A comparison of nuclide production and depletion using MCNPX and ORIGEN-ARP reactor models and a sensitivity study of reactor design parameters using MCNPX for nuclear forensics purposes

textThe Oak Ridge Isotope Generation and Depletion – Automatic Rapid Proccessing (ORIGEN-ARP) deterministic code has been extensively utilized for determining nuclide concentrations at various specific burnup values for a variety of nuclear reactor designs. Given nuclide concentrations or ratios, such calculations can be used in nuclear forensics and nuclear non-proliferation applications to reverse-calculate the type of reactor and specific burnup of the fuel from which the nuclides originated. Recently, Los Alamos National Laboratory has released a version of its probabilistic radiation transport code, MCNPX 2.6.0, which incorporates a fuel burnup feature which can also determine, via the probabilistic Monte Carlo method, nuclide concentrations as a function of fuel burnup. This dissertation compares the concentrations of 46 nuclides significant to nuclear forensics analyses for different reactor types using results from the ORIGEN-ARP and the MCNPX 2.6.0 codes. Three reactor types were chosen: the Westinghouse 17x17 Pressurized Water Reactor (PWR), the GE 8x8-4 Boiling Water Reactor (BWR), and the Canadian Deuterium Uranium, CANDU-37, reactor. Additionally, a sensitivity study of the different reactor parameters within the MCNPX Westinghouse 17x17 PWR model was performed. This study analyzed the different nuclide concentrations resulting from minor perturbations of the following parameters: assembly rod pitch, initial moderator boron concentration, fuel pin cladding thickness, moderator density, and fuel temperature.Mechanical Engineerin

Corpus consultation and advanced learners' writing skills in French

peer-reviewedIn the rapidly changing environment of language learning and teaching, electronic literacies have an increasingly important role to play. While much research on new literacies focuses on the World Wide Web, the aim in this study is to investigate the importance of corpus consultation as a new type of literacy which is of particular relevance in the context of language learning and teaching. After briefly situating the theoretical and pedagogical context of the study in relation to authenticity and learner autonomy, the paper describes an empirical study involving eight postgraduate students of French. As part of a Masters course they write a short text and subsequently attempt to improve it by using concordancing software to consult a small corpus containing texts on a similar subject. The analysis of the results reveals a significant number of changes made by the learners which may be classified as follows in order of frequency: grammatical errors (gender and agreement, prepositions, verb forms/mood, negation and syntax); misspellings, accents and hyphens; lexico- grammatical patterning (native language interference, choice of verb and inappropriate vocabulary); and capitalisation. The conclusion notes that the situation in which these students found themselves (i.e. faced with a text on which the teacher had indicated phrases which could be improved) is replicated in many cases every day, and suggests that corpus consultation may have a useful role to play in the context of interactive feedback, particularly in cases where traditional language learning resources are of little use.PUBLISHEDpeer-reviewe

Language learning as discourse analysis: Implications for the LSP learning environment

Au cours de la deuxième moitié du vingtième siècle, l’enseignement des langues de spécialité a été fortement influencé par l’approche communicative et par la recherche en analyse du discours, surtout dans le domaine du genre. L’intégration de la recherche en linguistique de corpus dans l’apprentissage des langues est un phénomène plus récent. À partir de 1990 les publications sur l’emploi des concordances par les professeurs et les apprenants de langues se sont multipliées. Le but de cette étude est de rapprocher d’une part l’apprentissage des langues, vu comme analyse du discours, et, d’autre part, l’apport potentiel des corpus à l’acquisition par les apprenants de ce que Swales (1990 :27) nomme l’expertise du discours (« discoursal expertise »). Des exemples sont tirés de plusieurs domaines, dont l’article de recherche, les sciences économiques et la communication en entreprise. L’auteur se penche non seulement sur le potentiel des corpus mais aussi sur les obstacles qui entravent la réussite de leur intégration dans l’apprentissage des langues.The teaching of Languages for Specific Purposes (LSP) in the second half of the twentieth century has been greatly influenced both by the communicative approach and by developments in research in discourse analysis, particularly with reference to genre. The integration of research in corpus linguistics in the language-learning environment has been a more recent phenomenon, with publications on the use of concordance data by language teachers and learners multiplying in the 1990s and the early years of the twenty-first century. This article aims to bring together the view of language learning as discourse analysis on the one hand, and on the other the contribution which corpus data can make to the development of “discoursal expertise” (Swales 1990: 27) by learners. Examples are included from areas such as academic writing, economics and business discourse. The article focuses not only on the potential of corpora but also on the obstacles to their integration in the language-learning environment

Guest Artist Recital: Angela Amici, Contralto; Harold Gray, Piano; Kevin Chambers, Piano; February 8, 1973

Centennial East Recital HallThursday EveningFebruary 8, 19738:15 p.m

Questions in English and French research articles in linguistics: a corpus-based contrastive analysis

Although research on evaluation in academic writing has profited from developments in contrastive linguistics since the late 1980s, very little empirical research has been conducted with respect to questions in contrastive studies. The aim of this study is to investigate the functions of questions as a means of reader engagement in academic research articles in English and French in the discipline of linguistics. To do this, a corpus-based contrastive analysis of two subcorpora of KIAP (Fløttum et al. in Academic voices across languages and disciplines, John Benjamins, Amsterdam, 2006) is conducted. The English and French subcorpora are assessed using Hyland’s model of stance and reader engagement in terms of questions and their seven functions as evaluative markers of reader engagement (Text 22(4):529–557, 2002; Discourse Stud 7(2):173–192, 2005b), including their form and distribution within the text. This analysis focuses on two particular functions of questions, namely ‘framing the discourse’ and ‘organising the text’. The results suggest that, although there is some degree of homogeneity in the use of questions in terms of function, form and distribution, there is also evidence of important differences between the two languages. These findings illustrate some distinctions in writing in these two discourse communities and their potential for informing language pedagogy in both English for academic purposes and Français langue académique

Sexually dimorphic effect of aging on skeletal muscle protein synthesis

BACKGROUND: Although there appear to be no differences in muscle protein turnover in young and middle aged men and women, we have reported significant differences in the rate of muscle protein synthesis between older adult men and women. This suggests that aging may affect muscle protein turnover differently in men and women. METHODS: We measured the skeletal muscle protein fractional synthesis rate (FSR) by using stable isotope-labeled tracer methods during basal postabsorptive conditions and during a hyperaminoacidemic-hyperinsulinemic-euglycemic clamp in eight young men (25–45 y), ten young women (25–45 y), ten old men (65–85 y) and ten old women (65–85 y). RESULTS: The basal muscle protein FSR was not different in young and old men (0.040 ± 0.004 and 0.043 ± 0.005%·h(-1), respectively) and combined insulin, glucose and amino acid infusion significantly increased the muscle protein FSR both in young (to 0.063 ± 0.006%·h(-1)) and old (to 0.051 ± 0.008%·h(-1)) men but the increase (0.023 ± 0.004 vs. 0.009 ± 0.004%·h(-1), respectively) was ~60% less in the old men (P = 0.03). In contrast, the basal muscle protein FSR was ~30% greater in old than young women (0.060 ± 0.003 vs. 0.046 ± 0.004%·h(-1), respectively; P < 0.05) and combined insulin, glucose and amino acid infusion significantly increased the muscle protein FSR in young (P < 0.01) but not in old women (P = 0.10) so that the FSR was not different between young and old women during the clamp (0.074 ± 0.006%·h(-1) vs. 0.072 ± 0.006%·h(-1), respectively). CONCLUSIONS: There is sexual dimorphism in the age-related changes in muscle protein synthesis and thus the metabolic processes responsible for the age-related decline in muscle mass