bluuebunny/crossref_metadata_2025 huggingface dataset:
Unified one-electron Hamiltonian formalism of spin–orbit Jahn–Teller and pseudo-Jahn–Teller problems in axial symmetries
Authors: Brown James , Pradhan Ekadashi , Zeng Tao
Published: November 2021

Spin–orbit coupling and vibronic coupling are both closely related to orbital degeneracy of electronic states. Both types of coupling play significant roles in determining properties of heavy element compounds and shall be treated on the same footing. In this work, we derive a unified one-electron Hamiltonian formalism for spin–orbit and vibronic interactions for systems in all axial symmetries. The one-electron formalism is usually adequate as the spin–orbit interaction can often be approximated as a one-electron interaction. For the first time, the formalism covers spin–orbit and vibronic couplings in all axial symmetries from C1 to D∞h, arbitrary types of vibrational modes in those symmetries, and an arbitrary number of those modes and gives Hamiltonian expansions up to an arbitrary order.
Photoionization from the Xe 4d orbitals of XeF2
Authors: Forbes R. , Hockett P. , Powis I. , Bozek J. D. , Holland D. M. P. , Pratt S. T.
Published: November 2021

We present a comparison of the photoionization dynamics of the 4d shell of XeF2 from threshold to 250 eV to those of the prototypical 4d shell of atomic Xe. The new experimental data include spin–orbit and ligand-field-resolved partial cross sections, photoelectron angular distributions, branching fractions, and lifetime widths for the 4d-hole states. The spin–orbit branching fractions and angular distributions are remarkably similar to the corresponding distributions from atomic Xe across a broad energy interval that includes both the intense shape resonance in the f continuum and a Cooper minimum in the same channel. The angular distributions and branching fractions are also in reasonably good agreement with our first-principles theoretical calculations on XeF2. Data are also presented on the lifetime widths of the substate-resolved 4d-hole states of XeF2. While the trends in the widths are similar to those in the earlier experimental and theoretical work, the linewidths are considerably smaller than in the previous measurements, which may require some reinterpretation of the decay mechanism. Finally, we present new data and an analysis of the Auger electron spectra for ionization above the 4d thresholds and resonant Auger spectra for several pre-edge features.
Reduced order model for nonlinear multi-directional ocean wave propagation
Authors: Bukka Sandeep Reddy , Law Yun Zhi , Santo Harrif , Chan Eng Soon
Published: November 2021

In this paper, we introduce a reduced order model (ROM) for the propagation of nonlinear multi-directional ocean wave-fields. The ROM relies on Galerkin projection of Zakharov equations embedded in the high-order spectral (HOS) method, which describes the evolution of nonlinear waves. The dominant flow features of wave evolution are computed from proper orthogonal decomposition (POD) and these modes are used for the projection. The HOS scheme to compute the vertical velocity is treated in a novel way for an efficient implementation of POD-based ROM. We refer to this alternative formalism of HOS as HOS-simple. The final reduced order model (ROM) is derived from the Galerkin projection of HOS-simple. For the case of irregular waves, where the number of modes required are in the range of 200, the ROM has no significant advantage since both HOS and HOS-simple are much faster than real-time. The real advantage is demonstrated in multi-directional (or short-crested) irregular waves, where the ROM is the only model capable of achieving real-time computation, a major improvement to the standard HOS method. The potential use of the ROM in propagating short-crested waves from far-field to near-field for real-world applications involving wave probes in a wave tank/controlled environment as well as X-band radar in open ocean is also demonstrated.
Implementation of artificial neurons with tunable width via magnetic anisotropy
Authors: Niu Chang , Zhao Yuansheng , Hu Wenjie , Shi Qian , Miao Tian , Yu Yang , Yin Lifeng , Xiao Jiang , Guo Hangwen , Shen Jian
Published: November 2021

We report an experimental implementation of width-tunable neurons to train a binary neural network. The angle-dependent magnetic behavior in an oxide thin film highly mimics neurons with width-controllable activation window, providing an opportunity to train the activation functions and weights toward binary values. We apply this feature to train the MNIST dataset using a 684-800-10 fully connected network and achieve a high accuracy of 97.4%, thus opening an implementation strategy toward training neural networks.
Mapping 13C hyperfine couplings and exchange interactions in short-lived charge separated states of rigid donor–bridge–acceptor dyads
Authors: Zhukov Ivan , Fishman Natalya , Kiryutin Alexey , Lukzen Nikita , Steiner Ulrich E. , Vieth Hans-Martin , Schäfer Julian , Lambert Christoph , Yurkovskaya Alexandra
Published: November 2021

A detailed experimental study on reversible photo-induced intramolecular charge separation is presented based on nuclear magnetic resonance detection of chemically induced dynamic nuclear polarization. From variation of such polarization with the external magnetic field, the coupling constants of isotropic and anisotropic hyperfine interactions at individual 13C sites are measured in the short-lived charge separated state of dyad molecules composed of donor–bridge–acceptor parts. The objects of study were rigid donor–bridge–acceptor dyads, consisting of triarylamine as a donor, naphthalene diimide as an acceptor, and a meta-conjugated diethynylbenzene fragment as a bridge. By systematic variation of side groups in the bridging moiety, their influence on the electron withdrawing strength is traced. In combination with similar data for the 1H positions obtained previously for the same compounds [I. Zhukov et al., J. Chem. Phys. 152, 014203 (2020)], our results provide a reliable basis for the determination of the spin density distribution in the charge separated state of such dyads.
Electronic and thermal properties of GeTe/Sb2Te3 superlattices by ab initio approach: Impact of Van der Waals gaps on vertical lattice thermal conductivity
Authors: Sklénard Benoît , Triozon François , Sabbione Chiara , Nistor Lavinia , Frei Michel , Navarro Gabriele , Li Jing
Published: November 2021

In the last decade, several works have focused on exploring the material and electrical properties of GeTe/Sb2Te3 superlattices (SLs), in particular because of some first device implementations demonstrating interesting performances such as fast switching speed, low energy consumption, and non-volatility. However, the switching mechanism in such SL-based devices remains under debate. In this work, we investigate the prototype GeTe/Sb2Te3 SLs to analyze fundamentally their electronic and thermal properties by ab initio methods. We find that the resistive contrast is small among the different phases of GeTe/Sb2Te3 because of a small electronic gap (about 0.1 eV) and a consequent semi-metallic-like behavior. At the same time, the out-of-plane lattice thermal conductivity is rather small, while varying up to four times among the different phases, from 0.11 to 0.45 W m−1 K−1, intimately related to the number of Van der Waals (VdW) gaps in a unit block. Such findings confirm the importance of the thermal improvement achievable in GeTe/Sb2Te3 superlattices devices, highlighting the impact of the material stacking and the role of VdW gaps on the thermal engineering of the phase-change memory cell.
Regulation of interference-sensitive crossover distribution ensures crossover assurance in
Arabidopsis
Authors: Li Xiang , Zhang Jun , Huang Jiyue , Xu Jing , Chen Zhiyu , Copenhaver Gregory P. , Wang Yingxiang
Published: November 2021

Significance

Meiotic crossovers (COs) are required for accurate chromosome segregation and mix parental genomes to generate genetically diversified gametes. The distribution of COs among chromosomes is not random. In most organisms, at least one CO is formed between each chromosome pair. However, the molecular mechanisms controlling CO distribution are not well understood. Here, we found that
Arabidopsis
AtFANCD2, AtFANCM, AtFIGL1, and AtRMI1 promote normal distribution of Class I CO to maintain CO assurance in addition to their previously described roles in regulating Class II CO number. These factors, alone or in combination, appear to control ∼50% of the variation between wild-type and random distributions. These discoveries provide genetic insights into understanding of the regulation of CO distribution among chromosomes.
Altered cell and RNA isoform diversity in aging Down syndrome brains
Authors: Palmer Carter R. , Liu Christine S. , Romanow William J. , Lee Ming-Hsiang , Chun Jerold
Published: November 2021

Down syndrome (DS), trisomy of human chromosome 21 (HSA21), is characterized by lifelong cognitive impairments and the development of the neuropathological hallmarks of Alzheimer’s disease (AD). The cellular and molecular modifications responsible for these effects are not understood. Here we performed single-nucleus RNA sequencing (snRNA-seq) employing both short- (Illumina) and long-read (Pacific Biosciences) sequencing technologies on a total of 29 DS and non-DS control prefrontal cortex samples. In DS, the ratio of inhibitory-to-excitatory neurons was significantly increased, which was not observed in previous reports examining sporadic AD. DS microglial transcriptomes displayed AD-related aging and activation signatures in advance of AD neuropathology, with increased microglial expression of C1q complement genes (associated with dendritic pruning) and the HSA21 transcription factor gene
RUNX1
. Long-read sequencing detected vast RNA isoform diversity within and among specific cell types, including numerous sequences that differed between DS and control brains. Notably, over 8,000 genes produced RNAs containing intra-exonic junctions, including amyloid precursor protein (
APP
) that had previously been associated with somatic gene recombination. These and related results illuminate large-scale cellular and transcriptomic alterations as features of the aging DS brain.
Vectorial channeling as a mechanism for translational control by functional prions and condensates
Authors: Gu Xinyu , Schafer Nicholas P. , Wolynes Peter G.
Published: November 2021

Significance

Messenger RNA (mRNA)/protein assemblies such as functional prions and condensates are involved in locally regulating translation in eukaryotic cells. The mode of regulation depends on the structure of these assemblies. We show that the vectorial processive nature of translation can couple to transport via diffusion so as to repress or activate translation depending on the structure of the RNA protein assembly. We find that multiple factors including diffusivity changes and free energy biases in the assemblies can regulate the translation rate of mRNA by changing the balance between substrate recycling and competition between mRNAs. We mainly focus on the example of CPEB, a functional prion that has been implicated in the mechanism of synaptic plasticity of neurons and in memory.
Citrus dwarfing viroid. [Distribution map].
Authors: CABI  , EPPO
Published: November 2021

A new distribution map is provided for Citrus dwarfing viroid. Pospiviroidae: Apscaviroid. Hosts:
Citrus
spp. Information is given on the geographical distribution in Africa (Egypt, Sudan, Tunisia), Asia (China, Chongqing, Hubei, Hunan, Iran, Israel, Japan, Laos, Nepal, Oman, Pakistan, Syria, Turkey), Europe (Cyprus, Greece, Crete, Italy, Sicily, Spain), North America (Cuba, Guatemala, Jamaica, Mexico, United States, California, Florida, Hawaii), Oceania (New Zealand), South America (Brazil, Rio de Janeiro, Sao Paulo, Colombia, Peru, Uruguay).
Coniella granati
. [Distribution map].
Authors: CABI  , EPPO
Published: November 2021

A new distribution map is provided for
Coniella granati
(Sacc.) Petr. & Syd. Sordariomycetes: Diaporthales: Schizoparmaceae. Host: pomegranate (
Punica granatum
), among others. Information is given on the geographical distribution in Africa (Kenya, South Africa, Tunisia), Asia (China, Anhui, Shaanxi, India, Andhra Pradesh, Bihar, Gujarat, Himachal Pradesh, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Meghalaya, Rajasthan, Iran, Israel, Myanmar, Pakistan, South Korea, Thailand, Turkey), Europe (Cyprus, Greece, Italy, Spain, Ukraine), North America (Mexico, United States, California, Florida, North Carolina), South America (Argentina, Brazil).
Reducing deforestation and forest degradation in Democratic Republic of Congo: market-based conservation in a context of limited statehood
Authors: Reyniers Camille
Published: November 2021

Reducing Emissions from Deforestation and Forest Degradation (REDD+) is an international mechanism linked to the UN Framework Convention on Climate Change. It has been described in the field of political ecology as the panacea of neoliberal nature conservation policies, in particular though the decreasing role of the state in the definition and implementation of forest policies in favour of market-based-mechanisms and non-governmental actors. The article explores the links between the privatisation of forest conservation and national sovereignty in the context of limited statehood through a case study in the Mai Ndombe province of the Democratic Republic of Congo. It proposes an original approach combining African political anthropology with Franz Neumann's political economy analyses of the power of authoritarian states. It argues that this model of forest conservation uses carbon accounting and results-based payment, which privileges private actors for the design and implementation of REDD+ activities; it also paradoxically strengthens Congelese state legitimacy.
Work in agro-industry and the social reproduction of labour in Mozambique: contradictions in the current accumulation system
Authors: Ali Rosimina , Stevano Sara
Published: November 2021

This article discusses the tensions between job creation and employment quality in the system of accumulation in Mozambique. Addressing job quality is central because Mozambique’s economic structure has mostly failed to generate stable work and pay and dignified working conditions. However, this is neglected in the mainstream view of labour markets, which is dominated by dualisms and limited by its blind spot regarding social reproduction. The authors follow a political economy approach informed by a social reproduction lens and draw on original primary evidence on agro-industries. They argue that low-quality jobs reflect the current mode of organisation of production, in which companies’ profitability depends on access to cheap and disposable labour and relies on workers’ ability to engage in multiple, interdependent paid and unpaid forms of work to sustain themselves. Unless the co-constitutive interrelations between production and reproduction are understood and addressed, the fragmentation of livelihoods will intensify the social system crisis.
Making memories with Bcl-6
Authors: Read Kaitlin A. , Oestreich Kenneth J.
Published: November 2021

For over a decade, mutual antagonism between the transcriptional repressors Bcl-6 and Blimp-1 has been appreciated as a key mechanistic determinant of lymphoid differentiation programs. Now, in this issue of JEM, Ciucci et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20202343) demonstrate that this relationship is "central" to the generation of T cell memory.
Sub-micrometer plasma-enhanced chemical vapor deposition using an atmospheric pressure plasma jet localized by a nanopipette scanning probe microscope
Authors: Yamamoto Sho , Nakazawa Kenta , Ogino Akihisa , Iwata Futoshi
Published: November 2021

We developed a localized plasma-enhanced chemical vapor deposition (PE-CVD) technique to deposit silicon oxide with a sub-micrometer width on a substrate using an atmospheric pressure plasma jet (APPJ) irradiated from a nanopipette nozzle. To realize fine material deposition, hexamethyldisiloxane (HMDSO) vapor was blown into the localized helium APPJ irradiated from the sub-micrometer aperture of the nanpopipette with the jet length limited to the aperture size of the nanopipette. The irradiation distance was controlled using a shear-force positioning technique using scanning probe microscopy (SPM). The proposed system successfully deposited silicon oxide dots with sub-micrometer width on a substrate. After the deposition, the topography of the deposited surface was observed by scanning the nanopipette, which can be used as an SPM probe. The localized PE-CVD properties were systematically investigated by varying the deposition parameters. The amount of deposited material could be controlled by the flow rate of the carrier gas of the HMDSO vapor, APPJ irradiation time, and nanopipette–substrate surface irradiation distance.
An energy-tunable positronium beam produced via photodetachment of positronium negative ions and its applications
Authors: Nagashima Yasuyuki , Michishio Koji , Chiari Luca , Nagata Yugo
Published: November 2021

Positronium is a bound state of one electron and one positron. It can be seen as the lightest neutral ‘atom’. It can also be seen as a neutralized electron or a neutralized positron. Since positronium is electrically neutral, special techniques are required to generate a variable energy beam of positronium. In recent years, it has become possible to efficiently generate positronium negative ions in which another electron is bound to positronium. It is possible to generate an energy-tunable positronium beam by accelerating positronium negative ions with an electric field and irradiating them with laser light to photodetach one electron. Generation of such a positronium beam has actually been realized, and applied research has begun. Here, we describe the energy-variable positronium beam generation, its applied research including the observation of the motion-induced resonance of positronium and the first measurement of the binding energy of positronium to one electron.
Seebeck effect in nanomagnets
Authors: Fedorov Dmitry V , Gradhand Martin , Tauber Katarina , Bauer Gerrit E W , Mertig Ingrid
Published: November 2021

We present a theory of the Seebeck effect in nanomagnets with dimensions smaller than the spin diffusion length, showing that the spin accumulation generated by a temperature gradient strongly affects the thermopower. We also identify a correction arising from the transverse temperature gradient induced by the anomalous Ettingshausen effect and an induced spin-heat accumulation gradient. The relevance of these effects for nanoscale magnets is illustrated by ab initio calculations on dilute magnetic alloys.
Investigating student understanding of a heat engine: a case study of a Stirling engine
Authors: Zhu Lilin , Xiang Gang
Published: November 2021

We report on the study of student difficulties regarding a heat engine in the context of a Stirling cycle by the method of measurement. An in-class test about a Stirling engine with a regenerator was taken by three classes, and the students were asked to perform one of the most basic activities—calculate the efficiency of the heat engine. Our data indicate that quite a few students have not developed a robust conceptual understanding of basic engineering knowledge of the heat engine. Notably, the error ratio of the class given a simple tutorial of engineering knowledge is smaller than those of the other two classes by more than 20%. In addition, both the written answers and post-test interviews show that most of the students cannot associate Carnot’s theorem with a Stirling cycle. Our results suggest that both scientific and engineering knowledge are important and should be included in instructional approaches, especially in the thermodynamics course taught in the countries and regions with a tradition of not paying much attention to experimental education or engineering training.
Lung cancer subtype classification using histopathological images based on weakly supervised multi-instance learning
Authors: Zhao Lu , Xu Xiaowei , Hou Runping , Zhao Wangyuan , Zhong Hai , Teng Haohua , Han Yuchen , Fu Xiaolong , Sun Jianqi , Zhao Jun
Published: November 2021

Objective. Subtype classification plays a guiding role in the clinical diagnosis and treatment of non-small-cell lung cancer (NSCLC). However, due to the gigapixel of whole slide images (WSIs) and the absence of definitive morphological features, most automatic subtype classification methods for NSCLC require manually delineating the regions of interest (ROIs) on WSIs. Approach. In this paper, a weakly supervised framework is proposed for accurate subtype classification while freeing pathologists from pixel-level annotation. With respect to the characteristics of histopathological images, we design a two-stage structure with ROI localization and subtype classification. We first develop a method called multi-resolution expectation-maximization convolutional neural network (MR-EM-CNN) to locate ROIs for subsequent subtype classification. The EM algorithm is introduced to select the discriminative image patches for training a patch-wise network, with only WSI-wise labels available. A multi-resolution mechanism is designed for fine localization, similar to the coarse-to-fine process of manual pathological analysis. In the second stage, we build a novel hierarchical attention multi-scale network (HMS) for subtype classification. HMS can capture multi-scale features flexibly driven by the attention module and implement hierarchical features interaction. Results. Experimental results on the 1002-patient Cancer Genome Atlas dataset achieved an AUC of 0.9602 in the ROI localization and an AUC of 0.9671 for subtype classification. Significance. The proposed method shows superiority compared with other algorithms in the subtype classification of NSCLC. The proposed framework can also be extended to other classification tasks with WSIs.
Allostery and molecular stripping mechanism in profilin regulated actin filament growth
Authors: Zhang Weiwei , Cao Yi , Li Wenfei , Wang Wei
Published: November 2021

Profilin is an actin-sequestering protein and plays key role in regulating the polarized growth of actin filament. Binding of profilin to monomeric actin (G-actin) allows continuous elongation at the barbed end (BE), but not the pointed end, of filament. How G-actin exchanges between the profilin-sequestered state and the filament state (F-actin) to support the BE elongation is not well understood. Here, we investigate the involved molecular mechanism by constructing a multi-basin energy landscape model and performing molecular simulations. We showed that the actin exchanging occurs by forming a ternary complex. The interactions arising from the BE binding drive the conformational change of the attached G-actin in the ternary complex from twist conformation to more flatten conformation without involving the change of nucleotide state, which in turn destabilizes the actin–profilin interface and promotes the profilin stripping event through allosteric coupling. We also showed that attachment of free profilin to the BE induces conformational change of the BE actin and facilitates its stripping from the filament. These results suggest a molecular stripping mechanism of the polarized actin filament growth dynamics controlled by the concentrations of the actin–profilin dimer and the free profilin, in which the allosteric feature of the monomeric actin plays crucial role.
Identifications of RR Lyrae Stars and Quasars from the Simulated Data of Mephisto-W Survey
Authors: Lei Lei , Chen Bing-Qiu , Li Jin-Da , Wu Jin-Tai , Jiang Si-Yi , Liu Xiao-Wei
Published: November 2021

We have investigated the feasibilities and accuracies of the identifications of RR Lyrae stars and quasars from the simulated data of the Multi-channel Photometric Survey Telescope (Mephisto) W Survey. Based on the variable sources light curve libraries from the Sloan Digital Sky Survey (SDSS) Stripe 82 data and the observation history simulation from the Mephisto-W Survey Scheduler, we have simulated the uvgriz multi-band light curves of RR Lyrae stars, quasars and other variable sources for the first year observation of Mephisto W Survey. We have applied the ensemble machine learning algorithm Random Forest Classifier (RFC) to identify RR Lyrae stars and quasars, respectively. We build training and test samples and extract ∼150 features from the simulated light curves and train two RFCs respectively for the RR Lyrae star and quasar classification. We find that, our RFCs are able to select the RR Lyrae stars and quasars with remarkably high precision and completeness, with purity = 95.4% and completeness = 96.9% for the RR Lyrae RFC and purity = 91.4% and completeness = 90.2% for the quasar RFC. We have also derived relative importances of the extracted features utilized to classify RR Lyrae stars and quasars.
CISBAT 2021 International Hybrid Conference Carbon Neutral Cities – Energy Efficiency & Renewables in the Digital Era
Authors: Scartezzini Prof. Dr Jean-Louis , Smith Barbara
Published: November 2021

Preface to the CISBAT 2021 Journal of Physics: Conference Series special issue

CISBAT 2021 took place from 8 to 10 September 2021 online and at the Swiss Tech Convention Center on the campus of the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland under the heading "Carbon Neutral Buildings - Energy Efficiency & Renewables in the Digital Era".

Focused on energy efficiency and the use of renewables in buildings and cities, CISBAT bi-annually offers a dynamic platform for scientific exchange in fields ranging from nanostructured materials for renewable energy applications to urban energy systems. While recent editions have seen machine learning applications for the built environment receive ever greater attention, CISBAT 2021 has further extended its reach to include research promoting circular economy, thus offering insights into a broad range of fields that ultimately have the same target: carbon-free, sustainable buildings and cities.

List of Editorial Committee, Organising Committee, Programming Committee, Scientific Committee, Academic Partners, Session chairs, Invited speakers, Sponsors are available in this pdf.
Targeting building energy efficiency using thermal infrared earth observation telescopes
Authors: Ben Hui , Mackie Erik , Parry Ian , Shuckburgh Emily , Hawker George , Jenkins Marco Gomez
Published: November 2021

Upgrading the energy performance of the UK’s entire building stock is the central pillar of any credible and cost-effective strategy to meeting net zero. This research aims to open up the revenue of using thermal infrared data from satellites to assist in processes on building energy performance improvement. High-resolution thermal infrared data output from space offers the potential for fast and effective monitoring provision that can cover large areas and targeted buildings or sites. We have interviewed a set of stakeholders from government, industry and community groups to build the specific use cases and find out detailed user requirements.
Using Machine Learning to estimate the technical potential of shallow ground-source heat pumps with thermal interference
Authors: Walch Alina , Castello Roberto , Mohajeri Nahid , Gudmundsson Agust , Scartezzini Jean-Louis
Published: November 2021

The increasing use of ground-source heat pumps (GSHPs) for heating and cooling of buildings raises questions regarding the technical potential of GSHPs and their impact on the temperature in the shallow subsurface. In this paper, we develop a method using Machine Learning to estimate the technical potential of shallow GSHPs, which enables such an estimation for Switzerland with limited data and computational resources. A training dataset is constructed based on meteorological and geological data across Switzerland. We analyse correlations and the importance of each of the input data for estimating the GSHP potential and compare different input feature sets and Machine Learning models. The Random Forest algorithm, trained on the full dataset, provides the best performance to estimate the GSHP potential. The resulting model yields an R2 score of 0.95 for the annual energy potential, 0.86 for the heat extraction rate, and 0.82 for the potential number of boreholes per GSHP system.
Classification of the Energy Production Potential of Water Lens Solar Concentrators Using Machine Learning
Authors: Zarrinkafsh Hamidreza , Eslamirad Nasim , Luca Francesco De
Published: November 2021

Assessing the potential of renewable energy sources for buildings in neighborhoods becomes a crucial task in the early planning stage. Integrating solar energy equipment into urban buildings poses many challenges, such as uncertainties and the complexity of urban built agglomeration. Due to the time-consuming solar energy potential assessment process and lack of knowledge of urban actors, a reliable framework is required to predict buildings’ solar energy potential. This research presents a comprehensive machine learning data processing framework to predict output energy of Water Lenses (WL) based on buildings specifications and relationship to the neighbourhood. The research used a raw dataset consisting of 7000 sample buildings in different situations by applying 12 years of climatic conditions in Tallinn, Estonia. The results were entered into a Supervised Machine Learning process and the Gaussian Naive Bayes technique was used for classification of building features to be implemented with solar systems. Finally, the process was measured by a confusion matrix that showed 80% accuracy of ML output predictions in the urban context.
Characteristics and Challenges in Prosumer-Dominated Thermal Networks
Authors: Licklederer Thomas , Zinsmeister Daniel , Elizarov Ilya , Perić Vedran , Tzscheutschler Peter
Published: November 2021

Prosumer-dominated thermal networks interconnect distributed prosumers. These networks form the infrastructure that allows to execute the trading of thermal energy as desired in the context of local energy markets. However, the significantly different behavior of such networks compared to conventional district heating and cooling networks has not yet been comprehensively investigated. This paper provides a compilation of instrinsic characteristics of prosumer-dominated thermal networks and discusses challenges that arise from these characteristics. As a basis for the investigations an underlying reference concept for the considered type of networks is described. Simulative case studies are combined with scientific deduction and literature references to gain new insights on the design and operation of this type of networks. It is found that due to the variability in these networks, the definition of a design case is a challenge for the dimensioning of concrete network implementations. To anticipate the strong coupling between prosumers and the nonlinear network behavior, it is concluded that centralized control combined with a model of the physical network behavior is necessary. The discussion of characteristics and challenges in prosumer-dominated thermal networks indicates open points in this field and thus provides a starting point for consecutive studies.
Key features of climate-neutral energy systems for municipalities in different climate zones
Authors: Stryi-Hipp Gerhard , Steingrube Annette , Triebel Marc-André , Albert-Seifried Vicky
Published: November 2021

The conditions for cities to supply themselves with climate-neutral energy sources vary greatly around the world and depend on many parameters such as the climate, settlement density, intensity of land use, geographical conditions and the economic development stage of the country. Climate-neutral energy system solutions for 7 cities and counties in Europe, Asia and Africa were calculated and compared to identify climate zone-depending patterns for the structures of climate-neutral energy systems. It could be demonstrated that climate zones have a strong influence on the design of climate-neutral energy supply systems, both in terms of renewable energy provision (e.g. solar radiation) and energy consumption (e.g. space heating demand).
Carbon Neutral Urban Block in Athens - 2050
Authors: Maragkaki Eleni-Marina , Rajput Kartikeya
Published: November 2021

Athens’ extensive urbanisation, lack of green areas and the extreme heat caused by increasingly frequent heat waves indicate the need for actions improving indoor and outdoor comfort, which is closely related to the energy consumption of the buildings. This work’s aim is to create a carbon neutral block in Athens on the 2050 horizon. The optimization of the block’s form based on principles of environmental design and climatic analysis was performed to enhance its environmental benefits. Simulations on the energy performance of the block and calculations on the ability to cover the energy loads by renewables were conducted. Finally, to meet the zero-carbon neutrality, a connection with the neighbouring blocks was established. The results demonstrate the benefits of a bioclimatic, carbon neutral building design in Athens and provide a practical prototype, which can be adapted in other projects, thereby enabling the shift to a more efficient and environmentally friendly built environment.
The assessment of outdoor thermal comfort inside oasis settlements in North Africa - Algeria
Authors: Matallah Mohamed Elhadi , Alkama Djamel , Mahar Waqas Ahmed , Attia Shady
Published: November 2021

Oasis settlements are the most common form in the Saharan regions of North Africa, identified by a strong harmony between urban forms and palm groves, which present the economic capital for these regions. On the other hand, these oases are significantly growing and impacting the people’s livelihood and thermal well-being, especially during summer season. This study aims at first to identify the close correlation between cultivated area (palm grove) and the built-up area throughout the Tolga Oasis Complex in Algeria, which is recognised by its palm groves and well-known as one of the largest oasis settlements of the Saharan regions in North Africa. Furthermore, the current work assesses the impact of palm groves by investigating the ‘oasis effect’ on the thermal heat stress levels during July and August daytime hours within 9 conducted stations. Suprisingly, the so-called oasis effect generated by palm groves was insignificant during the extreme hot days. On the other hand, the palm groves were extremly hot affected by a warming effect during daytime hours.
Automated modelling of building energy systems with mode-based control algorithms in Modelica
Authors: Cai Xiaoye , Xue Junyi , Kümpel Alexander , Müller Dirk
Published: November 2021

The increasing use of renewable energy in building energy systems has brought considerable challenges for the traditional planning process to develop appropriate control strategies. In previous work, we have introduced the MODI method to support the structured development of mode-based control algorithms, in which operating modes are core elements. However, modeling of energy systems and control algorithms for control tests is time-consuming and error-prone. Identification of permissible operating modes is also unfeasible. The paper introduces a methodology to identify permissible operating modes and model energy systems with mode-based control algorithms in the modeling language Modelica automatically. In the case study, we apply the methodology for an energy supply network and verify the functionality of the methodology. In future work, automated optimization of control algorithms will be integrated into the methodology.
Time Enhanced Architectural Modelling (T.E.A.M.): Virtual reality project for the planning and visualization of kinetic architecture and dynamic design
Authors: Temporin V. , Volpato J. , Cocco P.L. , D’Angelo A. , Tieghi M.
Published: November 2021

T.E.A.M. is a research project that was created to facilitate the design of kinetic projects and components created through a computational design process. Time is the ingredient that allows dynamism. The following paper examines the core features of Platform One, an experimental digital application born within the project and aimed at supporting designers during the development, in a VE (Virtual Environment) of dynamic architectures and components, as well as the principles that inspired it. The application presents two key features: the first one is that everything modified and developed in the VE retains its geometric characteristics, allowing the user to reach an informed 3D model at the end of the process; the second one is the ease and enjoyment with which the user manipulates complex dynamic geometries in the three-dimensional environment through a natural interface design approach that focuses on direct manipulation of architectural objects and components. The simulator is designed to be used in a 6DOF virtual environment using a commercial VR headset. It has currently been loaded with several archetypal test architectures and soon it will be available to designers who want to test their work with it.
Modelling climate related performances of building wall coatings and understanding the portability of the “Künzel” rule in different climates
Authors: Augello Andrea , Peren Joy Alexis , Fechner Heiko , Angelis Enrico De
Published: November 2021

How may a coating affect the hygrothermal performance of the building envelope in different climates? Years ago, Helmut Künzel, one of the fathers of Building Physics, proposed, a simple, well-known rule, relating two characteristics of a coating: its water absorption coefficient and its vapour diffusion. The “Künzel rule” (and the associated diagram), based on a model confirmed by field tests in the German climate, set an upper limit to both parameters and their product, became a German standard and a practice among experts, practitioners and manufacturers, in many European countries. This paper proposes the results of an analysis aiming to verify its portability in other climates and is based on an extensive simulation of the hygrothermal performances of a reference wall in six different climatic conditions.
Development of a Modelica-based simplified building model for district energy simulations
Authors: Maccarini Alessandro , Prataviera Enrico , Zarrella Angelo , Afshari Alireza
Published: November 2021

Urban Building Energy Simulation (UBES) is an efficient tool to investigate and subsequently reduce energy demand of urban areas. Nevertheless, UBES has always been a challenging task due the trade-off between accuracy, computational speed and parametrization. In order to reduce these computation and parameterization requirements, model reduction and simplification methods aim at representing building behaviour with an acceptable accuracy, but using less equations and input parameters. This paper presents the development and validation results of a simplified urban simulation model based on the ISO 13790 Standard and written in the Modelica language. The model describes the thermo-physical behaviour of buildings by means of an equivalent electric network consisting of five resistances and one capacitance. The validation of the model was carried out using four cases of the ANSI/ASHRAE Standard 140. In general, the model shows good accuracy and the validation provided values within the acceptable ranges.
Sustainable energy supply for self-sufficient buildings with seasonal energy storages – parametric study
Authors: Zakovorotnyi Andrii
Published: November 2021

To reduce greenhouse gas emissions, the efficiency of energy supply systems must be increased, for example, using renewable energy sources. Since the generation of renewable energy can depend on weather conditions and other parameters, the use of short- or long-term energy storage enables an increase in the covered building energy demand. Due to the large number of available technologies for renewable energy generation and storage, it is possible to combine these systems into different energy supply concepts. By optimizing and comparing the designed concepts, the most suitable one can be determined with respect to the current and future investments. A comprehensive comparison of energy supply concepts must include both economic and energy evaluation criteria. This study focuses on parametric numerical simulations to identify economically feasible and sustainable energy supply concepts for a practical case of new residential buildings. The results show that electrical storage and on-site power generation can provide the greatest benefits. In contrast, large thermal storage systems are not economically viable.
SEAMS: an alternative techno-economic system to foster the sustainable development of renewable energy use in urban areas
Authors: Bourguignon D , Crépeaux P , Adam F
Published: November 2021

To foster the sustainable development of renewable energy use in urban areas, we define an alternative, reciprocity-based, techno-economic system named SEAMS (“sharing energy amongst adjacent buildings”). We demonstrate its relevance through a statistical analysis of linear heat density across coastal cities from Northwestern mainland France, and a comparison of four implementations of three techno-economic systems within the perimeter of two adjacent building blocks, located in the city center of Lorient (Brittany). The SEAMS approach promises to address the multidimensional fragility issues currently surfacing with the conventional, market-based or redistribution-based, techno-economic systems, namely electricity and gas networks (EGN) or district heating and cooling networks (DHCN).
An integrated decision-making framework for sustainable data center operation through intelligent load scheduling
Authors: Lei Nuoa , Cheng Zhu , Cao Zhi , Masanet Eric
Published: November 2021

Intelligent load scheduling is an emerging approach that has the potential to facilitate extreme sustainable data center (DC) operation. However, scarcity of straightforward tools in the public domain challenges decision makers performing quantitative analysis of the DC load planning and its potential benefits. In this work, a novel integrated decision-making framework was developed to address this issue, which provides the basis for the multi-objective optimization of carbon-, water-, and economic-intelligent load scheduling. The proposed framework was demonstrated with a case study DC in California, which showed the usefulness of the proposed framework in informing sustainable DC operations.
Impact of demand response on BIPV and district multi-energy systems design in Singapore and Switzerland
Authors: Waibel Christoph , Hsieh Shanshan , Schlüter Arno
Published: November 2021

This paper demonstrates the impact of demand response (DR) on optimal multi-energy systems (MES) design with building integrated photovoltaics (BIPV) on roofs and façades. Building loads and solar potentials are assessed using bottom-up models; the MES design is determined using a Mixed-Integer Linear Programming model (energy hub). A mixed-use district of 170,000 m2 floor area including office, residential, retail, education, etc. is studied under current and future climate conditions in Switzerland and Singapore. Our findings are consistent with previous studies, which indicate that DR generally leads to smaller system capacities due to peak shaving. We further show that in both the Swiss and Singapore context, cost and emissions of the MES can be reduced significantly with DR. Applying DR, the optimal area for BIPV placement increases only marginally for Singapore (~1%), whereas for Switzerland, the area is even reduced by 2-8%, depending on the carbon target. In conclusion, depending on the context, DR can have a noticeable impact on optimal MES and BIPV capacities and should thus be considered in the design of future, energy efficient districts.
Application of indirect evaporative cooling strategies for a warm-humid climate
Authors: Chávez José Roberto García , Salas Anaís Carrillo , García Pardo Karina A
Published: November 2021

Energy consumption in buildings for air conditioning has augmented worldwide by the escalation in global warming. The application of passive cooling is a promising approach to mitigate this situation. The aim of this research was to assess and characterize the performance of indirect evaporative cooling strategies combined with other passive cooling techniques, applied in experimental modules, aimed at providing hygrothermal comfort. Results showed that the investigated strategies presented lower temperatures than the external conditions and the control module. The alternative that combined indirect evaporative cooling with thermal mass, solar protection, and night radiative cooling was the most promising, with a temperature reduction of 4.2 K, relative to the mean exterior temperature, and a decrease of 8.3 K of its maximum temperature relative to the maximum exterior temperature. An additional strategy was implemented in this alternative using a phase change material, that further reduced its temperature by 6.3 K, relative to the mean exterior temperature and a reduction of 11.5 K of its maximum temperature compared to the maximum exterior temperature. It is expected that these findings are applicable in actual buildings in warm-humid regions to reduce energy consumption for air conditioning, whilst improving hygrothermal comfort and health of occupants.
Sustainable long-term energy planning for a district in Suzhou City, China
Authors: Yazdanie Mashael , Zhou Chenyu
Published: November 2021

A city district in Suzhou aims to develop a progressive, long-term sustainable energy strategy. This study examines possible energy planning pathways for the district through the development of a long-term optimization model and a range of energy scenarios until 2050. The scenarios explore different CO2 emission reduction strategies and technology mixes/parameters. Results suggest which low-carbon energy conversion technologies and efficiency measures should be adopted by the district alongside supportive local policies and targets. Photovoltaic (PV) and waste energy converters are two renewable energy technologies which are taken up at maximum possible rates in the evaluated scenarios to reduce long-term CO2 emissions. Once local renewable resources are exhausted, natural gas-based combined-cycle plants (CCP) and combined heat and power plants (CHP) are required to further reduce emissions, alongside efficiency measures in the built environment. Carbon capture and storage (CCS) technologies also demonstrate the potential to drastically reduce emissions; however, local feasibility studies are needed to support their implementation. Study results prescribe renewable energy share and CO2 emission reduction targets until 2050 for the district. Appropriate local policy and planning targets should also be accompanied by supplementary support studies, including local feasibility, renewable energy resource, and demand-side management studies.