Tunnel construction in central and western China presents significant challenges primarily due to the complex geological conditions. The presence of water-rich zones compromises the stability of excavation faces, leading to potential safety risks and economic losses. This study investigates the Yingpan Mountain extra-long tunnel through numerical simulations, focusing on stress and displacement variations under varying conditions. The primary focus is on assessing the influence of water on tunnel stability, particularly under water-rich conditions. The study proposes effective evaluation methods for different construction stages. The findings offer valuable guidance for future engineering projects, thereby enhancing safety and efficiency in tunnel construction.
{"title":"Numerical simulation analysis of the stability of the construction face of a super long tunnel under conditions of precipitation and abundant water","authors":"Huoda Dun, Song Chen, Haitao Liu, Chen Chen, Yuansheng Zhang, Ying Yuan","doi":"10.3389/fmats.2024.1461308","DOIUrl":"https://doi.org/10.3389/fmats.2024.1461308","url":null,"abstract":"Tunnel construction in central and western China presents significant challenges primarily due to the complex geological conditions. The presence of water-rich zones compromises the stability of excavation faces, leading to potential safety risks and economic losses. This study investigates the Yingpan Mountain extra-long tunnel through numerical simulations, focusing on stress and displacement variations under varying conditions. The primary focus is on assessing the influence of water on tunnel stability, particularly under water-rich conditions. The study proposes effective evaluation methods for different construction stages. The findings offer valuable guidance for future engineering projects, thereby enhancing safety and efficiency in tunnel construction.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"6 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.3389/fmats.2024.1410277
Haitham A. Mahmoud, G. Shanmugasundar, Swapnil Vyavahare, Rakesh Kumar, Robert Cep, Sachin Salunkhe, Sharad Gawade, Emad S. Abouel Nasr
IntroductionAdditive manufacturing (AM) is a revolutionary technology transforming traditional production processes by providing exceptional mechanical characteristics.MethodsThe present study aims explicitly to predict the hardness of Polycarbonate (PC) parts produced using AM. The objectives of this study are: (1) To investigate the process parameters that impact the ability to estimate the hardness of PC materials accurately, and (2) To develop a best-performing ML model from a range of models that can reliably predict the hardness of additively manufactured PC parts. Initially, fused filament fabrication (FFF), the most affordable AM technique, was used for the manufacturing of parts. Four process parameters, infill density, print direction, raster angle, and layer thickness, are selected for investigation. A heatmap is generated to obtain the influence of process parameters on hardness. Then, machine learning (ML) techniques create a range of predictive models that can predict hardness value considering the level of process parameters.ResultsThe developed ML models include Linear Regression, Decision Tree, Random Forest, K-nearest neighbor, Support Vector Regression, AdaBoost, and Artificial Neural Network. Further, an investigation has been done that includes choosing and improving ML algorithms and assessing the models’ performance.DiscussionPrediction plots, residual plots, and evaluation metrics plots are prepared to gauge the performance of the developed models. Thus, the research enhances AM capabilities by applying predictive modeling to process parameters and improving the quality and reliability of fabricated components.
导言增材制造（AM）是一项革命性技术，它通过提供优异的机械特性改变了传统的生产工艺。方法本研究旨在明确预测使用增材制造技术生产的聚碳酸酯（PC）部件的硬度。本研究的目标是(1) 研究影响准确估算 PC 材料硬度的工艺参数；(2) 从一系列模型中开发出性能最佳的 ML 模型，从而可靠地预测快速成型 PC 零件的硬度。起初，我们使用最经济实惠的快速成型技术--熔融长丝制造（FFF）来制造零件。研究选择了四个工艺参数：填充密度、打印方向、光栅角度和层厚度。通过生成热图来了解工艺参数对硬度的影响。然后，机器学习（ML）技术创建了一系列预测模型，这些模型可以根据工艺参数的水平预测硬度值。讨论绘制了预测图、残差图和评估指标图，以衡量所开发模型的性能。因此，该研究通过对工艺参数应用预测建模，提高了 AM 能力，并改善了制造部件的质量和可靠性。
{"title":"Prediction of machine learning-based hardness for the polycarbonate using additive manufacturing","authors":"Haitham A. Mahmoud, G. Shanmugasundar, Swapnil Vyavahare, Rakesh Kumar, Robert Cep, Sachin Salunkhe, Sharad Gawade, Emad S. Abouel Nasr","doi":"10.3389/fmats.2024.1410277","DOIUrl":"https://doi.org/10.3389/fmats.2024.1410277","url":null,"abstract":"IntroductionAdditive manufacturing (AM) is a revolutionary technology transforming traditional production processes by providing exceptional mechanical characteristics.MethodsThe present study aims explicitly to predict the hardness of Polycarbonate (PC) parts produced using AM. The objectives of this study are: (1) To investigate the process parameters that impact the ability to estimate the hardness of PC materials accurately, and (2) To develop a best-performing ML model from a range of models that can reliably predict the hardness of additively manufactured PC parts. Initially, fused filament fabrication (FFF), the most affordable AM technique, was used for the manufacturing of parts. Four process parameters, infill density, print direction, raster angle, and layer thickness, are selected for investigation. A heatmap is generated to obtain the influence of process parameters on hardness. Then, machine learning (ML) techniques create a range of predictive models that can predict hardness value considering the level of process parameters.ResultsThe developed ML models include Linear Regression, Decision Tree, Random Forest, K-nearest neighbor, Support Vector Regression, AdaBoost, and Artificial Neural Network. Further, an investigation has been done that includes choosing and improving ML algorithms and assessing the models’ performance.DiscussionPrediction plots, residual plots, and evaluation metrics plots are prepared to gauge the performance of the developed models. Thus, the research enhances AM capabilities by applying predictive modeling to process parameters and improving the quality and reliability of fabricated components.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"6 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.3389/fmats.2024.1432704
R. Suresh, Saravanan Rajendran, Wei-Hsin Chen, Matias Soto-Moscoso, Thanigaivel Sundaram, Aishah Abdul Jalil, Suresh Kumar Rajamani Sekar
Wastewaters consist of organic pollutants that have environmental concerns. Wastewaters are treated by different methods, but efficient, low-cost, and sustainable techniques still need to be developed. Algae-based water pollution remediation techniques are considered to be sustainable approaches. This review exclusively discusses the facets of macro and microalgae in the treatment of organic toxicants. The current trends of algae-mediated water treatments have been discussed under adsorption and degradation methods. A focus on algae fuel cell, algae mediated activation of oxidizing agents, Fenton-like reactions, and photocatalysis was given. The need of algae-based adsorptive and catalytic materials was mentioned. The role of algae in the synthesis of catalysts which were employed in pollutant removal methods was also explained. The integrated algae-mediated water treatment techniques were also highlighted. The toxicant removal performances of different algae-based materials in the water medium were summarized. The conclusion and future prospects derived from the literature survey were described. This review will be helpful for researchers who are working in the field of sustainable water pollution remediation.
{"title":"A review on algae-mediated adsorption and catalytic processes for organic water pollution remediation","authors":"R. Suresh, Saravanan Rajendran, Wei-Hsin Chen, Matias Soto-Moscoso, Thanigaivel Sundaram, Aishah Abdul Jalil, Suresh Kumar Rajamani Sekar","doi":"10.3389/fmats.2024.1432704","DOIUrl":"https://doi.org/10.3389/fmats.2024.1432704","url":null,"abstract":"Wastewaters consist of organic pollutants that have environmental concerns. Wastewaters are treated by different methods, but efficient, low-cost, and sustainable techniques still need to be developed. Algae-based water pollution remediation techniques are considered to be sustainable approaches. This review exclusively discusses the facets of macro and microalgae in the treatment of organic toxicants. The current trends of algae-mediated water treatments have been discussed under adsorption and degradation methods. A focus on algae fuel cell, algae mediated activation of oxidizing agents, Fenton-like reactions, and photocatalysis was given. The need of algae-based adsorptive and catalytic materials was mentioned. The role of algae in the synthesis of catalysts which were employed in pollutant removal methods was also explained. The integrated algae-mediated water treatment techniques were also highlighted. The toxicant removal performances of different algae-based materials in the water medium were summarized. The conclusion and future prospects derived from the literature survey were described. This review will be helpful for researchers who are working in the field of sustainable water pollution remediation.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"6 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study systematically explores the relationship between the mechanical and shrinkage properties of cement-stabilized macadam (CSM) stone base layers and their resistance to segregation to address the issue of segregation in wide and thick base layers. It establishes three cement dosage levels and five aggregate gradation types (GW1, GW2, GW3, GW4, and GW5). This research evaluates the anti-segregation performance of the mixtures by introducing the shape segregation coefficient L and the sieving segregation coefficient Seg and investigates how these properties influence segregation resistance. The findings revealed that mixtures with GW3 and GW4 gradations exhibit superior segregation resistance, with the most concentrated gradation curves in each zone. These mixtures form a robust force chain structure that resists segregation tendencies during descent. With a 5% cement content, the shape segregation coefficient L decreases by an average of 3.1%, and the sieve segregation coefficient Seg reduces by 14.0%. In addition, mixtures with GW3 and GW4 gradations show optimal drying shrinkage properties. Effective segregation-resistant gradations can significantly reduce the dry shrinkage coefficient of the specimens.
本研究系统地探讨了水泥稳定碎石（CSM）石基层的机械和收缩性能与其抗离析能力之间的关系，以解决宽厚基层的离析问题。研究确定了三种水泥剂量水平和五种集料级配类型（GW1、GW2、GW3、GW4 和 GW5）。该研究通过引入形状离析系数 L 和筛分离析系数 Seg 来评估混合物的抗离析性能，并研究这些属性如何影响抗离析性。研究结果表明，具有 GW3 和 GW4 级配的混合物具有优异的抗离析性能，每个区域的级配曲线最为集中。这些混合物形成了坚固的力链结构，可在下降过程中抵抗离析趋势。水泥含量为 5%时，形状离析系数 L 平均降低 3.1%，筛分离析系数 Seg 降低 14.0%。此外，采用 GW3 和 GW4 级配的混合物显示出最佳的干燥收缩特性。有效的抗离析级配可显著降低试样的干燥收缩系数。
{"title":"Study on anti-segregation performance of cement stabilized macadam and its impact on mechanical and shrinkage properties","authors":"Xiaokun Chen, Caihong Deng, Xinming Zhai, Wenjin Di, Xuanhao Cao, Bowen Guan","doi":"10.3389/fmats.2024.1411558","DOIUrl":"https://doi.org/10.3389/fmats.2024.1411558","url":null,"abstract":"This study systematically explores the relationship between the mechanical and shrinkage properties of cement-stabilized macadam (CSM) stone base layers and their resistance to segregation to address the issue of segregation in wide and thick base layers. It establishes three cement dosage levels and five aggregate gradation types (GW1, GW2, GW3, GW4, and GW5). This research evaluates the anti-segregation performance of the mixtures by introducing the shape segregation coefficient L and the sieving segregation coefficient Seg and investigates how these properties influence segregation resistance. The findings revealed that mixtures with GW3 and GW4 gradations exhibit superior segregation resistance, with the most concentrated gradation curves in each zone. These mixtures form a robust force chain structure that resists segregation tendencies during descent. With a 5% cement content, the shape segregation coefficient L decreases by an average of 3.1%, and the sieve segregation coefficient Seg reduces by 14.0%. In addition, mixtures with GW3 and GW4 gradations show optimal drying shrinkage properties. Effective segregation-resistant gradations can significantly reduce the dry shrinkage coefficient of the specimens.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"6 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.3389/fmats.2024.1444769
Yamin Han, Bin Lao, Xuan Zheng, Sheng Li, Run-Wei Li, Zhiming Wang
Transition metal oxides (TMOs) have emerged as promising candidates for spintronic applications due to their unique electronic properties and novel quantum states. The intricate interplay between strong spin-orbit coupling and electronic correlations in TMOs gives rise to distinct spin and orbital textures, leading to enhanced spin-momentum locking and efficient charge-spin interconversion. Remarkably, recent researches have unveiled the significant and highly tunable nature of charge-spin interconversion efficiency in TMOs, which can be manipulated through strategies such as electric field gating, epitaxial strain, and heterostructure engineering. This review provides a comprehensive overview of the recent advances in understanding the electronic band structures of TMOs and their correlation with charge-spin interconversion mechanisms. We summarize the tunability of these properties through various experimental approaches and discuss the potential implications for spintronic device applications. The insights gained from this review can guide future research efforts towards the development of high-performance, energy-efficient spintronic devices based on TMOs.
{"title":"Transition metal oxides: a new frontier in spintronics driven by novel quantum states and efficient charge-spin interconversion","authors":"Yamin Han, Bin Lao, Xuan Zheng, Sheng Li, Run-Wei Li, Zhiming Wang","doi":"10.3389/fmats.2024.1444769","DOIUrl":"https://doi.org/10.3389/fmats.2024.1444769","url":null,"abstract":"Transition metal oxides (TMOs) have emerged as promising candidates for spintronic applications due to their unique electronic properties and novel quantum states. The intricate interplay between strong spin-orbit coupling and electronic correlations in TMOs gives rise to distinct spin and orbital textures, leading to enhanced spin-momentum locking and efficient charge-spin interconversion. Remarkably, recent researches have unveiled the significant and highly tunable nature of charge-spin interconversion efficiency in TMOs, which can be manipulated through strategies such as electric field gating, epitaxial strain, and heterostructure engineering. This review provides a comprehensive overview of the recent advances in understanding the electronic band structures of TMOs and their correlation with charge-spin interconversion mechanisms. We summarize the tunability of these properties through various experimental approaches and discuss the potential implications for spintronic device applications. The insights gained from this review can guide future research efforts towards the development of high-performance, energy-efficient spintronic devices based on TMOs.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"183 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present study involves the preparation of continuous carbon fiber samples treated with epoxy-based sizing agent (EP) and vinyl ester resin-based sizing agent (VE), alongside untreated fibers, aiming to explore the influence pattern of interfacial differences caused by these sizing agents on the compressive properties of carbon fiber composites. Surface analysis, including Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM), and X-ray Photoelectron Spectroscopy (XPS), followed by testing the mechanical properties of carbon fibers and the composite materials. Results indicate that, compared to unsized carbon fibers, EP and VE increase the O atom content on the carbon fiber surface by 13.0% and 18.1%, respectively, and enhance the proportion of active C atoms by 11.3% and 20.3%, respectively. The interlaminar shear strength (GB/T) of carbon fibers is improved by 9.3% and 20.0%, respectively. Given the compatibility between the sizing agent and the matrix resin, VE improves the open-hole compressive strength of composites by 6.7% compared to EP. This improvement in interface bonding performance positively impacts the open-hole compressive properties of the composites, though it has limited effect on the 0° compressive and post-impact compressive strengths. Following EP and VE sizing, the 0° compressive strength increases by 11.8% and 13.6%, respectively, with VE only resulting in a marginal 1.6% improvement over EP. The enhancements in both interlaminar shear strength and open-hole compressive strength are attributed to the increased number of active functional groups at the fiber-resin interface, facilitated by sizing agents, which promote stronger chemical bonding and thus improved load transfer between the fibers and the matrix. VE demonstrates superior performance over EP in regulating the interface state of carbon fibers.The presence or absence of a sizing agent has a more significant impact on the compressive properties of carbon fiber composites than the type of sizing agent used. These findings provide valuable insights for optimizing the preparation and enhancing the compressive performance of carbon fiber composite materials.
本研究制备了经过环氧基上浆剂（EP）和乙烯基酯树脂基上浆剂（VE）处理的连续碳纤维样品，以及未经处理的纤维，旨在探索这些上浆剂造成的界面差异对碳纤维复合材料抗压性能的影响模式。在进行了扫描电子显微镜（SEM）、原子力显微镜（AFM）和 X 射线光电子能谱（XPS）等表面分析后，还测试了碳纤维和复合材料的机械性能。结果表明，与未施胶的碳纤维相比，EP 和 VE 使碳纤维表面的 O 原子含量分别提高了 13.0% 和 18.1%，活性 C 原子的比例分别提高了 11.3% 和 20.3%。碳纤维的层间剪切强度（GB/T）分别提高了 9.3% 和 20.0%。鉴于施胶剂与基体树脂之间的相容性，与 EP 相比，VE 可将复合材料的开孔抗压强度提高 6.7%。界面粘结性能的提高对复合材料的开孔抗压性能产生了积极影响，但对 0° 抗压强度和冲击后抗压强度的影响有限。经过 EP 和 VE 施胶后，0° 抗压强度分别提高了 11.8% 和 13.6%，而 VE 只比 EP 稍微提高了 1.6%。层间剪切强度和开孔抗压强度的提高归因于纤维-树脂界面上活性官能团数量的增加，施胶剂促进了化学键的加强，从而改善了纤维与基体之间的载荷传递。在调节碳纤维界面状态方面，VE 的性能优于 EP。有无施胶剂对碳纤维复合材料抗压性能的影响比施胶剂的类型更为显著。这些发现为优化碳纤维复合材料的制备和提高其抗压性能提供了有价值的见解。
{"title":"Research on the effect of sizing agent on the interface and compression performance of carbon fiber composites","authors":"Xinfeng Ouyang, Guojie Ge, Yizhi Geng, Yangyang Zong, Tong Pan, Xiao Wang, Weiwei Zhu, Yuefeng Bai, Yunpeng Liu, Shuo Duan, Kangmin Niu","doi":"10.3389/fmats.2024.1437104","DOIUrl":"https://doi.org/10.3389/fmats.2024.1437104","url":null,"abstract":"The present study involves the preparation of continuous carbon fiber samples treated with epoxy-based sizing agent (EP) and vinyl ester resin-based sizing agent (VE), alongside untreated fibers, aiming to explore the influence pattern of interfacial differences caused by these sizing agents on the compressive properties of carbon fiber composites. Surface analysis, including Scanning Electron Microscope (SEM), Atomic Force Microscope (AFM), and X-ray Photoelectron Spectroscopy (XPS), followed by testing the mechanical properties of carbon fibers and the composite materials. Results indicate that, compared to unsized carbon fibers, EP and VE increase the O atom content on the carbon fiber surface by 13.0% and 18.1%, respectively, and enhance the proportion of active C atoms by 11.3% and 20.3%, respectively. The interlaminar shear strength (GB/T) of carbon fibers is improved by 9.3% and 20.0%, respectively. Given the compatibility between the sizing agent and the matrix resin, VE improves the open-hole compressive strength of composites by 6.7% compared to EP. This improvement in interface bonding performance positively impacts the open-hole compressive properties of the composites, though it has limited effect on the 0° compressive and post-impact compressive strengths. Following EP and VE sizing, the 0° compressive strength increases by 11.8% and 13.6%, respectively, with VE only resulting in a marginal 1.6% improvement over EP. The enhancements in both interlaminar shear strength and open-hole compressive strength are attributed to the increased number of active functional groups at the fiber-resin interface, facilitated by sizing agents, which promote stronger chemical bonding and thus improved load transfer between the fibers and the matrix. VE demonstrates superior performance over EP in regulating the interface state of carbon fibers.The presence or absence of a sizing agent has a more significant impact on the compressive properties of carbon fiber composites than the type of sizing agent used. These findings provide valuable insights for optimizing the preparation and enhancing the compressive performance of carbon fiber composite materials.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"29 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.3389/fmats.2024.1454120
Suraj Verma, Deepak Sahu, Bader O. Almutairi
Biodiesel is an eco-friendly, renewable alternative fuel, and it can be obtained from soybean oil, vegetable oils, animal fat, or microalgae. This study presents a comprehensive investigation into the production and characterization of microalgae biodiesel utilizing multiple analytical techniques, including CHNSO analysis, Fourier-transform infrared spectroscopy (FTIR), gas chromatography–mass spectrometry (GC–MS), and proton nuclear magnetic resonance spectroscopy (1H NMR). The CHNSO analysis revealed the elemental composition of biodiesel blends, highlighting the effects of TiO2 nanoparticle concentrations on carbon, nitrogen, sulfur, and oxygen content. With increasing TiO2 concentration, a steady increase in the carbon content and a gradual decrease in the nitrogen content were observed. According to the CHNSO analysis, the sulfur content of blended biodiesel was found to be lower than that of fossil diesel, with an empirical formula of CH2.26N0.000584S0.000993O0.0517. FTIR and 1H NMR spectroscopy confirmed the synthesis of biodiesel. Fourier-transform infrared resonance confirmed the presence of ester groups at 1732 cm-1, and a prominent peak at 1,455 cm-1 indicated a higher carbon content in the blended biodiesel. GC–MS analysis identified compounds of fatty acid methyl esters (FAMEs) and hydrocarbons. The major components of FAMEs were 9-octadecenoic acid methyl ester (C19H36O2), linoleic acid ethyl ester (C20H36O2), and hexadecanoic acid methyl ester (C17H34O2), with compositions 20.65%, 9.67%, and 6.26%, respectively. The presence of methyl ester in the blended fuel suggests its potential as an alternative fuel source.
{"title":"Production and characterization of biodiesel fuel produced from third-generation feedstock","authors":"Suraj Verma, Deepak Sahu, Bader O. Almutairi","doi":"10.3389/fmats.2024.1454120","DOIUrl":"https://doi.org/10.3389/fmats.2024.1454120","url":null,"abstract":"Biodiesel is an eco-friendly, renewable alternative fuel, and it can be obtained from soybean oil, vegetable oils, animal fat, or microalgae. This study presents a comprehensive investigation into the production and characterization of microalgae biodiesel utilizing multiple analytical techniques, including CHNSO analysis, Fourier-transform infrared spectroscopy (FTIR), gas chromatography–mass spectrometry (GC–MS), and proton nuclear magnetic resonance spectroscopy (<jats:sup>1</jats:sup>H NMR). The CHNSO analysis revealed the elemental composition of biodiesel blends, highlighting the effects of TiO<jats:sub>2</jats:sub> nanoparticle concentrations on carbon, nitrogen, sulfur, and oxygen content. With increasing TiO<jats:sub>2</jats:sub> concentration, a steady increase in the carbon content and a gradual decrease in the nitrogen content were observed. According to the CHNSO analysis, the sulfur content of blended biodiesel was found to be lower than that of fossil diesel, with an empirical formula of CH<jats:sub>2.26</jats:sub>N<jats:sub>0.000584</jats:sub>S<jats:sub>0.000993</jats:sub>O<jats:sub>0.0517</jats:sub>. FTIR and <jats:sup>1</jats:sup>H NMR spectroscopy confirmed the synthesis of biodiesel. Fourier-transform infrared resonance confirmed the presence of ester groups at 1732 cm<jats:sup>-1</jats:sup>, and a prominent peak at 1,455 cm<jats:sup>-1</jats:sup> indicated a higher carbon content in the blended biodiesel. GC–MS analysis identified compounds of fatty acid methyl esters (FAMEs) and hydrocarbons. The major components of FAMEs were 9-octadecenoic acid methyl ester (C<jats:sub>19</jats:sub>H<jats:sub>36</jats:sub>O<jats:sub>2</jats:sub>), linoleic acid ethyl ester (C<jats:sub>20</jats:sub>H<jats:sub>36</jats:sub>O<jats:sub>2</jats:sub>), and hexadecanoic acid methyl ester (C<jats:sub>17</jats:sub>H<jats:sub>34</jats:sub>O<jats:sub>2</jats:sub>), with compositions 20.65%, 9.67%, and 6.26%, respectively. The presence of methyl ester in the blended fuel suggests its potential as an alternative fuel source.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"29 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.3389/fmats.2024.1435059
Jikai Tang, Bin Liu, Lijing Kang, Wei Fan, Debo Zhao, Tao Wang, Liang He, Jing Xie
Fiber-reinforced polymer (FRP) confined concrete filled steel tube (CFST) structures effectively harness the advantages of FRP materials, improving the performance of CFST structures and overcoming durability issues of steel tubes. Three-dimensional detailed finite element (FE) models are usually employed to estimate the impact-resistant performance of FRP confined CFST members under impact loadings. However, detailed FE models are typically complex in modeling and low in calculation efficiency as well as require high performance in computer hardware. Hence, this paper aims to develop an alternative modeling method that can predict the impact behavior of FRP confined CFST members with high efficiency and low requirements in computer resources. The proposed method includes a contact model using mass-spring-damper elements to describe the contact behavior between the impactor and the impacted FRP confined CFST members and a nonlinear fiber-based beam-column element model to simulate the behavior of FRP-confined CFST members under impact loading. The accuracies of fiber-section beam-column elements are carefully examined for FRP confined CFST members based on quasi-static test data reported in the literature. It is found that the fiber-based elements considering confinement effects provided by FRP and steel tubes can accurately predict the force-deformation relationship of the FRP confined CFST members under monotonic loading. By incorporating the strain-rate effects of concrete, steel, and FRP materials, the validated fiber-section elements are employed to simulate eight impact tests on FRP confined CFST members. Good agreements are observed between the results obtained from the proposed models and the experimental data. The computational efficiency of the developed model is three orders of magnitude faster than that of the conventional detailed FE model.
{"title":"Numerically efficient analysis of FRP confined CFST members under lateral low-velocity impact loading","authors":"Jikai Tang, Bin Liu, Lijing Kang, Wei Fan, Debo Zhao, Tao Wang, Liang He, Jing Xie","doi":"10.3389/fmats.2024.1435059","DOIUrl":"https://doi.org/10.3389/fmats.2024.1435059","url":null,"abstract":"Fiber-reinforced polymer (FRP) confined concrete filled steel tube (CFST) structures effectively harness the advantages of FRP materials, improving the performance of CFST structures and overcoming durability issues of steel tubes. Three-dimensional detailed finite element (FE) models are usually employed to estimate the impact-resistant performance of FRP confined CFST members under impact loadings. However, detailed FE models are typically complex in modeling and low in calculation efficiency as well as require high performance in computer hardware. Hence, this paper aims to develop an alternative modeling method that can predict the impact behavior of FRP confined CFST members with high efficiency and low requirements in computer resources. The proposed method includes a contact model using mass-spring-damper elements to describe the contact behavior between the impactor and the impacted FRP confined CFST members and a nonlinear fiber-based beam-column element model to simulate the behavior of FRP-confined CFST members under impact loading. The accuracies of fiber-section beam-column elements are carefully examined for FRP confined CFST members based on quasi-static test data reported in the literature. It is found that the fiber-based elements considering confinement effects provided by FRP and steel tubes can accurately predict the force-deformation relationship of the FRP confined CFST members under monotonic loading. By incorporating the strain-rate effects of concrete, steel, and FRP materials, the validated fiber-section elements are employed to simulate eight impact tests on FRP confined CFST members. Good agreements are observed between the results obtained from the proposed models and the experimental data. The computational efficiency of the developed model is three orders of magnitude faster than that of the conventional detailed FE model.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"39 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.3389/fmats.2024.1425107
Benas Šilinskas, Iveta Varnagirytė-Kabašinskienė, Lina Beniušienė, Marius Aleinikovas
The study investigated the wood mechanical properties of black alder [Alnus glutinosa (L.) Gaertn.], a widely distributed deciduous tree in Europe valued for its suitability in silviculture and wood industry applications. The aim was to compare these properties among selected half-sib families and assess the relationship between wood hardness and other characteristics. Experimental plantations of black alder progenies from Lithuanian populations were established in different forest regions in 1998. The study analyzed various parameters for different genetic families, including tree diameter, height, wood hardness, moisture content, wood density, and mechanical properties. The findings revealed significant variability in wood properties among half-sib families, highlighting a strong genetic influence. Although the static modulus of elasticity showed no notable difference across families, other properties showed significant variations. Furthermore, the analysis identified weak correlations between wood hardness and other mechanical properties like density, modulus of elasticity, and bending strength. This suggests that wood hardness may not reliably indicate wood quality for industrial applications. Consequently, the study recommends considering alternative non-destructive properties, such as the dynamic modulus of elasticity, in future genetic studies of black alder for more accurate assessments of wood quality.
{"title":"Variations in mechanical wood properties of half-sibling genetic families of black alder [Alnus glutinosa (L.) Gaertn.]","authors":"Benas Šilinskas, Iveta Varnagirytė-Kabašinskienė, Lina Beniušienė, Marius Aleinikovas","doi":"10.3389/fmats.2024.1425107","DOIUrl":"https://doi.org/10.3389/fmats.2024.1425107","url":null,"abstract":"The study investigated the wood mechanical properties of black alder [<jats:italic>Alnus glutinosa</jats:italic> (L.) Gaertn.], a widely distributed deciduous tree in Europe valued for its suitability in silviculture and wood industry applications. The aim was to compare these properties among selected half-sib families and assess the relationship between wood hardness and other characteristics. Experimental plantations of black alder progenies from Lithuanian populations were established in different forest regions in 1998. The study analyzed various parameters for different genetic families, including tree diameter, height, wood hardness, moisture content, wood density, and mechanical properties. The findings revealed significant variability in wood properties among half-sib families, highlighting a strong genetic influence. Although the static modulus of elasticity showed no notable difference across families, other properties showed significant variations. Furthermore, the analysis identified weak correlations between wood hardness and other mechanical properties like density, modulus of elasticity, and bending strength. This suggests that wood hardness may not reliably indicate wood quality for industrial applications. Consequently, the study recommends considering alternative non-destructive properties, such as the dynamic modulus of elasticity, in future genetic studies of black alder for more accurate assessments of wood quality.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"41 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-19DOI: 10.3389/fmats.2024.1448765
Arnau Romaguera, Marisa Medarde
Frustrated magnets with ordered magnetic spiral phases that spontaneously break inversion symmetry have received significant attention from both fundamental and applied sciences communities due to the experimental demonstration that some of these materials can couple to the lattice and induce electric polarization. In these materials, the common origin of the electric and magnetic orders guarantees substantial coupling between them, which is highly desirable for applications. However, their low-magnetic ordering temperatures (typically < 100 K) greatly restrict their fields of application. Recently, investigations on Cu/Fe-based layered perovskites uncovered an unexpected knob to control the stability range of a magnetic spiral-chemical disorder-, which has been successfully employed to stabilize magnetic spiral phases at temperatures as high as 400 K. These unexpected observations, which are hard to conciliate with traditional magnetic frustration mechanisms, were recently rationalized in terms of an original, local frustration model that explicitly accounts for the presence of disorder. In this mini-review, we summarize the main experimental observations on Cu/Fe layered perovskites, which show excellent agreement with the predictions of this novel magnetic frustration mechanism. We also present different strategies aimed at exploiting these experimental and theoretical developments for the design of materials featuring magnetoelectric spirals stable up to temperatures high enough for daily-life applications.
自发打破反转对称性的有序磁螺旋相挫折磁体受到了基础科学和应用科学界的极大关注，因为实验证明其中一些材料可以与晶格耦合并诱导电极化。在这些材料中，电阶和磁阶的共同起源保证了它们之间的实质性耦合，这在应用中是非常理想的。然而，它们的低磁有序温度（通常为 100 K）极大地限制了它们的应用领域。最近，对铜/铁基层状包晶石的研究发现了一种意想不到的控制磁性螺旋稳定范围的方法--化学无序，这种方法已被成功用于在高达 400 K 的温度下稳定磁性螺旋相。这些意想不到的观察结果很难与传统的磁沮度机制相吻合，而最近的研究则从一个原创的局部沮度模型的角度对其进行了合理化，该模型明确考虑了无序的存在。在这篇微型综述中，我们总结了对铜/铁层包晶石的主要实验观察结果，这些观察结果与这种新型磁沮度机制的预测非常吻合。我们还介绍了不同的策略，旨在利用这些实验和理论进展，设计出具有磁电螺旋特性的材料，使其在足够高的温度下保持稳定，以满足日常生活应用的需要。
{"title":"Room temperature magnetoelectric magnetic spirals by design","authors":"Arnau Romaguera, Marisa Medarde","doi":"10.3389/fmats.2024.1448765","DOIUrl":"https://doi.org/10.3389/fmats.2024.1448765","url":null,"abstract":"Frustrated magnets with ordered magnetic spiral phases that spontaneously break inversion symmetry have received significant attention from both fundamental and applied sciences communities due to the experimental demonstration that some of these materials can couple to the lattice and induce electric polarization. In these materials, the common origin of the electric and magnetic orders guarantees substantial coupling between them, which is highly desirable for applications. However, their low-magnetic ordering temperatures (typically <jats:inline-formula><mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mo><</mml:mo></mml:math></jats:inline-formula> 100 K) greatly restrict their fields of application. Recently, investigations on Cu/Fe-based layered perovskites uncovered an unexpected knob to control the stability range of a magnetic spiral-chemical disorder-, which has been successfully employed to stabilize magnetic spiral phases at temperatures as high as 400 K. These unexpected observations, which are hard to conciliate with traditional magnetic frustration mechanisms, were recently rationalized in terms of an original, local frustration model that explicitly accounts for the presence of disorder. In this mini-review, we summarize the main experimental observations on Cu/Fe layered perovskites, which show excellent agreement with the predictions of this novel magnetic frustration mechanism. We also present different strategies aimed at exploiting these experimental and theoretical developments for the design of materials featuring magnetoelectric spirals stable up to temperatures high enough for daily-life applications.","PeriodicalId":12524,"journal":{"name":"Frontiers in Materials","volume":"26 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142221319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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