120 research outputs found
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THE EFFECT OF IMMEDIATE SALINE WATER CURING ON THE STRENGTH, COMPOSITION, AND MICROSTRUCTURE OF GEOPOLYMER CEMENT
The low durability and low resistance of ordinary Portland cement led to an investigation into the viability of geopolymer cement as an alternative to well cement for soil improvement in saline environments and well cement in offshore drilling and carbon sequestration projects. This thesis presents the results of a laboratory investigation into the effect of immediate saline water curing on the strength, composition, and microstructure of geopolymer cement. The experimental program began with preliminary work in designing adequate geopolymer cement and developing a curing environment that simulates offshore or underground conditions and facilitates immediate curing of cement specimens. Pure geopolymer cement with a Si/Al ratio of 1.78 was synthesized from an admixture of Class C fly ash and metakaolin and immediately cured in saline water of 0, 15, and 35 ppt concentrations. After 28 days of water curing, the specimens were removed from their curing environments and characterized for strength, composition, and microstructure. Class G well cement specimens were simultaneously cured under similar conditions and analyzed as a source of comparison. Results indicatethat the strength of the geopolymer cement increases with increasing salinity, while the Class G cement exhibits opposite behavior. Mineralogical compositional analysis (X-ray diffraction) demonstrates the formation of a geopolymer through alkali activation of amorphous silica and alumina. Chemical compositional analyses (pH, X-ray fluorescence) revealed an increased rate of chemical exchange between the cement slurry and curing water occurred with decreasing salinity for both cement types. The microstructural characterization was carried out using scanning electron microscopy and energy dispersive X-ray spectroscopy. The geopolymer cements possessed nanoporosity and observed reacted product that was independent of curing salinity. All of the findings suggest that geopolymer cement derived from an admixture of metakaolin and Class C fly ash would be a viable alternative to ordinary Portland cement in well cementing applications
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CleanTX Analysis on the Smart Grid
The utility industry in the United States has an opportunity to revolutionize its electric grid system by utilizing emerging software, hardware and wireless technologies and renewable energy sources. As electricity generation in the U.S. increases by over 30% from todayβs generation of 4,100 Terawatt hours per year to a production of 5,400 Terawatt hours per year by 2030, a new type of grid is necessary to ensure reliable and quality power. The projected U.S. population increase and economic growth will require a grid that can transmit and distribute significantly more power than it does today. Known as a Smart Grid, this system enables two- way transmission of electrons and information to create a demand-response system that will optimize electricity delivery to consumers. This paper outlines the issues with the current grid infrastructure, discusses the economic advantages of the Smart Grid for both consumers and utilities, and examines the emerging technologies that will enable cleaner, more efficient and cost- effective power transmission and consumption.IC2 Institut
MBOAT7 rs641738 increases risk of liver inflammation and transition to fibrosis in chronic hepatitis C
Cirrhosis likely shares common pathophysiological pathways despite arising from a variety of liver diseases. A recent GWAS identified rs641738, a polymorphism in the MBOAT7 locus, as being associated with the development of alcoholic cirrhosis. Here we explore the role of this variant on liver inflammation and fibrosis in two cohorts of patients with chronic hepatitis C. In 2,051 patients, rs641738 associated with severe hepatic inflammation and increased risk of fibrosis, as well as fast fibrosis progression. At functional level, rs641738 associated with MBOAT7 transcript and protein levels in liver and blood, and with serum inflammatory, oxidative stress and macrophage activation markers. MBOAT7 was expressed in immune cell subsets, implying a role in hepatic inflammation. We conclude that the MBOAT7 rs641738 polymorphism is a novel risk variant for liver inflammation in hepatitis C, and thereby for liver fibrosis
Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics
A detailed study is presented of the expected performance of the ATLAS
detector. The reconstruction of tracks, leptons, photons, missing energy and
jets is investigated, together with the performance of b-tagging and the
trigger. The physics potential for a variety of interesting physics processes,
within the Standard Model and beyond, is examined. The study comprises a series
of notes based on simulations of the detector and physics processes, with
particular emphasis given to the data expected from the first years of
operation of the LHC at CERN
Learning together for and with the Martuwarra Fitzroy River
Co-production across scientific and Indigenous knowledge systems has become a cornerstone of research to enhance knowledge, practice, ethics, and foster sustainability transformations. However, the profound differences in world views and the complex and contested histories of nation-state colonisation on Indigenous territories, highlight both opportunities and risks for Indigenous people when engaging with knowledge co-production. This paper investigates the conditions under which knowledge co-production can lead to improved Indigenous adaptive environmental planning and management among remote land-attached Indigenous peoples through a case study with ten Traditional Owner groups in the Martuwarra (Fitzroy River) Catchment in Western Australiaβs Kimberley region. The research team built a 3D map of the river and used it, together with an interactive table-top projector, to bring together both scientific and Indigenous spatial knowledge. Participatory influence mapping, aligned with Traditional Owner priorities to achieve cultural governance and management planning goals set out in the Fitzroy River Declaration, investigated power relations. An analytical framework, examining underlying mechanisms of social learning, knowledge promotion and enhancing influence, based on different theories of change, was applied to unpack the immediate outcomes from these activities. The analysis identified that knowledge co-production activities improved the accessibility of the knowledge, the experiences of the knowledge users, strengthened collective identity and partnerships, and strengthened Indigenous-led institutions. The focus on cultural governance and management planning goals in the Fitzroy River Declaration enabled the activities to directly affect key drivers of Indigenous adaptive environmental planning and managementβthe Indigenous-led institutions. The nation-state arrangements also gave some support to local learning and decision-making through a key Indigenous institution, Martuwarra Fitzroy River Council. Knowledge co-production with remote land-attached Indigenous peoples can improve adaptive environmental planning and management where it fosters learning together, is grounded in the Indigenous-led institutions and addresses their priorities
Streamlining Digital Modeling and Building Information Modelling (BIM) Uses for the Oil and Gas Projects
The oil and gas industry is a technology-driven industry. Over the last two decades, it has heavily made use of digital modeling and associated technologies (DMAT) to enhance its commercial capability. Meanwhile, the Building Information Modelling (BIM) has grown at an exponential rate in the built environment sector. It is not only a digital representation of physical and functional characteristics of a facility, but it has also made an impact on the management processes of building project lifecycle. It is apparent that there are many similarities between BIM and DMAT usability in the aspect of physical modeling and functionality. The aim of this study is to streamline the usage of both DMAT and BIM whilst discovering valuable practices for performance improvement in the oil and gas projects. To achieve this, 28 BIM guidelines, 83 DMAT academic publications and 101 DMAT vendor case studies were selected for review. The findings uncover (a) 38 BIM uses; (b) 32 DMAT uses and; (c) 36 both DMAT and BIM uses. The synergy between DMAT and BIM uses would render insightful references into managing efficient oil and gasβs projects. It also helps project stakeholders to recognise future investment or potential development areas of BIM and DMAT uses in their projects
MicroRNA Dysregulation in the Spinal Cord following Traumatic Injury
Spinal cord injury (SCI) triggers a multitude of pathophysiological events that are tightly regulated by the expression levels of specific genes. Recent studies suggest that changes in gene expression following neural injury can result from the dysregulation of microRNAs, short non-coding RNA molecules that repress the translation of target mRNA. To understand the mechanisms underlying gene alterations following SCI, we analyzed the microRNA expression patterns at different time points following rat spinal cord injury
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