Pub Date : 2021-09-30DOI: 10.5757/asct.2021.30.5.141
Jangjae Lee, C. Cho, M. Choi, Chang Seok Cho, T. J. Oh, Yong Shik Lee, J. Yim, Heung Cheol Yoo, Hee Soo Jung, S. You
In this experimental research, the characteristics of the discharge generated using a flexible electrode at intermediate pressure were investigated. We confirmed the discharge patterns according to the pulse width and frequency of a pulse generator with a fixed voltage under a pressure of 0.3 atm, which is the pressure at a typical flight altitude. Uniform discharge was found to occur at a frequency of 10 kHz with a pulse width of 4 μs and at a frequency of 20 kHz with a pulse width of 3 μs. To analyze the trend of discharge patterns, the voltage and current waveforms of the discharge in each condition were measured. In addition, the power dissipated by one cycle was calculated from the measured voltage and current waveforms. From the measurement and calculation results, it was confirmed that the dissipated power was large when the discharge occurred at a frequency of 20 kHz with a pulse width of 3 μs, that is, the brighter and more uniform discharge pattern, which was found to be the optimal discharge condition for the flexible electrode at a pressure of 0.3 atm.
{"title":"Experimental Study of Discharge with Flexible Electrodes at Intermediate Pressure for Radar Cross Section Reduction","authors":"Jangjae Lee, C. Cho, M. Choi, Chang Seok Cho, T. J. Oh, Yong Shik Lee, J. Yim, Heung Cheol Yoo, Hee Soo Jung, S. You","doi":"10.5757/asct.2021.30.5.141","DOIUrl":"https://doi.org/10.5757/asct.2021.30.5.141","url":null,"abstract":"In this experimental research, the characteristics of the discharge generated using a flexible electrode at intermediate pressure were investigated. We confirmed the discharge patterns according to the pulse width and frequency of a pulse generator with a fixed voltage under a pressure of 0.3 atm, which is the pressure at a typical flight altitude. Uniform discharge was found to occur at a frequency of 10 kHz with a pulse width of 4 μs and at a frequency of 20 kHz with a pulse width of 3 μs. To analyze the trend of discharge patterns, the voltage and current waveforms of the discharge in each condition were measured. In addition, the power dissipated by one cycle was calculated from the measured voltage and current waveforms. From the measurement and calculation results, it was confirmed that the dissipated power was large when the discharge occurred at a frequency of 20 kHz with a pulse width of 3 μs, that is, the brighter and more uniform discharge pattern, which was found to be the optimal discharge condition for the flexible electrode at a pressure of 0.3 atm.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"422 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78168385","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 : 2021-07-30DOI: 10.5757/asct.2021.30.4.95
Intek Song
A new way to prepare single crystals of ligand-coordinated chromium (II) acetate with quadruple bonds is presented. Coordination of water and pyridine with crystal growth occur by seed-mediated growth. The product was obtained as crystals with well-defined facets. Raman spectroscopy confirmed the high quality and purity of the products. Mechanism studies showed that the growth reaction is driven by heterogeneous crystallization at the interface of the seeds. Seed-mediated growth results in the high quality and large size of the crystals with improved yield for shorter reaction time.
{"title":"Fast Synthesis of Ligand-Coordinated Chromium (II) Acetate with Quadruple Bonds by Seed-Mediated Growth","authors":"Intek Song","doi":"10.5757/asct.2021.30.4.95","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.95","url":null,"abstract":"A new way to prepare single crystals of ligand-coordinated chromium (II) acetate with quadruple bonds is presented. Coordination of water and pyridine with crystal growth occur by seed-mediated growth. The product was obtained as crystals with well-defined facets. Raman spectroscopy confirmed the high quality and purity of the products. Mechanism studies showed that the growth reaction is driven by heterogeneous crystallization at the interface of the seeds. Seed-mediated growth results in the high quality and large size of the crystals with improved yield for shorter reaction time.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"3 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72513085","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 : 2021-07-30DOI: 10.5757/asct.2021.30.4.102
Seung-Wan Yoo, C. Cho, Kyung Tae Kim, Hyo-Chang Lee, Shinjae You
Fluorocarbon (C 7 F 14 , C 7 F 8 ) plasmas are investigated to verify their etching characteristics as an alternative etchant of SiO 2 etch process because C 7 F 8 and C 7 F 14 precursors are expected to have low Global warming potentials. Comparing the etch results of C 4 F 8 , C 7 F 14 , and C 7 F 8 plasmas, C 7 F 8 provides the highest selectivity for etching SiO 2 at a moderate etching rate of the three fluorocarbons. C 4 F 8 and C 7 F 14 plasmas show similar magnitudes of selectivity at the same O 2 injection. O 2 addition is used to control densities of carbon species and optimize etching conditions. From comparison of the species existing in the C 4 F 8 , C 7 F 14 , and C 7 F 8 plasmas by the electron-emitting source, CF radicals and carbon atoms are important in determining the remarkable selectivity of C 7 F 8 plasma. This understanding is verified using X-ray photoelectron spectroscopy analysis.
{"title":"Characteristics of SiO2 Etching by Capacitively Coupled Plasma with Different Fluorocarbon Liquids (C7F14, C7F8) and Fluorocarbon Gas (C4F8)","authors":"Seung-Wan Yoo, C. Cho, Kyung Tae Kim, Hyo-Chang Lee, Shinjae You","doi":"10.5757/asct.2021.30.4.102","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.102","url":null,"abstract":"Fluorocarbon (C 7 F 14 , C 7 F 8 ) plasmas are investigated to verify their etching characteristics as an alternative etchant of SiO 2 etch process because C 7 F 8 and C 7 F 14 precursors are expected to have low Global warming potentials. Comparing the etch results of C 4 F 8 , C 7 F 14 , and C 7 F 8 plasmas, C 7 F 8 provides the highest selectivity for etching SiO 2 at a moderate etching rate of the three fluorocarbons. C 4 F 8 and C 7 F 14 plasmas show similar magnitudes of selectivity at the same O 2 injection. O 2 addition is used to control densities of carbon species and optimize etching conditions. From comparison of the species existing in the C 4 F 8 , C 7 F 14 , and C 7 F 8 plasmas by the electron-emitting source, CF radicals and carbon atoms are important in determining the remarkable selectivity of C 7 F 8 plasma. This understanding is verified using X-ray photoelectron spectroscopy analysis.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"10 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89216665","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 : 2021-07-30DOI: 10.5757/asct.2021.30.4.98
Y. Kim
A Ba 0.9 Bi 0.1 TiO 3 solid solution was prepared by substituting 0.1 mole % Bi 2 O 3 at the Ba 2+ sites in BaTiO 3 , and its dielectric properties were investigated. The Ba 0 . 9 Bi 0 . 1 TiO 3 solid solution was sintered at 1310 ∘ C for 5 h. The stable formation of the perovskite structure was confirmed through X-ray diffraction, energy-dispersive X-ray spectroscopy, and field emission scanning electron microscopy. Unlike pure BaTiO 3 , pyrochlore Bi 2 Ti 2 O 7 was observed in Ba 0 . 9 Bi 0 . 1 TiO 3 at approximately 27.1 ∘ . Overall, the perovskite structure was well formed. The Ba 0 . 9 Bi 0 . 1 TiO 3 solid solution showed typical dielectric properties and followed the modified Curie–Weiss law. In addition, the curve of the dielectric constant vs. temperature showed an extremely gradual change compared to the phase transition behavior of BaTiO 3 .
{"title":"Influence of Bismuth Oxide on Dielectric Properties of Barium Titanate Solid Solution","authors":"Y. Kim","doi":"10.5757/asct.2021.30.4.98","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.98","url":null,"abstract":"A Ba 0.9 Bi 0.1 TiO 3 solid solution was prepared by substituting 0.1 mole % Bi 2 O 3 at the Ba 2+ sites in BaTiO 3 , and its dielectric properties were investigated. The Ba 0 . 9 Bi 0 . 1 TiO 3 solid solution was sintered at 1310 ∘ C for 5 h. The stable formation of the perovskite structure was confirmed through X-ray diffraction, energy-dispersive X-ray spectroscopy, and field emission scanning electron microscopy. Unlike pure BaTiO 3 , pyrochlore Bi 2 Ti 2 O 7 was observed in Ba 0 . 9 Bi 0 . 1 TiO 3 at approximately 27.1 ∘ . Overall, the perovskite structure was well formed. The Ba 0 . 9 Bi 0 . 1 TiO 3 solid solution showed typical dielectric properties and followed the modified Curie–Weiss law. In addition, the curve of the dielectric constant vs. temperature showed an extremely gradual change compared to the phase transition behavior of BaTiO 3 .","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"19 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78754207","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 : 2021-07-30DOI: 10.5757/asct.2021.30.4.111
Kyung Ho Kim, Jaieun An, Jun-Seob Kim, Joonwon Bae, Oh Seok Kwon
In this study, a convenient high-performance portable sensor platform for simple, fast, and efficient detection of H1N1 virus is demonstrated using a graphene-based transistor type architecture. A uniform graphene layer was generated and patterned by conventional methods such as lithography and vapor deposition, subsequently, electrodes were introduced on the patterned graphene layer to obtain transistor type sensor geometry. Then, the graphene surface was functionalized with antibody for H1N1 virus detection and sensor performance test. The transition curve, linearity, and sensitivity (10 pfu/mL) of the sensor component were measured. In addition, the portable H1N1 diagnosis platform for simple, fast, and convenient virus detection was produced and demonstrated. Consequently, the sensor performance was maintained in the portable sensor platform compared with the graphene-based sensor component. This presented portable H1N1 diagnosis platform showed better performance than the lateral flow assay.
{"title":"Graphene Field-Effect Transistor Based High-Performance Wireless Portable Device for H1N1 Detection","authors":"Kyung Ho Kim, Jaieun An, Jun-Seob Kim, Joonwon Bae, Oh Seok Kwon","doi":"10.5757/asct.2021.30.4.111","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.111","url":null,"abstract":"In this study, a convenient high-performance portable sensor platform for simple, fast, and efficient detection of H1N1 virus is demonstrated using a graphene-based transistor type architecture. A uniform graphene layer was generated and patterned by conventional methods such as lithography and vapor deposition, subsequently, electrodes were introduced on the patterned graphene layer to obtain transistor type sensor geometry. Then, the graphene surface was functionalized with antibody for H1N1 virus detection and sensor performance test. The transition curve, linearity, and sensitivity (10 pfu/mL) of the sensor component were measured. In addition, the portable H1N1 diagnosis platform for simple, fast, and convenient virus detection was produced and demonstrated. Consequently, the sensor performance was maintained in the portable sensor platform compared with the graphene-based sensor component. This presented portable H1N1 diagnosis platform showed better performance than the lateral flow assay.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"44 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89290524","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 : 2021-07-30DOI: 10.5757/asct.2021.30.4.107
Sangeun Cho, S. Noh, Hyungsang Kim, H. Im
Distinctive spectroscopic characteristics are observed in colloidal perovskite CsPbBr 3 quantum dot (QD) dispersed in octane doped with PPO. As the content of CsPbBr 3 -QD increases, the emission and the absorption energies decrease due to QD-cluster formed in case of the inter-QD distance smaller than diameter of QD. Spectroscopic evidences supporting QD-cluster are found in the Urbach energy and the carrier lifetime. Unusual absorption lines showing explicit QD dependence are observed in Fourier-transform infrared spectra, which is explained by vibrational modes of bound PPO hybridized with CsPbBr 3 -QD.
{"title":"Distinctive Spectroscopic Characteristics Observed in Colloidal Perovskite CsPbBr3 Quantum Dot","authors":"Sangeun Cho, S. Noh, Hyungsang Kim, H. Im","doi":"10.5757/asct.2021.30.4.107","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.107","url":null,"abstract":"Distinctive spectroscopic characteristics are observed in colloidal perovskite CsPbBr 3 quantum dot (QD) dispersed in octane doped with PPO. As the content of CsPbBr 3 -QD increases, the emission and the absorption energies decrease due to QD-cluster formed in case of the inter-QD distance smaller than diameter of QD. Spectroscopic evidences supporting QD-cluster are found in the Urbach energy and the carrier lifetime. Unusual absorption lines showing explicit QD dependence are observed in Fourier-transform infrared spectra, which is explained by vibrational modes of bound PPO hybridized with CsPbBr 3 -QD.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"2 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85960616","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 : 2021-07-30DOI: 10.5757/asct.2021.30.4.115
Hyun Sung Kim
In this study, Ru(bpy) 3 @ZIF-11 and Ru(bpy) 3 @ZIF-12 catalysts (bpy = 2,2 ′ ‐bipyridine) were synthesized by encapsulating [Ru(bpy) 3 ] 2+ in zeolitic imidazolate frameworks (ZIFs) ZIF-11 and ZIF-12, respectively, and their photocatalytic activities were compared. Samples of different composites were prepared from their powders, and their crystal morphologies and photocatalytic activities were evaluated by X-ray diffraction analysis and UV-visible absorption spectrometry. [Ru(bpy) 3 ] 2+ @ZIF-12 catalysts possessed excellent photocatalytic stability and exhibited a synergistic effect of [Ru(bpy) 3 ] 2+ and Co in the Ru(bpy) 3 @ZIF-12 composite, and efficient electron transfer from the [Ru(bpy) 3 ] 2+ moiety to the ZIF- 11 framework.
{"title":"Enhancement of Photocatalytic Activity of Tris (bipyridine) Ruthenium by Encapsulation in Zeolitic Imidazolate Framework-11 and 12","authors":"Hyun Sung Kim","doi":"10.5757/asct.2021.30.4.115","DOIUrl":"https://doi.org/10.5757/asct.2021.30.4.115","url":null,"abstract":"In this study, Ru(bpy) 3 @ZIF-11 and Ru(bpy) 3 @ZIF-12 catalysts (bpy = 2,2 ′ ‐bipyridine) were synthesized by encapsulating [Ru(bpy) 3 ] 2+ in zeolitic imidazolate frameworks (ZIFs) ZIF-11 and ZIF-12, respectively, and their photocatalytic activities were compared. Samples of different composites were prepared from their powders, and their crystal morphologies and photocatalytic activities were evaluated by X-ray diffraction analysis and UV-visible absorption spectrometry. [Ru(bpy) 3 ] 2+ @ZIF-12 catalysts possessed excellent photocatalytic stability and exhibited a synergistic effect of [Ru(bpy) 3 ] 2+ and Co in the Ru(bpy) 3 @ZIF-12 composite, and efficient electron transfer from the [Ru(bpy) 3 ] 2+ moiety to the ZIF- 11 framework.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"24 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81322672","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 : 2021-05-31DOI: 10.5757/ASCT.2021.30.3.92
Ju-Hong Cha, Sang‐Woo Kim, Ho‐Jun Lee
In high current implantation, improving the ion extractability is a decisive factor contributing to the equipment efficiency and process cost reduction. A direct current filament ion source and inductively coupled plasma ion source were prepared to observe the degree of plasma extraction according to the ion source characteristics. The plasma parameters used to optimize beam extraction for the filament and RF discharges were 600 W, Ar 2 × 10 −5 Torr, and Ø200 × 250 mm discharge space. In the thermionic ion source, the ion density, electron temperature, and Bohm current density were 5 × 10 9 1/cm 3 , ≥ 6 eV, and ≈ 3.5 A/m 2 , respectively. In the RF ion source, the ion density, electron temperature, and Bohm current density were approximately 5 × 10 10 1/cm 3 , ≈ 3 ∼ 4 eV, and ≈ 25 A/m 2 , respectively. Optimization and analysis of ion extraction according to the plasma and accelerator parameters were calculated using IBSimu. The beam emittance, which is the most important parameter of the ion beam quality, was measured as the beam envelope onto the phase space by an ellipse. A change in the plasma meniscus shape was observed according to the plasma parameters in the ion source, and the emittance of the extracted ion beam was calculated according to the electrode gap distance and aperture structure.
{"title":"A Study on Beam Extraction Characteristics of RF and DC Filament Ion Source for High Current Ion Implanters","authors":"Ju-Hong Cha, Sang‐Woo Kim, Ho‐Jun Lee","doi":"10.5757/ASCT.2021.30.3.92","DOIUrl":"https://doi.org/10.5757/ASCT.2021.30.3.92","url":null,"abstract":"In high current implantation, improving the ion extractability is a decisive factor contributing to the equipment efficiency and process cost reduction. A direct current filament ion source and inductively coupled plasma ion source were prepared to observe the degree of plasma extraction according to the ion source characteristics. The plasma parameters used to optimize beam extraction for the filament and RF discharges were 600 W, Ar 2 × 10 −5 Torr, and Ø200 × 250 mm discharge space. In the thermionic ion source, the ion density, electron temperature, and Bohm current density were 5 × 10 9 1/cm 3 , ≥ 6 eV, and ≈ 3.5 A/m 2 , respectively. In the RF ion source, the ion density, electron temperature, and Bohm current density were approximately 5 × 10 10 1/cm 3 , ≈ 3 ∼ 4 eV, and ≈ 25 A/m 2 , respectively. Optimization and analysis of ion extraction according to the plasma and accelerator parameters were calculated using IBSimu. The beam emittance, which is the most important parameter of the ion beam quality, was measured as the beam envelope onto the phase space by an ellipse. A change in the plasma meniscus shape was observed according to the plasma parameters in the ion source, and the emittance of the extracted ion beam was calculated according to the electrode gap distance and aperture structure.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"70 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76541235","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 : 2021-05-31DOI: 10.5757/ASCT.2021.30.3.74
Changdae Kim
CoIn 2 S 4 thin films were grown onto glass substrates by a spray pyrolysis method. For the growth, the substrate temperature was varied between 250 and 320 ∘ C, and the spray rate was fixed at 6 ml/min. The grown thin films were characterized X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), and optical spectroscopy. The XRD analysis showed that the thin films grown at 320 ∘ C were well crystallized in cubic spinel structure. The FE-SEM results demonstrated that the thin films have a uniform and homogeneous surface. The direct band gap energy was first obtained from the measurement of optical absorption spectra near the fundamental absorption edge at 292 K, and was founded to be 1.59 eV. We also observed two group absorption bands in the near-infrared region, which originate in cobalt ions of the constituent elements of CoIn 2 S 4 . The absorption bands were well assigned as due to the crystal-field transitions of Co 2 + ions occupying tetrahedral sites of the cubic spinel CoIn 2 S 4 host lattice.
{"title":"Growth and Optical Absorption of CoIn2S4 Thin Films by Spray Pyrolysis Method","authors":"Changdae Kim","doi":"10.5757/ASCT.2021.30.3.74","DOIUrl":"https://doi.org/10.5757/ASCT.2021.30.3.74","url":null,"abstract":"CoIn 2 S 4 thin films were grown onto glass substrates by a spray pyrolysis method. For the growth, the substrate temperature was varied between 250 and 320 ∘ C, and the spray rate was fixed at 6 ml/min. The grown thin films were characterized X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), and optical spectroscopy. The XRD analysis showed that the thin films grown at 320 ∘ C were well crystallized in cubic spinel structure. The FE-SEM results demonstrated that the thin films have a uniform and homogeneous surface. The direct band gap energy was first obtained from the measurement of optical absorption spectra near the fundamental absorption edge at 292 K, and was founded to be 1.59 eV. We also observed two group absorption bands in the near-infrared region, which originate in cobalt ions of the constituent elements of CoIn 2 S 4 . The absorption bands were well assigned as due to the crystal-field transitions of Co 2 + ions occupying tetrahedral sites of the cubic spinel CoIn 2 S 4 host lattice.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"16 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81885582","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 : 2021-05-31DOI: 10.5757/ASCT.2021.30.3.70
Hye-Young Ko, Dong H. Shin, Jeong-Hwan Oh, Hyeokjun Kang, Daeun Choi, S. Choi
Rotten citrus fruits, which spread odor gas during shipping season, pose a severe problem in Jeju Island, Republic of Korea. The existing methods for food waste management such as composting using electro-drying and microorganisms have a high electricity cost and require a precise temperature control, respectively. Herein, we conducted a basic numerical study on a plasma reactor using microwave plasma and liquefied petroleum gas as a combined heat source for drying and composting rotten citrus fruits. To determine the design and operating conditions of the plasma reactor, the thermal flow characteristics inside the reactor were analyzed using a computational fluid dynamics code in ANSYS-fluent. In particular, the temperature distribution in the plasma reactor was simulated at different air flow rates of the centrifugal fan. The numerical simulation accuracy was evaluated by comparing the numerical results and actual experimental data. The temperature of the reactor decreased with the increase in the air flow rate of the centrifugal fan. Above 10 m/s, the temperature of the drying chamber and the exhaust gas remained almost constant at 507 K. In the present work, the calculated temperature shows a difference 1.13 % from the measured temperature at the combustion chamber. were caused by the latent heat of water vaporization. The numerical simulation, however, show the correct prediction in the combustion chamber where the heat is suppled and provides reasonable trend of the temperature distribution according to the fresh air supply in the centrifugal fan. Using the simulation results of this study, the oper- ating condition of the plasma reactor as a treatment facility for rotten citrus fruits in Jeju Island are derived and it can be used as basic data for research on food waste disposal facilities.
{"title":"Numerical Simulation of Thermal Flow Characteristics in Plasma Reactor for Rotten Citrus Fruits Drying","authors":"Hye-Young Ko, Dong H. Shin, Jeong-Hwan Oh, Hyeokjun Kang, Daeun Choi, S. Choi","doi":"10.5757/ASCT.2021.30.3.70","DOIUrl":"https://doi.org/10.5757/ASCT.2021.30.3.70","url":null,"abstract":"Rotten citrus fruits, which spread odor gas during shipping season, pose a severe problem in Jeju Island, Republic of Korea. The existing methods for food waste management such as composting using electro-drying and microorganisms have a high electricity cost and require a precise temperature control, respectively. Herein, we conducted a basic numerical study on a plasma reactor using microwave plasma and liquefied petroleum gas as a combined heat source for drying and composting rotten citrus fruits. To determine the design and operating conditions of the plasma reactor, the thermal flow characteristics inside the reactor were analyzed using a computational fluid dynamics code in ANSYS-fluent. In particular, the temperature distribution in the plasma reactor was simulated at different air flow rates of the centrifugal fan. The numerical simulation accuracy was evaluated by comparing the numerical results and actual experimental data. The temperature of the reactor decreased with the increase in the air flow rate of the centrifugal fan. Above 10 m/s, the temperature of the drying chamber and the exhaust gas remained almost constant at 507 K. In the present work, the calculated temperature shows a difference 1.13 % from the measured temperature at the combustion chamber. were caused by the latent heat of water vaporization. The numerical simulation, however, show the correct prediction in the combustion chamber where the heat is suppled and provides reasonable trend of the temperature distribution according to the fresh air supply in the centrifugal fan. Using the simulation results of this study, the oper- ating condition of the plasma reactor as a treatment facility for rotten citrus fruits in Jeju Island are derived and it can be used as basic data for research on food waste disposal facilities.","PeriodicalId":8223,"journal":{"name":"Applied Science and Convergence Technology","volume":"10 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82104018","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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