Design of experiment for the optimisation of deep reactive ion etching of silicon inserts for micro-fabrication

The following paper describes a design of experiments investigation of the deep reactive of pillar structures on a silicon wafer. The etched wafers would subsequently be used as masters for the fabrication of nickel mould inserts for microinjection moulding. Undercuts occur when the pillar base has a smaller cross-section than the apex of the pillar. They therefore affect tolerances of the subsequent nickel mould, its strength and its de-mouldability from the silicon form. The response measured in these experiments was the degree of undercut of micro-scale (10 μm x 10 μm x 40 μm, 5 μm x 5 μm x 40 μm and 2 μm x 2 μm x 40 μm) The literature suggests that gas pressure, platen power, gas flow rate, phase switching times and mask size can all affect the degree of undercut. After examination of this literature, and of manufacturers guidelines, three parameters were selected for experimental testing: platen power, C 4F 8 gas flow rate during the passivation phase and switching times. Switching times was found to be the only statistically significant parameter for both 10x10 μm and 5x5 μm pillars. The 2x2 μm pillars were not successfully replicated and could therefore not undergo statistical evaluation

Medieval Smoke-blackened thatch in England

This paper summarized for a European audience what was known about the causes, distribution, and significance of smoke-blackened thatch in England, backed by the authors' photographs,and concludes with a caveat, based on original research, against uncritical acceptance of the evidence of thatch composition as an indication of late-medieval agricultural practices

Design practices used in the development of microfluidic devices: a services-based view

This paper presents the current state of microfluidic design from a practitioner’s perspective. The capture of microfluidic design practice was facilitated through a combination of industry survey and expert interviews, allowing the authors to draw out models for microfluidic design. Exploration of the current practice of microfluidic design showed that formal design methodologies were not in use. This research has also found that sub-section interactions have been addressed in an inadequate fashion by current design practices. The work presented in this paper outlines the scope for further research in the development of a formal design methodology for microfluidics

A study of legal aid and advice in England and Wales.

It is the purpose of this study to examine the social nature of legal aid. The thesis takes as its point of departure the dehates about the problems identified in the administration of the legal aid scheme and the suggestions to improve this scheme. It seeks firstly to provide the reader with an account of the historical changes in legal aid in order to acquaint him with the knowledge about legal aid on which the debates and suggestions are based. Following this the major protagonists are considered and categorised according to their approach towards the problems of legal aid. It is suggested that these varieties of approach, however, all suffer from fundamental limitations in that they fail to question or examine the social and historical basis of legal aid and the legal system. It is argued that only by examining this basis can the nature of legal aid be understood and suggestions for amelioration or change assessed. The second half of the thesis is a detailed study of the social basis of legal aid in the period of the 1920's, 1930's and early 1940's, a period chosen because of its importance for the growth of welfare services generally. The major groups involved in the creation of legal aid are identified and their interests examined; then the role of these groups in producing and changing legal aid is analysed. This is followed by a conclusion which draws together the main themes discussed in the production of legal aid in this period, stressing in particular the importance of the response of the lower classes to the scheme, and re-emphasises the need to understand the social basis of the phenomenon in order to assess policy recommendations. It is the development of this argument and its demonstrationin the analysis of the production of legal aid that is the major contribution of this thesis to sociology and socio-legal studies

A product-service system approach to telehealth application design

A considerable proportion of current point-of-care devices do not offer a wide enough set of capabilities if they are to function in any telehealth system. There is a need for intermediate devices that lie between healthcare devices and service networks. The development of an application is suggested that allows for a smartphone to take the role of an intermediate device. This research seeks to identify the telehealth service requirements for long-term condition management using a product-service system approach. The use of product-service system has proven to be a suitable methodology for the design and development of telehealth smartphone applications

A Catalogue of RR Lyrae Stars from the Northern Sky Variability Survey

A search for RR Lyrae stars has been conducted in the publicly available data of the Northern Sky Variability Survey (NSVS). Candidates have been selected by the statistical properties of their variation; the standard deviation, skewness and kurtosis with appropriate limits determined from a sample 314 known RRab and RRc stars listed in the GCVS. From the period analysis and light curve shape of over 3000 candidates 785 RR Lyrae have been identified of which 188 are previously unknown. The light curves were examined for the Blazhko effect and several new stars showing this were found. Six double-mode RR Lyrae stars were also found of which two are new discoveries. Some previously known variables have been reclassified as RR Lyrae stars and similarly some RR Lyrae stars have been found to be other types of variable, or not variable at all.Comment: Accepted for publication in MNRAS. Tables 1 and 2 are available here in full, but not in the printed editio

Theory and laboratory astrophysics

Science opportunities in the 1990's are discussed. Topics covered include the large scale structure of the universe, galaxies, stars, star formation and the interstellar medium, high energy astrophysics, and the solar system. Laboratory astrophysics in the 1990's is briefly surveyed, covering such topics as molecular, atomic, optical, nuclear and optical physics. Funding recommendations are given for the National Science Foundation, NASA, and the Department of Energy. Recommendations for laboratory astrophysics research are given