1,756 research outputs found

    Synthesis of perbromates

    Get PDF
    Salts of heptavalent bromine were synthesized by a hot atom process, the beta decay of radioactive selenium-83 incorporated into a selenate. Formation of an unreactive perbromate ion led to preparation of macro amounts of perborate. A rubidium salt was isolated

    Simultaneous dehydrogenation of organic compounds and hydrogen removal by hydride forming alloys

    Get PDF
    The applicability of hydrogen-absorbing metals in dehydrogenation reactions was investigated. Based on thermodynamic considerations, operating ranges were defined within which an increase of the reactant c onversion can be achieved owing to an in situ hydrogen removal by the alloy. Low plateau pressures (e.g. < 0.01 MPa) at high temperature (e.g. > 473 K) are required for economic applications. An (economic) improvement of the alkane-to-alkene conversion does not seem feasible owing to the extreme pressure and temperature conditions. In the present study as a model system, 2-propanol was dehydrogenated in a batch process at 473 K and 0.1-1.0 MPa over a Cu/CuO catalyst in the presence of an excess amount of Mg2.4Ni. The hydride forming metal alloy appears to be able to affect the hydrogen balance of the experimental system owing to absorption or desorption. However, an unexpected catalytic effect of the metal hydride was observed towards condensation reactions. Owing to the loss in selectivity, Mg2.4Ni, is not applicable for an improvement of the dehydrogenation processes for secondary alcohols

    Grammar and cognitive processing of news articles: exploring dual-processing theories

    Get PDF
    Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 17, 2010).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Thesis advisor: Dr. Paul Bolls.Includes bibliographical references.M.A. University of Missouri--Columbia 2009.Dissertations, Academic -- University of Missouri--Columbia -- Journalism.This study considers the impact of grammatical errors on cognitive processing and subsequent evaluation of news articles. It begins with an examination of the Elaboration Likelihood Model, the Heuristic-Systematic Processing Model, and grammar-related research. An experiment then tests the impact of grammatical errors on measures of cognitive processing. Participants read articles with varying levels of grammatical error and answer questions to reveal cognitive processing. The results show that grammatical errors in news articles are associated with high mental effort, low retention, and low perceived credibility. These measures indicate that grammatical errors are associated with deep processing of news articles. This study recommends that journalists focus more of their attention on fixing grammatical errors, as doing so will provide a better service to their readers

    A production trial with layers of four hybrids under different environmental conditions in the Eastern Province of Saudi Arabia.

    Get PDF
    161 Australorp X Rhode Island Red (RIR) X New Hampshire (NH) and 166 White Leghorn (WL) imported fowls were kept in insulated housing; 161 Australorp X RIR X NH, 166 WL, 154 RIR X WL and 148 RIR X NH X RIR fowls were kept in open houses. In the 6 groups resp., live weight at 126 days of age averaged 1602, 1227, 1578, 1234, 1397 and 1539 g, food consumption 4.02, 4.49, 4.03, 4.47, 4.25 and 4.17 kg/kg gain, overall laying percentage 56.6, 56.4, 52.5, 53.4, 55.0 and 37.5, egg production/hen 202, 201, 188, 191, 196 and 134, and egg weight 56.3, 56.3, 55.0, 55.8, 55.0 and 57.5 g. Egg mass averaged 1335, 1323, 1191, 1151, 1126 and 796 kg and food consumed/kg eggs produced 3.68, 3.53, 3.71, 3.25, 3.37 and 4.74 kg. Live weight at 16 mth of age averaged 2894, 2040, 2665, 1874, 2132 and 2517 g, and mortality 12.8, 11.1, 33.6, 43.5, 52.8 and 50.4%. (Abstract retrieved from CAB Abstracts by CABI’s permission

    Feeding layers with different levels of energy and protein in the Eastern Province of Saudi Arabia.

    Get PDF
    Three hundred day-old Single Comb White Leghorn hybrid chicks were kept in insulated units with ventilators and 930 in traditional open-air units under a corrugated galvanised sheet roof in Saudi Arabia. All were fed on a standard diet. Growth in both groups was almost equal, but feed conversion was slightly more favourable in the insulated house. Overall mortality was considered to be favourable. The remaining 995 pullets, when of laying age, were divided into 8 groups, 2 of which were kept in the insulated units, and the rest in open-air units. During the laying period, 4 groups were fed on a high-energy (HC) mash and 4 on low-energy (LC) mash. A 17-h lighting schedule was maintained. Feed intake and energy and protein conversion were higher in the LC groups, while gross feed conversion was better in the HC group and the hens tended to be slightly heavier. There was no difference in egg production between feed groups, but that of hens in insulated units was higher than that of hens in open units. Mortality was higher in the HC group, the main cause being visceral lymphomatosis, and higher in the open housed groups, where 33 died from heat stroke in July, than in the insulated units. The authors conclude that the favourable aspects of the HC feeding were offset by the higher mortality and the higher feeding costs, and so the LC mash might be more profitable. I. F. la C. (Abstract retrieved from CAB Abstracts by CABI’s permission

    Pre-clearing vegetation of the coastal lowlands of the Wet Tropics Bioregion, North Queensland

    Get PDF
    A pre-clearing vegetation map and digital coverage at approximately 1:50 000 scale for the coastal lowlands (up to about 200 m elevation) of the Wet Tropics Bioregion, North Queensland is presented. The study area covers about 508 000 ha from Cooktown, 420 km south almost to Townsville (latitude 15° 30’–18° 20’ longitude 144° 50’–146° 40’). Data sources included historical aerial photography, early surveyors’ plans, explorers’ journals, previous vegetation maps, and maps of soils and geology. The pre-clearing mapping was built around the remnant vegetation mapping of Stanton & Stanton (2005), and the vegetation classification of this latter work was adopted. Vegetation units were further classified into regional ecosystems compatible with the standard State-wide system used by Queensland government. The digital coverage is part of the current Queensland Herbarium regional ecosystem coverage (Queensland Herbarium and Wet Tropics Management Authority 2005). Coloured maps (1:100 000 scale) of the pre-clearing vegetation of the Herbert, Tully, Innisfail and Macalister/Daintree subregions are on an accompanying CD-ROM. An evaluation of vegetation loss through clearing on the coastal lowlands of the Wet Tropics revealed several nearextinct vegetation communities and regional ecosystems, and many others that are drastically reduced in area. Even ecosystems occurring on poorly drained lands have suffered a surprisingly high level of loss due to the effectiveness of drainage operations. Grassland ecosystems were found to be widespread on the Herbert and Tully floodplains, but are now close to extinction. The lowlands vegetation of the Wet Tropics that remains today continues to be fragmented and degraded despite the introduction of State-wide broad-scale tree-clearing laws in 1999, and the cessation of broadscale tree-clearing in December 2006

    How common are high-risk coronavirus contacts? A video-observational analysis of outdoor public place behavior during the COVID-19 pandemic

    Get PDF
    Epidemiological evidence and recommendations from the World Health Organization suggest that close face-to-face interactions pose a particular coronavirus transmission risk. The real-life prevalence and nature of such high-risk contacts are understudied, however. Here, we video-observed high-risk contacts in outdoor public places in Amsterdam, the Netherlands, during the COVID-19 pandemic. We found that high-risk contacts were relatively uncommon: Of the 7,813 individuals observed, only 20 (0.26%) displayed high-risk contacts. Further, we qualitatively examined the 20 high-risk contacts identified and found that they occurred disproportionally between affiliated persons engaged in affiliative behaviors. We discuss the potential public health implications of the relatively low incident rate of high-risk contacts
    • …
    corecore