Experimental and theoretical study of horizontal-axis wind turbines

An experimental and theoretical study of horizontal-axis wind turbines is undertaken. The theoretical analyses cover the four major areas of aerodynamics, turbulence. aeroelasticity and blade optimisation. EXisting aerodynamic theories based on blade-element theory for predicting the loads on a wind turbine blade are reviewed and extended to include non-uniform flow, tip losses and the 'turbulent wake' state. A theoretical model based on a free vortex representation of a turbine wake is developed enabling the flow field within the vicinity of a turbine to be ascertained and also providing an important cross-check with the far simpler blade~lement theory. The turbulent variations in the wind velocity over the rotor swept area are considered and in particular their effects on the loads and available energy. A simple numerical solution of the dynamics of a two-bladed rotor is developed enabling the loads within the rotor blade to be determined and also those which are transferred to the supporting structure. Three rotor configurations are examined in detail; hingeless, hinged and teetered. The important problem of determining the appropriate blade shape for a particular application is considered. In parallel with the theoretical study an experimental program is also undertaken. This includes the design, construction and testing of three turbines. The design of these turbines embodies the results from 2 the theoretical studies. Wherever possible the experimental results derived from measurements made on the three experimental turbines are used to test the accuracy of the theoretical analyses

Anharmonic Decay of Vibrational States in Amorphous Silicon

Anharmonic decay rates are calculated for a realistic atomic model of amorphous silicon. The results show that the vibrational states decay on picosecond timescales and follow the two-mode density of states, similar to crystalline silicon, but somewhat faster. Surprisingly little change occurs for localized states. These results disagree with a recent experiment.Comment: 10 pages, 4 Postscript figure

On Picturing a Candle: The Prehistory of Imagery Science

The past 25 years have seen a rapid growth of knowledge about brain mechanisms involved in visual mental imagery. These advances have largely been made independently of the long history of philosophical – and even psychological – reckoning with imagery and its parent concept ‘imagination’. We suggest that the view from these empirical findings can be widened by an appreciation of imagination’s intellectual history, and we seek to show how that history both created the conditions for – and presents challenges to – the scientific endeavor. We focus on the neuroscientific literature’s most commonly used task – imagining a concrete object – and, after sketching what is known of the neurobiological mechanisms involved, we examine the same basic act of imagining from the perspective of several key positions in the history of philosophy and psychology. We present positions that, firstly, contextualize and inform the neuroscientific account, and secondly, pose conceptual and methodological challenges to the scientific analysis of imagery. We conclude by reflecting on the intellectual history of visualization in the light of contemporary science, and the extent to which such science may resolve long-standing theoretical debates

Chemically specifi C multiscale modeling of clay-polymer nanocomposites reveals intercalation dynamics, tactoid self-assembly and emergent materials properties

A quantitative description is presented of the dynamical process of polymer intercalation into clay tactoids and the ensuing aggregation of polymerentangled tactoids into larger structures, obtaining various characteristics of these nanocomposites, including clay-layer spacings, out-of-plane clay-sheet bending energies, X-ray diffractograms, and materials properties. This model of clay-polymer interactions is based on a three-level approach, which uses quantum mechanical and atomistic descriptions to derive a coarse-grained yet chemically specifi c representation that can resolve processes on hitherto inaccessible length and time scales. The approach is applied to study collections of clay mineral tactoids interacting with two synthetic polymers, poly(ethylene glycol) and poly(vinyl alcohol). The controlled behavior of layered materials in a polymer matrix is centrally important for many engineering and manufacturing applications. This approach opens up a route to computing the properties of complex soft materials based on knowledge of their chemical composition, molecular structure, and processing conditions.This work was funded in part by the EU FP7 MAPPER project (grant number RI-261507) and the Qatar National Research Fund (grant number 09–260–1–048). Supercomputing time was provided by PRACE on JUGENE (project PRA044), the Hartree Centre (Daresbury Laboratory) on BlueJoule and BlueWonder via the CGCLAY project, and on HECToR and ARCHER, the UK national supercomputing facility at the University of Edinburgh, via EPSRC through grants EP/F00521/1, EP/E045111/1, EP/I017763/1 and the UK Consortium on Mesoscopic Engineering Sciences (EP/L00030X/1). The authors are grateful to Professor Julian Evans for stimulating discussions during the course of this project. Data-storage and management services were provided by EUDAT (grant number 283304)

Protein interacting with C kinase (PICK1) is a suppressor of spinocerebellar ataxia 3-associated neurodegeneration in Drosophila

Spinocerebellar ataxia 3 (SCA3) is the most common autosomal dominant ataxia. The disease is caused by an expansion of a CAG-trinucelotide repeat region within the coding sequence of the ATXN3 gene, and this results in an expanded polyglutamine (polyQ) tract within the Ataxin-3 protein. The polyQ expansion leads to neuronal dysfunction and cell death. Here, we tested the ability of a number of proteins that interact with Ataxin-3 to modulate SCA3 pathogenicity using Drosophila. Of 10 candidates, we found four novel enhancers and one suppressor. The suppressor, PICK1 (Protein interacting with C kinase 1), is a transport protein that regulates the trafficking of ion channel subunits involved in calcium homeostasis to and from the plasma membrane. In line with calcium homeostasis being a potential pathway mis-regulated in SCA3, we also found that down-regulation of Nach, an acid sensing ion channel, mitigates SCA3 pathogenesis in flies. Modulation of PICK1 could be targeted in other neurodegenerative diseases, as the toxicity of SCA1 and tau was also suppressed when PICK1 was down-regulated. These findings indicate that interaction proteins may define a rich source of modifier pathways to target in disease situations

Lees and Moonshine: Remembering Richard III, 1485-1635

Published version of article deposited in accordance with Sherpa Romeo guidelines. © University of Chicago Press, 2010publication-status: AcceptedNot long after Shakespeare’s birth (1564) the last witnesses to the reign of Richard III (1483-85) would have reached the end of their lives. Richard III (c. 1592) occupies a distinctive historical moment in relation to its subject – a period after the extinction of living memory, but still within the horizon of communicative memory, the period in which stories and recollections may be transmitted across multiple generations. This essay explores how memories and “postmemories” of Richard’s reign were preserved, transmitted and transformed over the course of the sixteenth century and into the seventeenth. Whilst reflecting the powerful influence of emerging contexts including the Reformation and, ultimately, Shakespeare’s play, these memories remained distinct from and sometimes at odds with textual history. They survived because they offered their bearers a resource for interpreting and resisting the predicaments of the present, from the problem of tyranny to the legacies of the Reformation

A relational analysis of an invisible illness: A meta-ethnography of people with chronic fatigue syndrome/myalgic encephalomyelitis and their support needs

Chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) is indicated by prolonged, medically unexplained fatigue (amongst other symptoms), not alleviated by rest, and causing substantial disability. There are limited treatments on offer, which may not be effective and/or acceptable for all people, and treatment views are polarised. We, thus, aimed to take a step back from this debate, to explore more broadly preferences for formal and informal support among people with CFS/ME. We used a meta-ethnography approach to examine the substantial qualitative literature available. Using the process outlined by Noblit and Hare, and guided by patient involvement throughout, 47 studies were analysed. Our synthesis suggested that to understand people with CFS/ME (such as their invisibility, loss of self, and fraught clinical encounters), it was useful to shift focus to a ‘relational goods’ framework. Emotions and tensions encountered in CFS/ME care and support only emerge via ‘sui generis’ real life interactions, influenced by how social networks and health consultations unfold, and structures like disability support. This relational paradigm reveals the hidden forces at work producing the specific problems of CFS/ME, and offers a ‘no blame’ framework going forward. Chronic fatigue syndrome; myalgic encephalomyelitis; meta-ethnography: qualitative; relational goods; social support; Users' Experience

Gamma Hydroxybutyric Acid (GHB) for the Treatment of Alcohol Dependence: A Review

Gamma-hydroxybutyric acid (GHB) is a short-chain fatty acid structurally similar to the inhibitory neurotransmitter γ-aminobutyric acid. Clinical trials have demonstrated that 50–100 mg/kg of GHB fractioned into three or six daily doses is able to suppress alcohol withdrawal symptoms and facilitates the maintenance of abstinence from alcohol. These studies have also shown that GHB craving episodes are a very limited phenomenon (about 10–15%). Thus, physicians with access should consider the clinical efficacy of GHB as a valid pharmacological tool for the treatment of alcohol addiction

The cellular redox environment alters antigen presentation

Cysteine-containing peptides represent an important class of T cell epitopes, yet their prevalence remains underestimated. We have established and interrogated a database of around 70,000 naturally processed MHC-bound peptides and demonstrate that cysteine-containing peptides are presented on the surface of cells in an MHC allomorph-dependent manner and comprise on average 5-10% of the immunopeptidome. A significant proportion of these peptides are oxidatively modified, most commonly through covalent linkage with the antioxidant glutathione. Unlike some of the previously reported cysteine-based modifications, this represents a true physiological alteration of cysteine residues. Furthermore, our results suggest that alterations in the cellular redox state induced by viral infection are communicated to the immune system through the presentation of S-glutathionylated viral peptides, resulting in altered T cell recognition. Our data provide a structural basis for how the glutathione modification alters recognition by virus-specific T cells. Collectively, these results suggest that oxidative stress represents a mechanism for modulating the virus-specific T cell response.This work was supported, in whole or in part, by National Institutes of Health Grant R01 NS036592. This work was also supported by an infrastructure grant (Grant LE100100036) from the Australian Research Council (ARC) and a project grant from the Juvenile Diabetes Research Foundation (17-2012-134)