bluuebunny/crossref_metadata_2025 huggingface dataset:
Pill Esophagitis: Clinical and Endoscopic Profile
Authors: Pemmada Vikas , Shetty Athish , Murali Megha , Shetty Shiran , Musunuri Balaji , Rajpurohit Siddheesh , Bhat Ganesh
Published: December 2023

Background Medications can rarely cause esophageal injury and present with acute symptoms. Multiple factors, including the type of medication, comorbidity, and method of ingestion play a role in causing drug-induced or pill esophagitis (PE). We analyzed the clinical, endoscopic, and histopathological profiles of PE cases at our gastroenterology outpatient clinic.

Methods Medical records of PE cases were reviewed retrospectively over a period of 5 years at a tertiary care hospital in India from May 2017 to May 2022. The data were collected and analyzed using descriptive statistical analysis.

Results A total of 30 patients diagnosed with PE were involved in the study. A slight male preponderance of 56.7% was noted with a mean age of 40.7 years. Odynophagia was the dominant symptom (70%) with a mean duration of symptoms of 5.63 days. The most common location was at the mid-esophagus (80%) followed by the lower esophagus (10%). The majority (56.7%; 17/30) had over-the-counter (OTC) drug consumption, followed by doxycycline (33.3%; 10/30). Kissing ulcers were seen in 30% of the subjects; 90% of the patients received a combination of proton pump inhibitors and sucralfate suspension for 2 weeks along with discontinuation of the causative drug, with a 96.7% resolution rate.

Conclusion OTC medication and antibiotics such as doxycycline are the leading cause of PE. Prompt recognition and discontinuation of the causative drug are crucial in preventing complications. Patient education is vital in preventing PE regarding the usage of OTC medicines in developing countries.
A novel detection method based on derivative for thermal defects of electrical equipment
Authors: Liu Kai , Yang Zhixiang , Xin Dongli , Sun Chuanming , Gao Bo , Dai Zhiqiang , Yang Siwei , Wei Wenfu , Gao Guoqiang , Wu Guangning
Published: December 2023

Thermal defects widely occur in electrical equipment and affect its stable operation. This paper proposes a novel detection method based on derivatives for thermal defects of electrical equipment. First, the equivalent models of the equipment are established to analyze the surface temperature formed by different defects. Second, the theoretical foundation of the derivative-based detection method is described, and numerical calculations on thermal defect detection based on derivative characteristic curves are carried out. The results show that the method can detect the position effectively and calculate the depth with an error of 1.6%. Then, the thermal defects in different situations are analyzed, and the results indicate that the method is effective in all cases. Finally, the experiment is conducted by artificially preparing samples with thermal defects, and the achieved calculation error of the experimental results is within 3.3%, which indicates the validity of this method.
Enrichment of fuel properties of biomass using non-oxidative torrefaction for gasification
Authors: Banik Rabindra Kangsha , Kalita Pankaj
Published: December 2023

The abundance and replenishment nature of solid biomass prompt fuel substitution for gasification and thermal power plants. However, many challenges are encountered while utilizing raw biomass, such as seasonality, strong hydrophilicity, low bulk and energy density, excess oxygen content, less compositional homogeneity, and poor grindability. It is, therefore, indispensable to augment the thermo-chemical properties of the solid biomass by performing suitable pretreatment. Among the various pretreatment techniques, non-oxidative torrefaction effectively upgrades solid biomass to coal-like fuel altering its physico-chemical properties. Therefore, in this work, torrefaction of rice husk and sugarcane bagasse have been performed in a fixed bed reactor by varying temperatures from 210–330 °C and residence time from 30–60 min under a non-oxidative environment. The experimental investigation illustrates a decrease in mass and energy yield of the biomass with a rise in temperature and residence time. Conversely, the higher heating value of rice husk and sugarcane bagasse has improved by 119.4% and 128.9%, respectively. The hydrogen-to-carbon (H/C) and oxygen-to-carbon (O/C) ratio of the torrefied biomass has reduced to enriched fuel variety as indicated by the van Krevelen plot. The decomposition and structural modifications were assessed using Fourier transform infrared spectroscopy, x-ray diffraction, and morphology analysis. Based on the experimental observations, it has been found that torrefaction of rice husk at 290 °C and 30 min and sugarcane bagasse at 270 °C and 30 min would generate enriched syngas using a dual fluidized bed gasification system. Furthermore, water gas shift reactions will be promoted to enhance the percentage of hydrogen in the gas mixture.
Aerodynamic optimization of NACA 0012 airfoils with attached Gurney flap in the rarefied gas flow
Authors: Lin Keren , Zhang Songqin , Liu Chenfan , Yang Haiwei , Zhang Bin
Published: December 2023

The aerodynamic optimization of a Gurney flap attached to the NACA 0012 airfoil in rarefied gas flow is studied in this study. In order to investigate the effects of Gurney flap geometry (height, mounting angle, and mounting location) and angle of attack on the aerodynamic characteristics of the airfoil in the rarefied gas flow, the flow fields around NACA 0012 airfoils with Gurney flap attached are simulated by using the direct simulation Monte Carlo method. Furthermore, the multi-objective aerodynamic optimization of the airfoil with Gurney flap is performed at the single design point, and the Pareto front is obtained. Based on the benchmark configuration (obtained from the Pareto front), aerodynamic optimization by controlling the mounting angle of the Gurney flap and the angle of attack is investigated over a wide range of Mach numbers (ranging from 2 to 4) and Knudsen numbers (ranging from 0.024 to 0.24) by constructing an artificial neural network model. The results show that through optimization, the lift-to-drag ratio of the airfoil is increased by up to 29.25% under the combination of different Mach numbers and Knudsen numbers, which significantly improves the aerodynamic characteristics.
Effective mass regulating of α-PbSe under pressure
Authors: Cheng Jiaen , You Cun , Wang Lu , Wang Xinglin , Zhao Wei , Wang Dianzhen , Qu Xin , Zhou Qiang , Tao Qiang , Dong Shushan , Zhu Pingwen
Published: December 2023

High pressure is an effective means to optimize the thermoelectric (TE) performance by sharply improving the electrical properties of materials. Studying the carrier effective mass (m*) is a feasible way to uncover the basic reason for superior electrical properties under high pressure. However, it is still difficult to obtain the m* under pressure in experiments. Thus, in this work, the m* of α-PbSe (Fm3̄m) under high pressure is calculated by band dispersion relation based on the density functional theory. It is found that the high pressure decreases m* of α-PbSe, which is the cause for excellent electrical properties. Moreover, the isotropy of m* enhances with the increase in the pressure, which means the high pressure further optimizes the isotropy of the carrier migration in the structure. It is reveled that the higher the pressure, the more beneficial to improve the electrical properties of α-PbSe, thus optimizing the TE performance before the phase transition pressure (4.5 GPa). This work is of great significance for exploring the mechanism of in situ high-pressure TE properties in the future, as well as the prediction and selection of high-performance TE materials under high pressure.
The Deep Space Network: Overburdened and underfunded
Authors: Means Hannah H.
Published: December 2023

NASA’s worldwide antenna array is bursting at the seams as new missions head into space.
The evaluation of the Plan–Do–Study–Act cycles for a healthcare quality improvement intervention in primary care
Authors: Manandi Deborah , Tu Qiang , Hafiz Nashid , Raeside Rebecca , Redfern Julie , Hyun Karice
Published: December 2023

Background The Plan–Do–Study–Act (PDSA) cycle is an iterative framework that has been gaining traction in primary care for quality improvement. However, its implementation remains understudied. This study evaluated the completion, achievement of goal, content quality, and enablers and barriers associated with completion of high-quality PDSA cycles in cardiovascular disease management in general practices. Methods This study analysed data from intervention practices of the QUality improvement in primary care to prevent hospitalisations and improve Effectiveness and efficiency of care for people Living people with coronary heart disease (QUEL) study. Content quality of cycles was assessed using a scoring system created based on established criteria of ideal PDSA cycles in the healthcare context. Practice-level factors associated with completion and cycles achieving the planned goal were explored through logistic regression models, and with content quality score through linear regression model. Enablers and barriers were assessed using thematic analysis of practices’ responses to the PDSA sections. Results Ninety-seven cycles were reported by 18/26 (69%) practices. Seventy-seven percent of the cycles were completed and 68% achieved the planned goal. Content quality was low, with a median score of 56% (interquartile interval: 44%, 67%). Odds of cycles that were completed and achieved what was planned increased by 3.6- and 9.6-fold, respectively, with more general practitioners (GPs) within practices. Content quality was higher by 15% with more GPs. Lack of interprofessional engagement was a barrier to implementation. Conclusions Cycles were well completed, but poor in content quality, with high variability between practices. Human or capital resources and organisational support may be critical for the completion and cycles achieving the planned goals.
Tadpole cosmology: Milne solution as a cosmological constant hideout
Authors: Appleby Stephen , Bernardo Reginald Christian
Published: December 2023

Dynamical cancellation frameworks present a potential means of mitigating the effect of a large vacuum energy, that would otherwise ruin the late-time, low energy dynamics of the Universe. Certain models in the literature, such as the Fab Four and Well Tempering, realize this idea by introducing some degeneracy in the dynamical equations. In this paper, we introduce a third potential route to self-tuning, and infer the existence of a new, exact Milne solution in the simplest tadpole plus cubic-Galileon scalar-tensor theory. We study the dynamics of the scalar field and metric in the vicinity of the Milne coordinate singularity, and find that the vacuum solution belongs to a more general family of Milne-like metrics. By numerically evolving the field equations for a range of initial conditions, we show that the Milne solution is not an attractor, and varying the initial scalar field data can lead to completely different asymptotic states; exponential growth of the scale factor, a static non-spatially flat metric or a severe finite-time instability in the scalar field and metric. We generalise the Milne solution to a class of FLRW spacetimes, finding that the tadpole-cubic Galileon model admits perfect-fluid-like solutions in the presence of matter. Finally, we present a second Horndeski model which also admits an exact Milne solution, hinting at the existence of a larger undiscovered model space containing vacuum-energy-screened solutions.
Rethinking building envelope design: Machine learning approaches to evaluate its impact on indoor ozone exposures
Authors: Ma N , Zhang Q , Braham W W
Published: December 2023

Ozone is widely recognized as an ambient air contaminant that causes acute and chronic health effects. However, there is a limited number of studies investigating indoor exposures to ozone in occupied houses and linking design variables to the predictive power of indoor ozone levels. This study focuses on typical envelope airflow paths used in residences in the Philadelphia area in the United States. The model development draws from the field data, including indoor and outdoor ozone concentration, environmental parameters, and building characteristics from four building envelopes. Five machine learning algorithms (i.e., support vector machine, lasso regression, random forest, Bayesian bridge regression, and gradient boosting) are employed, with indoor ozone concentration as the dependent variable, as it indicates how the hot and sunny weather that might lead to the possibility of indoor air quality (IAQ) alerts due to ozone. The results showed that gradient boosting model based on all field measurements had the highest R-squared value of 0.974 and low enough root mean square error (RMSE) and mean absolute error (MAE) which are 1.182 and 0.788, respectively. We conclude that indoor ozone forecasting model based on inputting environmental survey (ES) in addition to either design variables or indoor environment characteristics can effectively predict and can therefore be used at the building design phase to improve healthy living environments.
Experimental study of the performance of a novel solution with double skin façade and diffuse ceiling ventilation
Authors: Zhang C , Hu Y , Larsen O , Larsen T
Published: December 2023

In Denmark, about 80% of public schools were built before 1980, and most of them are with the Energy label D or lower. In addition, more than 60% of schools suffer from poor air quality and thermal comfort. The need for school renovation is undeniable. A novel renovation solution was proposed recently by combining double-skin façade (DSF) and diffuse ceiling ventilation (DCV). The integrated system can adapt its operating modes based on indoor and outdoor conditions. The performance of the above-mentioned solution was tested in a small-scale classroom and compared to a reference room with the traditional renovation solution. The results show that the novel solution was able to provide better indoor comfort than the traditional solution. Although significant overheating was observed in both rooms, the novel solution showed promise in mitigating the maximum operative temperature and shifting the peak hour. In terms of energy efficiency, the novel solution optimized the utilization of natural sources. The DSF was able to recover the transmission loss through the glazing and capture the heat gain by solar radiation. The heat recovery rate reached 1 when the solar radiation was strong.
A framework to generate local spectral skies for spectral daylight simulations
Authors: Balakrishnan Priji , Knoop Martine , Doppler Lionel
Published: December 2023

Spectral daylight simulations are becoming increasingly important in predicting non-visual responses to light and more accurate daylight colour and temporal patterns. However, the availability of locally measured spectral sky data is limited and current spectral sky models do not capture the local colour variability of skies. This paper presents a novel framework for generating high-accuracy, location-specific spectral sky data using typically measured atmospheric data at meteorological stations as inputs to physics-based radiative transfer programs like libRadtran. A comparison of measured and simulated data across the year demonstrates that using location-specific atmospheric profiles leads to significantly more accurate predictions of irradiances, spectral global and direct irradiances, and better captures the variability of clear skies regarding colour accuracy and appearance than simulations with default settings.
A VR-based workflow to assess perception of daylit views-out with a focus on dynamism and immersion
Authors: Cho Yunni , Karmann Caroline , Andersen Marilyne
Published: December 2023

Amongst the elements often overlooked in existing studies, dynamic movement and temporal changes in the content of views-out have been suggested to have a high potential to improve its perceived quality and occupant satisfaction. Moreover, in past and ongoing view-out research, most view quality indicators and representation methodologies primarily rely on static time-independent views and fail to acknowledge the importance of including dynamic features in the viewing content. To address this research gap, the present study introduces a novel VR representation workflow to accurately capture dynamic views in experimental settings. This study is the first to examine VR’s effectiveness in maintaining immersion and dynamism when studying daylit views-out, using original data based on human subjects. The results provide insights into VR’s suitability for representing office window views and assess a new workflow employing a dual fisheye lens and scale model to depict views in physically-based IVE.
Field study challenges: Customisation and personalisation during lighting control research in residences
Authors: Aries Myriam B C , Tabbah Alyaá , Fischl Géza
Published: December 2023

Residential lighting control can assist in creating a comfortable atmosphere, providing information, and supporting well-being. Field studies are used to investigate lighting control, but study protocol customisation or personalisation may be required due to actual life events and situations. An 8-week field study tested three protocols for effects on behaviour, well-being, and sleep patterns and was executed in 14 apartments during the winter. Light amount and timing were controlled: residents woke up with a dawn simulation, experienced lights turn-off as an indication to leave for work, and were prepared for bed during a dusk simulation scenario. Sleep trackers results showed later and more wide-ranged wake-up and bedtimes than assumed. As expected, the apartments’ different floorplans challenged comparable light exposure. Unexpectedly, several participants requested a reduced wake-up frequency and reported sleeping elsewhere on Fridays and Saturdays. Everybody experienced a full dawn simulation, but some people left home soon after wake-up, calling for lighting control customisation. Real-time field applications may demand a certain level of customisation or personalisation, affecting intentions and results. Discussing and documenting (un)intentional adjustments during final interviews and in scientific publications can benefit in explaining findings and further research.
Indoor thermal and visual well-being of people with autism: preliminary results from a field study in Denmark
Authors: Zaniboni L , Khanie M Sarey , Toftum J
Published: December 2023

The literature contains very little knowledge regarding the indoor well-being of people with autism spectrum conditions (ASC). Though, when dealing with higher autism levels and specific co-morbidities, the lack of autonomy of potential subjects makes standard comfort studies difficult or even impossible. As part of the EU-funded project “SENSEwellbeing”, the present paper shows the preliminary results of a field study on the indoor thermal and visual well-being of non-autonomous people with ASC, performed in a Danish care-center. Due to the fragility of the subjects involved and ethical issues related, we had to overcome several challenges. A determining example is the limited possibility to directly involve the subjects and make interventions in their private spaces in comfort-related experiments. For this reason, the caregivers working in the facility were involved in a semi-structured interview to indirectly characterize the thermal and visual preferences of subjects. Additionally, short- and long-term measurements of indoor quantities were taken in common rooms and empty living spaces. The interviews’ outcomes were linked to the environmental measurement, allowing a preliminary characterization of the adequacy of indoor design in terms of well-being of non-autonomous people with ASC. The study highlights the differences in perception of thermal and visual environment among people with ASC, and the necessity to find solutions to more directly involve non-autonomous subjects in studies on the indoor environment. The present research may also inspire other studies with people with special needs, whose comfort perception would otherwise be challenging to collect.
Simulation workflows in multi-objective lighting design optimisation for human well-being and building performance metrics: a scoping review
Authors: Tabbah Alyaá , Aries Myriam B C , Moscati Annika , Johansson Peter
Published: December 2023

Lighting in the built environment has effects on different aspects, ranging from building performance in terms of costs and energy consumption to human well-being in terms of thermal comfort, visual effects, and beyond-vision effects. Buildings optimised for specific performance metrics rarely consider performance aspects simultaneously, leading to sub-optimised, unbalanced, or non-trade-off solutions. Therefore, multi-objective optimisation has been more commonly used to overcome conflicting performance objectives. Recently, metrics to quantify light effects beyond vision became available, but it is unclear if and how they are integrated with other existing building performance metrics. A scoping review investigated the state-of-art in multi-objective lighting design optimisation regarding building performance and human well-being focusing on performance metrics, simulation workflows, and the overall information flow. The search in Scopus and Web of Science databases resulted in 89 journal articles and conference papers, and the 21 papers reaching the highest optimisation level were discussed. The information extracted was categorised into optimisation metrics, levels, and design variables. The results show that none of the papers combines visual and beyond-vison effects with other building performance metrics.
Vertical Sky Component (VSC) and daylight regulation compliance by the EN 17037 and BFS 2011:6 standards
Authors: Czachura A , Gentile N , Kanters J , Wall M
Published: December 2023

This paper explores the relationship between the Vertical Sky Component (VSC) metric and the European and Swedish daylighting regulations. VSC, a static geometrical metric, is considered a useful early indicator of indoor daylighting, as it is insensitive to late-stage design details such as material properties and internal layout. However, its relationship with modern building daylighting legislation has not been established. To address this gap, the paper investigates the relationship of VSC and daylight compliance by static and dynamic methods through simulations of a ‘shoebox’ room with varying Window-to-Floor Ratios (WFRs) and external obstruction dimensions. The results demonstrate that VSC has a large effect on daylighting compliance and can be a useful early planning tool. The study concludes that using VSC as a daylighting indicator in the urban planning process can lead to improved early design routines for better daylight compliance in the late design stages. Future work should aim to establish VSC performance thresholds.
Are the next-generation households ready for the energy transition? A survey on their positioning and practice with energy management tools
Authors: Antonini E , Marchi L , Gaspari J
Published: December 2023

In the last decades, significant effort has been put towards technological advancement in housing for energy transition. Massive retrofitting actions have been called for, and innovative technologies for smart energy management at home have been deployed. However, undesired energy trends in housing suggest that relevant factors have been neglected. Among these, increasing importance is now given to occupants’ behaviour, and their capacity to interact with energy management devices available in dwellings. This study investigates what is the position of next-generation users on energy transition at home. Two years ago, the authors launched a survey to explore people’s awareness of energy use practices, interaction with metering devices, and user motivation to change when informed. As a pilot survey, over 300 people from the academy were involved to see what was the position of a sample which was supposed to be informed more than the average, in Italy. The test yielded early outcomes on how people become more interested to change as they gain knowledge and are offered suggestions. Despite the expectations, the sample’s level of awareness was low. This suggested that a more user-centred approach is needed for wide-scale progress. Especially results from the youngest were below prospects. The questionnaire was relaunched to examine if the pandemic, energy crisis and latest news on climate change have affected positions of the youngsters. A testing session involving university students was performed, and results have been compared with the previous. As a result, reflections on the energy use patterns of the next-generation households are provided.
Is there an optimum balance between indoor environment, energy consumption and health?
Authors: Larsen T S , Rohde L , Jensen R L , Larsen O K
Published: December 2023

This study investigates the pros and cons of passive strategies in the indoor environment (IE) in relation to energy consumption (EC). It is widely accepted that IE improvements often require energy, particularly for thermal and atmospheric IE. As a result, demands for energy savings might compromise the indoor environmental comfort and health. However, the energy consumption can be reduced by introducing passive measures both regarding temperature and ventilation rates. To investigate this, measurements of temperature and ventilation rates were carried out in eight newly built single-family homes and four renovated single-family homes in a Danish context for three years. The study analyzes the effect of passive cooling using different types of solar shading. The findings show that external solar shading can effectively reduce high temperatures without additional energy consumption for cooling in a Scandinavian context. Also, the difference between mechanical and natural ventilation on CO2 levels in bedrooms and children’s rooms in relation to sleep quality are analysed. Here the results show, that natural ventilation is insufficient to ensure healthy sleeping conditions when it comes to proper ventilation rates and air quality. Supplemental ventilation by either window airing or mechanical aid is necessary.
Method to assess the integration of personalization, stimulus and environmental design principles in school classrooms
Authors: Piderit-Moreno María Beatriz , Leighton Javiera , Chandia Valentina , Perez-Fargallo Alexis
Published: December 2023

Studies have shown that a series of architectural factors of the physical learning environment affect the educational experiences of students in schools, particularly learning and well-being. This study proposes a method to holistically assess school classrooms considering three design principles: personalization, stimulus, and environmental. An evaluation matrix has been prepared considering 40 architectural factors, which are categorized into three ranges to generate a score and show their level of compliance. This was applied to a sample size of 30 classrooms from 23 Chilean schools. A classification was generated using the compliance levels, determining deciles and quartiles to set ranges appropriate to local realities along with three classroom classifications: insufficient, sufficient, and satisfactory. This classification proposes a starting point that can evolve as factors in the classroom improve or other cases are incorporated into the database. The method can be replicated in other contexts because it allows identifying which design parameters need to be improved or integrated into school classrooms.
Carbon budget for national building stock life-cycle emissions: a novel approach
Authors: Alaux N , Lackner T , Nabernegg S , Truger B , Röck M , Steininger K W , Passer A
Published: December 2023

Following the Paris Agreement, many countries such as Switzerland or Denmark have derived carbon budgets for their national building stock to support local policies by creating benchmarks. The aim is to calculate a quota for carbon emissions that a country can spend on its building stock by 2050 to ensure that it stays within a 1.5°C trajectory. The underlying allocation principle almost exclusively follows this procedure: (i) allocating the global budget to the national level, (ii) further allocating the national budget to the sectoral level, and (iii) to the building stock level (or even further down to the district or building level). However, this procedure of budget allocation does not do justice to the cross-sectoral and international nature of the national building stock’s life-cycle emissions. We propose a new approach for consistent, building stock-specific carbon budgets and demonstrate the proposed methodology for Austria. Adopting this approach for the building stock of other countries would enable consistent carbon budgets that reflect the field of action buildings for climate change mitigation.
Reuse practices in building construction: proposition of a life cycle assessment methodology and application to a case study in Switzerland
Authors: Frossard M , Lasvaux S , Petetin F , Gross L
Published: December 2023

This paper presents a life cycle assessment (LCA) methodology for evaluating the environmental impacts of reuse in building projects and apply it to a case study in Switzerland with 11% of reused components in its total mass. The results show that the life cycle GHG emissions on the construction domain that includes modules A1 to A4, B4, and C1-C4, are 487 kg CO2-eq./m2. In the other hand, the indirect effect of reuse lead to avoided GHG emissions of 76 kg CO2-eq./m2. At the level of a product’s supply chain, the analysis demonstrates a significant reduction in the embodied impacts of the reused components compared to newly manufactured ones. The potential benefits from avoided manufacturing and waste management depend on the type of material that is reused.
Stepwise renovation of buildings: what to refurbish first to minimize life-cycle carbon emissions?
Authors: Priore Y D , Schulthess L , Schwab S , Rollo D , Jusselme T
Published: December 2023

To tackle the upcoming renovation wave, this work evaluates renovation strategies with a life cycle GHG emissions perspective and includes time and sequencing in the decision-making process. A case study is used to conduct a full life cycle assessment of renovation strategies in line with the Swiss normative context. Improvements in the operational energy consumption are evaluated with an energy model using the software Lesosai and considering the normative limits from the SIA 380/1. GHG emissions are calculated using the Swiss KBOB data inventory and in line with the SIA 2032 methodology. The renovation measures are then examined individually with the carbon payback time indicator and strategies with cumulative emissions over time in contrast to carbon budgets. Results show that the sequence of the refurbishment steps can increase or decrease cumulative GHG emissions of ca. 30% over the lifetime of the building. Changing a fossil-fuel based heating system is the most impactful measure and must happen as soon as possible. Switching to decarbonized heating systems reduces the carbon effectiveness of subsequent renovation measures but poses the question of energy availability. Fully renovating a building but delaying the change of heating system by only 7 years can compromise the achievement of the carbon targets.
The GHG Emission Timeline – Integrating sustainability assessment into the early building design stage
Authors: Hischier I , Walker L , Piccioni V , Borkowski E , Galimshina A , Schlueter A
Published: December 2023

To address the challenges of integrating sustainability assessment such as life cycle assessment (LCA) in the early building design stage, we propose a new concept: The Greenhouse gas (GHG) Emission Timeline. The concept is derived from researching robustness assessment methods and personal experiences from teaching. Rather than aggregating environmental aspects into a single number, with the Timeline we want to highlight the temporality of GHG emissions in the context of ongoing transformation processes. Similarly to the previously proposed Material Pyramid for comparing the CO2 footprint of different materials, the Timeline is a pedagogical tool to visualize quantities, dynamics, and uncertainties aiming to provide a common ground for discussing sustainability in the early building design stage. The Timeline is compiled in a few simple steps with readily available resources. Hence, it does not need prior expert knowledge. The concept, as well as the first application examples of the Timeline from an architectural design studio at ETH Zurich are presented and discussed. By using GHG emission calculations for the compilation of a historic timeline, students created new lenses that addressed sustainability from a holistic viewpoint beyond GHG emissions.
Building within planetary boundaries: setting and assessing absolute sustainability targets at the building level
Authors: Francart N , Clausen C A , Bjørn A , Birgisdottir H
Published: December 2023

The planetary boundaries (PBs) are a widely used framework defining a “safe operating space” for environmental sustainability at the global level. However, they do not straightforwardly translate into indicators applicable in a building project. This paper proposes a procedure to set and assess absolute sustainability targets related to the PBs in a building project, exemplified in the case of Denmark. The first step is to ensure that the targets and the assessment method use comparable indicators. Common building life cycle assessment (LCA) tools use impact categories that do not directly match the PBs. Two options are considered to address this issue. Dedicated characterization factors can be used to convey LCA results in indicators consistent with the PBs. Alternatively, PB targets can be converted into LCA impact categories. Then, several distributive justice principles are reviewed to allocate a share of planetary sustainability targets to an individual country, to the housing sector within that country, and to an individual project. We argue that principles that conserve existing unsustainable paradigms are not appropriate to set planetary sustainability targets, and propose a novel approach for sectorial allocation based on sufficientarianism and “decent living” scenarios. Finally, challenges related to the assessment of these targets are highlighted. In particular, the paper draws attention to differences in system boundaries between the LCA and the targets.
Mitigating carbon emissions of single-family houses: Assessing the need for a limit value
Authors: Tozan B , Nielsen L H , Hoxha E , Birgisdóttir H
Published: December 2023

Reducing carbon emissions in the global building and construction sector is a crucial part of achieving climate targets. Laws that aim to limit the carbon emissions of new buildings have yet to be implemented on a larger scale, although some nations already have thresholds. These thresholds may not be sufficient to mitigate carbon emissions, and not all types of buildings are obliged to comply with them. In the case of Denmark, single-family houses (SFH) are not required to not comply with a limit, although they represented approximately 17% of all newly built areas from 2010 to 2022, indicating significant resource use and associated carbon emissions. This study aims to establish sufficient background data to support the need for implementing a limit value for SFHs in building regulations to ensure necessary reductions in carbon emissions. The study finds that the life cycle carbon emissions of Danish SFHs vary between 5.6 and 13.2 kg CO2e/m2/year, showing that compliance with the current limit value of larger buildings is possible and that a reduction of more than 50% in carbon emissions is possible. However, currently, there is no intentional investigation or achievement of potential carbon emissions in the construction industry. The study’s findings inform policymakers that a limit value for SFHs must be introduced no later than 2025 to initiate the necessary reduction of carbon emissions.
Turning dynamic LCA principles into practice
Authors: Andersen C E , Sørensen C G , Jensen O M , Hoxha E , Rasmussen F N , Birgisdóttir H
Published: December 2023

The building and construction sector quantifies the environmental impacts of buildings using the Life Cycle Assessment (LCA) method. To put LCA into practice often simplified application of the LCA method is used, without considering timely aspects. Instead, the method dynamic LCA includes timely aspects, which are more complex in the modeling and thus difficult to apply. To investigate the consequences of using the dynamic LCA method, this study develops a tool that takes data available in a simple LCA tool that follows the standardized LCA method and calculates dynamic LCA results. The tool reimplements the calculation engine from the simple LCA tool and adds the more complex aspects of dynamic LCA afterward. Doing so makes it possible to add other complex methods to the original calculation engine to help investigate more complex methodological aspects in the future.
The potential of agricultural residual waste as building material in South Sweden
Authors: Kanters Jouri , Kulsomboon Montanun , Bruijn Paulien Strandberg-de
Published: December 2023

A literature review and statistical analysis of the potential of agricultural residual waste as building materials in South Sweden was carried out. This data showed that there is a clear capacity for the use of mainly straw-generating crops as building materials in the region.
The Urban-Industrial metabolism: contribution of waste recycling to the circular economy objectives within the construction sector
Authors: Komkova A , Habert G
Published: December 2023

The construction and buildings sector is facing an urgent need to reduce GHG emissions and ensure efficient resource utilization while minimizing waste in order to comply with climate change policies and circular economy initiatives. Alkali-activated materials, as an alternative binder to CO2-intensive conventional cement, show potential in utilizing waste streams from urban environments in their production technology, thereby reducing CO2 emissions. This study examines two waste streams generated in Switzerland: incineration ashes from municipal solid waste treatment facilities and mineral wool waste from building stock renovation and demolition activities. Geospatial analysis is combined with LCA methods to assess optimal scenarios for waste recycling, utilizing a multi-objective optimization framework based on mixed integer linear programming. The objectives are to minimize the environmental impacts and costs associated with alternative supply chain networks, thereby identifying optimal locations for waste pre-treatment and concrete manufacturing. The proposed scenarios demonstrate reductions of 56% in global warming potential and 29% in costs when compared to the business-as-usual scenario of conventional cement concrete use and waste landfilling. Results show that recycling of urban waste streams in alternative concrete can reduce GHG emissions of industry and heavy transportation sectors by 0.46 mt. CO2 eq. by year 2030, equivalent to 23% and 4% of the Swiss carbon budget reduction targets for these sectors.
A Danish model of building macro-components to promote circularity
Authors: Francart N , Gummidi S R B , Hoxha E , Birgisdottir H
Published: December 2023

A better understanding of the material composition of the existing building stock is important for the development of circular economy strategies in the building sector. This paper presents a recently developed model to map the types and amounts of various materials in existing buildings in Denmark, with a high level of detail at the level of components rather than just material types. The model is meant to enable a detailed description of the building stock and a consideration of how components could be reused. Building properties are imported from the Danish national building registry (BBR) and processed into a relational database. Properties are combined with information on past construction techniques from architecture handbooks to estimate the most likely macro-components (types of wall, roof, etc) used in each building, and dimension these components. Material amount estimates from the model are compared with previous estimates as well as with material inventories from case study buildings. While the open-source model currently lacks accuracy, it is intended to be easily modifiable, and can support continuous improvements of the estimates based e.g. on new information from material passports, waste treatment facilities or remote sensing data. The paper discusses future opportunities to improve the model’s accuracy and use it to help develop circularity strategies and complement on-site inspections to overcome barriers to circularity.
PixelFrame: A reconfigurable, precast, post-tensioned concrete structural system for a circular building economy
Authors: Donovan I , Schnitzler J , Lee KJ , Wongsittikan P , Liu Y , Mueller CT
Published: December 2023

The demand to build for a growing urban population conflicts with the need to reduce the AEC (Architecture, Engineering and Construction) sector’s contributions to global CO2 emissions. Structural systems are a key factor in this challenge, as they contribute substantially to a building’s mass and are typically overdesigned. In this paper, we present PixelFrame, a new precast concrete structural system that is algorithmically designed to use less carbon upfront and be reused across multiple lifecycles. We achieve a high reuse potential for structural elements through building load demand analysis, a segmental externally post-tensioned design, and an integrated optimal assignment strategy. In addition to improving reuse potential, a segmental optimization strategy also yields higher efficiency in comparison to traditional prismatic concrete structural elements. The detailing of concrete mixes is informed by a statistical analysis of anticipated building load demands and a custom clustering asymmetric distance function and clustering algorithm. Compared to previous work in this area, our contribution is original in its bidirectional algorithmic approach; both the target building structure and the circular material inventory are computationally generated to achieve versatility while minimizing emissions.
Projected energy savings of a 3D printed selective heat transfer facade
Authors: Seshadri B , Morroni D , Hischier I , Masania K , Schlueter A
Published: December 2023

Dynamic building facades offer untapped potential for reducing building energy consumption and emissions. However, there is currently a lack of suitable technologies for bespoke components for new and retrofit applications. In previous work, we developed a 3D printed polymer facade component that selectively acts as a thermal conductor or insulator depending on outdoor and indoor conditions. Our experiments demonstrate that the element can achieve effective thermal conductivities as low as 0.03 W/mK and as high as 28 W/mK in insulating and conducting modes. In this work, we assess the potential impact of this technology on reducing heating and cooling energy demand. We conducted a parametric analysis of ten physical characteristics of the facade component. Then, we simulated the façade component employed in 270 building typologies and climate combinations. Our results indicate annual energy reduction of up to 80 kWh/m2 (heating) and 15 kWh/m2 (cooling) for building typology-climate combinations that can benefit the most from this technology.
A benchmark for the simulation of meshed district heating networks based on anonymised monitoring data
Authors: Boghetti R , Kämpf Jérôme H.
Published: December 2023

With the increasing interest in District Heating Networks (DHNs) as a potential solution to decarbonize heating, new simulation tools are being developed, raising the need for standardized benchmarks to validate their performance. Currently, the main benchmark used for DHN simulation models is the DESTEST, which consists in an inter-model comparison on the simulation of a toy radial network. However, no common benchmarks based on monitoring data from a meshed network exist at the moment, which would be needed to complement the DESTEST. To address this issue, this paper presents aggregated monitoring data from a medium-sized meshed DHN and proposes a benchmark based on this data. While aggregating the data and assuming steady-state conditions is not a suitable strategy for representing locally high dynamic behaviours, applying the benchmark to an existing simulation tool showed that the simulation results are coherent with the published monitoring data, as a low difference in temperature across most available sensors is found. The published data and the proposed benchmark aim to encourage the development of more accurate models for DHNs and to facilitate the evaluation of the performance of different simulation tools and enable their optimization, which will ultimately lead to more efficient and reliable DHNs.
Digitisation and analysis of energy data at municipal scale: an application to the municipality of Mendrisio
Authors: Belliardi Marco , Cereghetti Nerio , Bettini Albedo , Fusine Katia Dalle , Vismara Francesco , Sormani Michela , Briccola Mario , Martinenghi Gabriele , Muntaner Martin , Camponovo Paolo , Gottardi Filippo De , Pusterla Moreno , Gianolli Gabriele
Published: December 2023

The concept of Smart Cities has gained significant attention in recent years due to the increasing need for efficient energy management in urban areas. This paper describes a digital platform for the management of energy databases that aims to synchronize, update, and analyze different energy installations and uses in the municipality of Mendrisio 1according to the Smart City concept. The platform interweaves and compares various energy databases to ensure better efficiency in the use of thermal and electrical energy, as well as optimize the consumption and production of renewable energies. The geodigital platform created is capable of conducting energy assessments for the development of new district heating projects in the municipality and the creation of local energy communities. This paper presents the design and functionalities of the proposed digital platform, highlighting its potential for improving energy management in Smart Cities and facilitating the transition to more sustainable energy practices. The results of this study, financed by Swiss Energy together with Canton Ticino and AIM (Aziende Industriali Mendrisio), contribute to the growing body of research on digital technologies for energy management in urban areas and provide insights for policymakers and urban planners seeking innovative solutions for sustainable energy development.
“rubber band” - a practical support tool for integrated and resource-efficient early design in construction
Authors: Jenny David , Graser Konrad , Baldini Luca
Published: December 2023

The planning and construction sector is one of the world’s largest greenhouse gas emitters and has shown the lowest increase in productivity among economic sectors over the last century. Increasing complexity and performance requirements in building projects require the collaboration of ever more interdisciplinary project teams, but conventional planning tools often do not facilitate a tangible knowledge exchange between project stakeholders from different fields of expertise. This is most notable in early project phases when fundamental design decisions are made. To address this challenge, we introduce a flexible and expandable digital workflow using a single 3D-model to integrate and moderate expertise from multiple project stakeholders such as architects, structural engineers, energy planners, contractors, and future users. This workflow creates a “rubber band” between different interdependent design goals and constraints, offering an opportunity to negotiate and optimize design parameters early-on. The framework is an addition to conventional planning tools whose complexity and costs often prevent stakeholders in the building industry from embracing the potentials of the digital transformation.