317 research outputs found
Insights from inside the school walls: Contextual data crowdsourcing and feedback mechanisms for UK school stock modelling
The auto-generation of UK school building stock models could facilitate non-domestic
carbon emissions tracking. However, contextual fabric and building service data are
required to differentiate between asset or operational performance, and these may
only be available in situ from building users. Engaging such groups through proposed
data crowdsourcing would require robust feedback and data gathering mechanisms to
be developed to overcome motivational and informational barriers.
This paper describes five stakeholder sessions and a crowdsourcing survey of 139
responses from London schools to better understand these two mechanisms.
Aesthetics and budgetary drivers were found to be persistent amongst participants,
with a diversity of views on achieving these in practice. This research should inform
future data gathering and develop more updated and robust stock refurbishment
datasets
"Studs": a squat-type defect in rails
In the mid-2000s a rail defect that was classified as a "squat" became increasingly common on London Underground's track. By 2006 there were about 600 of these and they had become the Underground's single most common rail defect. This defect occurred almost exclusively on lines carrying relatively new rolling stock. The work reported here was undertaken initially to characterize this defect, advise as to whether it was indeed a squat and propose a hypothesis that explained its mechanism of formation. The paper includes observations and measurements from track and initial results of metallurgical analysis. The hypothesis for formation of the defects is presented, and both similarities and differences are discussed between these defects and the classical "squat". The defect on London Underground appears to be the same as that described by Marich and his colleagues in Australia and by Li and his colleagues in the Netherlands. It is evidently not a rolling contact fatigue defect. In order to avoid confusion arising from simple misuse of an established term, it is proposed that these defects be given a different name, for which āstudā is proposed. Evidence to date is that the "stud" is a significantly more benign defect than a "squat"
Modelling platform for schools (MPS): The development of an automated One-By-One framework for the generation of dynamic thermal simulation models of schools
The UK Government has recently committed to achieve net zero carbon status by year 2050. Schools are responsible for around 2% of the UKās total energy consumption, and around 15% of the UK public sectorās carbon emissions. A detailed analysis of the English school building stockās performance can help policymakers improve its energy efficiency and indoor environmental quality.
Building stock modelling is a technique commonly used to quantify current and future energy demand or indoor environmental quality performance of large numbers of buildings at the neighbourhood, city, regional or national level. āBuilding-by-buildingā stock modelling is a modelling technique whereby individual buildings within the stock are modelled and simulated, and performance results are aggregated and analysed at stock level.
This paper presents the development of the Modelling Platform for Schools (MPS) ā an automated generation of one-by-one thermal models of schools in England through the analysis and integration of a range of data (geometry, size, number of buildings within a school premises etc.) from multiple databases and tools (Edubase/Get Information About Schools, Property Data Survey Programme, Ordanance Survey and others). The study then presents an initial assessment and evaluation of the modelling procedure of the proposed platform.
The model evaluation has shown that out of 15,245 schools for which sufficient data were available, nearly 50% can be modelled in an automated manner having a high level of confidence of similarity with the actual buildings. Visual comparison between automatically-generated models and actual buildings has shown that around 70% of the models were, indeed, geometrically accurate
School building energy efficiency and NOā related risk of childhood asthma in England and Wales: Modelling study
Background: Climate change legislation will require dramatic increases in the energy efficiency of school buildings across the UK by 2050, which has the potential to affect air quality in schools. We assessed how different strategies for improving the energy efficiency of school buildings in England and Wales may affect asthma incidence and associated healthcare utilization costs in the future. / Methods: Indoor concentrations of traffic-related NO2 were modelled inside school buildings representing 13 climate regions in England and Wales using a building physics school stock model. We used a health impact assessment model to quantify the resulting burden of childhood asthma incidence by combining regional health and population data with exposure-response functions from a recent high-quality systematic review/meta-analysis. We compared the effects of four energy efficiency interventions consisting of combinations of retrofit and operational strategies aiming to improve indoor air quality and thermal comfort on asthma incidence and associated hospitalization costs. / Results: The highest childhood asthma incidence was found in the Thames Valley region (including London), in particular in older school buildings, while the lowest concentrations and health burdens were in the newest schools in Wales. Interventions consisting of only operational improvements or combinations of retrofit and operational strategies resulted in reductions in childhood asthma incidence (547 and 676 per annum regional average, respectively) and hospital utilization costs (Ā£52,050 and Ā£64,310 per annum regional average, respectively. Interventions that improved energy efficiency without operational measures resulted in higher childhood asthma incidence and hospital costs. / Conclusion: The effect of school energy efficiency retrofit on NO2 exposure and asthma incidence in schoolchildren depends critically on the use of appropriate building operation strategies. The findings from this study make several contributions to fill the knowledge gap about the impact of retrofitting schools on exposure to air pollutants and their effects on children's health
Scaling of spontaneous rotation with temperature and plasma current in tokamaks
Using theoretical arguments, a simple scaling law for the size of the
intrinsic rotation observed in tokamaks in the absence of momentum injection is
found: the velocity generated in the core of a tokamak must be proportional to
the ion temperature difference in the core divided by the plasma current,
independent of the size of the device. The constant of proportionality is of
the order of . When the
intrinsic rotation profile is hollow, i.e. it is counter-current in the core of
the tokamak and co-current in the edge, the scaling law presented in this
Letter fits the data remarkably well for several tokamaks of vastly different
size and heated by different mechanisms.Comment: 5 pages, 3 figure
Indoor Air Quality and Overheating in UK Classrooms ā an Archetype Stock Modelling Approach
Children spend a large part of their waking lives in school buildings. There is substantial evidence that poor indoor air quality (IAQ) and thermal discomfort can have detrimental impacts on the performance, wellbeing and health of schoolchildren and staff. Maintaining good IAQ while avoiding overheating in classrooms is challenging due to the unique occupancy patterns and heat properties of schools. Building stock modelling has been extensively used in recent years to quantify and evaluate performance of large numbers of buildings at various scales. This paper builds on an archetype stock modelling approach which represents the diversity of the school stock in England through an analysis of The Property Data Survey Programme (PDSP) and the Display Energy Certificates (DEC) databases. The model was used for simulating Indoor-to-Outdoor pollution ratios to estimate indoor air pollution levels (NO2, PM2.5 and CO2) and thermal comfort (overheating) in two climate areas in England: London and the West Pennines. analysis highlighted variations in classrooms' indoor CO2 levels in different seasons and explored the risk of overheating in relation to a classroom's orientation
Kinetic equations for thermal degradation of polymers
Kinetic equations are analyzed for thermal degradation of polymers. The
governing relations are based on the fragmentation-annihilation concept.
Explicit solutions to these equations are derived in two particular cases of
interest. For arbitrary values of adjustable parameters, the evolution of the
number-average and mass-average molecular weights of polymers is analyzed
numerically. Good agreement is demonstrated between the results of numerical
simulation and experimental data. It is revealed that the model can correctly
predict observations in thermo-gravimetric tests when its parameters are
determined by matching experimental data for the decrease in molecular weight
with exposure time
Dynamic modelling of indoor environmental conditions for future energy retrofit scenarios across the UK school building stock
UK schoolchildren spend on average 30% of their waking lives inside schools. While indoor environmental quality (IEQ) is critical for their health and attainment, school buildings are also a key part of the UK's carbon emissions reduction strategy. To address conflicts between energy efficiency and IEQ, predictive models of UK classroom stock should incorporate energy and IEQ performance criteria across dynamic scenarios comprising energy retrofit and IEQ improvement measures. On this basis, we have developed a novel approach for auto-generation, simulation, post-processing and analysis of EnergyPlus UK classroom archetype models. Such modelling facilitates the multi-parameter evaluation of school building performance, whilst incorporating stock-wide heterogeneity and longitudinal dynamic changes. As extent of retrofit increases, decreasing incremental energy demand reduction was quantified and increasing effectiveness of passive ventilation at mitigating overheating was identified. Negative impact of South facing orientation on overheating was reduced after applying a range of IEQ improvement methods. However, low ceiling heights in 1945ā1967 era classrooms impact the efficacy of these IEQ mitigations on calculated attainment, requiring design rather than mitigation strategies as a remedial solution. Strategies preventing NO2 pollution ingress could be more-effective than PM2.5, with night-time ventilation avoiding ingress during daily peaks and greater sensitivity to location. Future work shall incorporate multiple criteria into a single tool based on stakeholder preferences to improve quality of retrofit decision making
Feedback and Feedforward Mechanisms for Generating Occupant Datasets for UK School Stock Simulation Modelling
National construction and energy datasets coupled with batch building performance simulation techniques have made feasible the construction of a stock building simulation model of over 16,000 schools. Although this should provide insights for targeted energy efficiency measures, discrepancies between measured and calculated performance limit predictive powers.
A case study of building simulation models of three London schools built using the stock modelling process is presented. Discrepancies in calculated performance have been demonstrated when standardised variables are assumed for schedules, setpoints and equipment over the entire stock. Feedback mechanisms are proposed as a means of recruiting school building users to facilitate future data provision
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