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Frontiers of Structural and Civil engineering 2024年第1期18卷 66-79页

作者： Yaxin TAO Xiaodi DAI Geert de SCHUTTER Kim Van TITTELBOOM department of Structural engineering and building Materials Ghent UniversityGhent 9052Belgium

Robotic-based technologies such as automated spraying or extrusion-based 3-dimensional(3D)concrete printing can be used to build tunnel linings,aiming at reducing labor and mitigating the associated safety issues,especially in the high-geothermal ***-based 3D concrete printing(3DCP)has additional advantages over automated sprayings,such as improved surface quality and no ***,the effect of different temperatures on the adhesion performance of 3D-printed materials for tunnel linings has not been *** study developed several alkali-activated slag mixtures with different activator modulus ratios to avoid the excessive use of Portland cement and enhance sustainability of 3D printable *** thermal responses of the mixtures at different temperatures of 20 and 40℃ were *** adhesion strength of the alkali-activated material was evaluated for both early and later ***,the structural evolution of the material exposed to different temperatures was *** was followed by microstructure *** indicate that elevated temperatures accelerate material reactions,resulting in improved early-age adhesion ***,higher temperatures contribute to the development of a denser microstructure and enhanced mechanical strength in the hardened stage,particularly in mixtures with higher silicate content.

关键词： alkali-activated material 3DCP tunnel lining high-geothermal environment adhesion

High-performance formaldehyde prediction for indoor air quality assessment using time series deep learning

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building Simulation 2024年第3期17卷 415-429页

作者： Liu Lu Xinyu Huang Xiaojun Zhou Junfei Guo Xiaohu Yang Jinyue Yan School of Human Settlements and Civil engineering Xi’an Jiaotong UniversityXi’anChina department of building environment and Energy engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina Future Energy Profile School of BusinessSocietyand EngineeringMälardalen UniversityVästeråsSweden

Indoor air pollution resulting from volatile organic compounds(VOCs),especially formaldehyde,is a significant health concern needed to predict indoor formaldehyde concentration(Cf)in green intelligent building *** study develops a thermal and wet coupling calculation model of porous fabric to account for the migration of formaldehyde molecules in indoor air and cotton,silk,and polyester fabric with heat flux in Harbin,Beijing,Xi’an,Shanghai,Guangzhou,and Kunming,*** time-by-time indoor dry-bulb temperature(T),relative humidity(RH),and Cf,obtained from verified simulations,were collated and used as input data for the long short-term memory(LSTM)of the deep learning model that predicts indoor multivariate time series Cf from the secondary source effects of indoor fabrics(adsorption and release of formaldehyde).The trained LSTM model can be used to predict multivariate time series Cf at other emission times and *** LSTM-based model also predicted Cf with mean absolute percentage error(MAPE),symmetric mean absolute percentage error(SMAPE),mean absolute error(MAE),mean square error(MSE),and root mean square error(RMSE)that fell within 10%,10%,0.5,0.5,and 0.8,*** addition,the characteristics of the input dataset,model parameters,the prediction accuracy of different indoor fabrics,and the uncertainty of the data set are *** results show that the prediction accuracy of single data set input is higher than that of temperature and humidity input,and the prediction accuracy of LSTM is better than recurrent neural network(RNN).The method’s feasibility was established,and the study provides theoretical support for guiding indoor air pollution control measures and ensuring human health and safety.

关键词： multivariate time series formaldehyde concentration deep learning heat-humidity coupling mass transfer secondary source effect

The use of green infrastructure and irrigation in the mitigation of urban heat in a desert city

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building Simulation 2024年第5期17卷 679-694页

作者： Kai Gao Shamila Haddad Riccardo Paolini Jie Feng Muzahim Altheeb Abdulrahman AI Mogirah Abdullatif Bin Moammar Mattheos Santamouris School of Built environment Faculty of ArtsDesign and ArchitectureUniversity of New South WalesSydneyNSW 2052Australia Royal Commission of Riyadh City RiyadhSaudi Arabia Institute of Future Cities Chinese University of Hong KongHong KongChina department of building environment and Energy engineering The Hong Kong Polytechnic UniversityHong KongChina

Severe urban heat,a prevalent climate change consequence,endangers city residents ***-based mitigation strategies are commonly employed to address this ***,the Middle East and North Africa are under investigated in terms of heat mitigation,despite being one of the regions most vulnerable to climate *** study assesses the feasibility and climatic implications of wide-scale implementation of green infrastructure(GI)for heat mitigation in Riyadh,Saudi Arabia—a representative desert city characterized by low vegetation coverage,severe summer heat,and *** research forecasting model(WRF)is used to simulate GI cooling measures in Riyadh’s summer condition,including measures of increasing vegetation coverage up to 60%,considering irrigation and vegetation types(tall/short).In Riyadh,without irrigation,increasing GI fails to cool the city and can even lead to warming(0.1 to 0.3℃).Despite irrigation,Riyadh’s overall GI cooling effect is 50% lower than GI cooling expectations based on literature meta-analyses,in terms of average peak hour temperature *** study highlights that increased irrigation substantially raises the rate of direct soil evaporation,reducing the proportion of irrigation water used for transpiration and thus diminishing ***,water resource management must be tailored to these specific considerations.

关键词： green infrastructure evapotranspiration cooling desert city irrigation urban overheating

Sn-doped cobalt containing perovskite as the air electrode for highly active and durable reversible protonic ceramic electrochemical cells

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Journal of Advanced Ceramics 2024年第1期13卷 63-72页

作者： Min Fu Wenjing Hu Hua Tong Xin Ling Linggui Tan Fanglin Chen Zetian Tao School of Resources Environment and Safety EngineeringUniversity of South ChinaHengyang 421001China department of Mechanical engineering University of South CarolinaColumbia 29208USA

One potential solution to the problems of energy storage and conversion is the use of reversible protonic ceramic electrochemical cells(R-PCEC),which are based on the solid oxide fuel cell(SOFC)technology and offer a flexible route to the generation of renewable ***,the R-PCEC development faces a range of significant challenges,including slow oxygen reaction kinetics,inadequate durability,and poor round-trip efficiency resulting from the inadequacy of an air *** address these issues,we report novel B-sites doped Pr_(0.5)Ba_(0.5)Co_(0.7)Fe_(0.3)O_(3−δ)(PBCF)with varying amounts of Sn as the air electrode for R-PCEC to further enhance electrochemical performance at lower *** 600℃,R-PCEC with an air electrode consisting of Pr_(0.5)Ba_(0.5)Co_(0.7)Fe_(0.25)Sn_(0.05)O_(3+δ)has achieved peak power density of 1.12 W∙cm^(−2) in the fuel cell mode and current density of 1.79 A∙cm^(−2) in the electrolysis mode at a voltage of 1.3 ***,R-PCECs have shown good stability in the electrolysis mode of 100 *** study presents a practical method for developing durable high-performance air electrodes for R-PCECs.

关键词： triple conducting oxide dual-element doping protonic ceramic electrochemical cells(PCECs) catalytic

A fully distributed robust optimal control approach for air-conditioning systems considering uncertainties of communication link in IoT-enabled building automation systems

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Energy and Built Environment

Energy and Built environment 2024年第3期5卷 446-454页

作者： Wenzhuo Li Rui Tang Shengwei Wang Institute for environmental Design and engineering The BartlettUniversity College LondonUK department of building environment and Energy engineering The Hong Kong Polytechnic UniversityKowloonHong Kong Research Institute for Smart Energy The Hong Kong Polytechnic UniversityKowloonHong Kong

Internet of Things(IoT)technologies are increasingly implemented in buildings as the cost-effective smart sens-ing infrastructure of building automation systems(BASs).They are also dispersed computing resources for novel distributed optimal control ***,wireless communication networks are critical to fulfill these tasks with the performance influenced by inherent uncertainties in networks,e.g.,unpredictable occurrence of link *** and hierarchical distributed approaches are vulnerable against link failure,while the robustness of fully distributed approaches depends on the algorithms *** study therefore proposes a fully distributed robust optimal control approach for air-conditioning systems considering uncertainties of com-munication link in IoT-enabled *** distributed algorithm is adopted that agents know their out-neighbors *** directly coordinate with the connected neighbors for global *** are conducted to test and validate the proposed approach by comparing with existing approaches,i.e.,the centralized,the hierarchical distributed and the fully distributed *** show that different approaches are vulnerable against to uncertainties of communication link to different *** proposed approach always guarantees the optimal control performance under normal conditions and conditions with link failures,verifying its high *** also has low computation complexity and high optimization efficiency,thus applicable on IoT-enabled BASs.

关键词： Multi-agent system Edge computing Air-conditioning system Internet of Things(IoT) Communication link failure

Eigenfrequency analysis of bridges using a smartphone and a novel low-cost accelerometer prototype

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Frontiers of Structural and Civil engineering 2024年第2期18卷 202-215页

作者： Seyedmilad KOMARIZADEHASL Ye XIA Mahyad KOMARY Fidel LOZANO department of Civil and environment engineering Universitat Politècnica de CatalunyaBarcelona 08034Spain department of Bridge engineering Tongji UniversityShanghai 200092China department of Civil engineering Universidad de Castilla-La ManchaCiudad Real 13071Spain

Researchers are paying increasing attention to the development of low-cost and microcontroller-based accelerometers,in order to make structural health monitoring feasible for conventional bridges with limited monitoring *** with the low-cost sensor development,the use of the embedded accelerometers of smartphones for eigenfrequency analysis of bridges is becoming popular in the civil engineering *** paper,for the first time in the literature,studies these two promising technologies by comparing the noise density and eigenfrequency analysis of a self-developed,validated and calibrated low-cost Internet of things based accelerometer LARA(low cost adaptable reliable accelerometer)with those of a state of the art smartphone(iPhone XR).The eigenfrequency analysis of a footbridge in San Sebastian,Spain,showed that the embedded accelerometer of the iPhone XR can measure the natural frequencies of the under study bridge.

关键词： smartphone modal analysis eigenfrequency analysis low-cost accelerometers Arduino Raspberry Internet of things

Granular collapse in fluids:Dynamics and flow regime identification

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颗粒学报（英文版） 2024年第9期92卷 30-41页

作者： Hu Tang Bisong Lin Dengming Wang department of Mechanics and engineering Science School of Civil Engineering and MechanicsKey Laboratory of Mechanics on Disaster and Environment in Western China of Ministry of EducationLanzhou UniversityLanzhou730000China

The collapse of granular material in fluids is a prevalent phenomenon in both natural and industrial processes,displaying a notable sensitivity to initial configuration of the *** study is specifically oriented towards falling process of collapsing material under various fluid conditions,employing the computational fluid dynamics-discrete element method(CFD-DEM)to primarily investigate the dy-namics and scaling laws of deposit morphology of collapsed *** a comprehensive analysis of particle sedimentation in fluids,we introduce a refined inertial characteristic time for granular collapse within the inertial ***,we propose modifications to conventional fluid-particle density ratio and Reynolds number,aiming to enhance the accuracy of depicting collapse dy-namics and identifying flow regimes across diverse column heights and fluid ***,we construct a phase diagram of flow regimes using modified dimensionless numbers,emphasizing the role of column height in transition between viscous and inertial *** parameters demonstrate enhanced relevance in governing the collapse of immersed granular columns,thereby contributing to a more nuanced understanding of fluid-particle interations in dense granular flows under different regimes.

关键词： Collapse Computational fluid dynamics-discrete element method Dynamic Flow regime Immersed granular material

Breakthrough of Carbon-Ash Recalcitrance in Hydrochar via Molten Carbonate:engineering Mineral-Rich Biowaste Toward Sustainable Platform Carbon Materials

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engineering 2024年第5期36卷 167-177页

作者： Zihan Wang Leli Zhang Yuanhui Zhang Zhidan Liu Laboratory of environment-Enhancing Energy(E2E) Key Laboratory of Agricultural Engineering in Structure and EnvironmentMinistry of AgricultureCollege of Water Resources and Civil EngineeringChina Agricultural UniversityBeijing 100083China department of Agricultural and Biological engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801USA

The function-led design of porous hydrochar from mineral-rich biowaste for environmental applications inevitably suffers from carbon-ash ***,a method to alter the original carbon skeleton with ash remains elusive and hinders the availability of ***,we propose a facile strategy for breaking the rigid structure of carbon-ash coupled hydrochar using phase-tunable molten carbonates.A case system was designed in which livestock manure and NaHCO3 were used to prepare the activated hydrochar,and NH3 served as the target *** to the redox effect,we found that organic fractions significantly advanced the melting temperature of Na2CO3 below 800℃.The Na species steadily broke the carbon-ash interaction as the thermal intensity increased and transformed inorganic constituents to facilitate ash dissolution,rebuilding the hydrochar skeleton with abundant hierarchical channels and active defect *** surface polarity and mesopore distribution collectively governed the five cycles NH3 adsorption attenuation *** hydrochar delivered favorable potential for application with a maximum overall adsorption capacity of 100.49 mg·g^(-1).Integrated spectroscopic characterization and theoretical computations revealed that incorporating NH3 on the carbon surface could transfer electrons to chemisorbed oxygen,which promoted the oxidation of pyridine-N during *** work offers deep insight into the structure function correlation of hydrochar and inspires a more rational design of engineered hydrochar from high-ash biowaste.

关键词： Hydrochar Livestock manure Ammonia adsorption Deashing Oxygen activation

Evaluating different levels of information on the calibration of building energy simulation models

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building Simulation 2024年第4期17卷 657-676页

作者： Siyu Cheng Zeynep Duygu Tekler Hongyuan Ji Wenxin Li Adrian Chong department of the Built environment College of Design and EngineeringNational University of Singapore4 Architecture DriveSingapore117566Singapore School of Civil engineering and Architecture Chongqing University of Science and TechnologyChongqing401331China School of Energy and environment Southeast UniversityNanjing210096China

A poorly calibrated model undermines confidence in the effectiveness of building energy simulation, impeding the widespread application of advanced energy conservation measures (ECMs). Striking a balance between information-gathering efforts and achieving sufficient model credibility is crucial but often obscured by ambiguities. To address this gap, we model and calibrate a test bed with different levels of information (LOI). Beginning with an initial model based on building geometry (LOI 1), we progressively introduce additional information, including nameplate information (LOI 2), envelope conductivity (LOI 3), zone infiltration rate (LOI 4), AHU fan power (LOI 5), and HVAC data (LOI 6). The models are evaluated for accuracy, consistency, and the robustness of their predictions. Our results indicate that adding more information for calibration leads to improved data fit. However, this improvement is not uniform across all observed outputs due to identifiability issues. Furthermore, for energy-saving analysis, adding more information can significantly affect the projected energy savings by up to two times. Nevertheless, for ECM ranking, models that did not meet ASHRAE 14 accuracy thresholds can yield correct retrofit decisions. These findings underscore equifinality in modeling complex building systems. Clearly, predictive accuracy is not synonymous with model credibility. Therefore, to balance efforts in information-gathering and model reliability, it is crucial to (1) determine the minimum level of information required for calibration compatible with its intended purpose and (2) calibrate models with information closely linked to all outputs of interest, particularly when simultaneous accuracy for multiple outputs is necessary.

关键词： calibration building energy simulation(BES) energy conservation measure(ECM) level of information field measurements

Peat properties of a tropical forest reserve adjacent to a fire-break canal

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Journal of Forestry Research 2024年第1期35卷 155-167页

作者： Dayang Nur Sakinah Musa Mohd Zahirasri Mohd Tohir Xinyan Huang Luqman Chuah Abdullah Mohamad Syazaruddin Md Said Muhammad Firdaus Sulaiman Safety engineering Interest Group(SEIG) Department of Chemical and Environmental EngineeringFaculty of EngineeringUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia International Tropical Forestry Programme Faculty of Tropical ForestryUniversiti Malaysia SabahSabahMalaysia department of Land Management Faculty of AgricultureUniversiti Putra MalaysiaSelangorMalaysia Research Centre for Fire Safety engineering Department of Building Environment and Energy EngineeringThe Hong Kong Polytechnic UniversityHong KongPeople’s Republic of China

Tropical peat comprises decomposed dead plant material and acts like a sponge to absorb water,making it fully ***,drought periods dry it readily and increases its vulnerability to *** fires emit greenhouse gases and particles contributing to haze,and prevention by constructing fire-break canals to reduce fire spread into forest reserves is *** paper aims to determine peat physical and chemical properties near a fire-break canal at different fire frequency *** sampling was conducted at two forest reserves in Malaysia which represent low fire frequency and high fire frequency *** results show that peat properties were not affected by the construction of a fire-break canal,however lignin and cellulose content increased significantly from the distance of the canal in both *** study concluded that fire frequency did not significantly influence peat properties except for *** higher fibre content in the high frequency area did not influence moisture content nor the ability to regain ***,fire frequency might contribute differently to changes in physical and chemical properties,hence management efforts to construct fire-break canals and restoration efforts should protect peatlands from further *** findings will benefit future management and planning for forest reserves.

关键词： Peat fire Peat properties Fire-break canals Forest reserves