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Liu B, Yu M, Verma S, Kim KH. Anti-competitive adsorption of gaseous benzene on hydrophilic microporous carbon in humid conditions. Sci Total Environ 2024; 927:171998. [PMID: 38537821 DOI: 10.1016/j.scitotenv.2024.171998] [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] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 03/17/2024] [Accepted: 03/24/2024] [Indexed: 04/14/2024]
Abstract
The adsorption capture of ambient volatile organic compounds (VOCs) is of practical importance for air quality management. Herein, unique anti-competitive adsorption behavior of benzene on a hydrophilic activated carbon (Procarb-900 (P900)) is evidenced in the presence of competing components (e.g., formaldehyde (FA) and/or moisture). Contrary to general expectations, the adsorption capacity of 10 Pa benzene (QB) onto P900 (30 mg) at the 99 % breakthrough level improves from 144.8 to 187 mg g-1 as the relative humidity (RH) increases from 0 to 25 %. Such pattern is maintained at 183.9 mg g-1 even at the relatively high RH of 50 %. Furthermore, QB exhibits a remarkable increase of 56.1 % (to 226.0 mg g-1) in the binary phase (100 ppm benzene plus 50 ppm FA) relative to its single phase (144.8 mg g-1). The kinetic studies confirm the occurrence of anti-competitive adsorption of benzene under humid conditions with the unusual decrease in rate constants at the elevated RHs (i.e., 25 and 50 %). The thermodynamic studies suggest the exothermic nature of benzene adsorption onto P900. The hydrophilicity of P900's outer surface promotes the preferential adsorption of polar FA and water vapor over non-polar benzene, which deforms the activated carbon texture and lowers the pore size distribution (PSD). The narrow PSD enhances benzene uptake in the complex systems due to the confinement effect. Overall, this study offers insights into the unique anti-competitive adsorption of non-polar VOCs (e.g., benzene) on hydrophilic microporous adsorbents in the presence of potential interferences such as polar water vapor and FA. These findings offer a guideline for the practical implementation of adsorption techniques for gaseous VOCs in humid conditions.
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Affiliation(s)
- Botao Liu
- Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051, PR China; Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Republic of Korea
| | - Mingshen Yu
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Republic of Korea
| | - Swati Verma
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Republic of Korea
| | - Ki-Hyun Kim
- Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Republic of Korea.
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2
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Voronin BA, Tennyson J, Yurchenko SN, Chesnokova TY, Chentsov AV, Bykov AD, Makarova MV, Voronina SS, Cruz FC. The infrared absorption spectrum of radioactive water isotopologue H 215O. Spectrochim Acta A Mol Biomol Spectrosc 2024; 311:124007. [PMID: 38354674 DOI: 10.1016/j.saa.2024.124007] [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] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 01/16/2024] [Accepted: 02/05/2024] [Indexed: 02/16/2024]
Abstract
A room temperature line list for the H215O radioactive isotopologue of the water molecule is computed using the variational nuclear-motion DVR3D program suite and an empirical high-precision potential energy function. The line list consists of rotation-vibrational energies and Einstein-A coefficients, covering a wide spectral range from 0 to 25000 cm-1 and the total angular momenta J up to 30. Estimates of air-broadening coefficients are provided. Experimentally derived energies of H216O, H217O and H218O from the literature are used to provide improved energies for important states with uncertainty estimates for the H215O. A number of the wmost promising spectroscopic ranges for the detection of H215O are proposed. The calculated absorption spectrum should be useful for the study gaseous radioactive water at IR region, determining concentration, etc.
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Affiliation(s)
- Boris A Voronin
- Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, 13083-859, Brazil; V.E. Zuev Institute of Atmospheric Optics SB RAS, sq. Ak. Zuev 1, 643021 Tomsk, Russia
| | - Jonathan Tennyson
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK.
| | - Sergey N Yurchenko
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
| | - Tatyana Yu Chesnokova
- V.E. Zuev Institute of Atmospheric Optics SB RAS, sq. Ak. Zuev 1, 643021 Tomsk, Russia
| | - Aleksei V Chentsov
- V.E. Zuev Institute of Atmospheric Optics SB RAS, sq. Ak. Zuev 1, 643021 Tomsk, Russia
| | - Aleksandr D Bykov
- V.E. Zuev Institute of Atmospheric Optics SB RAS, sq. Ak. Zuev 1, 643021 Tomsk, Russia
| | - Maria V Makarova
- Faculty of Physics, St. Petersburg State University, 198504 St. Petersburg, Russia
| | - Svetlana S Voronina
- V.E. Zuev Institute of Atmospheric Optics SB RAS, sq. Ak. Zuev 1, 643021 Tomsk, Russia
| | - Flávio C Cruz
- Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, 13083-859, Brazil
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3
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Zou Y, Liu X, Wu K, Zhou Z, Xu M. The effect of multiple factors on changes in organic-inorganic fractions of condensable particulate matter during coal combustion. Chemosphere 2024; 353:141638. [PMID: 38442775 DOI: 10.1016/j.chemosphere.2024.141638] [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: 09/08/2023] [Revised: 01/05/2024] [Accepted: 03/01/2024] [Indexed: 03/07/2024]
Abstract
Condensable particulate matter (CPM) from coal combustion is the focus of current pollutant emission studies, and CPM can be divided into inorganic and organic fractions according to the component characteristics. At present, the effects of different factors in the combustion process on the organic and inorganic components of CPM have not been discussed systematically. Here, we conducted combustion experiments collected the generated CPM on a well-controlled drip tube furnace, and investigated the effects of different factors on the generation of organic and inorganic components of CPM by varying the furnace wall insulation temperature, the ratio of gas supply components and the water vapor content in the flue gas. The results showed that the increase in combustion temperature (1300-1500 °C) and oxygen concentration (15-25%) reduced the total CPM generation by 9.8% and 19.98%, respectively, and the intervention of water vapor increased the ability of the whole CPM sampling device to capture ultrafine condensable particles. The generation of CPM organic components decreased with the enhancement of combustion temperature and oxygen content on combustion characteristics, and alkanes shifted to low carbon content. The amount of CPM inorganic components increased with the increase of water vapor content in the flue gas, and this change was dominated by SO42-. The above results provide a feasible idea for the next step of the precise reduction of CPM components.
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Affiliation(s)
- Yue Zou
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, PR China.
| | - Xiaowei Liu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, PR China.
| | - Kui Wu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, PR China.
| | - Zijian Zhou
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, PR China.
| | - Minghou Xu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, PR China.
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Kim JH, Kim HY, Lee SJ, Lee DS. Water Vapor Therapy and Zonal Anatomy of the Prostate. Int Neurourol J 2024; 28:67-69. [PMID: 38569622 PMCID: PMC10990760 DOI: 10.5213/inj.2346278.139] [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] [Received: 10/04/2023] [Accepted: 12/27/2023] [Indexed: 04/05/2024] Open
Abstract
Water vapor therapy using Rezūm has been recently introduced as a minimally invasive surgery for benign prostatic hyperplasia and is being increasingly performed. However, there is a lack of real-time images showing this practice and how convective water vapor acts in the prostate gland. In real-time ultrasonography, convective water vapor rapidly spreads throughout the ipsilateral transitional zone and is mostly limited within the transitional zone. For educational purposes, we would like to present a case to help readers understand water vapor therapy by visualizing convective water vapor using real-time ultrasound.
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Affiliation(s)
- Jang Hwan Kim
- Department of Urology and Urological Science Institute, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hee Youn Kim
- Department of Urology, St. Vincent’s Hospital, The Catholic University of Korea, Suwon, Korea
| | - Seung-Ju Lee
- Department of Urology, St. Vincent’s Hospital, The Catholic University of Korea, Suwon, Korea
| | - Dong Sup Lee
- Department of Urology, St. Vincent’s Hospital, The Catholic University of Korea, Suwon, Korea
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Wu D, Meng Z, Bao Z, Deng M, Ou J, Chen Z. Experimental study on gas and particle emission characteristics of carbon black oxidation process in the presence of water and catalysts. Sci Total Environ 2023; 901:165748. [PMID: 37495122 DOI: 10.1016/j.scitotenv.2023.165748] [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] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 07/10/2023] [Accepted: 07/21/2023] [Indexed: 07/28/2023]
Abstract
The study of oxidation characteristics of carbon black particle is the basis to investigate the regeneration process and characteristics of diesel particulate filter (DPF). Based on the fixed-bed test bench, the gas and particle emission characteristics of carbon black oxidation process in the presence of water are investigated under different temperatures, Printex-U (PU) masses, and catalysts. The experimental results show that the rise of temperature and PU mass increases the emissions of CO, CO2 and the total average particle number (PN). The oxidation efficiency (η) increases with temperature, but decreases with PU mass. The addition of catalysts promotes PU oxidation, and reduces CO emission. Due to the influence of particle diffusion, CeO2 has slightly lower efficiency than Pt/Al2O3 in the same ratio (1:1), but it is beneficial to significantly reduce particle emission, especially as the ratio increases (1:5). Water decreases CO and the η in PU oxidation, and the negative impact is gradually reduced after 3 % water concentration; However, the PN significantly increases, and expands the particle size range, particularly at high temperature and adding Pt/Al2O3 (from about 10 nm to 6- 30 nm, and a large number of particles with 30- 100 nm are produced). Additionally, the CO2/CO ratio of carbon black oxidation gradually increases with water concentration. Controlling DPF regeneration needs to strike a balance between the benefits on increasing oxidation efficiency and the potential negatives on particulate and harmful gas emission.
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Affiliation(s)
- Daigeng Wu
- Key Laboratory of Fluid and Power Machinery, Ministry of Education (Xihua University), Chengdu 610039, PR China; Vehicle Measurement, Control and Safety Key Laboratory of Sichuan Province, Xihua University, Chengdu 610039, PR China
| | - Zhongwei Meng
- Key Laboratory of Fluid and Power Machinery, Ministry of Education (Xihua University), Chengdu 610039, PR China; Vehicle Measurement, Control and Safety Key Laboratory of Sichuan Province, Xihua University, Chengdu 610039, PR China.
| | - Zhongqiang Bao
- Key Laboratory of Fluid and Power Machinery, Ministry of Education (Xihua University), Chengdu 610039, PR China; Vehicle Measurement, Control and Safety Key Laboratory of Sichuan Province, Xihua University, Chengdu 610039, PR China
| | - Meng Deng
- Key Laboratory of Fluid and Power Machinery, Ministry of Education (Xihua University), Chengdu 610039, PR China; Vehicle Measurement, Control and Safety Key Laboratory of Sichuan Province, Xihua University, Chengdu 610039, PR China
| | - Juan Ou
- Power Machinery and Vehicular Engineering Institute, Zhejiang University, Hangzhou 310027, PR China
| | - Zhou Chen
- Key Laboratory of Fluid and Power Machinery, Ministry of Education (Xihua University), Chengdu 610039, PR China; Vehicle Measurement, Control and Safety Key Laboratory of Sichuan Province, Xihua University, Chengdu 610039, PR China
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Zhang X, Ni L, He A, Yang L, Noda I, Ozaki Y, Guo R, Xu Y. A new apparatus and the relevant method to retrieve IR spectra of solutes from the corresponding aqueous solutions. Spectrochim Acta A Mol Biomol Spectrosc 2023; 296:122598. [PMID: 36996520 DOI: 10.1016/j.saa.2023.122598] [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] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 03/01/2023] [Accepted: 03/06/2023] [Indexed: 06/19/2023]
Abstract
An apparatus and relevant approach to obtaining IR spectra of solutes from the corresponding aqueous solution were developed. In the experiment, aqueous solutions were converted into aerosols using an ultrasonic or a pneumatic device. Subsequently, water in the nebulized solution is completely gasified under a high-speed flow and low vacuum environment. Via this process, the aqueous solution changes into a mixture of a solute or solutes and gaseous water, whose single-beam IR spectra are collected. Then, the newly developed RMF (retrieving moisture-free IR spectrum) method and the relevant approach described in our recent papers have been adopted to treat the resultant single-beam sample spectrum. As a result, the spectral contribution of the vibrational-rotational peaks of gaseous water can be removed or significantly attenuated, and IR spectra of solutes can be obtained. The approach shows an obvious advantage in retrieving the IR spectrum of volatile solutes from its aqueous solution. This capability is showcased by obtaining IR spectra of isopropanol and ethyl acetate successfully. IR spectra of these compounds can be retrieved even if the concentration of the solute is below 10 wt%. Moreover, atomization via ultrasonic/pneumatic methods offers a mild way to gasify solutes whose boiling points are remarkably higher than that of water. This advantage is manifested by acquiring IR spectra of 1-butanol and 1,2-propanediol in the gaseous phase under ambient conditions.
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Affiliation(s)
- Xiaohua Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Lei Ni
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Anqi He
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Limin Yang
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, PR China.
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Yukihiro Ozaki
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669 - 1330, Japan
| | - Ran Guo
- PerkinElmer Inc., Jiuxianqiao Road, 14, Chaoyang District, Beijing 100015, PR China
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China.
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7
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Huang T, Li Y, Lolli S, Cheng JCH, Wang J, Lam DHY, Leung WH, Lee HF, Yim SHL. Influences of approaching tropical cyclones on water vapor and aerosols in the atmospheric boundary layer of Guangdong-Hong Kong-Macau Greater Bay Area of China. Sci Total Environ 2023; 880:163188. [PMID: 37001679 DOI: 10.1016/j.scitotenv.2023.163188] [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] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/09/2023] [Accepted: 03/27/2023] [Indexed: 05/27/2023]
Abstract
The outer circulation of tropical cyclones (TCs) on the western North Pacific has been reported to substantially influence the atmospheric environment over the Guangdong-Hong Kong-Macau Greater Bay Area (GBA) of China, whereas dynamic evolution and redistribution of water vapor and aerosol in the atmospheric boundary layer (ABL) responding to moving TCs have yet to be understood. This study aims to answer three key research questions related to the influences of the approaching TCs: (1) how do water vapor and aerosol particles over the GBA change during the TC approaching stage? (2) how does the ABL in terms of vertical wind structure respond to the approaching TCs? and (3) how does turbulence influence the vertical profile of aerosol during the approaching stage? Based on an intensive analysis of three-year reanalysis and Doppler LiDAR data, this study identified a dry-polluted time over the GBA when a TC was located at ~1000 km away on South China Sea. Before that, horizontal wind has consistently come from the northeast, creating a favorable condition for weak transboundary air pollution to the GBA. During the dry-polluted time, the highest surface PM2.5 concentration was resulted from the enhanced downdraft and early-stage wind shear, i.e., stronger wind started occurring at upper-level ABL, while the further turbulent mixing induced by wind shear enhancement and updrafts recovery pumped surface pollution upward to the upper level when TCs became closer. Our findings are expected to improve both weather and PM2.5 forecasts under the impacts of approaching TCs.
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Affiliation(s)
- T Huang
- Department of Geography and Resource Management, The Chinese University of Hong Kong, 999077, Hong Kong
| | - Y Li
- Department of Geography and Resource Management, The Chinese University of Hong Kong, 999077, Hong Kong
| | - S Lolli
- CNR-IMAA, Istituto di Metodologie Ambientali, Tito, PZ, Italy; Department of Physics, Kent State University, Florence Campus, 44240 Kent, OH, USA
| | - J C H Cheng
- Department of Geography and Resource Management, The Chinese University of Hong Kong, 999077, Hong Kong
| | - J Wang
- National Institute of Education, Nanyang Technological University, Singapore
| | - D H Y Lam
- Hong Kong Observatory, 999077, Hong Kong
| | - W H Leung
- Hong Kong Observatory, 999077, Hong Kong
| | - H F Lee
- Department of Geography and Resource Management, The Chinese University of Hong Kong, 999077, Hong Kong
| | - S H L Yim
- Asian school of the Environment, Nanyang Technological University, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore; Earth Observatory of Singapore, Nanyang Technological University, Singapore.
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Zhang X, Li T, He A, Yang L, Noda I, Ozaki Y, Xu Y. Comprehensive modified approaches to reducing the interference of moisture from an FTIR spectrum and the corresponding second derivative spectrum. Spectrochim Acta A Mol Biomol Spectrosc 2023; 287:122004. [PMID: 36327803 DOI: 10.1016/j.saa.2022.122004] [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] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 10/12/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
We proposed a modified and improved approach to removing the interference of moisture from an IR spectrum and the corresponding second derivative spectrum. The temperature fluctuation in the air of the optical path and baseline-drift lead to the small but persistent presence of the interference of moisture. The problem has been successfully addressed by adopting a double-matching strategy. Additionally, two-dimensional correlationspectra (2D-COS) are generated using the second derivative or third derivative spectrum of the negative base 10 logarithms of the single-beam spectra, thereby removing the linear slope or quadratic portion of baseline-drift. Using the newly adopted approach, the residual interferences of moisture are attenuated. We applied the new approach to the IR spectra and the second derivative spectra of neat hexadecanol and biaxially oriented polypropylene (BOPP) film, and some promising preliminary results are obtained. In hexadecanol, two highly overlapping peaks at 1464 and 1463 cm-1 are revealed. In BOPP, the envelope at 1458 cm-1 is found to be composed of a number of sub-peaks.
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Affiliation(s)
- Xiaohua Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Tianyi Li
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, China
| | - Anqi He
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Limin Yang
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, China.
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China; Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, United States
| | - Yukihiro Ozaki
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China; School of Biological and Environmental Sciences, Kwansei Gakuin University, Sanda, Hyogo 669 - 1330, Japan
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
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Cui X, Li Y, Jiang C, Yuan Z, Zhou S, Chen W, Yu B. In situ measurement of water vapor isotope ratios in air with a laser-based spectrometer. Spectrochim Acta A Mol Biomol Spectrosc 2022; 283:121762. [PMID: 35985233 DOI: 10.1016/j.saa.2022.121762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/04/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
Simultaneous measurement of H217O/H216O, H218O/H216O, and HDO/H216O in air with a compact spectrometer based on a mid-infrared distributed feedback (DFB) laser was described. The obtained mixing ratios of H216O, H217O, and H218O agreed reasonably well with those measured by a hygrometer. The precision and repeatability of the spectrometer were analyzed. Indoor air tests demonstrated that its 220-s precision was 0.08 ‰, 0.06 ‰, and 0.14 ‰ for δ18O, δ17O, and δ2H respectively. The measured values of δ18O, δ17O, and δ2H in indoor air were highly correlated with the water vapor mixing ratios. The compact spectrometer provides in situ measurements of water vapor isotopes with high precision and fast time response, which opens new possibilities for its application in atmospheric and hydrological research in the future.
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Affiliation(s)
- Xiaojuan Cui
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China.
| | - Yafan Li
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| | - Chaochao Jiang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| | - Zijian Yuan
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China
| | - Sheng Zhou
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
| | - Weidong Chen
- Laboratoire de Physicochimie de l'Atmosphère, Université du Littoral Côte d'Opale, 189A Avenue, Maurice Schumann, 59140 Dunkerque, France
| | - Benli Yu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, China; Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education, Anhui University, 230601 Hefei, China
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Li J, Cheng T, Ma X, Hou X, Wu H, Yang L. Effect of nitrogen functional groups on competitive adsorption between toluene and water vapor onto nitrogen-doped spherical resorcinol-formaldehyde resin-based activated carbon. Environ Sci Pollut Res Int 2022; 29:85257-85270. [PMID: 35793021 DOI: 10.1007/s11356-022-21179-w] [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] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
To elucidate the effect of nitrogen functional groups on the competitive adsorption of toluene and water vapor, a series of N-doped resorcinol-formaldehyde resin-based activated carbons using g-C3N4 as the nitrogen source were prepared, which possessed different N contents (1.29-6.14%). The competitive adsorption characteristics and mechanisms were investigated by characterizations, dynamic adsorption experiments, adsorption isotherms, and density functional theory calculations. Results showed that the normalized toluene adsorption capacity under 50 RH% was consistent with the N content, revealing that nitrogen functional groups can enhance the competitive adsorption for toluene under a humid atmosphere. Adsorption isotherms analysis suggested that nitrogen functional groups can not only accelerate the adsorption of toluene but also improve the hydrophobicity of carbon surface. Competitive adsorption mechanisms were ascribed to π-π interactions and electrostatic interactions. Specifically, graphitic-N and pyridinic-N enhance competitive adsorption for toluene through reinforced π-π interactions with toluene and weakened electrostatic interactions with water molecule. However, pyrrolic-N improve the competitive adsorption, which is principally attributed to enhanced π-π interactions with toluene. Furthermore, it was found that the reusability of activated carbon could be improved by nitrogen functional groups. This study provides theoretical hints to develop volatile organic compound adsorbents in the presence of water vapor.
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Affiliation(s)
- Jinjin Li
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, #2 Sipailou Road, Nanjing, Jiangsu, 210096, People's Republic of China
| | - Tangying Cheng
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, #2 Sipailou Road, Nanjing, Jiangsu, 210096, People's Republic of China
| | - Xiuwei Ma
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, #2 Sipailou Road, Nanjing, Jiangsu, 210096, People's Republic of China
| | - Xueyan Hou
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, #2 Sipailou Road, Nanjing, Jiangsu, 210096, People's Republic of China
| | - Hao Wu
- School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu, 210042, People's Republic of China
| | - Linjun Yang
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, #2 Sipailou Road, Nanjing, Jiangsu, 210096, People's Republic of China.
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Chen Y, Yao K, Zhang X, Shen B, Smith RL, Guo H. Siloxane-modified MnO x catalyst for oxidation of coal-related o-xylene in presence of water vapor. J Hazard Mater 2022; 436:129109. [PMID: 35594674 DOI: 10.1016/j.jhazmat.2022.129109] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/02/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
In coal-combustion energy production, presence of water vapor in flue gas causes catalyst deactivation and leads to the release of large quantities of volatile organic compounds (VOCs). In this study, design of a low-temperature, hydrophobic catalyst for flue gas purification was achieved by modifying support material with inorganic siloxane. Introduction of 5% water vapor into simulated flue gas at 300 °C reduced oxidation efficiency for o-xylene removal by 26% with unmodified MnOx/γ-Al2O3 catalyst, whereas with modified catalyst MnOx-Si0.9/γ-Al2O3 oxidation efficiency was reduced by only 5%. MnOx-Si0.9/γ-Al2O3 exhibited stable catalytic efficiency for o-xylene gas oxidation containing water vapor for over 200 min. Water-resistance of the catalyst was effective for removal of multi-coal combustion pollutants (Hg0 and NO) and moreover, hydrophobicity of the catalyst led to a reduction in surface sulfate deposition, thereby lowering toxicity of SO2 from simulated flue gas. DRIFTS analysis showed that the hydrophobic catalyst surface not only reduces water adsorption, but also promotes water volatilization. Based on molecular adsorption energies, catalyst support modification with siloxane inhibits water adsorption and promotes organic adsorption and thus provides a new strategy for preparing water-resistant catalysts for flue gas purification.
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Affiliation(s)
- Yingjian Chen
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, China; Tianjin Key Laboratory of Clean Energy and Pollution Control, Hebei University of Technology, Tianjin, China
| | - Kening Yao
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, China; Tianjin Key Laboratory of Clean Energy and Pollution Control, Hebei University of Technology, Tianjin, China
| | - Xiao Zhang
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, China; Tianjin Key Laboratory of Clean Energy and Pollution Control, Hebei University of Technology, Tianjin, China.
| | - Boxiong Shen
- School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, China; Tianjin Key Laboratory of Clean Energy and Pollution Control, Hebei University of Technology, Tianjin, China.
| | - Richard Lee Smith
- Graduate School of Environmental Studies, Tohoku University, Aramaki Aza Aoba 6-6-11, Aoba, Sendai 980-8579, Japan
| | - Haixin Guo
- Graduate School of Environmental Studies, Tohoku University, Aramaki Aza Aoba 6-6-11, Aoba, Sendai 980-8579, Japan
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12
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Cheng T, Li J, Ma X, Zhou L, Wu H, Yang L. Alkylation modified pistachio shell-based biochar to promote the adsorption of VOCs in high humidity environment. Environ Pollut 2022; 295:118714. [PMID: 34942291 DOI: 10.1016/j.envpol.2021.118714] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [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: 09/25/2021] [Revised: 11/25/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
The objective of this work was to evaluate the adsorption capacity of alkylated modified porous biochar prepared by esterification and etherification (PSAC-2) for low concentrate volatile organic compounds (VOCs, toluene and ethyl acetate) in high humidity environment by experiments and theoretical calculations. Results showed that PSAC-2 has a large specific surface area and weak surface polarity, at 80% relative humidity, its capacities for toluene and ethyl acetate adsorption could be maintained at 92% and 87% of the initial capacities (169.9 mg/g and 96.77 mg/g). The adsorption behaviors of toluene, ethyl acetate, and water vapor were studied by adsorption isotherms, and isosteric heat was obtained. The desorption activation energy was obtained by temperature programmed desorption experiment. The outcomes manifested that the PSAC-2 can achieve strong adsorption performance for weakly polar molecules. Through density functional theory (DFT) simulations, owing to the interaction of hydrogen bonds, oxygen-containing groups became a significant factor influencing the adsorption of VOCs in humid environments. These results could provide an important reference for VOCs control in a high humidity environment.
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Affiliation(s)
- Tangying Cheng
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu, 210096, People's Republic of China
| | - Jinjin Li
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu, 210096, People's Republic of China
| | - Xiuwei Ma
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu, 210096, People's Republic of China
| | - Lei Zhou
- National-Local Joint Engineering Research Center of Heavy Metals Polluants Control and Resource Utilization, College of Environmental and Chemical Engineering, Nanchang Hangkong University, Jiangxi, 330063, People's Republic of China
| | - Hao Wu
- School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing, Jiangsu, 210042, People's Republic of China
| | - Linjun Yang
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu, 210096, People's Republic of China.
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13
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Zhang X, He A, Guo R, Zhao Y, Yang L, Morita S, Xu Y, Noda I, Ozaki Y. A new approach to removing interference of moisture from FTIR spectrum. Spectrochim Acta A Mol Biomol Spectrosc 2022; 265:120373. [PMID: 34547685 DOI: 10.1016/j.saa.2021.120373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 08/25/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
An approach is developed to remove the interference of moisture from FTIR spectra. The interference arises from two aspects: the fluctuation on the temperature of the HeNe laser and the fluctuation on the transient concentration of moisture in the light - path of an FTIR spectrometer. The temperature fluctuation on the HeNe laser produces a systematic spectral shift between single-beam sample and background spectra, which often makes spectral subtraction method invalid in removing the interference of moisture. Herein, the Carbo similarity metric (the CAB value) is used to reflect the subtle spectral shift. A database of single-beam background spectra is established based on the concept of big-data and the pigeon-hole theory. The spectral shift is corrected by selecting suitable single-beam background spectra from the database to match with the given single-beam sample spectrum according to the CAB value. The interference caused by the fluctuation of the transient concentration of moisture is removed using a comprehensive 2D-COS method. We apply the approach on two polymeric samples to retrieve high-quality spectra and reliable second derivative spectra without the interference of moisture. The present work provides a new opportunity of obtaining the reliable second derivative spectra in the spectral region masked by moisture.
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Affiliation(s)
- Xiaohua Zhang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China
| | - Anqi He
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Ran Guo
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Beijing CKC, PerkinElmer Inc., Beijing 100015, PR China
| | - Ying Zhao
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Engineering Plastics, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Limin Yang
- State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, PR China.
| | - Shigeaki Morita
- Department of Engineering Science, Osaka Electro-Communication University, Osaka 572-8530, Japan
| | - Yizhuang Xu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Jiangsu JITRI Molecular Engineering Inst. Co., Ltd., Suzhou, Jiangsu 215500, PR China.
| | - Isao Noda
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, United States
| | - Yukihiro Ozaki
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, PR China; School of Biological and Environmental Sciences and Technology, Kwansei Gakuin University, Sanda, Hyogo 669-1337, Japan
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14
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Parida BR, Bar S, Kaskaoutis D, Pandey AC, Polade SD, Goswami S. Impact of COVID-19 induced lockdown on land surface temperature, aerosol, and urban heat in Europe and North America. Sustain Cities Soc 2021; 75:103336. [PMID: 34513574 PMCID: PMC8418702 DOI: 10.1016/j.scs.2021.103336] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 08/28/2021] [Accepted: 09/02/2021] [Indexed: 05/21/2023]
Abstract
The outbreak of SARS CoV-2 (COVID-19) has posed a serious threat to human beings, society, and economic activities all over the world. Worldwide rigorous containment measures for limiting the spread of the virus have several beneficial environmental implications due to decreased anthropogenic emissions and air pollutants, which provide a unique opportunity to understand and quantify the human impact on atmospheric environment. In the present study, the associated changes in Land Surface Temperature (LST), aerosol, and atmospheric water vapor content were investigated over highly COVID-19 impacted areas, namely, Europe and North America. The key findings revealed a large-scale negative standardized LST anomaly during nighttime across Europe (-0.11 °C to -2.6 °C), USA (-0.70 °C) and Canada (-0.27 °C) in March-May of the pandemic year 2020 compared to the mean of 2015-2019, which can be partly ascribed to the lockdown effect. The reduced LST was corroborated with the negative anomaly of air temperature measured at meteorological stations (i.e. -0.46 °C to -0.96 °C). A larger decrease in nighttime LST was also seen in urban areas (by ∼1-2 °C) compared to rural landscapes, which suggests a weakness of the urban heat island effect during the lockdown period due to large decrease in absorbing aerosols and air pollutants. On the contrary, daytime LST increased over most parts of Europe due to less attenuation of solar radiation by atmospheric aerosols. Synoptic meteorological variability and several surface-related factors may mask these changes and significantly affect the variations in LST, aerosols and water vapor content. The changes in LST may be a temporary phenomenon during the lockdown but provides an excellent opportunity to investigate the effects of various forcing controlling factors in urban microclimate and a strong evidence base for potential environmental benefits through urban planning and policy implementation.
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Affiliation(s)
- Bikash Ranjan Parida
- Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi 835205, India
| | - Somnath Bar
- Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi 835205, India
| | - Dimitris Kaskaoutis
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece
- Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 71003 Crete, Greece
| | - Arvind Chandra Pandey
- Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi 835205, India
| | | | - Santonu Goswami
- Earth and Climate Science Area, National Remote Sensing Centre, Indian Space Research Organization (ISRO), Hyderabad 500037, India
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15
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Jin K, Zhao Y, Fan Z, Wang H, Zhao H, Huang X, Hou K, Yao C, Xie K, Cai Z. A facile and green route to fabricate fiber-reinforced membrane for removing oil from water and extracting water under slick oil. J Hazard Mater 2021; 416:125697. [PMID: 33823481 DOI: 10.1016/j.jhazmat.2021.125697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 12/31/2020] [Revised: 02/27/2021] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Except the good separation performance, the membranes used for oil-water mixture separation should be fabricated with as little wastewater produced as possible. Thus, we proposed a green tactic--water vapor induced phase inversion to prepare the high-strength and superhydrophilic/underwater superoleophobic nonwoven fabric-based cotton/PA6/PAN membranes which is based on the polymer/solvent/nonsolvent ternary system analysis. Differing from adding additives in polymer solution or coagulation bath, above proposed strategy has an "subtractive effect" with the advantages of constructing three-dimensional porous structure and greatly reducing the organic wastewater produced during preparation process. Moreover, the obtained cotton/PA6/PAN membranes exhibited unexpected performances for separating oil-in-water emulsions. An ultrahigh permeation flux of up to 478,000 L m-2 h-1 bar-1 with a separation efficiency of > 99.9% was obtained under the driving pressure of 1.6 KPa, which was one order of magnitude higher than the conventional separation membranes with similar properties. In addition, it is surprising that the cotton/PA6/PAN membranes can also extract water from the slick oil/water immiscible mixture. Therefore, it is expected that the cotton/PA6/PAN membranes can be used in practical oily wastewater purification.
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Affiliation(s)
- Kaili Jin
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China
| | - Yaping Zhao
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China; College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China
| | - Zhuizhui Fan
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China
| | - Helan Wang
- China National Inspection & Testing Centre for Ophthalmic Optic Glass & Enamel Products, Research Institute of Donghua University, Shanghai 201620, China
| | - Hong Zhao
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China
| | - Xiqin Huang
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China
| | - Keru Hou
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China
| | - Chengjian Yao
- College of Fashion and Textiles, Shanghai University of Engineering Science, Shanghai 201620, PR China
| | - Kongliang Xie
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China; College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China
| | - Zaisheng Cai
- Key Lab of Science & Technology of Eco-textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China; College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, PR China.
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16
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Parida BR, Bar S, Roberts G, Mandal SP, Pandey AC, Kumar M, Dash J. Improvement in air quality and its impact on land surface temperature in major urban areas across India during the first lockdown of the pandemic. Environ Res 2021; 199:111280. [PMID: 34029544 PMCID: PMC9189601 DOI: 10.1016/j.envres.2021.111280] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 02/12/2021] [Accepted: 04/30/2021] [Indexed: 05/21/2023]
Abstract
The SARS CoV-2 (COVID-19) pandemic and the enforced lockdown have reduced the use of surface and air transportation. This study investigates the impact of the lockdown restrictions in India on atmospheric composition, using Sentinel-5Ps retrievals of tropospheric NO2 concentration and ground-station measurements of NO2 and PM2.5 between March-May in 2019 and 2020. Detailed analysis of the changes to atmospheric composition are carried out over six major urban areas (i.e. Delhi, Mumbai, Kolkata, Chennai, Bangalore, and Hyderabad) by comparing Moderate Resolution Imaging Spectroradiometer (MODIS) Aerosol Optical Depth (AOD) and land surface temperature (LST) measurements in the lockdown year 2020 and pre-lockdown (2015-2019). Satellite-based data showed that NO2 concentration reduced by 18% (Kolkata), 29% (Hyderabad), 32-34% (Chennai, Mumbai, and Bangalore), and 43% (Delhi). Surface-based concentrations of NO2, PM2.5, and AOD also substantially dropped by 32-74%, 10-42%, and 8-34%, respectively over these major cities during the lockdown period and co-located with the intensity of anthropogenic activity. Only a smaller fraction of the reduction of pollutants was associated with meteorological variability. A substantial negative anomaly was found for LST both in the day (-0.16 °C to -1 °C) and night (-0.63 °C to -2.1 °C) across select all cities, which was also consistent with air temperature measurements. The decreases in LST could be associated with a reduction in pollutants, greenhouse gases and water vapor content. Improvement in air quality with lower urban temperatures due to lockdown may be a temporary effect, but it provides a crucial connection among human activities, air pollution, aerosols, radiative flux, and temperature. The lockdown for a shorter-period showed a significant improvement in environmental quality and provides a strong evidence base for larger scale policy implementation to improve air quality.
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Affiliation(s)
- Bikash Ranjan Parida
- Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India.
| | - Somnath Bar
- Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India
| | - Gareth Roberts
- Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
| | - Shyama Prasad Mandal
- Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India
| | - Arvind Chandra Pandey
- Department of Geoinformatics, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India
| | - Manoj Kumar
- Department of Environmental Sciences, School of Natural Resource Management, Central University of Jharkhand, Ranchi, 835222, India
| | - Jadunandan Dash
- Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
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17
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Xu JL, Gowen AA. Time series Fourier transform infrared spectroscopy for characterization of water vapor sorption in hydrophilic and hydrophobic polymeric films. Spectrochim Acta A Mol Biomol Spectrosc 2021; 250:119371. [PMID: 33418477 DOI: 10.1016/j.saa.2020.119371] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/18/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
This work investigates the nature of the molecular interactions between water vapor and polymers using time series Fourier transform infrared (FTIR) spectroscopy. A detailed analysis of the frequency shifts and relative peak intensities led to the conclusion that polyvinyl alcohol (PVOH) sorbed a large quantity of water vapor molecules, resulting in swelling and dissolving of polymer crystallites. Difference spectra were calculated to investigate spectral changes occurring upon sorption by dividing the spectra of polymers during the sorption time series by the spectrum of the dry sample and subsequently subtracting the water vapor spectrum. Based on the absorbance area of the OH stretching vibration region (4000-3000 cm-1) in difference spectra, the amount of water sorbed was significantly higher in poly-L-lactic acid (PLLA) and polyvinyl chloride (PVC) than in polyethylene (PE) and polytetrafluoroethylene (PTFE), increasing with the hydrophilicity of the surface. The OH stretching band of difference spectra shifted from 3499 cm-1 for PVC, to 3416 cm-1 for PE and finally to 3387 cm-1 for PTFE, indicating a more strengthened hydrogen-bonding network in the PTFE matrix upon water vapor sorption.
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Affiliation(s)
- Jun-Li Xu
- School of Biosystems and Food Engineering, University College Dublin, Belfield, Ireland
| | - Aoife A Gowen
- School of Biosystems and Food Engineering, University College Dublin, Belfield, Ireland.
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18
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Vaquero-Martínez J, Antón M, Román R, Cachorro VE, Wang H, González Abad G, Ritter C. Water vapor satellite products in the European Arctic: An inter-comparison against GNSS data. Sci Total Environ 2020; 741:140335. [PMID: 32886972 DOI: 10.1016/j.scitotenv.2020.140335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
The European Arctic is a region of high interest for climate change. Water vapor plays a fundamental role in global warming; therefore, high-quality water vapor monitoring is essential for assimilation in forecast simulations. The seven analyzed instruments on-board satellite platforms are: Atmospheric Infrared Sounder (AIRS), Global Ozone Monitoring Instrument 2 (GOME-2), Moderate-Resolution Imaging Spectroradiometer (MODIS), Ozone Monitoring Instrument (OMI), SCanning Imaging Absorption Spectrometer for Atmospheric Carthography (SCIAMACHY) and Polarization and Directionality of the Earth's Reflectances (POLDER). The GNSS data from Ny-Ålesund are matched to satellite observations of IWV in a 30-min temporal window, and 100-km radius. Then, statistics and the distribution of satellite-ground differences under different conditions are studied. The correlation coefficient (R2) with ground-based measurements is about 0.7 for all products except OMI (R2=0.5), and MODIS NIR and POLDER (R2=0.3). OMI shows high bias and variability compared to the rest of products. RMSE values are of the order of 3 mm for all satellites, except OMI (7 mm) and POLDER (5 mm). Bias (MBE) is negligible for AIRS, close to +1.6 mm for GOME-2 and MODIS IR, +0.8 mm for MODIS NIR, +5.9 mm for OMI, -2.7 mm for POLDER and -1.2 mm for SCIAMCHY. All satellite products tend to overestimate small IWV values and underestimate large IWV values. Variability also increases with IWV. An underestimation of the satellite products and an increase on the variability is generally observed for large Solar Zenith Angle (SZA) values. Under cloudy conditions, underestimation and variability are increased. Seasonal behavior is driven by the typical cloud cover (CC), SZA, and IWV values. In summer, it is typical to find conditions with large IWV, small SZA and large CC values. Therefore, in summer months satellite products are more biased (either positively or negatively) and with more variability, but in relative terms they are less biased and exhibit less variability.
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Affiliation(s)
- Javier Vaquero-Martínez
- Departamento de Física, Universidad de Extremadura, Badajoz, Spain; Instituto Universitario de Investigación del Agua, Cambio Climático y Sostenibilidad (IACYS), Universidad de Extremadura, Badajoz, Spain.
| | - Manuel Antón
- Departamento de Física, Universidad de Extremadura, Badajoz, Spain; Instituto Universitario de Investigación del Agua, Cambio Climático y Sostenibilidad (IACYS), Universidad de Extremadura, Badajoz, Spain
| | - Roberto Román
- Grupo de Óptica Atmosférica, Universidad de Valladolid, Valladolid, Spain
| | | | - Huiqun Wang
- Smithsonian Astrophysical Observatory, Cambridge, MA, United States
| | | | - Christoph Ritter
- Alfred-Wegener-Institut, Telegrafenberg A45, 14473 Potsdam, Germany; Institut für Geophysik und Meteorologie, Universität zu Köln, Pohligstr. 3, 50969 Cologne, Germany
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19
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Pyrgou A, Hadjinicolaou P, Santamouris M. Urban-rural moisture contrast: Regulator of the urban heat island and heatwaves' synergy over a mediterranean city. Environ Res 2020; 182:109102. [PMID: 31927298 DOI: 10.1016/j.envres.2019.109102] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 05/26/2019] [Revised: 12/29/2019] [Accepted: 12/29/2019] [Indexed: 06/10/2023]
Abstract
The current study observed the effect of the synergistic interaction of urban heat island (UHI) and heatwaves (HWs) which is different from the sum of their separate effects on the medium-sized town of Nicosia, Cyprus. From an analysis of hourly meteorological records of eight consecutive years (2007-2014) we defined HWs with respect to air temperature (T95-over the 95th percentile air temperatures) as well as the heat index (HI65-heat index over 65degC) and studied their effects on the local UHI phenomenon. Both heatwave types were characterized by increased air temperature, lower wind speed and increased absolute humidity. HWs defined using the heat index (HI65) occurred more frequently and persisted for a longer period of time. UHI was intensified to about 0.9-1.3 °C during daytime hours under both HW definitions which was attributed to the evaporation of dew deposited on the upper top layer of soil that suppressed higher temperatures in the rural station due to a prolonged cooling effect. Model estimates of dew formation overnight and evaporation in the morning hours are hypothesized to be the main contributing factor in keeping rural air temperatures lower, thus increasing the UHI intensity. The results emphasize the critical role of latent cooling and evapotranspiration as a mitigation factor affecting extreme local temperatures.
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Affiliation(s)
- Andri Pyrgou
- Department of Civil Aviation, Pindarou 27 Str., Nicosia, 1429, Cyprus.
| | - Panos Hadjinicolaou
- Energy, Environment and Water Research Center, The Cyprus Institute, P.O. Box 27456, Nicosia, 1645, Cyprus
| | - Mat Santamouris
- The Anita Lawrence Chair in High Performance Architecture, School of Built Environment, University of New South Wales, Sydney, 2052, Australia
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20
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Ma H, Sun M, Zhan S, Zhang Q, Zha S, Wang G, Liu K, Yi M, Cao Z. Compact dual-gas sensor for simultaneous measurement of atmospheric methane, and water vapor using a 3.38 μm antimonide-distributed feedback laser diode. Spectrochim Acta A Mol Biomol Spectrosc 2020; 226:117605. [PMID: 31605968 DOI: 10.1016/j.saa.2019.117605] [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: 02/02/2019] [Revised: 07/21/2019] [Accepted: 10/06/2019] [Indexed: 06/10/2023]
Abstract
A simple, compact sensor involving a continuous-wave 3.38 μm distributed feedback laser in combination with a novel compact dense-pattern multipass cell was demonstrated for simultaneous measurement of atmospheric methane and water vapor. The calibration-free direct absorption spectroscopy approach was adopted for data generation and processing. Allan deviation analysis indicates that minimum detection limits (1σ) of 11.0 ppb for CH4 and 100 ppm for H2O were achieved with a 1-s integration time at an optimum pressure of 50 Torr. Atmospheric environmental mixing ratios of these two gases were recorded and analyzed. This newly developed mid-infrared dual-gas sensor is very suitable for trace gas sensing in weight-limited unmanned aerial vehicle- or balloon-embedded field observations.
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Affiliation(s)
- Hongliang Ma
- School of Physics and Electrical Engineering, Anqing Normal University, Anqing, 246133, China
| | - Mingguo Sun
- Key Laboratory of Atmospheric Optics, Chinese Academy of Sciences, Hefei, 230031, China
| | - Shengbao Zhan
- School of Physics and Electrical Engineering, Anqing Normal University, Anqing, 246133, China
| | - Qilei Zhang
- School of Physics and Electrical Engineering, Anqing Normal University, Anqing, 246133, China
| | - Shenlong Zha
- School of Physics and Electrical Engineering, Anqing Normal University, Anqing, 246133, China
| | - Guishi Wang
- Key Laboratory of Atmospheric Optics, Chinese Academy of Sciences, Hefei, 230031, China
| | - Kun Liu
- Key Laboratory of Atmospheric Optics, Chinese Academy of Sciences, Hefei, 230031, China
| | - Mingfang Yi
- School of Physics and Electrical Engineering, Anqing Normal University, Anqing, 246133, China
| | - Zhensong Cao
- Key Laboratory of Atmospheric Optics, Chinese Academy of Sciences, Hefei, 230031, China.
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21
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Gimžauskaitė D, Tamošiūnas A, Tučkutė S, Snapkauskienė V, Aikas M, Uscila R. Treatment of diesel-contaminated soil using thermal water vapor arc plasma. Environ Sci Pollut Res Int 2020; 27:43-54. [PMID: 31728949 DOI: 10.1007/s11356-019-06697-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 01/31/2019] [Accepted: 10/01/2019] [Indexed: 06/10/2023]
Abstract
Soil pollution with petroleum-based fuels is a serious issue causing environmental problems. Recently, the use of plasma technologies for soil remediation has shown an interest and great potential. The remediation process can be performed in a fast timeframe without adding supplementary chemical reagents or without additional pre-treatment of the polluted soil. As a result, the use of plasma enables to obtain highly effective degradation of pollutants. Thus, in the present experimental research, diesel fuel removal from contaminated soil by utilizing thermal water vapor arc plasma was investigated. It was found that increased concentration of diesel fuel in the soil raised carbon and hydrogen concentrations in the soil. Moreover, soil surface morphology was modified by causing the formation of bigger agglomerates. It was also determined that after the plasma treatment process, soil grains became akin in size and structure to clean soil grains. A complete desorption of carbon, which came from diesel fuel to the soil, and a slight decomposition of organic carbon present in the soil were observed during the soil remediation process. Thermogravimetric analysis showed that regardless of the diesel fuel concentration in the soil, four stages of mass loss were observed: moisture loss, vaporization, and combustion of diesel fuel as well as reduction of volatiles and char in the soil. Producer gas analysis indicated that during soil remediation diesel fuel was mainly converted to synthesis gas, i.e., a mixture of H2, CO, and CO2. Moreover, the decomposition of diesel fuel and the formation of synthesis gas depended on the amount of pollutant in the soil. According to the obtained results, thermal water vapor arc plasma was able to completely remove diesel fuel from polluted soil in the form of synthesis gas with no significant influence on soil's properties.
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Affiliation(s)
- Dovilė Gimžauskaitė
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos st. 3, LT-44403, Kaunas, Lithuania.
| | - Andrius Tamošiūnas
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos st. 3, LT-44403, Kaunas, Lithuania
| | - Simona Tučkutė
- Center for Hydrogen Energy Technologies, Lithuanian Energy Institute, Breslaujos st. 3, LT-44403, Kaunas, Lithuania
| | - Vilma Snapkauskienė
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos st. 3, LT-44403, Kaunas, Lithuania
| | - Mindaugas Aikas
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos st. 3, LT-44403, Kaunas, Lithuania
| | - Rolandas Uscila
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos st. 3, LT-44403, Kaunas, Lithuania
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22
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Guo J, Li Y, Wang B, Zhu T. Carbon consumption mechanism of activated coke in the presence of water vapor. Environ Sci Pollut Res Int 2020; 27:1558-1568. [PMID: 31749012 DOI: 10.1007/s11356-019-06747-x] [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: 07/23/2019] [Accepted: 10/11/2019] [Indexed: 06/10/2023]
Abstract
To reduce chemical carbon consumption in activated coke technology used for flue gas purification, the carbon consumption mechanism of commercial activated coke in the presence of water vapor was studied. A fixed-bed reactor and a Fourier transform infrared (FTIR) spectrometer were combined to study the amount of carbon consumption. Temperature-programmed desorption (TPD) coupled with in situ diffuse reflectance infrared Fourier transform (in situ DRIFT) spectra were used to investigate functional group changes of activated coke. The sources and factors influencing carbon consumption in various adsorption atmospheres and in the N2 regeneration atmosphere were compared. Carbon consumption during the adsorption and regeneration process was mainly due to the release of C-O and C=C groups. The addition of H2O increased the formation of carbonates and carboxylic acids during the adsorption process, which decomposed during the regeneration process, thereby increasing carbon consumption. Carbon consumption was reduced during regeneration in an H2O-SO2 adsorption atmosphere, mainly because of the formation of C-S bonds, which reduced the formation of CO2. The C-N bonds generated in an H2O-NO adsorption atmosphere were decomposed during the regeneration process, thereby increasing carbon consumption. In a complex atmosphere of SO2, NO, NH3, and H2O, SO2 was absorbed by NH3, and the amount of carbon consumption was consistent with that in the NO atmosphere during the regeneration process. The total carbon consumption in various adsorption atmospheres ranged from 85.4 to 125.2 μmol/g. Compared with an anhydrous atmosphere, chemical carbon consumption increased by 6.5-14.3% in the presence of H2O. Chemical carbon consumption was reduced by decreasing the H2O concentrations, which provides a reference concept for reducing the operating cost of the activated coke process in industry.
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Affiliation(s)
- Junxiang Guo
- Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yuran Li
- Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Bin Wang
- Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Tingyu Zhu
- Beijing Engineering Research Center of Process Pollution Control, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
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23
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Zhu J, Che H, Xia X, Yu X, Wang J. Analysis of water vapor effects on aerosol properties and direct radiative forcing in China. Sci Total Environ 2019; 650:257-266. [PMID: 30199671 DOI: 10.1016/j.scitotenv.2018.09.022] [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] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 08/31/2018] [Accepted: 09/02/2018] [Indexed: 06/08/2023]
Abstract
The effects of column water vapor (CWV) on aerosol optical properties, radiative effects and classification are studied by using aerosol and CWV data from eight Aerosol Robotic Network (AERONET) sites in China: Beijing, XiangHe, Shouxian, Taihu, Hong_Kong, Zhongshan_Univ, SACOL, and Mt_WLG, which represents 5 distinct aerosol climatologies in China. Contrast in correlations between aerosol optical depth (AOD) and CWV is found. High correlation coefficient (R) ranging from 0.63-0.94 is observed at Beijing and XiangHe (North China Plain), SACOL (Northwest China) and Mt_WLG (the Tibetan Plateau). R values at stations in the Middle-East China (Shouxian and Taihu) are within 0.32-0.45. AOD shows poor correlation to CWV in Southeast China (R at Hong_Kong and Zhongshan_Univ of 0.15 and 0.27). At most sites, the asymmetry (ASYM) of fine-mode aerosol increases with CWV with R larger than ~0.4. Aerosol direct radiative forcing efficiency (ADRFE) at the bottom of the atmosphere (BOA) is affected by CWV, with R >~0.5 over the north and Middle-East China sites. The statistic results show that an increase of CWV by 0.1 cm could result in enhancements of ADREF at the BOA by about 1.1-2.8 W m-2 at all the sites except Mt_WLG. The aerosol classification shows that the mix-small aerosol type is always dominated under the high CWV air. The clusters of back-trajectories with relative humidity (RH) from Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model indicate that the air mass with high RH is often from south and east directions. The influence of CWV on aerosol properties is mainly shown in the properties of fine mode aerosol, which needs to be considered in the study of aerosol radiative forcing and climate effects.
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Affiliation(s)
- Jun Zhu
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Huizheng Che
- State Key Laboratory of Severe Weather (LASW) and Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences (CAMS), CMA, Beijing 100081, China,.
| | - Xiangao Xia
- LAGEO, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Scienes, Beijing, 100049, China.
| | - Xingna Yu
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Jinhu Wang
- Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China
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24
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Yu Y, Zhang J, Zhong H. Heterogeneous condensation of magnetized water vapor on fine SiO 2 particles. Environ Res 2019; 169:173-179. [PMID: 30458353 DOI: 10.1016/j.envres.2018.11.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 09/04/2018] [Revised: 11/05/2018] [Accepted: 11/06/2018] [Indexed: 06/09/2023]
Abstract
The emission of fine particles from coal-fired power plants is one of the major healthy and environmental concerns. The enlargement of particles seems to be a promising pretreatment technology due to the low removal efficiency of traditional dusting devices. The study of particle amplification by heterogeneous condensation of magnetized water vapor was carried out based on the growth tube. And, the major component of particles from coal combustion SiO2 was tested. The experimental results indicate that the particle growth is more favored by the magnetized water compared with non-magnetized water. And the particle growth is closely related to the magnetic field strength. Additionally, the surface tension of magnetized water is reduced and the wettability of particle surface is improved to some extent. Meanwhile, the particle concentration has stronger effect on the particle growth with magnetized water at lower level of supersaturation. Numerical calculation results demonstrate that the critical supersaturation is lower and nucleation rate is elevated when the water magnetized. This work reveals the facilitating process of particle growth by magnetized water that is the physical method of ameliorating particle surface performance.
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Affiliation(s)
- Yan Yu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, People's Republic of China
| | - Jun Zhang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, People's Republic of China.
| | - Hui Zhong
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu 210096, People's Republic of China
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25
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Chae JS, Kim G. Dispersion and removal characteristics of tritium originated from nuclear power plants in the atmosphere. J Environ Radioact 2018; 192:524-531. [PMID: 30121498 DOI: 10.1016/j.jenvrad.2018.08.007] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 07/29/2018] [Accepted: 08/08/2018] [Indexed: 06/08/2023]
Abstract
The activities of tritium in water-vapor (n = 649) and precipitation (n = 2404) samples were measured from 1998 to 2015 around the Wolsong nuclear power plant (NPP) site where four pressurized heavy water reactors and two pressurized water reactors operated. The activity concentrations of tritium in the water-vapor and precipitation samples were in the ranges of 2.2-2200 Bq/L and 0.3-1090 Bq/L, respectively. The concentrations of tritium in the water-vapor in spring were approximately 7 times higher than those in fall and winter, mainly owing to the wind directions at the power plant location. The annual geometric mean activities of tritium in the water-vapor and precipitation samples varied within 56% and 83% from the average, respectively, depending primarily on the annual discharge amount of tritium to the atmosphere. The activities of tritium in the water-vapor and precipitation samples rapidly decreased away from the power plant. Approximately 0.5-30% of tritium discharged from the NPP site was removed by precipitation to the ground within an area with a radius of 30 km from the NPP site, which linearly depended on the precipitation amount. Our results suggest that the wind direction and precipitation, in addition to the amount of discharge, are important factors that control the tritium concentrations in air near the NPP site.
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Affiliation(s)
- Jung-Seok Chae
- School of Earth and Environmental Sciences/RIO, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea; Korea Institute of Nuclear Safety, 62 Gwahak-ro, Yuseong-gu, Daejeon, 34142, South Korea
| | - Guebuem Kim
- School of Earth and Environmental Sciences/RIO, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
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26
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Miao X, Zhu J, Zhao K, Zhan H, Yue W. Determining the Humidity-Dependent Ortho-to- Para Ratio of Water Vapor at Room Temperature Using Terahertz Spectroscopy. Appl Spectrosc 2018; 72:1040-1046. [PMID: 29714077 DOI: 10.1177/0003702818772853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The origin of the water spin isomers observed under various physico-chemical conditions is of great interest, including that of H2O molecules in the gas phase. Here, terahertz time-domain spectroscopy (THz-TDS) was used to study the humidity-dependent ortho-to- para (O/P) ratio of water vapor at room temperature. The relative contents of para and ortho molecules were obtained by fitting the absorption lines of water vapor showing the relationship between the spin isomer contents and humidity. Larger O/P ratios with values of ∼3.2 were observed at lower humidity (<20%) due to the stronger attractive forces of para molecules. The concentration of the ortho isomers then began to decrease at higher humidity (>20%) due to the preferential formation of dimers and clusters at increasing concentrations. Thus, the ratio gradually decreased with increasing humidity.
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Affiliation(s)
- Xinyang Miao
- 1 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China
- 2 Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, China University of Petroleum, Beijing, China
| | - Jing Zhu
- 2 Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, China University of Petroleum, Beijing, China
| | - Kun Zhao
- 1 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China
- 2 Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, China University of Petroleum, Beijing, China
| | - Honglei Zhan
- 2 Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, China University of Petroleum, Beijing, China
| | - Wenzheng Yue
- 1 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China
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27
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Thoury-Monbrun V, Gaucel S, Rouessac V, Guillard V, Angellier-Coussy H. Assessing the potential of quartz crystal microbalance to estimate water vapor transfer in micrometric size cellulose particles. Carbohydr Polym 2018; 190:307-314. [PMID: 29628251 DOI: 10.1016/j.carbpol.2018.02.068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 02/21/2018] [Accepted: 02/22/2018] [Indexed: 11/25/2022]
Abstract
This study aims at assessing the use of a quartz crystal microbalance (QCM) coupled with an adsorption system to measure water vapor transfer properties in micrometric size cellulose particles. This apparatus allows measuring successfully water vapor sorption kinetics at successive relative humidity (RH) steps on a dispersion of individual micrometric size cellulose particles (1 μg) with a total acquisition duration of the order of one hour. Apparent diffusivity and water uptake at equilibrium were estimated at each step of RH by considering two different particle geometries in mass transfer modeling, i.e. sphere or finite cylinder, based on the results obtained from image analysis. Water vapor diffusivity values varied from 2.4 × 10-14 m2 s-1 to 4.2 × 10-12 m2 s-1 over the tested RH range (0-80%) whatever the model used. A finite cylinder or spherical geometry could be used equally for diffusivity identification for a particle size aspect ratio lower than 2.
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Affiliation(s)
- Valentin Thoury-Monbrun
- JRU IATE 1208 - CIRAD, INRA, Montpellier Supagro, University of Montpellier, 2 Place Pierre Viala, Bat 31, F-34060 Montpellier 01, France.
| | - Sébastien Gaucel
- JRU IATE 1208 - CIRAD, INRA, Montpellier Supagro, University of Montpellier, 2 Place Pierre Viala, Bat 31, F-34060 Montpellier 01, France.
| | - Vincent Rouessac
- IEM ENSCM, UM, CNRS UMR 5635, Université de Montpellier, 2 Place Eugène Bataillon, 34095 Montpellier cedex 05, France.
| | - Valérie Guillard
- JRU IATE 1208 - CIRAD, INRA, Montpellier Supagro, University of Montpellier, 2 Place Pierre Viala, Bat 31, F-34060 Montpellier 01, France.
| | - Hélène Angellier-Coussy
- JRU IATE 1208 - CIRAD, INRA, Montpellier Supagro, University of Montpellier, 2 Place Pierre Viala, Bat 31, F-34060 Montpellier 01, France.
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28
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Xing Y, Li H, Huang L, Wu H, Shen H, Chen Z. The production of formaldehyde and hydroxyacetone in methacrolein photooxidation: New insights into mechanism and effects of water vapor. J Environ Sci (China) 2018; 66:1-11. [PMID: 29628075 DOI: 10.1016/j.jes.2017.05.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 02/28/2017] [Revised: 05/19/2017] [Accepted: 05/26/2017] [Indexed: 06/08/2023]
Abstract
Methacrolein (MACR) is an abundant multifunctional carbonyl compound with high reactivity in the atmosphere. In this study, we investigated the hydroxyl radical initiated oxidation of MACR at various NO/MACR ratios (0 to 4.04) and relative humidities (<3% to 80%) using a flow tube. Meanwhile, a box model based on the Master Chemical Mechanism was performed to test our current understanding of the mechanism. In contrast to the reasonable predictions for hydroxyacetone production, the modeled yields of formaldehyde (HCHO) were twice higher than the experimental results. The discrepancy was ascribed to the existence of unconsidered non-HCHO forming channels in the chemistry of CH3C(CH2)OO, which account for approx. 50%. In addition, the production of hydroxyacetone and HCHO were affected by water vapor as well as the initial NO/MACR ratio. The yields of HCHO were higher under humid conditions than that under dry condition. The yields of hydroxyacetone were higher under humid conditions at low-NOx level, while lower at high-NOx level. The reasonable explanation for the lower hydroxyacetone yield under humid conditions at high-NOx level is that water vapor promotes the production of methacrolein nitrate in the reaction of HOCH2C(CH3)(OO)CHO with NO due to the peroxy radical-water complex formation, which was evidenced by calculational results. And the minimum equilibrium constant of this water complex formation was estimated to be 1.89×10-18cm3/molecule. These results provide new insights into the MACR oxidation mechanism and the effects of water vapor.
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Affiliation(s)
- Yanan Xing
- State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| | - Huan Li
- State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Liubin Huang
- State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Huihui Wu
- State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Hengqing Shen
- State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Zhongming Chen
- State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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29
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Lebsock MD, L’Ecuyer TS, Pincus R. An Observational View of Relationships Between Moisture Aggregation, Cloud, and Radiative Heating Profiles. Surv Geophys 2017; 38:1237-1254. [PMID: 31997842 PMCID: PMC6956940 DOI: 10.1007/s10712-017-9443-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 10/19/2017] [Indexed: 06/10/2023]
Abstract
Data from several coincident satellite sensors are analyzed to determine the dependence of cloud and precipitation characteristics of tropical regions on the variance in the water vapor field. Increased vapor variance is associated with decreased high cloud fraction and an enhancement of low-level radiative cooling in dry regions of the domain. The result is found across a range of sea surface temperatures and rain rates. This suggests the possibility of an enhanced low-level circulation feeding the moist convecting areas when vapor variance is large. These findings are consistent with idealized models of self-aggregation, in which the aggregation of convection is maintained by a combination of low-level radiative cooling in dry regions and mid-to-upper-level radiative warming in cloudy regions.
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Affiliation(s)
- Matthew D. Lebsock
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 USA
| | | | - Robert Pincus
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309 USA
- Physical Sciences Division, NOAA Earth System Research Lab, Boulder, CO 80305 USA
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30
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Tamošiūnas A, Valatkevičius P, Gimžauskaitė D, Jeguirim M, Mėčius V, Aikas M. Energy recovery from waste glycerol by utilizing thermal water vapor plasma. Environ Sci Pollut Res Int 2017; 24:10030-10040. [PMID: 27858275 DOI: 10.1007/s11356-016-8097-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 06/13/2016] [Accepted: 11/11/2016] [Indexed: 06/06/2023]
Abstract
Glycerol, considered as a waste feedstock resulting from biodiesel production, has received much attention in recent years due to its properties, which offer to recover energy. The aim of this study was to investigate the use of a thermal water vapor plasma for waste (crude) glycerol conversion to synthesis gas, or syngas (H2 + CO). In parallel of crude glycerol, a pure glycerol (99.5%) was used as a reference material in order to compare the concentrations of the formed product gas. A direct current (DC) arc plasma torch stabilized by a mixture of argon/water vapor was utilized for the effective glycerol conversion to hydrogen-rich synthesis gas. It was found that after waste glycerol treatment, the main reaction products were gases with corresponding concentrations of H2 50.7%, CO 23.53%, CO2 11.45%, and CH4 3.82%, and traces of C2H2 and C2H6, which concentrations were below 0.5%. The comparable concentrations of the formed gas products were obtained after pure glycerol conversion-H2 46.4%, CO 26.25%, CO2 11.3%, and CH4 4.7%. The use of thermal water vapor plasma producing synthesis gas is an effective method to recover energy from both crude and pure glycerol. The performance of the glycerol conversion system was defined in terms of the produced gas yield, the carbon conversion efficiency, the cold gas efficiency, and the specific energy requirements.
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Affiliation(s)
- Andrius Tamošiūnas
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos str. 3, -44403, Kaunas, LT, Lithuania.
| | - Pranas Valatkevičius
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos str. 3, -44403, Kaunas, LT, Lithuania
| | - Dovilė Gimžauskaitė
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos str. 3, -44403, Kaunas, LT, Lithuania
| | - Mejdi Jeguirim
- Université de Haute-Alsace, Institut de Sciences des Matériaux de Mulhouse, 15 rue Jean Starcky, 68057, Mulhouse cedex, France
| | - Vladas Mėčius
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos str. 3, -44403, Kaunas, LT, Lithuania
| | - Mindaugas Aikas
- Plasma Processing Laboratory, Lithuanian Energy Institute, Breslaujos str. 3, -44403, Kaunas, LT, Lithuania
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31
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Vaquero-Martínez J, Antón M, Ortiz de Galisteo JP, Cachorro VE, Wang H, González Abad G, Román R, Costa MJ. Validation of integrated water vapor from OMI satellite instrument against reference GPS data at the Iberian Peninsula. Science of The Total Environment 2017; 580:857-864. [PMID: 27988187 DOI: 10.1016/j.scitotenv.2016.12.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 12/03/2016] [Accepted: 12/04/2016] [Indexed: 06/06/2023]
Abstract
This paper shows the validation of integrated water vapor (IWV) measurements retrieved from the Ozone Monitoring Instrument (OMI), using as reference nine ground-based GPS stations in the Iberian Peninsula. The study period covers from 2007 to 2009. The influence of two factors, - solar zenith angle (SZA) and IWV -, on OMI-GPS differences was studied in detail, as well as the seasonal dependence. The pseudomedian of the relative differences is -1 ± 1% and the inter-quartile range (IQR) is 41%. Linear regressions calculated over each station show an acceptable agreement (R2 up to 0.77). The OMI-GPS differences display a clear dependence on IWV values. Hence, OMI substantially overestimates the lower IWV data recorded by GPS (∼ 40%), while underestimates the higher IWV reference values (∼ 20%). In connection to this IWV dependence, the relative differences also show an evident SZA dependence when the whole range of IWV values are analyzed (OMI overestimates for high SZA values while underestimates for low values). Finally, the seasonal variation of the OMI-GPS differences is also associated with the strong IWV dependence found in this validation exercise.
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Affiliation(s)
- Javier Vaquero-Martínez
- Departamento de Física, Universidad de Extremadura, Badajoz, Spain; Instituto Universitario de Investigación del Agua, Cambio Climático y Sostenibilidad (IACYS), Universidad de Extremadura, Badajoz, Spain.
| | - Manuel Antón
- Departamento de Física, Universidad de Extremadura, Badajoz, Spain; Instituto Universitario de Investigación del Agua, Cambio Climático y Sostenibilidad (IACYS), Universidad de Extremadura, Badajoz, Spain
| | - José Pablo Ortiz de Galisteo
- Agencia Estatal de Meteorología (AEMET), Valladolid, Spain; Grupo de Óptica Atmosférica, Universidad de Valladolid, Valladolid, Spain
| | | | - Huiqun Wang
- Smithsonian Astrophysical Observatory, Cambridge, MA, United States
| | | | - Roberto Román
- Departamento de Física Aplicada, Universidad de Granada, Granada, Spain; Andalusian Institute for Earth System Research (IISTA-CEAMA), University of Granada, Autonomous Government of Andalusia, 18006, Granada, Spain
| | - Maria João Costa
- Departamento de Física, Instituto de Ciências da Terra, Escola de Ciências e Tecnología, Universidade de Évora, Évora, Portugal
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Henriet T, Gana I, Ghaddar C, Barrio M, Cartigny Y, Yagoubi N, Do B, Tamarit JL, Rietveld IB. Solid state stability and solubility of triethylenetetramine dihydrochloride. Int J Pharm 2016; 511:312-21. [PMID: 27377012 DOI: 10.1016/j.ijpharm.2016.06.140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 11/23/2022]
Abstract
The API triethylenetetramine dihydrochloride used as an alternative treatment of Wilson's disease is sensitive to water and it exhibits polymorphism. As this may become an issue for the drug formulation, the physical stability has been studied by differential scanning calorimetry, high-pressure thermal analysis, dynamic vapor sorption, and X-ray diffraction as a function of temperature. In addition, high-pressure liquid chromatography and mass spectrometry have been used to study the purity and chemical stability of the API. A pressure-temperature phase diagram of the pure compound has been constructed and it can be concluded that form II is monotropic in relation to form I, which is the only stable solid. The solubilities of the different solid forms have been determined with the help of a temperature - composition phase diagram. The API is very soluble, at 20° C about 10% of the saturated solution with respect to the dihydrate consists of API and the solubility of the pure form I is twice as high. Moreover, it has been shown that at 20°C, a relative humidity above 40% induces the formation of the dihydrate and at 70% a saturated solution appears. At higher temperatures, the formation of the dihydrate appears at lower relative humidity values. A clear link has been established between the API's chemical stability, its physical stability and the relative humidity in the air. Humidity levels above 40% are detrimental to the quality of the API.
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Pal S. On the factors governing water vapor turbulence mixing in the convective boundary layer over land: Concept and data analysis technique using ground-based lidar measurements. Sci Total Environ 2016; 554-555:17-25. [PMID: 26950615 DOI: 10.1016/j.scitotenv.2016.02.147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 02/06/2016] [Accepted: 02/20/2016] [Indexed: 06/05/2023]
Abstract
The convective boundary layer (CBL) turbulence is the key process for exchanging heat, momentum, moisture and trace gases between the earth's surface and the lower part of the troposphere. The turbulence parameterization of the CBL is a challenging but important component in numerical models. In particular, correct estimation of CBL turbulence features, parameterization, and the determination of the contribution of eddy diffusivity are important for simulating convection initiation, and the dispersion of health hazardous air pollutants and Greenhouse gases. In general, measurements of higher-order moments of water vapor mixing ratio (q) variability yield unique estimates of turbulence in the CBL. Using the high-resolution lidar-derived profiles of q variance, third-order moment, and skewness and analyzing concurrent profiles of vertical velocity, potential temperature, horizontal wind and time series of near-surface measurements of surface flux and meteorological parameters, a conceptual framework based on bottom up approach is proposed here for the first time for a robust characterization of the turbulent structure of CBL over land so that our understanding on the processes governing CBL q turbulence could be improved. Finally, principal component analyses will be applied on the lidar-derived long-term data sets of q turbulence statistics to identify the meteorological factors and the dominant physical mechanisms governing the CBL turbulence features.
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Affiliation(s)
- Sandip Pal
- Department of Meteorology, Pennsylvania State University, PA, USA; Department of Environmental Sciences, University of Virginia, VA, USA.
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Shen Y, Yasui K, Sun Z, Mei B, You M, Zhu T. Study on the spatial distribution of the liquid temperature near a cavitation bubble wall. Ultrason Sonochem 2016; 29:394-400. [PMID: 26585020 DOI: 10.1016/j.ultsonch.2015.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 10/22/2015] [Accepted: 10/22/2015] [Indexed: 05/11/2023]
Abstract
A simple new model of the spatial distribution of the liquid temperature near a cavitation bubble wall (Tli) is employed to numerically calculate Tli. The result shows that Tli is almost same with the ambient liquid temperature (T0) during the bubble oscillations except at strong collapse. At strong collapse, Tli can increase to about 1510 K, the same order of magnitude with that of the maximum temperature inside the bubble, which means that the chemical reactions occur not only in gas-phase inside the collapsing bubble but also in liquid-phase just outside the collapsing bubble. Four factors (ultrasonic vibration amplitude, ultrasonic frequency, the surface tension and the viscosity) are considered to study their effects for the thin liquid layer. The results show that for the thin layer, the thickness and the temperature increase as the ultrasonic vibration amplitude rise; conversely, the thickness and the temperature decrease with the increase of the ultrasonic frequency, the surface tension or the viscosity.
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Affiliation(s)
- Yang Shen
- School of Mechanical Engineering and Automation, Northeastern University, 3-11, Wenhua Road, Heping District, Shenyang 110004, China
| | - Kyuichi Yasui
- National Institute of Advanced Industrial Science and Technology (AIST), 2266-98 Anagahora, Shimoshidami, Moriyama-ku, Nagoya 463-8560, Japan
| | - Zhicheng Sun
- School of Mechanical Engineering and Automation, Northeastern University, 3-11, Wenhua Road, Heping District, Shenyang 110004, China
| | - Bin Mei
- School of Mechanical Engineering and Automation, Northeastern University, 3-11, Wenhua Road, Heping District, Shenyang 110004, China
| | - Meiyan You
- School of Mechanical Engineering and Automation, Northeastern University, 3-11, Wenhua Road, Heping District, Shenyang 110004, China
| | - Tong Zhu
- School of Mechanical Engineering and Automation, Northeastern University, 3-11, Wenhua Road, Heping District, Shenyang 110004, China.
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Davis RE, McGregor GR, Enfield KB. Humidity: A review and primer on atmospheric moisture and human health. Environ Res 2016; 144:106-116. [PMID: 26599589 DOI: 10.1016/j.envres.2015.10.014] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [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: 07/03/2015] [Revised: 10/14/2015] [Accepted: 10/14/2015] [Indexed: 05/18/2023]
Abstract
Research examining associations between weather and human health frequently includes the effects of atmospheric humidity. A large number of humidity variables have been developed for numerous purposes, but little guidance is available to health researchers regarding appropriate variable selection. We examine a suite of commonly used humidity variables and summarize both the medical and biometeorological literature on associations between humidity and human health. As an example of the importance of humidity variable selection, we correlate numerous hourly humidity variables to daily respiratory syncytial virus isolates in Singapore from 1992 to 1994. Most water-vapor mass based variables (specific humidity, absolute humidity, mixing ratio, dewpoint temperature, vapor pressure) exhibit comparable correlations. Variables that include a thermal component (relative humidity, dewpoint depression, saturation vapor pressure) exhibit strong diurnality and seasonality. Humidity variable selection must be dictated by the underlying research question. Despite being the most commonly used humidity variable, relative humidity should be used sparingly and avoided in cases when the proximity to saturation is not medically relevant. Care must be taken in averaging certain humidity variables daily or seasonally to avoid statistical biasing associated with variables that are inherently diurnal through their relationship to temperature.
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Affiliation(s)
- Robert E Davis
- Department of Environmental Sciences, University of Virginia, P.O. Box 400123, 291 McCormick Road, Charlottesville, VA 22904-4123, USA.
| | - Glenn R McGregor
- Department of Geography, Durham University, Durham DH1 3LE, United Kingdom.
| | - Kyle B Enfield
- Division of Pulmonary and Critical Care, Department of Medicine, University of Virginia Health System, Charlottesville, VA 22908, USA.
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Lindberg L, Grubb D, Dencker D, Finnhult M, Olsson SG. Detection of mouth alcohol during breath alcohol analysis. Forensic Sci Int 2015; 249:66-72. [PMID: 25676715 DOI: 10.1016/j.forsciint.2015.01.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 01/02/2015] [Accepted: 01/22/2015] [Indexed: 11/24/2022]
Abstract
The presence of mouth alcohol (MA) during alcohol breath test for law enforcement is the most common cause of falsely high breath alcohol concentrations (BrAC). A fast and reliable test for detection of MA roadside at the scene of the act would facilitate the police efforts for proper prosecution. A tentative technique to use orally exhaled water vapour as a reference gas to position the origin of alcohol was validated. BrAC and water vapour concentration (WVC) were simultaneously measured as a known MA component was added to subjects with existing blood alcohol. In the absence of MA, water always precedes alcohol in a volumetric expirogram. In the presence of MA this relationship reversed. A scatterplot of WVC versus BrAC from similar fractional exhaled volumes illustrates how their relative positions change by MA. A deviation area (DA) between the scatterplot curve and a fictitious linear relationship was defined as a measurement of MA. The accuracy and cut-off level of the DA to detect MA were determined with receiver operating characteristic (ROC) curve analysis. The area under the ROC curve (AUC) was 0.95 (95% CI 0.90-1.0), indicating excellent discriminatory ability. The optimal cut-off for DA to discriminate between MA ≥0.010 mg/L (1 μg/100 ml, 0.002 g/210 L) or lack of MA was -0.35, with a sensitivity of 0.91 and specificity of 0.95. Analysis of BrAC in relation to WVC is a practical method to detect and confirm MA contamination with high reliability.
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Ayoub GM, Dahdah L, Alameddine I, Malaeb L. Vapor-induced transfer of bacteria in the absence of mechanical disturbances. J Hazard Mater 2014; 280:279-87. [PMID: 25169809 DOI: 10.1016/j.jhazmat.2014.08.003] [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] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 07/10/2014] [Accepted: 08/05/2014] [Indexed: 05/20/2023]
Abstract
Transfer of bacteria through water vapor generated at moderate temperatures (30-50°C) in passive solar stills, has scarcely been reported. The objective of this research was to investigate whether bacteria in highly humid atmospheres can get transferred through water vapor in the absence of other transfer media to find their way to the distillate. To achieve this objective, passive solar reactors were chosen as the medium for experimentation, and distillation experiments were conducted by spiking a pure bacterial culture (Escherichia coli, Klebsiella pneumonia or Enterococcus faecalis) in low mineralized water vs. highly mineralized water in the dark under moderate temperatures ranges (30-35°C, 40-45°C and 50-55°C). Results showed that bacteria indeed get transferred with the vapor in stills when not exposed to solar U.V. radiation. The trends observed were adequately explained by a zero-modified Hurdle-Poisson model. The numbers of cultivable bacterial colonies transferred were bacterial size, water type and temperature dependent with highest transfers occurring in E. faecalis>E. coli>K. pneumonia at the 40°C range in low mineralized water. Proper management strategies are recommended to achieve complete disinfection in solar stills.
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Affiliation(s)
- G M Ayoub
- Department of Civil and Environmental Engineering, American University of Beirut, Lebanon.
| | - L Dahdah
- Department of Civil and Environmental Engineering, American University of Beirut, Lebanon
| | - I Alameddine
- Department of Civil and Environmental Engineering, American University of Beirut, Lebanon
| | - L Malaeb
- Water Desalination and Reuse Research Center, KAUST, Thuwal 23955-6900, Saudi Arabia
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Alhakeem E, AlShaikh S, Rosenfeld AB, Zavgorodni S. Sci-Thur AM: Planning - 01: Experimental and Monte Carlo verification of Acuros XB calculations near low and high density heterogeneities. Med Phys 2012; 39:4619. [PMID: 28516565 DOI: 10.1118/1.4740086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 11/07/2022] Open
Abstract
The purpose of this study was to examine the accuracy of AcurosXB and AAA algorithms near low and high density heterogeneities of different densities using EBT2 film, MOSFET detector "MOSkin" and Monte Carlo calculations using BEAMnrc/DOSXYZnrc. Three different interfaces were used that included a solid water phantom with 2×2×30cm3 rectangular air gap, rectangular steel insert, and a slab of water embedded between two slabs of lung material. 6MV photon beam with field size of 10×10cm2 was used for the first two geometries and a 3×3cm2 -field was used for the third. Percentage Depth Doses were measured and calculated at the beam central axis. Calculation voxel of 0.1×0.1×0.1cm3 was used by all three algorithms. For all configurations, AcurosXB and AAA agreed to within ±1.3% with MC before the inhomogeneity. The PDD measurements using MOSkin and EBT2 in water, apart from 0.2cm layer near heterogeneity, agreed with the MC within ±2.2%. Within 0.1cm before the water-air interface AcurosXB and AAA overestimated the dose by 4.7% and 1.6%, respectively. Whereas, in the 0.1cm beyond the air-water interface, AcurosXB and AAA overestimated the dose by 2.4% and 16.2% respectively. In the 0.1cm before the water-steel interface, AcurosXB overestimated the dose by 4.7% and AAA underestimated the dose by 9.5%; beyond the steel-water interface AcurosXB and AAA overestimated the dose by 3.6% and 7.7% respectively. For the lung phantom configuration, AcurosXB and AAA were in agreement with MC within 2% throughout the phantom. These results demonstrate improved performance of AcurosXB as compared to AAA in considered conditions.
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Affiliation(s)
- E Alhakeem
- Dept. of Physics & Astronomy, University of Victoria, Victoria, BC, Canada
| | - S AlShaikh
- Centre for Medical Radiation Physics, University of Wollongong, Australia.,Ministry of Health, Riyadh, Kingdom of Saudi Arabia
| | - A B Rosenfeld
- Centre for Medical Radiation Physics, University of Wollongong, Australia
| | - S Zavgorodni
- Dept. of Physics & Astronomy, University of Victoria, Victoria, BC, Canada.,Department of Medical Physics, British Columbia Cancer Agency-Vancouver Island Center
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Gebreamlak W, Tedeschi D, Alkhatib H. SU-F-BRCD-03: Dose Calculation of Electron Therapy Using Improved Lateral Buildup Ratio Method. Med Phys 2012; 39:3856. [PMID: 28517539 DOI: 10.1118/1.4735741] [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: 11/07/2022] Open
Abstract
PURPOSE To calculate the percentage depth dose of any irregular shape electron beam using modified lateral build-up-ratio method. METHOD AND MATERIALS Percentage depth dose (PDD) curves were measured using 6, 9, 12, and 15MeV electron beam energies for applicator cone sizes of 6×6, 10×10, 14×14, and 14×14cm2 . Circular cutouts for each cone were prepared from 2.0cm diameter to the maximum possible size for each cone. In addition, three irregular cutouts were prepared. The scanning was done using a water tank and two diodes - one for the signal and the other a stationary reference outside the tank. The water surface was determined by scanning the signal diode slowly from water to air and by noting the sharp change of the percentage depth dose curve at the water/air interface. RESULTS The lateral build-up-ratio (LBR) for each circular cutout was calculated from the measured PDD curve using the open field of the 14×14 cm2 cone as the reference field. Using the LBR values and the radius of the circular cutouts, the corresponding lateral spread parameter (sigma) of the electron shower was calculated. Unlike the commonly accepted assumption that sigma is independent of cutout size, it is shown that the sigma value increases linearly with circular cutout size. Using this characteristic of sigma, the PDD curves of irregularly shaped cutouts were calculated. Finally, the calculated PDD curves were compared with measured PDD curves. CONCLUSIONS In this research, it is shown that sigma increases with cutout size. For radius of circular cutout sizes up to the equilibrium range of the electron beam, the increase of sigma with the cutout size is linear. The percentage difference of the calculated PDD from the measured PDD for irregularly shaped cutouts was under 1.0%. Similar Result was obtained for four electron beam energies (6, 9, 12, and 15MeV).
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Affiliation(s)
- W Gebreamlak
- University of South Carolina, Columbia, SC.,Richland Memorial Hospital, Columbia, SC
| | - D Tedeschi
- University of South Carolina, Columbia, SC.,Richland Memorial Hospital, Columbia, SC
| | - H Alkhatib
- University of South Carolina, Columbia, SC.,Richland Memorial Hospital, Columbia, SC
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Biltekin F, Özyigit G, Celik D, Yeginer M, Akyol F, Cengiz M, Yildiz F. SU-E-T-208: The Secondary Malignancy Risk Estimation Due to the Neutron Contamination in 3D-CRT and IMRT Treatment Techniques by Using Bubble Detectors. Med Phys 2012; 39:3751. [PMID: 28517335 DOI: 10.1118/1.4735269] [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: 11/07/2022] Open
Abstract
PURPOSE In this study, the neutron measurements were performed in free in air and RW3 solid water phantom to estimate the secondary malignancy risk for three dimensional conformal radiotherapy (3D-CRT) and intensity modulated radiotherapy (IMRT) techniques in prostate cancer treatment. METHODS Neutron dose were measured in 18 MV Elekta Synergy Platform and Varian Clinac linear accelerators by using bubble detector for personal neutron dosimetry (BD-PND). To determine the neutron equivalent dose in different depths and different distance from the edge of treatment field RW3 solid water phantom was used and organs location was defined in Alderson Rando phantom with respect to target (prostate) position in the treatment field. By using these data, we determined the neutron equivalent dose and effective dose for the standard prostate cancer patient treated with 3D-CRT and IMRT with 18 MV photon energy. The total dose was 70 Gy in 3D-CRT and 76 Gy in IMRT treatment in the current study. For both of these treatment techniques, we estimated the risk of secondary malignancies due to the neutron contamination by using the International Commission on Radiological Protection (ICRP) report 103. RESULTS The equivalent dose and effective dose due the neutron contamination were considerably high in 18 MV IMRT technique. The secondary malignancy risk estimation for 3D-CRT and IMRT were found to be 0.44% and 1.15% for Elekta Synergy Platform linear accelerator, 0.92% and 2.38% for the Varian Clinac DHX High Performance linear accelerator, respectively. CONCLUSIONS Therefore, one should take care of the secondary malignancy risk in case of using 18 MV in IMRT applications.
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Abstract
PURPOSE To determine the accuracy of the GEANT4 Monte Carlo toolkit for ionization chamber calculations in radiotherapy photon beams. METHODS First, we used the Fano cavity example included in the GEANT4 distribution to validate calculations under Fano conditions. We determined a combination of parameters and physics list that provided results consistent within +/- 0.5% with the Fano theorem. Next we performed simulations to investigate the accuracy of using GEANT4 for ionization chamber calculations. Eight ionization chambers were modeled using detailed manufacturer specifications including A1, A1SL, NE2571, PTW30010, PTW30012, PTW31010, PTW31014 and PTW31016. The absorbed dose to water for a cylindrical water cavity and the absorbed dose to air in the ionization chambers' cavities were scored for 1.25 MeV photons. The ratio of these quantities was then compared to values from EGSnrc simulations. RESULTS Simulations using the Fano cavity example yielded results within +/- 0.5% with the Fano theorem across 1.25, 3 and 4 MeV incident photon energies. The most accurate and consistent results were obtained using the G4eIonisation ionization model and G4GoudsmitSaundersonMscModel multiple scattering (MS) model with a maximum step size limitation of 0.001 mm, which yielded results accurate to +/- 0.3% for all energies. This set of parameters and physics processes as well as the G4UrbanMscModel93 MS model were used for the ionization chamber calculations. The calculated quantities were compared to those used in Muir and Rogers 2010 (Med. Phys. 37: 5939-5950) and agreed to within sub-percentage differences for most chambers. CONCLUSIONS The GEANT4 toolkit can achieve sub-percentage accuracy for ionization chamber calculations in radiotherapy photon beams. This is achieved by using either the G4GoudsmitSaundersonMscModel or G4UrbanMscModel93 MS models. Although less accurate (+/- 0.5%), simulations employing the G4UrbanMscModel93 MS model are on average two orders magnitude faster than that of the G4GoudsmitSaundersonMscModel MS model (+/- 0.3%). Natural Sciences and Engineering Research Council of Canada.
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Vijande J, Granero D, Perez-Calatayud J, Ballester F. SU-E-T-467: Monte Carlo Dosimetric Study of the New Flexisource Co-60 High Dose Rate Source. Med Phys 2012; 39:3812. [PMID: 28517443 DOI: 10.1118/1.4735556] [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: 11/07/2022] Open
Abstract
PURPOSE Recently, a new HDR 60Co brachytherapy source, Flexisource Co-60, has been developed (Nucletron B.V.). This study aims to obtain quality dosimetric data for this source for its use in clinical practice as required by AAPM and ESTRO. METHODS Penelope2008 and GEANT4 Monte Carlo codes were used to dosimetrically characterize this source. Water composition and mass density was that recommended by AAPM. Due to the high energy of the 60Co, dose for small distances cannot be approximated by collisional kerma. Therefore, we have considered absorbed dose to water for r<0.75 cm and collisional kerma from 0.75<r<20 cm. To provide adequate spatial resolution, cells were 0.01 cm in thickness for r<2 cm from the source and a factor of 10 thicker for 2<r<20 cm respectively. Angular sampling was taken every 2°. Additional simulations were performed to obtain SK as recommended by AAPM. Mass-energy absorption coefficients in water and air were consistently derived and used to calculate collisional kerma. Along-away tables and TG-43 formalism parameters and functions were derived. Dosimetric data were also provided following the primary and scatter dose separation for the collapsed cone technique. RESULTS TG-43 dosimetry parameters with L = 0.35 cm were obtained. Results performed with both radiation transport codes showed agreement typically within 0.2% for r > 0.8 cm and up to 2% closer to the source. Using Penelope2008 and GEANT4, an average of Î> = 1.085±0.003 cGy/(h U) (with k = 1, Type A uncertainties) was obtained. Dose rate constant, radial dose function and anisotropy functions for the Flexisource Co-60 are compared with published data for other Co-60 sources. CONCLUSIONS Dosimetric data are provided for the new Flexisource Co-60 source not studied previously in the literature. Using the data provided by this study in the treatment planning systems, it can be used in clinical practice. This project has been funded by Nucletron BV.
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Affiliation(s)
- J Vijande
- University of Valencia, Valencia, Spain.,ERESA-Hospital General Universitario, Valencia, Spain.,Hospital La Fe, Valencia, Spain
| | - D Granero
- University of Valencia, Valencia, Spain.,ERESA-Hospital General Universitario, Valencia, Spain.,Hospital La Fe, Valencia, Spain
| | - J Perez-Calatayud
- University of Valencia, Valencia, Spain.,ERESA-Hospital General Universitario, Valencia, Spain.,Hospital La Fe, Valencia, Spain
| | - F Ballester
- University of Valencia, Valencia, Spain.,ERESA-Hospital General Universitario, Valencia, Spain.,Hospital La Fe, Valencia, Spain
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