Average Correction Factor Research Articles

Innovating building energy regulations enabled by radiative sky cooling: Enhanced code of practice for overall thermal transfer value (OTTV) of super-cool roofs

Radiative sky cooling, which utilizes outer space as the cooling source for heat dissipation, is attracting global interests for its ability to cool passively without using any energy. Considering the swift advancements in the production of cost-effective radiative sky cooling materials on a large scale, it is of practical significance to incorporate radiative sky cooling technology into buildings to improve energy efficiency, necessitating amendment of the corresponding regulations. With this objective, the present research particularly focuses on the impact of radiative sky cooling-based super-cool roof strategies on the code of practice for Overall Thermal Transfer Value (OTTV), which is a prescriptive building regulation introduced by the Hong Kong government for building design, aimed at providing correction factors for local typical roofs integrated with advanced radiative sky cooling materials. To achieve the purpose, a new model for predicting roof heat transfer based on radiative sky cooling was established. Scaled-down experiments were conducted to fully validate the developed model with sufficient accuracy. The findings indicate that the implementation of super-cool roof strategies through radiative cooling-based techniques can substantially decrease roof heat gains, with reductions ranging from 73.9 % to 90.7 %, yield considerable energy savings, averaging between 3.5 and 45.0 kWh/m2, as well as significant cost savings on cooling expenses, averaging from 5.8 to 74.2 HKD/m2. Moreover, the adoption of such strategies has the potential to reduce carbon emissions by 6.3 to 81.2 kg/m2 during the cooling season. These outcomes vary depending on factors like the coefficient of performance (COP), radiative cooling materials, and specific roof types. Correlations between roof heat gains and OTTVs are established with a high accuracy of fit, achieving a coefficient of determination as high as 0.978. The average correction factors of five cutting-edge radiative cooling materials range from −0.00563 to −0.01655 in response to different typical roof types. Utilizing these correction factors, incorporating radiative sky cooling materials results in the OTTV of super-cool roofs varying from −0.7216 to −0.239 W/m2, which are significantly below the prevailing OTTV limit of 21 W/m2 enforced for Hong Kong’s commercial buildings. The proposed approach in this study can provide a straightforward and practical approach to assess the OTTV of typical building roofs when integrated with cutting-edge radiative sky cooling materials. This research offers significant perspectives into evolution and innovation of building energy policies incorporating radiative sky cooling technology.

IMPROVING THE ACCURACY OF CALCULATION WEIGHTS BY VISUAL INPUT: A PILOT STUDY IN THE EMERGENCY DEPARTMENT OF A LOW MIDDLE-INCOME COUNTRY

Accurate weight estimation is critical in emergency medical scenarios requiring immediate interventions. This pilot study explores the feasibility of improving weight calculation accuracy through visual input, focusing on height-based estimations. The research aims to contribute valuable insights to weight estimation methodologies, particularly in resource-constrained settings. The objective of the pilot study is to explore the feasibility of improving weight calculation accuracy through visual input, focusing on height-based estimations. Data was collected encompassing diverse height ranges from 1.45 to 1.94 meters. Comprehensive datasets included actual body weights, estimated weights, standard deviation, and standard error. eBW(kg) = (N− 1)100 is the estimated body weight method, where "N" is the height measured in meters. Body weight classifications were employed to analyze the accuracy of estimations further. Correction factors for everyone were computed. The correction factor separates the obtained data into underweight, close to actual weight, and overweight. Following optimization, the average correction factor for every category is updated. These updated correction factors improve weight estimation precision. Linear regression analyses were conducted to compare actual and estimated weights, visually representing the discrepancies. The calculated correction factors are essential to improving weight calculations in medicine. The thorough research and improvement procedure resulted in revised correction factors significantly improving the precision of weight estimates in the medical field. We can say that the following equation provides a more accurate weight estimate. Wt corrected = (N-1) x 100 x Correction Factor. This revised weight is an enhanced estimate that considers the updated correction factors. The calculated correction variables are essential to improving weight estimations in medicine. The thorough research and improvement procedure resulted in revised correction factors that significantly improved the precision of weight estimations in the medical field. The derived correction factors demonstrate their effectiveness in enhancing weight estimations, notably in specific patient groups. The investigation classifies patients and delivers precise modifications to improve weight estimations, ensuring safer prescribing procedures. The proposed correction variables will be critical in evaluating emergency medicine doses for individuals.

Laboratory Characterisation of a Commercial RGB CMOS Camera for Measuring Night Sky Brightness

The use of RGB cameras in photometric applications has grown over the last few decades in many fields such as industrial applications, light engineering and the analysis of the quality of the night sky. In this last field, they are often used in conjunction with a Sky Quality Meter (SQM), an instrument used for the measurement of night sky brightness (NSB), mainly when there is a significant amount of artificial light at night (ALAN). The performances of these two instruments are compared here. A simple source composed of nine narrowband LEDs in an integrating sphere was used to excite the two instruments and therefore measure the spectral responsivity of the SQM and of the three channels of the camera. The estimated uncertainties regarding spectral responsivity were less than 10%. A synthetic instrument approximating the SQM’s responsivity can be created using a combination of the R, G and B channels. The outputs of the two instruments were compared by measuring the spectral radiance of the night sky. An evaluation of the spectral mismatch between the two instruments completed the analysis of their spectral sensitivity. Finally, the measurements of real SQMs in four sites experiencing different levels of light pollution were compared with the values obtained by processing the recorded RGB images. Overall, the analysis shows that the two instruments have significantly different levels of spectral responsivity, and the alignment of their outputs requires the use of a correction which depends on the spectral distribution of the light coming from the sky. A synthetic SQM will always underestimate real SQM measures; an average correction factor was evaluated considering nine sky spectra under low and medium levels of light pollution; this was determined to be 1.11 and, on average, compensated for the gap. A linear correction was also supposed based on the correlation between the NSB levels measured by the two instruments; the mean squared error after the correction was 0.03 mag arcsec−2.

Nanoscale flow-induced nonlinear vibration of multilayer graphene based-resonators: Slip and transition flow regimes

This paper presents a nanoscale fluid-structure interaction (FSI) model for flow-induced nonlinear vibration of multilayer graphene based-resonators in the slip and transition regimes. Based on the multibeam interlayer shear model with von Kármán geometric nonlinearity and nonlocal modified couple stress theory, the size-dependent equations of motion are obtained for beam resonators laminated of NG-graphene layer and (NG−1) interlayer crosslinks. The small-scale effect on effective viscosity and slip boundary conditions of nanoscale flow is formulated by introducing the average velocity correction factor. For unbounded and bounded (by a rigid wall) nanoflows, the closed-form expressions of velocity correction factor in terms of Knudsen number, as a dimensionless discriminant parameter, are developed to correct the pressure distribution predicted by the potential theory. The present FSI model considers the size effects through the length scale parameter for microstructure local rotation, the nonlocal parameter for long-range interatomic interactions, and Knudsen number for slip condition of nanoscale flow. The Galerkin's method in conjunction with the multiple-scale perturbation technique is used to obtain closed-form solutions of frequency ratio and time-history response. The natural frequencies of cantilever multilayer graphene nanostrips are validated with the ones existing in the literature. Parametric studies are carried out to investigate the influences of small-scale, number of layers, interlayer shear modulus, and fluid characteristics on the linear and nonlinear natural frequencies. Findings show that the critical upstream speed for dynamic instability of the coupled system can change considerably by taking into account the size effects of nanoflow and nanostructures. Therefore, the classical FSI model is inadequate for analyzing nanoscale flow-induced vibration of nanoresonators. Also, it is seen that the effect of geometric nonlinearity becomes very significant for multilayer graphene beams with small interlayer shear modulus.

Global Corrections to Reference Irradiance Spectra for Non-Clear-Sky Conditions.

Photochemical reactions in surface waters play important roles in element cycling and in the removal of organic contaminants, among other processes. A central environmental variable affecting photochemical processes in surface waters is the incoming solar irradiance, as this initiates these processes. However, clear-sky incident irradiance spectra are often used when evaluating the fate of aquatic contaminants, leading to an overestimation of contaminant decay rates due to photochemical transformation. In this work, incident irradiance satellite data were used to develop global-scale non-clear-sky correction factors for commonly used reference irradiance spectra. Non-clear-sky conditions can decrease incident irradiance by over 90% depending on the geographic location and time of the year, with latitudes above 40°N being most heavily affected by seasons. The impact of non-clear-sky conditions on contaminant half-lives was illustrated in a case study of triclosan in lake Greifensee, which showed a 39% increase in the triclosan half-life over the course of a year under non-clear-sky conditions. A global annual average correction factor of 0.76 was determined as an approximate way to account for non-clear-sky conditions. The correction factors are developed at monthly and seasonal resolutions for every location on the globe between 70°N and 60°S at a 4 km spatial resolution and can be used by researchers, practitioners, and regulators who need improved estimates of incident irradiance.

Finite-wing-analogy formula for compressibility correction to pressure coefficient of an underwater vehicle model at low Mach number

Wind tunnels are usually used to investigate the flows and forces associated with underwater vehicles when free-surface effects can be ignored. However, because of the large differences between air and water in density and viscosity, the freestream Mach number in a wind tunnel is much higher than that in a water tunnel or towing tank at the same Reynolds number. Therefore, compressibility correction is required for accurate measurement compatibility between wind tunnels and water tunnels or towing tanks. In the study reported here, the flows and forces associated with an underwater vehicle model at different Mach numbers were investigated by solving the Navier–Stokes equations for compressible flow numerically as virtual-wind tunnel experiments. The freestream Mach number Ma varies from 0.004 to 0.5. The distribution of the pressure coefficient on the hull and the effects of Ma on the peaks of the pressure coefficient are discussed in detail. The performances of the Prandtl–Glauert rule, the Karman–Tsien rule, and the Laitone rule for compressibility correction to the pressure coefficient of underwater vehicles are assessed. Defining the average correction factor with larger values for better correction effect, the values for these three compressibility correction formulas are 0.51, 0.38, and 0.23, respectively. A finite-wing-analogy formula to improve the compressibility correction to the pressure coefficient at low Ma is proposed. Inspired by the finite-wing correction to the lift slope of airfoils, the proposed formula offers good convergence of the pressure coefficient and highly accurate compressibility correction with an average correction factor of 0.84.

Benefits and limitations of field-based monitoring approaches for respirable dust and crystalline silica applied in a sandstone quarry

With the advent of new sensing technologies and robust field-deployable analyzers, monitoring approaches can now generate valuable hazard information directly in the workplace. This is the case for monitoring respirable dust and respirable crystalline silica concentration levels. Estimating the quartz amount of a respirable dust sample by nondestructive analysis can be carried out using portable Fourier transform infrared spectroscopy (FTIR) units. Real-time respirable dust monitors, combined with small video cameras, allow advanced assessments using the Helmet-CAM methodology. These two field-based monitoring approaches, developed by the National Institute for Occupational Safety and Health (NIOSH), have been trialed in a sandstone quarry. Twenty-six Helmet-CAM sessions were conducted, and forty-one dust samples were collected around the quarry and analyzed on-site during two events. The generated data generated were used to characterize concentration levels for the monitored areas and workers, to identify good practices, and to illustrate activities that could be improved with additional engineered control technologies. Laboratory analysis of the collected samples complemented the field finding and provided an assessment of the performance of the field-based techniques. Only a fraction of the real-time respirable dust monitoring sessions data could be corrected with laboratory analysis. The average correction factor ratio was 5.0. Nevertheless, Helmet-CAM results provided valuable information for each session. The field-based quartz monitoring approach overestimated the concentration by a factor of 1.8, but it successfully assessed the quartz concentration trends in the quarry. The data collected could be used for the determination of a quarry calibration factor for future events. The quartz content in the dust was found to vary from 14% to 100%, and this indicates the need for multiple techniques in the characterization of respirable dust and quartz concentration and exposure. Overall, this study reports the importance of the adoption of field-based monitoring techniques when combined with a proper understanding and knowledge of the capabilities and limitations of each technique.

Laboratory Determination of Gravimetric Correction Factors for Real-time Area Measurements of Electronic Cigarette Aerosols.

Research on secondhand electronic cigarette (ECIG) aerosol exposure using aerosol monitors has demonstrated that ECIG use can generate high concentrations of particulate matter (PM) and impact indoor air quality. However, quantifying indoor air PM concentrations using real-time optical monitors with on-site calibration specifically for different PM exposures has not been established. Therefore, the ECIG aerosol filter correction factors were calculated for different PM sizes (PM1, PM2.5, and PM10) and different aerosol optical monitors, the MiniWRAS, pDR, and SidePak. ECIG aerosol generation was achieved using five ECIGs representing three ECIG types, disposable, pod-mod, and box mod. The aerosol size distribution by mass was measured for the five ECIGs during PM generation. Compared to the discrete filter measurements, the MiniWRAS performed the best when the concentrations were low, followed by the pDR and SidePak. The average PM concentrations and correction factor ranges for the different ECIGs were 323-1,775 μg/m3 and 0.64-6.01 for the MiniWRAS, 1,388-13,365 μg/m3 and 0.41-0.80 for the pDR, and 4,632-55,339 μg/m3 and 0.13-0.20 for the SidePak, respectively. The mass median diameter ranged from 0.41 and 0.62 μm, and most particles generated from the ECIGs were smaller than 1 μm. This study demonstrates that aerosol size distribution varies between ECIGs. Likewise, the correction factors developed for the real-time aerosol monitors are specific to the ECIG used. Thus, these data can help improve ECIG aerosol exposure measurement accuracy.

Experimental Volumetric Hydrogen Uptake Determination at 77 K of Commercially Available Metal-Organic Framework Materials

Storage is still limiting the implementation of hydrogen as an energy carrier to integrate the intermittent operation of renewable energy sources. Among different solutions to the currently used compressed or liquified hydrogen systems, physical adsorption at cryogenic temperature in porous materials is an attractive alternative due to its fast and reversible operation and the resulting reduction in storage pressure. The feasibility of cryoadsorption for hydrogen storage depends mainly on the performance of the used materials for the specific application, where metal-organic frameworks or MOFs are remarkable candidates. In this work, gravimetric and volumetric hydrogen uptakes at 77 K and up to 100 bar of commercially available MOFs were measured since these materials are made from relatively cheap and accessible building blocks. These materials also show relatively high porous properties and are currently near to large-scale production. The measuring device was calibrated at different room temperatures to calculate an average correction factor and standard deviation so that the correction deviation is included in the measurement error for better comparability with different measurements. The influence of measurement conditions was also studied, concluding that the available adsorbing area of material and the occupied volume of the sample are the most critical factors for a reproducible measurement, apart from the samples’ preparation before measurement. Finally, the actual volumetric storage density of the used powders was calculated by directly measuring their volume in the analysis cell, comparing that value with the maximum volumetric uptake considering the measured density of crystals. From this selection of commercial MOFs, the materials HKUST-1, PCN-250(Fe), MOF-177, and MOF-5 show true potential to fulfill a volumetric requirement of 40 g·L−1 on a material basis for hydrogen storage systems without further packing of the powders.

Whole-cell biosensors for determination of bioavailable pollutants in soils and sediments: Theory and practice

The bioavailability of pollutants is a key factor affecting environmental risk. Whole-cell bioreporters are a demonstratedly effective tool for the investigation of pollutant bioavailability in water and soil/sediment. Unlike aqueous samples, transmittance of bioreporter optical signal is reduced in direct-contact assays with soil/sediment, which affects the accuracy of bioreporter-detected pollutant bioavailability. No studies have measured the magnitude and variability of soil/sediment effects on signal in direct-contact assays or how associated uncertainties influence results. In this study, we investigate the optical effects of soil/sediment particles in suspensions on bioreporter signal transmittance and quantify how variable these optical effects are from sample-to-sample. We find that neglecting bioreporter signal diminution by soil/sediment, as many studies do, can lead to order-of-magnitude errors in results, underestimating risk. Correction based on methods in ad hoc use (e.g. comparison to signal from non-inducible reporter or use of reference soil/sediment) are also problematic for some types of experiment, and could lead to errors in excess of 30%. Our findings have a sound basis in theory, and we provide recommendations concerning the most suitable type of approach to use for different experimental settings. Generally, if best accuracy is not needed to quantify bioavailability, for samples that have been ground, sieved, and are of reasonably uniform color, it may be possible to use a single or average correction factor, particularly for experiments performed at a single slurry concentration. For investigations studying bioavailability under varying solid-phase:water ratios (e.g., sorption/desorption), detailed compensation measurements are needed for independent variables, including each specific soil/sediment sample, slurry concentration, and in some cases bioreporter signal intensity. Our measurements and calculations indicate that best results are obtained when working in the region of ballistic photon transmittance. Findings herein will be useful in areas that require information on bioavailability, such as ecotoxicology and environmental risk assessment.

Neural Network aided PMSM multi-objective design and optimization for more-electric aircraft applications

This study uses the Neural Network (NN) technique to optimize design of surface-mounted Permanent Magnet Synchronous Motors (PMSMs) for More-Electric Aircraft (MEA) applications. The key role of NN is to provide dedicated correction factors for the analytical PMSM mass and loss estimation within the entire design space. Based on that, a globally optimal design can be quickly obtained. Matching the analytical estimation with Finite-Element Analysis (FEA) is the main research target of training the NN. Conventional analytical formulae serve as the basis of this study, but they are prone to loss accuracy (especially for a large design space) due to their assumptions and simplifications. With the help of the trained NNs, the analytical motor model can give an estimation as accurate as the FEA but with super less time during the optimization process. The Average Correction Factor (ACF) approach is regarded as the comparison method to demonstrate the excellent performance of the proposed NN model. Furthermore, a NN aided three-stage-seven-step optimization methodology is proposed. Finally, a Pole-10-Slot-12 PMSM case study is given to demonstrate the feasibility and gain of the NN aided multi-objective optimization approach. In this case, the NN aided analytical model can generate one motor design in 0.04 s while it takes more than 1 min for the used FEA model.

A new approach to radon temporal correction factor based on active environmental monitoring devices

The present study aims to identify novel means of increasing the accuracy of the estimated annual indoor radon concentration based on the application of temporal correction factors to short-term radon measurements. The necessity of accurate and more reliable temporal correction factors is in high demand, in the present age of speed. In this sense, radon measurements were continuously carried out, using a newly developed smart device accompanied by CR-39 detectors, for one full year, in 71 residential buildings located in 5 Romanian cities. The coefficient of variation for the temporal correction factors calculated for combinations between the start month and the duration of the measurement presented a low value (less than 10%) for measurements longer than 7 months, while a variability close to 20% can be reached by measurements of up to 4 months. Results obtained by generalized estimating equations indicate that average temporal correction factors are positively associated with CO2 ratio, as well as the interaction between this parameter and the month in which the measurement took place. The impact of the indoor-outdoor temperature differences was statistically insignificant. The obtained results could represent a reference point in the elaboration of new strategies for calculating the temporal correction factors and, consequently, the reduction of the uncertainties related to the estimation of the annual indoor radon concentration.

Monte Carlo verification of output correction factors for a TrueBeam STx®

The recent publication of the new code of practice IAEA/AAPM TRS-483 introduces output correction factors to correct detector response changes in relative dosimetry of small photon beams. In TRS-483, average correction factors are reported for several detectors in high-energy photon beams at 6 and 10 MV with and without flattening filter. These correction factors were determined by Monte Carlo simulation or experimental measurements using several linacs of different brands and vendors. The goal of this work was to validate the output correction factors reported in TRS-483 for 6 MV photon beams of a TrueBeam STx® linac. The validation was performed using Monte Carlo simulations of four radiation detectors employed in the dosimetry of small photon beams and whose output correction factors were determined using a different radiation source than TrueBeam STx®. The results show that Monte Carlo calculated output correction factors, and those reported in the code of practice TRS-483 fully agree within ∼1%. The use of generic correction factors for a TrueBeam STx® and the detectors studied in this work is suitable for small field dosimetry static beams within the uncertainties of Monte Carlo calculations and output correction factors reported in TRS-483.

Estimates of CO2 Anthropogenic Emission from the Megacity St. Petersburg

The estimates of anthropogenic CO2 emissions in the megacity of St. Petersburg per square kilometer and for the entire area of the city (integral emissions), obtained on the basis of ground-based measurements of the CO2 content within the city limits, are presented. To determine emissions, the inverse problem was solved using the results of comparison between the measured and calculated data (ODIAC dataset) of the anthropogenic contribution to the CO2 content from the city. Two approaches were applied. In the first, the tomographic method was used and the anthropogenic emissions of three city districts per square kilometer were determined. In the second, all available measurements were used to find the average correction factor R and estimates of the integral CO2 emissions of the entire megacity and its central part. The emissions per square kilometer for the south of the city are in the range of 32.7–48.3 kt/km2 year; for the center, 69.0–97.5 kt/km2 year; and for the north, 78.2 kt/km2 year. The integral CO2 emissions from the central part and the entire metropolis are 39.8 and 65.3 Mt/year, respectively. Inaccuracies in the estimate reach 20–40%. The estimates of the CO2 anthropogenic emissions in St. Petersburg are higher by approximately two times than earlier results.

Assessment of bottomside thickness parameters over magnetic equator and low latitudes during high solar activity of solar cycle 24

Bottomside thickness parameters of eight Digisonde stations over geomagnetic equator and low latitude regions have been investigated and compared with IRI model bottomside parameter during high solar activity (years 2013–2015) of the solar cycle 24. The studied years of each station rely on the GIRO data availability. The proposed B0 (B0_Pro) are computed by using the GIRO ionospheric data and the B0 expression in [16] with an average correction factor of “0.18733”. This average correction factor is derived from an average of 144 values of monthly average correction factors at eleven stations over geomagnetic equator and low latitude regions. The Results show that the seasonal variations of B0_Pro are in good agreements with those of B0_obs evidently as compared to B0_IRI at eight stations for all four seasons. For example, in the southern hemisphere, the absolute percentage distances between B0_Pro and B0_obs range from 13% to 33% with overall averages less than 26% and regional averages of 16.5%, but those between B0_IRI and B0_obs are higher. Moreover, the correlation coefficients between B0_Pro and B0_obs always are larger than 0.87 while excluding a lowest value of “0.7041”, but those between B0_IRI and B0_obs are lower. In the southern hemisphere, two remarkable features can always be reflected by B0_Pro for all studied stations. Meanwhile, in the northern hemisphere, the B0_Pro variations of each dip latitude has unique features at different locations, local times, and seasons. The inter-station differences of B0_Pro can be seen obviously in comparison with B0_IRI and described by the impacts of EEJ strength, vertical plasma drift, and PRE from local noontime to post-sunset periods. The remarkable findings from this present study may enhance the comprehension of bottomside variability and improve the IRI predictability in the future.

Evaluation of biokinetics and dosimetry in [131I]-NaI therapies: whole-body images quantification versus lower limb region

Evaluation of biokinetics and dosimetry in [131I]-NaI therapies: whole-body images quantification versus lower limb region

Point Load Strength Index of Half-Cut Core Specimens and Correlation with Uniaxial Compressive Strength

The point load strength index is a widely used index in rock engineering, and cylindrical core and irregular shaped specimens are used in its determination. But, in mine sites, the borehole cores are cut axially into two equal parts to obtain half-cut cores and one part of these half cores is sent to laboratory for geochemical analyses. This situation causes a problem that the remaining half of the cores from the specimens cannot be used not only in the strength and deformability tests, but also in the point load test. In this study, it is aimed to investigate the applicability of the point load test on half-cut cores, to adopt the previously suggested size correction formulations to the half-cut core specimens and to estimate the uniaxial compressive strength from the point load strength index determined from the half-core specimens. To achieve these goals, point load strength index and uniaxial compression tests were conducted on a number of half-cut and cylindrical core samples prepared from 12 different rock types and the test results were assessed based on the statistical analyses. The analysis results indicated that the point load strength index may also correctly be determined from the half-cut cores and uniaxial compressive strength may be estimated from the size corrected point load strength index values of half-cut cores with a low error margin using average size correction factor.

Improvement of Nonuniformity on Flatbed Scanner for Radiochromic Film Dosimetry Using Average Correction Factor with Multi-direction Scan Data

In order to correct the lateral effect caused by the light source of the flatbed scanner in the Gafchromic film EBT3, the usefulness of the correction method using the average value of the correction coefficient considering the scan directions were evaluated. EBT3 was scanned from four directions to measure the optical density (OD) of the red, blue, and, red/blue components and the correction coefficient were calculated. For the correction coefficients, average values were calculated for the purpose of use, when the scan directions could not be aligned (average lateral effect correction). Correction accuracy was verified with the pass rate of gamma analysis (3 mm/3%, threshold 30%) of the dose distribution using the EBT3 film irradiated with the step pattern. OD of the red, blue, and, red/blue components in the scanning vertical direction tended to be higher in the center than in the peripheral portion. The pass rate of the step pattern was the red component's before correction, from 26.9 to 45.1% (before correction), from 84.1 to 96.7% (after correction), the red/blue component, from 37.6 to 48.4% (before correction) and from 84.4 to 96.7% (after correction). When using the correction coefficient using the average value, the pass rate was 89.8% for the red component and 94.7% for the red/blue component. The lateral effect correction improves the accuracy of the dose distribution verification, and the correction coefficient using the average value is useful when the scanning direction is different from that at the time of obtaining the dose concentration curve.

Improving the modeling of bottomside thickness parameters over midlatitudes and high latitudes

This paper investigates bottomside thickness parameters at Digisonde stations over midlatitude and high latitude regions, and compares the diurnal, seasonal, and solar activity variations in 2014 and 2009. The geographic latitudes of high latitude considered in this work are located beyond ±60° and those of midlatitude are located between ±40° and ±60°. The IRI-modeled B0 with ABT-2009 option (B0_IRI) are also examined and compared with four kinds of the B0 values, i.e., the observed B0 (B0_obs) from GIRO, the computed B0 following to Jamjareegulgarn et al. (2017a) (B0_old), the calculated B0 with a correction factor regarding to Jamjareegulgarn et al. (2017b) (B0_new), and the B0 with an average correction factor (B0_new_c_av). The average correction factors are proposed additionally in this work so as to assist occasionally the experimental B0 nonexistence of Digisonde which are equal to 0.2658 and 0.2058 for midlatitudes and high latitudes, respectively. Results show that the diurnal variations of B0_new and B0_new_c_av are in a good agreement with those of B0_obs evidently compared with those of B0_IRI and B0_old at every station during the three seasons over high and middle latitudes. During the three seasons, the diurnal variations of B0_new_c_av show similar trends and are close to one another with the B0_obs and the B0_new with small deviations. The differences between the B0obs and the B0_new_c_av also show similar trends and are close to one another with those between the B0obs and the B0_new. In contrast, the B0_IRI with ABT-2009 option seems to predict the B0 values poorly during the three seasons at high latitudes and some seasons at midlatitudes. The proposed B0_new is useful for computing approximately the observed B0 and the ionogram-based total electron content (ITEC) of Digisonde, and the plasma scale height over midlatitudes and high latitudes.

Diffusion and Thermodiffusion of Atmospheric Neutral Gases: A Review

The current state of knowledge on diffusion and thermodiffusion of neutral gases that govern the composition of the greater part of the Earth’s thermosphere is reviewed. Hydrodynamic equations determining diffusion velocities of neutral gases of the multicomponent atmosphere are considered in the first-order approximation of the velocity distribution functions of the Chapman–Enskog method using the first- and second-order approximations of the Sonine polynomial expansion to transport multicomponent coefficients of neutral gases. The interrelations among various definitions for the multicomponent diffusivities are given. The thermodiffusion factors and binary diffusion coefficients of N2, O2, O, He, H, Ar, N, NO, and H2 used in atmospheric studies to calculate the diffusion velocities and number densities of these atmospheric gases are discussed. The recommended temperature dependencies of the binary diffusion coefficients and the recommended average multicomponent diffusion correction and thermodiffusion factors of the atmospheric neutral gases under consideration are presented.