bluuebunny/crossref_metadata_2025 huggingface dataset:
Craniofacial 3D Morphometric Analysis with Smartphone-Based Photogrammetry
Authors: Quispe-Enriquez Omar C. , Valero-Lanzuela Juan José , Lerma José Luis
Published: December 2023

Obtaining 3D craniofacial morphometric data is essential in a variety of medical and educational disciplines. In this study, we explore smartphone-based photogrammetry with photos and video recordings as an effective tool to create accurate and accessible metrics from head 3D models. The research involves the acquisition of craniofacial 3D models on both volunteers and head mannequins using a Samsung Galaxy S22 smartphone. For the photogrammetric processing, Agisoft Metashape v 1.7 and PhotoMeDAS software v 1.7 were used. The Academia 50 white-light scanner was used as reference data (ground truth). A comparison of the obtained 3D meshes was conducted, yielding the following results: 0.22 ± 1.29 mm for photogrammetry with camera photos, 0.47 ± 1.43 mm for videogrammetry with video frames, and 0.39 ± 1.02 mm for PhotoMeDAS. Similarly, anatomical points were measured and linear measurements extracted, yielding the following results: 0.75 mm for photogrammetry, 1 mm for videogrammetry, and 1.25 mm for PhotoMeDAS, despite large differences found in data acquisition and processing time among the four approaches. This study suggests the possibility of integrating photogrammetry either with photos or with video frames and the use of PhotoMeDAS to obtain overall craniofacial 3D models with significant applications in the medical fields of neurosurgery and maxillofacial surgery.
Characterization of Upper Extremity Kinematics Using Virtual Reality Movement Tasks and Wearable IMU Technology
Authors: Barclay Skyler A. , Klausing Lanna N. , Hill Tessa M. , Kinney Allison L. , Reissman Timothy , Reissman Megan E.
Published: December 2023

Task-specific training has been shown to be an effective neuromotor rehabilitation intervention, however, this repetitive approach is not always very engaging. Virtual reality (VR) systems are becoming increasingly popular in therapy due to their ability to encourage movement through customizable and immersive environments. Additionally, VR can allow for a standardization of tasks that is often lacking in upper extremity research. Here, 16 healthy participants performed upper extremity movement tasks synced to music, using a commercially available VR game known as Beat Saber. VR tasks were customized to characterize participants’ joint angles with respect to each task’s specified cardinal direction (inward, outward, upward, or downward) and relative task location (medial, lateral, high, and/or low). Movement levels were designed using three common therapeutic approaches: (1) one arm moving only (unilateral), (2) two arms moving in mirrored directions about the participant’s midline (mirrored), or (3) two arms moving in opposing directions about the participant’s midline (opposing). Movement was quantified using an XSens System, a wearable inertial measurement unit (IMU) technology. Results reveal a highly engaging and effective approach to quantifying movement strategies. Inward and outward (horizontal) tasks resulted in decreased wrist extension. Upward and downward (vertical) tasks resulted in increased shoulder flexion, wrist radial deviation, wrist ulnar deviation, and elbow flexion. Lastly, compared to opposing, mirrored, and unilateral movement levels often exaggerated joint angles. Virtual reality games, like Beat Saber, offer a repeatable and customizable upper extremity intervention that has the potential to increase motivation in therapeutic applications.
Agricultural Application Prospect of Fully Polarimetric and Quantification S-Band SAR Subsystem in Chinese High-Resolution Aerial Remote Sensing System
Authors: Liu Yabo , Wang Luhao , Zhu Shuang , Zhou Xiaojie , Liu Jia , Xie Binghong
Published: December 2023

The synthetic aperture radar (SAR) is a type of active radar that can obtain polarization scattering information of ground objects, which is an important supplement to optical remote sensing. This paper designs a high-precision quantitative SAR system that combines radiation and polarization calibration processing to achieve a subtle perception of the changes in soil moisture and straw coverage. In Yushu, Jilin, we conducted the first S-band agricultural remote sensing application experiment. The backscattering coefficient was measured under different water content and straw coverage conditions, and the results showed that the backscattering coefficient increased by about 2 dB and 6 dB, respectively. We estimated that the soil water content increased by about 0.01 cm3/cm3, which was consistent with the theoretical analysis. The polarization scattering characteristics also showed significant differences under different straw coverage. The results indicated that S-band quantitative SAR had an excellent response ability to water content and straw coverage, which provided a technical basis for further radar agricultural applications in the future.
Research on Convolutional Neural Network Inference Acceleration and Performance Optimization for Edge Intelligence
Authors: Liang Yong , Tan Junwen , Xie Zhisong , Chen Zetao , Lin Daoqian , Yang Zhenhao
Published: December 2023

In recent years, edge intelligence (EI) has emerged, combining edge computing with AI, and specifically deep learning, to run AI algorithms directly on edge devices. In practical applications, EI faces challenges related to computational power, power consumption, size, and cost, with the primary challenge being the trade-off between computational power and power consumption. This has rendered traditional computing platforms unsustainable, making heterogeneous parallel computing platforms a crucial pathway for implementing EI. In our research, we leveraged the Xilinx Zynq 7000 heterogeneous computing platform, employed high-level synthesis (HLS) for design, and implemented two different accelerators for LeNet-5 using loop unrolling and pipelining optimization techniques. The experimental results show that when running at a clock speed of 100 MHz, the PIPELINE accelerator, compared to the UNROLL accelerator, experiences an 8.09% increase in power consumption but speeds up by 14.972 times, making the PIPELINE accelerator superior in performance. Compared to the CPU, the PIPELINE accelerator reduces power consumption by 91.37% and speeds up by 70.387 times, while compared to the GPU, it reduces power consumption by 93.35%. This study provides two different optimization schemes for edge intelligence applications through design and experimentation and demonstrates the impact of different quantization methods on FPGA resource consumption. These experimental results can provide a reference for practical applications, thereby providing a reference hardware acceleration scheme for edge intelligence applications.
Securing Cloud-Assisted Connected and Autonomous Vehicles: An In-Depth Threat Analysis and Risk Assessment
Authors: Sheik Al Tariq , Maple Carsten , Epiphaniou Gregory , Dianati Mehrdad
Published: December 2023

As threat vectors and adversarial capabilities evolve, Cloud-Assisted Connected and Autonomous Vehicles (CCAVs) are becoming more vulnerable to cyberattacks. Several established threat analysis and risk assessment (TARA) methodologies are publicly available to address the evolving threat landscape. However, these methodologies inadequately capture the threat data of CCAVs, resulting in poorly defined threat boundaries or the reduced efficacy of the TARA. This is due to multiple factors, including complex hardware–software interactions, rapid technological advancements, outdated security frameworks, heterogeneous standards and protocols, and human errors in CCAV systems. To address these factors, this study begins by systematically evaluating TARA methods and applying the Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, and Elevation of privileges (STRIDE) threat model and Damage, Reproducibility, Exploitability, Affected Users, and Discoverability (DREAD) risk assessment to target system architectures. This study identifies vulnerabilities, quantifies risks, and methodically examines defined data processing components. In addition, this study offers an attack tree to delineate attack vectors and provides a novel defense taxonomy against identified risks. This article demonstrates the efficacy of the TARA in systematically capturing compromised security requirements, threats, limits, and associated risks with greater precision. By doing so, we further discuss the challenges in protecting hardware–software assets against multi-staged attacks due to emerging vulnerabilities. As a result, this research informs advanced threat analyses and risk management strategies for enhanced security engineering of cyberphysical CCAV systems.
Implementation of an Artificially Empathetic Robot Swarm
Authors: Siwek Joanna , Żywica Patryk , Siwek Przemysław , Wójcik Adrian , Woch Witold , Pierzyński Konrad , Dyczkowski Krzysztof
Published: December 2023

This paper presents a novel framework for integrating artificial empathy into robot swarms to improve communication and cooperation. The proposed model uses fuzzy state vectors to represent the knowledge and environment of individual agents, accommodating uncertainties in the real world. By utilizing similarity measures, the model compares states, enabling empathetic reasoning for synchronized swarm behavior. The paper presents a practical application example that demonstrates the efficacy of the model in a robot swarm working toward a common goal. The evaluation methodology involves the open-source physical-based experimentation platform (OPEP), which emphasizes empirical validation in real-world scenarios. The paper proposes a transitional environment that enables automated and repeatable execution of experiments on a swarm of robots using physical devices.
Model Predictive Control of a Semi-Active Vehicle-Mounted Vibration Isolation Platform
Authors: Wu Liang , Zhang Weizhou , Yuan Daofa , Youn Iljoong , Jia Weiwei
Published: December 2023

When conventional delivery vehicles are driven over complex terrain, large vibrations can seriously affect vehicle-loaded equipment and cargo. Semi-active vehicle-mounted vibration isolation control based on road preview can improve the stability of loaded cargo and instruments by enabling them to have lower vertical acceleration. A combined dynamic model including a vehicle and platform is developed first. In order to obtain a non-linear relationship between damping force and input current, a continuous damping control damper model is developed, and the corresponding external characteristic tests are carried out. Because some conventional control algorithms cannot handle complex constraints and preview information, a model predictive control algorithm based on forward road preview and input constraints is designed. Finally, simulations and real tests of the whole vehicle vibration environment are carried out. The results show that the proposed model predictive control based on road preview can effectively improve vibration isolation performance of the vehicle-mounted platform.
Case Analysis of Water Gushing in a Deep Foundation Pit Caused by Local Defects
Authors: Qiao Shifan , Liu Yiqi , Feng Chaobo , Cai Ziyong , Chen Daolong , Meng Fei , Xu Ping
Published: December 2023

Water gushing is a common engineering geological disaster in the process of foundation pit construction. Its successful judgment directly affects the safety of engineering construction. Taking the case of water gushing at the bottom of the foundation pitas as a research object, the mechanism and treatment of water gushing in foundation pits, the stability against water gushing, and its influencing factors are analyzed with a field investigation, field testing, and theoretical calculation. The calculation formula for the safety factor and critical thickness of the foundation pit against surges, considering the influence of multiple factors, is deduced. The influence of the height of the confined water level, the thickness of the water-resisting layer, the shear strength of the soil mass, the reinforcement depth of the soil mass in the pit, and the diameter of the bearing pile in the pit on the safety factor of the foundation pit surge are expounded. In addition, measures such as the reinforcement of the soil mass in the passive area in the pit, the increase in the thickness of the water-resisting layer, and the reduction in the confined water level are proposed to improve the anti-surge stability of the foundation pit. A new monitoring method is proposed for characterizing uplift deformation at the bottom of the pit without affecting normal construction. The research results show that: (1) the minimum safety factor against surges, considering multiple factors, is 1.455, and the critical thickness is 5.87 m, which is in line with specifications. (2) Measures such as reinforcing the soil in the passive zone of the pit, increasing the thickness of the water-insulating layer, and lowering the bearing pressure level are used to improve the stability of the pit against surges. (3) The pit, obtained by the pit bottom counter-pressure, pumping water out of the pit, and the timely construction of the pit bottom bedding to block the program, exhibits a measured maximum bottom plate pressure of 115.189 kPa, and the deformation corresponding to the method proposed in this paper is 1.406 mm, which is better disposed in the field. The research results provide a reference basis for the judgment of anti-surge stability of foundation pits and similar engineering applications.
Yb2+-Doped Silicate Glasses as Optical Sensor Materials for Cryogenic Thermometry
Authors: El Hamzaoui Hicham , Razdobreev Igor , Cieslikiewicz-Bouet Monika , Cassez Andy , Andrieux Vincent , Bouazaoui Mohamed
Published: December 2023

Optical sensors constitute attractive alternatives to resistive probes for the sensing and monitoring of temperature (T). In this work, we investigated, in the range from 2 to 300 K, the thermal behavior of Yb2+ ion photoluminescence (PL) in glass hosts for cryogenic thermometry. To that end, two kinds of Yb2+-doped preforms, with aluminosilicate and aluminophosphosilicate core glasses, were made using the modified chemical vapor deposition (MCVD) technique. The obtained preforms were then elongated, at about 2000 °C, to canes with an Yb2+-doped core of about 500 µm. Under UV excitation and independently of the core composition, all samples of preforms and their corresponding canes presented a wide visible emission band attributed to Yb2+ ions. Furthermore, PL kinetics measurements, recorded at two emission wavelengths (502 and 582 nm) under 355 nm pulsed excitation, showed an increase, at very low T, followed by a decrease in lifetime until room temperature (RT). A modified two-level model was proposed to interpret such a decay time dependence versus T. Based on the fit of lifetime data with this model, the absolute (Sa) and relative (Sr) sensitivities were determined for each sample. For both the preform and its corresponding cane, the aluminophosphosilicate glass composition featured the highest performances in the cryogenic domain, with values exceeding 28.3 µsK−1 and 94.4% K−1 at 30 K for Sa and Sr, respectively. The aluminophosphosilicate preform also exhibited the wider T operating range of 10–300 K. Our results show that Yb2+-doped silicate glasses are promising sensing materials for optical thermometry applications in the cryogenic domain.
Train Axlebox Bearing Fault Diagnosis Based on MSC–SGMD
Authors: Bai Yongliang , Xue Hai , Chen Jiangtao
Published: December 2023

Train axlebox bearings are subject to harsh service conditions, and the difficulty of diagnosing compound faults has brought greater challenges to the maintenance of high–quality train performance. In this paper, based on the traditional symplectic geometry mode decomposition (SGMD) algorithm, a maximum spectral coherence signal reconstruction algorithm is proposed to extract the intrinsic connection between the SGMD components with the help of the frequency domain coherence idea and reconstruct the key signal components so as to effectively improve the extraction of composite fault features of axlebox bearings under different speed conditions. Firstly, based on the traditional SGMD algorithm, the vibration signal of the axle box is decomposed to extract its symplectic geometry components (SGCs). Secondly, the spectral coherence coefficient between the SGCs is calculated, and the signal in which the maximum value is located is taken as the key component for the additive reconstruction Finally, the envelope spectrum is used to extract the reconstructed signal fault features. The inner race, outer race, and compound bearing failure vibration signal acquisition under different speed conditions were carried out on the equal scale axlebox bearing failure simulation test bench, and the effectiveness of the proposed algorithm was verified based on the axlebox vertical acceleration signal.
Physical Conditions That Limit Chickpea Root Growth and Emergence in Heavy-Textured Soil
Authors: Vance Wendy H. , Bell Richard W. , Johansen Chris
Published: December 2023

The tillage method determines several soil physical parameters that affect the emergence of post-rice chickpea (Cicer arietinum L.) in the Indo-Gangetic Plain of South Asia. Mechanised row-sowing with minimum soil disturbance and crop residue retention in medium-to-heavy-textured soils will alter the seedbed when compared to that prepared after traditional full tillage and broadcast sowing. Whilst minimum soil disturbance and timely sowing may alleviate the soil water constraint to crop establishment, other soil physical properties such as soil strength, bulk density, and aggregate size may still inhibit seedling emergence and root elongation. This study’s objective was to determine the limitations to chickpea crop establishment with increasing bulk density and soil strength, and different aggregate sizes below and above the seed. In two growth cabinet studies, chickpea seed was sown in clay soil with (i) a bulk density range of 1.3–1.9 Mg m−3 (Experiment 1) and (ii) the combination of bulk densities (1.3 and 1.8 Mg m−3) and aggregate sizes (<2 mm and >4 mm) above and below the seed (Experiment 2). Root length was significantly reduced with increasing bulk density (>1.4 Mg m−3), and soil strength impeded early root growth at >1 MPa. Where main root growth was impeded due to high bulk density and soil strength, a greater proportion of total root growth was associated with the elongation of lateral roots. The present study suggests that the soil above the seed needs to be loosely compacted (<1.3 Mg m−3) for seedling emergence to occur. Further research is needed to determine the size of the soil aggregates, which optimise germination and emergence. We conclude that soil strength values typical of field conditions in the Indo-Gangetic Plain at sowing will impede the root growth of chickpea seedlings. This effect can be minimised by changing tillage operations to produce seedbed conditions that are within the limiting thresholds of bulk density and soil strength.
Re-Conceptualizing Insider/Outsider Positionalities in Migration Research as ‘Liquid Positionalities’: An Analytical Tool for Migration Scholars
Authors: Tewolde Amanuel Isak
Published: December 2023

Dominant theoretical discussions on insider/outsider, co-ethnic/co-national migrant researcher positionalities have focused on the ideas of group identities such as nationality and ethnicity and how they shape and inform insider/outsider researchers’ positionalities. While some migration researchers argue that shared nationality and ethnicity make co-national or co-ethnic researchers insiders, others contend that the insiderness/outsiderness of co-national or co-ethnic researchers tends to be shaped and informed by multiple, fluid and changing situational factors. This paper draws on ‘fluid identity theory’ and secondary literature to argue that in migration research, insider/outsider positionalities tend to be fluid formations that change, shift and become unstable during research encounters with study participants. I develop an analytical concept that I term ‘liquid insider/outsider positionalities’ to contribute to the literature on insider/outsider researcher positionalities in migration research. By way of introducing this analytical concept, I critique presuppositions, conceptualizations and categorizations of migrant/migration researchers as either insiders or outsiders based on predetermined and rigid social identity markers such as ethnicity or nationality. Migration scholars and researchers may employ the concept of ‘liquid insider/outsider positionalities’ as a tool to frame the dynamic, changing and situational character of researcher positionalities in migration research during field research encounters.
Effect of Blood Flow Restriction during the Rest Periods of Squats on Accuracy of Estimated Repetitions to Failure
Authors: Hackett Daniel A. , Wang Boliang , Tran Derek L.
Published: December 2023

This study investigated the impact of resistance training with blood flow restriction during rest (BFRrest) on the accuracy of estimated repetitions to failure (ERF). It also explored associations between error in ERF and mean concentric velocity (MCV) along with physiological responses. In a randomised cross-over study, 18 male trainers (23.4 ± 2.7 years) performed three sets of squats at 70% of their one-repetition maximum until failure. One session integrated BFRrest, while another employed traditional passive inter-set rest (TRAD) during the 3 min inter-set rest intervals. Cardiorespiratory and metabolic measures were taken in the inter-set recovery periods. The results revealed no significant differences between BFRrest and TRAD in terms of ERF and error in ERF. A notable set effect for ERF was observed, with a greater ERF during set 1 compared to sets 2 and 3 (p < 0.001). Additionally, a lower error in ERF was observed during sets 2 and 3 compared to set 1 (p < 0.001). Error in ERF were strongly associated with the respiratory exchange ratio, and moderately associated with end-tidal carbon dioxide partial pressure, carbon dioxide output, and MCV variables. Notably, the precision of ERF seems to be predominantly influenced by indicators of physiological stress rather than the incorporation of BFRrest.
Changing Urban Temperature and Rainfall Patterns in Jakarta: A Comprehensive Historical Analysis
Authors: Maheng Dikman , Bhattacharya Biswa , Zevenbergen Chris , Pathirana Assela
Published: December 2023

The increasing global population and in-country migration have a significant impact on global land use land cover (LULC) change, which reduces green spaces and increases built-up areas altering the near-surface radiation and energy budgets, as well as the hydrological cycle over an urban area. The LULC change can lead to a combination of hazards such as increasing urban temperatures and intensified rainfall, ultimately resulting in increased flooding. This present study aims to discuss the changing pattern in urban temperature, daily rainfall, and flooding in Jakarta. The daily urban temperature and daily rainfall were based on a 30-year dataset from three meteorological stations of Jakarta in the period between 1987 and 2013. The changing trend was analyzed by using the Mann–Kendall and the Pettitt’s tests. The relation between daily rainfall and flooding was analyzed using a 30-year flooding dataset collected from several sources including the international disaster database, research, and newspaper. The results show that there was an increasing trend in the daily temperature and the daily rainfall in Jakarta. The annual maximum daily temperature showed that an increasing trend started in 2001 at the KMY station, and in 1996 at the SHIA station. In general, the highest annual maximum daily temperature was about 37 °C, while the lowest was about 33 °C. Moreover, the maximum daily rainfall started increasing from 2001. An increase in the maximum daily rainfall was observed mainly in January and February, which coincided with the flood events recorded in these months in Jakarta. This indicates that Jakarta is not only vulnerable to high urban temperature but also to flooding. While these two hazards occur in distinct timeframes, there is potential for their convergence in the same geographical area. This study provides new and essential insights to enhance urban resilience and climate adaptation, advocating a holistic approach required to tackle these combined hazards.
Holistic Assessment of Decarbonization Pathways of Energy-Intensive Industries Based on Exergy Analysis
Authors: Leisin Matthias , Radgen Peter
Published: December 2023

The decarbonization of the industrial sector plays a crucial role in a successful energy transition. This transformation is very costly and complex, as many of the existing production processes and plants will have to be partially or completely replaced to reduce carbon dioxide (CO2) emissions. This raises questions about how significant reductions in CO2 emissions resulting from decarbonization will affect the use of resources to produce a certain product and the overall value of sustainability. This article considers the relationship between CO2 reduction and the impact on the resource efficiency of an industrial production process. For this purpose, a methodology was developed that holistically assesses the decarbonization pathway of an industrial sector. This holistic assessment takes into account the energy carriers, raw materials, and auxiliary and construction materials used for the operation and building of the significant plant components and summarizes them as a total use of resources. For this purpose, the use of resources is represented by the thermodynamic quantity exergy, which takes into account both the energy and material components of a production process. The energy and material streams in a production process are balanced by applying exergetic analysis. This methodology is used for current state-of-the-art and future decarbonized production processes in order to quantify the effects of the decarbonization process. By comparing the calculated resource efficiencies, the thermodynamic impact on the sustainability of decarbonization paths can be set in relation to the amount of CO2 saved. For validation, the developed methodology is applied to a conventional and a decarbonized ammonia production process. The conventional production route represents the production of ammonia by methane steam reforming, and the decarbonized production route is represented by synthesis gas production via water electrolysis and an air separation unit. The resource efficiency of the conventional ammonia production route, taking into account the energy sources, raw materials, construction materials, and auxiliary materials used, is 59%, producing a total of 1539 kg of CO2 emissions per ton of ammonia. The decarbonized process has a resource efficiency of 45%, while no CO2 emissions are produced in this manufacturing process. This means that the decarbonization of the production process reduces resource efficiency by 14%. In relation to the reduced amount of CO2, specific resource efficiency decreases by 9.09%/tCO2. The decline in resource efficiency is mainly due to the high level of heat and energy recovery in the conventional process and the very electricity-intensive hydrogen production in the decarbonized production process.
The Effect of Size on the Mechanical Properties of 3D-Printed Polymers
Authors: Sadaghian Hamed , Dadmand Behrooz , Pourbaba Majid , Jabbari Soheil , Yeon Jung Heum
Published: December 2023

Most of the experiments on additively manufactured polymers are on a small scale, and it remains uncertain whether findings at a small scale can be extrapolated to their larger-scale counterparts. This uncertainty mainly arises due to the limited studies on the effect of size on three-dimensional (3D)-printed polymers, among many others. Given this background, this preliminary study aims to investigate the effect of geometric dimensions (i.e., the size effect) on the mechanical performance of four representative types of 3D-printable polymers, namely, (1) polycarbonate acrylonitrile butadiene styrene (PC/ABS), (2) acrylonitrile-styrene-acrylate (ASA), (3) polylactic acid (PLA) as a bio biodegradable and sustainable material, and (4) polyamide (PA, nylon), based on compression, modulus of elasticity, tension, and flexural tests. Eight different sizes were investigated for compression, modulus of elasticity, and tension tests, while seven different sizes were tested under flexure as per relevant test standards. A material extrusion technique was used to 3D-print the polymers in a flat build orientation and at an infill orientation angle of 45°. The results have shown that the mechanical properties of the 3D-printed polymers were size-dependent, regardless of the material type, with the most significant being flexure, followed by tension, compression, and modulus of elasticity; however, no clear general trend could be identified in this regard. All the materials except for nylon showed a brittle failure pattern, characterized by interfacial failure rather than filament failure. PLA outperformed the other three polymer specimens in terms of strength, irrespective of the type of loading.
Spatiotemporal Dynamics in Economic, Social, and Environmental Upgrading in China: Coupling Coordination and Influencing Factors
Authors: Cai Bowei , Yang Jiangmin , Huang Gengzhi
Published: December 2023

The focus on the concept of upgrading in the study of global production networks has expanded from economic upgrading to encompass social and environmental upgrading. However, rare research pays attention to the complex interplay among these three aspects. This paper tries to integrate the economic, social, and environmental upgrading into an analytical framework through the lens of coupling coordination. Using the Granger causality test and panel regression model, it provides empirical evidence and an explanation of the triad’s interaction based on the Chinese case study. It is found that, over the past twenty-five years from 1996 to 2020, China has seen a significant improvement in the coupling coordination of economic, social, and environmental upgrading with the coordination degree rising from 0.35 to 0.51, though it remains at a low level of coordination. Regional disparities in economic upgrading are more pronounced than those in social and environmental upgrading, and the inter-group disparities between economic and environmental upgrading have widened following the economic crisis. Panel regression analysis shows that economic globalization, public governance, legal environment, and environmental regulation positively influence the coupling coordination of the three types of upgrading, while economic privatization and corporate violations of law tend to have a negative impact.
Investigating New Environmentally Friendly Zeotropic Refrigerants as Possible Replacements for Carbon Dioxide (CO2) in Car Air Conditioners
Authors: Al-Zahrani Ahmed
Published: December 2023

The widespread use of automobiles and the increased duration spent within automobiles equipped with air conditioning systems have prompted various countries to enforce regulations that advocate for eco-friendly cooling substances (refrigerants) characterized by a slight global warming potential (GWP) and the absence of an ozone depletion potential (ODP). The imperative for automobiles to possess air conditioning systems that are both high-performing and eco-conscious has emerged as a means to mitigate their ecological impact, reduce fuel usage, and minimize carbon emissions. Zeotropic refrigerants, with a lower GWP than traditional alternatives, contribute to sustainability in car air conditioning by reducing the environmental impact and enhancing the energy efficiency, aligning with global regulations and fostering innovation in the automotive industry. This shift signifies a commitment to mitigating climate change and adopting environmentally conscious practices. The objective of the present study is to introduce blends of zeotropic refrigerants based on CO2 (R-744), namely R455A (a blend of R-744, R-32, and R-1234yf), R469A (a blend of R-744, R-32, and R-125), and R472A (a blend of R-744, R-32, and R-134a), to enhance the thermodynamic performance of pure CO2 refrigerant. Through the utilization of the Aspen HYSYS V11 software, an investigation is carried out involving thermodynamic energy and exergy analyses, as well as system optimization for an automotive air conditioning (AAC) system utilizing these novel zeotropic refrigerant blends, in comparison with the use of R-744 as the refrigerant. The study delves into the impact of parameters such as average evaporator temperature, condenser/cooler pressure, refrigerant flow rate, and condenser/cooler outlet temperature on AACs’ output parameters and subsequently presents the findings. The outcomes reveal that, under equivalent operational circumstances, the adoption of R455A, R469A, and R472A offers improvements in coefficient of performance (COP) by 35.4%, 18.75%, and 2%, respectively, when compared to R744. This shift is advantageous as it mitigates leakage-related issues stemming from the elevated operational pressure of R744 and eliminates the need for cumbersome equipment. R455A and R469A obtain the greatest COP and exergy efficiency (ηex) values, measuring 4.44 and 4.55, respectively, at the identical operating conditions with optimal condenser/cooler pressures of the examined blends. Furthermore, eco-friendly refrigerants R455A and R472A are recommended for integration into AAC systems in vehicles, as they help combat global warming and protect natural surroundings and leakage issues.
Impact and Spatial Effect of Socialized Services on Agricultural Eco-Efficiency in China: Evidence from Jiangxi Province
Authors: Wang Lu , Gao Xueping , Yuan Ruolan , Luo Mingzhong
Published: December 2023

Agricultural eco-efficiency (AEE) is a crucial indicator of the green development of agriculture. Agricultural socialized services (AS) provide services for the agricultural production process and they promote the effective input of production factors, such as science and technology, talent, information, and capital, into the agricultural production chain, deepening the division of labor and injecting vitality into agricultural development. We measured AEE based on field research data in Jiangxi Province, China. We also constructed an endogenous switching model to explore the impact of AS on AEE. Our results show that, based on the counterfactual assumption, the AEE increased by 13.19% among farmers who adopted the services compared to those who did not. From the perspective of scale and structural differences, the larger the scale of agricultural cultivation, the stronger the impact of AS on AEE. Furthermore, a large share of cash crops was found to inhibit the impact of AS on AEE. We also investigated whether farmers in close proximity to each other affect their neighbors through knowledge dissemination and technology spillover. The extent of the impact of AS on AEE depended on distance thresholds: it was more pronounced when we increased the distance threshold. Our results suggest that the government should improve the AS system, provide more public welfare services, and appropriately subsidize AS organizations. The AS for food crops should be emphasized; however, those for cash crops should not be ignored.
Experimental Investigation on the Effect of Salt Solution on the Soil Freezing Characteristic Curve for Expansive Soils
Authors: Yu Haiwen , Hao Fengfu , Yi Panpan , Zhang Qin , Ma Tiantian
Published: December 2023

With the development of the Belt and Road Initiative in China, high-speed railways are booming and inevitably pass through seasonal frost regions. In Nanyang basin, due to seasonal changes, railway subgrades will undergo frost heaving and thawing subsidence. The freezing characteristics of the soil are characterized by the freezing characteristic curve, and the important factors affecting the freezing characteristic curve are the content of expansive clay minerals in the soil and the salt solution. Therefore, three soil samples with different montmorillonite contents were saturated with salt solutions of different concentrations, and the freezing temperature of the soil samples was controlled by a cold bath. After the temperature equilibrium, the frozen stable soil samples were put into a nuclear magnetic resonance instrument to test the unfrozen water content, and the relationship between the freezing temperature and the unfrozen water content of expansive soil under different salt solution concentrations was obtained. Additionally, a unified model was used to simulate the test results. The results show that SFCC shifts to the left, that is, the sodium chloride salt solution reduces the freezing point of the soil sample so that it has more unfrozen water at the same temperature. At the same time, the soil’s freezing characteristic curves are closely related to content of expansive clay minerals in the soil. The more expansive clay mineral content, the greater the corresponding unfrozen water content. These results provide some basic insights for improving the frost heave and thaw subsidence problems of railway subgrades in seasonal permafrost regions, which will have a positive impact on promoting the management and rational application of land resources and the promotion of sustainable development.
A Novel Training Path to Promote the Ability of Mechanical Engineering Graduates to Practice and Innovate Using New Information Technologies
Authors: Xiang Feng , Cao Junjie , Zuo Ying , Duan Xianyin , Xie Liangxi , Zhou Min
Published: December 2023

In the context of the emerging era of smart manufacturing, the concept of sustainability is gaining substantial and widespread attention. Information technology has emerged as a potent tool for manufacturing companies, facilitating their transition toward greener practices and boosting operational efficiency. Additionally, the sustainable development of the industrial and information technology sectors not only presents promising prospects for future progress but is also intricately tied to the achievement of “dual carbon” objectives. Therefore, strategically integrating cutting-edge information technology into graduate education not only enhances the proficiency of postgraduates in the fields of information technology and manufacturing but also facilitates the achievement of green and sustainable development goals. To this end, this paper proposes a novel “Three-Level Advancement” talent development model aimed at cultivating a greater number of highly qualified talents oriented toward green and sustainable development. Built upon a one-semester graduate education framework, the model assesses the effectiveness of the “Three-Level Advancement” training approach. Subsequently, the efficacy of the new talent development model is validated through a class-based comparative analysis. Finally, based on the interview responses of the participants, both teachers and students unanimously affirmed the significant superiority of learning outcomes achieved through this pedagogical reform over traditional teaching methods. The results indicate that this new talent development model not only markedly enhances the quality of practical education but also contributes to the cultivation of sustainable talents in the field of information technology.
Implementation of Environmental Engineering Clinics: A Proposal for an Active Learning Methodology for Undergraduate Students
Authors: Rodríguez-Luna Dante , Rubilar Olga , Alvear Marysol , Vera Joelis , Zambrano Riquelme Marcia
Published: December 2023

Quality education focused on quality, inclusion, and opportunity is one of the United Nations Sustainable Development Goals to reduce inequality in the knowledge of the people who are educated. In this sense, universities have a role in rethinking the teaching model, changing their strategies, and including new experiences based on active learning. This article makes a didactic methodological proposal for undergraduate and graduate students using learning experiences for solving regional environmental problems proposed by municipalities. This method considered creating an agreement, defining topics, preparing bases and study areas, analyzing problem solutions, and delivering products. The results showed the implementation of the environmental engineering clinics (ECCs) in five subjects of the curriculum, with the participation of sixty students, who solved problems from seven municipalities. The results showed a correct implementation of the active learning methodology, allowing for knowledge to be transferred in a real-life scenario, significantly facilitating student learning. The plan–do–check–act (PDCA) cycle provides a practical framework for learning while solving real-world challenges, empowering learners to personally engage with authentic and meaningful challenges within their communities. As was previously stated, this article presents a methodology that can be introduced in universities to improve the learning process through active learning and the link with real problems of the territories where they are located, which also allows for improving the connection with the environment, contributing significantly to the sustainability of the territories.
Synthesis, Characterization and Performance of Materials for a Sustainable Future
Authors: Vakros John , Hapeshi Evroula , Cannilla Catia , Bonura Giuseppe
Published: December 2023

The commonly applied resource management strategies are rarely characterized by medium–long term sustainability, but an indispensable and urgent shift is necessary according to a circular economy approach that includes actions aimed at saving and reusing resources [...]
Ultrafiltration Harvesting of Microalgae Culture Cultivated in a WRRF: Long-Term Performance and Techno-Economic and Carbon Footprint Assessment
Authors: Mora-Sánchez Juan Francisco , González-Camejo Josué , Noriega-Hevia Guillermo , Seco Aurora , Ruano María Victoria
Published: December 2023

A cross-flow ultrafiltration harvesting system for a pre-concentrated microalgae culture was tested in an innovative anaerobic-based WRRF. The microalgae culture was cultivated in a membrane photobioreactor fed with effluent from an anaerobic membrane bioreactor treating sewage. These harvested microalgae biomasses were then anaerobically co-digested with primary and secondary sludge from the water line. Depending on the needs of this anaerobic co-digestion, the filtration harvesting process was evaluated intermittently over a period of 212 days for different operating conditions, mainly the total amount of microalgae biomass harvested and the desired final total solids concentration (up to 15.9 g·L−1 with an average of 9.7 g·L−1). Concentration ratios of 15–27 were obtained with average transmembrane fluxes ranging from 5 to 28 L·m−2·h−1. Regarding membrane cleaning, both backflushing and chemical cleaning resulted in transmembrane flux recoveries that were, on average, 21% higher than those achieved with backflushing alone. The carbon footprint assessment shows promising results, as the GHG emissions associated with the cross-flow ultrafiltration harvesting process could be less than the emissions savings associated with the energy recovered from biogas production from the anaerobic valorisation of the harvested microalgae.
Conceptual Framework and Prospective Analysis of EU Tourism Data Spaces
Authors: Ordóñez-Martínez Dolores , Seguí-Pons Joana M. , Ruiz-Pérez Maurici
Published: December 2023

This article delves deeply into the burgeoning field of Tourism Data Spaces (TDS) in Europe, focusing on how technologies like Big Data and IoT are redefining the tourism sector. This technological shift is steering traditional tourist destinations towards smarter, more sustainable models. The study utilizes a multifaceted approach, combining documentary and bibliographical analysis with empirical data from the EU’s DATES project. By employing the Drivers, Pressures, State, Impacts, Responses (DPSIR) model, it provides a nuanced understanding of the dynamics in TDS. The findings underscore TDS’s pivotal role in improving decision-making and personalizing tourism services. The study also acknowledges the growing need for detailed tourism information to enhance travel planning and experience personalization. Furthermore, it highlights the importance of efficient and secure data management in tourism. This comprehensive analysis points to a future where data-driven insights foster more sustainable, tailored travel experiences. Additionally, the research illuminates both the challenges and prospects inherent in implementing TDS, stressing the importance of clear governance, technical standards, and balancing diverse stakeholder interests in the tourism industry. By addressing these challenges, the article posits that TDS can make a significant contribution to the innovation and sustainability of the tourism sector.
Projected Summer Tourism Potential of the Black Sea Region
Authors: Turp Mustafa Tufan , An Nazan , Bilgin Başak , Şimşir Gamze , Orgen Bora , Kurnaz Mehmet Levent
Published: December 2023

The impacts of climate change and the extent of their consequences exhibit regional variability. The negative effects of climate change on the tourism industry require a comprehensive examination of the vulnerabilities of tourism–dependent countries. Considering that the tourism sector is an important source of income for these countries, it is imperative to evaluate the potential consequences of climate change. Its effects may lead to changes in the location and popularity of tourist destinations and the timing of the tourism season. If popular coastal destinations cannot respond effectively to the impacts of climate change, alternative tourism destinations need to be explored to reduce financial losses. This study aims to assess the potential of the Black Sea coasts as an alternative tourism destination. The evaluation was conducted using the Holiday Climate Index (HCI), a prominent indicator for determining human comfort. The research showed that Türkiye’s Black Sea coast may have the necessary comfort level for beach tourism in the summer season and may be attractive for more tourists considering the positive relationship between arrival and overnight stay and tourist comfort.