Deciphering eustatic and tectonic influences during parasequence development in the Mesoprotozoic Helena/Wallace Formation, Belt Supergroup, Montana and Idaho

The stratigraphic architecture of sedimentary basins results from a combination of changes in relative sea-level and tectonism, and resulting changes in sediment supply. The Helena/Wallace formations, Mesoproterozoic Belt Supergroup, Montana and Idaho, consists of \u3e500 meters of stacked meter-scale cycles (parasequences) that record in situ carbonate deposition as well as siliciclastic deposition from both the Laurentian craton and an unknown (tectonically active?) western source. In this study, statistical methods and 2-D forward modeling are combined with geochemical provenance analysis to examine parasequence stacking patterns and decipher the relative eustatic and tectonic controls on sequence development. Helena/Wallace parasequences are typically composed of a lower siliciclastic half cycle, which thickens and coarsens to the west, and an upper carbonate half cycle that contains sandy-to-silty siliciclastic interbeds. Parasequences are bounded by scoured surfaces and are frequently marked by a basal intraclast packstone lag that represents reworking of subjacent strata. Parasequences are interpreted as 4th or 5th order cycles likely driven by Milankovitch frequency eustasy. Statistical analysis of cycle thicknesses suggests non-random packaging of thicker- and thinner-than-average parasequence sets. Modified Fischer plots, which examine changes in both cycle thickness and siliciclastic:carbonate ratio within the cycles, indicate that compositional variability and parasequence packaging (3rd order cyclicity) was likely controlled by changing tectonic regime (subsidence rates or influx of siliciclastic sediment) rather than longer-term eustatic changes in sea level. 2-D forward modeling of how subsidence, sediment influx, sea-level fluctuations may have contributed to both changes in cycle thickness and compositional variability also supports a tectonic origin for parasequence sets and suggests that episodic increases in basin subsidence rates are responsible for observed parasequence stacking patterns. X-ray fluorescence analysis of siliciclastic residues from Helena/Wallace formation samples was performed to determine if tectonism along the western basin margin resulted in changes in the sediment source that can be identified based on the geochemical composition of Helena/Wallace formation rocks. Results of the analysis suggest that, despite tectonically driven changes in subsidence, the sediment source area did not change throughout deposition of the Helena/Wallace formations. The results of the analysis are consistent with sediment sourced via drainage from a cratonal source area that is geochemically distinct from the Laurentian craton. Siliciclastic strata of the \u3e15 km thick lower Belt Supergroup has long been recognized to record episodic rifting of the Belt basin. This study, however, is the first to suggest that shallow marine, mixed carbonate-siliciclastic strata of the Helena/Wallace formations also contain a subtle record of continued basin extension

Real-time algorithms for optimal CCD data reduction in high energy astronomy

This thesis presents novel and reusable algorithms and philosophies for the reduction of data produced by CCD detectors used for space astronomy. Some of the techniques described can be extended to other two-dimensional data sets, and all of them have relevance beyond the particular spacecraft on which they are currently being used. The author began the work described in this thesis in January 1993, looking at ways in which the data produced from a spectroscopic instrument on the XMM-Newton spacecraft could be reduced sufficiently to fit into the comparatively meagre telemetry bandwidth available to it. The work was also constrained by the use of a processor system with many fewer resources available than ideal, but chosen for its reliability and tolerance to radiation, both important factors in a ten-year mission. Chapter one introduces the need for spacecraft onboard data reduction, and the XMM-Newton spacecraft, and its instruments. Chapter two focusses on the principles of operation of CCDs, briefly considering the sources of noise that affect them in use. Chapter three examines the mechanics of the onboard software designed by the author, and arguments are made for trading data quality against data quantity. Chapter four describes the construction of a software, standalone instrument simulator able to quantify the quality of the existing onboard software, provide feedback to settings used, and analyse the impact of future modifications. Chapter five presents results from the testing of the onboard software and early data from the commissioning phase of XMM-Newton. The thesis concludes with some suggestions for further improvements to the onboard software, and hints at possible applications to other observational scenarios involving large data-sets

Is there a relationship between fingerprint donation and DNA shedding?

This research investigates the possible relationship between fingerprint donation and DNA shedding. Volunteers were asked to provide a series of fingerprint depletions on glass. The level of fingerprint detail developed and DNA profiling results obtained were compared for each donor to investigate whether a relationship between fingerprint donation and DNA shedding exists. Our results suggest that between comparisons of donors, there is no statistical difference between the left and right hand of our volunteers in terms of fingerprint donation, but there is a statistical difference in terms of DNA shedding with three of our eight donors. Our results also indicate that there is no correlation between fingerprint donation and DNA shedding, meaning that an enhanced fingerprint with full ridge detail will not necessarily give a full DNA profile. In serious crime, these two avenues of evidence must be explored

Testing for knowledge : maximising information obtained from fire tests by using machine learning techniques

A machine learning (ML) algorithm was applied to predict the onset of flashover in 1:5 scale Room Corner Test experiments with sandwich panels. Towards this end, a penalized logistic regression model was chosen to detect the relevant variables and consequently provided a tool that can be used to make predictions of unseen samples. The method indicates that a deeper understanding of the contributing factors leading to flashover can be achieved. Furthermore, it allows a more nuanced ranking than currently offered by the commonly used classification methods for reaction to fire tests. The proposed methodology shows a substantial value in terms of guidance for future large and intermediate scale testing. In particular, it is foreseen that the method will be extremely useful for assessing and understanding the behaviour of innovative materials and design solutions

Gated metabolic myocardial imaging, a surrogate for dual perfusion-metabolism imaging by positron emission tomography

Acknowledgments The authors are grateful for the help from Dr H Ali and Dr A Dawson. Funding: This study was performed using a research grant from the Aberdeen Royal Hospitals Trust's Endowment Fund, with further support from the Department of Medical Physics at the University of Aberdeen, for which the authors express their gratitude.Peer reviewedPublisher PD

The Use of Positive Pressure Ventilation Fans During Firefighting Operations in Underground Stations: An Experimental Study

Positive pressure ventilation (PPV) fans are widely used by the fire service during firefighting operations in buildings. Fans are positioned to create a flow through the enclosure. This flow can remove the smoke after the fire or affect the direction of the smoke to support firefighting operations. In subway stations, it is less common to use PPV fans. Here, 106 full-scale tests with up to four fans have been performed in a training building that represents a subway station. The fans were used as extraction fans. The generated flow through the subway station has been measured. The critical velocity for a hypothetical tunnel (W x H: 3.17 x 4.15 m) attached to the subway station has been calculated as 2.37 m/s. Reaching the critical velocity has been used as criterion for 'success'. All combinations with four fans exceed this velocity, supporting the idea that the fans could be used to facilitate a firefighting operation. The location of the fans was varied. Combinations with three fans on the platform and one at the top of the staircase performed better than combinations with two fans on the platform, one on the landing and one at the top of the staircase. There is an optimum value for the distance between the fans on the platform and the first step of the staircase. This value depends on the angle of inclination of the fans. The fans were not capable of creating a flow that exceeded the critical velocity in the station itself (L x W x H: 60 x 7.15 x 4.53 m). However, a velocity of 2.40 m/s corresponds to a flow rate that will limit the backlayering distance in the station to 15 m. This was only achieved by tests with four fans (three on the platform and one at the top of the staircase)

Formal Reasoning Using an Iterative Approach with an Integrated Web IDE

This paper summarizes our experience in communicating the elements of reasoning about correctness, and the central role of formal specifications in reasoning about modular, component-based software using a language and an integrated Web IDE designed for the purpose. Our experience in using such an IDE, supported by a 'push-button' verifying compiler in a classroom setting, reveals the highly iterative process learners use to arrive at suitably specified, automatically provable code. We explain how the IDE facilitates reasoning at each step of this process by providing human readable verification conditions (VCs) and feedback from an integrated prover that clearly indicates unprovable VCs to help identify obstacles to completing proofs. The paper discusses the IDE's usage in verified software development using several examples drawn from actual classroom lectures and student assignments to illustrate principles of design-by-contract and the iterative process of creating and subsequently refining assertions, such as loop invariants in object-based code.Comment: In Proceedings F-IDE 2015, arXiv:1508.0338