Fabrication and measurement of superconducting nanowires

An investigation was made into techniques that could be employed to produce sub-100nm wide superconducting nanowires. Nanowires of niobium and Y Ba$_2$Cu$_3$O$_{7-δ}$ (YBCO) were fabricated in thin films using focused gallium ion beam milling (FIB) to a range of widths (100nm-300nm). A procedure was developed to controllably reduce the wire widths using argon ion beam milling. Milling niobium wires under rotation at 75 degrees to the normal produced wires with width and thickness ∼70nm. The nanowires were cryogenically cooled to 4K and the resistance versus temperature characteristics measured. Nb and YBCO wires exhibited a broadening of the superconducting transition, which fitted reasonably with the theory of thermally activated phase slips. Further analysis of the voltage versus current characteristics of the wires showed behaviour not in agreement with the established theory. Various possible explanations were considered for this, with the conclusion that damage to the wires caused by implantation of gallium wa

Earth construction in Algeria between tradition and modernity

In the south of Algeria, many indigenous settlements have been built using local earth construction techniques; in the north, despite the availability of suitable earth, only a few rural contemporary settlements have been built using ‘improved’ earth construction. This paper adopts a case study approach to examine and compare structural deficiencies of two earth-built housing settlements in different regions in Algeria. In the indigenous earth settlement in the south, where adobe was used in combination with local timber and stones, the dwellings exhibit many structural defects. Stabilisation of the soil and introduction of modern materials in the contemporary rammed earth settlement in the north has not, however, helped produce structurally adequate dwellings. These dwellings also exhibited many cracks and debonding of rendering, and thus did not fulfil the requirements and aspirations of their occupants. The study concludes that for a potentially successful earth building scheme there are inter-related factors that should be considered: selection of an appropriate soil and construction technique, implementation of a suitable structural design, construction and post-completion processes, availability of relevant skills and provision of adequate training on the construction technique

Book Reviews

BOOK REVIEWS The Swiss Way of Welfare: Lessons for the Western World. Ralph Segalman. New York: Praeger, 1986, 205 pp., $39.95. - Reviewed by Isidor Walliman Vieillesses: Situations, Itineraires et Modes de Vie des Personnes Agees Aujourd\u27Hui. Christian Lalive d\u27Epiany (Ed.). Saint Saphorin, Switzerland: Edition Georgi, 1983. - Reviewed by Elizabeth D. Huttman with the assistance of Anna Marie Rampmaier and W and N. Weber. Wohlfahrtsstaat Schweiz (The Swiss Welfare State). Antonin Wagner. Bern: Paul Haupt, 1985, 248 pp., S.E 32. - Reviewed by Shimon S. Gottschalk The Mean Season: The Attack on the Welfare State. Fred Block, Richard A. Cloward, Barbara Ehrenreich, Frances Fox Piven. New York: Pantheon Books, 1987, 205 pp.,$8.95. - Reviewed by Robert Sheak Shared Responsibility: Families and Social Policy. Robert M. Moroney. Hawthorne, N.Y.: Aldine Publishing Co., 1986, $31.95 cloth,$14.94 paper. - Reviewed by Christina R. Curtiss

On the calibration of rectangular atomic force microscope cantilevers modified by particle attachment and lamination

A simple but effective method for estimating the spring constant of commercially available atomic force microscope (AFM) cantilevers is presented, based on estimating the cantilever thickness from knowledge of its length, width, resonant frequency and the presence or absence of an added mass, such as a colloid probe at the cantilever apex, or a thin film of deposited material. The spring constant of the cantilever can then be estimated using standard equations for cantilever beams. The results are compared to spring constant calibration measurements performed using reference cantilevers. Additionally, the effect of the deposition of Cr and Ti thin films onto rectangular Si cantilevers is investigated

Earth construction between tradition and modernity: Case studies on Algeria

In the south of Algeria, many indigenous settlements have been built using local earth construction techniques, whilst in the north, despite the availability of suitable earth, only a few rural contemporary settlements have been built using ‘improved’ earth construction. This paper adopts a case study approach to examine and compare structural deficiencies of two earth-built housing settlements in different regions in Algeria. In the indigenous earth settlement in the south, where adobe was used in combination with local timber and stones, the dwellings exhibited many structural defects. Stabilisation of the soil and introduction of modern materials in the contemporary rammed earth settlement in the north, have not however helped produce structurally adequate dwellings. These also exhibited many cracks and de-bonding of rendering, and thus not fulfilling the requirements and aspirations of their occupants. The study concludes for a potentially successful earth building scheme there are inter-related factors that should be considered, including: selection of appropriate soil and construction technique, implementing suitable design, construction and post completion processes, availability of relevant skills and provision of adequate training on the construction technique

Disability in higher education: do reasonable adjustments contribute to an inclusive curriculum?

The study focuses on the importance of inclusive curriculum design in Higher Education (HE) and the impact of reasonable adjustments in ensuring inclusive practices. Although making reasonable adjustments attempts to ensure inclusivity, the data gathered suggests that some staff struggle to accommodate disabled students, due to a lack of knowledge, training and awareness of disability. The findings are drawn from qualitative data collected from five participants by way of in-depth interviews. The study explored the perceptions of staff members in a Law School, and attempts to offer practical recommendations to ensure HE institutions adopt inclusive practices in their curriculum design. The findings suggest that having an inclusive curriculum can in some cases minimise or obviate the need to make reasonable adjustments. It is suggested that HE institutions should now switch their focus to the social model of disability which focuses on attitudes, so as to transform the perception of staff towards disabled students. Additionally, practical solutions are provided in an attempt to recognise that disabled students may need to be treated differently, in order to achieve their full potential, which ultimately ensures inclusion within the curriculum

Methods of assessing flood resilience of critical buildings

An overview is presented of recent advances in the assessment methods and mitigation solutions for the performance of critical buildings during flood events. This draws on research focusing on critical urban infrastructure, which is defined as assets that are essential for the continuity of economic activities in cities and for the basic living needs of the urban population. These assets include networks as well as buildings, the latter (termed ‘critical buildings’) having an important role in protecting equipment and personnel associated with the networks. Examples include power stations, transport control centres, communication hubs, fire stations, shelters and hospitals. Unlike domestic constructions, due to their specificity, these buildings cannot easily be categorised in terms of type of construction or age, and have to be treated as individual buildings. Three methods are presented as a framework with a logical progression for the assessment of building flood vulnerability and the identification of improvement measures: the ‘quick scan’ method, the ‘selection and evaluation tools for flood proofing of buildings’ and the ‘individual building flood damage tool’ (IBT). It is expected that building owners, insurance companies, local authorities and agencies with urban flood management responsibilities will benefit from the application of the framework and tools presented

Post-flood damage data: requirements for disaster forensic investigation

Disaster forensic investigation analyses the unfolding of a disaster and attempts to identify its multiple causes of damage which can lead to (i) improved disaster prevention and management from lessons learnt, and (ii) more effective mitigation measures in the aftermath of a disaster. The way in which damage data are collected after a flood event as well as the types of collected data influences their usability within forensic investigations. In order to explore whether or not existing data can be used for disaster forensic analysis, the European Project IDEA (Improving Damage assessments to Enhance cost-benefit Analyses) is investigating existing gaps in damage information so as to identify possible paths towards improving data quality. This paper focuses in detail on a forensic analysis of the interlinked damage to economic activities and infrastructure in the Severn floods of 2007 in the UK. Besides investigating the usability of existing data, this research investigated: (i) the relative weight of direct and indirect costs to business and infrastructure companies; (ii) to what extent damage to infrastructure has impacted on indirect damage to businesses. Finally recommendations for improving the data for use in forensic investigation are offered

Teacher agency and professional learning communities; what can Learning Rounds in Scotland teach us?

Recently there has been growth in researching teacher agency. Some research has considered the relationship between teacher agency and professional learning. Similarly, there has been growing interest in professional learning communities as resources for professional learning. Connections have been made between professional learning communities and teacher agency, with professional learning communities seen as an affordance for the exercise of teacher agency. However, it has also been argued that there is little detailed evidence of what happens inside professional learning communities or of teacher agency in action. The research reported here focuses on a form of professional learning community from Scotland: Learning Rounds. It uses data from transcripts of post classroom observation conversations to consider the extent to which Learning Rounds provide an affordance for teacher agency and the extent to which that affordance is utilised. This research makes a contribution in three ways: adding to an empirical understanding of what happens in professional learning communities; understanding how teacher agency is (or is not) exercised in practice; considering what factors might affect the utilisation (or otherwise) of affordances for teacher agency. The paper concludes with several recommendations for developing effective professional learning communities as an affordance for teacher agency