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Institution

University of Aberdeen

EducationAberdeen, United Kingdom
About: University of Aberdeen is a education organization based out in Aberdeen, United Kingdom. It is known for research contribution in the topics: Population & Randomized controlled trial. The organization has 21174 authors who have published 49962 publications receiving 2105479 citations. The organization is also known as: Aberdeen University.


Papers
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Journal ArticleDOI
TL;DR: It is found in numerical simulations of artificially generated power grids that tree-like connection schemes--so-called dead ends and dead trees--strongly diminish stability, which may indicate a topological design principle for future power grids: avoid dead ends.
Abstract: The cheapest and thus widespread way to add new generators to a high-voltage power grid is by a simple tree-like connection scheme. However, it is not entirely clear how such locally cost-minimizing connection schemes affect overall system performance, in particular the stability against blackouts. Here we investigate how local patterns in the network topology influence a power grid's ability to withstand blackout-prone large perturbations. Employing basin stability, a nonlinear concept, we find in numerical simulations of artificially generated power grids that tree-like connection schemes--so-called dead ends and dead trees--strongly diminish stability. A case study of the Northern European power system confirms this result and demonstrates that the inverse is also true: repairing dead ends by addition of a few transmission lines substantially enhances stability. This may indicate a topological design principle for future power grids: avoid dead ends.

368 citations

Journal ArticleDOI
TL;DR: In this paper, a comparative study of different materials, working principles, analysis, applications, advantages and disadvantages of various technologies available for supercapacitors is presented, and the potential issues and the perspectives for future research based on hybrid supercapACitors in energy applications are also presented.
Abstract: Supercapacitors have become the most significant energy conversion and storage system in recent renewable and sustainable nanotechnology. Due to its large energy capacity and supply with relatively short time and longer lifetime, supercapacitors breakthrough in advance energy applications. This review presents a comparative study of different materials, working principles, analysis, applications, advantages and disadvantages of various technologies available for supercapacitors. The aim of this article is to discuss the possibility of hybrid supercapacitor for the next generation of energy technology. The development of composite materials containing a wide range of active constituents (e.g., graphene, activated carbon, transition metals, metal oxides, perovskites and conducting polymers) by in-situ hybridization and ex-situ recombination is also discussed. This review consecrated largely the contribution of combining all materials (electrode and electrolyte) and their synthesis process and electrochemical performance. Enduringly, the potential issues and the perspectives for future research based on hybrid supercapacitors in energy applications are also presented.

368 citations

Journal ArticleDOI
TL;DR: Whether patient bleeding history and unselected coagulation testing predict abnormal perioperative bleeding and the positive predictive value and likelihood ratio for coagulating tests indicate that they are poor predictors of bleeding.
Abstract: Unselected coagulation testing is widely practiced in the process of assessing bleeding risk prior to surgery. This may delay surgery inappropriately and cause unnecessary concern in patients who are found to have 'abnormal' tests. In addition it is associated with a significant cost. This systematic review was performed to determine whether patient bleeding history and unselected coagulation testing predict abnormal perioperative bleeding. A literature search of Medline between 1966 and 2005 was performed to identify appropriate studies. Studies that contained enough data to allow the calculation of the predictive value and likelihood ratios of tests for perioperative bleeding were included. Nine observational studies (three prospective) were identified. The positive predictive value (0.03-0.22) and likelihood ratio (0.94-5.1) for coagulation tests indicate that they are poor predictors of bleeding. Patients undergoing surgery should have a bleeding history taken. This should include detail of previous surgery and trauma, a family history, and detail of anti-thrombotic medication. Patients with a negative bleeding history do not require routine coagulation screening prior to surgery.

368 citations

Journal ArticleDOI
TL;DR: It is concluded that the greater fatty acid content of pig oocytes is primarily due to more abundant triglyceride reserves, and that in respect of polyunsaturated fatty acid reserves, may underlie the contrasting chilling, culture and cryopreservation sensitivities of embryos derived from pig and ruminant oocytes.
Abstract: Cattle, pig and sheep oocytes isolated from healthy cumulus‐oocyte complexes were pooled, within species, to provide samples of immature denuded oocytes with intact zona pellucida (n = 1000 per sample) for determination of fatty acid mass and composition in total lipid, constituent phospholipid and triglyceride. Acyl-containing lipid extracts, transmethylated in the presence of a reference penta-decaenoic acid (15:0), yielded fatty acid methyl esters which were analysed by gas chromatography. Mean (± SEM) fatty acid content in samples of pig oocytes (161 ± 18 µg per 1000 oocytes) was greater than that in cattle (6 3±6µ g; P < 0.01) and sheep oocytes (8 9±7µ g; P < 0.05). Of 24 fatty acids detected, palmitic (16:0; 25‐35%, w/w), stearic (18:0; 14‐16%) and oleic (18:1n-9; 22‐26%) acids were most prominent in all three species. Saturated fatty acids (mean = 45‐55%, w/w) were more abundant than mono- (27‐34%) or polyunsaturates (11‐21%). Fatty acids of the n-6 series, notably linoleic (18:2n-6; 5‐8%, w/w) and arachidonic acid (20:4n-6; 1‐3%), were the most abundant polyunsaturates. Phospholipid consistently accounted for a quarter of all fatty acids in the three species, but ruminant oocytes had a lower complement of polyunsaturates (14‐19%, w/w) in this fraction than pig oocytes (34%, w/w) which, for example, had a three- to fourfold greater linoleic acid content. An estimated 74 ng of fatty acid was sequestered in the triglyceride fraction of individual pig oocytes compared with 23‐25 ng in ruminant oocytes (P < 0.01). It is concluded that the greater fatty acid content of pig oocytes is primarily due to more abundant triglyceride reserves. Furthermore, this speciesspecific difference, and that in respect of polyunsaturated fatty acid reserves, may underlie the contrasting chilling, culture and cryopreservation sensitivities of embryos derived from pig and ruminant (cattle, sheep) oocytes.

368 citations

Journal ArticleDOI
TL;DR: In this paper, a conceptual framework placing accessibility centrally in the social justice and social inclusion agenda is discussed, and the location of the idea of accessibility in the rural context, and as a "rural challenge" is traced.

367 citations


Authors

Showing all 21424 results

NameH-indexPapersCitations
Paul M. Thompson1832271146736
Feng Zhang1721278181865
Ian J. Deary1661795114161
Peter A. R. Ade1621387138051
David W. Johnson1602714140778
Pete Smith1562464138819
Naveed Sattar1551326116368
John R. Hodges14981282709
Ruth J. F. Loos14264792485
Alan J. Silman14170892864
Michael J. Keating140116976353
David Price138168793535
John D. Scott13562583878
Aarno Palotie12971189975
Rajat Gupta126124072881
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2023141
2022362
20212,195
20202,118
20191,846
20181,894