Diagenesis & Reservoir Quality of the Middle Bakken Formation

The largest continuous oil accumulation ever assessed by the USGS, the Bakken Formation in the Williston Basin, USA, is a tight oil resource with low recovery factors. Increasing the recovery factors from tight hydrocarbon formation has significant economic implications. In this study we show that the effects of diagenesis have significantly affected the reservoir quality of the middle Bakken Formation. Diagenetic processes in the middle Bakken are complex and vary across several scales. Early carbonate cementation exerts the primary control on porosity loss in the middle Bakken. Detailed petrographic examination by electron microscopy reveals multiple textural phases of calcite and dolomite, each of which contributes to changes in the reservoir quality. Cementation by calcite and dolomite has resulted in the low porosity and low permeability in the middle Bakken. Depositional facies have been defined within the middle Bakken. Cementation by carbonate minerals exert a key control on reservoir quality at scales below that of a facies. Porosity in the middle Bakken varies from ~2-10%. Low pressure nitrogen gas sorption experiments show this is composed of pores which are small; predominantly mesoporous in size. Mercury intrusion experiments show pores in the middle Bakken typically have pore throats with radii <100 nm and low pressure nitrogen gas sorption analysis shows pore bodies are <135 nm in size. A significant component of porosity forms as intragranular pores, predominantly in quartz, calcite and dolomite. Previous studies have struggled to unravel the timing and history of porosity-occluding carbonate cement due to its exceptionally fine-grained nature. We have taken a novel approach, using both sequential acid dissolution and in-situ Secondary Ion Mass Spectrometry (SIMS), to determine the carbon and oxygen isotope composition of individual carbonate phases. Coupled with grain-scale compositional analysis by SEM-WDS we show that diagenetic dolomite formed at 5-64°C by replacement of early calcite cement in low temperature, near surface ocean conditions at temperatures of 8-51°C. The results of this PhD show that multi-stage carbonate diagenesis has destroyed, preserved and created porosity in the middle member of the Bakken Formation

Land grant to Robert Brodie, Camden, South Carolina, 1794, featuring signature of William Moultrie.

Robert Brodie is granted One thousand acres Surveyed for him 19th Mar. 1794 Situate in the District of Camden on Waters of Sawney’s Creek bounded by a line running SW. by Rob. Martins land all other sides by Rob. Brodies. South Carolina,https://digitalcommons.wofford.edu/littlejohnmss/1096/thumbnail.jp

Human Powered Vehicle Team Challenge

Design and build a Human Powered Vehicle in a team of five. Compete at the ASME HPVC competition in March of 2022. Re-establish the Human Powered Vehicle Team at the University of Akron

Exploring co-design in the voluntary sector

Co-design is an approach to design that emphasises the creative contribution that can be made by potential users, clients and other stakeholders in developing products, systems or services. Co-design is widely used in the commercial sector to accelerate user acceptance and reduce product/service failure. Co-design is also becoming widespread in the public sector as a way of engaging citizens in design exploration. However, little is known about the capability of voluntary sector organisations, particularly small and medium sized organisations to undertake co-design activities; and resources that describe how to implement co-design tend to be oriented towards the needs and the context of larger commercial organisations. This paper presents findings from an ongoing investigation into co-design capability in small-and-medium-sized third sector organisations in the UK. The investigation combines an on-line survey, in-depth case studies and interviews

The role of the gut microbiome in sustainable teleost aquaculture

As the most diverse vertebrate group and a major component of a growing global aquaculture industry, teleosts continue to attract significant scientific attention. The growth in global aquaculture, driven by declines in wild stocks, has provided additional empirical demand, and thus opportunities, to explore teleost diversity. Among key developments is the recent growth in microbiome exploration, facilitated by advances in high-throughput sequencing technologies. Here, we consider studies on teleost gut microbiomes in the context of sustainable aquaculture, which we have discussed in four themes: diet, immunity, artificial selection and closed-loop systems. We demonstrate the influence aquaculture has had on gut microbiome research, while also providing a road map for the main deterministic forces that influence the gut microbiome, with topical applications to aquaculture. Functional significance is considered within an aquaculture context with reference to impacts on nutrition and immunity. Finally, we identify key knowledge gaps, both methodological and conceptual, and propose promising applications of gut microbiome manipulation to aquaculture, and future priorities in microbiome research. These include insect-based feeds, vaccination, mechanism of pro- and prebiotics, artificial selection on the hologenome, in-water bacteriophages in recirculating aquaculture systems (RAS), physiochemical properties of water and dysbiosis as a biomarker

The Beta Problem: A Study of Abell 262

We present an investigation of the dynamical state of the cluster A262. Existing optical line of sight velocities for select cluster galaxies have been augmented by new data obtained with the Automated Multi-Object Spectrograph at Lick Observatory. We find evidence for a virialized early-type population distinct from a late-type population infalling from the Pisces-Perseus supercluster ridge. We also report on a tertiary population of low luminosity galaxies whose velocity dispersion distinguishes them from both the early and late-type galaxies. We supplement our investigation with an analysis of archival X-ray data. A temperature is determined using ASCA GIS data and a gas profile is derived from ROSAT HRI data. The increased statistics of our sample results in a picture of A262 with significant differences from earlier work. A previously proposed solution to the "beta-problem" in A262 in which the gas temperature is significantly higher than the galaxy temperature is shown to result from using too low a velocity dispersion for the early-type galaxies. Our data present a consistent picture of A262 in which there is no "beta-problem", and the gas and galaxy temperature are roughly comparable. There is no longer any requirement for extensive galaxy-gas feedback to drastically overheat the gas with respect to the galaxies. We also demonstrate that entropy-floor models can explain the recent discovery that the beta values determined by cluster gas and the cluster core radii are correlated.Comment: 31 pages, 14 figures, AAS LaTeX v5.0, Encapsulated Postscript figures, to be published in The Astrophysical Journa

List of Species as recorded by Canadian and EU Bottom Trawl Surveys in Flemish Cap

13 páginas, 1 tabla.-- Scientific Council MeetingA list of species has been prepared with all records in each haul of both Canadian (1977-1985) and EU (1988-2002 and 2003-2012) bottom trawl surveys. Even though sampling intensity and taxonomic interest changed with time, the three periods can be considered almost homogeneous. Main change occurred when the EU survey increased the depth range, from 730 to 1460 meters depth, and all invertebrates were recorded.Peer reviewe

Evaluation of a new approach for modelling full ring stent bundles with the inclusion of manufacturing strains

Ring stent bundles have been used in several biomedical stent-graft devices for decades, yet in the published literature, the numerical models of these structures always present significant simplifications. In this paper, a finite element (FE) ring stent bundle has been developed and evaluated with a combination of beam and surface elements. With this approach, the shape, the global stiffness and the strains of the structure can all be well predicted at a low computational cost while the approach is suitable for application to non-symmetrical, patient-specific implant simulations. The model has been validated against analytical and experimental data showing that the manufacturing strains can be predicted to a 0.1% accuracy and the structural stiffness with 0–7% precision. The model has also been compared with a more computationally expensive FE model of higher fidelity, revealing a discrepancy of 0–5% of the strain value. Finally, it has been shown that the exclusion of the manufacturing process from the simulation, a technique used in the literature, quadruples the analysis error. This is the first model that can capture the mechanical state of a full ring stent bundle, suitable for complex implant geometry simulations, with such accuracy