Shear stresses in turbulent flow through concentric annuli

Bibliography: pages 161-164.A novel experimental approach to the direct measurement of wall shear stresses in fully developed turbulent flow in concentric annuli is presented. By means of a specially constructed 6 m test rig known as the 'floating sleeve', results of individual wall shear stresses, friction factors and shear stress distributions were obtained for Reynolds numbers from 25 000 to 220 000 with radius ratios from 0,091 to 0,376. Tests were conducted using both smooth and rough annuli. A summary of previous investigations and an examination of the measuring devices most commonly used in annular flow are also presented

Electroweak Theory Without Higgs Bosons

A perturbative SU(2)_L X U(1)_Y electroweak theory containing W, Z, photon, ghost, lepton and quark fields, but no Higgs or other fields, gives masses to W, Z and the non-neutrino fermions by means of an unconventional choice for the unperturbed Lagrangian and a novel method of renormalisation. The renormalisation extends to all orders. The masses emerge on renormalisation to one loop. To one loop the neutrinos are massless, the A -> Z transition drops out of the theory, the d quark is unstable and S-matrix elements are independent of the gauge parameter xi.Comment: 27 pages, LaTex, no figures; revised for publication; accepted by Int. J. Mod. Phys. A; includes biographical note on A. F. Nicholso

Intratextual Echoes of Christine de Pizan’s Rondeau LXII

The reception history of Rondeau LXII reveals divergent views as to whether this poem belongs to the corpus of Christine’s poems on widowhood, or not. This article sheds light on these views by showing that Christine develops a distinctive type of imagery (imminent submersion, drowning) to engage with the experience of abandonment, either as fictional lover (Rondeau LXII) or as grieving widow (notably the Cent balades, Rondeaux, the Advision Cristine and the Mutacion de Fortune). Even though the manuscript tradition makes it clear that the poem does not belong to the widowhood corpus, the identical imagery linking Rondeau LXII to works of Christine specifically related to the handling of her husband’s death blurs the distinction between lover and widow. It thus becomes easier to understand why some readers have read Rondeau LXII as though it were part of the widowhood corpus.L’histoire de la réception du Rondeau LXII présente des vues divergentes sur la question de savoir si ce poème appartient au corpus des écrits de Christine concernant le veuvage. Cet article entend jeter quelque lumière sur ces points de vue contradictoires, en montrant que Christine développe des images distinctives (submersion imminente, mort par noyade) dans son traitement de l’expérience de l’abandon, soit en tant qu’amante fictive (Rondeau LXII) soit en tant que veuve inconsolable (notamment les Cent balades, Rondeaux, l’Advision Cristine et la Mutacion de Fortune). Même si la tradition manuscrite démontre que le poème n’appartient pas au corpus sur le veuvage, les images identiques reliant le Rondeau LXII aux œuvres de Christine qui traitent spécifiquement de la mort de son mari estompent la distinction entre l’amante et la veuve. On comprend mieux donc les raisons pour lesquelles certain(e)s lecteurs/lectrices ont lu ce rondeau comme s’il appartenait aux poèmes sur le veuvage

Intratextual Echoes of Christine de Pizan’s Rondeau LXII

The reception history of Rondeau LXII reveals divergent views as to whether this poem belongs to the corpus of Christine’s poems on widowhood, or not. This article sheds light on these views by showing that Christine develops a distinctive type of imagery (imminent submersion, drowning) to engage with the experience of abandonment, either as fictional lover (Rondeau LXII) or as grieving widow (notably the Cent balades, Rondeaux, the Advision Cristine and the Mutacion de Fortune). Even though the manuscript tradition makes it clear that the poem does not belong to the widowhood corpus, the identical imagery linking Rondeau LXII to works of Christine specifically related to the handling of her husband’s death blurs the distinction between lover and widow. It thus becomes easier to understand why some readers have read Rondeau LXII as though it were part of the widowhood corpus.L’histoire de la réception du Rondeau LXII présente des vues divergentes sur la question de savoir si ce poème appartient au corpus des écrits de Christine concernant le veuvage. Cet article entend jeter quelque lumière sur ces points de vue contradictoires, en montrant que Christine développe des images distinctives (submersion imminente, mort par noyade) dans son traitement de l’expérience de l’abandon, soit en tant qu’amante fictive (Rondeau LXII) soit en tant que veuve inconsolable (notamment les Cent balades, Rondeaux, l’Advision Cristine et la Mutacion de Fortune). Même si la tradition manuscrite démontre que le poème n’appartient pas au corpus sur le veuvage, les images identiques reliant le Rondeau LXII aux œuvres de Christine qui traitent spécifiquement de la mort de son mari estompent la distinction entre l’amante et la veuve. On comprend mieux donc les raisons pour lesquelles certain(e)s lecteurs/lectrices ont lu ce rondeau comme s’il appartenait aux poèmes sur le veuvage

Towards the 3D Web with Open Simulator

Continuing advances and reduced costs in computational power, graphics processors and network bandwidth have led to 3D immersive multi-user virtual worlds becoming increasingly accessible while offering an improved and engaging Quality of Experience. At the same time the functionality of the World Wide Web continues to expand alongside the computing infrastructure it runs on and pages can now routinely accommodate many forms of interactive multimedia components as standard features - streaming video for example. Inevitably there is an emerging expectation that the Web will expand further to incorporate immersive 3D environments. This is exciting because humans are well adapted to operating in 3D environments and it is challenging because existing software and skill sets are focused around competencies in 2D Web applications. Open Simulator (OpenSim) is a freely available open source tool-kit that empowers users to create and deploy their own 3D environments in the same way that anyone can create and deploy a Web site. Its characteristics can be seen as a set of references as to how the 3D Web could be instantiated. This paper describes experiments carried out with OpenSim to better understand network and system issues, and presents experience in using OpenSim to develop and deliver applications for education and cultural heritage. Evaluation is based upon observations of these applications in use and measurements of systems both in the lab and in the wild.Postprin

Growing the use of Virtual Worlds in education : an OpenSim perspective

The growth in the range of disciplines that Virtual Worlds support for educational purposes is evidenced by recent applications in the fields of cultural heritage, humanitarian aid, space exploration, virtual laboratories in the physical sciences, archaeology, computer science and coastal geography. This growth is due in part to the flexibility of OpenSim, the open source virtual world platform which by adopting Second Life protocols and norms has created a de facto standard for open virtual worlds that is supported by a growing number of third party open source viewers. Yet while this diversity of use-cases is impressive and Virtual Worlds for open learning are highly popular with lecturers and learners alike immersive education remains an essentially niche activity. This paper identifies functional challenges in terms of Management, Network Infrastructure, the Immersive 3D Web and Programmability that must be addressed to enable the wider adoption of Open Virtual Worlds as a routine learning technology platform. We refer to specific use-cases based on OpenSim and abstract generic requirements which should be met to enable the growth in use of Open Virtual Worlds as a mainstream educational facility. A case study of a deployment to support a formal education curriculum and associated informal learning is used to illustrate key points.Postprin

The Aflatoxin QuicktestTM—A Practical Tool for Ensuring Safety in Agricultural Produce

Contamination of corn, peanuts, milk and dairy products with aflatoxins is a worldwide problem, particularly in subtropical regions where the climatic conditions are ideal for the growth of Aspergillus flavus, the fungi that produces these toxins. Developing countries have major difficulties in marketing these products abroad due to the stringent international regulations concerning this carcinogenic toxin. Adding to the problem is the analytical cost involved in monitoring the produce, which require sophisticated instrumentation and qualified personnel, neither of which are available for field testing. The development of a rapid Aflatoxin Quicktest™ provides an effective, reliable and cheaper option for screening levels of aflatoxin above the regulatory thresholds in such produce. The test consists of a lateral flow device (LFD) coated with antibodies specific to aflatoxin B1, although it detects other aflatoxins (i.e. G and M) with high cross-reactivity. Its high sensitivity allows analysis of these toxins in the range 2–40 μg/kg of sample in 15 minutes, plus the time for extraction, which varies among different products. Quantification of the test results is done using a Quick Reader, by comparing the readings of individual tests against a standard curve of the analytes in the same manner as it is done with any other analytical equipment. A validation study was carried out using peanuts from Australia and peanuts and corn from Timor-Leste to assess the performance of the Aflatoxin Quicktest™. Results obtained with the LFD showed a good correlation with the standard analytical measurements by HPLC-fluorescence (r2 above 0.90 for all cases), indicating the Aflatoxin Quicktest™ is capable of measuring levels of aflatoxins accurately and reliably. Given their ease of use, low cost and fast processing time, the Aflatoxin Quicktest™ can be used for screening agricultural produce in countries that cannot afford the costly alternative of using specialised personnel and equipment

Immersive Installation: “A Virtual St Kilda”

This paper discusses a Virtual Histories project, which developed a digital reconstruction of St Kilda. St Kilda is the most remote and western part of the United Kingdom. It was evacuated in the 1930s and lay empty for several decades. It is a world heritage site for both built and natural environment . The Virtual St Kilda acted as a focus for the collection and presentation of tangible and intangible cultural heritage. It was on show as an exhibition in the Taigh Chearsabah museum (Figure 5) located in North Uist Scotland. The exhibition is built around the OpenSimulator Open VirtualWorld server using commodity hardware. The simulation covers some 4 square km of virtual space, and models both tangible and intangible culture. It is integrated into an exhibition and articulates an interpretation of the St Kilda legacy through the prism of contemporary North Uist life.Postprin