264 research outputs found

    Alternatives to conventional rig for P&A on fixed installations

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    Looking forward, there will be a need of performing a considerable number of permanent plugging and abandoning (PP&A) of oil and gas wells on the Norwegian Continental Shelf (NCS). These wells just cannot be left behind. The permanent plugging needs to be done either with or without a conventional rig tower. This thesis will cover the different surface equipment that can do P&A operations and the different downhole equipment that can aid in doing P&A operations without a conventional rig tower. In 2015, a roadmap was made showing how one thought the development in rigless technologies would be [27]. One thought that within three years, the new development in rigless technologies would allow for P&A operations from start to finish, but even still today P&A operations are not done completely rigless. One can say that the development in this area has not been exactly how one anticipated. By investigating different rigless technologies and their applications, this thesis aims to contribute valuable insights into the ongoing development within the oil and gas industry. As operators seek more sustainable and cost-effective solutions, the exploration of innovative rigless technologies emerges as key factor in the future of well abandonment on the NCS. Today, the technologies for doing P&A without a conventional rig tower exists but not all the technologies are being used on the NCS due to HSE regulations. If the hydraulic workover units (HWO) make their pipe handling systems completely automated, and a red zone with no personnel activity while the equipment is in use, they will be allowed on the NCS. If the more advanced HWO’s are introduced, large parts of the P&A jobs can be performed without the use of conventional rig tower. It should also be noticed that improvements in downhole technologies will facilitate more use of rigless surface technologies. The surface technologies this thesis will cover combined with new development in downhole equipment make it possible to P&A from start to finish

    The Geomorphology and Nature of Seabed Seepage Processes

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    Skal behandlingen fortsette?

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    Vi ønsket å finne ut hva som var vanskelig for sykepleieren rundt døende i intensivavdelingen, som vi selv opplevde i praksis. Derfor endte vi med problemstillingen: Hva opplever sykepleier som etisk utfordrende i beslutningsprosessen rundt livsforlengende behandling i intensivavdelingen? Den medisinske utvikling har medført profesjonelle, økonomiske, sosiale, etiske og samfunnsmessige utfordringer. Teknologiens innmarsj på sykehusene har sammenheng med biomedisinsk og naturvitenskaplig utvikling. Det fører til en økende dehumanisering av pasient og helsepersonell når den teknologiske utviklingen har ført til at den gode terminale pleie drukner i ”summingen” av tekniske apparater. Faglitteratur og studier har vist at tendensen til overbehandling krenker både pasienten og pleiernes grunnleggende verdier. Til tross for økende fokus på pasients og pårørendes rettigheter har de etiske utfordringen ikke blitt lettere. Studiene vi har gjennomgått viser at både pasienten og pårørende ikke blir integrert godt nok i denne beslutningsprosessen. Vi har beskrevet forholdene på intensivavdelingen og valgt litteratur vi mener er relevant for å løse problemstillingen. Deriblandt etikk, juss og ulike menneskesyn. Forskning og tidligere studier fra praksis tar stor plass i vår hovedoppgave. Vi har begrenset oss til tre internasjonale studier, og to norske kvalitative studier. Vi har drøftet etiske problemstillinger i lys av Kari Martinsens sykepleieteori. Våre utvalgte studier sier at samarbeidet på avdelingen har betydning for beslutningsprosessen. Intensivpasienter er veldig dårlig, og få er beslutningsdyktige. Derfor kom vi frem til at pårørende bør i større grad bør inkluderes i belsutningsprosessen, slik at de føler seg bedre ivaretatt enn hva studiene viste. Gjennom drøfting viser vi at det kan være en konflikt mellom de to grunnleggende menneskesynene holisme og reduksjonisme

    Adaptive Backstepping Control of Nonlinear Hydraulic-Mechanical System Including Valve Dynamics

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    Published version of an article from the journal: Modeling Identification and Control. Also available from publisher: http://dx.doi.org/10.4173/mic.2010.1.3The main contribution of the paper is the development of an adaptive backstepping controller for a nonlinear hydraulic-mechanical system considering valve dynamics. The paper also compares the performance of two variants of an adaptive backstepping tracking controller with a simple PI controller. The results show that the backstepping controller considering valve dynamics achieves significantly better tracking performance than the PI controller, while handling uncertain parameters related to internal leakage, friction, the orifice equation and oil characteristics

    High diversity of microplankton surrounds deep-water coral reef in the Norwegian Sea

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    Coral reefs that exist in the depths of the oceans are surrounded by Eukarya, Archaea and bacterial communities that may play an important role in the nutrition and health of the reef. The first interdomain community structure of planktonic organisms in seawater from a deep-water coral reef is described. Community profiling and analysis of ribosomal RNA gene sequences from a coral reef system at 350 m depth in the Norwegian Sea revealed a rich diversity of Eukarya and Bacteria and a moderate diversity of Archaea. Most sequences affiliated with marine microplankton from deep-sea to cold-surface regions, with many sequences being similar to those described in studies of mesopelagic and oxygen minimum zones. Dominant phylotypes belonged to the Alveolata (group I, II, dinoflagellates), Stramenopiles (silicoflagellates), Alphaproteobacteria (Pelagibacter ubique), Gammaproteobacteria (ARCTIC96BD-19), Bacteroidetes (Flavobacteria) and mesophilic Crenarchaeota (Nitrosopumilus maritimus). Several rare and novel members of the community fell into distinct phylogenetic groups. The inferred function of dominant community members suggested autotrophs that utilise light, ammonium or sulphide, and lifestyles based on host associations. The high diversity reflected a microplankton community structure, which is significantly different from that of microplankton collected at the same depth at a pelagic station away from reefs

    Endozoicomonadaceae symbiont in gills of Acesta clam encodes genes for essential nutrients and polysaccharide degradation

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    Gammaproteobacteria from the family Endozoicomonadaceae have emerged as widespread associates of dense marine animal communities. Their abundance in coral reefs involves symbiotic relationships and possibly host nutrition. We explored functions encoded in the genome of an uncultured Endozoicomonadaceae ‘Candidatus Acestibacter aggregatus’ that lives inside gill cells of large Acesta excavata clams in deep-water coral reefs off mid-Norway. The dominance and deep branching lineage of this symbiont was confirmed using 16S rRNA gene sequencing and phylogenomic analysis from shotgun sequencing data. The 4.5 Mb genome binned in this study has a low GC content of 35% and is enriched in transposon and chaperone gene annotations indicating ongoing adaptation. Genes encoding functions potentially involved with the symbiosis include ankyrins, repeat in toxins, secretion and nutritional systems. Complete pathways were identified for the synthesis of eleven amino acids and six B-vitamins. A minimal chitinolytic machinery was indicated from a glycosyl hydrolase GH18 and a lytic polysaccharide monooxygenase LPMO10. Expression of the latter was confirmed using proteomics. Signal peptides for secretion were identified for six polysaccharide degrading enzymes, ten proteases and three lipases. Our results suggest a nutritional symbiosis fuelled by enzymatic products from extracellular degradation processes.publishedVersio

    Unlocking India’s Potential in Managing Endocrine-Disrupting Chemicals (EDCs): Importance, Challenges, and Opportunities

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    Endocrine-disrupting chemicals (EDCs) are a prime concern for the environment and health globally. Research shows that in developing countries such as India both the environment and human populations are severely exposed to EDCs and consequently experience rising incidents of adverse health effects such as diabetes and cancers. In this paper, we discuss the current EDC management approach in India, critically assess its limitations, and describe opportunities for potential improvements. Foremost, current EDC management actions and interventions in India are fragmented and outdated, and far behind the modern and comprehensive approaches adopted in the European Union and other developed countries. Strong and well-planned actions are required on various fronts of science, policy, commerce, and public engagement. These actions include the adoption of a dedicated and modern regulatory framework for managing EDCs, enhancing capacity and infrastructure for EDC monitoring in the environment and human population, employing public–private partnership programs for not only managing EDCs but also in the sectors that indirectly contribute toward the mismanagement of EDCs in the country, and raising awareness on EDCs and promoting health-preserving consumption habits among the public. As India hosts a large proportion of the global human population and biodiversity, the success or failure of its actions will substantially affect the direction of global efforts to manage EDCs and set an example for other developing countries.publishedVersio

    The risk of various types of cardiovascular diseases in mutation positive familial hypercholesterolemia; a review

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    Familial hypercholesterolemia (FH) is a common, inherited disease characterized by high levels of low-density lipoprotein Cholesterol (LDL-C) from birth. Any diseases associated with increased LDL-C levels including atherosclerotic cardiovascular diseases (ASCVDs) would be expected to be overrepresented among FH patients. There are several clinical scoring systems aiming to diagnose FH, however; most individuals who meet the clinical criteria for a FH diagnosis do not have a mutation causing FH. In this review, we aim to summarize the literature on the risk for the various forms of ASCVD in subjects with a proven FH-mutation (FH+). We searched for studies on FH+ and cardiovascular diseases and also included our and other groups published papers on FH + on a wide range of cardiovascular and other diseases of the heart and vessels. FH + patients are at a markedly increased risk of a broad range of ASCVD. Acute myocardial infarction (AMI) is the most common in absolute numbers, but also aortic valve stenosis is by far associated with the highest excess risk. Per thousand patients, we observed 3.6 incident AMI per year compared to 1.9 incident aortic valve stenosis, however, standardized incidence ratio (SIR) for incident AMI was 2.3 compared to 7.9 for incident aortic valve stenosis. Further, occurrence of ischemic stroke seems not to be associated with increased risk in FH+. Clinicians should be aware of the excess risk of almost all kind of ASCVD in FH+, and the neutral risk of stroke need to be studied further in FH + patients.publishedVersio
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