The oxidation of carbon monoxide by magnesium aluminate

In this research the catalytic oxidation of carbon monoxide was investigated on magnesium aluminate catalysts, MgO:xAl2O3, with five different compositions, x, ranging from 1.0 to 3.0. The reaction was run at temperatures ranging from 500 to 600 °C. with radioactive carbon monoxide as the tracer. An experimental technique has been devised for the analysis of unreacted CO which takes into account a correction for the solubility of CO in CO2. Four mathematical models were postulated to explain the mechanism of reaction. The models were examined against experimental data by means of non-linear least squares analysis. One model was found to fit the experimental data substantially better than the other models. This model is considered to represent a plausible explanation for the results of this study. From the mathematical modeling it was found that the oxidation reaction proceeds by the reaction of gaseous CO with chemisorbed oxygen. The chemisorption involved in the process is of the weak type; oxygen is chemisorbed as a boundary layer and not by transfer of electrons. The importance of the electronic properties of a catalyst are called into question in this work because of the fact that magnesium aluminate is an insulator. It is found that the activation energy and the number of active sites reaches a maximum at an Al2O3/MgO ratio equal to 1.667. The catalytic activity is not directly related to the number of cation vacancies. The active sites for weak oxygen adsorption are the normal aluminum lattice cations, located in octahedral positions of the spinel structure. The composition of crystal mixture in a single crystal structure is one of the factors which will greatly affect catalytic activity. The observed compensation effect of catalytic activity is related to the catalyst composition; the catalyst composition affects the strength of adsorption bond between the catalyst and adsorbed oxygen and also the number of pre-precipitation nuclei. The former affects the activation energy; the latter affects the number of active sites

A community approach to road safety education using practical training methods : the Drumchapel project

Research shows that practical training methods, in which children receive guided experience of solving traffic problems in realistic traffic situations, are amongst the most effective in improving children's pedestrian competence. However, practical training is both time consuming and labour intensive, making it difficult to capitalise on the strengths of the method. The report describes a solution to this problem by adopting a community participation approach in which local volunteers carried out all roadside training, working in co-operation with schools and project staff. The project took place in an area of Glasgow known for its exceptionally high child pedestrian accident rate

From Forest, Stream, and Sea: Aspects of Self-Sufficiency in the Nineteenth Century Louisiana Diet. (Volumes I and II).

Studies of foodstuff self-sufficiency in the antebellum South have shown that during the middle third of the nineteenth century, as represented by the census years 1840, 1850 and 1860, certain regions of Louisiana suffered from meat production deficits. It has been assumed by most interested scholars that these deficits were overcome by importing pork and beef from the midwest or Upper South. Other possible sources of meat supplements that have not been generally considered are the wild game and fishery resources of the state. Hunting and fishing have long traditions as important activities in the South in general and in Louisiana as both subsistence and social activities. While the importance of these activities to general subsistence in the pioneer and frontier periods has been accepted, their continued use as food sources through the nineteenth century has generally been ignored. Archival collections and the contemporary literature show that a very wide variety of wild game and fishery resources were taken in Louisiana and neighboring regions of adjacent states. As the population and agricultural activities in Louisiana increased during the time period in question, the numbers and distributions of some game birds and animals were dramatically affected. Some increased in number while others were driven to or over the edge of extinction in the state. Analysis of available data was conducted on estimated nineteenth century population numbers, range acreages, and carrying capacities, in conjunction with edible meat production ratios, for wild game and fishery resources. The results of these analyses show that a reliance on these as food sources could have made up all or substantial percentages of the projected meat deficits for the middle third of the century. While imports from other regions might not have been totally eliminated, locally available food sources could have substantially limited the size and importance of such imports

The effects of adult guidance and peer discussion on the development of children's representations: evidence from the training of pedestrian skills

It was hypothesised that practical training is effective in improving children's pedestrian skills because adult scaffolding and peer discussion during training specifically promote E3 level representation (linguistically-encoded, experientially-grounded, generalisable knowledge), as defined by Karmiloff-Smith's (1992) representational redescription (RR) model. Two studies were conducted to examine in detail the impact of this social input, in the context of simulation-based training in roadside search skills. Five- to eight-year-olds were pre-tested on ability to detect relevant road crossing features. They then participated in four training sessions designed to promote attunement to these, under peer discussion condition vs adult guidance conditions (Study 1), and adult-child vs adult-group conditions (Study 2). Performance at post-test was compared to that of controls who underwent no training. Study 1 found that children in the adult guidance condition improved significantly more than those in the peer discussion or control conditions, and this improvement was directly attributable to appropriation of E3 level representations from adult dialogue. Study 2 found that progress was greater still when adult scaffolding was supplemented by peer discussion, with E3 level representation attributable to children's exploration of conflicting ideas. The implications of these findings for the RR model and for practical road safety education are discussed

Popular and informal environmental education: the need for more research in an "emerging" field of practice

Environmental education that fosters meaningful community participation and learning has been considered a requisite to sustaining our human and natural environments in many of the global conferences, agreements, declarations and charters since the 1972 UN Conference on the Environment in Stockholm. Despite this growing consensus there is a small amount of published research in Australia in this field of practice we have decided to call popular and informal environmental education - education that often involves adults in social action. The authors argue, however, that there is no shortage of educational practice that can be described as popular and informal environmental education. The autors propose a typology that will assist in defining this field of practice and establish theoretical links with the emerging field of environmental adult education

Common and distinct organ and stress responsive transcriptomic patterns in Oryza sativa and Arabidopsis thaliana

<p>Abstract</p> <p>Background</p> <p><it>Arabidopsis thaliana </it>is clearly established as the model plant species. Given the ever-growing demand for food, there is a need to translate the knowledge learned in Arabidopsis to agronomically important species, such as rice (<it>Oryza sativa</it>). To gain a comparative insight into the similarities and differences into how organs are built and how plants respond to stress, the transcriptomes of Arabidopsis and rice were compared at the level of gene orthology and functional categorisation.</p> <p>Results</p> <p>Organ specific transcripts in rice and Arabidopsis display less overlap in terms of gene orthology compared to the orthology observed between both genomes. Although greater overlap in terms of functional classification was observed between root specific transcripts in rice and Arabidopsis, this did not extend to flower, leaf or seed specific transcripts. In contrast, the overall abiotic stress response transcriptome displayed a significantly greater overlap in terms of gene orthology compared to the orthology observed between both genomes. However, ~50% or less of these orthologues responded in a similar manner in both species. In fact, under cold and heat treatments as many or more orthologous genes responded in an opposite manner or were unchanged in one species compared to the other. Examples of transcripts that responded oppositely include several genes encoding proteins involved in stress and redox responses and non-symbiotic hemoglobins that play central roles in stress signalling pathways. The differences observed in the abiotic transcriptomes were mirrored in the presence of <it>cis</it>-acting regulatory elements in the promoter regions of stress responsive genes and the transcription factors that potentially bind these regulatory elements. Thus, both the abiotic transcriptome and its regulation differ between rice and Arabidopsis.</p> <p>Conclusions</p> <p>These results reveal significant divergence between Arabidopsis and rice, in terms of the abiotic stress response and its regulation. Both plants are shown to employ unique combinations of genes to achieve growth and stress responses. Comparison of these networks provides a more rational approach to translational studies that is based on the response observed in these two diverse plant models.</p