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Characteristics of fine dust pollution PM₂.₅ in Hanoi in 2021 2021 年河内微尘污染 PM₂.₅ 的特征

Nuclear Science and Technology Pub Date : 2024-06-03 DOI: 10.53747/nst.v13i4.450

Thu Bac Vuong, Lan Anh Ha, Dinh Kien Mai, Huyen Trang Nguyen

{"title":"Characteristics of fine dust pollution PM₂.₅ in Hanoi in 2021","authors":"Thu Bac Vuong, Lan Anh Ha, Dinh Kien Mai, Huyen Trang Nguyen","doi":"10.53747/nst.v13i4.450","DOIUrl":"https://doi.org/10.53747/nst.v13i4.450","url":null,"abstract":"Fine particulate matter (PM2.5) is one of the most dangerous pollutions in the atmosphere in the Hanoi capital. PM2.5 fine dust pollution characteristics in Hanoi in the duration from 5/2021 to 3/2022 have been studied. The concentration of main chemical elements (such as As, Br, Ca, Cd, Ce, Cl, Cu, Fe, K, Mn, Pb, S, Sr, Ti, Zn, Zr…), main water-soluble ions (such as Na+, NH4+, K+, Mg2+, Ca2+, SO42-, Cl-, NO3-, F-, NO2-) and black carbon (BC) in the PM2.5 sample have been analyzed. The average PM2.5 fine dust concentration was (78.09 ± 51.71) µg/m3 and ranged from 17.55 to 271.39 µg/m3. PM2.5 tends to increase and is about 3.12 times larger than Who Air Quality Guidelines 2005 (25 µg/m3 for PM2.5 24h). The average PM2.5 concentration in the rainy season from 5/2021 to 9/2021 was (51.97 ± 16.40) µg/m3. This value for the dry season from 10/2021 to 3/2022 was (104.70 ± 61.19) µg/m3. It is much higher than that in the rainy season about 2.01 times. The major contributors were the secondary components such as NH4+, SO42-, NO3- and BC... The main pollution contribution sources and the potential pollution areas map have been identified. This research shows a worrying picture of fine dust PM2.5 in Hanoi in the studying duration.","PeriodicalId":19445,"journal":{"name":"Nuclear Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141268648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of chemical pre-treatment methods combined with electron beam irradiation on the quality of “Edor” longan 化学预处理方法与电子束辐照相结合对 "Edor "龙眼质量的影响

Nuclear Science and Technology Pub Date : 2024-06-03 DOI: 10.53747/nst.v13i4.409

Khanh Chu, T. Nguyen, V. Cao, Thi Thu Hong Pham, Binh Doan, Hoa Truc Tran, Tran Diem Ha Nguyen

{"title":"Effects of chemical pre-treatment methods combined with electron beam irradiation on the quality of “Edor” longan","authors":"Khanh Chu, T. Nguyen, V. Cao, Thi Thu Hong Pham, Binh Doan, Hoa Truc Tran, Tran Diem Ha Nguyen","doi":"10.53747/nst.v13i4.409","DOIUrl":"https://doi.org/10.53747/nst.v13i4.409","url":null,"abstract":"Using electron beam (EB) radiation as a quarantine treatment when exporting fresh fruit is a development trend in the world. In this study, the effect of EB irradiation treatment in the quarantine dose (400 to 1000 Gy) on the quality of export \"Edor\" longan was investigated. Investigation of chemical pre - treatments measure combined with EB irradiation to decrease pericarp browning of longan has also been carried out. “Edor” longan were treated by SO2 fumigation or dipping in 1,5 N HCl solution for 20 min after EB irradiation at low quarantine dose (400 Gy). Untreated and non-irradiated fruits were used as control. That all were then stored assumed commercial conditions (25-26°C). The results showed that the treated samples delayed a decrease in the total phenolic content and had lower pericarp browning than control. In addition, the treated samples were no significantly difference in terms of weight loss, TSS, total acid content, vitamin C, ... compared with the control. In particular, the treated samples had delayed the degree of damage level due to rotting when extending shelf life up to 22 days compared the control (12 days). Therefore, the method of combining SO2 fumigation treatment with EB irradiation (400 Gy) can be used for quarantine treatment of export \"Edor\" longan; and treatment with 1,5 N HCl solution can be considered to replace the traditional SO2 fumigation method.","PeriodicalId":19445,"journal":{"name":"Nuclear Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141271193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The characteristics of the vertical distribution of radionuclide in free troposphere from simplified release scenarios: a case study 从简化释放情景看自由对流层中放射性核素的垂直分布特征：案例研究

Nuclear Science and Technology Pub Date : 2024-05-04 DOI: 10.53747/nst.v13i3.436

Xiangming Sun, K. Chung, Qiudan Dai

{"title":"The characteristics of the vertical distribution of radionuclide in free troposphere from simplified release scenarios: a case study","authors":"Xiangming Sun, K. Chung, Qiudan Dai","doi":"10.53747/nst.v13i3.436","DOIUrl":"https://doi.org/10.53747/nst.v13i3.436","url":null,"abstract":"Dose estimation in the upper air is not studied as much as on ground level or in boundary layer. However, there is a need from stakeholders in aviation industry for a reasonable estimation of the radioactive plume impact at cruising levels. This study aims to provide a quantitative estimation of the dose and how reliable it is for dispersion processes up to seven days. A Lagrangian atmospheric dispersion model is used to estimate quantitively the vertical extension of radionuclides from simplified hypothetical radionuclide release scenarios. Sources at different latitudes are selected for simulation in a boreal winter case. Three meteorological data are examined to test the sensitivity of vertical plume distribution to driving meteorological data. The vertical distribution of air concentration of radionuclides is investigated and the associated uncertainties are analysed. It is found that the vertical extension of plumes is sensitive to meteorological data being used where vertical turbulent velocities play an important role. It is therefore necessary to address the uncertainties of air concentration or dose in the free troposphere and caution must be taken when providing the results to stakeholders.","PeriodicalId":19445,"journal":{"name":"Nuclear Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141013942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cross-section induced uncertainties in neutron source mission rate calculations 中子源任务率计算中截面引起的不确定性

Nuclear Science and Technology Pub Date : 2024-05-04 DOI: 10.53747/nst.v13i3.426

J. Lűley, B. Vrban, Š. Čerba, Vendula Filová, V. Necas, Matej Krivošík, P. Blahušiak, A. Javorník, J. Slučiak

{"title":"Cross-section induced uncertainties in neutron source mission rate calculations","authors":"J. Lűley, B. Vrban, Š. Čerba, Vendula Filová, V. Necas, Matej Krivošík, P. Blahušiak, A. Javorník, J. Slučiak","doi":"10.53747/nst.v13i3.426","DOIUrl":"https://doi.org/10.53747/nst.v13i3.426","url":null,"abstract":"Analysis presented in the paper is focused on the characterization of uncertainties induced by cross-section data, which contributing to the overall uncertainty of the correction factors. Advances in computational methods and computational power shifted the calculation of correction factors among the standard steps of the manganese bath method what decrease an interest about this part of the method. Anyway, with the development of computational tools, the cross-section data were also improved, and new evaluations of nuclear data libraries include more information about the cross-section data covariances. Therefore, the propagation of uncertainties induced by neutron cross-sections can be carried out within standard transport calculation of the manganese sulphate bath model. In this paper, the super-sequence SAMPLER module that implements stochastic techniques is used to assess the uncertainty in computed results. Reaction rates on all nuclides of the solution are computed in 400 cases with uncertain parameters and the results are evaluated by an auxiliary tool. Consideration of nuclear data uncertainty in calculations is a general trend that requires the attention of nuclear researchers and should draw attention in metrology. Additional 1.5 % (one-sigma) uncertainty is introduced to the overall uncertainty through correction factor.","PeriodicalId":19445,"journal":{"name":"Nuclear Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141013188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An approach to assess the consequence of a hypothetical radionuclide release in Singapore - a densely populated urban setting 在新加坡这个人口稠密的城市环境中评估假设放射性核素释放后果的方法

Nuclear Science and Technology Pub Date : 2024-05-04 DOI: 10.53747/nst.v13i3.431

Siao Yang Chai, Xiangming Sun

引用次数: 0

Use of di-(2-ethylhexyl)-orthophosphoric acid for the extraction of lanthanum, neodymium, samarium and yttrium from nitric acid solutions 用二（2-乙基己基）正磷酸从硝酸溶液中萃取镧、钕、钐和钇

Nuclear Science and Technology Pub Date : 2024-05-04 DOI: 10.53747/nst.v13i3.444

Vladimir Alexandrovich Karelin, Bach Thuan Kieu, Hai Son Le, N. V. Karelina

{"title":"Use of di-(2-ethylhexyl)-orthophosphoric acid for the extraction of lanthanum, neodymium, samarium and yttrium from nitric acid solutions","authors":"Vladimir Alexandrovich Karelin, Bach Thuan Kieu, Hai Son Le, N. V. Karelina","doi":"10.53747/nst.v13i3.444","DOIUrl":"https://doi.org/10.53747/nst.v13i3.444","url":null,"abstract":"The process of separating rare-earth elements into individual components is considered the most important problem in rare-earth technology because of the similarity in their physical and chemical properties. Currently in the world dialkyl phosphate compounds are widely used as effective extractors for rare earths. However, most extraction processes have been studied from hydrochloric acid or perchlorate solutions. In Russia, tributyl phosphate has long been used to extract rare earths from nitric acid solutions, but the distribution coefficients of the elements are not high, and the process must be repeated multiple times. In this study di-(2-ethylhexyl)-orthophosphoric acid was used for the extraction of lanthanum, neodymium, samarium, and yttrium from nitric acid solutions. When the concentration of nitric acid increased, distribution coefficient of elements gradually decreased to minimum (in the range of 1 to 5M) then increased backward. However, when the concentration was too high (C > 5M), nitric acid was extracted to the organic phase due to the properties of the phosphoryl group. Moreover, the study of dependence of solvation number of neodymium on the concentrations of nitric acid shows that rare earths in the organic phase can be extracted as Re(HA2)3 (C < 1M) or Re(NO3)3«3HA (C > 5M).","PeriodicalId":19445,"journal":{"name":"Nuclear Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141014398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simulation of gamma spectra from soil samples by using MCNP: A case study 利用 MCNP 模拟土壤样本的伽马能谱：案例研究

Nuclear Science and Technology Pub Date : 2024-05-04 DOI: 10.53747/nst.v13i3.416

An Trung Nguyen, Hao Quang Nguyen, Thi Thu Ha Nguyen, D. Duong

{"title":"Simulation of gamma spectra from soil samples by using MCNP: A case study","authors":"An Trung Nguyen, Hao Quang Nguyen, Thi Thu Ha Nguyen, D. Duong","doi":"10.53747/nst.v13i3.416","DOIUrl":"https://doi.org/10.53747/nst.v13i3.416","url":null,"abstract":"A comparison between the MCNP simulated gamma spectrums based on the nuclear data from NuDat with the current version 3.0 and Nucléide-Lara against measured spectra based on the IAEA reference samples has been performed to assess the influence of nuclear data of photon decay processes and cross-section of photon interactions on the quality of the simulated spectra. As the results, the appearance of some abnormal energy peaks; namely 215 keV, 571 keV, 675 keV, 1227 keV of the NuDat-based simulated spectra and 90 keV, 94 keV, 106 keV, 416 keV of the Nucléide-Lara-based simulated spectra, which were present in neither the measured spectrum nor remaining simulated spectra, indicating issues with accuracy and completeness of these dataset. In addition, the good correlation between the combined dataset-based simulated spectra and reference samples-based measured spectra within the range of 50 keV to 2620 keV suggests that this MCNP simulation configuration can be used to generate a large simulated dataset for Machine Learning (ML) models that automatically identify and qualify radioactive isotope from gamma-ray spectra, overcoming the practical limitation of number of reference samples to sufficiently generate data for training and testing ML algorithms in the field of environmental radiation [1].","PeriodicalId":19445,"journal":{"name":"Nuclear Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141012908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Assessing effective half-life of I-131 in 39 thyroid cancer patients at Dong Nai General Hospital 评估东奈综合医院 39 名甲状腺癌患者体内 I-131 的有效半衰期

Nuclear Science and Technology Pub Date : 2024-05-04 DOI: 10.53747/nst.v13i3.427

Tan Duoc Nguyen, Ha Phuong Do, Pham Ngoc Trinh Tran

引用次数: 0

Nuclide identification algorithm for Polyvinyl Toluene scintillation detector based on Deep Neural Network 基于深度神经网络的聚乙烯醇闪烁探测器核素识别算法

Nuclear Science and Technology Pub Date : 2024-02-20 DOI: 10.53747/nst.v12i4.347

Hiep Cao, Tien Hung Dinh, Kim Chien Dinh, Thi Thoa Nguyen, D. Pham, X. H. Nguyen

引用次数: 0

Thermal Simulation of Burned Nuclear Fuel Elements 燃烧核燃料元件的热模拟

Nuclear Science and Technology Pub Date : 2024-02-20 DOI: 10.53747/nst.v13i1.404

Tuan Anh Nguyen

引用次数: 0