A revised chronostratigraphic framework for International Ocean Discovery Program Expedition 355 sites in Laxmi Basin, eastern Arabian Sea

AbstractInternational Ocean Discovery Program Expedition 355 drilled Sites U1456 and U1457 in Laxmi Basin (eastern Arabian Sea) to document the impact of the South Asian monsoon on weathering and erosion of the Himalaya. We revised the chronostratigraphic framework for these sites using a combination of biostratigraphy, magnetostratigraphy and strontium isotope stratigraphy. The sedimentary section at the two sites is similar and we divided it into six units bounded by unconformities or emplaced as a mass-transport deposit (MTD). Unit 1 underlies the MTD, and is of early–middle Miocene age at Site U1456 and early Paleocene age at Site U1457. An unconformity (U1) created by emplacement of the MTD (unit 2) during the late Miocene Epoch (at c. 9.83–9.69 Ma) separates units 1 and 2 and is identified by a marked change in lithology. Unit 3 consists of hemipelagic sediment with thin interbeds of graded sandstone of late Miocene age, separated from unit 4 by a second unconformity (U2) of 0.5–0.9 Myr duration. Unit 4 consists of upper Miocene interbedded mudstone and sandstone and hemipelagic chalk deposited between c. 8 and 6 Ma. A c. 1.4–1.6 Myr hiatus (U3) encompasses the Miocene–Pliocene boundary and separates unit 4 from unit 5. Unit 5 includes upper Pliocene – lower Pleistocene siliciclastic sediment that is separated from unit 6 by a c. 0.45 Myr hiatus (U4) in the lower Pleistocene sediments. Unit 6 includes a thick package of rapidly deposited Pleistocene sand and mud overlain by predominantly hemipelagic sediment deposited since c. 1.2 Ma

sCO2 Compression

TutorialSupercritical Carbon Dioxide (sCO2) power cycles are a transformational technology for the energy industry, providing higher thermal efficiency compared to traditional heat-source energy conversion including conventional fossil and alternative energy sources. The novel cycle significantly reduces capital costs due to smaller equipment footprints and design modularity. In addition, it allows for rapid cyclic load and source following to balance solar and wind energy power swings. Compressing CO2 is not novel, but mostly at lower vapor pressures, and at higher pressure and lower temperatures as a liquid. Compression near the dome (near critical pressure and temperature) is a new interest that has many advantages and challenges. The key advantage is the low head requirement when compressing near the CO2 dome (95oF [35oC] and 1,233 psi [8.5 MPa]). To pressurize from 1,233 psi (target inlet pressure of power cycles) to 3,916 psi (27.0 MPa), only a single high-speed compressor stage is required. This low head requirement means less power is required to compress and leads to an increase in thermal efficiency of these cycles. High-efficiency compression technology can reduce the power of Enhanced Oil Recovery (EOR) and Carbon Capture and Sequestration (CCS) applications. This type of compression also brings many challenges. A compressor for this application pushes many current technology limits, including but not limited to: pressure rise per stage, bearing technologies, sealing technologies, damping, rotordynamics, compact machinery packaging, and high-density, high-speed compression. In addition, when compressing near the CO2 dome, there are large swings in density for slight changes in temperature. This is a unique challenge not observed when CO2 is pumped as a liquid or compressed as a vapor. Due to these large changes in density, range extension is required to maintain high compression efficiency and controlled mass flow over a range of operating temperatures. Recent testing finished on a state-of-the-art sCO2 compressor operating near the dome that was designed, manufactured, and tested by Southwest Research Institute (SwRI) and General Electric Global Research (GE-GRC). This tutorial will highlight many of the unique aspects of the design, especially those challenges and decisions that were focused on high pressure ratio compression stages, high-density and high-speed flow, special rotordynamic considerations, and the overall challenges of compact high-pressure turbomachinery. It will then cover how the design and analysis translated to testing with a real gas that experiences rapid changes in fluid properties for minimal fluctuations in temperature. In addition, due to its need for compact, high-power, and high-speed machinery, the development of sCO2 machinery aids in the development of many advanced components and hardware that can also be used in other applications. This includes high-pressure and high-temperature end seals, zero- to low-emission seals, hermetically sealed systems with gas or magnetic bearings, high-pressure single stage compressors, range extension technologies like variable Inlet Guide Vanes (IGVs), and high-density and high-critical speed ratio operation

Torsional Rotordynamics of Machinery Equipment Strings

Short Cours

API 684 - Torsional Aspects

Short Cours

Expedition 306 summary

The overall aim of the North Atlantic paleoceanography study of Integrated Ocean Drilling Program Expedition 306 is to place late Neogene–Quaternary climate proxies in the North Atlantic into a chronology based on a combination of geomagnetic paleointensity, stable isotope, and detrital layer stratigraphies, and in so doing generate integrated North Atlantic millennial-scale stratigraphies for the last few million years. To reach this aim, complete sedimentary sections were drilled by multiple advanced piston coring directly south of the central Atlantic “ice-rafted debris belt” and on the southern Gardar Drift. In addition to the North Atlantic paleoceanography study, a borehole observatory was successfully installed in a new ~180 m deep hole close to Ocean Drilling Program Site 642, consisting of a circulation obviation retrofit kit to seal the borehole from the overlying ocean, a thermistor string, and a data logger to document and monitor bottom water temperature variations through time

Cenozoic Antarctic DiatomWare/BugCam: An aid for research and teaching

Cenozoic Antarctic DiatomWare/BugCam© is an interactive, icon-driven digital-imagedatabase/software package that displays over 500 illustrated Cenozoic Antarctic diatom taxa along with original descriptions (including over 100 generic and 20 family-group descriptions). This digital catalog is designed primarily for use by micropaleontologists working in the field (at sea or on the Antarctic continent) where hard-copy literature resources are limited. This new package will also be useful for classroom/lab teaching as well as for any paleontologists making or refining taxonomic identifications at the microscope. The database (Cenozoic Antarctic DiatomWare) is displayed via a custom software program (BugCam) written in Visual Basic for use on PCs running Windows 95 or later operating systems. BugCam is a flexible image display program that utilizes an intuitive thumbnail “tree” structure for navigation through the database. The data are stored on Micrsosoft EXCEL spread sheets, hence no separate relational database program is necessary to run the package