In-situ measurement via the flow-through method and numerical simulations for radon exhalation during measurements of the radon exhalation rate

Small-scale measurements of the radon exhalation rate using the flow-through and closed-loop methods were conducted on the surface of a uranium tailing pond to better understand the differences between the two methods.An abnormal radon exhalation behavior was observed,leading to computational fluid dynamics(CFD)-based simulations in which dynamic radon migration in a porous medium and accumulation chamber was considered.Based on the in-situ experimental and numerical simulation results,variations in the radon exhalation rate subject to permeability,flow rate,and insertion depth were quantified and analyzed.The in-situ radon exhalation rates measured using the flow-through method were higher than those measured using the closed-loop method,which could be explained by the negative pressure difference between the inside and outside of the chamber during the measurements.The consistency of the variations in the radon exhalation rate between the experiments and simulations suggests the reliability of CFD-based techniques in obtaining the dynamic evolution of transient radon exhalation rates for diffusion and convection at the porous medium-air interface.The synergistic effects of the three factors(insertion depth,flow rate,and permeability)on the negative pressure difference and measured exhalation rate were quantified,and multivariate regression models were established,with positive correlations in most cases;the exhalation rate decreased with increasing insertion depth at a permeability of 1×10^(−11) m^(2).CFD-based simulations can provide theoretical guidance for improving the flow-through method and thus achieve accurate measurements.

Numerical simulations for radon migration and exhalation behavior during measuring radon exhalation rate with closed-loop method

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.

Exhaled Breath Vapor of Humans Reflects the Changes in Deuterium Concentration in the Body Water

The concentration of the heavy isotope of hydrogen, deuterium (D), is not routinely measured in (human) medical laboratory tests, even though an increasing number of papers prove the pivotal role of D in tumor growth, cell cycle regulation, cell metabolism, and aging. Data from a prospective phase 2 clinical study and numerous retrospective clinical studies proved the anticancer effect of deuterium depletion achieved by replacing the regular water intake with deuterium-depleted water (DDW). In previous studies, the changes in serum D concentration of DDW-consuming patients were followed using blood samples and mass spectrometry, which was invasive, costly, and time-consuming. As future clinical trials will also require a follow-up of internal D level and the patient’s compliance, a new sampling device and procedure was developed based on condensing the exhaled breath water vapor and measuring its D content using a liquid water isotope laser analyzer. Test results showed that the device provided accurate, reliable, and reproducible data. According to the data, the internal D level in a person consuming normal water was stable. In contrast, exclusive consumption of DDW for several days resulted in a gradual decrease of D concentration in exhaled breath condensate (EBC), which was proportional to the D concentration of DDW. These data confirm that orally applied DDW equilibrates with the person’s water pool quickly, leading to a reduced internal D level reflected in the D content of EBC.

呼出气一氧化氮测定在老年哮喘诊治中的应用研究

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。

Genesis of the Zhaokalong Fe-Cu Polymetallic Deposit at Yushu, China: Evidence from Ore Geochemistry and Fluid Inclusions

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.

Significance of Fractional Exhaled Nitric Oxide Combined with Serum Procalcitonin and C-Reactive Protein in Evaluation of Elderly Asthma

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.

Exhaled breath analysis in hepatology: State-of-the-art and perspectives

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.

Early Silurian Wuchuan–Sihui–Shaoguan exhalative sedimentary pyrite belt, South China: constraints from zircon dating for K-bentonite of the giant Dajiangping deposit

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.

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

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.

Radiological characterization of building materials used in Malaysia and assessment of external and internal doses

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.

Effect of Inhabitation Mouthwash Solution Containing Chlorine Dioxide (Pro Fresh^®) on Oral Malodor

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.

Control of relay structure on mineralization of sedimentary-exhalative ore deposit in growth faults of graben systems

Based on the study of ore deposits and orebody structures of two sedimentary-exhalative ore deposits, i.e., Changba and Xitieshan Ore Deposits, it is found that the structural patterns of metallogenic basin of seafloor exhalative sulfide deposits in the ancient graben systems are controlled by relay structures in normal faults. The shapes of metallogenic basins are composed of tilting ramp, fault-tip ramp and relay ramp, which dominate migration of gravity current of ore-hosted fluid and shape of orebody sedimentary fan in the ramp. By measuring and comparing the difference of length-to-thickness ratios of orebody sedimentary fan, the result shows that the occurrence of the ramp has a remarkable impact on the shape of orebody.

Usefulness of Fractional Exhaled Nitric Oxide-Guided Treatment in Patients with Asthma-Chronic Obstructive Pulmonary Disease Overlap

Background: Some patients present clinical features of both asthma and chronic obstructive pulmonary disease (COPD), which has led to the recent proposal of asthma-COPD overlap (ACO) as a diagnosis. Fractional exhaled nitric oxide (FeNO) is a candidate biomarker to diagnose ACO. We assessed the effect of an add-on treatment with budesonide/formoterol (BUD/FM) combination in patients with ACO, which was diagnosed by FeNO. Methods: This was a prospective, single-arm, open-label, before and after comparison study. Subjects included 83 patients with COPD who attended outpatient clinics for routine checkups at Shizuoka General Hospital between June and November 2016. All patients fulfilled the GOLD definition of COPD and were receiving long-acting muscarinic antagonist (LAMA) or LAMA/long-acting β2 agonist (LABA) combinations. After an 8-week run-in period, BUD/FM was added to the patients with FeNO levels of ≥35 ppb, defined as having ACO. For patients receiving LAMA/LABA, BUD/FM was added after the discontinuation of LABA. The modified British Medical Research Council (mMRC) score, COPD assessment test (CAT) score, spirometric indices, forced oscillation parameters, and FeNO were assessed before and after 8 weeks of BUD/ FM add-on treatment. Results: Twenty-four patients (28.9%) had FeNO levels ≥ 35 ppb, and 17 patients completed the study (mean age: 73 years and GOLD I/II/III/IV, 5/10/1/1). The mean CAT scores significantly improved (9.2 to 5.4, p = 0.015) and 10 patients (58.8%) showed ≥2 points improvement, a minimal clinically important difference. The mean FeNO levels significantly decreased from 63.0 to 34.3 ppb (p Conclusions: FeNO-guided treatment with BUD/FM improves symptoms in patients with ACO.

Comparative Proteomics Analysis of Exhaled Breath Condensate in Lung Cancer Patients

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.

Radon Concentration in Soil and Radon Exhalation Rate at Al-Dora Refinery and Surrounding Area in Baghdad

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.

Geology and geochemistry of Huanggangliang stratabound skarn deposit in Inner Mongolia,China

Over the recent three decades, exploration of a large-size Sn-Fe polymetallic ore deposit at the Huanggangliang, the Da Hinggan Mountains, Inner Mongolia, China, has been largely focused on the premise that the mineralization represents epigenetic magmatic hydrothermal ore deposit in genetic connection with the Mesozoic magmatism. The Huanggangliang Sn-Fe polymetallic ore deposits occurred in Permian strata, with silt- stone/marble of the Zhesi Formation and spilite/andesite/tuff of the Dashizhai Formation. The characteristics of geological and geochemical data demonstrated that sedimentary hydrothermal mineralization occurred during the basin evolution at the Permian, rather than representing epigenetie magmatic hydrothermal genesis with the following evidences. The ore-bearing skarus are stratiform with underlying metasedimentary rocks and overlying volcanic sedimentary rocks. Sedimentary hydrothermal textures and structures are observed in the stratabound ore-bearing skarn such as bedded-laminated skarn and magnetite ores with small-size folding or soft deforma- tion, synsedimentary breccia of skarn and magnetite ores and concentric shell structure of magnetite ores. So the stratabound ore-bearing skarns associated with magnetite ore and micro-disseminated tin, are peculiar examples of exhalite. The REE contents of the stratabound ore-bearing skarns display ∑LREE-rich （36.91×10^-6） but EHREE-depletion （6. 42 ×10^-6） , with positive Eu anomaly （Eu/Eu ＊ 1.28） and negative Ce anomaly （Ce/ Ce ＊ 0.88 ） , which is totally different from REE pattern of the Huanggang magmatic rocks（ with ∑REE 277.73 ×10^-6, ELREE 220.24 ×10^-6, ∑HREE 57.49 ×10^-6, Eu/Eu＊ 0.06, Ce/Ce＊ 1.52） , which is comparable with modern sea-floor hydrothermal fluid,sedimentary hydrothermal ore deposit and associated hydrothermal sedimentary rocks. Calcite samples with δ13CPDB from -5. 400 ‰ to -4. 397 ‰ and δ18SOSMOW from 9. 095 ‰ to 9. 364 ‰ in the stratabound ore-bearing skarns show sedimentary hydrothermal genesis of the Huanggangliang deposit. This proposition is useful not only for interpretation of the genesis of the Huanggangliang large Sn-Fe polymetallic ore deposit but also significant for mineral exploration in the area especially for finding large deposits caused by sedimentary exhalative mineralization processes.

The Characteristics of the Hydrothermal Exhalative Dolostone of Lucaogou Formation in Santanghu basin and its Geology Setting Indication

The NW-SE trending Santanghu basin is located in Xinjiang,NW China,between Tianshan Mountains and Altai Mountains.The tectonic evolution history of north Xinjiang has long been debated,especially the question when did that area began its intraplate rift evolution stage.This abstract discusses the features and possible origin of the hydrothermal exhalative dolostone of Lucaogou Formation in Santanghu basin,aiming to provide relevant information about this question.The target dolostone are characterized by extreme thin lamina of 0.3cm–1 cm thick.Dolomite,ankerite,potassium feldspar and analcite are dominant composition.Most dolomite is poor crystallized and is in anhedral or subhedral shapes.Ankerite is generally porphyritic,few is in irregular shapes.It has to be noted that the porphyritic ankerite commonly develop zonal textures characterized by rings with various Fe O content.Potassium feldspar and analcite（<50%）are commonly observed in dolostones.Thin sections show some analcite is tetragonal trisoctahedron with harbour–like corrosion rims.Besides,few fragments of carbonatite rocks are observed in Lucaogou Formation and they perform intermittent or scattered distribution in rock layers.Previous work done by our study team showsδ13C PDB values are 4.8‰;1.4‰,6.93‰on average.Theδ18 O PDB values are between-5‰;21.1‰,-10.94‰on average.Paleosalinity calculated byδ13C andδ18 O is between 128.35 and 136.81,134.42 on average.Sr content of dolostones in study area reaches to164×10-6;37×10-6（379.1×10-6 on average）,most dolostone in target area are between 0.70457;.706194, average at 0.705360.Considering either accompanying residual tuff or residual leucite is found via electron probe,this indicates the analcite may derive form analcime phonolite.Furthermore,fragments of carbonatite rocks proves mantle-derived magmatism exist.The rapid variation ofδ18 O indicates multiple interactions of hydrothermal fluids with lake water during Lucaogou sedimentary period.87Sr/86Sr values are much lower than that of crustal silica rocks while are more close to mantle derived rocks,which indicates diagenetic hydrothermal fluid is mantle-origin.It has been reported that dolostone does not intergrow with iron-rich dolostone in study area.According to the latest X diffraction results of cores,iron-rich dolostone distributes rather locally.Given that ankerite commonly develop zonal textures characterized by various Fe O content,we confirm it is due to multiple hydrothermal fluids activities in different hydrothermal vents.There should be abundant hydrothermal vents during Lucaogou period.Deep faults and its relevant fractures built plenty paths for mantle-origin hydrothermal fluids to run up.Different vents owned various fluid properties,so did relevant sedimentation products.Hence we inclined to believe Santanghu basin was at intraplate rift evolution stage,under regional extension condition in late Carboniferous.During early-mid Permian the basin was a starved,deep lacustrine intracontinental rift basin.Accordingly,in northern Xinjiang,ocean basin may close in late Carboniferous and started continental sedimentary development in early Permian.

Assessment of Exposure Due to Technologically Enhanced Natural Radioactivity in Various Samples of Moroccan Building Materials

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.

IN—SITU MEASUREMENTS OF RADON EXHALATION RATE FROM BUILDING SURFACE IN HONG KONG

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-2·s-1. This may be the cause of a relatively high indoor radon concentration in Hong Kong.

Measurement of Natural Radioactivity and Radon Exhalation Rate in Coal Ash Samples from a Thermal Power Plant

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 226Ra activities and 232Th in both ash samples are well above the permissible activity. The values of the external risk index (Hex) and internal one (Hin) for these ashes are below unity, with the exception of 1.28 in fly ash for Hin. The obtained values for the equivalent radium Raeq and annual effective doses Ėin 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⋅m-2⋅h-1 and 381 mBq⋅m-2⋅h-1, 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.