754 research outputs found
Trombe walls with nanoporous aerogel insulation applied to UK housing refurbishments
There is an opportunity to improve the efficiency of passive Trombe walls and active solar air collectors by replacing their conventional glass covers with lightweight polycarbonate panels filled with nanoporous aerogel insulation. This study investigates the thermal performance, energy savings, and financial payback period of passive Aerogel Trombe walls applied to the existing UK housing stock. Using parametric modeling, a series of design guidance tables have been generated, providing estimates of the energy savings and overheating risk associated with applying areas of Trombe wall to four different house types across the UK built to six notional construction standards. Calculated energy savings range from 183 kWh/m2/year for an 8 m2 system retrofitted to a solid walled detached house to 62 kWh/m2/year for a 32 m2 system retrofitted to a super insulated flat. Predicted energy savings from Trombe walls up to 24 m2 are found to exceed the energy savings from external insulation across all house types and constructions. Small areas of Trombe wall can provide a useful energy contribution without creating a significant overheating risk. If larger areas are to be installed, then detailed calculations would be recommended to assess and mitigate potential overheating issues.The EPSRC, Brunel University, and Buro Happold Lt
Colloidal dual-band gap cell for photocatalytic hydrogen generation
We report that the internal quantum efficiency for hydrogen generation in spherical, Pt-decorated CdS nanocrystals can be tuned by quantum confinement, resulting in higher efficiencies for smaller than for larger nanocrystals (17.3% for 2.8 nm and 11.4% for 4.6 nm diameter nanocrystals). We attribute this to a larger driving force for electron and hole transfer in the smaller nanocrystals. The larger internal quantum efficiency in smaller nanocrystals enables a novel colloidal dual-band gap cell utilising differently sized nanocrystals and showing larger external quantum efficiencies than cells with only one size of nanocrystals (9.4% for 2.8 nm particles only and 14.7% for 2.8 nm and 4.6 nm nanocrystals). This represents a proof-of-principle for future colloidal tandem cell
Zero-one survival behavior of cyclically competing species
Coexistence of competing species is, due to unavoidable fluctuations, always
transient. In this Letter, we investigate the ultimate survival probabilities
characterizing different species in cyclic competition. We show that they often
obey a surprisingly simple, though non-trivial behavior. Within a model where
coexistence is neutrally stable, we demonstrate a robust zero-one law: When the
interactions between the three species are (generically) asymmetric, the
`weakest' species survives at a probability that tends to one for large
population sizes, while the other two are guaranteed to extinct. We rationalize
our findings from stochastic simulations by an analytic approach.Comment: 4 pages, 3 figure
The state of workplace union reps organisation in Britain today
This article provides a brief evaluation of the state of workplace union reps’ organization in Britain as we approach the second decade of the 2000s. It documents the severe weakening of workplace union organization over the last 25 years, which is reflected in the declining number of reps, reduced bargaining power and the problem of bureaucratization. But it also provides evidence of the continuing resilience, and even combativity in certain areas of employment, of workplace union reps organization, and considers the future potential for a revival of fortunes
Evidence for the association of the S100beta gene with low cognitive performance and dementia in the elderly
Revisiting the 'Missing Middle' in English Sub-National Governance
In the light of the new Coalition Government’s proposed ‘rescaling’ of sub-national governance away from the regional level, it is an opportune time to re-consider the strength and weaknesses of the city or sub-regional approach to economic development and to search, once more, for the ‘missing middle’ in English Governance. In this context, the article initially assesses the case for city or sub regions as tiers of economic governance, before examining the lessons to be learnt from the experiences of the existing city regions in the North East of England. It argues that while contemporary plans to develop Local Enterprise Partnerships (LEPs) can be usefully considered within the context of the emerging city regional developments under the previous Labour Governments, a number of important challenges remain, particularly in relation to ensuring accountable structures of governance, a range of appropriate functions, adequate funding, and comprehensive coverage across a variety of sub-regional contexts. While the proposals of the new Government create the necessary ‘space’ to develop sub-regional bodies and offer genuine opportunities for both city and county LEPs, the scale of the sub-regional challenge should not be underestimated, particularly given the context of economic recession and major reductions in the public sector
Spatial distribution of cerebral white matter lesions predicts progression to mild cognitive impairment and dementia
CONTEXT White matter lesions (WML) increase the risk of dementia. The relevance of WML location is less clear. We sought to determine whether a particular WML profile, based on the density and location of lesions, could be associated with an increased risk of mild cognitive impairment (MCI) or dementia over the following 7 years. METHODS In 426 healthy subjects from a cohort of community-dwelling people aged 65 years and over (ESPRIT Project), standardized cognitive and neurological evaluations were repeated after 2, 4 and 7 years. Patterns of WML were computed with a supervised data mining approach (decision trees) using the regional WML volumes (frontal, parietal, temporal, and occipital regions) and the total WML volume estimated at baseline. Cox proportional hazard models were then constructed to study the association between WML patterns and risk of MCI/dementia. RESULTS Total WML volume and percentage of WML in the temporal region proved to be the best predictors of progression to MCI and dementia. Specifically, severe total WML load with a high proportion of lesions in the temporal region was significantly associated with the risk of developing MCI or dementia. CONCLUSIONS Above a certain threshold of damage, a pattern of WML clustering in the temporal region identifies individuals at increased risk of MCI or dementia. As this WML pattern is observed before the onset of clinical symptoms, it may facilitate the detection of patients at risk of MCI/dementia.The ESPRIT Project is financed by the regional government of Languedoc-Roussillon (http://www.laregion.fr), the Agence Nationale de la Recherche
(ANR: http://www.agence-nationale-recherche.fr) and an unconditional grant from Novartis (http://www.novartis.fr). This study is also supported by France
Alzheimer (http://www.francealzheimer.org/)
Metabolic Syndrome and Risk for Incident Alzheimer's Disease or Vascular Dementia: The Three-City Study
OBJECTIVE—Associations between metabolic syndrome and its individual components with risk of incident dementia and its different subtypes are inconsistent
Eating Fish and Risk of Type 2 Diabetes: A population-based, prospective follow-up study
Objective: To investigate the relation between total fish, type of fish (lean and fatty), and EPA&DHA intake and risk of type 2 diabetes in a population-based cohort. Research design and methods: The analysis included 4,472 Dutch participants aged =55 years without diabetes at baseline. Dietary intake was assessed with a semi-quantitative food frequency questionnaire. Hazard ratios (RR) with 95% confidence intervals (95% CI) were used to examine risk associations adjusted for age, sex, lifestyle, and nutritional factors. Results: After 15 years of follow-up, 463 participants developed type 2 diabetes. Median fish intake, mainly lean fish (81% ), was 10 g/d. Total fish intake was associated positively with risk of type 2 diabetes; the RR was 1.32 (95% CI 1.02, 1.70) in the highest total fish group (=28 g/d) compared with non-fish eaters (p for trend= 0.04). Correspondingly, lean fish intake tended to be associated positively with type 2 diabetes (RR highest group (=23 g/d): 1.30 (95% CI 1.01, 1.68), p for trend= 0.06), but fatty fish was not. No association was observed between EPA&DHA intake and type 2 diabetes (RR highest group (=149.4 mg/d): 1.22 (95% CI 0.97, 1.53)). When additionally adjusted for intake of selenium, cholesterol, and vitamin D this RR decreased to 1.05 (95% CI 0.80, 1.38) (p for trend= 0.77). Conclusion: The findings do not support a beneficial effect of total fish, type of fish, or EPA&DHA intake on the risk of type 2 diabetes. Alternatively, other dietary components, like selenium, and unmeasured contaminants present in fish might explain our result
Mental Distress Under Occupation: The Journal of Madeleine Blaess
Madeleine Blaess a British doctoral student studying at the Sorbonne was trapped in Paris unable to return home to York for the duration of the Occupation. In October 1940 she began a diary which she kept diligently until September 1944. This unique testimony written from the perspective of a British student at liberty to roam wartime Paris, focuses more on the civilian struggle through the everyday than on the political and military situation which Blaess, vulnerable to arrest, thinks wise to mention as little as possible. This exhaustively documented, voluminous record of the minutiae of a daily struggle with material hardship discloses a struggle with mental illness articulated and managed through the writing of the diary. That diaries can have a therapeutic purpose for writers under mental strain is axiomatic and this article examines a variety of palliative strategies both deliberate and involuntary invoked through the writing process. In so doing, the article will survey the incidence and causes of civilian mental distress on the home front over the period; an area of inquiry which, other than recent work into the psychological impact of Allied bombing of civilians, has been largely neglected in recent work foregrounding and valorising the historical importance of life-writing sources in the field of Occupation studies
- …