bluuebunny/crossref_metadata_2025 huggingface dataset:
Life cycle assessment of pavement construction: A case study
Authors: Koh D , Tokbolat S , Blaauw S A
Published: July 2024

Road construction is often associated with carbon emissions from direct and indirect sources, primarily due to construction and maintenance activities. Currently, there is a lack of comprehensive Life Cycle Assessment (LCA) benchmarks to evaluate flexible composite pavement, fully flexible pavement and pavement rehabilitation options under various ground conditions. The objective of this study is to investigate the environmental impact associated with different pavement designs over a 60-year analysis period, comprising a 40-year basic design period with maintenance extended up to 60 years. This research paper encompasses a literature review on pavement LCA and conducts and LCA on various pavement design and construction options, following the ISO 14040 framework and PAS 2080 methodology. The LCA in this study specifically focuses on material production, transportation, construction, maintenance, and end-of-life phases. Using global warming potential as an environmental indicator, the study calculates and compares a range of potential impacts for each component. In terms of carbon emissions, the rehabilitation option was found to be most favourable when compared to other full-depth reconstruction options, while the flexible composite pavement option exhibited the highest carbon emission value compared to other pavement build-ups assessed. Additionally, a sensitivity analysis was conducted to identify ‘hotspots’ in the study, which increase the confidence level of the results.
Evaluating novel building products through a building design-oriented LCA approach: Example of VIPs in terrace applications
Authors: Božiček D. , Košir M. , Zach J. , Novák V. , Peterková J. , Bubeník J. , Lešek A. , Jordan S. , Malovrh Rebec K.
Published: July 2024

INTRODUCTION: The construction industry is considered conservative in adopting new products/technologies, and environmental characteristics are one of the most important features of novel solutions. In this context, our study aims to present a building design-oriented assessment of a novel building product by extending the functional unit scope and involving multiple realistic building design scenarios. The task will be performed using the example of vacuum insulation panels (VIPs), a superinsulation product that can be used in various building applications. The study will focus on terrace insulation applications, where VIPs are an attractive solution for building designers due to the possibility of barrier-free floor design. However, they lack environmental evaluation. METHOD: A life cycle assessment (LCA) analysis is performed on two hypothetical buildings located in Ljubljana (Slovenia) for the cradle-to-gate and operational energy life cycle stages (A1-A3 + B6 according to EN 15978). A whole-year dynamic thermal response simulation was executed using the Design Builder software. Five barrier-free terrace design scenarios that influence the embodied and operational carbon footprint (while maintaining the functional and architectural integrity of the building design) were examined. RESULTS: The study showed that although EPS insulation showed a smaller embodied carbon footprint on the product level, the building level analysis showed that using VIPs in terrace applications leads to favourable or comparable environmental impact. CONCLUSIONS: Building products can be evaluated on three functional unit levels: product, application and building. By extending the boundaries from the product/application level to the entire building level, the study provides an example of a building design-oriented approach to LCA. The complexity increases by upgrading the functional unit scope to the building level, while the results become more case-specific and less general. Ideally, a novel building product should show environmental superiority on all three levels. However, as there are almost countless design possibilities in buildings, environmental superiority (or inferiority) on the product level does not necessarily indicate superiority (or inferiority) on the building level.
Evaluating environmental impacts of concrete in Lima: Bridging the gap between quantitative LCA results and local contexts
Authors: Rondinel-Oviedo Daniel R. , Keena Naomi
Published: July 2024

Concrete production significantly contributes to environmental impacts in the built environment, especially in rapidly developing urban areas like Lima, Peru, where concrete is a predominant building material, accounting for over 80% of the weight in typical housing structures and significantly influencing environmental impacts. While traditional studies have concentrated on the environmental repercussions of cement production (10-20% of the concrete mix), a major contributor to carbon emissions, this study also focuses on the often-overlooked other impacts of concrete production. These impacts are often felt on a more local scale. They are associated with the other non-cement constituents of concrete, namely water, aggregates, and sand, representing about 80% of the mix mass. While the carbon impacts of non-cementitious materials may appear relatively low compared to cement, their significance becomes evident when viewed within the local context and their potentially correlated qualitative effects throughout the entire life cycle. In this sense, this paper does not only look at climate change impacts of cement production but also eight other critical environmental indicators, including particulate matter, land use, water use, and resource consumption, which are quantitively evaluated using a Life Cycle Assessment (LCA). Hence, this paper employs a quantitative approach to analyze the life cycle impacts of concrete use in Lima. The results offer valuable insights into the environmental impacts within the concrete supply chain in Lima, corroborating existing literature and affirming the robustness of the LCA methodology. Moreover, the results underline the pivotal role played by non-cementitious components like water, sand, and gravel in shaping the overall environmental footprint of concrete. However, the study primarily underscores the necessity of integrating alternative evaluation methods to comprehensively understand impacts, particularly for identifying overall local impacts. Consequently, a key contribution of this paper is highlighting the gaps in focusing solely on LCA to understand the sustainability of concrete production. It emphasizes how the results of an LCA may assist in identifying such gaps and pose questions for considering a more holistic understanding of the social and local impacts of concrete production. This approach aims to uncover entropic impacts across the production spectrum, paving the way for future research in unexplored areas of concrete production’s environmental and social implications.
A Systems Perspective on the Interactions Between Urban Green Infrastructure and the Built Environment
Authors: Reitberger R , Pattnaik N , Parhizgar L , Trost C , Yazdi H , Rahman M A , Pauleit S , Roetzer T , Pretzsch H , Traidl-Hoffmann C , Ludwig F , Reischl A , Plaza Garcia M P , Lang W
Published: July 2024

This research addresses the intricate dynamics between urban green infrastructure (UGI) and the built environment, focusing on the effects of urban heat islands, building energy demand, and human health. Following the idea of the Socio-Ecological-Technological Systems framework, we investigate key indicators related to green and grey infrastructure and their interactions at the urban scale. We construct a comprehensive causal-loop diagram through an iterative approach involving literature analysis and expert consultation. The outcomes highlight the significance of urban form and green infrastructure in connecting indoor and outdoor spaces. This research enhances the understanding of systemic behavior in the urban fabric and offers insights into the complex interactions between UGI and the built environment. The approach underscores the value of iterative modeling, fostering collaborative efforts and providing a foundation for further system modeling. Future research should focus on quantitative validation of the identified connections. Additionally, connection strengths and spatial elements would be valuable extensions of the presented system model.
Visual Impression of urban waterways in shrinking cities: Case study of Matsue canal network around the castle
Authors: Nguyen Tran YK , Nguyen Tran THN , Kouno R , Loh JH
Published: July 2024

Matsue City in Japan, known as the “City of Water,” has historically celebrated its urban waterways for their scenic beauty. However, due to factors like rapid urbanization, an aging population, and recent isolation challenges, these waterways have lost their prominence. This research aims to understand the visual impression of Matsue City’s waterways and their connection to the city. Our approach involves a mixed data collection method. We mapped physical elements along the waterways, categorized them, and analysed the results. We also captured photos of the sceneries, examining their composition using photo segmentation. Additionally, a photographic questionnaire was conducted with respondents familiar with these areas, cross-referencing their responses with interviews that included renderings of the sceneries. The outcomes reveal insights into the visual appeal of urban waterways and their impact on inhabitants. By identifying elements that resonate and understanding shortcomings in the current landscape, our research contributes to revitalization efforts. The findings emphasize the potential of Matsue City’s historical waterways for sustainable development strategies, highlighting the importance of preserving and enhancing these natural assets for the benefit of residents and the city’s overall development.
Review of urban water thermal environment cooling
Authors: Qiu Y F F , He B J
Published: July 2024

The urban underlying surface undergoes constant changes due to the acceleration of urbanization. The increasingly prominent heat island phenomenon has led to higher energy consumption and worsened thermal conditions, significantly impacting people’s daily outdoor activities and health. Water bodies, as a unique form of underlying surface, play a crucial role in enhancing the urban microclimate through their large heat capacity, high latent heat of evaporation, and low reflectivity.

Previous research on the thermal comfort effect of water bodies primarily focuses on meteorology, environmental science, and landscape architecture. While quantitative studies have been conducted at both macro-scale city regions and micro-scale field domains to investigate the mechanisms behind these effects, there is a lack of translation from data into practical application strategies. In this study, we aim to adopt an interdisciplinary approach to review previous research achievements comprehensively. Firstly, we will examine the mechanisms and influencing factors involved in water body thermal regulation. Secondly, we will explore major methods and techniques for cooling urban water bodies while establishing an interactive model that considers landscape elements alongside physical factors affecting microclimate conditions. By developing a climate-adaptive design framework that addresses human thermal comfort requirements effectively, our goal is to create more livable and sustainable urban environments through scientifically sound strategies for cooling urban water bodies.
Use of Crash Data Repositories: Combining Digital Tools with Analog Built Environment Assessments to Promote Physical Activity
Authors: Bjerke W
Published: July 2024

Among promising instruments and evaluation systems for neighborhood development are digital crash data repositories including the UConn Connecticut Crash Data Repository (CTCDR) combined with Built Environment (BE) assessments and walkability audits (WA). Users of these tools include transportation authorities, community planners, and community-centered commissions established to promote safety and physical activity. The Norwalk Bike Walk Commission (NBWC) was created in 2017 to promote walking, biking, and related BE policies in Norwalk, Connecticut (CT). NBWC projects include compliance with the Complete Streets Law, and bicycle/pedestrian plans for Norwalk. The NBWC works directly with city officials associated with transportation and city planning. A top priority of the NBWC is to examine high-risk areas of pedestrian and bike fatalities and injuries in the city using digital and analog tools as well as identifying ways to merge the information gained from these distinct tools. The CTCDR was created in 2015 to permit public access to all crash data in CT. By identifying the highest risk areas of a community (Norwalk), future projects of the NBWC can be prioritized and coordinated. The CTCDR was used to generate broad and specific data in CT that involve pedestrians and bicycles. The number, type, and severity of crashes were specified. Subsequently, the specific locations of these crashes are identified. Specific locations were further assessed using Google Maps combined with BE and WA tools. In aggregate, these details identify high-risk and high-priority areas. In Norwalk, there are an average of 43 crashes involving pedestrians and 16 related to cyclists per year. Specific locations were identified and assessed using BE and WA tools. Combined approaches identified the highest priority locations. Combining digital and analog tools may optimize built environment policies and promote physical activity in communities.
A review of the contribution of nature-based solutions to the urban metabolism of the informal settlements
Authors: Nalumu D J , Perrotti D
Published: July 2024

The role of nature-based solutions (NBS) in improving access to resources is growing across research, particularly within the urban metabolism literature. However, research on NBS towards material flow stock in the informal settlements (IS) of the Global South is limited, despite an increasing focus across social and environmental sciences on the capacity of NBS to address the needs of vulnerable communities. This study uses the social-ecological analytical framework to analyse the role of NBS in the contribution of material flow stocks in the IS. A Boolean search methodology was adopted to obtain relevant literature from the Scopus preview database. The results show that NBS play multiple roles in providing basic needs in the IS. Additionally, the IS dependence on NBS is due to the exclusion from the municipal provisioning services. However, residents of the IS contribute immensely to the sustainable development of most cities. This study recommends a bottom-up social-ecological system approach to understand human and nature interaction at the intra-urban scale, particularly in the IS to achieve sustainable and inclusive cities.
From Material Cadastres to a Materiality Informed City Information Modelling
Authors: Schiller G , Gruhler K , Zhang N , Blum A
Published: July 2024

Urbanization and built environment significantly impact resource consumption, posing sustainability challenges, especially regionally, due to bulk material dominance. Circular practices, like closing, slowing, and narrowing offer solutions. However, effective circularity management requires understanding built environment material stock comprehensively. Material cadastres model city and regional materiality using typology approaches and GIS Modelling, offering insights into circularity potential and supporting strategic circular city management. Conversely, urban planning digitalization introduced City Information Modelling, linking GIS for urban structure mapping with Building Information Modelling systems for digital building integration and thus support urban planning. Yet, empirically, materiality and circularity issues lack systematic and comprehensive integration in such approaches. To this end, this paper discusses the potential of developing digital material cadastre concepts towards materiality-based urban information modelling using case study results that reveal strengths and limitations of existing cadastre concepts. We present a methodological overview covering a general approach to built environment material cadastres and the main components of the underlying bottom up Material Flow approach: material composition indicators and GIS based building stock modelling and a dynamization approach. To discuss circularity potentials of the built environment in a larger urban regional development context, we furthermore designed material cadastres for two case study cities and calculated exemplary circularity potentials for closing, slowing and narrowing approaches. The findings and drafted conclusions were then reflected with urban planning and development actors in workshops and group discussions. As a result, we present consolidated propositions with respect to bridging the methodological gap between strategic and operational materiality informed urban and regional planning in the transition of the built environment towards circularity.
Analyzing the environmental impact of conventional wooden and modern reinforced concrete construction systems
Authors: Keles Cagla , Cruz Rios Fernanda , Hoque Simi
Published: July 2024

Anatolia is a homeland for many traditional construction techniques due to its rich historical background. One such technique is the hımış system, which involves filling a wooden frame with masonry material (brick, stone, and adobe). This construction method, commonly found in Anatolia, represents one of the most prevalent types of traditional houses. However, with the increasing adoption of reinforced concrete systems in modern construction, Anatolia’s buildings are now being constructed with concrete systems. This paper aims at comparing the embody energy use and carbon emissions of the traditional hımış system, compared to modern reinforced concrete systems. The findings of the study suggest that the total embodied energy per m2 of wall space in modern structures spans from 3000 to 1700 MJ/m2, in contrast to traditional structures where it ranges between 1200 and 300 MJ/m2. Furthermore, the range of total embodied carbon emissions in modern buildings is observed to be between 320 and 120 CO2kg-eq/m2, while in modern structure systems, it varies from 150 to 20 CO2kg-eq/m2. This inconsistency underscores the environmental advantages of traditional building techniques over their modern counterparts in terms of both embodied energy and carbon emissions. The relative share of concrete significantly affected the results for modern systems, while the presence of lime plaster increased the environmental impacts of the hımış systems.
Carbon-storing Prefabricated Retrofit Panel Designs
Authors: Pope H , Carver M , Conley B
Published: July 2024

There is a need for proven, resilient, scalable building envelope assemblies and construction systems for rapidly decarbonizing and adapting existing Canadian houses and buildings to changing climatic conditions. NRCan’s Prefabricated Exterior Energy Retrofit (PEER) project developed and demonstrated a methodology for mass, deep building retrofit using prefabricated panels. In 2023, CanmetENERGY launched a new project to incorporate promising carbon-storing, but unproven materials into prefabricated retrofit panels. In this paper, carbon-storing materials were evaluated and selected according to a variety of criteria including lifecycle carbon, hygric and thermal properties, constructability, cost, and Canadian availability. The most promising materials were selected and integrated into a panel concept. A panel concept and associated construction details were developed and modelled for embodied carbon and thermal performance. Finally, prototypes were fabricated, and a pilot project was conducted to assess constructability. The modelled thermal resistance of the panel design ranged from RSI 4.65 to 5.04 (depending on insulation material), sufficient to achieve net-zero or passive house performance for typical, existing Canadian homes. Carbon storage potential ranged from 7.6 to 34 kg CO2e/m2. If deployed at scale, such solutions could help to offset the embodied carbon associated with construction of new homes/buildings in Canada each year.
Material evaluation of earth block masonry in the context of Belgium: a survey
Authors: Vries N de , Novais Passarelli R , Nuyts E , Knapen E
Published: July 2024

Earth block masonry (EBM) has a low embodied energy and a high circular potential, making it an environmentally responsible alternative to conventional building materials in Belgian mainstream construction. Additionally, its similarity with conventional equivalents makes EBM suitable to substitute large volumes of carbon-intensive building materials without drastic changes in the industry. Despite its potential, the application of EBM scarcely occurs in contemporary construction. While current research on EBM mainly focuses on technical properties and product development, insufficient research has been conducted on material evaluation, perception and experience by potential (end-) users. To understand which factors are important during the process of material evaluation, literature in this field is discussed, and a framework for material evaluation is formulated. Through a survey, this framework is employed to map the material evaluation of potential users, using five mock-up walls of EBM with various earth block (EB) types, earth mortars and jointing techniques. The results show that the most mentioned sensory attributes are the colour and roughness of the material. From an experiential point of view, respondents experience the walls as being (technically) trustworthy but often also as traditional or unstylish. Finally, most respondents indicate having a positive attitude towards potential implementation, even though plastering of the walls is preferred. These results are a first step in understanding users’ perceptions and experiences and help identify aspects that need extra attention when further developing, commercialising, and communicating with regard to EBM in Belgium.
Environmental assessment of materials in preparing alkali-activated materials using bauxite residue
Authors: Guha R , Bambier P , Ouellet-Plamondon C M
Published: July 2024

Aluminum is a highly produced metal globally. In the built environments alone, aluminum is known for its light weight and anti-corrosive properties and is a common choice of material in window frames, curtain walls, and light fixtures. The metal is processed from its oxide, alumina, the production of which releases a caustic byproduct known as bauxite residue (BR). BR is stored in massive reservoirs, however, due to the sheer volume of production, industries handling the material are reaching their storage limits. It is of high importance to research methods to valorize BR. Researchers have proposed a multitude of valorization methods, which include metal recovery from the byproduct, and using BR as raw material in production of another material. However, it is counterproductive to expend considerable amounts of energy and use excessive raw materials to manage utilization of BR. This study compared a method of valorization of bauxite residue with clay bricks. The method of preparing alkali-activated materials (AAM) with bauxite residue as a precursor was semi-quantitatively analyzed to compare the raw materials in the AAM with clay bricks. The materials were analyzed for climate change, ozone depletion, human toxicity, and aquatic ecotoxicity using OpenLCA software and the ecoinvent version 3.4 database. While the alkali activators possessed high values of the environmental impact when measured by the kilogram, the impacts were greatly reduced due to their small percentage in weight contained in the AAM. This study is the first stage of analyzing the environmental costs of valorizing bauxite residue. The AAM showed low environmental impact in material use when impacts of toxicity are considered. However, it displayed a higher climate change impact than that of clay bricks. Transport of raw materials to the preparation site played a significant role in the analysis. The next step is to compare the energy used in preparing AAMs.
Review of the environmental effects of deploying small wind turbines in cities
Authors: Tsionas I , Llaguno-Munitxa M , Stephan A , Gambale Alessandro , Kumar Raghunathan Srikumar Sampath , Mosca Gabriele
Published: July 2024

As the uptake of renewable energy systems increases in cities, attention is drawn to urban Small Urban Wind Turbine (SUWT) implementations. Their installation in cities and replacement of current energy sources can contribute to the mitigation of climate change through reduced local emissions and fewer energy losses, and to resilience through energy independence. These benefits can be directly linked to the UN Sustainability Goals. However, the exploitation of the wind potential using SUWTs in urban areas poses challenges given the variability in the urban morphology and materiality, and their effect on wind patterns. In addition, SUWTs may pose challenges in terms of noise, aesthetics, or safety amongst others. The understanding of the potential environmental effects of urban wind energy harvesting is still limited. Therefore, examining the environmental effect of SUWTs could contribute to establishing necessary regulations and gaining social acceptance, ultimately accelerating deployment. In this paper, we review the recent literature in four databases to identify the potential environmental effects of SUWTs. These effects are classified across two scales: the macro-scale for global effects, and the micro-scale for local effects. The review of the literature shows that the effects are strongly related to the technology of the turbines and the installation location, among other factors.…
A Tri-party Collaboration Empowering Tenants and Employees to Strive Towards Sustainability Goals – The Industry-first ESG Partnership Programme
Authors: Wong Y T , Chan C W
Published: July 2024

With the global aspiration for net zero carbon emissions by 2050, it has become common practice in building design to strive for the implementation of smart and innovative technologies in development projects. This is done to achieve excellent energy and environmental performance while minimizing carbon emissions. However, despite the adoption of various sustainable strategies during the design and construction phases, it should be acknowledged that operational carbon can still contribute significantly to the total carbon emissions over the building’s lifecycle. To effectively work towards the carbon net zero target in building development, a suggested approach is the implementation of a Landlord-Individual-Tenant (LIT) ESG Partnership Programme. This program aims to realize the potential for carbon reduction during the operational phase. In the case study of The Henderson, which is Henderson Land Development Company Limited’s upcoming flagship commercial development in Central Hong Kong, an industry-first Landlord-Individual-Tenant (LIT) ESG Partnership Programme is set to be launched. The LIT ESG Partnership Programme involves a three-way collaboration that includes not only corporate tenants of the commercial development but also their individual employees, all working together to pursue ambitious, data-driven sustainability goals. The ultimate goal of the program is to reshape the current ESG landscape in the property sector by showcasing that an effective ESG partnership program can create synergy between the developer, tenants, and individual occupants to achieve carbon reduction targets.
Building passports in their role as building information systems - background, framework, implications
Authors: Buchholz M , Lützkendorf T
Published: July 2024

Building-related information is essential for performing tasks and making decisions in the design, construction, and management of buildings as well as in transactions. This is increasingly recognized by actors of the real estate industry and by policy makers. As a result, there is a renewed interest in information management solutions and, in particular, building information systems (BISs) with an interface character for multiple tools, such as building passports (BPs) and digital building logbooks (DBLs). Gradually, a better understanding of their main goals and functionalities is evolving due to initiatives in politics, academia, and the real estate industry. However, for wider adoption, a sufficient level of common characteristics regarding the functions, covered data categories, and technical foundations is crucial. Therefore, an information system architecture (ISA) for BPs is proposed that builds upon basics of research on building-related information management and BISs. In addition, selected references are made to insights from business informatics, as this has only marginally been done in traditional approaches of the real estate industry. The ISA provides a holistic view on the relevant elements of a BP and thus serves as a basis for further developments, standardization, and harmonization. The findings are used to discuss practical implications not only for BP design, but also for their use. The authors conclude that the foundation is laid for BPs to become a very useful tool for the transformation of the building stock to support a sustainable development.
A study on rent burden of private rental housings in Japan
Authors: Konno A , Utsumi K , Hasegawa H
Published: July 2024

In Japan, there is a lack of adequate consideration of “appropriate rent burden” that is essential for appropriate promoting of housing safety net measures. Therefore, we intended to obtain basic data to examine the appropriate rent burden. Specifically, using the latest findings of the National Survey of Family Income, Consumption and Wealth that provides the most detailed picture of household finances, we analyzed the rent burden and expenditure elasticity, thereby obtaining the following findings. Rents do not differ significantly according to life stage and annual household income. With regard to expenditure elasticity, the expenditure elasticity of rent is remarkably low compared with other expenditure items. Consequently, Rent is therefore an expense that is difficult to cut even for low-income earners, and the burden is greater among low-income earners. Furthermore, the characteristics of rent burden also differ depending on the household size, also there are clear differences in rent between metropolitan and non-metropolitan areas. Therefore, it was suggested that in promoting the housing safety net measures, it is necessary to study the future of the rent burden in consideration of the household size, and examine the level as a regional minimum in addition to the level as a national one.
Office environment and workers’ productivity in the era of hybrid work: analysis considering office environment and home environment
Authors: Arata Shiro , Sugiuchi Masaki , Kawakubo Shun
Published: July 2024

Since the COVID-19 pandemic, many workers now work both at the office and at home. Although this hybrid workstyle reduces energy consumption and enables businesses to function during natural disasters and pandemics, it is not without controversy. Differences in worker productivity between the office and home are reported to be due to personal attributes such as gender and occupation. Worker productivity may also be affected by the office and home environments. Determining the relationship between worker productivity and the work environment would make it possible to assess the value of offices in the era of hybrid work. This study compared differences in worker productivity between the office and home environments. A survey was conducted of workers in 61 offices in Tokyo, Japan, and productivity was found to be 9.1% higher on average when working at the office than at home. Productivity tended to be higher at the office among workers with high levels of job satisfaction. The probability of increased worker productivity was about 1.46 times higher when the total office environmental performance was superior than when it was inferior. The results suggest that improvements in office environments are needed even in the era of hybrid work.
Fuel starvation in automotive PEMFC stacks: hydrogen stoichiometry and electric cell-to-cell interaction
Authors: Nissen Jens , Boye Jan-Peter , Schwämmlein Jan Nicolas , Hölzle Markus
Published: July 2024

Fuel gross starvation (FGS) in a polymer electrolyte membrane fuel cell is an error state, during which the supplied amount of fuel is insufficient to sustain the requested electrical current. A novel experimental technique was developed to intentionally provoke well-controlled fuel starvation situations of one single cell in a multi-cell fuel cell stack. This modification was implemented in a 20 cell stack of automotive-sized cell geometry and carbon composite bipolar plates (BP). The intentional fuel starvation situation was analyzed using a printed circuit board to measure the current density distribution (CDD) in addition to a multipoint cell voltage monitoring (CVM) to measure local cell voltages. The provoked detrimental subsidiary reactions of the anode were found to take place spatially separated from the normal hydrogen oxidation reaction. It was therefore possible to determine and intentionally vary the hydrogen stoichiometry of the fuel starved cell. This error state caused intense distortions of the starved cells CDD and local cell voltages. The maximum difference obtained between outlet and inlet voltage of the modified cell was 1.4 V. Compared to the average current density, a more than 4-times higher maximum local current density was measured in the affected cell. Adjacent cells were also affected via electric cell-to-cell interaction. Characteristic patterns therefore became visible in the cell voltage distribution, measured by the inlet and outlet CVM. The use of carbon composite BP is favoring the occurrence of these patterns due to their relatively high electric sheet resistance. Using the new hardware setup, we could investigate the relation between the hydrogen stoichiometry of the affected cell during FGS and the observed irregular redistribution of current density and local cell voltages.
Parametric study to investigate mechanical properties of welded dissimilar Al6063 and Al 7073 alloys through FSW process
Authors: Singh Bipin Kumar , Gautam Sujeet Kumar , Anand Anshu , Singh Ritesh Kumar , Tiwari Sanjiv Kumar , Subhani Amir Raza , Upadhyaya Rajat
Published: July 2024

Aluminium alloys have been the most prominent materials that have applications in every industry due to their high strength-to-weight ratio. The low melting point and easy recyclability also attract the scientific community to apply such material in modern manufacturing. The revolution in aluminium alloys came after the invention of friction stir welding, which provided high-end welding results and catastrophically increased its application in aerospace industries. Still, many inconclusive studies need to be explored for its high-end application, especially for newly invented aluminium alloy composites. Hence, this study investigates the application of friction stir welding process for welding dissimilar Aluminium alloy compositions. The investigation starts by analysing the effect of rotational speed, feed rate, and force on temperature generation, hardness, and welding strength. Three levels of process parameters, i.e. rotational speed in the range of 1000–1200 rpm, force of 12–18 N and feed rate of 40–60 mm min−1, are selected to analyse the effect on hardness and strength of the weld. After analysis, the optimum conditions obtained were a rotational speed of 1200 rpm, a feed rate of 50 mm min−1, and an average load of 15 N for a maximum hardness of 93.16 BHN and welding strength of 228 MPa. The investigation’s findings indicated that several phenomena, including the effects of high blending activity, plastic disfigurement, the repercussions of grain structure, and frictional intensity, may influence the hardness and strength of the weld. The growth of uniform structure at the stirred area is caused by pin movement during welding, specifically from the retreating side to the advancing side.
Innovative spoke design for non-pneumatic tyres with enhanced load-bearing capacity and customizability for all vehicles
Authors: Mane Shubham Suresh , Awate Pankaj P
Published: July 2024

For over a century, pneumatic tyres have been a crucial part of automobiles. Recently, non-pneumatic (airless) tyres have emerged, offering innovation but facing challenges in complexity, vehicle safety, adaptability, and load-bearing capacity. This research introduces a new spoke design for non-pneumatic tyres that outperforms conventional honeycomb and diamond spokes tyres in load-bearing capacity, while being less complex and customizable for various vehicles, including public transport. The study is structured into two phases. In Phase 1, the spoke design is selected from various CAD models using SolidWorks. This involves comparing the parabola design against prior design studies and honeycomb and diamond spokes concerning total deformation, maximum shear stress, equivalent (von Mises) stress, and maximum principal elastic strain with the help of FEA software Ansys. Results show that the Parabola design surpasses the pneumatic tyres in terms of load-bearing capacity, The parabola spoke design shows a consistent vertical stiffness under varying loads, ranging from 1500 N to 4500 N, with no sudden spikes or drops indicating structural instability. The objective is to identify the spoke design that best meets the performance objectives for phase 2 analysis. In Phase 2, the material selection and analysis are conducted. The goal is to determine the optimal polyurethane durometer rating for bus tyres. In this phase, the insights from Phase 1 are applied to scale up the design and choose suitable materials, showcasing the design’s adaptability from car tyres to bus tyres. Ansys will be used for analysing the total deformation of the tyre under a force of 40,000N, simulating the extreme operating conditions for bus tyres. This paper provides valuable data on non-pneumatic tyre spoke design, material selection, deformation analysis, design optimization, and standardization, enhancing vehicle safety and performance in public transport.
Expectations Versus Fantasies and Vaccine Hesitancy: How Suffering From COVID-19 Versus Suffering From Vaccines Interact
Authors: Kim SunYoung , Gollwitzer Peter M , Oettingen Gabriele
Published: June 2024

Background

Previous research on COVID-19 vaccination highlights future thoughts associated with possible Coronavirus infection and vaccine side effects as key predictors of vaccine hesitancy. Yet, research has focused on independent contributions of such future thoughts, neglecting their interactive aspects.

Purpose

We examined whether thoughts about two possible COVID-related futures (suffering from COVID-19 and vaccine side effects) interactively predict vaccine hesitancy and vaccination behavior among unvaccinated and vaccinated people. Importantly, we compared two forms of future thinking: beliefs or expectations (likelihood judgments) versus fantasies (free thoughts and images describing future events).

Methods

In Study 1, we conducted a longitudinal study with an unvaccinated group (N = 210). We assessed expectations versus fantasies about the two COVID-related futures as predictors. As outcome variables, we measured vaccine hesitancy, and 9 weeks later we assessed information seeking and vaccine uptake. Study 2 was a cross-sectional study comparing vaccine hesitancy of an unvaccinated group (N = 307) to that of a vaccinated group (N = 311).

Results

Study 1 found that more negative fantasies about COVID-19 impact and less negative fantasies about vaccine side effects interactively predicted lower vaccine hesitancy and more vaccine-related behaviors among unvaccinated people; no such interaction was observed between respective expectations. Study 2 replicated these results of Study 1. Additionally, for vaccinated people, low expectations of negative COVID-19 impact and high expectations of negative vaccine impact interactively predicted higher vaccine hesitancy, whereas no such interaction was observed for respective fantasies.

Conclusions

Research on vaccine hesitancy should explore interactions between future thinking about disease and about vaccine side effects. Importantly, there is much to be gained by distinguishing expectations versus fantasies: vaccination interventions aiming to boost vaccine uptake among unvaccinated people should tap into their negative future fantasies regarding both disease and vaccine side effects.
Diagnosis of acute myocardial infarction in patients with renal failure using high-sensitivity cardiac troponin T
Authors: Knott Jonathan D , Ola Olatunde , De Michieli Laura , Akula Ashok , Mehta Ramila A , Dworak Marshall , Crockford Erika , Lobo Ronstan , Slusser Joshua , Rastas Nicholas , Karturi Swetha , Wohlrab Scott , Hodge David O , Grube Eric , Tak Tahir , Cagin Charles , Gulati Rajiv , Sandoval Yader , Jaffe Allan S
Published: June 2024

Aims

Diagnosing myocardial infarction (MI) in patients with chronic kidney disease (CKD) is difficult as they often have increased high-sensitivity cardiac troponin T (hs-cTnT) concentrations.

Methods and results

Observational US cohort study of emergency department patients undergoing hs-cTnT measurement. Cases with ≥1 hs-cTnT increase > 99th percentile were adjudicated following the Fourth Universal Definition of MI. Diagnostic performance of baseline and serial 2 h hs-cTnT thresholds for ruling-in acute MI was compared between those without and with CKD (estimated glomerular filtration rate < 60 mL/min/1.73 m2). The study cohort included 1992 patients, amongst whom 501 (25%) had CKD. There were 75 (15%) and 350 (70%) patients with CKD and 80 (5%) and 351 (24%) without CKD who had acute MI and myocardial injury. In CKD patients with baseline hs-cTnT thresholds of ≥52, >100, >200, or >300 ng/L, positive predictive values (PPVs) for MI were 36% (95% CI 28–45), 53% (95% CI 39–67), 73% (95% CI 50–89), and 80% (95% CI 44–98), and in those without CKD, 61% (95% CI 47–73), 69% (95% CI 49–85), 59% (95% CI 33–82), and 54% (95% CI 25–81). In CKD patients with a 2 h hs-cTnT delta of ≥10, >20, or >30 ng/L, PPVs were 66% (95% CI 51–79), 86% (95% CI 68–96), and 88% (95% CI 68–97), and in those without CKD, 64% (95% CI 50–76), 73% (95% CI 57–86), and 75% (95% CI 58–88).

Conclusion

Diagnostic performance of standard baseline and serial 2 h hs-cTnT thresholds to rule-in MI is suboptimal in CKD patients. It significantly improves when using higher baseline thresholds and delta values.
Beta-blocker initiation under dobutamine infusion in acute advanced heart failure: a target trial emulation with observational data
Authors: Mori Yuichiro , Inoue Kosuke , Sato Hiroyuki , Tsushima Takahiro , Fukuma Shingo
Published: July 2024

Aims

In patients with advanced heart failure requiring dobutamine infusion, it is usually recommended to initiate beta-blockers after weaning from dobutamine. However, beta-blockers are sometimes initiated under dobutamine infusion in a real-world scenario. The association between such early beta-blocker initiation with clinical outcomes is unknown. Therefore, this study investigates the association between initiating beta-blockers under dobutamine infusion and survival outcomes.

Methods and results

This observational study with a multicentre inpatient-care database emulated a pragmatic randomized controlled trial (RCT) of the beta-blocker initiation strategy. First, 1151 patients on dobutamine and not on beta-blockers on the day of heart failure admission (Day 0) were identified. Among 1095 who met eligibility criteria, patients who were eventually initiated beta-blockers under dobutamine infusion by Day 7 (early initiation strategy) were 1:1 matched to those who were not initiated (conservative strategy). The methods of cloning, censoring, and weighting were applied to emulate the target trial. Patients were followed up for up to 30 days. The primary outcome was all-cause death. Among 780 matched patients (median age, 81 years), the adjusted hazard ratio was 1.11 (95% confidence interval 0.75–1.64, P = 0.59) for the early initiation strategy. The estimated 30-day all-cause mortalities in the early initiation strategy and the conservative strategy were 19.3% (10.6–30.7) and 16.2% (9.2–25.3), respectively. The results were consistent when we used different days to determine strategies (i.e. 5 and 9) instead of 7 days.

Conclusion

The present observational study emulating a pragmatic RCT found no positive or negative association between beta-blocker initiation under dobutamine infusion and overall survival.
Using personal development activities to improve learners’ well-being
Authors: Orosz Agnes
Published: June 2024

During the semester of Oct 2022 to Feb 2023, I decided to incorporate personal development activities into my C1-level General English classes at an Ecuadorian teacher training university in the hope that it would positively impact my students’ well-being both in the present and in preparation for their future careers and lives beyond the classroom. This was only the second face-to-face semester after the COVID pandemic had forced us into online learning for two years, and many students were struggling with a whole host of issues affecting their lives and learning. Throughout the 16-week semester, I supplemented the textbook with various activities focusing on mental and physical health that I had come across in my own self-development journey. This article hopes to point to a possible way to weave well-being competencies into the English language curriculum, which practitioners elsewhere may be interested in applying in their own classrooms.
Trends in Memory Function and Memory Impairment Among Older Adults in the United States and Europe, 1996–2018
Authors: Myrskylä Mikko , Hale Jo Mhairi , Schneider Daniel C , Mehta Neil K
Published: June 2024

Background

Single-country studies document varying time trends in memory function and impairment. Comparative analyses are limited.

Methods

We used self-respondent data on adults aged 50+ years in 13 countries from 3 surveys (United States: Health and Retirement Study, 1998–2018; England: English Longitudinal Study of Ageing, 2002–2018; 11 European countries: Survey of Health, Ageing and Retirement in Europe, 2004–2019). Memory is measured with tests of immediate and delayed word recall. Unweighted age- and gender-adjusted mixed effects regression models as well as models with adjustments for additional sociodemographic characteristics and health behaviors were examined. Heterogeneity in trends by gender, age group, and educational attainment was measured.

Results

The age-adjusted 10-year improvement in average test score is 0.04 standard deviations (SDs) (95% confidence interval [CI]: 0.03, 0.05) in the United States, 0.17 SDs (95% CI: 0.15, 0.19) in England, and 0.24 SDs (95% CI: 0.23, 0.25) in SHARE countries. Trends are largely similar across gender, age groups, and educational attainment. Regional differences in trends remain after adjustment for potential mechanisms. The difference between the United States and other countries is particularly large under 75 years of age compared to 75 years and older.

Conclusions

Pace of improvement in memory function varies strongly across countries. On average, the 11 European countries studied had the fastest improvement, followed by England. The trend in the United States indicates improvement, but at a much slower pace compared to that in England and other European countries. Uncovering the causes for the cross-country heterogeneity in time trends, and in particular the reasons for the comparatively poor performance of the United States, should be both a research and public health priority.