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This study aimed to clarify the dosimetric impact of calibration beam quality for calibration coefficients of the absorbed dose to water for an ionization chamber in an on-site dosimetry audit. Institution-measured doses of 200 photon and 184 electron beams were compared with the measured dose using one year data before and after the calibration of the ionization chamber used. For photon and electron reference dosimetry, the agreements of the institution-measured dose against two measured doses in this audit were evaluated using the calibration coefficients determined using 60Co (⁠|${N}_{D,\mathrm{w},{}^{60}\mathrm{Co}}$|⁠) and linear accelerator (linac) (⁠|${N}_{D,\mathrm{w},Q}$|⁠) beams. For electron reference dosimetry, the agreement of two institution-measured doses against the measured dose was evaluated using |${N}_{D,\mathrm{w},Q}$|⁠. Institution-measured doses were evaluated using direct- and cross-calibration coefficients. For photon reference dosimetry, the mean differences and standard deviation (SD) of institution-measured dose against the measured dose using |${N}_{D,\mathrm{w},{}^{60}\mathrm{Co}}$| and |${N}_{D,\mathrm{w},Q}$| were −0.1% ± 0.4% and −0.3% ± 0.4%, respectively. For electron reference dosimetry, the mean differences and SD of institution-measured dose using the direct-calibration coefficient against the measured dose using |${N}_{D,\mathrm{w},{}^{60}\mathrm{Co}}$| and |${N}_{D,\mathrm{w},Q}$| were 1.3% ± 0.8% and 0.8% ± 0.8%, respectively. Further, the mean differences and SD of institution-measured dose using the cross-calibration coefficient against the measured dose using |${N}_{D,\mathrm{w},Q}$| were −0.1% ± 0.6%. For photon beams, the dosimetric impact of introducing calibration coefficients determined using linac beams was small. For electron beams, it was larger, and the measured dose using |${N}_{D,\mathrm{w},Q}$| was most consistent with the institution-measured dose, which was evaluated using a cross-calibration coefficient. [ABSTRACT FROM AUTHOR]

Supersaturation of total dissolved gas (TDG) is a common occurrence in high dams during the spill process, which can lead to fish bubble disease and threaten aquatic organisms. As a result, many scholars have taken a keen interest in this issue. Research into the gas-liquid mass transfer mechanism has improved the accuracy of TDG prediction models. This article investigates the factors affecting TDG dissipation through laboratory experiments. Especially, the mass transfer coefficient across the bubble interface based on the slip penetration model was calibrated, and the coaxial bubble coalescence added to the coefficient was studied. The results show that the aeration rate has the most significant impact, followed by water depth, and then the aeration aperture. The TDG dissipation rate increases with the parameter β, and the parameter of 0.35 shows the highest correlation with the experimental data. Furthermore, the concentration change rate after coalescence is lower than before, suggesting that aggregation negatively impacts mass transfer. This study improves TDG concentration prediction accuracy and proposes measures for mitigating supersaturation to avoid fish bubble disease. [ABSTRACT FROM AUTHOR]

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An accurate determination of water content in garnet is critical to quantify the transport of water to the deep mantle by the subducted oceanic crust beyond the breakdown of hydrous phases. Fourier transform infrared spectroscopy (FTIR) is the most widely used approach to determine the species and contents of water in garnet. Accurate quantification of OH in garnet requires independent calibration using an external method, as OH absorbance is mineral and composition specific. To obtain the infrared absorption coefficients of structural hydroxyl in garnet, a combined study of spectrometric analyses by FTIR and a method combining a thermal conversion elemental analyser with isotope ratio mass spectrometry (TC/EA‐MS) was carried out for fourteen gem‐quality natural garnet crystals with variable compositions. The obtained molar absorption coefficients were 9322 ± 338 and 240 ± 26 l mol−1 cm−2 for grossular‐ and spessartine‐rich garnet and pyrope‐almandine garnet, respectively. These results are within the range of previous studies. A new molar absorption coefficient of 689 ± 177 l mol−1 cm−2 was obtained for pyrope‐spessartine garnet. The large variation in the absorption coefficient indicates it is controlled by both garnet composition and OH‐absorption bands. The obtained absorption coefficients are only appropriate for certain types of eclogitic garnet, and more studies should be carried out on eclogitic garnets. [ABSTRACT FROM AUTHOR]

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this paper is to compare incremental and integral techniques in non-uniform residual stress measurement by the ring-core method and to present a procedure to determine the calibration coefficients of the integral technique. The mathematical basis of the integral technique for use in the ring-core method is explained. To determine the calibration coefficients of the integral technique a 3D FE model was introduced and the calibration coefficients are also presented in separate tables. The FE analysis of the pure bending and ring-core method were used to show the effectiveness of the presented coefficients and compare the integral and incremental techniques. The results indicated that the calculated non-uniform residual stresses by the integral technique were closer to the real values in comparison with the incremental method. Moreover, it was observed that the accuracy of the results decreased by increasing the depth of the groove.

It has been observed that the lab-based calibration coefficients of a satellite instrument differ in the actual in-orbit operation due to different environmental conditions. The lab-based coefficients are measured when all the components of the satellite instrument are in thermal equilibrium, while during in-orbit operations, there may be significant variations in temperature between various components as well as the diurnal temperature gradients of subsystems, especially in the geostationary platform due to midnight sunray intrusion. This article proposes a new technique to measure the in-orbit calibration coefficients using the collocated matchup data at different electrooptical module temperatures of the INSAT-3D/3DR imager counts and hyperspectral sounder radiances such as Advanced InfraRed Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI) that are considered as the reference instruments. The radiances generated by new calibration coefficients show less bias and standard deviations for all infrared (IR) channels of INSAT-3D and INSAT-3DR when compared with the convolved radiances generated from the AIRS and IASI radiances using the procedure established by the Global Space-based Intercalibration System (GSICS). [ABSTRACT FROM AUTHOR]

The rectangular sharp-crested weir often finds in irrigation open channels. The function of the rectangular sharp-crested weir measures and divides the water flow to be distributed to agricultural lands. The Rehbock equation, the Kinsvater-Carter equation, and the General equation are used to approach the discharge. On a laboratory scale, the measurement of the discharge using a small rectangular sharp-crested weir was used for experiments and simulations. Because of using The Rehbock equation, The Kinsvater-Carter equation, and The General equation for a field discharge measurements, it is necessary to research to find out the accuracy of the Rehbock Equation, the Kinsvater-Carter equation and the General equation in the laboratory scale. The research data included the dimensions of rectangular weirs, the height of the water on the rectangular sharp-crested weir, the width of the channel on the hydraulic bench and the actual discharge. Data collection of the height of water on the rectangular sharp-crested weir and the actual discharge was carried out 5 times the measurements with different discharges. These data were analyzed using the Rehbock equation, the Kinsvater-Carter equation, and the General equation. The discharge of the analysis results was compared with the actual discharge to find out the value of the calibration coefficient. The experimental results show that the Kinsvater-Carter equation and General equation can be applied for discharge measurements on the laboratory scale. The calibration coefficient for the Kinsvater-charter equation was 0.89 and the calibration coefficient for the general equation was 0.94.

Calibration standards are used for the calibration of a vector network analyzer to characterize the microwave components under test. For the direct characterization of coplanar waveguide components, two-port CPW open, short and line are proposed to complement the existing calibration techniques. The developed CPW standards are characterized in the frequency range of 10 MHz to 10 GHz. As these are planar structures, effects of small superstrates on the calibration coefficients of open and short are studied also. The CPW line has shown slight changes in impedance due to superstrates, whereas a few calibration coefficients of open and short standards showed dependence on superstrates. Similar observations are noted by improving the polynomial models of CPW open and short standards up to fifth and sixth order, respectively, which better matches for CPW standards. The reported results are helpful to estimate any change in the measurement uncertainty on using such calibration standards due to superstrates. [ABSTRACT FROM AUTHOR]

Purpose: To clinically implement and comprehensively evaluate two independent methods for beam monitor calibration of scanning proton beam. Methods: Seven proton energies that represent the lowest to highest energy proton beams were selected. Single energy layer circular fields of diameter 15 cm with 2.5 mm spot spacing and 10 times of repainting (FS15cm) were designed for all energies. The effective measurement points of Bragg peak chamber (BPC), advanced Markus chamber (AMC) and farmer chamber (FC) were all aligned to 2 cm depth in water using SSD setup. The BPC and AMC were cross‐calibrated with farmer chamber (FC) using the field FS15cm. In order to evaluate BPC's lateral response uniformity, a collimated narrow proton beam (5.8 mm diameter) was delivered to the active area and edge of the BPC. The dose area product (DAP) was measured using two methods by two BPCs, one AMC and one FC. For method 1, a single spot proton beam was delivered to the geometric center of the BPC. For method 2, the fields FS15cm were delivered to FC and AMC, respectively. Accumulated charges by these chambers were converted to DAPs, and the quantitative difference of DAPs between both methods was calculated. The causes of the uncertainties were discussed, and the advantages of the two methods were compared. Results: The two BPCs showed different lateral response uniformity. BPC1 has a uniform response from the center up to a radius of 3.5 cm. BPC2 has a uniform response only to 2 cm and the response dropped 1% to 2% at 3.5 cm from center. BPC2 also has significant over‐response compared to BPC1. A 2.2% systematic error would be transferred to DAP if the over‐response from BPC2 was not considered. The DAPs measured by method 1 with two BPCs and by method 2 with FC and AMC were consistent to 0.5%. The major uncertainty component of method 1 is from the cross‐calibration of the BPC. Conclusions: The two independent methods for DAP were shown to give consistent results, given the sources of uncertainties were carefully addressed in the measurements. Direct measurement of DAP with BPC is very efficient, but it may be subject to more than 2% systematic error if the BPC lateral response is not carefully evaluated. [ABSTRACT FROM AUTHOR]

A spoke type permanent magnet synchronous motor generates axial leakage magnetic flux due to its flux-concentrating rotor structure, and therefore degrades the motor performance. Although a three-dimensional finite element method (3-D FEM) can be used to estimate the axial leakage magnetic flux, it requires a significant amount of time for analysis. In this article, a calibration coefficient is proposed to estimate the axial leakage magnetic flux using the two-dimensional finite element method (2-D FEM) instead of 3-D FEM. This calibration coefficient is expressed in terms of the major geometric parameters of a motor and can be calculated using the material information of the permanent magnet and the bridge of the rotor core in 2-D FEM. The validity of the proposed equation is verified through 3-D FEM and other tests. [ABSTRACT FROM AUTHOR]

BackgroundMeasurement of radiation environment γ dose rate is greatly influenced by the high energy charged particles of cosmic rays which varies in different inspection sites. Different types of radiometers are affected differently due to the different cosmic ray response and calibration coefficient.PurposeThis study aims to verify the feasibility of the terrestrial measuring method for cosmic ray response and calibration coefficient of radiometer.MethodsFirst of all, calculation of cosmic ray response and calibration coefficient of radiometer by radiation test field measurement was proposed, then, two types of radiometer 6150AD and RSS-131 were employed to measure radiation field at two different γ dose rate levels. Repeat measurements were performed using the same radiometers at short intervals (4 days) to investigate the repeatability of measurement fitting results. Finally, four types of radiometer, i.e., RSS-131, 6150AD, BH3103 and RED-100, 14 sets in total γ radiometers, were used in both radiation inspection field and one test site of WanLv lake (in Guangdong province) for comparison and verification.ResultsMeasured results at radiation test field show that best cosmic ray response transfer effect is achievable between the same type of radiometers in the low dose rate with maximum dose rate less than 500 nGy·h-1. Experimental results of 11 radiometers of four types show that cosmic ray response values obtained by the calculation method determined by experiments, are basically consistent with the actual measured values of the same radiometer in Wanlv lake, and the relative deviation between the calibration coefficient determined by this method and the effective calibration coefficient of the radiometer is within 10%.ConclusionsThe terrestrial measurement method can replace the actual measurement to determine the cosmic ray response and calibration coefficient of the radiometer.

Abstract The 18F F-labeled fluoro-2-deoxyglucose (18F-FDG) is the most widely used cyclotron-generated positron-emitting radiopharmaceutical in the clinical applications of PET scans. The production of radiopharmaceuticals such as 18F-FDG always presents internal contamination risks for the occupationally exposed workers. It is important to perform Individual monitoring on workers in case of incorporation or routinely. Usually, the calibration of these internal monitoring systems is performed using physical phantoms. This work aims to present the development of a physical head phantom for the calibration of an 18F-FDG in vivo internal monitoring system. Two materials, M1 and M2, composed of water, agar, and urea were proposed for the solid brain equivalent tissue. These materials presented the required characteristics of a brain equivalent tissue for the physical phantom construction in terms of morphology, material distribution, radiation attenuation, consistency, availability and low cost. Computational studies were performed to evaluate the effectiveness of the proposed materials. The calibration coefficients obtained for physical head phantom produced with material M2 and a known activity of 18F-FDG showed a good correlation with Monte Carlo results. Highlights • Calibration process using a physical head phantom. • Production of a physical head phantom for internal dosimetry of 18F-FDG. • Monte Carlo simulations of a head phantom. [ABSTRACT FROM AUTHOR]

In recent years, Korea has sustained consistent access to remote sensed data by launching Korea Multi-Purpose Satellite-3A (KOMPSAT-3A, K3A)—an updated version of the high-resolution KOMPSAT series. This KOMPSAT-3A required calibration and validation (Cal/Val) before and after its launch to enable proper functional characterization and to maintain the veracity of data collected. The Korea Aerospace Research Institute (KARI) executed the initial prelaunch calibration in the laboratory and we performed the Cal/Val of KOMPSAT-3A during the Launch and Early Operation Phase (LEOP) in the field. Two suitable sites in Korea and Mongolia with stable weather, almost uniform terrain, and near Lambertian diffusion, provided the necessary tarp reflectance to calculate the absolute radiometric calibration coefficients. The surface reflectance was determined using 12 and four well-calibrated reference reflectance tarps employing the FieldSpec® 3(Analytical Spectral Devices Inc., Boulder, CO, USA) Spectroradiometer. Subsequently, the top of atmosphere (TOA) radiance was estimated using radiative transfer code (RTC) software based on the Atmospheric and Topographic Correction (ATCOR). In addition, cross calibration was simultaneously performed at the Libya-4 pseudo invariant calibration site (PICS) for KOMPSAT-3A TOA radiance, using the spectral band adjustment factor (SBAF) compensated Landsat 8 reflectance and the Second Simulation of Satellite Signal in the Solar Spectrum (6S) to compute cross calibration coefficients. The results of the KOMPSAT-3A absolute calibration coefficient show that the R2 values were over 0.99, implying a significant correlation for almost all bands between the TOA radiance and the KOMPSAT-3A spectral band response at both campaign sites. However, this study reveals a difference of less than 5% calibration gains for all bands compared to the prelaunch values, while the cross calibration gain is below 5% in visible bands and above 5% in the near infrared band. An effort to optimize the reliability of the absolute calibration coefficients resorted to the rigorous quantification of uncertainties amongst atmospheric conditions, the digital number (DN), the reflectance tarp, the bidirectional reflectance distribution function (BRDF), and ozone levels. Therefore, we presumed that the total uncertainty was 4.27%, which conforms to some published results.

Introduced in 2011, the supervised vicarious calibration (SVC) approach is a promising approach to radiometric calibration and atmospheric correction of airborne hyperspectral (HRS) data. This paper presents a comprehensive study by which the SVC method has been systematically examined and a complete protocol for its practical execution has been established—along with possible limitations encountered during the campaign. The technique was applied to multi-sourced HRS data in order to: (1) verify the at-sensor radiometric calibration and (2) obtain radiometric and atmospheric correction coefficients. Spanning two select study sites along the southeast coast of France, data were collected simultaneously by three airborne sensors (AisaDUAL, AHS and CASI-1500i) aboard two aircrafts (CASA of National Institute for Aerospace Technology INTA ES and DORNIER 228 of NERC-ARSF Centre UK). The SVC ground calibration site was assembled along sand dunes near Montpellier and the thematic data were acquired from other areas in the south of France (Salon-de-Provence, Marseille, Avignon and Montpellier) on 28 October 2010 between 12:00 and 16:00 UTC. The results of this study confirm that the SVC method enables reliable inspection and, if necessary, in-situ fine radiometric recalibration of airborne hyperspectral data. Independent of sensor or platform quality, the SVC approach allows users to improve at-sensor data to obtain more accurate physical units and subsequently improved reflectance information. Flight direction was found to be important, whereas the flight altitude posed very low impact. The numerous rules and major outcomes of this experiment enable a new standard of atmospherically corrected data based on better radiometric output. Future research should examine the potential of SVC to be applied to super-and-hyperspectral data obtained from on-orbit sensors.

Abstract This paper presents experimental and theoretical determination of CR-39 and Makrofol calibration coefficients in diffusion chambers for radon measurements. Experimental calibration was performed by irradiation of detectors in a calibration chamber; radon concentration in the chamber was continuosly measured by RAD7 device. Calculations were performed by the previously developed software for CR-39 detector. In addition the software was modified to enable calculation for Makrofol by implementing V function and other relevant data for this kind of detector. A good agreement was found between experimental and theoretical approaches. The comparison enabled selecting V function for CR-39 that gave the best agreement with the experimental results. Optimisation of chamber and detector dimensions was theoretically performed for different etching times. The dependence of calibration coefficient on 218Po deposition fraction was also analysed. Highlights • Experimental and theoretical calibration of CR-39 and Makrofol detectors were done. • V function for Makrofol was presented. • Previously developed software was modified to enable Makrofol calibration. • Optimisation of chamber and detector dimensions was theoretically performed. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A proper calibration of newly developed dosimeter is essential for achieving a satisfactory therapeutic outcome in radiotherapy treatment. The uncertainty in each process phase must be kept within predefined acceptable ranges. This study investigated the effects of various experimental uncertainties during the calibration of the Ge-doped cylindrical optical fibre (GeDCOF) and TLD-100. The calibration curves for GeDCOF and TLD-100 were developed utilizing 6 MV and 10 MV photon beams at doses ranging from 1.25 Gy to 2.75 Gy. The GeDCOF and TLD-100 were calibrated against the NE 2571 ionization chamber under reference conditions. The absorbed dose for each thermoluminescence (TL) dosimeter was determined following the TRS 398 Code of Practice. The uncertainties for individual parameters used for calculating the calibration coefficients (N) of GeDCOF and TLD-100 were analyzed based on the combined effects of the Type A and Type B uncertainties. In the calibration of GeDCOF and TLD-100, a substantial positive correlation between TL signals and the absorbed dose was observed, with a coefficient of determination (R2) greater than 0.99 for both 6 MV and 10 MV photon beams. The uncertainties in measuring N were determined to be caused by three major contributors: 1) uncertainties in the absorbed dose to water provided by the ionization chamber system (u(D i)), 2) uncertainties in GeDCOF and TLD-100 readings within the capsule (u(R i)), and 3) uncertainties in the dosimeter position (u(pR i)). The combined uncertainty in calibration coefficients (u c (N)) of GeDCOF and TLD-100 was calculated to be 0.76% and 0.73% for 6 MV photon beam, respectively, and 0.81% and 0.79% for 10 MV photon beam. The analysis demonstrates that the uncertainties in the calibration coefficient of the GeDCOF and TLD-100 are comparable and that the 2% dose uncertainty estimates for relative dosimetry systems are realistic. [ABSTRACT FROM AUTHOR]

Calibration of radiometer systems using physical temperature monitoring have been developed to compensate the temperature drift. Because calibration standards are not necessary to obtain the system response characteristic, it is good candidate for applications of the limited weight and power. Besides, the estimation of the calibration accuracy could be improved by stable condition based on multiple temperature sensors. In this paper, we analyzed the estimated calibration accuracy under indoor environmental conditions using multiple temperature sensors for a $W$ -band direct detection radiometer system. The method was implemented to obtain the radiometer calibration coefficient based on the relationship between the temperature sensors at multiple positions and the gain variation. The estimated accuracy of the brightness temperature was determined by the temperature sensor response with respect to the receiver gain variation under environmental conditions. The distributed temperature sensors were considered for optimum regression of the radiometer gain variation in a heated environment. [ABSTRACT FROM PUBLISHER]

Introduced in 2011, the supervised vicarious calibration (SVC) approach is a promising approach to radiometric calibration and atmospheric correction of airborne hyperspectral (HRS) data. This paper presents a comprehensive study by which the SVC method has been systematically examined and a complete protocol for its practical execution has been established-along with possible limitations encountered during the campaign. The technique was applied to multi-sourced HRS data in order to: (1) verify the at-sensor radiometric calibration and (2) obtain radiometric and atmospheric correction coefficients. Spanning two select study sites along the southeast coast of France, data were collected simultaneously by three airborne sensors (AisaDUAL, AHS and CASI-1500i) aboard two aircrafts (CASA of National Institute for Aerospace Technology INTA ES and DORNIER 228 of NERC-ARSF Centre UK). The SVC ground calibration site was assembled along sand dunes near Montpellier and the thematic data were acquired from other areas in the south of France (Salon-de-Provence, Marseille, Avignon and Montpellier) on 28 October 2010 between 12:00 and 16:00 UTC. The results of this study confirm that the SVC method enables reliable inspection and, if necessary, in-situ fine radiometric recalibration of airborne hyperspectral data. Independent of sensor or platform quality, the SVC approach allows users to improve at-sensor data to obtain more accurate physical units and subsequently improved reflectance information. Flight direction was found to be important, whereas the flight altitude posed very low impact. The numerous rules and major outcomes of this experiment enable a new standard of atmospherically corrected data based on better radiometric output. Future research should examine the potential of SVC to be applied to super-and-hyperspectral data obtained from on-orbit sensors. [ABSTRACT FROM AUTHOR]

We present a more accurate method for the quantification of superoxide anion (O·) and hydrogen peroxide (HO) simultaneously in human HepG2 cell extracts. After the xanthine/xanthine oxidase system was added into cell extract which was devoid of O· and HO, steady-state and in-situ produced O· and HO by xanthine/xanthine oxidase system was labeled by fluorescent probes and subsequently separated by microchip electrophoresis. Based on this method, two differential equations with the calibration coefficients were established for O· and HO, respectively. Using the established dual-calibration coefficients, we obtained the calibrated concentrations of O· and HO that produced in human HepG2 cells, which were lower (0.66±0.03 and 0.82±0.04 µmol/L for O· and HO, respectively) than that (0.85±0.03 and 0.96±0.03 µmol/L for O· and HO, respectively) obtained from statutory working curve. The proposed dual-calibration coefficient protocol takes into account both the complex matrix effect of the biological system and real time decaying of O· and HO, providing a method with higher accuracy. [ABSTRACT FROM AUTHOR]