Heng Mao, Wei Yu, Zhuanyun Cai, Guixian Liu, Limin Liu, R. Wen, Yaqiong Su, Kai Xi, Benqiang Li, Xinyu Da, H. Kou, Wei Yan, Shujiang Ding
Uncontrolled dendrite formation in the high energy density of lithium metal batteries (LMBs) may pose serious safety risks. Numerous works have been reported to protect separator. However, these methods still couldn’t inhibit the dendrite upward growth to protect the separator, effectively. Here, we introduce a novel “orientated-growth” strategy that makes the depositional interface transfer to the anode/current collector interface from the anode/separator interface. We placed a layer of cellulose/graphene carbon composite aerogel (CCA) between the current collector and the anode (CCA-Li). This layer works as the charge organizer; it induces a higher current density distribution and makes Li prefer to deposit in the bottom CCA layer of CCA-Li electrode. Both in-situ and ex-situ images of the electrode demonstrate the anode part of the cell has been flipped; with the new deposited particles facing the current collector and smooth surface facing the separator. Electrochemical characterization of the electrode in half and full cells showed outstanding cyclic stability and rate capability, with the CCA-Li/LPF full cell able to maintain 94% of its initial capacity after 1000 cycles. We believe that the innovative strategy would promote the leapfrog development for LMBs.
{"title":"Current Density Regulating Lithium Metal Directional Deposition for Long Cycle Life Lithium Metal Batteries","authors":"Heng Mao, Wei Yu, Zhuanyun Cai, Guixian Liu, Limin Liu, R. Wen, Yaqiong Su, Kai Xi, Benqiang Li, Xinyu Da, H. Kou, Wei Yan, Shujiang Ding","doi":"10.2139/ssrn.3751761","DOIUrl":"https://doi.org/10.2139/ssrn.3751761","url":null,"abstract":"Uncontrolled dendrite formation in the high energy density of lithium metal batteries (LMBs) may pose serious safety risks. Numerous works have been reported to protect separator. However, these methods still couldn’t inhibit the dendrite upward growth to protect the separator, effectively. Here, we introduce a novel “orientated-growth” strategy that makes the depositional interface transfer to the anode/current collector interface from the anode/separator interface. We placed a layer of cellulose/graphene carbon composite aerogel (CCA) between the current collector and the anode (CCA-Li). This layer works as the charge organizer; it induces a higher current density distribution and makes Li prefer to deposit in the bottom CCA layer of CCA-Li electrode. Both in-situ and ex-situ images of the electrode demonstrate the anode part of the cell has been flipped; with the new deposited particles facing the current collector and smooth surface facing the separator. Electrochemical characterization of the electrode in half and full cells showed outstanding cyclic stability and rate capability, with the CCA-Li/LPF full cell able to maintain 94% of its initial capacity after 1000 cycles. We believe that the innovative strategy would promote the leapfrog development for LMBs.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"146 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88644661","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}
Yanpei Tian, Hong Shao, Xiaojie Liu, Fangqi Chen, Yongsheng Li, Changyu Tang, Y. Zheng
Passive daytime radiative cooling (PDRC) cools an object down by simultaneously reflecting sunlight and thermally radiating heat to the cold outer space through the Earth's atmospheric window. However, for practical applications, current PDRC materials are facing unprecedented challenges such as complicated and expensive fabrication approaches and performance degradation arising from surface contamination. Here, we develop scalable cellulose-fiber-based hierarchical composites with excellent self-cleaning and self-cooling capabilities, through air-spraying ethanolic polytetrafluoroethylene (PTFE) microparticles suspensions embedded within the micropores of the cellulose fiber. The formed superhydrophobic PTFE coating not only protects the cellulose-fiber-based paper from water wetting and dust contamination for real-life applications but also reinforces its solar reflectance by sunlight backscattering. It results in a sub-ambient cooling performance of 5°C and radiative cooling power of 104 W/m2 under direct solar irradiance of 834 W/m2 and 671 W/m2, respectively. The self-cleaning surface of the hierarchical composites extends its lifespan and keep its good cooling performance for outdoor applications. Additionally, dyed cellulose-fiber-based paper can absorb appropriate visible wavelengths to display specific colors and effectively reflect near-infrared lights to reduce solar heating, which synchronously achieves effective radiative cooling and aesthetic varieties.
{"title":"Self-Cleaning and Self-Cooling Cellulose-Fiber-Based Hierarchical Composites","authors":"Yanpei Tian, Hong Shao, Xiaojie Liu, Fangqi Chen, Yongsheng Li, Changyu Tang, Y. Zheng","doi":"10.2139/ssrn.3748560","DOIUrl":"https://doi.org/10.2139/ssrn.3748560","url":null,"abstract":"Passive daytime radiative cooling (PDRC) cools an object down by simultaneously reflecting sunlight and thermally radiating heat to the cold outer space through the Earth's atmospheric window. However, for practical applications, current PDRC materials are facing unprecedented challenges such as complicated and expensive fabrication approaches and performance degradation arising from surface contamination. Here, we develop scalable cellulose-fiber-based hierarchical composites with excellent self-cleaning and self-cooling capabilities, through air-spraying ethanolic polytetrafluoroethylene (PTFE) microparticles suspensions embedded within the micropores of the cellulose fiber. The formed superhydrophobic PTFE coating not only protects the cellulose-fiber-based paper from water wetting and dust contamination for real-life applications but also reinforces its solar reflectance by sunlight backscattering. It results in a sub-ambient cooling performance of 5°C and radiative cooling power of 104 W/m2 under direct solar irradiance of 834 W/m2 and 671 W/m2, respectively. The self-cleaning surface of the hierarchical composites extends its lifespan and keep its good cooling performance for outdoor applications. Additionally, dyed cellulose-fiber-based paper can absorb appropriate visible wavelengths to display specific colors and effectively reflect near-infrared lights to reduce solar heating, which synchronously achieves effective radiative cooling and aesthetic varieties.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"12 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80404188","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}
Pub Date : 2020-12-11DOI: 10.15587/1729-4061.2020.212820
P. Tryshyn, N. Honchar, Eduard Kondratiuk, D. Stepanov
Polymer-abrasive brush rotating tools are increasingly used for finishing operations in automated manufacturing. Given this, studying the process of their fibers’ wear has become important; and such a type of wear as the detachment of a whole fiber at the point of fixing has not been investigated in detail up to now. This phenomenon can lead to the disruption of stable equipment operation and the catastrophic wear of brushes. Therefore, it is a relevant task to search for and identify those limitations that could prevent fibers from detachment. This study involved the disc and cylindrical polymer-abrasive brushes as the most common in production. The current study has established that the detachment occurs at an unfavorable combination of the processing regimes and brushes’ parameters at rotations close to the limits specified by the manufacturer. When checking the temperature level at the fiber anchoring point, it was determined that the heating of the fibers in this region during operation was not enough to melt the polymeric base of the fibers and detach them. It has been established that the reason for the detachment of fibers is the accumulation of fatigue changes, which significantly accelerate under the limit modes. Studying the cyclical durability of fibers has made it possible to determine the ratios of critical processing modes to the tool parameters, which lead to the fatigue destruction of fibers at their fixing point. The following technological restrictions have been defined to warrant that fibers are not detached: ‒ it is not recommended to use circumferential cutting speeds exceeding 40 m/s; ‒ the tension during operation should not exceed 10 % of the fibers’ overhang magnitude. These limitations ensure the integrity of the tool, its high durability, as well as the stability of the process of parts’ finishing machining under an automated mode
{"title":"Development of Technological Restrictions When Operating Disc Polymer-Abrasive Brushes","authors":"P. Tryshyn, N. Honchar, Eduard Kondratiuk, D. Stepanov","doi":"10.15587/1729-4061.2020.212820","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.212820","url":null,"abstract":"Polymer-abrasive brush rotating tools are increasingly used for finishing operations in automated manufacturing. Given this, studying the process of their fibers’ wear has become important; and such a type of wear as the detachment of a whole fiber at the point of fixing has not been investigated in detail up to now. This phenomenon can lead to the disruption of stable equipment operation and the catastrophic wear of brushes. Therefore, it is a relevant task to search for and identify those limitations that could prevent fibers from detachment. This study involved the disc and cylindrical polymer-abrasive brushes as the most common in production. The current study has established that the detachment occurs at an unfavorable combination of the processing regimes and brushes’ parameters at rotations close to the limits specified by the manufacturer. When checking the temperature level at the fiber anchoring point, it was determined that the heating of the fibers in this region during operation was not enough to melt the polymeric base of the fibers and detach them. It has been established that the reason for the detachment of fibers is the accumulation of fatigue changes, which significantly accelerate under the limit modes. Studying the cyclical durability of fibers has made it possible to determine the ratios of critical processing modes to the tool parameters, which lead to the fatigue destruction of fibers at their fixing point. The following technological restrictions have been defined to warrant that fibers are not detached: ‒ it is not recommended to use circumferential cutting speeds exceeding 40 m/s; ‒ the tension during operation should not exceed 10 % of the fibers’ overhang magnitude. These limitations ensure the integrity of the tool, its high durability, as well as the stability of the process of parts’ finishing machining under an automated mode","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"76 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79095809","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}
The fundamental origin of the giant magnetostriction in the dual-phase nanostructured systems is under energetic discussion in recent years. Previous studies have revealed that the formation of tetragonal nanoinclusions induced the enlargement in local magnetocrystalline anisotropy, leading to a strengthened magneto-elastic coupling coefficient, which was considered to promote magnetostriction. As the other key factor of magnetostriction, the influence of the nanoinclusions on the elastic constants of the lattices is still unnoticeably. In this work, we propose a mechanism based on the experimental and theoretical results of binary and rare-earth (RE) doped FeGa single-crystals. Doping traces of RE atoms effectively increase the density of nanoinclusions in the A2 matrix, because of the high selectivity of RE atoms so that they possess stronger bonding interaction with Fe atoms rather than Ga atoms. As a sequence, the elastic constant ς 12 significantly increases with the rising density of tetragonal nanoinclusions as opposed to a constant ς 11, resulting in a remarkable enhancement in magnetostriction due to the inversely proportional relationship between magnetostriction (λ 001) and ς 11 - ς 11. A superior magnetostriction of 390 ppm is obtained in the RE-doped single-crystal due to the lattice softening induced by the nanoinclusions. This model sheds light into the contribution of RE atoms to magnetostriction in FeGa single-crystals, and establishes a foundation for developing new-generation dual-phase magnetostrictive materials to achieve unprecedented levels of magnetostriction.
{"title":"Giant Heterogeneous Magnetostriction Induced by Charge Accumulation-Mediated Nanoinclusion Formation in Dual-Phase Nanostructured Systems","authors":"Yijun Chen, Z. Fu, Yuye Wu, Yichen Xu, Yu Xiao, Jingmin Wang, Ruifeng Zhang, Chengbao Jiang","doi":"10.2139/ssrn.3742924","DOIUrl":"https://doi.org/10.2139/ssrn.3742924","url":null,"abstract":"The fundamental origin of the giant magnetostriction in the dual-phase nanostructured systems is under energetic discussion in recent years. Previous studies have revealed that the formation of tetragonal nanoinclusions induced the enlargement in local magnetocrystalline anisotropy, leading to a strengthened magneto-elastic coupling coefficient, which was considered to promote magnetostriction. As the other key factor of magnetostriction, the influence of the nanoinclusions on the elastic constants of the lattices is still unnoticeably. In this work, we propose a mechanism based on the experimental and theoretical results of binary and rare-earth (RE) doped FeGa single-crystals. Doping traces of RE atoms effectively increase the density of nanoinclusions in the A2 matrix, because of the high selectivity of RE atoms so that they possess stronger bonding interaction with Fe atoms rather than Ga atoms. As a sequence, the elastic constant ς 12 significantly increases with the rising density of tetragonal nanoinclusions as opposed to a constant ς 11, resulting in a remarkable enhancement in magnetostriction due to the inversely proportional relationship between magnetostriction (λ 001) and ς 11 - ς 11. A superior magnetostriction of 390 ppm is obtained in the RE-doped single-crystal due to the lattice softening induced by the nanoinclusions. This model sheds light into the contribution of RE atoms to magnetostriction in FeGa single-crystals, and establishes a foundation for developing new-generation dual-phase magnetostrictive materials to achieve unprecedented levels of magnetostriction.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77582078","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}
Yu Yin, Qiyang Tan, Qiang Sun, W. Ren, Jingqi Zhang, Shiyang Liu, Yingang Liu, M. Bermingham, Houwen Chen, Mingxing Zhang
A novel heterogeneous lamella (HL) design strategy was proposed to improve mechanical properties of a new cost-effective Fe 35 Ni 35 Cr 25 Mo 5 compositionally complicated alloy (CCA). A HL structure was produced by single-step heat treatment (800 °C for 1h) after cold rolling. This HL structure consists of alternative lamellae regions of coarse-grained FCC matrix (5∼20 μm), and regions containing ultra-fine grains or subgrains (200∼500 nm) together with nanoprecipitates (20-500 nm) and annealing twins. The 800 °C annealed sample with HL structure demonstrated a superior tensile property, with yield strength over 1.0 GPa and ductility of ~13%. Formation of the annealing twins and nanoprecipitates decorated HL structure was a result of the concurrent partial recrystallization and precipitation of σ phase at the shear bands with a high density of lattice defects (e.g. high-density dislocation walls and deformation twins). The latter restricted the growth of recrystallized grains, leading to the formation of ultrafine subgrains within the HL structure. The high yield strength resulted from the multistage hetero-deformation induced (HDI) strengthening and precipitation strengthening associated with heterogeneous lamella structures containing nanoprecipitates. The ductility was originated from the coexistence of multiple deformation mechanisms, which started with dislocation slip and formation of stacking faults at the initial stage, followed by nano-twinning at the higher strain level. This HL design strategy, comprising of composition and thermomechanical process designs, and the resultant microstructure tuning, open a broader window for development of cost-effective CCAs with enhanced performance.
为了提高Fe 35 Ni 35 Cr 25 Mo 5复合合金(CCA)的力学性能，提出了一种新的非均相片层(HL)设计策略。冷轧后单步热处理(800℃，保温1h)得到HL组织。这种HL结构由粗晶FCC基体(5 ~ 20 μm)的交替片层区域和含有超细晶粒或亚晶粒(200 ~ 500 nm)以及纳米沉淀物(20 ~ 500 nm)和退火孪晶的区域组成。经800℃退火后的HL组织试样具有优异的抗拉性能，屈服强度大于1.0 GPa，延展性为~13%。退火孪晶和装饰HL结构的纳米沉淀的形成是在具有高密度晶格缺陷(如高密度位错壁和变形孪晶)的剪切带处σ相的部分再结晶和析出同时发生的结果。后者限制了再结晶晶粒的生长，导致在HL组织内形成超细亚晶粒。高屈服强度是由含有纳米沉淀物的非均相片层结构引起的多级异质变形诱导(HDI)强化和沉淀强化引起的。延性源于多种变形机制的共存，在初始阶段始于位错滑移和层错的形成，随后在高应变水平上发生纳米孪晶。这种HL设计策略，包括成分和热机械工艺设计，以及由此产生的微观结构调整，为开发具有更高性能的成本效益的cca打开了更广阔的窗口。
{"title":"Heterogeneous Lamella Design to Tune the Mechanical Behaviour of a New Cost-Effective Compositionally Complicated Alloy","authors":"Yu Yin, Qiyang Tan, Qiang Sun, W. Ren, Jingqi Zhang, Shiyang Liu, Yingang Liu, M. Bermingham, Houwen Chen, Mingxing Zhang","doi":"10.2139/ssrn.3751555","DOIUrl":"https://doi.org/10.2139/ssrn.3751555","url":null,"abstract":"A novel heterogeneous lamella (HL) design strategy was proposed to improve mechanical properties of a new cost-effective Fe 35 Ni 35 Cr 25 Mo 5 compositionally complicated alloy (CCA). A HL structure was produced by single-step heat treatment (800 °C for 1h) after cold rolling. This HL structure consists of alternative lamellae regions of coarse-grained FCC matrix (5∼20 μm), and regions containing ultra-fine grains or subgrains (200∼500 nm) together with nanoprecipitates (20-500 nm) and annealing twins. The 800 °C annealed sample with HL structure demonstrated a superior tensile property, with yield strength over 1.0 GPa and ductility of ~13%. Formation of the annealing twins and nanoprecipitates decorated HL structure was a result of the concurrent partial recrystallization and precipitation of σ phase at the shear bands with a high density of lattice defects (e.g. high-density dislocation walls and deformation twins). The latter restricted the growth of recrystallized grains, leading to the formation of ultrafine subgrains within the HL structure. The high yield strength resulted from the multistage hetero-deformation induced (HDI) strengthening and precipitation strengthening associated with heterogeneous lamella structures containing nanoprecipitates. The ductility was originated from the coexistence of multiple deformation mechanisms, which started with dislocation slip and formation of stacking faults at the initial stage, followed by nano-twinning at the higher strain level. This HL design strategy, comprising of composition and thermomechanical process designs, and the resultant microstructure tuning, open a broader window for development of cost-effective CCAs with enhanced performance.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83036114","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}
Abstract Nucleation of crystalline defects such as dislocations lies at the heart of mechanical deformation. Here, we demonstrate a technique for observing the nucleation of individual dislocations during in situ transmission electron microscopy (TEM) tensile testing and measuring fundamental parameters relevant for plasticity from the individual events. Our method relies on systematic detection of dislocation slip traces with automated image analysis in an oriented single crystal Ni sample. Using the identification of individual defect traces from in situ testing, a cumulative probabilistic function is applied to correlate the relationship between a dislocation nucleation event and the corresponding stress level. Our analysis allows for the extrapolation of the activation parameters for individual dislocation nucleation events using the data on one sample in one tensile test. Precise and quantitative correlation of activation parameters for dislocation nucleation from in situ TEM nanomechanical testing can provide direct quantitative measurements useful for computational models of plasticity.
{"title":"Precise Measurement of Activation Parameters for Individual Dislocation Nucleation During in Situ Tem Tensile Testing of Single Crystal Nickel","authors":"Xiaoqing Li, A. Minor","doi":"10.2139/ssrn.3737304","DOIUrl":"https://doi.org/10.2139/ssrn.3737304","url":null,"abstract":"Abstract Nucleation of crystalline defects such as dislocations lies at the heart of mechanical deformation. Here, we demonstrate a technique for observing the nucleation of individual dislocations during in situ transmission electron microscopy (TEM) tensile testing and measuring fundamental parameters relevant for plasticity from the individual events. Our method relies on systematic detection of dislocation slip traces with automated image analysis in an oriented single crystal Ni sample. Using the identification of individual defect traces from in situ testing, a cumulative probabilistic function is applied to correlate the relationship between a dislocation nucleation event and the corresponding stress level. Our analysis allows for the extrapolation of the activation parameters for individual dislocation nucleation events using the data on one sample in one tensile test. Precise and quantitative correlation of activation parameters for dislocation nucleation from in situ TEM nanomechanical testing can provide direct quantitative measurements useful for computational models of plasticity.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"83 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80071848","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}
The paper has been described one of the recent effective optimization technique i.e. Over all Evaluation Criteria (OEC) to controlling the process parameter during Electrical discharge machining (EDM) of Al – 20 wt.% SiCP metal matrix composite (MMC). The MMC is one of the advance material in compare to the conventional material. To exploit the industrial application of this material with EDM it needs to optimize the process parameter for reliable and economical production of this process. For that the experiment is carried out by Central composite design (CCD) method by considering the input process parameters like peak current, pulse on time and flushing pressure and the output are material removal rate, tool wear rate, radial over cut and surface roughness (Ra). In order to optimize the process parameter a combine effect of Entropy weight measurement method and Over all Evaluation Criteria (OEC) is used to get a single numerical index. Finally, the present work.is is carried out by confirmation test to analyse the desirable approach of the selected model.
{"title":"Using Entropy Weight and Over All Evaluation Criteria Optimize the Parameters in EDM of Al–20 Wt. % SICP MMC","authors":"R. Bhuyan, A. Parida, P. Behera","doi":"10.2139/ssrn.3735855","DOIUrl":"https://doi.org/10.2139/ssrn.3735855","url":null,"abstract":"The paper has been described one of the recent effective optimization technique i.e. Over all Evaluation Criteria (OEC) to controlling the process parameter during Electrical discharge machining (EDM) of Al – 20 wt.% SiCP metal matrix composite (MMC). The MMC is one of the advance material in compare to the conventional material. To exploit the industrial application of this material with EDM it needs to optimize the process parameter for reliable and economical production of this process. For that the experiment is carried out by Central composite design (CCD) method by considering the input process parameters like peak current, pulse on time and flushing pressure and the output are material removal rate, tool wear rate, radial over cut and surface roughness (Ra). In order to optimize the process parameter a combine effect of Entropy weight measurement method and Over all Evaluation Criteria (OEC) is used to get a single numerical index. Finally, the present work.is is carried out by confirmation test to analyse the desirable approach of the selected model.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"283 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72707677","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}
S. R., D. S. Guru, Manjunath Aradhya, Anitha Raghavendra
The children face recognition system plays a vital role in application towards the track and recognize the children who are missing at a young age due to child trafficking or kidnapping. In this study, an attempt is made to find the rate of recognition of a young child face images from age 1 to 15 years, where the frequency of facial growth is higher in this interval. To study the effectiveness of the problem, a dimensionality reduction technique is adopted such as PCA followed by random forest classifier as one method and deep convolutional neural network as another method. The proposed model was vindicated with a relatively large dataset that was created to address this problem. The total number of longitudinal face images of 47 children each 12-15 years was 685 and each year consists of a single sample. Experimentation was carried out by varying the number of decision trees and the number of classes for efficacious analysis of the problem. The procured results were promising with deep learning classification techniques with 93% of mini-batch accuracy.
{"title":"Children Longitudinal Face Recognition Using Random Forest","authors":"S. R., D. S. Guru, Manjunath Aradhya, Anitha Raghavendra","doi":"10.2139/ssrn.3735819","DOIUrl":"https://doi.org/10.2139/ssrn.3735819","url":null,"abstract":"The children face recognition system plays a vital role in application towards the track and recognize the children who are missing at a young age due to child trafficking or kidnapping. In this study, an attempt is made to find the rate of recognition of a young child face images from age 1 to 15 years, where the frequency of facial growth is higher in this interval. To study the effectiveness of the problem, a dimensionality reduction technique is adopted such as PCA followed by random forest classifier as one method and deep convolutional neural network as another method. The proposed model was vindicated with a relatively large dataset that was created to address this problem. The total number of longitudinal face images of 47 children each 12-15 years was 685 and each year consists of a single sample. Experimentation was carried out by varying the number of decision trees and the number of classes for efficacious analysis of the problem. The procured results were promising with deep learning classification techniques with 93% of mini-batch accuracy.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73270018","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 wireless sensor networks, establishing a suitable link between the base station and nodes is an essential task. Link establishing is termed as routing which helps the network for reliable and efficient communication. At the same time attacks in the routing schemes to gain access to the data also increases and it significantly affects the network performance. Privacy preservation, encryption, and authentication can't handle some routing attacks. The trust has recently introduced a mechanism to increase safety and better node interaction. The routing mechanism of trust allows you to avoid that nodes are routed by the solution to be credible. Many trust-based Routing Protocol (RP) use routing that accounts for various routing attacks. This study aims to analyze the recent situation and search open research topics by investigating the existing proposed scheme. The paper presents the trust-based system and routing protocols. Eventually, comparative performance analysis of RP is made using the NS-2 network simulator.
{"title":"Implementing Trust Aware Routing Protocols for Privacy Preservation in MANET: Implementation & Synthesis","authors":"Shubham Joshi, D. Mishra","doi":"10.2139/ssrn.3735719","DOIUrl":"https://doi.org/10.2139/ssrn.3735719","url":null,"abstract":"In wireless sensor networks, establishing a suitable link between the base station and nodes is an essential task. Link establishing is termed as routing which helps the network for reliable and efficient communication. At the same time attacks in the routing schemes to gain access to the data also increases and it significantly affects the network performance. Privacy preservation, encryption, and authentication can't handle some routing attacks. The trust has recently introduced a mechanism to increase safety and better node interaction. The routing mechanism of trust allows you to avoid that nodes are routed by the solution to be credible. Many trust-based Routing Protocol (RP) use routing that accounts for various routing attacks. This study aims to analyze the recent situation and search open research topics by investigating the existing proposed scheme. The paper presents the trust-based system and routing protocols. Eventually, comparative performance analysis of RP is made using the NS-2 network simulator.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87366598","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}
Anil Johny, Dr. Madhusoodanan K. N., Dr. Tom J Nallikuzhy
The field of pathology has advanced so rapidly that it is now possible to produce whole slide images (WSI) from glass slides with digital scanners producing high-quality images. Image analysis algorithms applied to such digitized images facilitate automatic diagnostic tasks whilst assisting a medical expert. Successful detection of malignancy in histopathological images largely depends on the expertise of radiologists, though they sometimes disagree with their decisions. Computer-aided diagnosis provides a platform for a second opinion in diagnosis, which can improve the reliability of an expert's opinion. Deep learning provides promising results compared to the conventional approach that relies on manual extraction of features which is time-consuming and labor-intense. Due to the huge size, whole slide images are converted into patches and trained using a Convolutional Neural Network (CNN), a variant of the deep learning model for images. Experimental results show that the proposed native model achieved patch wise classification accuracy of 92.8% and area under ROC curve 0.97 which is close to the values while comparing with the existing pre-trained models.
{"title":"Optimization of CNN Model With Hyper Parameter Tuning for Enhancing Sturdiness in Classification of Histopathological Images","authors":"Anil Johny, Dr. Madhusoodanan K. N., Dr. Tom J Nallikuzhy","doi":"10.2139/ssrn.3735831","DOIUrl":"https://doi.org/10.2139/ssrn.3735831","url":null,"abstract":"The field of pathology has advanced so rapidly that it is now possible to produce whole slide images (WSI) from glass slides with digital scanners producing high-quality images. Image analysis algorithms applied to such digitized images facilitate automatic diagnostic tasks whilst assisting a medical expert. Successful detection of malignancy in histopathological images largely depends on the expertise of radiologists, though they sometimes disagree with their decisions. Computer-aided diagnosis provides a platform for a second opinion in diagnosis, which can improve the reliability of an expert's opinion. Deep learning provides promising results compared to the conventional approach that relies on manual extraction of features which is time-consuming and labor-intense. Due to the huge size, whole slide images are converted into patches and trained using a Convolutional Neural Network (CNN), a variant of the deep learning model for images. Experimental results show that the proposed native model achieved patch wise classification accuracy of 92.8% and area under ROC curve 0.97 which is close to the values while comparing with the existing pre-trained models.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80915793","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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