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Abstract  

It is demonstrated that lanthanum can be used as a carrier for trace amounts of gold. The theoretical motivation is discussed.

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Abstract  

Radon in the indoor environment is a recognized environmental hazard. The Environmental Protection Agency (EPA) has established several programs to develop, demonstrate, and transfer radon mitigation technology. Administration and management of these programs are shared by EPA's Office of Radiation Programs and Office of Research and Development. One measure of success of these programs is that, by 1990, approximately 90,000 houses have been professionally mitigated in the United States. Future success depends, in part, upon strong motivational campaigns conducted in local communities with regional and national support.

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Résumé  

L'analyse de l'homme, c'est à dire la recherche de la compositon chimique du sujet humain intact, est d'intérêt (bien que non nécessairement d'importance) pour les cliniciens et les physiologistes. Le problème constitue aussi une motivation considérable pour les chimistes, aussi bien que pour les physiciens et les biologistes qui ont entrepris récemment de contribuer au développement et à l'application des techniques analytiques. L'analyse par activation neutronique in vivo a été appliquée à l'étude de la composition du corps entier et une région limitée du corps. La technique comporte de nombreuses difficultés expérimentales et éthiques et n'a obtenu jusqu'ici que des succès limités; mais elle est probablement capable de se développer utilement. Pour plusieurs éléments, une autre approche (basée sur l'emploi des indicateurs et l'analyse par activation in vitro) mérite une plus grande attention.

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Abstract  

The subjects of the paper are the mechanism of vitrification and the glass transition, and a definition of the temperature of the glass transition. A comprehensive description of the structural changes occurring in the amorphous phase (‘real’ and ‘semi-ordered’) in a vicinity of the glass transition is presented. One of the major motivation of our studies is to investigate the finite size effect of the glass transition that could be related to the cooperative motion in supercooled liquids. Also, new formula, describing the relaxation time temperature change, is applied in order to better reveal themechanismof the supermolecular formation under different internal and external factors. The results of the basic methods of thermal analysis, obtained for different polymeric systems, were used in this study. The proposed approach let us correlate the thermodynamic and the structural parameters, which are estimated from the experiments, and describe all well known shapes of the DSC traces, which can be recorded in the glass transition region. Based on positron annihilation lifetime spectroscopy and dilatometric results, the significance of the free and the specific volumes for the activation of the relaxing units is discussed.

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Abstract  

Although many areas of major national need depend critically on professionals trained in nuclear and radiochemistry, educational opportunities and student interest in this area have declined steadily for the last twenty years. One major contributing factor to the lack of student interest is that most students in science and chemistry courses are never introduced to these topics. This deficiency in science curricula, coupled with the negative public perception towards all things nuclear, has resulted in a serious shortage of individuals with a background in this area. We propose to address this problem by educating the educators — providing faculty from two- and four-year colleges and high school science teachers with the curriculum materials, training, and motivation to incorporate these topics on a continuing basis in their curricula. Two advantages of this approach are: (1) it will generate scientists with a basic understanding of this field and (2) as teachers incorporate nuclear topics, many students will have the opportunity to reflect on the role of science in a technological society.

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motivation of the present study is therefore to relax the requirement of freestanding specimens and thus increase the versatility of the 3& technique. We achieve this by developing an analytical model which accounts for the heat loss to the substrate so that

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. Therefore, there is motivation and opportunities to find efficient and cost-effective new technologies that improve the heavy oil recovery and upgrading, minimize the use of energy and water-based processes, and reduce the air emissions. Nanoparticles could

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Journal of Thermal Analysis and Calorimetry
Authors:
Zuzana Cibulková
,
Andrea Černá
,
Peter Šimon
,
Ján Uhlár
,
Karol Kosár
, and
Peter Lehocký

regenerating another one so that the latter does not become consumed or by the two antioxidants functioning by different mechanisms [ 2 ]. Sometimes the motivation to find a suitable combination of antioxidants with synergistic effects is the attempt to extend

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Introduction The chemistry and physics of the compounds formed by the elements in groups III and V is extraordinarily rich and their usefulness in the semiconductor industries has been a motivation for numerous experimental and

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experimental measurement of the heat capacity of a complex system which consists of two components of comparable weight fractions, namely, a silica gel KSK and calcium chloride confined to its pores [ 1 ]. The main motivation was to obtain for this composite

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