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Numerical simulations for radon migration and exhalation behavior during measuring radon exhalation rate with closed-loop method
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作者 Ming Xia Yong-Jun Ye Shu-Yuan Liu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第1期81-95,共15页
Accurate measurements of the radon exhalation rate help identify and evaluate radon risk regions in the environment.Among these measurement methods,the closed-loop method is frequently used.However,traditional experim... Accurate measurements of the radon exhalation rate help identify and evaluate radon risk regions in the environment.Among these measurement methods,the closed-loop method is frequently used.However,traditional experiments are insufficient or cannot analyze the radon migration and exhalation patterns at the gas–solid interface in the accumulation chamber.The CFD-based technique was applied to predict the radon concentration distribution in a limited space,allowing radon accumulation and exhalation inside the chamber intuitively and visually.In this study,three radon exhalation rates were defined,and two structural ventilation tubes were designed for the chamber.The consistency of the simulated results with the variation in the radon exhalation rate in a previous experiment or analytical solution was verified.The effects of the vent tube structure and flow rate on the radon uniformity in the chamber;permeability,insertion depth,and flow rate on the radon exhalation rate and the effective diffusion coefficient on back-diffusion were investigated.Based on the results,increasing the inser-tion depth from 1 to 5 cm decreased the effective decay constant by 19.55%,whereas the curve-fitted radon exhalation rate decreased(lower than the initial value)as the deviation from the initial value increased by approximately 7%.Increasing the effective diffusion coefficient from 2.77×10^(-7) to 7.77×10^(-6) m^(2) s^(-1) made the deviation expand from 2.14 to 15.96%.The conclusion is that an increased insertion depth helps reduce leakage in the chamber,subject to notable back-diffusion,and that the closed-loop method is reasonably used for porous media with a low effective diffusion coefficient in view of the back-diffusion effect.The CFD-based simulation is expected to provide guidance for the optimization of the radon exhalation rate measurement method and,thus,the accurate measurement of the radon exhalation rate. 展开更多
关键词 Radon exhalation Numerical simulation Accumulation chamber
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Reference device for calibration of radon exhalation rate measuring instruments and its performance
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作者 Wei-Gang Li De-Tao Xiao +2 位作者 Zheng-Zhong He Xiang-Yuan Deng Shou-Kang Qiu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第8期131-141,共11页
Environmental radon emanates from the exhalation and release of soil,rocks,and building materials.Environmental radon contamination tracing and radon pollution prevention and control require the measurement of the rad... Environmental radon emanates from the exhalation and release of soil,rocks,and building materials.Environmental radon contamination tracing and radon pollution prevention and control require the measurement of the radon exhalation rate on media surfaces.Reliable measurements of the radon exhalation rate cannot be achieved without regular calibration of the measuring instrument with a high-performance reference device.In this study,a reference device for the calibration of radon exhalation rate measuring instruments was developed using a diffusion solid radon source with a high and stable radon emanation coefficient,an integrated diffusion component composed of a plasterboard and a high-density wooden board,an air pressure balance device,a radon accumulation chamber,and a support structure.The uniformity and stability of the reference device were evaluated using the activated carbon-γspectrum and open-loop method,respectively,to measure the radon exhalation rate.The reference device achieved different radon exhalation rates by using different activities of diffusion solid radon sources.Nineteen measurement points were regularly selected on the radon exhalation surface of the reference device,and the uniformity of the radon exhalation rate exceeded 5%.The short-term stability of the reference device was better than 5%under different environmental conditions and was almost unaffected by the ambient air pressure,environmental temperature,and relative humidity. 展开更多
关键词 Radon exhalation rate Stability UNIFORMITY High-density wooden board PLASTERBOARD
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Radon Concentration in Soil and Radon Exhalation Rate at Al-Dora Refinery and Surrounding Area in Baghdad 被引量:1
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作者 Nada F. Tawfiq Jaafar Jaleel 《Detection》 2015年第4期37-44,共8页
Radongas concentrations in soil samples were determined from depths (surface, 15, and 30) cm for nine locations in Al-Dora refinery and surrounding area using “sealed can technique” and CR-39 solid state nuclear tra... Radongas concentrations in soil samples were determined from depths (surface, 15, and 30) cm for nine locations in Al-Dora refinery and surrounding area using “sealed can technique” and CR-39 solid state nuclear track detectors. The radon concentration in surface samples ranged from 810.08 to 1380.08 Bq/m3 with an average 1137.71 Bq/m3. The radon concentration in soil at the depth 15 cm was ranged from 490.5 to 1197.52 Bq/m3 with an average 732.78 Bq/m3 and at the depth 30 cm was ranged from 362.07 to 889.53 Bq/m3 with an average 529.41 Bq/m3. The surface exhalation rate in surface soil samples ranged was 0.44, to 0.99 Bq·m-2·h-1 with average 0.61 Bq·m-2·h-1. The surface exhalation rate in soil samples at the depth 15 cm was ranged from 0.22 to 0.64 Bq·m-2·h-1 with average 0.39 Bq·m-2·h-1. The surface exhalation rate in soil samples at the depth 15 cm was ranged from 0.22 to 0.64 Bq·m-2·h-1 with average 0.39 Bq·m-2·h-1. The surface exhalation rate and the mass exhalation rate in soil samples at the depth 30 cm ranged from 0.19, to 0.48 Bq·m-2·h-1 with average 0.28 Bq·m-2·h-1. The mass exhalation rate in surface soil samples ranged from 0.09 to 0.21 Bq·kg-1·h-1 with average 0.12 Bq·kg-1·h-1. The mass exhalation rate in soil samples from depth 15 cm was ranged from 0.046 to 0.14 Bq·kg-1·h-1 with average 0.08 Bq·kg-1·h-1. The mass exhalation rate in soil samples at the depth 30 cm was ranged from 0.042 to 0.1 Bq·kg-1·h-1 with average 0.06 Bq·kg-1·h-1. 展开更多
关键词 RADON Concentration SOIL Sample CR-39 Track Detector RADON exhalation Rate
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Measurement of Natural Radioactivity and Radon Exhalation Rate in Coal Ash Samples from a Thermal Power Plant 被引量:1
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作者 Aziz Boukhair Laila Belahbib +3 位作者 Khadija Azkour Hamid Nebdi Mohammed Benjelloun Abdelmjid Nourreddine 《World Journal of Nuclear Science and Technology》 2016年第3期153-160,共8页
Coal is the main energy source for electricity generation in the world. In Morocco, 37% of electricity generation comes from combustion coal in thermal power plants. This combustion process generates large amounts of ... Coal is the main energy source for electricity generation in the world. In Morocco, 37% of electricity generation comes from combustion coal in thermal power plants. This combustion process generates large amounts of fly and bottom ashes. In recent years, these ashes became a great topic of interest because of their different uses and especially in construction materials. In this work, we assess radiation risks due to natural radioactivity in samples of fly and bottom ashes collected from JLEC (Jorf Lasfar Energy Company) thermal power plant, and different analyses are performed through two nuclear techniques such as gamma spectrometry and alpha dosimetry based on the use of LR115 films detectors. Our analysis shows that <sup>226</sup>Ra activities and <sup>232</sup>Th in both ash samples are well above the permissible activity. The values of the external risk index (H<sub>ex</sub>) and internal one (H<sub>in</sub>) for these ashes are below unity, with the exception of 1.28 in fly ash for H<sub>in</sub>. The obtained values for the equivalent radium Ra<sub>eq</sub> and annual effective doses &#278;in fly and bottom ashes are 324 Bq/kg and 210 Bq/kg, and 0.18 mSv/y and 0.11 mSv/y, respectively. The surface radon exhalation rates for the samples of fly and bottom ashes are 276 mBq&sdot;m<sup>-2</sup>&sdot;h<sup>-1</sup> and 381 mBq&sdot;m<sup>-2</sup>&sdot;h<sup>-1</sup>, respectively. Based on these results, we have shown that fly ash and bottom one from thermal power plant JLEC didn’t have, in any case, a health risk to the public so it can be effectively used in various construction activities. 展开更多
关键词 Natural Radioactivity Gamma Spectrometry LR115 Fly Ash Bottom Ash Equivalent Radium Annual Effective Doses exhalation of Radon
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IN—SITU MEASUREMENTS OF RADON EXHALATION RATE FROM BUILDING SURFACE IN HONG KONG
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作者 余君岳 关祖杰 +1 位作者 杨健明 M.J.Stokes 《Nuclear Science and Techniques》 SCIE CAS CSCD 1993年第3期176-180,共5页
EPA-standardized activated charcoal canisters were used to collect radon exhaled from building surfaces and analyzed using γ-spectroscopy to obtain the radon exhalation rates. More than 120 samples were analyzed in m... EPA-standardized activated charcoal canisters were used to collect radon exhaled from building surfaces and analyzed using γ-spectroscopy to obtain the radon exhalation rates. More than 120 samples were analyzed in more than 10 buildings situated in different areas of Hong Kong. Variations were identified in the exhalation rates at different levels in a building, for different covering materials and for the presence of cracks in walls. The radon exhalation rate from the most common concrete walls and covering materials was found to be approximately 13 mBq·m<sup>-2</sup>·s<sup>-1</sup>. This may be the cause of a relatively high indoor radon concentration in Hong Kong. 展开更多
关键词 Charcoal canisters RADON exhalation rate BUILDING SURFACES BUILDING materials
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Assay of some volatile compounds in human exhalation
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作者 Qin Tao Xu Xiao-bai +1 位作者 Pacakova Vera Stulik Karel 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1998年第1期39-44,共6页
AsayofsomevolatilecompoundsinhumanexhalationQinTao,XuXiaobaiResearchCenterforEcoEnvironmentalSciences,Chines... AsayofsomevolatilecompoundsinhumanexhalationQinTao,XuXiaobaiResearchCenterforEcoEnvironmentalSciences,ChineseAcademyofScie... 展开更多
关键词 trapping column low molecular weight compounds human exhalation.
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Breath-by-breath measurement of exhaled ammonia by acetonemodifier positive photoionization ion mobility spectrometry via online dilution and purging sampling
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作者 Lu Wang Dandan Jiang +7 位作者 Lei Hua Chuang Chen Dongming Li Weiguo Wang Yiqian Xu Qimu Yang Haiyang Li Song Leng 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2023年第4期412-420,共9页
Exhaled ammonia(NH_(3))is an essential noninvasive biomarker for disease diagnosis.In this study,an acetone-modifier positive photoionization ion mobility spectrometry(AM-PIMS)method was developed for accurate qualita... Exhaled ammonia(NH_(3))is an essential noninvasive biomarker for disease diagnosis.In this study,an acetone-modifier positive photoionization ion mobility spectrometry(AM-PIMS)method was developed for accurate qualitative and quantitative analysis of exhaled NH_(3)with high selectivity and sensitivity.Acetone was introduced into the drift tube along with the drift gas as a modifier,and the characteristic NH_(3)product ion peak of(C_(3)H_(6)O)_(4)NH_(4)^(+)(K_(0)=1.45 cm^(2)/V·s)was obtained through the ion-molecule reaction with acetone reactant ions(C_(3)H_(6)O)_(2)H^(+)(K_(0)=1.87 cm^(2)/V·s),which significantly increased the peak-to-peak resolution and improved the accuracy of exhaled NH_(3)qualitative identification.Moreover,the interference of high humidity and the memory effect of NH_(3)molecules were significantly reduced via online dilution and purging sampling,thus realizing breath-by-breath measurement.As a result,a wide quantitative range of 5.87-140.92μmol/L with a response time of 40 ms was achieved,and the exhaled NH_(3)profile could be synchronized with the concentration curve of exhaled CO_(2).Finally,the analytical capacity of AM-PIMS was demonstrated by measuring the exhaled NH_(3)of healthy subjects,demonstrating its great potential for clinical disease diagnosis. 展开更多
关键词 Photoionization ion mobility spectrometry Acetone modifier Exhaled ammonia Breath analysis
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Diagnostic role of fractional exhaled nitric oxide in pediatric eosinophilic esophagitis, relationship with gastric and duodenal eosinophils
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作者 Panamdeep Kaur Rachel Chevalier +3 位作者 Craig Friesen Jamie Ryan Ashley Sherman Stephanie Page 《World Journal of Gastrointestinal Endoscopy》 2023年第5期407-419,共13页
BACKGROUND Eosinophilic esophagitis(EoE)is an eosinophilic-predominant inflammation of the esophagus diagnosed by upper endoscopy and biopsies.A non-invasive and cost-effective alternative for management of EoE is bei... BACKGROUND Eosinophilic esophagitis(EoE)is an eosinophilic-predominant inflammation of the esophagus diagnosed by upper endoscopy and biopsies.A non-invasive and cost-effective alternative for management of EoE is being researched.Previous studies assessing utility of fractional exhaled nitric oxide(FeNO)in EoE were low powered.None investigated the contribution of eosinophilic inflammation of the stomach and duodenum to FeNO.AIM To assess the utility of FeNO as a non-invasive biomarker of esophageal eosinophilic inflammation for monitoring disease activity.METHODS Patients aged 6-21 years undergoing scheduled upper endoscopy with biopsy for suspected EoE were recruited in our observational study.Patients on steroids and with persistent asthma requiring daily controller medication were excluded.FeNO measurements were obtained in duplicate using a chemiluminescence nitric oxide analyzer(NIOX MINO,Aerocrine,Inc.;Stockholm,Sweden)prior to endoscopy.Based on the esophageal peak eosinophil count(PEC)/high power field on biopsy,patients were classified as EoE(PEC≥15)or control(PEC≤14).Mean FeNO levels were correlated with presence or absence of EoE,eosinophil counts on esophageal biopsy,and abnormal downstream eosinophilia in the stomach(PEC≥10)and duodenum(PEC≥20).Wilcoxon rank-sum test,Spearman correlation,and logistic regression were used for analysis.P value<0.05 was considered significant.RESULTS We recruited a total of 134 patients,of which 45 were diagnosed with EoE by histopathology.The median interquartile range FeNO level was 17 parts per billion(11-37,range:7-81)in the EoE group and 12 parts per billion(8-19,range:5-71)in the control group.After adjusting for atopic diseases,EoE patients had significantly higher FeNO levels as compared to patients without EoE(Z=3.33,P<0.001).A weak yet statistically significant positive association was found between the number of esophageal eosinophils and FeNO levels(r=0.30,P<0.005).On subgroup analysis within the EoE cohort,higher FeNO levels were noted in patients with abnormal gastric(n=23,18 vs 15)and duodenal eosinophilia(n=28,21 vs 14);however,the difference was not statistically significant.CONCLUSION After ruling out atopy as possible confounder,we found significantly higher FeNO levels in the EoE cohort than in the control group. 展开更多
关键词 Nitric oxide Fractional exhaled nitric oxide Eosinophilic esophagitis ESOPHAGUS PEDIATRIC GASTROENTEROLOGY
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The IOMT-Based Risk-Free Approach to Lung Disorders Detection from Exhaled Breath Examination
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作者 Mohsin Ghani Ghulam Gilanie 《Intelligent Automation & Soft Computing》 SCIE 2023年第6期2835-2847,共13页
The lungs are the main fundamental part of the human respiratory system and are among the major organs of the human body.Lung disorders,including Coronavirus(Covid-19),are among the world’s deadliest and most life-th... The lungs are the main fundamental part of the human respiratory system and are among the major organs of the human body.Lung disorders,including Coronavirus(Covid-19),are among the world’s deadliest and most life-threatening diseases.Early and social distance-based detection and treatment can save lives as well as protect the rest of humanity.Even though X-rays or Computed Tomography(CT)scans are the imaging techniques to analyze lung-related disorders,medical practitioners still find it challenging to analyze and identify lung cancer from scanned images.unless COVID-19 reaches the lungs,it is unable to be diagnosed.through these modalities.So,the Internet of Medical Things(IoMT)and machine learning-based computer-assisted approaches have been developed and applied to automate these diagnostic procedures.This study also aims at investigating an automated approach for the detection of COVID-19 and lung disorders other than COVID-19 infection in a non-invasive manner at their early stages through the analysis of human breath.Human breath contains several volatile organic compounds,i.e.,water vapor(5.0%–6.3%),nitrogen(79%),oxygen(13.6%–16.0%),carbon dioxide(4.0%–5.3%),argon(1%),hydro-gen(1 ppm)(parts per million),carbon monoxide(1%),proteins(1%),isoprene(1%),acetone(1%),and ammonia(1%).Beyond these limits,the presence of a certain volatile organic compound(VOC)may indicate a disease.The proposed research not only aims to increase the accuracy of lung disorder detection from breath analysis but also to deploy the model in a real-time environment as a home appliance.Different sensors detect VOC;microcontrollers and machine learning models have been used to detect these lung disorders.Overall,the suggested methodology is accurate,efficient,and non-invasive.The proposed method obtained an accuracy of 93.59%,a sensitivity of 89.59%,a specificity of 94.87%,and an AUC-Value of 0.96. 展开更多
关键词 Lung disorders detection risk-free covid-19 detection exhaled breath examination
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呼出气一氧化氮测定在老年哮喘诊治中的应用研究 被引量:4
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作者 张树荣 胡剑超 +4 位作者 袁丽 崔盼盼 郭守福 李小梅 杨清霞 《西南国防医药》 CAS 2014年第6期594-596,共3页
目的:探讨呼出气一氧化氮( FeNO)测定在老年哮喘诊治中的应用价值。方法对我院在2013年3月-2014年2月收治的38例老年支气管哮喘患者进行FeNO检测,并与同期收治的38例非呼吸系统疾病老年患者进行比较。结果治疗前哮喘组FeNO[(59.2&#... 目的:探讨呼出气一氧化氮( FeNO)测定在老年哮喘诊治中的应用价值。方法对我院在2013年3月-2014年2月收治的38例老年支气管哮喘患者进行FeNO检测,并与同期收治的38例非呼吸系统疾病老年患者进行比较。结果治疗前哮喘组FeNO[(59.2±16.8)ppb]显著高于对照组[(18.6±6.1)ppb](P﹤0.01);哮喘组FeNO在治疗3 d后[(51.5±13.7)ppb]和出院时[(36.1±9.4)ppb],均较治疗前明显下降( P﹤0.05或P﹤0.01),但仍显著高于对照组( P﹤0.01)。对16例哮喘患者在出院3个月后进行随访,其FeNO为(27.3±8.2)ppb,较出院时明显下降( P﹤0.01),但也仍高于对照组( P﹤0.01)。结论 FeNO在老年哮喘患者中明显增高,FeNO检测对老年哮喘的诊治有很好的指导作用。 展开更多
关键词 支气管哮喘 呼出气一氧化氮 老年 诊断 治疗 FRACTIONAL exhaled NITRIC oxide( FeNO)
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Radiological characterization of building materials used in Malaysia and assessment of external and internal doses 被引量:1
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作者 Shittu Abdullahi Aznan Fazli Ismail Supian Samat 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第3期82-96,共15页
In this study, the activity concentrations of ^(226)Ra,^(232)Th,^(222)Rn, and ^(40)K, emanation fractions(P),equilibrium equivalent concentration(EEC), and mass exhalation rates(E_m) of radon released from building ma... In this study, the activity concentrations of ^(226)Ra,^(232)Th,^(222)Rn, and ^(40)K, emanation fractions(P),equilibrium equivalent concentration(EEC), and mass exhalation rates(E_m) of radon released from building materials used in Malaysia were studied using gamma-ray spectrometer with HPGe detector. Radiological parameters[activity concentration index(ACI), indoor air-absorbed dose rate(D_(in)), annual effective dose(AED_(in)) from external and internal(E_(Rn)), soft tissues(H_(ST)) and lung(H_L), and effective dose equivalent(H_(eff))] were estimated to evaluate radiological hazards due to the use of these building materials: sand, cement, gravel, bricks, tiles, fly ash, white cement, and ceramic raw materials. The measured P, EEC,and E_m vary from 10 to 30%, 0.9 to 22 Bq m^(-3), and 33 to 674 mBq h^(-1) kg^(-1), respectively, while the calculated ACI and AED_(in) vary from 0.1 ± 0.01 to 2.1 ± 0.1 and 0.1 ± 0.01 to 2.4 ± 0.6 mSv y^(-1), respectively. On the other hand, the internal annual effective dose ranges from 0.1 to 1.4 mSv y^(-1). The estimated radiological risk parameters were below the recommended maximum values, and radiological hazards associated with building materials under investigation are therefore negligible. 展开更多
关键词 Indoor radon EMANATION fraction Equilibrium EQUIVALENT concentration Mass exhalation rate Annual EFFECTIVE DOSE EFFECTIVE DOSE EQUIVALENT
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U-Pb Geochronology and Geochemistry of Stratiform Garnet from the Aqishan Pb-Zn Deposit,Eastern Tianshan,Xinjiang,NW China:Constraints on Genesis of the Deposit
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作者 WEN Bin ZHANG Yuanhou +4 位作者 YANG Wanzhi DU Shangze WANG Peng LIU Jinwei CHEN Lei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2022年第1期135-146,共12页
The Aqishan lead-zinc deposit,located in the Jueluotag metallogenic belt of eastern Tianshan,Xinjiang,Northwest China,has a stratiform occurrence in the marine volcanic tuff of the Yamansu Formation.The ore body has a... The Aqishan lead-zinc deposit,located in the Jueluotag metallogenic belt of eastern Tianshan,Xinjiang,Northwest China,has a stratiform occurrence in the marine volcanic tuff of the Yamansu Formation.The ore body has a typical double-layer structure,having a stratified,stratoid,lenticular upper part and a veined,stockwork-like lower part.The occurrence of the upper orebody is consistent with that of the volcanic tuff wall rock.The ore minerals are mainly chalcopyrite,pyrite,sphalerite,galena and magnetite,the altered minerals mainly being silicified,such as sericite,chlorite,epidote,garnet.The garnetized skarn,being stratiform and stratoid,is closely related to the upper part of the orebody.Geological observations show that the limestone in the ore-bearing Yamansu Formation is not marbleized and skarnized.Spatially,it is associated with the ferromanganese deposits in the marine volcanic rocks of the Yamansu Formation.These geological features reflect the likelihood that the Aqishan lead-zinc deposit is a hydrothermal exhalation sedimentary deposit.The results from the EPMA show that the garnet is mainly composed of grossular-andradite series,contents being in a range of 34.791-37.8%SiO_(2),32.493-34.274%CaO,8.454-27.275%FeO,0.012-15.293%Al_(2)O_(3),0.351-1.413%MnO,and lower values of 0.013-1.057%TiO_(2).The content of SiO_(2) vs.CaO and FeO vs.Al_(2)O_(3) has a significant positive correlation.The results of ICP-MS analysis for the garnet show that the REE pattern is oblique to right in general.The total amount of rare earth elements is relatively low,ΣREE=71.045-826.52 ppm,which is relatively enriched for LREE and depleted for HREE.LREE/HREE=8.66-4157.75,La_(N)/Yb_(N)=23.51-984.34,with obvious positive Eu and Ce anomalies(δEu=2.27-76.15,δCe=0.94-1.85).This result is similar to the REE characteristics of ore-bearing rhyolite volcanic rocks,showing that the garnet was formed in an oxidizing environment and affected by clear hydrothermal activity.The U-Pb isotopic dating of garnet by fs-LA-HR-ICP-MS gives an age of 316.3±4.4 Ma(MSWD=1.4),which is consistent with the formation time of the Yamansu Formation.According to the study of deposit characteristics and geochemical characteristics,this study concludes that the Aqishan lead-zinc deposit is a hydrothermal exhalation sedimentary deposit,the garnet being caused by hydrothermal exhalative sedimentation. 展开更多
关键词 garnet LA-ICP-MS U-Pb dating hydrothermal exhalation sedimentary deposits garnet trace element geochemistry Aqishan Pb-Zn deposit
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Assessment of Exposure Due to Technologically Enhanced Natural Radioactivity in Various Samples of Moroccan Building Materials
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作者 Bouchaib Kassi Aziz Boukhair +3 位作者 Khadija Azkour Mohamed Fahad Mohammed Benjelloun Abdel-Mjid Nourreddine 《World Journal of Nuclear Science and Technology》 2018年第4期176-189,共14页
The aim of our present work is to measure the specific activities of the radionuclides 226Ra, 232Th, 40K and the exhalation rates in terms of area and mass of 222Rn in some samples of building materials commonly used ... The aim of our present work is to measure the specific activities of the radionuclides 226Ra, 232Th, 40K and the exhalation rates in terms of area and mass of 222Rn in some samples of building materials commonly used in Morocco in order to evaluate the radiological risk caused by natural radioactivity. To this end, the analyses were carried out, using two nuclear techniques, namely high resolution gamma spectrometry and alpha dosimetry based on the use of LR115, on 50 samples collected from large commercial suppliers in Morocco. The results of these analyses show that the average specific activities of 226Ra, 232Th and 40K in these materials vary from 9 to 52 Bq/kg, 3 to 63 Bq/kg and 68 to 705 Bq/kg respectively. These activities remain within the permissible limits of 35 Bq/kg, 30 Bq/kg and 370 Bq/kg respectively, with the exception of a few samples of red brick, gray cement, ceramic and granite. The activity of the radium equivalent (Raeq), the internal (Hin) and external (Hex) hazard indices, the absorbed dose rate, the total annual effective dose , the excess lifetime cancer risk (ELCR) as well as volumic activities, exhalation rates in terms of area (ES) and mass (EM) are calculated for the samples analyzed in this work in order to assess the radiological risks resulting from the use of these materials in various construction activities. It seems that the values of these indices vary from 19 to 196 Bq/kg, 0.08 to 0.67, 0.05 to 0.53, 9 to 91 nGy/h, 0.05 to 0.56 mSv/y, 0.19 × 10&minus;3 to 1.96 × 10&minus;3, 72 to 350 Bq/m3, 56 to 273 mBq&sdot;m&minus;2&sdot;h&minus;1 and 3 to 15 mBq&sdot;kg&minus;1&sdot;h&minus;1 respectively. The lowest values are identified for gypsum, while the highest are attributed to granite. All of the obtained results of these indices respect the permissible limits except for the Raeq in some granite samples, the ELCR index in all samples except gypsum and the radon volumic activity in some gray cement samples, ceramic and granite. As a result, the different types of building materials analyzed in our work do not present a health risk to the public and can be used in various construction activities, with the exception of a few samples of red brick, gray cement, ceramic and granite. The choice of the use of red brick, gray cement and ceramic should be monitored and adapted according to the criteria of the limitation of the doses whereas the use of the granite must be moderate in order to limit over time the health risk which increases with the duration of exposure of humans to these building materials. 展开更多
关键词 Building Materials Natural RADIOACTIVITY RADIONUCLIDE RADON exhalation Rate RADIUM Equivalent Annual Effective Dose
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Assessment of the Radiological Impact on the Environment near a Storage Site of Coal Ashes in a Thermal Power Plant
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作者 Aziz Boukhair Laila Belahbib +3 位作者 Khadija Azkour Hamid Nebdi Mohammed Benjelloun Abdelmjid Nourreddine 《World Journal of Nuclear Science and Technology》 2016年第4期206-216,共11页
The radiological impact of coal ashes, with enhanced natural radioactivity in the storage site, is due to the presence of naturally occurring radionuclides. Some of these radionuclides have a radioactive period of sev... The radiological impact of coal ashes, with enhanced natural radioactivity in the storage site, is due to the presence of naturally occurring radionuclides. Some of these radionuclides have a radioactive period of several million years and will, therefore, have time to migrate to the soil, atmospheric air, surface water, and groundwater. This impact depends mainly on the activity of these coal ashes, the duration of exposure to such waste, transfers to the air, and the leaching phenomenon by rainwater. In this study, and so as to assess the radiological impact of coal ashes of the storage site of the JLEC-Morocco thermal power plant on environment, some analyses are performed by alpha dosimetry and a digital dosimeter on samples of coal ashes, soil, atmospheric air, surface water and groundwater belonging to a perimeter of 10 km around that site. The obtained results show that, within the studied area, the radiological impact on the soil of the coal ashes of the storage site is insignificant even though the concentrations of radon in the near vicinity (1 to 2 km) are moderately important, and remain below 200 Bq/m3. In the atmospheric air, this impact remains medium for the neighborhoods of the storage site (2 to 3 km) with radon activities superior to 10 Bq/m3. These results also show that there may be a water contamination of wells located at the storage site without any transfer of radioactivity into the groundwater of the area studied where the concentrations of radon are less than 11.1 Bq/l. 展开更多
关键词 Storage Site Coal Ashes Environment Radiological Impact Soil Water Atmospheric Air LR115 RADON Volumetric Activity exhalation of Radon
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Genesis of the Zhaokalong Fe-Cu Polymetallic Deposit at Yushu, China: Evidence from Ore Geochemistry and Fluid Inclusions 被引量:15
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作者 LI Huan XI Xiaoshuang +1 位作者 WU Chengming Koichiro WATANABE 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2013年第2期486-500,共15页
The ore types of the Zhaokalong Fe-Cu deposit are divided into two categories: sulfide-type and oxide-type. The sulfide-type ore include siderite ore, galena-sphalerite ore and chalcopyrite ore, whereas the oxide-typ... The ore types of the Zhaokalong Fe-Cu deposit are divided into two categories: sulfide-type and oxide-type. The sulfide-type ore include siderite ore, galena-sphalerite ore and chalcopyrite ore, whereas the oxide-type ore include magnetite ore and hematite ore. The ore textures and structures indicate that the Zhaokalong deposit is of the sedimentary-exhalative mineralization type. Geochemical analyses show that the two ore types have a high As, Sb, Mn, Co and Ni content. The REE patterns reveal an enrichment of the LREE compared to the HREE. Isotopic analysis of siderite ore reveal that the j13CpDB ranges from -2.01 to 3.34 (%0) whereas the JISOsMow ranges from 6.96 to 18.95 (%0). The fluid inclusion microthermometry results indicate that homogenization temperatures of fluid inclusions in quartz range from 131 to 181~C, with salinity values of 1.06 to 8.04 wt% NaCI eq. The mineralizing fluid therefore belongs to the low temperature - low salinity system, with a mineralizing solution of a CO2-Ca2+(Na+, K+)-SO42- (F-, CI--H20 system. The geochemical results and fluid inclusion data provide additional evidence that the Zhaokalong deposit is a sedex-type deposit that experienced two stages of mineralization. The sulfide mineralization probably occurred first, during the sedimentary exhalative process, as exhibited by the abundance of marine materials associated with the sulfide ores, indicating a higher temperature and relatively deoxidized oceanic depositional environment. After the main exhalative stage, hydrothermal activity was superimposed to the sulfide mineralization. The later stage oxide mineralization occurred in a low temperature and relatively oxidized environment, in which magmatic fluid circulation was dominant. 展开更多
关键词 exhalative sedimentary deposit (SEDEX) fluid inclusions ore geochemistry Zhaokalong Sanjiang ore belt
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Significance of Fractional Exhaled Nitric Oxide Combined with Serum Procalcitonin and C-Reactive Protein in Evaluation of Elderly Asthma 被引量:7
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作者 吴纪珍 马利军 +3 位作者 赵丽敏 张晓宇 陈献亮 况红艳 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2013年第2期185-188,共4页
Bronchial asthma is a common chronic airway inflammatory disease. Asthma is associated with high mortality, especially in the elderly patients. Repeated exacerbations cause disease progression. Therefore, identifying ... Bronchial asthma is a common chronic airway inflammatory disease. Asthma is associated with high mortality, especially in the elderly patients. Repeated exacerbations cause disease progression. Therefore, identifying the onset of acute elderly asthma as soon as possible and giving the effective treatment is crucial to improve the prognosis. This study was to investigate the significance of fractional exhaled nitric oxide (FeNO) combined with serum procalcitonin (PCT) and C-reactive protein (CRP) in the evaluation of elderly asthma. A total of 120 elderly patients with an acute attack of asthma from July, 2010 to May, 2012 were studied. On presentation, FeNO, serum PCT and CRP concentrations were measured and sputum culture was also performed. The elderly patients were re-evaluated when they had returned to their stable clinical state. The elderly patients were classified into two groups: positive bac- terial culture group (A) and negative bacterial culture group (B). The results showed that: (1) In patients with an acute exacerbation of asthma, 48 (40%) patients had positive sputum bacterial culture and 72 (60%) had negative sputum bacterial culture. (2) The levels of FeNO in patients with acute exacerbation of asthma were significantly higher than in those with no acute exacerbation state (63.8±24.6 vs. 19±6.5 ppb, P〈0.05). There was no significant difference in FeNO between group A and group B (P〉0.05). (3) The levels of PCT and CRP in group A patients with an acute exacerbation of asthma were significantly higher (P〈0.05) than in group B (for PCT: 27.46±9.32 vs. 7.85±3.52 ng/mL; for CRP: 51.25±11.46 vs. 17.11±5.87 mg/L, respectively). When they had returned to stable clinical state, the levels of PCT and CRP in group A were decreased significantly (P〈0.05), and those in group B had no significant change (P〉0.05) when compared with the exacerbation group. There were no significant differences in the levels of PCT and CRP between the two groups in non-acute exacerbation state (/9〉0.05). These results suggest that the increase in FeNO indicates the acute exacerbation of asthma, and the elevation of serum PCT and CRP levels may be associated with bacterial infection. 展开更多
关键词 ELDERLY ASTHMA fractional exhaled nitric oxide PROCALCITONIN C-reactive protein bacterial infection
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Exhaled breath analysis in hepatology: State-of-the-art and perspectives 被引量:3
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作者 Antonio De Vincentis Umberto Vespasiani-Gentilucci +2 位作者 Anna Sabatini Raffaele Antonelli-Incalzi Antonio Picardi 《World Journal of Gastroenterology》 SCIE CAS 2019年第30期4043-4050,共8页
Liver disease is characterized by breath exhalation of peculiar volatile organic compounds(VOCs).Thanks to the availability of sensitive technologies for breath analysis,this empiric approach has recently gained incre... Liver disease is characterized by breath exhalation of peculiar volatile organic compounds(VOCs).Thanks to the availability of sensitive technologies for breath analysis,this empiric approach has recently gained increasing attention in the context of hepatology,following the good results obtained in other fields of medicine.After the first studies that led to the identification of selected VOCs for pathophysiological purposes,subsequent research has progressively turned towards the comprehensive assessment of exhaled breath for potential clinical application.Specific VOC patterns were found to discriminate subjects with liver cirrhosis,to rate disease severity,and,eventually,to forecast adverse clinical outcomes even beyond existing scores.Preliminary results suggest that breath analysis could be useful also for detecting and staging hepatic encephalopathy and for predicting steatohepatitis in patients with nonalcoholic fatty liver disease.However,clinical translation is still hampered by a number of methodological limitations,including the lack of standardization and the consequent poor comparability between studies and the absence of external validation of obtained results.Given the low-cost and easy execution at bedside of the new technologies(e-nose),larger and well-structured studies are expected in order to provide the adequate level of evidence to support VOC analysis in clinical practice. 展开更多
关键词 Exhaled BREATH ANALYSIS Electronic nose Gas chromatography BREATH print LIVER cirrhosis NONALCOHOLIC fatty LIVER disease Hepatic ENCEPHALOPATHY
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Early Silurian Wuchuan–Sihui–Shaoguan exhalative sedimentary pyrite belt, South China: constraints from zircon dating for K-bentonite of the giant Dajiangping deposit 被引量:1
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作者 Yingying Zhang Taiyi Luo +2 位作者 Tian Gan Mingzhong Zhou Xinqiao Han 《Acta Geochimica》 EI CAS CSCD 2021年第1期1-12,共12页
The Wuchuan-Sihui-Shaoguan(WSS)exhalative sedimentary pyrite belt in the southwestern part of the Qinzhou-Hangzhou(Qin-Hang)belt is the most important sulfur industry base in China.However,a wide range of metallogenet... The Wuchuan-Sihui-Shaoguan(WSS)exhalative sedimentary pyrite belt in the southwestern part of the Qinzhou-Hangzhou(Qin-Hang)belt is the most important sulfur industry base in China.However,a wide range of metallogenetic ages spanning from Ediacaran to Devonian has been reported in the literature.This age range does not support the idea that the typical character of"coeval mineralization"in an exhalative sedimentary mineralization belt in China and worldwide.Therefore,the precise determination of mineralization ages of representative deposits is necessary to provide guides for exploration and metallogenetic models.The Dajiangping pyrite deposit is a typical example of this kind of deposits and is also the largest deposit with a proven reserve of 210 Mt.This deposit was thought to have formed in Ediacaran or Devonian.In this study,2-3 layers of 10-25 cm thick 2M1-type microcrystalline muscovite slate abruptly embedded in the No.Ⅳmassive orebody of the deposit has been identified to be low-grade metamorphic K-bentonite.A Concordia zircon LA-ICP-MS U-Pb age of 432.5±1.3 Ma(mean standard weighted deviation of concordance and equivalence=1.2;N=11)has been yielded for the low-grade metamorphic K-bentonite.This age is distinctly different from the Rb-Sr isochron age of630.1±7.3 Ma for siliceous rock at the top of the No.Ⅲbanded orebody and the Re-Os isochron age of 389±62 Ma for pyrites from a laminated orebody.Instead,it is close to the intercept age(429 Ma)of the youngest detrital zircons from sandstone interlayers of the No.Ⅲbanded orebody.The Concordia age is also coincident with those of the Late Caledonian(400-460 Ma)magmatism-metamorphism events which are widely distributed in Cathaysia Block.Particularly,it agrees well with that of the Early Silurian extensional volcanism(434-444 Ma)which have been revealed in the Dabaoshan,Siqian-Hekou,and Nanjing volcanic basins in northern Guangdong Province and southern Jiangxi Province.Hence,the dating result in this study confirms that the sedimentary time of the ore-host Daganshan Formation is Early Silurian,and implies that the mineralization age of the Dajiangping pyrite deposit should also be Early Silurian.In combination with the Early Silurian age of Shezui pyrite deposit and the Dabaoshan volcanic basin along the WSS pyrite belt,it could be inferred that the WSS pyrite belt provides a record of the northern expanding of Qinzhou-Fangcheng trough in Early Silurian and that the exhalative pyrite mineralization was triggered by the postcollisional extension of the margin of Cathaysia Block after the intracontinental collision between Cathaysia Block and Yangtze Block during Late Caledonian stage. 展开更多
关键词 Wuchuan–Sihui–Shaoguan exhalative sedimentary pyrite belt Dajiangping pyrite deposit Lowgrade metamorphic K-bentonite Zircon U–Pb dating
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Effect of Inhabitation Mouthwash Solution Containing Chlorine Dioxide (Pro Fresh<sup>®</sup>) on Oral Malodor 被引量:1
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作者 Masaki Sawa Senichi Suzuki +4 位作者 Masakazu Azuma Tomoko Yoshizawa Kaiho Otomi Takuji Yamaguchi Hiroyuki Kobayashi 《Health》 2015年第2期211-219,共9页
Recently, the interest in oral malodor has been grown and the number of people having trouble with oral malodor is increasing year by year. Generally, as the branch of medicine which deals with patients complaining ab... Recently, the interest in oral malodor has been grown and the number of people having trouble with oral malodor is increasing year by year. Generally, as the branch of medicine which deals with patients complaining about oral malodor, dentistry is mostly chosen. On the current situation, however, the dental office side typically finds it difficult to deal with several kinds of oral malodor which show no improvement even though cavities or periodontal disease is completely cured. Main components to cause oral malodor are volatile sulfur compounds (methyl mercaptan, dimethyl sulfide, hydrogen sulfide);in the present study, therefore, the effect of mouthwash solution containing chlorine dioxide to relieve oral malodor and increase saliva production was tested. The subjects were 92 patients (Control group: 2 males, 3 females, age;30.8 ± 4 years old, Mouthwash group: 28 males, 59 females, age: 36.9 ± 1.3 years old) who visited the hospital complaining about oral malodor. Intraoral gas, exhaled gas, the saliva production at rest, the ability for salivation and the buffering ability of saliva were examined twice, before the subjects used the mouthwash solution every day for one month. The simple chromatography oral chroma, which was insulated from the influence of temperature and humidity and also was able to measure with a high degree of accuracy, was used to measure odor as the device analysis method. The control group did not change in VSCs, saliva production and the buffering ability of saliva. After using mouthwash solution, the concentration of the 3 major components gas of intraoral gas and exhaled gas, i.e. methyl mercaptan, dimethyl sulfide, hydrogen sulfide, were all decreased. As for hydrogen sulfide, intraoral gas (from 225.8 ± 28.1 ppb to 41.1 ± 8.8 ppb) and exhaled gas (from 212.0 ± 50.4 ppb to 34.6 ± 16.6 ppb) was significantly decreased. Also, saliva production at rest (from 1.3 ± 0.1 ml to 1.7 ± 0.1 ml) and the ability to salivate (from 4.5 ± 0.3 ml to 5.1 ± 0.3 ml) were both significantly increased. As for the buffering ability of saliva, significant changes were not detected on the change of salivary pH after using mouthwash solution, and it did not have any effects on the buffering ability of saliva. In conclusion, these results suggest that the mouthwash solution containing chlorine dioxide has significant effects on inhibiting malodor. 展开更多
关键词 Chlorine Dioxide Oral MALODOR Volatile Sulfur Compounds INTRAORAL GAS Exhaled GAS
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Comparative Proteomics Analysis of Exhaled Breath Condensate in Lung Cancer Patients 被引量:1
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作者 Zujian Cheng Craig R. Lewis +1 位作者 Paul S. Thomas Mark J. Raftery 《Journal of Cancer Therapy》 2011年第1期1-8,共8页
The prognosis for patients with non-small cell lung cancer (NSCLC) remains poor in spite of better treatments. This relates mainly to the fact that the majority of patients present with advanced disease. There is a ne... The prognosis for patients with non-small cell lung cancer (NSCLC) remains poor in spite of better treatments. This relates mainly to the fact that the majority of patients present with advanced disease. There is a need to identify tools which can improve screening for lung cancer in the at risk patient population. The aim of this study was to compare the breath proteomic profile of NSCLC patients with healthy control subjects to explore the potential of new biomarkers of lung cancer. Comparative proteomic analysis of exhaled breath condensate (EBC) between 14 patients with NSCLC and 13 healthy control subjects were carried out using LTQ FT Ultra mass spectrometry and database searching to determine any unique proteins. In total, 29 unique proteins were identified using multiple protein identification algorithms. A comparison of lung cancer, smoker, and ex-smoker proteomes showed that 18 proteins were shared among the three groups. While one unique protein was found in smokers and lung cancer patients, four proteins were unique to ex-smokers. This data set provides a foundation for evaluation of these proteins from EBC as potential biomarkers for non-invasive lung cancer diagnosis. 展开更多
关键词 LUNG Cancer Exhaled BREATH CONDENSATE MASS SPECTROMETRY PROTEOMICS
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