Pub Date : 2021-01-29DOI: 10.21303/2461-4262.2021.001619
T. Jabbarov, J. Aslanov, R. Shahmarova
Sintering of multicomponent systems is characterized by a number of features, consisting in the fact that sintering of dissimilar materials is a complex eutectic process. Along with self-diffusion, which causes the transfer of mass to the contact area of the particles, there is mutual diffusion, which ensures the homogenization of the composition by equalizing the concentrations of unlike atoms within the sample. Under conditions of limited solubility or complete insolubility of the components, sintering of the system is complicated by the isolation of homogeneous particles from mutual contact, hindering self-diffusion and thereby worsening the sintering conditions. The saturation of particles of vacuum glass brand S88–5 (GOST 11.027.010–75, Russia) and glass “Pyrex” (TS, Russia), which are part of iron and “iron-cast iron glass” materials, depending on the sintering temperature, has been studied. To improve the interfacial interaction, and, consequently, to increase the mechanical and tribotechnical properties of powdered iron-glass materials, the effect of the glass melting temperature on the saturation of glass with metal was investigated. The dependences of the content of base metal and silicon ions in glass on the sintering temperature are plotted. The effect of the glass melting temperature on increasing the saturation of glass with metal is predicted. The saturation of the glass with the base metal depends on the viscosity of the glass at sintering temperatures and is accompanied by an increase in microhardness and refractive indices up to 1.2 times compared to the initial state of the glass. The microhardness of particles of vacuum glass of grade S88-5 after sintering of metal-glass samples increases noticeably than in samples with Pyrex glass. When sintering "iron-cast iron-glass" materials, the metal base is saturated with silicon, which leads to an increase in the hardness of iron up to 1.8 times
{"title":"Saturation of Glass Particles with Metal during Sintering of a Composite Material of the Iron–Cast Iron–Glass System","authors":"T. Jabbarov, J. Aslanov, R. Shahmarova","doi":"10.21303/2461-4262.2021.001619","DOIUrl":"https://doi.org/10.21303/2461-4262.2021.001619","url":null,"abstract":"Sintering of multicomponent systems is characterized by a number of features, consisting in the fact that sintering of dissimilar materials is a complex eutectic process. Along with self-diffusion, which causes the transfer of mass to the contact area of the particles, there is mutual diffusion, which ensures the homogenization of the composition by equalizing the concentrations of unlike atoms within the sample. Under conditions of limited solubility or complete insolubility of the components, sintering of the system is complicated by the isolation of homogeneous particles from mutual contact, hindering self-diffusion and thereby worsening the sintering conditions. The saturation of particles of vacuum glass brand S88–5 (GOST 11.027.010–75, Russia) and glass “Pyrex” (TS, Russia), which are part of iron and “iron-cast iron glass” materials, depending on the sintering temperature, has been studied. To improve the interfacial interaction, and, consequently, to increase the mechanical and tribotechnical properties of powdered iron-glass materials, the effect of the glass melting temperature on the saturation of glass with metal was investigated. The dependences of the content of base metal and silicon ions in glass on the sintering temperature are plotted. The effect of the glass melting temperature on increasing the saturation of glass with metal is predicted. The saturation of the glass with the base metal depends on the viscosity of the glass at sintering temperatures and is accompanied by an increase in microhardness and refractive indices up to 1.2 times compared to the initial state of the glass. The microhardness of particles of vacuum glass of grade S88-5 after sintering of metal-glass samples increases noticeably than in samples with Pyrex glass. When sintering \"iron-cast iron-glass\" materials, the metal base is saturated with silicon, which leads to an increase in the hardness of iron up to 1.8 times","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91488411","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 Intermetallic phase-based alloys, in particular transition-metal aluminides, are potential structural and coating materials for high-temperature applications. Such applications usually involve interdiffusion between two dissimilar materials. To simulate interdiffusion microstructures quantitatively, it becomes essential to solve alloy phase-field models in conjunction with multicomponent CALPHAD databases. This coupling, however, still remains a challenge when considering binary or multicomponent intermetallic phases. Here, a novel method that incorporates successfully diffusion potential dependent-properties of bulk multicomponent phases into a grand-potential based multi-phase-field model is proposed. It uses phase-specific properties directly precomputed from CALPHAD-type databases as discrete functions of solute diffusion potentials. Six different alloy cases, ranging from a five-phase binary (Ni-Al) to a two-phase quaternary (Al-Cr-Ni-Fe) alloy, are simulated to illustrate the application and correctness of the method. The cases include both substitutional and intermetallic phases. Where a comparison is possible, the simulations show good agreement with DICTRA and experimental results, thus validating our proposed method. In contrast to our approach, we find that DICTRA fails in three of the simulations involving ordered intermetallics. We further show that the interface width in this model can be varied without accuracy loss, thus enabling computationally affordable simulations at experimentally comparable length and time scales.
{"title":"A Grand-Potential Based Phase-Field Approach for Simulating Growth of Intermetallic Phases in Multicomponent Alloy Systems","authors":"S. Chatterjee, N. Moelans","doi":"10.2139/ssrn.3683514","DOIUrl":"https://doi.org/10.2139/ssrn.3683514","url":null,"abstract":"Abstract Intermetallic phase-based alloys, in particular transition-metal aluminides, are potential structural and coating materials for high-temperature applications. Such applications usually involve interdiffusion between two dissimilar materials. To simulate interdiffusion microstructures quantitatively, it becomes essential to solve alloy phase-field models in conjunction with multicomponent CALPHAD databases. This coupling, however, still remains a challenge when considering binary or multicomponent intermetallic phases. Here, a novel method that incorporates successfully diffusion potential dependent-properties of bulk multicomponent phases into a grand-potential based multi-phase-field model is proposed. It uses phase-specific properties directly precomputed from CALPHAD-type databases as discrete functions of solute diffusion potentials. Six different alloy cases, ranging from a five-phase binary (Ni-Al) to a two-phase quaternary (Al-Cr-Ni-Fe) alloy, are simulated to illustrate the application and correctness of the method. The cases include both substitutional and intermetallic phases. Where a comparison is possible, the simulations show good agreement with DICTRA and experimental results, thus validating our proposed method. In contrast to our approach, we find that DICTRA fails in three of the simulations involving ordered intermetallics. We further show that the interface width in this model can be varied without accuracy loss, thus enabling computationally affordable simulations at experimentally comparable length and time scales.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80625393","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}
Jingjing Wang, Leipeng Cao, Cong Li, Zhenghua Huang, Xuan Luo, Yuhuan Liu, R. Ruan
The hydrolysis of rice straw and swine wastewater by acclimatized paddy soil fungus for enhancing biomethane yield was investigated in two-phase liquid anaerobic digestion (L-AD). The results showed the order of impact factors on total organic carbon (TOC) and volatile fatty acid (VFA) yield was carbon/nitrogen ratio (C/Nratio)>temperature>inoculum/substance ratio (I/S ratio)>immersed height. The maximum TOC and VFA yields could be obtained after 7 days hydrolysis of rice straw under the condition of C/N ratio of 40, 37 o C, I/S ratio of 2:1, and 6.0 cm immersed height. The hydrolysis of rice straw has been terminated after 3 times hydrolysis. The cumulative CH4 production gradually increased from 54.06 mL/g VS to 177.02 mL/g VS while the retention rate declined from 75% to 45%. Considering the cost-efficiency of rice straw hydrolysis, 45% retention rate for twice degradation of rice straw were most suitable parameters for CH4 yield in two-phase L-AD.
{"title":"Multiple Degradation of Rice Straw by Acclimatized Paddy Soil Microbes for Enhancement of Methane Yield in Two-Phase Liquid Anaerobic Digestion","authors":"Jingjing Wang, Leipeng Cao, Cong Li, Zhenghua Huang, Xuan Luo, Yuhuan Liu, R. Ruan","doi":"10.2139/ssrn.3933561","DOIUrl":"https://doi.org/10.2139/ssrn.3933561","url":null,"abstract":"The hydrolysis of rice straw and swine wastewater by acclimatized paddy soil fungus for enhancing biomethane yield was investigated in two-phase liquid anaerobic digestion (L-AD). The results showed the order of impact factors on total organic carbon (TOC) and volatile fatty acid (VFA) yield was carbon/nitrogen ratio (C/Nratio)>temperature>inoculum/substance ratio (I/S ratio)>immersed height. The maximum TOC and VFA yields could be obtained after 7 days hydrolysis of rice straw under the condition of C/N ratio of 40, 37 o C, I/S ratio of 2:1, and 6.0 cm immersed height. The hydrolysis of rice straw has been terminated after 3 times hydrolysis. The cumulative CH4 production gradually increased from 54.06 mL/g VS to 177.02 mL/g VS while the retention rate declined from 75% to 45%. Considering the cost-efficiency of rice straw hydrolysis, 45% retention rate for twice degradation of rice straw were most suitable parameters for CH4 yield in two-phase L-AD.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83869249","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}
Hong Wang, Fan Zhang, Linghao Li, Hai-Lun Yu, Ren Tu, Zhiwen Jia, En-chen Jiang, Xi-wei Xu
As an excellent reaction medium, molten salt had large heat capacity, high thermal conductivity and stable chemical properties. Therefore, a new pretreatment method, molten salt pyrolysis (MT) pretreatment, was studied to pretreat Camellia oleifera shell (COS). The effect of temperature (160~280°C) on MT was mainly studied and compared with conventional dry and hydrothermal torrefaction. Furthermore, the physicochemical and pyrolysis characteristics of COS and torrefied biochar were also studied. The analysis of pyrolysis characteristics indicated that the energy of activation of biochar was reduced after MT, which was conducive to the occurrence of pyrolysis reaction. The content of phenols compounds rose considerably with MT pretreatment. The relative content of phenols at MT-240°C was 74.11%, which was higher than that of hydrothermal and dry torrefaction. In this study, an innovative and successful pretreatment process for converting COS into high-value phenols was proposed.
{"title":"Influence of Molten Salt Torrefaction Pretreatment on Upgrading of Bio-Oil from Camellia Oleifera Shell","authors":"Hong Wang, Fan Zhang, Linghao Li, Hai-Lun Yu, Ren Tu, Zhiwen Jia, En-chen Jiang, Xi-wei Xu","doi":"10.2139/ssrn.3899840","DOIUrl":"https://doi.org/10.2139/ssrn.3899840","url":null,"abstract":"As an excellent reaction medium, molten salt had large heat capacity, high thermal conductivity and stable chemical properties. Therefore, a new pretreatment method, molten salt pyrolysis (MT) pretreatment, was studied to pretreat Camellia oleifera shell (COS). The effect of temperature (160~280°C) on MT was mainly studied and compared with conventional dry and hydrothermal torrefaction. Furthermore, the physicochemical and pyrolysis characteristics of COS and torrefied biochar were also studied. The analysis of pyrolysis characteristics indicated that the energy of activation of biochar was reduced after MT, which was conducive to the occurrence of pyrolysis reaction. The content of phenols compounds rose considerably with MT pretreatment. The relative content of phenols at MT-240°C was 74.11%, which was higher than that of hydrothermal and dry torrefaction. In this study, an innovative and successful pretreatment process for converting COS into high-value phenols was proposed.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80881779","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 Near-equiatomic NiTi alloys are known to exhibit a thermoelastic B2–B19′ martensitic transformation, which gives rise to their unique properties of the shape memory effect and pseudoelastic effect. This transformation can be induced by the application of a stress. The stress-induced transformation nucleates locally and randomly within the body of the material, making the initiation and propagation of the transformation unpredictable. In addition, the propagation of the transformation occurs often in a Luders-like manner, which defines a typical condition of mechanical instability, thus making the deformation behaviour uncontrollable. To overcome these challenges, this study explored a design strategy to create geometrically graded NiTi components in which the stress-induced martensitic transformation can be controlled to initiate and propagate in a pre-designed direction within a wide stress or temperature window for improved controllability. This paper reports the design, experimental evaluation, and finite element simulation of several geometrically graded NiTi structures. The samples in series design configuration exhibited full controllability with complete stress gradient in deformation over the stress-induced transformation, whereas the samples in parallel design configuration exhibited a partially controllable stress window.
{"title":"Controlled Initiation and Propagation of Stress-Induced Martensitic Transformation in Functionally Graded NiTi","authors":"B. Shariat, S. Bakhtiari, Hong Yang, Y. Liu","doi":"10.2139/ssrn.3509321","DOIUrl":"https://doi.org/10.2139/ssrn.3509321","url":null,"abstract":"Abstract Near-equiatomic NiTi alloys are known to exhibit a thermoelastic B2–B19′ martensitic transformation, which gives rise to their unique properties of the shape memory effect and pseudoelastic effect. This transformation can be induced by the application of a stress. The stress-induced transformation nucleates locally and randomly within the body of the material, making the initiation and propagation of the transformation unpredictable. In addition, the propagation of the transformation occurs often in a Luders-like manner, which defines a typical condition of mechanical instability, thus making the deformation behaviour uncontrollable. To overcome these challenges, this study explored a design strategy to create geometrically graded NiTi components in which the stress-induced martensitic transformation can be controlled to initiate and propagate in a pre-designed direction within a wide stress or temperature window for improved controllability. This paper reports the design, experimental evaluation, and finite element simulation of several geometrically graded NiTi structures. The samples in series design configuration exhibited full controllability with complete stress gradient in deformation over the stress-induced transformation, whereas the samples in parallel design configuration exhibited a partially controllable stress window.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83172893","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}
A. Voskanyan, K. Lilova, S. McCormack, W. Kriven, A. Navrotsky
High entropy oxides (HEOs) have experienced a meteoric rise in the past decade. Here, we report a new class of entropy stabilized A6B2O17 (A = Zr, Hf; B = Nb, Ta) oxides whose enthalpies of formation have been determined by high temperature oxide melt solution calorimetry. All four compounds have endothermic enthalpies of formation from binary oxides (AO2 and B2O5), indicating that these modulated phases are entropy stabilized. The unfavorable energetics of formation are counterbalanced by large configurational entropy arising from cation disorder. The calculated configurational entropy per formula unit for A6B2O17 is 4.50R J/mol·K, which is ~2.8 times higher than the maximum configurational entropy value of 1.61R for an equimolar five cation containing “high entropy oxide”. Based on X-ray and neutron diffraction data, measured enthalpies of formation and calculated configurational entropies, one can infer that all four compounds have a high degree of disorder.
在过去的十年里，高熵氧化物(HEOs)经历了飞速的增长。本文报道了一类新的熵稳定的A6B2O17 (a = Zr, Hf;B = Nb, Ta)氧化物，其生成焓已由高温氧化物熔体溶液量热法测定。所有四种化合物都有二元氧化物(AO2和B2O5)的吸热生成焓，表明这些调制相是熵稳定的。由阳离子无序引起的大构型熵抵消了不利的生成能量。计算得到A6B2O17的每单位构型熵为4.50R J/mol·K，是含“高熵氧化物”等摩尔五阳离子的最大构型熵值1.61R的2.8倍。根据x射线和中子衍射数据，测量的生成焓和计算的构型熵，可以推断这四种化合物都具有高度的无序性。
{"title":"A New Class of Entropy Stabilized Oxides: Commensurately Modulated A 6B 2O 17 (A = Zr, Hf, B = Nb, Ta) Structures","authors":"A. Voskanyan, K. Lilova, S. McCormack, W. Kriven, A. Navrotsky","doi":"10.2139/ssrn.3869215","DOIUrl":"https://doi.org/10.2139/ssrn.3869215","url":null,"abstract":"High entropy oxides (HEOs) have experienced a meteoric rise in the past decade. Here, we report a new class of entropy stabilized A<sub>6</sub>B<sub>2</sub>O<sub>17</sub> (A = Zr, Hf; B = Nb, Ta) oxides whose enthalpies of formation have been determined by high temperature oxide melt solution calorimetry. All four compounds have endothermic enthalpies of formation from binary oxides (AO<sub>2</sub> and B<sub>2</sub>O<sub>5</sub>), indicating that these modulated phases are entropy stabilized. The unfavorable energetics of formation are counterbalanced by large configurational entropy arising from cation disorder. The calculated configurational entropy per formula unit for A<sub>6</sub>B<sub>2</sub>O<sub>17</sub> is 4.50R J/mol·K, which is ~2.8 times higher than the maximum configurational entropy value of 1.61R for an equimolar five cation containing “high entropy oxide”. Based on X-ray and neutron diffraction data, measured enthalpies of formation and calculated configurational entropies, one can infer that all four compounds have a high degree of disorder.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84187900","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 high costs, health implications of energy derived from fossil fuel and its negative impact on environment has called for an alternative source of energy, among which biogas has been identified as eco-friendly. This study analyzed biogas production from digestion of cattle dung and co-digestion with Typha latifolia in Funtua, Katsina State Nigeria. The experiment was conducted batch wise in mixing ratio 1:1 of cattle dung: T. latifolia at mesophilic temperature under 38 days retention time. The quantity of cattle dung fed into digester was determined with a weighing balance. Descriptive statistics was used to analyse the rate of biogas production while the difference in the biogas produced by the substrates was analysed using inferential statistics. Total of 9,923 (Fresh T. latifolia - FTCD), 35 (Powdered T. latifolia - PTCD) and 8,418 seconds (Fresh cattle dung - FCD) worth of biogas was produced. There was no statistically significant difference (P < 0.084) in the biogas production between the substrates. The highest daily peak was 1008 (18.8 minutes) and 937 second (15.6 minutes) from FTCD and FCD respectively. On average 1kg of cattle dung co digested with T. latifolia produced biogas worth 1240 seconds (21minutes) while mono digestion of cattle dung produced 1052 seconds (16minutes). Co-digestion with fresh T. latifolia improves biogas production by 15%. T. latifolia does not significantly has potential in biogas production. It is recommended that an investigation on effect of additives in biogas production from cattle dung and co-digestion with powdered Typha latifolia be conducted.
{"title":"Analysis of Biogas Production from Digestion of Cattle Dung and Co-Digestion with Typha Latifolia in Funtua, Katsina State – Nigeria","authors":"Saddam Saleh Yusuf, Muhammad Ismail, A. Jibrin","doi":"10.2139/ssrn.3881695","DOIUrl":"https://doi.org/10.2139/ssrn.3881695","url":null,"abstract":"The high costs, health implications of energy derived from fossil fuel and its negative impact on environment has called for an alternative source of energy, among which biogas has been identified as eco-friendly. This study analyzed biogas production from digestion of cattle dung and co-digestion with Typha latifolia in Funtua, Katsina State Nigeria. The experiment was conducted batch wise in mixing ratio 1:1 of cattle dung: T. latifolia at mesophilic temperature under 38 days retention time. The quantity of cattle dung fed into digester was determined with a weighing balance. Descriptive statistics was used to analyse the rate of biogas production while the difference in the biogas produced by the substrates was analysed using inferential statistics. Total of 9,923 (Fresh T. latifolia - FTCD), 35 (Powdered T. latifolia - PTCD) and 8,418 seconds (Fresh cattle dung - FCD) worth of biogas was produced. There was no statistically significant difference (P < 0.084) in the biogas production between the substrates. The highest daily peak was 1008 (18.8 minutes) and 937 second (15.6 minutes) from FTCD and FCD respectively. On average 1kg of cattle dung co digested with T. latifolia produced biogas worth 1240 seconds (21minutes) while mono digestion of cattle dung produced 1052 seconds (16minutes). Co-digestion with fresh T. latifolia improves biogas production by 15%. T. latifolia does not significantly has potential in biogas production. It is recommended that an investigation on effect of additives in biogas production from cattle dung and co-digestion with powdered Typha latifolia be conducted.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84646633","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}
Taraka R K Pamidi, Örjan Johansson, Torbjörn Löfqvist
In pulp and paper manufacturing cellulose fibers are modified in various process steps to obtain an end product with certain specifications. In this chain of interlinked processes, the mechanical refining stage has a significant impact on modifying the properties of the fiber wall. However, refining is identified as the most energy intensive process in paper manufacturing and in order to reduce the energy use for a more sustainable process, the development of alternative refining methods are of increasing interest. Ultrasound cavitation has proved to be a efficient refining process but so far it is limited to small volumes and batch process’s. The developed ultrasonic reactor is capable of handling larger fiber volumes in a continuous, scalable, flow process. The proposed method could therefore be an alternative and efficient way of processing fibers to minimize energy usage and waste. In this study, both numerical simulations and experiments are combined and analysed to establish a design of a scalable, flow-through ultrasound reactor. The implemented model is based on the linearized wave equation in the frequency domain with appropriate addition of nonlinear attenuation by cavitation bubbles. The influence of ultrasound cavitation was experimentally verified by characterization of the modification of CTMP softwood cellulose fiber properties. Results shows that the proposed method using ultrasound cavitation can modify the fiber’s mechanical properties at energy levels of 804 kWh/bdt. However, there was no significant change in paper strength properties as per ISO 1924-3.
{"title":"Acoustic Optimization of a Flow Through Ultrasonic Cavitation Reactor for Treatment of Cellulose Fibers","authors":"Taraka R K Pamidi, Örjan Johansson, Torbjörn Löfqvist","doi":"10.2139/ssrn.3926151","DOIUrl":"https://doi.org/10.2139/ssrn.3926151","url":null,"abstract":"In pulp and paper manufacturing cellulose fibers are modified in various process steps to obtain an end product with certain specifications. In this chain of interlinked processes, the mechanical refining stage has a significant impact on modifying the properties of the fiber wall. However, refining is identified as the most energy intensive process in paper manufacturing and in order to reduce the energy use for a more sustainable process, the development of alternative refining methods are of increasing interest. Ultrasound cavitation has proved to be a efficient refining process but so far it is limited to small volumes and batch process’s. The developed ultrasonic reactor is capable of handling larger fiber volumes in a continuous, scalable, flow process. The proposed method could therefore be an alternative and efficient way of processing fibers to minimize energy usage and waste. In this study, both numerical simulations and experiments are combined and analysed to establish a design of a scalable, flow-through ultrasound reactor. The implemented model is based on the linearized wave equation in the frequency domain with appropriate addition of nonlinear attenuation by cavitation bubbles. The influence of ultrasound cavitation was experimentally verified by characterization of the modification of CTMP softwood cellulose fiber properties. Results shows that the proposed method using ultrasound cavitation can modify the fiber’s mechanical properties at energy levels of 804 kWh/bdt. However, there was no significant change in paper strength properties as per ISO 1924-3.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88140735","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}
Shyam Katnagallu, S. Vernier, M. Charpagne, B. Gault, N. Bozzolo, P. Kontis
Abstract The mechanism of inverse precipitation of γ-like shells forming around primary γ' leading to heteroepitaxial recrystallization after thermomechanical processing was studied. The wrought nickel-based AD730™ alloy was subjected to a sub-solvus heat treatment at 1050°C and cooled at 5°C/min in order to form heteroepitaxial γ-like shells on primary γ'. Electron backscattered diffraction analysis confirmed no measurable crystal misorientation between the γ-like shells and primary γ'. Atom probe tomography revealed segregation of Cr, Co and Fe at dislocations within the primary γ', while the γ-like shell was found enriched in these solutes compared to the γ matrix. A mechanism rationalizing the inverse precipitation of γ-like shells is proposed aiming to better understand the nucleation process of heteroepitaxial recrystallization in polycrystalline Ni-based superalloys.
{"title":"Nucleation Mechanism of Hetero-Epitaxial Recrystallization in Wrought Nickel-Based Superalloys","authors":"Shyam Katnagallu, S. Vernier, M. Charpagne, B. Gault, N. Bozzolo, P. Kontis","doi":"10.2139/ssrn.3674187","DOIUrl":"https://doi.org/10.2139/ssrn.3674187","url":null,"abstract":"Abstract The mechanism of inverse precipitation of γ-like shells forming around primary γ' leading to heteroepitaxial recrystallization after thermomechanical processing was studied. The wrought nickel-based AD730™ alloy was subjected to a sub-solvus heat treatment at 1050°C and cooled at 5°C/min in order to form heteroepitaxial γ-like shells on primary γ'. Electron backscattered diffraction analysis confirmed no measurable crystal misorientation between the γ-like shells and primary γ'. Atom probe tomography revealed segregation of Cr, Co and Fe at dislocations within the primary γ', while the γ-like shell was found enriched in these solutes compared to the γ matrix. A mechanism rationalizing the inverse precipitation of γ-like shells is proposed aiming to better understand the nucleation process of heteroepitaxial recrystallization in polycrystalline Ni-based superalloys.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82985245","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}
Thi Thuong Nguyen, Bao-Tran Tran Pham, Hon Nhien Le, L. Bach, C. N. Ha Thuc
The aim of the present work is to investigate the combinative effects two natural extracts PBLE (piper betle L.) and SOE (Sonneratia ovate) on the physico-mechanical and biological properties of chitosan films (CS) and evaluate polyphenol release from formulated films in different food simulants. Bio-films containing the extracts showed better water permeation barrier, UV-protection property, antioxidant and antibacterial activities than control chitosan films. The co-addition of PBLE and SOE balanced the mechanical behavior and thermostability as well as antioxidant and antimicrobial activities of the chitosan based blend film. Moreover, the mechanism and kinetics of polyphenol release from bio-films in different solvents were investigated. The highest amount of polyphenols released from all chitosan blend films was observed in acidic environment due to chitosan solubility. It was also found that the release data are well-fitted with Peleg’s model and the release process was controlled by quasi-Fickian diffusion mechanism.
{"title":"Comparative Characterization and Release Study of Edible Bio-Films of Chitosan and Synergistic Natural Extracts","authors":"Thi Thuong Nguyen, Bao-Tran Tran Pham, Hon Nhien Le, L. Bach, C. N. Ha Thuc","doi":"10.2139/ssrn.3931690","DOIUrl":"https://doi.org/10.2139/ssrn.3931690","url":null,"abstract":"The aim of the present work is to investigate the combinative effects two natural extracts PBLE (piper betle L.) and SOE (Sonneratia ovate) on the physico-mechanical and biological properties of chitosan films (CS) and evaluate polyphenol release from formulated films in different food simulants. Bio-films containing the extracts showed better water permeation barrier, UV-protection property, antioxidant and antibacterial activities than control chitosan films. The co-addition of PBLE and SOE balanced the mechanical behavior and thermostability as well as antioxidant and antimicrobial activities of the chitosan based blend film. Moreover, the mechanism and kinetics of polyphenol release from bio-films in different solvents were investigated. The highest amount of polyphenols released from all chitosan blend films was observed in acidic environment due to chitosan solubility. It was also found that the release data are well-fitted with Peleg’s model and the release process was controlled by quasi-Fickian diffusion mechanism.","PeriodicalId":11974,"journal":{"name":"EngRN: Engineering Design Process (Topic)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81716397","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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