Energy efficiency in the building sector: a combined middle-out and practice theory approach

The building sector in Sweden and Europe is a major energy consumer, accounting for around 40% of total energy use. It is a challenge to optimize available technical and social strategies for the fragmented construction industry. Professionals such as architects and different building engineers play a crucial role in the technology adoption process. This study aims to contribute to the understanding of how and why energy efficiency and saving measures are implemented by different professionals. The paper combines perspectives focusing the “the middle” in an organisation and social practice theory (SPT) to develop a framework which can be used to enhance the understanding of how and why energy efficiency measures are adopted in building processes. By combining these theoretical perspectives it is possible to arrive at a deeper understanding of what needs to be changed in the planning and management process to achieve a highly energy efficient renovation

Exploring PV adoption by Non-Residential Property Owners: Applying Social Practice Theory

This article investigates the adoption of Photovoltaics (PV) systems by non-residential property owners in Sweden using a social practice theory approach. 25 semi-structured interviews were conducted with private and public non-residential property owners in the south of Sweden. The results show that about half of the property owners had had PV systems installed for a long period and had developed a PV adoption practice. These property owners had established routines within the company, aggregated relevant knowledge, and had established trusted relationships with PV installers which supported the PV adoption process. On the contrary, first-time installers and non-adopters were missing these elements and had not yet established a PV adoption practice. This study is the first step towards understanding PV adoption as a practice for non-residential property owners and contributes to an analysis of the elements that are required for a PV adoption practice to emerge. The practical relevance of the study is that it can facilitate and support non-residential property owners to adopt PV systems and contribute to a renewable electricity transition

Understanding tenants’ responses to energy efficiency renovations in public housing in Sweden: From the resigned to the demanding

This study focuses on the experiences of tenants in renovation projects of public housing rental apartments in Sweden. Tenants’ perspectives are under-researched in the context of energy efficiency renovation projects, which is a considerable oversight given the many ways in which such projects impact their lives. The aim of the paper is to reveal rare qualitative insights into tenants’ experiences of, and attitudes towards, energy efficiency renovations in a public housing context and the extent to which they feel motivated and able to influence the renovation project. Participatory observations at tenant meetings were conducted as well as semi-structured phone interviews. An empirically driven typology is developed indicating that tenants have different interests and attitudes regarding energy efficiency renovations. Six different types are identified: the satisfied; the demanding, the conservative, the resigned, the sceptical and the resistant

Fastighetsägare som prosumenter – stödstrukturer och hinder

Solceller har en viktig roll att fylla för att uppnå politiskt fattade mål om 100%hållbart elsystem. Det är rimligt att anta att det är i bebyggelsen som en storutbyggnad kommer att behöva ske eftersom det är existerande strukturermed nätanslutningar där det också finns möjlighet att använda den solel somproduceras. Fastighetsägare blir därmed en viktig aktörsgrupp att engagera.En relativt outforskad grupp är fastighetsägare till lokaler och det är dem somär fokuserade i detta projekt.Det övergripande syftet med detta projekt är att kartlägga och analyseraförutsättningar för att vi ska se en betydande ökning av antalet prosumenterhos privata och offentliga fastighetsägare av lokaler och vilken betydelse ensådan ökning kommer att få för elsystemens etablerade aktörer.Studien har genomförts i samverkan mellan Lunds universitet och EnergikontorSkåne. En litteraturstudie, en enkät och intervjuer har kombinerats ochdet är fastighetsägare med fastigheter i Skåne som varit i fokus.De vanligaste hindren för att installera solpaneler var kopplade till ekonomi,information och kunskap och administration. Även brist på lagringsmöjligheteroch affärsmodeller för hur kostnader och vinster ska fördelas bland hyresgästernämndes av flera. Vanliga drivkrafter som omnämndes var tillgången tillsubventioner, att det fanns ett miljöengagemang i företaget och möjlighetenatt minska framtida kostnader. I Sverige lyfte fastighetsägarna också frambyggnadsrenoveringar som en drivkraft, där en renovering skapade möjlighetenatt samtidigt installera solceller.Teknik omnämndes av viss som hinder och andra som möjlighet. En delfastighetsägare var entusiastiska över att testa den nya tekniken och såg solcellersom en enkel teknik. Andra fastighetsägare tyckte att tekniken kändessvår att ha i fastigheten. Ytterligare några vara oroliga att effektiviteten hossolcellerna skulle minska snabbare än vad säljarna uppgav eller att teknikensnart skulle bli föråldrad på grund av den snabba tekniska utvecklingen

Frequency of myelin oligodendrocyte glycoprotein antibodies in a large cohort of neurological patients

Background Myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOG-AD) is recognized as a distinct nosological entity. IgG antibodies against MOG (MOG-Ab) overlap with neuromyelitis optica spectrum disorders (NMOSD) phenotype in adults. However, an increasing number of clinical phenotypes have been reported to be associated with MOG-Ab. Objective To investigate the seroprevalence of MOG-Ab under consideration of demographics, disease entities and time course in a large cohort of unselected neurological patients. Methods Blood samples of 2.107 consecutive adult neurologic patients admitted to our department between 2016-2017 were tested for MOG-Ab using a cell-based assay. MOG-Ab persistence was analyzed in follow-up samples. External validation was performed in two independent laboratories. Results We found MOG-Ab in 25 of 2.107 (1.2%) patients. High antibody ratios were mostly associated with NMOSD and MOG-AD phenotype (5/25). Low ratios occurred in a wide range of neurological diseases, predominantly in other demyelinating CNS diseases (5/25) and stroke (6/25). MOG-Ab persistence over time was not confined to NMOSD and MOG-AD phenotype. Conclusion The present study demonstrates the occurrence of MOG-Ab in a wide range of neurological diseases. Only high MOG-Ab ratios were associated with a defined clinical phenotype, but low MOG-Ab ratios were not. The diagnostic value of low MOG-Ab is thus highly limited

On-demand generation of background--free single photons from a solid-state source

True on--demand high--repetition--rate single--photon sources are highly sought after for quantum information processing applications. However, any coherently driven two-level quantum system suffers from a finite re-excitation probability under pulsed excitation, causing undesirable multi--photon emission. Here, we present a solid--state source of on--demand single photons yielding a raw second--order coherence of $g^{(2)}(0)=(7.5\pm1.6)\times10^{-5}$ without any background subtraction nor data processing. To this date, this is the lowest value of $g^{(2)}(0)$ reported for any single--photon source even compared to the previously best background subtracted values. We achieve this result on GaAs/AlGaAs quantum dots embedded in a low--Q planar cavity by employing (i) a two--photon excitation process and (ii) a filtering and detection setup featuring two superconducting single--photon detectors with ultralow dark-count rates of $(0.0056\pm0.0007) s^{-1}$ and $(0.017\pm0.001) s^{-1}$, respectively. Re--excitation processes are dramatically suppressed by (i), while (ii) removes false coincidences resulting in a negligibly low noise floor

Entanglement swapping with photons generated on-demand by a quantum dot

Photonic entanglement swapping, the procedure of entangling photons without any direct interaction, is a fundamental test of quantum mechanics and an essential resource to the realization of quantum networks. Probabilistic sources of non-classical light can be used for entanglement swapping, but quantum communication technologies with device-independent functionalities demand for push-button operation that, in principle, can be implemented using single quantum emitters. This, however, turned out to be an extraordinary challenge due to the stringent requirements on the efficiency and purity of generation of entangled states. Here we tackle this challenge and show that pairs of polarization-entangled photons generated on-demand by a GaAs quantum dot can be used to successfully demonstrate all-photonic entanglement swapping. Moreover, we develop a theoretical model that provides quantitative insight on the critical figures of merit for the performance of the swapping procedure. This work shows that solid-state quantum emitters are mature for quantum networking and indicates a path for scaling up.Comment: The first four authors contributed equally to this work. 17 pages, 3 figure

Resonance fluorescence of GaAs quantum dots with near-unity photon indistinguishability

Photonic quantum technologies call for scalable quantum light sources that can be integrated, while providing the end user with single and entangled photons on-demand. One promising candidate are strain free GaAs/AlGaAs quantum dots obtained by droplet etching. Such quantum dots exhibit ultra low multi-photon probability and an unprecedented degree of photon pair entanglement. However, different to commonly studied InGaAs/GaAs quantum dots obtained by the Stranski-Krastanow mode, photons with a near-unity indistinguishability from these quantum emitters have proven to be elusive so far. Here, we show on-demand generation of near-unity indistinguishable photons from these quantum emitters by exploring pulsed resonance fluorescence. Given the short intrinsic lifetime of excitons confined in the GaAs quantum dots, we show single photon indistinguishability with a raw visibility of $V_{raw}=(94.2\pm5.2)\,\%$, without the need for Purcell enhancement. Our results represent a milestone in the advance of GaAs quantum dots by demonstrating the final missing property standing in the way of using these emitters as a key component in quantum communication applications, e.g. as an entangled source for quantum repeater architectures

Comparison of iron-reduced and iron-supplemented semisynthetic diets in T cell transfer colitis

Clinical observations in inflammatory bowel disease patients and experimental studies in rodents suggest that iron in the intestinal lumen derived from iron-rich food or oral iron supplementation could exacerbate inflammation and that iron depletion from the diet could be protective. To test the hypothesis that dietary iron reduction is protective against colitis development, the impact of iron reduction in the diet below 10 mg/kg on the course of CD4+ CD62L+ T cell transfer colitis was investigated in adult C57BL/6 mice. Weight loss as well as clinical and histological signs of inflammation were comparable between mice pretreated with semisynthetic diets with either < 10mg/kg iron content or supplemented with 180 mg/kg iron in the form of ferrous sulfate or hemin. Accumulation and activation of Ly6C(high) monocytes, changes in dendritic cell subset composition and induction of proinflammatory Th1/Th17 cells in the inflamed colon were not affected by the iron content of the diets. Thus, dietary iron reduction did not protect adult mice against severe intestinal inflammation in T cell transfer induced colitis