An empirical study of electricity and gas demand drivers in large food retail buildings of a national organisation

AbstractFood retail buildings account for a measurable proportion of a country's energy consumption and resultant carbon emissions so energy-operating costs are key business considerations. Increased understanding of end-use energy demands in this sector can enable development of effective benchmarking systems to underpin energy management tools. This could aid identification and evaluation of interventions to reduce operational energy demand. Whilst there are a number of theoretical and semi-empirical benchmarking and thermal modelling tools that can be used for food retail building stocks, these do not readily account for the variance of technical and non-technical factors that can influence end-use demands.This paper discusses the various drivers of energy end-uses of typical UK food retail stores. It reports on an empirical study of one organisation's hypermarket stock to evaluate the influence of various factors on annual store electricity and gas demands. Multiple regression models are discussed in the context of the development and application of a methodology for estimating annual energy end-use demand in food retail buildings. The established models account for 75% of the variation in electricity demand, 50% of the variation in gas demand in stores without CHP and 77% of the variation in gas demand in stores with CHP

Superconductivity and magnetism in platinum-substituted SrFe2As2 single crystals

Single crystals of SrFe2-xPtxAs2 (0 < x < 0.36) were grown using the self flux solution method and characterized using x-ray crystallography, electrical transport, magnetic susceptibility, and specific heat measurements. The magnetic/structural transition is suppressed with increasing Pt concentration, with superconductivity seen over the range 0.08 < x < 0.36 with a maximum transition temperature Tc of 16 K at x = 0.16. The shape of the phase diagram and the changes to the lattice parameters are similar to the effects of other group VIII elements Ni and Pd, however the higher transition temperature and extended range of superconductivity suggest some complexity beyond the simple electron counting picture that has been discussed thus far.Comment: 6 pages, 6 figure

NHEJ protects mycobacteria in stationary phase against the harmful effects of desiccation

The physiological role of the non-homologous end-joining (NHEJ) pathway in the repair of DNA double-strand breaks (DSBs) was examined in Mycobacterium smegmatis using DNA repair mutants (DeltarecA, Deltaku, DeltaligD, Deltaku/ligD, DeltarecA/ku/ligD). Wild-type and mutant strains were exposed to a range of doses of ionizing radiation at specific points in their life-cycle. NHEJ-mutant strains (Deltaku, DeltaligD, Deltaku/ligD) were significantly more sensitive to ionizing radiation (IR) during stationary phase than wild-type M. smegmatis. However, there was little difference in IR sensitivity between NHEJ-mutant and wild-type strains in logarithmic phase. Similarly, NHEJ-mutant strains were more sensitive to prolonged desiccation than wild-type M. smegmatis. A DeltarecA mutant strain was more sensitive to desiccation and IR during both stationary and especially in logarithmic phase, compared to wild-type strain, but it was significantly less sensitive to IR than the DeltarecA/ku/ligD triple mutant during stationary phase. These data suggest that NHEJ and homologous recombination are the preferred DSB repair pathways employed by M. smegmatis during stationary and logarithmic phases, respectively

An Ecopath with Ecosim model of the Norwegian Sea and Barents Sea validated against time series of abundance

We here present a fitted and partly validated Ecopath with Ecosim model for the Norwegian Sea and Barents Sea. Ecopath mass-balance model parameters were obtained from the literature on Norwegian and Barents Sea organisms and from approximations. Predator-prey vulnerability parameters for Ecosim were fitted by driving a past state model balanced for the year 1950 from 1950 to 2000 and comparing the modelled biomass time series with series from VPA and acoustic surveys. Estimated fishing mortalities or reported catch were used to drive the modelled biomass through the 50-year period. The vulnerability parameters from the fitted 1950 model were then used as input for a simulation model balanced for the year 2000. The fits were reasonably good, and were improved after including fluctuation in the yearly phytoplankton production through a primary production forcing function. The fluctuating biomass trends characteristic for many of the short-lived groups in the model were better reproduced when including the primary production forcing function, suggesting that bottom-up control is important in this marine system. When evaluating the vulnerability parameters through a comparison between modelled and observed diet compositions, the parameter settings seemed reasonable for cod as a predator, but less so for haddock. The optimal long-term fishing pressure modelled in the model was consistent with advice from the International Council for the Exploration of the Sea (ICES) for the stocks for which values of target reference points are estimated.Her presenterer me ein Ecopath med Ecosim økosystemmodell for Norskehavet og Barentshavet som til dels er validert mot mengdemålingstidsseriar. Ecopath modellparametre på norskehavs- og barentshavsorganismar er henta frå litteraturen eller frå tilnærmingar viss ikkje annan informasjon er tilgjengeleg. Sårbarhetsparameteren som beskriv kor sårbart eit gitt bytte er for ein gitt predator, og som modellen er svært sensitiv ovafor, blei tilpassa ved å kjøra ein historisk modell balansert for året 1950 til 2000 og modellerte mengdemålingstidsseriar mot tidsseriar frå akustiske tokt eller VPA-kjøringar. Estimert fiskedødelighet eller rapportert fangst blei trekt frå biomassen for kvar modellert organismegruppe gjennom 50-årsperioden. Sårbarhetsparameteren blei ekstarhert ut frå den balanserte 1950-modellen, og blei deretter brukt inn i ein modell for det same området og med identiske organismegrupper, men balansert for året 2000. Samsvaret mellom den modellerte biomassen og den observerte var rimeleg god og blei forbedra ved å inkludera fluktuasjon i årleg planteplanktonproduksjon. Særleg den fluktuerande biomassen som er karakteristisk for fleire av dei pelagiske bestandane blei meir realistisk gjenskapt ved å inkludera primærproduksjonen, noko som indikerer at botn-opp kontroll er viktig i dette marine systemet. Den sensitive sårbarhetsparameteren blei delvis evaluert gjennom ein samanlikning mellom modellert og observert diettsamansetting hos torsk og hyse. Dietten til torsk blei rimeleg godt gjenskapt i modellen, men dietten for hyse i mindre grad. Optimalt fisketrykk ved langtidshausting som blei modellert med modellen balansert for år 2000, var konsistent med rådet frå det internasjonale råd for havforsking (ICES) for dei bestandane kor referansepunkt blir estimert

Towards task shifting? A comparison of the accuracy of acute trauma-radiograph reporting by medical officers and senior radiographers in an African hospital

Introduction: Due to the universal shortage of radiologists, medical officers are largely responsible for acute trauma radiograph reporting in public sector healthcare facilities in well-resourced countries. In poorly-resourced countries, a shortage of medical officers results in most acute trauma radiographs being unreported. In the European Union (EU), experienced radiographers with no specific training have been shown to be more accurate than medical officers in trauma radiograph reporting, while EU radiographers who receive additional training can reach accuracies comparable to radiologists. In some EU countries, the role of the radiographer has been extended to include trauma reporting. However, there has been no study of the accuracy of trauma radiograph reporting by radiographers in Africa, where task-shifting could yield potentially greater benefits, due to shortages of both radiologists and medical officers. The aim of this study was therefore to compare the accuracy of acute traumaradiograph reporting by medical officers and senior radiographers in an African setting. Methods: A prospective study was conducted at a South African hospital from November 2013-April 2014. Medical officers and senior radiographers reported the same set of appendicular skeleton trauma radiographs. Reporting accuracy, sensitivity and specificity were calculated using a consultant radiologist's report as the reference standard. Differences were evaluated using the Mann-Whitney U test, with p &lt; 0.05 significant. Results: Senior radiographers achieved significantly higher reporting accuracy and sensitivity than medical officers (81.5% vs 67.8%, p = 0.002). Conclusion: Senior radiographers represent a potentially important resource for acute trauma-radiograph reporting in the public healthcare sector in Africa

Electronic Structure and Lattice dynamics of NaFeAs

The similarity of the electronic structures of NaFeAs and other Fe pnictides has been demonstrated on the basis of first-principle calculations. The global double-degeneracy of electronic bands along X-M and R-A direction indicates the instability of Fe pnictides and is explained on the basis of a tight-binding model. The de Haas-van Alphen parameters for the Fermi surface (FS) of NaFeAs have been calculated. A $\mathbf{Q}_{M}=(1/2,1/2,0)$ spin density wave (SDW) instead of a charge density wave (CDW) ground state is predicted based on the calculated generalized susceptibility $\chi(\mathbf{q})$ and a criterion derived from a restricted Hatree-Fock model. The strongest electron-phonon (e-p) coupling has been found to involve only As, Na z-direction vibration with linear-response calculations. A possible enhancement mechanism for e-p coupling due to correlation is suggested

Determination of characteristic muon precession and relaxation signals in FeAs and FeAs2, possible impurity phases in pnictide superconductors

We report muon-spin relaxation measurements of highly homogeneous samples of FeAs and FeAs2, both previously found as impurity phases in some samples of recently synthesized pnictide superconductors. We observe well defined muon precession in the FeAs sample with two precession frequencies of 38.2(3) and 22.7(9) MHz at 7.5 K, with the majority of the amplitude corresponding to the lower frequency component. In FeAs2 we confirm previous measurements showing that no long-ranged magnetic order occurs above 2 K and measure the muon spin relaxation rate, which increases on cooling. Our results exclude the possibility that previous muon-spin relaxation measurements of pnictide superconductors have been measuring the effect of these possible impurities.Comment: 4 pages, 3 figures, corrected Figure