bluuebunny/crossref_metadata_2025 huggingface dataset:
Comprehensive Eco-Environmental Effects Caused by Land Use Transition from the Perspective of Production–Living–Ecological Spaces in a Typical Region: A Case Study of the Guangxi Zhuang Autonomous Region, China
Authors: Chen Zipeng , Liu Yongqiang , Tu Shuangshuang
Published: November 2022

With the promotion of rapid economic and social development, land use has undergone profound processes of transition worldwide, leaving the production–living–ecological spaces (PLES) and landscape pattern reconfigured, thus further affecting regional eco-environmental quality and landscape ecological risk. This paper first introduces a research framework of comprehensive eco-environmental effects caused by shifts in land use, to analyze the relations and interactions among land use transition, interconversion of PLES, eco-environmental quality, and landscape ecological risk, and then this framework was applied to the empirical analysis of the Guangxi Zhuang Autonomous Region (Guangxi), to examine the comprehensive eco-environmental effects caused by land use transition there. The results show the following: (1) During 1990–2018, ecological space in Guangxi tended to continuously shrink in area, while the area of production and living space kept expanding. The areas of forest ecological land, grass ecological land, and agricultural production land clearly decreased over time, having been mainly converted into both urban living land as well as industrial and mining production land. (2) The eco-environmental quality in Guangxi showed a trend of continual decline, this characterized by high and medium-high quality zones decreasing in area as the low-quality zone expanded. Further, the spatial distribution of eco-environmental quality tended to diminish when moving from Guangxi’s surrounding towards its central and southern parts. (3) However, the landscape ecological risk continued to rise mainly because of reductions in ecological space. Its spatial distribution was the inverse of that of eco-environmental quality; i.e., being at high risk in the central and southern parts, but lower in the surroundings. (4) The bivariate global Moran’s I analysis revealed a significant negative correlation between the eco-environmental quality and landscape ecological risk. Going from remote mountainous and hilly areas to rural areas, and then into urban areas, the eco-environmental quality displayed a gradually decreasing trend, while landscape ecological risk was initially reduced but then augmented. We conclude that land use transition in Guangxi has caused a continuous reduction in its regional eco-environmental quality, and also exacerbated its landscape ecological risk. Hence, it is of great importance to balance the PLES and optimize the landscape pattern, so as to restore the eco-environmental quality while also mitigating the landscape ecological risk of Guangxi and similar regions.
How to Realize the Integration of Urbanization and Rural Village Renewal Strategies in Rural Areas: The Case Study of Laizhou, China
Authors: Yuan Wenhua , Li Jianchun , Liu Chengqing , Shang Ran
Published: November 2022

To promote the coordinated development of urban and rural areas, China has adopted a hybrid strategy of urbanization and rural village renewal. Due to the large development differences between villages, choosing appropriate strategies is significant for rural development. By introducing a new idea to promote urban–rural integration development through a “rural cluster”, this paper explores the comparative advantages of villages in urbanization and renewal, identifies the spatial interaction between villages, and proposes a rural cluster strategy based on the same characteristics and close relationships. Taking Laizhou city, a coastal county in eastern China, as the study area, it provides a new way to deal with village problems at a small scale but of a large number due to difficult development in China. The results indicated that some villages have both high or low rural urbanization suitability (RUS) and village renewal potential (VRP), which makes it difficult to choose development strategies. Compared with the VRP, the spatial interaction of villages in the RUS is closer, but fewer villages participated. The results of village clustering show that the scale of different village clusters and the degree of interaction between villages in Laizhou differ greatly, and village clusters across townships are very common. Since the driving forces of the different scale of rural groups vary, this paper suggests that the development direction and investment focus should be determined according to the scale and characteristics of individual rural groups.
Urban Growth Modeling and Land-Use/Land-Cover Change Analysis in a Metropolitan Area (Case Study: Tabriz)
Authors: Mahmoudzadeh Hassan , Abedini Asghar , Aram Farshid
Published: November 2022

During the last three decades, the expansion of the Tabriz Metropolitan Area (TMA) to the surrounding areas has caused the destruction of environmental resources and problems such as disturbing ecological balance, increasing service costs, construction over unsuitable lands, exacerbation of air pollution, and lack of consideration of existing deteriorated textures and previous ongoing trends, reducing the environmental quality of the TMA. The goal of this study was to perform ecological modeling of urban development in the TMA with respect to the preservation of environmental resources, prevention of urban sprawl, and the management of the physical expansion of the TMA in an eco-friendly manner. In this research, to investigate the previous pattern of growth of the TMA, Landsat satellite imagers from 1984 to 2018 were used to discover the non-ecological and sprawl development of the TMA, and artificial neural networks and logistic regression techniques were applied to simulate future development up to 2038. According to information from the Iranian Statistical Center and 34 year of satellite imagery analysis, the population of the TMA increased from 1,007,992 to 1,961,560 during this period. Additionally, urban and rural land area increased from 7220.34 hectares to 27,640.57 hectares. A lack of coordination between population and urban expansion, as well as a decrease of 8513.61 hectares of agricultural and garden lands was inferred from the Holdern model. Detailed Calculations of the Holdern index (sprawl tendency) showed a lack of consideration of urban development capacity with population growth rate, and the Holdern index is equal to 0.6 in Tabriz. For future ecologic development of the TMA, hexagonal blocking of the urbanization probability map was used alongside environmental development policies in the form of using 30 percent of infill development capacities of inefficient land uses to prevent sprawl growth in Tabriz. Additionally, to preserve ecological landscapes, ecological networks in the form of green belts and bows with a length of 91 km were designed that may be effective in preventing the merging of small cities and nearby villages in the Tabriz metropolis.
Ecological and Environmental Effects of Land Use and Cover Changes on the Qinghai-Tibetan Plateau: A Bibliometric Review
Authors: Liang Ying , Song Wei
Published: November 2022

The Qinghai-Tibetan Plateau (QTP), known as the “Third Pole of the Earth”, contains fragile ecosystems and is sensitive to global environmental changes. With the intensification of climate change and human activities, the land cover of the QTP is changing significantly, which affects its function as an ecological security barrier. This paper searched 379 papers in the Web of Science core database, conducted a bibliometric analysis, and proposed potential future research directions to gain a macroscopic understanding of the impact of land use and cover change (LUCC) on the regional and global ecological environment of the QTP. The results are as follows. (1) The period from 1995 to 2022 witnessed an overall increase in the number of publications in this field with a high development potential. (2) Climate change, land use, China, impacts, conservation, and management were high-frequency keywords in the field; among these, climate change has received increasing research attention since 2018. (3) The field included three main research directions: the impact of LUCC on biodiversity, the impact of land degradation on ecosystems, and the impact of climate change and land use changes on ecosystem services. (4) The development and evolution of research hotspots were mainly focused on three aspects: the impact of cultivated land expansion and deforestation, the impact of land use management and conservation, and the impact of climate change and human activities on LUCC. (5) Future research should focus on improving the accuracy of land use and cover data on the QTP, assessing and preventing the ecological risks of LUCC, investigating the impacts of human activities on LUCC and the ecological environment, and exploring the interactions between climate change and human activities on the ecological environment. The findings of this paper will help researchers and stakeholders gain a rapid and comprehensive understanding of this research area and thus contribute to the sustainable development of the QTP.
Targeting the Influences of Under-Lake Coal Mining Based on the Value of Wetland Ecosystem Services: What and How?
Authors: Hou Huping , Ding Zhongyi , Zhang Shaoliang , Chen Zanxu , Wang Xueqing , Sun Aibo , An Shi , Xiong Jinting
Published: November 2022

Under the growing restrictions of the Chinese eco-environmental policies, the impact of under-lake coal mining on wetlands is receiving increasing attention from both coal mining enterprises and local governments. This paper focuses on the impact of under-lake coal mining on the Nansi Lake wetland from 1991 to 2021. Field measurements, resident surveys, and remote sensing inversion were comprehensively employed to quantitatively assess the impact. The calculation of the assessment indicators refers to the elastic coefficient, the information for which comes from four major categories of ecosystem service values (ESVs) and eight sub-ESVs. According to the results of the remote sensing interpretation and inversion, by 2021 the range had enlarged by 32.3 km2, and the water depth had increased by 1.9 m in the mining-disturbed area relative to 1991. The ESV fluctuations in the Nansi Lake wetland also exhibited a generally increasing trend over time. Our results show that the under-lake mining disturbs the ESVs, but the disturbance is not sufficient to result in significant consequences. Based on the data analysis, we suggest several well-directed, appropriate restoration strategies to achieve the desired objectives and target the response of the ESV changes. Such measures will help to relieve some of the anxiety and concern about the wetland changes caused by the under-lake mining.
Ranking of Empirical Evapotranspiration Models in Different Climate Zones of Pakistan
Authors: Hamed Mohammed Magdy , Khan Najeebullah , Muhammad Mohd Khairul Idlan , Shahid Shamsuddin
Published: November 2022

Accurate estimation of evapotranspiration (ET) is vital for water resource development, planning and management, particularly in the present global warming context. A large number of empirical ET models have been developed for estimating ET. The main limitations of this method are that it requires several meteorological variables and an extensive data span to comprehend the ET pattern accurately, which is not available in most developing countries. The efficiency of 30 empirical ET models has been evaluated in this study to rank them for Pakistan to facilitate the selection of suitable models according to data availability. Princeton Global Meteorological Forcing daily climate data with a 0.25° × 0.25° resolution for 1948–2016 were utilized. The ET estimated using Penman–Monteith (PM) was considered as the reference. Multi-criteria group decision making (MCGDM) was used to rank the models for Pakistan. The results showed the temperature-based Hamon as the best model for most of Pakistan, followed by Hargreaves–Samani and Penman models. Hamon also showed the best performance in terms of different statistical metrics used in the study with a mean bias (PBias) of −50.2%, mean error (ME) of −1.62 mm and correlation coefficient (R2) of 0.65. Ivan showed the best performance among the humidity-based models, Irmak-RS and Ritch among the radiation-based models and Penman among the mass transfer-based models. Northern Pakistan was the most heterogeneous region in the relative performance of different ET models.
Consumers as Unassisted Minors: Asymmetrical Sanction for Unfair Contract Terms
Authors: Blicharz Grzegorz J.
Published: November 2022

The consumer distance contract regulated within the European Union was compared to the Roman law solution known by its medieval name as negotium claudicans, thus to the contract with unassisted pupilli (children under the age of puberty, i.e., minors). This article builds on this comparison and applies it to yet another EU directive which follows even more closely the idea to interfere with the binding nature of contractual terms. The recent case law of the CJEU regarding the sanction enclosed in the Article 6(1) of Directive 93/13/EEC, its implementation into national laws, and the standpoints of various legal doctrines especially in Polish law inspire to ask about the nature of sanction for unfair contract terms and its importance for the modern discussion on the typology of nullity. The paper tries to answer these questions by marrying solutions applied in different times and contexts. It compares the EU sanction with the Roman law of contracts with unassisted minors and with its legacy in European and South African law. Both examples, according to us, are related by the similar nature of the sanctions which bear strikingly similar characteristics: they are asymmetrical and escape the modern typologies of nullity.
Screening for Volatile α-Unsaturated Ester-Producing Yeasts from the Feces of Wild Animals in South Africa
Authors: Tan Mélissa , Caro Yanis , Lebeau Juliana , Shum-Cheong-Sing Alain , François Jean Marie , Regnier Thierry , Petit Thomas
Published: November 2022

α-unsaturated esters are fruity-aromatic compounds which are largely spread in the volatilome of many different fruits, but they are rarely found in the volatilome of yeasts. The yeast S. suaveolens has been recently shown to produce relatively high amounts of α-unsaturated esters and it appears to be an interesting model for the production of these compounds. This study aimed to isolate new α-unsaturated ester-producing yeasts by focusing on strains displaying a similar metabolism to S. suaveolens. While the production of α-unsaturated esters by S. suaveolens is believed to be closely related to its ability to grow on media containing branched-chain amino acids (isoleucine, leucine and valine) as the sole carbon source (ILV+ phenotype), in this study, an original screening method was developed that selects for yeast strains displaying ILV+ phenotypes and is able to produce α-unsaturated esters. Among the 119 yeast strains isolated from the feces of 42 different South African wild animal species, 43 isolates showed the ILV+ phenotype, among which 12 strains were able to produce α-unsaturated esters. Two interesting α-unsaturated esters were detected in two freshly isolated strains, both identified as Galactomyces candidus. These new esters were detected neither in the volatilome of the reference strain S. suaveolens, nor in any other yeast species previously studied for their aroma production. This work demonstrated the efficiency of an original method to rapidly screen for α-unsaturated ester-producing yeasts. In addition, it demonstrated that wild animal feces are interesting resources to isolate novel strains producing compounds with original aromas.
Physical, Mechanical and Radiological Characteristics of a Fly Ash Geopolymer Incorporating Titanium Dioxide Waste as Passive Fire Insulating Material in Steel Structures
Authors: Salazar Pedro Antonio , Fernández Carlos Leiva , Luna-Galiano Yolanda , Sánchez Rosario Villegas , Fernández-Pereira Constantino
Published: November 2022

This research analyzes whether a titanium dioxide waste (TiO2 waste) can be used as a source material for geopolymers with good fire resistance properties. Samples with different proportions were prepared, replacing fly ashes with titanium dioxide waste on geopolymers (0, 20, 30, 40 and 100% w/w). The activating solution has a Na2O/SiO2 molar ratio of 0.98. Physical (bulk density, moisture content and water absorption) and mechanical (superficial hardness and compressive strength) characteristics have been evaluated. In addition, their thermal behavior at high temperatures (fire resistance, compressive strength at elevated temperature and absorbed energy) has also been evaluated to see if they can be used as fire insulating materials. This work also studies the radiological activity of geopolymer materials. The replacement of FA with WTiO2 increases the bulk density due to its higher specific bulk density. The highest compressive strength values were obtained with a TiO2 waste content between 30 and 40% w/w. The compressive strength decreases at high temperatures, especially when more TiO2 waste is added. When the amount of TiO2 waste is increased, so is the plateau of evaporation, and this, in turn, increases the resistance to fire. Geopolymers containing FA and TiO2 waste do not present radiological problems, although, when the TiO2 waste is increased, the activity index of the geopolymer also rises.
Recrystallization Behavior of a Mg-5Zn Alloy Influenced by Minor SiCp during Hot Compression
Authors: Shi Quanxin , Wang Cuiju , Deng Kunkun , Nie Kaibo , Liang Wei
Published: November 2022

The influence of minor SiCp on the dynamic recrystallization (DRX) and dynamic precipitation behaviors of the Mg-5Zn matrix were investigated through the hot compression test. The results showed that the addition of SiCp improved the DRXed ratio of Mg-5Zn matrix, but the recrystallized grains in 1 vol.% 5 μm SiCp/Mg-5Zn material were mainly formed by the “bulging” nucleation of the grain boundary at a low compressive strain (~0.05, ~0.1 and ~0.35), and PDZ (particle deformation zone) around SiCp had little effect on the recrystallization nucleation. However, the fine recrystallized grains appeared around the particles when the compressive strain reached ~0.7, which was attributed to the promotion effect of PDZ on recrystallization nucleation. This shows that PDZ around particles can promote DRX nucleation under large strain. Meanwhile, compared to the Mg-5Zn alloy, the volume fraction and size of the secondary phase in the SiCp/Mg-5Zn material increased due to the influence of SiCp on the recrystallization behavior of Mg-5Zn matrix.
Investigation of the Effect of Supersonic Flow of Dissociated Nitrogen on ZrB2–HfB2–SiC Ceramics Doped with 10 vol.% Carbon Nanotubes
Authors: Simonenko Elizaveta P. , Simonenko Nikolay P. , Kolesnikov Anatoly F. , Chaplygin Aleksey V. , Lysenkov Anton S. , Nagornov Ilya A. , Mokrushin Artem S. , Kuznetsov Nikolay T.
Published: November 2022

The method of fabricating dense ultra-high temperature ceramic materials ZrB2–HfB2–SiC–CCNT was developed using a combination of sol-gel synthesis and reaction hot pressing approaches at 1800 °C. It was found that the introduction of multilayer nanotubes (10 vol.%) led to an increase in the consolidation efficiency of ceramics (at temperatures > 1600 °C). The obtained ZrB2–HfB2–SiC and ZrB2–HfB2–SiC–CCNT materials were characterized by a complex of physical and chemical analysis methods. A study of the effects on the modified sample ZrB2–HfB2–SiC–CCNT composition speed flow of partially dissociated nitrogen, using a high-frequency plasmatron, showed that, despite the relatively low temperature established on the surface (≤1585 °C), there was a significant change in the chemical composition and surface microstructure: in the near-surface layer, zirconium–hafnium carbonitride, amorphous boron nitride, and carbon were present. The latter caused changes in crucial characteristics such as the emission coefficient and surface catalyticity.
Multi-Frequency Light Sources Based on CVD Diamond Matrices with a Mix of SiV− and GeV− Color Centers and Tungsten Complexes
Authors: Bogdanov Kirill V. , Kaliya Ilya E. , Baranov Mikhail A. , Grudinkin Sergey A. , Feoktistov Nikolay A. , Golubev Valery G. , Davydov Valery Yu. , Smirnov Alexander N. , Baranov Alexander V.
Published: November 2022

Recently, nanodiamonds with negatively charged luminescent color centers based on atoms of the fourth group (SiV−, GeV−) have been proposed for use as biocompatible luminescent markers. Further improvement of the functionality of such systems by expanding the frequencies of the emission can be achieved by the additional formation of luminescent tungsten complexes in the diamond matrix. This paper reports the creation of diamond matrices by a hot filament chemical vapor deposition method, containing combinations of luminescing Si-V and Ge-V color centers and tungsten complexes. The possibility is demonstrated of creating a multicolor light source combining the luminescence of all embedded emitters. The emission properties of tungsten complexes and Si-V and Ge-V color centers in the diamond matrices were investigated, as well as differences in their luminescent properties and electron-phonon interaction at different temperatures.
Seismic Response of Star-Type Grid Concrete Wall Structure by Numerical Modeling
Authors: Tang Baizan , Dong Yuying , Bai Wen , Chen Hua-Peng , Zhuang Haiyang , Deng Wenchao
Published: November 2022

Cement polystyrene shell mold (CPSM) grid concrete walls have been widely applied in the construction of low and mid-rise buildings with higher load-bearing and insulation properties. A star-type grid concrete wall was constructed based on the infill wall simplified to an equivalent diagonal bracing model. To investigate the seismic responses and behavior of a star-type grid concrete wall structure, an overall time-history numerical simulation was carried out in this paper. Typical results, including acceleration, deformation, hysteresis curve and failure pattern of this novel construction system, were interpreted. Results indicate that the star-type grid concrete wall structure has satisfactory seismic performance, including energy dissipation capacity. The structure has higher lateral stiffness and can work in an elastic state under major earthquakes. Accordingly, it is more sensitive to near-fault ground motion with higher frequency components. Meanwhile, the structural inter-story drift angle is less than the limit value of lighter damage when subjected to a super-major earthquake, and the structure presents shear deformation. The openings significantly affect the failure mode, the star-type grid concrete wall with a window (a small aspect ratio less than 1.11) conforms to shear failure, and the wall with a door (aspect ratio of 2.5) conforms to bending-shear failure. The diagonal bracing can distribute the stress in the wall, especially the concrete lattice beam, and effectively resist the lateral forces via the concrete lattice column, improving the ductility and integrity of the structural system.
Determination of Water Content in Direct Resin Composites Using Coulometric Karl Fischer Titration
Authors: Faria-e-Silva André , Heckel Lea , Belli Renan , Lohbauer Ulrich
Published: November 2022

This study evaluated the water content and sorption of direct composites over 60 days using coulometric Karl Fischer titration (KFT). Plate-shaped specimens (10 × 10 × 1 mm3 of thickness) were built up using the composites Clearfil Majesty Posterior (CM), Grandio SO (GS), and Filtek Supreme XT (FS). Water contents were determined in non-stored specimens (control) or after storage in distilled water for up to 60 days (n = 5). The amount of water transferred from the specimens heated at 200 °C (isothermal mode) was measured in the Coulometer. The water content of non-stored specimens ranged from 0.28 to 1.69 wt% (5.6 to 31.2 μg/mm3) for GS and FS, respectively. The highest values of water sorption were observed for FS (25.3 μg/mm3 after 60 days). GS and CM showed similar water sorption after 60 days (≈9 μg/mm3), but an ultimate higher water content was observed for CM (0.9 wt%; 22.0 μg/mm3) than GS (0.7 wt%; 14.8 μg/mm3). Except for CM, no significant water sorption was observed between 21 and 60 days of storage. Since all composites presented some base water content, water sorption data alone do not account for the ultimate water content in direct resin-based composites.
Influence of Different Aqueous Media on the Corrosion Behavior of B4C-Modified Lightweight Al-Mg-Si Matrix Composites
Authors: Kumar Neeraj , Sharma Ashutosh , Manoj Manoranjan Kumar
Published: November 2022

In this study, we have investigated the electrochemical corrosion behavior of boron carbide (B4C) ceramic-reinforced Al-Mg-Si matrix composites in various aqueous environments (NaOH, NaCl, HCl, and H2SO4). The samples were produced by the powder metallurgy (P/M) route and the corrosion investigations were conducted by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) methods. The morphology of the as-prepared and corroded samples was examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) studies. The investigations revealed that the corrosion resistance of Al-Mg-Si composites is highest in NaCl medium due to a less negative corrosion potential, higher charge transfer (Rct) resistance, and lower double-layer capacitance (Cdl) as compared to other media. The SEM morphology suggests that B4C ceramics enhance corrosion resistance by forming a protective barrier layer of OH- and Cl- deposits in the composite and unreinforced alloy, respectively.
A Simplified Method of the Assessment of Magnetic Anisotropy of Commonly Used Sapphire Substrates in SQUID Magnetometers
Authors: Gas Katarzyna , Sawicki Maciej
Published: November 2022

Solid-state wafers are indispensable components in material science as substrates for epitaxial homo- or heterostructures or carriers for two-dimensional materials. However, reliable determination of magnetic properties of nanomaterials in volume magnetometry is frequently affected by unexpectedly rich magnetism of these substrates, including significant magnetic anisotropy. Here, we describe a simplified experimental routine of magnetic anisotropy assessment, which we exemplify and validate for epi-ready sapphire wafers from various sources. Both the strength and the sign of magnetic anisotropy are obtained from carefully designed temperature-dependent measurements, which mitigate all known pitfalls of volume SQUID magnetometry and are substantially faster than traditional approaches. Our measurements indicate that in all the samples, two types of net paramagnetic contributions coexist with diamagnetism. The first one can be as strong as 10% of the base diamagnetism of sapphire [−3.7(1) × 10−7 emu/gOe], and when exceeds 2%, it exhibits pronounced magnetic anisotropy, with the easy axis oriented perpendicularly to the face of c-plane wafers. The other is much weaker, but exhibits a ferromagnetic-like appearance. These findings form an important message that nonstandard magnetism of common substrates can significantly influence the results of precise magnetometry of nanoscale materials and that its existence must be taken for granted by both industry and academia.
Bridge Non-Destructive Measurements Using a Laser Scanning during Acceptance Testing: Case Study
Authors: Tysiac Pawel , Miskiewicz Mikolaj , Bruski Dawid
Published: November 2022

Owing to the recent proliferation of inventory works on roads and railways, bridge acceptance tests have increased exponentially. These tests’ results are often misinterpreted owing to the use of various measuring equipment types, rendering integrated interpretation problematic. It is also problematic that adjusting the measurement method is difficult when the structure’s response to load is uncertain. Therefore, it is important to observe the largest possible range of possible deformations. For this reason, the present study suggests a novel approach to bridge non-destructive measurements using a laser scanner during acceptance testing. The main advantage of our method is the ability it affords to observe all points of the structure during testing, an ability that is extremely important is the absence of unambiguous data regarding the bridge’s condition. To significantly increase the scanning accuracy (up to 0.5 mm), measurements from a limited number of linear sensors are used (whose accuracy is up to 0.1 mm). To achieve optimal accuracy, we performed the following steps: first, we adapted the precision requirements to the numerical project. For this purpose, we used potentiometric sensors to measure linear deformations. Next, we performed laser scanning measurements from two scan positions. Finally, we filtered the data for the selected cross-section and modelled the points into polynomial deflection. The performed tests confirmed that the structure’s response was as predicted by the FEM model, and the object was approved for use. Our future tests will be based on the selection of a structure with minimal measurement errors, and the results will be compared using a total station, ensuring the highest possible quality of service, which can be repeated in simple steps. As study objects, we presented two items: the first without proper calibration on a linear sensor and the second using linear sensors to present the highest possible accuracy of our experiment.
Influence of Grain Size and Its Distribution on Charpy Impact Properties of TA3 Alloy
Authors: Xin Chao , Wang Qi , Ren Junqiang , Zhang Yonghong , Zhang Liang , Sang Biao , Li Le
Published: November 2022

In practice, most components often receive impact loads during service. In order to ensure the service safety of components, impact toughness evaluation is essential. To the best of our knowledge, the previous studies were mainly focused on the quasi-static tensile deformation, and the impact toughness of bimodal grain structured metals have rarely been reported. Three different grain size characteristics TA3 alloy, i.e., fine grained sample (FG Ti), the mixture of coarse and fine grained sample (MG Ti), and coarse grained (CG Ti), were produced, and their tensile and Charpy impact properties were comparatively investigated. Owing to the strengthening of retained β phase and the twining inducing plasticity effect, MG Ti display the highest tensile strength and impact absorbed energy, together with an intermediate tensile elongation. The impact deformed microstructures revealed that the primary deformation modes of FG Ti, MG Ti and CG Ti sample are: dislocation slips, a combination of dislocation slip in fine grained region and {101¯2} deformation twins in coarse grained region, and {112¯1} deformation twins in sequence.
Deep Eutectic Solvent for Facile Synthesis of Mn3O4@N-Doped Carbon for Aqueous Multivalent-Based Supercapacitors: New Concept for Increasing Capacitance and Operating Voltage
Authors: Zdolšek Nikola , Perović Ivana , Brković Snežana , Tasić Gvozden , Milović Miloš , Vujković Milica
Published: November 2022

The capacitance and operating voltage of supercapacitors as well as their energy density have been increased by development of different materials and electrolytes. In this paper, two strategies, for the first time, were used to improve energy density: Mn3O4- and N-dual doped carbon electrode and aqueous mixture of multivalent ions as electrolyte. Mn3O4- and N-dual doped carbon was prepared by a novel and cost-effective procedure using deep eutectic solvent. XRD, XPS, and FTIR confirmed presence of Mn3O4 and nitrogen, while SEM and EDS elemental mapping showed micrometer-sized nanosheets with uniform distribution of C, O, N, and Mn atoms. Charge storage behavior of carbon was tested in aqueous multivalent-based electrolytes and their mixture (Ca2+-Al3+). Regarding both specific capacitance and workable voltage, the Ca2+-Al3+ mixed electrolyte was found as the best optimal solution. The calcium addition to the Al-electrolyte allows the higher operating voltage than in the case of individual Al(NO3)3 electrolyte while the addition of Al3+ ion in the Ca(NO3)2 electrolyte improves the multivalent-ion charge storage ability of carbon. As a result, the specific energy density of two-electrode Mn3O4@N-doped carbon//Al(NO3)2+Ca(NO3)2//Mn3O4@N-doped carbon supercapacitor (34 Wh kg−1 at 0.1 A g−1) overpasses the reported values obtained for Mn-based carbon supercapacitors using conventional aqueous electrolytes.
Study of the Structure and Properties of Electrical Sand Concrete under Prolonged Exposure to Sulfate Environment
Authors: Gordina Anastasiya , Gumenyuk Aleksandr , Polyanskikh Irina , Yakovlev Grigory , Pudov Igor
Published: November 2022

Destructive processes accompanying sulfate corrosion of concrete significantly affect the durability of products and structures based on Portland cement. In the presented study, the long-term effect of sulfate corrosion on the electrical properties of electrically conductive sand concrete was studied. In the course of the study, the following were tested: an electrically conductive composition and a control composition based on plain Portland cement. The analysis of changes in the mineral composition of the samples over the course of time in an aggressive solution was carried out. The results show that during the exposure period of the samples from 28 to 224 days, the absorption of sulfate ions slows down and averages 26% for the control composition and 29% for the electrically conductive composition, of the total volume of absorbed sulfates. At the same time, the course of sulfate corrosion was accompanied by a 6% increase in the density of samples of both compositions, as well as a cyclic change in mechanical strength within 15%. In its turn, the key indicator of the electrical characteristics of the compositions—electrical resistivity—tended to increase throughout the experiment. These results can be recommended for assessing the durability and the nature of the operating conditions of electrical concretes used in aggressive environments.
Analysis of a Collaborative Scheduling Model Applied in a Job Shop Manufacturing Environment
Authors: Varela Leonilde R. , Alves Cátia F. V. , Santos André S. , Vieira Gaspar G. , Lopes Nuno , Putnik Goran D.
Published: November 2022

Collaborative Manufacturing Scheduling (CMS) is not yet a properly explored decision making practice, although its potential for being currently explored, in the digital era, by combining efforts among a set of entities, either persons or machines, to jointly cooperate for solving some more or less complex scheduling problem, namely occurring in job shop manufacturing environments. In this paper, an interoperable scheduling system integrating a proposed scheduling model, along with varying kinds of solving algorithms, are put forward and analyzed through an industrial case study. The case study was decomposed in three application scenarios, for enabling the evaluation of the proposed scheduling model when envisioning the prioritization of internal–makespan-or external–number of tardy jobs-performance measures, along with a third scenario assigning a same importance or weight to both kinds of performance measures. The results obtained enabled us to realize that the weighted application scenario permitted reaching more balanced, thus a potentially more attractive global solution for the scheduling problem considered through the combination of different kinds of scheduling algorithms for the resolution of each underlying sub problem according to the proposed scheduling model. Besides, the decomposition of a global more complex scheduling problem into simpler sub-problems turns them easier to be solved through the different solving algorithms available, while further enabling to obtain a wider range of alternative schedules to be explored and evaluated. Thus, contributing to enriching the scheduling problem-solving process. A future exploration of the application in other types of manufacturing environments, namely occurring in the context of extended, networked, distributed or virtual production systems, integrating an increased and variable set of collaborating entities or factories, is also suggested.
Natural Convection of Heat-Generating Liquid of Variable Viscosity under Wall Cooling Impact
Authors: Kudrov Alexander I. , Sheremet Mikhail A.
Published: November 2022

This research presents a computational investigation of the thermal convection of a heat-generating liquid having variable viscosity in a semi-cylindrical cavity. The analysis is carried out to obtain the time patterns of the average Nusselt number at the lower border of the chamber and understand the impact of the variable viscosity, the Prandtl number, and the Rayleigh number on this parameter. The natural convection in the cavity is defined by the set of non-dimensional equations based on the Boussinesq approach employing the non-primitive parameters such as vorticity and stream function. These governing equations are worked out numerically based on the finite difference technique. The time dependencies have been obtained at the Rayleigh number equal to 104, 105, and 106 and the Prandtl number taking values of 7.0, 70, and 700. The results obtained for variable and constant viscosity have been compared. Additionally, the paper represents maps of isotherms and streamlines for the mentioned values of the Rayleigh number. The influence of variable viscosity on the parameters of natural convection is poorly studied in closed systems; therefore, this research gives necessary data to understand the general time nature of the average Nusselt number at cooling surface of various parameters. Additionally in this research, the model for simulating the natural convection in non-primitive variables is presented in polar coordinates when the dynamic viscosity varies with temperature. The computational model designed could be used to simulate the free convection in systems with inner heat production such as chemical reactors, inductive metal melting facilities, or corium in-vessel retention to analyze the impact of various factors on the parameters of the natural convection in such systems.
Comment on Mahariq et al. Investigation and Analysis of Acoustojets by Spectral Element Method. Mathematics 2022, 10, 3145
Authors: Minin Igor V. , Minin Oleg V.
Published: November 2022

The paper under discussion has some shortcomings in regard to mathematical formulation of the problem related to acoustics, its justification, some references analyses and the text, and we feel that this study has not been finished to its full extent. From the point of view of acoustic jet formation, the mathematical model used by the authors has a number of significant limitations which are not taken into account. Moreover, the formal analogy between the parameters of electromagnetic waves and acoustic waves should be used with caution in the conditions of localized beams (acoustic jet), and the limits of their application should be justified.
Nonparametric Estimation of the Expected Shortfall Regression for Quasi-Associated Functional Data
Authors: Ait-Hennani Larbi , Kaid Zoulikha , Laksaci Ali , Rachdi Mustapha
Published: November 2022

In this paper, we study the nonparametric estimation of the expected shortfall regression when the exogenous observation is functional. The constructed estimator is obtained by combining the double kernels estimator of both conditional value at risk and conditional density function. The asymptotic proprieties of this estimator are established under weak dependency condition. Precisely, we assume that the observations are generated from quasi-associated functional time series and we prove the almost complete convergence of the constructed estimator. This asymptotic result is obtained under a standard condition of functional time series analysis. The finite sample performance of this estimator is evaluated using artificial data.
Reply to Minin, I.V.; Minin, O.V. Comment on “Mahariq et al. Investigation and Analysis of Acoustojets by Spectral Element Method. Mathematics 2022, 10, 3145”
Authors: Mahariq Ibrahim
Published: November 2022

This reply provides one-to-one responses to comments regarding the article entitled: “Investigation and Analysis of Acoustojets by Spectral Element Method” that has been published in Mathematics by MDPI. As a corresponding author, I am happy to receive constructive criticism about the aforementioned article, in particular, suggestions and/or comments that, when addressed, may further help the reader in understanding the published material.
Introducing Two Parsimonious Standard Power Mixture Models for Bimodal Proportional Data with Application to Loss Given Default
Authors: Larney Janette , Grobler Gerrit Lodewicus , Allison James Samuel
Published: November 2022

The need to model proportional data is common in a range of disciplines however, due to its bimodal nature, U- or J-shaped data present a particular challenge. In this study, two parsimonious mixture models are proposed to accurately characterise this proportional U- and J-shaped data. The proposed models are applied to loss given default data, an application area where specific importance is attached to the accuracy with which the mean is estimated, due to its linear relationship with a bank’s regulatory capital. In addition to using standard information criteria, the degree to which bias reduction in the estimation of the distributional mean can be achieved is used as a measure of model performance. The proposed models outperform the benchmark model with reference to the information criteria and yield a reduction in the distance between the empirical and distributional means. Given the special characteristics of the dataset, where a high proportion of observations are close to zero, a methodology for choosing a rounding threshold in an objective manner is developed as part of the data preparation stage. It is shown how the application of this rounding threshold can reduce bias in moment estimation regardless of the model choice.
Axioms of Decision Criteria for 3D Matrix Games and Their Applications
Authors: Özkaya Murat , İzgi Burhaneddin , Perc Matjaž
Published: November 2022

In this paper, we define characteristic axioms for 3D matrix games and extend the definitions of the decision criteria under uncertainty to three dimensions in order to investigate the simultaneous effect of two different states on the decision process. We first redefine the Laplace, Wald, Hurwicz, and Savage criteria in 3D. We present a new definition depending on only the ∞-norm of the 3D payoff matrix for the Laplace criterion in 3D. Then, we demonstrate that the Laplace criterion in 3D explicitly satisfies all the proposed axioms, as well as the other three criteria. Moreover, we illustrate a fundamental example for a three-dimensional matrix with 3D figures and show the usage of each criterion in detail. In the second example, we model a decision process during the COVID-19 pandemic for South Korea to show the applicability of the 3D decision criteria using real data with two different states of nature for individuals’ actions for the quarantine. Additionally, we present an agricultural insurance problem and analyze the effects of the hailstorm and different speeds of wind on the harvest by the 3D criteria. To the best of our knowledge, this is the first study that brings 3D matrices in decision and game theories together.
Prediction of Sea Level with Vertical Land Movement Correction Using Deep Learning
Authors: Raj Nawin
Published: November 2022

Sea level rise (SLR) in small island countries such as Kiribati and Tuvalu have been a significant issue for decades. There is an urgent need for more accurate and reliable scientific information regarding SLR and its trend and for more informed decision making. This study uses the tide gauge (TG) dataset obtained from locations in Betio, Kiribati and Funafuti, Tuvalu with sea level corrections for vertical land movement (VLM) at these locations from the data obtained by the Global Navigation Satellite System (GNSS) before the sea level trend and rise predictions. The oceanic feature inputs of water temperature, barometric pressure, wind speed, wind gust, wind direction, air temperature, and three significant lags of sea level are considered in this study for data modeling. A new data decomposition method, namely, successive variational mode decomposition (SVMD), is employed to extract intrinsic modes of each feature that are processed for selection by the Boruta random optimizer (BRO). The study develops a deep learning model, namely, stacked bidirectional long short-term memory (BiLSTM), to make sea level (target variable) predictions that are benchmarked by three other AI models adaptive boosting regressor (AdaBoost), support vector regression (SVR), and multilinear regression (MLR). With a comprehensive evaluation of performance metrics, stacked BiLSTM attains superior results of 0.994207, 0.994079, 0.988219, and 0.899868 for correlation coefficient, Wilmott’s Index, the Nash–Sutcliffe Index, and the Legates–McCabe Index, respectively, for Kiribati, and with values of 0.996806, 0.996272, 0.992316, and 0.919732 for correlation coefficient, Wilmott’s Index, the Nash–Sutcliffe Index, and the Legates–McCabe Index, respectively, for the case of Tuvalu. It also shows the lowest error metrics in prediction for both study locations. Finally, trend analysis and linear projection are provided with the GNSS-VLM-corrected sea level average for the period 2001 to 2040. The analysis shows an average sea level rate rise of 2.1 mm/yr for Kiribati and 3.9 mm/yr for Tuvalu. It is estimated that Kiribati and Tuvalu will have a rise of 80 mm and 150 mm, respectively, by the year 2040 if estimated from year 2001 with the current trend.
Targeting EGFR in Combination with Nutritional Supplements on Antitumor Efficacy in a Lung Cancer Mouse Model
Authors: Guo Chih-Hung , Li Wen-Chin , Peng Chia-Lin , Chen Pei-Chung , Lee Shih-Yu , Hsia Simon
Published: November 2022

Selenium (Se) and fish oil (FO) exert anti-epidermal growth factor receptor (EGFR) action on tumors. This study aimed to compare the anti-cancer efficacy of EGFR inhibitors (gefitinib and erlotinib) alone and in combination with nutritional supplements of Se/FO in treating lung cancer. Lewis LLC1 tumor-bearing mice were treated with a vehicle or Se/FO, gefitinib or gefitinib plus Se/FO, and erlotinib or erlotinib plus Se/FO. The tumors were assessed for mRNA and protein expressions of relevant signaling molecules. Untreated tumor-bearing mice had the lowest body weight and highest tumor weight and volume of all the mice. Mice receiving the combination treatment with Se/FO and gefitinib or erlotinib had a lower tumor volume and weight and fewer metastases than did those treated with gefitinib or erlotinib alone. The combination treatment exhibited greater alterations in receptor signaling molecules (lower EGFR/TGF-β/TβR/AXL/Wnt3a/Wnt5a/FZD7/β-catenin; higher GSK-3β) and immune checkpoint molecules (lower PD-1/PD-L1/CD80/CTLA-4/IL-6; higher NKp46/CD16/CD28/IL-2). These mouse tumors also had lower angiogenesis, cancer stemness, epithelial to mesenchymal transitions, metastases, and proliferation of Ki-67, as well as higher cell cycle arrest and apoptosis. These preliminary results showed the Se/FO treatment enhanced the therapeutic efficacies of gefitinib and erlotinib via modulating multiple signaling pathways in an LLC1-bearing mouse model.