| 1. |
M. Otaka, T. Arima, J. Lai, K. Ikeda, K. Kamataki, N. Yamashita, T. Okumura, N. Itagaki, K. Koga, M. Shiratani, Spatio-temporal measurements Ar 2p1 excitation rates and optical emission spectroscopy by capacitively coupled Ar and Ne mixed gas plasma, MRS Adv., 10.1557/s43580-022-00306-2, 2022.07. |
| 2. |
P. Attri, K. Koga, T. Okumura, F. L. Chawarambwa, T. E. Putri, Y. Tsukada, K. Kamataki, N. Itagaki, M. Shiratani, Treatment of organic wastewater by a combination of non-thermal plasma and catalyst: a review, Rev. Mod. Plasma Phys, 10.1007/s41614-022-00077-1, 6, 17, 2022.07. |
| 3. |
S. Ono, S. H. Hwang, T. Okumura, K. Kamataki, N. Yamashita, N. Itagaki, K. Koga, M. Shiratani, J. S. Oh, S. Takabayashi, T. Nakatani, Raman spectral analysis of the as-deposited aC: H films prepared by CH4+ Ar plasma CVD, MRS Adv., 10.1557/s43580-022-00310-6, 7, 718–722, 2022.07. |
| 4. |
T. Okumura, P. Attri, K. Kamataki, N. Yamashita, Y. Tsukada, N. Itagaki, M. Shiratani, Y. Ishibashi, K. Kuchitsu, K. Koga, Detection of NO3− introduced in plasma-irradiated dry lettuce seeds using liquid chromatography-electrospray ionization quantum mass spectrometry (LC-ESI QMS), Sci. Rep., 10.1038/s41598-022-16641-1, 12, 12525, 2022.07. |
| 5. |
K. Kamataki, D. Nagamatsu, T. Yang, K. Abe, A. Yamamoto, I. Nagao, T. Arima, M. Otaka, Y. Yamamoto, D. Yamashita, T. Okumura, N. Yamashita, N. Itagaki, K. Koga, M. Shiratani, Effects of amplitude modulated discharge on growth of nanoparticles in TEOS/O2/Ar capacitively coupled plasma, AIP Adv, 10.1063/5.0097691, 12, 8, 085220, 2022.08. |
| 6. |
K. Kamataki, D. Nagamatsu, T. Yang, K. Abe, A. Yamamoto, I. Nagao, T. Arima, M. Otaka, Y. Yamamoto, D. Yamashita, T. Okumura, N. Yamashita, N. Itagaki, K. Koga, M. Shiratani, Effects of amplitude modulated discharge on growth of nanoparticles in TEOS/O2/Ar capacitively coupled plasma, AIP Adv., 10.1063/5.0097691, 12, 085220, 2022.08. |
| 7. |
K. Abe, K. Kamataki, A. Yamamoto, I. Nagao, M. Otaka, D. Yamashita, T. Okumura, N. Yamashita, N. Itagaki, K . Koga, M. Shiratani, Effects of amplitude modulated capacitively coupled discharge Ar plasma on kinetic energy and angular distribution function of ions impinging on electrodes:particle-in-cell/Monte Carlo collision model simulation, Jpn. J. Appl. Phys., 10.35848/1347-4065/ac7626, 61, 10, 106003, 2022.09. |
| 8. |
K. Koga, P. Attri, T. Okumura, T. Anan, T. Nakao, K. Kamataki, N. Yamashita, N. Itagaki, M. Shiratani, Role of short-lived nitrogen species generated at low-pressure RF plasma on the germination and seedling growth, Bull. Am. Phys. Soc., 2022.10. |
| 9. |
K. Kamataki, T. Sato, K. Tomita, P. Yimin, D. Yamashita, N. Yamashita, T. Okumura, N. Itagaki, K. Koga, M. Shiratani, Measurements of strength and fluctuation of 2D electric fields in plasmas using a fine particle trapped with laser tweezers, Bull. Am. Phys. Soc., 2022.10. |
| 10. |
S. Toko, T. Hasegawa, T. Okumura, K. Kamataki, K. Takenaka, K. Koga, M. Shiratani, Y. Setsuhara, Relationship between vibrational temperature and CO2 methanation with plasma catalysis, Bull. Am. Phys. Soc., 2022.10. |
| 11. |
I. Nagao, A. Yamamoto, Y. Yamamoto, K. Kamataki, T. Okumura, N. Yamashita, N. Itagaki, K. Koga, M. Shiratani, Effects of amplitude modulation discharge on behavior of oxygen ions in Ar/O2 capacitively coupled plasma studied by particle-in-cell/Monte Carlo collision model, Bull. Am. Phys. Soc., 2022.10. |
| 12. |
M. Otaka, T. Arima, J. Lai, K. Ikeda, K. Kamataki, N. Yamashita, T. Okumura, N. Itagaki, K. Koga, M. Shiratani, Pressure dependence on spatio-temporal distribution of excitation rates of Ar 2p1 and Ne 2p1 in Ar and Ar/Ne capacitively coupled plasmas, Bull. Am. Phys. Soc., 2022.10. |
| 13. |
M. Shiratani, T. Anan, T. Nakao, T. Okumura, P. Attri, K. Koga, Reproducibility in plasma agriculture, Bull. Am. Phys. Soc., 2022.10. |
| 14. |
T. Anan, T. Nakao, T. Okumura, P. Attri, K. Kamataki, N. Yamashita, N. Itagaki, K. Koga, M. Shiratani, Effect of plasma irradiation on germination of lettuce seeds with fluctuating dormancy, Bull. Am. Phys. Soc., 2022.10. |
| 15. |
P. Attri, T. Okumura, K. Koga, K. Kamataki, N. Itagaki, M. Shiratani, N. Takeuchi, Plasma induced conversion of CO2 with water to useful compounds, Bull. Am. Phys. Soc., 2022.10. |
| 16. |
S. Ono, T. Okumura, K. Kamataki, N. Yamashita, N. Itagaki, K. Koga, M. Shiratani, Process analysis of cracking aC: H/CNP/aC: H sandwich films under stress using nanoindentation, Bull. Am. Phys. Soc., 2022.10. |
| 17. |
T. Okumura, T. Anan, P. Attri, Y. Tsukada, K. Kamataki, N. Yamashita, N. Itagaki, K. Koga, M. Shiratani, Y. Ishibashi, Plasma irradiation-introduced RONS amount into plant seeds and their response analysis, Bull. Am. Phys. Soc., 2022.10. |
| 18. |
S. Shenoy, C. Chuaicham, T. Okumura, K. Sekar, K. Sasaki, Simple tactic polycondensation synthesis of Z-scheme quasi-polymeric g-C3N4/CaFe2O4 composite for enhanced photocatalytic water depollution via p-n heterojunction, Chem. Eng. J, 10.1016/j.cej.2022.139758, 453, 139758, 2022.10. |
| 19. |
R. Narishige, N. Yamashita, K. Kamataki, T. Okumura, K. Koga, M. Shiratani, H. Yabuta, N. Itagaki , Effects of substrate surface polarity on heteroepitaxial growth of pseudobinary ZnO–InN alloy films on ZnO substrates(Invited), J. Mater. Res., 10.1557/s43578-022-00827-4, 2022.11. |
| 20. |
I. Nagao, K. Kamataki, A. Yamamoto, M. Otaka, Y. Yamamoto, D. Yamashita, N. Yamashita, T. Okumura, N. Itagaki, K. Koga, M. Shiratani, One-dimensional particle-in-cell/Monte Carlo collision simulation for investigation of amplitude modulation effects in RF capacitive discharges, MRS Adv., 10.1557/s43580-022-00417-w, 7, 911-917, 2022.12. |
| 21. |
N. Yamashita, R. Mitsuishi, Y. Nakamura, K. Takeda, M. Hori, K. Kamataki, T. Okumura, K. Koga, M. Shiratani, Role of insoluble atoms in the formation of a three-dimensional buffer layer in inverted Stranski–Krastanov mode, J. Mater. Res, 10.1557/s43578-022-00886-7, 1-8, 2023.01. |
| 22. |
Sulakshana Shenoy, Chitiphon Chuaicham, Takamasa Okumura, Karthikeyan Sekar, Keiko Sasaki, Simple tactic polycondensation synthesis of Z-scheme quasi-polymeric g-C3N4/CaFe2O4 composite for enhanced photocatalytic water depollution via p-n heterojunction, Chemical Engineering Journal, https://doi.org/10.1016/j.cej.2022.139758, 453, 2, 2023.02. |
| 23. |
Takamasa Okumura, Pankaj Attri, Kunihiro Kamataki, Naoto Yamashita, Yuichi Tsukada, Naho Itagaki, Masaharu Shiratani, Yushi Ishibashi, Kazuyuki Kuchitsu, Kazunori Koga , Detection of NO3− introduced in plasma-irradiated dry lettuce seeds using liquid chromatography-electrospray ionization quantum mass spectrometry (LC-ESI QMS), Scientific Reports, https://doi.org/10.1038/s41598-022-16641-1, 12, 12525, 2022.07. |
| 24. |
P.Attri, K. Koga, T. Okumura, N. Takeuchi, M. Shiratani, Green route for ammonium nitrate synthesis: fertilizer for plant growth enhancement, RSC Adv., 10.1039/D1RA04441A , 11, 46, 28521-28529, 2021.08. |
| 25. |
P. Attri, T. Anan, R. Arita, T. Okumura, H. Tanaka, D. Yamashita, K. Matsuo, N. Itagaki, K. Kamataki, K. Koga, M. Shiratani, K. Kuchitsu, Y. Ishibashi, Plasma Treatment Effect on the Paramagnetic Species of Barley Seed Radical’s Intensity: An EPR study, Plasma Medicine, 10.1615/PlasmaMed.2020036353, 10, 3, 159-168, 2021.12. |
| 26. |
S. Toko, M. Ideguchi, T. Hasegawa, T. Okumura, K. Kamataki, K.Takenaka, K. Koga, M. Shiratani, Y. Setsuhara, Effect of gas flow rate and discharge volume on CO2 methanation with plasma catalysis, Jpn. J. Appl. Phys., 10.35848/1347-4065/ac4822, 2022.01. |
| 27. |
P. Attri, T. Okumura, K. Koga, M. Shiratani, D. Wang, K. Takahashi, K. Takaki, Outcomes of Pulsed Electric Fields and Nonthermal Plasma Treatments on Seed Germination and Protein Functions, Agronomy 2022, 10.3390/agronomy12020482, 12, 2, 482, 2022.02. |
| 28. |
D. Takahashi, N. Yamashita, D. Yamashita, T. Okumura, K. Kamataki, K. Koga, M. Shiratani, N. Itagaki, Epitaxial Growth of Zn1-xMgxO Films on Sapphire Substrates via Inverted Stranski-Krastanov Mode Using Magnetron Sputtering, MRS Adv., 10.1557/s43580-022-00234-1, 2022.02. |
| 29. |
Takamasa Okumura, Yuji Muramoto, Noriyuki Shimizu, Influence of DC Electric Field on Growth of Daikon Radish (Raphanus sativus), IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION, 10.1109/TDEI.2012.6396985, 19, 6, 2237-2241, 2012.12, This paper reports the influence of dc electric field on plant growth. We used daikon radish as the sample. Seeds of the daikon radish were grown under two conditions; one is under dc electric fields, and the other is without electric fields. We have confirmed the following: 1. The application of dc electric field improves the germination rate. 2. The dc electric field increases the length and the weight of the sample. 3. However, after removal of water by vacuum treatment, the weight of the sample subjected to the dc electric fields is lower than that of the sample not subjected to electric field. This result suggests that the dc electric field accelerates the growth of the plant; it does not increase the real plant weight, but just improves the stem elongation by water absorption, and encourages the consumption of substances stored in the seed. These effects of the dc electric field are similar to those of Gibberellin phytohormones.. |
| 30. |
Takamasa Okumura, Yuji Muramoto, Noriyuki Shimizu, Dependency of Arabidopsis thaliana Growth on DC Electric Field Intensity, IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION, 10.1109/TDEI.2013.004085, 21, 2, 913-917, 2014.04, In this paper, the dependency of Arabidopsis thaliana growth on dc field intensity was studied. One group of Arabidopsis thaliana seeds was cultivated under one intensity of electric field. Four values of 2.5, 5.0, 10.0 and 15.0 kV/m were chosen for applied field intensity. Applying duration was four days. Then, seed germination rate and stem length of seedling were obtained. As a result, it is shown that dc field improves seed germination rate and seedling stem length. Also, the length of seedling stem is increased with dc field up to 10.0 kV/m with comparatively high reliability by the statistical test, while above 10.0 kV/m it seems to saturate.. |
| 31. |
Takamasa Okumura, Kazuki Yamada, Taro Yaegashi, Katsuyuki Takahashi, Bunei Syuto, Koichi Takaki, External AC Electric Field-Induced Conformational Change in Bovine Serum Albumin, IEEE TRANSACTIONS ON PLASMA SCIENCE, 10.1109/TPS.2017.2657748, 45, 3, 489-494, 2017.03, An ac electric field (acEF) application technology has been reported as a principle technique for food preservation. With this method, conformational changes in the protein molecules of food materials may be induced. Conformational changes were experimentally examined using bovine serum albumin (BSA) as a model protein using an acEF technology. The amplitude of acEF was 66.7 kV/m. BSA with acEF (ac-BSA) and BSA without the ac field (n-BSA) were trypsinized under the same conditions. The derived peptides were compared by using sodium dodecyl sulfate polyacrylamide gel electrophoresis patterns. Formation of tryptic peptides was increased in n-BSA, and trypsin digestion was suppressed in ac-BSA. These results indicate that conformational changes in BSA molecules were induced by acEF application.. |
| 32. |
Yoshiko Oshika, Yudai Tsuchiya, Takamasa Okumura, Yuji Muramoto, Alternating current breakdown voltage of ice electret, Journal of Physics: Conference Series, 897, 2017.09. |
| 33. |
Takamasa Okumura, Chaoyi Zhou, Eijiro Kubo, Tetsuji Shimizu, Tomoki Nakajima, Takehiko Sato, Electric potential developed by single-pulse needle-water discharge, Applied Physics Express, 11, 2017.12. |
| 34. |
Katsuyuki Takahashi, Yoshinori Saito, Rikuya Oikawa, Takamasa Okumura, Koichi Takaki, Takuya Fujio, Development of automatically controlled corona plasma system for inactivation of pathogen in hydroponic cultivation medium of tomato, Journal of Electrostatics, 10.1016/j.elstat.2017.12.006, 91, 61-69, 2018.02, A nutrient solution treatment system using corona plasma is developed for practical use in hydroponics. A gas-liquid separated reactor and a high voltage power supply based on a 20 kHz inverter neon-transformer are developed to archive the treatment with high energy efficiency, a low initial cost and a low running cost. The performance of the system on bacteria inactivation in the nutrient solution is evaluated in a continuous treatment system operation. The results show that the standard plate count for background microflora and R. solanacearum is drastically reduced by the plasma treatment and is not detected after 8 days treatment. The nutrient solution is decontaminated by 4 log cycle with plasma treatment under the continuous operation condition.. |
| 35. |
P. Attri, K. Ishikawa, T. Okumura, K. Koga, M. Shiratani, Plasma agriculture from laboratory to farm: A review, Processes, 10.3390/pr8081002, 8, 8, 1002, 2020.08. |
| 36. |
S. H. Hwang, T. Okumura, K. Kamataki, N. Itagaki, K. Koga, T. Nakatani, M. Shiratani, Low stress diamond-like carbon films containing carbon nanoparticles fabricated by combining rf sputtering and plasma chemical vapor deposition, Jpn. J. Appl. Phys. , 10.35848/1347-4065/abbb20, 59, 10, 100906, 2020.10. |
| 37. |
S. H. Hwang, T. Okumura, K. Kamataki, N. Itagaki, K. Koga, M. Shiratani, Size and flux of carbon nanoparticles synthesized by Ar+CH4 multi-hollow plasma chemical vapor deposition, Diam Relat Mater, 10.1016/j.diamond.2020.108050, 109, 108050, 2020.11. |
| 38. |
Sung Hwa Hwang, Kazunori Koga, Yuan Hao, Pankaj Attri, Takamasa Okumura, Kunihiro Kamataki, Naho Itagaki, Masaharu Shiratani, Jun-Seok Oh, Susumu Takabayashi, Tatsuyuki Nakatani, Time of Flight Size Control of Carbon Nanoparticles Using Ar+CH4 Multi-Hollow Discharge Plasma Chemical Vapor Deposition Method, Processes, 10.3390/pr9010002, 9, 1, 2-2, 2020.12, As the application of nanotechnology increases continuously, the need for controlled size nanoparticles also increases. Therefore, in this work, we discussed the growth mechanism of carbon nanoparticles generated in Ar+CH4 multi-hollow discharge plasmas. Using the plasmas, we succeeded in continuous generation of hydrogenated amorphous carbon nanoparticles with controlled size (25–220 nm) by the gas flow. Among the nanoparticle growth processes in plasmas, we confirmed the deposition of carbon-related radicals was the dominant process for the method. The size of nanoparticles was proportional to the gas residence time in holes of the discharge electrode. The radical deposition developed the nucleated nanoparticles during their transport in discharges, and the time of flight in discharges controlled the size of nanoparticles.. |
| 39. |
P.Attri, K. Koga, T.Okumura, M. Shiratani, Impact of atmospheric pressure plasma treated seeds on germination, morphology, gene expression and biochemical responses, Jpn. J. Appl. Phys., 10.35848/1347-4065/abe47d, 60, 4, 040502, 2021.03. |
| 40. |
S. H. Hwang, R. Iwamoto, T. Okumura, K. Kamataki, N. Itagaki, K. Koga, T. Nakatani, M. Shiratani, Comparison between Ar+CH4 Cathode and Anode Coupled Capacitively Coupled Plasma Chemical Vapor Deposition of Hydrogenated Amorphous Carbon Films, Thin Solid Films, 10.1016/j.tsf.2021.138701, 729, 138701, 2021.07. |
| 41. |
P. Attri, K. Koga, T. Okumura, N. Takeuchi, M. Shiratani, Green route for ammonium nitrate synthesis: fertilizer for plant growth enhancement, RSC Advances, 10.1039/D1RA04441A , 46, 2021.08, Soil fertility management is of great importance for farmers. The use of synthetic nitrogen (N)-fertilizer increased by 20 fold in the last 50 years to feed the increasingly hungry population. This study aims to enrich the plant soil with nitrogen content (NH4NO3 fertilizer in soil) using the low-temperature and low-pressure plasma [without H2 and catalyst]. Subsequently, we used plasma N-enriched soil for plant (radish and tomato) growth. We investigated the germination percentage, seedling growth, seedling weight, phytohormones and antioxidant activity of radish and tomato plants after treatment with plasma N-enriched soil and compared with control soil and soil + commercial N-fertilizer. The plasma N-enriched soil treatment results in significant growth enhancement for both radish and tomato plants. Further, substantial changes in phytohormone and antioxidant levels were observed for the plants grown in plasma N-enriched soil compared to control soil and soil + commercial N-fertilizer. The energy consumption (EC) for total N-fixation was 12 MJ mol−1. EC for ammonia and nitrate fixation was 17 and 41 MJ mol−1, respectively, without H2 gas. Further to understand the plasma chemistry, we performed 1D simulation using COMSOL Multiphysics® software. This study showed that direct N-fixation in the soil by plasma could be used as fertilizer for the plants and open a new window for future decentralized N-fertilizer production at the farm site.. |
