bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution of the main channel of the Yangtze River
Authors: Lu Jinyou , Zhu Yonghui , Jin Zhongwu , Guo Xiaohu , Guo Chao , Chen Peng , Wang Yanjun , Hu Chengwei , Yuan Yuan 
Published: August 2023

AbstractThe construction and operation of the Three Gorges Reservoir and the cascade reservoirs upstream have significantly altered the processes of flow and sediment in the main and tributary channels of the Yangtze River. This has led to substantial adjustments in the riverbed through erosion and deposition, thereby impacting flood protection, water resource utilization, navigation, and the aquatic environment in the Yangtze River basin. In this study, prototype measurements were used to analyze the variations in runoff and sediment load in the main channel of the Yangtze River, as well as the changes and evolution of the riverbed. Mathematical modeling was done to predict the trends in reservoir sedimentation and riverbed adjustments. The results indicate that, apart from the significantly increased runoff and sediment load in the river source region (Zhimenda station) over the past two decades, there is no clear unidirectional trend of increasing or decreasing in the main and tributary annual runoff of the Yangtze River. However, the release of reservoir outflows undergoes significant changes throughout the year due to reservoir regulation. Suspended sediment load in the upper Yangtze River has been decreasing since the 1990s, especially after the operation of the Three Gorges Reservoir and the four cascade reservoirs in the lower reach of the Jinsha River. The factors influencing flow and sediment variations include mainly climate change and human activities such as reservoir operation and soil and water conservation. The significant changes in flow and sediment conditions have disrupted the original relative equilibrium state of the main channel of the Yangtze River, leading to riverbed adjustments. The river sections in the upper reach, located within reservoir areas, have shifted from erosional state under natural conditions to accumulative state, while the middle and lower reaches have transitioned from a relatively equilibrium state to a process dominated by erosion and reconstruction. Overall, the river regime in the reservoir area and downstream of the Three Gorges Dam remains relatively stable, but there have been adjustments in some local river sections, for example, in the curved sections, particularly in the sharply curved sections downstream of the Three Gorges Dam, where gradual or abrupt chute cutoff has occurred. In the foreseeable future, the river channel downstream of the Three Gorges Dam will remain in an unsaturated state regarding sediment transport. The process of river channel erosion will persist for a long time and have far‐reaching consequences. Some long straight sections, multiple bifurcation sections, and sections with large curvature are expected to undergo certain adjustments in the river regime, necessitating continuous observation, long‐term monitoring, and timely river management and channel governance.
Preparation of Fe3O4 Magnetic Material Modified by Fulvic Acid and Its Adsorption Performance for Methylene Blue
Authors: Wu Zeqing , Fan Hongxian , Hu Xiaoxue , Zhang Songmei , Wen Yeqian , Li Gang 
Published: August 2023

AbstractIn this paper, a kind of Fe3O4 magnetic nano material modified by fulvic acid (FA) was prepared and used for removing methylene blue in wastewater. The structure and morphology of the material were characterized by FT‐IR, PXRD, BET, XPS, VSM, SEM and TEM. The results showed that FA successfully coated on the surface of Fe3O4 magnetic nano particles. The newly prepared magnetic material had large specific surface area and porous structure. The specific surface area of the material was 92.15 m2/g. The average pore size of the material was 8.917 nm. Its saturation magnetization could reach to 55.74 emu/g. The magnetic responsiveness of the material was obvious. The magnetic material could be recovered by the magnet so it was easy to separate with the solution. The adsorption kinetic data fitted better with pseudo second order kinetic equation. The isothermal adsorption processes of the modified material to methylene blue had better linear correlation with Langmuir isothermal adsorption model. The thermodynamic parameter results indicated that the adsorption processes of the material to methylene blue were spontaneous exothermic processes. The results of the cyclic experiments indicated that the material had a certain value for reuse.
A Theoretical Molecular Design of Acridine/Anthracene‐Polyoxometalate Hybrid Materials for Enhanced Dye‐Sensitized Solar Cells Performance
Authors: Al‐Khafaji Mariam K. , Al‐Yasari Ahmed , Mohammed Adnan I. 
Published: August 2023

AbstractFour novel organoimido‐substituted hexamolybdate dyes featuring acridine/anthracene donors for dye‐sensitized solar cells (DSSCs) have been designed and studied using a combination of density functional theory (DFT) and time‐dependent density functional theory (TDDFT) calculations. The energy levels of frontier molecular orbitals, absorption spectra with electronic transition characters, and photovoltaic parameters of dyes 1–4 were systematically evaluated. The results confirm the suitability of all the studied dyes for n‐type DSSCs. The investigated dyes could be introduced as an active co‐absorbent as well as main dye. All dyes showed remarkable reorganization energy for electron transport (λe) and hence increased electron transfer rate. Due to the strong absorption in the visible region, as well as high light harvesting efficiency (LHE), dye regeneration efficiency (DRE), and electron injection efficiency (Φinj), dyes 2 and 3 are the most promising candidates for high performance DSSC materials.
A Combined Ultrasound–Microwave Assisted Alcoholic–Alkaline Method for Preparation of Granulated Cold‐Water‐Soluble Starch
Authors: Liu Yao , Zhu Lvzhou , Yu Xi , Xu Yuqing , Zhong Tian 
Published: August 2023

AbstractIn order to further improve the solubility of granulated cold‐water‐soluble starch (GCWSS), this study develops a new, combined ultrasound–microwave assisted method based on the traditional alcoholic–alkaline method. Following a single‐factor experiment, an orthogonal experiment is conducted to determine optimized parameters and proportions. Three typical samples with relatively low, medium, and high solubility, respectively, are selected for characterization, including with scanning electron microscopy (SEM), polarization characteristics, Brabender viscosity, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The results show that the combined ultrasound–microwave treatment significantly improves the solubility of modified starch, achieving a highest sample solubility of 92.45%.
Flow Simulation of a New Horizontal Axis Wind Turbine with Multiple Blades for Low Wind Speed
Authors: Abo-Serie Essam , Oran Elif 
Published: August 2023

AbstractIn this paper, a new design of a small horizontal-axis wind turbine is introduced. The design is based on the authors’ patent, which uses permanent magnets impeded into a shroud that holds the rotor blades. The generator coils are installed on a fixed diffuser that houses the rotor and acts as a wind concentrator. Therefore, the new design has no hub and is based on direct coupling for electricity generation. The main features of the design have been explored to highlight the advantages with a focus on how the new design can be integrated with the recent development of green buildings. The effect of increasing the number of blades and blade chord distribution on turbine performance has been investigated for the new turbine. Initial design and analysis were carried out using the Blade Element Momentum method and CFD simulations to identify the turbine performance and examine the flow characteristics. The results showed that further energy can be extracted from the turbine if the blade chord size increases at the shroud location and reduces at the turbine hub for a low Tip Speed Ratio TSR within the range of 1.5–3. Furthermore, having more blades can significantly increase the power coefficient and extend the range of operation with a high power coefficient. The number of blades, however, has to be optimised to achieve maximum power relative to the cost. Adding a diffuser and flanges surrounding the turbine can further increase the energy extracted from the wind at low speed.
Assessment of Effectiveness of Hollow Fins for Performance Enhancement of Solar Still Device Using Simulation Approach
Authors: Ullah Hafiz Khadim , Ismail Sikiru Oluwarotimi , Prasad Kumar Shantanu 
Published: August 2023

AbstractUnavailability of relatively clean water for several industrial, domestic and agricultural purposes is a serious concern to many regions of the world today. This challenge is growing worse with the increasing world global warming and human population. Therefore, there is need to research into an innovative, sustainable and/or improved technology for an efficient and effective solution, such as desalination. Desalination of freely available sea water is considered a promising source of fresh water. Solar radiation is abundant and can be used to desalinate water, using a solar still device. Also, it is important to increase the productivity of the solar still device through hollow fin modification. Therefore, the effectiveness of this improvement was investigated in this study, using an analysis system (ANSYS) Fluent computational fluid dynamic (CFD) simulation. Appropriate models were used to describe the physical processes, including condensation, evaporation, multiphase flow, surface tension and solar radiation. A close agreement between the simulation values of solar energy and the water temperature in the basin was observed when compared with the experimental data from the literature. Velocity of 0.259 m/s, pressure of 55.8 Pa, temperature of 57.85 ºC and mass transfer rate of 1.41 kg/m3/s were obtained in the mid-plane of the improved double slope single basin (DSSB). The degree of improvement was 5–7% when compared with the existing models. Importantly, this process is economically efficient and can support the concepts of sustainability and healthy living, especially in rural areas.
Development of a CFD Model for the Estimation of Windage Losses Inside the Narrow Air Gap of an Enclosed High-Speed Flywheel
Authors: Eltaweel Mahmoud , Kalyvas Christos , Chen Yong , Herfatmanesh Mohammad Reza 
Published: August 2023

AbstractConcerns over global warming and the need to reduce carbon emissions have prompted the development of novel energy recovery systems. During urban driving, a significant amount of energy is lost due to continuous braking, which can be recovered and stored. The flywheel energy storage system can efficiently recover and store the vehicle's kinetic energy during deceleration. In this study, a Computational Fluid Dynamics (CFD) model was developed to assess the impact of air gap size, and rotor cavity pressure environment on the aerodynamic performance of an enclosed non-ventilated flywheel energy recovery system. Consequently, the flywheel rotor skin friction coefficients for various air gap sizes have been numerically determined to predict the windage losses over a wide operating range. The presented study aims to identify a correlation that accurately fits the rotor skin friction coefficients for a range of air gap sizes and operating conditions. Model validation was carried out to assess the validity of the CFD results, which showed good agreement between numerical and experimental data. The results demonstrated that the increase in the air gap size can lead to up to a 19% reduction in the windage loss depending on the operating speed of the flywheel, while the windage loss can be reduced by 33% when the operating pressure is reduced to 500 mbar. Windage losses can be reduced by 45% when the airgap size is greatest, and the operating pressure is lowest.
The Impact of Strategic Environmental Management Capabilities on the Competitiveness of an Oil and Gas Industry’s Supply Chain: An Empirical Evaluation of the Natural Resource-Based View of Firms
Authors: Olajide Olatunde , Kamal Muhammad Mustafa , Kwak Dong-Wook , He Qile , Lim Ming 
Published: August 2023

AbstractThe Oil and Gas (O&G) industry has been subjected to stringent environmental regulations and increasing stakeholders’ criticisms because of its devastating negative environmental impacts. Consequently, firms operating in the industry’s supply chain are increasingly facing intense pressures to develop the strategic capabilities for implementing green practices to reduce the environmental impacts of operations. From a theoretical perspective, the Natural Resource-Based View (NRBV) suggests that the strategic environmental capabilities of pollution prevention (PPC), product stewardship (PSC) and clean technology (CTC) can generate sustained competitive advantage for firms. However, the extant empirical research investigating the impact of the three NRBV strategic environmental capabilities (PPC, PWC and CTC) on firms’ competitive performance has yielded inconsistent results. Therefore, this paper adopts the theoretical lens of NRBV to develop and empirically assess an integrated framework of strategic environmental management capabilities (SEMC) and competitiveness in the context of the Nigerian O&G industry. Using a multiple regression technique to analyse the responses of 214 managers across the supply chain of the Nigerian O&G industry, this study examines the impact of the three NRBV-based SEMC (PPC, PWC and CTC) on the economic and environmental competitiveness of the firms operating in the supply chain of the Nigerian O&G industry. First, the results indicate that the three SEMCs have positive impacts on the environmental competitiveness of the O&G firms. However, while PPC and PSC are positively related to the economic competitiveness of firms, CTC has no statistically significant impact on economic competitiveness. These findings suggest that O&G firms in developing nations need to channel efforts to build their SEMCs for implementing green practices to enhance their economic and environmental competitiveness. The results further highlight the need for policymakers in petroleum-producing nations to promote policies that foster the adoption of green practices by O&G firms.
Multi-objective Optimisation of a Wastewater Anaerobic Digestion System
Authors: Ashraf R. J. , Nixon Jonathan D. , Brusey J. 
Published: August 2023

AbstractThis paper looks at multi-objective optimisation of a wastewater AD system where the model is demonstrated for a case study plant. Anaerobic Digestion Model No. 1 (ADM1) was used to predict biogas yields from the digester. Interviews, with plant owners, and plant data were used to identify the objective functions and decision variables. The decision variables were defined to be the substrate feeding rate for each of the digesters and the ratio of biogas sent between a combined heat and power (CHP) plant and a biogas upgrading unit (BUU). The objectives set were to maximise the overall substrate feeding rate through the AD plant, maximise the overall energy output and minimise the running cost of the plant. Results from the optimisation study showed that the amount of sludge processed through the AD plant increased by 17.7% and the running cost of the plant reduced by 6.2%. These results demonstrate how performance of AD plants can be significantly improved by multi-objective optimisation techniques.
Performance of Different Optimization Solvers for Designing Solar Linear Fresnel Reflector Power Generation Systems
Authors: Sirimanna M. P. G. , Nixon Jonathan D. , Innocente M. S. 
Published: August 2023

AbstractLinear Fresnel Reflector (LFR) is an emerging solar thermal power generation technology that benefits from a simple and low-cost construction in comparison to more conventional Concentrating Solar thermal Power (CSP) generation technologies such as parabolic trough and power tower. Although LFR technology presents the drawbacks of lower energy conversion efficiency and higher energy cost, these can be offset by optimizing its design. This has not been sufficiently addressed due to the complex interactions between solar rays, heat transfer modes, and design variables. This work presents a systematic approach to select suitable optimization methods for the design of LFR systems. Thus, a mathematical model is developed to carry out simultaneous raytracing and thermal simulations aiming to provide an estimation of the system’s total conversion efficiency to be maximized. In order to compare the performance at solving this problem of a range of optimization algorithms with different characteristics, three derivative-based, two derivative-free, one population-based, and the simulated annealing methods are used in the numerical experiments. Only one design variable and a simple LFR system with a trapezoidal receiver are considered in the first instance. Only those algorithms which are successful at solving this simple problem are then tested on the optimal design with multiple variables. An exhaustive search is also conducted to check accuracy. Results show that pattern search, simulated annealing, and genetic algorithms perform best at solving the simulation-based LFR optimal design problem.
Pre-existing Mathematics Teacher Characteristics
Authors: Chapman Olive 
Published: August 2023

AbstractThis chapter addresses the pre-existing mathematics teacher characteristics (PMTC) of prospective mathematics teachers on entry to their teacher education program. Pre-existing teacher characteristics include abilities, knowledge, and attitudes that a candidate for admission to a teacher preparation program possesses on entry, as well as a candidate’s aptitude for teaching. The chapter provides an overview of a survey of mathematics education research for the period 2000 to 2020 with a focus on the three categories of the types and nature of pre-existing teacher characteristics the studies addressed. These categories emerging from the survey are pre-existing mathematical content knowledge and skills, pre-existing mathematics-related pedagogical knowledge and ability, and pre-existing mathematics-related beliefs. The studies are also discussed from the perspective of the evolution of the research on PMTC and implications regarding future evolution of research on PMTC.
The Research on Mathematics Teaching and Planning: Theoretical Perspectives and Implications of Teachers’ Pre-post Classroom Activities
Authors: Manizade Agida G. , Moore Alexander S. , Beswick Kim 
Published: August 2023

AbstractLesson planning, assessment, and reflection constitute the key actions that teachers perform when students are not present in the classroom (henceforth, “Type D” variable). These “pre- and post-”actions are the most direct ways through which teachers shape their observable teaching work as mediated by their goals for their teaching. These goals are representations of teachers’ epistemological commitments apropos of teaching mathematics, whether those commitments be consciously espoused or unconsciously reproduced due to constraints within which they work. In this chapter, we survey the literature on lesson planning, assessment, and reflection according to eight epistemological paradigms that are widely known in the field of mathematics teaching. These epistemological paradigms are: Situated Learning Theory, Behaviorism, Cognitive Learning Theory, Social Constructivism, Structuralism, Problem Solving, Culturally Relevant Pedagogy, and Project- and Problem-Based Learning. We situate other perspectives on learning theory, which are derivatives of these prevailing paradigms, within this overarching frame. Our literature search revealed that some of the theoretical perspectives are well-reported in the literature whilst others have not received the same amount of attention from researchers. We detail each perspective, providing a definition, goals for teaching, pros and cons, and examples from the literature. We posit that, with the advent of the digital era of mathematics education, researchers must engage more explicitly with the theoretical perspectives we identified as underserved and must reckon with their own epistemological commitments more intentionally when reporting on studies regarding Type D.
Student Mathematics Learning Outcomes
Authors: Radišić Jelena 
Published: August 2023

AbstractThe research focused on the student (learning) outcomes captured upon completion of mathematics teaching is the end goal of presage-process–product research. Student learning outcomes are generally agreed upon as representing the ultimate purpose of teaching and the final criterion on which any assessment of ‘good’ teaching is based. Traditionally, student outcomes are seen as changes in students’ understanding of mathematics, here as measured in a school-based or external evaluation, both nationally and internationally. However, what is measured is primarily influenced by how the outcome is conceptualised. This chapter will discuss the very idea of student outcomes, their assessment and the assessments’ purpose. In addition, we observe the intake of technology in this process, revisiting the notion of outcomes from the lifelong learning perspective and demands of society today.
Individual Student Characteristics, Abilities and Personal Qualities and the Teacher’s Role in Improving Mathematics Learning Outcomes
Authors: Faragher Rhonda M. 
Published: August 2023

AbstractTeachers of students in general mathematics classrooms accept and welcome the learners they are assigned to teach. The characteristics of students influence the planning teachers undertake, the learning activities they provide, and the learning outcomes achieved by their students as a result. This chapter explores the impact of student characteristics that are beyond the control of teachers, and yet are within their powers through their actions to make a considerable difference to the mathematics learning outcomes of their students. In recent times, two significant developments—the recognition of streaming as harmful and the recognition of inclusive education as beneficial—have changed the nature of general mathematics classrooms. In practice, these developments mean that teachers can expect to teach students across the breadth of human variation. Addressing an area of research focused on units of analysis that are not under the direct control of a teacher, this chapter explicitly relates to learners with intellectual disabilities, learning difficulties and learned difficulties in the context of mathematics education research. Intellectual disability and mathematics learning difficulties are learner qualities while learned difficulties are not; these are traits acquired through the course of education, such as mathematics anxiety. Two recent studies of the inclusion in general primary and secondary mathematics classes of students with Down syndrome provide data that is analysed through the lens of the framework of Manizade et al. (2019) and Medley (1987), and expanded in the first chapter of this volume. Type G (individual student traits) variables and their interaction with particularly Type B (Student mathematics learning activities) and A (Student mathematics learning outcomes) are studied. Through this analysis, it is clear that the mathematical experiences teachers plan for their students are adjusted in complex ways. Where teachers provided year-level adjusted mathematics curriculum, students were able to demonstrate learning outcomes aligned with the school year-level and often many years ahead of their deemed level of mathematics accomplishment. As a way out of low attainment, the possibilities of year-level adjusted curriculum is a critical aspect of mathematics education and an imperative of mathematics education research.