bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of High-Sensitivity Optical Fiber Sensor by an Improved Arc-Discharge Heating System
Authors: Ma Chao , Wang Jian , Yuan Libo
Published: March 2023

We proposed a high-sensitivity optical fiber sensor based on a dual-resonance helical long-period fiber grating (HLPG). The grating is fabricated in a single-mode fiber (SMF) by using an improved arc-discharge heating system. The transmission spectra and the dual-resonance characteristics of the SMF-HLPG near the dispersion turning point (DTP) were studied through simulation. In the experiment, a four-electrode arc-discharge heating system was developed. The system can keep the surface temperature of optical fiber relatively constant during the grating preparation process, which shows an advantage in preparing high-quality triple- and single-helix HLPGs. In particular, benefiting from this manufacturing system, the SMF-HLPG operating near the DTP was successfully prepared directly by arc-discharge technology, without secondary processing of the grating. As a typical application example of the proposed SMF-HLPG, physical parameters such as temperature, torsion, curvature and strain can be measured with high sensitivity by monitoring the variation of the wavelength separation in the transmission spectrum. Therefore, the proposed sensor and its fabrication technology have potential application prospects in practical sensing measurement.
Analysis of the Snake Robot Kinematics with Virtual Reality Visualisation
Authors: Sibilska-Mroziewicz Anna , Hameed Ayesha , Możaryn Jakub , Ordys Andrzej , Sibilski Krzysztof
Published: March 2023

In this article, we present a novel approach to performing engineering simulation in an interactive environment. A synesthetic design approach is employed, which enables the user to gather information about the system’s behaviour more holistically, at the same time as facilitating interaction with the simulated system. The system considered in this work is a snake robot moving on a flat surface. The dynamic simulation of the robot’s movement is realised in dedicated engineering software, whereas this software exchanges information with the 3D visualisation software and a Virtual Reality (VR) headset. Several simulation scenarios have been presented, comparing the proposed method with standard ways for visualising the robot’s motion, such as 2D plots and 3D animations on a computer screen. This illustrates how, in the engineering context, this more immersive experience, allowing the viewer to observe the simulation results and modify the simulation parameters within the VR environment, can facilitate the analysis and design of systems.
YOLO-LWNet: A Lightweight Road Damage Object Detection Network for Mobile Terminal Devices
Authors: Wu Chenguang , Ye Min , Zhang Jiale , Ma Yuchuan
Published: March 2023

To solve the demand for road damage object detection under the resource-constrained conditions of mobile terminal devices, in this paper, we propose the YOLO-LWNet, an efficient lightweight road damage detection algorithm for mobile terminal devices. First, a novel lightweight module, the LWC, is designed and the attention mechanism and activation function are optimized. Then, a lightweight backbone network and an efficient feature fusion network are further proposed with the LWC as the basic building units. Finally, the backbone and feature fusion network in the YOLOv5 is replaced. In this paper, two versions of the YOLO-LWNet, small and tiny, are introduced. The YOLO-LWNet was compared with the YOLOv6 and the YOLOv5 on the RDD-2020 public dataset in various performance aspects. The experimental results show that the YOLO-LWNet outperforms state-of-the-art real-time detectors in terms of balancing detection accuracy, model scale, and computational complexity in the road damage object detection task. It can better achieve the lightweight and accuracy requirements for object detection for mobile terminal devices.
Flavonol-Glycoside and Rare Triterpenoid Derivatives Isolated from Leaves of Combretum glutinosum Perr. Ex Dc. with In Vitro Cytotoxic Activity
Authors: Sweilam Sherouk Hussein , Ebrahim Maha B. O. , Kamal Mehnaz , Khafagy El-Sayed , Abdalla Ashraf N. , Elzubier Mohamed E. , Moglad Ehssan H.
Published: March 2023

Combretaceae plants are used traditionally by many cultures, especially in Sudanese patients for the treatment of diverse ailments such as anti-inflammatory, antimicrobial, antitumor, and antioxidant disorders. Of these plants, the genus Combretum are traditional medicinal plants. Thus, they are formed from the non-polar or polar extracts of many isolated phytochemicals. Of these necessities, the use of Combretum extracts for their medicinal properties can be found in the earliest of myths and traditions used to document the plants’ ability to treat diseases. Combretum glutinosum Perr. Ex Dc. is a common shrub native to the African continent, especially Sudan. Currently, there are no published data regarding its cytotoxic activity. Additionally, there are few chemical and biological reports of C. glutinosum. Therefore, the current study aimed to isolate the chemical bioactive compounds (1–6) from the ethyl acetate (EtOAc) extract of C. glutinosum. A new flavonoid compound, namely, glutosinumoside (4), was afforded, and five known compounds were obtained: three oleanane-glycosides (1–3) and two phenolic acids (5,6). The structures of the six compounds were determined by spectroscopic analysis, including one- and two-dimensional (1D and 2D) NMR, mass spectrometry, and chromatographic analysis. Moreover, an in vitro cytotoxic evaluation of the successive extracts and the bioactive EtOAc fractions of C. glutinosum against MCF7 (breast), HT29 (colon), HepG2 (liver), and MRC5 (normal lung) cell lines was performed. The isolated compounds showed comparable cytotoxic activities with the crude EtOH extract and doxorubicin against the tested cell lines. Compounds (1) and (6) exhibited the highest cytotoxicity against MCF7 (1.37 ± 0.21 and 1.48 ± 0.34 µg/mL, respectively) and HepG2 (3.30 ± 0.02 and 2.10 ± 0.22 µg/mL, respectively) in the MTT assay. In addition, compounds (1) and (3) demonstrated a significant upregulation of cancer’s two important hallmarks (caspase 3 and bax genes) by inducing apoptosis and perturbing the MCF7 cell cycle.
Moringa oleifera L. Screening: SFE-CO2 Optimisation and Chemical Composition of Seed, Leaf, and Root Extracts as Potential Cosmetic Ingredients
Authors: Kessler Júlia C. , Manrique Yaidelin A. , Martins Isabel M. , Rodrigues Alírio E. , Barreiro Maria Filomena , Dias Madalena M.
Published: March 2023

Moringa oleifera L. tree (Mo) has emerged as a rich alternative source of bioactive compounds to design cosmetic formulations. Supercritical carbon dioxide fluid extraction (SFE-CO2) was successfully applied on the screening of Mo seed, leaf, and root extracts. The extraction yield was evaluated by response surface methodology (RSM), for pressure and temperature ranges of 117–273 bar and 41–60 °C, respectively, using a design of experiments (DOE). The pressure significantly affected the results (α=0.05), with the highest extraction efficiency obtained at conditions above 195 bar. The extracts’ composition, evaluated by gas chromatography-mass spectrometer (GC-MS), revealed an increasing correlation between the pressure, total extract solubility, and mass of extract at a constant temperature, due to the higher extraction yield. Seed extracts presented more than 80% of oleic acid in relative composition (8.04 mgcompound∙gplantpart−1). Leaf extracts performed well for the obtainment of linolenic acid (>20%; 3.10 mg∙g−1), nonacosane (>22%; 0.46 mg∙g−1), and α-tocopherol (>20%; 0.21 mg∙g−1). Mo root resulted in higher relative composition for sterol molecules, despite its very low affinity with CO2. The most promising bioactive compounds, oleic acid and α-tocopherol, were more abundant when operating at 250 bar at 45 °C and 195 bar at 55 °C, for Mo seed and leaf SFE-CO2 extracts, respectively.
Strategic Competence Model for Understanding Smart Territorial Development
Authors: Fric Urška , O’Gorman William , Rončević Borut
Published: March 2023

In this paper, the authors propose a multi-level model for the strategic competence of territorial units, which can help explain why some territorial units manage to respond appropriately to global challenges and thrive while others fail. Strategic competence is defined by two components: substantive knowledge and strategic connections. This is the foundation for the development of four ideal types of strategic competences at the level of territorial actors—Conductor, Broker, Lone Wolf, or Rent Seeker—and four at the level of territorial units—Pioneers, Absorbers, Drifters, or Laggers. This multi-level model forms the basis for future research to transform the concepts into a set of measurable indicators to determine the current strategic competence of regions and territories. Additionally, it will provide the basis for research-informed policymaking for the purpose of co-designing, co-developing, co-implementing and co-measuring policy initiatives and their results.
Doing More with Ambient Light: Harvesting Indoor Energy and Data Using Emerging Solar Cells
Authors: Bouclé Johann , Ribeiro Dos Santos Daniel , Julien-Vergonjanne Anne
Published: March 2023

On one side, the capacity of the world’s photovoltaic (PV) systems is experiencing unprecedented growth; on the other side, the number of connected devices is rapidly increasing due to the development of advanced communication technologies. These fields are not completely independent, and recent studies show that indoor energy harvesting is a great candidate for answering the energy challenges of future generations of telecommunications, namely 5G and 6G, ideal for internet-of-things (IoT) scenarios, i.e., smart homes, smart cities, and smart factories. The emerging PV technologies have shown amazing capabilities for indoor energy harvesting, displaying high power conversion efficiency, good flexibility, and champion-specific powers. Recently, the excellent dynamic performance of PV devices enabled them to be used as data receivers in optical wireless communication (OWC) scenarios, calling forth an innovative system able to simultaneously harvest energy and receive communication data with a single PV device. This article reviews the recent literature devoted to the exploitation of photovoltaic technologies for simultaneous indoor energy harvesting and OWC data reception. This contribution highlights the strong potential of the approach toward the next generation of Green IoT systems and the current challenges that need to be addressed with regard to the physics of solar cells, from laboratory to large-scale applications.
Effects of Biological Nitrification Inhibitor on Nitrous Oxide and nosZ, nirK, nirS Denitrifying Bacteria in Paddy Soils
Authors: Huang Xingchen , Zou Yuning , Qiao Cece , Liu Qiumeng , Liu Jingwen , Kang Rui , Ren Lantian , Wu Wenge
Published: March 2023

This study aimed to investigate the effects of a biological nitrification inhibitor on nitrous oxide emission and rice yield quality in paddy soils and its effects on denitrifying the bacteria of nosZ, nirK, and nirS types. Two treatments were performed: (1) using a local conventional fertilizer as the control CK; (2) using the partial application of a conventional fertilizer + biological nitrification inhibitor as SW. N2O emission was measured using gas chromatography; qPCR amplification was performed using primers for the targeted functional genes, nosZ, nirS, and nirK, and denitrifying functional gene abundance and denitrifying microbial community structure were analyzed using fluorescence quantification and high–throughput sequencing, respectively. The results reveal that the biological nitrification inhibitor resulted in a 41.83% reduction in N2O, relative to the normal fertilizer treatment. Meanwhile, rice yield increased by 15.45% and related quality indexes were also improved. This can promote the reproduction of bacteria with the nosZ gene while inhibiting the growth of bacteria with nirS and nirK genes. The core bacteria, Nitrosospira, Rhodanobacter, Bradyrhizobium, Tardiphaga, Rhodopseudomonas, and Paracoccus, positively correlated with N2O emissions, while core bacteria Azospirillum, Burkholderia, and Mesorhizobium negatively correlated with N2O emissions. Therefore, the application of a biological nitrification inhibitor could be an effective measure to promote rice yield and quality, reduce N2O emissions, and affect key denitrifying bacteria.
Electricity-Related Water Network Analysis in China Based on Multi-Regional Input–Output Analysis and Complex Network Analysis
Authors: Zhang Yiyi , Fu Huanzhi , He Xinghua , Shi Zhen , Hai Tao , Liu Peng , Xi Shan , Zhang Kai
Published: March 2023

The transfer of electricity-related water across regions and sectors provides an opportunity to alleviate water stress and make the development of the power system sustainable. Yet, the key node identification and properties of the electricity-related water network have not been studied. In this study, the properties and key nodes of the regional sectoral electricity-related water network in China were analyzed based on a multi-regional input–output model and complex network analysis. An iterative method was proposed to calculate the water consumption index inventory. The results showed electricity transmission can affect the regional water consumption index. Degree, intensity, betweenness centrality, and closeness centrality indicators of nodes were used to identify the key nodes. Sector 24 in Shandong was the key node with the largest closeness centrality. Sector 9 in Xinjiang was the key node with the largest betweenness centrality. They were the best choice for establishing points to observe and control flows, respectively. The transfer network did not have the small-world nature with the average clustering coefficient being 0.478 and the average path length being 2.327. It is less likely to cause large-scale clustering change in the network. This study can provide references for the common sustainable development of power systems and water resources.
The Three-Level Supply Chain Finance Collaboration under Blockchain: Income Sharing with Shapley Value Cooperative Game
Authors: Li Shuai , Qu Shaojian
Published: March 2023

With the gradual and widespread application of blockchain technology in the supply chain, its characteristics can help solve the financing problem of MSMEs. To this end, this paper constructs a cooperative game model for suppliers, manufacturers and retailers in the case of a cross-level guarantee of order-to-factoring, studies the pricing strategy of supply chain finance members based on blockchain technology by adopting the Stackelberg primary-secondary game method, and makes a reasonable allocation of total supply chain revenue with the help of the Shapley value of the cooperative game. The study found that the adoption of blockchain can be effective in increasing the benefits to supply chain members and systems. The adoption of blockchain increases the blockchain costs but decreases the financing costs for the supplier. The Shapley value of the cooperative game is used to distribute the benefits, allowing for Pareto improvements in the benefits to supply chain members. In the next step, we will focus on examining the impact of risk assessment and the degree of information disclosure on supply chain finance with blockchain technology.
How E-Government Can Help Societies during a Crisis: Implications of UTAUT Model in Lebanon
Authors: El Hajj Bassel , Karadas Georgiana , Zargar Pouya
Published: March 2023

Introduction: Information and communication technology (ICT) usage has grown rapidly, with a significant rise following the occurrence of the COVID-19 pandemic. This study assesses the relationships among task–technology fit, sense of virtual community, and the continuous intention to use electronic government services (e-government). Methods: Through quantitative approach using surveys, a total of 390 data was obtained from registered citizens in Tripoli municipality during the pandemic. The data were analyzed using partial least square-structural equation modeling (PLS-SEM). Results: The mediating role of the unified theory of acceptance and use of technology (UTAUT) model was observed, which shows that task–technology fit, sense of virtual community, and the consideration of society and its development are essential factors for citizens to use ICTs. Systems should entail features that meet the needs of citizens, community-building elements, and satisfactory performance. The importance of e-government ICTs in community development, particularly in a fragile state such as Tripoli, Lebanon, is the highlight of the current results. This can be beneficial for governmental authorities in the region of the Middle East, helping them to increase communication effectiveness by implementing appropriate digital means for the public during a crisis. Community development is a highly effective aspect that governments can implement in their digital services to provide opportunities for learning, awareness, and social progress to the public.
Factors Influencing the Conservation Intentions of Visitors to a World Heritage Site: A Case Study of Libo Karst
Authors: Zhang Haipeng , Xiong Kangning , Fei Guangyu , Jin Ao , Zhang Shirong
Published: March 2023

The behavioral intention of tourists to protect the environment is a popular topic in tourism geography research. Understanding the mechanisms that influence the post-tour behavioral intentions of heritage site visitors can effectively promote the generation of positive behavioral intentions for the sustainable development of heritage sites. Starting from the “cognitive–emotional–behavioral” path of attitude theory, we introduced environmental knowledge awareness (EKA), geomorphological value perception (GVP), place attachment (PA) and behavioral intention (BI) variables to construct a model of the influence mechanism of tourists’ behavioral intentions towards conservation in heritage sites; we test this model on the Libo World Natural Heritage Site, a karst in southern China, as an example. The results show the following: (1) environmental knowledge awareness (EKA) is the basis of place attachment (PA) and behavioral intention (BI), and place attachment (PA) plays an influential mediating role. (2) Geomorphological value perception (GVP) has a positive effect on behavioral intention. (3) The “GEPB” conceptual model fits the “cognitive–emotional response–behavioral intention” chain of tourists in natural world heritage sites and passes the empirical test; (4) The direct positive effect of place attachment on behavioral intention is significant as an essential emotional factor that promotes behavioral intention. This study provides an empirical foundation for the synergistic development of conservation and tourism in World Heritage Karst Sites. It also discusses theoretical and managerial implications based on the findings and provides directions for future research.
Roadmap to a Circular Economy by 2030: A Comparative Review of Circular Business Model Visions in Germany and Japan
Authors: Montag Laura
Published: March 2023

Circular business models operate differently from traditional linear models: by developing products designed for disassembly, reuse, and recycling; by using materials and products for as long as possible; and by replacing physical products with virtual ones, they aim to reduce the environmental impact of their operations and facilitate the creation of a more sustainable future. In this article, the framework for circular business models is discussed from two perspectives: first, a systematic literature review is conducted to explore the academic point of view; second, a comparative policy review is conducted to analyze the past, present, and future visions of Germany and Japan in relation to their circular transition, particularly with regard to each country’s vision of circular business models. A first outcome is a synthesis of current circular business model archetypes and the developed circular business model matrix, which adds value to the literature by providing information on circular goals, strategies, the actors involved, and the social and political implications of each circular business model typology. A second outcome is a comparative, in-depth analysis of the current policy frameworks and strategies for circular business models in Germany and Japan. This article outlines the main ways in which both countries are currently making the transition to a circular economy, providing an important knowledge base for further development.
Effect of COVID-19-Induced Changes on Job Insecurity, Presenteeism, and Turnover Intention in the Workplace—An Investigation of Generalized Anxiety Disorder among Hotel Employees Using the GAD-7 Scale
Authors: Kim Yeon-Sun , Shin Dong-Jin , Kim Bo-Kyeong
Published: March 2023

In this study, we investigated COVID-19′s (coronavirus disease 2019’s) effect on job insecurity, presenteeism, and turnover intention in hotel environments by measuring hotel staffs’ generalized anxiety disorder (GAD-7) levels. We surveyed 351 hotel employees from the office, facilities, food and beverage, and cooking departments. Convenience sampling was performed from December 2021 to March 2022. Job insecurity was measured with seven items (easily annoyed, tension, anxiety, nervousness, a lot of worry, fear, uncontrollable worry, restlessness, and discomfort) and demonstrated a significantly positive effect on presenteeism and turnover intention in the high GAD-7 group compared with the low GAD-7 group. Our study contributes academic value to research on GAD-7 in the hotel industry. In addition, it provides a theoretical basis for the relationship between job insecurity and hotel employees’ psychological response to the pandemic. Based on the findings, we recommend periodically implementing the GAD-7 scale for employee assessments. Consequently, hotel companies can create guidelines for human resource management post-COVID-19.
Reliability and Robustness Assessment of Highway Networks under Multi-Hazard Scenarios: A Case Study in Xinjiang, China
Authors: Zhu Weihua , Wang Shoudong , Liu Shengli , Gao Xueying , Zhang Pengchong , Zhang Lixiao
Published: March 2023

The robustness and reliability capacities of highways are particularly critical when dealing with emergencies in order to ensure user safety following disaster events. Assessing the robustness and reliability of highways under multi-hazard scenarios and evaluating the impact of planning on them have become urgent topics. In this study, we use the Xinjiang Production and Construction Corps’ (XPCC) existing and planned arterial highway networks in China for research. Based on the multi-hazard information, we established and employed four attack strategies on the existing and planned arterial highway networks. The results show that the exposure susceptibility coefficient (ESC) strategy has a higher destruction capability than the random attack strategy, which is close to the greedy algorithm coefficient (GAC) strategy. In addition, attacks have negligible impacts on connectivity reliability and robustness but significantly affect travel time reliability and robustness. When the number of removed edges reaches 20 using the ESC strategy, the travel time reliability drops to 0.4 for the existing highway network. In addition, the planned highway network significantly improves the reliability and robustness with regard to multi-hazard scenarios, especially for travel time reliability. Travel time reliability is improved by 10% under the historical damage records coefficient (HDRC) and ESC attacks. Our study shows that planning promotes the construction of a resilient transportation system in multi-hazard scenarios, providing valuable information for resilient transportation construction.
Investigation Properties of Pervious and Water-Retaining Recycled Concrete to Mitigate Urban Heat Island Phenomena
Authors: Haddad Bechara , Karaky Hamzé , Boutouil Mohamed , Boudart Bertrand , Sebaibi Nassim
Published: March 2023

The urban heat island (UHI) effect poses significant challenges to urban environmental quality and public health. Over the decades, research efforts have been made to develop various UHI mitigation strategies, including pavement materials, such as, water-retentive pavement, reflective pavement, and pervious concrete. This paper focuses on the improvement of the hygric and water retention properties of pervious concrete to mitigate UHI phenomena. The hydric and hygroscopic tests were carried out under dry and wet conditions on four different pervious concretes, where natural aggregates were replaced with recycled aggregates at different mass percentages. The results show a significant improvement in these properties by increasing the amount of recycled aggregates incorporated in the mixtures. The mixes made from recycled aggregates alone showed an absorption that reached 75 L more than the control in one cubic meter under wet condition. With an upwelling capacity of up to 30 kg of retained water in a square meter under dry condition, these improvements in water performance represent this permeable concrete as a water retention pavement solution for UHI mitigation. Regarding the mechanical properties, a decrease of 50% in compressive strength was noted only when 100% of the recycled aggregate was incorporated, remaining at 20 MPa for other mixtures.
Comparing Societal Impact Planning and Evaluation Approaches across Four Urban Living Labs (in Food-Energy-Water Systems)
Authors: Black Daniel , Charlesworth Susanne , Dal Poz Maria Ester , Francisco Erika Cristina , Paytan Adina , Roderick Ian , von Wirth Timo , Winter Kevin
Published: March 2023

Achieving societal impact, as opposed to academic impact, is a growing area of focus for the research community globally. Central to this changing mission is the focus on multiple interconnected complex systems and the need for research that is not just interdisciplinary, but also transdisciplinary and grounded in stakeholder co-production. This document compares multiple approaches to impact planning and evaluation across four newly formed urban living labs in Sao Paolo (Brazil), Western Cape (South Africa), Bristol (UK) and Rotterdam (Netherlands), each of which sought to address societal issues linked to the food-energy-water nexus. A comparison matrix and a disaggregated impact table are derived from a comprehensive review of key definitions. These new tools were completed by each ULL alongside a post hoc pathway to impact statements. Comparisons are presented and discussed, the strengths and weaknesses of this approach are considered and opportunities for improvement in societal impact planning and evaluation are provided. Our main findings include the importance of establishing clear shared definitions while accepting plural understandings, the need to acknowledge resource as a critical factor in impact delivery and the headline need for far greater focus in this area from both funders and research groups.
Waste-to-Energy Recovery from Municipal Solid Waste: Global Scenario and Prospects of Mass Burning Technology in Brazil
Authors: Dadario Natália , Gabriel Filho Luís Roberto Almeida , Cremasco Camila Pires , Santos Felipe André dos , Rizk Maria Cristina , Mollo Neto Mario
Published: March 2023

Inadequate disposal of Municipal Solid Waste (MSW) is one of the greatest environmental issues confronted nowadays. One of the techniques used for its final disposal is incineration, otherwise known as mass burning. Although this procedure remains very controversial in Brazil, some recent studies published in Europe reveal a large amount of misinformation about it. It has been widely used in European countries, Japan, and a few U.S. cities and has been increasingly and significantly adopted in China. Therefore, this article aims to carry out a literature review on the evolution of waste-to-energy recovery from Municipal Solid Waste (MSW) worldwide and the progress of mass-burning technologies, particularly in the Brazilian context. For such a purpose, global scientific databases were selected and some of their results allowed us to present how the main WtE recovery technologies function, as well as their benefits and impacts. Moreover, it was possible to systematize the main regulatory frameworks on the theme in Brazil and to reveal the country’s electricity generation capacity, in addition to depicting the progress of Waste-to-Energy Plants (WtEPs) undergoing licensing processes in the state of São Paulo.
Experimental Study on the Effective Production of Biocement for Soil Solidification and Wind Erosion Control
Authors: Hang Lei , Yang Feng , Xu Jie , Zhao Zihao , Xiao Wei , He Jia
Published: March 2023

Biocement can be achieved through the microbially induced carbonate precipitation (MICP) process. Such a method can potentially be utilized as an eco-friendly method for civil and environmental engineering applications such as soil ground improvement and wind erosion control of surface soil. In this method, one key step is the effective production of ureolytic bacteria. In previous laboratory and field studies, the cultivation and production of the bacteria used for the MICP were usually expensive and time-consuming. The purpose of this study was to optimize the cultivation method of the ureolytic bacteria (Sporosarcina pasteurii), and soil stabilization tests were conducted to verify the effectiveness of the cultured bacteria used to strengthen soil against the wind-induced erosion. Bacterial cultivation methods were studied by investigating the effects of different cultivation media and conditions. Testing variables included the types and concentrations of nitrogen sources (urea or NH4Cl), pH values (7.5–9.5), cultivation conditions (batch or chemostat condition), and different carbon sources. It was found that, with the same amount of nitrogen source, the test with pure urea had the highest biomass yield, urease activity, and specific urease activity than the other tests with pure NH4Cl or both NH4Cl and urea. The use of urea as the nitrogen source in the media also led to an increase in pH, which was not found in the test with pure NH4Cl. As for the factor of urea concentration, the tests with a higher urea concentration had a higher biomass yield, urease activity, and pH. The factor of pH values also played an important role. The test with an 8.5 initial pH value had a higher biomass yield, urease activity, and specific urease activity than the tests with 7.5 and 9.5 initial pH values. In the chemostat condition, the ureolytic bacteria could be effectively produced with urease activity up to 7 mmol/L/min, as compared with around 12 mmol/L/min activity in the batch condition. Thus, the optimum nitrogen source, pH value, and cultivation condition for the cultivation of Sporosarcina pasteurii was urea, 8.5, and batch condition, respectively. In addition, when soybean milk powder or milk powder was used as the carbon source, the urease activity was around 2.5 mmol/L/min, which is also high enough to be used for biocement.
Neural Networks Based Dynamic Load Modeling for Power System Reliability Assessment
Authors: Maraaba Luqman , Almuhaini Mohammad , Habli Malek , Khalid Muhammad
Published: March 2023

The reliability of a power system is considered as a critical requirement in planning and operating the system due to the increasing demand for more reliable service with a lower frequency and duration of interruption. Hence, reliability is also considered as a major challenge in the development of future power systems as they become more advanced and complex, making the accuracy of the reliability assessment dependent on several factors such as supply and load modeling. Recent studies on power systems’ reliability and stability have focused on load modeling, where loads are either assumed to be static or dynamic, by introducing significant constraints. However, the emergence of new types of loads necessitates the development of models that can incorporate them with accuracy, as this would facilitate their effective use in flow and stability simulation studies, as well as reliability analyses. In this study, dynamic loads are modeled using a feed-forward neural network where a simulation test bed is developed in MATLAB/Simulink to generate operating data used during training and validating of the neural network model. Subsequently, Electrical Transient Analyzer Program (ETAP) software is used to verify the effect of load modeling on power system reliability assessment platform. Bus 2 of Roy Billinton Test System (RBTS) is employed as a case study to investigate the sensitivity of the reliability indices, such as System Average Interruption Duration Index (SAIDI) and System Average Interruption Frequency Index (SAIFI), on the load modeling technique with mixed loads (dynamics and statics).
Estimating Mohr–Coulomb Strength Parameters from the Hoek–Brown Criterion for Rock Slopes Undergoing Earthquake
Authors: Wu Di , Chen Xin , Tao Yongchao , Meng Xiaodong
Published: March 2023

The direct application of the Hoek–Brown failure criterion to practical slope engineering is still an urgent problem. The slope geometries and earthquake effect need to be considered in the determination of linear Mohr–Coulomb (MC) strength parameters from the Hoek–Brown criteria for slope stability analysis. This study adopted the tangential method to construct a three-dimensional (3D) rotational failure mechanism using the Hoek–Brown failure criterion for homogeneous rock slopes undergoing earthquake. The quasi-static method was employed to treat the seismic action as an external seismic force in the work–energy equation of the limit analysis theory. Based on the numerical optimization, the least upper-bound solutions and equivalent MC strength parameters were derived with respect to different strength parameters and seismic loads. The influences of nonlinear strengths, geometric parameters and earthquake load on the equivalent MC strength parameters were thoroughly investigated. The results suggested that the nonlinear parameters have different influences on the equivalent MC parameters for general steep slopes and vertical slopes. The effects of nonlinear parameters on the equivalent MC parameters become obvious for vertical slopes. The disturbance factor D affects the equivalent MC parameters only for very steep slopes in fractured rock masses. Additionally, the effect of slope inclination on the equivalent MC parameters becomes obvious for slopes in fractured hard rock masses. The 3D effect of the rock slope on the equivalent MC parameters was found to be slight. Moreover, the impact of earthquakes on the approximate MC parameters becomes weaker for steeper rock slopes. The tables of approximate MC strength parameters were given for various slopes with different nonlinear strength parameters. The presented tables can provide certain references for practical slope engineering.
Influence of Labour Experience in the Generation of Construction Material Waste in the Sri Lankan Construction Industry
Authors: Karunasena Gayani , Fernando Gayan , Ashokkumar Dilogini , Liu Chunlu
Published: March 2023

The construction industry consumes a huge quantity of raw materials, some of which ends up as waste in the construction process. Among many factors, studies suggest that the inexperience of labour is one factor that generates construction material waste. However, an in-depth analysis of construction material waste generation concerning the different levels of labour experience has not been undertaken. Thus, this study investigates the influence of labour experience in the generation of brick and tile material waste in the Sri Lankan construction industry and, thereby, develops a model to predict average waste generation with respect to labour experience. Bricks and tiles were considered since they are identified as the materials most wasted in the Sri Lankan construction industry. To carry out this research, nine similar commercial projects under construction using bricks and tiles were selected from three large building construction organizations in Sri Lanka. Non-participant direct observations and unstructured interviews were adopted as data collection techniques. A simple arithmetical mean method was adopted to analyse material wastage and a scatter diagram was used to identify the correlation and regression to develop a prediction model. The findings revealed that, when labour experience increased, brick and tile wastage generation decreased, although there were slight fluctuations.
Climate Change as Liminal Experience—The Psychosocial Relevance of a Phenomenological Approach
Authors: Gavriluță Nicu , Mocrei-Rebrean Lucian
Published: March 2023

Liminality is a sufficiently comprehensive concept to allow the description and interpretation of how we experience change as existing in a “betwixt and between time”. A situation of liminality implies an intrusion, always difficult to manage, of chaos, of the erratic, into the harmony of everyday life. The activation of ecological sensitivities can lead to spontaneous liminal experiences, triggered by the awareness that the world around us is a changing environment. We intend to show that notions from phenomenology, such as home-world and alien-world, allow the interpretation of climate change as a situation of liminality that we experience due to the de-familiarization of the environment. The way we understand and interpret the world we live in is based on its normality, understood as constantly experienced in our daily bodily behavior. The notion of the home-world expresses the inter-subjective way in which we experience the natural world, as a world that is already given to us. Because its environmental meanings are actively imprinted in our lived corporeality, the home-world becomes a foundational standard against which changes in the natural environment are always cognitively compared within intuitive, already-constituted terms. The same world may appear alien to us when we become aware of sufficiently significant changes in the normality of our everyday experience, associated with discontinuities or disturbances. Because it places the familiar and known in tension with the unfamiliar and unknown, a liminal experience is always, at a subjective level, epistemologically transformative. To the extent that the surrounding natural world loses its already-given character, we will perceive it as an alien-world, more or less different from the one in which we lived our daily lives.
A Study of the Impact of Population Aging on Fiscal Sustainability in China
Authors: Liu Qiongzhi , Zhao Dapeng
Published: March 2023

China has entered a deeply aging society, and the aging population poses a significant public risk to fiscal sustainability. In this regard, researchers have conducted a large number of studies, but the fiscal sustainability indicators used in the existing literature are not scientific enough, the sample data are too macro, and the heterogeneity analysis is not comprehensive enough. This paper innovatively constructs fiscal sustainability indicators based on data from 4 municipalities directly under the central government, 8 provincial capitals, and 88 prefecture-level cities in China from 2010–2019, and analyzes the impact of population aging on fiscal sustainability in eastern, central, western, and multi-level cities in China, using methods such as two-way fixed-effects models. The study finds that (1) fiscal sustainability is significantly hampered by population aging; that is, the more aging there is, the less fiscal sustainability there is. (2) The inhibitory effect of population aging on fiscal sustainability is greater in developed regions compared to backward regions. Compared to prefecture-level cities, provincial cities (including municipalities and provincial capitals) are much more negatively impacted by population aging on fiscal sustainability. (3) The paths through which population aging inhibits fiscal sustainability are healthcare expenditures and social security employment expenditures. The policy recommendations put forward in this paper are to raise the fertility rate, protect the fiscal expenditures of developed regions and provincial capitals to deal with population aging, and increase the effectiveness of the use of funds for medical and health expenditures and social security employment expenditures. The conclusions and policy recommendations drawn in this paper have a positive effect on China’s response to the fiscal sustainability problems caused by an aging population.
Identifying and Predicting Trends of Disruptive Technologies: An Empirical Study Based on Text Mining and Time Series Forecasting
Authors: Xiang Minhao , Fu Dian , Lv Kun
Published: March 2023

Disruptive technologies are related to a country’s competitiveness and international status. Accurately identifying and predicting the trends in disruptive technologies through scientific methods can effectively grasp the dynamics of technological development, adjust the national science and technology strategic layout, and better seize the high ground in international competition. Based on patent text data, this paper uses the improved LDA2Vec model combined with relevant indicators to identify the main topics in disruptive technologies, and predicts and analyzes the development trend through the establishment of an ARIMA model. Taking the energy technology field as an example, the main topics and development trends concerning disruptive technologies in this field are obtained. The study found that ten technologies, including energy storage technology, energy internet management technology, and offshore wind energy technology, are disruptive technologies in the energy technology field, and the development speed of energy storage technology is the fastest. To verify the correctness of the conclusion, this paper compares the results with artificial verification methods such as expert interviews and document verification, and finds that the two are basically consistent, thus verifying the effectiveness and feasibility of the proposed method.
Integrated vs. Specialized Farming Systems for Sustainable Food Production: Comparative Analysis of Systems’ Technical Efficiency in Nebraska
Authors: Afi Maroua , Parsons Jay
Published: March 2023

Complementarities between crops and livestock production have the potential to increase input use efficiency and maintain a diversified livelihood. This paper uses non-parametric data envelopment analysis (DEA) to assess the technical efficiency (TE) of integrated crop–livestock systems (ICLS) compared to specialized cropping and specialized livestock systems in the state of Nebraska, in the central United States. We classify each county of Nebraska into one of three systems according to their dominant agricultural production revenues. We use DEA to measure the TE of each county compared, first, to a group production frontier (in-system comparison) and second, to a metafrontier (cross-system comparison). Thirty percent of the cropping systems counties were evaluated as fully efficient in the in-system comparison with other cropping systems counties. Thirty-six percent of the livestock systems counties and 18% of the ICLS counties were evaluated as fully efficient in their in-system comparisons. The ICLS counties are less likely to appear on the metafrontier, with a total of only 7% compared to 39% and 32% for the specialized cropping and specialized livestock systems, respectively. These results highlight the need for further research on optimal crop–livestock integration that allows for the realization of synergies and complementarities needed for higher efficiency and sustainable intensification of food production.
Vulnerability Assessment of Ecological–Economic–Social Systems in Urban Agglomerations in Arid Regions—A Case Study of Urumqi–Changji–Shihezi Urban Agglomeration
Authors: Zhang Xiaofen , Simayi Zibibula , Yang Shengtian , Mamitimin Yusuyunjiang , Shen Fang , Zhang Yunyi
Published: March 2023

This study aims to clarify the vulnerability characteristics of the ecological–economic–social system of oasis city clusters in arid zones, promote the deepening of research on the sustainable development of urban clusters, and provide crucial practical reference significance for solving the series of problems brought about by urbanization. This article takes the arid zone oasis city cluster, the Urumqi–Changji–Shihezi urban agglomeration, as the research object and constructs an indicator system from three dimensions of ecological environment, regional economic, and social development, and adopts the comprehensive index method, GeoDetector, the GM(1, 1) gray prediction model, and other methods to study the vulnerability pattern and spatial and temporal changes of the urban cluster from 2009 to 2018. The results show that (1) from 2009 to 2018, the change in the integrated ecological–economic–social system vulnerability index of the Urumqi–Changji–Shihezi urban agglomeration shows a general downward trend, followed by significant differences in the vulnerability of each dimension, with an average vulnerability index of 1.8846, 1.6377, and 0.9831 for the social vulnerability, regional economic, and ecological environment dimensions, respectively; (2) the evolution of the spatial pattern of changes in the vulnerability index of different systems in each region of the Urumqi–Changji–Shihezi urban agglomeration tends to change from large to slight spatial differences, in which the social and ecological environmental vulnerability changes are more prominent in addition to the vulnerability changes of the regional economy; (3) parkland area per capita, arable land area per capita, GDP per capita, social fixed asset investment, population density, and urban road area per capita are the main drivers of decreasing vulnerability of ecological–economic–social systems in urban agglomerations; (4) by predicting and calculating the vulnerability index of each region of the ecological–economic–social system of urban agglomerations, it is found that the vulnerability index of urban agglomerations will show a decreasing trend from 2009 to 2018, and the difference of the vulnerability index between systems will narrow; (5) finally, targeted countermeasures and suggestions to reduce the vulnerability of ecological–economic–social systems are proposed to provide scientific references for the sustainable development of arid oasis cities.
Characteristics of Mercury Fluxes between Soil and Air in the Farming-Pastoral Ecotone of Songnen Grassland
Authors: Sun Yan , Zhang Zhe , Zhang Gang , Zong Jing , Zhang Hongjie , Deng Yuqi , Yang Kaili , Wang Zhaojun , Cui Dan , Yang Canchao
Published: March 2023

In order to understand the characteristics and influencing factors of surface release fluxes in the typical agro-pastoral mosaic region of the Songnen grasslands of northern China, this study selected two sample plots to, respectively, represent the L. chinensis covered grassland (L), and the Z. mays covered fields (Z) in the Waizi area of Changling County, with western Jilin Province as the study area. This study investigated the atmospheric mercury (Total Gaseous Mercury (TGM)) concentrations, surface soil mercury concentrations, the gaseous elemental mercury exchange fluxes, and related environmental factors. The results showed that the TGM concentrations in two sample plots in the study area were basically the same during the summer and autumn months, but were higher in summer than in autumn, and there was a clear diurnal pattern. The average mercury concentrations in the surface soil were also higher in summer than in autumn. Furthermore, the surface soil has a clear mercury release process, and the mercury release were higher in the sheep grass field than the maize field during the same season. The mercury release fluxes in each site within the ecotone were related to the solar radiation and soil temperature values, and the effects of them on the soil mercury release were independent from one another.