Generation of long time creep data on refractory alloys at elevated temperatures Quarterly report, 14 Dec. 1967 - 27 Mar. 1968

Creep analysis of refractory metal alloys at high temperatures under ultrahigh vacuum condition

Generation of long time creep data on refractory alloys at elevated temperatures Quarterly report, 28 Mar. - 13 Jun. 1968

Creep tests of molybdenum alloys, and tantalum alloy

EACOF: A Framework for Providing Energy Transparency to enable Energy-Aware Software Development

Making energy consumption data accessible to software developers is an essential step towards energy efficient software engineering. The presence of various different, bespoke and incompatible, methods of instrumentation to obtain energy readings is currently limiting the widespread use of energy data in software development. This paper presents EACOF, a modular Energy-Aware Computing Framework that provides a layer of abstraction between sources of energy data and the applications that exploit them. EACOF replaces platform specific instrumentation through two APIs - one accepts input to the framework while the other provides access to application software. This allows developers to profile their code for energy consumption in an easy and portable manner using simple API calls. We outline the design of our framework and provide details of the API functionality. In a use case, where we investigate the impact of data bit width on the energy consumption of various sorting algorithms, we demonstrate that the data obtained using EACOF provides interesting, sometimes counter-intuitive, insights. All the code is available online under an open source license. http://github.com/eaco

Mechanical behavior of tantalum-base T-111 alloy at elevated temperature

Mechanical behavior of tantalum T-111 alloy at high temperatures and ultrahigh vacuu

Emission Optics of the Steigerwald Type Electron Gun

The emission optics of a Steigerwald type electron gun is re-examined. The virtual and real points of divergence, divergence angles and beam-widths of the electron beams at different telefocusing strength are measured in detail for first time . Two different Wehnelt cylinders are used to establish a contrasting viewpoint. The original `focusing' curves measured by Braucks are reconstructed and will be explained only through a `new' interpretation which is different from the conventional views. While the image of the emitting surface in front of the filament is indeed telefocused beyond the anode, the envelope of the beam does not `focus' as expected. A new model for the emission mechanism is established based on our results.Comment: 14 pages, 10 figure

Highly tunable low-threshold optical parametric oscillation in radially poled whispering gallery resonators

Whispering gallery resonators (WGR's), based on total internal reflection, possess high quality factors in a broad spectral range. Thus, nonlinear optical processes in such cavities are ideally suited for the generation of broadband or tunable electromagnetic radiation. Experimentally and theoretically, we investigate the tunability of optical parametric oscillation in a radially structured WGR made of lithium niobate. With a 1.04 /mum pump wave, the signal and idler waves are tuned from 1.78 to 2.5 \mum - including the point of degeneracy - by varying the temperature between 20 and 62 {\deg}C. A weak off-centering of the radial domain structure extends considerably the tuning capabilities. The oscillation threshold lies in the mW-power range.Comment: 4 pages, 5 figure

Generation of long time creep data on refractory alloys at elevated temperatures Monthly report, 17 Mar. - 14 Dec. 1967

Creep tests of molybdenum base TZC, TZM alloys tantalum base T-111 and Astar 811C in vacuum environment

Obtaining Critical Values for Test of Markov Regime Switching

Abstract For Markov regime-switching models, testing for the possible presence of more than one regime requires the use of a non-standard test statistic. Carter and Steigerwald (2013, Journal of Econometric Methods) derive in detail the analytic steps needed to implement the test of Markov regime-switching proposed by Cho and White (2007, Econometrica). We summarize the implementation steps and address the computational issues that arise. A new command to compute regime-switching critical values, rscv, is introduced and presented in the context of empirical research

An Evaluation Of Provision In A School Designated As Catering For Pupils Categorised As Having 'Emotional And Behavioural Difficulties' In The Light Of The Perspectives And Expectations Of Its Various Stakeholders

Line End is an 11-16 day school for pupils categorised as having emotional and behavioural difficulties (EBD). It is maintained by Farside Local Education Authority, and provides secondary education for pupils who are statemented as having emotional and behavioural difficulties. Some have additional learning difficulties, this assessment being based on reading ages that are considerably lower than their chronological ages, and scores in KS2 SATs that are below National averages. All referrals come through the local authority’s special educational needs department; invariably, the pupils who are placed at Line End either transfer from the EBD primary unit, or are those who have been excluded from mainstream secondary schools within the borough. The aim of the study is to establish the extent to which Line End is felt to be effective by its various stakeholders; and in establishing this position, it is first important to elicit the criteria by which the various stakeholders judge the school to be effective. The first phase of the study, therefore, is aimed at eliciting these stakeholder criteria, whilst the second phase focuses on the extent to which the school is perceived to be effective in its various areas of provision, based on these very criteria. A subsequent analysis of findings seeks to examine stakeholder perspectives, and the extent to which there is congruence and/or divergence of perspective amongst and between stakeholders might create conflict or tensions between and amongst stakeholders. Findings from the first phase of the study suggest that there is broad agreement amongst stakeholders about what should constitute effective provision for Line End pupils: addressing both academic and emotional/behavioural needs effectively, providing a safe and positive environment in which to make such provision, and providing opportunities for the reintegration of pupils to mainstream where appropriate and practicable. These three areas reflect the three major aims of the school as outlined in the staff handbook, and alongside these as key indicators of quality, stakeholders included relationships between home and school, and the management/organisation of the school -the extent to which it was strategically or ‘crisis’ managed. Findings from the second phase of the research suggested that the school was perceived to be effective by virtually all of its stakeholders - in some areas for some of the time. There were differences of perspective within stakeholder groups, and sometimes differences of emphasis between stakeholder groups. These differences did not necessarily lead to tension, as it was possible for differing perspectives to co-exist; the tensions became evident when perspectives conflicted rather than co-existed, as the group or individual who held the greatest power would invariably have its way in translating its perspective into policy and practic