Effect of extended ball milling on graphite

Graphite has been milled for up to 1000 h in a laboratory scale tumbling ball mill under vacuum. Raman spectroscopy of the powders indicated the increasing dominance of D-type graphitic sp bonding over G-type bonding with increasing milling time. Diamond-like sp bonding and possibly fullerene-like bonding also became evident after milling. TEM of the 100 h sample showed the presence of ribbons which were composed of sheets showing defects, delamination, translation, warping and curvature. Interplanar spacings of 0.40–0.50 nm were measured with the spacing increasing towards the edge of the ribbons where delamination was evident. Thermogravimetric analysis in argon of the powder after exposure to air showed an increasing mass loss with milling time indicating the presence of chemisorbed gas. Using TG–FTIR the gas was found to be a mixture of CO and an unidentified gas (probably oxygen). BET surface area measurements showed a maximum in the surface area; however, this was shown to be massively in error for the longer milling times due to the presence of the chemisorbed gas

Behavioural, developmental and psychological characteristics in children with germline PTEN mutations:a carer report study

Background: PTEN is primarily known as a tumour suppressor gene. However, research describes higher rates of difficulties including intellectual disability and difficulties relating to autism spectrum conditions (ASCs) in people with germline PTEN mutations. Other psychological characteristics/experiences are less often reported and are explored in this study. Methods: The parents of 20 children with PTEN mutations completed an online survey exploring adaptive behaviour, ASC‐associated behaviours, anxiety, mood, hypermobility, behaviours that challenge, sensory experiences, quality of life and parental wellbeing. Published normative data and data from groups of individuals with other genetic neurodevelopmental conditions were used to contextualise findings. Results: Overall levels of adaptive behaviour were below the ‘typical’ range, and no marked relative differences were noted between domains. Higher levels of ASC‐related difficulties, including sensory experiences, were found in comparison with ‘typically developing’ children, with a possible peak in restrictive/repetitive behaviour; ASC and sensory processing atypicality also strongly correlated with reported joint hypermobility. A relative preservation of social motivation was noted. Anxiety levels were found to be elevated overall (and to relate to sensory processing and joint hypermobility), with the exception of social anxiety, which was comparable with normative data. Self‐injurious behaviour was common. Conclusions: Results suggest a wide range of possible difficulties in children with PTEN mutations, including elevated anxiety. Despite elevated ASC phenomenology, social motivation may remain relatively strong. Firm conclusions are restricted by a small sample size and potential recruitment bias, and future research is required to further explore the relationships between such characteristics

Tarrant Launceston: Survey and excavation of a long barrow with secondary burial at Race Down.

In March 2003, it was noted that rabbit burrowing had uncovered possible human remains close to the centre of Race Down long barrow. In order to determine whether the bones were human and/or of forensic interest, the School of Conservation Sciences (now the Department of Archaeology, Anthropology & Forensic Science), Bournemouth University, carried out a limited investigation on behalf of Dorset Police and the landowner, Defence Estates. The spoil heap of the rabbit burrow was excavated and this process revealed other displaced human bones, including long bones. A human osteologist examined the recovered bones and determined that the burial was ancient. Based upon results of the initial investigation, Dorset Police concluded that, although the remains were human, they would not be carrying out a criminal investigation due to the antiquity of the remains. In March 2004, a small excavation team from Bournemouth University returned to the site to fully recover any in situ human remains, together with recording the burial context and stratigraphy. A wider topographic survey of the long barrow was also carried out. This paper reports on the results of this field survey and excavation

Pleistocene landscape evolution in the Avon valley, southern Britain: optical dating of terrace formation and Palaeolithic archaeology

This paper presents the first comprehensive Optically Stimulated Luminescence dating programme from a sequence of Pleistocene river terraces in the Avon valley (Wiltshire-Hampshire-Dorset), southern Britain. These results offer the most complete chronometric framework for Pleistocene landscape evolution and Palaeolithic occupation in the Avon valley, allowing for the first time: (1) an assessment of the timing of terrace formation and landscape evolution, (2) the dating of hominin presence in the area, and (3) an investigation of the relationship between terrace formation and Quaternary climatic change. Analysis of 25 samples collected from terraces 10 and 7 to 4 show that the middle Avon terraces formed in response to the main Pleistocene climatic oscillations (Marine Isotope Stage (MIS) 10, 8, 6) and that fluvial mechanisms changed through time, resulting in three different types of terrace architecture. The highest and oldest deposits are compound terraces deposited during the Early Pleistocene before the Mid Pleistocene Transition. The middle reach of the valley is characterised by well-developed strath terraces overlain with thick fluvial deposits, reflecting the greater degree of incision in response to the increased amplitude of climate cycles in the Middle Pleistocene. The youngest deposits in the confined modern floodplain represent cut-and-fill terraces deposited after MIS5e. The results indicate that the two main Palaeolithic sites in the area, Milford Hill and Woodgreen, date to between at least MIS 10 and 8 with a pre-MIS 10 human occupation at a third main site at Bemerton. This is significant because the sites date to a period previously associated with a decline in hominin presence in Britain. The dating of the Avon valley terrace sequence highlights the complex nature of terrace formation during the Pleistocene and the need to critically reassess the chronological understanding of these fluvial archives in southern Britain. This research demonstrates that with a detailed and multidisciplinary approach shifts in hominin landscape use can be discovered, providing new information on hominin behavioural change during the Pleistocene

Effects of environmental factors on development of Pyrenopeziza brassicae (light leaf spot) apothecia on oilseed rape debris

Publication no. P-2001-0221-01R. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 2001The development of Pyrenopeziza brassicae (light leaf spot) apothecia was studied on petiole debris from artificially infected oilseed rape leaves incubated at temperatures from 6 to 22 degreesC under different wetness regimes and in 16 h light/8 h dark or continuous darkness. There was no significant difference between light treatments in numbers of apothecia that developed. Mature apothecia developed at temperatures from 5 to 18 degreesC but not at 22 degreesC. The rate of apothecial development decreased as temperature decreased from 18 to 5 degreesC; mature apothecia were first observed after 5 days at 18 degreesC and after 15 days at 6 degreesC. Models were fitted to estimates of the time (days) for 50% of the maximum number of apothecia to develop (t(1); model 1, t(1) = 7.6 + 55.8(0.839)(T)) and the time for 50% of the maximum number of apothecia to decay (t(2); model 2, t(2) = 24.2 + 387(0.730)(T)) at temperatures (T) from 6 to 18 degreesC. An interruption in wetness of the petiole debris for 4 days after 4, 7, or 10 days of wetness delayed the time to observation of the first mature apothecia for approximate to4 days and decreased the number of apothecia produced (by comparison with continuous wetness). A relationship was found between water content of pod debris and electrical resistance measured by a debris-wetness sensor. The differences between values of tl predicted by model 1 and observed values of t(1) were 1 to 9 days. Model 2 did not predict t(2); apothecia decayed more quickly under natural conditions than predicted by model 2.Peer reviewe

Time and energy constraints and the relationships between currencies in foraging theory

Measured foraging strategies often cluster around values that maximize the ratio of energy gained over energy spent while foraging (efficiency), rather than values that would maximize the long-term net rate of energy gain (rate). The reasons for this are not understood. This paper focuses on time and energy constraints while foraging to illustrate the relationship between efficiency and rate-maximizing strategies and develops models that provide a simple framework to analyze foraging strategies in two distinct foraging contexts. We assume that while capturing and ingesting food for their own use (which we term feeding), foragers behave so as to maximize the total net daily energetic gain. When gathering food for others or for storage (which we term provisioning), we assume that foragers behave so as to maximize the total daily delivery, subject to meeting their own energetic requirements. In feeding contexts, the behavior maximizing total net daily gain also maximizes efficiency when daily intake is limited by the assimilation capacity. In contrast, when time available to forage sets the limit to gross intake, the behavior maximizing total net daily gain also maximizes rate. In provisioning contexts, when daily delivery is constrained by the energy needed to power self-feeding, maximizing efficiency ensures the highest total daily delivery. When time needed to recoup energetic expenditure limits total delivery, a low self-feeding rate relative to the rate of energy expenditure favors efficient strategies. However, as the rate of self-feeding increases, foraging behavior deviates from efficiency maximization in the direction predicted by rate maximization. Experimental manipulations of the rate of self-feeding in provisioning contexts could be a powerful tool to explore the relationship between rate and efficiency-maximizing behavio

Virtual Avebury: Exploring sense of place in a virtual archaeology simulation

This paper describes and discusses creating and evaluating a virtual reality simulation of Avebury Stone Circle and Henge complex as it might have appeared and sounded circa 2300 BCE. Avebury is a Neolithic heritage site in the UK which is part of the Stonehenge, Avebury and Associated Sites UNESCO World Heritage Site. The overall aim of the project was to better understand the sense of place and presence that visitors can experience in virtual simulations of heritage sites. We investigated how virtual spaces might become experienced as places by visitors through their exploration, active participation, sensory stimulation and communication with other visitors in the simulation. More than 1200 members of the public experienced the simulation, both at Avebury itself and at three public exhibitions. The specific objectives of the project were to explore if and how the believability of a simulation was associated with feeling a sense of place in the virtual landscape, and if some personal characteristics, viz. age, disability, sex, immersive tendency, familiarity with IT and frequency of playing computer games, were associated with levels of enjoyment in, and learning from, the simulation. We analysed the data from a detailed questionnaire completed by 388 of the 702 visitors to Avebury from June to September 2018 who experienced the simulation, supported by observational data from all participants at all events. We found that believability was associated with a sense of place in the simulation, i.e. that the more believable the simulation appeared, the greater the sense of place experienced by the participants. We also found that personal characteristics had very little influence upon visitor reactions to the simulation, suggesting that such simulations might have wide appeal for heritage and museum visitors, regardless of age, gender or familiarity with technology

Geospatial Approaches to Mapping Archaeological Deposits in Dynamic Landscapes: The Battlefield of Waterloo, Belgium

Abstract for paper to be presented at 2022 Spatial Humanities conference

Geophysical approaches to the archaeological prospection of early modern battlefield landscapes: a review of methods and objectives

This paper reviews methodological approaches in battlefield archaeology with a focus on sites of the early modern period, ca. 17th-19th century. The challenges associated with the prospection of these sites partially explains the relative lack of serious research in this area until the late 20th century. While acknowledging the foundational role of conventional metal detection in overcoming these difficulties, it is argued that other less widely deployed geophysical methods should be increasingly used as part of an integrated approach to studying battlefield landscapes. Targets of interest are reviewed alongside the geophysical properties that might enable their detection and a selection of case studies successfully deploying these approaches within battlefield archaeology and adjacent disciplines are considered