Y. Wang, Jichun He, B. Xu, Nahid A Osman, Hassan Algadi, H. Abo-Dief, Na Lu, P. Wasnik, D. Sridhar, Abdullah K. Alanazi, Qinglong Jiang, B. Qiu, Zhanhu Guo
Various iron materials have been used to improve methane production rate in the anaerobic sludge. The effect of iron materials including zerovalent iron (ZVI), magnetite (Fe3O4) and iron (III) oxide (Fe2O3) on the methane production rate was compared. It was found that all the iron materials can improve the methane production rate, and ZVI, Fe3O4 and Fe2O3 increased by 19.8%, 13.7% and 17.9% in which the ZVI performed better on improving the methane production. Then the long-term effects of ZVI on the methane production rate by anaerobic organisms was further studied. ZVI increased the methane production rate by 7.2%, the improvement was unstable and decreased due to the corrosion and loss of the ZVI in the anaerobic wastewater treatment system. The improved performance was recovered after the ZVI was re-added into the anaerobic sludge, the methane production rate increased by 6.1%. The added ZVI obviously enriched exoelectrogenic archaea Methanobacterium due to its ability of direct interspecific electron transfer, and its relative abundance was up to 61.99%. The enhanced direct interspecific electron transfer was disclosed as the main mechanism involved in enhanced methanogenesis in the anaerobic sludge.
{"title":"Iron materials facilitated methane production from anaerobic wastewater treatment","authors":"Y. Wang, Jichun He, B. Xu, Nahid A Osman, Hassan Algadi, H. Abo-Dief, Na Lu, P. Wasnik, D. Sridhar, Abdullah K. Alanazi, Qinglong Jiang, B. Qiu, Zhanhu Guo","doi":"10.1680/jemmr.23.00034","DOIUrl":"https://doi.org/10.1680/jemmr.23.00034","url":null,"abstract":"Various iron materials have been used to improve methane production rate in the anaerobic sludge. The effect of iron materials including zerovalent iron (ZVI), magnetite (Fe3O4) and iron (III) oxide (Fe2O3) on the methane production rate was compared. It was found that all the iron materials can improve the methane production rate, and ZVI, Fe3O4 and Fe2O3 increased by 19.8%, 13.7% and 17.9% in which the ZVI performed better on improving the methane production. Then the long-term effects of ZVI on the methane production rate by anaerobic organisms was further studied. ZVI increased the methane production rate by 7.2%, the improvement was unstable and decreased due to the corrosion and loss of the ZVI in the anaerobic wastewater treatment system. The improved performance was recovered after the ZVI was re-added into the anaerobic sludge, the methane production rate increased by 6.1%. The added ZVI obviously enriched exoelectrogenic archaea Methanobacterium due to its ability of direct interspecific electron transfer, and its relative abundance was up to 61.99%. The enhanced direct interspecific electron transfer was disclosed as the main mechanism involved in enhanced methanogenesis in the anaerobic sludge.","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48794648","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}
J. Junwen, A. Zavdoveev, D. Vedel, T. Baudin, S. Motrunich, I. Klochkov, S. Friederichs, N. Strelenko, M. Skoryk
Cold metal transfer (CMT) technology is considered in an application for wire arc additive manufacturing WAAM of refractory high corrosion resistant Inconel 625 alloy. Based on the fabricated wall it has been shown the suitability of CMT WAAM for the sound formation of weld and homogenous distribution of mechanical properties has been shown. Microscopy analysis has revealed that the microstructure of the deposited alloy along the height of the wall element is relatively uniform. The minor differences in the microstructure are observed in the bottom part, caused by welding specifically. It should be noted that there is a slight decrease in strength indicators from the bottom to the top of the welded product, but they do not exceed 5%, which is considered entirely satisfactory. This phenomenon is caused by structural transformations that take place in slightly different cooling conditions, namely in the lower layers, the substrate on which the surfacing was carried out plays a more significant role in heat flow. This leads to more intensive cooling of the lower layers and as a result slightly higher values of strength.
{"title":"CMT-based wire arc additive manufacturing of Inconel 625 alloy","authors":"J. Junwen, A. Zavdoveev, D. Vedel, T. Baudin, S. Motrunich, I. Klochkov, S. Friederichs, N. Strelenko, M. Skoryk","doi":"10.1680/jemmr.23.00053","DOIUrl":"https://doi.org/10.1680/jemmr.23.00053","url":null,"abstract":"Cold metal transfer (CMT) technology is considered in an application for wire arc additive manufacturing WAAM of refractory high corrosion resistant Inconel 625 alloy. Based on the fabricated wall it has been shown the suitability of CMT WAAM for the sound formation of weld and homogenous distribution of mechanical properties has been shown. Microscopy analysis has revealed that the microstructure of the deposited alloy along the height of the wall element is relatively uniform. The minor differences in the microstructure are observed in the bottom part, caused by welding specifically. It should be noted that there is a slight decrease in strength indicators from the bottom to the top of the welded product, but they do not exceed 5%, which is considered entirely satisfactory. This phenomenon is caused by structural transformations that take place in slightly different cooling conditions, namely in the lower layers, the substrate on which the surfacing was carried out plays a more significant role in heat flow. This leads to more intensive cooling of the lower layers and as a result slightly higher values of strength.","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43479805","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}
I. Sharma, Shruti Mahajan, V. Arora, Mehak Arora, Nitin Mahajan, Kanika Aggarwal, Anupinder Singh
The main goal of this study is to analyze the magnetic, dielectric, and magneto-dielectric characteristics of Pb1− x La x Ti1− x O 3 - (Ba1–3 x Nd2 x )4Co2Fe36O60 (where x = 0.25) composite material at various temperatures T1-T3 (i.e 1100°C ,1200°C, 1300°C respectively). The X-ray diffraction investigation has been introduced in order to pinpoint the creation of the U-type hexaferrite phase. SEM micrographs reveal that sample sintered at T2 reached the maximum value of grain size and the largest experimental density value of 6.14 g/cm3 due to the composite material's intensified grain growth. The magnetic investigations further indicate that the sample T2 achieved the highest remnant magnetization, measuring 1.550 emu/g, revealing the accuracy of the sintering temperature. The magneto-dielectric investigations demonstrate the presence of multiferroicity in all samples, and came to the conclusion that sample T2 exhibits the highest magneto-dielectric response of 41.99 at 1.2 Tesla and a magneto-dielectric coefficient (γ) of around 0.7609 g2/emu2. Numerous metrics, including nyquist plots, impedance, electrical modulus, dielectric constant, and conductivity, were carefully examined in order to determine the electrical properties of the proposed sample. It was found that sample T2 produced the enhanced results and had the right temperature for the substance to develop.
本研究的主要目的是分析Pb1−x La x Ti1−x O 3 - (Ba1-3 x Nd2 x)4Co2Fe36O60 (x = 0.25)复合材料在T1-T3(分别为1100℃、1200℃、1300℃)不同温度下的磁性、介电和磁介电特性。为了查明u型六铁素体相的形成，引入了x射线衍射研究。SEM显微图显示，T2烧结试样的晶粒尺寸最大值和实验密度最大值为6.14 g/cm3，这是由于复合材料晶粒生长加剧所致。磁性研究进一步表明，T2样品的残余磁化强度最高，为1.550 emu/g，表明烧结温度的准确性。磁介电特性研究表明，所有样品均存在多铁性，并得出结论，样品T2在1.2特斯拉时的磁介电响应最高，为41.99，磁介电系数(γ)约为0.7609 g2/emu2。许多指标，包括奈奎斯特图，阻抗，电模量，介电常数和电导率，仔细检查，以确定所提出的样品的电学性质。发现样品T2产生了增强的结果，并且具有合适的温度来形成物质。
{"title":"Effect of Magnetic field on dielectric properties in PLT/BNCFO composites","authors":"I. Sharma, Shruti Mahajan, V. Arora, Mehak Arora, Nitin Mahajan, Kanika Aggarwal, Anupinder Singh","doi":"10.1680/jemmr.22.00183","DOIUrl":"https://doi.org/10.1680/jemmr.22.00183","url":null,"abstract":"The main goal of this study is to analyze the magnetic, dielectric, and magneto-dielectric characteristics of Pb1− x La x Ti1− x O 3 - (Ba1–3 x Nd2 x )4Co2Fe36O60 (where x = 0.25) composite material at various temperatures T1-T3 (i.e 1100°C ,1200°C, 1300°C respectively). The X-ray diffraction investigation has been introduced in order to pinpoint the creation of the U-type hexaferrite phase. SEM micrographs reveal that sample sintered at T2 reached the maximum value of grain size and the largest experimental density value of 6.14 g/cm3 due to the composite material's intensified grain growth. The magnetic investigations further indicate that the sample T2 achieved the highest remnant magnetization, measuring 1.550 emu/g, revealing the accuracy of the sintering temperature. The magneto-dielectric investigations demonstrate the presence of multiferroicity in all samples, and came to the conclusion that sample T2 exhibits the highest magneto-dielectric response of 41.99 at 1.2 Tesla and a magneto-dielectric coefficient (γ) of around 0.7609 g2/emu2. Numerous metrics, including nyquist plots, impedance, electrical modulus, dielectric constant, and conductivity, were carefully examined in order to determine the electrical properties of the proposed sample. It was found that sample T2 produced the enhanced results and had the right temperature for the substance to develop.","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48630431","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 : 2023-06-01DOI: 10.1680/jemmr.2023.12.2.101
F. Heim
{"title":"Editorial: Materials for a more sustainable usage","authors":"F. Heim","doi":"10.1680/jemmr.2023.12.2.101","DOIUrl":"https://doi.org/10.1680/jemmr.2023.12.2.101","url":null,"abstract":"","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44685290","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}
S. Pujari, S. Santosh Kumar, N. Naveen, C. Devi, Sivarao
The demand for organic fibres with remarkable mechanical, magnetic, and physical properties is rising. As a result, the current study investigated the impact of magnetite reinforcement on Kenaf fiber. The test samples were prepared by the hand-layup process with the addition of magnetite in the range of 10–40 wt%. Test results showed that samples with 30% magnetite content exhibit the best mechanical, physical, and tribological characteristics. It shows water absorption of 0 g, average wear of 112 microns, and an average frictional force of 1.1 N. Magnetic absorption in samples with 30 and 40 weight percent magnetite is -0.000378 to 0.00038623 emu/g and -0.000260218 to 0.000257814 emu/g, respectively.
{"title":"Effect of Magnetite on physical, tribological and magnetic characteristics of Kenaf fiber","authors":"S. Pujari, S. Santosh Kumar, N. Naveen, C. Devi, Sivarao","doi":"10.1680/jemmr.22.00162","DOIUrl":"https://doi.org/10.1680/jemmr.22.00162","url":null,"abstract":"The demand for organic fibres with remarkable mechanical, magnetic, and physical properties is rising. As a result, the current study investigated the impact of magnetite reinforcement on Kenaf fiber. The test samples were prepared by the hand-layup process with the addition of magnetite in the range of 10–40 wt%. Test results showed that samples with 30% magnetite content exhibit the best mechanical, physical, and tribological characteristics. It shows water absorption of 0 g, average wear of 112 microns, and an average frictional force of 1.1 N. Magnetic absorption in samples with 30 and 40 weight percent magnetite is -0.000378 to 0.00038623 emu/g and -0.000260218 to 0.000257814 emu/g, respectively.","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45346482","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}
Austenitic and Duplex Stainless steel was majorly preferred for the heat exchangers and the chemical containers. This research work proposed to investigate the failure mechanism of dissimilar welded joints of AISI 347 and DSS 2205. The welded specimens were investigated under tensile shear test, cross tension test, coach peel test, and micro-hardness test. The specimen absorbed a maximum tensile shear load of 18 kN during the tensile shear test and the failure mode was button pull out with brittle fracture. The test sample absorbed a load of 15.1 kN during the cross tension test and the failure mode was button pull out with brittle fracture. During coach peel test, the sample absorbed a maximum load of 4 kN and ductile fracture was witnessed at the vicinity of the nugget. The failure mode in coach peel test was button pull out type. The microhardness test recorded a maximum hardness of 312.8 HV which is 78.74% and 7.1% higher than the base metal hardness values of AISI 347 and AISI 2205 respectively. The specimen failed under pull out failure mode in all the tests and hence the weld zone was intact in all the specimen arrangement and loading conditions.
{"title":"Investigation of failure mechanism of dissimilar resistance spot welding of steels","authors":"M. Prabhakaran, D. Jeyasimman, M. Varatharajulu","doi":"10.1680/jemmr.22.00224","DOIUrl":"https://doi.org/10.1680/jemmr.22.00224","url":null,"abstract":"Austenitic and Duplex Stainless steel was majorly preferred for the heat exchangers and the chemical containers. This research work proposed to investigate the failure mechanism of dissimilar welded joints of AISI 347 and DSS 2205. The welded specimens were investigated under tensile shear test, cross tension test, coach peel test, and micro-hardness test. The specimen absorbed a maximum tensile shear load of 18 kN during the tensile shear test and the failure mode was button pull out with brittle fracture. The test sample absorbed a load of 15.1 kN during the cross tension test and the failure mode was button pull out with brittle fracture. During coach peel test, the sample absorbed a maximum load of 4 kN and ductile fracture was witnessed at the vicinity of the nugget. The failure mode in coach peel test was button pull out type. The microhardness test recorded a maximum hardness of 312.8 HV which is 78.74% and 7.1% higher than the base metal hardness values of AISI 347 and AISI 2205 respectively. The specimen failed under pull out failure mode in all the tests and hence the weld zone was intact in all the specimen arrangement and loading conditions.","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42036213","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}
Yuanji Shi, Y.Q. Dai, Junwan Li, Cheng Cheng, Jingxiao Li
The Nd-TiO2 micro-arc oxidation (MAO) coatings were formed in phosphate-based electrolyte with the addition of Nd2O3 using suitable voltage and frequency. SEM results revealed that the coatings were varied with different voltage and frequency. And composition analysis showed the Nd-TiO2 coatings are mainly composed of anatase and rutile phase. Meanwhile, the anatase content increased and then decreased. In addition, XPS results indicated that the Ti2p spin-orbit components of Nd-TiO2 coatings are shifted towards higher binding energy, suggesting that some of the Nd3+ ions are combined with TiO2 lattice and led dislocation. Furthermore, the photocatalytic experiment results showed that the photocatalytic activity of Nd-TiO2 coatings can be greatly enhanced with moderate amount of Nd3+. However, excessive amount of Nd3+ is not of an effective impact on the improvement of photocatalytic activity.
{"title":"Photocatalytic performance of Nd-TiO2 coatings: effect of voltage and frequency","authors":"Yuanji Shi, Y.Q. Dai, Junwan Li, Cheng Cheng, Jingxiao Li","doi":"10.1680/jemmr.22.00063","DOIUrl":"https://doi.org/10.1680/jemmr.22.00063","url":null,"abstract":"The Nd-TiO2 micro-arc oxidation (MAO) coatings were formed in phosphate-based electrolyte with the addition of Nd2O3 using suitable voltage and frequency. SEM results revealed that the coatings were varied with different voltage and frequency. And composition analysis showed the Nd-TiO2 coatings are mainly composed of anatase and rutile phase. Meanwhile, the anatase content increased and then decreased. In addition, XPS results indicated that the Ti2p spin-orbit components of Nd-TiO2 coatings are shifted towards higher binding energy, suggesting that some of the Nd3+ ions are combined with TiO2 lattice and led dislocation. Furthermore, the photocatalytic experiment results showed that the photocatalytic activity of Nd-TiO2 coatings can be greatly enhanced with moderate amount of Nd3+. However, excessive amount of Nd3+ is not of an effective impact on the improvement of photocatalytic activity.","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43169390","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}
Okra fiber is the natural cellulosic bast fiber extracted from the bark of the Abelmoschus esculentus plant stem. India is the largest producer of okra for the cultivation of “okra fruit.” After harvesting the okra plant in the field, the okra fruit is collected as a vegetable, and the okra plant is thrown out as agricultural waste. In India, an estimated 4.5 million tons of green okra plants were discarded annually as agricultural waste. The okra plant has the potential to produce 150–160 kg of okra fibers per hectare and about 13.4 million kg of okra fibers annually. The okra plant is cultivated in two seasons: summer and winter. The summer variety (SV) and winter variety (WV) were extracted from okra plants cultivated in the summer and winter seasons, respectively. In this study, characteristics of the summer and winter varieties of okra fibers (morphological, thermal, and structural) are investigated by optical and electron microscopy (SEM), thermogravimetric analysis (TGA, DTG, DSC), X-ray diffraction analysis (XRD), and Fourier transform infrared spectrometry (FTIR). This study analyzed the characteristics of both varieties of okra fiber, compared them, and proved their potential for commercial applications like banana, jute, flax, hemp, and kenaf bast fibers.
{"title":"Characteristics of Abelmoschus Esculentus (Indian okra) fiber varieties","authors":"Prafull P. Kolte, V. Shivankar","doi":"10.1680/jemmr.22.00230","DOIUrl":"https://doi.org/10.1680/jemmr.22.00230","url":null,"abstract":"Okra fiber is the natural cellulosic bast fiber extracted from the bark of the Abelmoschus esculentus plant stem. India is the largest producer of okra for the cultivation of “okra fruit.” After harvesting the okra plant in the field, the okra fruit is collected as a vegetable, and the okra plant is thrown out as agricultural waste. In India, an estimated 4.5 million tons of green okra plants were discarded annually as agricultural waste. The okra plant has the potential to produce 150–160 kg of okra fibers per hectare and about 13.4 million kg of okra fibers annually. The okra plant is cultivated in two seasons: summer and winter. The summer variety (SV) and winter variety (WV) were extracted from okra plants cultivated in the summer and winter seasons, respectively. In this study, characteristics of the summer and winter varieties of okra fibers (morphological, thermal, and structural) are investigated by optical and electron microscopy (SEM), thermogravimetric analysis (TGA, DTG, DSC), X-ray diffraction analysis (XRD), and Fourier transform infrared spectrometry (FTIR). This study analyzed the characteristics of both varieties of okra fiber, compared them, and proved their potential for commercial applications like banana, jute, flax, hemp, and kenaf bast fibers.","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49174521","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}
Coal mine overburden as well as thick inseam parting materials found in the lower Gondwana basin are often treated as mine wastes. Unused fly ash from coal fired plants is another waste material. This investigation focused on using these wastes to develop better composite materials. Composite materials of varying composition with coal mine wastes from 50% to 90% and fly ash from 10% to 50% were developed with 2 to 6% cement additives. Their physical, chemical and geotechnical properties were determined. OPC strongly influenced the geotechnical properties. Fly ash presence were optimized for unconfined compressive strength (UCS) and California bearing ratio for both the mine wastes. Composite materials with 70% overburden, 30% fly ash, and 6% cement showed 4.01 MPa UCS at 56 days. Similarly, 80% inseam parting, 20% fly ash, and 6% cement produced 4.90 MPa UCS at 56 days. Analysis of fly ash present in the two composites and their strength values produced linear correlations. Pearson and Spearman’s coefficients produced high correlation of −0.9 for the composite prepared with parting materials. Microstructural analysis showed C-S-H gel formation occurring at 28 days. The composites meet the strength criterion for the base and sub-base of the coal mine haul road.
{"title":"Development and evaluation of coalmine waste materials for gainful utilisation","authors":"S. Choudhury, M. Mishra","doi":"10.1680/jemmr.22.00185","DOIUrl":"https://doi.org/10.1680/jemmr.22.00185","url":null,"abstract":"Coal mine overburden as well as thick inseam parting materials found in the lower Gondwana basin are often treated as mine wastes. Unused fly ash from coal fired plants is another waste material. This investigation focused on using these wastes to develop better composite materials. Composite materials of varying composition with coal mine wastes from 50% to 90% and fly ash from 10% to 50% were developed with 2 to 6% cement additives. Their physical, chemical and geotechnical properties were determined. OPC strongly influenced the geotechnical properties. Fly ash presence were optimized for unconfined compressive strength (UCS) and California bearing ratio for both the mine wastes. Composite materials with 70% overburden, 30% fly ash, and 6% cement showed 4.01 MPa UCS at 56 days. Similarly, 80% inseam parting, 20% fly ash, and 6% cement produced 4.90 MPa UCS at 56 days. Analysis of fly ash present in the two composites and their strength values produced linear correlations. Pearson and Spearman’s coefficients produced high correlation of −0.9 for the composite prepared with parting materials. Microstructural analysis showed C-S-H gel formation occurring at 28 days. The composites meet the strength criterion for the base and sub-base of the coal mine haul road.","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47605064","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}
We used first-principles electronic structure calculations and Boltzmann transport theories to understand the thermoelectric behavior of tetrahedrites. We performed calculations on the Zn substituted derivatives with Zn occupied each lattice site in the parent compound Cu12Sb4S13, to study Zn substitution mechanism, and the relation between Zn substitution site and thermoelectric performance. We found that the most energetically favorable sites for Zn is the Cu(1) sites, and the next is the Cu(2) sites. And the room-temperature Seebeck coefficient of the host was enhanced nearly 255 and 7 times by Zn doping at Cu(1) and Cu(2) sites, owing to the decrease of carrier concentration and the increase of band effective mass, respectively. However, the electrical conductivity showed a marked decrease upon Zn doping at Cu(1) and Cu(2) sites, due to the decrease in carrier contribution and low mobility, respectively. As a result, the Cu12Sb4S13 compounds substituted with Zn at Cu(1) sites have a preferable optimizing power factor at room temperature. The optimizing power factor of the host could get an about 8-time improvement at room temperature upon Zn substituting at Cu(1) sites.
{"title":"The effects of Zn doping on the thermoelectric performance of Cu12Sb4S13","authors":"Mian Liu, Changsong Liu, X. Qin","doi":"10.1680/jemmr.21.00144","DOIUrl":"https://doi.org/10.1680/jemmr.21.00144","url":null,"abstract":"We used first-principles electronic structure calculations and Boltzmann transport theories to understand the thermoelectric behavior of tetrahedrites. We performed calculations on the Zn substituted derivatives with Zn occupied each lattice site in the parent compound Cu12Sb4S13, to study Zn substitution mechanism, and the relation between Zn substitution site and thermoelectric performance. We found that the most energetically favorable sites for Zn is the Cu(1) sites, and the next is the Cu(2) sites. And the room-temperature Seebeck coefficient of the host was enhanced nearly 255 and 7 times by Zn doping at Cu(1) and Cu(2) sites, owing to the decrease of carrier concentration and the increase of band effective mass, respectively. However, the electrical conductivity showed a marked decrease upon Zn doping at Cu(1) and Cu(2) sites, due to the decrease in carrier contribution and low mobility, respectively. As a result, the Cu12Sb4S13 compounds substituted with Zn at Cu(1) sites have a preferable optimizing power factor at room temperature. The optimizing power factor of the host could get an about 8-time improvement at room temperature upon Zn substituting at Cu(1) sites.","PeriodicalId":11537,"journal":{"name":"Emerging Materials Research","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41547144","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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