechanism of CO oxidation on Pt/SnO2-based catalysts has been developed and is discussed

    Blurring the boundaries of the Mackintosh room

    Get PDF
    In this paper we describe a prototype interactive systemsupporting a shared synchronous experience for physical,World Wide Web and virtual reality visitors to anexhibition devoted to the designer and architect C.R.Mackintosh. The system provides awareness betweenvisitors that spans multiple media while also providinglocation- and device-sensitive content to each visitor

    Reactivation of a Tin-Oxide-Containing Catalyst

    Get PDF
    The electrons in electric-discharge CO2 lasers cause dissociation of some CO2 into O2 and CO, and attach themselves to electronegative molecules such as O2, forming negative O2 ions, as well as larger negative ion clusters by collisions with CO or other molecules. The decrease in CO2 concentration due to dissociation into CO and O2 will reduce the average repetitively pulsed or continuous wave laser power, even if no disruptive negative ion instabilities occur. Accordingly, it is the primary object of this invention to extend the lifetime of a catalyst used to combine the CO and O2 products formed in a laser discharge. A promising low-temperature catalyst for combining CO and O2 is platinum on tin oxide (Pt/SnO2). First, the catalyst is pretreated by a standard procedure. The pretreatment is considered complete when no measurable quantity of CO2 is given off by the catalyst. After this standard pretreatment, the catalyst is ready for its low-temperature use in the sealed, high-energy, pulsed CO2 laser. However, after about 3,000 minutes of operation, the activity of the catalyst begins to slowly diminish. When the catalyst experiences diminished activity during exposure to the circulating gas stream inside or external to the laser, the heated zone surrounding the catalyst is raised to a temperature between 100 and 400 C. A temperature of 225 C was experimentally found to provide an adequate temperature for reactivation. During this period, the catalyst is still exposed to the circulating gas inside or external to the laser. This constant heating and exposing the catalyst to the laser gas mixture is maintained for an hour. After heating and exposing for an appropriate amount of time, the heated zone around the catalyst is allowed to return to the nominal operating temperature of the CO2 laser. This temperature normally resides in the range of 23 to 100 C. Catalyst activity can be measured as the percentage conversion of CO to CO2. In the specific embodiment described above, the initial steady-state conversion percentage was 70 percent. After four days, this conversion percentage decreased to 67 percent. No decrease in activity is acceptable because the catalyst must maintain its activity for long periods of time. After being subjected to the reactivation process of the present invention, the conversion percentage rose to 77 percent. Such a reactivation not only returned the catalyst to its initial steady state but resulted in a 10-percent improvement over the initial steady state value

    Catalysts for long-life closed-cycle CO2 lasers

    Get PDF
    Long-life, closed-cycle operation of pulsed CO2 lasers requires catalytic CO-O2 recombination both to remove O2, which is formed by discharge-induced CO2 decomposition, and to regenerate CO2. Platinum metal on a tin (IV) oxide substrate (Pt/SnO2) has been found to be an effective catalyst for such recombination in the desired temperature range of 25 to 100 C. This paper presents a description of ongoing research at NASA-LaRC on Pt/SnO2 catalyzed CO-O2 recombination. Included are studies with rare-isotope gases since rare-isotope CO2 is desirable as a laser gas for enhanced atmospheric transmission. Results presented include: (1) achievement of 98% to 100% conversion of a stoichiometric mixture of CO and O2 to CO2 for 318 hours (greater than 1 x 10 to the 6th power seconds), continuous, at a catalyst temperature of 60 C, and (2) development of a technique verified in a 30-hour test, to prevent isotopic scrambling when CO-18 and O-18(2) are reacted in the presence of a common-isotope Pt/Sn O-16(2) catalyst
    • …
    corecore