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This paper presents a new class of graded metamaterial beams by leveraging actively controllable resonators (ACR). The metamaterial comprises a homogeneous host beam that is mounted with negative capacitance shunted piezoelectric cantilever beams, each of which has a tip mass block. Properly changing the negative capacitances (NCs) in the stiffening/softening shunt circuits can control the formed bandgaps, providing greater adjustability and flexibility. Specifically, using modal analysis and considering higher modes of flexural vibrations, the ACR is simplified to an equivalent lumped parameter system with a correction factor applied to the reaction force. We demonstrate the relationship between the derived equivalent parameters of the ACR and NC for different circuitry configurations. A finite element model is built to validate the theoretical models of the ACR and the proposed metamaterial. Subsequently, a grading strategy is proposed to determine the NC values of ACR arrays for achieving broadband vibration suppression. A mechanical damping enhancement phenomenon that can contribute to forming an aggregated band is observed when resistances are introduced into the stiffening circuits. Three circuit configurations are examined, i.e., stiffening, softening, and hybrid circuits. The results showed that a proper grading coefficient can effectively suppress broadband vibration in the low-frequency range. [ABSTRACT FROM AUTHOR]

While characterizing space-charge-limited current (SCLC) is important for numerous applications, no analytical solutions for SCLC with monoenergetic initial velocity exist for two-dimensional (2D) geometries. Here, we derive approximate closed-form solutions for uniform SCLC with monoenergetic emission of electrons in a 2D planar diode, where emission is restricted to a long patch of width W for electrodes separated by a distance D. We also derive a semiempirical approach for estimating the SCLC for these cases by treating the geometric and velocity correction factors as multiplicative corrections to the SCLC for a one-dimensional vacuum diode given by the Child–Langmuir (CL) law. We show that the SCLC for a finite patch with nonzero velocity can exceed the CL law by three orders of magnitude. The theoretically calculated SCLCs for various emission widths and initial velocities in the 2D diode agree well with particle-in-cell simulations using the over-injection method in XOOPIC; they agree with the semiempirical relationship for lower initial velocities. In the limit of high initial velocity, the geometry and velocity corrections to the CL law cannot be decoupled, invalidating the assumption of the semiempirical approach and causing it to diverge from the theoretical solution and XOOPIC simulations. These results provide valuable estimates for determining the onset of virtual cathode formation for photocathodes and thermionic cathodes, which operate in the over-injection regime to avoid beam quality degradation. [ABSTRACT FROM AUTHOR]

Clinical prediction models have been widely acknowledged as informative tools providing evidence‐based support for clinical decision making. However, prediction models are often underused in clinical practice due to many reasons including missing information upon real‐time risk calculation in electronic health records (EHR) system. Existing literature to address this challenge focuses on statistical comparison of various approaches while overlooking the feasibility of their implementation in EHR. In this article, we propose a novel and feasible submodel approach to address this challenge for prediction models developed using the model approximation (also termed "preconditioning") method. The proposed submodel coefficients are equivalent to the corresponding original prediction model coefficients plus a correction factor. Comprehensive simulations were conducted to assess the performance of the proposed method and compared with the existing "one‐step‐sweep" approach as well as the imputation approach. In general, the simulation results show the preconditioning‐based submodel approach is robust to various heterogeneity scenarios and is comparable to the imputation‐based approach, while the "one‐step‐sweep" approach is less robust under certain heterogeneity scenarios. The proposed method was applied to facilitate real‐time implementation of a prediction model to identify emergency department patients with acute heart failure who can be safely discharged home. [ABSTRACT FROM AUTHOR]

The JWST is allowing new measurements of gas-phase metallicities in galaxies between cosmic noon and cosmic dawn. The most robust approach uses luminosity ratios between the excited auroral transition, [O  iii ] 4364 Å, and the lower [O  iii ] 5008 Å/4960 Å lines to determine the gas temperature. The ratio of the luminosities in the latter transitions to those in hydrogen Balmer series lines then yield relatively clean metallicity estimates. In the absence of detection of the [O  iii ] auroral line, the ratios of various [O  iii ], [O  ii ], [N  ii ], and Balmer lines are used to determine metallicities. Here, we present a refined approach for extracting metallicities from these 'strong line diagnostics'. Our method exploits empirical correlations between the temperature of O  iii /O  ii regions and gas-phase metallicity. We then show, from first principles, how to extract metallicities and break degeneracies in these estimates using traditional strong line diagnostics, R 2, R 3, R 23, and O3O2 and N2O2. We show that these ratios depend also on volume correction factors, that is, on accounting for the fraction of the volume of H  ii regions that are in O  iii and O  ii , but that these can be determined self-consistently along with the metallicities. We quantify the success of our method using metallicities derived from galaxies with auroral line determinations and show that it generally works better than previous empirical approaches. The scatter in the observed line ratios and redshift evolution are largely explained by O3O2 variations. We provide publicly available routines for extracting metallicities from strong line diagnostics using our methodology. [ABSTRACT FROM AUTHOR]

We derive the nitrogen and oxygen abundances in the narrow line regions (NLRs) of a sample of 38 local (⁠|$z \: \lt \: 0.4$|⁠) Seyfert 2 nuclei. For that, we consider narrow optical emission line intensities and direct estimates of the electron temperatures (⁠|$T_{\rm e}$| -method). We obtain a new theoretical expression for the nitrogen ionization correction factor [ICF(⁠|$\rm N^{+}$|⁠)] for NLRs. Applying this new ICF, we unexpectedly find that NLRs and disc H  ii regions exhibit similar ICF distributions. We find nitrogen abundances in the range |$7.6 \: \lt \: \rm 12+log(N/H) \: \lt \: 8.6$| (mean value |$8.06\pm 0.22$|⁠) or |$\rm 0.4 \: \lt \: (N/N_{\odot }) \: \lt 4.7$|⁠ , in the metallicity regime |$8.3 \: \lt \: \rm 12+log(O/H) \: \lt \: 9.0$|⁠. Our results indicate that the dispersion in N/H abundance for a fixed O/H value in AGNs of |$\sim 0.2$| dex agrees with that for disc H  ii regions with similar metallicity. We show that Seyfert 2 nuclei follow a similar (N/O)–(O/H) relation to the one followed by star-forming objects. Finally, we find that active galaxies called as ..nitrogen-loud.. observed at very high redshift (⁠|$z \: \gt \: 5$|⁠) show N/O values in consonance with those derived for local NLRs. This result indicates that the main star-formation event is completed in the early evolution stages of active galaxies. [ABSTRACT FROM AUTHOR]

Aims: Dried blood volumetric absorptive microsamples (VAMS) may facilitate home‐based sampling to enhance therapeutic drug monitoring after transplantation. This study aimed to clinically validate a liquid chromatography–tandem mass spectrometry assay using 2 VAMS devices with different sampling locations (Tasso‐M20 for the upper arm and Mitra for the finger). Patient preferences were also evaluated. Methods: Clinical validation was performed for tacrolimus and mycophenolic acid by comparison of paired VAMS and venipuncture samples using Passing–Bablok regression and Bland–Altman analysis. Conversion of mycophenolic acid VAMS to serum concentrations was evaluated using haematocrit‐dependent formulas and fixed correction factors defined a priori. Patients' perspectives, including useability, acceptability and feasibility, were also investigated using established questionnaires. Results: Paired samples (n = 50) were collected from 25 kidney transplant recipients. Differences for tacrolimus whole‐blood concentration were within ±20% for 86 and 88% of samples from the upper arm and fingerstick, respectively. Using correction factors of 1.3 for the upper‐arm and 1.47 for finger‐prick samples, 84 and 76% of the paired samples, respectively, were within ±20% for mycophenolic acid serum concentration. Patient experience surveys demonstrated limited pain and acceptable useability of the upper‐arm device. Conclusions: Tacrolimus and mycophenolic acid can be measured using 2 common VAMS devices with similar analytical performance. Patients are supportive of home‐based monitoring with a preference for the Tasso‐M20 device. [ABSTRACT FROM AUTHOR]

The thermomechanical buckling of imperfect sandwich plates made of functionally graded material (FGM) is addressed analytically in this study. A novel hyperbolic four-variable integral shear deformation theory is used to arrive at the solution. Sandwich plates come in two varieties: the first with homogeneous core and FG face sheets and the second with the opposite. The displacement field is constructed using undetermined integrals in order to reduce the number of unknown variables which consequently reduces the calculation time unlike other similar theories. The proposed model does not require a shear correction factor and ensures the free-stress at the upper and lower surfaces of structure. The materials properties of the structure are computed via power-law function with considering the porosity effect which may appear during manufacturing due to the difference in solidification temperature of the constituents (ceramic/metal). Four types of geometric imperfection are examined with even, uneven, logarithmic uneven and linear uneven distributions. On the basis of the minimal total potential energy concept, the governing equations are developed. The Navier's method is used to solve these equations for simply supported plates. The results of simply supported FGM sandwich plates' critical buckling load and temperature increment are contrasted with the available solutions in the literature. Even, uneven, linear uneven and logarithmic uneven models of distribution are taken into consideration and studied in order to incorporate porosity in the FG face sheet and core. Investigation is conducted into the effects of layer thickness, porosity models, porosity coefficients and geometrical parameters on the thermomechanical buckling response of imperfect FG sandwich plates. [ABSTRACT FROM AUTHOR]

Numerous studies rely on long-term PM2.5 speciation data from the EPA's Chemical Speciation Network (CSN), for example, to estimate health impacts or investigate the sources and transport of PM2.5 pollution. These studies rely on consistent, long-term time series measurements of PM2.5 species to draw conclusions about PM2.5 emissions sources and their health impacts. However, changes in contractors and associated methodological changes in 2015 and 2018 led to disruptions in the consistency of the CSN data, specifically, concentration discontinuities in the CSN time series for ions and elemental carbon (EC) from November 2015 to September 2018 and from October 2018 onward, respectively. To address the impact of these changes on downstream air quality and health analyses, this study developed correction factors by comparing collocated CSN measurements to measurements from the Interagency Monitoring of Protected Visual Environment (IMPROVE) network, which used consistent instrumentation and contractors throughout the study period. These correction factors reduced the discontinuities in the ions and EC concentration time series data, which could be critical for time series source apportionment receptor modeling, air pollution policy and accountability investigations, and health effect studies. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Mineral dust from the Sahara desert can travel long distances at high altitudes, perturbing the energy budget of the atmosphere. Charging of dust has been observed to occur near the surface through triboelectric charging during dust lofting, potentially affecting particle coagulation, fall speeds, and the lofting process itself. Apart from near-surface studies, measurements at elevated dust layers, where charge may play a role in particle long-range transport, are rare. This study presents new observations from an uncrewed aircraft system (UAS) of type MASC-3, through an elevated Saharan dust layer over Cyprus on 6 April 2022. The dust layer ranged from 1500 to 2500 meters above sea level (a.s.l), with maximum particle number concentrations (PNC) of 80–100 cm − 3 , primarily consisting of particles up to 2.5 µm in size. Measurements showed elevated charge within the dust layer, with magnitude proportional to PNC. It was concluded that there was a small influence of aircraft charge on the measurements, which was handled by developing a PNC-based correction factor. Corrected charge within the dust layer ranged from 0.2 to 3 pC m − 3 , with most of the charge at the upper and lower dust layer boundaries. The magnitude and location of the charge was consistent with predictions of ion-particle attachment. This suggests that most of the measured charge did not originate from the lofting process, but dust particles were charged on site through ion-particle attachment processes. [ABSTRACT FROM AUTHOR]

This study aims to develop adjustment factors for ground-motion models such as Pezeshk et al., which were developed for regions outside the Coastal Plain to be used for sites within the Coastal Plain region. The adjustment factors developed are a function of sediment thickness and rupture distance R rup in the Coastal Plain region. We use the newly developed sediment thickness contour maps by Boyd et al. Also, the adjustment factors are developed using a combined data set, which consists of the Next Generation Attenuation (NGA)-East original data set, the data set from Chapman and Guo, and the newly compiled and verified data set by Thompson et al. We calculate residuals by taking the difference between the logarithms of the observed data and those predicted by the Pezeshk et al. ground-motion model (GMM), considering the site amplification model of Stewart et al. and utilizing the combined data set. This model is applicable for R rup as far as 1000 km. We perform residual analyses using a mixed-effects regression to partition the total residuals into between-event and within-event components. To develop the correction factors for stations within the Coastal Plain region, we fit the within-event residuals to an equation that is a function of sediment thickness and R rup . The results indicate that for stations within the Coastal Plain region, for most periods, the residual trend has been eliminated (with respect to sediment thickness, R rup , and time-averaged shear wave velocity in the first 30 m under the surface, V S30 ) using the proposed adjustment factors. The results of this study can be utilized in seismic hazard and risk analyses for sites within the Coastal Plain. [ABSTRACT FROM AUTHOR]

Background: In modern positron emission tomography (PET) with multi‐modality imaging (e.g., PET/CT and PET/MR), the attenuation correction (AC) is the single largest correction factor for image reconstruction. One way to assess AC methods and other reconstruction parameters is to utilize software‐based simulation tools, such as a lesion insertion tool. Extensive validation of these simulation tools is required to ensure results of the study are clinically meaningful. Purpose: To evaluate different PET AC methods using a synthetic lesion insertion tool that simulates lesions in a patient cohort that has both PET/MR and PET/CT images. To further demonstrate how lesion insertion tool may be used to extend knowledge of PET reconstruction parameters, including but not limited to AC. Methods: Lesion quantitation is compared using conventional Dixon‐based MR‐based AC (MRAC) to that of using CT‐based AC (CTAC, a "ground truth"). First, the pre‐existing lesions were simulated in a similar environment; a total of 71 lesions were identified in 18 pelvic PET/MR patient images acquired with a time‐of‐flight simultaneous PET/MR scanner, and matched lesions were inserted contralaterally on the same axial slice. Second, synthetic lesions were inserted into four anatomic target locations in a cohort of four patients who didn't have any observed clinical lesions in the pelvis. Results: The matched lesion insertions resulted in unity between the lesion error ratios (mean SUVs), demonstrating that the inserted lesions successfully simulated the original lesions. In the second study, the inserted lesions had distinct characteristics by target locations and demonstrated negative max‐SUV%diff trends for bone‐dominant sites across the patient cohort. Conclusions: The current work demonstrates that the applied lesion insertion tool can simulate uptake in pelvic lesions and their expected SUV values, and that the lesion insertion tool can be extended to evaluate further PET reconstruction corrections and algorithms and their impact on quantitation accuracy and precision. [ABSTRACT FROM AUTHOR]

Several external and internal factors can affect the performance and variability of Hemoglobin concentration [Hb] measurements using HemoCue, and documentation on the contribution of different sources of [Hb] variation is limited. We used an experimental repeated measurements design with nine randomly selected participants, three HemoCue devices, and three trained field workers. HemoCue measurements for all samples were repeated three times. The [Hb] measurement system considers four sources of error: 1) HemoCue devices, 2) field workers, 3) between individuals, and 4) within individuals. A concordance analysis was used to assess accuracy and precision, and a linear mixed model was used to estimate mean differences (bias) from blood specimens, anticoagulants, and to estimate the contribution of the 4 sources of error to [Hb] measurements. Positive mean [Hb] differences were found: 1.34 g/dL for capillary drops, 0.81 g/dL for pooled capillary blood samples, 0.756 g/dL for venous blood stored with EDTA, and 0.911 g/dL for venous blood stored with heparin. The mean [Hb] difference for venous blood with EDTA was used as a correction factor for all results measured using a HemoCue. After adjustment, capillary drops showed a mean difference of 0.585 g/dL, and pooled capillary samples were not significantly different. The individual variability was 95.8% of total variance, HemoCue devices contributed 2.1% of measurement error, field staff contributed 0.4%, and the residual was 1.7%. The HemoCue [Hb] measurement system is reliable in controlled environments, with a small measurement error of 4.2%. [ABSTRACT FROM AUTHOR]

Aiming at the fuzzy diffusion characteristics of microcrack regions in Si3N4 ceramic bearing rolling elements, an adaptive region segmentation method is proposed to achieve precise extraction of microcrack features. The fuzzy diffusion effect of the microcrack region is analyzed, and a structural complexity matrix is defined to represent the degree of structural variation in the image. A threshold point is determined through histogram analysis, and the matrix dispersion rate is calculated using a box plot to update the correction factor, optimizing the overlap of noise in the microcrack image. The causes of distortion in the microcrack region are analyzed, and pixel points are assigned based on spatial metrics and LAB color features. The fuzzy boundaries and overlapping regions are segmented using the fuzzy C‐means clustering algorithm. A grid search algorithm is embedded to quantitatively evaluate the optimal combination of hyperparameters, enabling comprehensive extraction of microcrack features in Si3N4 ceramic bearing rolling elements. The optimized image achieves an average peak signal‐to‐noise ratio of 39.3, an information fidelity criterion of 7.9328, and an average extraction accuracy of approximately 0.92, effectively overcoming the impact of the fuzzy diffusion effect on the accuracy of microcrack feature extraction in Si3N4 ceramic bearing rolling elements. [ABSTRACT FROM AUTHOR]

This work aims to study the influence of the material and geometric parameters that characterize re-entrant hexagonal honeycomb auxetic structures in the maximum transverse static deflection of beams. In addition, this study considers the composition of the material through the thickness results from the mixture of a metallic phase and one of four different selected ceramics, using the exponential volume fraction law. The first-order shear deformation theory within an equivalent single-layer approach is used to assess the material and geometric parameters' influence on the structures' deflection. Considering this theoretical approach, the impact of the material and geometric parameters on the shear correction factors, calculated for each specific case, is also analyzed. The results allow us to conclude how the shear correction factors and the structures' maximum static deflection are affected by the re-entrant hexagonal honeycomb auxetic cells' aspect ratios, by the angle associated with the direction of the inclined members of the hexagonal cells and the use of materials with differentiated Poisson's ratios. [ABSTRACT FROM AUTHOR]

Annular sectored containers are widely used in nuclear engineering, aerospace, marine, and civil engineering. It is crucial for the safety assessment of such containers to accurately describe their sloshing behavior under external disturbances and seismic conditions. Many studies have been conducted on the sloshing behavior in regular-shaped containers (rectangular, circular, and annular cross sections); however, the studies on the sloshing in annular sectored containers are relatively limited. Specifically, there is a lack of studies on sloshing damping and nonlinear behaviors under large-amplitude resonance conditions and earthquakes. This paper examines the effects of excitations and geometry (curvatures and sizes) on the dynamic sloshing characteristics and transient response of annular sectored containers through shaking table experiments. Experimental results show significant nonlinear sloshing, including breaking waves, at sharp inner corners of annular sectored containers under large harmonic and seismic excitations. It also shows that curvature has a small effect on the frequency and sloshing damping; however, it significantly influences wave heights and hydrodynamic pressures on the outer curved surface. Based on potential flow theory, we derived a wave height formula with damping for the annular sectored container under arbitrary ground motion excitation. Through experiments, we also determined a correction factor for wave height under large-amplitude excitation. The results were compared with experimental data, volume-of-fluid (VOF) results, and the corrected wave height formula for rectangular containers. The comparison shows that under large-amplitude excitation, both the VOF method and potential flow theory show significant errors compared to experimental results, while the corrected formula for the annular sectored container agrees well with the experimental results. [ABSTRACT FROM AUTHOR]

Liquefaction can significantly alter the ground response. However, no existing design spectrum accounts for the severity of soil liquefaction. This work aims to develop correction factors that can be used to adjust code-based design spectra to reflect the specific liquefaction susceptibility of a site. The correction factor is derived as the ratio of response spectra calculated by two types of 1D nonlinear site response analyses: effective stress analysis, which can model porewater pressure (PWP) generation, and total stress analysis. We considered seven real profiles and 200 motions in our analysis. Four combinations of soil nonlinear models and PWP generation models are also utilized to account for epistemic uncertainties. Results show that the response spectral ratio for liquefied sites typically falls below one for periods less than 1–2 s and rises above one for longer periods. Meanwhile, the response spectral ratio reflects the overall liquefaction susceptibility influenced by PWP, factor of safety, and liquefiable layer depth, while the liquefaction potential index (LPI) captures their complex interplay. Accordingly, we propose four LPI-dependent factors: three correction factors for peak ground acceleration, 0.2 s spectral acceleration (Sa), and 1.0 s Sa, and a long-period adjustment factor applicable for periods exceeding 1 s. The correction factors linearly decrease with increasing LPI, while the adjustment factor exhibits the opposite trend. A design spectrum for a liquefiable site can be readily constructed by adjusting the code-based design spectrum using the proposed correction factor, as illustrated in the example. This approach is applicable as long as LPI is available from a simplified liquefaction analysis or a liquefaction hazard map. [ABSTRACT FROM AUTHOR]

Describing living community compositions is essential to monitor ecosystems in a rapidly changing world, but it is challenging to produce fast and accurate depiction of ecosystems due to methodological limitations. Morphological methods provide absolute abundances with limited throughput, whereas metabarcoding provides relative abundances of genes that may not correctly represent living communities from environmental DNA assessed with morphological methods. However, it has the potential to deliver fast descriptions of living communities provided that it is interpreted with validated species‐specific calibrations and reference databases. Here, we developed a quantitative approach to retrieve from metabarcoding data the assemblages of living large benthic foraminifera (LBF), photosymbiotic calcifying protists, from Indonesian coral reefs that are under increasing anthropogenic pressure. To depict the diversity, we calculated taxon‐specific correction factors to reduce biological biases by comparing surface area, biovolume and calcite volume, and the number of mitochondrial gene copies in seven common LBF species. To validate the approach, we compared calibrated datasets of morphological communities from mock samples with bulk reef sediment; both sample types were metabarcoded. The calibration of the data significantly improved the estimations of genus relative abundance, with a difference of ±5% on average, allowing for comparison of past morphological datasets with future molecular ones. Our results also highlight the application of our quantitative approach to support reef monitoring operations by capturing fine‐scale processes, such as seasonal and pollution‐driven dynamics, that require high‐throughput sampling treatment. [ABSTRACT FROM AUTHOR]

Stroboscopic nutation has proved to be invaluable for pulse width calibration (P. S. C. Wu and G. Otting, Rapid pulse length determination in high-resolution NMR, J. Magn. Reson.2005, 176, 115–119), though it is not without its issues. Herein it is proposed that a correction factor be applied to correct for the inaccuracy of the method which is dependent on the NMR system including the probe, observed nucleus, sample type set (solvent, concentration, ionic strength, etc.), temperature, etc. Poor performance of the stroboscopic nutation experiment was also found to be a harbinger of a serious hardware problem. [ABSTRACT FROM AUTHOR]

The solubility data of spectinomycin dihydrochloride pentahydrate (SDP) in three binary solvents were determined over a temperature range of 278.15–318.15 K by the gravimetric method. Among the selected binary solvents, the solubility of SDP increased with the rise in temperature and initial methanol composition of binary solvents, and the general order of solubility of SDP under the same conditions was: (methanol + ethanol) > (methanol + n-propanol) > (methanol + i-propanol). Subsequently, solubility–temperature models including van't Hoff equation, λh equation, Yaws equation, and Apelblat equation; solubility–solvent composition models including general single model; solubility–temperature and solvent composition models including NRTL equation and modified Jouyban–Acree model were used to correlate the solubility data. Regarding the application of the NRTL equation in binary solvent systems, the influence of solvent composition on model parameters was first taken into account by introducing a solvent composition correction factor, thereby exhibiting an enhancement in fitting accuracy. To gain deeper insights into the dissolving behavior of SDP, molecular electrostatic potential surface, Hirshfeld surface analysis and the KAT-LSER model were applied to analyze the molecular interactions between SDP molecules and the solvent effects. Meanwhile, entire solubility data in three binary solvent systems at 298.15 K were associated as a function of solvent properties on the basis of KAT-LSER model. The results revealed that SDP primarily acts as hydrogen bond acceptors in solution, and polar interactions between SDP and solvent molecules can play a crucial role in promoting the dissolution of SDP. [ABSTRACT FROM AUTHOR]

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The dataset presents a 43 year-long reanalysis of pollen seasons for three major allergenic genera of trees in Europe: alder (Alnus), birch (Betula), and olive (Olea). Driven by the meteorological reanalysis ERA5, the atmospheric composition model SILAM predicted the flowering period and calculated the Europe-wide dispersion pattern of pollen for the years 1980–2022. The model applied an extended 4-dimensional variational data assimilation of in-situ observations of aerobiological networks in 34 European countries to reproduce the inter-annual variability and trends of pollen production and distribution. The control variable of the assimilation procedure was the total pollen release during each flowering season, implemented as an annual correction factor to the mean pollen production. The dataset was designed as an input to studies on climate-induced and anthropogenically driven changes in the European vegetation, biodiversity monitoring, bioaerosol modelling and assessment, as well as, in combination with intra-seasonal observations, for health-related applications. [ABSTRACT FROM AUTHOR]

Brush seals are extensively used in rotating equipment, such as gas turbines and compressors, providing effective sealing while accommodating radial, axial, and angular movements between components. In this study, the performance of brush seals with and without clearances was predicted through axisymmetric 2D computational fluid dynamic (CFD) simulations using a porous media model. Because the accurate modeling of a brush seal requires the appropriate porosity to be determined and the flow resistance to be calculated, a porosity correction was performed based on the brush seal's geometry and pressure ratio. The corrected porosity was then used to calculate the flow resistance and the leakage flow rate was predicted. Based on the results, the corrected porosity significantly improved the accuracy of the previously unreliable leakage flow rate predictions, regardless of the presence of clearances. For cases with a clearance, the blow-down effect was determined through CFD simulations for the given geometry and was compared with experimental data. The leakage flow rate predictions were highly accurate, with a relative error of less than 5% across a pressure ratio range of 1.5–4. [ABSTRACT FROM AUTHOR]

In surface and subsurface drip irrigation systems, predicting the size expansion of the wetting bulb and the irrigation time is mandatory for water saving, and helps drive their design and scheduling, which cannot ignore the soil hydraulic properties. Toward this aim, different hydrological models that consider the soil hydraulic properties, highly affecting the design choices, have been suggested. In this paper, we focused on the model presented by Philip, who provided dimensionless analytical solutions for bulb geometry. The equations presented in the Philip model, for special cases, i.e., for the horizontal size at the burial plane and along the vertical direction, are very simple and were applied by many researchers. However, for an accurate design of emitters' spacing, the maximum lateral expansion of the bulb, which is below the burial plane and was not provided by Philip, is required. In this paper, the Philip model was revisited, and the maximum lateral expansion of the wetted bulb for both buried and surface point sources was addressed. The new but long solutions were also approximated by simpler equations that fit the analytical ones well. Important implications in drip irrigation engineering arose. Design relationships that make it possible to calculate the irrigation time, the spacing, and the burial depth of emitters to wet a desired rooting depth were derived. Applications showing the important effect of the soil hydraulic parameters were performed, and the results were tested by using the analytical solutions of the bulb considered in the Philip model and by applying the exact but numerical demanding Richards equation via Hydrus 2D/3D. Practical Applications: This paper aims to provide an easy-to-apply tool for surface and subsurface drip irrigation, to design the emitters' spacing, their depth (in the case of buried emitters), and the irrigation time. The latter is particularly important because exceeding the irrigation time determines wastewater as deep percolation, whereas low values of the irrigation times determine the underwatering of the root zone. Compared to other design procedures, the work is based on the analytical solutions first introduced by Philip; thus, no calibration coefficients are required, but physical parameters that describe the soil hydrological properties on which the design parameters depend. Because simplifying assumptions are adopted, errors are expected that more sophisticated design methodologies do not commit, but the latter are not easy to apply for practical use. Further research is needed to investigate this issue and to provide correction factors that hopefully would improve the results of this work. [ABSTRACT FROM AUTHOR]

Increasing the operating speed of the trains on modern networks necessitates performing dynamic analyses to assess the performance of bridges under passage of trains. The detailed investigation of their responses requires constructing complex computational models capable to take the train–track–bridge interaction effects into account. Such models have successfully been developed; however, employing those elaborated models for practical engineering applications, or to perform studies that require a large number of analyses may become infeasible. Among such situations are conducting probabilistic investigations, screening of entire networks, or sensitivity analyses. These concerns have been addressed by employing simplified models mostly relying on moving load modeling strategy which disregards the train–track–bridge interaction effects. Those neglected contributions can be compensated by implementing additional correction factors. The distribution of loads within track is one of those disregarded effects where a reduction factor is recommended by design guidelines to take its contribution into account. It has been shown that the existing relationship for these reduction factors delivers an acceptable performance for vertical accelerations, while showing a less favorable performance for displacements. Then, a data-driven strategy is adopted in this study to propose easy-to-apply relationships for reduction factors of deflections, due to load distribution within the track. In this context, three different distributive lengths of triangular load footprints have been considered, namely 2.0, 2.5 and 3.0m. The procedure employed has trained and tested for more than 1200 train configurations, comprising conventional, articulated and regular vehicles, and including several tens of thousand data points for each distributive length. The performance observed in the new models revealed a considerable improvement with respect to the existing relationship. [ABSTRACT FROM AUTHOR]

Non-orthogonal sonic anemometers are used extensively in flux networks and biomicrometeorological research. Previous studies have hypothesized potential underestimation of the vertical velocity turbulent perturbations, necessitating correction to increase flux measurements by approximately 10 %, while some studies have refuted that any correction is needed. Those studies have used cross comparisons between sonic anemometers and numerical simulations. Here we propose a method that yields a correction factor for vertical velocity that requires only a single sonic anemometer in situ but requires some assumptions and adequate fetch at a sufficient distance above roughness elements where surface similarity is valid. Correction factors could be important in adjusting flux network and other flux data, as well as assessing the energy budget closure that is used as one of the flux data quality measures. The correction factor is confirmed in one field experiment and comparison between a CSAT3 and RMY 81000VRE, but it does not work well for the more complex form factors shown in a field comparison of an IRGAson and a CSAT3a. [ABSTRACT FROM AUTHOR]

Translation abstract Analysis of Flow Rates in Cracked Reinforced ConcreteCracks in reinforced concrete structures are part of the construction principle and acceptable as long as they do not exceed certain limits. According to Eurocode 2, part 3, (as well as the guideline of the German Committee for Structural Concrete (DAfStb)) the autogenous healing of separation cracks with a width ≤ 0.20 mm can be considered under certain hydraulic conditions. However, practical experience shows that self‐healing does not always reliably occur even when this crack width is maintained. This study examines the flow rates of centrally cracked and water‐permeated concrete using Edvardsen's method. Based on the experimental results, an analytical approach following Hagen‐Poiseuille is developed to estimate the flow rate immediately after the start of the water flow, which is particularly relevant for tightness class TC0. This flow rate also serves as an indicator for evaluating the efficiency of autogenous self‐healing in structures of tightness class TC1. The initial flow rate Q0 through cracked concrete is mainly influenced by the crack width distribution across the cross‐section, the water pressure, the roughness of the crack flanks, and the tortuosity of the crack path. Therefore, a reliable estimation of the flow rate necessitates the introduction of a correction factor ξ, which is proposed with 0.52 due to the high variability of the experimental data. [ABSTRACT FROM AUTHOR]

Nuclear magnetic resonance (NMR) techniques are key in the study of porous reservoir rocks. They can provide valuable insight into the pore size distribution of the pore space of a given rock sample due to its dependence on the magnetic fluid/matrix interaction. The pore space is often studied at the μm scale through the use of micro-CT images, which are often composed of hundreds of millions of voxels, posing significant challenges to numerical simulations. In this paper, we present an image-based, fully explicit, and matrix-free finite element implementation for the simulation of NMR relaxation process that is capable of handling such large 3D problems in single GPUs. The chosen explicit time-integration scheme uses a lumped capacitance formulation and stabilization via hyperbolization, and it is capable of handling arbitrary time-step sizes with controllable error levels. The image-based representation of the pore space is used for a memory-efficient, matrix-free formulation of the time integration using massively parallel processes on a single GPU. In addition, we propose the substitution of a global digital roughness correction factor that depends on the porous space's geometry for a problem-independent local correction factor, based on nodal neighborhoods. We show that the numerical scheme converges with successive refinements as expected and that our local correction coefficient is capable of estimating the correct S/V parameter of several different classical geometries. We tested our formulation against an image-based Random Walk simulation of four digital rock core samples, achieving good agreement between them. We manage to simulate a giga-voxel image-based model on a personal use GPU (less than 10GB of memory use) in 33 min with our FEM implementation. [ABSTRACT FROM AUTHOR]

AbstractThin-walled tubes are commonly used as crucial structures for energy absorption. It is an efficient and convenient research method to establish a small-scale model of the energy-absorbing thin-walled tube for experiments. However, due to the inevitable difference between the design velocity of the test and the actual velocity of the test, it cannot meet the traditional similarity theory. Because of this limitation, this article constructs a similarity design method for the velocity distortion of the multi-cell energy-absorbing tube at the front end of the train under axial impact. Firstly, according to the motion equation of the train system, the design criterion of the similar model under the velocity distortion is derived. Then, the collision mass correction factor is derived based on the elastic-plastic structural energy equation, aiming at the error of the collision peak force and the error of the collision time, the correction factor of the wall thickness of the energy absorbing tube is obtained based on the simulation analysis results. Finally, it is verified that the velocity distortion similarity model can accurately predict the dynamic response of the prototype, and reveals the influence of the mass and wall thickness correction factors on the error. [ABSTRACT FROM AUTHOR]

The far-ultraviolet (FUV) flare activity of low-mass stars has become a focus in our understanding of the exoplanet atmospheres and how they evolve. However, direct detection of FUV flares and measurements of their energies and rates are limited by the need for space-based observations. The difficulty of obtaining such observations may push some works to use widely available optical data to calibrate multiwavelength spectral models that describe UV and optical flare emission. These models either use single temperature blackbody curves to describe this emission, or combine a blackbody curve with archival spectra. These calibrated models would then be used to predict the FUV flare rates of low-mass stars of interest. To aid these works, we used TESS optical photometry and archival HST FUV spectroscopy to test the FUV predictions of literature flare models. We tested models for partially (M0–M2) and fully convective (M4–M5) stars, 40 Myr and field age stars, and optically quiet stars. We calculated FUV energy correction factors that can be used to bring the FUV predictions of tested models in line with observations. A flare model combining optical and NUV blackbody emission with FUV emission based on HST observations provided the best estimate of FUV flare activity, where others underestimated the emission at all ages, masses, and activity levels, by up to a factor of 104 for combined FUV continuum and line emission and greater for individual emission lines. We also confirmed previous findings that showed optically quiet low-mass stars exhibit regular FUV flares. [ABSTRACT FROM AUTHOR]

The present research applies a 2D refined plate theory and isogeometric analysis (IGA) for free vibration analysis of functionally graded (FG) sandwich plates, whose governing equations are treated based on a unified formulation (UF), and nonuniform rational Lagrange (NURL)-based IGA technique. The constitutive model of FG materials is approximated via a Voigt’s rule of mixture based on an equivalent single-layer (ESL) theory. The present framework offers several advantages, including high precision of vibration response by employing higher-order plate theory and the capability of NURL basis functions to capture the exact form of plate geometries. Moreover, higher-order theories postulated by the UF are exempt from the Poisson locking phenomenon and do not require a shear correction factor. Additionally, by employing UF, the effect of thickness stretching on vibration response is considered. Furthermore, higher-order NURL basis functions effectively mitigate shear locking. A large numerical investigation shows the accuracy of results and investigates the effects of several key parameters, such as gradient index, thickness-to-length ratios, layer-to-thickness ratios, and boundary conditions, on the vibration response of FG sandwich plates. [ABSTRACT FROM AUTHOR]

Current sensors based on the tunneling magnetoresistive effect (TMR) are widely used for current measurement due to their high sensitivity, small size, and low power consumption. This paper proposes an effective error correction model to rectify the eccentricity of the transmission line, which can cause a significant measurement error in the ring‐array single‐axis TMR sensor. The model employs a convolutional neural network (CNN) to identify the relationship between the conductor eccentricity and the output of three sensors. The resulting correction factor is then fed back to eliminate the error associated with wire eccentricity. Concurrently, the Sparrow search algorithm (SSA) is employed to optimize the hyperparameters of the convolutional neural network (CNN) in order to enhance the model's performance. The experimental results demonstrate that the maximum error of the ring‐array single‐axis TMR current sensor, corrected by SSA‐CNN, is less than 0.42%, which markedly enhances the precision of the measurement. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Dental age estimation (DAE) is key to establishing an individual's identity, and this is relevant in minors. A widely used method for DAE in children is Cameriere's open apices (CAM). Despite its wide dissemination, there are no clear reports of its use in Latin American populations. A scoping review was conducted using a search strategy in the PubMed/MEDLINE database, Web of Science, and a complementary manual search. Only papers using CAM or its regression equation models for evaluating Latin American populations were included. Ten studies published between 2007 and 2020 responded to the search objective. Brazil was the country with the most studies using CAM (7/10), and the University of Macerata (Italy) was the most declared affiliation (6/10). Seven studies used the original CAM formula in populations from Brazil and Peru, while the European formula (EuCAM) was applied in Mexico, Colombia, and Brazil. Although the method underestimated the age values with acceptable error margins, the correction factor substantially improved the predictive power of the method. Some limitations of the method are highlighted. CAM and its variants can be useful for validation in Latin American settings, but attention to population structures and terminologies is suggested for future research. [ABSTRACT FROM AUTHOR]

Passive acoustic monitoring can be an effective way of monitoring wildlife populations that are acoustically active but difficult to survey visually, but identifying target species calls in recordings is non-trivial. Machine learning (ML) techniques can do detection quickly but may miss calls and produce false positives, i.e., misidentify calls from other sources as being from the target species. While abundance estimation methods can address the former issue effectively, methods to deal with false positives are under-investigated. We propose an acoustic spatial capture-recapture (ASCR) method that deals with false positives by treating species identity as a latent variable. Individual-level outputs from ML techniques are treated as random variables whose distributions depend on the latent identity. This gives rise to a mixture model likelihood that we maximize to estimate call density. We compare our method to existing methods by applying it to an ASCR survey of frogs and simulated acoustic surveys of gibbons based on real gibbon acoustic data. Estimates from our method are closer to ASCR applied to the dataset without false positives than those from a widely used false positive "correction factor" method. Simulations show our method to have bias close to zero and accurate coverage probabilities and to perform substantially better than ASCR without accounting for false positives. [ABSTRACT FROM AUTHOR]

Background: Optically stimulated luminescent dosimeters (OSLDs) can be bleached and reused, but questions remain about the effects of repeated bleaching and fractionation schedules on OSLD performance. Purpose: The aim of this study was to investigate how light sources with different wavelengths and different fractionation schemes affect the performance of reused OSLDs. Methods: OSLDs (N = 240) were irradiated on a cobalt‐60 beam in different step sizes until they reached an accumulated dose of 50 Gy. Between irradiations they were bleached using light sources of different wavelengths: the Imaging and Radiation Oncology Core (IROC) bleaching system (our control); monochromatic red, green, yellow, and blue lights; and a polychromatic white light. Sensitivity and linearity‐based correction factors were determined as a function of dose step‐size. The rate of signal removal from different light sources was characterized by sampling these OSLDs at various time points during their bleaching process. Relative doses were calculated according to the American Association of Physicists in Medicine Task Group‐191. Signal repopulation was investigated by irradiating OSLDs (N = 300) to various delivered doses of 2, 10, 20, 30, 40, and 50 Gy in a single fraction, bleached with one of the colors, and read over time. Fractionation effects were evaluated by irradiating OSLDs up to 30 Gy in different size steps. After reading, the OSLDs were bleached following IROC protocol. OSLDs (N = 40) received irradiations in 5, 10, 15, 30 Gy fractions until they had an accumulated dose of 30 Gy; The sensitivity response of these OSLDs was compared with reference OSLDs that had no accumulated dose. Results: Light sources with polychromatic spectrums (IROC and white) bleached OSLDs faster than did sources with monochromatic spectra. Polychromatic light sources (white light and IROC system) provided the greatest dose stability for OSLDs that had larger amounts of accumulated dose. Signal repopulation was related to the choice of bleaching light source, timing of bleaching, and amount of accumulated dose. Changes to relative dosimetry were more pronounced in OSLDs that received larger fractions. At 5‐Gy fractions and above, all OSLDs had heightened sensitivity, with OSLDs exposed to 30‐Gy fractions being 6.4% more sensitive than reference dosimeters. Conclusions: The choice of bleaching light plays a role in how fast an OSLD is bleached and how much accumulated dose an OSLD can be exposed to while maintaining stable signal sensitivity. We have expanded upon investigations into signal repopulation to show that bleaching light plays a role in the migration of deep traps to dosimetric traps after bleaching. Our research concludes that the bleaching light source and fractionation need to be considered when reusing OSLD. [ABSTRACT FROM AUTHOR]

The Analytical Quality by Design (AQbD) concept was adopted to establish a quantitative analysis of multi-components with a single marker (QAMS) method for industrial lanolin alcohol, targeting cholesterol, lanosterol, and 24,25-dihydrolanosterol. The potential critical method parameters (CMPs) were identified as column temperature, flow rate, and gradient. Definitive screening design and statistical modeling were employed to optimize the gradient conditions of the mobile phase, column temperature, and flow rate. The Method Operable Design Region (MODR) was determined using a risk-based quantification approach. The robustness was assessed using a Plackett–Burman experimental design, followed by methodological validation. Optimal analytical conditions were as follows: acetonitrile (B)—water (A) mobile phase system; flow rate of 1.58 mL/min; detection wavelength of 205 nm; injection volume of 10 µL; and column temperature of 37 °C. A gradient elution program was implemented as follows: 0–19.0 min, 90.5% B; 19.0–25.0 min, 90.5–100% B; and 25.0–55.0 min, 100% B. Cholesterol served as an internal standard for quantifying lanosterol and 24,25-dihydrolanosterol, with relative correction factors of 0.4227 and 0.8228, respectively. This analytical method utilized only the cholesterol reference substance as an internal standard to quantify the content of cholesterol, lanosterol, and 24,25-dihydrolanosterol in industrial lanolin alcohol. It reduced the testing costs and enhanced efficiency, making it potentially suitable for widespread adoption in lanolin alcohol processing industries. [ABSTRACT FROM AUTHOR]

Skin cancer is a pressing global health issue, with high incidence and mortality rates. Convolutional neural network (CNN) models have been proven to be effective in improving performance in skin lesion image classification and reducing the medical burden. However, the inherent class imbalance in training data caused by the difficulty of collecting dermoscopy images leads to categorical overfitting, which still limits the effectiveness of these data‐driven models in recognizing few‐shot categories. To address this challenge, we propose a dynamic multi‐output convolutional neural network (DMO‐CNN) model that incorporates exit nodes into the standard CNN structure and includes feature refinement layers (FRLs) and an adaptive output scheduling (AOS) module. This model improves feature representation ability through multi‐scale sub‐feature maps and reduces the inter‐layer dependencies during backpropagation. The FRLs ensure efficient and low‐loss down‐sampling, while the AOS module utilizes a trainable layer selection mechanism to refocus the model's attention on few‐shot lesion categories. Additionally, a novel correction factor loss is introduced to supervise and promote AOS convergence. Our evaluation of the DMO‐CNN model on the HAM10000 dataset demonstrates its effectiveness in multi‐class skin lesion classification and its superior performance in recognizing few‐shot categories. Despite utilizing a very simple VGG structure as the sole backbone structure, DMO‐CNN achieved impressive performance of 0.885 in BACC and 0.983 in weighted AUC. These results are comparable to those of the ensemble model that won the ISIC 2018 challenge, highlighting the strong potential of DMO‐CNN in dealing with few‐shot skin lesion data. [ABSTRACT FROM AUTHOR]

This paper derives a general Bartlett correction formula to improve the inference based on the likelihood ratio test in a multivariate model under a quite general parameterization, where the mean vector and the variance-covariance matrix can share the same vector of parameters. This approach includes a number of models as special cases such as non-linear regression models, errors-in-variables models, mixed-effects models with non-linear fixed effects, and mixtures of the previous models. We also employ the Skovgaard adjustment to the likelihood ratio statistic in this class of multivariate models and derive a general expression of the correction factor based on Skovgaard approach. Monte Carlo simulation experiments are carried out to verify the performance of the improved tests, and the numerical results confirm that the modified tests are more reliable than the usual likelihood ratio test. Applications to real data are also presented for illustrative purposes. [ABSTRACT FROM AUTHOR]

Precipitation records in North Patagonia (Argentina) are scarce, which hinders climate research. This research aims to assess the performance of four novel local monthly datasets together with three commonly used global datasets for North Patagonia to evaluate the advantages and disadvantages of each one. First, four different local observed-interpolated datasets were built, two using the Angular Distance Weighted (ADW) method and two using ordinary Kriging. In addition, the global datasets CRU, ERA5-Land, and GPCC were evaluated. To assess the performance of the precipitation datasets, four metrics were used to evaluate the systematic errors (bias), the mean errors, the representation of time variations, and the representation of the probability density function. The ERA5-Land with a correction factor stands out as the best global dataset and it also presents the overall best representation of the probability density function (PDF). The built dataset with ADW using a precipitation index presents the overall best performance, especially in representing the time variations. Even though ADW presents an overall better performance, ERA5-Land with a correction factor presents a better performance in terms of errors in the southern region (south of 40°S). The novel dataset is freely available through the link provided in the conclusions section. [ABSTRACT FROM AUTHOR]

This article presents the findings of a systematic literature review focusing on the impact of interferences in host materials on Respirable Crystalline Silica (RCS) measurement, and the development of a validated method of calibration for RCS instrumentation for in-field use. The impact of interferences in host materials on RCS measurement has been shown to be critical information required for in-field use of portable RCS devices. Portable RCS instruments such as FTIR and XRD have been established to have good sensitivity for measurement but relatively low specificity due to interference in host materials. It has been shown that correction factors are needed to be applied to account for known interferences, especially when calibrating portable RCS instrumentation in-field. The potential to obtain reliable and repeatable results from RCS analysis instrumentation has also been demonstrated. There was significant evidence that interference materials could be present in host materials, and they influence RCS measurement. There is the potential and possibility of using portable RCS instrument for in-field measurement however the challenge is the calibration of such instrumentation in the field to account for changing host materials and thus potential interferences. [ABSTRACT FROM AUTHOR]

In the present work, a novel refined three-variable quasi-3D shear deformation theory incorporates a correction factor is developed to analyze the buckling behavior of multi-directional functionally graded (FG) curved beams. The proposed displacement field is formulated in accordance with the Euler-Bernoulli beam theory. The research investigated two types of coated Functionally Graded (FG) nanobeams: Hardcore (HC) FG curved nanobeams and Softcore (SC) FG curved nanobeams. Three different material distributions are taken into consideration: a bidirectional material distribution referred to as "2D-FG," a unidirectional transverse material distribution known as "T-FG," and a unidirectional axial material distribution called "A-FG." Eringen's nonlocal elasticity theory is employed to capture small-scale effects. The total potential energy principle is utilized to derive the equilibrium equations of curved nanobeams. A novel solution, utilizing Galerkin's method, has been developed to effectively address a range of boundary conditions. The curved FG beam is supported by an elastic foundation following the Winkler/Pasternak/Kerr model. A comprehensive analysis has been conducted to examine the impacts of various FG schemes, curved beam geometry, nonlocal parameter, elastic foundations, and various boundary conditions on the dimensionless critical buckling loads. This analysis aims to provide a comprehensive understanding of how each of these factors influences the critical buckling loads of the nanobeams. [ABSTRACT FROM AUTHOR]

The Kumaraswamy distribution is doubly limited, continuous, very flexible, and is widely applied in hydrology and related areas. Recently, several families of distributions based on this distribution have emerged. To make a contribution regarding some asymptotic aspects related to the inferential analysis, we derived an analytic expression of order n − 1 / 2 , where n is the sample size, for the skewness coefficient of the distribution of the maximum likelihood estimators of the parameters of the Kumaraswamy distribution. A simulation study and an application are presented to illustrate that, when the sample size is small, the likelihood inferences may not be reliable. We also obtain Bartlett correction factors for the likelihood ratio statistic as well as the results of the bootstrap likelihood ratio test and bootstrap Bartlett correction and present a Monte Carlo simulation study to compare the rejection rates of the tests in question. [ABSTRACT FROM AUTHOR]

This study presents correction factors for the Norwegian fatigue load model for railway bridges. The fundamental idea of a correction factor is to ensure that the load model induces the same fatigue damage as actual traffic. Load measurements from traffic on a representative line on the Norwegian railway network are used to propose correction factors for improved fatigue life estimation with freight and passenger trains. Correction factors improve the accuracy of the estimated fatigue life and reduce the conservatism of the load model. The validity and conservatism of the most damaging train assumption for fatigue load modeling is also considered. The suitability and consequences of using the proposed correction factors for other lines and historic traffic are discussed. [ABSTRACT FROM AUTHOR]

This paper developed a method for more accurate permittivity extraction of high-loss materials using the waveguide method to reduce the effect of the air gap. This method improves the Baker-Jarvis algorithm. It makes the errors of S-parameters caused by the air gap compensated by a correction factor β of the form: (S21 + S12) + β(S11 + S22). In our study, the correction results of β for materials on different frequencies and air gap sizes are quantitatively investigated. Furthermore, we propose a method to obtain an optimal frequency-independent β for different materials. A typical high-loss BeO-SiC ceramic commonly used in vacuum electron tubes is analyzed and discussed in detail. It shows that compared to traditionally utilizing only S21 (β = 0), adopting an optimal β can reduce the average errors of the complex permittivity from 17.7% to 7.9% with a 0.10 mm air gap. The proposed method is verified by measurements of unshaved and shaved samples. [ABSTRACT FROM AUTHOR]

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In this study, the pore structure and gas permeability of river sand concrete and manufactured sand concrete (mixed with various stone powders) are examined under dry and wet conditions. First, the pore structure of concrete was tested using the mercury-in-pressure (MIP), hydrostatic balance (HB), and nuclear magnetic resonance (NMR) methods. Second, the gas permeability of concrete was measured using the quasi-stationary flow method. Finally, a numerical model was developed based on the relationship between the pore structure and gas permeability. The results indicated that the gas permeability of dry concrete has a quadratic linear relationship with the porosity and volumetric characteristic pore size. The pore structure of partially water-saturated concrete can be corrected using a correction factor and the relaxation rate of the dry material. Finally, a random hierarchical bundle model using the HB–NMR method is proposed. The maximum relative deviation between the predicted and experimental values is 48.28%. [ABSTRACT FROM AUTHOR]

This work aims to stimulate a reflection on the fact that organizations that have or adopt very complex organizational structures may encounter results in risk assessment that are not entirely reliable or compromised by their complexity. The work examines the main approaches to risk analysis organizations adopt, particularly the models and techniques used to assess processes and information management risks. Risk analysis is an essential process to ensure adequate governance for the organization. For it to be effective, it is also necessary to define a Risk Analysis Model (a methodology) capable of preserving specific properties such as completeness and repeatability. These are some of the indispensable elements to ensure a (recurrent) risk assessment that can consider the evolution of the corporate asset protection system over time and thus determine whether the system as a whole increases or decreases its performance. In this context, some factors can jeopardize the quality and reliability of the results obtained, and one of these factors is the complexity of the organization. Organisations are becoming increasingly complex due to their structure, processes, and rapidly changing external environment, and we know that some limitations exist in using the graph theory applied to RACI. The study of corporate complexity measurement is a vast subject, but this simplified tool is intended to support risk analysis processes in complex organisations specifically. Measuring organizational complexity is a subject that can be addressed with multiple approaches. This work proposes a strategy based on graph and flow network tools applied to RACI matrices. This tool can reproduce an organization starting from its representation produced through RACI matrices and, with the necessary assumptions, express an index of the complexity of the organization itself using the algebraic properties of graphs. The reflection that emerges is that risk assessment could be subject to errors caused by the detection of input data used to calculate the level of risk. The generation of these errors is linked to the size and complexity of an organization. To manage this phenomenon, the work introduces a correction parameter of the results produced by risk analysis (an "adjustment" factor) that can mitigate any measurement errors produced precisely by the complexity dimension. Complexity can significantly compromise the reliability of risk assessment results, and organizations must implement correction parameters to mitigate such measurement errors, ensuring better governance and performance over time. [ABSTRACT FROM AUTHOR]

The API p-y method is widely used in the design of offshore wind turbines (OWTs) monopiles at present. This study systematically evaluates the model uncertainty of the p-y method for OWT monopiles and proposes a two-stage calibration approach for evaluating the model bias factor. To overcome the difficulty of limited field tests, a high-fidelity base model is employed as a bridge between the field test data to the p-y method. The field test data is used to calibrate the base model and determine the model error of the base model. Synthetic numerical cases are subsequently generated using the base model to evaluate the correction factor of the p-y method. By combining the model error of the base model and the correction factor of the p-y method, the model bias factor of the p-y method can be evaluated. The reliability analysis of the monopile in an offshore wind project in China is taken as an example. The results serve as a valuable tool for correcting the lateral bearing capacity of OWT monopiles based on the specific soil conditions and risk preferences for the offshore wind turbine project. [ABSTRACT FROM AUTHOR]

The use of a Monte Carlo code in the assessment of residual radioactivity for decommissioning of a medical cyclotron facility requires a reasonable approximation to the facility's history of operations. A periodic irradiation scenario simulating the cyclotron's daily operation for radioisotope production is generally considered reasonable, but its implementation in the code's input file can be cumbersome because more than thousands of irradiation cycles must be modeled. In practice, two simplified scenarios with continuous irradiation are commonly used instead: (i) omitting the downtime between two irradiation periods and (ii) extending the irradiation duration across the entire operational lifespan of the facility, albeit with a reduced beam current to maintain workload consistency. A systematic comparison of residual radionuclide productions across various half-lives under these three scenarios was performed. This technical note presents the resulting correction factors for the two simplified continuous irradiation models, enhancing their applicability in estimating radioactive inventories under a range of circumstances. [ABSTRACT FROM AUTHOR]

Stocking–Lord (SL) linking is a popular linking method for group comparisons based on dichotomous item responses. This article proposes a bias correction technique based on the simulation extrapolation (SIMEX) method for SL linking in the 2PL model in the presence of uniform differential item functioning (DIF). The SIMEX-based method is compared to the analytical bias correction methods of SL linking. It turned out in a simulation study that SIMEX-based SL linking performed best, is easy to implement, and can be adapted to other linking methods straightforwardly. [ABSTRACT FROM AUTHOR]

Featured Application: This study presents a simple method for correcting field measurements of grounding resistance, allowing for a highly accurate value of this parameter to be obtained. The measurement of the grounding resistance of grounding grids in large installations as well as grounding electrodes in urban areas is addressed in this article. The resistance value is obtained using a three-pin array by measuring the fall-of-potential on the ground surface. The resistance measured by this method is adjusted to its true value using a correction factor that aligns the measured resistance with the actual value. The proposed measurement method obtains correct values of the grounding resistance even when the auxiliary and potential electrodes of the tree-pin array are close to the electrode to be measured. Thus, it can be applied to large electrodes as well as electrodes in urban areas. Several simulated examples are used to illustrate the method, and some real cases with field measurements are presented for a final validation of the method. [ABSTRACT FROM AUTHOR]