Pub Date : 2019-09-09DOI: 10.4995/ampere2019.2019.9765
S. Kumari, Sujoy Kumar Samanta, B. Saxena
Economical and efficient warming of pre-transfusion human blood has been a subject of extensive investigation. The objective of this study is to identify and analyze the effect of enhanced microwave warming of bank blood. The sample here has been assumed to be a 2D cylinder interacting with microwave irradiation. The mathematical interpretation for the study is performed by solving the equation of electromagnetic wave propagation along with the equation of energy balance and pertinent boundary conditions. The samples after being subjected to both lateral and radial irradiations of same intensity are investigated for the power absorption in the sample with respect to the sample size. The preliminary observations obtained are further analyzed and extended for spatial distribution scrutiny. The collaborative analysis of the spatial distributions of temperature and power in the human blood along with high heating rate and low thermal non-uniformity determine the optimal heating strategy. The observations at different sample sizes recommend radial irradiation as the optimal heating strategy for samples corresponding to OP: 1 and 3, and lateral irradiation for samples corresponding to OP: 2, respectively. Considering all the aspects, the present work recommends an efficient way for enhanced microwave assisted heating of body fluid samples (2D cylindrical geometry) with known or measurable dielectric properties.
{"title":"THEORETICAL ANALYSIS ON EFFICIENT MICROWAVE WARMING OF HUMAN BLOOD","authors":"S. Kumari, Sujoy Kumar Samanta, B. Saxena","doi":"10.4995/ampere2019.2019.9765","DOIUrl":"https://doi.org/10.4995/ampere2019.2019.9765","url":null,"abstract":"Economical and efficient warming of pre-transfusion human blood has been a subject of extensive investigation. The objective of this study is to identify and analyze the effect of enhanced microwave warming of bank blood. The sample here has been assumed to be a 2D cylinder interacting with microwave irradiation. The mathematical interpretation for the study is performed by solving the equation of electromagnetic wave propagation along with the equation of energy balance and pertinent boundary conditions. The samples after being subjected to both lateral and radial irradiations of same intensity are investigated for the power absorption in the sample with respect to the sample size. The preliminary observations obtained are further analyzed and extended for spatial distribution scrutiny. The collaborative analysis of the spatial distributions of temperature and power in the human blood along with high heating rate and low thermal non-uniformity determine the optimal heating strategy. The observations at different sample sizes recommend radial irradiation as the optimal heating strategy for samples corresponding to OP: 1 and 3, and lateral irradiation for samples corresponding to OP: 2, respectively. Considering all the aspects, the present work recommends an efficient way for enhanced microwave assisted heating of body fluid samples (2D cylindrical geometry) with known or measurable dielectric properties.","PeriodicalId":277158,"journal":{"name":"Proceedings 17th International Conference on Microwave and High Frequency Heating","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117005188","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 : 2019-09-09DOI: 10.4995/ampere2019.2019.9815
S. Horikoshi
More than 30 years have passed since Clements, et. al. succeeded in generating plasma in liquid (in-Liquid plasma: LP). Meanwhile, then plasma generation experiments using AC and DC power sources have been performed in electrolyte solutions. On the other hand, in 2000, by Nomura, et. al., they succeeded in generating plasma in aqueous solution by using microwave as a power source. When the microwave is used as a power source, there is a problem that the electrode is deteriorated and melted by the heat of plasma, and there is a problem that the device cannot be used continuously. We solved this problem using a semiconductor (solid-state) microwave generator. In order to investigate the possibility of using this new plasma, we have applied to wastewater treatment (e.g. degradation of 1,4-dioxane, rhodamine B dye and hypochlorous) and gel synthesis (polyvinylpyrrolidone (PVP) gel and silicone hydrogel gel). The photograph of the LP apparatus is illustrated in Figures 1. The MW generator was constructed using an Ampleon M2A-R semiconductor generator (2.45-GHz; maximal power, 1300 W) coupled to an isolator (air cooling device), a power monitor, a three-stub tuner and a short-circuit plunger. Microwaves continuously irradiated the liquid through the tungsten antenna (dia.: 10 mm; length: 200 mm). The tungsten antenna was isolated from the reactor and the waveguide using a ceramic spacer to irradiate MW in the solution. In the application of LP for wastewater treatment, the model wastewater of rhodamine B dye (RhB) were decomposed by LP irradiation, and degradation efficency of LP method was compared with conventional methods (UV photodegradation, NaClO chemical treatment, UV/NaClO chemical/photodegradation and the UV/TiO2 photocatalytic degradation method). The degradationon rate of LP method was remarkably fastest to conventional methods (Figure 2). In the application of LP for gel-synthesis, synthesizing the polymer-gel (PVP-gel and HySi-gel) was tried by the LP method. This feature of the method can significantly reduce (or eliminate) the initiator and crosslinking agent needed for conventional synthesis. Because these chemicals are very toxic, the LP approach is effective in green chemistry. In addition, it will further extend the application of these gels to the medical field.More than 30 years have passed since Clements, et. al. succeeded in generating plasma in liquid (in-Liquid plasma: LP) [1]. Meanwhile, then plasma generation experiments using AC and DC power sources have been performed in electrolyte solutions. On the other hand, in 2000, by Nomura, et. al., [1], they succeeded in generating plasma in aqueous solution by using microwave as a power source. When the microwave is used as a power source, there is a problem that the electrode is deteriorated and melted by the heat of plasma, and there is a problem that the device cannot be used continuously. We solved this problem using a semiconductor (solid-state) microwave generator [2]. In or
{"title":"IN-LIQUID PLASMA USING MICROWAVE POWER FOR APPLICATIONS","authors":"S. Horikoshi","doi":"10.4995/ampere2019.2019.9815","DOIUrl":"https://doi.org/10.4995/ampere2019.2019.9815","url":null,"abstract":"More than 30 years have passed since Clements, et. al. succeeded in generating plasma in liquid (in-Liquid plasma: LP). Meanwhile, then plasma generation experiments using AC and DC power sources have been performed in electrolyte solutions. On the other hand, in 2000, by Nomura, et. al., they succeeded in generating plasma in aqueous solution by using microwave as a power source. When the microwave is used as a power source, there is a problem that the electrode is deteriorated and melted by the heat of plasma, and there is a problem that the device cannot be used continuously. We solved this problem using a semiconductor (solid-state) microwave generator. In order to investigate the possibility of using this new plasma, we have applied to wastewater treatment (e.g. degradation of 1,4-dioxane, rhodamine B dye and hypochlorous) and gel synthesis (polyvinylpyrrolidone (PVP) gel and silicone hydrogel gel). The photograph of the LP apparatus is illustrated in Figures 1. The MW generator was constructed using an Ampleon M2A-R semiconductor generator (2.45-GHz; maximal power, 1300 W) coupled to an isolator (air cooling device), a power monitor, a three-stub tuner and a short-circuit plunger. Microwaves continuously irradiated the liquid through the tungsten antenna (dia.: 10 mm; length: 200 mm). The tungsten antenna was isolated from the reactor and the waveguide using a ceramic spacer to irradiate MW in the solution. In the application of LP for wastewater treatment, the model wastewater of rhodamine B dye (RhB) were decomposed by LP irradiation, and degradation efficency of LP method was compared with conventional methods (UV photodegradation, NaClO chemical treatment, UV/NaClO chemical/photodegradation and the UV/TiO2 photocatalytic degradation method). The degradationon rate of LP method was remarkably fastest to conventional methods (Figure 2). In the application of LP for gel-synthesis, synthesizing the polymer-gel (PVP-gel and HySi-gel) was tried by the LP method. This feature of the method can significantly reduce (or eliminate) the initiator and crosslinking agent needed for conventional synthesis. Because these chemicals are very toxic, the LP approach is effective in green chemistry. In addition, it will further extend the application of these gels to the medical field.More than 30 years have passed since Clements, et. al. succeeded in generating plasma in liquid (in-Liquid plasma: LP) [1]. Meanwhile, then plasma generation experiments using AC and DC power sources have been performed in electrolyte solutions. On the other hand, in 2000, by Nomura, et. al., [1], they succeeded in generating plasma in aqueous solution by using microwave as a power source. When the microwave is used as a power source, there is a problem that the electrode is deteriorated and melted by the heat of plasma, and there is a problem that the device cannot be used continuously. We solved this problem using a semiconductor (solid-state) microwave generator [2]. In or","PeriodicalId":277158,"journal":{"name":"Proceedings 17th International Conference on Microwave and High Frequency Heating","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126732768","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 : 2019-09-09DOI: 10.4995/ampere2019.2019.9887
L. Gil-Flores, M. Salvador, F. Peñaranda-Foix, R. Rosa, P. Veronesi, C. Leonelli, A. Borrell
Zirconia is one of the most used ceramics, especially for biomedical applications, due to its exceptional mechanical properties. However, it is commonly known that its properties can be diminished owing to a low temperature degradation (LTD). This phenomenon consists on a spontaneous phase transformation, from tetragonal to monoclinic, under certain conditions, which is accelerated when the samples are exposed under high levels of humidity at a temperature range between 20-300 ºC. In addition to the fact that the monoclinic phase presents worse mechanical properties than the tetragonal one, there is a volume change of 4% between phases that gives rise to defects in the material as microcracks. Due to this reason, zirconia prostheses failed catastrophically inside the human body between 1999 and 20011. Previous researches reveal that Al2O3 addition suppress the propagation of phase transformation2. Thus, the aim of the present work is to study the hydrothermal ageing of zirconia doped with ceria and toughened with alumina (10Ce-TZP/Al2O3) composite, which has been sintered by microwave employing two different frequencies: 2.45 and 5.8 GHz. Microwave heating technology is based on the absorption of electromagnetic radiation by the material, which allows the sample to be heated. So far, most microwave heating equipments use 2.45 GHz; accordingly, the novelty of this study is to employ a frequency of 5.8 GHz and to investigate its effect on LTD. LTD is carried out in an autoclaved in steam at 120 ºC and 1.2 bar, because these conditions accelerate the hydrothermal aging process3. In order to characterize the degraded samples, micro-Raman spectroscopy, AFM, nanoindentation technique and electronic microscopy have been performed. References 1. Norton, M. R., Yarlagadda, R., Anderson, G. H. J. Bone Joint Surg. Br., 2002, 84–B, 631–635. 2. Fabbri, P., Piconi, C., Burresi, E., Magnani, G., Mazzanti, F., Mingazzini, C. Dent. Mater., 2014. 3. Presenda, Á., Salvador, M. D., Moreno, R., Borrell, A. J. Am. Ceram. Soc., 2015, 98, 3680–3689.
{"title":"LOW TEMPERATURE DEGRADATION BEHAVIOUR OF 10Ce-TZP/Al2O3 BIOCERAMICS OBTAINED BY MICROWAVE SINTERING TECHNOLOGY","authors":"L. Gil-Flores, M. Salvador, F. Peñaranda-Foix, R. Rosa, P. Veronesi, C. Leonelli, A. Borrell","doi":"10.4995/ampere2019.2019.9887","DOIUrl":"https://doi.org/10.4995/ampere2019.2019.9887","url":null,"abstract":"Zirconia is one of the most used ceramics, especially for biomedical applications, due to its exceptional mechanical properties. However, it is commonly known that its properties can be diminished owing to a low temperature degradation (LTD). This phenomenon consists on a spontaneous phase transformation, from tetragonal to monoclinic, under certain conditions, which is accelerated when the samples are exposed under high levels of humidity at a temperature range between 20-300 ºC. In addition to the fact that the monoclinic phase presents worse mechanical properties than the tetragonal one, there is a volume change of 4% between phases that gives rise to defects in the material as microcracks. Due to this reason, zirconia prostheses failed catastrophically inside the human body between 1999 and 20011. Previous researches reveal that Al2O3 addition suppress the propagation of phase transformation2. Thus, the aim of the present work is to study the hydrothermal ageing of zirconia doped with ceria and toughened with alumina (10Ce-TZP/Al2O3) composite, which has been sintered by microwave employing two different frequencies: 2.45 and 5.8 GHz. Microwave heating technology is based on the absorption of electromagnetic radiation by the material, which allows the sample to be heated. So far, most microwave heating equipments use 2.45 GHz; accordingly, the novelty of this study is to employ a frequency of 5.8 GHz and to investigate its effect on LTD. LTD is carried out in an autoclaved in steam at 120 ºC and 1.2 bar, because these conditions accelerate the hydrothermal aging process3. In order to characterize the degraded samples, micro-Raman spectroscopy, AFM, nanoindentation technique and electronic microscopy have been performed. References 1. Norton, M. R., Yarlagadda, R., Anderson, G. H. J. Bone Joint Surg. Br., 2002, 84–B, 631–635. 2. Fabbri, P., Piconi, C., Burresi, E., Magnani, G., Mazzanti, F., Mingazzini, C. Dent. Mater., 2014. 3. Presenda, Á., Salvador, M. D., Moreno, R., Borrell, A. J. Am. Ceram. Soc., 2015, 98, 3680–3689. ","PeriodicalId":277158,"journal":{"name":"Proceedings 17th International Conference on Microwave and High Frequency Heating","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131230553","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 : 2019-09-09DOI: 10.4995/ampere2019.2019.9913
T. Santos, N. Santos, C. Gomes, L. Hennetier, V. Costa, L. Costa
The energy dependence on fossil resources and the increasing competitiveness of the stoneware industry, which is a relevant natural gas consumer, leads to new and more environmentally friendly firing methods. Microwave radiation is herein presented as an alternative heating technology for stoneware firing. The samples were fired in a multimode furnace with 6 magnetrons in its core, each one operating at a nominal power of 900 W and frequency of 2.45 GHz. A pyrometer and a thermocouple were installed in the microwave furnace for temperature measuring, control and monitoring. Pyrometer was calibrated in an electric furnace for accurate temperature measurements. During calibration, the thermocouple used in the microwave furnace was installed in the electric furnace, giving a temperature difference from the control (electric furnace) of 2 to 5 ºC, from room temperature up to 1450 ºC. To help the stoneware firing, a silicon carbide (SiC) plate was used as microwave susceptor, also working as a support base for the stoneware samples (mugs). The microstructure of the microwave fired stoneware shows features similar to those of conventionally fired samples (gas and electric heating), with the microwave requiring lower firing temperature to reach an equal structure. X-Ray diffraction and scanning electron micrograph show the relevant transformations taking place for lower temperatures when using microwave heating.
{"title":"FEATURES OF UTILITARIAN STONEWARE FIRED WITH MICROWAVE RADIATION","authors":"T. Santos, N. Santos, C. Gomes, L. Hennetier, V. Costa, L. Costa","doi":"10.4995/ampere2019.2019.9913","DOIUrl":"https://doi.org/10.4995/ampere2019.2019.9913","url":null,"abstract":"The energy dependence on fossil resources and the increasing competitiveness of the stoneware industry, which is a relevant natural gas consumer, leads to new and more environmentally friendly firing methods. Microwave radiation is herein presented as an alternative heating technology for stoneware firing. The samples were fired in a multimode furnace with 6 magnetrons in its core, each one operating at a nominal power of 900 W and frequency of 2.45 GHz. A pyrometer and a thermocouple were installed in the microwave furnace for temperature measuring, control and monitoring. Pyrometer was calibrated in an electric furnace for accurate temperature measurements. During calibration, the thermocouple used in the microwave furnace was installed in the electric furnace, giving a temperature difference from the control (electric furnace) of 2 to 5 ºC, from room temperature up to 1450 ºC. To help the stoneware firing, a silicon carbide (SiC) plate was used as microwave susceptor, also working as a support base for the stoneware samples (mugs). The microstructure of the microwave fired stoneware shows features similar to those of conventionally fired samples (gas and electric heating), with the microwave requiring lower firing temperature to reach an equal structure. X-Ray diffraction and scanning electron micrograph show the relevant transformations taking place for lower temperatures when using microwave heating.","PeriodicalId":277158,"journal":{"name":"Proceedings 17th International Conference on Microwave and High Frequency Heating","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116617501","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 : 2019-09-09DOI: 10.4995/ampere2019.2019.9646
Khashayar Teimoori, F. Hassani, A. Sasmito, Ali Madiseh
In this study, a rock model which consists of a conceptual block (host rock and ore sample) is numerically modeled by using the finite element method. The rock model is subjected to several single-mode microwave treatments with different power levels, distances from the antenna, and exposure times in order to calculate and compare the corresponding effects including temperature distribution and mechanical stress/damage profiles. The main objective of the present study is to analyze the distribution of temperature and mechanical stress at the boundary of two different attached rocks when exposed to microwaves. This enables comparing the intensity of the distribution with respect to the applied microwave input operating parameters and, consequently, understanding rock preconditioning. The results of the present study verify that an increase in temperature by microwave treatment facilitates the rock weakening process. Also, a more efficient selection of the distance from the antenna and the power level can maximize the overall impact of the microwave treatment on rock preconditioning which ultimately helps with the rock breakage mechanism.
{"title":"Numerical Investigations of the Single-Mode Microwave Treatment Effects on Rock Breakage","authors":"Khashayar Teimoori, F. Hassani, A. Sasmito, Ali Madiseh","doi":"10.4995/ampere2019.2019.9646","DOIUrl":"https://doi.org/10.4995/ampere2019.2019.9646","url":null,"abstract":"In this study, a rock model which consists of a conceptual block (host rock and ore sample) is numerically modeled by using the finite element method. The rock model is subjected to several single-mode microwave treatments with different power levels, distances from the antenna, and exposure times in order to calculate and compare the corresponding effects including temperature distribution and mechanical stress/damage profiles. The main objective of the present study is to analyze the distribution of temperature and mechanical stress at the boundary of two different attached rocks when exposed to microwaves. This enables comparing the intensity of the distribution with respect to the applied microwave input operating parameters and, consequently, understanding rock preconditioning. The results of the present study verify that an increase in temperature by microwave treatment facilitates the rock weakening process. Also, a more efficient selection of the distance from the antenna and the power level can maximize the overall impact of the microwave treatment on rock preconditioning which ultimately helps with the rock breakage mechanism. ","PeriodicalId":277158,"journal":{"name":"Proceedings 17th International Conference on Microwave and High Frequency Heating","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122111168","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 : 2019-09-09DOI: 10.4995/ampere2019.2019.9635
S. Taheri, G. Brodie, D. Gupta
Lentil is one of the important pulse crops in the world with a high proportion of easily digestible protein. However, there are several pests and pathogens which cause losses during crop growth, harvesting and post-harvest storage. Microwave processing has shown great potential to eradicate pests and pathogens from grains; however, there is still concerns about its heat uniformity, which is of crucial importance in pest and pathogen control. Fluidization using forced hot air is one of the potential solutions for having uniform temperature during microwave processing. In this study, a single mode microwave cavity, with a 2.45 GHz microwave source, was modified to have a microwave fluidized bed and used to evaluate its potential to eliminate the Botrytis grey mold (BGM) pathogen, which is one of the important seed-borne pathogens of lentil crops in Australia. Air speed was maintained to be constant during the experiment and was just enough to fluidize 100g of red lentils in the sample holder. Two wet based (w.b.) seed moisture contents (m.c.) of 10.5% and 18.5% were prepared and the process parameters were selected as: air temperature at 50 and 60°C; microwave power at 0, 300, 400 W for 18.5% m.c. and 0, 400, 500 W for 10.5% m.c.; and exposure times of 5 and 10 min. These parameters were chosen to reach the final temperature of below 70°C. The effect of process parameters on seed moisture loss, seed germination, electrical conductivity of seed soaking water and percentage of infected seeds (IS%) were analyzed using general factorial regression and analysis of variance. The results showed that the most effective factors on moisture loss, after seed moisture content, was exposure time, followed by microwave power and air temperature. While final bed temperature was affected mostly by air temperature, and then by microwave power. Furthermore, based on general full factorial regression and pareto chart of standardized effects, moisture content had by far the most influence on the reduction of IS%. Seed pathogen inoculum reduction, without significant seed viability loss, was obtained by applying microwave power of 300W and set air temperature of 60°C (actual inlet air temperature of 57±1°C) on seeds with m.c. of 18.5% for 10 min. This gave a 27% reduction in IS% (from 82% to 55%).
{"title":"EFFECTIVENESS OF A MICROWAVE FLUIDISED BED DRYER IN ERADICATION OF SEED-BORNE BOTRYTIS GREY MOLD OF LENTILS","authors":"S. Taheri, G. Brodie, D. Gupta","doi":"10.4995/ampere2019.2019.9635","DOIUrl":"https://doi.org/10.4995/ampere2019.2019.9635","url":null,"abstract":"Lentil is one of the important pulse crops in the world with a high proportion of easily digestible protein. However, there are several pests and pathogens which cause losses during crop growth, harvesting and post-harvest storage. Microwave processing has shown great potential to eradicate pests and pathogens from grains; however, there is still concerns about its heat uniformity, which is of crucial importance in pest and pathogen control. Fluidization using forced hot air is one of the potential solutions for having uniform temperature during microwave processing. In this study, a single mode microwave cavity, with a 2.45 GHz microwave source, was modified to have a microwave fluidized bed and used to evaluate its potential to eliminate the Botrytis grey mold (BGM) pathogen, which is one of the important seed-borne pathogens of lentil crops in Australia. Air speed was maintained to be constant during the experiment and was just enough to fluidize 100g of red lentils in the sample holder. Two wet based (w.b.) seed moisture contents (m.c.) of 10.5% and 18.5% were prepared and the process parameters were selected as: air temperature at 50 and 60°C; microwave power at 0, 300, 400 W for 18.5% m.c. and 0, 400, 500 W for 10.5% m.c.; and exposure times of 5 and 10 min. These parameters were chosen to reach the final temperature of below 70°C. The effect of process parameters on seed moisture loss, seed germination, electrical conductivity of seed soaking water and percentage of infected seeds (IS%) were analyzed using general factorial regression and analysis of variance. The results showed that the most effective factors on moisture loss, after seed moisture content, was exposure time, followed by microwave power and air temperature. While final bed temperature was affected mostly by air temperature, and then by microwave power. Furthermore, based on general full factorial regression and pareto chart of standardized effects, moisture content had by far the most influence on the reduction of IS%. Seed pathogen inoculum reduction, without significant seed viability loss, was obtained by applying microwave power of 300W and set air temperature of 60°C (actual inlet air temperature of 57±1°C) on seeds with m.c. of 18.5% for 10 min. This gave a 27% reduction in IS% (from 82% to 55%).","PeriodicalId":277158,"journal":{"name":"Proceedings 17th International Conference on Microwave and High Frequency Heating","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130786633","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 : 2019-09-09DOI: 10.4995/ampere2019.2019.9784
Kenta Hagiwara, S. Horikoshi
Since the first serendipity of carbon quantum dots (CQDs)1, it is expected to be used for imaging materials for reusable living bodies (e.g. Hela cells). However, the reported CQDs synthetic methods have yet to be at the practical levels; the quantum yields is low, and synthetic condition is over 5 hrs under more than 30 atms. In this research, we ameliorated the problems of CQDs synthesis and luminescence (quantum yields) by the novel synthesis protocol using microwave chemistry. Specifically, we synthesized high quantum yields CQDs (61%) by utilizing a microwave chemical synthesis, synthesizing at low pressure condition (lower than 5 atom) and short reaction time (3 hrs). The achievement of this high quantum yields made it clear that the contribution of polyethylene glycol (PEG) shell to CQDs is large. It was confirmed from the DLS and TEM image that the particle size of the synthesized particles was 8 to 13 nm (Fig. 1). On the other hand, the relationship between the polymerization degree of added PEG and the quantum yields to the addition amount is summarized in Table 1. The quantum yields of CQDs without addition of PEG was 16.7 %, while it was improved at 61.1 % when 0.6 g of PEG6000 (Molecular weight: 6000) was added.We succeeded in remarkably improving the quantum yields by using PEG, which is usually used as a protective agent, as a shell. By using this method, we succeeded in improving the quantum yields of the existing report by approximately 3 times. From the surface modified structure of PEG, the mechanism of improvement of quantum yields will be considered.[1] X. Xu et al., J. Am. Chem. Soc., 2004, 126, 12736–12737.
由于碳量子点(CQDs)的首次发现，它有望用于可重复使用的活体(例如海拉细胞)的成像材料。然而，已报道的CQDs合成方法尚未达到实际水平;量子产率低，在30多台机器下的合成条件在5 HRS以上。在本研究中，我们通过微波化学的新合成方案改善了CQDs的合成和发光(量子产率)问题。具体而言，我们利用微波化学合成，在低压条件下(低于5个原子)和短反应时间(3小时)合成了高量子产率(61%)的CQDs。高量子产率的成就清楚地表明聚乙二醇(PEG)壳层对CQDs的贡献是巨大的。DLS和TEM图像证实，合成的颗粒粒径为8 ~ 13 nm(图1)。另一方面，添加的PEG的聚合度与量子产率与添加量的关系如表1所示。未添加PEG的CQDs的量子产率为16.7%，而添加0.6 g PEG6000(分子量为6000)的CQDs的量子产率为61.1%。我们成功地将通常用作保护剂的聚乙二醇作为壳层，显著提高了量子产率。通过使用这种方法，我们成功地将现有报告的量子产率提高了约3倍。从聚乙二醇的表面修饰结构出发，考虑提高量子产率的机理。[1]徐旭等。化学。Soc。浙江农业学报，2004,26(1):12736-12737。
{"title":"Rapid Synthesis of highly luminescent Carbon Quantum Dots using Low-Pressurized Microwave Solvothermal Heating","authors":"Kenta Hagiwara, S. Horikoshi","doi":"10.4995/ampere2019.2019.9784","DOIUrl":"https://doi.org/10.4995/ampere2019.2019.9784","url":null,"abstract":"Since the first serendipity of carbon quantum dots (CQDs)1, it is expected to be used for imaging materials for reusable living bodies (e.g. Hela cells). However, the reported CQDs synthetic methods have yet to be at the practical levels; the quantum yields is low, and synthetic condition is over 5 hrs under more than 30 atms. In this research, we ameliorated the problems of CQDs synthesis and luminescence (quantum yields) by the novel synthesis protocol using microwave chemistry. Specifically, we synthesized high quantum yields CQDs (61%) by utilizing a microwave chemical synthesis, synthesizing at low pressure condition (lower than 5 atom) and short reaction time (3 hrs). The achievement of this high quantum yields made it clear that the contribution of polyethylene glycol (PEG) shell to CQDs is large. It was confirmed from the DLS and TEM image that the particle size of the synthesized particles was 8 to 13 nm (Fig. 1). On the other hand, the relationship between the polymerization degree of added PEG and the quantum yields to the addition amount is summarized in Table 1. The quantum yields of CQDs without addition of PEG was 16.7 %, while it was improved at 61.1 % when 0.6 g of PEG6000 (Molecular weight: 6000) was added.We succeeded in remarkably improving the quantum yields by using PEG, which is usually used as a protective agent, as a shell. By using this method, we succeeded in improving the quantum yields of the existing report by approximately 3 times. From the surface modified structure of PEG, the mechanism of improvement of quantum yields will be considered.[1] X. Xu et al., J. Am. Chem. Soc., 2004, 126, 12736–12737. ","PeriodicalId":277158,"journal":{"name":"Proceedings 17th International Conference on Microwave and High Frequency Heating","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123583878","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 : 2019-09-09DOI: 10.4995/ampere2019.2019.9940
A. Mohekar, B. Tilley, V. Yakovlev
The loss factor of a material is a key characteristic behind heat generation during EM heating. For typical ceramics, the loss factor increases exponentially with temperature potentially initiating thermal runaway which can damage the material through melting or cracking. Equilibrium of EM heating can be represented by a parametric plot of the average steady-state temperature as function of the applied power that is known as a power response curve. In a layered structure, for wavelengths of the incident wave that are much larger than the layer’s thickness, the power response curve is an S-shaped bifurcation diagram (or S-curve). Stable temperatures are low at the lower branch of the S-curve and may be very high (up to ~2000 K) at the upper branch. The recent analytical and numerical models show that, for a triple (lossless-lossy-lossless) layered system, when thickness of the structure is comparable with the wavelength, an electric field resonance can be achieved in the lossy layer. This resonance causes the S-curve to acquire another (middle) stable branch and become a double S-curve. That suggests that temperatures during thermal runaway may be controlled by the field resonance. However, these models assume two-side symmetric irradiation. In this paper, we show that the resonance producing a double S-curve can be achieved in a more practical scenario with one-side irradiation: in the system with a metal plate the resonance is achieve by choosing layer's thickness and triggering a constructive interference of the incident and reflected waves. A series of double S-curves computed with COMSOL Multiphysics are analyzed, and practical ways of controlling thermal runaway in EM heating of layered structures are discussed.
{"title":"PLANE WAVE IRRADIATION OF A LAYERED SYSTEM: RESONANCE-BASED CONTROL OVER THERMAL RUNAWAY","authors":"A. Mohekar, B. Tilley, V. Yakovlev","doi":"10.4995/ampere2019.2019.9940","DOIUrl":"https://doi.org/10.4995/ampere2019.2019.9940","url":null,"abstract":"The loss factor of a material is a key characteristic behind heat generation during EM heating. For typical ceramics, the loss factor increases exponentially with temperature potentially initiating thermal runaway which can damage the material through melting or cracking. Equilibrium of EM heating can be represented by a parametric plot of the average steady-state temperature as function of the applied power that is known as a power response curve. In a layered structure, for wavelengths of the incident wave that are much larger than the layer’s thickness, the power response curve is an S-shaped bifurcation diagram (or S-curve). Stable temperatures are low at the lower branch of the S-curve and may be very high (up to ~2000 K) at the upper branch. The recent analytical and numerical models show that, for a triple (lossless-lossy-lossless) layered system, when thickness of the structure is comparable with the wavelength, an electric field resonance can be achieved in the lossy layer. This resonance causes the S-curve to acquire another (middle) stable branch and become a double S-curve. That suggests that temperatures during thermal runaway may be controlled by the field resonance. However, these models assume two-side symmetric irradiation. In this paper, we show that the resonance producing a double S-curve can be achieved in a more practical scenario with one-side irradiation: in the system with a metal plate the resonance is achieve by choosing layer's thickness and triggering a constructive interference of the incident and reflected waves. A series of double S-curves computed with COMSOL Multiphysics are analyzed, and practical ways of controlling thermal runaway in EM heating of layered structures are discussed.","PeriodicalId":277158,"journal":{"name":"Proceedings 17th International Conference on Microwave and High Frequency Heating","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116414467","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 : 2019-09-09DOI: 10.4995/ampere2019.2019.9706
A. Leshchinskaya
MICROWAVE WOOD CHIP TREATMENT USE IN CHEMICAL PULP MANUFACTURING (TECHNICAL-ECONOMIC ASSESMENT) A. Leshchinskaya Plekhanov Russian University of Economics. 36 Stremyannyy Pereulok, 115093 Moscow, Russia, e-mail: alixfl@mail.ru] Keywords: chemical pulping, microwave wood modification, pulp, softwood, wood chips. Large volumes of cellulose are produced from wood chips by chemical methods. Low permeability of many wood species causes problems in the chemical pulp industry. These include: very long cooking times, high chemical consumption, large material losses, high energy consumption, and environmental pollution. New microwave (MW) wood modification technology can provide an increase in wood permeability for liquids and gases, which solves many of these problems. The technology works by applying intensive MW power to green wood, which generates steam pressure within wood cells. High internal pressure destroys weak elements of wood structure, opens pores and forms micro and macro cracks. A several thousand-fold increase in wood permeability can be achieved in species previously found to be impermeable to liquids and gases. It allows a significant increase in the speed of pulp cooking and improves a production processes. The study of the technology showed radical potential improvements in the pulp industry through: increase in mill throughput significant reduction of chemical consumptionreduction of energy consumption • increase in pulp quality and yield improvement of environmental performance. Pulp manufacturing process includs timber chipping, microwave chip treatment, steaming, cooking, washing, and pulp making. The use of MW wood chip treatment in pulp mills with outputs of 50,000 to 500,000 air dry tons (ADT) per year requires MW equipment with power from 1000 to 10,000 kW. Economic modelling of this technology used in different pulp mill conditions allowed assessment of the effect of capital costs, electricity costs, labour costs and other cost components to specific total costs of MW chip processing. Economic assessment of MW technology application showed that specific costs of softwood chip processing at electricity costs of 0.08 - 0.12 US$/kWh are 25.4 -33.7 US$/ADT of pulp. Electricity costs form the most significant part of the total specific costs of MW processing and form 51-69% shear in the total specific costs. Under the same conditions capital costs form 15-20% shear, and labour costs form 5-18% shear of the total specific costs. The electricity cost increase from $0.04 to $0.24/kWh provides specific MW processing cost rise by 2.7 to 3.1 times at pulp mill output range 50,000 to 500,000 ADT/year. New technology use allows benefits up to 7 – 22 Mil US$ per year for pulp mills with output of more than 200,000 ADT/year. The technology can be used by pulp mills with batch and continuous digesting and is not limited by mill throughput. Ecological impacts and high economic advantages of this MW technology application in pu
{"title":"A. Leshchinskaya. MICROWAVE WOOD CHIP TREATMENT USE IN CHEMICAL PULP MANUFACTURING (TECHNICAL-ECONOMIC ASSESMENT)","authors":"A. Leshchinskaya","doi":"10.4995/ampere2019.2019.9706","DOIUrl":"https://doi.org/10.4995/ampere2019.2019.9706","url":null,"abstract":"MICROWAVE WOOD CHIP TREATMENT USE IN CHEMICAL PULP MANUFACTURING (TECHNICAL-ECONOMIC ASSESMENT) A. Leshchinskaya Plekhanov Russian University of Economics. 36 Stremyannyy Pereulok, 115093 Moscow, Russia, e-mail: alixfl@mail.ru] Keywords: chemical pulping, microwave wood modification, pulp, softwood, wood chips. Large volumes of cellulose are produced from wood chips by chemical methods. Low permeability of many wood species causes problems in the chemical pulp industry. These include: very long cooking times, high chemical consumption, large material losses, high energy consumption, and environmental pollution. New microwave (MW) wood modification technology can provide an increase in wood permeability for liquids and gases, which solves many of these problems. The technology works by applying intensive MW power to green wood, which generates steam pressure within wood cells. High internal pressure destroys weak elements of wood structure, opens pores and forms micro and macro cracks. A several thousand-fold increase in wood permeability can be achieved in species previously found to be impermeable to liquids and gases. It allows a significant increase in the speed of pulp cooking and improves a production processes. The study of the technology showed radical potential improvements in the pulp industry through: increase in mill throughput significant reduction of chemical consumptionreduction of energy consumption • increase in pulp quality and yield improvement of environmental performance. Pulp manufacturing process includs timber chipping, microwave chip treatment, steaming, cooking, washing, and pulp making. The use of MW wood chip treatment in pulp mills with outputs of 50,000 to 500,000 air dry tons (ADT) per year requires MW equipment with power from 1000 to 10,000 kW. Economic modelling of this technology used in different pulp mill conditions allowed assessment of the effect of capital costs, electricity costs, labour costs and other cost components to specific total costs of MW chip processing. Economic assessment of MW technology application showed that specific costs of softwood chip processing at electricity costs of 0.08 - 0.12 US$/kWh are 25.4 -33.7 US$/ADT of pulp. Electricity costs form the most significant part of the total specific costs of MW processing and form 51-69% shear in the total specific costs. Under the same conditions capital costs form 15-20% shear, and labour costs form 5-18% shear of the total specific costs. The electricity cost increase from $0.04 to $0.24/kWh provides specific MW processing cost rise by 2.7 to 3.1 times at pulp mill output range 50,000 to 500,000 ADT/year. New technology use allows benefits up to 7 – 22 Mil US$ per year for pulp mills with output of more than 200,000 ADT/year. The technology can be used by pulp mills with batch and continuous digesting and is not limited by mill throughput. Ecological impacts and high economic advantages of this MW technology application in pu","PeriodicalId":277158,"journal":{"name":"Proceedings 17th International Conference on Microwave and High Frequency Heating","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132674175","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 : 2019-09-09DOI: 10.4995/ampere2019.2019.9813
S. Aravindan, S. Tamang
The joining of dissimilar Pure Copper (Cu) to Stainless Steel (SS304) is necesilated in many industrial applications such as heat exchangers and electrical contacts. Advantages of both the materials such as high electrical conductivity of copper and better corrosion resistance of SS304 can be harnessed by way of joining both the metals. However, joining to Cu to itself or other materials is a challenge since the input heat is dissipated rapidly. Most of the conventional welding methods such as arc and gas are incompetent and unconventional methods such as Explosion Welding, EBW, Diffusion Bonding are very expensive.In this study a new economical process of joining of dissimilar metals i.e. Cu to SS304 by microwave hybrid heating is investigated. Microwave joining is made possible by applying a powder (in this work Nickel metal powder) as an interlayer and exposing to microwave surrounding the interlayer with a susceptor. In this study the interlayer of Ni powder having average size 200nm and 45μm was used. On exposure to microwave, the interlayer meal powder heats up [1] and then it promotes melting and thereby bonding to facilitate dissimilar joint. The microstructure of the joint is studied by optical microscope and scanning electron microscope. The joints formed with 200nm Ni powder were observed to have a defect free microstructure as illustrated in Fig. 1. The EDS and XRD analysis determines the formation of solid solution between Cu-Ni interface and an intermetallic compound at Fe-Ni interface. The diffusion of elements across the joint was further analyzed by EDS line scan. The hardness variation was studied by Vickers’ micro-hardness. It can be concluded that smaller size Ni heat up faster in microwave and produce stronger joint of Cu to SS304 by microwave hybrid heating. References 1. M. S. Srinath, A. K. Sharma, et al. ,Materials & Design , 2011, 32, 2685–2694
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