Search

Background: Retina fundus images conducted in Greenland are telemedically assessed for diabetic retinopathy by ophthalmological nurses in Denmark. Applying an AI grading solution, in a Greenlandic setting, could potentially improve the efficiency and cost-effectiveness of DR screening.Method: We developed an AI model using retina fundus photos, performed on persons registered with diabetes in Greenland and Denmark, using Optos® ultra wide-field scanning laser ophthalmoscope, graded according to ICDR.Using the ResNet50 network we compared the model’s ability to distinguish between different images of ICDR severity levels in a confusion matrix.Results: Comparing images with ICDR level 0 to images of ICDR level 4 resulted in an accuracy of 0.9655, AUC of 0.9905, sensitivity and specificity of 96.6%.Comparing ICDR levels 0,1,2 with ICDR levels 3,4, we achieved a performance with an accuracy of 0.8077, an AUC of 0.8728, a sensitivity of 84.6% and a specificity of 78.8%. For the other comparisons, we achieved a modest performance.Conclusion: We developed an AI model using Greenlandic data, to automatically detect DR on Optos retina fundus images. The sensitivity and specificity were too low for our model to be applied directly in a clinical setting, thus optimising the model should be prioritised.

This study presents a methodology that integrates EnergyPLAN and Quintel Energy Transition Model (ETM). Quintel ETM encompasses a holistic view of energy demand and supply from a fixed base year and its user interface enables unparalleled public engagement, but it is constrained by its limited flexibility in updating deeply embedded cost parameters. This shortcoming becomes critical when considering the rapid pace of technological change and market volatility which is characteristic of contemporary energy systems. EnergyPLAN, with its focus on detailed, customizable cost analysis in heating and power sectors, compensates for these limitations by offering a user-friendly interface and a track record of validated costing approaches. This work contributes the `epnlink` python library for EnergyPLAN – a flexible input-output parser with functionality that extends beyond this study. A soft-linking methodology to map ETM outputs to EnergyPLAN inputs is developed and demonstrated on a case study of Northern Ireland. Alternative pathways to net zero carbon by 2050 are explored, where infrastructure for power and non-industrial heat, and total fuel usage are costed. The demonstrated pipeline has broad applicability as a template to enhance the agility and precision of key cost projections for responsive and strategic energy planning across diverse geographical contexts.

To fully realize the potential of solid oxide electrolysis (SOE) systems, improvements in long-term durability and scalability are required. Investigating and comparing different degradation mechanisms under different conditions is crucial. A multi-scale cell to system level time-dependent simulation framework for SOE systems including various degradation phenomena is presented. Galvanostatic, Potentiostatic, and Potentio-Galvanostatic operation, a combination of the two previous modes, are investigated. The time and space evolution of various performance and degradation parameters are compared. Potentio-Galvanostatic operation consistently maintains stable efficiency throughout its lifetime. Near thermoneutral condition is maintained in Potentiostatic and Potentio-Galvanostatic operations, while degradation eventually leads to exothermic operation in Galvanostatic mode. Cathode overpotential is higher in Galvanostatic operation, while in Potentio-Galvanostatic operation, it drops over time as the temperature increases. After 25,000 h of operation under specified conditions, the area-specific resistance (ASR) experiences a 51% and 62% increase in Galvanostatic and Potentiostatic operations, respectively, while Potentio-Galvanostatic operation results in only a 4% increase compared to the beginning of life. Interconnect oxidation is most pronounced in Potentio-Galvanostatic mode, highlighting the need for high-quality steels and coatings in this operation strategy. Over time, in Galvanostatic operation, the current density shifts from being highest at the inlet towards the outlet.

With this volume 40 the International Journal of Sustainable Energy Planning and Management can celebrate its 10 years anniversary. In this editorial we take a closer look at the journals impact over its first 10 years of existence and highlight the articles that have made the largest impacts in the scientific community from a citation perspective. The topic of the journal – sustainable energy planning and management – has not decreased in importance over the first ten years of the journal’s existence – and fortunately the results published in the journal has garnered interest and the impact of the journal has significantly increased. In terms of citation, the journals 275 published articles, has received 1484 citations as per March 2024 and nine articles have 40 or more citations in Scopus. CiteScore ranks the journal in the top 10% out of 700+ journals within the topic of Geography, Planning and Development.

# Introduction Lateral ankle sprain is the most common ankle injury and up to 40% of those who sustain a lateral ankle sprain will develop chronic ankle instability (CAI). The aim of this study was to explore the thoughts and expectations of CAI-patients concerning their condition and expectations of care in an orthopedic setting. # Study Design Qualitative study # Methods Nine semi-structured one-to-one interviews were conducted with CAI-patients who were referred to an orthopedic setting. Interviews were recorded, transcribed, and analyzed using systematic text condensation with an inductive goal free approach. # Results Seven themes emerged. The themes were *Injury history and symptoms* (Lateral ankle sprain during sport, pain and instability), *Information from health professional* (conflicting information about management and prognosis), *Management* (mental and physical challenges), *Expectation and hope* (explanation of symptoms, prognosis and imaging to provide clarification of condition), *Activity and participation* (restriction in sport and daily life and feelings of uncertainty), *Support* (support from family/friends) and *Identity* (low ability to participate in sport and social life result in loss of identity). # Conclusion The impact of CAI exceeds an experience of pain and instability. Patients experienced loss of identity, having to manage uncertainty regarding their diagnosis and prognosis and had hopes of being able to explain their condition. # Level of Evidence Not applicable

The development of highly efficient and stable visible-light-driven photocatalysts for the removal of herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) from water is still a challenge. In this work, Bi2MoO6 (BMO) materials with different morphology were successfully prepared via a simple hydrothermal method by altering the solvent. The morphology of the BMO material is mainly influenced by the solvent used in the synthesis (H2O, ethanol, and ethylene glycol or their mixtures) and to a lesser extent by subsequent thermal annealing. BMO with aggregated spheres and nanoplate-like structures hydrothermally synthesized in ethylene glycol (EG) and subsequently calcined at 400 °C (BMO-400 (EG)) showed the highest adsorption capacity and photocatalytic activity compared to other synthesized morphologies. Complete degradation of 2,4-D on BMO upon irradiation with a blue light-emitting diode (LED, λmax = 467 nm) was reached within 150 min, resulting in 2,4-dichlorophenol (2,4-DCP) as the main degradation product. Holes (h+) and superoxide radicals (⋅O2−) are assumed to be the reactive species observed for the rapid conversion of 2,4-D to 2,4-DCP. The addition of H2O2 to the reaction mixture not only accelerates the degradation of 2,4-DCP but also significantly reduces the total organic carbon (TOC) content, indicating that hydroxyl radicals are crucial for the rapid mineralization of 2,4-D. Under optimal conditions, the TOC value was reduced by 84.5% within 180 min using BMO-400 (EG) and H2O2. The improved degradation performance of BMO-400 (EG) can be attributed to its particular morphology leading to lower charge transfer resistance, higher electron–hole separation, and larger specific surface area.

The importance of construction automation has grown worldwide, aiming to deliver new machineries for the automation of roads, tunnels, bridges, buildings and earth-work construction. This need is mainly driven by (i) the shortage and rising costs of skilled workers, (ii) the tremendous increased needs for new infrastructures to serve the daily activities and (iii) the immense demand for maintenance of ageing infrastructure. Shotcrete (sprayed concrete) is increasingly becoming popular technology among contractors and builders, as its application is extremely economical and flexible as the growth in construction repairs in developed countries demand excessive automation of concrete placement. Even if shotcrete technology is heavily mechanized, the actual application is still performed manually at a large extend. RoBétArméEuropean project targets the Construction 4.0 transformation of the construction with shotcrete with the adoption of breakthrough technologies such as sensors, augmented reality systems, high-performance computing, additive manufacturing, advanced materials, autonomous robots and simulation systems, technologies that have already been studied and applied so far in Industry 4.0. The paper at hand showcases the development of a novel robotic system with advanced perception, cognition and digitization capabilities for the automation of all phases of shotcrete application. In particular, the challenges and barriers in shotcrete automation are presented and the RoBétArmésuggested solutions are outlined. We introduce a basic conceptual architecture of the system to be developed and we demonstrate the four application scenarios on which the system is designated to operate.

Bone healing is a complex process orchestrated by various factors, such as mechanical, chemical and electrical cues. Creating synthetic biomaterials that combine several of these factors leading to tailored and controlled tissue regeneration, is the goal of scientists worldwide. Among those factors is piezoelectricity which creates a physiological electrical microenvironment that plays an important role in stimulating bone cells and fostering bone regeneration. However, only a limited number of studies have addressed the potential of combining piezoelectric biomaterials with state-of-the-art fabrication methods to fabricate tailored scaffolds for bone tissue engineering. Here, we present an approach that takes advantage of modern additive manufacturing techniques to create macroporous biomaterial scaffolds based on a piezoelectric and bioactive ceramic-crystallised glass composite. Using binder jetting, scaffolds made of barium titanate and 45S5 bioactive glass are fabricated and extensively characterised with respect to their physical and functional properties. The 3D-printed ceramic-crystallised glass composite scaffolds show both suitable mechanical strength and bioactive behaviour, as represented by the accumulation of bone-like calcium phosphate on the surface. Piezoelectric scaffolds that mimic or even surpass bone with piezoelectric constants ranging from 1 to 21 pC/N are achieved, depending on the composition of the composite. Using MC3T3-E1 osteoblast precursor cells, the scaffolds show high cytocompatibility coupled with cell attachment and proliferation, rendering the barium titanate/45S5 ceramic-crystallised glass composites promising candidates for bone tissue engineering.

At the local level, energy communities are at the forefront of the European Green Deal strategy offering new opportunities for citizens to get actively involved in energy markets. The scope of this study is to propose a multi-objective optimization framework to minimize both carbon dioxide emissions and total annual costs in an energy community, considering, within different constraints, a wide availability of decision variables including local renewable energy sources, sector coupling, storage and hydrogen. The methodology involves the coupling of the software EnergyPLAN with a multi-objective evolutionary algorithm, considering 2030 and 2050 as target years and modelling a set of eight types of scenarios, each consisting of 100 optimal systems out of 10,000. The case study is an energy community in the European Alps. The results show, on the one hand, the key role of sector coupling technologies such as cogeneration, heat pumps and electric vehicles in exploiting local renewable energy sources and, on the other hand, the higher costs in introducing both electricity storage to achieve a complete decarbonisation and hydrogen as an alternative strategy in the electricity, thermal and transport sectors.

This 38th volume of the International Journal of Sustainable Energy Planning and Management presents some of the newest work within in the energy planning, energy systems analyses and district heating area. Articles focus on multi objective optimisarion for a community in the Alps, carbon neutrality in Estonia, the prospects of heat pumps combined with thermal energy storage in maximising self-consumpotion from a photovoltaic field and methods for assessing district heating options. Other work focus on gamification tools for assessing energy efficiency measures, country analyses of economic and environmental indicators, the adaption of alternative fuel vehicles, and the use of waste heat sources for district heating.

The transportation sector is gradually evolving to become independent of fossil fuels. Here, the authors report a metal-based monolithic solid oxide fuel cell with a power density of 5.6 kW/L suitable for transport applications.

Research on 100% renewable energy systems is a relatively recent phenomenon. It was initiated in the mid-1970s, catalyzed by skyrocketing oil prices. Since the mid-2000s, it has quickly evolved into a prominent research field encompassing an expansive and growing number of research groups and organizations across the world. The main conclusion of most of these studies is that 100% renewables is feasible worldwide at low cost. Advanced concepts and methods now enable the field to chart realistic as well as cost- or resource-optimized and efficient transition pathways to a future without the use of fossil fuels. Such proposed pathways in turn, have helped spur 100% renewable energy policy targets and actions, leading to more research. In most transition pathways, solar energy and wind power increasingly emerge as the central pillars of a sustainable energy system combined with energy efficiency measures. Cost-optimization modeling and greater resource availability tend to lead to higher solar photovoltaic shares, while emphasis on energy supply diversification tends to point to higher wind power contributions. Recent research has focused on the challenges and opportunities regarding grid congestion, energy storage, sector coupling, electrification of transport and industry implying power-to-X and hydrogen-to-X, and the inclusion of natural and technical carbon dioxide removal (CDR) approaches. The result is a holistic vision of the transition towards a net-negative greenhouse gas emissions economy that can limit global warming to 1.5°C with a clearly defined carbon budget in a sustainable and cost-effective manner based on 100% renewable energy-industry-CDR systems. Initially, the field encountered very strong skepticism. Therefore, this paper also includes a response to major critiques against 100% renewable energy systems, and also discusses the institutional inertia that hampers adoption by the International Energy Agency and the Intergovernmental Panel on Climate Change, as well as possible negative connections to community acceptance and energy justice. We conclude by discussing how this emergent research field can further progress to the benefit of society.

Artiklen argumenterer for, at jo mere praktikere er involveret i at udforske og definere problemstillinger i deres arbejdsliv, des bedre er mulighederne for, at der konstrueres relevante forståelser og handlekompetence. Vi har udviklet metoden den lærende kortlægning med afsæt i aktionsforskning og pragmatisk læringsteori. Metoden står i kontrast til traditionelle ekspertdrevne kortlægningstilgange, der definerer problemstillinger på en abstrakt og dekontekstualiseret måde. Læring skabes transaktionelt i mødet mellem forsker- og arbejdspraksisser, hvor deltagernes erfaringer og viden perspektiveres og forstyrres i mødet med arbejdsmiljømæssige forskningsbegreber (instrumenter). Ved at skabe forstyrrelser og kritisk udforske eksisterende erfaringer skabes nye erkendelser og betydningsindhold både for deltagerne og forskerne. Disse erkendelser vil ikke kunne begribes i samme kontekstuelle dybde gennem traditionel dataindsamling. I det metodiske design anvendes bl.a. udsagnskort, perspektivsamtaler og spejling. Gennem analytiske nedslag i en ud af 17 cases i et samarbejdsprojekt mellem RUC og regionale arbejdspladser viser vi eksemplarisk, hvordan erkendelser og rekonstruktioner af problemforståelser understøttes og skabes. Afslutningsvis diskuterer vi styrker og udfordringer ved den lærende kortlægning.

A critical-size bone defect in load-bearing areas is a challenging clinical problem in orthopaedic surgery. Titanium alloy (Ti6Al4V) scaffolds have advantages because of their biomechanical stability but lack electrical activity, which hinders their further use. This work is focused on the fabrication of Ti6Al4V-Barium Titanate (BaTiO3) bulk composite scaffolds to combine the biomechanical stability of Ti6Al4V with electrical activity through BaTiO3. For the first time, a hollow cylindrical Ti6Al4V is additively manufactured by electron beam melting and combined with piezoelectric BaTiO3 powder for joint processing in field-assisted sintering. Scanning electron microscope images on the interface of the Ti6Al4V-BaTiO3 composite scaffold showed that after sintering, the Ti6Al4V lattice structure bounded with BaTiO3 matrix without its major deformation. The Ti6Al4V-BaTiO3 scaffold had average piezoelectric constants of (0.63 ± 0.12) pC/N directly after sintering due to partial dipole alignment of the BaTiO3 tetragonal phase, which increased to (4.92 ± 0.75) pC/N after a successful corona poling. Moreover, the nanoindentation values of Ti6Al4V exhibited an average hardness and Young’s modulus of (5.9 ± 0.9) GPa and (130 ± 14) GPa, and BaTiO3 showed (4.0 ± 0.6) GPa and (106 ± 10) GPa, respectively. It reveals that the Ti6Al4V is the harder and stiffer part in the Ti6Al4V-BaTiO3 composite scaffold. Such a scaffold has the potential to treat critical-size bone defects in load-bearing areas and guide tissue regeneration by physical stimulation.

Aims: Assess the incidence and prevalence of diabetic retinopathy (DR) among all persons registered with diabetes in the electronic medical records (EMR) from 2016 to 2020 and investigate factors associated with both incident and prevalent DR. Methods: We calculated the five-year incidence rate of DR per 1000 person years, and calculated the prevalence of DR, using Poisson regression analysis. We calculated the incidence rate ratios (IRR) in univariate and multivariate Poisson regression analysis, to assess risk factors associated with incident DR. We calculated the Odds ratios (OR) to assess risk factors of prevalent DR in univariate and multivariate Logistic regression analyses. Results: We found 10.4% persons developed incident DR during follow-up, equivalent to an incidence rate of DR of 29.2 pr. 1000 (95%CI: 22.9–37.3) person years. The total prevalence of DR was 13.6%. Higher HbA1c levels and longer diabetes duration were significantly associated with incident and prevalent DR. Higher levels of LDL cholesterol were significantly associated with a lower risk of incident DR. Conclusion: The incidence and prevalence of DR in Greenland is lower than in most other parts of the world. In agreement with previous studies on risk factors for DR, HbA1c levels and diabetes duration were associated with incident/prevalent DR.

Oxygen transport membranes have the potential to deliver pure and cheap oxygen to chemical reactors, combustors, gasifiers etc., given that geometry, microstructure and material properties are optimized. This work demonstrates the first successful preparation of dual-phase tubular, asymmetric oxygen transport membranes consisting of a new electronic conductor LaCr0.85Cu0.10Ni0.05O3-δ mixed with (Sc2O3)0.10(Y2O3)0.01(ZrO2)0.89 as ionic conductor. Challenges related to Cr-volatility were overcome by using Fe2O3 as a sintering aid. The sintering aid decreased mismatches in shrinkage and thermal expansion between the four layers in the asymmetric membrane and decreased the sintering temperature such that the Cr-volatility was suppressed. The membranes reached an oxygen flux of 0.28 ml∙min−1∙cm−2 in an air/N2 atmosphere at 950 °C. Furthermore, the membranes showed a stable oxygen flux after exposure to different atmospheres, including air/CO2 and air/H2 gradients. The successful fabrication of stable, asymmetric, tubular membranes opens the possibility for future integration in syngas or oxy-combustion applications.

In the design of flow geometries consisting of channels such as high-temperature gas heat exchangers, a great number of design parameters can be chosen, why solving the turbulent Reynolds Averaged Navier-Stokes (RANS) equations by CFD coupled with other physics can become computational demanding. Therefore, we here propose a method for a significant reduction of computational resources and consequent high speed. This is done by using the less computational demanding Darcy’s Law (DL) to approximate the laminar and turbulent flows in channels with circular and arbitrary cross-sections. To obtain the right velocity profile, an artificial permeability variation across the cross-section of the channel is determined. This is obtained based on the analogy of the DL and Darcy–Weisbach equation (DW). Results demonstrate that the DL approximations predict velocities and pressures distributions from the laminar and turbulent flows in the channels with circular and arbitrary cross-sections very well. At the same time, the models with DL approximations reduce the runtime up to ~40 times as compared to RANS, and improve the stability and convergence of the model. Lastly, a cross-flow heat exchanger is studied as an application of the DL approximations.

Abstract Background Visible light, predominantly in the blue range, affects mood and circadian rhythm partly by activation of the melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs). The light-induced responses of these ganglion cells can be evaluated by pupillometry. The study aimed to assess the blue light induced pupil constriction in patients with bipolar disorder (BD). Methods We investigated the pupillary responses to blue light by chromatic pupillometry in 31 patients with newly diagnosed bipolar disorder, 22 of their unaffected relatives and 35 healthy controls. Mood state was evaluated by interview-based ratings of depressive symptoms (Hamilton Depression Rating Scale) and (hypo-)manic symptoms (Young Mania Rating Scale). Results The ipRGC-mediated pupillary responses did not differ across the three groups, but subgroup analyses showed that patients in remission had reduced ipRGC-mediated responses compared with controls (9%, p = 0.04). Longer illness duration was associated with more pronounced ipRGC-responses (7% increase/10-year illness duration, p = 0.02). Conclusions The ipRGC-mediated pupil response to blue light was reduced in euthymic patients compared with controls and increased with longer disease duration. Longitudinal studies are needed to corroborate these potential associations with illness state and/or progression.

This 34th volume of the International Journal of Sustainable Energy Planning and Management includes papers from the 2021 conference on Sustainable Development of Energy, Water and Environmental Systems (SDEWES) held October 10-15, 2021, in Dubrovnik, Croatia as well as the 7th International Conference on Smart Energy Systems held September 21-22 in Copenhagen, Denmark and two normal papers. A focus area of this issue is district heating and district cooling systems, with articles addressing resources for district heating and cooling systems, impacts of having individual district heating metres for consumers and approaches to analysing district heating systems. Another focus area is stakeholder involvement where two groups of researchers focus on stakeholders from an energy island perspective as well as from a positive energy district perspective. Both groups note the importance of factoring in stakeholders when devising transition plans. Plans for increasing the penetration of renewable energy sources for the Estonian, Latvia and Lithuanian systems are analysed using the Backbone model, finding modest increases in system costs. Lastly, an article sets up an indicator system for assessing environmental performance of European Union member states ranking, e.g., Estonian, Latvia and Lithuanian as moderate (Estonia and Latvia) to weak (Lithuania) in terms of sustainable energy performance score, based on 2019 data.

The production of regenerated cellulosic fibres, such as viscose, modal and lyocell, is based mainly on the use of dissolving wood pulp as raw material. Enzymatic processes are an excellent alternative to conventional chemical routes in the production of dissolving pulp, in terms of energy efficiency, reagent consumption and pulp yield. The two main characteristics of a dissolving pulp are the cellulose purity and the molecular weight, both of which can be controlled with the aid of enzymes. A purification process for paper-grade kraft pulp has been proposed, based on the use of xylanases in combination with hot and cold caustic extraction, without the conventional pre-hydrolysis step before kraft pulping. This enzyme aided purification allowed the production of a dissolving pulp that met the specifications for the manufacture of viscose, < 3% xylan, > 92% ISO brightness and 70% Fock’s reactivity. Endoglucanases (EGs) can efficiently reduce the average molecular weight of the cellulose while simultaneously increasing the pulp reactivity for viscose production. It is shown in this study that lytic polysaccharide monooxygenases act synergistically with EGs in the modification of bleached dissolving pulp.

Summary: Addressing climate change with the rising global energy usage necessitates electricity sector decarbonization by rapidly moving toward flexible and efficient off-grid renewable energy systems (RESs). This paper analyzes the wind and solar micro-grids, with batteries and pumped hydro storage for a robust off-grid RES techno-economic operation, while considering diverse multi-objective optimization cases. This research has considered the RES variable operational losses in the developed methodology and relations between different indicators are evaluated, revealing a basic understanding between them. The results reveal that the reliability index is inversely related to the oversupply index, while directly related to the system self-sufficiency index. The cost of energy is more sensitive to technical indicators rather than the storage cost and so can be used as a primary monetary index. Energy and cost balance analysis showed that 16%–20% of the used energy was drained in RES operational losses, which were usually ignored in previous studies.

This editorial introduces the 31st volume of the International Journal of Sustainable Energy Planning and Management. This volume reports some of the latest developments in energy systems analyses of smart energy systems and of district heating as well as in methods and analyses using multi-objective optimisation. In one of the analyses, the authors investigate the effects of decentralised storage in district heating systems, finding positive effects on grid design as the impact of peaks can be reduced. Three contributions address the more sociological factors influencing acceptance and energy system development such as ownership, awareness, and moral.

To assess the prevalence of diabetic retinopathy (DR) among persons with diabetes and prediabetes participating in the 2018 Population Health Survey in Greenland (B2018), a follow-up survey of three previous health surveys. Participants were invited to a diabetes complication screening. We assessed the prevalence of DR using Optos Daytona Ultra-wide field fundus camera and assessed differences in prevalence according to demographic and clinical characteristics using chi square test and a t-test and assessed DR based on ethnicity. The overall prevalence of DR was 2% (10/483). Among participants with HbA1c ≥48 mmol/mol (6.5%) DR prevalence was 9% (9/91), compared with

This editorial introduces the 27th volume of the International Journal of Sustainable Energy Planning and Management, which reports some of the latest developments in energy systems analyses of smart energy systems as well as district heating. The issue looks into district heating in Estonia and Norway – as part in a renewable energy transition and flexibility-providing measure. Other analyses look into future prices of renewable energy-based power production systems and optimal design of carbon-neutral energy systems combing EnergyPLAN and EPLANOpt.

Identifying active sites and designing rationally heterogeneous catalysts are not inherently straightforward due to their complexity. Here, the authors reveal the nature of active sites for efficient C–H bond activation in C1-C4 alkanes over bare ZrO2 and provide fundamentals for controlling their concentration.

AIM:In glaucoma, depression and disturbed sleep has been associated with degeneration of the intrinsically photosensitive retinal ganglion cells, that mediate non-image forming effects of light such as regulation of circadian rhythm, alertness and mood. In this study we assessed associations between seasonal mood and behavior variation and retinal ganglion cell damage in outpatients with glaucoma. METHODS:The seasonal pattern assessment questionnaire was administered to outpatients with glaucoma. Data on visual field defects identified by autoperimetry and retinal nerve fiber layer thickness visualized by ocular coherence tomography were collected from patient charts. The correlations between seasonality and retinal damage were tested and the adjusted effects of retinal function on seasonality were evaluated in a linear regression model. RESULTS:In total, 113 persons completed the questionnaire. Of these, 4% fulfilled the criteria for seasonal affective disorder (SAD) and 8% for subsyndromal seasonal affective disorder (sSAD). Mean global seasonal score was 4.3. There were no significant correlations between seasonality and either visual field or retinal nerve fiber layer thickness. In the adjusted analysis there were trends toward differential effects of visual field on seasonality in subgroups with different sex and type of glaucoma. CONCLUSION:There were no strong associations between seasonality and visual field or retinal nerve fiber layer thickness. Sex, age and glaucoma subtype may modify light effects on complex regulatory systems.

Energy efficiency improvements of buildings is widely recognized as an important part of reaching future sustainable energy systems, as these both reduce the need for energy and improve the efficiency of the heat supply. Finding the correct level of efficiency measures, depends on the type of measure, on the supply system typology as well as on the heat supply cost. As this information is often building-specific, most analyses related to energy efficiency in buildings are carried out in relation to specific renovation projects, while energy plans for larger areas make crude assumptions regarding levels of savings and costs. This article aims at improving the latter, by using a detailed heat atlas in combination with specific marginal energy renovation costs, in a study of Aalborg Municipality in Denmark. In the analysis, all buildings in the municipality are mapped at building level and both the marginal energy efficiency measure costs and the marginal heat supply costs are identified. The buildings are then sorted by their supply type, and marginal costs curves on supply and savings are compared to determine the feasible level of efficiency measures in each building. The results show that both the building type and the supply costs have a large influence on the feasible measures. Furthermore, the results show that a demand reduction of 30% in district heating areas, 35% for buildings with heat pumps and 37% for buildings with oil boilers, for the examined buildings, is socio economically feasible in a Business as Usual 2050 Aalborg Municipality scenario.

This editorial introduces the 20th volume of the International Journal of Sustainable Energy Planning and Management. Papers included are all from the conference on 4th generation District heating and Smart Energy Systems, Aalborg, 2017, treating the control of heat systems, technical and non-technical barriers to low-temperature district heating. Temperature levels are also key-parameters in an investigation of heat pumps and heat sources for heat pumps in Tallinn. In parallel to apps focusing on electricity systems, an app focusing on heat systems is presented.

Objectives: The aim of this in vitro study was to evaluate how a deviation from the horizontal plane, affects the image quality in two different CBCT-devices. Methods: A phantom head SK150 (RANDO, The Phantom Laboratory, Salem, NY, USA) was examined in two CBCT-units: Accuitomo 80 and Veraviewepocs 3D R100 (J. Morita Mfg. Corp. Kyoto, Japan). The phantom head was placed with the hard palate parallel to the horizontal plane and tilted 20 ° backwards. Exposures were performed with different field of views (FOVs), voxel sizes, slice thicknesses and exposure settings. Effective dose was calculated using PCXMC 2.0 (STUK, Helsinki, Finland). Image quality was assessed using contrast-to-noise-ratio (CNR). Region of interest (ROI) was set at three different levels of the mandibular bone and soft tissue, uni- and bilaterally in small and large FOVs, respectively. CNR values were calculated by CT-value and standard deviation for each ROI. Factor analysis was used to analyze the material. Results: Tilting the phantom head backwards rendered significantly higher mean CNR values regardless of FOV. The effective dose was lower in small than in large FOVs and varied to a larger extent between CBCT-devices in large FOVs. Conclusions: Head position can affect the image quality. Tilting the head backward improved image quality in the mandibular region. However, if influenced by other variables e.g. motion artifacts in a clinical situation, remains to be further investigated. Advances in knowledge: Image quality assessed using CNR values to investigate the influence of different patient positions and FOVs. Keywords: Image quality, CBCT, Radiation dose, Patient position, FOV

This paper addresses economic aspects of heat savings in the context of strategic heat planning. The analysis uses the city of Aalborg, Denmark, as a case where municipalisation through a recent acquisition of a coal-fired cogeneration of heat and power (CHP) plant has made an update of a municipal strategic energy plan necessary. Combining datasets on buildings and insulation techniques with economic methods, we investigate how the local district heating tariff can be adapted to improve the conditions for heat savings and support the transition to lower supply temperatures in line with the requirements of future fourth generation district heating systems. The paper concludes that implementing a fully variable heat tariff scheme improves the financial incentive for heat savings, while also making the system development less vulnerable to fluctuations and shortages in capital markets. The paper supplements existing literature on heat savings with novelty in its approach and in its systematic investigation of the interplay between tariff policies and interest rates.

This editorial introduces the 16th volume of the International Journal of Sustainable Energy Planning and Management, which addresses different angles of district heating ranging from the planning of district heating systems and economic incentives for flexible district heating plants to comparisons between low and ultra-low-temperature district heating systems and methods for determining thermal conductivity in district heating pipes.

Hybridisation of district heating systems can contribute to more efficient heat generation through cogeneration power plants or through the share increase of renewable energy sources in total energy consumption while reducing negative aspects of particular energy source utilisation. In this work, the performance of a hybrid district energy system for a small town in Croatia has been analysed. Mathematical model for process analysis and optimisation algorithm for optimal system configuration has been developed and described. The main goal of the system optimisation is to reduce heat production costs. Several energy sources for heat production have been considered in 8 different simulation cases. Simulation results show that the heat production costs could be reduced with introduction of different energy systems into an existing district heating system. Renewable energy based district heating systems could contribute to heat production costs decrease in district heating systems up to 30% in comparison with highly efficient heat production technologies based on conventional fuels.

ObjectiveContinuous and intermittent stimuli with green light affect the pupillary light response (PLR) differently. Since the majority of pupillometric studies use blue and red lights, we investigated the effect of continuous and intermittent stimulations on the PLR using red and blue lights.MethodsSeventeen healthy subjects underwent continuous- and intermittent light stimuli, using red (643 nm) and blue light (463 nm). To avoid the influence of pupil size on the amount of light entering the eye, the procedures were repeated with the stimulus–eye in dilated condition. The maximal pupillary constriction and the early redilation phase of post-illumination pupillary response (PIPREarly) represented the mixed response of melanopsin and rod–cone photoreceptors. The late redilation phase of PIPR (PIPRLate) was the marker of melanopsin-containing retinal ganglion cells.ResultsIntermittent stimuli with blue light elicited significantly larger maximal contraction during dilated condition (P = 0.001), and larger sustained pupillary contraction under dilated as well as undilated condition (P

This editorial introduces the 13th volume of the International Journal of Sustainable Energy Planning and Management, which addresses thermal storage systems in district heating systems, simulation of scheduling of energy units as well as the structure of pricing systems for district heating in Sweden. Beyond the area of district heating, the volume probes into the effects of energy price reductions on energy demand in Hungary as well as the geographical distribution of electricity demand and production in Germany.

District heating systems are prevailing in parts of Northern Europe and this editorial introduces work on the optimisation of such systems in Denmark, Britain and Norway. Focus of two of the articles are on low temperature systems. This is either directly through lowering the forward temperature and analysing system consequences and optimal forward temperatures as in the work of Lund et al. – or it is by the use of the return pipe water for heating in district heating system functioning at relatively high temperature levels, as in the work by Ianakiev on Nottingham. Analyses by Trømborg et al. probe into future Norwegian electricity market prices and their effects on the operation of district heating storage and electric boilers. Finally, Ogundari et al. compare photo voltaic systems to diesel systems in standalone systems for Abuja, Nigeria.

This paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used in future sustainable smart energy systems. Based on a concrete proposal to implement the Danish governmental 2050 fossil-free vision, this paper identifies marginal heat production costs and compares these to marginal heat savings costs for two different levels of district heating. A suitable least-cost heating strategy seems to be to invest in an approximately 50% decrease in net heat demands in new buildings and buildings that are being renovated anyway, while the implementation of heat savings in buildings that are not being renovated hardly pays. Moreover, the analysis points in the direction that a least-cost strategy will be to provide approximately 2/3 of the heat demand from district heating and the rest from individual heat pumps.

Increasing amounts of intermittent renewable energy sources (RES) are being integrated into energy systems worldwide. Due to the nature of these sources, they are found to increase the importance of mechanisms for balancing the electricity system. Small-scale combined heat and power (CHP) plants based on gas have proven their ability to participate in the electricity system balancing, and can hence be used to facilitate an integration of intermittent RES into electricity systems. Within the EU electricity system, balancing reserves have to be procured on a market basis. This paper investigates the ability and challenges of a small-scale CHP plant based on natural gas to participate in the German balancing reserve for secondary control. It is found that CHP plants have to account for more potential losses than traditional power plants. However, it is also found that the effect of these losses can be reduced by increasing the flexibility of the CHP unit.

Energy systems in cities need to be decarbonized and are becoming more integrated via energy sector coupling. Today, cities often use simple methods to assess their low carbon targets, e.g., carbon calculators, and these methods use annualized carbon reduction potentials. For example, reductions from heat savings in buildings or fuel demand in transport. This is done because it is simple and fast. This paper describes a methodology that goes beyond carbon calculators and assesses highly renewable energy systems. The methodology is carried out for a case city—Sønderborg, Denmark. Using a national 100% renewable energy study and a suitable energy system analysis tool (EnergyPLAN), the method accounts for inter-sector coupling and energy system dynamics. The energy system is assessed by comparing the results from the analysis tool against numerous key sustainability factors for a Smart Energy System. The paper illustrates how the method delivers a sustainable 100% renewable Smart Energy System for Sønderborg, which can be part of the Danish energy system in 2050 based on local resources. The paper discusses the broader applicability of the method within strategic energy planning.

It is often highlighted how the transition to renewable energy supply calls for significant electricity storage. However, one has to move beyond the electricity-only focus and take a holistic energy system view to identify optimal solutions for integrating renewable energy. In this paper, an integrated cross-sector approach is used to determine the most efficient and least-cost storage options for the entire renewable energy system concluding that the best storage solutions cannot be found through analyses focusing on the individual sub-sectors. Electricity storage is not the optimum solution to integrate large inflows of fluctuating renewable energy, since more efficient and cheaper options can be found by integrating the electricity sector with other parts of the energy system and by this creating a Smart Energy System. Nevertheless, this does not imply that electricity storage should be disregarded but that it will be needed for other purposes in the future.

OBJECTIVES: The aim of this study was to (i) investigate the consequences of self-rostering for working hours, recovery, and health, and (ii) elucidate the mechanisms through which recovery and health are affected. METHODS: Twenty eight workplaces were allocated to either an intervention or reference group. Intervention A encompassed the possibility to specify preferences for starting time and length of shift down to 15 minutes intervals. Interventions B and C included the opportunity to choose between a number of predefined duties. Questionnaires (N=840) on recovery and health and objective workplace reports of working hours (N=718) were obtained at baseline and 12 months later. The interaction term between intervention and time was tested in mixed models and multinomial logistic regression models. RESULTS: The odds ratio (OR) of having short [OR 4.8, 95 % confidence interval (95% CI) 1.9–12.3] and long (OR 4.8, 95% CI 2.9–8.0) shifts increased in intervention A. Somatic symptoms (β= -0.10, 95% CI -0.19– -0.02) and mental distress (β= -0.13, 95% CI -0.23– -0.03) decreased, and sleep (β= 1.7, 95% CI 0.04–0.30) improved in intervention B, and need for recovery was reduced in interventions A (β= -0.17, 95% CI -0.29– -0.04) and B (β= -0.17, 95% CI -0.27– -0.07). There were no effects on recovery and health in intervention C, and overall, there were no detrimental effects on recovery or health. The benefits of the intervention were not related to changes in working hours and did not differ by gender, age, family type, degree of employment, or working hour arrangements. CONCLUSIONS: After implementation of self-rostering, employees changed shift length and timing but did not compromise most recommendations for acceptable shift work schedules. Positive consequences of self-rostering for recovery and health were observed, particularly in intervention B where worktime control increased but less extensively than intervention A. The effect could not be statistically explained by changes in actual working hours.

Local ownership models have proven to be an important way to avoid local resistance to onshore wind turbines. As wind power expands into onshore and nearshore wind farms, such ownership models become of increasing importance, while also undergoing further development. This paper uses the Choice Awareness theory to examine some of the barriers connected to the implementation of these new ownership models and presents recommendations to overcome such barriers. Choice Awareness addresses societal aspects (discourse, socioeconomics, and public regulation) mainly related to implementing alternatives to existing technologies. For the theory to be able to embrace the complexity of the transition of the energy system more holistically, we explore and specify the organizational dimension of choice-eliminating mechanisms. Based on the case of an NGO’s attempt to bid for a tender for nearshore wind turbines, it is shown how the central administration prevents new innovative ownership models from entering the tender. A strong path dependency has led to a conscious or unconscious elimination of projects based on organizational structures that do not fit the definition of large energy companies. As a result of this, the paper makes three recommendations for policy changes with the aim to secure equal possibilities for actors involved in nearshore wind power tenders.

Energy systems are becoming increasing increasingly complex, integrating across traditionally separate sectors such as transportation, heating, cooling and electricity. Integration through the use of district heating is the main topic of this editorial introducing volume 10 of the International Journal of Sustainable Energy Planning and Management. The editorial and the volume presents work on district heating system scenarios in Austria, grid optimisation using genetic algorithms and finally design of energy scenarios for the Italian Alpine town Bressanone-Brixen from a smart energy approach.

We propose an efficient strategy to find optimal control functions for state-to-state quantum control problems. Our procedure first chooses an input state trajectory, that can realize the desired transformation by adiabatic variation of the system Hamiltonian. The shortcut-to-adiabaticity formalism then provides a control Hamiltonian that realizes the reference trajectory exactly but on a finite time scale. As the final state is achieved with certainty, we define a cost functional that incorporates the resource requirements and a perturbative expression for robustness. We optimize this functional by systematically varying the reference trajectory. We demonstrate the method by application to population transfer in a laser driven three-level Λ-system, where we find solutions that are fast and robust against perturbations while maintaining a low peak laser power.

Climate change mitigation calls for energy systems minimising end-use demands, optimising the fuel efficiency of conversion systems, increasing the use of renewable energy sources and exploiting synergies wherever possible. In parallel, global fresh water resources are strained due to amongst others population and wealth increase and competitive water uses from agriculture and industry is causing many nations to turn to desalination technologies. This article investigates a Jordanian energy scenario with two different desalination technologies; reverse osmosis (RO) driven by electricity and Multi Stage Flash (MSF) desalination driven by Cogeneration of Heat and Power (CHP). The two systems impact the energy systems in different ways due to the technologies’ particular characteristics. The systems are analyses in the energy systems analysis model EnergyPLAN to determine the impacts on energy system performance. Results indicate that RO and MSF are similar in fuel use. While there is no use of waste heat from condensing mode plants, efficiencies for CHP and MSF are not sufficiently good to results in lower fuel usage than RO. The Jordanian energy system is somewhat inflexible giving cause to Critical Excess Electricity Production (CEEP) even at relatively modest wind power penetrations. Here RO assists the energy system in decreasing CEEP – and even more if water storage is applied.