Finite element modelling investigation of the effects of cladding texture on creep in PWR fuel pins

In order to examine the impact of anisotropy in creep deformation of the zirconium alloy clad in pressurised water reactors (PWR), finite element analysis was used through the Abaqus CAE v11.2 software. A qualitative link between the deformation of a single hexagonal-closed-packed zirconium crystal (c/a < 1.63) under uniaxial loading and Hill’s anisotropic criterion was devised, which allowed for the additions of anisotropic creep strain on the zirconium clad. A 21/2-D axisymmetric (r, z) test element was used to examine the application of anisotropic creep strain using the Hill potential via the CREEP subroutine and the *POTENTIAL command, and comparisons with analytical solutions were drawn. This lead to the development of an axisymmetric 21/2-D elastic fuel pin model. The material properties for the uranium dioxide pellet and zirconium alloy clad used were of empirical nature. An empirical gap conductance model, consisting of an open and closed gap conductance component, was used via the GAPCON subroutine and a smooth gap closure was achieved during a highly non-linear coupled temperature-displacement analysis. The thermal profile of a PWR fuel pin under nominal operating conditions was produced and comparisons with the analytical solutions, where possible, were made. An empirical anisotropic creep strain model, consisting of thermal and irradiation induced creep components, was lastly implemented in the thermo-mechanical elastic fuel pin model. An isotropic case and two differing textures were examined. These were a high preferential basal pole alignment in the radial and axial direction. The differing textures resulted in profound differences in the stress distribution on the metallic clad and consequently the final creep strain deformation varied. It was found that the radially aligned texture resulted in high axial elongation and the axially aligned texture resulted in a bigger diametric increase of the tube. The investigation concluded that texture plays a crucial role on the stress distribution and hence the creep strain deformation of the zirconium alloy tube, influencing both the mechanics and chemistry of pellet-cladding interactions, and hence needs to be investigated further in the future.Open Acces

New Rules for Letters of Credit: Time to Update the UCP 600

This article addresses the need for a revision of the UCP 600, international rules governing letters of credit. It identifies key articles that need amendments and is the first legal article to draft new provisions for the potential ?UCP 700?. The significance of updating the rules can be pinpointed as increasing bank operation efficiency and faster completion of international trade transactions

Collaborating for First Foods: Archaeological Investigations of Chinookan and Lower Chehalis Foodways in Willapa Bay, Washington

In the U.S., Indigenous communities often suffer poor health at greater rates than non-Native populations. This is due, in part, to economic stresses, restricted access to food sources, and the colonization of Native American territories that physically severed the ties between Indigenous peoples and their land, weakening or destroying their culturally informed subsistence practices. To remedy these health disparities, many Indigenous communities are reviving traditional foodways, establishing food sovereignty, and reclaiming their rights to local food sources. This dissertation explores collaborative and applied methods of archaeological research and argues that an archaeological understanding of past foodways can help Indigenous groups accomplish these community-set agendas. When conducted in collaboration with the community, in adherence to their values, and motivated by their interests, archaeology can be a useful tool in cultural revitalization efforts. To illustrate this point, this dissertation describes archaeological research conducted with two communities on the Northwest Coast—the Shoalwater Bay Indian Tribe and the Chinook Indian Nation—and how such research contributes to their fight for sovereignty as it relates to food systems and community health. Investigations focused on Nukaunlth, a Lower Chehalis and Chinookan village occupied during the Late Pacific, protocontact, and postcontact periods. As the descendant communities are most interested in revitalizing marine-based foodways, this project sought to ascertain (1) the importance of marine resources among Chinookan and Lower Chehalis peoples living at this ancestral village, and (2) the makeup of the larger subsistence system within which marine resource use was situated. More specifically, this study addresses whether shellfish was a key resource that was managed, and/or harvested intensively to meet important dietary needs of the community, or a low-priority resource that was harvested and consumed only opportunistically. While many other resources, such as plants, were likely consumed at this village but are underrepresented in the archaeological record currently available, zooarchaeological analysis demonstrates that marine resources—shellfish (cockles, mussels, and various species of clam, in particular), marine mammals (especially whale), and fish (salmon, flounder, and sturgeon, most notably)—were key food resources for those who lived at Nukaunlth and were arguably indispensable to their lifeways. Such marine resources may have been good sources of essential caloric and noncaloric nutrients such as fat, protein, iron, and omega-3 fatty acids. By all measures, shellfish dominate the faunal assemblage and makes up the largest portion of edible food reflected by the archaeological record. Shellfish, while providing fewer calories and less fat than other food sources, could have been a critical source of vitamins and minerals that were difficult to obtain from other food sources. This dissertation concludes by outlining the community-enriching programs and public goods the Shoalwater Bay Indian Tribe has created using the outcomes of this research. Through these initiatives, the descendant community is using Western scientific data to corroborate a long-held Indigenous understanding that local natural resources, especially marine, were indispensable to life before European settlement and that the right to access these resources is an inherent right of Indigenous peoples. In this way, archaeology that is done in tandem with descendant communities and motivated by their interests and needs can be more than the data it generates; it can be a creative process by which Indigenous communities can explore their history on their own terms and craft possible futures that champion culture, health, and wellness.PHDAnthropologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/168007/1/asanton_2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/168007/2/asanton_1.pd

PICK1 links Argonaute 2 to endosomes in neuronal dendrites and regulates miRNA activity.

MicroRNAs fine-tune gene expression by inhibiting the translation of mRNA targets. Argonaute (Ago) proteins are critical mediators of microRNA-induced post-transcriptional silencing and have been shown to associate with endosomal compartments, but the molecular mechanisms that underlie this process are unclear, especially in neurons. Here, we report a novel interaction between Ago2 and the BAR-domain protein, PICK1. We show that PICK1 promotes Ago2 localization at endosomal compartments in neuronal dendrites and inhibits Ago2 function in translational repression following neuronal stimulation. We propose that PICK1 provides a link between activity-dependent endosomal trafficking and local regulation of translation in neurons

Investigating the Possibility of Distributed Leadership in Schools in Cyprus: A Qualitative Case Study in a Public Upper Secondary School

This study is an attempt to investigate whether distributed leadership is developed in practise in Cypriot schools from the point of view of six people which are employed in a public upper secondary school. This particular school is involved in this study in order to shed some light on the wider situation in Cyprus. The methodology followed in this study was a qualitative case study. The semistructured interviewing method was used to collect data from three teachers, one assistant head teacher, one assistant head teacher A and one head teacher. The data were presented by a multiple case design, while the data analysis was performed by the method of cross-checking data. Results showed that although the centralisation of the educational system prevents the development of distributed leadership, there seems to be a basis of this development. Moreover, the attitude of a head teacher on leadership seems to be a determinant factor in the emergence of distributed leadership, as well as the willingness of the school staff to take on responsibilities. These results appear to go beyond this particular school, as the participants expressed their thoughts and understandings about leadership in education and generally, about the educational system of Cyprus. However, the findings are based on the perceptions of only six persons; thus, they cannot be generalised. Therefore, extensive research is needed involving a higher number of schools and teachers

Phonological Factors Affecting L1 Phonetic Realization of Proficient Polish Users of English

Acoustic phonetic studies examine the L1 of Polish speakers with professional level proficiency in English. The studies include two tasks, a production task carried out entirely in Polish and a phonetic code-switching task in which speakers insert target Polish words or phrases into an English carrier. Additionally, two phonetic parameters are studied: the oft-investigated VOT, as well as glottalization vs. sandhi linking of word-initial vowels. In monolingual Polish mode, L2 interference was observed for the VOT parameter, but not for sandhi linking. It is suggested that this discrepancy may be related to the differing phonological status of the two phonetic parameters. In the code-switching tasks, VOTs were on the whole more English-like than in monolingual mode, but this appeared to be a matter of individual performance. An increase in the rate of sandhi linking in the code-switches, except for the case of one speaker, appeared to be a function of accelerated production of L1 target items

Choosing Suitable Indicators for the Assessment of Urban Air Mobility: A Case Study of Upper Bavaria, Germany

Technological advances are disrupting mobility patterns and transport technologies, both on the ground and in the air. The latter has been recently observed in the research community of urban air mobility (UAM). Research in this area has studied several areas of its implementation, such as vehicle concepts, infrastructure, transport modeling, or operational constraints. Few studies however have focused on evaluating this service as an alternative among existing transportation systems. This research presents an approach for the selection of indicators for a multi-criteria analysis for the assessment of UAM, in a case study of Upper Bavaria, Germany. A 5-stage approach is showcased including an expert assessment for the relevance and feasibility of indicators, based on two rating scales. A threshold for selection is presented, applied and validated for both scales. The results included a list of indicators for assessing the potentials of UAM integration to existing public transportation systems; the chosen indicators were then compared against existing ones for sustainable urban mobility. A high match between resulting indicators and previous ones further validate the results, and suggest that there is a need for an iterative approach in the assessment of disruptive transport technologies

Visiting the “enemy”: visitation in politically unstable destinations

Purpose This study aims to examine the factors shaping the intentions of people to visit a hostile outgroup. Design/methodology/approach An exploratory, qualitative research approach was followed. Specifically, 77 semi-structured interviews with citizens of the divided island of Cyprus were conducted. Findings This study identifies several categories of visitors and non-visitors, depicted along a continuum, and concludes that there is a multiplicity of factors in the socio-political environment which influence the travel intentions of people. Originality/value This study not only imparts insights into the way travel decision-making evolves in politically unstable situations but also serves as a stepping stone towards understanding the conditions under which reconciliation between hostile nations may be encouraged by travel

Evaluation of the BOADICEA risk assessment model in women with a family history of breast cancer

The ability of the Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) model to predict BRCA1 and BRCA2 mutations and breast cancer incidence in women with a family history of breast cancer was evaluated. Observed mutations in 263 screened families were compared to retrospective predictions. Similarly, observed breast cancers in 640 women were compared to retrospective predictions of breast cancer incidence. The ratios of observed to expected number of BRCA1- , BRCA2- and BRCA(1 or 2) mutations were 1.43 (95% CI 1.05–1.90), 0.63 (95% CI 0.34–1.08), and 1.12 (95% CI 0.86–1.44), showing a significant underestimation of BRCA1 mutations. Discrimination between carriers and non-carriers as measured by area under the receiver operating characteristic (ROC) curve was 0.83 (95% CI 0.76–0.88). The ratio of observed to expected number of invasive breast cancers was 1.41 (0.91–2.08). The corresponding area under the ROC curve for prediction of invasive breast cancer at individual level was 0.62 (95% CI 0.52–0.73). In conclusion, the BOADICEA model can predict the total prevalence of BRCA(1 or 2) mutations and the incidence of invasive breast cancers. The mutation probability as generated by BOADICEA can be used clinically as a guideline for screening, and thus decrease the proportion of negative mutation analyses. Likewise, individual breast cancer risks can be used for selecting women whose risk of breast cancer indicates follow-up. Application of local mutation frequencies of BRCA1 and BRCA2 could improve the ability to distinguish between the two genes