2,189 research outputs found
Determination of gas volume trapped in a closed fluid system
Technique involves extracting known volume of fluid and measuring system before and after extraction, volume of entrapped gas is then computed. Formula derived from ideal gas laws is basis of this method. Technique is applicable to thermodynamic cycles and hydraulic systems
Lightweight reflector assembly
An inexpensive, lightweight reflective assembly member having good optical quality and particularly adaptable to accommodating temperature variations without providing destructive thermal stresses and reflective slope errors is described. The reflective assembly consists of a thin sheet of glass with appropriate reflective coating and a cellular glass block substrate bonded together. The method of fabrication includes abrading the cellular substrate with an abrasive master die to form an appropriate concave surface. An adhesive is applied to the abraded surface and a lamina reflective surface is placed under a uniform pressure to conform the reflective surface onto the desired abraded surface of the substrate
Mid crustal thrust tectonic processes: examples from the Dalradian of N.W. Donegal
A D2 ductile thrust imbricate stack has been identified within the mid greenschist facies (Appin Group) metasediments of the Breaghy Head area of Co. Donegal. Major stratigraphy parallel tectonic slides detach arrays of subsidiary ductile thrust imbricates, which display patterns of intensifying strain and minor structures generally regarded as being diagnostic of the much broader thrust sense shear zones (tectonic slides) which typify deformation within metamorphic "parts of mountain belts. This commonality of structural associations implies that the. Breaghy Head imbricates and their broader larger scale counterparts must share similar generative and propagative processes. The imbricates have 'shaped' geometries with long bedding parallel flats and shorter 20-30º ramps preserved as hanging wall anticlines, footwall synclines or complex remnant zones of climbing vein arrays. At a number of localities, ramps have escaped direct incorporation into mature thrust profiles and have been preserved within thrust hanging walls, ' frozen' at early on _intermediate stages of development. This has enabled identification of three distinct ramp styles; "Vein array ramps" characterised by vein array complexes, and "fold ramps" & "fabric slip ramps", both hosted by primary F2 folds. These fold hosted ramps can be seen to nucleate or 'result from coallescent propagation of ductile thrust dislocation cells (F5R & PR respectively).The concept of thrust dislocation cells is supported by the presence of D2 extensional flow within the imbricate stack, expressed by shear bands and boudinage. These structures are kinematically and temporally intimate, forming combinant structures at a number of localities. These structures characteristically intensify towards the thrust planes but are never seen to deform them, such that extensional flow is detached at the thrust plane to which it is seen to intensify. The extensional and contractional flow clearly relates spatially and temporally to the generation and movement of individual imbricates and must, therefore, coexist kinematically as this takes place. This can be explained by Theologically focusing (localising) deformation to produce stratigraphy parallel dislocation cells. The development and subsequent propagation of these features produces the observed structural patterns and displacement connectivity via ramp generation to produce mature 'shaped' ductile thrust profiles. Local polyphase fold and fabric histories are seen to be generated during continuum D2 ductile thrusting. These structures are temporally and spatially restricted, chiefly as hanging wall strains produced by local thrust stacking processes (eg. Imbricate back-steepening and culmination extension). Local polyphase sequences are also generated by development of rare backthrusts, buttressing and footwall collapse of ramps and hard band block rotations. These structures are clearly D2 ductile thrust secondary structures, related to local kinematic processes and do not therefore reflect regional polyphase deformation
Scenic gems of Daytona, Florida.
Photographs of Daytona Beach and Ormond Beach including citrus, hotels, and palm trees.https://stars.library.ucf.edu/floridaheritage/1078/thumbnail.jp
News Clipping - Huggins Memorial Arch
News Clipping about the Huggins Memorial Arch, erected by alumni in memory of Professor J. D. Huggins.https://digitalcommons.gardner-webb.edu/gardner-webb-buildings-and-grounds-arch/1003/thumbnail.jp
Rifting and Mafic Magmatism in the Hebridean Basins
Acknowledgements and Funding Research in the BPIP was supported by NERC grant GR9/1581, and the Carnegie Trust for the Universities of Scotland. H. Rollinson and E. Gazel are thanked for helpful and constructive criticisms, particularly of the modelling aspects of the paper, and T. Rooney is thanked for invaluable scientific and editorial assistance.Peer reviewedPostprin
Frontier exploration and the North Atlantic Igneous Province : new insights from a 2.6 km offshore volcanic sequence in the NE Faroe–Shetland Basin
Acknowledgements and Funding This work was funded by Chevron. The authors would like to acknowledge the Chevron West of Shetlands team along with the Joint Venture partners OMV, Faroe Petroleum and Indemitsu for access to data along with permission to publish this study. PGS is thanked for access to the Corona Ridge Regional Geostreamer (CRRG) data and permission to publish the seismic line. The paper was improved thanks to insightful reviews by S. M. Jones and A. Saunders, which substantially improved an earlier draft. J. Still and F. Thompson gave invaluable technical support at the University of Aberdeen, and K. Wall helped with real-time cuttings analysis.Peer reviewedPostprin
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Scientific drilling of the Boltysh impact crater, Ukraine
Introduction: The Boltysh crater has been known for several decades and was first drilled in the 1960s as part of a study of economic oil shale deposits. Unfortunately, the cores were not curated and have been lost. We have re-drilled the impact crater and have recovered a near continuous record of ~400 m of organicrich sediments together with 15 m of suevite
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Organic geochemistry of the crater-fill sediments from Boltysh impact crater, Ukraine
The Boltysh impact crater, is a complex structure formed on the basement rocks of the Ukrainian shield which has been dated at 65.17±0.64 Ma [1]. The Boltysh crater has been know for several decades and was originally drilled in the 1960s-1980s in a study of economic oil shale deposits. Unfortunately, the cores were not curated and have been lost. However we have recently re-drilled the impact crater and have recovered a near continuous record of ~400 m of organic rich sediments deposited in a deep isolated lake which overlie the basement rocks spanning a period ~10 Ma. At 24km diameter, Boltysh will not have contributed substantially to the worldwide devastation at the end of the
Cretaceous. However, the precise age of the Boltysh impact relative to the Chicxulub impact and its location on a stable low lying coastal plain which allowed formation of the postimpact crater lake make it a particularly important locality. After the impact, the crater quickly filled with water in a short marine phase but returned to fresh water which persisted for >10Ma [2]. These strata contain a valuable record of Paleogene environmental change in central Europe, and one of very few terrestrial records of the KT event. This pre-eminent record of the Paleogene can help us to answer several related scientific questions including the relative age of Boltysh compared with Chicxulub, recovery from the impact, and later climate signals. The organic geochemistry and playnology indicate main inputs to be algal and higher plant within most of the core although there are some marked changes in inputs in some sections. A number of carbon isotope excursions are also present within the core which are currently being further investigated
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