Pub Date : 2020-06-30DOI: 10.15587/1729-4061.2020.203391
Totok Suwanda, R. Soenoko, Y. Irawan, Moch. Agus Choiron
In the previous study, Continuous Drive Friction Welding (CDFW) had been investigated to determine the strength of joining, burn off, and temperature distribution. In this study, Dissimilar Metal CDFW was studied to assess temperature cycle analysis. Aluminum 6061 (A6061) workpiece was fixed, and an AISI 304 was rotated at 1,000 rpm. The temperature distribution was measured by using an OMEGA Thermocouple Data Logger. The thermocouple was installed near joining location 5 mm distance from the joint. In the computer simulation, the geometry of CDFW was designed using ANSYS Design Modeler. Computer simulation with transient thermal combined with static structural analysis was modeled by using ANSYS academic version Rel. 18.1. The boundary condition was set based on the experimental condition, where the Aluminum 6061 was fixed, and the AISI 304 was rotated at 1,000 rpm. Based on the experimental results, the temperature profile as the outer surface of the distance of the center of the joint location can be measured. From the simulation results, it can be seen that the temperature cycle profile is the same trend with experimental results. The mechanical properties provided that this phenomenon is shown in the characteristics of tensile strength, microstructure and hardness test as model analysis to denote the connection from temperature cycle profile with mechanical properties test results. Microstructure observation revealed that there is no significant difference in grain size and grain shape on the stainless steel side. Computer simulation results showed that the welded aluminum-stainless steel joint shows marks of heat affected zone near the weld interface only on the aluminum side, and this was confirmed by experimental results
{"title":"Temperature Cycle Analysis of A6061-AISI304 Dissimilar Metal Continuous Drive Friction Welding","authors":"Totok Suwanda, R. Soenoko, Y. Irawan, Moch. Agus Choiron","doi":"10.15587/1729-4061.2020.203391","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.203391","url":null,"abstract":"In the previous study, Continuous Drive Friction Welding (CDFW) had been investigated to determine the strength of joining, burn off, and temperature distribution. In this study, Dissimilar Metal CDFW was studied to assess temperature cycle analysis. Aluminum 6061 (A6061) workpiece was fixed, and an AISI 304 was rotated at 1,000 rpm. The temperature distribution was measured by using an OMEGA Thermocouple Data Logger. The thermocouple was installed near joining location 5 mm distance from the joint. In the computer simulation, the geometry of CDFW was designed using ANSYS Design Modeler. Computer simulation with transient thermal combined with static structural analysis was modeled by using ANSYS academic version Rel. 18.1. The boundary condition was set based on the experimental condition, where the Aluminum 6061 was fixed, and the AISI 304 was rotated at 1,000 rpm. Based on the experimental results, the temperature profile as the outer surface of the distance of the center of the joint location can be measured. From the simulation results, it can be seen that the temperature cycle profile is the same trend with experimental results. The mechanical properties provided that this phenomenon is shown in the characteristics of tensile strength, microstructure and hardness test as model analysis to denote the connection from temperature cycle profile with mechanical properties test results. Microstructure observation revealed that there is no significant difference in grain size and grain shape on the stainless steel side. Computer simulation results showed that the welded aluminum-stainless steel joint shows marks of heat affected zone near the weld interface only on the aluminum side, and this was confirmed by experimental results","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80739571","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 : 2020-06-30DOI: 10.15587/1729-4061.2020.203186
F. Fachruddin, I. Susanto, Ching-Cheng Chen, Nugroho Eko Setijogiarto, F. Zainuri, S. Permana, J. Soedarsono
The core-shell structure of Ce-doped TiO 2 @SiO 2 @(Ni-Cu-Zn) ferrite noted of CTSF as composite nanoparticles (NPs) was synthesized using a modified sol-gel method. The physicochemical properties of as-prepared products were characterized completely by X-ray diffraction (XRD), Brunauer-Emmit-Teller (BET), X-ray photoelectron spectroscopy (XPS) and superconducting quantum interference device (SQUID), serially. Meanwhile, assessment of the photocataly s tic activity of catalyst was performed by ultraviolet-visible spectrometry (UV-vis). The results of the study show that the anatase phase related to the TiO 2 structure was constructed on the outer shell coating of composite NPs. However, the second phase associated with the Ce structure was not easy to be detected on the XRD pattern, confirming that the doping Ce had been incorporated into the TiO 2 crystal structure. The mesoporous structure of Ce-doped TiO 2 layers was demonstrated by the type IV isotherm and H3 type hysteresis loop. The homogenous pore size was generated with the specific surface area up to 111.916 m 2 /g and 0.241 cc/g of pore volume. The stoichiometry of the chemical composition formed with fewer defects on the surface of TiO 2 layers was exhibited by the symmetry curve of Ti 2p 3/2 and Ti 2p 1/2 peaks of XPS spectra. Meanwhile, the redox couple corresponding to Ce 3+ /Ce 4+ was incorporated inside the thin TiO 2 coating. Furthermore, the catalyst magnetic NPs can be also separated by using an external magnetic field from the reaction system. The product performance associated with the degradation efficiency was achieved to be 50 % in the aqueous solution of methylene blue (MB)
{"title":"Surface Modification of Magnetic TiO2 Core-Shell with Doped Cerium for Enhancement of Photocatalytic Performance","authors":"F. Fachruddin, I. Susanto, Ching-Cheng Chen, Nugroho Eko Setijogiarto, F. Zainuri, S. Permana, J. Soedarsono","doi":"10.15587/1729-4061.2020.203186","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.203186","url":null,"abstract":"The core-shell structure of Ce-doped TiO 2 @SiO 2 @(Ni-Cu-Zn) ferrite noted of CTSF as composite nanoparticles (NPs) was synthesized using a modified sol-gel method. The physicochemical properties of as-prepared products were characterized completely by X-ray diffraction (XRD), Brunauer-Emmit-Teller (BET), X-ray photoelectron spectroscopy (XPS) and superconducting quantum interference device (SQUID), serially. Meanwhile, assessment of the photocataly s tic activity of catalyst was performed by ultraviolet-visible spectrometry (UV-vis). The results of the study show that the anatase phase related to the TiO 2 structure was constructed on the outer shell coating of composite NPs. However, the second phase associated with the Ce structure was not easy to be detected on the XRD pattern, confirming that the doping Ce had been incorporated into the TiO 2 crystal structure. The mesoporous structure of Ce-doped TiO 2 layers was demonstrated by the type IV isotherm and H3 type hysteresis loop. The homogenous pore size was generated with the specific surface area up to 111.916 m 2 /g and 0.241 cc/g of pore volume. The stoichiometry of the chemical composition formed with fewer defects on the surface of TiO 2 layers was exhibited by the symmetry curve of Ti 2p 3/2 and Ti 2p 1/2 peaks of XPS spectra. Meanwhile, the redox couple corresponding to Ce 3+ /Ce 4+ was incorporated inside the thin TiO 2 coating. Furthermore, the catalyst magnetic NPs can be also separated by using an external magnetic field from the reaction system. The product performance associated with the degradation efficiency was achieved to be 50 % in the aqueous solution of methylene blue (MB)","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78557169","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 : 2020-06-30DOI: 10.15587/1729-4061.2020.205226
M. Sashnova, Andreii Zahorulko, T. Savchenko, Sergii Gakhovich, I. Parkhomenko, D. Pankov
Based on the information structure of an automated quality monitoring system, we have designed a system to analyze information on the quality of forming the shape of PET-packaging, with a possibility of statistical control over the technological process using Shewhart control charts. That has been demonstrated using an example of the proposed technique of quality estimation of the finished PET bottles based on the thickness of their walls. Obtaining high-quality PET-packaging directly depends on the degree of perfection of all technological stages, thereby predetermining the necessity to build an effective system to control and manage the technological process of the shape formation of bottles made from polyethylene terephthalate. An analysis of information about the quality of PET-packaging shape formation based on monitoring the information structure of an automated system would make it possible to ensure operative adjustment of shape forming parameters at the minimized percentage of defects by organizing selective control over the products made. The use of statistical methods based on Shewhart control charts could enable the development of authentic algorithms for monitoring the shape formation quality aimed to track violations of technological parameters and compile recommendations on improving the process quality, as well as resource-use efficiency. The statistical estimation of cause-effect relations between the main technological parameters and product quality indicators involves the algorithm that monitors the quality of PET-packaging shape formation. This makes it possible to ensure the minimum level of defects in bottles when applying the devised Shewhart control chart. We have proposed a fuzzy cognitive chart for defining the preventive corrective actions directed at the elimination of the main causes of a defect at bottle shape formation, taking into consideration the interrelations of factors and their consequences on the resulting process quality
{"title":"Improving the Quality of the Technological Process of Packaging Shape Formation Based on the Information Structure of an Automated System","authors":"M. Sashnova, Andreii Zahorulko, T. Savchenko, Sergii Gakhovich, I. Parkhomenko, D. Pankov","doi":"10.15587/1729-4061.2020.205226","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.205226","url":null,"abstract":"Based on the information structure of an automated quality monitoring system, we have designed a system to analyze information on the quality of forming the shape of PET-packaging, with a possibility of statistical control over the technological process using Shewhart control charts. That has been demonstrated using an example of the proposed technique of quality estimation of the finished PET bottles based on the thickness of their walls. Obtaining high-quality PET-packaging directly depends on the degree of perfection of all technological stages, thereby predetermining the necessity to build an effective system to control and manage the technological process of the shape formation of bottles made from polyethylene terephthalate. An analysis of information about the quality of PET-packaging shape formation based on monitoring the information structure of an automated system would make it possible to ensure operative adjustment of shape forming parameters at the minimized percentage of defects by organizing selective control over the products made. The use of statistical methods based on Shewhart control charts could enable the development of authentic algorithms for monitoring the shape formation quality aimed to track violations of technological parameters and compile recommendations on improving the process quality, as well as resource-use efficiency. The statistical estimation of cause-effect relations between the main technological parameters and product quality indicators involves the algorithm that monitors the quality of PET-packaging shape formation. This makes it possible to ensure the minimum level of defects in bottles when applying the devised Shewhart control chart. We have proposed a fuzzy cognitive chart for defining the preventive corrective actions directed at the elimination of the main causes of a defect at bottle shape formation, taking into consideration the interrelations of factors and their consequences on the resulting process quality","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80295374","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 concrete does not attain its original shape after unloading as it is not an elastic material. It is a non-linear material as depicted by its stress-strain curve. Hence, the elastic constants like modulus and Poisson’s ratio are not strictly applicable to such a complex, heterogeneous and nonlinear construction material. However, an elastic behaviour is assumed for the analysis and design of concrete structures by making use of these constants. The modulus of elasticity of concrete is its inherent property of undergoing an elastic deformation. Higher value of modulus leads to an enhanced stiffness of the structural elements. Curing is one of the important parameters influencing the modulus value. Curing caters to maintaining the required temperature, preventing water loss and shrinkage associated with it. The Shrinkage Reducing Admixture (SRA) in the form of Polyethylene Glycol 400 (PEG 400) liquid, added as a self-curing agent, plays an important role of reducing the water evaporation from the concrete mass, resulting into an improved water retention capacity of the concrete. PEG 400 is hydrophilic in nature. It plays a dual role of controlling evaporation and attracting moisture from the atmosphere. Self-curing leads to uninterrupted and effective curing by retaining the required quantity of water for an adequate cement hydration and maintaining the high relative humidity (RH), thereby resulting in to hard and dense concrete, with reduced thermal and shrinkage cracks. To provide a practical solution for the nonavailability of better quality water or lack of proper curing due to negligence, producing a self-curing concrete is a sustainable option. Generally, self-curing is advocated for the High Strength Concrete (HSC) having low water-cement ratio (w/c), because of chemical shrinkage associated with Portland cement hydration and low permeability of these materials. Moreover, it is an effective way to reduce the self-desiccation, autogenous shrinkage, plastic shrinkage cracking, drying shrinkage cracking and water absorption. Though the structural elements like Reinforced Cement Concrete (RCC) slabs are cast using lower grade concrete like M20, generally with higher w/c ratio, they are directly exposed to the harsh environment while concreting and a considerable period after concreting. To add to this, many times, the curing is not sufficient on the construction site. This leads to the undesirable situation of concrete properties not getting developed to their full potential values; the vital parameters being strength and modulus. Modulus of elasticity of concrete is known to be a function of its compressive strength. Development of required modulus of elasticity, for a structural element with a particular concrete grade, makes it adequately stiff thereby satisfying the limit state of serviceability for deflection. Excessive deflection of any structural element is highly undesirable phenomenon; moreover, it is well established fact in RCC the
{"title":"Computation of Static Modulus of Elasticity and Poisson's Ratio of M20 Grade Self-Curing Concrete with PEG-400 as a Self Curing Agent Using IS Code and ASTM Standard","authors":"D. Patil, S. Anadinni","doi":"10.2139/ssrn.3702271","DOIUrl":"https://doi.org/10.2139/ssrn.3702271","url":null,"abstract":"The concrete does not attain its original shape after unloading as it is not an elastic material. It is a non-linear material as depicted by its stress-strain curve. Hence, the elastic constants like modulus and Poisson’s ratio are not strictly applicable to such a complex, heterogeneous and nonlinear construction material. However, an elastic behaviour is assumed for the analysis and design of concrete structures by making use of these constants. The modulus of elasticity of concrete is its inherent property of undergoing an elastic deformation. Higher value of modulus leads to an enhanced stiffness of the structural elements. Curing is one of the important parameters influencing the modulus value. Curing caters to maintaining the required temperature, preventing water loss and shrinkage associated with it. The Shrinkage Reducing Admixture (SRA) in the form of Polyethylene Glycol 400 (PEG 400) liquid, added as a self-curing agent, plays an important role of reducing the water evaporation from the concrete mass, resulting into an improved water retention capacity of the concrete. PEG 400 is hydrophilic in nature. It plays a dual role of controlling evaporation and attracting moisture from the atmosphere. Self-curing leads to uninterrupted and effective curing by retaining the required quantity of water for an adequate cement hydration and maintaining the high relative humidity (RH), thereby resulting in to hard and dense concrete, with reduced thermal and shrinkage cracks. To provide a practical solution for the nonavailability of better quality water or lack of proper curing due to negligence, producing a self-curing concrete is a sustainable option. Generally, self-curing is advocated for the High Strength Concrete (HSC) having low water-cement ratio (w/c), because of chemical shrinkage associated with Portland cement hydration and low permeability of these materials. Moreover, it is an effective way to reduce the self-desiccation, autogenous shrinkage, plastic shrinkage cracking, drying shrinkage cracking and water absorption. Though the structural elements like Reinforced Cement Concrete (RCC) slabs are cast using lower grade concrete like M20, generally with higher w/c ratio, they are directly exposed to the harsh environment while concreting and a considerable period after concreting. To add to this, many times, the curing is not sufficient on the construction site. This leads to the undesirable situation of concrete properties not getting developed to their full potential values; the vital parameters being strength and modulus. Modulus of elasticity of concrete is known to be a function of its compressive strength. Development of required modulus of elasticity, for a structural element with a particular concrete grade, makes it adequately stiff thereby satisfying the limit state of serviceability for deflection. Excessive deflection of any structural element is highly undesirable phenomenon; moreover, it is well established fact in RCC the","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84055614","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 : 2020-06-23DOI: 10.15587/1729-4061.2020.205656
A. Khalatov, G. Kovalenko, M. Muliarchuk
Cylinder cross-flow is a common phenomenon in many fields of technology. Technological simplicity of tubular structures makes them attractive, especially when using working bodies that are under different pressure values. However, the cylinders belong to the category of «poorly streamlined» bodies, and there are many opportunities to improve their hydrodynamics and heat transfer. For a circular cylinder, there is a speed range in which its hydraulic resistance can decrease due to the deformation of the cylinder surface. This phenomenon can be used for the rational design of heat exchangers. In the open-type wind tunnel, heat transfer coefficients and hydraulic resistances of single-row cylinder bundles with several types of spiral grooves on the outer surface have been determined. The largest increase in heat transfer (64 %) was shown by the cylinder with the smallest pitch of the groove (10 mm), the second place was taken by the cylinder with a relatively large step – 40 mm. Using the best spiral groove allowed reducing the hydraulic resistance by 19 %. Visualization and computer simulation have been used to explain the effects. The conformity of computer simulations to the experimental results was determined by comparing the average heat transfer coefficient (calculated and determined using an ice calorimeter). As a result, the turbulence model RNG_ke has been chosen, which provides a better fit of the experimental model. Computer simulations have explained the physical picture of the flow around cylinders with spiral grooves, including their mutual influence with a different axial orientation in the bundle. It has been shown that the presence of a spiral groove, which on the one hand increases heat transfer and on the other hand reduces hydraulic resistance, can significantly increase thermohydraulic efficiency (Reynolds analogy factor).
{"title":"Research of Hydrodynamics and Heat Transfer During the Transverse Air Flow of a Row of Cylinders With Screw Grooves","authors":"A. Khalatov, G. Kovalenko, M. Muliarchuk","doi":"10.15587/1729-4061.2020.205656","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.205656","url":null,"abstract":"Cylinder cross-flow is a common phenomenon in many fields of technology. Technological simplicity of tubular structures makes them attractive, especially when using working bodies that are under different pressure values. However, the cylinders belong to the category of «poorly streamlined» bodies, and there are many opportunities to improve their hydrodynamics and heat transfer. For a circular cylinder, there is a speed range in which its hydraulic resistance can decrease due to the deformation of the cylinder surface. This phenomenon can be used for the rational design of heat exchangers. In the open-type wind tunnel, heat transfer coefficients and hydraulic resistances of single-row cylinder bundles with several types of spiral grooves on the outer surface have been determined. The largest increase in heat transfer (64 %) was shown by the cylinder with the smallest pitch of the groove (10 mm), the second place was taken by the cylinder with a relatively large step – 40 mm. Using the best spiral groove allowed reducing the hydraulic resistance by 19 %. Visualization and computer simulation have been used to explain the effects. The conformity of computer simulations to the experimental results was determined by comparing the average heat transfer coefficient (calculated and determined using an ice calorimeter). As a result, the turbulence model RNG_ke has been chosen, which provides a better fit of the experimental model. Computer simulations have explained the physical picture of the flow around cylinders with spiral grooves, including their mutual influence with a different axial orientation in the bundle. It has been shown that the presence of a spiral groove, which on the one hand increases heat transfer and on the other hand reduces hydraulic resistance, can significantly increase thermohydraulic efficiency (Reynolds analogy factor).","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76715776","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}
C. Hisey, J. Hearn, Y. Nursalim, D. Hansford, C. Blenkiron, L. Chamley
Extracellular vesicles (EVs) are micro and nanoscale packages that circulate in all bodily fluids and play an important role in intercellular communication by shuttling biomolecules to nearby and distant cells. However, producing sufficient amounts of EVs for many types of in vitro studies using standard culture methods can be challenging, and despite the success of some bioreactors in increasing EV-production, it is still largely unknown how individual culture conditions can alter the production and content of EVs. In this study, we demonstrate a simple and inexpensive micropatterning technique that can be used to produce polystyrene microtracks over a 100 mm diameter growth surface area. We then demonstrate that these microtracks can play a significant role in increasing EV production using a triple-negative breast cancer cell line (MDA-MB-231) and that these changes in EV production correlate with increases in cellular aspect ratio, alignment of the cells' long axes to the microtrack direction, and single-cell migration rates. These findings have implications in both biomanufacturing of EVs and potentially in enhancing the biomimicry of EVs produced in vitro.
{"title":"Micropatterned Growth Surface Topography Affects Extracellular Vesicle Production","authors":"C. Hisey, J. Hearn, Y. Nursalim, D. Hansford, C. Blenkiron, L. Chamley","doi":"10.2139/ssrn.3612306","DOIUrl":"https://doi.org/10.2139/ssrn.3612306","url":null,"abstract":"Extracellular vesicles (EVs) are micro and nanoscale packages that circulate in all bodily fluids and play an important role in intercellular communication by shuttling biomolecules to nearby and distant cells. However, producing sufficient amounts of EVs for many types of in vitro studies using standard culture methods can be challenging, and despite the success of some bioreactors in increasing EV-production, it is still largely unknown how individual culture conditions can alter the production and content of EVs. In this study, we demonstrate a simple and inexpensive micropatterning technique that can be used to produce polystyrene microtracks over a 100 mm diameter growth surface area. We then demonstrate that these microtracks can play a significant role in increasing EV production using a triple-negative breast cancer cell line (MDA-MB-231) and that these changes in EV production correlate with increases in cellular aspect ratio, alignment of the cells' long axes to the microtrack direction, and single-cell migration rates. These findings have implications in both biomanufacturing of EVs and potentially in enhancing the biomimicry of EVs produced in vitro.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73900782","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}
Pâmella Vasconcelos Borges Pinho, A. Chartier, J. Moussy, D. Menut, F. Miserque
Abstract Changes in the shape of X-ray photoemission (XPS) spectra can be related to changes in the local structure of a transition metal. By combining Crystal Field Multiplet calculations and well-controlled molecular beam epitaxy growth of α-Cr2O3(0001) thin films on α-Al2O3(0001) substrates, we prove that it is possible to link the features of Cr 2p XPS spectra with local distortions of CrO6 octahedra and d-orbitals reorganization. Hence, we show that the splitting of the Cr 2p3/2 envelope is related to the degeneracy of the t2g orbital triplet, which corresponds to a fully relaxed structure. Conversely, the broad unstructured Cr 2p3/2 envelope relies on splitting of t2g orbitals and it is the fingerprint of large trigonal distortions of CrO6 octahedra. Then, using the Cr 2p XPS as a structural tool for α-Cr2O3, we show that the Cr2O3 protective layer formed by oxidation of polycrystalline Ni30Cr alloy exhibits in-plane strains at early oxidation stages and grows preferentially along the c-axis.
{"title":"Crystal Field Effects on the Photoemission Spectra in Cr2o3 Thin Films: From Multiplet Splitting Features to the Local Structure","authors":"Pâmella Vasconcelos Borges Pinho, A. Chartier, J. Moussy, D. Menut, F. Miserque","doi":"10.2139/ssrn.3563939","DOIUrl":"https://doi.org/10.2139/ssrn.3563939","url":null,"abstract":"Abstract Changes in the shape of X-ray photoemission (XPS) spectra can be related to changes in the local structure of a transition metal. By combining Crystal Field Multiplet calculations and well-controlled molecular beam epitaxy growth of α-Cr2O3(0001) thin films on α-Al2O3(0001) substrates, we prove that it is possible to link the features of Cr 2p XPS spectra with local distortions of CrO6 octahedra and d-orbitals reorganization. Hence, we show that the splitting of the Cr 2p3/2 envelope is related to the degeneracy of the t2g orbital triplet, which corresponds to a fully relaxed structure. Conversely, the broad unstructured Cr 2p3/2 envelope relies on splitting of t2g orbitals and it is the fingerprint of large trigonal distortions of CrO6 octahedra. Then, using the Cr 2p XPS as a structural tool for α-Cr2O3, we show that the Cr2O3 protective layer formed by oxidation of polycrystalline Ni30Cr alloy exhibits in-plane strains at early oxidation stages and grows preferentially along the c-axis.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75028283","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 gas turbine in its most common from is a rotary heat engine operating by means of series of processes consisting of air taken from the atmosphere increase of gas temperature by constant pressure combustion of the fuel the whole process being continuous. The turbine inlet temperature in modern gas turbines is far above the permissible metal temperature. Turbines need to run at very high temperatures to reduce fuel burn, but they require internal cooling to maintain structural integrity and meet service-life requirements. A blade can be defined as the medium of transfer of energy from the gases to the turbine rotor. To increase the efficiency of gas turbine inlet Temperature should be high as possible. Turbine blades have internal passages that provide cooling during operation in a high temperature engine. The design of the cooling passages is critical to achieve near uniform temperature of the blade during operation. The temperature of the blade is dependent on the thermal properties of the blade material as well as the fluid dynamics of the air circulating in the cooling passages. Computational optimization methods have successfully been applied to design lighter and more efficient structures for many aerospace structures. An extension of these techniques is now applied to guiding the thermal design of a turbine blade by designing the optimal cooling passage layout. Optimization methods will be applied to determine the optimum pattern of the cooling passages and then to optimize the size of the individual cooling passages. The goal is to produce a more thermally efficient turbine blade design that will produce blades with longer lives and better performance. In this project the model blade of the gas turbine is created in PTC Creo Parametric 3.0. The cooling passages were modeled into the blade shape and the entire model was meshed in Hyper Mesh 2019.
{"title":"A Project on Optimizing Cooling Passages in Turbine Blades","authors":"Jahnvi Burman","doi":"10.2139/ssrn.3608733","DOIUrl":"https://doi.org/10.2139/ssrn.3608733","url":null,"abstract":"The gas turbine in its most common from is a rotary heat engine operating by means of series of processes consisting of air taken from the atmosphere increase of gas temperature by constant pressure combustion of the fuel the whole process being continuous. The turbine inlet temperature in modern gas turbines is far above the permissible metal temperature. Turbines need to run at very high temperatures to reduce fuel burn, but they require internal cooling to maintain structural integrity and meet service-life requirements. A blade can be defined as the medium of transfer of energy from the gases to the turbine rotor. To increase the efficiency of gas turbine inlet Temperature should be high as possible. Turbine blades have internal passages that provide cooling during operation in a high temperature engine. The design of the cooling passages is critical to achieve near uniform temperature of the blade during operation. The temperature of the blade is dependent on the thermal properties of the blade material as well as the fluid dynamics of the air circulating in the cooling passages. Computational optimization methods have successfully been applied to design lighter and more efficient structures for many aerospace structures. An extension of these techniques is now applied to guiding the thermal design of a turbine blade by designing the optimal cooling passage layout. Optimization methods will be applied to determine the optimum pattern of the cooling passages and then to optimize the size of the individual cooling passages. The goal is to produce a more thermally efficient turbine blade design that will produce blades with longer lives and better performance. In this project the model blade of the gas turbine is created in PTC Creo Parametric 3.0. The cooling passages were modeled into the blade shape and the entire model was meshed in Hyper Mesh 2019.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89091385","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}
Here, we systematically investigate optical behaviors of ruthenium (Ru)-coated nanoporous anodic aluminum oxide (AAO) nanoarchitectures in the visible and NIR regions, where they are fabricated by using an atomic layer deposition (ALD) process. Depending on the Ru thickness and the AAO dimensions, the Ru nanoarchitectures could be completely changed (tubular-type or wire-type Ru nanostructures), and the corresponding optical properties are critically affected. Brilliant structural colors are found from the Ru-coated AAO nanostructures, in which the color display covers the full visible range. Beyond the visible region, we also examine the optical behaviors of Ru-coated AAO nanostructures in the NIR region.
{"title":"Structural Color and Nir Tunability of Ruthenium-Coated Anodic Aluminum Oxide by Atomic Layer Deposition","authors":"Kyungju Lee, Hak-Bong Kim, Jae‐Hyun Kim, D. Choi","doi":"10.2139/ssrn.3603427","DOIUrl":"https://doi.org/10.2139/ssrn.3603427","url":null,"abstract":"Here, we systematically investigate optical behaviors of ruthenium (Ru)-coated nanoporous anodic aluminum oxide (AAO) nanoarchitectures in the visible and NIR regions, where they are fabricated by using an atomic layer deposition (ALD) process. Depending on the Ru thickness and the AAO dimensions, the Ru nanoarchitectures could be completely changed (tubular-type or wire-type Ru nanostructures), and the corresponding optical properties are critically affected. Brilliant structural colors are found from the Ru-coated AAO nanostructures, in which the color display covers the full visible range. Beyond the visible region, we also examine the optical behaviors of Ru-coated AAO nanostructures in the NIR region.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87523284","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}
J. González-León, F. Simon, Christophe Besson, P. Nicol
Granular fertilizers are not usually produced near the regions where they are applied. They have to be stored and transported after their production for long periods before being actually applied on the fields. During this time, most fertilizers, including those containing phosphorous, can agglomerate, or cake, making their manipulation and application more difficult or even impossible. Caking is the result of various physical and chemical processes that may occur simultaneously, which are more or less affected by external and internal variables during their production, storage and transportation process. In this paper, a study of the impact of different variables such as time, temperature, moisture and pressure on the caking tendency of different fertilizers containing phosphorous is presented. The principal variables affecting the caking process are discussed, based on results from mechanical tests and chemical analytical measurements such as scanning electron microscopy and x-ray fluorescence. Solutions to decrease the caking of granular fertilizers, notably by the use of bio-sourced protecting coatings and their characteristics, are also discussed.
{"title":"Variables Affecting Caking on Granular Phosphorous Containing Fertilizers","authors":"J. González-León, F. Simon, Christophe Besson, P. Nicol","doi":"10.2139/ssrn.3604187","DOIUrl":"https://doi.org/10.2139/ssrn.3604187","url":null,"abstract":"Granular fertilizers are not usually produced near the regions where they are applied. They have to be stored and transported after their production for long periods before being actually applied on the fields. During this time, most fertilizers, including those containing phosphorous, can agglomerate, or cake, making their manipulation and application more difficult or even impossible. Caking is the result of various physical and chemical processes that may occur simultaneously, which are more or less affected by external and internal variables during their production, storage and transportation process. \u0000 \u0000In this paper, a study of the impact of different variables such as time, temperature, moisture and pressure on the caking tendency of different fertilizers containing phosphorous is presented. The principal variables affecting the caking process are discussed, based on results from mechanical tests and chemical analytical measurements such as scanning electron microscopy and x-ray fluorescence. Solutions to decrease the caking of granular fertilizers, notably by the use of bio-sourced protecting coatings and their characteristics, are also discussed.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77740879","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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