Investigating the construction methods of an opus vermiculatum mosaic panel

From the third century BC to the second century AD small detailed central panels (emblemata) made using the opus vermiculatum technique were used as focal points in larger mosaic pavements. They were custom made in stone or terracotta trays to facilitate their transport and placement. Although mosaic panels in opus vermiculatum have been discovered throughout the Hellenistic and Roman Mediterranean, the location of the workshops specialising in the production of the finely worked panels is still unclear. Their association with named artists, for example Dioskourides of Samos, and the locations of finds (such as the fragments of the floor by Hephaistion at Pergamon) point to workshops in the eastern Mediterranean. A large unidentified fragment of an emblema, still in its terracotta tray, from the collections of the Department of Greece and Rome in the British Museum was the subject of analytical examination. These investigations of the tesserae (glass cubes), traces of pigments and mortar aimed to determine the raw materials and manufacturing processes for the mosaic and to characterise the nature of the application of paint to the mortar. Egyptian blue pigment and traces of hematite and carbon suggest that a fully coloured drawing was executed on the fresh mortar to guide the positioning of the tesserae. In addition, samples from the terracotta tray were taken in an attempt to identify its provenance. This contribution describes how the results of these investigations have been used to provide a deeper understanding of opus vermiculatum construction methods

Edward John Dent’s glass springs, archive and technical analysis combined

Clockmakers have long pioneered the design and experimentation of new materials, often in response to demands from the state as well as the market. Late eighteenth and early nineteenth century research into the errors to which marine chronometers were liable is a superb example of this. Balance springs made of hard-drawn gold, resistant to oxidation, were used by John Arnold from the late 1770s, and subsequently by his son John Roger, until Arnold senior’s death. In 1828, Johann Gottlieb Ulrich patented a non-ferrous balance, while, in Glasgow that same year, James Scrymgeour produced a flat spiral made entirely of glass. It is the remarkable application of glass to the construction of balance springs that is the concern of this article. Specifically, the efforts of the firm of Arnold & Dent, and later Dent alone, to secure the performance of their marine chronometers against variations in homogeneity, magnetism, temperature and elasticity, by using new materials for their balance springs.Antiquarian Horological Society research gran

Spatial and Temporal Stability of Airglow Measured in the Meinel Band Window at 1191.3 nm

We report on the temporal and spatial fluctuations in the atmospheric brightness in the narrow band between Meinel emission lines at 1191.3 nm using an R=320 near-infrared instrument. We present the instrument design and implementation, followed by a detailed analysis of data taken over the course of a night from Table Mountain Observatory. The absolute sky brightness at this wavelength is found to be 5330 +/- 30 nW m^-2 sr^-1, consistent with previous measurements of the inter-band airglow at these wavelengths. This amplitude is larger than simple models of the continuum component of the airglow emission at these wavelengths, confirming that an extra emissive or scattering component is required to explain the observations. We perform a detailed investigation of the noise properties of the data and find no evidence for a noise component associated with temporal instability in the inter-line continuum. This result demonstrates that in several hours of ~100s integrations the noise performance of the instrument does not appear to significantly degrade from expectations, giving a proof of concept that near-IR line intensity mapping may be feasible from ground-based sites.Comment: 15 figures, submitted to PAS

Dialogic pedagogy in graduate teacher education research advisement: A narrative account of three teacher educators

Research methods courses often tend to focus on transferring technical information to students rather than offer a more dialogical approach to learning (Barraket, 2005; Kilburn et al., 2014). By drawing on the concept of self-study (Bullough & Pinnegar, 2001), through personal journals and retrospective reflections, this paper explores learning activities introduced in three teacher education graduate research methods courses to support student learning beyond the mastering of research skills or techniques. Narratives of three teacher educators illustrate how teacher candidates can dialogically reflect on research-related topics with peers, bring questions forward for discussion in class and online, apply their emerging technical research skills through collective analysis of a situation, and grow collective knowledge. Teacher candidates recognize the importance of research in their work, although their passion for conducting research is influenced by varied constraints, including research design, programmatic and personal limitations

Participation in sport as a mechanism to transform the lives of young people within the criminal justice system::an academic exploration of a theory of change

Sport is often framed as a panacea for social disharmony, especially within the context of marginalised youth populations, and is widely promoted as a mechanism through which a multiplicity of social policy objectives can be achieved. Yet while political rhetoric has long pointed towards sport’s transformative abilities, the basis for such claims remains unproven. Theory-based approaches to evaluation have been posited as a useful device to explore the impact of specific initiatives and indicate where best practice may operate. The aim of this paper is to highlight one such theory-based framework that has been devised by practitioners in recent years around the operationalisation and evaluation of sporting interventions in criminal justice settings and which has come to be adopted as the dominant ‘theory of change’ across sport and criminal justice practitioner settings in the UK, but has, as yet, eluded academic scrutiny. To address this omission, the present discussion offers an in-depth analysis of this framework with the aim of discerning more clearly ‘what might work’ within sport and criminal justice contexts. In turn, the paper aims to stimulate further academic debate around the instrumental role of sport within criminal justice and the value of such frameworks for both policy and practice

Function block programming for distributed control : a thesis presented in complete fulfilment of the requirements for the Master of Engineering, 216.899 thesis at Massey University, Wellington, New Zealand

This report discusses research and development using the draft IEC 61499 function block standard for distributed control with embedded microprocessor applications. This is a function block programming language that is currently under development for programming distributed control systems. The report covers what is required to develop an IEC 61499 compliant product and its suitablity for use with distributed control systems. To utilise the IEC 61499 standard, research and development of an embedded Java platform was performed. This required porting a Java virtual machine to run on an embedded microprocessor. An existing industrial network protocol DeviceNet was chosen for distributing the data between the network of control devices. To achieve this an upgrade was required to an existing DeviceNet communications engine to support distributed control. A third party IEC 61499 software application engine was ported to run on an embedded microprocessor. This option was chosen rather than completely developing a software engine as a commercial decision by the developer company. It also allowed support from other companies and researchers working with this standard. To test distributed control using this function block programming standard a test application consisting of a conveyor and three axis robot was developed. The test application demonstrated the feasibility of distributed control using IEC 61499 function blocks and some of the advantages of distributed control. Further outcomes of this research have highlighted some of the problems that require rectifying before this function block programming standard is feasible for commercial products

The chemical and isotopic analysis of English forest glass

Glass is one of several early modern industries where the development from small-scale workshop to large-scale industry offers a valuable insight into wider socio-economic trends. Previously, medieval and early modern forest (wood ash) glass has been studied using a range of analytical techniques. However, characterisations of production centres and exchange systems for forest glasses are difficult to verify, in part because very few examples of raw glass from furnace sites have been investigated. The necessity for an independent means of provenancing glass used in the study of exchange systems is clear. Compositional analysis can provide evidence for the raw materials used and can sometimes provide compositional groupings specific to sites. However, strontium, neodymium and oxygen isotope determinations can actually provenance the glass by linking the geological ages, or sources, of raw materials to production sites. The potential of using Sr and O isotopes in the study of plant ash glasses has recently been established (Henderson et al., J. Archaeol. Sci., 32, 2005). Using EPMA-WDS over 179 raw glass samples from 12 English production sites in operation between the 14th and 17th centuries have been analysed. These analyses have shown compositional types which are relatable to the region or, in some cases, the period of production. Over 60 archaeological glass, raw material and model glass samples from these sites have also been analysed using mass spectrometry to determine strontium, neodymium and oxygen isotope ratios. The isotopic analyses have also been very effective in showing differences between sites, even those within the same region. This thesis will argue that the combination of these techniques offers a promising new way of provenancing archaeological glass and provide an insight into the organisation of production at this time