Portable Gamma Spectrometry Surveys of Sites in Portugal in Support of the VADOSE Project

The VADOSE project involves the use of multiple techniques to evaluate dose rate variability on different spatial scales. Several sites in central northern Portugal, mostly in the vicinity of Aveiro, have been investigated. As part of this investigation, portable gamma spectrometry techniques were used to map areas of approximately 100x100m around each sampling location. The SUERC portable gamma spectrometry system used consists of a 3x3” NaI(Tl) spectrometer with integral GPS receiver. Measurements were conducted with 10s integration time. Maps of the dose rate variability in each area were generated in the field, and used to confirm data quality and coverage and identify any remaining locations that would benefit from further measurements prior to leaving the site. Maps of natural radionuclide distribution (40K, 214Bi from the 238U decay series, and 208Tl from the 232Th decay series) were produced after the conclusion of measurements each day. Natural radionuclide specific activities (Bq kg-1 ) were estimated using a spectral windows method with stripping1 , using a working calibration assuming planar geometry and uniform activity distribution. As agreed prior to the start of work, a working calibration derived from field measurements and photon fluence calculations conducted for similar detectors in the 1990s2 has been used here, with calibration parameters given in the appendix. This report presents the dose rate maps produced during the field work, with a very brief description of the data. Summary statistics for each data set are presented in Table 1. All data have been mapped using a UTM (zone 29T) grid, with the approximate location of ground features added by hand as a guide. Further work could be conducted to produce more accurate overlays of ground features. At each site in-situ gamma spectrometry measurements were also conducted by ITN, and the data collected by the two detector systems and the soil samples will be compared at a later date

Precedence relationship representations of mechanical assembly sequences

Two types of precedence relationship representations for mechanical assembly sequences are presented: precedence relationships between the establishment of one connection between two parts and the establishment of another connection, and precedence relationships between the establishment of one connection and states of the assembly process. Precedence relationship representations have the advantage of being very compact. The problem with these representations was how to guarantee their correctness and completeness. Two theorems are presented each of which leads to the generation of one type of precedence relationship representation guaranteeing its correctness and completeness for a class of assemblies

The effect of flight line spacing on radioactivity inventory and spatial feature characteristics of airborne gamma-ray spectrometry data

Airborne Gamma Spectrometry (AGS) is well suited to the mapping of radioactivity in the environment. Flight parameters (e.g. speed and line spacing) directly affect the rate of area coverage, cost, and data quality of any survey. The influences of line spacing have been investigated for data from inter‐tidal, coastal and upland environments with a range of <sup>137</sup>Cs activity concentrations and depositional histories. Estimates of the integrated <sup>137</sup>Cs activity (‘inventory’) within specified areas and the shapes of depositional features were calculated for subsets of the data at different line spacings. Features with dimensions greater than the line spacing show variations in inventory and area of less than 3%, and features with dimensions less than the line spacing show larger variations and a decreased probability of detection. The choice of line spacing for a task is dependent on the dimensions of the features of interest and required edge definition. Options for line spacing for different tasks are suggested. It is noted that for regional mapping, even 5–10 km line spacing can produce useful data

Mobile Gamma Spectrometry Survey of the Scottish Enterprise Technology Park, East Kilbride, 17th-19th August 2009

<p>Environmental radioactivity arises from natural geological sources, the redistribution of natural activity through industrial processes, the nuclear industry including routine and accidental discharges into the environment, and various medical or industrial uses of radioisotopes. Mobile gamma spectrometry provides a powerful means of measuring the distribution of radioactivity in the environment. Data collected by such methods provide measures of environmental quality, references for public health assurance, means to assess environmental change, and other uses. Airborne Gamma Spectrometry (AGS) has been developed at SUERC for environmental purposes since 1988, and provides a capability for very rapid and cost effective surveys of large areas, and provides for visualisation and classification of enhanced features of radioactivity within the context of natural variations. Ground based approaches, with equipment mounted on vehicles or backpacks, provide more detailed spatial resolution for smaller areas at significantly reduced area coverage rates.</p> <p>A portable gamma spectrometry system has been developed at SUERC, consisting of a 3x3” NaI(Tl) detector with a digital spectrometer and GPS receiver using a netbook computer for data acquisition. This system can be carried as a backpack and used to conduct surveys of environmental radioactivity in urban areas, where people spend their time.</p> <p>Detector backgrounds and stripping matrices have been measured. A survey of approximately 50,000 m2 of the Scottish Enterprise Technology Park (SETP) has been conducted with two detector systems. The SETP is on the site of the National Engineering Laboratory (NEL) established in East Kilbride in 1948, and acquired by Scottish Enterprise in 1994. In recent years there has been an ongoing programme of renovation on the site, including demolition of old buildings and new construction along with landscaping operations.</p> This report presents the results of initial detector characterisation and the survey of part of the SETP site. Detector stripping matrices were determined from measurements made on the 18th August 2009, with background measurements on Loch Lomond collected on the 28th. The site survey was conducted between 17th and 19th August 2009, with over 4600 spectra with 10s integration time collected. Maps of the distribution of 137Cs, 40K, 214Bi, 208Tl and gamma dose rate were produced. The 137Cs activity clearly shows areas undisturbed since 1986, with fallout from the Chernobyl accident still present on the grass. The footprint of the demolished research reactor at SUERC is evident as a negative feature in the 137Cs map. The natural series activities and gamma dose rate show the range of materials used for building and road construction, including one small area of Technologically Enhanced Naturally Occurring Radioactive Material (TENORM), and the local geology and soils. This demonstrates the capability of the SUERC portable gamma spectrometry system to collect high quality data of an area with a complex history, land use and range of buildings. Further application of the technique to other urban areas, and the rest of the SETP site, would allow similar assessments of the radiation environments of a range of different locations

Luminescence investigations at Quendale (Broo Peninsula, Shetland)

This report is concerned with optically stimulated luminescence (OSL) investigations of sediment samples collected from ongoing University of Southern Maine archaeological excavations at the Links of Quendale, southern Shetland, investigating the early-modern township of Broo. 11 sediment samples were submitted to the luminescence laboratory at SUERC for OSL dating by Ian Simpson. This report summaries the protocols, and laboratory analysis, employed in quartz single aliquot regenerative (SAR) OSL dating, as used to construct an OSL chronology for wind-blown sands in proximity to the Broo excavations, in association with archaeological structures (5 samples), and for sands in the coastal and inland dune systems (6 samples). The chronology established for the inland sands, in contexts associated with the Broo 2 building and enclosure, spans from AD1540 ± 40 (SUTL2441) through to AD1810 ± 25 (SUTL2519), encompassing the archaeological period of interest. The dates obtained for sands within the enclosed and unenclosed areas to the immediate east and southwest of the excavated Broo site, are AD1760 ± 30 - AD1760 ± 25, and AD1810 ± 25 (SUTL2517-2518 and 2519, respectively), are consistent with the expectation that the clean sands which infill these structures, post-date the period in which the Broo township was abandoned. The coastal sand accumulations, as so far dated, yielded luminescence ages of 2380 ± 230 BC (SUTL2526), 1510 ± 270 BC (SUTL2527), AD 1030 ± 80 (SUTL2528), AD 1690 ± 50 (SUTL2529), AD 1720 ± 20 (SUTL2530) and a mixed-age sample with youngest component at AD 1955 ± 15 (SUTL2531), implying periods of sand mobilisation, synchronous with sand deposition in Orkney and northern Scotland, in the late Neolithic, the Early Bronze Age, the Norse period, the early-modern, and modern periods. This work suggests that the present-day physio-geographical setting of the Quendale Links, comprised of the coastal sand barrier, and the inland dune fields, is a product of a prolonged history of sand mobilisation, erosion and deposition from the Neolithic to the present day. Furthermore, the emerging temporal framework, coupled with the spatial distribution of dune forms across the Links, raises questions as to whether Little Ice Age storms were responsible for deposition, or erosive destruction of older dune-forms, and the re-mobilisation of this sediment. To test these ideas, profiling methods, both field- and laboratory- based, could be employed to obtain a more complete temporal and spatial characterisation of the dune systems and excavated sequences. Further OSL sampling and dating would be needed to define the vertical and lateral chronostratigraphies of the environmental features in the landscape and their relationships to archaeological structures

Demonstration of lightweight gamma spectrometry systems in urban environments

Urban areas present highly complex radiation environments; with small scale features resulting from different construction materials, topographic effects and potential anthropogenic inputs from past industrial activity or other sources. Mapping of the radiation fields in urban areas allows a detailed assessment of exposure pathways for the people who live and work there, as well as locating discrete sources of activity that may warrant removal to mitigate dose to the general public. These areas also present access difficulties for radiometric mapping using vehicles or aircraft. A lightweight portable gamma spectrometry system has been used to survey sites in the vicinity of Glasgow to demonstrate the possibilities of radiometric mapping of urban areas, and to investigate the complex radiometric features such areas present. Variations in natural activity due to construction materials have been described, the presence of 137Cs used to identify relatively undisturbed ground, and a previously unknown NORM feature identified. The effect of topographic enclosure on measurements of activity concentration has been quantified. The portable system is compared with the outputs that might be expected from larger vehicular or airborne systems. For large areas airborne surveys are the most cost effective approach, but provide limited spatial resolution, vehicular surveys can provide sparse exploratory data rapidly or detailed mapping of open areas where off-road access is possible. Backpack systems are ideally suited to detailed surveys of small areas, especially where vehicular access is difficult

Task planning and control synthesis for robotic manipulation in space applications

Space-based robotic systems for diagnosis, repair and assembly of systems will require new techniques of planning and manipulation to accomplish these complex tasks. Results of work in assembly task representation, discrete task planning, and control synthesis which provide a design environment for flexible assembly systems in manufacturing applications, and which extend to planning of manipulatiuon operations in unstructured environments are summarized. Assembly planning is carried out using the AND/OR graph representation which encompasses all possible partial orders of operations and may be used to plan assembly sequences. Discrete task planning uses the configuration map which facilitates search over a space of discrete operations parameters in sequential operations in order to achieve required goals in the space of bounded configuration sets

Patients', caregivers' and clinicians' understandings of an advance care planning process: the example of ambulance palliative care plans.

BACKGROUND: With the introduction of New South Wales Ambulance Authorised Palliative Care Plans within a metropolitan palliative care service, the perspectives of patients, caregivers and clinicians and their understandings of the processes involved in completing the Plans were investigated. METHODS: This qualitative sub-study used semi-structured interviews. Nineteen patients and caregivers who had received an Ambulance Palliative Care Plan and 10 clinicians who completed the Plans were interviewed (n=4) or participated in a focus group (n=6). Grounded theory provided theoretical and procedural direction. Thematic content analysis utilized the constant comparative method. RESULTS: Thematic analysis of patient/caregiver interviews revealed four major themes (I) a lack of involvement in signing the Plan; (II) a need for clear communication about the Plan; (III) trust in the handing over of difficult decisions to family; and (IV) control over where to receive end of life care. Patients indicated that they had little understanding or memory of what the document was or of its purpose, and there were some significant caregiver anxieties about the Plans. Those who were clear on the rationale for the Ambulance Palliative Care Plan demonstrated more prognostic awareness about their condition and the benefits or burdens of resuscitation and treatment. Clinicians identified the main benefit as avoidance of Emergency Department (ED) admission and for patients to be able to choose their preferred place of death. Barriers were mainly systemic and included a lack of clarity around the signature processes and the early implementation of the Plan where the palliative care service was new to patients and families. CONCLUSIONS: The Ambulance Palliative Care Plans are a complex intervention that are sometimes misunderstood by patients, particularly those who are very unwell or who have little prognostic awareness. Clinicians perceive the major benefit to be avoidance of admission to the emergency department

Ecosystem Management in Pasture Communities: Tools from Restoration Ecology

Pasture systems have the potential to improve both economic and environmental sustainability in agricultural communities worldwide. To achieve maximum benefits, pasture plant communities must be tailored to the climate, the site type and the goals of the producer. Little is known about how to accomplish this, beyond very broad recommendations. We approached the problem by adapting a three-step conceptual framework from restoration ecology for use in managed pasture communities of the northeastern United States. The three steps, inventory, assessment and remediation, were designed for managers interested in restoring degraded native ecosystems, but can be applied equally well in managed ecosystems

Spatial information retrieval and geographical ontologies: an overview of the SPIRIT project

A large proportion of the resources available on the world-wide web refer to information that may be regarded as geographically located. Thus most activities and enterprises take place in one or more places on the Earth's surface and there is a wealth of survey data, images, maps and reports that relate to specific places or regions. Despite the prevalence of geographical context, existing web search facilities are poorly adapted to help people find information that relates to a particular location. When the name of a place is typed into a typical search engine, web pages that include that name in their text will be retrieved, but it is likely that many resources that are also associated with the place may not be retrieved. Thus resources relating to places that are inside the specified place may not be found, nor may be places that are nearby or that are equivalent but referred to by another name. Specification of geographical context frequently requires the use of spatial relationships concerning distance or containment for example, yet such terminology cannot be understood by existing search engines. Here we provide a brief survey of existing facilities for geographical information retrieval on the web, before describing a set of tools and techniques that are being developed in the project SPIRIT : Spatially-Aware Information Retrieval on the Internet (funded by European Commission Framework V Project IST-2001-35047)