[en] Computerised tomography (CT) has been developed for medical imaging purposes using a variety of X-ray scanners. This paper reports on the suitability of one medical scanner, the EMI CT5005, as an industrial scanning tool. A variety of problems were encountered when scanning non-medical objects, and an alternative approach, to construct an experimental scanner based on gamma-ray sources, to overcome the problems of beam hardening, and provide versatility and, perhaps, portability was taken. The greatest limitation on this sort of device is the time needed to produce a scan. However an experimental scanner was constructed and developed to the stage of producing very acceptable images, albeit of moderate resolution. The basic theory of reconstructing images using CT is outlined and the development of the experimental scanner described. The scanner itself, details of control, data processing and the problems encountered are also described. The statistical limitations and the way these affect the quality of the final CT image is investigated in detail. A variety of applications of the scanner are suggested, both in its present form and with foreseeable developments, and a catalogue of the scans obtained using the scanner is provided. (U.K.)

[en] TRACR3D is a computer code developed at Los Alamos National Laboratory to model three-dimensional fluid flow and mass transport in a porous medium. The code is being considered for use in performance assessment modeling of a potential repository for high-level radioactive wastes at Yucca Mountain in Nye County, Nevada. This report describes modifications made during the installation and implementation of the code at Sandia National Laboratories and the results of some test problems. The operating system commands necessary to direct TRACR3D on the CRAY-1 computer at Sandia are included, and a flow chart outlining the code structure is presented

[en] The IAEA require the analysis of plutonium to accuracy commensurate with the effective implementation of International Safeguards. Controlled potential coulometry has been identified as a suitable technique for the determination of plutonium in small samples to be received for analysis at the IAEA Safeguards Analytical Laboratory (SAL), Seibersdorf, Austria. To overcome the potential for erroneous results arising from chemical interferences in coulometry, it is desirable to present the plutonium for measurement in the form of a pure sample. Within the auspices of the UK Support Programme to the IAEA, two tasks have beer undertaken to provide a capability for the measurement of small plutonium samples by coulometry. The first task, UK A00553, involved developing a capability for the measurement of plutonium at the 1mg level by controlled potential coulometry. The second task, UK A00748, involved the development of a procedure for the quantitative purification of 1mg plutonium samples, and implementation of the procedure using a robotic system for the automated purification and measurement of plutonium. This report briefly reviews the work undertaken within Task UK A00553 and describes the development of an automated system within Task UK A00748. The work was completed in December 2000 with delivery to SAL of a robotic system for the purification and measurement of small plutonium samples. (author)

[en] This book makes the first serious appraisal of the current offshore safety regulatory regime instituted after Piper Alpha, and of the oil industry's attempts to contain subsequent unwelcome regulatory interference. It concludes that, as yet, offshore safety is little or not at all improved. The fraught history of trade unionism in the offshore industry and the largely successful strategies of employers to sustain a virtually union-free environment is also examined. The conflict over health and safety offshore has been inextricably bound up with the sometimes brutal struggle over union rights as the workforce has attempted to achieve a collective voice in the reform of safety and production standards. Paying for the Piper shows how the offshore unions have attempted to alter the unfavourable balance of class forces shaped by some of the world's most powerful concerns. (author)

[en] Space-times for which j⁺ (future null infinity) is not necessarily homeomorphic to R x S² are considered. It is shown that, depending on the global conformal structure of j⁺, a given space-time either (1) possesses an asymptotic symmetry group with a normal subgroup of supertranslations, similar in structure to the BMS group, or (2) possesses a simpler kind of asymptotic symmetry group, not involving supertranslations, or (3) has no asymptotic symmetry. The setting is Newman and Unti's approach to asymptotically flat space-times and use is made of the characterization of the asymptotic symmetry transformation as a conformal motion of j= that preserves null angles

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[en] In recent years, advances in the rf gun technology have made it possible to produce small beam emittances suitable for short period microundulators which take advantage of the low emittance beam to reduce the wavelength of FELs. At the Advanced Photon Source, we are studying the design of a compact 50-MeV superconducting mm-wave linac-based FEL for the production of short wavelengths (∼300 nm) to carry out FEL demonstration experiments. The electron source considered for the linac is a 30- GHz, 3 1/2-cell π-mode photocathode rf gun. For cold model rf measurements a 15-GHz prototype structure was fabricated. Here we report on the design, numerical modelling and the initial cold-model rf measurement results on the 15-GHz prototype structure

[en] The principles and practical implementation of computerized reconstructive tomography are examined including the theory of tomographic image reconstruction, and experimental photon tomography. Present uses of this technique in industry and prospective future applications are discussed. (U.K.)

[en] The intuitive definition of asymptotic symmetry is compared with more formal definitions due to Tamburino and Winicour (Phys. Rev.; 150:1039 (1966)), and to Penrose (Phys. Rev. Lett.; 10:66 (1963), Relativity, Groups and Topology. (New York, Gordon and Breach) p. 521 (1964), Proc. R. Soc.; A270:103 (1962)), and within the context of the approach of Newman and Unti (J. Math. Phys.; 3:891 (1962)) to asymptotically flat empty space-times these are shown to be equivalent. Natural interpretations of the transformations inherent in the work of Newman and Unti are given in terms of the conformal approach of Penrose. (author)