bluuebunny/crossref_metadata_2025 huggingface dataset:
A green approach for the preparation of ZnO@C nanocomposite using agave americana plant extract with enhanced photodegradation
Authors: Jakhrani Mansab Ali , Tahira Aneela , Bhatti Muhammad Ali , Shah Aqeel Ahmed , Shaikh Nek Muhammad , Mari Riaz Hussain , Vigolo Brigitte , Emo Mélanie , Albaqami Munirah D , Nafady Ayman , Ibupoto Zafar Hussain
Published: September 2022

The present study demonstrates the crucial role of agave americana extract in enhancing the optical properties of zinc oxide (ZnO) through thermal treatment method. Various analytical and surface science techniques have been used to identify the morphology, crystalline structure, chemical composition, and optical properties, including scanning electron microscopy, x-ray diffraction, high resolution transmission electron microscopy (HRTEM), x-ray spectroscopy (EDS) and UV–visible spectroscopy techniques. The physical studies revealed the transformation of ZnO nanorods into nanosheets upon addition of an optimized amount of agave americana extract, which induced large amount of amorphous carbon deposited onto ZnO nanostructures as confirmed by HRTEM analysis. The use of increasing amount of americana extract has significantly reduced the average crystallite size of ZnO nanostructures. The resultant hybrid system of C@ZnO has produced a significant effect on the ultraviolet light-assisted photodegradation of malachite green (MG) dye. The photocatalyst dose was fixed at 10 mg for each study whereas the amount of agave americana extract and MG dye concentration are varied. The functionality of hybrid system was greatly enhanced when the amount of agave americana extract increased while dye concentration kept at lower level. Ultimately, almost 100% degradation efficiency was achieved via the prepared hybrid material, revealing combined contribution from synergy, stabilization of ZnO due to excess of carbon together with the high charge separation rate. The obtained results suggest that the driving role of agave americana extract for surface modification of photocatalyst can be considered for other nanostructured photocatalysts.
Non-negative constrained dictionary learning for compressed sensing of ECG signals
Authors: Zhang Bing , Xiong Pengwen , Liu Jizhong , Wu Jianhua
Published: September 2022

Objective. Overcomplete dictionaries are widely used in compressed sensing (CS) to improve the quality of signal reconstruction. However, dictionary learning under the

ℓ

0

-norm or

ℓ

1

-norm constraint inevitably produces dictionary atoms that are negatively correlated with the original signal; meanwhile, when we use a sparse linear combination of dictionary atoms to represent a signal, it is suboptimal for the dictionary atoms to “cancel each other out” by addition and subtraction to approximate the sample. In this paper, we propose a non-negative constrained dictionary learning (NCDL) algorithm to improve the reconstruction performance of CS with electrocardiogram (ECG) signals. Approach. Non-NCDL was divided into an encoding stage and a dictionary learning stage. In the encoding stage, non-negative constraints were imposed on the encoding coefficients and obtained the sparse solution using the alternating direction method of multipliers. At the same time, a penalty term was integrated into the objective function in order to remove small coding coefficients and achieve the effect of sparse coding. In the dictionary learning stage, the block coordinate descent algorithm was utilized to update the dictionary with a view to obtaining an overcomplete dictionary. Results. The performance of the proposed NCDL algorithm was evaluated using the standard MIT-BIH database. Quantitative performance metrics, such as percent root mean square difference (PRD1) and root mean square error, were compared with existing CS approaches to quantify the efficacy of the proposed scheme. For a PRD1 value of 9%, the compression ratio (CR) of the NCDL approach was around 2.78. When CR ranged from 1.05 to 2.78, the proposed NCDL approach outperformed the method of optimal direction, k-means singular value decomposition, and online dictionary learning approaches in ECG signal reconstruction based on CS. Significance. This promising preliminary result demonstrates the capability and feasibility of the proposed bioimpedance method and may open up a new direction for this application. The non-NCDL method proposed in this paper can be used to obtain a sparse basis and improve the performance of CS reconstruction.
Optimization of anti-bending deformation of aerogel sandwich thermal protection structure
Authors: Xu Yahui , Zhang Peiwei , Tian Zhiqiang , Fei Qingguo
Published: September 2022

The failure of the thermal protection structure is very important to the safety of the aircraft structure. In order to accurately predict the flexural behavior of the aerogel sandwich thermal protection structure, first of all, for the sandwich structure in the form of statically indeterminate beam with variable cross-section, the beam theory considering the transverse shear deformation of the core layer was deduced. Secondly, by comparing the deflections, the forms of deflection curve and the maximum strains of the upper panel, the accuracy of the theoretical prediction was analyzed. Then, according to the requirements of heat protection and integrity of the thermal protection structure, the optimization analyses of the parameters of the core layer, such as the thickness, the density and the elastic modulus, were carried out. The results showed that the beam theory considering the transverse shear deformation of the core layer had better prediction accuracy. The maximum deflection error was the smallest, which was -17%, and the form of the deflection curve was the most reasonable. Within the range of the physical parameters of the core layer studied, the theoretical basis and guiding direction were given for the regulation of the performance of the aerogel core layer.
Development of FSM corrosion monitoring system based on Cloud Server
Authors: Qi Yonggang , Yang Xuyun , Duan Rujiao , Fu Zhiqiang
Published: September 2022

FSM (field signature method) is a new non plug-in on-line monitoring method for pipeline corrosion. The traditional FSM corrosion monitoring equipment is generally a single machine to copy data or collect terminal client wireless transmission data, which is not convenient for data management. In this paper, cloud service is introduced into the monitoring system, and the FSM corrosion monitoring system based on cloud server is developed, which realizes the functions of real-time, online and remote control. The monitoring system can obtain the current status data of the monitored pipeline in real time, and calculate the corrosion parameters of the pipeline according to the data sent back by the measuring device. The system can draw trend diagram and morphology diagram according to the calculated corrosion parameters, display database data tables and relevant charts, and send monitoring information regularly.
Bijective plannar parameterization based on a hyperelasticity analogy
Authors: Gao Jiajia , Gao Yunyun , Ma Tao , Hou Ningtao , Wei Zhen , Guo Wei , Huo Rikun , Huo Zhijie
Published: September 2022

Isogeometric analysis (IGA) is a promising alternative for finite element analysis (FEA) with simplified design-through-analysis workflow. However, existing models in CAD software cannot be used directly for analysis. Parameterization of the input geometry is necessary to transform it into an analysis-suitable model. But it is non-trivial to produce smooth non-folding results. In this paper, we present a novel parameterization scheme based on the hyperelasticity analogy in solid mechanics. Compared with other state-of-the-art techniques, numerical examples prove that the proposed method guarantees bijective results with excellent smoothness.
Microstructure and mechanical properties of spray formed 7055 aluminum alloy by fiber laser-arc hybrid welding
Authors: Xu Fei , Zhao Xiaolong , Guo Luyun
Published: September 2022

The spray formed 7055 aluminum alloy with 4.2mm thickness was welded by laser-arc hybrid heat source. The microstructures and properties of the welded joints are studied. The results show that the weld appearance is very full and the weld zone is primary composed of equiaxed crystals. Those equiaxed crystals morphology in different positions are also different, and only a small amount of columnar crystals are locally formed in the fusion zone. The average microhardness values of the weld zone and the heat affected zone are lower than that of the base metal, reaching 64% and 82% respectively. The average tensile strength of welded joints with as-welded state reaches 51% of the base metal. However, the tensile properties of the joints are significantly improved after the two-stage solution and aging heat treatment, and the average tensile strength can reach 515MPa, which was about 84% of the strength of the base metal.
Research on the strength of selective laser sintering core
Authors: Li Jiuru , Qu Jiuhe , Chen Juhui , Zhou Haitian , Sun Yongguo , Fu Lin
Published: September 2022

Taking the tensile strength as the inspection index, the single-factor influence experiment was carried out on the addition of phenolic resin and the four factors of laser power, laser scanning rate and sand thickness in the sintering process, and the optimal level combination of each factor was obtained: the addition of phenolic resin. 5%, laser power 38W, laser scanning rate 3400mm/s, sand thickness 0.25mm.
Effect of particle size on flowability of Lithium hydroxide powder
Authors: Guo Hua , Yu Wangyang , Zhou Jian , Li Hongjun , Shen Fangming , Zhang Jinjian
Published: September 2022

In order to improve the flowability of lithium hydroxide powder, the lithium hydroxide powder in a company was selected under the conveying condition. The degree of circularity was used to quantitatively characterize the micro-morphology of the powder, and the influence of particle size on the flowability of lithium hydroxide powder was studied by the angle of repose method, HR method and Carr flowability index method. The results show that the lithium hydroxide powder gets better with the increasing of particle size. But the flowability of fine particles (≤ 100μm) is poor, while the flowability of medium particles (100~200μm) and coarse particles (≥ 200μm) is good. Based on the experimental results. It is suggested that the inclination angle of silo should be designed to be no less than 500 and the content of powder with particle size less than 100μm in lithium hydroxide should be controlled to improve the conveying efficiency of lithium hydroxide powder.
Lightweight design of the planetary gear reducer of reduction drive hub motors
Authors: Wang Shilin , Xu Xiang , Chen Xinbo , Li Renzheng
Published: September 2022

Hub motor is the development direction of new energy vehicles in the future. Usually, the reduction drive hub motor is directly arranged in the narrow rim space, so there are strict restrictions on the volume and weight of its reducer. This paper presents a highly integrated transmission scheme which can improve the working life of the reducer. For the planetary gear reducer integrated by the reduction drive hub motor, a multi-objective optimization function with minimum volume and large coincidence degree is constructed. In terms of constraints, the necessary conditions of planetary gear transmission are fully considered, the gear module meets the requirements of national standards, and the strength conditions of gear transmission. Using genetic optimization algorithm, the optimal solution satisfying the constraints is obtained. The optimization results show that the coincidence degree of the engagement between the sun gear and the planetary gear increases by 67% and the equivalent volume decreases by 31%, which can reduce the volume and reduce the transmission noise at the same time.
Machine learning based short fatigue crack growth rate prediction for aluminium alloys
Authors: Liu Xinyu
Published: September 2022

As a result of different fatigue characteristics influenced by intricate microstructures, comparing with fatigue crack growth rate in long fatigue crack region, the growth in the short one is more complex to be fitted with fewer parameters. There have been more restrictions for traditional models in describing the nonlinearity between the fatigue crack growth rate and stress intensity factor range in short crack regime. Due to their outstanding ability in prediction with high accuracy and in description of nonlinearity with satisfactory flexibility, machine learning approaches have been payed more attention. The machine learning models have been the better choices to deal with the limitation in fatigue-related problems which traditional solutions cannot overcome. In this paper, two machine learning algorithms: k-nearest neighbour algorithm (KNN) and random forest (RF) are implemented to predict the short fatigue crack growth rate for 2024-T3 and LC9cs aluminium alloys. The testing outcomes of these applied machine learning algorithms are compared to evaluate their prediction abilities. The final results reveal that the values of Pearson correlation coefficient R2
of the KNN are generally higher than that of another method for each material. Each of them has an excellent performance in accuracy and effectiveness, and all of them have excellent extrapolation capabilities to predict the nonlinearity.
Design and Mechanical Efficiency Improvement of Micro Reducer
Authors: Wang Yaqin
Published: September 2022

Micro reducer is widely used, but its mechanical efficiency is not high. Selecting metal materials and engineering plastics to form the motion pair can reduce friction and wear. Selecting new materials in the design of the reducer and adopting new molding technologies can improve the precision of gear transmission and reduce noise and vibration. For a reducer with a large transmission ratio and many transmission stages, rational allocation of the transmission ratios at all levels in the structural design can improve the efficiency of the reducer. Different planetary gear structural designs will also affect the mechanical efficiency, and the structural design is optimized so that the reducer can better take into account the relationship between load and mechanical efficiency.
Research on vibration control of bearingless motorized spindle
Authors: Meng Jie , Guo Sirui , Liang Xi
Published: September 2022

Bearingless motorized spindle is a new type of motorized spindle composed of bearingless motor and motorized spindle. With the increasing speed, the spindle will produce obvious gyro effect and vibration interference, so it is of practical significance to study the vibration control of bearingless motorized spindle. In this paper, the principle of minimum rotor vibration displacement is introduced, and a compensation controller based on adaptive feedback is designed and verified by simulation.
A multi-channel power input automatic switching system based on power quality analysis
Authors: Zhang Leilei , Ding Wei , Wei Ying
Published: September 2022

Abstact

A Multi-channel power input automatic switching system used for mobile vehicle equipment based on power quality analysis is proposed in this paper. The basic measurement principle of power quality analysis is introduced first, based on this principle, a hardware implementation of the power quality analysis unit is fulfilled, including function diagram, measurement sampling circuit, and communication interface circuit. A communication interface protocol is designed based on CAN bus used for interaction between the multi-channels of power supply input. Based on the power quality analysis unit, the multi-channel power input automatic switching system is proposed driven by the priority of input channel determined by sharing the data of the power quality between the multi-channel power supplies.
Robust Identification Algorithm for Unmanned Underwater Vehicles Dynamics Model Parameters
Authors: Zeng Dezheng , Yan Lijing , Cao Xuanwei , Zeng Keren
Published: September 2022

As the exploration of marine resources continues to deepen, the Unmanned Underwater Vehicles (UUV) have gradually become the focus of industries such as military, fishery, seabed prospecting and marine platform monitoring. At present, the identification technology of the dynamic model parameters of the UUV is not mature yet, and the robustness is poor. In order to solve the problem that the identification algorithm is susceptible to underwater noise when the robot is navigating underwater, this paper integrates the Huber loss function into the recursive least square method, and proposes a robust identification algorithm to improve the control of the underwater robot Accuracy. Finally, the dynamic model of the underwater vehicle is simulated in Simulink to obtain a reasonable input signal, and then this algorithm is used to simulate and identify the model under Gaussian noise with ‘outliers’. The simulation results show that the algorithm has strong robustness while ensuring the identification accuracy.
Fly-by-wire Flight Control Comparative Analysis of Resident and Detached Application Sources of Civil Aircraft
Authors: Shen Yingchun , Chang Shuo , Wei Qiang
Published: September 2022

Starting from the current multifunctional integration and architecture design development status of the flight control system for the mainstream civil aircraft, this paper proposes the system design concepts of “In and Out as a Whole”, “Direct Connection and Transmission”, and “Same Sources and Routes” for the external sensors application sources of the fight control system. External application sources are air data, inertial Reference data and angle of attack sensors in this paper, specifically. This paper analyzes and compares the functional residence and separation processing of external application sources for fly-by-wire flight control system. In addition, it demonstrates the correctness of this design concept and its practical engineering value, systematically. This work has provided a significant reference for future civil aircraft design.
CMOS pixel sensors optimized for large ionizing dynamic
Authors: Ren W. , Baudot J. , Federici L. , Finck C. , Hu-Guo C. , Kachel M. , Reidel C.-A. , Schui C. , Sefri R. , Spiriti E. , Weber U. , Zhao Y.
Published: September 2022

Monolithic active pixel sensors (MAPS) are now well established as a technology for tracking charged particles, especially when low material budget is desirable. For such applications, sensors focus on spatial resolution and pixels with digital output or modest charge measurement ability are well suited. Within the European Union STRONG-2020 project, which focuses on experiments using hadrons, the TIIMM (Tracking and Ions Identifications with Minimal Material budget) joint research activity intends to expand granular MAPS capacity to energy-loss (ΔE) measurement for ion species identification. The TIIMM prototypes are developed in the Tower Jazz 180 nm CMOS image sensor (CIS) process. The Time-Over-Threshold (ToT) method is applied to the sensor for the energy-loss measurement. The main design details and the preliminary test results from laboratory measurements of the initial TIIMM prototype are presented in this work.
Determination of groundwater recharge area using environmental isotopes and hydrochemical data in Raimanuk area, East Nusa Tenggara
Authors: Manta W F , Hendrayana H , Amijaya D H
Published: September 2022

The Raimanuk area, located in East Nusa Tenggara, had a population growth rate of 0.94% in 2019. The area used for harvested agricultural land was 205 Ha. As the population and agricultural land increase, the water demand also increases. Groundwater extraction is feared to be out of control because Raimanuk is a drought-prone area. The availability of groundwater is closely related to the amount of water infiltration and the amount taken. In accordance to that, it is necessary to find out the origin of groundwater in the Raimanuk area. This study aimed to determine the groundwater recharge area using environmental isotopes analysis of 2H and 18O and hydrochemistry. Rainwater samples were taken in March and April 2021 once in every month at 4 locations with different elevations. Groundwater sampling was carried out at 10 drilled wells, 6 dug wells, and 4 springs. Groundwater in the Raimanuk area can be grouped into 4 groups. The groundwater recharge area is in the Mandeu hills at an altitude above 390 masl. The composition of groundwater is dominated by calcium (Ca), sodium-potassium (NaK), and bicarbonate (HCO3).
Study of Methane Gas Emissions from Agricultural Activities and its Coping Strategies in Bedog Sub-watershed
Authors: Ramadhan M F , Ufiyatun E , Maulana K M , Jatmika Y B A S , Sari L R , Nurjani E , Sudrajat  , Rachmawati R
Published: September 2022

Food production through agricultural activities needs to be intensified to meet food demand. Agricultural activities can also emit methane (CH4) emissions and thus contribute to climate change. Assessing agricultural activities can be done by measuring CH4 emissions, which we implemented in the Bedog Sub-watershed. The purposes of this paper are (1) to calculate CH4 emissions from agricultural activities, and (2) to propose strategies to deal with CH4 emissions. Emissions calculation was done by using IPCC 2006 framework. The mapping results of agricultural area in 2015 and 2020, which consists of rice field area and rice variety, were used in this study, along with Tier 1 IPCC factor. The results of this study show (1) the value of CH4 emissions from rice fields in 2015 was 0.73 Gg CH4/year and decreased by 0.64 Gg CH4/year in 2020. Meanwhile, methane emissions from animal husbandry were 0.35 Gg CH4/year in 2020. This decrease was caused by land-use change in the Bedog Sub-watershed. (2) Theoretically, adaptation and mitigation strategies that can be implemented in the Bedog sub-watershed are the technology for water management and farming, capacity building, determining the appropriate variety and feed, fertilizing, regulating water regimes, method of tillage, and processing biogas.
Evaluation of Settlement Relocation Due to the 2018 Palu Earthquake
Authors: Marwasta D
Published: September 2022

The earthquake followed by the Tsunami and Liquefaction in Palu City, Donggala Regency and Sigi Regency, Central Sulawesi Province on Friday, September 28, 2018 with a magnitude of 7.4 on the Richter Scale has resulted in hundreds of people missing, more than two thousands of people injured and thousands of people dying. BNPB informed that there was quite a lot of physical damage to facilities and infrastructure, including several houses and public facilities in residential locations. The steps taken in response to the incident were the relocation of settlements in disaster-affected areas, one of which was in the Sidera Transmigration settlement area. This article aims to analyze and evaluate the relocation of settlements, especially in the Sidera Transmigration settlement area. The method used is thematic mapping of the factors that determine land suitability for settlements, and spatial analysis using map overlay techniques complemented by quantitative descriptive analysis. The results of the analysis and evaluation indicate that the transmigration area used as a residential relocation area for disaster victims is quite appropriate and meets the requirements for living, feasible for business, suitable for development, and environmental friendly.
Building density and its implications to COVID-19 health risk management: An example from Yogyakarta, Indonesia
Authors: Larasati Ajeng , Handayani Warsini , Febriarta Erik
Published: September 2022

Transmission rates of COVID-19 have been associated with the density of buildings where contact among individuals partially contributes to transmission. The research sought to analyze the spatial distribution of building density derived from satellite images and determine its implications to COVID-19 health risk management using Yogyakarta and its surrounding districts as an example. Fine-scale building distribution obtained through remote sensing data transformation was analyzed with GIS. NDBI was applied to Landsat 8 imagery; then, using multiple linear regression analysis, it was correlated to building density’s training samples generated from high-resolution imagery. The derived percent of building density (PBD) was combined with publicly available records of COVID-19 infection to assess risk. This research found that PBD could explain the uneven COVID-19 diffusion at different stages of its development. Instead of dividing regions into zones based on confirmed cases, government and public health officials should observe new cases in high-PBD districts; then, when the cases are decreasing, their attention should shift to low-PBD districts. Remote sensing data allow for moderate-scale PBD mapping and integrating it with confirmed cases produces spatial health risks, determining target areas for interventions and allowing regionally tailored responses to anticipate or prevent the next wave of infections.
Coastal Hazard Modeling in Indonesia Small Island: Case Study of Ternate Island
Authors: Handayani W , Mutaqin B W , Marfai M A , Tyas D W , Alwi M , Rosaji F S C , Hilmansyah A A , Musthofa A , Fahmi M S I
Published: September 2022

Indonesia’s small islands have a high potential for multi coastal hazards, including tsunami and coastal floods due to sea-level rise and tidal waves. Meanwhile, most small island populations live in coastal areas, which increases the potential for disaster risk. Hazard assessment is one of the essential stages and bases in disaster management. This study focuses on tsunami and coastal flood hazards modeling in Ternate Island and analyzing the potential impact on coastal land use. This research combined detailed remote sensing data and geographic information system methods to assess the coastal hazard models. A very detailed resolution remote sensing imagery of Pleiades and detail resolution imagery of SPOT 7 are used as input for physical parameter extraction. DEMNAS (Digital Elevation Models Nasional) data as a topographic parameter is used in potential tsunami and coastal flood hazard area coverage. A numerical model is applied to assess the tsunami hazard model using surface roughness, slope, and run-up scenarios based on historical data. At the same time, the coastal flood model integrates sea level rise parameters and average tidal waves. The research results are believed to contribute as important input data for disaster management based on the sister island concept in Indonesia.
Socio-Demographic Factors Affecting Food Security for Low-Income Household During the COVID-19 Pandemic in the Special Region of Yogyakarta
Authors: Hermawati I , Hanjarwati A , Akil H A
Published: September 2022

The COVID-19 pandemic has affected household food security, especially those with low incomes. This study aims to: (1) analyze the influence of socio-demographic factors (gender, age, mother’s education, marital status, occupation, dependents, income, and social assistance) on food security. (2) Measuring the level of food security of low-income families in the Special Region of Yogyakarta seen from the share of food expenditure, using a cross-sectional design and a quantitative approach and involved a sample of 250 low-income households, determined randomly by purposive sampling technique. We collected data through questionnaires, and the data were analyzed using descriptive statistical methods and multiple linear regression models using SPSS software. Three socio-demographic variables affect food security: employment, income, and the number of dependents. Simultaneously, these factors significantly affect the respondents’ food consumption expenditure. This study found that only 42.4% of respondents had food security. It shows that the current COVID-19 pandemic has exacerbated the poverty experienced by respondents. As for recommendations: (1) The government needs to provide social protection to help low-income households through food assistance programs. (2) Social protection programs need to be combined with household-based socio-economic empowerment programs to improve the food security of low-income households sustainably.
The Strategies of Sustainable Watershed Management at Bedog Sub-Watershed, Special Region of Yogyakarta
Authors: Adhitama S Y , Musthofa A , ‘A Rohmah A , Nurwidiani T , Sejati M A , Wati E T , Saputro R , Rachmawati R , Nurjani E , Sudrajat
Published: September 2022

A watershed plays significant roles for maintaining the balance of ecosystem, particularly on the fluvial landform dynamics. Bedog Sub-Watershed as a part of Progo Watershed flows across 11 sub-districts from Sleman and Bantul Regency. This sub-watershed indicates rural-urban characteristics and multi-aspects problems, such as the loss of croplands, a massive land-use changes into built-up area, and the decrease of environmental carrying capacity. On the purposes of preventing the negative aftermaths, this research aimed to create the strategies of sustainable environmental management in case of Bedog Sub-Watershed. This research used secondary data from regional planning products, PODES data, and the relevant literature. Primary data was acquired from in-depth interview with BPDASHL Serayu-Opak-Progo and agricultural-related government agency to gain governmental perspective of watershed management. This research used qualitative descriptive technique to analyse the result of interview. Livelihood assets were calculated by scoring index. The SWOT and DPSIR analysis were conducted to create the relevant strategies implying physical, social-economy, and regional development perspectives in the post-COVID-19 pandemic. The strengthening of government’s institutional aspects was the key to the management followed by necessary comprehensive study in Bedog Sub-Watershed management.
Sustainable Livelihoods of Boarding House (Indekos) Entrepreneurs in Sleman Regency During the Covid-19 Pandemic
Authors: Al Tumus M G R , Khadijatusalma  , Rahajeng P D , Khairina N G , Ardianto S D , Fajarwati A , Rijanta R.
Published: September 2022

Sleman Regency, known as the Student City, is greatly affected by the mobility restriction policy which results in a gradual emptying process of boarding houses, so there is an urgency for regional studies regarding the impact of the pandemic on the livelihoods of boarding house business actors in Sleman Regency. In addition, there is no latest policy from the regency government to overcome the said impact other than the policy of implementing health protocols. Hence, the study focuses on the living conditions and livelihood strategies of boarding house entrepreneurs who are heavily affected by the Covid-19 pandemic. The paper aimed to look at two points of view, namely the bottom-up approach to see the affected objects related to changes in the livelihood strategies of boarding house entrepreneurs during the Covid-19 pandemic and the response of business actors in dealing with shock due to the pandemic; and the top-down approach to see the parties who have legal authority by conducting a critical study of the policies at the regency level related to boarding house business actors before and during the Covid-19 pandemic. This research found that there were changes in the assets and livelihood strategies of entrepreneurs which varied following the capacity of the boarding house entrepreneur. Whereas based on a top-down point of view; despite the change in social assistance policies in terms of the type of assistance, targets, and the amount of assistance provided before and during the Covid-19 pandemic; there is no social assistance that is directed specifically to boarding house business actors.
Reconsidering the assessment method of Environmental implications of Circular Economy in the Built Environment
Authors: Andersen S C , Birkved M
Published: September 2022

Are we capable of addressing environmental consequences on societal scale of circular solutions for the Built Environment, or merely capable of addressing these impacts applying a narrow product/corporation perspective? Considering evaluations and quantifications of environmental implications associated with implementations of Circular Economy (CE) design processes in the Built Environment, we postulate that these solutions necessitate decision-support tool-advancement, as CE does not allow for business-as-usual (BAU) assessments only. The BAU assessments of environmental impacts in the built environment, seem to paint a certain picture of the circularity paradigm. The question, however, is whether, by relying on simplified assessments, we end up barely making it to the finish line, very late, and risking loosing focus and creating sectoral burden-shifting. Application of LCA has created a paradoxical situation in the building industry. Gaining more experience in application of LCA, the industry steadily increases the complexity level of the questions to be addressed by LCA, thus increasing scale and complexity of systems to be assessed. Hence, currently, large systems such as CE models for the built environment, are often assessed in the same manner as we assess single buildings and building parts, despite that CE models have a much higher potential to generate feedback effects, so that the system under assessment, changes due to the entity/service being assessed. The main question is hence whether life cycle assessors operating within the built environment are aware of the challenges they are facing when answering questions regarding CE, and if these are addressed, assessment wise, in the /appropriate manner? Secondly, we need to consider how we facilitate assessment of systems at various physical and temporal scales in such a way that it becomes economically and technically feasible for the industry to address complex sustainability questions. This paper discusses possible future application potentials of LCA and propose consistent scenario definition, and thus looks into the question: how come, that we assess almost all systems in a ‘static’ manner, while being completely aware of that we live in a dynamic world? Are we, within LCA, addressing the need for improving the realism of the models that we derive in a sufficient and applicable manner?
Paving the way towards circularity in the building sector. Empa’s Sprint Unit as a beacon of swift and circular construction
Authors: Kakkos E , Hischier R
Published: September 2022

In order to achieve the CO2 targets stipulated within the Paris Agreement, future buildings must be constructed in such a way, that their emission profile will be close to zero. In order to achieve this, a radical shift towards a circular construction manner which encompasses topics like material reuse (i.e. design for multiple lifecycles), design-for-disassembly (allowing for maximum recovery of materials and minimization of construction waste) must be promoted against todays, conventional construction practices. Furthermore, the current Covid-19 pandemic has shown that buildings must be constructed in a more flexible manner, in order to be adaptable to changing needs as quickly as possible – including new types of needs. A transition to such a circular construction practice requires also new approaches for Life Cycle Assessment (LCA), taking into account issues such as the circularity or multiple life cycle of materials. Conventional LCA methods fail to deliver trustworthy results as they are designed to assess products and buildings that have only a single life cycle. In this context, a newly constructed unit, set to be the embodiment of the circular construction principle that incorporates all the above-mentioned concepts in the form of a cluster of flexible office spaces, has been integrated into the research building NEST (Next Evolution in Sustainable Building Technologies) – a platform located at the Empa campus in Dübendorf (Switzerland), where novel building technologies can be tested and validated under realistic conditions. Its name: Sprint. In this paper, the environmental performance of Sprint is assessed through LCA, using three different approaches – the EN15804 method, the Product Environmental Footprint method and the Linear Degressive approach – with the latter two approaches considering the circularity of materials, while each one having an own, distinctive allocation rule for the split of the impacts between the current, the previous and the subsequent lifecycles.
Demolish or reuse? – The balance between operational and embodied emissions in the retrofit of commercial buildings
Authors: Abbey D , Arbabi H , Gillott C , Ward W , Tingley D D
Published: September 2022

There are two clear options for reducing the emissions of poorly-performing buildings: refurbishment of the space to a higher standard or demolition and replacement with a better performing building. Non-residential buildings are subject to the latter of these options more than dwellings due to higher rates of ownership changes. This study assesses the carbon emissions of each of the above options for a poorly-performing retail building in Sheffield, UK. The embodied carbon and operational performance of each scenario are calculated to identify the most sustainable option over a 50 year lifespan. The scenario with the lowest emissions is found to be a retrofit case study relying upon electricity as its sole fuel source. The new build scenarios emitted significantly more carbon over the building’s lifespan despite performing better operationally than the refurbishment scenario. It was also found that, due to the decarbonisation of the national grid, relying on gas boilers instead of electric fuel sources would make carbon emissions approximately 2.5x bigger in the refurbishment model, despite being legal under UK building regulations.
Drivers and Challenges for Implementing Sustainability-oriented Upgrading in Social Housing in Brazil
Authors: Vasconcellos L H , Kowaltowski D , Gomes V
Published: September 2022

Social housing (SH) development is, in general, triggered by policies and regulations, which stimulate interventions, create financing mechanisms, and designate agents conducive to retrofit processes. European directives for energy efficiency and the recent call for a ‘retrofit wave’ have an evident influence. In Brazil, delivery and management of SH are based on the public offer of housing units and their immediate ownership transfer. National or state housing agencies are responsible for basic maintenance for five years, but other post-delivery interventions depend exclusively on the effort and expenses of the occupant. SH budgets leave little or no margin for extra spending and bringing SH to international sustainability standards is yet not mandatory. The issues that arise to implement upgrading in this context are therefore related to the following questions: What are the priority actions in upgrading processes? What type of financing would be required or is available? What is the project execution model and who are the stakeholders involved? This article focuses on the issue of prioritization of actions for upgrading SH. A systematic literature review examined reported sustainability-related housing improvements. A critical review of a Brazilian building label and two international sustainability assessment methods then supported ranking the upgrading actions according to the relevance assigned in their respective contexts. Finally, a panel of construction professionals provided insights regarding the technical feasibility and intrusiveness of their implementation in both single- and multi-family SH projects. Findings show that minor upgrading actions, such as changing hydraulic or electrical fixtures or landscaping, usually do not cost more than implementing them from the outcome and are equally applicable to single- and multi-family SH projects. But, when high-level (deep upgrading) interventions are on the table, costs rapidly increase due to the need to substantially change existing systems or supporting structures, which makes them often financially and/or technically unfeasible.
New Angles for Adaptive Building Reuse Research
Authors: Bowyer E C , Stephenson V , Hawkins W , Ibell T
Published: September 2022

This paper seeks to establish the current state of research into adaptive building reuse with the view to highlighting new approaches and opportunities for expanding the collective knowledge on this subject. This approach focuses on appraisal and evaluation of current methods by looking through a structural engineering lens and considering the most beneficial options in terms of reducing additional embodied carbon intensity in our built environment.
Exploring long-term building stock strategies in Switzerland in line with IPCC carbon budgets
Authors: Priore Y D , Jusselme T , Habert G
Published: September 2022

Stringent limits and reduction strategies paths on greenhouse gas (GHG) emissions are being defined at different levels for long-term temperature stabilization. Given the nearly linear relationship between warming and cumulative net emissions, a carbon budget approach is required to limit global warming, as stated by the IPCC. In this setting, the built environment, as a cross-sectorial and transnational area of activity, plays a crucial role in today’s carbon emissions and future reduction potentials. Previous research showed the need for effective and aligned carbon-targets to support and guide all actors in the construction sector towards these challenging global goals. In this context, previous research compared top-down derived carbon budgets for the Swiss built environment with a preliminary estimation of future cumulative emissions of the sector. Findings showed the misalignment of current best practices and the significant magnitude of effort that would be required to comply with such objectives. Nevertheless, limitations in the preliminary work emerged, such as the lack of dynamicity of the parameters included in the model restricting the representativity of its results. The current paper brings further this previous work by integrating the dynamic evolution of the energy supply, the materials’ production, and the renovation rate. Results are then presented by mean of a parallel coordinate interactive graph. This interactive component allows the parametric exploration of the compliance with limited global budgets by varying the input parameters. This way the influence of macro-level strategies to decarbonize the Swiss building stock can easily be visualized with reference to the IPCC carbon budgets. Ultimately, the available interactive tool might support policy makers in decisions taken at the building stock level.
Fringe Timber: Informing Regional Mass Timber Urban Environments with Biodiverse Forests
Authors: Wikstrom L , Yu C Z
Published: September 2022

Trees present a vast array of performance in density, growth speed, height, fibre strength, and rates of carbon absorption. This paper explores how biodiverse mass timber is a way to support forest health and improve the health conditions of the most vulnerable—those who have experienced the pollution of mineral-based materials for generations. This symbiotic relationship between forests and urban environments incentivizes better care for both spaces, the transfer of materials should be reciprocal. Fringe Timber looks at the forest surrounding a city to inform its scale of growth and reduce its carbon footprint. Using three case studies in New York City, Denver, and Tulsa, this paper posits city-specific, species-driven supply chains beyond softwoods for mass timber, including hardwoods and hybrids, to support the appropriate scale and speed for urban development.
Benefits of wooden structure reuse: the case of an Austrian building
Authors: Hoxha E , Soust-Verdaguer B , Scherz M , Passer A
Published: September 2022

The building sector is responsible for 39% of greenhouse gas (GHG) emissions; thus, it has a significant amount of potential to reduce the effects of climate change. Several active- and passive solutions and strategies have been developed and proposed in the literature. Among them, wood is highlighted as a promising solution to minimize GHG from buildings. However, the benefits, especially in the circular economy, are not fully evaluated due to methodological choices. Motivated by this knowledge gap, this article aims to evaluate the benefits of wood reuse compared to traditional building construction solutions. For this purpose, we have calculated the environmental impacts of a building situated in Graz, Austria. Four different scenarios are considered. The first scenario is a fully reinforced concrete building. The second scenario is a structural beam-column made from reinforced concrete with walls made of concrete blocks. The third scenario is a beam-column made from reinforced concrete with external walls based on clay blocks. Finally, the last scenario is a full wooden building. Following the standardized life cycle assessment (LCA) method, global warming potential (GWP) is calculated through a 0/0 approach. These evaluations were made possible by correlating the impacts released from producing wooden elements and the uptake of biogenic carbon from the forest. Without considering the possibility of material reuse, the wooden structure has a 5 % lower GWP value than the reinforced concrete building. Comparatively, the other building scenarios have almost similar impacts as the building in reinforced concrete. In the case of material reuse, the wooden structure building shows potential to develop projects with 44% lower environmental impacts.
Designing sustainable office spaces – how to combine workspace characteristics with sufficiency strategies
Authors: Fauth R , Pieper M
Published: September 2022

Contemporary workspace and office concepts are part of many major commercial real estate projects and have been continuously developed over many years. With a rising awareness for sustainable development, workspace and office concepts are increasingly being considered in terms of their environmental performance. Sustainable design strategies therefore traditionally differentiate between efficiency, consistency, and sufficiency, whereas the latter approach is the least explored in the construction industry. Sufficiency can be described by a user behaviour characterized by frugality and modesty, as opposed to wasteful consumption. Moreover, the strategy of sufficiency is linked to a high and critical awareness of using natural resources and environmental impacts which also affects the built environment. The aim of this paper is therefore to combine these two subject areas in a structured way and derive potentials for the sufficient development of office concepts.

Based on a literature review in the field of workspace design and flexible workplace management, design features of office spaces are conceived and compiled according to planning aspects in office concepts based on employee needs. Another literature review in the field of sufficiency in the building sector provides the corresponding structure for the considered sufficiency strategies. Sufficiency measures follow recurring principles for the reduction of resource consumption. Essential principles of impact are identified and presented in this paper. The investigated topic areas are compiled together in a logical model based on a developed mapping framework. This forms the basis for defining sufficient measures that can be derived to sufficiency strategies in the project development of office buildings. The basis of all measures is to strive for a minimum level of resource consumption that is necessary to satisfy the needs of the users and that is considered valuable by them, following the basic idea of the sufficiency approach. The results are validated using an office building in the planning stage. The paper leads to a common understanding and structuring of design features of future office spaces and their environmental impact. Furthermore, the approach provides guidance for concepts on how design features can be considered regarding sufficiency strategies.