Šárka Nenadálová, Kazuo Umemura, Ian McAndrew, S. Harikrishnan
{"title":"Advanced Materials and Technologies in Engineering Applications","authors":"Šárka Nenadálová, Kazuo Umemura, Ian McAndrew, S. Harikrishnan","doi":"10.4028/b-m7wsba","DOIUrl":"https://doi.org/10.4028/b-m7wsba","url":null,"abstract":"","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140382592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Assawasaengrat, Thanasuta Limsakul, Penpichcha Bunprasert, Wasan Chokelarb, Pongsert Sriprom
This research aimed to improve the thermo-physical properties of plam oil with NaA zeolite. Palm oil was selected for heating oil due to its high flash point and environmental friendliness compared to synthetic or mineral oil. The effect of NaA zeolite concentration suspended in palm oil was investigated in terms of the specific heat capacity (Cp), viscosity (μ), viscosity index (VI), thermal analysis (TGA) and density (ρ) of palm oil. The NaA zeolite was synthesized by crystallization technique, and X-ray diffraction analysis was performed to determine NaA zeolite crystallinity. The size of NaA zeolite was measured using a particle size analyzer. The average size of the synthesized NaA zeolite was 4767 nm. After grinding process for 180 min, the average size of zeolite decreased to 632 nm. An average 632 nm NaA zeolite particle size was added to palm oil at 0.25, 0.5, 0.75 and 1 wt%. The results showed that when the NaA zeolite concentration increased, the nanofluid’s viscosity at 40 °C and 100 °C was increased. The addition of 1 wt% NaA zeolite resulted in the nanofluid having a maximum viscosity of 41.31 and 8.47 cSt at 40 °C and 100 °C, respectively. The highest viscosity index was 195 cSt when added with 0.5 wt% NaA zeolite. The density of palm oil slightly increased with increasing NaA zeolite concentrations. The specific heat capacity of palm oil increased when NaA zeolite was added. The results showed that NaA zeolite allowed palm oil to store heat energy better than palm oil, enabling it to release and absorb more heat during heat transfer. Thermogravimetric analysis, palm oil initiated to degrade at 263 °C, while the addition NaA zeolite in palm oil indicated that palm oil initiated to degrade at 350 °C. The shift in the degradation curve demonstrated that the nanofluid could withstand high temperatures. Adding NaA zeolite to palm oil showed that palm oil could endure more heat and has a long service life.
{"title":"Improving the Thermo-Physical Properties of Plam Oil with Zeolite Nanoparticles","authors":"P. Assawasaengrat, Thanasuta Limsakul, Penpichcha Bunprasert, Wasan Chokelarb, Pongsert Sriprom","doi":"10.4028/p-6dmet0","DOIUrl":"https://doi.org/10.4028/p-6dmet0","url":null,"abstract":"This research aimed to improve the thermo-physical properties of plam oil with NaA zeolite. Palm oil was selected for heating oil due to its high flash point and environmental friendliness compared to synthetic or mineral oil. The effect of NaA zeolite concentration suspended in palm oil was investigated in terms of the specific heat capacity (Cp), viscosity (μ), viscosity index (VI), thermal analysis (TGA) and density (ρ) of palm oil. The NaA zeolite was synthesized by crystallization technique, and X-ray diffraction analysis was performed to determine NaA zeolite crystallinity. The size of NaA zeolite was measured using a particle size analyzer. The average size of the synthesized NaA zeolite was 4767 nm. After grinding process for 180 min, the average size of zeolite decreased to 632 nm. An average 632 nm NaA zeolite particle size was added to palm oil at 0.25, 0.5, 0.75 and 1 wt%. The results showed that when the NaA zeolite concentration increased, the nanofluid’s viscosity at 40 °C and 100 °C was increased. The addition of 1 wt% NaA zeolite resulted in the nanofluid having a maximum viscosity of 41.31 and 8.47 cSt at 40 °C and 100 °C, respectively. The highest viscosity index was 195 cSt when added with 0.5 wt% NaA zeolite. The density of palm oil slightly increased with increasing NaA zeolite concentrations. The specific heat capacity of palm oil increased when NaA zeolite was added. The results showed that NaA zeolite allowed palm oil to store heat energy better than palm oil, enabling it to release and absorb more heat during heat transfer. Thermogravimetric analysis, palm oil initiated to degrade at 263 °C, while the addition NaA zeolite in palm oil indicated that palm oil initiated to degrade at 350 °C. The shift in the degradation curve demonstrated that the nanofluid could withstand high temperatures. Adding NaA zeolite to palm oil showed that palm oil could endure more heat and has a long service life.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Kuan, Mohd Khairul Afiq, Scollastica Jane Lumpong
Environmental issues over the eventual fate of post-consumer polymers can be dealt with in two separate ways which is recycling or using biodegradable polymers. However, it is evident that recycling polymers from post-consumer polymers can decrease the mechanical properties over time. Hence, to strengthen the recycled polymers, integrating fibers, such as luffa, into the High-Density Polyethylene (HDPE) matrix, was carried out to produce a fiber reinforced recycled polymer (FRrP) composite. The tensile testing of the FRrP composite shows that the 10% fiber volume fraction (FVF) composite exhibits a higher tensile strength of 3.9% than the neat recycled HDPE (RHDPE). In terms of Young’s Modulus, the 5% FVF of FRrP is shown to have a higher value than the neat RHDPE by 54%. The low density of luffa fibers also contributes to the composites lightweight character. The impact testing shows that the FRrP enhances the impact properties when compared to the neat RHDPE. The peak load, perforation energy, and the total energy absorbed by the FRrP indicate an increasing trend when luffa, of up to 15% FVF, is added as the reinforcement. Thus, the addition of luffa as reinforcement in RHDPE shows significant potential as a high-performance, sustainable, and environmentally friendly material, such as automotive parts and protective gear.
{"title":"Mechanical Properties of Luffa Fiber Reinforced Recycled Polymer Composite","authors":"H. Kuan, Mohd Khairul Afiq, Scollastica Jane Lumpong","doi":"10.4028/p-jrgi9s","DOIUrl":"https://doi.org/10.4028/p-jrgi9s","url":null,"abstract":"Environmental issues over the eventual fate of post-consumer polymers can be dealt with in two separate ways which is recycling or using biodegradable polymers. However, it is evident that recycling polymers from post-consumer polymers can decrease the mechanical properties over time. Hence, to strengthen the recycled polymers, integrating fibers, such as luffa, into the High-Density Polyethylene (HDPE) matrix, was carried out to produce a fiber reinforced recycled polymer (FRrP) composite. The tensile testing of the FRrP composite shows that the 10% fiber volume fraction (FVF) composite exhibits a higher tensile strength of 3.9% than the neat recycled HDPE (RHDPE). In terms of Young’s Modulus, the 5% FVF of FRrP is shown to have a higher value than the neat RHDPE by 54%. The low density of luffa fibers also contributes to the composites lightweight character. The impact testing shows that the FRrP enhances the impact properties when compared to the neat RHDPE. The peak load, perforation energy, and the total energy absorbed by the FRrP indicate an increasing trend when luffa, of up to 15% FVF, is added as the reinforcement. Thus, the addition of luffa as reinforcement in RHDPE shows significant potential as a high-performance, sustainable, and environmentally friendly material, such as automotive parts and protective gear.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140382475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Md. Shamim Ahsan, Md. Arif Istiaq Arafat, Tasmima Akter, I. Sohn, Hun-Kook Choi
We demonstrate the enhancement of light extraction efficiency of surface-emitting white Organic Light Emitting Diodes (OLEDs) by incorporating micro/nano-metric structures on the outer surface of the 3-layer substrate (SiO2-Si3N4-SiO2). To enhance light extraction efficiency of the OLEDs, various light scattering structures including plano-convex & plano-concave micro-lens array, flat-top & round-top nano-pillars array, and wavy structures were engraved on the outer surface of the substrate layer. For optimization, we varied the thickness of the internal layers of the OLEDs, and height, width, period, and radius of the micro/nano-scale structures. The performance of the micro/nano-structured OLEDs was simulated and analyzed using Lumerical FDTD and GPVDM simulators. We examined the far field light intensity, transmitted power, angular distribution of light, photon escape probability, photon density, internal & external quantum efficiency, and current-voltage curve of the designed OLEDs. We investigated the results in different locations, especially after the substrate layer: Far Field-1 (0 μm), and Far Field-2 (2.5 μm). Compared to conventional OLEDs, the micro/nano-structured OLEDs showed higher external quantum efficiency. The highest external quantum efficiency of 67.304% (Far Field-1) was detected in the round-top nano-pillars array engraved white OLED having structure period of 1.2 μm. We strongly believe that, the proposed micro/nano-structured white OLEDs are suitable for lighting applications.
{"title":"Light Extraction Efficiency Enhancement of White Organic Light-Emitting Diodes (OLEDs) by Micro/Nano-Patterning the Substrate Layer","authors":"Md. Shamim Ahsan, Md. Arif Istiaq Arafat, Tasmima Akter, I. Sohn, Hun-Kook Choi","doi":"10.4028/p-bx2ouv","DOIUrl":"https://doi.org/10.4028/p-bx2ouv","url":null,"abstract":"We demonstrate the enhancement of light extraction efficiency of surface-emitting white Organic Light Emitting Diodes (OLEDs) by incorporating micro/nano-metric structures on the outer surface of the 3-layer substrate (SiO2-Si3N4-SiO2). To enhance light extraction efficiency of the OLEDs, various light scattering structures including plano-convex & plano-concave micro-lens array, flat-top & round-top nano-pillars array, and wavy structures were engraved on the outer surface of the substrate layer. For optimization, we varied the thickness of the internal layers of the OLEDs, and height, width, period, and radius of the micro/nano-scale structures. The performance of the micro/nano-structured OLEDs was simulated and analyzed using Lumerical FDTD and GPVDM simulators. We examined the far field light intensity, transmitted power, angular distribution of light, photon escape probability, photon density, internal & external quantum efficiency, and current-voltage curve of the designed OLEDs. We investigated the results in different locations, especially after the substrate layer: Far Field-1 (0 μm), and Far Field-2 (2.5 μm). Compared to conventional OLEDs, the micro/nano-structured OLEDs showed higher external quantum efficiency. The highest external quantum efficiency of 67.304% (Far Field-1) was detected in the round-top nano-pillars array engraved white OLED having structure period of 1.2 μm. We strongly believe that, the proposed micro/nano-structured white OLEDs are suitable for lighting applications.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aaron Zaeh F. Dilidili, Jhoneliza B. Habiling, Paul Eric C. Maglalang, J. C. Millare
This study investigates Halloysite Nanotube (HNT) dispersibility in ethanol-water mixtures – 0% and 10% ethanol at 100, 300, and 500 ppm HNT concentrations. Overall, the study finds that changes in HNT concentration linearly affect the response variables and showed that the 10% ethanol solvent has a higher zeta potential, smaller particle size, higher viscosity, and settling velocity. The enlargement of HNT particles at 10% ethanol while keeping better stability than water solvent is unexpected and can open novel studies about the dispersion of HNT in this solvent system.
{"title":"Halloysite Nanotube (HNT) Dispersion Stability in 10% Ethanol-Water Mixture and Water","authors":"Aaron Zaeh F. Dilidili, Jhoneliza B. Habiling, Paul Eric C. Maglalang, J. C. Millare","doi":"10.4028/p-vu0wmb","DOIUrl":"https://doi.org/10.4028/p-vu0wmb","url":null,"abstract":"This study investigates Halloysite Nanotube (HNT) dispersibility in ethanol-water mixtures – 0% and 10% ethanol at 100, 300, and 500 ppm HNT concentrations. Overall, the study finds that changes in HNT concentration linearly affect the response variables and showed that the 10% ethanol solvent has a higher zeta potential, smaller particle size, higher viscosity, and settling velocity. The enlargement of HNT particles at 10% ethanol while keeping better stability than water solvent is unexpected and can open novel studies about the dispersion of HNT in this solvent system.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the field of construction, with regard to social and design requirements, it is necessary to look for innovative and advanced solutions for the materials of building and structural elements. The topic of this paper is precisely from this area, where material engineering and the field of concrete belong. The aim of the research task is to compare the properties of three different mixtures. The main goal is the analysis and comparison of samples after exposure of test samples to elevated temperatures of up to 900 °C. The mixtures are based on the same ingredients. The first mixture was a reference one, where the binder was Portland cement. In the second mix, cement was replaced, and an alkali-activated binder was used. And in the third mix, which was a modification of the first mix, part of the aggregate was replaced with light artificial aggregate. The experimental part also focused on testing and comparing the workability in the fresh state and subsequently the basic mechanical characteristics, which include strength in compression, split tension, or static modulus of elasticity. In addition, tests of resistance to frost and defrosting chemicals or determination of the tear strength of the surface layer on the test beams were also carried out.
在建筑领域，考虑到社会和设计要求，有必要为建筑材料和结构元素寻找创新和先进的解决方案。本文的主题正是来自这一领域，即材料工程和混凝土领域。研究任务的目的是比较三种不同混合物的特性。主要目标是分析和比较将测试样品暴露在高达 900 °C 的高温下后的样品。这些混合物基于相同的成分。第一种混合物是参考混合物，粘合剂是硅酸盐水泥。在第二种混合物中，水泥被取代，并使用了碱激活粘结剂。第三种混合物是对第一种混合物的改良，用轻质人工骨料代替了部分骨料。实验部分还重点测试和比较了新鲜状态下的可操作性以及随后的基本机械特性，包括压缩强度、劈裂拉伸强度或静态弹性模量。此外，还进行了抗霜冻和抗解冻化学品试验，或测定试验梁表层的撕裂强度。
{"title":"Comparison of Concrete Mixtures and Alkaline Activated Material with Regard to Selected Properties for Structural Design","authors":"Jan Jeřábek","doi":"10.4028/p-lc2j6q","DOIUrl":"https://doi.org/10.4028/p-lc2j6q","url":null,"abstract":"In the field of construction, with regard to social and design requirements, it is necessary to look for innovative and advanced solutions for the materials of building and structural elements. The topic of this paper is precisely from this area, where material engineering and the field of concrete belong. The aim of the research task is to compare the properties of three different mixtures. The main goal is the analysis and comparison of samples after exposure of test samples to elevated temperatures of up to 900 °C. The mixtures are based on the same ingredients. The first mixture was a reference one, where the binder was Portland cement. In the second mix, cement was replaced, and an alkali-activated binder was used. And in the third mix, which was a modification of the first mix, part of the aggregate was replaced with light artificial aggregate. The experimental part also focused on testing and comparing the workability in the fresh state and subsequently the basic mechanical characteristics, which include strength in compression, split tension, or static modulus of elasticity. In addition, tests of resistance to frost and defrosting chemicals or determination of the tear strength of the surface layer on the test beams were also carried out.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Within the framework of the project GAČR 21-24070S Model of fibre segregation in dependence on rheological properties of fresh HPC, the rheological properties and fibre segregation in fresh concrete mix depending on temperature changes have been verified. The rheological properties and fibre segregation have been verified under three temperature conditions (very low temperatures around 5 °C, normal temperature conditions around 20 °C and high temperatures above 30 °C). Comparison of the properties of UHPC with fibres at different temperature conditions has been performed on fresh mixtures mainly by spill tests. Subsequently, hardened test bodies, i.e. 40/40/160 beams, were verified in tensile bending and compression in all cases. The actual fibre segregation within the individual samples has also been verified by microscopic analysis. Different temperature conditions have been simulated by heating or cooling the input raw materials. The results have been compared by degree of changes in rheological properties and mechanical parameters.
{"title":"Rheological Properties and Segregation of Fresh UHPC with Fibers Affected by Initial Temperature of Concrete Mix","authors":"Tomáš Bittner, Karel Hurtig, D. Jiroutová","doi":"10.4028/p-j1wmcb","DOIUrl":"https://doi.org/10.4028/p-j1wmcb","url":null,"abstract":"Within the framework of the project GAČR 21-24070S Model of fibre segregation in dependence on rheological properties of fresh HPC, the rheological properties and fibre segregation in fresh concrete mix depending on temperature changes have been verified. The rheological properties and fibre segregation have been verified under three temperature conditions (very low temperatures around 5 °C, normal temperature conditions around 20 °C and high temperatures above 30 °C). Comparison of the properties of UHPC with fibres at different temperature conditions has been performed on fresh mixtures mainly by spill tests. Subsequently, hardened test bodies, i.e. 40/40/160 beams, were verified in tensile bending and compression in all cases. The actual fibre segregation within the individual samples has also been verified by microscopic analysis. Different temperature conditions have been simulated by heating or cooling the input raw materials. The results have been compared by degree of changes in rheological properties and mechanical parameters.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140382441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Townsend, Cinthya Astudillo, Karla Larrea, Juan Carlos Suárez
The objective of this research work is to analyze the behavior between fiberglass laminate under tensile tests, assembled under different humidity conditions. For which specimens were designed under the regime of the international standard ASTM D3039; which took an assembly process within a controlled environment; the design variables used were relative humidity and curing time. Subsequently, the traction-displacement behavior was checked under a uniaxial force, obtaining the maximum take-off force. In addition, Simpson numerical integration was applied to calculate elastic energy. Obtaining that the relative humidity and the days of curing influence the chemical and mechanical properties of the material. Se shows that the percentage of humidity recommended for assembling laminates in GRP is 66% since it has greater elastic energy and take-off force. Finally, it is concluded that to have a high resistance in the material at least 7 days of curing of the epoxy resin must be applied.
{"title":"Research on the Influence of Humidity on the Manufacture of GFRP Vessels in the Equatorial","authors":"P. Townsend, Cinthya Astudillo, Karla Larrea, Juan Carlos Suárez","doi":"10.4028/p-22wfse","DOIUrl":"https://doi.org/10.4028/p-22wfse","url":null,"abstract":"The objective of this research work is to analyze the behavior between fiberglass laminate under tensile tests, assembled under different humidity conditions. For which specimens were designed under the regime of the international standard ASTM D3039; which took an assembly process within a controlled environment; the design variables used were relative humidity and curing time. Subsequently, the traction-displacement behavior was checked under a uniaxial force, obtaining the maximum take-off force. In addition, Simpson numerical integration was applied to calculate elastic energy. Obtaining that the relative humidity and the days of curing influence the chemical and mechanical properties of the material. Se shows that the percentage of humidity recommended for assembling laminates in GRP is 66% since it has greater elastic energy and take-off force. Finally, it is concluded that to have a high resistance in the material at least 7 days of curing of the epoxy resin must be applied.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article deals with the possible combination of high temperature fly ash with fluidised fly ash. The aim of this experiment is to verify the effect of the combination of these two energy by-products not only on the parameters of cement mortar in the fresh state, but especially on its mechanical parameters in the hardened state.
{"title":"Usability of the Combination of Fly Ash from Different Species","authors":"M. Meruňka, Petr Šperling, M. Ťažký, Rudolf Hela","doi":"10.4028/p-0xrtoo","DOIUrl":"https://doi.org/10.4028/p-0xrtoo","url":null,"abstract":"This article deals with the possible combination of high temperature fly ash with fluidised fly ash. The aim of this experiment is to verify the effect of the combination of these two energy by-products not only on the parameters of cement mortar in the fresh state, but especially on its mechanical parameters in the hardened state.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140383729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Concentrated solar power technology represents a novel approach to generating solar power, characterized by high solar radiation density and uninterrupted operation. To store thermal energy and extend system operating hours, concentrated solar power systems rely on thermal energy storage. Selecting the appropriate heat storage media is crucial for designing a cost-efficient and straightforward system capable of withstanding high processing conditions. Among many powder materials, bauxite powder stands out as alternatives to conventional molten salt for thermal storage media due to its widespread availability and suitability for operating conditions. Particle shape, particularly its sphericity, plays a vital role in efficiently packing particles which directly affects to heat transfer properties. To investigate this effect, three samples of particles with different shape were formed: spheres, ellipses, and cylinders using Discrete Element Method with equal volume and material properties, and only variation of their sphericity factors. The study focused on the analysis of the porosity of the packed bed of particles with different shapes and its influence on the packing structure properties. The analysis of local packing fraction revealed that elliptical and cylindrical particles samples exhibited reduced heap formation and a more uniform distribution along z direction during vertical packing. The coordination number and radial distribution function analyses for these non-spherical particles showed a greater number of contacts between particles and disordered distribution of particles due to mechanical interlocking of non-spherical particles. The results indicated that the deviation of sphericity has a positive impact on the denser packing of particles generated more contacts and higher local packing fraction.
聚光太阳能发电技术是一种新型的太阳能发电方法，具有太阳辐射密度高和不间断运行的特点。为了储存热能并延长系统运行时间，聚光太阳能发电系统需要依靠热能储存。选择合适的储热介质对于设计一个成本效益高且能承受高加工条件的简单系统至关重要。在众多粉末材料中，铝矾土粉末因其广泛的可获得性和对操作条件的适用性，在传统熔盐储热介质的替代品中脱颖而出。颗粒形状，尤其是其球形度，在有效堆积颗粒方面起着至关重要的作用，这直接影响到传热性能。为了研究这种影响，采用离散元素法，在体积和材料属性相同的情况下，仅改变球度系数，形成了三种不同形状的颗粒样品：球形、椭圆形和圆柱形。研究重点是分析不同形状颗粒填料床的孔隙率及其对填料结构特性的影响。对局部堆积分数的分析表明，椭圆形和圆柱形颗粒样品在垂直堆积过程中减少了堆积的形成，沿 Z 方向的分布更加均匀。对这些非球形颗粒的配位数和径向分布函数分析表明，由于非球形颗粒的机械交错，颗粒之间的接触数量增加，颗粒分布紊乱。结果表明，球形度的偏差对粒子的密集堆积有积极影响，会产生更多的接触和更高的局部堆积分数。
{"title":"Numerical Analysis of Non-Sphericity of Particles of Powder Material and their Effect on Packing Structure for Concentrated Solar Power Applications","authors":"A. Boribayeva, Xeniya Gvozdeva, Boris Golman","doi":"10.4028/p-j8hsln","DOIUrl":"https://doi.org/10.4028/p-j8hsln","url":null,"abstract":"Concentrated solar power technology represents a novel approach to generating solar power, characterized by high solar radiation density and uninterrupted operation. To store thermal energy and extend system operating hours, concentrated solar power systems rely on thermal energy storage. Selecting the appropriate heat storage media is crucial for designing a cost-efficient and straightforward system capable of withstanding high processing conditions. Among many powder materials, bauxite powder stands out as alternatives to conventional molten salt for thermal storage media due to its widespread availability and suitability for operating conditions. Particle shape, particularly its sphericity, plays a vital role in efficiently packing particles which directly affects to heat transfer properties. To investigate this effect, three samples of particles with different shape were formed: spheres, ellipses, and cylinders using Discrete Element Method with equal volume and material properties, and only variation of their sphericity factors. The study focused on the analysis of the porosity of the packed bed of particles with different shapes and its influence on the packing structure properties. The analysis of local packing fraction revealed that elliptical and cylindrical particles samples exhibited reduced heap formation and a more uniform distribution along z direction during vertical packing. The coordination number and radial distribution function analyses for these non-spherical particles showed a greater number of contacts between particles and disordered distribution of particles due to mechanical interlocking of non-spherical particles. The results indicated that the deviation of sphericity has a positive impact on the denser packing of particles generated more contacts and higher local packing fraction.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140384233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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