Household-differentiated demand modelling for communities

Micro-generation schemes are increasingly being proposed for and incorporated in new-build housing developments. Community composition dependant demand prediction for such schemes is poorly understood and modelled. Using a previously developed higher-order Markovchain occupancy model, differentiated for different household types, an occupancy-driven electricity demand model has been developed from high resolution appliance-level data to realistically distribute demand cycles for individual households. The model incorporates a novel event-based method for linking the time-of-day probability of appliance cycles relative to occupancy, which allows accurate replication of expected demand patterns and improves computational efficiency compared to existing models. Additional socio-economic and behavioural factors are also included to better capture demand diversity

An occupant-differentiated, higher-order Markov Chain method for prediction of domestic occupancy

Household energy demand is closely correlated with occupant and household types and their associated occupancy patterns. Existing occupancy model performance has been limited by a lack of occupant differentiation, poor occupancy duration estimation, and ignoring typical occupancy interactions between related individuals. A Markov-Chain based method for generating realistic occupancy profiles has been developed that aims to improve accuracy in each of these areas to provide a foundation for future energy demand modelling and to allow the occupancy-driven impact to be determined. Transition probability data has been compiled for multiple occupant, household, and day types from UK Time-Use Survey data to account for typical behavioural differences. A higher-order method incorporating ranges of occupancy state durations has been used to improve duration prediction. Typical occupant interactions have been captured by combining couples and parents as single entities and linking parent and child occupancy directly. Significant improvement in occupancy prediction is shown for the differentiated occupant and occupant interaction methods. The higher-order Markov method is shown to perform better than an equivalent higher-order ’event’-based approach. The benefit of the higher-order method compared to a first-order Markov model is less significant and would benefit from more comprehensive occupancy data for an objective comparison

Modelling the impact of micro generation on the electrical distribution system

In the UK and elsewhere there is considerable debate as to the future form of the electricity distribution system. The coming years will see a rise in the amount of micro-generation connected to the network at low voltages and the emergence of highly-distributed power systems (HDPS). However, there is considerable uncertainty as to the impact that this micro-generation will have on the quality of power supplied to our homes or to the stability of the electricity system as a whole. To address these engineering challenges the UK Engineering and Physical Sciences Research Council (EPSRC) is funding a three year research programme featuring a multi-disciplinary team from a variety of UK Universities: Supergen HDPS. This paper documents one piece of work emerging from the consortium, where a multi-tool approach is used to analyse the impact of micro-generation on the electricity system. This used a building simulation tool to produce electrical generation profiles for domestic cogeneration device models. These, along with profiles produced for other micro-generation technology models and electrical load profiles are then replicated and aggregated using a customised statistical approach. The profiles were then used as boundary conditions for a set of electrical load flow simulations on a model of a section of real network, where the number of microgenerators was varied according to different scenarios for the future of the UK electricity grid. The results indicate that a significant number of micro-generation devices can be accommodated before any power quality problems arise, however this is dependent upon maintaining a robust central grid

Local pathways to low-carbon domestic heat : exploring the options in the UK

Currently, natural gas is the predominant source of domestic heat provision. Take-up of heat pumps and district heating remains at a minimal penetration of around 0.5%. In total, only around 2.5% of heat comes from low carbon sources, compared with more than 45% of electricity. As heat accounts for around 40% of UK energy consumption and 20% of GHG emissions, the decarbonisation of the heat sector is seen as vital for the UK to reach UK emission reduction targets. Different trajectories in heat provision using parallel energy vectors (electricity, gas, alternative gases, heat networks) imply a range of infrastructure impacts. In order to explore the form of different local energy systems under decarbonisation scenarios, this work seeks to: - Capture the broad forms of ’last-mile’ network: Urban, Suburban, Rural (on/off gas grid ) seen as exemplar of the UK energy system; - Downscale whole system-derived technology mixes and construct demonstrative local energy systems representing key use cases; - Using multi-carrier optimisation, determine the impacts of heat decarbonisation on current and future system actors

Local pathways to low-carbon domestic heat : exploring the options in the UK

Currently, natural gas is the predominant source of domestic heat provision. Take-up of heat pumps and district heating remains at a minimal penetration of around 0.5%. In total, only around 2.5% of heat comes from low carbon sources, compared with more than 45% of electricity. As heat accounts for around 40% of UK energy consumption and 20% of GHG emissions, the decarbonisation of the heat sector is seen as vital for the UK to reach UK emission reduction targets. Different trajectories in heat provision using parallel energy vectors (electricity, gas, alternative gases, heat networks) imply a range of infrastructure impacts. In order to explore the form of different local energy systems under decarbonisation scenarios, this work seeks to: - Capture the broad forms of ’last-mile’ network: Urban, Suburban, Rural (on/off gas grid ) seen as exemplar of the UK energy system; - Downscale whole system-derived technology mixes and construct demonstrative local energy systems representing key use cases; - Using multi-carrier optimisation, determine the impacts of heat decarbonisation on current and future system actors

Diagnosing horizontal and inter-channel observation error correlations for SEVIRI observations using observation-minus-background and observation-minus-analysis statistics

It has been common practice in data assimilation to treat observation errors as uncorrelated; however, meteorological centres are beginning to use correlated inter-channel observation errors in their operational assimilation systems. In this work, we are the first to characterise inter-channel and spatial error correlations for Spinning Enhanced Visible and Infrared Imager (SEVIRI) observations that are assimilated into the Met Office high-resolution model. The errors are calculated using a diagnostic that calculates statistical averages of observation-minus-background and observation-minus-analysis residuals. This diagnostic is sensitive to the background and observation error statistics used in the assimilation, although, with careful interpretation of the results, it can still provide useful information. We find that the diagnosed SEVIRI error variances are as low as one-tenth of those currently used in the operational system. The water vapour channels have significantly correlated inter-channel errors, as do the surface channels. The surface channels have larger observation error variances and inter-channel correlations in coastal areas of the domain; this is the result of assimilating mixed pixel (land-sea) observations. The horizontal observation error correlations range between 30 km and 80 km, which is larger than the operational thinning distance of 24 km. We also find that estimates from the diagnostics are unaffected by biased observations, provided that the observation-minus-background and observation-minus-analysis residual means are subtracted

Effects of vitamin D supplementation on bone density in healthy children: systematic review and meta-analysis

Objective To determine the effectiveness of vitamin D supplementation for improving bone mineral density in children and adolescents and if effects vary with factors such as vitamin D dose and vitamin D status

Occurrence of a telson gland in the genus \u3cem\u3eSuperstitionia\u3c/em\u3e Stahnke, 1940 (Scorpiones: Superstitioniidae)

In this note, we record for the first time the occurrence of a telson gland in the monotypic genus Superstitionia Stahnke 1940 (Scorpiones: Superstitioniidae). The putative gland is marked by an elongated patch of wrinkled cuticle restricted to the dorso-apical surface of the telson vesicle of adult males, and is absent from females and immatures. Similar presumed glandular structures have been observed in a number of other scorpions, including many South American Bothriuridae, and the recently defined vaejovid genera Chihuahuanus González-Santillán et Prendini, 2013 and Maaykuyak González-Santillán et Prendini, 2013

High Morbidity during Treatment and Residual Pulmonary Disability in Pulmonary Tuberculosis: Under-Recognised Phenomena

BACKGROUND In pulmonary tuberculosis (PTB), morbidity during treatment and residual pulmonary disability can be under-estimated. METHODS Among adults with smear-positive PTB at an outpatient clinic in Papua, Indonesia, we assessed morbidity at baseline and during treatment, and 6-month residual disability, by measuring functional capacity (six-minute walk test [6MWT] and pulmonary function), quality of life (St George's Respiratory Questionnaire [SGRQ]) and Adverse Events ([AE]: new symptoms not present at outset). Results were compared with findings in locally-recruited volunteers. RESULTS 200 PTB patients and 40 volunteers were enrolled. 6WMT was 497m (interquartile range 460-529) in controls versus 408m (IQR 346-450) in PTB patients at baseline (p<0.0001) and 470m (IQR 418-515) in PTB patients after 6 months (p=0.02 versus controls). SGRQ total score was 0 units (IQR 0-2.9) in controls, versus 36.9 (27.4-52.8) in PTB patients at baseline (p<0.0001) and 4.3 (1.7-8.8) by 6 months (p<0.0001). Mean percentage of predicted FEV1 was 92% (standard deviation 19.9) in controls, versus 63% (19.4) in PTB patients at baseline (p<0.0001) and 71% (17.5) by 6 months (p<0.0001). After 6 months, 27% of TB patients still had at least moderate-severe pulmonary function impairment, and 57% still had respiratory symptoms, despite most achieving 'successful' treatment outcomes, and reporting good quality of life. More-advanced disease at baseline (longer illness duration, worse baseline X-ray) and HIV positivity predicted residual disability. AE at any time during treatment were common: itch 59%, arthralgia 58%, headache 40%, nausea 33%, vomiting 16%. CONCLUSION We found high 6-month residual pulmonary disability and high AE rates. Although PTB treatment is highly successful, the extent of morbidity during treatment and residual impairment could be overlooked if not specifically sought. Calculations of PTB-related burden of disease should acknowledge that TB-related morbidity does not stop at 6 months. Early case detection and treatment are key in minimising residual impairment.The study received funding from the Australian Respiratory Council, Royal Australasian College of Physicians (Covance Award to APR), National Health and Medical Research Council (NHMRC) of Australia (Grants 605806 and 496600, a scholarship to APR, and fellowships to APR, TWY, PMK, NMA). Graeme Maguire is supported by an NHMRC Practitioner Fellowship and the Margaret Ross Chair in Indigenous Health. Views expressed in this publication are those of the authors and do not reflect the views of NHMRC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript