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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

The Measurement of Decomposition Products of Select Gases as an Indicator of a Concealed Mine Fire

Lindsay, Clifford Fry 08 December 2014 (has links)
Currently, techniques used to determine whether or not there is a concealed fire in an inaccessible area of a coal mine are not definitive. Inaccessible areas of coal mines include: 1. A mined-out area, such as a long-wall gob. 2. A mine area, or entire mine, that has been sealed to extinguish a fire. 3. The interior of pillars in a mine. 4. Abandoned mines. Mined-out areas — gobs — are particularly problematic. The standard practice is to obtain measurements for certain gas concentrations from an inaccessible area, and to apply certain rules to the obtained concentrations in order to try to decipher whether or not there is a fire in the area. Unfortunately, none of the gas measurements, and the associated rules that are applied, are free of potential problems. Therefore, there is always some degree of uncertainty in any decision that is based on the current methods. A more definitive method of determining whether or not a concealed fire exists would be valuable; perhaps avoiding unnecessary exposure of miners to risks, and unnecessary exposure of mining companies to economic loss. This study details the inadequacies of the current methods for determining the presence of a fire in an inaccessible area of a coal mine, and proposes two novel methods for overcoming the current inadequacies. The first method that was studied involves looking for the presence of the radioisotope carbon-fourteen in the carbon monoxide in the return airways of coal mines. For the vast majority of coal mines, if there is no fire anywhere in the coal mine, carbon monoxide should not have any carbon-fourteen in it. If there is a fire, the carbon monoxide should have carbon-fourteen in it. This method is based on the Boudouard Reaction, which documents a reaction between carbon, carbon monoxide, and carbon dioxide that only occurs at temperatures that only occur with a fire. Because of the very small amounts of carbon-fourteen in carbon dioxide in the atmosphere, and the small amount of carbon monoxide usually present in a coal mine atmosphere, there does not appear to be any way, currently, to implement this method. Instrumentation that may allow implementation of this method, in the future, is discussed. The second method, that was studied, involves introducing a select, gaseous, organic compound into an inaccessible area; and then using a gas chromatograph to test for the presence of definitive fire decomposition products of the initial organic compound in the atmosphere that is exiting the inaccessible area. Laboratory tests, conducted as part of this study, established the concept of this novel method of using select, organic compounds for definitively determining whether or not a concealed fire exists in an inaccessible part of a coal mine. Based on an initial screening of 5 different compounds, two compounds have been selected for use as 'fire indicator gases' with the acronym of 'FIGs.' These two compounds are: 1. C6-Perfluoroketone (CF3CF2C(=O)CF(CF3)2 ) 2. 1,1 Difluoroethane (CH3CHF2) This study provides suggestions as to how to look for other potential FIGs, and how to improve the testing of potential FIGs. Examples of all four of the types of inaccessible areas listed above are discussed, particularly from the viewpoint of how FIGs could be utilized in each case, and how FIGs could provide better information in each case. In addition, as a by-product of the experiments conducted for this work, this study identifies at least six gases that might be used simultaneously as tracer gases for complex ventilation studies in a mine, or elsewhere. / Ph. D.
122

The Chronology of Abrupt Climate Change and Late Upper Palaeolithic Human Adaptation in Europe

Blockley, S.P.E., Blockley, S.M., Donahue, Randolph E., Lane, C.S., Lowe, J.J., Pollard, A. Mark January 2006 (has links)
No / his paper addresses the possible connections between the onset of human expansion in Europe following the Last Glacial Maximum, and the timing of abrupt climate warming at the onset of the Lateglacial (Bölling/Allerød) Interstadial. There are opposing views as to whether or not human populations and activities were directly forced by climate change, based on different comparisons between archaeological and environmental data. We review the geochronological assumptions and approaches on which data comparisons have been attempted in the past, and argue that the uncertainties presently associated with age models based on calibrated radiocarbon dates preclude robust testing of the competing models, particularly when comparing the data to non-radiocarbon-based timescales such as the Greenland ice core records. The paper concludes with some suggestions as to the steps that will be necessary if more robust tests of the models are to be developed in the future.
123

Excavations at a Neolithic Enclosure at Lower Luggy, near Welshpool, Powys, Wales

Gibson, Alex M., Bradley, P., Francis, Robert, Hill, Belinda, Higton, Alex, Ogden, Alan R., Sutherland, Tim L. January 2006 (has links)
No / Excavation at a cropmark enclosure in the Upper Severn Valley was undertaken to try and obtain material from which to provide relative and absolute dating for the site. Lying within an area rich in Neolithic and Bronze Age archaeology and in close proximity to a proven long barrow, the conventional later prehistoric date postulated for the enclosure was questioned. Excavation proved the site to have been a ditched enclosure with internal bank and a possible gate structure. Post-pits ran inside the bank. Finds were few but radiocarbon dates from the floor of the ditch proved the early Neolithic credentials of the monument which seemed to have continued in use for at least some 500 years.
124

New Exploration in the Chitral Valley, Pakistan: An Extension of the Gandharan Grave Culture

Batt, Catherine M., Ali, I., Coningham, Robin A.E., Young, R.L. January 2002 (has links)
No / New survey in the Chitral Valley has doubled the number of recorded Gandharan Grave culture sites in the region and extended their geographical range. The numbers and location of sites indicates that the Gandharan Grave culture was well established in the Chitral valley, suggesting that the valley may have been central to this cultural development, rather than marginal.
125

The integration of chronological and archaeological information to date building construction: an example from Shetland, Scotland, UK.

Outram, Zoe, Batt, Catherine M., Rhodes, E.J., Dockrill, Stephen J. January 2010 (has links)
No / This paper presents new chronological data applied to the problem of providing a date for the construction of a prehistoric building, with a case study from the Old Scatness Broch, Shetland. The innovative methodology employed utilises the combination of radiocarbon and optically stimulated luminescence (OSL) dates with the archaeological information, which includes the stratigraphic relationships of sampled deposits, context information, and evidence relating to the formation of the deposit. This paper discusses the scientific validity of the dates produced, and the advantages that the methodology employed at this site offers for archaeological interpretation. The combined dating evidence suggests that the broch at Old Scatness is earlier than the conventionally accepted dates for broch construction. More broadly it shows the value of integration of the specialists at the planning stages of the excavation. The application of a Bayesian statistical model to the sequences of dates allowed investigation of the robustness of the dates within the stratigraphic sequences, as well as increasing the resolution of the resulting chronology. In addition, the value of utilising multiple dating techniques on the same deposit was demonstrated, as this allowed different dated events to be directly compared as well as issues relating to the formation of the sampled deposit. This in turn impacted on the chronological significance of the resulting dating evidence, and therefore the confidence that could be placed in the results.
126

Gristhorpe man: an early bronze age log-coffin burial scientifically defined

Melton, Nigel D., Montgomery, Janet, Knüsel, Christopher J., Batt, Catherine M., Needham, S., Parker Pearson, M., Sheridan, A., Heron, Carl P., Horsley, T., Schmidt, Armin R., Evans, Adrian A., Carter, E.A., Edwards, Howell G.M., Hargreaves, Michael D., Janaway, Robert C., Lynnerup, N., Northover, P., O'Connor, Sonia A., Ogden, Alan R., Taylor, Timothy F., Wastling, Vaughan, Wilson, Andrew S. January 2010 (has links)
No / A log-coffin excavated in the early nineteenth century proved to be well enough preserved in the early twenty-first century for the full armoury of modern scientific investigation to give its occupants and contents new identity, new origins and a new date. In many ways the interpretation is much the same as before: a local big man buried looking out to sea. Modern analytical techniques can create a person more real, more human and more securely anchored in history. This research team shows how.
127

Constructing chronologies in Viking Age Iceland: Increasing dating resolution using Bayesian approaches

Batt, Catherine M., Schmid, M.M.E., Vésteinsson, O. 14 July 2015 (has links)
Yes / Precise chronologies underpin all aspects of archaeological interpretation and, in addition to improvements in scientific dating methods themselves, one of the most exciting recent developments has been the use of Bayesian statistical analysis to reinterpret existing information. Such approaches allow the integration of scientific dates, stratigraphy and typological data to provide chronologies with improved precision. Settlement period sites in Iceland offer excellent opportunities to explore this approach, as many benefit from dated tephra layers and AMS radiocarbon dates. Whilst tephrochronology is widely used and can provide excellent chronological control, this method has limitations; the time span between tephra layers can be large and they are not always present. In order to investigate the improved precision available by integrating the scientific dates with the associated archaeological stratigraphy within a Bayesian framework, this research reanalyses the dating evidence from three recent large scale excavations of key Viking Age and medieval sites in Iceland; Aðalstræti, Hofstaðir and Sveigakot. The approach provides improved chronological precision for the dating of significant events within these sites, allowing a more nuanced understanding of occupation and abandonment. It also demonstrates the potential of incorporating dated typologies into chronological models and the use of models to propose sequences of activities where stratigraphic relationships are missing. Such outcomes have considerable potential in interpreting the archaeology of Iceland and can be applied more widely to sites with similar chronological constraints. / British Academy (MD120020) awarded to C. Batt. Rannís PhD funding for M.Schmid. / The full text was made available at the end of the publisher's embargo.
128

Arran pitchstone (Scottish volcanic glass: new dating evidence

Ballin, T.B. January 2015 (has links)
Yes / In the present paper, the author offers new absolute and contextual dating evidence for Scottish archaeological pitchstone. Much archaeological pitchstone from the Scottish mainland is recovered from unsealed contexts of multi-period or palimpsest sites, and pitchstone artefacts from radiocarbon-dated pits therefore provide important dating evidence for this material group and its associated exchange network. In Scotland, all archaeological pitchstone derives from outcrops on the Isle of Arran, in the Firth of Clyde, and on the source island pitchstone-bearing assemblages include diagnostic types from the Mesolithic, Neolithic and Early Bronze Age period. Off Arran, pitchstone-bearing assemblages never include Mesolithic types, such as microliths, suggesting a post Mesolithic date. This suggestion is supported by worked pitchstone from radiocarbon-dated pits, where all presently available dates indicate that, on the Scottish mainland, Arran pitchstone was traded and used after the Mesolithic period, and in particular during the Early Neolithic period.
129

To Cut a Long Story Short: Formal Chronological Modelling for the Late Neolithic Site of Ness of Brodgar, Orkney

Card, N., Mainland, Ingrid L., Timpany, S., Towers, R., Batt, Catherine M., Bronk Ramsey, C., Dunbar, E., Reimer, P., Bayliss, A., Marshall, P., Whittle, A. 05 November 2016 (has links)
Yes / In the context of unanswered questions about the nature and development of the Late Neolithic in Orkney, we present a summary of research up to 2015 on the major site at the Ness of Brodgar, Mainland Orkney, concentrating on the impressive buildings. Finding sufficient samples for radiocarbon dating was a considerable challenge. There are indications from both features and finds of activity predating the main set of buildings exposed so far by excavation. Forty-six dates on 39 samples are presented and are interpreted in a formal chronological framework. Two models are presented, reflecting different possible readings of the sequence. Both indicate that piered architecture was in use by the thirtieth century cal BC and that the massive Structure 10, not the first building in the sequence, was also in existence by the thirtieth century cal BC. Activity associated with piered architecture came to an end (in Model 2) around 2800 cal BC. Midden and rubble infill followed. After an appreciable interval, the hearth at the centre of Structure 10 was last used around 2500 cal BC, perhaps the only activity in an otherwise abandoned site. The remains of some 400 or more cattle were deposited over the ruins of Structure 10: in Model 2, in the mid-twenty-fifth century cal BC, but in Model 1 in the late twenty-fourth or twenty-third century cal BC. The chronologies invite comparison with the near-neighbour of Barnhouse, in use from the later thirty-second to the earlier twenty-ninth century cal BC, and the Stones of Stenness, probably erected by the thirtieth century cal BC. The Ness, including Structure 10, appears to have outlasted Barnhouse, but probably did not endure as long in its primary form as previously envisaged. The decay and decommissioning of the Ness may have coincided with the further development of the sacred landscape around it; but precise chronologies for other sites in the surrounding landscape are urgently required. The spectacular feasting remains of several hundred cattle deposited above Structure 10 may belong to a radically changing world, coinciding (in Model 2) with the appearance of Beakers nationally, but it was arguably the by now mythic status of that building which drew people back to it. / We are very grateful to many institutions and individuals, in particular: Ness of Brodgar Trust, Foundation for World Health, Orkney Islands Council, University of the Highlands and Islands, Orkney Archaeology Society, American Friends of the Ness of Brodgar, Northlink, Talisman- Sinopec, Hiscox Insurance, Historic Environment Scotland, and numerous other supporters and volunteers; Mark Edmonds, Ann MacSween, Colin Richards, and Alison Sheridan for encouragement, advice, and critical comments on an earlier draft of this article; three anonymous referees for their comments; and Kirsty Harding for help with the figures. Dating and modelling have been supported by a European Research Council Advanced Investigator Grant (295412), The Times of Their Lives (www.totl.eu), led by Alasdair Whittle and Alex Bayliss.
130

Dating human occupation and adaptation in the southern European last glacial refuge: The chronostratigraphy of Grotta del Romito (Italy)

10 February 2020 (has links)
Yes / Grotta del Romito has been the subject of numerous archaeological, chronological and palaeoenvironmental investigations for more than a decade. During the Upper Palaeolithic period the site contains evidence of human occupation through the Gravettian and Epigravettian periods, multiple human burials, changes in the pattern of human occupation, and faunal, isotopic and sedimentological evidence for local environmental change. In spite of this rich record, the chronological control is insufficient to resolve shifts in subsistence and mobility patterns at sufficiently high resolution to match the abrupt climate fluctuations at this time. To resolve this we present new radiocarbon and tephrostratigraphic dates in combination with existing radiocarbon dates, and develop a Bayesian age model framework for the site. This improved chronology reveals that local environmental conditions reflect abrupt and long-term changes in climate, and that these also directly influence changing patterns of human occupation of the site. In particular, we show that the environmental record for the site, based on small mammal habitat preferences, is chronologically in phase with the main changes in climate and environment seen in key regional archives from Italy and Greenland. We also calculate the timing of the transitions between different cultural phases and their spans. We also show that the intensification in occupation of the site is chronologically coincident with a rapid rise in Mesic Woody taxa seen in key regional pollen records and is associated with the Late Epigravettian occupation of the site. This change in the record of Grotta del Romito is also closely associated stratigraphically with a new tephra (the ROM-D30 tephra), which may act as a critical marker in environmental records of the region. / Leverhulme Trust (F/0 0235/I) and by a Natural Environment Research Council ORADS radiocarbon dating award (NF/2011/2/7).

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