Isospin splitting of the Dirac mass probed by the relativistic Brueckner-Hartree-Fock theory in the full Dirac space

The isospin splitting of the Dirac mass obtained with the relativistic Brueckner-Hartree-Fock (RBHF) theory is thoroughly investigated. From the perspective in the full Dirac space, the long-standing controversy between the momentum-independence approximation (MIA) method and the projection method on the isospin splitting of the Dirac mass in asymmetric nuclear matter (ANM) is analyzed in detail. We find that, the \textit{assumption procedure} of the MIA method, which assumes that the single-particle potentials are momentum independent, is not a sufficient condition that directly leads to the wrong sign of the isospin splitting of the Dirac mass, while the \textit{extraction procedure} of the MIA method, which extracts the single-particle potentials from the single-particle potential energy, leads to the wrong sign. By approximately solving the set of equations involved in the \textit{extraction procedure}, a formal expression of the Dirac mass is obtained. The wrong isospin splitting of the Dirac mass is mainly caused by that the \textit{extraction procedure} forcely assumes the momentum dependence of the single-particle potential energy to be a quadratic form where the strength is solely determined by the constant scalar potential.Comment: 13 pages, 4 figure

Dual-Decoder Consistency via Pseudo-Labels Guided Data Augmentation for Semi-Supervised Medical Image Segmentation

Medical image segmentation methods often rely on fully supervised approaches to achieve excellent performance, which is contingent upon having an extensive set of labeled images for training. However, annotating medical images is both expensive and time-consuming. Semi-supervised learning offers a solution by leveraging numerous unlabeled images alongside a limited set of annotated ones. In this paper, we introduce a semi-supervised medical image segmentation method based on the mean-teacher model, referred to as Dual-Decoder Consistency via Pseudo-Labels Guided Data Augmentation (DCPA). This method combines consistency regularization, pseudo-labels, and data augmentation to enhance the efficacy of semi-supervised segmentation. Firstly, the proposed model comprises both student and teacher models with a shared encoder and two distinct decoders employing different up-sampling strategies. Minimizing the output discrepancy between decoders enforces the generation of consistent representations, serving as regularization during student model training. Secondly, we introduce mixup operations to blend unlabeled data with labeled data, creating mixed data and thereby achieving data augmentation. Lastly, pseudo-labels are generated by the teacher model and utilized as labels for mixed data to compute unsupervised loss. We compare the segmentation results of the DCPA model with six state-of-the-art semi-supervised methods on three publicly available medical datasets. Beyond classical 10\% and 20\% semi-supervised settings, we investigate performance with less supervision (5\% labeled data). Experimental outcomes demonstrate that our approach consistently outperforms existing semi-supervised medical image segmentation methods across the three semi-supervised settings

Neutron-proton effective mass splitting in neutron-rich matter

Nucleon effective masses in neutron-rich matter are studied with the relativistic Brueckner-Hartree-Fock (RBHF) theory in the full Dirac space. The neutron and proton effective masses for symmetric nuclear matter are 0.80, which agrees well with the empirical values. In neutron-rich matter, the effective mass of the neutron is found larger than that of the proton, and the neutron-proton effective mass splittings at the empirical saturation density are predicted as $0.187\alpha$ with $\alpha$ being the isospin asymmetry parameter. The result is compared to other ab initio calculations and is consistent with the constraints from the nuclear reaction and structure measurements, such as the nucleon-nucleus scattering, the giant resonances of $^{208}$Pb, and the Hugenholtz-Van Hove theorem with systematics of nuclear symmetry energy and its slope. The predictions of the neutron-proton effective mass splitting from the RBHF theory in the full Dirac space might be helpful to constrain the isovector parameters in phenomenological density functionals.Comment: 14 pages, 4 figure

Polynomial Normal Transform Based on L-moments and Its Application to Structural Reliability

Information on the distribution of the basic random variable is essential for the accurate analysis of structural reliability. The usual method for determining the distributions is to fit a candidate distribution to the histogram of available statistical data of the variable. Generally, such candidate distribution would have parameters that may be evaluated from the statistical moments of the statistical data. Probability distributions are usually determined using one or two parameters evaluated from the mean and standard deviation of statistical data. However, these distributions are not flexible enough to represent the skewness and the kurtosis of statistical data. Normal transformation is often used in probabilistic analysis especially when multivariate non-normal random variables are involved. This study proposes a probability distribution based on polynomial normal transform, of which parameters are determined using the first four L-moments (L-mean, L-standard deviation, L-skewness and L-kurtosis) of the available data. The simplicity, generality, flexibility and advantages of this distribution in statistical data analysis are discussed. The results are found to better than two- and three-parameter distributions, and similar to cubic normal distribution based on central moments (C-moments). With the aiming at illustrate the stability of polynomial normal transform based on L-moments, several extreme values are added to data. The proposed distribution is demonstrated to provide significant stability and flexibility. Then this method is applied to reliability index calculation, and its significance in structural reliability evaluation is discussed. The calculation results are compared with Monte Carlo calculations. Several numerical examples are further presented to demonstrate the accuracy and efficacy of the distribution for conducting reliability analyses.The study is partially supported by the National Natural Science Foundation of China (Grant No.: 51820105014, 51738001). The support is gratefully acknowledged

Free chlorine loss during spray of membrane-less acidic electrolyzed water (MLAEW) and its antimicrobial effect on airborne bacteria from poultry house

Spray-application of membrane-less acidic electrolyzed water (MLAEW) is a novel technique for disinfection in livestock houses. This study investigated the loss of free chlorine (FC, the major germicidal component in MLAEW) over distance during spray, as affected by air temperature and initial FC concentration. The antimicrobial effect of MLAEW on airborne bacteria from an aviary laying-hen house was examined. MLAEW was prepared with two FC concentrations (app. 15 and 60 mg L-1), and was sprayed at three air temperatures (18, 25, 32°C). The original MLAEW solution and MLAEW aerosols collected at 0, 25, and 50 cm from the spray nozzle were analyzed for FC concentrations. Bacteria were immersed into these MLAEW samples and numerated for viable count after 0.5-, 2-, and 5-min treatments. MLAEW aerosols collected at 0 cm lost 11.7 – 13.2% FC as compared to the original MLAEW solution. This initial loss was affected neither by the initial FC concentration (P = 0.13) nor by air temperature (P = 0.57). The rate of FC loss during travelling was 0.79 – 0.87 % per centimeter of aerosol travel distance (% cm-1) at 18°C, 1.08 – 1.15 % cm-1 at 25°C, and 1.35 – 1.49 % cm-1 at 32°C. This travelling loss was affected by air temperature (P = 0.02), but not by initial FC concentration (P = 0.38). Bacteria were completely inactivated in 0.5 min when treated with MLAEW samples with FC \u3e 16.8 mg L-1, in 2 min when FC \u3e 13.8 mg L-1, and in 5 min when FC \u3e 7.2 mg L-1. Airborne bacteria from aviary hen house can be effectively inactivated by MLAEW with adequate FC concentration and contact time. During spray, antimicrobial efficacy of MLAEW aerosols decreased over distance due to FC loss which exacerbates at higher air temperature

Active Infrared Sensing of Impact Damage in Carbon Fibre Reinforced Polymer

With the growing demand of carbon fibre reinforced plastic (CFRP) in aerospace, marine and automobile industries, much attention is devoted to characterizing the material strength and characteristics of failure. This paper demonstrated the feasibility to estimate the internal damage non-destructively as a result of a quantified impact applied on 16-ply fabric CFRP. On thermography images at different heating time, differences were observed between intact area and area with internal damage. The estimation of 1D extent of damage using thermographic analysis was compared with images observed with cross sectional microscopic. The results suggest that qualitative analysis using thermography shows potential to be used as a tool for measuring impact damage

Free chlorine loss during spraying of membraneless acidic electrolyzed water and its antimicrobial effect on airborne bacteria from poultry house

Spray-application of membraneless acidic electrolyzed water (MLAEW) is a novel technique for disinfection in livestock houses. This study investigated the loss of free chlorine (FC – the major germicidal component in MLAEW) over distance during spraying, as affected by air temperature and initial FC concentration. The anti-microbial effect of MLAEW on airborne bacteria from an aviary laying-hen house was examined. materials and methods. MLAEW was prepared at two FC concentrations: app. 15 and 60 mg L -1 , and sprayed at three air temperatures (18, 25, 32 °C). The original MLAEW solution and MLAEW aerosols collected at 0, 25, and 50 cm from the spray nozzle were analyzed for FC concentrations. Bacteria were immersed into these MLAEW samples and numerated for viable count after 0.5, 2 and 5-min treatments. results. MLAEW aerosols collected at 0 cm lost 11.7–13.2% FC, compared with the original MLAEW solution. This initial loss was affected neither by the initial FC concentration (P = 0.13) nor by air temperature (P = 0.57). The rate of FC loss during travelling was 0.79–0.87 % per cm of aerosol travel distance (% cm -1 ) at 18 °C, 1.08–1.15 % cm -1 at 25 °C, and 1.35–1.49% cm -1 at 32 °C. This travelling loss was affected by air temperature (P = 0.02), but not by initial FC concentration (P = 0.38). Bacteria were completely inactivated at 0.5 min when treated with MLAEW samples with FC \u3e 16.8 mg L -1 , in 2 min when FC \u3e 13.8 mg L -1 , and in 5 min when FC \u3e 7.2 mg L -1 . conclusion. Airborne bacteria from aviary hen house can be effectively inactivated by MLAEW with adequate FC concentration and contact time. During spraying, the anti-microbial efficacy of MLAEW aerosols decreased over distance due to FC loss which exacerbated at higher air temperatures