Abstract We present here a quantitative study of dislocation cross-slip, an essential thermally activated process in deformation of metals, in discrete dislocation dynamics (DDD) simulations. We implemented a stress-dependent line-tension model in DDD simulations, with minimal information from molecular dynamics (MD) simulations. This model allows reproducing in DDD simulations the probabilistic cross-slip rate calculated in MD simulations for Cu in a large range of stresses and temperatures. The implementation of an atomically-scale accurate cross-slip model allows simulating more accurately phenomena such as deformation softening, dislocation-precipitate interaction and dislocation patterning in DDD simulations.
{"title":"A Molecular Dynamics-Informed Probabilistic Cross-Slip Model in Discrete Dislocation Dynamics","authors":"A. Malka-Markovitz, B. Devincre, D. Mordehai","doi":"10.2139/ssrn.3603549","DOIUrl":"https://doi.org/10.2139/ssrn.3603549","url":null,"abstract":"Abstract We present here a quantitative study of dislocation cross-slip, an essential thermally activated process in deformation of metals, in discrete dislocation dynamics (DDD) simulations. We implemented a stress-dependent line-tension model in DDD simulations, with minimal information from molecular dynamics (MD) simulations. This model allows reproducing in DDD simulations the probabilistic cross-slip rate calculated in MD simulations for Cu in a large range of stresses and temperatures. The implementation of an atomically-scale accurate cross-slip model allows simulating more accurately phenomena such as deformation softening, dislocation-precipitate interaction and dislocation patterning in DDD simulations.","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"233 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72841549","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}
Haitao Zhao, Wei Chen, Zhuo Wang, Zhehao Sun, Chensu Wang, Fuming Lai, Hao Huang, O. A. Moses, M. Adam, Zijian Chen, Yichuan He, C. Pang, Yang Lu, P. K. Chu, Z. Yin, Xuefeng Yu
Digital manufacturing of materials in a rational and designable strategy and is gaining popularity on the macro-scale . However, it is challenging to control the nanocrystal morphologies on a nano-scale. Herein, we introduce Crystputer as a state-of-the-art cyber- physical system , which will enable digital manufacture of nanocrystals through convergence of cyber and physical systems. In the cyber system, an all-programmable process with rational design including codes, working files, mathematic models, and databases is designed. In the physical system, controllable synthesis is achieved by synergistic coupling of robot-assisted synthesis and nanocrystal growth , which are benefited from the identified structure-directing agents on the macro-scale as triggers of the surface energy to control the morphology on the atomic-scale. Driven by the Crystputer efficiency, over 2,300 experiments are conducted autonomously together with in situ characterization to build up the Au nanocrystals genome. The genome architecture with logic gates is further designed for the Crystputer. It is demonstrated that the Crystputer can be trained as an experienced expert for retrosynthesis and scale-up synthesis of targeted Au nanorods by taking advantage of the machine learning prediction and logic computation. The sophisticated mechanism encompassing design-control-synthesis-characterization-computing-retrosynthesis enables this Crystputer to deliver unprecedented performance and efficiency for rational design, controllable synthesis, and retrosynthesis of target Au nanocrystals. The insights and new knowledge open an opportunity to enhance the feasibility of Crystputer for intelligent digital manufacturing of customized nanocrystals in order to facilitate the paradigm shift of data-driven materials innovation from ‘code’ to ‘nanocrystals’.
{"title":"Cyber-Physical System Enabled Digital Manufacturing of Nanocrystals: A Crystputer","authors":"Haitao Zhao, Wei Chen, Zhuo Wang, Zhehao Sun, Chensu Wang, Fuming Lai, Hao Huang, O. A. Moses, M. Adam, Zijian Chen, Yichuan He, C. Pang, Yang Lu, P. K. Chu, Z. Yin, Xuefeng Yu","doi":"10.2139/ssrn.3898779","DOIUrl":"https://doi.org/10.2139/ssrn.3898779","url":null,"abstract":"Digital manufacturing of materials in a rational and designable strategy and is gaining popularity on the macro-scale . However, it is challenging to control the nanocrystal morphologies on a nano-scale. Herein, we introduce Crystputer as a state-of-the-art cyber- physical system , which will enable digital manufacture of nanocrystals through convergence of cyber and physical systems. In the cyber system, an all-programmable process with rational design including codes, working files, mathematic models, and databases is designed. In the physical system, controllable synthesis is achieved by synergistic coupling of robot-assisted synthesis and nanocrystal growth , which are benefited from the identified structure-directing agents on the macro-scale as triggers of the surface energy to control the morphology on the atomic-scale. Driven by the Crystputer efficiency, over 2,300 experiments are conducted autonomously together with in situ characterization to build up the Au nanocrystals genome. The genome architecture with logic gates is further designed for the Crystputer. It is demonstrated that the Crystputer can be trained as an experienced expert for retrosynthesis and scale-up synthesis of targeted Au nanorods by taking advantage of the machine learning prediction and logic computation. The sophisticated mechanism encompassing design-control-synthesis-characterization-computing-retrosynthesis enables this Crystputer to deliver unprecedented performance and efficiency for rational design, controllable synthesis, and retrosynthesis of target Au nanocrystals. The insights and new knowledge open an opportunity to enhance the feasibility of Crystputer for intelligent digital manufacturing of customized nanocrystals in order to facilitate the paradigm shift of data-driven materials innovation from ‘code’ to ‘nanocrystals’.","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79787233","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}
3D In painting is a method for changing a 2D picture over to a3D photograph and saving the harmed, debilitating, or missing regions of the photograph by filling it into a perfect image. The principal issue in this cycle happens when making the profundity map, recognizing the missing segments, filling the missing bits utilizing fitting filling techniques. These issues are fundamental and regular in 3D photograph in painting procedures. So the fundamental point of this review is recognizing each progression in 3D in painting procedures and distinguishing their disappointment cases. Numerous strategies utilize different pictures as information and numerous techniques utilize a single picture as input sources.
{"title":"A Review on 3D Photo in Painting Techniques","authors":"Ayana T. K, Binoy K. P.","doi":"10.2139/SSRN.3781302","DOIUrl":"https://doi.org/10.2139/SSRN.3781302","url":null,"abstract":"3D In painting is a method for changing a 2D picture over to a3D photograph and saving the harmed, debilitating, or missing regions of the photograph by filling it into a perfect image. The principal issue in this cycle happens when making the profundity map, recognizing the missing segments, filling the missing bits utilizing fitting filling techniques. These issues are fundamental and regular in 3D photograph in painting procedures. So the fundamental point of this review is recognizing each progression in 3D in painting procedures and distinguishing their disappointment cases. Numerous strategies utilize different pictures as information and numerous techniques utilize a single picture as input sources.","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"117 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79382457","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 : 2020-11-30DOI: 10.21303/2585-6847.2020.001509
O. Morozova, E. Gevorkyan
This descriptive review presents current knowledge about the bioengineering use of a zirconium dioxide, the advantages and disadvantages of the material, and the prospects for research in this direction. The work reflects the success of the practical application of the zirconium dioxide as a material for dental structures and biological implants. Such practical characteristics, such as color-stability, chemical stability, good aesthetics, biocompatibility and durability, allowed to actively use the zirconium dioxide as a material for producing various dental structures. In comparison with other ceramics, the presence of high-performance of strength and fracture toughness of the zirconium dioxide enables the use of this material as an alternative material for the reconstructions in the readings with considerable loads. High hardness determines the zirconium dioxide as an excellent material for articular prostheses, because of its hardness, provides a low level of wear and excellent biocompatibility. However, along with positive characteristics, a widespread practical problem of using the zirconium dioxide in dentistry is a chip or fracture of veneering ceramics. It has also been reported that there is a shortage of orthopedic implants such as hydrothermal stability. The solution of such problems is indicated and the use of composite materials based on the zirconium dioxide, which allows to solve a similar problem, as well as to increase the service life and reliability of orthopedic implants by providing a higher fracture toughness and mechanical strength. The existence of such composite materials based on the zirconium dioxide provides a significant increase in the wear resistance of orthopedic implants, which is essential for successful prosthetics
{"title":"Current State of Appliance Zirconium Dioxide in Bioengineering","authors":"O. Morozova, E. Gevorkyan","doi":"10.21303/2585-6847.2020.001509","DOIUrl":"https://doi.org/10.21303/2585-6847.2020.001509","url":null,"abstract":"This descriptive review presents current knowledge about the bioengineering use of a zirconium dioxide, the advantages and disadvantages of the material, and the prospects for research in this direction. The work reflects the success of the practical application of the zirconium dioxide as a material for dental structures and biological implants. Such practical characteristics, such as color-stability, chemical stability, good aesthetics, biocompatibility and durability, allowed to actively use the zirconium dioxide as a material for producing various dental structures. In comparison with other ceramics, the presence of high-performance of strength and fracture toughness of the zirconium dioxide enables the use of this material as an alternative material for the reconstructions in the readings with considerable loads. High hardness determines the zirconium dioxide as an excellent material for articular prostheses, because of its hardness, provides a low level of wear and excellent biocompatibility. However, along with positive characteristics, a widespread practical problem of using the zirconium dioxide in dentistry is a chip or fracture of veneering ceramics. It has also been reported that there is a shortage of orthopedic implants such as hydrothermal stability. The solution of such problems is indicated and the use of composite materials based on the zirconium dioxide, which allows to solve a similar problem, as well as to increase the service life and reliability of orthopedic implants by providing a higher fracture toughness and mechanical strength. The existence of such composite materials based on the zirconium dioxide provides a significant increase in the wear resistance of orthopedic implants, which is essential for successful prosthetics","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79839213","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 radiation responses of two newly developed ferritic/martensitic steels, FC92-B and -N, were tested in comparison to reference alloys HT9 and Gr.92. Ion irradiations on the steels were performed up to 480 dpa at 475 °C using 3.5-MeV Fe++ ions with a helium pre-implantation of 1 appm/dpa. Void swelling and M2X precipitation were characterized using FE-TEM and EDS. Swelling resistance was the greatest in FC92-N, which showed suppressed void nucleation and growth. The swelling rate in FC92-N was determined as 0.007 %/dpa, indicating that FC92-N did not reach the steady-state swelling regime with void nucleation behavior. The least swelling-resistant alloy was HT9 with a swelling rate of 0.038 %/dpa. Cr-rich carbide, M2X, was observed in only 9Cr-FC92 series; however, its formation did not depend on radiation damage. This exceptional M2X evolution in FC92 series may be attributed to B and N alloying, which resulted in suppressed M23C6 carbide formation during metallurgical production and sequentially high C contents in the alloy solution of FC92 series. A narrower range (800 nm) of M2X evolution compared to that of cavity formation (1,000 nm) indicates that radiation-induced precipitation (RIP) is sensitive to the injected interstitial effect. Precipitation-induced Cr depletion and preferential interstitial outward sinking to the free surface synergistically modified local chemical composition before void evolution and led to double-peak swelling by locally forming a low-alloyed zone. This study provides the first experimental evidence that RIP modifies the swelling–depth profiles and in turn, determines double-peak swelling in ion-irradiated steels.
{"title":"Radiation-Induced Swelling and Precipitation in Fe ++ Ion-Irradiated Ferritic/Martensitic Steels","authors":"M. Lee, Yunsong Jung, Sangjoon Ahn","doi":"10.2139/ssrn.3726291","DOIUrl":"https://doi.org/10.2139/ssrn.3726291","url":null,"abstract":"The radiation responses of two newly developed ferritic/martensitic steels, FC92-B and -N, were tested in comparison to reference alloys HT9 and Gr.92. Ion irradiations on the steels were performed up to 480 dpa at 475 °C using 3.5-MeV Fe++ ions with a helium pre-implantation of 1 appm/dpa. Void swelling and M2X precipitation were characterized using FE-TEM and EDS. Swelling resistance was the greatest in FC92-N, which showed suppressed void nucleation and growth. The swelling rate in FC92-N was determined as 0.007 %/dpa, indicating that FC92-N did not reach the steady-state swelling regime with void nucleation behavior. The least swelling-resistant alloy was HT9 with a swelling rate of 0.038 %/dpa. Cr-rich carbide, M2X, was observed in only 9Cr-FC92 series; however, its formation did not depend on radiation damage. This exceptional M2X evolution in FC92 series may be attributed to B and N alloying, which resulted in suppressed M23C6 carbide formation during metallurgical production and sequentially high C contents in the alloy solution of FC92 series. A narrower range (800 nm) of M2X evolution compared to that of cavity formation (1,000 nm) indicates that radiation-induced precipitation (RIP) is sensitive to the injected interstitial effect. Precipitation-induced Cr depletion and preferential interstitial outward sinking to the free surface synergistically modified local chemical composition before void evolution and led to double-peak swelling by locally forming a low-alloyed zone. This study provides the first experimental evidence that RIP modifies the swelling–depth profiles and in turn, determines double-peak swelling in ion-irradiated steels.","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79807717","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. Haratian, F. Niessen, F. Grumsen, M. Nancarrow, E. Pereloma, M. Villa, T. Christiansen, M. Somers
Abstract Surface engineering of Zr51.3Al8.5Cu31.3Ni4Ti4.9 bulk metallic glass (BMG) by gaseous oxidizing below the glass-transition temperature is investigated as a means to introduce compressive residual stress in the surface region. The ZrCuAl-based BMG was exposed to an extremely low oxygen partial pressure of 10−41 bar at 600 K for 60 h. The oxidizing treatment led to the formation of an internal oxidation zone, consisting of finely dispersed nano-crystalline cubic ZrO2 (c-ZrO2), metallic regions inclined with the surface and Cu-hillocks at the surface. The stresses introduced by the volume expansion associated with oxidation were evaluated from i) the lattice strains within c-ZrO2, as determined with an X-ray diffraction (XRD) based method, and ii) strain-relaxation as a response to annular focused ion beam (FIB) milling, as monitored with digital image correlation (DIC). XRD analysis yielded -1.5 GPa (compressive stress) in the nano-crystalline c-ZrO2, while the strain relaxation monitored with FIB-DIC analysis indicated compressive residual stresses of −1.4 GPa in the internal oxidation zone. The strains and stresses determined with the independent measurement methods are discussed. The quantitative macro-strains are discussed in relation to the microstructural features and stress relaxation mechanisms during evolution of the internal oxidation zone.
{"title":"Strain, Stress and Stress Relaxation in Oxidized Zrcual-Based Bulk Metallic Glass","authors":"S. Haratian, F. Niessen, F. Grumsen, M. Nancarrow, E. Pereloma, M. Villa, T. Christiansen, M. Somers","doi":"10.2139/ssrn.3639770","DOIUrl":"https://doi.org/10.2139/ssrn.3639770","url":null,"abstract":"Abstract Surface engineering of Zr51.3Al8.5Cu31.3Ni4Ti4.9 bulk metallic glass (BMG) by gaseous oxidizing below the glass-transition temperature is investigated as a means to introduce compressive residual stress in the surface region. The ZrCuAl-based BMG was exposed to an extremely low oxygen partial pressure of 10−41 bar at 600 K for 60 h. The oxidizing treatment led to the formation of an internal oxidation zone, consisting of finely dispersed nano-crystalline cubic ZrO2 (c-ZrO2), metallic regions inclined with the surface and Cu-hillocks at the surface. The stresses introduced by the volume expansion associated with oxidation were evaluated from i) the lattice strains within c-ZrO2, as determined with an X-ray diffraction (XRD) based method, and ii) strain-relaxation as a response to annular focused ion beam (FIB) milling, as monitored with digital image correlation (DIC). XRD analysis yielded -1.5 GPa (compressive stress) in the nano-crystalline c-ZrO2, while the strain relaxation monitored with FIB-DIC analysis indicated compressive residual stresses of −1.4 GPa in the internal oxidation zone. The strains and stresses determined with the independent measurement methods are discussed. The quantitative macro-strains are discussed in relation to the microstructural features and stress relaxation mechanisms during evolution of the internal oxidation zone.","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76078417","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 : 2020-10-23DOI: 10.15587/1729-4061.2020.211425
O. Mytrofanov, A. Proskurin, Andrii Poznanskyi
This paper reports the results of an experimental study of the prototype rotary-piston air motor RPD-4,4/1,75 in the form of speed characteristics. The maxima of the air motor's performance effective indicators have been determined, as well as the rotation change ranges that correspond to them. It has been established that for the intake receiver's air pressure change range within 0.4...0.8 MPa the maximum value of effective power is 1.7...2.5 kW. In this case, the maximum value of the torque and mean effective pressure for a given pressure range in the intake receiver is 17.0...18.2 N∙m and 0.13...0.18 MPa, respectively. The dependence has been derived of the hourly air consumption on the rotations and pressure in the intake receiver. Depending on the test mode, the hourly air consumption is within 25…226 kg/hour. It has been established that the minimum values of the specific effective air consumption correspond to 800...1,000 rpm. Thus, for a maximum value of air pressure in the intake receiver of 0.8 MPa, the specific effective consumption is 60.8...93.2 kg/(kW∙h), for the minimum value of 0.4 MPa – 49.7...81.3 kg/(kW∙h). The potential of the adiabatic expansion capacity has been determined, brought to the air motor, as well as the effective adiabatic efficiency. The maximum efficiency of the air motor corresponds to 800...1,000 rpm. In this case, the maximum efficiency value was achieved at a pressure in the intake receiver of 0.4 MPa; it is 0.41. The dependences have been derived of the change in the pressure of spent air in the exhaust receiver, the maximum value of which does not exceed 0.075 MPa
{"title":"Determining the Effective Indicators of a Rotary-Piston Motor Operation","authors":"O. Mytrofanov, A. Proskurin, Andrii Poznanskyi","doi":"10.15587/1729-4061.2020.211425","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.211425","url":null,"abstract":"This paper reports the results of an experimental study of the prototype rotary-piston air motor RPD-4,4/1,75 in the form of speed characteristics. The maxima of the air motor's performance effective indicators have been determined, as well as the rotation change ranges that correspond to them. It has been established that for the intake receiver's air pressure change range within 0.4...0.8 MPa the maximum value of effective power is 1.7...2.5 kW. In this case, the maximum value of the torque and mean effective pressure for a given pressure range in the intake receiver is 17.0...18.2 N∙m and 0.13...0.18 MPa, respectively. The dependence has been derived of the hourly air consumption on the rotations and pressure in the intake receiver. Depending on the test mode, the hourly air consumption is within 25…226 kg/hour. It has been established that the minimum values of the specific effective air consumption correspond to 800...1,000 rpm. Thus, for a maximum value of air pressure in the intake receiver of 0.8 MPa, the specific effective consumption is 60.8...93.2 kg/(kW∙h), for the minimum value of 0.4 MPa – 49.7...81.3 kg/(kW∙h). The potential of the adiabatic expansion capacity has been determined, brought to the air motor, as well as the effective adiabatic efficiency. The maximum efficiency of the air motor corresponds to 800...1,000 rpm. In this case, the maximum efficiency value was achieved at a pressure in the intake receiver of 0.4 MPa; it is 0.41. The dependences have been derived of the change in the pressure of spent air in the exhaust receiver, the maximum value of which does not exceed 0.075 MPa","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84250365","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}
Yubao Zhao, Jingyu Gao, Lina Li, Sheng Chen, Chun Hu, W. Choi
Solar-driven hydrogen peroxide (H2O2) production presents unique merits of sustainability and environmental friendliness. Herein, highly efficient solar-driven H2O2 production through dioxygen reduction is achieved by employing polymeric carbon nitride (PCN) framework with sodium cyanaminate moiety (PCN-NaCA), affording a superior H2O2 production rate of 175 μmol/h on 10 mg photocatalyst and a notable apparent quantum yield of 27.6% at 380 nm. The overall photocatalytic transformation process is systematically analyzed using various steady-state/transient spectroscopic and computational methods. The presence of sodium cyanaminate moiety in PCN-NaCA induces the following multiple effects: enhancing photon absorption, creating the coexistence of p-type and n-type domains, strengthening surface adsorption of dioxygen, and favoring highly selective 2e− ORR. In particular, the adsorption of dioxygen on PCN-NaCA enhances the population and lifetime of trapped electrons in the ps-ns time regime, which should have a notable synergic effect on oxygen reduction process.
{"title":"Identification and Analysis of Multiple Factors Controlling Solar-Driven H 2O 2 Synthesis Using Engineered Polymeric Carbon Nitride","authors":"Yubao Zhao, Jingyu Gao, Lina Li, Sheng Chen, Chun Hu, W. Choi","doi":"10.2139/ssrn.3606779","DOIUrl":"https://doi.org/10.2139/ssrn.3606779","url":null,"abstract":"\u0000 Solar-driven hydrogen peroxide (H2O2) production presents unique merits of sustainability and environmental friendliness. Herein, highly efficient solar-driven H2O2 production through dioxygen reduction is achieved by employing polymeric carbon nitride (PCN) framework with sodium cyanaminate moiety (PCN-NaCA), affording a superior H2O2 production rate of 175 μmol/h on 10 mg photocatalyst and a notable apparent quantum yield of 27.6% at 380 nm. The overall photocatalytic transformation process is systematically analyzed using various steady-state/transient spectroscopic and computational methods. The presence of sodium cyanaminate moiety in PCN-NaCA induces the following multiple effects: enhancing photon absorption, creating the coexistence of p-type and n-type domains, strengthening surface adsorption of dioxygen, and favoring highly selective 2e− ORR. In particular, the adsorption of dioxygen on PCN-NaCA enhances the population and lifetime of trapped electrons in the ps-ns time regime, which should have a notable synergic effect on oxygen reduction process.","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86103792","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 paper presents a novel research study of the behavior analysis regarding failure/repair rates of subunits of a screw plant system comprising various of subunits of varying manufacturing nature. A screw plant consists of four subsystems such as Heading (A), Slotting (B), Threading (C), and Polishing Machine (D). These units arranged in the arrangement. Furthermore, these papers viably utilize the regenerative point technique and deliver consistent failure /repair rates.
{"title":"Behavior Analysis of a Screw Plant","authors":"Arun Kumar","doi":"10.2139/ssrn.3686514","DOIUrl":"https://doi.org/10.2139/ssrn.3686514","url":null,"abstract":"This paper presents a novel research study of the behavior analysis regarding failure/repair rates of subunits of a screw plant system comprising various of subunits of varying manufacturing nature. A screw plant consists of four subsystems such as Heading (A), Slotting (B), Threading (C), and Polishing Machine (D). These units arranged in the arrangement. Furthermore, these papers viably utilize the regenerative point technique and deliver consistent failure /repair rates.","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80599722","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 In this investigation we report the formation of a graded microstructure in copper/tantalum ultrafine grained (UFG) multi-layered composite fabricated by cross accumulative roll bonding (CARB) process at high temperatures. The microstructure, micro-texture and bulk texture evolution in the copper/tantalum composite was established. A gradient microstructure develops along the thickness of the specimen during the CARB process. The fragmentation of tantalum in between copper layers and the grain refinement with evolving passes has been explained. The deformed copper layers show rotated cube texture and deformed tantalum layers show cube texture with γ-fibre. The overall texture of copper/tantalum composite weakens after the process of ARB; copper undergoing texture randomization post annealing. The crucial role of interfaces on the evolution of texture is demonstrated. The microstructural gradient in the specimen possess equiaxed, lamellar as well as large deformed grains with tantalum's grain size being in the scale of 200 nm. The correlation of microstructural gradient with orientation relationship (OR) between copper and tantalum layers was studied, confirming higher misorientation in OR at regions under high strain. Dynamic recrystallization taking place at the copper/tantalum interface has been elaborated with the aid of microtexture analysis.
{"title":"Graded Microstructure and Texture in Ultrafine Grained Multi-Layered Immiscible Bimetallic System","authors":"K. Dash, K. U. Yazar, K. Chattopadhyay, S. Suwas","doi":"10.2139/ssrn.3606802","DOIUrl":"https://doi.org/10.2139/ssrn.3606802","url":null,"abstract":"Abstract In this investigation we report the formation of a graded microstructure in copper/tantalum ultrafine grained (UFG) multi-layered composite fabricated by cross accumulative roll bonding (CARB) process at high temperatures. The microstructure, micro-texture and bulk texture evolution in the copper/tantalum composite was established. A gradient microstructure develops along the thickness of the specimen during the CARB process. The fragmentation of tantalum in between copper layers and the grain refinement with evolving passes has been explained. The deformed copper layers show rotated cube texture and deformed tantalum layers show cube texture with γ-fibre. The overall texture of copper/tantalum composite weakens after the process of ARB; copper undergoing texture randomization post annealing. The crucial role of interfaces on the evolution of texture is demonstrated. The microstructural gradient in the specimen possess equiaxed, lamellar as well as large deformed grains with tantalum's grain size being in the scale of 200 nm. The correlation of microstructural gradient with orientation relationship (OR) between copper and tantalum layers was studied, confirming higher misorientation in OR at regions under high strain. Dynamic recrystallization taking place at the copper/tantalum interface has been elaborated with the aid of microtexture analysis.","PeriodicalId":18731,"journal":{"name":"Materials Processing & Manufacturing eJournal","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82693061","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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