Finite element nonlinear stability analysis of framed structures

Bibliography: pages 97-98.The development of efficient and accurate finite element modelling techniques for the routine analysis of elastic-plastic stability problems in frame structures is addressed. The necessary models, solution procedure and geometric algorithm used for nonlinear stability analysis of frames are presented. An available finite element code, NOSTRUM, which had the basic algorithms necessary to carry out nonlinear analysis was used as the starting point. The Timoshenko beam/frame elements with a layered representation of the cross-section, uniaxial elasticplastic constitutive models, different integration procedures and simplified large deformation geometric assumptions incorporated into NOSTRUM are discussed in detail. Numerical examples are given to validate the algorithms implemented and to provide the experience necessary to give guidelines for the adequate choice of discretization and numerical schemes to be used in routine nonlinear stability analysis of frame structures

Modelling of the binary alloy solidification process

Bibliography: leaves 129-132.A thermodynamically consistent model capable of modelling a binary alloy undergoing solidification or melting is developed. The theory is continuum based, and the solid-liquid phase change system is described macroscopically by a single set of conservation equations. The model is an extension of that presented in the literature. The thermodynamic theories of this type in the current literature are based on the assumption of local equilibrium. This assumption is not representative of most alloy solidification processes where the solid-liquid phase region, termed the mushy region, is of dendritic nature with the rates of diffusion in the liquid being orders of magnitude faster than that in the solid. The propose model includes the assumption of local non-equilibrium where solute diffusion in the solid phase is assumed to be zero. The thermodynamic formulation is expressed in terms of three thermodynamic variables: pressure, temperature and average solute concentration for both the equilibrium and non-equilibrium case. A generalized set of conservation equations of mass, energy, momentum and solute with the necessary constitutive equations is presented. A Finite Element (FE) formulation of a simplified form of the governing equations is developed. The reduced set of equations implemented in the FE formulation consists of a fully coupled heat conduction and solute diffusion formulation, with solid-liquid phase change, where the effects of pressure and convection are neglected. The FE formulation is based on the fixed grid technique where the elements are two dimensional, four noded quadrilaterals with the primary variables being enthalpy and average solute concentration. Temperature and solid mass fraction are calculated on a local level at each integration point of an element. A fully consistent Newton-Raphson method is used to solve the global coupled equations and an Euler backward difference scheme is used for the temporal discretization. The solution of the enthalpy-temperature relationship is carried out at the integration points using a Newton-Raphson method. A secant method employing the regula falsi technique takes into account sudden jumps or sharp changes in the enthalpy-temperature behaviour which occur at the phase zone interfaces. The Euler backward difference integration rule is used to calculate the solid mass fraction and its derivatives for the non-equilibrium case. Two solidification examples, using both the local equilibrium and the local non-equilibrium cases, are analyzed. The finite element results obtained for the two cases are compared, and the accuracy of the finite element model is checked. Both dendritic and eutectic phase change are tackled. Even though the discrete eutectic phase change is approximated using the fixed grid approach, the results are considered to be reasonable approximations to what occurs in reality. Favorable comparisons of the results are obtained with that in the literature and convergence of the finite element results for different mesh sizes are shown. For dilute alloy solutions, the solidification results for the local equilibrium and the local non-equilibrium cases are shown to differ markedly, whereas for near eutectic solutions little difference is observed. The use of the local non-equilibrium assumption in the finite element solidification model is shown to effect the macro-segregation of solute

Are work-integrated learning (WIL) students better equipped psychologically for work post-graduation than their non-work-integrated learning peers? Some initial findings from a UK university

Work-integrated learning (WIL) provides an opportunity to develop the skills, knowledge, competence, and experience, which increase employability and lead to more satisfying careers. Research indicates that WIL results in improved academic- and occupationally-related outcomes. However, there is a paucity of quantitative research examining the psychological impact of WIL. The study aimed to determine whether students who pursue WIL in the UK, differ significantly in terms of self-concept, self-efficacy, hope, study skills, motivation, and procrastination than students who have not participated in WIL. The methodology used a cross-sectional analysis of a large sample (n=716) of undergraduate students at the University of Huddersfield, UK. Results showed significant differences predominantly centred upon measures which pertain to students’ confidence in setting and attaining goals. The increased hope and confidence in goal attainment suggest that gaining work experience perhaps enhances the ability to set and achieve goals once in the work force. (Asia-Pacific Journal of Cooperative Education, 2013, 14(2), 117-125) Keywords: Employability; Psychological factors; Work-integrated learning; Placement; Confidence; Self estee

From unskilled to employable: using a qualitative examination of the ‘Placement Timeline Research Method’ to explore student professional and personal development whilst on multiple WIL experiences.

This paper explores the method and findings of a qualitative examination into multiple work integrated learning (MWIL) placements. The research consisted of 14 reflective interviews with students from across discipline areas who had undertaken a series of work placements. The range of MWIL experiences included professional placements in nursing and youth work, yearlong placements in accountancy and engineering, self-directed WIL experiences in arts, informal and part-time placements. The aim of this study was to explore the transitions that took place throughout multiple placements that helped the student to become a work ready and an effective professional. A research method, 'Placement Timeline' was developed. This allows a reflective structure for the researcher to tease out skill development and work readiness. All interviews were transcribed and coded using NVivo qualitative software. The paper will discuss selected findings from the research. These provide insights into how multiple WIL experiences may benefit students in their preparation for work. In effect it was as if the work readiness and skills relating to an uncertain and ever changing job market skills were fast tracked over MWIL.This research highlights the key transitional features of MWIL

Barycentres and Hurricane Trajectories

The use of barycentres in data analysis is illustrated, using as example a dataset of hurricane trajectories.Comment: 19 pages, 7 figures. Contribution to Mardia festschrift "Geometry Driven Statistics". Version 2: added further reference to HURDAT2 data format. Version 3: various minor corrections, and added dedication to Mardi

Researchers and Social Networking Sites usage: the application of UTAUT theory

Purpose (limit 100 words) This study aims to investigate the use of SNS by researchers and their behaviours when conducting research-related activities by applying the UTAUT theory Design/methodology/approach (limit 100 words) An online survey was distributed. This study's design is derived from the UTAUT framework's questionnaire items. The sample of this study comprised 216 respondents from 40 universities in the United Kingdom. Descriptive statistics were used to analyse the data. Findings (limit 100 words) Respondents revealed a positive relationship between the four constructs of the UTAUT framework (performance expectancy, effort expectancy, social influence, and facilitating condition) associated with their intention to use SNS. Research limitations/implications (limit 100 words) Most of the respondents were from the University of Strathclyde, so we cannot generalize the findings to other universities. Practical implications (limit 100 words) The findings will offer an extensive understanding of the value of social networking sites, which will aid researchers to increase their visibility, and research activities online. Originality/value (limit 100 words) The results will provide an in-depth knowledge of the importance of social networking sites, helping scholars to become more visible and engage in online research. A number of factors impacted how researchers behaved on social networking sites and what they intended to use for research-related activity. School administrators, experts, and other sponsors could take action to promote the use of social networking sites (SNSs) in educational settings based on the findings. The study's findings offer insightful knowledge to those who create SNS websites. By using this information, they will be able to improve these sites for research and study and gain a better understanding of the demands of SNS users

Timing, Duration, and Pathways of Harlequin Duck Migration to Pacific Molting and Wintering Areas

The core breeding range for Harlequin Ducks (Histrionicus histrionicus) in western North America extends from Alaska, and south through the Yukon, Northwest Territories, and British Columbia. Smaller breeding populations exist in southwestern Alberta, Washington, Oregon, Idaho, Wyoming, and Montana. Each state and province in these areas has identified the Harlequin Duck as a species of conservation priority, given its small and isolated populations, its specific nesting requirements, and changes in abundance or distribution. Conservation objectives for all areas have identified the importance of mapping migration routes that connect breeding sites to Pacific coast molting and wintering locations, as well as determining migration timing, duration, habitat use, and stopover sites. In spring 2016, we captured Harlequin Duck pairs on breeding streams and surgically implanted satellite transmitters in the males and attached geolocators to the leg bands of females. We marked 18 harlequin pairs (Alberta = 10 (minus one female), Montana = 5, Wyoming = 2, Washington = 1). Migration initiation dates varied by breeding areas and occurred from June 3 to July 10. Male migration lasted between 1-17 days and stopovers occurred approximately half-way to the coast and included rivers, mountain streams, and lakes. They arrived at their molting areas between June 5-July 24 and these areas ranged from southeast Alaska to northwestern Washington. The majority (71%) of harlequins departed molt locations to differing winter locations. Efforts will be made to retrieve the geolocators from females in spring 2017 to compare locations between males and females from different devices

Cytochrome P4501A biomarker indication of the timeline of chronic exposure of Barrow’s goldeneyes to residual Exxon Valdez oil

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Pollution Bulletin 62 (2011): 609-614, doi:10.1016/j.marpolbul.2010.11.015.We examined hepatic EROD activity, as an indicator of CYP1A induction, in Barrow's goldeneyes captured in areas oiled during the 1989 Exxon Valdez spill and those from nearby unoiled areas. We found that average EROD activity differed between areas during 2005, although the magnitude of the difference was reduced relative to a previous study from 1996/97, and we found that areas did not differ by 2009. Similarly, we found that the proportion of individuals captured from oiled areas with elevated EROD activity ( 2 times unoiled average) declined from 41% in winter 1996/97 to 10% in 2005 and 15% in 2009. This work adds to a body of literature describing the timelines over which vertebrates were exposed to residual Exxon Valdez oil and indicates that, for Barrow's goldeneyes in Prince William Sound, exposure persisted for many years with evidence of substantially reduced exposure by 2 decades after the spill.This research was supported primarily by the Exxon Valdez Oil Spill Trustee Council

Innovation in technology-enhanced assessment in the UK and the USA: future scenarios and critical considerations

This paper uses methods derived from the field of futures studies to explore the future of technology-enhanced assessment. Drawing on interviews and consultation activities with experts, the paper aims to discuss the conditions that can impede or foster ‘innovation’ in assessment and education more broadly. Through a review of relevant research, the paper suggests an interpretive model of the factors sustaining the conservatism of educational assessment: the utilitarian view of education, dominant beliefs about academic excellence, and market or quasi-market dynamics. In the central section of the paper, three scenarios of innovation in assessment are described, developed through an iterative process involving researchers, representatives from the e-assessment industry, and experts from British awarding organisations. In the final section, a critical discussion draws attention to the implications that data pervasiveness and computer-generated predictive models may have for the future of education