bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectrum Index for Estimating Ground Water Content Using Hyperspectral Information
Authors: Lee Kicheol , Kim Ki Sung , Park Jeongjun , Hong Gigwon
Published: November 2022

Quality control considerably affects road stability and operability and is directly linked to the underlying ground compaction. The degree of compaction is largely determined by water content, which is typically measured at the actual construction site. However, conventional methods for measuring water content do not capture entire construction sites efficiently. Therefore, this study aimed to apply remote sensing of hyperspectral information to efficiently measure the groundwater content of large areas. A water content prediction equation was developed through an indoor experiment. The experimental samples comprised 0–40% (10% increase) of fine contents added to standard sand. As high water content is not required in road construction, 0–15% (1% increase) of water content was added. The test results were normalized, the internal and external environments were controlled for precise results, and a wavelength–reflection curve was derived for each test case. Data variability analyses were performed, and the appropriate wavelength for water content reflection, as well as reflectance, was determined and converted into a spectrum index. Finally, various fitting models were applied to the corresponding spectrum index for water content prediction. Reliable results were obtained with the reflectance corresponding to a wavelength of 720 nm applied as the spectrum index.
Applicable Investigation of SPH in Characterization of Fluid Flow in Uniform and Non-Uniform Periodic Porous Media
Authors: Mohammadi Masoud , Riazi Masoud
Published: November 2022

Today, the use of numerical modeling for characterizing properties of porous media and related concepts has been widely extended, especially in subsurface flow issues such as geological CO2 storage and petroleum recovery. Therefore, in this study, the fundamental problem of laminar fluid flow through uniform or non-uniform and periodic array of cylinders was functionally investigated using the smoothed particle hydrodynamics (SPH) method as a modern and applied method of modeling in order to develop the past studies and introduce a complementary numerical tool alongside laboratory methods. All modeling processes were performed in the form of dimensionless processes for generalization and applicability at different scales. The results were used to characterize properties of porous media and to investigate basic properties such as fluid velocity, permeability, streamlines, and hydraulic tortuosity. Accuracy of modeling was shown in comparison with the results obtained in the literature. In this study, the potential of the method has been investigated in order to show the ability in modeling characteristic laboratory experiments of porous media and the possibility of using it instead of them. For this purpose, three periodic models of uniform and randomly distributed non-uniform porous media with arrays of circular, square, and diamond-shaped cylinders in a porosity range of 30–95%, with different types of cylinder distribution at the pore scale, were investigated. New equations were proposed for permeability as a function of porosity. Moreover, the method of tortuosity calculation was investigated directly through the time history of properties in the SPH method, and shape factors were obtained for the studied porous media models. The results showed that the geometry of a square cylinder with distribution in a square grid led to a higher permeability than circular and diamond-shaped grids. In contrast, diamond-shaped geometry with distribution in a hexagonal grid led to higher permeability than the other two models. Furthermore, diamond-shaped geometry had higher tortuosity, and circular and square geometries had almost identical tortuosity. Increasing the size of the modeling domain and decreasing the size of cylinders (i.e., decreasing resolution) reduces effects of the shape and the geometry of cylinders and achieves the same results. Random and non-uniform distribution of cylinders within porous media reduces fluid velocity, permeability, tortuosity, and shape factor (p) compared to the uniform models.
Sustainable Economic Growth and FDI Inflow: A Comparative Panel Econometric Analysis of Low-Income and Middle-Income Nations
Authors: Haque Mohammad Anamul , Raza Shah Syed Mehmood , Arshad Muhammad Usman
Published: November 2022

The study examines the effect of sustainable economic growth on “FDI inflow” using comparative panel econometrics on two panels: “low-income” and “middle-income” economies between 1970 and 2021. For this, 18 “low-income” and 53 “middle-income” economies constitute the sample. The data were retrieved from the “world development indicator” website. Pre-diagnostic and post-diagnostic estimations were performed using static panel and dynamic panel approaches. Sustainable growth increases “FDI inflow” in “low-income” and “middle-income” economies during the study period, according to the findings. In addition, trade openness and the exchange rate have the potential to boost “FDI inflow” in “low-income” economies. Similarly, in “middle-income” economies, the real growth rate and exchange rate are significant boosts, however inflation significantly reduces the “FDI inflow”. The findings show that policymakers in “low-income” and “middle-income” economies should maintain long-term, sustainable economic growth in order to attract more “FDI inflow” in their respective economies. Compared to the current state of knowledge in the subject, the study’s findings provide evidence for “low-income” and “middle-income” nations that have been mainly overlooked in terms of sustainable growth for attracting FDI inflow. The study’s outcomes are applicable and generalizable only for “middle-income” and “low-income” economies. Future researchers may include additional control factors and expand the scope of the study to include “high-income” groups.
Time for Tea: Factors of Service Quality, Memorable Tourism Experience and Loyalty in Sustainable Tea Tourism Destination
Authors: Ng Siew Imm , Lim Xin-Jean , Hall C. Michael , Tee Keng Kok , Basha Norazlyn Kamal , Ibrahim Wan Siti Nabilah Binti , Naderi Koupaei Sara
Published: November 2022

Underpinned by Script Theory and the S-O-R model, this research enhances the green tourism consumption literature to identify how destination service quality contributes to visitors’ memorable experiences and loyalty towards a place-based food tourism attraction. A total of 202 tourists who visited the Best of Highlands tea plantation in Malaysia were surveyed using an online questionnaire. Using PLS-SEM, this study has several notable findings: (i) destination service quality factors: activities, cleanliness, language, and security emerged as predictors of memorable tourism experiences; (ii) memorable tourism experiences strongly predicted destination loyalty; and (iii) memorable tourism experiences mediate the path between destination service quality and destination loyalty. This study therefore provides new insights into both sustainable tea tourism and script theory with respect to how memories guide future decision making. These results also provide insights for tea tourism providers in designing an unforgettable destination that stimulates the tourist’s intention to revisit the destination and to communicate it to others.
Study on the Accessibility of Community Sports Facilities in Fuzhou, China
Authors: Xiao Wei , Wang Wei
Published: November 2022

With the coordinate data of community sports facilities in Fuzhou and the Geographic Information System platform, this paper developed a research framework of accessibility from three aspects of distribution, service coverage and access equality level. In addition, based on this, this paper analyzed the level and characteristics of the accessibility of community sports facilities within the third ring road of Fuzhou, China. The results showed that the community sports facilities within the third ring road of Fuzhou basically achieved the coverage of being within a ten-minute walking distance, but there were still some deficiencies regarding to the distribution of facilities and the equality level of accessibility. In addition, the results showed poor spatial matching between the number of facilities and population. A shortage of community sports facilities was found in the old central urban area, leading to poor accessibility. It is suggested in this paper that an overall improvement could be carried out through urban renewal.
Flood Risk Assessment to Enable Improved Decision-Making for Climate Change Adaptation Strategies by Central and Local Governments
Authors: Yu Insang , Jung Huicheul
Published: November 2022

This study assessed the flood risk in the Republic of Korea, considering representative concentration pathway (RCP) climate change scenarios, after applying the concept of “risk” as proposed by the Intergovernmental Panel on Climate Change. For the hazard assessment, hazard indicators were constructed utilizing design rainfall standards, which represented the local flood protection capability, as a flood threshold. We constructed high-resolution spatial images from data of buildings, roads, agriculture areas, and the population that have suffered significant flood damage in the Republic of Korea. We also calculated flood exposure levels by analyzing the scales of the targets in low-lying areas. Environmental and anthropogenic conditions that can directly increase or decrease river flooding and urban flooding were set as indicators and utilized as proxy variables. As a result of the risk assessment, we found 43 risk areas in the historical period, accounting for 19% of the total administrative districts, 42 in the projected period under RCP 4.5 (18%), and 51 in the projected period under RCP 8.5 (22%). This study’s results can be utilized by the central government to determine flood risk priority areas in various administrative districts and by the local government to select priority areas to install flood reduction facilities.
Young Adults’ Intentions toward the Prevention of Microplastic Pollution in Taiwan: Examining Personality and Information Processing in Fear-Appeal Communication
Authors: Li Shu-Chu Sarrina , Zeng Huai-Kuan , Lo Shih-Yu
Published: November 2022

This study adopted the extended parallel process model (EPPM) and dual process models to examine how recipients’ reactance proneness affected the appraisal of threat and efficacy, which, in turn, influenced their use of information-processing modes, attitudes, and behavioral intentions regarding the mitigation of microplastic pollutions in Taiwan. An experiment was conducted using 362 college students as the subjects. The results yielded three conclusions: (1) Fear-induced communication was an effective persuasive approach because this approach was more likely to guide the recipients to adopt a systematic mode to process messages. (2) Recipients’ reactance proneness was discovered to first affect their perceived threat and perceived efficacy, which, in turn, influenced their attitudes and behavioral intention regarding the prevention of microplastic pollution, demonstrating that individual differences mediate fear-appeal messages to affect persuasive outcomes. (3) Perceived threat was important for fear-appeal messages to obtain persuasive outcomes.
Spatial–Temporal Pattern and Influencing Factors of Vegetation Phenology and Net Primary Productivity in the Qilian Mountains of Northwest China
Authors: Wu Xuan , Jiao Liang , Du Dashi , Xue Ruhong , Ding Xingyu , Wei Mengyuan , Zhang Peng
Published: November 2022

Understanding how vegetation growth responds to climate change is a critical requirement for predicting future ecosystem dynamics. Global warming causes significant changes in the vegetation characteristics of mountain ecosystems, particularly affecting vegetation phenology and net primary productivity (NPP). The Qilian Mountains are located in an arid and semiarid region, and the mechanisms of vegetation phenology in response to climate change still need to be further explored. We used MODIS data (2001–2020) to extract vegetation phenology and NPP, quantitatively evaluated their spatial–temporal dynamics, and analyzed the response mechanism of vegetation phenology–climate and vegetation phenology–NPP combined with meteorological data. The results showed that from southeast to northwest, the vegetation phenology changes significantly with the change in vegetation type, with SOS (start of the growing season) advancing at a rate of −0.415 d/year, EOS (end of the growing season) and LOS (length of the growing season) delaying at a rate of 0.20 d/year and 0.374 d/year, respectively, and NPP continues to increase. There was also an elevation gradient effect, with SOS delayed by 15.6 d/km, EOS advanced by 12.02 d/km and LOS shortened by 19.24 d/km. We found that the preseason temperature and SPEI (standardized precipitation evapotranspiration index) have a strong influence on the SOS and EOS, with the mean minimum temperature being the most significant and requiring attention, while the influence of precipitation cannot be ignored. We also found that the vegetation phenology is closely related to NPP, and SOS has the most significant effect. This study will provide a scientific basis for the response mechanisms of vegetation phenology in arid and semiarid regions under climate change. It will provide a reference for the implementation of effective ecosystem management.
An Overview of Micro(Nano)Plastics in the Environment: Sampling, Identification, Risk Assessment and Control
Authors: Peng Licheng , Mehmood Tariq , Bao Ruiqi , Wang Zezheng , Fu Dongdong
Published: November 2022

Advances in urban infrastructure, a flourishing polymer sector, and more traffic have all contributed to a rise in micro(nano)plastics in the environment. Researchers are exploring the production, fate, toxicity threshold, and severity of micro(nano)plastic exposure. Albeit, understanding sampling protocols, preservation of samples, and characterization of micro(nano)plastics obtained from the different mediums (e.g., soil, water, air, and living bodies) is still challenging. Particularly identification of micro(nano)plastics, on the other hand, is restricted and limited to the typical generic definition of contaminating sources. In addition, before micro(nano)plastics degrade naturally, many challenges must be overcome, enhancing the need for research on assisted degradation. Thus, a systematic review is presented, which begins by discussing micro(nano)plastic identification, sampling, and handling; then showcases the environmental and health consequences and how to control them; finally, it discusses environmental micro(nano)plastics management options. According to studies, biological and chemical methods to break down micro(nano)plastics have risen in popularity. However, these methods often only cover one type of plastic. Furthermore, these solutions can transform polymers into micro(nano)plastics and may also produce byproducts, increasing environmental contamination risk. Therefore, control, prevention, and management strategies are all investigated to generate more realistic and long-term solutions. The literature suggests a combination of different microorganisms (e.g., different bacterial species) and different approaches (e.g., filtration with degradation) could be more effective in the treatment of micro(nano)plastics. Furthermore, according to the literature, relevant health risks associated with micro(nano)plastics to humans from various exposure routes are currently unclear. Likewise, standardization of methods supported with sophisticated state-of-the-art apparatus for detecting micro(nano)plastics is required. Overall, precision in micro(nano)plastic identification and treatment strategy selection is critical, and their usage should be regulated if their environmental behavior is not properly addressed.
Genome-Wide Association Study Based on Plant Height and Drought-Tolerance Indices Reveals Two Candidate Drought-Tolerance Genes in Sweet Sorghum
Authors: Xin Yue , Gao Lina , Hu Wenming , Gao Qi , Yang Bin , Zhou Jianguo , Xu Cuilian
Published: November 2022

To understand the molecular mechanism of drought tolerance in sweet sorghum [Sorghum bicolor (L.) Moench], we found the genetic loci associated with single nucleotide polymorphism (SNP) markers and explored drought-tolerance candidate genes. A genome-wide association study (GWAS) of sweet sorghum was performed using the general linear model (GLM), mixed linear model (MLM) and the fixed and random model circulating probability unification (FarmCPU) method in R. Mean productivity (MP), relative drought index (RDI) and stress-tolerance index (STI), based on plant height under two water treatments, were obtained from 354 sweet sorghum accessions from home and abroad. These plant-height drought-tolerance indices showed continuous quantitative variation. Except for the RDI, the others were close to normal distribution. A total of 6186 SNPs were obtained from the resequencing data after quality control and filling. The marker densities on chromosomes 9, 10 and 5 were higher than those on other chromosomes, which were 40.4, 16.5 and 10.0 SNPs within 1 Mb, respectively. The GWAS results showed that 49, 5 and 25 significant SNP loci were detected by the GLM, the MLM and FarmCPU, respectively, many of which were detected by two or more models. Two candidate genes of drought tolerance were annotated: Sb08g019720.1, homologous to the gene encoding the early flowering MYB protein transcription factor in Arabidopsis thaliana; and Sb01g037050.1, homologous to the gene encoding the basic leucine zipper transcription factor in maize. The results of this study can facilitate the cultivar development of drought-tolerant sweet sorghum.
Evolution and Future Prospects of Education Evaluation Research in China over the Last Decade
Authors: Wang Shanshan , Qiu Junping , Zhou Jia , Yu Yunlong
Published: November 2022

With the popularity of educational evaluation studies, researchers have begun to mine text data to provide helpful information for educational stakeholders. Despite the frequent adoption of textual analysis, few studies have been found to search and analyze data from research projects. As the highest-level and most authoritative research projects in China, the Chinese National Education Science Planning projects could fully reflect the research fronts and hotspots in the field. This study examines the educational evaluation projects in the Chinese National Education Science Planning from 2011 to 2020, adopting bibliometric, textual analysis, and visualization methods to present an overview of the educational evaluation research in China. The results have revealed a steady growth of projects on educational evaluation in China as there were 219 projects approved during the 13th Five-Year Plan period, 68 more than that of the 12th Five-Year Plan period, and accounted for 9.00% of the total number of projects launched in the same period. The educational evaluation project organizations are diversified, including universities, scientific research institutions, primary and secondary schools, administrative departments, educational societies, and publishing units. The research trends focus on the close integration of educational evaluation with informatization, needs in educational practice, and national strategic development. This study offers an applicable methodology and framework for the future bibliometric study of educational evaluation.
Phosphorus Species, Influencing and Release Risks Assessment in Mangrove Wetland Sediments of Dongzhai Harbor on Hainan Island, China
Authors: Zhang Gucheng , Xue Guicheng , Ruan Ming , He Yusheng , Lin Di , Du Sumin
Published: November 2022

Mangrove wetlands are superior sites for the deposition of various pollutants, but they are also more susceptible to environmental contamination. To investigate the health threats of phosphorus to mangrove ecosystems, this study presents the distribution, chemical speciation and factors influencing phosphorus (P) forms in 38 surface sediments from the mangrove wetlands of Dongzhai Harbor on Hainan Island, China. P forms were measured using the sequential extraction (SEDEX) procedures. The results showed that the total phosphorus content in the sediment was at a high level, and there was a significant spatial variability of phosphorus in each form. Among them, inorganic phosphorus accounted for 74.64% of the total phosphorus, and organic phosphorus accounted for 25.35% of the total phosphorus. Among the inorganic phosphorus, detrital limestone phosphorus and Ca-bound phosphorus were dominant, while the content of exchangeable phosphorus and Fe-bound phosphorus had a smaller percentage. The concentration of biologically available phosphorus, ranged from 1.76 umol/g to 18.57 umol/g, and the Fe-bound and organic forms of phosphorus had a controlling effect on it. Based on Corg/OP, N/P and land use surveys, it was concluded that phosphorus was mainly an exogenous input. The correlation analysis concluded that the main sources of phosphorus in the study area are agriculture and aquaculture. The development of agriculture and aquaculture led to moderate levels of phosphorus pollution in the study area as a whole, with more serious a phosphorus pollution at the wetland park in the southeast corner of Dongzhai Harbor and in the western areas, with lush vegetation and developed river systems, mainly influenced by human activities, topography, vegetation and water system conditions.
Research on Training Effectiveness of Professional Maintenance Personnel Based on Virtual Reality and Augmented Reality Technology
Authors: Liu Xiao-Wei , Li Cheng-Yu , Dang Sina , Wang Wei , Qu Jue , Chen Tong , Wang Qing-Li
Published: November 2022

The maintenance training method based on Virtual Reality (VR) and Augmented Reality (AR) technology has the characteristics of safety, no space limitation, and good reusability. Compared with the traditional training method, it can reduce the training cost, shorten the training period, and improve training effectiveness. Therefore, more and more maintenance training use VR and AR to replace training based on actual equipment to improve training effectiveness. However, in the context of multi-level tasks, there is still no clear research conclusion on how to choose training methods, maximize the advantages of each training method, and achieve higher training effectiveness. In response to this problem, this study constructed three training platforms based on VR, AR, and actual equipment, designed three maintenance tasks at different levels, and created a comparative analysis of the training effects of 60 male trainees under the three tasks and three training platforms. The results show that for single-level maintenance tasks, the training effect of the traditional group was significantly better than that of the AR group and the VR group. For multi-level maintenance tasks, the training effect of AR group was significantly better than that of the VR group. With the increasing difficulty of maintenance tasks, the training efficiency of the AR group was more than 10% higher than that of the VR group and traditional group and the AR group had less cognitive load. The conclusions of this study can provide a theoretical basis for the selection of training methods and evaluation design and help to formulate training strategies, thereby shortening the training period of professional maintenance personnel.
Oasis Change Characteristics and Influencing Factors in the Shiyang River Basin, China
Authors: Fang Yu , Wang Xulian , Cheng Yufei , Wang Zhongjing
Published: November 2022

The variability of the natural environment and the complexity of human activities result in dynamic changes in oasis areas, which is directly related to the sustainable development of arid and semi-arid areas. In order to better balance economic development and environmentally sustainable development, based on land use data and social and economic data from 1980 to 2015, this paper analyzed the oasis change characteristics under natural and human factors in the Shiyang River Basin in Northwest China. The results indicated that the oasis in the Shiyang River Basin showed an expansion trend from 1980 to 2015, with the expansion mainly occurring in the diluvial and alluvial fan, and along the middle and lower reaches of the river. The oasis changed actively in areas at an elevation of 1350 m, with a slope of 2°, at the distance of 1500 m to rivers, and with precipitation of 120 mm and temperature of 15 °C. Furthermore, the oasis mainly evolved towards gentler slopes and lower altitudes, and migrated closer to rivers before 1992 and farther away from rivers afterwards. Population growth and economic development were the important inducers of oasis change, and government policies on agricultural benefits and ecological conservation also influenced the oasis change, especially after 2000. The evolution patterns of oasis distribution revealed in this study can provide a reference for promoting oasis ecological restoration and sustainable development.
A Case Study: Arsenic, Cadmium and Copper Distribution in the Soil–Rice System in Two Main Rice-Producing Provinces in China
Authors: Liu Jing , Su Jiayi , Wang Jun , Song Xu , Wang Haiwen
Published: November 2022

Arsenic (As) and cadmium (Cd) pose great risk to rice plants and human health. Copper (Cu) agrichemicals also draw increasing attention. This study investigated the distributions of As, Cd and Cu in the soil–rice system in two major rice-producing provinces, Hunan and Jiangxi, China. Arsenic in soils at site A in Hunan reached 47.95–60.25 mg/kg, all exceeding the national standard (GB15618-2018), but As in rice was all below the safe limit for humans (0.20 mg/kg, GB2762-2017). In contrast, As in all rice husks and 5% of grain samples from Jiangxi exceeded the safe limit, while As in soils was 3.40–9.92 mg/kg, all below the standard. Cadmium in soils at site A and site B in Hunan were 3.96–5.11 and 1.83–2.77 mg/kg, respectively, all exceeding the national standard; Cd in 60% of rice grains exceeded the safe limit (0.20 mg/kg, GB2762-2017). Despite Cd in soils from Jiangxi being much lower (0.20–0.34 mg/kg), Cd in 56% of the rice grains exceeded the safe limit. The different distribution patterns of As and Cd in the soil–rice system probably result from the dynamic environmental conditions during farming practice. Risk from dietary products made from rice husks should also be considered. Although not regulated in rice, Cu in the soil from Hunan exceeds the national standard. This study helps to understand As and Cd pollution in paddies and its risk to human health, and suggests limiting the application of Cu-based agrichemicals.
A Study on the Interaction Behavior between an Earth-Rock Dam and a New-Typed Polymer Anti-Seepage Wall
Authors: Zhang Jingwei , Huang Chuhao , Li Jia , Liu Guangzong
Published: November 2022

Polymer anti-seepage wall has been gradually applied in earth-rock dam reinforcement projects as a new seepage control technique. However, due to all-pervasive properties of the new materials and root-like connection between the materials and soils, the interface characteristics between the polymer wall and the earth-rock dam, as well as the interaction behavior of both, are complex and still not clear, which obstruct studying coordination mechanism of dam and wall under earthquake. Therefore, the interface characteristics and interaction behavior of dam and wall were studied in the article. Firstly, the dynamic shear stress-displacement, shear stiffness and damping ratio of the interface between polymer and soil were investigated by ring shear test. In addition, the viscoelastic constitutive model of polymer materials were researched by dynamic mechanical analysis (DMA) test. Based on tests results, a finite element model of earth-rock dam with polymer wall was established, including a non-linear simulation interface element and viscoelastic polymer constitutive model. Next, the validity of the simulation model was verified based on dynamic centrifuge test results. Then, the interaction behavior and seismic response of the dam with polymer wall were explored by using the verified model. The research results provide a scientific basis for the development and application of new-typed polymer anti-seepage wall in reinforcement engineering.
Implementing a Design Thinking Approach to De-Risk the Digitalisation of Manufacturing SMEs
Authors: Mesa David , Renda Gianni , III Robert Gorkin , Kuys Blair , Cook Simon M.
Published: November 2022

Industry 4.0 (I4.0) has proposed a significant shift in the way companies approach manufacturing. However, this new paradigm is not without faults. The integration of processes and equipment (‘digitalisation’) can be prohibitively expensive or too technically complex for small-to-medium enterprises (SMEs) with limited resources and technical expertise. Another barrier to digitalisation lies in the ambiguity of not knowing what precise practices to adopt to improve productivity. Although these challenges have been identified in the literature, there is still little evidence on how to tackle them. Thus, we explore how design thinking can help overcome these challenges, given that it has been used in many organisations and disciplines to deal with complex and ambiguous problems. We do so by investigating the research question ‘How can designers and design thinking processes assist manufacturing SMEs’ digitalisation?’ We address this research question by presenting a case study of a university–industry collaboration where the authors utilised a design-thinking process to select and implement technologies to capture, process and analyse data for an Australian medical device manufacturer. By reflecting on the case study, we identified the user-centeredness of design thinking as crucial in selecting technologies for implementation that prioritised usability and brought value to all stakeholders. Furthermore, iterative prototyping was critical to scale up the required expertise and deliver a successful sustainable solution without investing vast resources. Our work suggests that designers and design thinking have the potential to help de-risk digitalisation. Finally, we suggest a framework that may assist in guiding other SMEs approaching digitalisation and provide a starting point for further design thinking research in this area.
About Calculation and Forecast of Temperature in the Layer Cell of Self-Heating of Raw Materials in a Silo
Authors: Olshanskyi Vasil , Kharchenko Serhii , Kharchenko Farida , Kovalyshyn Stepan , Shchur Taras , Gabriel Yuriy , Bałdowska-Witos Patrycja , Tomporowski Andrzej , Kasner Robert
Published: November 2022

The article clarifies an approximate variant for calculating the temperature in an inhomogeneous layer cell without a clear boundary under the assumption of significant distance in its center between the upper and lower ends of the silo when heat exchange conditions have little effect on the development of temperature in the layer cell due to poor thermal conductivity. The normal Gaussian law concerning distribution of thermal sources in the cell on an axis of a silo is accepted. The integral cosine of the Fourier transform is used to construct the analytical solution of the nonstationary thermal conductivity problem. A compact formula for calculating the increase in excess temperature in the center of the self-heating cell over time is derived and used to identify the parameters of the cell. The change in temperature at other points of the raw material is expressed through incomplete gamma function that is reduced to the probability integral. Calculations show that for the selected distribution of thermal sources, the temperature increase slows down rapidly with separation from the center of the cell. The possibility of determining the pattern distribution of the localized field of excess ambient temperature over time is proved. Examples of density identification of thermal sources are given. After identification, the calculation formulas become consistent with the experiment and suitable for the theoretical prediction of temperature rise in the raw material. The approbation of the proposed mathematical expressions to identify the parameters of the self-heating process of raw materials showed high accuracy relative to experimental data with a deviation of 0.01–0.015%. It is possible not only to determine the parameters of the self-heating cell but also to predict the time of reaching a flammable temperature in it.
Performance of Strengthened, Reinforced Concrete Shear Walls with Opening
Authors: Mamdouh Hala , Zenhom Nasr , Hasabo Mahmoud , Deifalla Ahmed Farouk , Salman Amany
Published: November 2022

Shear walls are one of the primary lateral resisting structural elements. Due to architectural and technical needs, openings in the structural wall are almost inevitable. Discontinuity regions and a reduction in wall stiffness result from these openings. The use of fiber-reinforced-polymer (FRP) systems is a sustainable construction solution for strengthening these areas and is a viable method to restore their integrity and serviceability. This paper presents an experimental and analytical study on the behavior of reinforced concrete (RC) shear walls with openings of various sizes and positions strengthened using glass-fiber-reinforced-polymer (GFRP) sheets. Ten RC shear walls were cast and tested; initially without strengthening; and then retested with a layer of bi-directional GFRP sheet added around the opening. The finite-element (FE) program ANSYS was used for modeling since using FE contributes to sustainability. The results showed that for un-strengthened walls with a 6.25% opening and strengthened walls with an 11.11% opening, the rate of stiffness degradation was reasonably low. As the opening size was enlarged, the strength and stiffness values were drastically reduced; and the shear walls with an opening at the mid-height position also have smaller load capacities compared to the bottom and top opening positions. In addition, the ability of the GFRP sheets to control stress redistribution and crack propagation improved the overall performance of the walls. The FE and experimental results match well. Furthermore, the ACI and ECP calculations revealed a good prediction of lateral load capacity without considering the opening position, whereas the other proposed models were inaccurate. Finally, the author proposed a reduction factor (β) to the shear strength equation provided by ECP-203-2020 depending on openings sizes and locations; and suggests that FRP sheets be used around openings to assure the appropriate performance and avoid unexpected failure.
Study on the Disintegration Characteristics and Mechanism of Modified Dispersive Soil Based on the C-S-H Synthesis Principle
Authors: Liu Yifei , Tang Chaoxin , Fan Henghui , Zhu Zhen , Jiang Shoufang , Zhang Bo
Published: November 2022

Since dispersive soil has the characteristic of dispersing and disappearing when making contact with water, lime, fly ash, and cement are often used to modify dispersive soil in engineering. This often causes environmental pollution. Current studies tend to search for environmentally friendly modification methods. A new Ca−Si-modified dispersive soil method was proposed based on the synthesis principle of calcium silicate hydrate (C-S-H). Pinhole, mud ball, dispersion, and disintegration tests were used to investigate the modification effect and physical, chemical, and microscopic tests were used to investigate the mechanism. The results show that the dispersivity of soil can be eliminated by using 0.8% CaO or 4% nanosilica. The dispersivity of Ca−Si-treated soil can be eliminated at a 0.5 C/S and a 1% solid dosage. The disintegration characteristics of CaO-modified and Ca−Si-modified soils are different from those of dispersive soil. The final disintegration time of CaO-modified soil was shortened, and the disintegration rate was stable. The Ca−Si-modified soil had the best disintegration resistance at a 0.5 C/S and a 2% solid dosage. With the increase in the C/S, the disintegration resistance was reduced. The mechanism of Ca−Si-modified soil includes reducing the pH and exchangeable sodium percentage and generating calcium silicate hydrate cement. The results show that the Ca−Si treatment method based on the C-S-H synthesis principle can effectively eliminate soil dispersivity and improve disintegration resistance, which can theoretically support the reduction in contamination caused by traditional materials and improve engineering safety.
Innovation Strategy for Green Development and Carbon Neutralization in Guizhou—An Overview
Authors: Yan Jun , Yang Wu , Min Zhang , Yang Mingxing
Published: November 2022

A carbon peak in 2030 and carbon neutrality in 2060 are major strategic development goals for China. Driven by the ambitious goal of achieving a carbon peak and carbon neutrality, the development of green innovation technology is an important method of achieving these aims. Speeding up energy transformation and tapping into the carbon sink capacity of the natural ecosystem are key to this process. The strategic path of green development deserves further discussion. This study takes Guizhou province as an example. Based on the actual situation of Guizhou province and the characteristics of karst areas, through the collection and collation of the existing literature, policies, and technologies and the analysis of typical cases, this paper summarizes and analyzes ecological restoration and negative carbon emissions in karst areas; water-energy-carbon coupling, energy saving, and emissions reduction technologies; industrial energy saving and emission-reduction technologies in karst areas; and CCUS technology for carbon dioxide capture, utilization, and storage. On this basis, the trend and orientation of green development in Guizhou are studied and judged, and countermeasures such as adhering to clean and efficient low-carbon utilization, strengthening the research on and development of carbon emission-reduction technology, and implementing carbon sink capacity buildings are put forward. Key core technology research and development innovation are recommended to establish a low-carbon science and technology innovation system. The efficient use of energy, the recycling of resources, negative emissions, and other strategies should be promoted. We also posit specific suggestions such as accelerating the transformation and application of green and low-carbon scientific and technological achievements.
Market Analysis of Characteristic Agricultural Products from the Perspective of Multi-Source Data: A Case Study of Wild Edible Mushrooms
Authors: Luan Guize , Zhao Fei , Jia Yanwen , Xia Jisheng , Yan Yao , Wang Yutong , Huang Ziyu , Zhang Sujin
Published: November 2022

Wild edible mushrooms are a characteristic product in Yunnan, but no quantitative evaluation system yet exists for them. This study puts forward a sustainable development potential index of characteristic agricultural products (SDPI) based on various methods. It also performs a correlation analysis of multi-source points of interest (POI) and online shopping data related to wild edible mushrooms in Yunnan from a quantitative point of view, to understand the economics of wild edible mushrooms and to explore the sustainable development potential of such mushrooms in Yunnan from the perspectives of the tourism and sales markets. The results show that Dêqên Tibetan and the central region dominated by Kunming dominate both the tourism and sales markets and have a high SDPI. In contrast, the current situation and development prospects of the wild edible mushroom market in cities such as Lincang and Nujiang Lisu are poor. Yunnan Province has a large wild edible mushroom market and a promising development prospect. This paper provides comprehensive reference information for the development of Yunnan wild edible mushroom production economics.
Effects of Waste Powder, Fine and Coarse Marble Aggregates on Concrete Compressive Strength
Authors: Basaran Bogachan , Kalkan Ilker , Aksoylu Ceyhun , Özkılıç Yasin Onuralp , Sabri Mohanad Muayad Sabri
Published: November 2022

The use of marble wastes in concrete mixtures, causing air and water pollution, has been promoted in the academic and practical spheres of the construction industry. Although the effects of various forms (powder, fine, coarse and mixed) of this waste on the concrete compressive strength has been subject to a decent number of studies in the literature, the difficulties in reaching specific conclusions on the effect of each test parameter constitute a major restraint for the proliferation of the use of marble wastes in the concrete industry. Most of these studies are far from underscoring all of the parameters affecting the concrete compressive strength. Due to the urgent need in the literature for comprehensive studies on concrete mixtures with marble wastes, the results of the axial compression tests on a total of 429 concrete mixtures with marble aggregates were compiled by paying special attention to reporting all test variables (form and content of marble wastes, water–cement ratio, cement content, proportion of coarse and fine aggregates in all aggregates) affecting the concrete strength. In this context, multivariate regression analyses were carried out on the existing test results. These regression analyses yielded to relationships between the change in concrete compressive strength and the test parameters for each and every form of marble waste (powder, fine and coarse aggregate). The study indicated that independent from the form of marble wastes (as powder, fine aggregate or coarse aggregate), aggregate replacements of up to 50% can yield to significant changes in the concrete compressive strength. In addition, the analytical estimates from the developed equations exhibited a high correlation (a least r value of 0.91) with the experimental results from the previous studies, yielding to rather low error values (RMSE value is 5.06 MPa at max). For this reason, the developed equations can consistently predict the changes in concrete compressive strength with varying amounts and forms of the marble aggregates as well as the other test variables.
The Enhancement of Energy-Carrying Capacity in Liquid with Gas Bubbles, in Terms of Solitons
Authors: Asghar Umair , Faridi Waqas Ali , Asjad Muhammad Imran , Eldin Sayed M.
Published: November 2022

A generalized (3 + 1)-dimensional nonlinear wave is investigated, which defines many nonlinear phenomena in liquid containing gas bubbles. Basic theories of the natural phenomenons are usually described by nonlinear evolution equations, for example, nonlinear sciences, marine engineering, fluid dynamics, scientific applications, and ocean plasma physics. The new extended algebraic method is applied to solve the model under consideration. Furthermore, the nonlinear model is converted into an ordinary differential equation through the next wave transformation. A well-known analytical approach is used to obtain more general solutions of different types with the help of Mathematica. Shock, singular, mixed-complex solitary-shock, mixed-singular, mixed-shock singular, mixed trigonometric, periodic, mixed-periodic, mixed-hyperbolic solutions are obtained. As a result, it is found that the energy-carrying capacity of liquid with gas bubbles and its propagation can be increased. The stability of the considered model is ensured by the modulation instability gain spectrum generated and proposed with acceptable constant values. Two-dimensional, three-dimensional, and contour surfaces are plotted to see the physical properties of the obtained solutions.
Bubble Nucleation from a de Sitter–Planck Background with Quantum Boltzmann Statistics
Authors: Fiscaletti Davide , Licata Ignazio , Tamburini Fabrizio
Published: November 2022

Every physical theory involving quantum fields requires a model of quantum vacuum. The vacuum associated to quantum gravity must incorporate the prescriptions from both the theory of relativity and quantum physics. In this work, starting from the hypothesis of nucleation of sub-Planckian bubbles from a de Sitter vacuum, we study the necessary conditions to obtain baby universes, black holes and particles. The de Sitter-Planck background is described by an “infinite” Quantum Boltzmann statistics that generates fermions and bosons, and manifests itself as a deformation of the geometry that leads to a generalized uncertainty principle, a unified expression for the generalized Compton wavelength and event horizon size, drawing a connection between quantum black holes and elementary particles, seen as a collective organization of the bubbles of the vacuum described by the generalized Compton wavelength. The quantum thermodynamics of black holes is then outlined and the physical history of each bubble is found to depend on the cosmological constant described in terms of thermodynamic pressure. A treatment of the Casimir effect is provided in the de Sitter-Planck background, and finally wormholes are explored as bubble coalescence processes.
Quantum Explosions of Black Holes and Thermal Coordinates
Authors: Aref’eva Irina , Volovich Igor
Published: November 2022

The Hawking temperature for a Schwarzschild black hole is T=1/8πM, where M is the black hole mass. This formula is derived for a fixed Schwarzschild background metric, where the mass M could be arbitrary small. Note that, for vanishing M→0, the temperature T becomes infinite. However, the Schwarzschild metric itself is regular when the black hole mass M tends to zero; it is reduced to the Minkowski metric, and there are no reasons to believe that the temperature becomes infinite. We point out that this discrepancy may be due to the fact that the Kruskal coordinates are singular in the limit of the vanishing mass of the black hole. To elucidate the situation, new coordinates for the Schwarzschild metric are introduced, called thermal coordinates, which depend on the black hole mass M and the parameter b. The parameter b specifies the motion of the observer along a special trajectory. The thermal coordinates are regular in the limit of vanishing black hole mass M. In this limit, the Schwarzschild metric is reduced to the Minkowski metric, written in coordinates dual to the Rindler coordinates. Using the thermal coordinates, the Schwarzschild black hole radiation is reconsidered, and it is found that the Hawking formula for temperature is valid only for large black holes, while for small black holes, the temperature is T=1/2π(4M+b). The thermal observer in Minkowski space sees radiation with temperature T=1/2πb, similar to the Unruh effect with non-constant acceleration. The thermal coordinates for more general spherically symmetric metrics, including the Reissner–Nordstrom, de Sitter, and anti-de Sitter, are also considered. In these coordinates, one sees a Planck distribution with constant temperature. One obtains that the thermal Planck distribution of massless particles is not restricted to the cases of black holes or constant acceleration, but is valid for any spherically symmetric metric written in thermal coordinates.
Design and Implementation of Simplified Symmetry Chaotic Circuit
Authors: Wang Zhonglin , Liu Shutang
Published: November 2022

In order to reduce the circuit cost and improve the stability and flexibility of the circuit, a simplified symmetry chaotic circuit was designed and implemented by using an inverse integration circuit and a voltage follower as isolators. The change of different symmetry chaotic dynamic behaviors caused by the change of parameters can be realized by adjusting the time constant. The behavior coexistence characteristics and amplitude control characteristics under different initial conditions were verified. The results of circuit experiments are in good agreement with those of numerical simulation and theoretical analysis. This method is effective and feasible.