bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of imbibition phenomenon in homogeneous porous medium model for oil recovery with temporal-fractional approach
Authors: Yadav Jyoti U. , Singh Twinkle R.
Published: December 2023

In this article, the phenomenon of countercurrent imbibition in a specific displacement method occurs within a dipping homogeneous porous medium. This phenomenon plays a vital role in the process of oil recovery, which motivates our analysis. To overcome the difficulties associated with the nonlinear partial differential equation governing the countercurrent imbibition phenomenon, we have been using two distinct methods: the natural transform decomposition method and the variational iteration transform method with their convergence analysis for solutions. These techniques give different perspectives and enable us to obtain approximate solutions. Notably, both the proposed methods demonstrate the potential for substantial production of oil during the secondary oil recovery process in the petroleum industry. The obtained results by the proposed methods show the efficiency in optimizing the oil recovery rate.
Effects of polarization direction, amplitude, and photon energy of linearly polarized laser on high order harmonic generation of C60
Authors: Yin Haifeng , Liu Dandan , Zeng Fanju , Chen Wenjing
Published: December 2023

The study of high-order harmonic generation (HHG) in confined quantum systems is essential for developing a comprehensive physical description of harmonic generation from atoms to bulk solids. Using the time-dependent density-functional theory, we demonstrate how the symmetry of the system modulates the generation of high-order harmonic in fullerene C60 molecules along different orthogonal directions, as well as the effects of amplitude and photon energy of a linearly polarized laser on high-order harmonics generation. We found that the generation of high-order harmonics perpendicular to the laser polarization direction (LPD) is related to the symmetry of molecules along the LPD and the symmetry of molecules perpendicular to the LPD. Within a certain parameter range, the cut-off energy is linearly proportional to the laser amplitude and the laser photon energy.
Thermochemical non-equilibrium hypersonic flow over a rectangular cavity embedded on a compression ramp
Authors: Redding Jeremy , Gamertsfelder Jacob , Bravo Luis , Khare Prashant
Published: December 2023

This paper reports a systematic computational investigation that elucidates the fundamental thermochemical non-equilibrium physics that occurs when air at Mach number of 11 encounters a rectangular cavity of aspect ratio L/D = 2.0 embedded on a 25° compression ramp. The mechanistic details of this highly complex flow phenomenon are obtained by solving the compressible form of the Navier–Stokes equations in two dimensions using a finite-volume open-source library. Chemical and thermal non-equilibrium processes are treated using a five-species, 12-reaction chemical kinetics, and a two-temperature model, respectively. Following a detailed validation and grid sensitivity study, two simulations are conducted, one with isothermal boundary conditions and the other with conjugate heat transfer (CHT) to identify the effect of energy transmission to the material on surface heat flux. Fast Fourier transforms and near-wall velocity profiles inside and in the neighborhood of the cavity are used to identify primary oscillatory modes and shear layer dynamics. Two new descriptive states defined as “states I and II,” representative of the minimum and maximum deflection of the shear layer, are used to discuss the dynamical behaviors in the cavity, including the separation region before the cavity, trailing edge effects, frequency analysis of probe data collected at several key locations, and the effect of CHT on surface heat flux. It is found that the flow features at the cavity's center strongly influence the separation upstream of the cavity, and the transrotational temperature near the cavity's trailing edge is strongly correlated with the oscillations of the shear layer.
Highly active nickel-loaded β-SiC nanowire catalysts for photocatalytic H2 production by water splitting
Authors: Wang Ying , Yang Shuai , Li Xiang , Huang Wei , He Zheng-fa , Fu Xian-liang , Zhu Li , Xu Man
Published: December 2023

Developing a highly efficient water-splitting photocatalyst for hydrogen production under visible light is urgent. In this study, β-SiC nanowire photocatalysts loaded with 0.01–0.1 wt. % nickel were prepared. Their microstructure and hydrogen production activity were studied. The catalyst with 0.05 wt. % nickel and a sacrificial agent Na2S–Na2SO3 shows the highest hydrogen production rate of 375.4 µmol g−1 h−1 since the loaded nickel prohibits the recombination of photogenerated electron–hole pairs in the system, which enhances the photocatalytic activity.
Modeling and comparative assessment of solar thermal systems for space and water heating: Liquid water versus air-based systems
Authors: Khan Sardar Muhammad Aneeq , Badar Abdul Waheed , Siddiqui M. Salman , Siddique Muhammad Zeeshan , Ul Haq Muhammad Saad , Butt Fahad Sarfraz
Published: December 2023

This work pertains to the transient modeling and comparative study of active solar thermal space and water heating systems using liquid and air-type solar thermal collectors as the main energy source. The study utilizes TRNSYS to simulate the two systems in the context of Taxila's weather data (located at 33.74°N, 72.83°E), with the goal of meeting peak space and domestic water heating demands of 20 kW and 200 lit/day, respectively. The liquid water-based system (S-1) is primarily composed of a liquid solar collector, thermal storage, an auxiliary heater, connections to the hot water supply, and the space heating load through a water–air heat exchanger. In contrast, the air-based system (S-2), employs a pebble bed storage to store heat extracted from the solar thermal air collector. The heated air is subsequently used directly for space heating and passed through an air–water heat exchanger for water heating. Dynamic simulations of both systems span the entire winter season, and various performance metrics, including solar fraction, primary energy savings, and solar collector thermal efficiency, are computed. The results revealed that at the same collector area, the liquid water-based system (S-1) shows a higher solar fraction than the air-based systems (S-2) while the primary energy savings of the S-1 resulted in lower values than S-2 at smaller collector areas (< ∼30 m2) but surpasses the S-2 with increasing collector size. The optimal collector tilt for both systems is determined to be 50°, while specific storage volumes corresponding to maximum primary energy savings are estimated to be 100 and 40 L/m2 for S-1 and S-2, respectively.
The phase translation of the fluid by shockwave in the hard-sphere model
Authors: Zheng Yue , Xu Junjun , Tang Ke
Published: December 2023

The dynamic phase transition of fluid has been specifically induced by the shockwave within the context of the hard-sphere model. Fundamental thermal and dynamic attributes of the fluid have been primarily examined, and the conditions following the Rankine–Hugoniot (RH) theory have been applied using the Euler equations. Due to the magnitude of the shockwave’s impact on the undisturbed equilibrium of the fluid, three archetypal states of excitation are manifested, encompassing liquid–liquid, liquid–solid, and liquid-coexistence states, categorized according to RH conditions subsequent to the influence of the shockwave. The characteristics of the fluid are portrayed employing the hard-sphere model, while the excited state of the fluid has been substantiated through an inquiry into the RH conditions and the generation of entropy. In consonance with the research, the excited state of the fluid exhibits a robust interrelation with its unperturbed equilibrium. The hard-sphere model stands as a suitable framework for examination of the shock-induced phase transition of the fluid.
A numerical model for simulation of two-phase flows interaction with flexible slender bodies
Authors: Wang Chao , Lin Pengzhi , Ren Bing
Published: December 2023

This paper introduces a fluid–structure interaction (FSI) model for simulation of the coupled dynamics between two-phase flows and elastic slender structures. This model is extended from the early FSI model for single-phase flows by Wang et al. [“A coupled flow and beam model for fluid–slender body interaction,” J. Fluids Struct. 115, 103781 (2022)] to two-phase flows with interfaces of two liquids or free surfaces between gas and liquid. To better capture the interface movement of the two-phase flows and the interaction with the deformable structure, a consistent mass and momentum flux scheme is developed to reduce the spurious oscillation of fluid velocities near the interface, especially in the lower density (e.g., air) region. The proposed model is validated by a series of two-dimensional laboratory experiments of flow impact on a deformable plate, demonstrating that the model has good capabilities of conserving mass and momentum during the process of plate deformation by impulsive flow forces. The model is also applied to the investigation of three-dimensional dam break flow impact on a column of elastic plates. The complex interaction between the plates and the flow is discussed based on the simulation results.
Signs of stress
Authors: Hoffmann Alex C.
Published: December 2023

Different conventions exist for the signs of normal and shear stresses in fluid dynamics. Understanding how stresses act in fluids is a key to understanding the entire subject of fluid dynamics, and if the stress sign convention is not clearly set out, the danger is that the student battles through the subject in constant confusion about signs. This paper explains the conventions used in some of the most popular textbooks, compares them, and discusses briefly the advantages and disadvantages of each convention and the ramifications for the Navier–Stokes equations.
Ceres, a window into how planets could harbor life
Authors: Neveu Marc
Published: December 2023

Exploration of the large asteroid by NASA’s Dawn mission reveals a puzzling, active, water-rich world.
Hybrid quantum algorithms for flow problems
Authors: Bharadwaj Sachin S. , Sreenivasan Katepalli R.
Published: December 2023

For quantum computing (QC) to emerge as a practically indispensable computational tool, there is a need for quantum protocols with end-to-end practical applications—in this instance, fluid dynamics. We debut here a high-performance quantum simulator which we term QFlowS (Quantum Flow Simulator), designed for fluid flow simulations using QC. Solving nonlinear flows by QC generally proceeds by solving an equivalent infinite dimensional linear system as a result of linear embedding. Thus, we first choose to simulate two well-known flows using QFlowS and demonstrate a previously unseen, full gate-level implementation of a hybrid and high precision Quantum Linear Systems Algorithms (QLSA) for simulating such flows at low Reynolds numbers. The utility of this simulator is demonstrated by extracting error estimates and power law scaling that relates

T
0

(a parameter crucial to Hamiltonian simulations) to the condition number

κ

of the simulation matrix and allows the prediction of an optimal scaling parameter for accurate eigenvalue estimation. Further, we include two speedup preserving algorithms for a) the functional form or sparse quantum state preparation and b) in situ quantum postprocessing tool for computing nonlinear functions of the velocity field. We choose the viscous dissipation rate as an example, for which the end-to-end complexity is shown to be

O
(

polylog

(
N
/
ϵ
)

κ
/

ϵ

QPP

)

, where

N

is the size of the linear system of equations,

ϵ

is the solution error, and

ϵ

QPP

is the error in postprocessing. This work suggests a path toward quantum simulation of fluid flows and highlights the special considerations needed at the gate-level implementation of QC.
Combining common heuristic sets for a new exhaustive usability evaluation of e-learning interface
design
Authors: Menad Nadia
Published: December 2023

With global school shut-downs due to the pandemic, in 2020 many educational institutions and universities were
making use of e-learning like never before, but designing lesson plans for a digital space came with its own set of challenges. In
most modern universities, education is still based on traditional learning methods and the teacher-centred physical classrooms.
However, with nationwide school closures, teachers had no choice but to turn to e-learning for solutions. Usability evaluation of
this kind of platform, therefore, has become essential, and a priority in the application development process. A set of usability
evaluation methods have been developed to allow specialists to systematically determine whether graphical interfaces are usable.
The usability assessment questionnaire is one of the most used methods and is intended to be answered by end-users of the
application. This method is preferred due to its simplicity and low demand for resources.

In this paper, a usability evaluation which combines existing work is presented. Based on existing heuristics, we
propose a new questionnaire for evaluating e-learning interface design. In addition, we illustrate two different methodologies for
evaluating e-learning interface design, and provide a quantitative rate, Usability Percentage (UP), which
complements the usual qualitative data provided by this kind of evaluation.
La mediación textual a partir de estrategias de reformulación
Authors: Nadal Laura , Thome Sarah
Published: December 2023

El Aprendizaje Integrado de Lengua y Contenidos o CLIL (por sus siglas en inglés, Content
Language Integrated Learning) constituye un enfoque ecléctico en el que la lengua meta se emplea como medio para la
enseñanza de contenidos de diferentes áreas. En este contexto, las actividades comunicativas de mediación propuestas por el Marco
Común Europeo de Referencia (MCER) cobran especial interés. Este estudio a pequeña escala compara, a partir de una actividad de
mediación lingüística de procesamiento textual, el rendimiento de dos grupos de alumnos de alemán como lengua extranjera
(DaF) de nivel A2-B1: uno inmerso en un programa CLIL y otro bajo un enfoque tradicional (grupo no CLIL). A
la luz del análisis de los datos se comprueba que los alumnos CLIL demuestran mayor recursividad en el empleo de estrategias de
reformulación en la presentación de un texto mediado. Igualmente, los datos permiten observar un efecto positivo en la integración
de la L1 en actividades comunicativas de mediación.
Can equine communication via audible exhales improve the welfare of therapy horses? – A pilot practice project
Authors: Naber Anna , Völk Magdalena , Hediger Karin , Zink Roswitha
Published: December 2023

Background: Human-animal interactions in human services are on the rise, with an increased focus on the welfare of animals involved as well as on client safety. Based on scientifically based training methods, it has been proposed that horses involved in therapy settings could benefit from learning proactive strategies to reduce stress. One possible strategy is audible exhale communication (AEC). Inviting horses to actively use this strategy with humans could enhance the welfare of horses in equine-assisted therapy (EAT), thereby increasing client safety.

Methods: A pilot project was conducted to test the feasibility of training 20 therapy horses to use AEC as a veto signal for an activity, while therapists responded to the signals. The number of audible exhales from the horses was compared between the initial and final training sessions. Furthermore, we tested whether age, years of training experience, and therapy experience served as moderating variables for the outcome. Additionally, qualitative observations were made by therapists working with the horses.

Results: It has become apparent that training the horses to use AEC was successful. After 6 months of training, the horses showed a significantly higher number of audible exhales than in the initial training session, with a large effect size. Neither age nor years of training or therapy experience was found to be a moderating variable. The horses were eagerly engaged with newly acquired tools. These showed fewer indications of stress, greater sense of relaxation, and more positive emotions.

Conclusion: Based on the findings of this pilot study, training horses to use AEC might be a feasible approach to reduce stress in horses working in therapeutic settings, increase client safety, enhance human-animal relationships, and open up new possibilities for improving the therapeutic process. This method is applicable to all horses, regardless of their age, training level, or experience in therapy. For future research, it would be interesting to replicate and extend the approach by addressing the aforementioned limitations and using a randomized controlled design to investigate the introduction and impact of AEC in a therapeutic setting and to gain more comprehensive insights.
Machine-learning Love: classifying the equation of state of neutron stars with transformers
Authors: Gonçalves Gonçalo , Ferreira Márcio , Aveiro João , Onofre Antonio , Freitas Felipe F. , Providência Constança , Font José A.
Published: December 2023

The use of the Audio Spectrogram Transformer (AST) model for gravitational-wave data
analysis is investigated. The AST machine-learning model is a convolution-free classifier that
captures long-range global dependencies through a purely attention-based mechanism. In this paper
a model is applied to a simulated dataset of inspiral gravitational wave signals from binary
neutron star coalescences, built from five distinct, cold equations of state (EOS) of nuclear
matter. From the analysis of the mass dependence of the tidal deformability parameter for each EOS
class it is shown that the AST model achieves a promising performance in correctly classifying the
EOS purely from the gravitational wave signals, especially when the component masses of the binary
system are in the range [1,1.5]M
⊙. Furthermore, the generalization ability of the model
is investigated by using gravitational-wave signals from a new EOS not used during the training of
the model, achieving fairly satisfactory results. Overall, the results, obtained using the
simplified setup of noise-free waveforms, show that the AST model, once trained, might allow for
the instantaneous inference of the cold nuclear matter EOS directly from the inspiral
gravitational-wave signals produced in binary neutron star coalescences
Revisiting coupled CDM-massive neutrino perturbations in diverse cosmological backgrounds
Authors: Pal Sourav , Samanta Rickmoy , Pal Supratik
Published: December 2023

Massive neutrinos are well-known to cause a characteristic suppression in the growth of structures at scales below the neutrino free-streaming length. A detailed understanding of this suppression is essential in the era of precision cosmology we are entering into, enabling us to better constrain the total neutrino mass and possibly probe (beyond)-ΛCDM cosmological model(s). Instead of the usual N-body simulation or Boltzmann solver, in this article we consider a two-fluid framework at the linear scales, where the neutrino fluid perturbations are coupled to the CDM (+ baryon) fluid via gravity at redshifts of interest. Treating the neutrino mass fraction f
ν as a perturbative parameter, we find solutions to the system with redshift-dependent neutrino free-streaming length in ΛCDM background via two separate approaches. The perturbative scale-dependent solution is shown to be in excellent agreement with numerical solution of the two-fluid equations valid to all orders in f
ν, and also agrees with results from CLASS to a good accuracy. We further generalize the framework to incorporate different evolving dark energy backgrounds and found sub-percent level differences in the suppression, all of which lie within the observational uncertainty of BOSS-like surveys. We also present a brief discussion on the prospects of the current analysis in the context of upcoming missions.
Simulation of High-contrast Polarimetric Observations of Debris Disks with the Roman Coronagraph Instrument
Authors: Anche Ramya M , Douglas Ewan , Milani Kian , Ashcraft Jaren , Millar-Blanchaer Maxwell A. , Debes John H , Milli Julien , Hom Justin
Published: December 2023

The Nancy Grace Roman Space Telescope Coronagraph Instrument will enable the polarimetric imaging of debris disks and inner dust belts in the optical and near-infrared wavelengths, in addition to the high-contrast polarimetric imaging and spectroscopy of exoplanets. The Coronagraph uses two Wollaston prisms to produce four orthogonally polarized images and is expected to measure the polarization fraction with measurement errors <3% per spatial resolution element. To simulate the polarization observations through the Hybrid Lyot Coronagraph (HLC) and Shaped Pupil Coronagraph (SPC), we model disk scattering, the coronagraphic point-response function, detector noise, speckles, jitter, and instrumental polarization and calculate the Stokes parameters. To illustrate the potential for discovery and a better understanding of known systems with both the HLC and SPC modes, we model the debris disks around Epsilon Eridani and HR 4796A, respectively. For Epsilon Eridani, using astrosilicates with 0.37 ± 0.01 as the peak input polarization fraction in one resolution element, we recover the peak disk polarization fraction of 0.33 ± 0.01. Similarly, for HR 4796A, for a peak input polarization fraction of 0.92 ± 0.01, we obtain the peak output polarization fraction as 0.80 ± 0.03. The Coronagraph design meets the required precision, and forward modeling is needed to accurately estimate the polarization fraction.
Quasi-classical motion of a particle in a bulk dissipative medium
Authors: Sazonov S V
Published: December 2023

A version of the quasi-classical approach is proposed, which makes it possible to describe the straight-line motion of a micro-particle in a bulk dissipative medium. From the side of the medium, the particle is acted upon by the force of viscous friction and the drag force, which are proportional to the velocity and the square of the velocity, respectively. In addition, an external conservative force is applied to the particle. The Green’s function of the particle and the quasi-classical coherent state in the form of a three-dimensional localized wave packet are found. It is shown that the translational motion of the wave packet is accompanied by a monotonic increase in the uncertainties of the particle coordinates up to certain maximum asymptotic values. Due to the drag force, these asymptotic uncertainties contain information about the corresponding initial uncertainties in the coordinates of the micro-particle, about its initial velocity, as well as about the external conservative force.
Exploring assumptions for air infiltration rate estimates using indoor radon in UK homes
Authors: Symonds P , Chalabi Z , Petrou G , Wang Y , Hutchinson E , Milner J , Hsu S , Davies M
Published: December 2023

Radon, a known carcinogen, is one of the most commonly monitored indoor contaminants. This paper utilises findings from a previous study on indoor radon measurements in United Kingdom (UK) homes to explore the UK Government’s Standard Assessment Procedure (SAP) assumptions for air infiltration rates. These assumptions are important as they are used to assess the energy performance of dwellings and compliance with building regulations. Indoor radon data is aggregated by 16 combinations of home energy efficiency measures (loft and wall insulation, glazing upgrades and draught proofing) and fitted using a simple analytic radon model. We find indoor radon to be inversely proportional to air change rate and proportional to a fit coefficient, k, of 42.2 ± 3.1 (95% Confidence Interval (CI)). We also show that the assumptions within SAP used to estimate home infiltration rates can be modified to include the impact of home energy efficiency which improves the fit (R
2 from 0.38 to 0.51) to the radon data. This work provides evidence to help improve assumptions regarding the effects of home energy efficiency on infiltration rates.
Autodigit-RAD: Towards an automation of the radon’s concentration dataflow in a new and innovative building
Authors: Rey J F , Cesari M , Schoenenweid M , Montet F , Gandolla M , Bonvin L , Bourquin V , Jacot C L , Roman J , Mahecha S Duque , Moreno S Aguacil , Hennebert J , Pernot J Goyette
Published: December 2023

Radon is a noble, natural, and radioactive gas coming mainly from the ground which might accumulate indoors and lead each year to 200-300 deaths from lung cancer in Switzerland. A brand new and innovative living lab will be built as of 2023 in Fribourg (Switzerland) which will allow to tackle the built environment and the relationship with its occupants. Among a large panel of environmental parameters, radon gas will be continuously monitored under and around the building as well as in the building envelope. This paper aims to present the overall process of the radon dataflow: 1) design of the sensor probes, 2) implementation of the radon sensor probes in the ground and 3) go-live with the data sharing platform with the building users. Such an infrastructure will bring the opportunity to researchers to lead new and innovative radon-related research.
Investigation of personal air pollution exposures and occupants’ fresh air demands in two office buildings in Switzerland
Authors: Yun S Y , Licina D S
Published: December 2023

This study assessed personal exposures to indoor air pollutants in office environments with dynamic occupancy profiles. A two-week field campaign was conducted in two Swiss office buildings, examining three target areas in each building. We measured air temperature (T), relative humidity (RH), CO2, PM2.5, and PM10 levels at three stationary locations of each target area. Four office workers carried a customized vest to monitor personal CO2 and PM levels near their breathing zone. Using smartwatches, the workers completed hourly surveys about their activity profiles and preferences for outdoor air. We found that CO2 and PM10 concentrations were 1.2–1.3x and 1.8–2.5x higher, respectively, in the personal monitor compared to stationary sensors. Occupants had higher personal CO2 levels during sitting activity and higher personal PM levels during standing activity. Lunch/coffee/call activities were associated with discernible peaks of personal exposure to CO2, PM2.5, and PM10. The higher T coupled with lower RH measured at the personal level was associated with higher occupant demands for outdoor air.
Hybrid ventilation in residential and office buildings
Authors: Hoffmann C , Hauri C , Primas A , Dorer V , Huber H
Published: December 2023

This project is focused on hybrid ventilation systems, a combination of natural and mechanical ventilation in residential and office buildings. Especially in dwellings hybrid ventilation systems are quite common. For instance, this can be the frequently occurring combination of exhaust fans in bathroom and toilet and / or a range hood in the kitchen with window ventilation in the other rooms. Currently, these systems are part of the planning reality, however, there are neither planning aids nor focused building standards available. A recently completed research project documents the state of the scientific knowledge, identifies most common planning challenges, and thus provides the basis for future planning aids for hybrid ventilation. This paper sets out to define the term “hybrid ventilation”, presents the most common hybrid ventilation systems in Switzerland and gives planning guidelines for current components of hybrid ventilation systems.
Potential of physical barriers integrated with personal exhaust ventilation in decreasing airborne infection risk for people
Authors: Nateghi S K , Kaczmarczyk J , Lipczynska A
Published: December 2023

A new approach was presented in this study that combines partition screens and personal exhaust ventilation to reduce the risk of infection transmission among individuals seated closely together at short distances. The effectiveness of this approach was experimentally studied in a test room using N2O as a tracer gas to simulate pollutant dispersion from an infected person. The concentration of N2O was measured at three different points near the source location. The results showed that using partitions alone might increase the probability of virus transmission compared to the case without partitions. However, combining personal exhaust with partitions significantly reduces the infection risk.
Integrated assessment of buildings visual and thermal performance with translucent bricks
Authors: Hassoun L , Khayatian F , Ganobjak M , Wernery J , Vivian J
Published: December 2023

In response to the growing need to reduce building energy consumption while ensuring occupants’ visual and thermal comfort, the Building Energy Materials and Components Lab at Empa developed a high-performance translucent construction element based on aerogel-filled glass bricks. The translucence and thermal insulation characteristics of this brick allows the exploration of different configurations of opaque and transparent surfaces to improve the integrated visual and thermal performance of the indoor environment. This paper presents a workflow to simulate the building performance in order to investigate the effects arising when the mentioned bricks are embedded in the building envelope. Simulations were conducted on a reference building in a continental climate assuming different orientations and window-to-wall ratios. Results show a clear trade-off between minimizing the cooling demand and maximizing occupant visual and thermal comfort. The application of the brick on the northern façade exhibited the best trade-off in terms of energy and comfort.
Use of digital 3D urban models for view evaluation in building envelope design
Authors: Majima R , Koga Y , Okamoto T , Jarrin F , Kojima Y , Ohki C , Kawano A , Takagi N
Published: December 2023

A feature of digital 3D urban models is that they provide semantic information on various objects in urban space. This paper proposes a basic framework for obtaining visual information about the external conditions of a building to be designed using a 3D urban model. Ray emission and collision detection are used in a game engine to identify the type and distance of objects surrounding the building in the 3D urban model. Tagging the objects with their semantics identifies their type such as sky, building, road, greenery and so on. This paper also proposes setting two different viewpoints at the façade and the interior to consider the building design and the indoor visual environment design from both aspects of the whole building and individual rooms.
Students’ Perceptions of acoustic comfort in traditional and flexible learning environments: a study in Chile
Authors: Ipinza-Olatte Constanza , Piderit-Moreno María Beatriz , Bluyssen Philomena , Trebilcock-Kelly Maureen
Published: December 2023

The acoustic quality of educational spaces has an important impact on well-being and occupant performance. This study investigates noise perception and hearing ability among primary students in traditional learning environments (TLE) and flexible learning environments (FLE). A survey was conducted in Santiago de Chile, involving 21 teachers and 315 children from 13 schools, to gather responses on acoustic comfort. Additionally, a checklist was used to inspect the physical spaces. The analysis of students’ responses revealed that self-reported complaints related to indoor environmental quality (IEQ) predominantly focused on noise discomfort in both types of learning environments. A significant relationship was found between the type of space and children’s perception of noise from their peers. Although students in TLE reported greater annoyance with noise, those in FLE experienced slightly more listening problems. Interestingly, in FLE, students with an occupancy density greater than 2.1 m2 per student did not feel bothered by the noise produced by their classmates speaking. Although further research is needed, these findings highlight the crucial role of acoustic conditions in ensuring the comfort and hearing abilities of young students. Adequate acoustic treatment and enough space per student are important to mitigate potential indoor noise issues.
Enhancing personalised thermal comfort models with Active Learning for improved HVAC controls
Authors: Tekler Zeynep Duygu , Lei Yue , Dai Xilei , Chong Adrian
Published: December 2023

Developing personalised thermal comfort models to inform occupant-centric controls (OCC) in buildings requires collecting large amounts of real-time occupant preference data. This process can be highly intrusive and labour-intensive for large-scale implementations, limiting the practicality of real-world OCC implementations. To address this issue, this study proposes a thermal preference-based HVAC control framework enhanced with Active Learning (AL) to address the data challenges related to real-world implementations of such OCC systems. The proposed AL approach proactively identifies the most informative thermal conditions for human annotation and iteratively updates a supervised thermal comfort model. The resulting model is subsequently used to predict the occupants’ thermal preferences under different thermal conditions, which are integrated into the building’s HVAC controls. The feasibility of our proposed AL-enabled OCC was demonstrated in an EnergyPlus simulation of a real-world testbed supplemented with the thermal preference data of 58 study occupants. The preliminary results indicated a significant reduction in overall labelling effort (i.e., 31.0%) between our AL-enabled OCC and conventional OCC while still achieving a slight increase in energy savings (i.e., 1.3%) and thermal satisfaction levels above 98%. This result demonstrates the potential for deploying such systems in future real-world implementations, enabling personalised comfort and energy-efficient building operations.
Scalable decarbonisation using automated operation optimisation
Authors: Baranski M , Bode G , Nienaber F , Bruhn B , Grant P , Ziegeldorf H
Published: December 2023

One of the biggest challenges in facing the climate crisis is the decarbonization of the large and diverse building stock. A reduction of carbon dioxide emissions can be achieved by technical measures and engaging the building occupants to adapt their behaviour. Among the technical measures, implementing predictive control as an upgrade of the existing heating, ventilation, air conditioning and cooling system is especially promising as it allows reductions at potentially low running cost. However, the effort for adapting, implementing and deploying these methods to fit specific buildings and scenarios is high and requires special domain knowledge, hindering the wide-spread application. In this paper, we present a highly automated and data-driven implementation process utilizing an open-source container orchestration system, and the results from real-life case studies in existing buildings in which predictive control was retrofitted. Additionally, occupant information systems were installed in the buildings for increasing transparency about the building performance and the effect of the occupants’ behaviour. The shown method is useful for reducing the time required and manual effort for implementing new control strategies, and thus reducing carbon dioxide emissions while simultaneously increasing thermal comfort and air quality.
Automated data labeling of building automation systems using time series data and conditional probabilities
Authors: Maghnie M , Stinner F , Kümpel A , Müller D
Published: December 2023

As energy efficiency demands increase, buildings get smarter, and the amount of data to analyze grows, where each building device may generate multiple data streams. These extensive quantities of monitoring data serve as a great opportunity for detecting anomalies in building automation systems and for optimizing their control. However, each building usually uses a custom format for data labels, therefore requiring an individual data label analysis per building. This makes the conceptually manageable task of detecting energy systems from the raw data increasingly complex and error-prone, which is a further hurdle that any building operation optimizer must resolve. This paper presents a methodology for automatically categorizing and labeling raw monitoring data from building automation systems. Using statistical features of the data, the method checks which data streams follow which known building operation rules and patterns. Therefore, an initial labeling of the data streams takes place. Furthermore, examining the correlation between the data streams indicates possible related system components using the concept of conditional probability. As a use case for the methodology, unlabeled data from a real building automation system are examined. The results show that, using unlabeled time series, data types from certain sensors and actuators can be reliably identified. The proposed methodology could therefore simplify the implementation of energy applications such as operation optimization and fault detection of building automation systems
Greenery, sun exposure and ventilation of public spaces in residential units in Tirana
Authors: Tashi P. , Tola A. , Tashi A.
Published: December 2023

When referring to residential units, well-ventilated and lit green spaces are considerable contributors to increasing the quality of life of its residents. This research aims to analyse the transformation of the spaces between the buildings in the context of Tirana, by simultaneously stressing the key distinctions between their original design and their current situation. A typical residential complex close to Tirana’s centre is used as a case study to further illustrate this topic. The research starts with a qualitative morphological analysis of greenery, lighting, and ventilation condition of public space between residential units. It expands with a quantitative-comparative analysis, based on questionnaires conducted with residents, as well as by-passers of the selected residential area. The apparent reduction of greenery in spaces between residential units was one of the study’s most obvious findings. Originally intended as green spaces, public spaces between residential units have since been used for a variety of purposes, including being occupied by extensions of buildings or open parking lots. These interventions have resulted in a shift of usage to the inner streets of the residential block, which are now used for vehicles and are no longer either quiet or exclusively dedicated to pedestrians. The overall value of this space has been transferred from a straightforward recreational area to an economic space. Consequently, designers and urban planners have a responsibility to re-evaluate the significance of green surfaces, in addition to the shape and orientation of the residential unit as a foundation of sustainable urban development.
Inequalities in exposure to indoor environmental hazards across England and Wales – can more energy efficient homes help?
Authors: Ferguson L , Mavrogianni A , Symonds P , Davies M , Ruyssevelt P
Published: December 2023

Housing is an important modifier of outdoor environmental hazards due to features such as the amount of passive and active ventilation a dwelling receives, the proportion of the façade that is glazed and the building’s thermal insulation levels. Using Artificial Neural Networks based on an indoor building physics model, we simulate indoor temperature and air pollution concentrations in ~15 million English and Welsh dwellings and assess how exposure to indoor hazards varies for different population groups. The model is derived using simulations from the dynamic thermal modelling tool EnergyPlus, taking a spatially-distributed housing stock as input. Results are linked to the latest 2021 Census data on area-measures of population demographics to assess if vulnerable subgroups bear a disproportionate risk from indoor environmental hazards. We find neighbourhoods in England and Wales with a higher proportion of infants, ethnic minorities and income-deprived populations experience higher two-day maximum indoor temperatures in summertime; whilst more ethnically diverse areas have elevated annual average indoor concentrations of outdoor-sourced PM2.5. Areas with a higher proportion of those aged 65+ had a lower standardised indoor temperature (SIT) in winter, increasing the risk of fuel poverty. We then implement a stock-wide, home energy retrofit, in line with national decarbonisation targets. Results suggest energy-efficient building interventions may exacerbate heat inequalities without the provision of external shading, but improve population exposure to winter indoor temperatures and indoor concentrations of ambient-sourced PM2.5.
People flow management in a healthcare facility through crowd simulation and agent-based modeling methods
Authors: Locatelli M , Pellegrini L , Accardo D , Sulis E , Tagliabue L C , Giuda G M Di
Published: December 2023

The study investigates the optimization of user flow and space management in a hospital located in Turin by simulating activities and patient flows of the blood drawing center. The simulation aims to verify the maximum number of people allowed to occupy the spaces simultaneously, manage user flows, and verify compliance with COVID-19 pandemic restrictions. Pedestrian Dynamics, supported by Building Information Modeling (BIM) methods, and NetLogo are used to simulate and optimize user flow and space management relying on crowd simulation and Agent-Based Modeling. Patients’ movements and hospital activities are modeled to identify bottlenecks, crowded situations, and other issues. The methodology also allows the comparison of the two selected tools via the two simulations that are set with equal parameters. The results of the simulations enabled the analysis of current conditions and the testing of scenarios and hypotheses without inconveniencing users and interrupting hospital activities. Some improvements in space and people flow management could be proposed, e.g., distributing patients’ entries over the center opening times via an online booking system and modifying room functions. The proposed improvements support the facility managers to avoid, or at least minimize, crowded situations during which is not possible for patients to comply with COVID-19 pandemic restrictions, while minimizing layout changes and consequently the costs and efforts of implementing the changes. The proposed methodology will enable better management of future emergencies in healthcare facilities. The tool comparison will support future studies on simulation tool selection according to simulation and stakeholder needs.
Embodied net-zero compatible buildings? They already exist!
Authors: Priore Y D , Jusselme T , Habert G
Published: December 2023

This paper identifies buildings on pathway to meet carbon targets for embodied emissions aligned with global carbon budgets and mitigation pathways. A simplified bottom-up model is used, assessing multiple variations of a new construction archetype to identify the main strategies to achieve the targets. The model estimates the quantities of the main components with a few input geometry parameters. Life cycle emissions are then computed based on predefined building components. The reference building is representative of a typical new construction with standard operational values and massive construction. Strategies evaluate design optimization measures, construction techniques, and materials variations. Results show that (1) characteristics and volume of the building play a determining role. The existence and size of underground floors can determine the achievement of todays and future targets. (2) Construction choices can half emissions just by switching from concrete to wood and using natural insulation. (3) Future improvements in the supply chain of materials do not follow the required reduction pathway determined by the Swiss climate strategy. Net-zero compatible buildings are already possible, it is just a matter of making the right choices.
To renovate or to reconstruct – A comparative life-cycle assessment study over an existing building in Fribourg, Switzerland
Authors: Nault E , Cattin E
Published: December 2023

This study presents a simple and agile yet holistic comparative assessment of the impact, in terms of non-renewable cumulative energy demand (nrCED) and global warming potential (GWP), of two envisioned scenarios for the future of an existing administrative building located in Fribourg, Switzerland: its demolition and reconstruction versus its in-depth renovation. Based on our set of hypotheses, results show that over all life-cycle phases (construction and operation) and the building’s lifetime, the renovation scenario’s GWP is 540 kgCO2-eq/m2 lower than that of the reconstruction scenario, corresponding to a 50% savings. In terms of nrCED, the difference is of about 2 MWh/m2, a 45% savings in the renovation scenario. Both scenarios are found to comply with the SIA 2040 target values. These results, including findings on the most impactful elements, provide useful quantitative information for the decision-making and design team in their next steps toward defining the project.
The role of LCA in the renovation’s early decision-making for the design of a multifunctional, modular building envelope system
Authors: Konstantinou T , Moya T Armijos , Cetin M Yuksel , Tsikos M , Eguiarte O , Arregi B
Published: December 2023

The renovation of buildings has a high capacity to influence the environmental impacts and global objectives of climate change mitigation. In the context of designing low-energy buildings with minimized environmental impacts, the life cycle assessment (LCA) has been proven a straightforward method, to evaluate the direct and indirect environmental impacts of a building concept. Even though it is the most energy-intensive element, the use phase is not only a source of environmental concern but also the whole life cycle of the building and its components. However, energy-efficient renovation decisions tend to be financially motivated events, subject to exogenous constraints or barriers, that do not integrate whole life cycle thinking. This study aims to identify how the LCA information can be considered in comparing renovation options. compare renovation options, taking into account the modular envelope system developed as part of the European research project ENSNARE (ENvelope meSh aNd digitAl framework for building Renovation) case study. The study analysed different renovation scenarios, generated according to combinations of renewable energy sources and compare them to the base case and typical renovation scenario. Such information can support the design team in making decisions that consider the whole building and its components’ life cycles.
The carbon dioxide storage potential of building materials: a systematic literature review
Authors: Maierhofer D , Zögl I , Saade M Ruschi Mendes , Passer A
Published: December 2023

This study assesses the carbon dioxide storage ranges within new and innovative building materials. We conduct a Systematic Literature Review and gather data for carbon dioxide storage in building materials from 27 studies. The obtained values are classified into derived Eurostat categories ‘biomass - fast growing’, ‘biomass - slow growing’, ‘non-metallic minerals - industrial’ and ‘non-metallic minerals - natural’ and harmonized to the unit of gram carbon dioxide storage per kilogram of material (gCO2/kg). Based on the systematic review, the mean value of carbon dioxide storage for the category ‘biomass - fast growing’ results in 1758.0 gCO2/kg and for the category ‘biomass - slow growing’ in 1787.0 gCO2/kg, while the mean value for ‘non-metallic minerals - industrial’ results in 137.7 gCO2/kg and for ‘non-metallic minerals - natural’ in 574.1 gCO2/kg. The obtained statistical summaries provide a basis for future research on the path towards a net-zero carbon built environment.