bluuebunny/crossref_metadata_2025 huggingface dataset:
Compounded Impacts of Global Warming and Anthropogenic Disturbances on Snowmelt in Northern Baffin Island
Authors: He Liming , White H. Peter , Chen Wenjun
Published: January 2023

Fugitive dust arising from mining operations in the Arctic can be a concern to surrounding communities. The Mary River Mine operation on northwest Baffin Island in the Qikiqtani region, Nunavut, is one example. Yet, the short and long-term impacts of fugitive dust remain poorly understood. Dust lowers snow albedo which can contribute to early snowmelt. This influences the spring snowmelt freshet period, significant to the land-atmosphere interactions, hydrology, ecology, and socioeconomic activities in the Arctic. Here, we map dust extents indicated by snow discoloration and examine for areas of early snowmelt using a 21-year MODIS time series snow cover product in 2000–2020. We found an episode of dust plume extended far beyond the reference dust sampler sites from where Nil dustfall is detected. A snow albedo decrease of 0.014 was seen more than 60 km away from the mine site. Incidents of early snowmelt existed extensively and progressively prior to the Mary River Mine operations; however, localized and even earlier snowmelt also appear around Mine’s operations; we estimated that the snow-off date was advanced by one week and three weeks for the background, and areas around the Mine facilities, respectively, during the 21-year period. Furthermore, the area increase in early snowmelt around the Mine facilities correlates to ore production growth. This study demonstrates rapid changes in early snowmelt beyond observed regional trends when additional drivers are introduced.
A Novel Strategy for Selective Thyroid Hormone Determination Based on an Electrochemical Biosensor with Graphene Nanocomposite
Authors: Baluta Sylwia , Romaniec Marta , Halicka-Stępień Kinga , Alicka Michalina , Pieła Aleksandra , Pala Katarzyna , Cabaj Joanna
Published: January 2023

This article presents a novel and selective electrochemical bioassay with antibody and laccase for the determination of free thyroid hormone (free triiodothyronine, fT3). The biosensor was based on a glassy carbon electrode modified with a Fe3O4@graphene nanocomposite with semiconducting properties, an antibody (anti-PDIA3) with high affinity for fT3, and laccase, which was responsible for catalyzing the redox reaction of fT3. The electrode modification procedure was investigated using a cyclic voltammetry technique, based on the response of the peak current after modifications. All characteristic working parameters of the developed biosensor were analyzed using differential pulse voltammetry. Obtained experimental results showed that the biosensor revealed a sensitive response to fT3 in a concentration range of 10–200 µM, a detection limit equal to 27 nM, and a limit of quantification equal to 45.9 nM. Additionally, the constructed biosensor was selective towards fT3, even in the presence of interference substances: ascorbic acid, tyrosine, and levothyroxine, and was applied for the analysis of fT3 in synthetic serum samples with excellent recovery results. The designed biosensor also exhibited good stability and can find application in future medical diagnostics.
Uncovering Youth’s Invisible Labor: Children’s Roles, Care Work, and Familial Obligations in Latino/a Immigrant Families
Authors: Delgado Vanessa
Published: January 2023

This paper examines Latino/a children’s roles and obligations to their immigrant families. Bridging insights from the literature on the “new sociology of childhood,” immigrant incorporation, and care work, this essay argues that children perform important—but often invisible—labor in immigrant families. Dominant ideologies depict childhood as an “innocent” time wherein young people are in need of guidance and are too underdeveloped to make meaningful contributions. However, this construction of childhood ignores the lived realities of the children of immigrants, who often serve as gatekeepers and connect their families to services and resources in their communities. This essay examines six dimensions of support that the children of immigrants provide to their families, namely, language and cultural help, financial contributions, bureaucratic assistance, emotional labor, legal support, and guidance with technology. This essay concludes with implications for scholars, students, and policymakers on the importance of recognizing this labor, along with future directions for research.
Contrasting Toxicity of a Fomesafen-Based Herbicide on Three Freshwater Phytoplanktonic Species
Authors: Naoum Jonathan , Lavoie Michel , Gomes Marcelo Pedrosa , Juneau Philippe
Published: January 2023

Pesticides leaching and run-off to nearby freshwater sources are a major ecological concern. The emergence of herbicide-resistant weeds led to the increased usage of fomesafen, a diphenyl ether herbicide inhibiting protoporphyrinogen oxidase (PPO). This recent rise in demand and use for this molecule invariably increases the chance of this herbicide entering freshwater environments and affecting non-target organisms. However, there is still a lack of information in the literature regarding the impact of this herbicide on the physiology of freshwater phytoplankton. This study aimed to determine the impact of five concentrations (0, 5, 10, 40, 320 µg · L−1) of a fomesafen-based herbicide (Reflex®) on the physiology of two species of green microalgae (Raphidocelis subcapitata FACHB-271; Chlamydomonas snowii) and one cyanobacterial species (Microcystis aeruginosa CPCC 632). While physiological biomarkers (growth, photosynthesis, pigment content, oxidative stress and morphology) of R. subcapitata were significantly affected by the fomesafen treatments, no significant effects were observed in the physiology of C. snowii and M. aeruginosa. We hypothesize that this difference in fomesafen resistance is most likely due to intracellular morphological and genetic differences between species. Modeling of fomesafen uptake in R. subcapitata showed that alteration of cell biovolume is unlikely to be an efficient mechanism modulating fomesafen toxicity and that potential fomesafen efflux or breakdown would need to be very fast (and operate at a high energy cost) in order to protect against uptake and toxicity. This study provides new insights into the sensitivity of different algae species toward fomesafen as well as the associated cellular toxicity mechanisms.
Numerical Parametric Study and Design of Pultruded GFRP Composite Channel Columns
Authors: Anbarasu M , Kasiviswanathan M , Kathiresan M , Mohan Ganesh G
Published: January 2023

This article reports the finite element (FE) investigation of the axial capacities of pultruded fiber-reinforced polymer (PFRP) composite channel columns. The nonlinear finite element model (FEM) was developed by using the ABAQUS package for glass fiber-reinforced polymer (GFRP) composite channel columns, which included geometric and initial geometric imperfections. The developed FEMs were verified against an experimental result available in the literature for GFRP channel columns. The validated FEMs were used to carry out the parametric study comprising 61 FE models to investigate the effect of different geometries, plate slenderness and the length of members on the axial capacities of GFRP pultruded channel columns. The results obtained from the parametric study were used to examine the accuracy of the current Italian guidelines, American pre-standard and the Direct Strength Method (DSM) proposed in the literature for GFRP channel profiles. Based on the obtained results, the suitability of the current design guidelines is assessed and, also, a new set of design equations is proposed to estimate the axial capacity of the pultruded GFRP channel columns. The new proposed set of reliable design equations witnessed a less scattered and a high degree of accuracy in determining the axial load capacity of the pultruded GFRP composite channel columns.
Standard Measuring of E-Learning to Assess the Quality Level of E-Learning Outcomes: Saudi Electronic University Case Study
Authors: Singh Prakash , Alhassan Ibrahim , Binsaif Nasser , Alhussain Thamer
Published: January 2023

Education in multiple forms and diverse geographical contexts delivers quality in all aspects of learning in which stakeholders such as students, instructors, and educational institutions play an important role. Quality assurance in higher education ensures the smooth functioning of the teaching and learning process by supporting the attainment of the desired quality levels of learning outcomes. This further leads to educational sustainability, as education has been acknowledged as a strategic constituent of sustainability-focused strategies in many educational contexts. Hence, it has become very important for educational institutions to maintain quality standards through the implementation of appropriate strategies, as quality is the lifeline of both Traditional Learning and E-Learning, and a lack of a suitable assessment standard affects the quality of learning. This research study attempts to address the existing gaps observed following a review of the related literature. This study collected qualitative data using an observation method through the observations and review of online software used at the Saudi Electronic University, namely Blackboard Learning Management System (LMS), Tawkeed Quality Management E-System, and Blue Survey software. In addition to this, the expertise of the research team members was also utilized for this research study in designing E-Learning quality dimensions. The purpose of this study was to propose an E-Learning Quality Assessment Standard that will help third-level educational institutions to assess their current teaching and learning practices of E-Learning and support them in enhancing the overall students’ experiences toward E-Learning within their institutions. As a research outcome, a conceptual quality assessment standard titled “SPECIFIERS” was proposed to offer a helping hand during the E-Learning quality assessment process to ensure sustainable education development of global educational institutions.
Numerically Evaluation of Dynamic Behavior of Post-Tensioned Concrete Flat Slabs under Free Vibration
Authors: Tahmasebinia Faham , Hu Zhiyuan , Wei Qianhao , Ma Wenjie
Published: January 2023

The objective of this paper is to investigate the dynamic behaviour of post-tensioned concrete flat slabs with different geometries and damping ratios. Four groups of models with different lengths, widths, thicknesses and damping ratios designed according to the AS3600 standard. These were used to determine the influence of each parameter on the vibration serviceability by comparing the control variable method with the reference model. The vibration assessment parameters were used as natural frequency, peak acceleration, and response factor. Both the SCI/CSTR43 standard theoretical calculations method and the Strand7 finite element analysis (FEA) method are used to determine the effect of different geometries and damping ratios on vibration. The feasibility of the Strand7 FEA method for vibration analysis is also assessed by calculating the errors of the two methods. The paper concludes that the Strand7 FEA method is highly accurate and feasible. The span in both directions has a large effect on the natural frequency, and increasing both the slab thickness and the damping ratio are effective methods to improve the vibration serviceability. Based on the research in this paper, recommendations are provided for future vibration design of post-tensioned concrete slabs.
Design and Control of Novel Single-Phase Multilevel Voltage Inverter Using MPC Controller
Authors: Ayub Muhammad Ahsan , Aziz Saddam , Liu Yitao , Peng Jianchun , Yin Jian
Published: January 2023

In this article, a single-phase five-level voltage inverter topology with six switches is suggested for renewable energy applications. Control inverters that are low-cost, highly efficient, and resilient are required for modern renewable energy grids. The basic goal is to collect as much power as possible from the sources and feed the current into the grid with as little loss and harmonic distortion as possible. The suggested inverter’s low switch count (six switches) with only two switches switched ON in a single state greatly decreases switching and conduction losses. Furthermore, a multi-error feedback controller with modified sinusoidal pulse width modulation (SPWM) is presented to manage the switching operation and maintain the output voltage in the appropriate range under different input and output voltage conditions. Furthermore, the lack of a clamping diode and bulky capacitors in the topology allows it to be controlled using a simple model predictive controller, lowering the cost of the circuit and improving the overall efficiency of the five-level inverter. Furthermore, for the variable input waveform, the total harmonic distortion (THD) evaluated by FFT analysis is within the allowed range of 1.8–4.5%. To validate the originality of this study, simulation and hardware results are provided and compared with current topologies.
A Smallholders’ Mariculture Device for Rearing Seafood: Environmentally Friendly and Providing Improved Quality
Authors: Lin Tsang-Yuh , Chen Chung-Ling , Shih Yung-Yen , Hsieh Hsueh-Han , Huang Wei-Ji , Santschi Peter H. , Hung Chin-Chang
Published: January 2023

The aquaculture industry in Taiwan grosses more than USD 1.1 billion annually; however, it also generates considerable waste discharge (causing eutrophication in estuarine and coastal waters) and heavy groundwater withdrawals (causing land subsidence in coastal areas). Many aquaculture facilities using earth ponds are affected by benthic algae, resulting in an earthy odor, and fixed-cage farms are difficult to relocate during cold weather events. In this study, we tested small-scale (~15 ton) mobile cage tanks for the nearshore rearing of white shrimp and grouper in the Yung-An district of Kaohsiung, Taiwan. At the conclusion of the mariculture experiment, the content of free amino acids in shrimp and groupers reared in our mobile tanks surpassed that in animals reared locally in traditional earthy ponds. In a blind taste test involving 42 volunteers, groupers reared in mobile cage tanks were deemed more palatable than those raised in ponds. Our results demonstrate that small-scale mobile cage tanks are a feasible approach to the sustainable rearing of high-quality shrimp or fish. Note that wastewater from the mobile tanks is easily diluted by seawater, thereby reducing the likelihood of eutrophication in coastal regions. The proposed system could also be used for recreational fishing activities to increase income for smallholders of fishermen and/or aquaculture farmers.
Land Surface Temperature Variation in Response to Land Use Modes Changes: The Case of Mefou River Sub-Basin (Southern Cameroon)
Authors: Ebodé Valentin Brice
Published: January 2023

Land surface temperature (LST) estimation at the river sub-basin level is crucial for developing land use planning at the basin scale and beyond. The main goal of this study was to analyze LST variations in response to land use mode (LUM) changes in the Mefou River sub-basin (Southern Cameroon) using geospatial techniques. To achieve this goal, we used Landsat 7 Enhanced Thematic Mapper Plus (2000 and 2010) and Landsat 8 Operational Land Imager (OLI)/Thermal Infrared Sensor (TIRS) data for 2020. We also used air surface temperature data from the Climatic Research Unit (CRU) to validate the LST. Our results reveal that between 2000 and 2020, the Mefou watershed recorded significant changes in LUMs, which were mainly manifested by an increase in impervious areas (IAs) (buildings and roads (+10%); bare soils and farmlands (+204.9%)) and forest reduction (−31.2). This decrease in the forest was also reflected by a reduction in NDVI values, the maximum of which went from 0.47 in 2000 to 0.39 in 2020. Contrary to the forest area and the NDVI values, the LSTs of the investigated basin increased over the period studied. There is a strong negative correlation between LST and NDVI. In general, high LSTs correspond to low NDVI values. For the years 2000, 2010 and 2020, the links between these two variables are materialized by respective correlation coefficients of −0.66, −0.74 and −0.85. This study could contribute to understanding the impact of LUM changes on the local climate, and could further provide assistance to policymakers in regard to land use planning and climate change mitigation strategies.
Research on Coordination in a Dual-Channel Green Supply Chain under Live Streaming Mode
Authors: Chen Tianwen , Zhou Ronghu , Liu Changqing , Xu Xiang
Published: January 2023

In this paper, we study the coordination issue in a dual-channel green supply chain with one manufacturer and one retailer. The demand in the traditional channel is assumed to be dependent on retail price, sales effort and green degree. Due to the characteristic of live broadcast selling, the demand in the direct channel is assumed to be dependent on price and discount. On the basis of analyzing price, sales effort and green degree strategies in the supply chain under the centralized model, two decentralized models and two coordination models are presented. Moreover, we prove the feasibility of sharing the R&D costs of the green degree and sales effort costs of the advertisement (CS-GS) contract through bargaining problems achieving a win-win situation, but the revenue sharing and wholesale price (RSC) contract commonly used cannot efficiently coordinate the supply chain. Finally, numerical analysis is given to show the impacts of coordination contracts on the supply chain’s performance as well as the impacts of parameters on profits and decisions in the four models. It reveals that the CS-GS contract can not only help to improve the green degree and the price of the product, but also improve the profitability of all supply chain members.
Modeling and Simulation of Shared Electric Automated and Connected Mobility Systems with Autonomous Repositioning: Performance Evaluation and Deployment
Authors: Benarbia Taha , Kyamakya Kyandoghere , Al Machot Fadi , Kambale Witesyavwirwa Vianney
Published: January 2023

The boom seen in artificial intelligence in recent years has led to a revolution in the automotive industry. Numerous automakers around the world, such as Tesla, Toyota, Honda, and BMW, have achieved giant strides in the development of e-autonomous vehicles. Consequently, shared electric automated vehicle mobility (SEAVM) systems, which are a crucial part of future innovative transportation solutions, have attracted significant attention from the research community, particularly from a design perspective. However, the flexibility of shared automated mobility systems may lead to a self-operating technology issue (unequal distribution of vehicles), since users in these systems can pick up and drop off electric vehicles wherever they like. With this in mind, this paper addressed the issues of autonomous repositioning and the assignment of shared autonomous electric vehicle systems to balance a system’s network and fulfill its demand. Modeling, analysis and assessment of the system’s performance were carried out using stochastic Petri nets formalism, which included determining the average time areas were empty/congested and the number of unserved consumers, and estimating the redistribution service launch moment. Furthermore, many simulation scenarios were analyzed, including repositioning and without repositioning scenarios, in order to evaluate the efficiency of the model and to show the potential of using Petri nets as a probabilistic formalism approach for the modeling of e-automated mobility systems.
Influence of Rock Structure on Migration of Radioactive Colloids from an Underground Repository of High-Level Radioactive Waste
Authors: Malkovsky Victor I. , Petrov Vladislav A. , Yudintsev Sergey V. , Ojovan Michael I. , Poluektov Valeri V.
Published: January 2023

Studies of leaching of vitrified simulated high-level radioactive waste (HLW) evidence that most of actinides or their simulators enter leaching water in a colloidal form. In this paper, we consider a mechanism of colloid-facilitated migration of radionuclides from an underground repository of HLW located at a depth of a few hundreds of meters in fractured crystalline rocks. The comparison between data of field and laboratory measurements showed that the bulk permeability of the rock massif in field tests is much greater than the permeability of rock samples in laboratory experiments due to an influence of a network of fractures in the rock massif. Our theoretical analysis presents evidence that this difference can take place even in a case when the network is not continuous, and the fractures are isolated with each other through a porous low-permeable matrix of the rock. Results of modelling revealed a possibility of mechanical retention of radionuclide-bearing colloid particles in the frame of rock during their underground migration.
The Moderating Role of Host Investment Environments on the Relationship between Enterprises’ OFDI and Green Innovation: Evidence from China
Authors: Ji Li , Mou Jiaqi
Published: January 2023

This study investigates whether and how outward foreign direct investment (OFDI) affects green innovation using a sample of Chinese A-share listed companies from 2006 to 2020. We find that OFDI significantly promotes green innovation, not only for gaining legitimacy, but also to mitigate liabilities of foreignness and cultivate competitiveness. The result is robust for endogeneity and among other robustness tests. Moreover, host economic development, environmental regulation, and national governance positively moderate the relationship between OFDI and green innovation, indicating that the heterogeneity of host investment environments effectively affects OFDI enterprises’ motivation to make green innovation. Further analysis shows that OFDI promotes green innovation more significantly in state-owned and less-overseas-experienced enterprises, heavy pollution industries, and areas with strict environmental regulations in the home country. This study introduces the heterogenous host investment environments into the relationship between OFDI and green innovation, and examines its moderating role, which reveals the mechanism of OFDI affecting green innovation. This study also provides a valuable reference for guiding enterprises’ internationalization and resisting overseas investment risks.
Simulation Study on Spatial Form of the Suspended Roof Structure of Working Face in Shallow Coal Seam
Authors: He Yanpeng , Huang Qingxiang
Published: January 2023

Longwall fully comprehensive mechanized mining is mainly used for the working faces of shallow coal seam with large mining height, which usually have a large suspended roof at the face end. The overhang at the face end leads to stress concentration, which affects the safe mining of the working face. In this paper, we use the 15210 working face with a suspended roof (overhanging area 50~70 m2) of the Zhangjiamao coal mine as study background, with physical simulation, numerical calculation and theoretical analysis, the spatial morphologies and changes in the roof structure at the face ends of the working face in shallow coal seam are obtained, in which the suspended roof increase from the bottom to top, forming step-laminated structures. The caving interval of the suspended roof at the face end is about two times the period weighting interval, and the suspended roof area at the tailgate is smaller than at the headgate. The distribution of the shear and the principal stress field at the face-end region is arc-shaped, and the distribution of the plastic zone shows that the collapse of a suspended ceiling has obvious hysteresis. According to the simplified analysis of the Marcus plate, when the layers of the stepped curved triangular plates increase, the length of the suspended roof on the solid coal side also increases, which is consistent with the results of the physical simulation and numerical calculations. The formation mechanism of the roof at the end of the working face provides a research foundation for the control of roofs found at face ends and further improves the theory of roof structure and the safety mining of suspended roof areas.
Development of Spatio-Temporal Orientation of Children with Down Syndrome through Educational Platforms after Romanian Pandemic Lockdown
Authors: Popescu Ofelia , Leonte Nicoleta
Published: January 2023

The restrictions due to COVID-19 have left their mark on the education of children with disabilities. Conducting physical therapy classes online was a necessity and at the same time a challenge for both teachers and parents. The purpose of this paper was to investigate spatio-temporal orientation, followed by the design and implementation of stimulation programs for education, by applying multisensory intervention programs conducted online. The study included 27 students with DS and associated conditions. The groups were established according to the kinetic diagnosis, motor and psychomotor disorders of each child. The statistical analysis was quantitative, with a significance level of 95%. The dependent test was used to highlight the significance of the rate of progress achieved by the children. Results obtained for the psychomotor component—spatial orientation registered an increase of 1.81 units, between the initial and the final test. The value of the Student-t test calculated t between the two tests is 6.20 so 6.20 > 2.056 (Table Fischer) and as a result the differences are significant (p < 0.05). Regarding the psychomotor component, for temporal orientation, the results registered an increase of 1.37 units between the initial and the final test. The value of the Student t test calculated between the two tests is 7.68 so 7.68 > 2.056 (Table Fischer), and as a result the differences are significant between the averages of the two tests (p < 0.05). Following the experiment, the results obtained by the subjects, at the final test, were superior to the initial ones, with differences between statistically significant arithmetic averages for all components of the investigated psychomotor ability: spatial orientation and temporal orientation.
Tax Payment and the Performance of SMEs: A Longitudinal Analysis on EU Countries
Authors: Roman Teodora , Marcu Nicu , Rusu Valentina Diana , Doacă Erika Maria , Siriteanu Adelina Andreea
Published: January 2023

Small and medium enterprises (SMEs) are considered the engine of any economy and actively contribute to the economic growth of countries. For this reason, there are concerns regarding the identification of the factors that influence the activity of SMEs and, in particular, how they manage to adapt and obtain better performance in a constantly changing economic environment. The tax burden is high and discouraging for many enterprises, so we aimed to analyse the relationship between the taxes imposed on SMEs and their performance. Thus, the main purpose of our study was to analyse the relationship between the taxes paid by SMEs and their performance. The period of analysis consisted of the 14 years between 2008 and 2021. The analysed sample comprised the 27 member countries of the European Union. To test the relationship, we used panel data methods, and we considered two indicators that measure the performance of SMEs as dependent variables and indicators that measure the taxes paid by businesses as independent variables. For a more in-depth analysis, we used clusters of countries. The main results show that the taxes that SMEs have to pay are seen as obstacles in the way of improving performance. Moreover, the relationship between taxes and the performance of SMEs depends on the specifics of the economy of the country.
Feature-Weighting-Based Prediction of Drought Occurrence via Two-Stage Particle Swarm Optimization
Authors: Sundararajan Karpagam , Srinivasan Kathiravan
Published: January 2023

Drought directly affects environmental sustainability. Predicting the drought at the earliest opportunity will help to execute drought mitigation plans. Several drought indices are used to predict the severity of drought across different geographical regions. The two main drought indices used in India for meteorological drought are the standardized precipitation index (SPI) and standardized precipitation evapotranspiration index (SPEI). This work is a study to find the ability of above mentioned indices to predict meteorological drought for the state of Tamil Nadu using 62 years of data. The prediction results are evaluated using the performance metrics of precision, recall, f1 score, Matthews correlation coefficient, and accuracy. The dataset is severely imbalanced due to the low number of drought incidence years. Hence there exists a tug of war between precision and recall, so for improving it without affecting one another, a multi-objective optimization process is applied. The prediction performance is improved by using the filter-global-supervised feature weighting and wrapper-global-supervised feature weighting techniques. In the filter-based feature weighting approach, the information gain measure and Pearson correlation coefficient are used as feature weights. For the wrapper-based feature weighting approach, two-stage particle swarm optimization (PSO) is designed to calculate the weights of the features, and the random forest is used as the classifier. This two-stage PSO constructs the best population set for individual objectives and then searches around it to find the best particle so that the multiple contradicting objectives will converge into the best solution easier. When compared to classification without feature weighting, two-stage PSO feature weighting achieves a 45% improvement in precision. However, only a moderate improvement in recall is obtained. According to the findings, SPI3 and SPEI12 should be given more weightage in metrological drought prediction.
Application of a Combined FEM/DEM Approach for Teaching a Deep Rock Mass Mechanics Course
Authors: Feng Fan , Xie Zhiwei , Xue Tianxi , Wang Eryu , Huang Ruifeng , Li Xuelong , Gao Shixian
Published: January 2023

Deep rock mass mechanics is a professional course which is offered to undergraduate and postgraduate students in some mining universities. This course mainly includes the following topics: the geological structure of deep rock mass, the mechanical properties of deep rocks, the strength theory of deep rock masses, stability analysis and control of deep surrounding rock classification of engineering rock masses, and the application of deep rock mechanics in underground mining engineering The purpose of this course is to present students with a basic theoretical knowledge of deep rock mass engineering. Analyzing the limitations of traditional deep rock mass mechanics teaching methods, here, we propose integrating a combined FEM/DEM (Finite Element Method/Discrete Element Method) approach into the teaching of a course on deep rock mass mechanics. The mechanical behaviors and failure instability process of rock at laboratory and engineering scales were analyzed using ELFEN software (a finite/discrete element code). The results show that a combined FEM/DEM approach as a deep rock mass mechanics teaching method is completely feasible and reasonable; this approach has the advantages of strong intuition, high reliability, time and labor savings, and low cost, which can offset the shortcomings of traditional teaching methods. Moreover, the proposed approach can stimulate students’ interests in a mining course on deep rock mass mechanics, deepen students’ understanding of the course curriculum, and cultivate students’ innovative abilities and subjective initiatives.
Gamified Project-Based Learning: A Systematic Review of the Research Landscape
Authors: Huang Wendan , Li Xiuhan , Shang Junjie
Published: January 2023

The information era puts higher requirements on current students’ learning methods to develop 21st-century skills. Project-based learning (PBL) and gamified learning have been two effective learning approaches, leading to an innovative exploration of combining both to improve learning outcomes. This study presents a systematic review of the literature published on “gamified PBL” (GPBL) over the past six years, focusing on GPBL approaches, learning outcomes, technical tools and theories. The results show that the gamified approaches of project-based learning can be divided into four types: gamify structure and procedure of PBL, gamify content of PBL, integrate prefabricated educational/serious games in PBL, and make a game as the activity of PBL. Most of the studies affirmed the positive effects of GPBL in enhancing students’ learning outcomes, especially for learning experience and motivation. Adopted techniques and theories in the reviewed studies were also summarized. In conclusion, we acquired four findings based on the discussion: the characteristics of GPBL are diverse; design-based learning are an innovative and creative method used in GPBL; studies of GPBL emphasized collection and description of the whole-process data; technical issues should be paid great attention to. In addition, a number of suggestions for future research are provided in this review.
Effects and Mechanisms of China’s Pilot Free Trade Zones on Green and High-Quality Development from the Dual-Circulation Perspective
Authors: Chang Yanjun , Lai Liuliu
Published: January 2023

Under the dual pressure of economic growth and environmental pressure, green and high-quality development become a critical strategy for China to achieve win-win development for both the economy and the environment. In the dual-circulation pattern, a deep and high level of openness is the primary prerequisite for encouraging green and high-quality development. Previous studies have overlooked the crucial pivotal role of pilot free trade zones (PFTZs) in domestic and international circulation. The PFTZ is essential in driving China’s green modernization and high-quality development as a crucial area of opening up. This paper utilizes the propensity score matching and difference-in-differences (PSM-DID) on panel data from 27 provinces from 2007 to 2020 to investigate the green policy effects of PFTZ building and its underlying mechanism. The results show that (1) the establishment of PFTZs significantly enhances regional green and high-quality development, with a net policy impact of roughly 4%. The several robustness tests demonstrate that the outcomes are extremely reliable; (2) According to the heterogeneity analysis, compared with inland areas, coastal locations may more effectively foster green and high-quality development; and (3) The influencing mechanism test results show that PFTZs primarily have a positive impact on technological progress, scale expansion, and innovation-driven effects, which, in turn, support green and high-quality development. The mediating effect of innovation-driven and technological progress is extremely significant among them. These research findings can provide empirical support and policy rationale for PFTZs to better promote China’s green and high-quality development.
A Critical Review on the Microbial Ecology of Landfill Leachate Treatment Systems
Authors: Remmas Nikolaos , Manfe Nicola , Zerva Ioanna , Melidis Paraschos , Raga Roberto , Ntougias Spyridon
Published: January 2023

Sanitary landfilling is still considered worldwide as one of the most common methods applied for the management of the municipal solid waste. As a consequence, vast amounts of landfill leachate are generated annually, which are characterized by variability in physicochemical composition, owing to the stabilization process that occurs over the years. However, sustainable management of landfill leachate is a challenging issue, due to diverse chemical composition and high concentration in heavy metals and xenobiotics. Despite the fact that several studies have been reported on the biotreatment of landfill leachate, only in recent years has the microbial composition in such systems have been examined. In the present review, the key role of the microbial ecology involved in depurification and detoxification of landfill leachate in activated sludge and anaerobic systems is interpreted and ecological considerations influencing landfill leachate treatment are stated. Apart from the assessment of landfill toxicity on certain model organisms, this work provides an extensive overview on microbial communities performing key biological processes during landfill leachate treatment, including nitrification-denitrification, anammox and anaerobic digestion. Moreover, microbial aspects affecting nutrient removal efficiency in such biosystems are discussed.
Radar Method of Measuring the Velocity of the Fragments
Authors: Sweklej Paweł , Wasilewski Aleksander , Magier Mariusz
Published: January 2023

Thousands of debris dangerous to personnel are generated during controlled explosion of warheads containing explosives. To ensure the safety of people, it is necessary to define a zone in which people can stay without risking their lives. A major focus of modern engineering is to maximize the safety of operating technical equipment. In order to implement the above, it is necessary to determine the kinetic energy of the fragments, for which the safe level is below 17 joules (like for air gun). Simultaneous registration of the velocity of such a large amount of fragments is a significant research problem. The article presents a comparison of the two methods of measuring the velocity of splinters formed during detonation of the fragmentation generator. The first common method is to use a chronometer and aluminum foil. The second method, new for this application, is to use a Doppler radar. It allows you to measure the velocity at any moment of the path traveled by the splinter. The article also describes attempts to measure the velocity with both methods, using different variants of Doppler radar settings. Difficulties resulting from the measurements were described, as well as the methods of their elimination.
Sustainability Indexing Model for Saudi Manufacturing Organizations
Authors: Al-Alqam Mohammed Saeed , Rehman Ateekh Ur , Alsultan Marwan
Published: January 2023

Saudi Arabia has a 2030 Vision in which sustainability is a central pillar. Sustainability in manufacturing organizations has become a topic of discussion as a potential solution to help them survive and prosper in a competitive market. Here, the objective is to establish a sustainability indexing model for Saudi manufacturing organizations that will help organizations to prepare their sustainability reports in line with international sustainability standards. This study will also help Saudi manufacturing organizations evaluate their level of sustainability and identify barriers to improving their sustainability. The model presented has three sustainability dimensions, 12 criteria, and 29 sub-criteria. The model was implemented in a Saudi manufacturing organization as a case study. To improve the organization’s sustainability level, sustainability barriers were identified and analyzed. The model indicates that eight sub-criteria scored below the threshold value, which was found to be 0.19. These sub-criteria were further considered as sustainability barriers in the case organization.
Multi-Criteria Energy Management with Preference Induced Load Scheduling Using Grey Wolf Optimizer
Authors: Ayub Sara , Ayob Shahrin Md , Tan Chee Wei , Arif Saad M. , Taimoor Muhammad , Aziz Lubna , Bukar Abba Lawan , Al-Tashi Qasem , Ayop Razman
Published: January 2023

Minimizing energy costs while maintaining consumer satisfaction is a very challenging task in a smart home. The contradictory nature of these two objective functions (cost of energy and satisfaction level) requires a multi-objective problem formulation that can offer several trade-off solutions to the consumer. Previous works have individually considered the cost and satisfaction, but there is a lack of research that considers both these objectives simultaneously. Our work proposes an optimum home appliance scheduling method to obtain an optimum satisfaction level with a minimum cost of energy. To achieve this goal, first, an energy management system (EMS) is developed using a rule-based algorithm to reduce the cost of energy by efficient utilization of renewable energy resources and an energy storage system. The second part involves the development of an optimization algorithm for optimal appliance scheduling based on consumer satisfaction level, involving their time and device-based preferences. For that purpose, a multi-objective grey wolf accretive satisfaction algorithm (MGWASA) is developed, with the aim to provide trade-off solutions for optimal load patterns based on cost per unit satisfaction index (Cs_index) and percentage satisfaction (%S). The MGWASA is evaluated for a grid-connected smart home model with EMS. To ensure the accuracy of the numerical simulations, actual climatological data and consumer preferences are considered. The Cs_index is derived for six different cases by simulating (a) optimal load, (b) ideal load, and (c) base (random) load, with and without EMS. The results of MGWASA are benchmarked against other state-of-the-art optimization algorithms, namely, binary non-dominated sorting genetic algorithm-2 (NSGAII), multi-objective binary particle swarm optimization algorithm (MOBPSO), Multi-objective artificial bee colony (MOABC), and multi-objective evolutionary algorithm (MOEA). With the proposed appliance scheduling technique, a % reduction in annual energy cost is achieved. MGWASA yields Cs_index at 0.049$ with %S of 97%, in comparison to NSGAII, MOBPSO, MOABC, and MOEA, which yield %S of 95%, 90%, 92%, and 94% at 0.052$, 0.048$, 0.0485$, and 0.050$, respectively. Moreover, various related aspects, including energy balance, PV utilization, energy cost, net present cost, and cash payback period, are also analyzed. Lastly, sensitivity analysis is carried out to demonstrate the impact of any future uncertainties on the system inputs.
Study of Ion Adsorption and Shear Strength of Red Clay under Leaching Action
Authors: Song Yu , Li Hui , Geng Yukun , Xia Lulu , Yan Rongtao
Published: January 2023

To study the soil-water effect of red clay, a leaching test is conducted by loading red clay into a soil column and collecting the leaching waste liquid periodically for analysis of the ion content and conductivity changes in the leaching waste liquid. After leaching and filtering, the soil is removed from the column and reconstituted as a straight-shear specimen for a straight-shear test. Ca2+, Mg2+, and SO42− ions increased and then stabilized in water samples as leaching time increased, while Na+, Cl−, and NO3− declined and then stabilized. Due to their presence in the leaching solution, Ca2+, Mg2+, and SO42− ions are initially adsorbed by the soil and then saturated by adsorption. In contrast, Na+, Cl−, and NO3− precipitate out of the soil due to the dissolution and ion exchange of the soil sample, thereby weakening their effects. Consequently, these ions appear to vary in various ways. The relationship between ion content in solution and conductivity has also been discovere, and the conductivity varies with the total ion charge in the solution. The angle of internal friction decreases as the leaching time increases, but the cohesion of the soil increases.
Is the Load Capacity Curve Hypothesis Valid for the Top Ten Tourism Destinations?
Authors: Pata Ugur Korkut , Tanriover Banu
Published: January 2023

Environmental deformations and changes put countries under socioeconomic stress at the global level and are, therefore, an essential topic of discussion. In this context, this paper analyzes the impact of financial development, tourism, and economic growth on three different environmental indicators using second-generation panel data techniques for the top ten tourism destinations. This study tests whether there is a U-shaped relationship between income and the load capacity factor and an inverse U-shaped link between carbon emissions, ecological footprint and income for the period 2004–2018. Despite the environmental Kuznets curve (EKC) hypothesis, which is often analyzed in this context, this empirical analysis investigates a new one—that of the load capacity curve (LCC) hypothesis. The results of the study show that the LCC and EKC hypotheses are not valid. The long-run panel estimators also indicate that international tourist arrivals are a factor that improves environmental quality, while financial development reduces the load capacity factor. Based on the results, it is recommended to support eco-friendly tourism for sustainable development.
D2D Communication Network Interference Coordination Scheme Based on Improved Stackelberg
Authors: Li Xinzhou , Chen Guifen , Wu Guowei , Sun Zhiyao , Chen Guangjiao
Published: January 2023

The sudden explosive growth of data in intelligent devices and existing communication networks has brought great challenges to existing communication networks. On the one hand, D2D (device to device) technology greatly improves the utilization of spectrum resources; on the other hand, it improves the communication quality of users. It has become an important part of the future communication network. Aiming at the problem that the existing D2D communication network system has complex user interference, and the communication quality of cellular users is difficult to guarantee, a D2D communication network interference coordination scheme based on improved Stackelberg is proposed. Using resource allocation and power control to solve the interference coordination problem, this paper proposes an improved Stackelberg model based on DQN (deep Q network), establishes the master–slave game between cellular users and multiplexing resource users (D2D users; relay communication users), optimizes the cost parameters in the Stackelberg mode and improves the transmission power and resource allocation scheme of multiplexing resource users. The simulation results show that compared with similar algorithms, the algorithm proposed in this paper has the best performance in guaranteeing the QoS of cellular users in the system and has good interference management capability for D2D communication networks.
A Model of Integrated Community-Based Bamboo Management for the Bamboo Industry in Ngada Regency, East Nusa Tenggara, Indonesia
Authors: Ekawati Desy , Karlinasari Lina , Soekmadi Rinekso , Machfud
Published: January 2023

The potentials of bamboo resources owned by the community in Ngada Regency has not been managed and appropriately utilized. There were no integrated programs between the on-farm and off-farm sectors and no clear roles and responsibilities among the stakeholders involved. Soft System Methodology (SSM) framework approach was carried out through stakeholder analysis, CATWOE analysis, and gap analysis. The root definition of the current situation was that the model of sustainable community bamboo management and utilization (W) is responsible to the local and central government as well as the bamboo manufacturing industry as off-taker (O) with integrated supporting programs and regulations, ensuring the potential of bamboo resources and the bamboo product market (E) which was carried out together with stakeholders (A) through active participation and synergy programs (T) to improve the welfare of the community of bamboo owners, craftsmen, and bamboo entrepreneurs (C). The study produces a suitable and appropriate strategy based on the corrective actions of existing problems and recommendations formulated from conceptual models and existing actual conditions on integrated sustainable bamboo management.