bluuebunny/crossref_metadata_2025 huggingface dataset:
Fe-N-Doped Conjugated Organic Polymer Efficiently Enhanced the Removal Rate of Cr(VI) from Water
Authors: Tang Cheng , Hu Tao , Du Chengzhen , Liao Ziqin , Cheng Wenyan , Wang Fen , Hu Xiaoli , Song Kunpeng
Published: July 2023

A Fe-N conjugated organic polymer (SMP-Fr-Py) was prepared from ferrocene and pyrrole using a Scholl coupling reaction, which significantly improved the performance of Cr(VI) removal compared to the polymer (HCP-Fr-Py) prepared by adding the cross-linker formaldehyde dimethyl acetal (FDA). The results showed that at a pH of 2 and at 25 °C, the removal of Cr(VI) reached 90% for SMP-Fr-Py and only 58% for HCP-Fr-Py after 20 min of reaction. Subsequently, 99% and 78% were achieved after 120 min of reaction, respectively. The test results showed that the removal reaction followed a pseudo-second-order kinetic model. The removal efficiency decreased with increasing solution pH and initial Cr(VI) concentration, but increased with increasing SMP-Fr-Py dosage, reaching three cycles. The characterization of the reaction complexes and measurements of Cr species conversion revealed the near absence of Cr(VI) species in the solution. Approximately 38% of Cr(VI) was found to be adsorbed on the material surface, with another fraction present in solution (24%) and on the material surface (38%) in the form of Cr(III). The overall study showed that the direct connection of ferrocene and pyrrole in SMP-Fr-Py through C-C bonding increased the conjugated structure of the polymer backbone, which facilitated electron transfer and transport. Furthermore, the Fe-N elements worked synergistically with each other more easily, which improved the removal performance of Cr(VI) and provided a reference for the subsequent work.
Injectable Lyophilized Chitosan-Thrombin-Platelet-Rich Plasma (CS-FIIa-PRP) Implant to Promote Tissue Regeneration: In Vitro and Ex Vivo Solidification Properties
Authors: Milano Fiona , Chevrier Anik , De Crescenzo Gregory , Lavertu Marc
Published: July 2023

Freeze-dried chitosan formulations solubilized in platelet-rich plasma (PRP) are currently evaluated as injectable implants with the potential for augmenting the standard of care for tissue repair in different orthopedic conditions. The present study aimed to shorten the solidification time of such implants, leading to an easier application and a facilitated solidification in a wet environment, which were direct demands from orthopedic surgeons. The addition of thrombin to the formulation before lyophilization was explored. The challenge was to find a formulation that coagulated fast enough to be applied in a wet environment but not too fast, which would make handling/injection difficult. Four thrombin concentrations were analyzed (0.0, 0.25, 0.5, and 1.0 NIH/mL) in vitro (using thromboelastography, rheology, indentation, syringe injectability, and thrombin activity tests) as well as ex vivo (by assessing the implant’s adherence to tendon tissue in a wet environment). The biomaterial containing 0.5 NIH/mL of thrombin significantly increased the coagulation speed while being easy to handle up to 6 min after solubilization. Furthermore, the adherence of the biomaterial to tendon tissues was impacted by the biomaterial-tendon contact duration and increased faster when thrombin was present. These results suggest that our biomaterial has great potential for use in regenerative medicine applications.
Flame Retardancy and Smoke Suppression of Silicone Rubber Foam with Microencapsulated Sepiolite and Zinc Borate
Authors: Kang Furu , Tu Jiayao , Zhao Heng , Bai Zujin , Zhang Tiantian
Published: July 2023

The flame-retardant micro-encapsulated sepiolite (MSEP) was successfully prepared by sol-gel method. Fourier transform infrared, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy were utilized to prove that sepiolite was encapsulated. Then, the mechanical properties, flame retardance, smoke suppression, and pyrolysis characteristics of silicone rubber foam (SiFs) with MSEP and zinc borate (ZB) were analyzed. The results indicated that the tensile and compressive properties of SiFs could evidently improve with the incorporation of MSEP/ZB. SiFs with 3 wt% MSEP and 6 wt% ZB could achieve an limiting oxygen index value of 30.9 vol% and UL-94 V-0 rating, the time to ignition was 64.7% above that of pure SiFs, the peak heat release rate and total heat release were 42.7% and 25.0% lower than that of pure SiFs, respectively. Furthermore, the peak smoke production rate and total smoke production of SiFs with 3 wt% MSEP and 6 wt% ZB were merely 54.22% and 64.10% of pure SiFs. Especially, the thermal stability of SiFs was significantly enhanced, and the carbon residue of SiFs became denser and more complete after adding 3 wt% MSEP and 6 wt% ZB.
A Parallel Solution of Timing Synchronization in High-Speed Remote Sensing Data Transmission
Authors: Teng Fei , Yang Wenge , Yan Jining , Ma Hongbin , Jiao Yiwen , Gao Zefu
Published: July 2023

Considering the problem that the timing synchronization calculation in high-speed remote sensing signal reception is complex and it is difficult for it to be parallel, this paper deduces and designs a parallel timing error estimation and correction scheme. This paper presents the design of polyphase DFT filter banks with non-maximum decimation. The feedforward timing error estimation and correction method is then improved to enhance synchronization performance. Finally, an implementation scheme for parallel timing error estimation and correction is proposed using the polyphase filter bank time domain decomposition method and the filter polyphase model. In the estimation module, the parallel implementation structure of the joint second-order and fourth-order cyclic statistics methods is designed, which improves the estimation accuracy. In the correction module, a fractional delay filtering method with higher accuracy is adopted in order to improve the calibration accuracy and reduce the computational complexity. The timing synchronization of a high-speed remote sensing signal with timing error is simulated and verified. The experimental results show that the parallel method proposed in this paper greatly reduces the processing speed of subband data, and has a good synchronization performance, which is close to the theoretical limit in the demodulation error rate. This paper utilizes a multi-phase DFT filter bank architecture to achieve parallel timing synchronization, which presents a novel approach for the future parallel reception of high-speed remote sensing signals.
How Does Wind Influence Near-Nadir and Low-Incidence Ka-Band Radar Backscatter and Coherence from Small Inland Water Bodies?
Authors: Fayne Jessica V. , Smith Laurence C.
Published: July 2023

While many studies have been conducted regarding wind-driven Ka-band scattering on the ocean and sea surfaces, few have identified the impacts of Ka-band scattering on small inland water bodies, and fewer have identified the influence of wind on coherence over water. These previous studies have been limited in spatial scale, covering only large water bodies >25 km2. The recently launched Surface Water and Ocean Topography (SWOT) mission is the first Ka-band InSAR satellite designed for mapping water surface elevations and open water areas for rivers as narrow as 100 m and lakes as small as 0.0625 km2. Because measurements of these types are novel, there remains some uncertainty about expected backscatter amplitudes given wind-driven water surface roughness variability. A previous study using the airborne complement to SWOT, AirSWOT, found that low backscatter and low coherence values were indicative of higher errors in the water surface elevation products, recommending minimum thresholds for backscatter and coherence for filtering the data to increase the accuracy of averaged data for lakes and rivers. We determined that the global average wind speed over lakes is 4 m/s, and after comparing AirSWOT backscatter and coherence data with ERA-5 wind speeds, we found that the minimum required speed to retrieve high backscatter and coherence is 3 m/s. We examined 11,072 lakes across Canada and Alaska, with sizes ranging from 350 m2 to 156 km2, significantly smaller than what could be measured with previous Ka-band instruments in orbit. We found that small lakes (0.0625–0.25 km2) have significantly lower backscatter (3–5 dB) and 0.20–0.25 lower coherence than larger lakes (>1 km2). These results suggest that approximately 75% of SWOT observable lake areas around the globe will have consistently high-accuracy water surface elevations, though seasonal wind variability should remain an important consideration. Despite very small lakes presenting lower average backscatter and coherence, this study asserts that SWOT will be able to accurately resolve the water surface elevations and water surface extents for significantly smaller water bodies than have been previously recorded from satellite altimeters. This study additionally lays the foundation for future high-resolution inland water wind speed studies using SWOT data, when the data become available, as the relationships between wind speed and Ka-band backscatter reflect those of traditional scatterometers designed for oceanic studies.
SG-Det: Shuffle-GhostNet-Based Detector for Real-Time Maritime Object Detection in UAV Images
Authors: Zhang Lili , Zhang Ning , Shi Rui , Wang Gaoxu , Xu Yi , Chen Zhe
Published: July 2023

Maritime search and rescue is a crucial component of the national emergency response system, which mainly relies on unmanned aerial vehicles (UAVs) to detect objects. Most traditional object detection methods focus on boosting the detection accuracy while neglecting the detection speed of the heavy model. However, improving the detection speed is essential, which can provide timely maritime search and rescue. To address the issues, we propose a lightweight object detector named Shuffle-GhostNet-based detector (SG-Det). First, we construct a lightweight backbone named Shuffle-GhostNet, which enhances the information flow between channel groups by redesigning the correlation group convolution and introducing the channel shuffle operation. Second, we propose an improved feature pyramid model, namely BiFPN-tiny, which has a lighter structure capable of reinforcing small object features. Furthermore, we incorporate the Atrous Spatial Pyramid Pooling module (ASPP) into the network, which employs atrous convolution with different sampling rates to obtain multi-scale information. Finally, we generate three sets of bounding boxes at different scales—large, medium, and small—to detect objects of different sizes. Compared with other lightweight detectors, SG-Det achieves better tradeoffs across performance metrics and enables real-time detection with an accuracy rate of over 90% for maritime objects, showing that it can better meet the actual requirements of maritime search and rescue.
Insights for Sea Outfall Turbid Plume Monitoring with High-Spatial-Resolution Satellite Imagery Application in Portugal
Authors: Faria Bruna , Mendes Renato , Lopes Carina Lurdes , Picado Ana , Sousa Magda , Dias João Miguel
Published: July 2023

Coastal municipalities and industries often discharge poorly treated wastewater into proximate marine and estuarine environments. The urban and/or effluent input can lead to eutrophication and lower water quality, as it holds high concentrations of nutrients and pollutants. One widely applied tool to increase effluent dispersion and direct it away from coastal areas, thus causing fewer impacts on human activities, is sea outfall. In Aveiro, Portugal, the São Jacinto sea outfall construction was completed in 1998; however, limited literature regarding the sea outfall’s monitoring using satellite data is available. The methodology in this study involved collecting four years’ worth (2016–2019) of satellite data to investigate visible traces of the interaction between the S. Jacinto sewage water mass and the Ria de Aveiro lagoon ecosystem using ocean color and spectral analysis, and producing new qualitative data regarding sea outfall plume dispersion monitoring through high-resolution Sentinel-2 imagery. The results showed a clear spectral signature of the sewage water mass, and a seasonal pattern was observed in which the plume was more evident in winter and autumn. Additionally, the coastal longshore current and the Aveiro lagoon’s runoff were able to restrict the marine outfall’s dispersion superficially. Ocean color data were revealed to be a factual and cost-effective tool to monitor the plume water. Finally, an exchange between the marine outfall water mass and Ria de Aveiro lagoon could happen in high tide under northern wind conditions. Therefore, it is important to monitor the water quality to ensure the coastal ecosystem’s good environmental state.
Editorial for the Special Issue “Radar Techniques for Structures Characterization and Monitoring”
Authors: Fernandes Francisco , Rasol Mezgeen , Schirinzi Gilda , Zhou Feng
Published: July 2023

This Special Issue focuses on the potential of radar-based remote techniques for characterizing and monitoring natural and building structures [...]
Feature Extraction of a Non-Stationary Seismic–Acoustic Signal Using a High-Resolution Dyadic Spectrogram
Authors: Seuret-Jiménez Diego , Trutié-Carrero Eduardo , Nieto-Jalil José Manuel , García-Aquino Erick Daniel , Díaz-González Lorena , Carballo-Sigler Laura , Quintana-Fuentes Daily , Gaggero-Sager Luis Manuel
Published: July 2023

Using a novel mathematical tool called the Te-gram, researchers analyzed the energy distribution of frequency components in the scale–frequency plane. Through this analysis, a frequency band of approximately 12 Hz is identified, which can be isolated without distorting its constituent frequencies. This band, along with others, remained inseparable through conventional time–frequency analysis methods. The Te-gram successfully addresses this knowledge gap, providing multi-sensitivity in the frequency domain and effectively attenuating cross-term energy. The Daubechies 45 wavelet function was employed due to its exceptional 150 dB attenuation in the rejection band. The validation process encompassed three stages: pre-, during-, and post-seismic activity. The utilized signal corresponds to the 19 September 2017 earthquake, occurring between the states of Morelos and Puebla, Mexico. The results showcased the impressive ability of the Te-gram to surpass expectations in terms of sensitivity and energy distribution within the frequency domain. The Te-gram outperformed the procedures documented in the existing literature. On the other hand, the results show a frequency band between 0.7 Hz and 1.75 Hz, which is named the planet Earth noise.
Method to Solve Underwater Laser Weak Waves and Superimposed Waves
Authors: Kang Chuanli , Lin Zitao , Wu Siyi , Yang Jiale , Zhang Siyao , Zhang Sai , Li Xuanhao
Published: July 2023

With the rapid development of Lidar technology, the use of Lidar for underwater terrain detection has become feasible. There is still a challenge in the process of signal resolution: the underwater laser echo signal is different to propagating in the air, and it is easy to produce weak waves and superimposed waves. However, existing waveform decomposition methods are not effective in processing these waveform signals, and the underwater waveform signal cannot be correctly decomposed, resulting in subsequent data-processing errors. To address these issues, this study used a drone equipped with a 532 nm laser to detect a pond as the study background. This paper proposes an improved inflection point selection decomposition method to estimate the parameter. By comparing it with other decomposition methods, we found that the RMSE is 2.544 and R2 is 0.995975, which is more stable and accurate. After estimating the parameters, this study used oscillating particle swarm optimization (OPSO) and the Levenberg–Marquardt algorithm (LM) to optimize the estimated parameters; the final results show that the method in this paper is closer to the original waveform. In order to verify the processing effect of the method on complex waveform, this paper decomposes and optimizes the simulated complex waveforms; the final RMSE is 0.0016, R2 is 1, and the Gaussian component after decomposition can fully represent the original waveform. This method is better than other decomposition methods in complex waveform decomposition, especially regarding weak waves and superimposed waves.
A Tactile Skin System for Touch Sensing with Ultrasound Tomography
Authors: Soleimani Manuchehr , Rymarczyk Tomasz
Published: July 2023

The tomographic imaging method is promising in large-area touch-sensing applications. This paper presents a new type of such touch sensor using ultrasonic tomography (UST) via sound attenuation imaging. UST is gaining popularity as a portable, fast, and inexpensive imaging system for medical and industrial applications. UST can be developed in different operation modes. A transmission mode UST is being investigated as a force- and touch-sensitive skin. A prototype skin sensor was developed in a 200 mm diameter circular UST array containing two sets of 16 transducers, with one operating at a central frequency of 40 kHz and the other at 300 kHz. The extension of the sensor in terms of dimension, up to 400 mm diameter, and number of sensors, up to 32 transducers, is possible where eight points of contact were reconstructed successfully. The medium contains a 20 mm high water region, and a soft silicone membrane covers the liquid region. When touchpoints or forces are applied to the soft skin of the membrane, the sound pathway is disrupted, resulting in an image of the touch position and touch force intensity using a tomographic UST algorithm. Several static and dynamic experiments are conducted to demonstrate this novel application of UST. In addition, a correlation analysis is carried out to establish the force quantification potential for the UST-based tactile skin.
Low-Cost GNSS and PPP-RTK: Investigating the Capabilities of the u-blox ZED-F9P Module
Authors: Robustelli Umberto , Cutugno Matteo , Pugliano Giovanni
Published: July 2023

GNSS has become ubiquitous in high-precision applications, although the cost of high-end GNSS receivers remains a major obstacle for many applications. Recent advances in GNSS receiver technology have led to the development of low-cost GNSS receivers, making high-precision positioning available to a wider range of users. One such technique for achieving high-precision positioning is Precise Point Positioning-Real Time Kinematic (PPP-RTK). It is a GNSS processing technique that combines the PPP and RTK approaches to provide high-precision positioning in real time without the need for a base station. In this work, we aim to assess the performance of the low-cost u-blox ZED-F9P GNSS module in PPP-RTK mode using the low-cost u-blox ANN-MB antenna. The experiment was designed to investigate both the time it takes the receiver to resolve the phase ambiguity and to determine the positioning accuracies achievable. Results showed that the u-blox ZED-F9P GNSS module could achieve centimeter-level positioning accuracy in about 60 s in PPP-RTK mode. These results make the PPP-RTK technique a good candidate to fulfill the demand for mass-market accurate and robust navigation since uses satellite-based corrections to provide accurate positioning information without the need for a local base station or network. Furthermore, due to its rapid acquisition capabilities and accurate data georeferencing, the technique has the potential to serve as a valuable method to improve the accuracy of the three-S techniques (GIS, remote sensing, and GPS/GNSS).
Multimode Optical Interconnects on Silicon Interposer Enable Confidential Hardware-to-Hardware Communication
Authors: Zhang Qian , Charania Sujay , Rothe Stefan , Koukourakis Nektarios , Neumann Niels , Plettemeier Dirk , Czarske Juergen W.
Published: July 2023

Following Moore’s law, the density of integrated circuits is increasing in all dimensions, for instance, in 3D stacked chip networks. Amongst other electro-optic solutions, multimode optical interconnects on a silicon interposer promise to enable high throughput for modern hardware platforms in a restricted space. Such integrated architectures require confidential communication between multiple chips as a key factor for high-performance infrastructures in the 5G era and beyond. Physical layer security is an approach providing information theoretic security among network participants, exploiting the uniqueness of the data channel. We experimentally project orthogonal and non-orthogonal symbols through 380 μm long multimode on-chip interconnects by wavefront shaping. These interconnects are investigated for their uniqueness by repeating these experiments across multiple channels and samples. We show that the detected speckle patterns resulting from modal crosstalk can be recognized by training a deep neural network, which is used to transform these patterns into a corresponding readable output. The results showcase the feasibility of applying physical layer security to multimode interconnects on silicon interposers for confidential optical 3D chip networks.
Influence of Safety Climate on Safety Performance in Gas Stations in Indonesia
Authors: Lestari Fatma , Modjo Robiana , Wibowo Aryo , Sunindijo Riza Yosia
Published: July 2023

Accidents in gas stations may cause injury or even death to people. Moreover, an accident in a gas station might halt its operation for some time. When an accident takes place in a region with scant amount of gas stations, it may lead to fuel scarcity in the area, affecting the economy and sparking other issues. Therefore, safety climate and safety performance in gas stations need to be evaluated. Safety climate has been used as a tool to assess the safety performance of an organization at a given time. The aim of this study was to understand the influence of safety climate on safety performance in gas stations in Indonesia. A total of 129 gas stations were selected. To assess safety climate, a safety climate questionnaire was used, while the safety performance was captured by conducting on site structured observations. The assessment shows that gas stations have a good level of safety climate, especially when it is compared with other industrial sectors in Indonesia, such as construction. The study findings also show that safety climate has a significant positive impact on safety performance. Three safety climate dimensions with significant positive influence on safety performance are management commitment, communication, and personal accountability. Therefore, improvement efforts should focus more on these dimensions to boost safety performance in gas stations.
Improving Indoor Air Quality through Standardization
Authors: Saffell John , Nehr Sascha
Published: July 2023

Human beings experience a large fraction of their exposure to air pollutants in indoor environments. Air pollution is a large environmental health risk, and exposure to ambient air pollution and indoor air pollution contribute equally to the total number of fatalities worldwide. Although legislative authorities have established limit values for ambient outdoor air and stack emissions, there are inconsistent and variable national and regional limit values for gaseous substances and airborne particulate matter in the built environment (schools, homes, healthcare facilities, offices, and other public spaces). This lack of regulation is unsurprising, because indoor spaces are characterized by complex air chemistry, and their construction materials and types of activities vary significantly. The current understanding of indoor pollutants, including short-lived oxidants, degradation of VOCs, particle formation, and particle composition, is incomplete. It is necessary to identify and assess emerging pollutants and their toxicity, and to consider new consumer products and green construction materials and their impact on indoor air quality (IAQ). Learning from IAQ surveys and audit protocols, research methodologies should be regularized for cross-research comparisons. Some indoor air quality guidance and standards have been written, and several more are in development, with the international ISO 16000 series of indoor standards leading the way for improving indoor air data quality. The WHO has established some ambient air limit values which can mostly be translated into indoor limit values. The built environment needs to harmonize energy efficiency, thermal comfort and air quality standards and guidance. In this review, we discuss the next steps for improving international, regional and national standards and guidance, leading to better and more complete indoor air quality regulations.
Analysis of Spatial-Temporal Changes and Driving Forces of Desertification in the Mu Us Sandy Land from 1991 to 2021
Authors: Ji Xinyang , Yang Jinzhong , Liu Jianyu , Du Xiaomin , Zhang Wenkai , Liu Jiafeng , Li Guangwei , Guo Jingkai
Published: July 2023

Desertification is one of the most critical environmental and socioeconomic issues in the world today. Located in the transitional region between the desert and the Loess Plateau, the Mu Us Sandy Land is one of the nine most environmentally sensitive areas in the world. Remote sensing provides an effective technical method for desertification monitoring. In order to analyze the spatiotemporal distribution of desertification in the Mu Us Sandy Land from 1991 to 2021, the “MSAVI-Albedo” model was employed to extract desertification data in 1991, 2002, 2009 and 2021. The clustering characteristics of desertification were analyzed based on Moran’s I statistic. Subsequently, the driving forces in desertification changes were investigated using a geographical detector to analyze the influence of soil, meteorology, and topography on desertification. Additionally, the impact of meteorological and human factors on desertification change in the Mu Us Sandy Land was assessed. From 1991 to 2021, the degree of desertification of the Mu Us Sandy Land showed an overall decreasing trend, and the percentage of land classified as undergoing extremely severe, severe, moderate and mild desertification was improved by 86.11%, 81.82%, 52.5% and 37.42%, respectively. The proportion of land classified as undergoing extremely severe desertification decreased from 29.22% to 5.62%, and the proportion of land undergoing no desertification increased from 4.16% to 18.33%. At the same time, the desertification center shifted westward, and the desertification distribution showed a clustering trend. It is known that different factors affect the formation and distribution of desertification in the Mu Us Sandy Land in the following order: soil, meteorology, and topography. Over the past 30 years, the mean annual temperature and annual precipitation increased at rates of 0.01871 °C/a and 1.0374 mm/a, respectively, while the mean annual wind speed decreased at a rate of 0.00945 m/s·a. These changes provided more favorable natural conditions for vegetation growth and sand fixation. Human factors, such as economic development, agriculture and animal husbandry practices, and the policy of returning farmland to forest (grassland) also had a significant impact on the desertification process, leading to a year-by-year improvement in the ecological environment of the Mu Us Sandy Land.
Rethinking the Role of Technology for Citizens’ Engagement and Sustainable Development in Smart Cities
Authors: Caputo Francesco , Magliocca Pierpaolo , Canestrino Rossella , Rescigno Erika
Published: July 2023

Recognizing the interdisciplinary debate about the digital devices and infrastructure needed to support the emergence and viability of smart cities, the latter can be considered one of the most challenging topics within recent decades due to its relevant role in supporting and enhancing citizens’ participation in public management. Using a deductive approach, in this paper, we propose a sustainability-based conceptual framework to support both policymakers and managers in better understanding at which level to act to improve citizens’ engagement as a way to ensure sustainable development in smart cities. The purpose of this paper is to explore how citizens’ involvement in smart cities can be steered toward positive attitudes and behaviors within the context of sustainable development. Drawing on a managerial perspective, we aim to provide preliminary reflections about the key role that digital technologies on which smart cities are based can play in promoting effective sustainable development for all.
How Active Are European Seniors—Their Personal Ways to Active Ageing? Is Seniors’ Activity in Line with the Expectations of the Active Ageing Strategy?
Authors: Przybysz Klaudia , Stanimir Agnieszka
Published: July 2023

The study is directed towards the growing importance of active ageing (AA). Active ageing is a concept proposed in 1990 to recognise not only factors related to health care but also other factors influencing the ageing of individuals and populations. In the following years, as the needs of the ageing societies and the possibilities of meeting these needs increased, Healthy Ageing was defined. Active ageing is one of the areas of care for older people in the Decade for Healthy Ageing. In the study, we referred to the pillars of the AA strategy and the active ageing index (AAI) guidelines. Research on active ageing is gaining momentum in conjunction with pursuing the Sustainable Development Goals (SDG 2030 Agenda), especially in social inclusion. The aim of our study was to compare EU countries in terms of seniors’ subjective assessment of AA-related activities and to check whether the similarities and differences in the ratings of seniors from different countries changed in 2020 compared to 2018. As we did not want seniors to participate in a survey directly focused on AA, we chose the European Social Survey database (ESS is a cross-national, representative survey conducted every two years across Europe since 2001), ensuring that the sample was representative. We used questions not directly related to AA. We conducted the analysis by gender and two age groups (65–74 and 75+). In the analysis, we used Kaufman–Rousseeuw normalisation and Ward’s method for clustering. Our analysis resulted in four classifications in each study run. We identified groups of countries where respondents’ assessments are similar. In addition, we identified recurring patterns of behaviour corresponding to AA.
Gross Ecosystem Product Accounting of a Globally Important Agricultural Heritage System: The Longxian Rice–Fish Symbiotic System
Authors: Liu Jianfang , Zhang Qian , Wang Qianyi , Lv Yaoping , Tang Yingqi
Published: July 2023

The Rice–Fish Symbiotic System in the Longxian village is the first Globally Important Agricultural Heritage System (GIAHS) in Asia. This paper examined the value transformation mechanism of the Longxian Rice–Fish Symbiotic System from the micro perspective of material cycle and energy flow and quantified its economic value using the gross ecosystem product (GEP). Using the InVEST model and ArcGIS tools, the GEP was estimated to be approximately CNY 116.51 million (approx. CNY 252,624 per hectare per year). The ecosystem regulating service value occupied more than 80% of the GEP. Within the regulating ecosystem services, the climate regulation value was the highest (CNY 55.72 million) followed by flood storage value (CNY 32.77 million). These two categories contributed 94.44% of the total value of regulating ecosystem services. The paper recommends employing GEP to evaluate the value of commodities and services provided by an ecosystem. The methodology and approach of the research can serve as an important reference for other GIAHS programs and provides a scientific and rigorous framework for accessing the economic value of agricultural heritage systems.
Spatial Effect Analysis of a Long Strip Pit Partition Wall and Its Influence on Adjacent Pile Foundations
Authors: Zhou Nan , Yang Jianhui
Published: July 2023

The spatial effect at the end of the foundation pit partition wall is significant, and the displacement of the retaining wall and soil caused by its demolition leads to an additional displacement and bending moment of the adjacent pile foundations, which in turn deteriorates the work behavior of the pile foundation. Taking the project of an open tunnel under a viaduct located in Hangzhou as an example, site monitoring was performed to determine the effect of the demolition of the partition wall on the displacement of the surrounding retaining wall and the soil in the adjacent area and the monitoring data were compared to the finite element analysis results to check the rationality of the finite element model. This model was used to study the influence of the distance from the pile foundation to the partition wall as well as the stiffness of the retaining wall on the displacement and bending moment of the pile foundation during excavation. These results indicate that because of the support effect of the foundation pit partition wall on the retaining wall, the spatial effect at the end of the partition wall is large, and the displacement and bending moments of the pile foundation in the vicinity of the partition wall are lower than those in the far distance. Demolition of the partition wall will increase the displacement and bending moment of adjacent pile foundations, and this effect decreases with increasing distance. The range of influence of the spatial effect at the end of the partition wall is approximately 1.1 times the depth of the foundation pit. When the pile foundation is in the immediate vicinity of the partition wall, the response of the front-row and rear-row piles to the demolition of the partition wall is significantly different. The front row piles are more affected, while the rear row piles are less affected. As the distance increases, the difference in response gradually decreases and tends to be consistent. As the stiffness of the retaining wall increases, the effect of the demolition of the partition wall on the pile foundation decreases. It is recommended that the stiffness of the supporting system near the partition wall be reduced appropriately, and the partition wall should be set at the foundation pit section near the pile foundation, but the response of the foundation pit and the adjacent pile foundation should be paid close attention to when the partition wall is demolished.
Research on Power Battery Recycling in the Green Closed-Loop Supply Chain: An Evolutionary Game-Theoretic Analysis
Authors: Li Gang , Lu Mengyu , Lai Sen , Li Yonghong
Published: July 2023

The used power batteries of new energy vehicles have become a combined issue of environmental pollution, resource scarcity, and economic sustainability. Power battery recycling is inevitably becoming the key link in the formation of the green closed-loop supply chain for new energy vehicles and the green cycle of the new energy vehicles industry. This study establishes a three-party evolutionary game model of “new energy vehicle manufacturers, power battery manufacturers, and power battery recyclers”, simulates the dynamic evolution process of each game player’s strategy, and analyzes the effects of the digital transformation factor and other factors leading to the evolution trend. The main results show that: (i) in the absence of sufficient incentives and constraints, the green closed-loop power battery supply chain cannot be formed naturally; (ii) digital transformation is an important factor in the journey of the green closed-loop supply chain for power battery recycling, and (iii) government rewards and penalties can promote the formation of the green closed-loop supply chain for power batteries. This research innovatively investigates the concept of the green closed-loop power battery supply chain and its formation mechanism, which provides theoretical support to promote the recycling of used power batteries to achieve sustainability.
The Impact of Marketization on Enterprise Performance from the Perspective of Enterprise Debt
Authors: Xie Fusheng , Yang Peixiang
Published: July 2023

The problem of corporate debt is a hidden danger to China’s economic growth and financial stability. This paper studies the effect of regional marketization on the debt burden of the local enterprises based on a fixed effects model. The result demonstrates that the higher the market-oriented degree, the lower the debt burden of the enterprises in that region. Further analysis demonstrates that the improvement of marketization not only directly reduces the enterprise debt, but also reduces debt burden by increasing the enterprise productivity and promoting the enterprise property rights reform. Improving the level of regional marketization is conducive to the enterprise debt issue, and this provides some suggestions to the policy makers.
A Review of the Recent Advancement of Bioconversion of Carbon Dioxide to Added Value Products: A State of the Art
Authors: Almomani Fares , Abdelbar Amera , Ghanimeh Sophia
Published: July 2023

Excessive dependence on fossil fuels increases GHG emissions and carbon levels in the atmosphere, leading to climatic changes. This phenomenon can be reversed by capturing the carbon via “carbon capture and storage” (CCS) or “carbon capture and utilize” (CCU) technologies. In CCS methods, the captured carbon is stored in natural sinks (e.g., oceans), whereas, in CCU methods, the carbon is converted into useful products. Among CCU methods, the biological conversion of CO2 (BioConCO2) into value-added chemicals has gained great attention. This review focuses on providing an overview of the recent advances in CO2 utilization technology with a focus on the BioConCO2. The theoretical background and technical drivers, challenges, and setbacks of upscaling and commercialization of BioConCO2 are critically discussed with implications for future improvements. The BioConCO2 is increasingly attracting the attention of researchers and industrialists for its capacity to operate under low CO2 concentrations and in the presence of impurities (common conditions in industrial flue gases)—among other numerous advantages. While upscaling algae-based BioConCO2 has operational and financial challenges, bioconversion via bacteria and genetically engineered cyanobacterial seems promising due to their efficiency and flexibility.
A Study on the Accessibility of the Emergency Medical Services for Urban Kindergartens and Nursing Homes Based on Urban Pluvial Flooding Scenarios
Authors: Shi Hongbin , Zhou Miao , Kong Nana , Zhang Yongling , Li Xin
Published: July 2023

Vulnerable groups such as children and the elderly are the focus of emergency medical rescue during urban pluvial floods. Taking the Erqi District of Zhengzhou City as an example, the SCS-CN model and Chicago rainfall model are used to simulate pluvial flooding based on the comprehensive consideration of urban rainfall, runoff, topography, and drainage. Additionally, the accessibility of emergency medical aid for kindergartens and nursing homes is evaluated in the Erqi District of Zhengzhou under different pluvial flooding scenarios using GIS network analysis technology. The results showed that the number of kindergartens and nursing homes without timely access to emergency medical rescue increased with the increase in precipitation return periods. Under the 500-year and 1000-year pluvial flooding scenarios, kindergartens and nursing homes that can obtain emergency medical rescue had delayed response times. Furthermore, with the increase in the precipitation return periods, both the number and delay time of kindergartens and nursing homes significantly increased. The accessibility and delay time of emergency medical rescue in kindergartens and nursing homes were determined by the intensity of pluvial flooding (including inundation area and depth), road traffic conditions, and the number and location of medical institutions, nursing homes, and kindergartens. The research results can provide a scientific basis for improving the refinement level of urban flood disaster management and emergency response services.
Complex Quantum Hydrodynamics in Momentum Space with Broken Time-Reversal Symmetry
Authors: Schuch Dieter , Bonilla-Licea Moise
Published: July 2023

Shortly after Schrödinger’s wave mechanics in terms of complex wave functions was published, Madelung formulated this theory in terms of two real hydrodynamic-like equations. This version is also the formal basis of Bohmian mechanics, albeit with a different ontological interpretation. A point of criticism raised by Pauli against Bohmian mechanics is its missing symmetry between position and momentum that is present in classical phase space as well as in the quantum mechanical position and momentum representations. Both Madelung’s quantum hydrodynamics formulation and Bohmian mechanics are usually expressed only in position space. Recently, with the use of complex quantities, we were able to provide a hydrodynamic formulation also in momentum space. In this paper, we extend this formalism to include dissipative systems with broken time-reversal symmetry. In classical Hamiltonian mechanics and conventional quantum mechanics, closed systems with reversible time-evolution are usually considered. Extending the discussion to include open systems with dissipation, another form of symmetry is broken, that under time-reversal. There are different ways of describing such systems; for instance, Langevin and Fokker–Planck-type equations are commonly used in classical physics. We now investigate how these aspects can be incorporated into our complex hydrodynamic description and what modifications occur in the corresponding equations, not only in position, but particularly in momentum space.
Super-Connectivity of the Folded Locally Twisted Cube
Authors: You Lantao , Han Yuejuan , Jiang Jianfeng
Published: July 2023

The hypercube Qn is one of the most popular interconnection networks with high symmetry. To reduce the diameter of Qn, many variants of Qn have been proposed, such as the n-dimensional locally twisted cube LTQn. To further optimize the diameter of LTQn, the n-dimensional folded locally twisted cube FLTQn is proposed, which is built based on LTQn by adding 2n−1 complementary edges. Connectivity is an important indicator to measure the fault tolerance and reliability of a network. However, the connectivity has an obvious shortcoming, in that it assumes all the adjacent vertices of a vertex will fail at the same time. Super-connectivity is a more refined index to judge the fault tolerance of a network, which ensures that each vertex has at least one neighbor. In this paper, we show that the super-connectivity κ(1)(FLTQn)=2n for any integer n≥6, which is about twice κ(FLTQn).
Evaluation of Tourism Ecological Security and Its Driving Mechanism in the Yellow River Basin, China: Based on Open Systems Theory and DPSIR Model
Authors: He Xiaorong , Cai Chaoyue , Shi Jizhi
Published: July 2023

Tourism ecological security (TES) has gradually become a frontier topic because it is related to the virtuous circle of ecosystems and sustainable development, especially in river basins with fragile ecosystems. Based on the Driver–Pressure–State–Impact–Response (DPSIR) model and open systems theory, we constructed a TES evaluation system in the Yellow River Basin (YRB), China. Then, the TES index was measured from 2004 to 2019 and its spatio-temporal characteristics and driving mechanism were analyzed. The results show that: (1) In terms of temporal evolution, the comprehensive TES index shows a steady upward trend, but the difference between cities increases over time. Moreover, the proportion of cities with low status levels of TES declined rapidly, while the proportion of cities with high status levels of TES has grown slowly. (2) Spatially, low-TES value cities have always been in the majority, and the high-value cities show a scattered spatial distribution, most of which are along the river. Moreover, TES is randomly distributed in space before 2013, but it shows a significant positive spatial clustering feature thereafter. Specifically, the range of hot spots extends from the intersection of the middle and upper reaches to downstream, while the cold spots are always scattered. Furthermore, the trend surface in the east–west direction is always smooth, while it gradually manifests an inverted U-shape in the north–south direction. (3) In the dynamic transfer, TES lacks the vitality of transfer, but the probability of shifting upward becomes more significant when adjacent to higher-level cities; the opposite is true when adjacent to lower-ranked cities. (4) In terms of the driving mechanism, the factors related to tourism and the economy are the most important driving forces, and the effect of tourism-related factors on TES is becoming increasingly significant. Moreover, the driving mechanism is constructed. Finally, this study provides targeted policy implications for improving TES in the YRB, which has reference value for the development of ecological protection and high-quality tourism.
Enabling Sustainable Adaptation and Transitions: Exploring New Roles of a Tourism Innovation Intermediary in Andalusia, Spain
Authors: Roser Thorsten , Kuzmina Ksenija , Koria Mikko
Published: July 2023

Tourism is a major global and local industry creating value through services that are enhanced and enabled through intermediaries that support innovation in the sector. This exploratory case study examines the roles and activities of a publicly funded tourism innovation intermediary for small medium-sized enterprises (SMEs) and professionals in Andalucia, Spain. We note the gap in knowledge on how intermediaries may best support stakeholders in achieving resilience and sustainability in transitions in tourism service ecosystems. Building on interviews, reports, and observations, this study finds that the intermediary has successfully supported its stakeholders in enhancing their adaptability in the current service ecosystem. There is less evidence of achieving deliberate transformations towards long-term sustainability and resilience. As the intermediary is uniquely positioned at the meso-level of the regional tourism service ecosystem, this study proposes exploring engagement to cover both macro and micro-level activities to enable moving towards becoming a transition intermediary and a regional sustainability catalyst. This study furthermore proposes an expanded range of roles and activities for the intermediary to enable moving towards resilience and sustainability, while contributing to the understanding of innovation intermediaries supporting sustainability in the tourism sector.
Cardiac Toxicity Induced by Long-Term Environmental Levels of MC-LR Exposure in Mice
Authors: Yan Canqun , Liu Ying , Yang Yue , Massey Isaac Yaw , Cao Linghui , Osman Muwaffak Al , Yang Fei
Published: July 2023

Cyanobacterial blooms are considered a serious global environmental problem. Recent studies provided evidence for a positive association between exposure to microcystin-LR (MC-LR) and cardiotoxicity, posing a threat to human cardiovascular health. However, there are few studies on the cardiotoxic effects and mechanisms of long-term low-dose MC-LR exposure. Therefore, this study explored the long-term toxic effects and toxic mechanisms of MC-LR on the heart and provided evidence for the induction of cardiovascular disease by MC-LR. C57BL/6 mice were exposed to 0, 1, 30, 60, 90, and 120 μg/L MC-LR via drinking water for 9 months and subsequently necropsied to examine the hearts for microstructural changes using H&E and Masson staining. The results demonstrated fibrotic changes, and qPCR and Western blots showed a significant up-regulation of the markers of myocardial fibrosis, including TGF-β1, α-SMA, COL1, and MMP9. Through the screening of signaling pathways, it was found the expression of PI3K/AKT/mTOR signaling pathway proteins was up-regulated. These data first suggested MC-LR may induce myocardial fibrosis by activating the PI3K/AKT/mTOR signaling pathway. This study explored the toxicity of microcystins to the heart and preliminarily explored the toxic mechanisms of long-term toxicity for the first time, providing a theoretical reference for preventing cardiovascular diseases caused by MC-LR.