bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Leading Smartwatches for the Detection of Hypoxemia: Comparison to Reference Oximeter
Authors: Walzel Simon , Mikus Radek , Rafl-Huttova Veronika , Rozanek Martin , Bachman Thomas E. , Rafl Jakub
Published: November 2023

Although smartwatches are not considered medical devices, experimental validation of their accuracy in detecting hypoxemia is necessary due to their potential use in monitoring conditions manifested by a prolonged decrease in peripheral blood oxygen saturation (SpO2), such as chronic obstructive pulmonary disease, sleep apnea syndrome, and COVID-19, or at high altitudes, e.g., during sport climbing, where the use of finger-sensor-based pulse oximeters may be limited. The aim of this study was to experimentally compare the accuracy of SpO2 measurement of popular smartwatches with a clinically used pulse oximeter according to the requirements of ISO 80601-2-61. Each of the 18 young and healthy participants underwent the experimental assessment three times in randomized order—wearing Apple Watch 8, Samsung Galaxy Watch 5, or Withings ScanWatch—resulting in 54 individual experimental assessments and complete datasets. The accuracy of the SpO2 measurements was compared to that of the Radical-7 (Masimo Corporation, Irvine, CA, USA) during short-term hypoxemia induced by consecutive inhalation of three prepared gas mixtures with reduced oxygen concentrations (14%, 12%, and 10%). All three smartwatch models met the maximum acceptable root-mean-square deviation (≤4%) from the reference measurement at both normal oxygen levels and induced desaturation with SpO2 less than 90%. Apple Watch 8 reached the highest reliability due to its lowest mean bias and root-mean-square deviation, highest Pearson correlation coefficient, and accuracy in detecting hypoxemia. Our findings support the use of smartwatches to reliably detect hypoxemia in situations where the use of standard finger pulse oximeters may be limited.
Leveraging Larger AES Keys in LoRaWAN: A Practical Evaluation of Energy and Time Costs
Authors: Thaenkaew Phithak , Quoitin Bruno , Meddahi Ahmed
Published: November 2023

Internet of Things (IoT) devices increasingly contribute to critical infrastructures, necessitating robust security measures. LoRaWAN, a low-power IoT network, employs the Advanced Encryption Standard (AES) with a 128-bit key for encryption and integrity, balancing efficiency and security. As computational capabilities of devices advance and recommendations for stronger encryption, such as AES-256, emerge, the implications of using longer AES keys (192 and 256 bits) on LoRaWAN devices’ energy consumption and processing time become crucial. Despite the significance of the topic, there is a lack of research on the implications of using larger AES keys in real-world LoRaWAN settings. To address this gap, we perform extensive tests in a real-world LoRaWAN environment, modifying the source code of both a LoRaWAN end device and open-source server stack to incorporate larger AES keys. Our results show that, while larger AES keys increase both energy consumption and processing time, these increments are minimal compared to the time on air. Specifically, for the maximum payload size we used, when comparing AES-256 to AES-128, the additional computational time and energy are, respectively, 750 ms and 236 μJ. However, in terms of time on air costs, these increases represent just 0.2% and 0.13%, respectively. Our observations confirm our intuition that the increased costs correlate to the number of rounds of AES computation. Moreover, we formulate a mathematical model to predict the impact of longer AES keys on processing time, which further supports our empirical findings. These results suggest that implementing longer AES keys in LoRaWAN is a practical solution enhancing its security strength while not significantly impacting energy consumption or processing time.
Supervised Multi-Layer Conditional Variational Auto-Encoder for Process Modeling and Soft Sensor
Authors: Tang Xiaochu , Yan Jiawei , Li Yuan
Published: November 2023

Variational auto-encoders (VAE) have been widely used in process modeling due to the ability of deep feature extraction and noise robustness. However, the construction of a supervised VAE model still faces huge challenges. The data generated by the existing supervised VAE models are unstable and uncontrollable due to random resampling in the latent subspace, meaning the performance of prediction is greatly weakened. In this paper, a new multi-layer conditional variational auto-encoder (M-CVAE) is constructed by injecting label information into the latent subspace to control the output data generated towards the direction of the actual value. Furthermore, the label information is also used as the input with process variables in order to strengthen the correlation between input and output. Finally, a neural network layer is embedded in the encoder of the model to achieve online quality prediction. The superiority and effectiveness of the proposed method are demonstrated by two real industrial process cases that are compared with other methods.
A New Technique for Broadband Matching of Open-Ended Rectangular Waveguide Radiator
Authors: Heo Ji-Won , Xu Songyuan , Altanzaya Erdenesukh , Zhang Qiongyue , Lee Chan-Soo , Ahn Bierng-Chearl , Ahn Jae-Hyeong , Choi Seong-Gon
Published: November 2023

The maximum reflection at an open end of a standard rectangular waveguide is about −10 dB in its operating frequency range. It is often used without matching. For critical applications, it is desirable to further reduce the reflection coefficient. In this paper, a new technique is presented for the broadband impedance matching of an open-ended rectangular waveguide. The proposed technique employs three thin capacitive matching elements placed at proper intervals via a low-loss dielectric material. The capacitance of, and distance between, the matching elements are optimized for broadband impedance matching using a simulation tool. Based on the proposed technique, two design examples are presented for the matching of a WR75 waveguide radiator. A reflection coefficient of less than −16 dB and −20 dB has been achieved over a ratio bandwidth of 2.13:1 and 1.62:1, respectively.
Electrocardiogram-Based Biometric Identification Using Mixed Feature Extraction and Sparse Representation
Authors: Zhang Xu , Liu Qifeng , He Dong , Suo Hui , Zhao Chun
Published: November 2023

(1) Background: The ability to recognize identities is an essential component of security. Electrocardiogram (ECG) signals have gained popularity for identity recognition because of their universal, unique, stable, and measurable characteristics. To ensure accurate identification of ECG signals, this paper proposes an approach which involves mixed feature sampling, sparse representation, and recognition. (2) Methods: This paper introduces a new method of identifying individuals through their ECG signals. This technique combines the extraction of fixed ECG features and specific frequency features to improve accuracy in ECG identity recognition. This approach uses the wavelet transform to extract frequency bands which contain personal information features from the ECG signals. These bands are reconstructed, and the single R-peak localization determines the ECG window. The signals are segmented and standardized based on the located windows. A sparse dictionary is created using the standardized ECG signals, and the KSVD (K-Orthogonal Matching Pursuit) algorithm is employed to project ECG target signals into a sparse vector–matrix representation. To extract the final representation of the target signals for identification, the sparse coefficient vectors in the signals are maximally pooled. For recognition, the co-dimensional bundle search method is used in this paper. (3) Results: This paper utilizes the publicly available European ST-T database for our study. Specifically, this paper selects ECG signals from 20, 50 and 70 subjects, each with 30 testing segments. The method proposed in this paper achieved recognition rates of 99.14%, 99.09%, and 99.05%, respectively. (4) Conclusion: The experiments indicate that the method proposed in this paper can accurately capture, represent and identify ECG signals.
A Dynamic Path-Planning Method for Obstacle Avoidance Based on the Driving Safety Field
Authors: Liu Ke , Wang Honglin , Fu Yao , Wen Guanzheng , Wang Binyu
Published: November 2023

Establishing an accurate and computationally efficient model for driving risk assessment, considering the influence of vehicle motion state and kinematic characteristics on path planning, is crucial for generating safe, comfortable, and easily trackable obstacle avoidance paths. To address this topic, this paper proposes a novel dual-layered dynamic path-planning method for obstacle avoidance based on the driving safety field (DSF). The contributions of the proposed approach lie in its ability to address the challenges of accurately modeling driving risk, efficient path smoothing and adaptability to vehicle kinematic characteristics, and providing collision-free, curvature-continuous, and adaptable obstacle avoidance paths. In the upper layer, a comprehensive driving safety field is constructed, composed of a potential field generated by static obstacles, a kinetic field generated by dynamic obstacles, a potential field generated by lane boundaries, and a driving field generated by the target position. By analyzing the virtual field forces exerted on the ego vehicle within the comprehensive driving safety field, the resultant force direction is utilized as guidance for the vehicle’s forward motion. This generates an initial obstacle avoidance path that satisfies the vehicle’s kinematic and dynamic constraints. In the lower layer, the problem of path smoothing is transformed into a standard quadratic programming (QP) form. By optimizing discrete waypoints and fitting polynomial curves, a curvature-continuous and smooth path is obtained. Simulation results demonstrate that our proposed path-planning algorithm outperforms the method based on the improved artificial potential field (APF). It not only generates collision-free and curvature-continuous paths but also significantly reduces parameters such as path curvature (reduced by 62.29% to 87.32%), curvature variation rate, and heading angle (reduced by 34.11% to 72.06%). Furthermore, our algorithm dynamically adjusts the starting position of the obstacle avoidance maneuver based on the vehicle’s motion state. As the relative velocity between the ego vehicle and the obstacle vehicle increases, the starting position of the obstacle avoidance path is adjusted accordingly, enabling the proactive avoidance of stationary or moving single and multiple obstacles. The proposed method satisfies the requirements of obstacle avoidance safety, comfort, and stability for intelligent vehicles in complex environments.
Preserving Community Interests in Ocean Governance towards Sustainability: An Editorial Note
Authors: Zou Keyuan , Chang Yen-Chiang
Published: November 2023

It is becoming increasingly evident that the preservation of the marine environment and the sustainable development of marine resources stand as the most critical elements of global ocean governance [...]
Designing the Distribution Network of Essential Items in the Critical Conditions of Earthquakes and COVID-19 Simultaneously
Authors: Abbasi Sina , Vlachos Ilias , Rekabi Shabnam , Talooni Mohammad
Published: November 2023

Current societies must make the necessary plans for effective responses and to reduce the destructive effects of disasters. For this reason, this research has developed a mathematical programming model under uncertainty for earthquake relief and response during COVID-19. In the presented model, the possibility of facility failure is considered according to the intensity of the earthquake and COVID-19 to increase reliability. The simultaneous occurrence of these disasters presents unique challenges in ensuring the timely delivery of essential supplies to affected regions. Distribution centers (DCs) are considered to be of two types: the first type is local DCs, which use public centers and are close to accident points. These types of centers are prone to failure because they use public facilities. Another type is the reliable DCs built outside the disrupted area, which have a very low probability of loss due to spending more money to build them. In addition, to consider the reliability capabilities, the new model has tried to provide a complete model for transportation planning by considering the multi-trip mode of vehicles. Moreover, this model considers distance restriction at the demand point for the first time because of COVID-19 during the earthquake. The proposed network design aims to offer effective solutions in promptly delivering essential items to affected areas, thereby enhancing disaster management strategies and minimizing the impact of these crises on vulnerable populations. Uncertainty is presented using the probability approach based on the modeling scenario and a case study from the city of Istanbul to illustrate the performance of the suggested model. Finally, the suggested mode is solved with an Lp-metric and goal programming (GP) approach. The results show that in this case, the proposed model shows that effective and efficient aid delivery is possible in terms of time and cost. Therefore, it can help crisis managers respond by providing the required budget and appropriate logistics planning.
Does Servant Leadership Decrease Bad Behaviors? The Mediating Role of Psychological Safety and the Moderating Effect of Corporate Social Responsibility
Authors: Roh Taewoo , Kim Min-Jik , Hong Yunsook
Published: November 2023

The aim of this research is to elucidate the intricate dynamics of the effects of servant leadership on employee behavior, particularly focusing on counterproductive work behavior. Drawing on the context–attitude–behavior framework, this study underscores the mediating role of psychological safety in this relationship. Additionally, it unveils the pivotal moderating role of corporate social responsibility (CSR), emphasizing its interaction with servant leadership in influencing psychological safety. To empirically test our hypotheses, we gathered survey data from 394 South Korean workers with a three-wave time-lagged research design. Findings indicate that in contexts with pronounced CSR, servant leadership significantly elevates psychological safety, mitigating negative employee behaviors. Conversely, in organizations with less CSR engagement, these positive effects are attenuated. The results underscore the integral role of CSR in complementing leadership initiatives, advocating for its holistic incorporation into organizational strategies to foster conducive work environments. This research bridges several gaps in the current literature, highlighting the imperative for organizations to intertwine servant leadership with robust CSR endeavors to curtail detrimental employee behaviors. This paper also proposes potential directions for future research in this crucial area.
Sustainability and Consumer Behavior in Electronic Commerce
Authors: Štofejová Lenka , Kráľ Štefan , Fedorko Richard , Bačík Radovan , Tomášová Mária
Published: November 2023

Environmental awareness among consumers is on the rise as they are starting to prefer sustainable products and services. The aim of this research was to examine the relationships between consumer behavior when shopping online for green products and the factors that influence it from the point of view of sustainability. Primary data were obtained using a questionnaire survey and subsequently processed using descriptive analysis, confirmatory factor analysis and structural equation modeling. The obtained research results showed that Digitization in Green Marketing has a significant impact on Environmental Attitude, and that aspects like Environmental Attitude, Environmental Oriented Lifestyle, Willingness to Pay for Green Products and Subjective Norms have a significant impact on Environmental Purchasing Behavior. Moreover, the study found that the factors Environmental Oriented Lifestyle, Willingness to Pay for Green Products, Subjective Norms and Environmental Purchasing Behavior have a significant impact on Future Purchase Intention. The research results can help online retailers in planning and implementing green marketing strategies not only in sales but also in other business processes. In order to stay competitive, businesses should be able to respond promptly to changes in consumer behavior trends, while it is undeniable that the aspect of sustainability plays an increasingly important role here.
Seed Longevity in Desert Species and the Possibility of Forming a Persistent Soil Seed Bank
Authors: Suleiman Majda K. , Bhatt Arvind , Jacob Sheena , Thomas Rini R. , Sivadasan Mini T.
Published: November 2023

The formation of soil seed banks could be an important survival strategy for desert plant species that determine their persistence under harsh conditions, where temperature is extremely high, and chances of rainfall are low and unpredictable. Therefore, the assessment of the seed viability and germination potential of in-situ stored seeds could be important for understanding their reproductive strategies. Seeds of the studied species were collected in 2017 and divided into two batches. The first batch (fresh seeds) of each species was tested for seed germination within one week after collection. However, the second batch (in-situ stored seeds) was tested for seed germination in the first week of October 2022. In the current study, the germination potential of in-situ stored seeds was investigated in order to determine their ability to remain viable under natural conditions. Stored seeds of studied species showed higher germination percentages (53–89%) than fresh seeds (3–34%), except for Peganum harmala, indicating the presence of seed dormancy at the time of seed maturation. Seed germination percentages of all the species were significantly enhanced by storage, indicating their ability to form persistent soil seed banks, although the extent was species-specific. Fresh seeds of all the species attained higher germination in light as compared to complete darkness, suggesting that the germination of seeds can be restricted if they are buried deep in the soil under natural conditions. However, depending on species, in-situ seed storage changed the light requirement for germination. Additionally, the absence of an increase in the ratio of dead seeds between fresh and stored seeds indicates their ability to remain persistent in a soil seed bank and thus may offer great potential for maintaining and restoring desert ecosystems.
Unraveling Debris-Enhanced Local Scour Patterns around Non-Cylindrical Bridge Piers: Experimental Insights and Innovative Modeling
Authors: Al-Jubouri Muhanad , Ray Richard P. , Al-Khafaji Mahmoud Saleh
Published: November 2023

Bridge structures face a critical threat from localized scour-induced damage, prompting urgent attention to civil infrastructure resilience. Prior research has primarily focused on the influence of pier shapes on scour patterns. However, the exploration of the combined effects of various debris shapes, each possessing distinct properties, on predictive scour depth models around the non-cylindrical pier has hitherto remained less researched. This study explored the complex dynamics governing local scour around bridge piers, focusing on the influence of surface and near-surface debris. This research shed light on changes in scour depth by investigating factors like pier geometries, debris arrangements, and submersion depths. The experiments and analysis revealed the effects of various pier shapes—cylindrical, square, rectangular, oblong, oval, and lenticular—on scour patterns. Different geometries influenced primary scour zones and affected areas, with square piers causing the deepest scour and lenticular ones showing shallower instances. Scour depths typically peaked upstream across geometries, but ogival and lenticular shapes exhibited unique patterns. The research also introduced a formula that integrated debris attributes into predictive scour depth modeling, validated with favorable accuracy. Ultimately, this predictive model advances scour prediction, particularly in debris-laden flows, offering valuable insights for engineering and management practices in understanding real-world scour mechanisms and hydraulic dynamics.
What Have We Learned? A Bibliometric Review of a Three-Decade Investigation into the Supply Chain Uncertainty and a Revised Framework to Cope with the Challenges
Authors: Abdul-Hamid Asma-Qamaliah , Osman Lokhman Hakim , Omar Ahmad Raflis Che , Rahman Mara Ridhuan Che Abdul , Ali Mohd Helmi
Published: November 2023

Three decades ago, supply chain uncertainty was recognized as a significant conceptual problem that must be resolved to successfully satisfy supply and demand activities. For this reason, firms have developed several workable approaches and techniques (including lean, agility, and resilient framework) in response to the need to maintain such activities in the face of uncertainty. Despite this, the current pandemic’s onset has hampered supply chain management, indicating that current solutions fall short of being sufficient to shield firms from being impacted. Therefore, it raises the question of what we have learned from decades of research and studies to prepare us for such adversities. And what plans must the firms have put in place to address this disaster? To focus on this, the current study intends to explore supply chain uncertainty trends and patterns, to emphasize the future orientation. Using the PRISMA 2020 (Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020) protocol, 884 peer-reviewed journal articles were selected from the Web of Science database and analyzed using bibliometric analysis through MS Excel and VOSviewer software (version 1.6.18). There are two ways the results are presented. First, performance analysis revealed that 2335 writers had written 884 publications (1993–2022), which had an average 32.2 citation level across 176 journals. Second, the science mapping analysis included well-known methods, such as citation analysis, co-citation analysis, bibliographic coupling, co-word analysis, and co-authorship analysis. The original contribution of this study lies in the identification of four clusters through the analysis, namely, overall impact of uncertainty, demand uncertainty, challenges uncertainty, and uncertain strategy. This led to recommendations for future research that practitioners could use.
Enhancing Cementitious Concrete Durability and Mechanical Properties through Silica Fume and Micro-Quartz
Authors: Khan Mohammad Iqbal , Abbas Yassir M. , Fares Galal
Published: November 2023

The existing body of literature has witnessed extensive research efforts dedicated to exploring the impact of supplementary cementitious materials (SCMs) possessing pozzolanic characteristics on concrete. Nevertheless, the holistic concept of micro-scale fillers has frequently been a subject that remains insufficiently explored. This study endeavors to formulate binary cementitious systems that incorporate silica fume (SF) and micro-quartz filler (MQF) to enhance the durability and mechanical properties of cementitious concrete. We systematically investigate the effects of varying replacement levels of SF and MQF, alongside changes in the water-to-binder (w/b) ratio. With w/b ratios spanning 0.25 to 0.40, we explored replacement levels of 8, 10, and 12% (wt.) for SF, and 5, 8, 10, 15, 25, and 35% (wt.) for MQF. The findings revealed a consistent decrease in porosity and permeability as the replacement levels increase. Notably, a marked increase in compressive strength is observed with SF replacement, reaching its peak at an 8% MQF replacement level. Even as MQF replaces 15% of SF, concrete mixtures with 12% SF consistently exhibit superior strength. Importantly, MQF’s ultrafine particle size mirrors SF’s impact on enhancing compressive strength, porosity reduction, and permeability, despite its high crystalline structure. The study employs an analysis of variance (ANOVA) to rigorously assess the influence of each variable on the studied responses.
Exploring the Success Factors of Smart City Adoption via Structural Equation Modeling
Authors: Alkdour Tayseer , Almaiah Mohammed Amin , Shishakly Rima , Lutfi Abdalwali , Alrawad Mahmoud
Published: November 2023

This study investigated the roles of security and technological factors in the adoption of smart cities, with the aim of developing a deeper understanding of the key aspects of the successful adoption of smart cities in Jordanian traditional cities. This study developed a conceptual model to investigate the importance of security and technological factors in the adoption of smart cities. The proposed model was tested using the structural equation modeling method after collecting data from ICT experts. The findings of the study revealed that perceived security, perceived trust, and service quality play pivotal roles in enhancing the adoption of smart city services. Moreover, the results indicated that information security and information privacy positively impact intentions toward adopting smart city services. These research findings provide valuable insights into the critical factors that can drive the adoption of smart city services. Policymakers and academics could utilize this knowledge to devise and implement new strategies aimed at increasing the adoption of smart city services.
Enhancing Sustainability through Accessible Health Platforms: A Scoping Review
Authors: Ramírez-Saltos Domenica , Acosta-Vargas Patricia , Acosta-Vargas Gloria , Santórum Marco , Carrion-Toro Mayra , Ayala-Chauvin Manuel , Ortiz-Prado Esteban , Maldonado-Garcés Verónica , González-Rodríguez Mario
Published: November 2023

The digital transformation of healthcare platforms has ushered in a new era of accessibility, making health information and services widely available. This comprehensive scoping review delves into the accessibility landscape of health platforms by analyzing 29 carefully selected research articles. These studies employ automated tools and manual evaluations to evaluate platform accessibility comprehensively. This study revealed that (52%) of these articles are based on automated methods, while 34% combine automated and manual approaches. Most studies show compliance with the latest versions of the Web Content Accessibility Guidelines (WCAG), with a significant focus (70%) on compliance with level A. This study reveals recurring issues within the perceivable operable, understandable, and robust categories, underscoring the pressing need for strict the accessibility testing of health platforms. This study demonstrates substantial agreement between raters, reinforced by a Cohen’s kappa coefficient of 0.613, indicating their reliability in classifying the articles. Future efforts should persist in refining accessibility standards, advocating for compliance with the WCAG, exploring innovative methods to assess the accessibility of healthcare platforms, and conducting user-centered research. This review highlights the paramount importance of ensuring equitable access to health information and services for people, regardless of their abilities or conditions, which resonates significantly with the issue of sustainability in healthcare and its socioeconomic and environmental implications.
Properties of Concrete Reinforced with a Basalt Fiber Microwave-Absorbing Shielding Layer
Authors: Jiang Aqing , Song Zihao , Wang Xuancang , Zhao Jing , Ren Junru
Published: November 2023

The purpose of this study was to propose a highly efficient, durable, and environmentally friendly method for the rapid removal of ice and snow. A microwave-absorbing functionality layer was placed between a conductive metal mesh and magnetite sand shielding layer, and ordinary cement concrete (OC). Microwave heating, mechanical strength determination, and indoor and outdoor de-icing tests were performed on the cement concrete specimens with the shielding layer. Basalt fibers were added to the absorbing functionality layer, and the formed specimens were tested for strength and durability. The microstructure was observed using SEM experiments. The results show that the temperature rise of microwave-absorbing cement concrete with a magnetite sand shielding layer (MCMS) and microwave-absorbing cement concrete with a conductive metal mesh shielding layer (MCMM) increased by approximately 17.2% and 27.1%, respectively, compared to that of microwave-absorbing concrete (MAC). After freeze–thaw cycles, the compressive strength and flexural strength of microwave-absorbing concrete with basalt fiber (MAB) increased by 4.35% and 7.90% compared to those of MAC, respectively. The compressive strength and flexural strength of microwave-absorbing concrete with a magnetite sand shielding layer and basalt fiber (MAMB) increased by 8.07% and 6.57%, respectively, compared to those of MCMS. Compared to specimens without basalt fiber, the wear rate per unit area of MAMB decreased by 8.8%, and the wear rate of MAB decreased by 9.4%. The water absorption rate of MAMB specimens decreased by 13.1% and 12.0% under the conditions of 20 and 40 microwave freeze–thaw cycles, respectively, compared to that of MCMS. The water absorption rate of MAB specimens decreased by 9.9% and 8.3% under the conditions of 20 and 40 microwave freeze–thaw cycles, respectively, compared to that of MAC. SEM analysis showed that the addition of basalt fibers improved the compactness and stability of the cement concrete structure as a whole. This study provides valuable references for the promotion and application of microwave de-icing technology.
Geographical Influences on Job–Housing Balance: A Study of Coastal Urban Areas in Boston
Authors: Long Xiaoyu , Wang Luyao , Li Weipeng
Published: November 2023

As cities expand, residents are experiencing increasing commuting distances and a growing trend of job–housing separation, which is often associated with traffic congestion, inefficiency in commuting, and air pollution. In the process of studying the urban job–housing balance, most scholars focus on exploring socio-economic indicators, overlooking the more fundamental characteristics—the geographical features and barriers of the city. This paper delves into the intricate dynamics of the job–housing balance in urban areas, focusing on the city of Boston, characterized by its unique geographic and demographic tapestry. Through the job–housing distribution data of over 3 million residents in Boston and a measurement of spatial proximity to natural barriers, we explore the impact of geographic barriers on residential and employment distributions. Our findings reveal a pronounced divergence in employees’ preferences for job and housing locations, with tracts in the margin areas showing higher aggregation of job distributions and those near geographic barriers exhibiting a low job–housing ratio (JHR) index. Using regression models, our study determined that for every 1% increase in proximity to the Atlantic Ocean on Boston’s right side, job opportunities would decrease by 0.102%, and the JHR would experience a reduction of 0.246%. Our findings prove the importance of the effects of natural barriers on the job–housing balance and provide insights into traffic congestion and the uneven distribution of housing supply prices and have significant implications for urban planning and policy formulation, particularly in coastal cities. By exploring the multifaceted nature of urban residency and employment and the role of geographical constraints therein, this paper contributes valuable perspectives for fostering equitable and sustainable urban development.
Powering the Future: Progress and Hurdles in Developing Proton Exchange Membrane Fuel Cell Components to Achieve Department of Energy Goals—A Systematic Review
Authors: Madheswaran Dinesh Kumar , Thangamuthu Mohanraj , Gnanasekaran Sakthivel , Gopi Suresh , Ayyasamy Tamilvanan , Pardeshi Sujit S.
Published: November 2023

This comprehensive review explores recent developments in Proton Exchange Membrane Fuel Cells (PEMFCs) and evaluates their alignment with the ambitious targets established by the U.S. Department of Energy (DOE). Notable advancements have been made in developing catalysts, membrane technology advancements, gas diffusion layers (GDLs), and enhancements in bipolar plates. Notable findings include using carbon nanotubes and graphene oxide in membranes, leading to substantial performance enhancements. Innovative coatings and materials for bipolar plates have demonstrated improved corrosion resistance and reduced interfacial contact resistance, approaching DOE targets. Nevertheless, the persistent trade-off between durability and cost remains a formidable challenge. Extending fuel cell lifetimes to DOE standards often necessitates higher catalyst loadings, conflicting with cost reduction objectives. Despite substantial advancements, the ultimate DOE goals of USD 30/kW for fuel cell electric vehicles (FCEVs) and USD 600,000 for fuel cell electric buses (FCEBs) remain elusive. This review underscores the necessity for continuous research and innovation, emphasizing the importance of collaborative efforts among academia, industry, and government agencies to overcome the remaining technical barriers.
The Role of the Circular Economy in Fostering Sustainable Economic Growth in the GCC
Authors: Binsuwadan Jawaher , Yousif Ghadda , Abdulrahim Hiyam , Alofaysan Hind
Published: November 2023

Adopting a circular economy (CE) can play a role in achieving economic sustainability for all countries. Material and production waste must be recycled to make better use of limited resources. Developments in the CE need to transition linear economies into circular ones. Although the CE has a role in reaching economic sustainability, few studies have investigated the effect of transitioning to a CE in emerging economies. Thus, it is critical to examine the effect of circular economic influences on economic growth. This paper analyses particular indicators of the CE in the Gulf Cooperation Council (GCC) countries. The analysis employs econometric techniques such as unit root tests, random-effect models, and the autoregressive distributed lag (ARDL) model to examine different components, including environmental, social, and economic. Panel data are used to determine the dependency of circular economic factors on economic growth in GCC countries. The data was collected from the World Bank database covering the years 2000 to 2020. The paper is based on the analysis of the CE filed in GCC countries and intends to contribute to the studies in the field. The results gained from the GCC situation are valuable for both emerging and developing countries looking to include sustainable development measures in their policies and regulations. The findings highlight the importance of the CE to sustainability within GCC countries. This investigation of CE indicators based on the results of the economic model contributes to the empirical literature on the transition to a CE in emerging and developing countries.
Properties of High-Performance Materials for the Crack Repair of Segment Structures
Authors: Sun Xuewei , Zhong Jianjun , Gao Peiwei , Li Guoqing , Xiao Dingkan , Zhang Zhixiang , Gan Ting
Published: November 2023

In order to improve the crack repair effect of high-performance segment structure crack repair materials, in this paper, we used the orthogonal test research method of four factors and three levels to analyze changes in the microstructure of crack repair materials under different material compatibility levels, followed by analysis through the performance testing of repair materials. The flow performance, setting time, compressive and flexural strength, and bonding and tensile strength were studied. The results show that (1) excessively thick epoxy polymer film affects the bond strength, an appropriate increase in the polymer–cement ratio can promote the hydration of cement, and an appropriate increase in gel material can enhance the repair function of repair material; (2) the setting time clearly increases with increases in the polymer–cement and water–cement ratios and the decrease range clearly increases with an increase in the water–cement ratio; (3) the adhesive flexural strength of epoxy polymer repair material increased the most in 28 days; and (4) the bonding tensile strength of the repair material increases first and then decreases with increases in epoxy polymer content. An appropriate increase in the polymer–cement ratio can promote cement hydration.
Soil Tillage and Cropping System Effects on the Physical-Hydric Properties of a Soil under No-Tillage
Authors: da Silva Tiago Stumpf , Suzuki Luis Eduardo Akiyoshi Sanches , Tormena Cássio Antonio , Schmidt Marcelo Raul , Mazurana Michael , Levien Renato
Published: November 2023

A no-tillage system (NT) is an alternative to replace soil management with intense soil tillage and degradation. Our objective was to evaluate the physical–hydric properties of soil under NT for four years after undergoing 13 years of minimum (4NTM) and conventional tillage (4NTC) with reference to continuous NT for 17 years (17NT). The soil bulk density, porosity, storage capacities of water and air, visual evaluation of soil structure (VESS), and saturated hydraulic conductivity were determined. The root dry biomass of soybean, maize, and palisade grass was also measured. NT during four years established after receiving 13 years of tillage did not significantly affect soil properties compared to 17NT, which means that four years of NT reached structural stability similar to continuous 17NT. The VESS scores were less sensitive to identifying soil compaction. Crops have no significative influence on soil properties, but the roots of maize seem to be less sensitive to soil compaction, which is important considering it is in a crop rotation system. The treatments (soil tillage and crop rotation) presented soil compaction below a 10 cm depth, and to our loamy textural class soil, a Bd > 1.60 Mg m−3 restricted soil aeration due to macroporosity < 0.10 m3 m−3.
Nuclear Shape-Phase Transitions and the Sextic Oscillator
Authors: Lévai Géza , Arias José M.
Published: November 2023

This review delves into the utilization of a sextic oscillator within the β degree of freedom of the Bohr Hamiltonian to elucidate critical-point solutions in nuclei, with a specific emphasis on the critical point associated with the β shape variable, governing transitions from spherical to deformed nuclei. To commence, an overview is presented for critical-point solutions E(5), X(5), X(3), Z(5), and Z(4). These symmetries, encapsulated in simple models, all model the β degree of freedom using an infinite square-well (ISW) potential. They are particularly useful for dissecting phase transitions from spherical to deformed nuclear shapes. The distinguishing factor among these models lies in their treatment of the γ degree of freedom. These models are rooted in a geometrical context, employing the Bohr Hamiltonian. The review then continues with the analysis of the same critical solutions but with the adoption of a sextic potential in place of the ISW potential within the β degree of freedom. The sextic oscillator, being quasi-exactly solvable (QES), allows for the derivation of exact solutions for the lower part of the energy spectrum. The outcomes of this analysis are examined in detail. Additionally, various versions of the sextic potential, while not exactly solvable, can still be tackled numerically, offering a means to establish benchmarks for criticality in the transitional path from spherical to deformed shapes. This review extends its scope to encompass related papers published in the field in the past 20 years, contributing to a comprehensive understanding of critical-point symmetries in nuclear physics. To facilitate this understanding, a map depicting the different regions of the nuclide chart where these models have been applied is provided, serving as a concise summary of their applications and implications in the realm of nuclear structure.
Gravity = Yang–Mills
Authors: Bonezzi Roberto , Chiaffrino Christoph , Díaz-Jaramillo Felipe , Hohm Olaf
Published: November 2023

This essay’s title is justified by discussing a class of Yang–Mills-type theories of which standard Yang–Mills theories are special cases but which is broad enough to include gravity as a double field theory. We use the framework of homotopy algebras, where conventional Yang–Mills theory is the tensor product K⊗g of a ‘kinematic’ algebra K with a color Lie algebra g. The larger class of Yang–Mills-type theories are given by the tensor product of K with more general Lie-type algebras, of which K itself is an example, up to anomalies that can be canceled for the tensor product with a second copy K¯. Gravity is then given by K⊗K¯.
Comparative Analysis of Alpha and Beta HPV E6 Oncoproteins: Insights into Functional Distinctions and Divergent Mechanisms of Pathogenesis
Authors: Skelin Josipa , Tomaić Vjekoslav
Published: November 2023

Human papillomaviruses (HPVs) represent a diverse group of DNA viruses that infect epithelial cells of mucosal and cutaneous tissues, leading to a wide spectrum of clinical outcomes. Among various HPVs, alpha (α) and beta (β) types have garnered significant attention due to their associations with human health. α-HPVs are primarily linked to infections of the mucosa, with high-risk subtypes, such as HPV16 and HPV18, being the major etiological agents of cervical and oropharyngeal cancers. In contrast, β-HPVs are predominantly associated with cutaneous infections and are commonly found on healthy skin. However, certain β-types, notably HPV5 and HPV8, have been implicated in the development of non-melanoma skin cancers in immunocompromised individuals, highlighting their potential role in pathogenicity. In this review, we comprehensively analyze the similarities and differences between α- and β-HPV E6 oncoproteins, one of the major drivers of viral replication and cellular transformation, and how these impact viral fitness and the capacity to induce malignancy. In particular, we compare the mechanisms these oncoproteins use to modulate common cellular processes—apoptosis, DNA damage repair, cell differentiation, and the immune response—further shedding light on their shared and distinct features, which enable them to replicate at divergent locations of the human body and cause different types of cancer.
Doxorubicin as a Potential Treatment Option in Canine Mammary Tumors
Authors: Gherman Madalina Luciana , Zanoaga Oana , Budisan Liviuta , Raduly Lajos , Berindan-Neagoe Ioana
Published: November 2023

Canine mammary tumors represent one of the leading malignant pathologies in female dogs, displaying the importance of efficient therapeutic findings, besides the golden-standard surgery, able to limit the development of the disease. Studies in human cancers demonstrated that Doxorubicin presents a good effect in different biological processes like apoptosis, autophagy, the cell cycle, cell invasion, and the epithelial-to-mesenchymal transition. This study followed the effects of Doxorubicin on two canine mammary cancer cell lines P114 and CMT-U27. Doxorubicin treatment in both cell lines shows an inhibitory effect in cell proliferation and an alteration in expression of the EMT-related genes. The obtained results provide valuable information for revealing the link between Doxorubicin, phenotypic changes, and proliferation dynamics in canine mammary tumor models.
A Participatory Approach to Exploring Nexus Challenges: A Case Study on the Pinios River Basin, Greece
Authors: Malamataris Dimitrios , Chatzi Anna , Babakos Konstantinos , Pisinaras Vassilios , Hatzigiannakis Evangelos , Willaarts Barbara A. , Bea Manuel , Pagano Alessandro , Panagopoulos Andreas
Published: November 2023

The conservation of natural resources is indispensable for supporting sustainable development. Water–Energy–Food–Ecosystem (WEFE) nexus management is widely acknowledged as the utmost priority of our time. Considering the specificities of the different nexus sectors, conflicting views of sustainability may arise from different stakeholders. This paper presents and analyses an effective stakeholders’ participation strategy aiming at identifying WEFE challenges in the Pinios River Basin (PRB), the most agriculturally productive and natural resource-stressed basin of Greece. The presented methodology was developed in the context of a Learning and Action Alliance (LAA) scheme adopted by the H2020 REXUS project, intended to support resilient nexus system management with the engagement of stakeholders. The proposed comprehensive methodology comprises multiple phases, including “framing”, “mapping”, “involvement”, “co-production”, and “sharing” phases. The involvement phase is the most interactive one, including the organisation and outputs of efficient crowdsourcing theme sessions organised in the framework of the first REXUS PRB stakeholders’ workshop. This paper illustrates and analyses stakeholders’ perceptions regarding nexus status in the PRB and reveals the most critical challenges in the pilot basin, along with their interdependencies and correlations. The determination of nexus challenges insights by stakeholders could significantly contribute to redefining policies so that they align with sustainable development aims. This methodology is proposed to form the baseline strategy in stakeholders’ engagement for future nexus management studies.
Numerical Simulation of Radiatively Driven Convection in a Small Ice-Covered Lake with a Lateral Pressure Gradient
Authors: Smirnov Sergei , Smirnovsky Alexander , Zdorovennova Galina , Zdorovennov Roman , Efremova Tatiana , Palshin Nikolay , Bogdanov Sergey
Published: November 2023

The results of a numerical simulation of radiatively driven convection (RDC) in a small ice-covered lake with a lateral pressure gradient are shown. RDC influences aquatic ecosystems as convective flow transfers heat and dissolved and suspended matter through the water column. There is a hypothesis that a continuum of convective cells with areas of ascending and descending water flows exists in a convective mixed layer (CML). Until now, little has been known about how the structure of the CML changes in lakes with lateral transport. In this work, the evolution of the CML in the computational domain with a lateral pressure gradient over several days is reproduced using an Implicit Large Eddy Simulation. We show that after a few days of lateral pressure gradient occurrence, convective cells are replaced by rolls oriented along the lateral transport direction. The change in the CML’s turbulence patterns under a lateral pressure gradient is confirmed by Anisotropic Invariant Map analysis. The study revealed a heterogeneity of pulsations of the horizontal and vertical velocity components over the entire depth of the CML and showed that when a horizontal gradient is present, the velocity pulsations generally increase.