Investigating an Adequate Level of Modelling for Energy Analysis of Domestic Buildings

This paper investigates what level of modelling is required to appropriately support energy analysis of domestic buildings. The paper analyses the effect of simplications made in thermal zoning and internal loads scheduling through a case study of a UK domestic building. The case study provides quantified effects of common simplications made in practice on the accuracy of energy predictions by making simplications in the model incrementally and estimating the effect of individual simplications on electricity and heating demand predictions

Investigating an adequate level of modelling for retrofit decision-making: A case study of a British semi-detached house

This paper investigates what level of modelling (zoning or internal load scheduling) is required to support heating related retrofit decision-making. First, this paper tests the effect of thermal zoning by incrementally reducing the number of thermal zones from modelling every room as a separate zone to modelling the house as a single zone. Second, this paper examines the influence of internal load schedules (occupancy, lighting and equipment schedules) on prediction accuracy. Actual internal load schedules were derived from the smart meter data of 666 households collected by the Customer-Led Network Revolution project. Cluster analysis was applied to extract a set of prototypical schedules to capture major variations across all households. Last, this paper evaluates the effects of the zoning and internal load scheduling modelling assumptions in the context of thermal retrofit decision-making. For the specific parameters studied and the specific building design, the use of different zoning strategies and different internal load schedules yielded the same ranking of top retrofit options. For the specific climate and the baseline assumptions for the retrofits, different cluster schedules resulted in different magnitudes of energy savings, but the ranking of top retrofit options was not impacted by the choice of household internal load schedules. However, the actual internal load schedules affected the energy-saving potentials achievable by the same set of retrofit options. The case study highlights that the optimal set of retrofit options selected given the specific physical characteristics of a house is the same regardless of differences in the input of internal load schedules. However, it was found that energy-saving potentials achievable by the same retrofit option substantially vary according to the actual internal load schedules. This finding implies that energy retrofit policies can be tailored to target certain groups of households selected by clustering their actual energy use profiles to cost-effectively maximise energy savings from the domestic sector

Revealing the role of local stress on the depolarization of BNT-BT-based relaxors

Canonical relaxors exhibit an electric-field-induced phase transition between a macroscopically nonpolar and polar phase that can be tuned from being stable at low temperature to being reversible at high temperature. The reversibility of this phase change determines the electromechanical performance and large strains can be achieved if the polar phase is intrinsically unstable. This paper is on the thermal depolarization characteristics of a BNT-BT-based multiphase relaxor ceramic observed through the transition temperature from field-induced polar to nonpolar state. It is shown that the progress of detexturization strongly depends on the crystallographic phase. In the more susceptible phase, it becomes significant about 40 °C below the macroscopically observed transition temperature. Additionally, the surface domain structure vanishes at lower temperatures than expected from both dielectric and structural measurements. The development of strong interfacial stresses aiding depolarization, and a mismatch in chemical pressure between surface and bulk, are discussed as the origins for the observed effects. Tailoring of interfacial stresses through chemical adaption of crystallographic phase fractions opens up a pathway to optimize the strain performance of actuator materials and can become a useful tool to stabilize metastable crystallographic phases as well as for property tuning in piezotronics, Mott insulators and multiferroics

Evaluation of the Dietary Effect of Hallabong Peel Oil on Growth, Hematological, and Immune Gene Expression in Rock Bream, Oplegnathus fasciatus Challenged with Edwardsiella tarda

In the present study we evaluated the dietary effect of Hallabong peel oil (HPO) on growth, disease resistance, and immune gene expression of rock bream, Oplegnathus fasciatus challenged with Edwardsiella tarda after a 4 week feeding trial with 5 treatments: control-C, probiotic–P, HPO (0.1%), HPO (0.5%), and P+HPO, diets. All fish groups were assessed for growth performance, innate immune parameters, serum biochemical profile, and immune gene expression in head kidney on 2nd, and 4th week, and 1st, 3rd and 7th day post infection with Edwardsiella tarda. Fish fed the HPO enriched diets showed increased growth performance with significantly decreased (P>0.05) mortality compared with the control and probiotic diet groups. The positive effects of HPO enriched diet were also found in all assessed innate immune and biochemical parameters which included increased respiratory burst and lysozyme activity, with significantly increased erythrocyte and leukocytes counts, increased serum protein, decreased glucose, triglycerides, cholesterol level in serum compared with control diet fed fish. Moreover, the probiotic bacterial count in the intestine of fish was enhanced with the HPO diet and the P+HPO diet compared to fish fed the probiotic diet. The head kidney of HPO enriched diet fed fish showed up-regulated expression of inflammatory cytokines genes such as TNFα, IL-1β, and FST, after 4th week of feeding trial which was increased ~2 to 3 times on 1dpi and 3 dpi. These results indicate that limonene rich (91.26%), HPO enriched diets enhance growth and immunity and enhance disease resistance of Oplegnathus fasciatus challenged against E. tarda

Predicting intra-day load profiles under time-of-use tariffs using smart meter data

The installation of smart meters enabling electricity load to be measured on a half-hourly basis provides an innovative demand-side management opportunity that it is advantageous for utility companies and customers. Time-of-use (tou) tariffs are widely considered to be the most promising solution for optimising energy consumption in residential sectors. Although much of the existing research on demand response in electricity pricing has focused upon the evaluation of the impact of tou tariffs, a practical framework to forecast user adaptation under different tou tariffs has not fully developed. The novelty of this work is to provide the first data driven modelling of residential customers’ demand response following the adoption of a tou tariff and measure its accuracy in a standardised measure mape. This paper uses a public dataset for modelling, therefore any future study is able to built a model and compare its accuracy against us. The mape value in forecasting average load for a group of households with the Decision Tree is 3.38% for a day period and 2.74% in the peak time period

Direct measurement of the intermolecular forces confining a single molecule in an entangled polymer solution

We use optical tweezers to directly measure the intermolecular forces acting on a single polymer imposed by surrounding entangled polymers (115 kbp DNA, 1 mg/ml). A tube-like confining field was measured in accord with the key assumption of reptation models. A time-dependent harmonic potential opposed transverse displacement, in accord with recent simulation findings. A tube radius of 0.8 microns was determined, close to the predicted value (0.5 microns). Three relaxation modes (~0.4, 5 and 30 s) were measured following transverse displacement, consistent with predicted relaxation mechanisms.Comment: 11 pages, 3 figure