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Fukuda S, Kondo K, Fukumoto S, Takenaka N, Uchikawa O, Yoshida I. Correction to " N-Nitrosodimethylamine Formation in Metformin Drug Products by the Reaction of Dimethylamine and Atmospheric NO 2". Org Process Res Dev 2024; 28:325. [PMID: 38268772 PMCID: PMC10804400 DOI: 10.1021/acs.oprd.3c00473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Indexed: 01/26/2024]
Abstract
[This corrects the article DOI: 10.1021/acs.oprd.3c00274.].
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Matsubara T, Thanh TC, Hue BTB, Takenaka N, Maeda Y. Bio-diesel Fuel Material Supply in Vietnam and Its Current and Future Potentiality with a Focus on Rubber Seed Oil. J Oleo Sci 2023; 72:219-232. [PMID: 36740251 DOI: 10.5650/jos.ess22309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Diesel fuel usage in Vietnam is increasing rapidly, but most of it is imported from overseas. In this study, we investigated the possibility of popularizing bio-diesel fuel (BDF) made from Vietnamese origin resources as a sustainable energy solution. The world's energy cost fluctuates significantly depending on economic or political movements, especially after the Russian invasion of Ukraine began in 2022. This caused energy prices soar, attacking the global economy in a short period and requiring a wide range of energy supply sources. We aim to promote commercial BDF production in Vietnam for future energy security and contribution to the Vietnamese economy. Eight necessary factors were investigated to choose suitable material for BDF production. The factors are as follows: 1) material with Vietnamese origin, 2) sufficient and continuous supply volume, 3) sufficient quality to run diesel engines, including common-rail diesel engines, 4) inedibility, 5) low enough freezing point, 6) ease of collection, 7) affordability, and 8) availability of valuable elements in the material. If a suitable material candidate is not stable, it may be changed over time. In this study, the focus material was rubber seed oil. Because rubber production in Vietnam is quite stable with over 900,000 ha plantation area, and there is a potentiality to collect seeds and produce about 50,000 tons of BDF annually. In addition, the quality of rubber seeds based BDF is very high, such as low enough freezing point, etc. However, most of those rubber seeds are currently not collected and used.
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Affiliation(s)
| | | | | | - Norimichi Takenaka
- Graduate School of Sustainable System Sciences, Osaka Metropolitan University
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3
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Dang T, Maeda Y, Fujii Y, Takenaka N. Optimization of Procedure for Determining Dissolved Oxygen in Surface Water and Seawater Exploiting the UV-vis Absorption of Mn(III) Species. ANAL SCI 2021; 37:1517-1523. [PMID: 33867404 DOI: 10.2116/analsci.21p079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We present an analytical method for dissolved oxygen based on the quantification of Mn(III) absorbance in a water sample. After Mn(II) reacts with the oxygen molecules in water, Mn(III) is formed and stabilized by hexa-metaphosphate under acidic conditions. The UV visible absorbance of Mn(III) is proportional to the oxygen concentration in the water sample. Compared to the Winkler method, the proposed method has the same accuracy (R = 0.9992 at 0 - 52 mg dm-3) but requires fewer reagents; furthermore, it does not involve titration. Interferences from nitrite and iodate were not observed. This procedure can be used to accurately and quickly determine the oxygen concentrations in different natural water sources, including seawater.
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Affiliation(s)
- Tu Dang
- Graduated School of Humanities and Sustainable System Sciences, Osaka Prefecture University
| | - Yasuaki Maeda
- Research Organization for University-Community Collaborations, Osaka Prefecture University
| | - Yusuke Fujii
- Graduated School of Humanities and Sustainable System Sciences, Osaka Prefecture University
| | - Norimichi Takenaka
- Graduated School of Humanities and Sustainable System Sciences, Osaka Prefecture University
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Abstract
A photometric method to determine molecular oxygen in water was developed. When manganese(II) is oxidized by oxygen under alkaline conditions, the presence of polyphosphate can prevent precipitation due to a coacervate reaction. The oxidized manganese later dissolves in acid to form a pink Mn(III) species, which has a stable UV/vis spectrum. Monitoring of the oxygen concentration based on the absorbance of the pink Mn(III) species at 517 nm showed a strong correlation with both the Winkler method and an optical sensor. As a result, the present method can measure not only dissolved oxygen, but also fine bubbles oxygen in in the water sample with high reliability (0 - 26 mg dm-3, r2 = 0.9995). During this process, no significant interference from nitrite or metal ions was observed. The accuracy of the measurement was steady at high temperatures of the water samples (≤ 363 K).
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Affiliation(s)
- Tu Dang
- Graduated School of Humanities and Sustainable System Sciences, Osaka Prefecture University
| | | | - Yusuke Fujii
- Graduated School of Humanities and Sustainable System Sciences, Osaka Prefecture University
| | - Kenji Okitsu
- Graduated School of Humanities and Sustainable System Sciences, Osaka Prefecture University
| | - Yasuaki Maeda
- Research Organization for University-Community Collaborations, Osaka Prefecture University
| | - Norimichi Takenaka
- Graduated School of Humanities and Sustainable System Sciences, Osaka Prefecture University
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Fujii Y, Tohno S, Ikeda K, Mahmud M, Takenaka N. A preliminary study on humic-like substances in particulate matter in Malaysia influenced by Indonesian peatland fires. Sci Total Environ 2021; 753:142009. [PMID: 32890879 DOI: 10.1016/j.scitotenv.2020.142009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/25/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
In this paper, ambient total suspended particulates (TSP) with a focus on humic-like substances (HULIS) are characterized based on intensive ground-based field samplings collected in Malaysia during non-haze and haze periods caused by peatland fires on the Indonesian island of Sumatra. Furthermore, concentrations of water-soluble organic carbon (WSOC) and carbon content of HULIS (HULIS-C) were determined, and fluorescence spectra of the HULIS samples were recorded by excitation emission matrix (EEM) fluorescence spectroscopy. The concentrations of WSOC and HULIS-C over the entire period ranged from 4.1 to 24 and 1.3 to 18 μgC m-3, respectively. The concentrations of WSOC and HULIS-C during the peatland fire-induced strong haze periods were over 4.3 and 6.1 times higher, respectively, than the average values recorded during the non-haze periods. Even during the light haze periods, the concentrations of WSOC and HULIS-C were significantly higher than their averages during the non-haze periods. These results indicate that peatland fires induce high concentrations of WSOC, particularly HULIS-C, in ambient TSP at receptor sites. EEM fluorescence spectra identified fulvic-like fluorophores at the highest intensity level in the EEM fluorescence spectra of the haze samples. A peak at excitation/emission (Ex/Em) ≈ (290-330)/(375-425) nm is also observed at high intensity, though this peak is normally associated with marine humic-like fluorophores. It is shown that a peak at Ex/Em ≈ (290-330)/(375-425) nm is not derived from marine sources only; furthermore, peatland fires are shown to be important contributors to HULIS around this peak.
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Affiliation(s)
- Yusuke Fujii
- Department of Sustainable System Sciences, Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Susumu Tohno
- Department of Socio-Environmental Energy Science, Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhiro Ikeda
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
| | - Mastura Mahmud
- Faculty of Social Sciences and Humanities, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
| | - Norimichi Takenaka
- Department of Sustainable System Sciences, Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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Okitsu K, Kurisaka I, Nanzai B, Takenaka N, Bandow H. Mechanism for sonochemical reduction of Au(III) in aqueous butanol solution under Ar based on the analysis of gaseous and water-soluble products. Ultrason Sonochem 2020; 69:105241. [PMID: 32645664 DOI: 10.1016/j.ultsonch.2020.105241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/20/2020] [Accepted: 06/25/2020] [Indexed: 05/20/2023]
Abstract
When an aqueous Au(III) solution containing 1-butanol was sonicated under Ar, Au(III) was reduced to Au(0) to form Au particles. This is because various reducing species are formed during sonication, but the reactivity of these species has not yet been evaluated in detail. Therefore, in this study, we analyzed the effects of Au(III) on the rates of the formation of gaseous and water-soluble compounds (CH4, C2H6, C2H4, C2H2, CO, CO2, H2, H2O2, and aldehydes), and the rate of Au(III) reduction as a function of 1-butanol concentration. The following facts were recognized: 1) for Au(III) reduction, the contribution of the radicals formed by the pyrolysis of 1-butanol was higher than that of the secondary radicals formed by the abstraction reactions of 1-butanol with ·OH, 2) ·CH3 and CO acted as reductants, 3) the contribution of ·H to Au(III) reduction was small in the presence of 1-butanol, 4) aldehydes and H2 did not act as reductants, and 5) the types of species that reduced Au(III) changed with 1-butanol concentration.
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Affiliation(s)
- Kenji Okitsu
- Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Itsuya Kurisaka
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Ben Nanzai
- Shizuoka Institute of Science and Technology, 2200-2 Yoyosawa, Fukuroi, Shizuoka 437-8555, Japan
| | - Norimichi Takenaka
- Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Hiroshi Bandow
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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Ohyama M, Nishimura H, Azuma K, Minejima C, Takenaka N, Adachi S. Lowest observed adverse effect level of pulmonary pathological alterations due to nitrous acid exposure in guinea pigs. Environ Health Prev Med 2020; 25:56. [PMID: 32979924 PMCID: PMC7520026 DOI: 10.1186/s12199-020-00895-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 09/15/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We previously demonstrated that continuous exposure to nitrous acid gas (HONO) for 4 weeks, at a concentration of 3.6 parts per million (ppm), induced pulmonary emphysema-like alterations in guinea pigs. In addition, we found that HONO affected asthma symptoms, based on the measurement of respiratory function in rats exposed to 5.8 ppm HONO. This study aimed to investigate the dose-response effects of HONO exposure on the histopathological alterations in the respiratory tract of guinea pigs to determine the lowest observed adverse effect level (LOAEL) of HONO. METHODS We continuously exposed male Hartley guinea pigs (n = 5) to four different concentrations of HONO (0.0, 0.1, 0.4, and 1.7 ppm) for 4 weeks (24 h/day). We performed histopathological analysis by observing lung tissue samples. We examined samples from three guinea pigs in each group under a light microscope and measured the alveolar mean linear intercept (Lm) and the thickness of the bronchial smooth muscle layer. We further examined samples from two guinea pigs in each group under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). RESULTS We observed the following dose-dependent changes: pulmonary emphysema-like alterations in the centriacinar regions of alveolar ducts, significant increase in Lm in the 1.7 ppm HONO-exposure group, tendency for hyperplasia and pseudostratification of bronchial epithelial cells, and extension of the bronchial epithelial cells and smooth muscle cells in the alveolar duct regions. CONCLUSIONS These histopathological findings suggest that the LOAEL of HONO is < 0.1 ppm.
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Affiliation(s)
- Masayuki Ohyama
- Department of Environmental Health, Osaka Institute of Public Health, 1-3-69, Nakamichi, Higashinari-ku, Osaka, 537-0025, Japan.
| | - Hiroshi Nishimura
- Department of Planning and Coordination, Osaka Institute of Public Health, Osaka, 537-0025, Japan
| | - Kenichi Azuma
- Department of Environmental Medicine and Behavioural Science, Kindai University Faculty of Medicine, Osakasayama, 589-8511, Japan
| | - Chika Minejima
- Department of Natural Sciences, College of Liberal Arts, International Christian University, Mitaka, 181-8585, Japan
| | - Norimichi Takenaka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, Sakai, 599-8531, Japan
| | - Shuichi Adachi
- Department of Public Health, Sagami Women's University, Sagamihara, 252-0383, Japan
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Le BA, Okitsu K, Imamura K, Takenaka N, Maeda Y. Ultrasound Assisted Cascade Extraction of Oil, Vitamin E, and Saccharides from Roselle (Hibiscus Sabdariffa L.) Seeds. ANAL SCI 2020; 36:1091-1097. [PMID: 32336730 DOI: 10.2116/analsci.20p073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/14/2020] [Indexed: 08/09/2023]
Abstract
Roselle seeds, a waste biomass of the roselle calyx processing industry, were utilized to recover valuable compounds of oil, vitamin E, and water-soluble saccharides. Firstly, ultrasound-assisted extraction (UAE) and conventional stirring extraction were conducted for saccharide extraction, and the advantage of UAE was confirmed. Secondly, oil, vitamin E, and saccharides extracted from Vietnamese roselle seeds by UAE were analyzed for the first time. Oil of tri-, di-, and mono-glycerides, fatty acids of linoleic-, oleic-, palmitic-, and stearic-acids, vitamin E of γ- and α-tocopherol, and saccharides of sucrose, raffinose, stachyose, etc. were identified, and the amounts of these components were compared with those in other country's roselle seeds. Thirdly, cascade extraction of oil, vitamin E, and saccharides by UAE was investigated with solvents of hexane, hexane:ethyl acetate binary solvent, and water. The results indicated that the order of using solvents was very important for high and selective extraction: the best order to recover oil (almost 100%), vitamin E (95.7%), and saccharides (86.2%) was hexane, and then water.
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Affiliation(s)
- Bang Anh Le
- Graduate School of Engineering, Osaka Prefecture University, Sakai, 599-8531, Japan
| | - Kenji Okitsu
- Graduate School of Humanity and Sustainable System Sciences, Osaka Prefecture University, Sakai, 599-8531, Japan.
| | - Kiyoshi Imamura
- Graduate School of Humanity and Sustainable System Sciences, Osaka Prefecture University, Sakai, 599-8531, Japan
| | - Norimichi Takenaka
- Graduate School of Humanity and Sustainable System Sciences, Osaka Prefecture University, Sakai, 599-8531, Japan
| | - Yasuaki Maeda
- Graduate School of Humanity and Sustainable System Sciences, Osaka Prefecture University, Sakai, 599-8531, Japan
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Kitada K, Suda Y, Takenaka N. Cyanide Formation in Freezer Stored Foods: Freezing of a Glycine and Nitrite Mixture. Chem Res Toxicol 2020; 33:1809-1814. [PMID: 32283925 DOI: 10.1021/acs.chemrestox.0c00054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Freezing is not always the best way to keep foods safely. Some reactions are known to be accelerated in ice. Furthermore, some other reactions that are not observed in solution are also promoted in ice. We found that the formation of nitrosamines through the reaction of an amine with a nitrite is accelerated in ice. Surprisingly, cyanide is formed through the reaction of glycine with nitrite in ice but not in solution. Amines are present in many kinds of foods. Nitrite is present in vegetables and is used as a food coloring agent and to inhibit the reproduction of Clostridium botulinum. The maximum amount of cyanide formed reaches a dangerous level, and the intake of this formed cyanide in a few tens of cubic centimeters causes some people to get headaches. These facts suggest that hazardous compounds could be generated in frozen processed foods. We report here the formation of cyanide and its possible formation pathway in ice. Finally, we propose a way to prevent cyanide formation in food under frozen conditions.
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Affiliation(s)
- Kodai Kitada
- Laboratory of Environmental Materials Chemistry, Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka 599-8531, Japan
| | - Yusuke Suda
- Laboratory of Environmental Materials Chemistry, Department of Sustainable System Sciences, Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka 599-8531, Japan
| | - Norimichi Takenaka
- Laboratory of Environmental Materials Chemistry, Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka 599-8531, Japan.,Laboratory of Environmental Materials Chemistry, Department of Sustainable System Sciences, Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka 599-8531, Japan
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Harada A, Goto M, Ikeya M, Takenaka N, Tanaka A, Sakurai H. Neonatal transplantation of iPSC-derived MSCs affects systemic collagen vi restoration in ullrich congenital muscular dystrophy mice. Cytotherapy 2020. [DOI: 10.1016/j.jcyt.2020.03.143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Huy DH, Thanh LT, Hien TT, Takenaka N. Comparative study on water-soluble inorganic ions in PM 2.5 from two distinct climate regions and air quality. J Environ Sci (China) 2020; 88:349-360. [PMID: 31862076 DOI: 10.1016/j.jes.2019.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/06/2019] [Accepted: 09/11/2019] [Indexed: 06/10/2023]
Abstract
Recently, air quality has significantly improved in developed country, but that issue is of concern in emerging megacity in developing country. In this study, aerosols and their precursor gas were collected by NILU filter pack at two distinct urban sites during the winter and summer in Osaka, Japan and dry and rainy seasons in Ho Chi Minh City (HCMC), Vietnam. The aims are to investigate the contribution of water-soluble inorganic ions (WSIIs) to PM2.5, thermodynamic characterization and possible formation pathway of secondary inorganic aerosol (SIA). The PM2.5 concentration in Osaka (15.8 μg/m3) is lower than that in HCMC (23.0 μg/m3), but the concentration of WSIIs in Osaka (9.0 μg/m3) is two times higher than that in HCMC (4.1 μg/m3). Moreover, SIA including NH4+, NO3- and SO42- are major components in WSIIs accounting for 90% and 76% (in molar) in Osaka and HCMC, respectively. Thermodynamic models were used to understand the thermodynamic characterization of urban aerosols. Overall, statistical analysis results indicate that very good agreement (R2 > 0.8) was found for all species, except for nitrate aerosol in HCMC. We found that when the crustal species present at high amount, those compositions should be included in model calculation (i.e. in the HCMC situation). Finally, we analyzed the characteristics of NH4+- NO3-- SO42- system. A possible pathway to produce fine nitrate aerosol in Osaka is via the homogeneous reaction between NH3 and HNO3, while non-volatile nitrate aerosols can be formed by the heterogeneous reactions in HCMC.
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Affiliation(s)
- Duong Huu Huy
- Faculty of Food Science and Technology, Ho Chi Minh City University of Food Industry, 140 Le Trong Tan Street, Tan Phu District, Ho Chi Minh City, Viet Nam.
| | - Le Tu Thanh
- Faculty of Environment, University of Science, Vietnam National University-Ho Chi Minh City, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City, Viet Nam
| | - To Thi Hien
- Faculty of Environment, University of Science, Vietnam National University-Ho Chi Minh City, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City, Viet Nam
| | - Norimichi Takenaka
- Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka 599-8531, Japan
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Ohyama M, Nakajima T, Minejima C, Azuma K, Oka K, Itano Y, Kudo S, Takenaka N. Association between indoor nitrous acid, outdoor nitrogen dioxide, and asthma attacks: results of a pilot study. Int J Environ Health Res 2019; 29:632-642. [PMID: 30585082 DOI: 10.1080/09603123.2018.1559924] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/13/2018] [Indexed: 06/09/2023]
Abstract
The association between nitrogen dioxide (NO2) and asthma has been investigated. However, conventional NO2 assays measure nitrous acid (HONO) as NO2. In this pilot epidemiological observational study, we assessed exposure to indoor HONO and some air pollutants in pediatric asthma patients and examined possible association between exposure and asthma symptoms. Indoor HONO and nitric oxide (NO), which are primarily generated by the combustion of certain substances, were significantly associated with asthma attacks in 2010. In 2010, indoor HONO was closely correlated with indoor NO than with outdoor NO2. Conversely, in 2012, indoor HONO was closely correlated with outdoor NO2 and NO than with indoor NO2 and NO. Outdoor NO2 was significantly associated with asthma attacks in 2012. Our results highlight the need for further epidemiological studies of the association between indoor HONO and asthma symptoms using multivariate analyses to examine the role of NO2 in asthma symptoms. Abbreviations: CXCL1: the chemokine (C-X-C motif) ligand 1; EP: the entire study period; FP: the first half of study period; HONO: nitrous acid; NO: nitric oxide; NO2: nitrogen dioxide; OH radical: hydroxyl radical; SP: the second half of study period; TNF-α: tumor necrosis factor-α; US EPA: United States Environmental Protection Agency; WHO: World Health Organization.
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Affiliation(s)
- Masayuki Ohyama
- Department of Environmental Health, Osaka Institute of Public Health , Osaka , Japan
| | - Takae Nakajima
- Department of Environmental Health, Osaka Institute of Public Health , Osaka , Japan
| | - Chika Minejima
- Department of Natural Sciences, College of Liberal Arts, International Christian University , Mitaka , Japan
| | - Kenichi Azuma
- Department of Environmental Medicine and Behavioural Science, Faculty of medicine Kindai University , Osaka-sayama , Japan
| | - Kenji Oka
- Department of Research, Institute of Environment, Agriculture and Fisheries, Osaka Prefectural Government , Osaka , Japan
| | - Yasuyuki Itano
- Osaka City Research Center of Environmental Science , Osaka , Japan
| | - Shouichiro Kudo
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University , Sakai , Japan
| | - Norimichi Takenaka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University , Sakai , Japan
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Ohyama M, Horie I, Isohama Y, Azuma K, Adachi S, Minejima C, Takenaka N. Effects of nitrous acid exposure on baseline pulmonary resistance and Muc5ac in rats. Inhal Toxicol 2018; 30:149-158. [PMID: 29860904 DOI: 10.1080/08958378.2018.1476628] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
We examined the baseline pulmonary resistance (RLung), baseline dynamic lung compliance (Cdyn), cytokine inductions, and histological alterations in rats exposed to nitrous acid (HONO) with secondary products of nitrogen dioxide (NO2) and nitric oxide (NO) to assess its biological effects. We exposed three groups of nine male F344 rats to different doses of HONO for six weeks (24 h/day). The cumulative values of HONO concentration were measured twice. The average concentrations of nitrogen oxide for each group were 5.8 parts per million (ppm) HONO with secondary products of 0.7 ppm NO2 and 2.3 ppm NO, 4.1 ppm HONO with 0.1 ppm NO2 and 0.6 ppm NO, and a clean air control. We measured baseline RLung and baseline Cdyn using tracheal cannulation. A tracheal tube was inserted into the trachea by tracheostomy, and lung function measurements (baseline RLung and baseline Cdyn) were conducted in mechanically ventilated rats. We measured mRNA levels of Cxcl-1, TNF-α, and Muc5ac in the right lung using quantitative RT-PCR, and observed histological alterations and the alveolar mean linear intercept (Lm) on the left lung. Our results demonstrated that HONO exposure significantly increased baseline RLung, Lm and Muc5ac expression, but did not affect baseline Cdyn or expression of Cxcl-1 and TNF-α. Further, we identified bronchial smooth muscle hypertrophy, pulmonary emphysema-like alterations in the alveolar duct centriacinar regions, and increased goblet cells in HONO-exposed rats. The present results suggest that HONO (with secondary products) adversely affects respiratory function, but that these pathologies may be unrelated to inflammation.
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Affiliation(s)
- Masayuki Ohyama
- a Department of Environmental Health , Osaka Prefectural Institute of Public Health , Osaka , Japan
| | - Ichiro Horie
- b Laboratory of Applied Pharmacology , Tokyo University of Science , Noda , Japan
| | - Yoichiro Isohama
- b Laboratory of Applied Pharmacology , Tokyo University of Science , Noda , Japan
| | - Kenichi Azuma
- c Department of Environmental Medicine and Behavioural Science , Kindai University Faculty of medicine , Osakasayama , Japan
| | - Shuichi Adachi
- d Department of Public Health , Sagami Women's University , Sagamihara , Japan
| | - Chika Minejima
- e Department of Natural Sciences , College of Liberal Arts, International Christian University , Mitaka , Japan
| | - Norimichi Takenaka
- f Department of Applied Chemistry , Graduate School of Engineering, Osaka Prefecture University , Sakai , Japan
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Le HNT, Imamura K, Watanabe N, Furuta M, Takenaka N, Boi LV, Maeda Y. Biodiesel Production from Rubber Seed Oil by Transesterification Using a Co‐solvent of Fatty Acid Methyl Esters. Chem Eng Technol 2018. [DOI: 10.1002/ceat.201700575] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Hanh Ngoc Thi Le
- Osaka Prefecture University Department of Quantum and Radiation Engineering Graduate School of Engineering 1-2 Gakuen-cho, Naka-ku, Sakai 599-8570 Osaka Japan
- An Giang University Faculty of Education 618 Ung Van Khiem Street, Dong Xuyen Ward Long Xuyen City, An Giang Vietnam
| | - Kiyoshi Imamura
- Osaka Prefecture University Research Organization for University-Community Collaborations 1-2 Gakuen-cho, Naka-ku, Sakai 599-8570 Osaka Japan
| | - Norie Watanabe
- Bridgestone Co. Central Research Division 3-1-1 Ogawahigashi-cho, Kodaira-shi 187-8531 Tokyo Japan
| | - Masakazu Furuta
- Osaka Prefecture University Department of Quantum and Radiation Engineering Graduate School of Engineering 1-2 Gakuen-cho, Naka-ku, Sakai 599-8570 Osaka Japan
| | - Norimichi Takenaka
- Osaka Prefecture University Graduate School of Engineering 1-1 Gakuen-cho, Naka-ku, Sakai-shi 599-8531 Osaka Japan
| | - Luu Van Boi
- Hanoi University of Science Faculty of Chemistry, VNU 519 Le Thanh Tong St., Hoan Kiem District Hanoi Vietnam
| | - Yasuaki Maeda
- Osaka Prefecture University Research Organization for University-Community Collaborations 1-2 Gakuen-cho, Naka-ku, Sakai 599-8570 Osaka Japan
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15
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Okitsu K, Kurisaka I, Nanzai B, Takenaka N, Bandow H. Sonochemistry of aqueous NaAuCl 4 solutions with C3-C6 alcohols under a noble gas atmosphere. Ultrason Sonochem 2018; 41:397-403. [PMID: 29137767 DOI: 10.1016/j.ultsonch.2017.09.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/22/2017] [Accepted: 09/22/2017] [Indexed: 06/07/2023]
Abstract
The effect of the type of C3-C6 alcohol, solution temperature, and dissolved gas on the rate of Au(III) reduction was investigated in NaAuCl4 aqueous alcohol solution with a 200-kHz ultrasound irradiation system. It was confirmed in the presence of C3-C6 alcohol that more highly hydrophobic alcohols more effectively accumulated at the argon bubble interface region, and the reducing radicals formed here. To avoid changes in the bubble temperature during collapsing bubble, the effects of the solution temperature on the rate of Au(III) reduction and on the rate of formation of the gaseous compounds (CO, CO2, CH4, C2H2, C2H4, C2H6) were investigated in the presence of low concentration (1.0-mM) of 1-hexanol. Both of the rates showed a good relationship with the gas solubility: the amount of dissolved gas at different solution temperatures affected the number of high-temperature bubbles formed. The changes in the concentrations of the gaseous compounds formed from 1-hexanol degradation suggested that CO and the pyrolysis radicals acted as reductants. Finally, the effect of the type of dissolved gas was investigated in the presence of 1.0-mM Au(III) and 1.0-mM 1-hexanol. The rates of 1-hexanol degradation, Au(III) reduction, and gaseous compound formation increased in the order He<Ne<Ar<Kr<Xe, and this order was related to the amount of noble gas dissolved in the aqueous solution.
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Affiliation(s)
- Kenji Okitsu
- Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Itsuya Kurisaka
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Ben Nanzai
- Shizuoka Institute of Science and Technology, 2200-2 Yoyosawa, Fukuroi, Shizuoka 437-8555, Japan
| | - Norimichi Takenaka
- Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Hiroshi Bandow
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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16
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Kitada K, Suda Y, Takenaka N. Acceleration and Reaction Mechanism of the N-Nitrosation Reaction of Dimethylamine with Nitrite in Ice. J Phys Chem A 2017; 121:5383-5388. [PMID: 28662583 DOI: 10.1021/acs.jpca.7b03246] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Some reactions (e.g., oxidation of nitrite, denitrification of ammonium) are accelerated in freeze-concentrated solution (FCS) compared to those in aqueous solution. Ice is highly intolerant to impurities, and the ice excludes those that would accelerate reactions. Here we show the acceleration of the N-nitrosation reaction of dimethylamine (DMA) with nitrite to produce N-nitrosodimethylamine (NDMA) in FCS. NDMA is a carcinogenic compound, and this reaction is potentially accelerated in frozen fish/meat. The eaction rate of the N-nitrosation reaction becomes fastest at specific pH. This means that it is a third-order reaction. Theoretical pH values of the peak in the third-order reaction are higher than the experimental one. Freeze-concentration of acidic solution causes pH decrement; however, the freeze-concentration alone could not explain the difference of pH values. The theoretical value was obtained under the assumption that no solute took part in ice. However, solutes are incorporated in ice with a small distribution coefficient of solutes into ice. This small incorporation enhanced the decrement of pH values. Using the distribution coefficient of chloride and sodium ion and assuming those of nitrite and DMA to explain the enhancement, we succeeded in estimating the distribution coefficients of nitrite: 2 × 10-3 and DMA: 3 × 10-2.
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Affiliation(s)
- Kodai Kitada
- Laboratory of Environmental Materials Chemistry, Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University , 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka 599-8531, Japan
| | - Yusuke Suda
- Laboratory of Environmental Materials Chemistry, Department of Sustainable System Sciences, Graduate School of Humanities and Sustainable System Sciences, Osaka Prefecture University , 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka 599-8531, Japan
| | - Norimichi Takenaka
- Laboratory of Environmental Materials Chemistry, Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University , 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka 599-8531, Japan
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17
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Truong HT, Luu PD, Imamura K, Matsubara T, Takahashi H, Takenaka N, Boi LV, Maeda Y. Binary Solvent Extraction of Tocols, γ-Oryzanol, and Ferulic Acid from Rice Bran Using Alkaline Treatment Combined with Ultrasonication. J Agric Food Chem 2017; 65:4897-4904. [PMID: 28541677 DOI: 10.1021/acs.jafc.7b00055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Alkaline treatment (Alk) combined with ultrasound-assisted extraction (UAE) (Alk+UAE) was examined as a means of extracting tocols and γ-oryzanol from rice bran into an organic phase while simultaneously recovering ferulic acid into an aqueous phase. The tocols and γ-oryzanol/ferulic acid yields were determined using high-performance liquid chromatography with fluorescence and UV detection. The effects of extraction conditions were evaluated by varying the Alk treatment temperature and extraction duration. The maximum yields of tocols and γ-oryzanol were obtained at 25 °C over a time span of 30 min. When the temperature was increased to 80 °C, the yield of ferulic acid increased dramatically, whereas the recovery of γ-oryzanol slightly decreased. Employing the Alk+UAE procedure, the recovered concentrations of tocols, γ-oryzanol, and ferulic acid were in the ranges of 146-518, 1591-3629, and 352-970 μg/g, respectively. These results are in good agreement with those reported for rice bran samples from Thailand.
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Affiliation(s)
- Hoa Thi Truong
- Research Organization for University-Community Collaborations, Osaka Prefecture University , 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Phuong Duc Luu
- Faculty of Chemistry, Hanoi University of Science, VNU , 19 Le Thanh Tong Street, Hoan Kiem District, Hanoi, Vietnam
| | - Kiyoshi Imamura
- Research Organization for University-Community Collaborations, Osaka Prefecture University , 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Takeo Matsubara
- Yanmar Company Ltd. , 1-9 Tsurunocho, Kita-ku, Osaka 530-8311, Japan
| | - Hideki Takahashi
- Yanmar Company Ltd. , 1-9 Tsurunocho, Kita-ku, Osaka 530-8311, Japan
| | - Norimichi Takenaka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University , 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Luu Van Boi
- Faculty of Chemistry, Hanoi University of Science, VNU , 19 Le Thanh Tong Street, Hoan Kiem District, Hanoi, Vietnam
| | - Yasuaki Maeda
- Research Organization for University-Community Collaborations, Osaka Prefecture University , 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
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Trinh HT, Imanishi K, Morikawa T, Hagino H, Takenaka N. Gaseous nitrous acid (HONO) and nitrogen oxides (NO x) emission from gasoline and diesel vehicles under real-world driving test cycles. J Air Waste Manag Assoc 2017; 67:412-420. [PMID: 27689311 DOI: 10.1080/10962247.2016.1240726] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/20/2016] [Indexed: 06/06/2023]
Abstract
UNLABELLED Reactive nitrogen species emission from the exhausts of gasoline and diesel vehicles, including nitrogen oxides (NOx) and nitrous acid (HONO), contributes as a significant source of photochemical oxidant precursors in the ambient air. Multiple laboratory and on-road exhaust measurements have been performed to estimate the NOx emission factors from various vehicles and their contribution to atmospheric pollution. Meanwhile, HONO emission from vehicle exhaust has been under-measured despite the fact that HONO can contribute up to 60% of the total hydroxyl budget during daytime and its formation pathway is not fully understood. A profound traffic-induced HONO to NOx ratio of 0.8%, established by Kurtenbach et al. since 2001, has been widely applied in various simulation studies and possibly linked to under-estimation of HONO mixing ratios and OH radical budget in the morning. The HONO/NOx ratios from direct traffic emission have become debatable when it lacks measurements for direct HONO emission from vehicles upon the fast-changing emission reduction technology. Several recent studies have reported updated values for this ratio. This study has reported the measurement of HONO and NOx emission as well as the estimation of exhaust-induced HONO/NOx ratios from gasoline and diesel vehicles using different chassis dynamometer tests under various real-world driving cycles. For the tested gasoline vehicle, which was equipped with three-way catalyst after-treatment device, HONO/NOx ratios ranged from 0 to 0.95 % with very low average HONO concentrations. For the tested diesel vehicle equipped with diesel particulate active reduction device, HONO/NOx ratios varied from 0.16 to 1.00 %. The HONO/NOx ratios in diesel exhaust were inversely proportional to the average speeds of the tested vehicles. IMPLICATIONS Photolysis of HONO is a dominant source of morning OH radicals. Conventional traffic-induced HONO/NOx ratio of 0.8% has possibly linked to underestimation of the total HONO budget and consequently underestimation of OH radical budget. The recently reported HONO/NOx ratio of ~1.6% was used to stimulate HONO emission, which resulted in increased HONO concentrations during morning peak hours and its impact of 14% OH increment in the morning. However, the results were still lower than the measured concentrations. More studies should be conducted to establish an updated traffic-induced HONO/NOx ratio.
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Affiliation(s)
- Ha T Trinh
- a Department of Applied Chemistry , Graduate School of Engineering, Osaka Prefecture University , Naka-ku, Sakai-shi, Osaka-fu , Japan
| | - Katsuma Imanishi
- a Department of Applied Chemistry , Graduate School of Engineering, Osaka Prefecture University , Naka-ku, Sakai-shi, Osaka-fu , Japan
| | - Tazuko Morikawa
- b Japan Automobile Research Institute , Tsukuba-shi , Ibaraki-ken , Japan
| | - Hiroyuki Hagino
- b Japan Automobile Research Institute , Tsukuba-shi , Ibaraki-ken , Japan
| | - Norimichi Takenaka
- a Department of Applied Chemistry , Graduate School of Engineering, Osaka Prefecture University , Naka-ku, Sakai-shi, Osaka-fu , Japan
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Huy DH, Thanh LT, Hien TT, Noro K, Takenaka N. Characteristics of ammonia gas and fine particulate ammonium from two distinct urban areas: Osaka, Japan, and Ho Chi Minh City, Vietnam. Environ Sci Pollut Res Int 2017; 24:8147-8163. [PMID: 28144866 DOI: 10.1007/s11356-017-8496-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 01/20/2017] [Indexed: 06/06/2023]
Abstract
Continuous and simultaneous measurements of ammonia gas (NH3) and fine particulate ammonium (PM2.5NH4+) were performed in two distinct urban areas: Osaka, Japan, and Ho Chi Minh City (HCMC), Vietnam. Measurements were performed using a new online instrument. Two measurement periods were conducted during February 11-March 12, 2015 (cold period), and July 1-September 14, 2015 (warm period), at the urban site in Osaka, while 17 days of measurements, from May 21 to June 8, 2015, were conducted at the urban site in HCMC. The average NH3 concentration at the HCMC site was much higher than that at the Osaka site. The differences in the NH3 levels between the two cities are a result of their different emission sources. Traffic emission is a significant contributor to the NH3 levels within the urban area in Osaka. Conversely, the contribution of traffic emission to the NH3 levels in the HCMC urban area is negligible. With a population of around 8.5 million people living in the urban area of HCMC, the high NH3 level is due to human sources and poor waste management systems, especially because of the high temperature (30 °C) and dense population of the city (density up to 42,000 inhabitants per km2). In contrast to the NH3 levels, the highest PM2.5NH4+ level occurred during the cold period at the Osaka site, and the average level at this site was higher than that at the HCMC site. The availability of atmospheric acids, low temperature, and high humidity facilitates the formation of ammonium. Our results indicate that NH3 plays a key role in secondary inorganic aerosol formation; therefore, it contributes to a significant amount of PM2.5 at the Osaka site. In contrast, the high levels of PM2.5 observed at the HCMC site are likely from road traffic emission, mainly motorcycles, rather than secondary inorganic aerosol formation.
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Affiliation(s)
- Duong Huu Huy
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka, 599-8531, Japan.
- Faculty of Environmental Science, University of Science, Vietnam National University, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam.
| | - Le Tu Thanh
- Faculty of Environmental Science, University of Science, Vietnam National University, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam
| | - To Thi Hien
- Faculty of Environmental Science, University of Science, Vietnam National University, 227 Nguyen Van Cu Street, District 5, Ho Chi Minh City, Vietnam
| | - Kazushi Noro
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka, 599-8531, Japan
| | - Norimichi Takenaka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka, 599-8531, Japan
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Thang PQ, Muto Y, Maeda Y, Trung NQ, Itano Y, Takenaka N. Increase in ozone due to the use of biodiesel fuel rather than diesel fuel. Environ Pollut 2016; 216:400-407. [PMID: 27396671 DOI: 10.1016/j.envpol.2016.04.102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 04/27/2016] [Accepted: 04/28/2016] [Indexed: 06/06/2023]
Abstract
The consumption of fuel by vehicles emits nitrogen oxides (NOx) and non-methane hydrocarbons (NMHCs) into the atmosphere, which are important ozone precursors. Ozone is formed as a secondary pollutant via photochemical processes and is not emitted directly into the atmosphere. In this paper, the ozone increase resulting from the use of biodiesel and diesel fuels was investigated, and the different ozone formation trends were experimentally evaluated. Known amounts of exhaust gas from a power generator operated using biodiesel and diesel fuels were added to ambient air. The quality of the ambient air, such as the initial NMHC and NOx concentrations, and the irradiation intensity have an effect on the ozone levels. When 30 cm(3) of biodiesel fuel exhaust gas (BFEG) or diesel fuel exhausted gas (DFEG) was added to 18 dm(3) of ambient air, the highest ratios of ozone increase from BFEG compared with DFEG in Japan and Vietnam were 31.2 and 42.8%, respectively, and the maximum ozone increases resulting from DFEG and BFEG compared with the ambient air in Japan were 17.4 and 26.4 ppb, respectively. The ozone increase resulting from the use of BFEG was large and significant compared to that from DFEG under all experimental conditions. The ozone concentration increased as the amount of added exhaust gas increased. The ozone increase from the Jatropha-BFEG was slightly higher than that from waste cooking oil-BFEG.
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Affiliation(s)
- Phan Quang Thang
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka, 599-8531, Japan; Institute of Environmental Technology (IET), Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet Street, Nghia Do, Cau Giay, Hanoi, Viet Nam.
| | - Yusuke Muto
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka, 599-8531, Japan
| | - Yasuaki Maeda
- Research Organization for University-Community Collaborations, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Nguyen Quang Trung
- Institute of Environmental Technology (IET), Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet Street, Nghia Do, Cau Giay, Hanoi, Viet Nam
| | - Yasuyuki Itano
- Osaka City Institute of Public Health & Environmental Sciences, 8-34 Tojo-cho, Tennoji-ku, Osaka, 543-0026, Japan
| | - Norimichi Takenaka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai-shi, Osaka, 599-8531, Japan
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Luu PD, Truong HT, Luu BV, Pham LN, Imamura K, Takenaka N, Maeda Y. Production of biodiesel from Vietnamese Jatropha curcas oil by a co-solvent method. Bioresour Technol 2014; 173:309-316. [PMID: 25310867 DOI: 10.1016/j.biortech.2014.09.114] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2014] [Revised: 09/20/2014] [Accepted: 09/22/2014] [Indexed: 06/04/2023]
Abstract
Biodiesel fuels (BDFs) was successfully produced from Vietnamese Jatropha curcas oil with high content of free fatty acids (FFAs) in two stages. In the first stage, the esterification process was carried out with the optimal conditions as follows; a methanol-to-FFAs molar ratio of 6:1, 1 wt% H2SO4, at a temperature of 65 °C, and using 30% (wt/wt) acetonitrile as co-solvent. This step reduced the concentration of FFAs in the reaction mixture from 15.93 to 2 wt% in 60 min. In the second stage, the transesterification process generated fatty acid methyl esters (FAMEs) with 99% efficiency was performed in 30 min with the optimal conditions as follows; a methanol-to-oil molar ratio of 6:1, 1 wt% KOH, at a temperature of 40 °C, and 20% (wt/wt) acetone as co-solvent. The produced biodiesel quality meets the standards JIS K2390 and EN 14214 regarding FAME yield, FFAs and water contents.
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Affiliation(s)
- Phuong Duc Luu
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan; Faculty of Chemistry, Hanoi University of Science, VNU, 19 Le Thanh Tong St., Hoan Kiem District, Hanoi, Viet Nam.
| | - Hoa Thi Truong
- Danang Environmental Technology Center, Institute of Environmental Technology, Vietnam Academy of Science and Technology, Tran Dai Nghia Road, Ngu Hanh Son District, Danang, Viet Nam.
| | - Boi Van Luu
- Faculty of Chemistry, Hanoi University of Science, VNU, 19 Le Thanh Tong St., Hoan Kiem District, Hanoi, Viet Nam.
| | - Lan Ngoc Pham
- Faculty of Chemistry, Hanoi University of Science, VNU, 19 Le Thanh Tong St., Hoan Kiem District, Hanoi, Viet Nam.
| | - Kyoshi Imamura
- Research Organization for University-Community Collaborations, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Norimichi Takenaka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
| | - Yasuaki Maeda
- Research Organization for University-Community Collaborations, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
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Kameda T, Inazu K, Asano K, Murota M, Takenaka N, Sadanaga Y, Hisamatsu Y, Bandow H. Prediction of rate constants for the gas phase reactions of triphenylene with OH and NO3 radicals using a relative rate method in CCl4 liquid phase-system. Chemosphere 2013; 90:766-771. [PMID: 23084261 DOI: 10.1016/j.chemosphere.2012.09.071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 09/11/2012] [Accepted: 09/20/2012] [Indexed: 06/01/2023]
Abstract
The kinetics of CCl(4) liquid-phase reactions of ten kinds of polycyclic aromatic compounds (PACs) including triphenylene (TP) with NO(3) radicals have been investigated at 273K by a relative rate method using naphthalene (NA) as a reference compound. The obtained relative reaction rates of the tested PACs to NA in CCl(4) were as follows: 2.57±0.24 (acenaphthene), 2.11±0.30 (2,3-dimethylnaphthalene), 1.21±0.13 (fluoranthene), 0.56±0.07 (fluorene), 1.85±0.19 (1-methylnaphthalene), 1.77±0.12 (2-methylnaphthalene), 0.11±0.03 (1-nitronaphthalene), 1.59±0.23 (phenanthrene), 2.40±0.29 (pyrene), 0.22±0.04 (TP). TP is a semi-volatile PAC with four aromatic rings and it is chemically changed into mutagenic 2-nitrotriphenylene (2-NTP) via the gas-phase OH or NO(3) radical-initiated reactions. On the basis of the relative reactivity of the PACs in the CCl(4) liquid phase-system, the rate constants of the gas-phase reactions of TP with OH and NO(3) radicals at 298 K were predicted to be (8.6±1.2)×10(-12) cm(3) molecule(-1) s(-1) and (6.6±1.5)×10(-29)[NO(2)] cm(3) molecule(-1) s(-1), respectively. Based on the ambient concentrations of TP and 2-NTP and the obtained rate constant for the reaction of TP with OH radicals, the atmospheric loss rate of 2-NTP was also evaluated.
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Affiliation(s)
- Takayuki Kameda
- Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
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Murakawa H, Sugimoto K, Miyata K, Asano H, Takenaka N, Saito Y. Visualization of Water Behavior in the In-plane and Throughplane Directions in a PEFC using a Neutron Image Intensifier. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.phpro.2013.03.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Takenaka N, Takahashi I, Suekane H, Yamamoto K, Sadanaga Y, Bandow H. Acceleration of Ammonium Nitrite Denitrification by Freezing: Determination of Activation Energy from the Temperature of Maximum Reaction Rate. J Phys Chem A 2011; 115:14446-51. [DOI: 10.1021/jp2093466] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Norimichi Takenaka
- Department of Applied Chemistry, Graduate Scool of Engineering, Osaka Prefecture University, Naka-ku, Sakai-shi, Osaka, Japan.
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Sadanaga Y, Fukumori Y, Kobashi T, Nagata M, Takenaka N, Bandow H. Development of a Selective Light-Emitting Diode Photolytic NO2 Converter for Continuously Measuring NO2 in the Atmosphere. Anal Chem 2010; 82:9234-9. [DOI: 10.1021/ac101703z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yasuhiro Sadanaga
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Yuki Fukumori
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Tadashi Kobashi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Makoto Nagata
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Norimichi Takenaka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Hiroshi Bandow
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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Yuba A, Sadanaga Y, Takami A, Hatakeyama S, Takenaka N, Bandow H. Measurement System for Particulate Nitrate Based on the Scrubber Difference NO−O3 Chemiluminescence Method in Remote Areas. Anal Chem 2010; 82:8916-21. [DOI: 10.1021/ac101704w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- A. Yuba
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan, and Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - Y. Sadanaga
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan, and Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - A. Takami
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan, and Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - S. Hatakeyama
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan, and Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - N. Takenaka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan, and Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
| | - H. Bandow
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan, and Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan
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Thanh LT, Okitsu K, Sadanaga Y, Takenaka N, Maeda Y, Bandow H. A two-step continuous ultrasound assisted production of biodiesel fuel from waste cooking oils: a practical and economical approach to produce high quality biodiesel fuel. Bioresour Technol 2010; 101:5394-401. [PMID: 20219362 DOI: 10.1016/j.biortech.2010.02.060] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 02/09/2010] [Accepted: 02/11/2010] [Indexed: 05/24/2023]
Abstract
A transesterification reaction of waste cooking oils (WCO) with methanol in the presence of a potassium hydroxide catalyst was performed in a continuous ultrasonic reactor of low-frequency 20 kHz with input capacity of 1 kW, in a two-step process. For the first step, the transesterification was carried out with the molar ratio of methanol to WCO of 2.5:1, and the amount of catalyst 0.7 wt.%. The yield of fatty acid methyl esters (FAME) was about 81%. A yield of FAME of around 99% was attained in the second step with the molar ratio of methanol to initial WCO of 1.5:1, and the amount of catalyst 0.3 wt.%. The FAME yield was extremely high even at the short residence time of the reactants in the ultrasonic reactor (less than 1 min for the two steps) at ambient temperature, and the total amount of time required to produce biodiesel was 15h. The quality of the final biodiesel product meets the standards JIS K2390 and EN 14214 for biodiesel fuel.
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Affiliation(s)
- Le Tu Thanh
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.
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Kishida M, Imamura K, Takenaka N, Maeda Y, Viet PH, Kondo A, Bandow H. Characteristics of the abundance of polychlorinated dibenzo-p-dioxin and dibenzofurans, and dioxin-like polychlorinated biphenyls in sediment samples from selected Asian regions in Can Gio, Southern Vietnam and Osaka, Japan. Chemosphere 2010; 78:127-133. [PMID: 19892385 DOI: 10.1016/j.chemosphere.2009.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 10/01/2009] [Accepted: 10/01/2009] [Indexed: 05/28/2023]
Abstract
The levels of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) were determined in sediment samples from Can Gio, South Vietnam, and Osaka, Japan. Can Gio is known for the defoliation of its mangrove forests by aerial spraying with Agent Orange during the Vietnam War, whereas Osaka is renowned for a PCDD/PCDF pollution accident at a municipal solid-waste incinerator. For comparison, we also analyzed PCDD/PCDFs and DL-PCBs in sediment samples from Hue and Hanoi, Vietnam. The toxic equivalent quantity (TEQ) values in Can Gio were as high as those in Hue, Hanoi, and suburban areas of Osaka, but much lower than those in urban areas of Osaka. The proportion of the World Health Organization (WHO)-TEQ value contributed by 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) in Can Gio was approximately 30%, higher than the values in the other sample areas. These data suggest that residual sedimentary TCDD that originated from aerial spraying of Agent Orange occur in only low concentrations in Can Gio. The main contributors to WHO-TEQ values in Can Gio are natural sources, as in Hue. In contrast, commercial PCBs are the dominant contributors to WHO-TEQ values in Hanoi. In Osaka, agrochemicals used in rice cultivation, the incineration of solid waste, and commercial PCBs equally contributed to WHO-TEQ values at suburban locations. The dumping of incinerator-related materials and/or the inadequate management of commercial PCBs have resulted in significantly elevated WHO-TEQ values of 240-370 ng kg(-1)dw at urban locations in Osaka.
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Affiliation(s)
- Masao Kishida
- Research Institute for Environment, Agriculture, and Fisheries, Osaka Prefectural Government, 1-3-62 Nakamichi, Higashinari-ku, Osaka 537-0025, Japan.
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Thanh LT, Okitsu K, Sadanaga Y, Takenaka N, Maeda Y, Bandow H. Ultrasound-assisted production of biodiesel fuel from vegetable oils in a small scale circulation process. Bioresour Technol 2010; 101:639-45. [PMID: 19736002 DOI: 10.1016/j.biortech.2009.08.050] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 08/10/2009] [Accepted: 08/11/2009] [Indexed: 05/20/2023]
Abstract
Biodiesel production from canola oil with methanol was performed in the presence of a base-catalyst by a circulation process at room temperature. In this process, the transesterification was accelerated by ultrasonic irradiation of low frequency (20 kHz) with an input capacity of 1 kW. The influences of various parameters on the transesterification reaction, including the amount of catalyst, the molar ratio of methanol to oil and the reaction time, were investigated. The objective of this work was to produce biodiesel satisfying the biodiesel-fuel standards of low energy consumption and material savings. The optimal conditions were: methanol/oil molar ratio of 5:1 and 0.7 wt.% catalyst in oil. Under these conditions, the conversion of triglycerides to fatty acid methyl esters was greater than 99% within the reaction time of 50 min. Crude biodiesel was purified by washing with tap water and drying at 70 degrees C under reduced pressure.
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Affiliation(s)
- Le Tu Thanh
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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Kishida M, Mio C, Fujimori K, Imamura K, Takenaka N, Maeda Y, Lan TTN, Shibutani Y, Bandow H. Seasonal change in the atmospheric concentration of particulate polycyclic aromatic hydrocarbons in Ho Chi Minh City, Vietnam. Bull Environ Contam Toxicol 2009; 83:747-751. [PMID: 19471847 DOI: 10.1007/s00128-009-9779-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2008] [Accepted: 05/07/2009] [Indexed: 05/27/2023]
Abstract
We analyzed atmospheric particulate polycyclic aromatic hydrocarbons (PAHs) in Ho Chi Minh City, Vietnam, for 19 months. The average concentrations of total PAHs at dry and rainy seasons were 4.28 +/- 2.83 and 15.71 +/- 8.21 ng m(-3), respectively. The use of motorcycles without catalytic converters, estimated to be main emission sources of PAHs, would be higher during the dry season. PAH concentrations show a negative correlation with sunshine duration (r = -0.51). Furthermore, the ratio of average PAH concentration in the dry season to that in the rainy season shows a positive correlation with photolytic half-life (r = 0.94). Thus, seasonal changes in PAH concentrations are attributable to their photolytic degradation.
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Affiliation(s)
- Masao Kishida
- Research Institute for Environment, Agriculture, and Fisheries, Osaka Prefectural Government, Osaka 537-0025, Japan.
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32
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Takenaka N, Takayama K, Ojiro N, Shimazaki W, Ohira K, Soda H, Suzue T, Sadanaga Y, Bandow H, Maeda Y. The Chemistry of Drying an Aqueous Solution of Salts. J Phys Chem A 2009; 113:12233-42. [DOI: 10.1021/jp9054395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Norimichi Takenaka
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
| | - Kayoko Takayama
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
| | - Naofumi Ojiro
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
| | - Wataru Shimazaki
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
| | - Kingo Ohira
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
| | - Hiroyuki Soda
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
| | - Takahiko Suzue
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
| | - Yasuhiro Sadanaga
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
| | - Hiroshi Bandow
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
| | - Yasuaki Maeda
- Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai, Osaka 599-8531, Japan
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Okitsu K, Nanzai B, Kawasaki K, Takenaka N, Bandow H. Sonochemical decomposition of organic acids in aqueous solution: understanding of molecular behavior during cavitation by the analysis of a heterogeneous reaction kinetics model. Ultrason Sonochem 2009; 16:155-162. [PMID: 18722800 DOI: 10.1016/j.ultsonch.2008.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Revised: 06/19/2008] [Accepted: 06/30/2008] [Indexed: 05/26/2023]
Abstract
The sonochemical decomposition of a low concentration of butyric acid was performed in an aqueous solution by use of 200 kHz ultrasound to discuss the reaction kinetics and molecular behavior during cavitation. Taking into account a Langmuir-type adsorption model, we propose a heterogeneous reaction kinetics model, which is based on the local reaction zone at the interface region of the cavitation bubbles, where the adsorption and desorption of butyric acid molecules from the bulk solution occur during bubble oscillation and then the existing molecules inside the local reaction zone are finally decomposed. To confirm our proposed kinetics model, the rates of decomposition were investigated as a function of the initial concentration of butyric acids in the different pH solutions. It was confirmed that our model could be reasonably applied to explain the obtained results and the pseudo rate constant (k) and the equilibrium constant (K) were able to be calculated: k is 8.0 microM min(-1) (pH 2) and 3.5 microM min(-1) (pH 10), and K is 5.7 x 10(-3) microM(-1) (pH 2) and 8.0 x 10(-3) microM(-1) (pH 10), respectively. By the analysis of the obtained K values, it was clear that the ionized organic acid molecules are relatively difficult to accumulate at the reaction zone, because of their lower hydrophobicity compared with that of the neutral ones. The results obtained in the sonochemical decomposition of benzoic acid were also able to be analyzed with the proposed kinetics model. In addition, we proposed an opinion toward the interpretation of a Langmuir-type adsorption model which has often been applied to explain heterogeneous reaction systems.
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Affiliation(s)
- Kenji Okitsu
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
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Nanzai B, Okitsu K, Takenaka N, Bandow H, Tajima N, Maeda Y. Effect of reaction vessel diameter on sonochemical efficiency and cavitation dynamics. Ultrason Sonochem 2009; 16:163-168. [PMID: 18625574 DOI: 10.1016/j.ultsonch.2008.05.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 05/27/2008] [Accepted: 05/28/2008] [Indexed: 05/26/2023]
Abstract
The influence of reaction vessel diameter on the sonochemical yield was investigated by using reaction vessels with five different diameters. It was revealed that the formation of H(2)O(2) and chloride ion, from the sonolysis of pure water and 1,2,4-trichlorobenzene aqueous solution, was affected by the reaction vessel diameter. That is, these yields increased as the reaction vessel diameter increased up to ø 90 mm and then decreased over ø 90 mm. From the analyses of the measurement of sonochemiluminescence and the calorimetry, it was suggested that active cavitation bubbles were formed at certain zones. In the case of a larger diameter reaction vessel, it was suggested that bubble nuclei that have not grown up to the resonance size, escaped from the sonication zone to the non-sonication zone and dissolved away. As a result, the number of active cavitation bubbles and the yields of H(2)O(2) and chloride ion would decrease in the case of a larger diameter reaction vessel.
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Affiliation(s)
- Ben Nanzai
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
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Hamai K, Takenaka N, Nanzai B, Okitsu K, Bandow H, Maeda Y. Influence of adding salt on ultrasonic atomization in an ethanol-water solution. Ultrason Sonochem 2009; 16:150-4. [PMID: 18707914 DOI: 10.1016/j.ultsonch.2008.07.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 06/23/2008] [Accepted: 07/03/2008] [Indexed: 05/11/2023]
Abstract
Ethanol was enriched by ultrasonic atomization. Enrichment ratios were increased by adding salt to the ethanol solution. Different enrichment ratios were observed for different types of salts in a range of low ethanol concentrations. The enrichment ratio was significantly improved by adding K(2)CO(3) or (NH(4))(2)SO(4). It is concluded that this is due to enhanced interfacial adsorption of the ethanol. Addition of Na(2)CO(3) to the ethanol solution also enhanced the interfacial adsorption of the ethanol, but the effect was relatively small. Addition of NaCl to the ethanol solution did not enhance the interfacial adsorption of the ethanol.
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Affiliation(s)
- Koumei Hamai
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-Ku, Sakai-shi, Osaka 599-8531, Japan
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Kishida M, Imamura K, Takenaka N, Maeda Y, Viet PH, Bandow H. Concentrations of atmospheric polycyclic aromatic hydrocarbons in particulate matter and the gaseous phase at roadside sites in Hanoi, Vietnam. Bull Environ Contam Toxicol 2008; 81:174-9. [PMID: 18496630 DOI: 10.1007/s00128-008-9450-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2007] [Accepted: 04/24/2008] [Indexed: 05/20/2023]
Abstract
We analyzed the concentrations of polycyclic aromatic hydrocarbons (PAHs) in both particulate matter (PM) and the gaseous phase at 10 roadside sites in Hanoi, Vietnam. The average concentrations of 47 PAHs ( summation 47PAHs) were 63 +/- 82 ng m(-3) in PM and 480 +/- 300 ng m(-3) in the gaseous phase. The PAHs mainly originated from motorcycles without catalytic converters. The highest concentrations of summation 47PAHs in both PM and the gaseous phase were observed at a terminal for buses and trucks. The operation of large commercial vehicles led to increased PAH pollution at the terminal site.
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Affiliation(s)
- Masao Kishida
- Research Institute of Environment, Agriculture, and Fisheries, Osaka Prefectural Government, Higashinari-ku, Osaka, 537-0025, Japan.
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Affiliation(s)
- Keiichi Sato
- Graduate School of Engineering, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai-City, Osaka 599-8531, Japan
| | - Norimichi Takenaka
- Graduate School of Engineering, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai-City, Osaka 599-8531, Japan
| | - Hiroshi Bandow
- Graduate School of Engineering, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai-City, Osaka 599-8531, Japan
| | - Yasuaki Maeda
- Graduate School of Engineering, Osaka Prefecture University, 1-1, Gakuen-cho, Naka-ku, Sakai-City, Osaka 599-8531, Japan
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Nanzai B, Okitsu K, Takenaka N, Bandow H, Maeda Y. Sonochemical degradation of various monocyclic aromatic compounds: relation between hydrophobicities of organic compounds and the decomposition rates. Ultrason Sonochem 2008; 15:478-483. [PMID: 17706451 DOI: 10.1016/j.ultsonch.2007.06.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 06/12/2007] [Accepted: 06/25/2007] [Indexed: 05/09/2023]
Abstract
Various aromatic compounds, i.e., nitrobenzene, aniline, phenol, benzoic acid, salicylic acid, 2-chlorophenol, 4-chlorophenol, styrene, chlorobenzene, toluene, ethylbenzene and n-propylbenzene were decomposed under identical ultrasonic irradiation conditions. The relationships between the initial rates of degradation of these aromatic compounds and their physicochemical parameters were systematically investigated. It was revealed that some correlations between the degradation rates and parameters of volatility, Henry's law constant and vapor pressure, were observed only in the limited high range of parameters. It was suggested that the Henry's law constant and vapor pressure had influenced on the rate of degradation for some of the tested aromatic compounds. In contrast, better correlations between the initial rates of degradation and hydrophobic parameters, water solubility and LogP (water-octanol partition coefficient), were observed over the wide range of chosen parameters. These results meant that the hydrophobicity of the compounds significantly affected their accumulation at the gas-liquid interface of the bubbles and it was the most important factor for the sonochemical degradation of aromatic compounds. In particular, for the sonolysis of water-insoluble organic compounds, LogP was found to be the representative parameter for understanding the hydrophobic properties of water-insoluble compounds.
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Affiliation(s)
- Ben Nanzai
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Kenji Okitsu
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan.
| | - Norimichi Takenaka
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Hiroshi Bandow
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Yasuaki Maeda
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
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Okitsu K, Kawasaki K, Nanzai B, Takenaka N, Bandow H. Effect of carbon tetrachloride on sonochemical decomposition of methyl orange in water. Chemosphere 2008; 71:36-42. [PMID: 18166211 DOI: 10.1016/j.chemosphere.2007.10.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Revised: 10/19/2007] [Accepted: 10/23/2007] [Indexed: 05/25/2023]
Abstract
Two types of sonicators were used for the sonochemical decomposition of methyl orange (MO) in the presence and absence of carbon tetrachloride (CCl4): One is a 45kHz ultrasonic cleaning bath (a low intensity sonicator) and the other is a 200kHz ultrasonic reactor (a high intensity sonicator). It was clearly confirmed that the rates of the sonochemical decomposition of MO increased with increasing the concentration of CCl4 in both sonicators. The enhancement effect of CCl4 was much higher in the high intensity sonicator than in the low intensity one: by the addition of 100ppm of CCl4, the decomposition ratio of MO with the high intensity sonicator became 41 times larger, while that with the low intensity sonicator became 4.8 times larger. Based on the obtained results, it was suggested that the formed cavitation phenomenon was different between sonicators. It was also suggested that the sonochemical decomposition of MO in the presence of CCl4 would be useful to evaluate the sonochemical efficiency, because the rate of MO decomposition can be effectively enhanced by the sonolysis of CCl4.
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Affiliation(s)
- Kenji Okitsu
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan.
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40
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O'Driscoll P, Minogue N, Takenaka N, Sodeau J. Release of nitric oxide and iodine to the atmosphere from the freezing of sea-salt aerosol components. J Phys Chem A 2008; 112:1677-82. [PMID: 18251528 DOI: 10.1021/jp710464c] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The known room-temperature, solution-phase reaction between nitrite ions and iodide ions, which occurs in acidic conditions (pH < 5.5), is shown to be accelerated when neutral aqueous solutions are frozen. The reaction is proposed to occur in liquid "micropockets" within the ice structure at temperatures between the freezing point and the eutectic temperature. The products, nitric oxide and molecular iodine, are known to play significant roles in atmospheric compositional change, and therefore, the results obtained here, which are not dependent on acidification, may impact on observed snowpack chemistry. Investigation of the effect of oxygen on the chemical processing indicates that a chain reaction mechanism is operative.
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Abstract
Some reactions are accelerated in ice compared to aqueous solution at higher temperatures. Accelerated reactions in ice take place mainly due to the freeze-concentration effect of solutes in an unfrozen solution at temperatures higher than the eutectic point of the solution. Pincock was the first to report an acceleration model for reactions in ice,1 which successfully simulated experimental results. We propose here a modified version of the model for reactions in ice. The new model includes the total molar change involved in reactions in ice. Furthermore, we explain why many reactions are not accelerated in ice. The acceleration of reactions can be observed in the cases of (i) second- or higher-order reactions, (ii) low concentrations, and (iii) reactions with a small activation energy. Reactions with a buffer solution or additives in order to adjust ion strength, zero- or first-order reactions, or reactions containing high reactant concentrations are not accelerated by freezing. We conclude that the acceleration of reactions in the unfrozen solution of ice is not an abnormal phenomenon.
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Affiliation(s)
- Norimichi Takenaka
- Laboratory of Environmental Chemistry, Graduate School of Engineering, Osaka Prefecture University, Gakuen-cho 1-1, Sakai-shi, Osaka 599-8531, Japan.
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Okitsu K, Suzuki T, Takenaka N, Bandow H, Nishimura R, Maeda Y. Acoustic multibubble cavitation in water: A new aspect of the effect of a rare gas atmosphere on bubble temperature and its relevance to sonochemistry. J Phys Chem B 2007; 110:20081-4. [PMID: 17034176 DOI: 10.1021/jp064598u] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Acoustic cavitation generates transient microbubbles with extremely high temperatures and high pressures, which can provide unique reaction routes. The maximum bubble temperature attained is widely known to be dependent on the polytropic index and thermal conductivity of the dissolved gas. Here, we show for the first time experimental evidence that the bubble temperature induced by a high frequency ultrasound is almost the same among different rare gases and the chemical efficiency is in proportion to the gas solubility of rare gases, which would be closely related to the number of active bubbles.
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Takenaka N, Tanaka M, Okitsu K, Bandow H. Rise in the pH of an unfrozen solution in ice due to the presence of NaCl and promotion of decomposition of gallic acids owing to a change in the pH. J Phys Chem A 2007; 110:10628-32. [PMID: 16956245 DOI: 10.1021/jp0634095] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Oxidative decomposition of gallic acid occurs in alkaline solutions but hardly arises in acidic solutions. We have found that the addition of sodium chloride promotes the decomposition of gallic acid caused by freezing even under neutral and acidic conditions. Even at pH 4.5, gallic acid was decomposed by freezing in the presence of NaCl; however, in the absence of NaCl, it was hardly decomposed by freezing at pH lower than 7. Chloride ions are more easily incorporated in ice than sodium ions when the NaCl solution is frozen. The unfrozen solution in ice becomes positively charged, and as a result, protons transfer from the unfrozen solution to the ice. We measured the pH in the unfrozen solution which coexists with single-crystal ice formed from a 5 mmol dm(-3) NaCl solution and determined the pH to be 8.6 at equilibrium with CO(2) of 380 ppm or 11.3 in the absence of CO(2) compared to pH 5.6 in the original solution. From the model calculation performed for gallic acid solution in the presence of 5 mmol dm(-3) NaCl, it can be estimated that the amount of OH(-) transferred from the ice to the solution corresponds to 1.26 x 10(-5) mol dm(-3). The amount of OH(-) transferred is concentrated into the unfrozen solution and affects the pH of the unfrozen solution. Therefore, the pH in an unfrozen gallic acid solution in ice becomes alkaline, and the decomposition of gallic acid proceeds. It is expected that other base-catalyzed reactions in weakly acidic solutions also proceed by freezing in the presence of NaCl without the need for any alkaline reagents.
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Affiliation(s)
- Norimichi Takenaka
- Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai-City, Osaka 599-8531, Japan.
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Itano Y, Bandow H, Takenaka N, Saitoh Y, Asayama A, Fukuyama J. Impact of NOx reduction on long-term ozone trends in an urban atmosphere. Sci Total Environ 2007; 379:46-55. [PMID: 17451788 DOI: 10.1016/j.scitotenv.2007.01.079] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 01/11/2007] [Accepted: 01/12/2007] [Indexed: 05/15/2023]
Abstract
We investigated the relationships between ambient O(3) concentrations and the concentrations of its precursors, NO(x) and NMHC, in Osaka, Japan. The levels of O(x)' (where [O(x)']=[O(3)]+[NO(2)]-0.1x[NO(x)] where the last term accounts for primary emissions of NO(2)) were uniform within the city even in the photochemically active season. We suggested that NO oxidation by peroxy radicals was a minor contributor, and that oxidation of locally emitted NO by background O(3) in the city was the primary control on NO(2) concentrations. Ozone concentrations increased linearly from 1985 to 2002 at a rate of 0.6 ppbv/yr, even though O(x)' concentrations remained constant after the mid 1990s. The trend for O(x)' concentrations could not be explained in terms of an increase in local O(3) production, and the trend was found to reflect background O(3) concentrations in Japan. There was a clear relationship between the NO(2)/O(x)' ratio and NO(x) concentration: the ratio decreased with decreasing NO(x) concentration. As a consequence, O(3) increased with decreasing NO(x) concentration. The reduction of NO(x) emissions was deemed to be an important factor for the recent trend of increasing O(3) concentrations in Osaka City.
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Affiliation(s)
- Yasuyuki Itano
- Osaka City Institute of Public Health and Environmental Sciences, Osaka 543-0026, Japan.
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Kameda T, Nakao T, Stavarache C, Maeda Y, Hien TT, Takenaka N, Okitsu K, Bandow H. Determination of Polycyclic Aromatic Hydrocarbons and Nitrated Polycyclic Aromatic Compounds in Diesel-engine Exhaust Particles from Combustion Process of Biodiesel Fuel. BUNSEKI KAGAKU 2007. [DOI: 10.2116/bunsekikagaku.56.241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Takayuki Kameda
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University
- Present address, Division of Environmental Science and Engineering, Graduate School of Natural Science and Technology, Kanazawa University
| | - Takeshi Nakao
- Department of Applied Materials Science, School of Engineering, Osaka Prefecture University
| | - Carmen Stavarache
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University
| | - Yasuaki Maeda
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University
| | - To Thi Hien
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University
| | - Norimichi Takenaka
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University
| | - Kenji Okitsu
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University
| | - Hiroshi Bandow
- Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University
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Kameda T, Asano K, Inazu K, Hisamatsu Y, Takenaka N, Bandow H. A Novel Technique to Determine the Rate Constants for the Gas-phase Reactions of Low-volatile Compounds with OH Radical Using a Relative-rate Method in CCl4Liquid Phase-system. CHEM LETT 2005. [DOI: 10.1246/cl.2005.758] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Asano H, Takenaka N, Fujii T, Nakamatsu E, Tagami Y, Takeshima K. Image processing methods to obtain symmetrical distribution from projection image. Appl Radiat Isot 2004; 61:625-30. [PMID: 15246409 DOI: 10.1016/j.apradiso.2004.03.090] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Flow visualization and measurement of cross-sectional liquid distribution is very effective to clarify the effects of obstacles in a conduit on heat transfer and flow characteristics of gas-liquid two-phase flow. In this study, two methods to obtain cross-sectional distribution of void fraction are applied to vertical upward air-water two-phase flow. These methods need projection image only from one direction. Radial distributions of void fraction in a circular tube and a circular-tube annuli with a spacer were calculated by Abel transform based on the assumption of axial symmetry. On the other hand, cross-sectional distributions of void fraction in a circular tube with a wire coil whose conduit configuration rotates about the tube central axis periodically were measured by CT method based on the assumption that the relative distributions of liquid phase against the wire were kept along the flow direction.
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Affiliation(s)
- H Asano
- Department of Mechanical Engineering, Kobe University, 1-1, Rokodai-Cho, Nada-ku, Kobe 657-8501, Japan.
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Okitsu K, Nakamura H, Takenaka N, Bandow H, Maeda Y, Nagata Y. Sonochemical reactions occurring in organic solvents: reaction kinetics and reaction site of radical trapping with 1,1-diphenyl-2-picrylhydrazyl. Res Chem Intermed 2004. [DOI: 10.1163/1568567041856864] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Abstract
Adiabatic and boiling gas-liquid two-phase flows in a simulated plate heat exchanger with a single-ribbed channel were visualized by a thermal neutron radiography method. In the experiments under adiabatic condition, the air-water two-phase flows in an aluminum test section were visualized. In the boiling two-phase flow experiments, chlorofluorocarbon R141b was used as the working fluid. Two-dimensional distributions of void fraction were measured from visualized images via some image processing techniques. As a result, it was shown that both the phases tended to flow straight in the ribbed channel, and mixing of gas and liquid phases was weak. Moreover, when working fluids flew into the test section as a gas-liquid mixture, the phase distributions were strongly affected by a liquid pool at the test section inlet.
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Affiliation(s)
- H Asano
- Department of Mechanical Engineering, Kobe University, 1-1, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan.
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Ozawa M, Umekawa H, Furui S, Hayashi K, Takenaka N. Quantitative flow visualization of fluidized-bed heat exchanger by neutron radiography. Appl Radiat Isot 2004; 61:715-24. [PMID: 15246422 DOI: 10.1016/j.apradiso.2004.03.099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Quantitative flow visualization of a gas-solid fluidized-bed installed vertical tube-bank has been successfully conducted using neutron radiography and image processing technique. The quantitative data of void fraction distribution as well as the fluctuation data are presented. The time-averaged void fraction is well correlated by the drift-flux model. The bubbles formed in the bed, rise along the vertical tubes and the observed bubble size is smaller than that in a free bubbling bed without tube-banks. The bubble diameter is well correlated by the modified Mori and Wen's correlation taking into account the pitch of tube arrangement. The bubble rise velocity is also well correlated by applying the drift-flux model. These results are consistent for both bed materials of Geldart's B- and A-particles, while the bubble size is significantly different between two kinds of particles.
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Affiliation(s)
- M Ozawa
- Department of Mechanical Engineering, Kansai University, Yamate-cho 3-3-35, Suita, Osaka 564-8680, Japan.
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