Pub Date : 2024-12-01DOI: 10.1016/j.rinma.2024.100635
Debora Nameme , George S. Manyali , Michael Nakitare Waswa , Job W. Wafula
<div><div>The structural, elastic, electronic, and optical properties of BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> have been theoretically investigated, but their thermoelectric properties have not been reported. The current work aimed at conducting an exhaustive study on the bulk, electronic, and optical properties as well as the thermoelectric property of BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> zintl phase compounds. Density functional theory implemented in Quantum ESPRESSO code combined with other processing codes such as Thermo<span><math><msub><mrow></mrow><mrow><mo>−</mo></mrow></msub></math></span>pw and BoltzTrap were employed in this study. The lattice constants computed were found to agree well with the other theoretical and experimental results, demonstrating validity of the study. Both compounds are brittle, elastically anisotropic and mechanically as well thermodynamically stable. The materials in this investigation were discovered to be semiconductors with indirect band gaps of 0.73 eV and 1.14 eV for BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> respectively. Therefore, both materials are appropriate for use in the electronics sector, notably in temperature control applications. The PDOS analysis suggests that P and As in BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, respectively, dominate the conduction band, whereas Ge dominates the valence band in both cases. The results also show that BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> out-performs BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> in terms of optical absorption coefficient. Both BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mro
{"title":"First-principles calculations to investigate the bulk, electronic, optical and thermoelectric properties of BaGe2As2 and BaGe2P2 alloys","authors":"Debora Nameme , George S. Manyali , Michael Nakitare Waswa , Job W. Wafula","doi":"10.1016/j.rinma.2024.100635","DOIUrl":"10.1016/j.rinma.2024.100635","url":null,"abstract":"<div><div>The structural, elastic, electronic, and optical properties of BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> have been theoretically investigated, but their thermoelectric properties have not been reported. The current work aimed at conducting an exhaustive study on the bulk, electronic, and optical properties as well as the thermoelectric property of BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> zintl phase compounds. Density functional theory implemented in Quantum ESPRESSO code combined with other processing codes such as Thermo<span><math><msub><mrow></mrow><mrow><mo>−</mo></mrow></msub></math></span>pw and BoltzTrap were employed in this study. The lattice constants computed were found to agree well with the other theoretical and experimental results, demonstrating validity of the study. Both compounds are brittle, elastically anisotropic and mechanically as well thermodynamically stable. The materials in this investigation were discovered to be semiconductors with indirect band gaps of 0.73 eV and 1.14 eV for BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> respectively. Therefore, both materials are appropriate for use in the electronics sector, notably in temperature control applications. The PDOS analysis suggests that P and As in BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, respectively, dominate the conduction band, whereas Ge dominates the valence band in both cases. The results also show that BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>P<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> out-performs BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> in terms of optical absorption coefficient. Both BaGe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>As<span><math><msub><mro","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100635"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.rinma.2024.100645
Olivier Richard , Ali Soltani , Rahma Adhiri , Ali Ahaitouf , Hassan Maher , Vincent Aimez , Abdelatif Jaouad
Controlling properties of GaN/dielectric interfaces is crucial for determining the characteristics of MOS-HEMT devices and their stability. Interface properties are largely affected by the techniques and specific conditions of dielectric deposition. In this work, a Taguchi design of experiment was applied to study the effect of plasma parameters during deposition of SiO by PECVD for passivation of n-GaN. SiO/GaN MIS capacitors were fabricated and characterized by capacitance measurement at a high probing frequency of 1 MHz. The interface states density, hysteresis and flatband voltage were analyzed and modeled in relation with the flow of SiH, plasma power, chamber pressure and temperature. Excellent fits could be obtained on a single model including linear terms for all studied parameters and quadratic terms for the flow of SiH and temperature. We show that it is possible to obtain some control of the flatband voltage while maintaining a good interface quality. Positive flatband voltages are potentially of interest to enable normally-off operation for MOS-HEMTs and this could be obtained mainly by using a high SiH/NO ratio. To the contrary, negative flatband voltage values often ensure the most stable operation of MOS-HEMTs and this was achieved with a low SiH/NO and high plasma power. MIS capacitors with near-zero flatband voltage were also obtained with low SiH/NO ratio and low plasma power. Hysteresis and interface states density in relation with deposition plasma conditions are also analyzed in order to offer the best trade-offs depending on the end applications of MOS-GaN devices. By demonstrating the great impact of plasma conditions during dielectric deposition on electronic properties of MIS devices, we show that the process of gate insulation can be optimized to simultaneously control the density of defects and fixed charge at the interface.
{"title":"Impact of PECVD deposition on dielectric charge and passivation for n-GaN/SiOx interfaces","authors":"Olivier Richard , Ali Soltani , Rahma Adhiri , Ali Ahaitouf , Hassan Maher , Vincent Aimez , Abdelatif Jaouad","doi":"10.1016/j.rinma.2024.100645","DOIUrl":"10.1016/j.rinma.2024.100645","url":null,"abstract":"<div><div>Controlling properties of GaN/dielectric interfaces is crucial for determining the characteristics of MOS-HEMT devices and their stability. Interface properties are largely affected by the techniques and specific conditions of dielectric deposition. In this work, a Taguchi design of experiment was applied to study the effect of plasma parameters during deposition of SiO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span> by PECVD for passivation of n-GaN. SiO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>/GaN MIS capacitors were fabricated and characterized by capacitance measurement at a high probing frequency of 1 MHz. The interface states density, hysteresis and flatband voltage were analyzed and modeled in relation with the flow of SiH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>, plasma power, chamber pressure and temperature. Excellent fits could be obtained on a single model including linear terms for all studied parameters and quadratic terms for the flow of SiH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> and temperature. We show that it is possible to obtain some control of the flatband voltage while maintaining a good interface quality. Positive flatband voltages are potentially of interest to enable normally-off operation for MOS-HEMTs and this could be obtained mainly by using a high SiH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O ratio. To the contrary, negative flatband voltage values often ensure the most stable operation of MOS-HEMTs and this was achieved with a low SiH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O and high plasma power. MIS capacitors with near-zero flatband voltage were also obtained with low SiH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>/N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O ratio and low plasma power. Hysteresis and interface states density in relation with deposition plasma conditions are also analyzed in order to offer the best trade-offs depending on the end applications of MOS-GaN devices. By demonstrating the great impact of plasma conditions during dielectric deposition on electronic properties of MIS devices, we show that the process of gate insulation can be optimized to simultaneously control the density of defects and fixed charge at the interface.</div></div>","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100645"},"PeriodicalIF":0.0,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-17DOI: 10.1016/j.rinma.2024.100637
Carolina Parada-Quinayá , Karen Garces-Porras , Elena Flores
In this study, chuño starch films were elaborated using acid hydrolysis, which was incorporated with different concentrations of eucalyptus essential oil (EEO). The reinforcement of the films was made by adding microfibers of Stipa obtusa (MFSO), a native Peruvian natural fiber rich in cellulose. The films were produced through the tape casting technique. The barrier properties presented swelling and solubility values of 1.478 and 0.439 g/g, respectively, at an optimal ratio of 7 % starch on a dry basis. An improvement in the modulus of elasticity of the films obtained was observed by incorporating concentrations of MFSO, starting at 0.55 %, in the polymeric matrix during the synthesis process. The FTIR spectra of the control film and the films reinforced with MFSO exhibited the same bands, due to the chemical similarities between starch and cellulose; micrographs of the reinforced films showed less homogeneous and compact structures compared to the control film, this effect became more pronounced as higher concentrations of MFSO and EEO were incorporated.
{"title":"Development of biobased films incorporated with an antimicrobial agent and reinforced with Stipa obtusa cellulose microfibers, via tape casting","authors":"Carolina Parada-Quinayá , Karen Garces-Porras , Elena Flores","doi":"10.1016/j.rinma.2024.100637","DOIUrl":"10.1016/j.rinma.2024.100637","url":null,"abstract":"<div><div>In this study, chuño starch films were elaborated using acid hydrolysis, which was incorporated with different concentrations of eucalyptus essential oil (EEO). The reinforcement of the films was made by adding microfibers of <em>Stipa obtusa</em> (MFSO), a native Peruvian natural fiber rich in cellulose. The films were produced through the tape casting technique. The barrier properties presented swelling and solubility values of 1.478 and 0.439 g/g, respectively, at an optimal ratio of 7 % starch on a dry basis. An improvement in the modulus of elasticity of the films obtained was observed by incorporating concentrations of MFSO, starting at 0.55 %, in the polymeric matrix during the synthesis process. The FTIR spectra of the control film and the films reinforced with MFSO exhibited the same bands, due to the chemical similarities between starch and cellulose; micrographs of the reinforced films showed less homogeneous and compact structures compared to the control film, this effect became more pronounced as higher concentrations of MFSO and EEO were incorporated.</div></div>","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100637"},"PeriodicalIF":0.0,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The increasing demand for sustainable and lightweight materials in defense and security applications has driven the development of natural fiber-reinforced polymer composites (NFRPCs) for ballistic protection. This paper explores the potential of NFRPCs in ballistic armor, focusing on material design, performance evaluation, and the challenges encountered in their application. Natural fibers, such as jute, flax, and hemp, offer significant environmental and weight advantages over traditional synthetic fibers while providing acceptable impact resistance when embedded in polymer matrices. The design considerations for NFRPCs-based ballistic protection systems are examined, highlighting the interplay between fiber type, matrix selection, and composite architecture. The ballistic impact behavior of these composites is assessed through various testing methodologies, emphasizing their energy absorption, deformation mechanisms, and multi-hit performance under different threat levels. Furthermore, this study presents an analysis of the key challenges—ranging from fiber variability and moisture absorption to the optimization of mechanical properties—that hinder widespread adoption in high-performance armor applications. The results underline the potential of NFRPCs as a cost-effective, eco-friendly alternative for protective armor while emphasizing the need for further research to overcome performance limitations. Ultimately, this work aims to provide a foundation for advancing sustainable ballistic protection materials through innovative design and testing strategies.
{"title":"Natural fiber reinforced polymer composites for ballistic protection: Design, performance, and challenges","authors":"Md. Syduzzaman , Salman Enayet Chowdhury , Nadvi Mamun Pritha , Abir Hassan , Sajid Hossain","doi":"10.1016/j.rinma.2024.100639","DOIUrl":"10.1016/j.rinma.2024.100639","url":null,"abstract":"<div><div>The increasing demand for sustainable and lightweight materials in defense and security applications has driven the development of natural fiber-reinforced polymer composites (NFRPCs) for ballistic protection. This paper explores the potential of NFRPCs in ballistic armor, focusing on material design, performance evaluation, and the challenges encountered in their application. Natural fibers, such as jute, flax, and hemp, offer significant environmental and weight advantages over traditional synthetic fibers while providing acceptable impact resistance when embedded in polymer matrices. The design considerations for NFRPCs-based ballistic protection systems are examined, highlighting the interplay between fiber type, matrix selection, and composite architecture. The ballistic impact behavior of these composites is assessed through various testing methodologies, emphasizing their energy absorption, deformation mechanisms, and multi-hit performance under different threat levels. Furthermore, this study presents an analysis of the key challenges—ranging from fiber variability and moisture absorption to the optimization of mechanical properties—that hinder widespread adoption in high-performance armor applications. The results underline the potential of NFRPCs as a cost-effective, eco-friendly alternative for protective armor while emphasizing the need for further research to overcome performance limitations. Ultimately, this work aims to provide a foundation for advancing sustainable ballistic protection materials through innovative design and testing strategies.</div></div>","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100639"},"PeriodicalIF":0.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.rinma.2024.100640
Ayman Ali Abd-Eltwab , Essam Khalaf Saied , Ahmed Mohamed Atia , Nouby M. Ghazaly , A.A. Gomaa , Karim Mohamed Atia
Externally toothed parts such as gears, splined and coupling sleeves can be manufactured by machining, casting, and forming. The machining process is costly because of using a special tool, consuming power, and wasting material during the machining process. The casting processes usually need other finishing processes. In this study, a new forming tool based on the ballizing technique is suggested to perform the forming of the toothed parts with external splines in one stroke. The set is made up of six steel balls each having a 20 mm diameter. The process was performed on the lathe machine with data acquisition recording to record the process consumed load. Die with splines on the inner surface opposite the required splines was mounted in the lath check. The required tooth shape was obtained by forcing the forming tool into the hole by pushing the specimen into the die cavity. the mathematical model was formulated to calculate required force deformation. The model depends on the process dynamics and contact area between the tool and the specimen. The effect of process parameters on the load and the product properties was conducted. The study parameters were forming depths of 2, 3, 4, and 5 mm, the rotational speed of 50, 76, 120, and 150 rpm, axial feed 0.1, 0.15, 0.3, and 0.6 mm/rpm specimen inner diameter of 66, 64, 62 and 60 mm. A comparison was made between results of mathematical model and results of experimental. Rotational speed, axial feed, and cross-in feed were found to be the three factors that have the greatest impact on forming load and overall product quality. Also, it was found that deformation load increased with the increasing rotational speed, cross-in feed, and axial feed.
{"title":"Investigation of externally toothed parts forming using ballizing technique","authors":"Ayman Ali Abd-Eltwab , Essam Khalaf Saied , Ahmed Mohamed Atia , Nouby M. Ghazaly , A.A. Gomaa , Karim Mohamed Atia","doi":"10.1016/j.rinma.2024.100640","DOIUrl":"10.1016/j.rinma.2024.100640","url":null,"abstract":"<div><div>Externally toothed parts such as gears, splined and coupling sleeves can be manufactured by machining, casting, and forming. The machining process is costly because of using a special tool, consuming power, and wasting material during the machining process. The casting processes usually need other finishing processes. In this study, a new forming tool based on the ballizing technique is suggested to perform the forming of the toothed parts with external splines in one stroke. The set is made up of six steel balls each having a 20 mm diameter. The process was performed on the lathe machine with data acquisition recording to record the process consumed load. Die with splines on the inner surface opposite the required splines was mounted in the lath check. The required tooth shape was obtained by forcing the forming tool into the hole by pushing the specimen into the die cavity. the mathematical model was formulated to calculate required force deformation. The model depends on the process dynamics and contact area between the tool and the specimen. The effect of process parameters on the load and the product properties was conducted. The study parameters were forming depths of 2, 3, 4, and 5 mm, the rotational speed of 50, 76, 120, and 150 rpm, axial feed 0.1, 0.15, 0.3, and 0.6 mm/rpm specimen inner diameter of 66, 64, 62 and 60 mm. A comparison was made between results of mathematical model and results of experimental. Rotational speed, axial feed, and cross-in feed were found to be the three factors that have the greatest impact on forming load and overall product quality. Also, it was found that deformation load increased with the increasing rotational speed, cross-in feed, and axial feed.</div></div>","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100640"},"PeriodicalIF":0.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diverse strategies were designed and evaluated for enhancement of concrete resistance to microbial-induced corrosion through refinement of concrete chemistry, pore structure, transport attributes, and amenability to microbial growth. Laboratory and insitu field experiments were implemented in order to screen different strategies. The study considered strategies involving; the use of hydrophobic additives for rendering capillary pores water-repelling; blend of pozzolans to refine the chemistry and pore system characteristics of concrete; use of polymer emulsions for refinement of concrete porosity, affinity for moisture and amenability to microbial growth; use of anti-microbial constituent for reducing the amenability of concrete to microbial growth; and incorporation of polyvinyl alcohol fibers for enhancing mechanical performance of concrete mixtures, were investigated.
Test results indicate that two admixture formulations comprising of hydrophobic additive, and blend of pozzolan offer the best promise to achieve substantially enhanced resistance to microbial-induced corrosion and acid resistance in the aggressive sewer environment.
{"title":"Development and evaluation of mixture formulations to enhance concrete resistance to microbial-induced corrosion","authors":"Roz-Ud-Din Nassar , Parviz Soroushian , Tewodros Ghebrab , Muhammad Sufyan-Ud-Din","doi":"10.1016/j.rinma.2024.100644","DOIUrl":"10.1016/j.rinma.2024.100644","url":null,"abstract":"<div><div>Diverse strategies were designed and evaluated for enhancement of concrete resistance to microbial-induced corrosion through refinement of concrete chemistry, pore structure, transport attributes, and amenability to microbial growth. Laboratory and insitu field experiments were implemented in order to screen different strategies. The study considered strategies involving; the use of hydrophobic additives for rendering capillary pores water-repelling; blend of pozzolans to refine the chemistry and pore system characteristics of concrete; use of polymer emulsions for refinement of concrete porosity, affinity for moisture and amenability to microbial growth; use of anti-microbial constituent for reducing the amenability of concrete to microbial growth; and incorporation of polyvinyl alcohol fibers for enhancing mechanical performance of concrete mixtures, were investigated.</div><div>Test results indicate that two admixture formulations comprising of hydrophobic additive, and blend of pozzolan offer the best promise to achieve substantially enhanced resistance to microbial-induced corrosion and acid resistance in the aggressive sewer environment.</div></div>","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100644"},"PeriodicalIF":0.0,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.rinma.2024.100643
Omotayo Sanni , Jianwei Ren , Tien-Chien Jen
Transparent materials are essential to our daily lives. It's very well recognized that their use in windshields, cars, windows, mirrors, and eyewear makes our everyday tasks more comfortable. In addition to these, several other instances may be found in the culinary, medical, and solar industries, among other spheres of human endeavor. Unfortunately, under typical operating conditions, this material experiences fogging owing to the unavoidable condensation of water vapor on solid surface. Researchers are becoming more and more interested in antifogging nano-coatings with remarkable water repellence as a result of the growth of the coating industries and material engineering. Numerous compounds have been created by researchers thus far to prepare antifogging films. There have been reports on the mechanisms and guidelines for the creation of these agents by various technologies as a result of the core requirements of various fields. We present the latest developments in antifogging nanocoatings and antifogging performance test procedures in this review. Additionally, there has been a focus on offering understanding of the latest advancement in superhydrophobic coating through the application of nanotechnology. According to the literature, the reported antifogging films do not show sufficient results and continue to pose a practical issue that requires real-world application. As a result, antifogging techniques need to be improved further.
{"title":"An overview of antifogging nanocoatings: Recent developments and application","authors":"Omotayo Sanni , Jianwei Ren , Tien-Chien Jen","doi":"10.1016/j.rinma.2024.100643","DOIUrl":"10.1016/j.rinma.2024.100643","url":null,"abstract":"<div><div>Transparent materials are essential to our daily lives. It's very well recognized that their use in windshields, cars, windows, mirrors, and eyewear makes our everyday tasks more comfortable. In addition to these, several other instances may be found in the culinary, medical, and solar industries, among other spheres of human endeavor. Unfortunately, under typical operating conditions, this material experiences fogging owing to the unavoidable condensation of water vapor on solid surface. Researchers are becoming more and more interested in antifogging nano-coatings with remarkable water repellence as a result of the growth of the coating industries and material engineering. Numerous compounds have been created by researchers thus far to prepare antifogging films. There have been reports on the mechanisms and guidelines for the creation of these agents by various technologies as a result of the core requirements of various fields. We present the latest developments in antifogging nanocoatings and antifogging performance test procedures in this review. Additionally, there has been a focus on offering understanding of the latest advancement in superhydrophobic coating through the application of nanotechnology. According to the literature, the reported antifogging films do not show sufficient results and continue to pose a practical issue that requires real-world application. As a result, antifogging techniques need to be improved further.</div></div>","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100643"},"PeriodicalIF":0.0,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1016/j.rinma.2024.100638
C. Accettura , L. Baudin , A. Bertarelli , C. Brabetz , F. Carra , A.S. Martynenko , A. Morena , A. Moros , L. Peroni , M. Scapin , P. Neumayer , M. Tomut , L. Wegert
In the present work the results of an extensive experimental campaign in which laser-shocks were used to assess the mechanical strength of graphitic materials are presented. The aim of the project was to study innovative advanced materials used in high energy particle accelerators for beam intercepting devices (BIDs), such as collimators, absorber blocks and dumps. In this framework, thin targets of graphitic materials relevant for the use as particle accelerator BIDs were submitted to high-power laser driven shocks at the PHELIX laser facility in GSI. Online diagnostics such as shadowgraphy and laser velocimetry were deployed together with post-mortem analysis on collected debris and shocked specimens.
The experimental results were compared with results obtained in literature. In this work the data acquired for the performed shots are presented with a focus on graphite samples. The testing campaign provided large amount of information to cross-check and validate the models implemented for laser-matter interaction, shockwave propagation and spall strength concerning a wide range of materials, all relevant for the use in beam intercepting devices of particle accelerators.
{"title":"Experimental investigation under laser-driven shocks of the dynamic behavior of materials for beam-intercepting devices in particle accelerators","authors":"C. Accettura , L. Baudin , A. Bertarelli , C. Brabetz , F. Carra , A.S. Martynenko , A. Morena , A. Moros , L. Peroni , M. Scapin , P. Neumayer , M. Tomut , L. Wegert","doi":"10.1016/j.rinma.2024.100638","DOIUrl":"10.1016/j.rinma.2024.100638","url":null,"abstract":"<div><div>In the present work the results of an extensive experimental campaign in which laser-shocks were used to assess the mechanical strength of graphitic materials are presented. The aim of the project was to study innovative advanced materials used in high energy particle accelerators for beam intercepting devices (BIDs), such as collimators, absorber blocks and dumps. In this framework, thin targets of graphitic materials relevant for the use as particle accelerator BIDs were submitted to high-power laser driven shocks at the PHELIX laser facility in GSI. Online diagnostics such as shadowgraphy and laser velocimetry were deployed together with post-mortem analysis on collected debris and shocked specimens.</div><div>The experimental results were compared with results obtained in literature. In this work the data acquired for the performed shots are presented with a focus on graphite samples. The testing campaign provided large amount of information to cross-check and validate the models implemented for laser-matter interaction, shockwave propagation and spall strength concerning a wide range of materials, all relevant for the use in beam intercepting devices of particle accelerators.</div></div>","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100638"},"PeriodicalIF":0.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1016/j.rinma.2024.100642
Luca Lavagna, Giovanna Colucci, Matteo Pavese
In this paper the possible use of end-of-life tire rubber as a substitute for aggregate in cement mortars was explored. The aim of this paper was to investigate the effect of rubber surface modification by acidic treatment on the final properties of mortars. In fact, through treatment with sulfuric acid at moderate concentrations, a significant improvement in rubber wettability and interaction with cement has been observed. The compressive strength of mortars containing 15%w treated rubber as a replacement of natural aggregate is comparable to those of standard mortars. This suggests that surface modification of rubber plays a very important role in the possible integration of end-of-life tire rubber in mortar and concrete. The results presented in this paper confirm that recycling in mortar and concrete is a promising way for improving rubber waste management and sustainable innovation in the construction industry.
{"title":"Effect of oxidation of end-of-life tire rubber as aggregate substitute in cement mortars","authors":"Luca Lavagna, Giovanna Colucci, Matteo Pavese","doi":"10.1016/j.rinma.2024.100642","DOIUrl":"10.1016/j.rinma.2024.100642","url":null,"abstract":"<div><div>In this paper the possible use of end-of-life tire rubber as a substitute for aggregate in cement mortars was explored. The aim of this paper was to investigate the effect of rubber surface modification by acidic treatment on the final properties of mortars. In fact, through treatment with sulfuric acid at moderate concentrations, a significant improvement in rubber wettability and interaction with cement has been observed. The compressive strength of mortars containing 15%w treated rubber as a replacement of natural aggregate is comparable to those of standard mortars. This suggests that surface modification of rubber plays a very important role in the possible integration of end-of-life tire rubber in mortar and concrete. The results presented in this paper confirm that recycling in mortar and concrete is a promising way for improving rubber waste management and sustainable innovation in the construction industry.</div></div>","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100642"},"PeriodicalIF":0.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-13DOI: 10.1016/j.rinma.2024.100641
Mohammed E. Seno , Husein Ali Zeini , Hamza Imran , Mohammed Noori , Sadiq N. Henedy , Nouby M. Ghazaly
The significance of accurately predicting the creep index coefficient for assessing the long-term settlement of soil is critical in geotechnical engineering. However, current empirical methods for determining the creep coefficient often lack precision, highlighting the need for a more accurate predictive model. This study employs the Multivariate Adaptive Regression Splines (MARS) model to predict the creep index in clay, a critical parameter in geotechnical engineering. The dataset was divided into training and testing subsets. Grid search hyperparameter tuning was applied to optimize the MARS model, as well as a black-box model (Support Vector Machine, SVM) and a white-box model (Lasso), with five-fold cross-validation used to assess their performance. MARS demonstrated superior predictive accuracy, as evidenced by the mean and median R2 and RMSE values obtained from the five-fold cross-validation results. The optimized MARS model was then applied to the test set, achieving excellent predictive accuracy. Finally, the model's performance was compared to previously developed machine learning models and empirical equations across the entire dataset. The MARS model outperformed all others based on RMSE, R2, MAE, and KGE metrics, highlighting its robustness and reliability in predicting the clay creep index.
在岩土工程中，准确预测蠕变指数系数对于评估土壤的长期沉降具有重要意义。然而，目前确定蠕变系数的经验方法往往缺乏精确性，因此需要更精确的预测模型。本研究采用多元自适应回归样条（MARS）模型来预测岩土工程中的关键参数--粘土的蠕变指数。数据集分为训练子集和测试子集。网格搜索超参数调整用于优化 MARS 模型、黑盒模型（支持向量机，SVM）和白盒模型（Lasso），并使用五次交叉验证来评估它们的性能。从五倍交叉验证结果得出的 R2 和 RMSE 的平均值和中位数可以看出，MARS 的预测准确性更胜一筹。然后，将优化后的 MARS 模型应用于测试集，取得了极佳的预测准确性。最后，将该模型的性能与之前开发的机器学习模型和整个数据集的经验方程进行了比较。根据 RMSE、R2、MAE 和 KGE 指标，MARS 模型的表现优于其他所有模型，这突出表明了它在预测粘土蠕变指数方面的稳健性和可靠性。
{"title":"Advancing in creep index of soil prediction: A groundbreaking machine learning approach with Multivariate Adaptive Regression Splines","authors":"Mohammed E. Seno , Husein Ali Zeini , Hamza Imran , Mohammed Noori , Sadiq N. Henedy , Nouby M. Ghazaly","doi":"10.1016/j.rinma.2024.100641","DOIUrl":"10.1016/j.rinma.2024.100641","url":null,"abstract":"<div><div>The significance of accurately predicting the creep index coefficient for assessing the long-term settlement of soil is critical in geotechnical engineering. However, current empirical methods for determining the creep coefficient often lack precision, highlighting the need for a more accurate predictive model. This study employs the Multivariate Adaptive Regression Splines (MARS) model to predict the creep index in clay, a critical parameter in geotechnical engineering. The dataset was divided into training and testing subsets. Grid search hyperparameter tuning was applied to optimize the MARS model, as well as a black-box model (Support Vector Machine, SVM) and a white-box model (Lasso), with five-fold cross-validation used to assess their performance. MARS demonstrated superior predictive accuracy, as evidenced by the mean and median R<sup>2</sup> and RMSE values obtained from the five-fold cross-validation results. The optimized MARS model was then applied to the test set, achieving excellent predictive accuracy. Finally, the model's performance was compared to previously developed machine learning models and empirical equations across the entire dataset. The MARS model outperformed all others based on RMSE, R<sup>2</sup>, MAE, and KGE metrics, highlighting its robustness and reliability in predicting the clay creep index.</div></div>","PeriodicalId":101087,"journal":{"name":"Results in Materials","volume":"24 ","pages":"Article 100641"},"PeriodicalIF":0.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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