Intercomparison of Indoor Radon Measurements Under Field Conditions In the Framework of MetroRADON European Project

Interlaboratory comparisons are a basic part of the regular quality controls of laboratories to warranty the adequate performance of test and measurements. The exercise presented in this article is the comparison of indoor radon gas measurements under field conditions performed with passive detectors and active monitors carried out in the Laboratory of Natural Radiation (LNR). The aim is to provide a direct comparison between different methodologies and to identify physical reasons for possible inconsistencies, particularly related to sampling and measurement techniques. The variation of radon concentration during the comparison showed a big range of values, with levels from approximately 0.5 to 30 kBq/m3. The reference values for the two exposure periods have been derived from a weighted average of participants’ results applying an iterative algorithm. The indexes used to analyze the participants’ results were the relative percentage difference D(%), the Zeta score ( ζ ), and the z-score ( z ). Over 80% of the results for radon in air exposure are within the interval defined by the reference value and 20% and 10% for the first and the second exposure, respectively. Most deviations were detected with the overestimating of the exposure using passive detectors due to the related degassing time of detector holder materials.

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Heart rate turbulence in healthy dogs and dogs with dilated cardiomyopathy

Polish Journal of Veterinary Sciences ◽

10.2478/v10181-012-0072-9 ◽

2012 ◽

Vol 15 (3) ◽

pp. 469-475 ◽

Cited By ~ 3

Author(s):

A. Noszczyk-Nowak

Keyword(s):

Heart Failure ◽

Heart Rate ◽

Dilated Cardiomyopathy ◽

Autonomic Neuropathy ◽

Regression Line ◽

Reference Value ◽

Control Group ◽

Heart Rate Turbulence ◽

Percentage Difference ◽

Healthy Dogs

Abstract Heart rate turbulence (HRT) is modulated by the baroreceptor reflex and it was suggested that it could be used as a measure of autonomic dysfunction. Impaired HRT is of a significant prognostic value in humans after myocardial infarction, suffering from dilated cardiomyopathy and patients with heart failure. So far no studies were performed assessing the importance of HRT in dogs. The aim of this study was to prospectively evaluate the HRT turbulence onset (TO) and the turbulence slope (TS) in healthy dogs and in dogs with DCM and to compare the HRT in dogs with DCM that died during the first 30 days of observation and dogs with DCM that survived the first 30 days after the HRT analysis. The current study was aimed at determining reference value of the TO and TS of HRT in healthy dogs (control group) and dogs with dilated cardiomyopathy (DCM group). The tests were carried out on 30 healthy dogs and 30 dogs with DCM composed of Boxers, Doberman pinschers and Great Danes, of different sexes and body weights from 22 to 72 kg, aged between 1.5 and 11.5 years, submitted to the 24-hour Holter monitoring. HRT parameters were calculated using an HolCard software algorithm. TO is a percentage difference between the heart rate immediately following ventricular premature complex (VPC) and the heart rate immediately preceding VPC. TS corresponds to the steepest slope of the linear regression line for each sequence of five consecutive normal intervals in the local tachogram. The average TO in healthy dogs was determined as -13.55 ± 11.12%, TS was 21.33 ± 9.66 ms/RR. TO in dogs with DCM was determined as - 2.61 ± 2.1% and TS was 6.15 ± 3.86 ms/RR. Parameters of HRT were statistically significantly decreased (p<0.01) in dogs with DCM. HRT TO and TS were statistically significantly decreased in dogs with DCM. Dogs with DCM that survived more than 30 days of observation had HRT statistically significantly decreased in comparison to dogs with DCM that died after the 30’th day of observation. Decreased HRT parameters in dogs with DCM suggest an autonomic neuropathy which principally consists of the withdrawal of the cardiac parasympathetic tone. The more the autonomic neuropathy is advanced the faster the death of the dog with DCM might occur, with no correlation with the level of the heart failure.

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Influencing factors of cardiorespiratory fitness in allogeneic stem cell transplant candidates prior to transplantation

Supportive Care in Cancer ◽

10.1007/s00520-020-05485-y ◽

2020 ◽

Vol 29 (1) ◽

pp. 359-367

Author(s):

Matthias Limbach ◽

Rea Kuehl ◽

Peter Dreger ◽

Thomas Luft ◽

Friederike Rosenberger ◽

...

Keyword(s):

Physical Activity ◽

Stem Cell ◽

Influencing Factors ◽

Cardiorespiratory Fitness ◽

Area Under The Curve ◽

Reference Value ◽

Female Gender ◽

Hemoglobin Level ◽

Cell Transplant ◽

Percentage Difference

Abstract Purpose Cardiorespiratory fitness (CRF) seems to be prognostic prior to allogeneic stem cell transplantation (allo-HSCT). Influencing factors of CRF in allo-HSCT candidates have not been studied so far. Aim was to identify potentially influencing factors on CRF. Methods To assess CRF, a maximal cardiopulmonary exercise test (CPET) was performed on average 2.6 ± 7.2 days prior to admission. A regression analysis was conducted, with the following predictors: gender, age, body mass index (BMI), time between last therapy and allo-HSCT (t_Therapies), number of cardiotoxic therapies (n_Cardiotox), number of transplantations (n_Transplantations), comorbidity index (HCT-CI), hemoglobin level of the last 3 months (area under the curve), and physical activity. Results A total of 194 patients performed a CPET. VO2peak was significantly reduced compared with reference data. In total, VO2peak was 21.4 ml/min/kg (− 27.5%, p < 0.05). Men showed a significant larger percentage difference from reference value (− 29.1%, p < 0.05) than women (− 24.4%). VO2peak was significantly (p < 0.05) influenced by age (β = − 0.11), female gender (β = − 3.01), BMI (β = − 0.44), n_Cardiotox (β = − 0.73), hemoglobin level (β = 0.56), and physical activity prior to diagnosis (β = 0.10). Conclusions Our study demonstrates a decreased CRF indicating the potential need of prehabilitative exercise. We revealed some influencing factors on CRF. Those patients could benefit the most from exercise.

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Determination of the Key Comparison Reference Value from Multiple Field Calibration of Sentinel-2B/MSI over the Baotou Site

Remote Sensing ◽

10.3390/rs12152404 ◽

2020 ◽

Vol 12 (15) ◽

pp. 2404

Author(s):

Caixia Gao ◽

Yaokai Liu ◽

Jinru Liu ◽

Lingling Ma ◽

Zhifeng Wu ◽

...

Keyword(s):

Weighted Average ◽

Reference Value ◽

Atmospheric Conditions ◽

Key Comparison ◽

Field Calibration ◽

Average Value ◽

True Value ◽

Chi Squared ◽

Calibration Samples ◽

Relative Differences

Field calibration is a feasible way to evaluate space-borne optical sensor observations via natural or artificial sites on Earth’s surface with the aid of synchronous surface and atmospheric characteristic data. Since field calibration is affected by the coupled effects of surface and atmospheric characteristics, the single calibration results acquired under different surface and atmospheric conditions have different biases and different uncertainties, making it difficult to determine the consistency of these multiple calibration results. In view of this, by assuming that the radiometric performance is invariant during field calibration and the calibration samples are independent of each other, the surface–atmosphere invariant Key Comparison Reference Value (KCRV) is essentially derived from various calibration results. As the number of calibration samples increases, the uncertainty in the KCRV should decrease, and the KCRV should approach the “true” value. This paper addresses a novel method for estimating a weighted average value from multiple calibration results that can be used to compare each calibration result, and this value is accepted as the KCRV. Furthermore, this method is preliminarily applied to the field calibration of the Multispectral Instrument (MSI) onboard the Sentinel-2B satellite via the desert target at the Baotou site, China. After employing a chi-squared test to verify that 12 calibration samples are independent from each other, the KCRV of the 12 calibration samples at the Baotou site is derived, which exhibits much lower uncertainty than a single sample. The results show that the KCRVs of the relative differences between the simulated and observed at-sensor reflectance are 3.75%, 5.11%, 6.09%, and 5.03% for the four bands of Sentinel-2B/MSI, respectively, and the corresponding uncertainties are 1.84%, 1.87%, 1.90%, and 1.93%. It is noted that the KCRV uncertainty obtained with only 12 calibration samples is reduced significantly, and in the future, more samples in other instrumented sites will be used to validate this method thoroughly.

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The airborne mass spectrometer AIMS – Part 2: Measurements of trace gases with stratospheric or tropospheric origin in the UTLS

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-8-13567-2015 ◽

2015 ◽

Vol 8 (12) ◽

pp. 13567-13607 ◽

Cited By ~ 1

Author(s):

T. Jurkat ◽

S. Kaufmann ◽

C. Voigt ◽

D. Schäuble ◽

P. Jeßberger ◽

...

Keyword(s):

Nitrogen Oxide ◽

Mass Spectrometer ◽

Chemical Ionization ◽

Trace Gases ◽

Measurement Techniques ◽

Ion Source ◽

Trace Gas ◽

Ionization Mass ◽

Custom Made ◽

Gas Measurements

Abstract. Understanding the role of climate-sensitive trace gas variabilities in the upper troposphere and lower stratosphere region (UTLS) and their impact on its radiative budget requires accurate measurements. The composition of the UTLS is governed by transport and chemistry of stratospheric and tropospheric constituents, such as chlorine, nitrogen oxide and sulphur components. The Airborne chemical Ionization Mass Spectrometer AIMS has been developed to accurately measure a set of these constituents on aircraft by means of chemical ionization. Here we present a setup using chemical ionization with SF5− reagent ions for the simultaneous measurement of trace gas concentrations in the pptv to ppmv (10−12 to 10−6 mol mol−1) range of HCl, HNO3 and SO2 with in-flight and online calibration called AIMS-TG. Part 1 of this paper (Kaufmann et al., 2015) reports on the UTLS water vapour measurements with the AIMS-H2O configuration. The instrument can be flexibly switched between two configurations depending on the scientific objective of the mission. For AIMS-TG, a custom-made gas discharge ion source has been developed generating a characteristic ionization scheme. HNO3 and HCl are routinely calibrated in-flight using permeation devices, SO2 is permanently calibrated during flight adding an isotopically labelled 34SO2 standard. In addition, we report on trace gas measurements of HONO which is sensitive to the reaction with SF5−. The detection limit for the various trace gases is in the low ten pptv range at a 1 s time resolution with an overall uncertainty of the measurement in the order of 20 %. AIMS has been integrated and successfully operated on the DLR research aircraft Falcon and HALO. Exemplarily, measurements conducted during the TACTS/ESMVal mission with HALO in 2012 are presented, focusing on a classification of tropospheric and stratospheric influences in the UTLS region. Comparison of AIMS measurements with other measurement techniques allow to draw a comprehensive picture of the sulphur, chlorine and reactive nitrogen oxide budget in the UTLS. The combination of the trace gases measured with AIMS exhibit the potential to gain a better understanding of the trace gas origin and variability at and near the tropopause.

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A comparison of retrospective radon gas measurement techniques carried out in the Serbian spa of Niska Banja

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp0902094z ◽

2009 ◽

Vol 24 (2) ◽

pp. 94-99 ◽

Cited By ~ 2

Author(s):

Zora Zunic ◽

Kevin Kelleher ◽

Igor Celikovic ◽

Predrag Ujic ◽

Johan Paridaens ◽

...

Keyword(s):

Indoor Radon ◽

Measurement Techniques ◽

Measurement Methods ◽

Radon Progeny ◽

Surface Trap ◽

Radon Measurement ◽

The Past ◽

Radon Gas ◽

Gas Measurement ◽

The University

Indoor radon retrospective concentrations were obtained and compared using two radon measurement methods. Both methods rely on the measurement of the long-lived radon progeny 210Pb, collected either on the surfaces (surface trap technique), most frequently glass, or in a volume trap, usually sponge from furniture (volume trap technique). These techniques have been used to retrospectively estimate radon gas concentrations that have existed in dwellings in the past. The work presented here compares the results provided by the surface trap technique devised at the University College of Dublin, Ireland, and the volume trap technique devised at the Scientific Research Center, Mol, Belgium. The field campaign was carried out by the research team of the ECE Laboratory of the Vinca Institute of Nuclear Sciences at the spa of Niska Banja, identified as a region of Serbia with a high indoor radon and ground water radium and radon content.

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Problems in radon measurements in context of epidemiological studies

Archive of oncology ◽

10.2298/aoo0401013y ◽

2004 ◽

Vol 12 (1) ◽

pp. 13-17 ◽

Cited By ~ 1

Author(s):

Ilia Yarmoshenko ◽

Ivan Kirdin

Keyword(s):

Temporal Variation ◽

Indoor Radon ◽

Epidemiological Studies ◽

Radon Progeny ◽

Indoor Radon Concentration ◽

Special Investigation ◽

Equilibrium Factor ◽

Average Value ◽

Long Time ◽

Gas Measurements

Epidemiological case control study is considered to be primary instrument to investigate the relationship between population indoor radon exposure and risk of lung cancer. A number of such studies had been completed in last 15 years and others are running now. Considering indoor radon and progeny some specific efforts should be undertaken to assess the exposure. While the lungs exposure after inhalation arises mainly due to radon progeny, in the case of the radon gas measurements application the researchers have to address the disequilibrium between radon and radon progeny. It is widely accepted by researchers and approved by ICRP that worldwide average value of equilibrium factor is 0.4 though real equilibrium factor value can deviate significantly from average. Temporal variation of indoor radon concentration complicates the evaluation of exposure as well. Three types of variation can be emphasized: diurnal, seasonal and long time. Experimental and modeling investigation of radon entry shown that pattern of indoor radon temporal variation firmly depends on relationship between entry rates of primary radon sources (diffusive and advective) and influencing factors are construction characteristics, climatic condition and life style. To find appropriate parameters describing radon disequilibrium and temporal variation it is necessary to perform special investigation in the representative sample of houses.

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Reducing measurement uncertainties of high-pressure gas flow calibrations by using reference values based on multiple independent traceability chains

tm - Technisches Messen ◽

10.1515/teme-2018-0019 ◽

2018 ◽

Vol 85 (12) ◽

pp. 754-763

Author(s):

Jos van der Grinten ◽

Henri Foulon ◽

Arnthor Gunnarsson ◽

Bodo Mickan

Keyword(s):

High Pressure ◽

Gas Flow ◽

Weighted Average ◽

Reference Value ◽

Polynomial Equation ◽

Calibration Data ◽

Traceability Chain ◽

Uncertainty Sources ◽

Flow Reynolds Number ◽

Measurement Uncertainties

Abstract This paper describes the recently updated realization of the harmonized cubic metre for natural gas. It is a procedure based on an intercomparison, that combines the mutually independent traceability chains of four primary laboratories in the field of high-pressure gas flow measurement. The reference value, also called harmonized cubic metre, is the weighted average of at least two laboratories with weighing factors that are inversely proportional to the squared uncertainties of the calibration results. This results in lower uncertainties for the laboratories as long as the stochastic contributions (Type A) to the overall measurement uncertainties are significantly smaller than the uncertainties arising from the traceability chain (Type B). This condition is fulfilled in practice as traceability uncertainties are at least a factor ten greater than the other uncertainty sources. When evaluating the data of intercomparisons, curve fitting is used for the representation of the calibration data. A polynomial equation of maximum four degrees, expressed in the logarithm of the flow Reynolds number, proves to be the optimum choice for fitting the calibration curve of the turbine gasmeters.

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High accuracy measurements of dry mole fractions of carbon dioxide and methane in humid air

Atmospheric Measurement Techniques ◽

10.5194/amt-6-837-2013 ◽

2013 ◽

Vol 6 (3) ◽

pp. 837-860 ◽

Cited By ~ 116

Author(s):

C. W. Rella ◽

H. Chen ◽

A. E. Andrews ◽

A. Filges ◽

C. Gerbig ◽

...

Keyword(s):

Carbon Dioxide ◽

Greenhouse Gas ◽

Water Vapour ◽

Measurement Techniques ◽

Dew Point ◽

Correction Factors ◽

Gas Streams ◽

Water Vapour Concentration ◽

Vapour Concentration ◽

Gas Measurements

Abstract. Traditional techniques for measuring the mole fractions of greenhouse gases in the well-mixed atmosphere have required dry sample gas streams (dew point < −25 °C) to achieve the inter-laboratory compatibility goals set forth by the Global Atmosphere Watch programme of the World Meteorological Organisation (WMO/GAW) for carbon dioxide (±0.1 ppm in the Northern Hemisphere and ±0.05 ppm in the Southern Hemisphere) and methane (±2 ppb). Drying the sample gas to low levels of water vapour can be expensive, time-consuming, and/or problematic, especially at remote sites where access is difficult. Recent advances in optical measurement techniques, in particular cavity ring down spectroscopy, have led to the development of greenhouse gas analysers capable of simultaneous measurements of carbon dioxide, methane and water vapour. Unlike many older technologies, which can suffer from significant uncorrected interference from water vapour, these instruments permit accurate and precise greenhouse gas measurements that can meet the WMO/GAW inter-laboratory compatibility goals (WMO, 2011a) without drying the sample gas. In this paper, we present laboratory methodology for empirically deriving the water vapour correction factors, and we summarise a series of in-situ validation experiments comparing the measurements in humid gas streams to well-characterised dry-gas measurements. By using the manufacturer-supplied correction factors, the dry-mole fraction measurements have been demonstrated to be well within the GAW compatibility goals up to a water vapour concentration of at least 1%. By determining the correction factors for individual instruments once at the start of life, this water vapour concentration range can be extended to at least 2% over the life of the instrument, and if the correction factors are determined periodically over time, the evidence suggests that this range can be extended up to and even above 4% water vapour concentrations.

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Non-Intrusive Measurements to Incorporate the Air Renovations in Dynamic Models Assessing the In-Situ Thermal Performance of Buildings

Energies ◽

10.3390/en14010037 ◽

2020 ◽

Vol 14 (1) ◽

pp. 37

Author(s):

María José Jiménez ◽

José Alberto Díaz ◽

Antonio Javier Alonso ◽

Sergio Castaño ◽

Manuel Pérez

Keyword(s):

Mechanical Ventilation ◽

Reference Values ◽

Dynamic Models ◽

Measurement Techniques ◽

Co2 Concentration ◽

Air Leakage ◽

Tracer Gas ◽

Gas Measurements ◽

Different Levels

This paper reports the analysis of the feasibility to characterise the air leakage and the mechanical ventilation avoiding the intrusiveness of the traditional measurement techniques of the corresponding indicators in buildings. The viability of obtaining the air renovation rate itself from measurements of the concentration of the metabolic CO2, and the possibilities to express this rate as function of other climatic variables, are studied. N2O tracer gas measurements have been taken as reference. A Test Cell and two full size buildings, with and without mechanical ventilation and with different levels of air leakage, are considered as case studies. One-month test campaigns have been used for the reference N2O tracer gas experiments. Longer periods are available for the analysis based on CO2 concentration. When the mechanical ventilation is not active, the results indicate significant correlation between the air renovation rate and the wind speed. The agreement between the N2O reference values and the evolution of the metabolic CO2 is larger for larger initial values of the CO2 concentration. When the mechanical ventilation is active, relevant variations have been observed among the N2O reference values along the test campaigns, without evidencing any correlation with the considered boundary variables.

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The AquaVIT-1 intercomparison of atmospheric water vapor measurement techniques

Atmospheric Measurement Techniques ◽

10.5194/amt-7-3177-2014 ◽

2014 ◽

Vol 7 (9) ◽

pp. 3177-3213 ◽

Cited By ~ 58

Author(s):

D. W. Fahey ◽

R.-S. Gao ◽

O. Möhler ◽

H. Saathoff ◽

C. Schiller ◽

...

Keyword(s):

Water Vapor ◽

Measurement Techniques ◽

Reference Value ◽

Atmospheric Water Vapor ◽

Mixing Ratio ◽

Atmospheric Water ◽

Atmospheric Measurements ◽

Core Subset ◽

Moving Platforms ◽

Chamber Volume

Abstract. The AquaVIT-1 intercomparison of atmospheric water vapor measurement techniques was conducted at the aerosol and cloud simulation chamber AIDA (Aerosol Interaction and Dynamics in the Atmosphere) at the Karlsruhe Institute of Technology, Germany, in October 2007. The overall objective was to intercompare state-of-the-art and prototype atmospheric hygrometers with each other and with independent humidity standards under controlled conditions. This activity was conducted as a blind intercomparison with coordination by selected referees. The effort was motivated by persistent discrepancies found in atmospheric measurements involving multiple instruments operating on research aircraft and balloon platforms, particularly in the upper troposphere and lower stratosphere, where water vapor reaches its lowest atmospheric values (less than 10 ppm). With the AIDA chamber volume of 84 m3, multiple instruments analyzed air with a common water vapor mixing ratio, by extracting air into instrument flow systems, by locating instruments inside the chamber, or by sampling the chamber volume optically. The intercomparison was successfully conducted over 10 days during which pressure, temperature, and mixing ratio were systematically varied (50 to 500 hPa, 185 to 243 K, and 0.3 to 152 ppm). In the absence of an accepted reference instrument, the absolute accuracy of the instruments was not established. To evaluate the intercomparison, the reference value was taken to be the ensemble mean of a core subset of the measurements. For these core instruments, the agreement between 10 and 150 ppm of water vapor is considered good with variation about the reference value of about ±10% (±1σ). In the region of most interest between 1 and 10 ppm, the core subset agreement is fair with variation about the reference value of ±20% (±1σ). The upper limit of precision was also derived for each instrument from the reported data. The implication for atmospheric measurements is that the substantially larger differences observed during in-flight intercomparisons stem from other factors associated with the moving platforms or the non-laboratory environment. The success of AquaVIT-1 provides a template for future intercomparison efforts with water vapor or other species that are focused on improving the analytical quality of atmospheric measurements on moving platforms.

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