4,375 research outputs found
Specificities of floating offshore wind turbines for risk and safety evaluation of anchoring systems: Spécificités des éoliennes flottantes pour l’évaluation du risque et de la sécurité de leurs systems d’ancrages
No full textFloating offshore wind turbines (FWT) are still in their infancy and represent only 0.2% of currently installed commercial offshore wind capacity (193 MW of 65 GW) but will be critical to achieve net-zero objectives by 2050. The design of mooring systems and anchors for FWTs relies heavily on established Oil and Gas (O&G) practice, although governed by different design requirements. Reassessment and refinement of anchor system design methods and practices is necessary, recognising the different risks from FWT failure and the imperative for mass-production within the next 25 years. This paper identifies first the main differences between floating O&G and FWT and the associated geotechnical challenges and risks; then four key developments relevant to industry needs are selected and the solutions to reduce risk and uncertainty are then detailed: (i) Shared anchors; (ii) Farm-wide reliability assessment; (iii) Whole-life geotechnical design; and (iv) Screw pile installation. These examples show how physical, numerical and theoretical modelling can compensate for the current lack of FWT field experience to reduce design risk and raise project viability. Finally, technical project-wide risk is put into perspective by a comparison with the planet-wide risk resulting from delayed offshore wind farm installation
Rapporteur’s report – innovative geotechnologies for energy transition
No full textThe 9th Society for Underwater Technology (SUT) International Conference on Offshore Site Investigation and Geotechnics (OSIG) closed with a Rapporteur’s report given by the author. This paper provides a record of that report, transcribed from a video recording. The presentation slides are shown as Figures.</p
DEFRApH - Sample collection and handling procedures
No full textAll chemical and biogeochemical process in the sea are affected by the acidity of the water. Acidity is therefore fundamental property of seawater. The growing concern that the acidity of the oceans might be increasing has revealed weaknesses in our knowledge of this fundamental property and its variation in space and time. In 2008 the DEFRApH project (DEFRA contract ME4133) was initiated to provide this missing information in UK related waters. It required sampling for and analysis of the total inorganic carbon and total alkalinity content of samples. This reports documents the procedures sued for sampling. A companion document Hartman Dumousseaud and Roberts (NOC Internal Document No. 01) describes in detail the analytical procedures used and the calculation of the results
Representations of sl(2,?) in category O and master symmetries
No full textWe show that the indecomposable sl(2,?)-modules in the Bernstein-Gelfand-Gelfand category O naturally arise for homogeneous integrable nonlinear evolution systems. We then develop a new approach called the O scheme to construct master symmetries for such integrable systems. This method naturally allows computing the hierarchy of time-dependent symmetries. We finally illustrate the method using both classical and new examples. We compare our approach to the known existing methods used to construct master symmetries. For new integrable equations such as a Benjamin-Ono-type equation, a new integrable Davey-Stewartson-type equation, and two different versions of (2+1)-dimensional generalized Volterra chains, we generate their conserved densities using their master symmetries
Author Correction:Prefrontal cortical ChAT-VIP interneurons provide local excitation by cholinergic synaptic transmission and control attention (Nature Communications, (2019), 10, 1, (5280), 10.1038/s41467-019-13244-9)
No full textThe original version of this Article contained an error in the spelling of the author Wilma D.J. van de Berg, which was incorrectly given as Wilma D.J. van den Berg. This has now been corrected in both the PDF and HTML versions of the Article.</p
Sunitinib treatment exacerbates intratumoral heterogeneity in metastatic renal cancer
No full textThis work was supported by the Chief Scientist Office, Scotland (ETM37; to G.D. Stewart, A.C.P. Riddick, M. Aitchison, and D.J. Harrison), Cancer Research UK (Experimental Cancer Medicine Centre; to T. Powles, London and D.J. Harrison, Edinburgh), Medical Research Council (to A. Laird and D.J. Harrison), Royal College of Surgeons of Edinburgh (to A. Laird), Melville Trust (to A. Laird), Medical Research Council (MC_UU_12018/25; to I.M. Overton), Royal Society of Edinburgh Scottish Government Fellowship cofunded by Marie Curie Actions (to I.M. Overton), Renal Cancer Research Fund (to G.D. Stewart), Kidney Cancer Scotland (to G.D. Stewart) and an educational grant from Pfizer (to T. Powles).Purpose: The aim of this study was to investigate the effect of VEGF targeted therapy (sunitinib) on molecular intratumoral heterogeneity (ITH) in metastatic clear cell renal cancer (mccRCC). Experimental design: Multiple tumor samples (n=187 samples) were taken from the primary renal tumors of mccRCC patients who were sunitinib treated (n=23, SuMR clinical trial) or untreated (n=23, SCOTRRCC study). ITH of pathological grade, DNA (aCGH), mRNA (Illumina Beadarray) and candidate proteins (reverse phase protein array) were evaluated using unsupervised and supervised analyses (driver mutations, hypoxia and stromal related genes). ITH was analysed using intratumoral protein variance distributions and distribution of individual patient aCGH and gene expression clustering. Results: Tumor grade heterogeneity was greater in treated compared to untreated tumors (P=0.002). In unsupervised analysis, sunitinib therapy was not associated with increased ITH in DNA or mRNA. However, there was an increase in ITH for the driver mutation gene signature (DNA and mRNA) as well as increasing variability of protein expression with treatment (p<0.05). Despite this variability, significant chromosomal and transcript changes to key targets of sunitinib, such as VHL, PBRM1 and CAIX, occurred in the treated samples. Conclusions: These findings suggest that sunitinib treatment has significant effects on the expression and ITH of key tumor and treatment specific genes/proteins in mccRCC. The results, based on primary tumor analysis, do not support the hypothesis that resistant clones are selected and predominate following targeted therapy.Peer reviewe
Late reduction in congenital dislocation of the hip and the need for secondary surgery: radiologic predictors and confounding variables
No full textBackground: Despite early recognition and appropriate treatment of congenital dislocation of the hip, there are a number of cases that subsequently require further surgery to prevent progressive dysplasia, instability, and eventual early osteoarthritis. This study aimed (1) to determine the incidence of pelvic osteotomy (PO) after late open (OR) or closed (CR) reduction for failed initial conservative treatment or late presentation; (2) study potential radiologic predictors of those that will require a secondary procedure; (3) and to evaluate the effect of potential confounding variables including age of reduction, Pavlik harness treatment, and surgical experience on PO rate.Methods: All cases of congenital dislocation of the hip that presented late or had failed conservative treatment with subsequent late OR versus CR, that were carried out during 1988 to 2003, by the lead surgeon were included. Dislocations secondary to neuromuscular causes or teratologic causes were excluded. Intraoperative arthrograms confirmed the concentric or eccentric reduction and determined subsequent intervention. The AP pelvis plain radiograph was used to measure the height of dislocation, as described by Tonnis, and monitor Acetabular index, and ossific nucleus width and height postreduction.Results: After 134 OR's, 24 hips (19%, 95% CI: 16-23%) later required a pelvic osteotomy compared with 59 out of 104 hips (58%, 95% CI: 49-68%) in the CR cohort. There was no statistical difference in avascular necrosis rates between late OR (10.9%, 95% CI: 4.8-17%) and CR (11.4%, 95% CI: 5.8-17%). Acetabular index was a reliable predictor for the need of subsequent PO becoming significantly different in those that did (PO group) and did not (non-PO group) require further surgery approximately 1.5 years postreduction. There was no difference in the ON development after reduction in both PO and non-PO groups. The PO requirement was not affected by earlier failed Pavlik harness treatment but did change with ongoing surgical experience. Late OR produced the lowest secondary procedure rate without an increase in the incidence of avascular necrosis. There is a learning curve to this procedure that will affect these outcomes.Level of Evidence: Level III (Case-control study).<br/
Reply to the discussion by McCarron on “Modelling spatial variability in as-laid embedment for high pressure and high temperature (HPHT) pipeline design”
No full textN/AThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Wavelength tunable 10-GHz 3-ps pulse source using a dispersion decreasing fiber-based nonlinear optical loop mirror
No full textWe experimentally demonstrate the use of a dispersion decreasing fiber (DDF)-based nonlinear optical loop mirror (NOLM) for the generation of wavelength tunable soliton-like pulses at a repetition rate of 10 GHz. We compress ~12 ps Gaussian pulses from an electro-absorption modulator (EAM) (followed by 125 m of DCF for preliminary linear dispersion compensation) into 3 ps pedestal-free pulses using both high-order soliton compression and nonlinear switching effects within an 8.5 km DDF-based loop mirror. The output pulses from the DDF-based NOLM show considerable pedestal reduction compared to those obtained by directly compressing the EAM seed pulses via a single passage through the DDF. Wavelength tuning of the compressed pulses over a ~15 nm bandwidth (from 1541 to 1556 nm) is demonstrated without a significant increase in pulse duration or degradation in pulse quality
An introduction to management science: quantitative approaches to decision making
No full textRetaining the accessible application-driven approach for which An Introduction to Management Science is highly regarded, adapting author Mik Wisniewski has carefully reworked the existing US textbook to benefit students across the UK, Europe, Middle East and Africa. Packed with diverse realistic examples from Scotland to Saudi Arabia, the landmark text from the ASW team is now available in a truly internationalised version for students studying Management Science and Operations Research at postgraduate and undergraduate level
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