167 research outputs found

    Neutrino Oscillations for Dummies

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    The reality of neutrino oscillations has not really sunk in yet. The phenomenon presents us with purely quantum mechanical effects over macroscopic time and distance scales (milliseconds and 1000s of km). In order to help with the pedagogical difficulties this poses, I attempt here to present the physics in words and pictures rather than math. No disrespect is implied by the title; I am merely borrowing a term used by a popular series of self-help books

    Evidence on evidence-informed policy and practice

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    Vehicle-to-grid feasibility: A techno-economic analysis of EV-based energy storage

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    © 2017 Elsevier LtdThe potential for electric vehicles to obtain income from energy supplied to a commercial building together with revenue accruing from specific ancillary service markets in the UK is evaluated in this work. A hybrid time-series/probabilistic simulation environment using real-world data is described, which is applied in the analysis of electricity trading with vehicle-to-grid to vehicles, buildings and markets. Key parameters are found to be the electric vehicle electricity sale price, battery degradation cost and infrastructure costs. Three vehicle-to-grid scenarios are evaluated using pool vehicle trip data, market pricing index data and half-hourly electricity demand for a commercial building. Results show that provision of energy to the wholesale electricity market with additional income from the capacity market results in the greatest projected return on investment, producing an individual vehicle net present value of âˆŒÂŁ8400. This is over 10 years for a vehicle supplying energy three times per week to the half-hour day-ahead market and includes the cost of installing the vehicle-to-grid infrastructure. The analysis also shows that net income generation is strongly dependent upon battery degradation costs associated with vehicle-to-grid cycling

    Silk-Cellulose Acetate Biocomposite Materials Regenerated from Ionic Liquid

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    The novel use of ionic liquid as a solvent for biodegradable and natural organic biomaterials has increasingly sparked interest in the biomedical field. As compared to more volatile traditional solvents that rapidly degrade the protein molecular weight, the capability of polysaccharides and proteins to dissolve seamlessly in ionic liquid and form fine and tunable biomaterials after regeneration is the key interest of this study. Here, a blended system consisting of Bombyx Mori silk fibroin protein and a cellulose derivative, cellulose acetate (CA), in the ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIMAc) was regenerated and underwent characterization to understand the structure and physical properties of the films. The change in the morphology of the biocomposites (by scanning electron microscope, SEM) and their secondary structure analysis (by Fourier-transform infrared spectroscopy, FTIR) showed that the samples underwent a wavering conformational change on a microscopic level, resulting in strong interactions and changes in their crystalline structures such as the CA crystalline and silk beta-pleated sheets once the different ratios were applied. Differential scanning calorimetry (DSC) results demonstrated that strong molecular interactions were generated between CA and silk chains, providing the blended films lower glass transitions than those of the pure silk or cellulose acetate. All films that were blended had higher thermal stability than the pure cellulose acetate sample but presented gradual changes amongst the changing of ratios, as demonstrated by thermogravimetric analysis (TGA). This study provides the basis for the comprehension of the protein-polysaccharide composites for various biomedical applications

    Bridging the gap: A case study of a partnership approach to skills development through student engagement in bristol’s green capital year

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    © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. HEIs are well placed to engage with local communities, and can connect students with organisations through several pathways, such as volunteering opportunities, placements, internships, or projects. The University of the West of England, Bristol (UWE), the University of Bristol and their respective Students’ Unions have been working in partnership with the city and local communities, using HEFCE Catalyst funding to promote student involvement in sustainability activity during Bristol’s year as European Green Capital. The Green Capital Student Capital project has created a broad programme of citywide impact through mobilising the enthusiasm of the city’s student body. It delivered a wide-ranging programme of engagement in city sustainability and in so doing developed skills, knowledge and attributes in the student body that support the development of graduate attributes and amore sustainable lifestyle. The project demonstrates how institutions can collaborate across cities and communities to have internal and external impacts for sustainability

    A loyalty scheme to encourage physical activity in office workers: a cluster RCT

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    Background: Increasing physical activity in the workplace can provide physical and mental health benefits for employees and economic benefits for the employer through reduced absenteeism and increased productivity. However, there is limited evidence on effective behaviour change interventions in workplace settings that led to maintained physical activity. This study aimed to address this gap and contribute to the evidence base for effective and cost-effective workplace interventions. Objectives: To determine the effectiveness and cost-effectiveness of the Physical Activity Loyalty scheme, a multicomponent intervention based on concepts similar to those that underpin a high-street loyalty card, which was aimed at encouraging habitual physical activity behaviour and maintaining increases in mean number of steps per day. Design: A cluster randomised controlled trial with an embedded economic evaluation, behavioural economic experiments, mediation analyses and process evaluation. Setting: Office-based employees from public sector organisations in Belfast and Lisburn city centres in Northern Ireland. Participants: A total of 853 participants [mean age 43.6 years (standard deviation 9.6 years); 71% of participants were female] were randomly allocated by cluster to either the intervention group or the (waiting list) control group. Intervention: The 6-month intervention consisted of financial incentives (retail vouchers), feedback and other evidence-based behaviour change techniques. Sensors situated in the vicinity of the workplaces allowed participants to monitor their accumulated minutes of physical activity. Main outcome measures: The primary outcome was mean number of steps per day recorded using a sealed pedometer (Yamax Digiwalker CW-701; Yamax, Tasley, UK) worn on the waist for 7 consecutive days and at 6 and 12 months post intervention. Secondary outcomes included health, mental well-being, quality of life, work absenteeism and presenteeism, and the use of health-care resources. Results: The mean number of steps per day were significantly lower for the intervention group than the control group [6990 mean number of steps per day (standard deviation 3078) vs. 7576 mean number of steps per day (standard deviation 3345), respectively], with an adjusted mean difference of –336 steps (95% confidence interval –612 to –60 steps; p = 0.02) at 6 months post baseline, but not significantly lower at 12 months post baseline. There was a small but significant enhancement of mental well-being in the intervention group (difference between groups for the Warwick–Edinburgh Mental Wellbeing Scale of 1.34 points, 95% confidence interval 0.48 to 2.20 points), but not for the other secondary outcomes. An economic evaluation suggested that, overall, the scheme was not cost-effective compared with no intervention. The intervention was £25.85 (95% confidence interval –£29.89 to £81.60) more costly per participant than no intervention and had no effect on quality-adjusted life-years (incremental quality-adjusted life-years –0.0000891, 95% confidence interval –0.008 to 0.008). Limitations: Significant restructuring of participating organisations during the study resulted in lower than anticipated recruitment and retention rates. Technical issues affected intervention fidelity. Conclusions: Overall, assignment to the intervention group resulted in a small but significant decline in the mean pedometer-measured steps per day at 6 months relative to baseline, compared with the waiting list control group. The Physical Activity Loyalty scheme was deemed not to be cost-effective compared with no intervention, primarily because no additional quality-adjusted life-years were gained through the intervention. Research to better understand the mechanisms of physical activity behaviour change maintenance will help the design of future interventions. Trial registration: Current Controlled Trials ISRCTN17975376. Funding: This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 7, No. 15. See the NIHR Journals Library website for further project information

    Characterizing the diurnal patterns of errors in the prediction of evapotranspiration by several land‐surface models: An NACP analysis

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    Land‐surface models use different formulations of stomatal conductance and plant hydraulics, and it is unclear which type of model best matches the observed surface‐atmosphere water flux. We use the North American Carbon Program data set of latent heat flux (LE) measurements from 25 sites and predictions from 9 models to evaluate models' ability to resolve subdaily dynamics of transpiration. Despite overall good forecast at the seasonal scale, the models have difficulty resolving the dynamics of intradaily hysteresis. The majority of models tend to underestimate LE in the prenoon hours and overestimate in the evening. We hypothesize that this is a result of unresolved afternoon stomatal closure due to hydrodynamic stresses. Although no model or stomata parameterization was consistently best or worst in terms of ability to predict LE, errors in model‐simulated LE were consistently largest and most variable when soil moisture was moderate and vapor pressure deficit was moderate to limiting. Nearly all models demonstrate a tendency to underestimate the degree of maximum hysteresis which, across all sites studied, is most pronounced during moisture‐limited conditions. These diurnal error patterns are consistent with models' diminished ability to accurately simulate the natural hysteresis of transpiration. We propose that the lack of representation of plant hydrodynamics is, in part, responsible for these error patterns. Key Points Land‐surface models produce subdaily patterns of latent heat flux error Error patterns are characterized by the stomatal conductance formulation used Current models lack a mechanism to simulate hysteretic transpirationPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108341/1/jgrg20246.pd
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