To ensure the safe and reliable operation of nuclear power plants, continuous monitoring of key process parameters using transmitters is essential. Accordingly, evaluating the reliability of these instruments is critical for maintaining long-term performance and safety. This study presents a nonlinear Wiener process-based method for reliability analysis and prediction of pressure transmitters in nuclear environments. The approach begins by extracting the maximum absolute error from field calibration data as a degradation indicator. A Wiener process model is then developed to capture the inverse S-shaped degradation trend observed under nuclear conditions. Subsequently, the reliability prediction is achieved based on the first passage time (FPT) theory. A case study based on actual plant data shows that the reliability remains above 99.9943 % even when the calibration interval is extended to 24 months, thereby providing quantitative support for interval extension.
Modern experimental techniques can generate magnetic fields of the form H(t) = H0 z-hat + H1 [x-hat cos(ωt) + y-hat sin(ωt)], at frequencies within an order of magnitude of the nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) frequencies, ωn0 and ωe0, respectively, when acting on atoms or molecules. We derive simple closed-form expressions for the exact nuclear- and electronic-spin wave functions that enable controlled transitions between entangled states, allowing an atom or molecule to function as a quantum computer. These solutions also enable precise NMR or EPR measurements of nuclear moments in atoms and molecules. We present examples relevant to measurements of the nuclear moments of 14N, 7Li, and 133Cs. Because existing hyperfine measurements of the lowest three nuclear moments of 133Cs are mutually inconsistent, the proposed NMR/EPR experiments provide a route to measuring all seven of its nuclear moments with high precision.
The adoption of Generative AI (GenAI) suggests major changes for software engineering, including technical aspects but also human aspects of the professionals involved. One of these aspects is how individuals perceive themselves regarding their work, i.e., their work identity, and the processes they perform to form, adapt and reject these identities, i.e., identity work. Existent studies provide evidence of such identity work of software professionals triggered by the adoption of GenAI, however they do not consider differences among diverse roles, such as developers and testers. In this paper, we argue the need for considering the role as a factor defining the identity work of software professionals. To support our claim, we review some studies regarding different roles and also recent studies on how to adopt GenAI in software engineering. Then, we propose a research agenda to better understand how the role influences identity work of software professionals triggered by the adoption of GenAI, and, based on that, to propose new artifacts to support this adoption. We also discuss the potential implications for practice of the results to be obtained.
TANG Xian, LIANG Jixin, FAN Caiyun, CHEN Baojun, LUO Zhifu
Radioisotopes and radiopharmaceuticals increasingly contribute to human health in nuclear medicine. Herein, a brief overview of the development of radioisotope production and radiopharmaceuticals in the past seven decades at the China Institute of Atomic Energy (CIAE) was presented. For radioisotope production, a review was made with an emphasis on the development of some reactor-produced radioactive isotopes (99Mo, 131I, 125I, 60Co, 177Lu, etc.), cyclotron-produced isotopes (18F, 123I, 225Ac, etc.) and radionuclide generators (99Mo-99Tcm generator, etc.). For radiopharmaceuticals, the review covers imaging agents (including 99Tcm-, 131I-, 18F-labelled compounds and cold kits for 99Tcm radiolabelling), therapeutic radiotracer agents (containing 153Sm-, 32P-, 90Y-, 177Lu-, 225Ac-labelled agents), compounds for boron neutron capture therapy (BNCT), radioactive seed sources for brachytherapy, and radioimmunoassay kits. Meanwhile, prospects for radioisotope production and radiopharmaceuticals are provided, and CIAE is expected to play a more important role in this field in the future.
The 5th Industrial Revolution (5IR) is reshaping the global business landscape by integrating artificial intelligence, robotics, and the Internet of Things with a renewed focus on human-centered innovation. Talent management (TM), traditionally regarded as a human resources function, must re-envision itself within this paradigm. This paper develops a conceptual framework that applies systems thinking and design thinking to talent management in the context of the 5IR, enabling organizations to remain agile, innovative, and resilient. Systems thinking offers a holistic perspective on understanding the interconnections within the talent ecosystem, while design thinking promotes creative, empathetic, and human-centered solutions. Drawing on recent research on coopetition in SMEs, project-based talent development, global talent practices, and digital readiness in the public sector, the framework highlights the importance of upskilling, leadership support, and the responsible adoption of AI. The outcomes suggest that organizations should adopt holistic and adaptive talent management practices to address skills gaps, foster innovation, and maintain a competitive advantage in the rapidly evolving global environment.
The helical tube bundle is widely used in fast reactor and fourth generation nuclear power reactor because of its compact structure and high heat transfer efficiency. The bundle arrangement of adjacent layers wound in the opposite direction for helical-tube heat exchanger is constantly changing in the axial section of the helix. In addition, turbulence makes the fluid in the shell-side present flow instability in the subcritical region, and the vibration form of coil tube bundle coupled to the fluid is not specified. There is no basis for the safety prediction and evaluation of FIV (flow induced vibration) for the bundle wound in the opposite direction. The robustness of the 3D fluid-structure interaction numerical model was verified by measuring the in-plane and out-of-plane vibration responses of coil tubes. In order to prove the reliability of 3D fluid-structure interaction numerical models, an impact test system about FIV was designed and established. On the basis of the impact experiment to verify the excitation model in regard to helical tube bundle, the mechanism of the relative position of the tubes and the structural parameters of the tube bundle on the vibration response of the helical tube was systematically studied by using the helical tube bundle excitation model. The influence of pitch diameter ratio between adjacent tubes on the vibration response of the tubes is stronger than that of pitch diameter ratio between tubes in the same layer and helix angle. The more compact the bundle arrangement is, the greater the vibration response of the tubes is, and the more drastic the amplitude fluctuation is. With the increase of helix angle, the difference of vibration response between front tube and back tube became smaller, and the amplitude increased slightly. With the increase of flow rate between the tubes, the amplitude in both directions increased gradually, while the amplitude in the out-of-plane is significantly larger than that in the in-plane, and it is the first to occur fluid-elastic instability. Based on the quasi-static model, the semi-empirical formula of critical velocity for the tube bundle is presented. The paper addresses the FIV mechanism for helical tube bundle with adjacent layers wound in reverse, and lays a theoretical foundation for the structural design of the helical tube bundle and the calculation assessment of FIV of the heat exchanger, which is great significance for the design and application of helical tube heat exchanger.
Leah J. Broussard, Andreas Crivellin, Martin Hoferichter
et al.
Processes that violate baryon number, most notably proton decay and $n\bar n$ transitions, are promising probes of physics beyond the Standard Model (BSM) needed to understand the lack of antimatter in the Universe. To interpret current and forthcoming experimental limits, theory input from nuclear matrix elements to UV complete models enters. Thus, an interplay of experiment, effective field theory, lattice QCD, and BSM model building is required to develop strategies to accurately extract information from current and future data and maximize the impact and sensitivity of next-generation experiments. Here, we briefly summarize the main results and discussions from the workshop "INT-25-91W: Baryon Number Violation: From Nuclear Matrix Elements to BSM Physics," held at the Institute for Nuclear Theory, University of Washington, Seattle, WA, January 13-17, 2025.
We demonstrate that energy levels of excited states in a hydrogenic system consisting of an arbitrary nucleus and an antiproton can be calculated within the framework of nonrelativistic quantum electrodynamics, even for a large nuclear charge $Z$. It is because for rotational states the expansion parameter is $Z\,α/n$. The main advantage of this approach is the possibility of exact inclusion of the finite nuclear mass, which we achieve up to the $(Z\,α)^6$ order. In addition, we include unperturbatively the one-loop and two-loop electron vacuum polarization (evp) potentials in the nonrelativistic Hamiltonian, as well as in the leading relativistic correction. The obtained results for $l>1$ states of antiprotonic atoms with spinless nucleus are the most accurate to date. We make available a user-friendly {\sl Mathematica} code for antiprotonic atoms {\sl PbarSpectr}, which can be further improved by combining evp potentials with $(Z\,α)^5$ QED effects, by adding three-loop evp, and by extending to an arbitrary nuclear spin. Finally, we note that rotational states of antiprotonic atoms can be used to determine the mean square nuclear charge radius much more accurately than from electronic or muonic atoms.
With the aim to determine the potential corrosion effects of solid boric acid (BA) on light water reactors or other BA-involved equipment, the corrosion behaviors of solid BA on 304 stainless steel (SS) at different temperatures were investigated. Upon comparing the corrosion behaviors of solid BA at different temperatures, significant localized corrosion was observed on 304 SS surfaces at 150 °C following 90-day. This localized corrosion exhibited a characteristic pattern of scattered corrosion craters including B-containing Cr-rich oxides. These oxides were found to originate within micro-cracks, gradually evolving into scar-like protrusions within the craters. The proposed corrosion mechanisms entail the interactions between solid BA and chromium oxides/hydroxides, leading to the formation of B-containing Cr-rich oxides. Our findings offer insights into potential corrosion incidents and protective strategies for industries dealing with solid BA.
Gastric examination is a common endoscopic procedure that can be used to assess stomach diseases and lesions. However, because the stomach examination requires the use of radiation imaging technology, patients are exposed to radiation risks. Therefore, the aim of this study is to develop a specialized database of endoscopy and integrate it with an image annotation platform to achieve effective control of gastric examination radiation. An image labeling platform was developed to label gastric lesions and structures, annotate and label endoscopic images, and describe the details of gastric lesions more comprehensively and accurately. A complete radiation imaging control system for gastric examination was formed by integrating professional database and image labeling platform. Through this integrated system, doctors can quickly access the endoscopy images in the database when performing stomach exams, and label lesions on the image labeling platform to more accurately evaluate the lesions and structure of the stomach, while reducing the number of times patients undergo radiation examinations. The results show that the radiation imaging of gastric examination can be effectively controlled through the integration of endoscopy database and image annotation platform. This integrated system helps to improve the accuracy and safety of the examination, and has important clinical application value for both doctors and patients.
Medical physics. Medical radiology. Nuclear medicine, Nuclear engineering. Atomic power
There is renewed interest in studies of muonic atoms, which may provide detailed information on nuclear structure. A major limiting factor in the interpretation of measurements is the nuclear polarization contribution. We propose a method to determine this contribution to the hyperfine structure in muonic atoms from a combination of theory and experiment for hydrogenlike ions and muonic atoms. Applying the method to $^{203,205}$Tl and $^{209}$Bi, for which there are H-like ion and muonic atom hyperfine experimental data, we find that the nuclear polarization contribution for these systems is small, and place a limit on its size of less than $10\%$ the total hyperfine splitting. We have also performed direct calculations of the nuclear polarization contribution using a semi-analytical model, which indicate that it may be as much as two orders of magnitude smaller. Therefore, we conclude that the nuclear polarization correction to the hyperfine structure of muonic atoms does not represent a limiting factor for next-generation experiments.
LEI Wenming;LI Jinglun;AI Xianyun;XIAO Wuyun;ZHANG Jipeng;XIAO Xiong;ZHANG Bin;ZHAO Wei;WANG Ying
Silicon photomultiplier (SiPM) is a new type of photoelectric conversion device with high gain and low power consumption since the 21st century. It consists of thousands of single photon avalanche diodes (SPADs) operating in Geiger mode connected in parallel with each other. It is widely used in medical imaging, high-energy physics, environmental monitoring and defence and security. The SiPM coupled with cerium-doped gadolinium gallium aluminium garnet (GAGG(Ce)) crystals is a promising detector for energy spectrum measurement and imaging detection. In this paper, the temperature drift characteristics of an 8×8 array SiPM-coupled Φ2 in×2 in GAGG(Ce) crystal detector were investigated, and a gain compensation system based on the feedback adjustment of the operating voltage of the SiPM-GAGG(Ce) detector by a temperature sensor was designed and built. Experiments such as power supply reliability test, power supply ripple test and temperature compensation test were carried out separately. The experimental results show that the power supply has high long-term operating stability and the power supply ripple noise is less than 0.001%. The output voltage range is 0-100 V, meeting the operating voltage requirements of most common SiPM models. The experimental results show that in the temperature range of -20-40 ℃. The maximum peak sites of 662, 1 173, 1 332, and 59.5 keV full-energy peaks are 515.9, 915.8, 1 041.0, and 43.1, and the minimum peak sites are 507.1, 899.0, 1 022.9, and 43.1. The maximum positive drifts are 4.6, 7.8, 8.1 and 0.5 lanes and the maximum negative drifts are 4.2, 8.7, 9.8 and 0.5 lanes respectively. Compared to the 662 keV for 137Cs, 1 173 and 1 332 keV for 60Co and 59.5 keV for 241Am peak sites measured without temperature compensation, the average drifts of the peak sites with SiPM-only temperature compensation are reduced from 45.34%, 45.13%, 44.98%, and 43.85% to 23.68%, 23.67%, 23.68% and 18.30%. The temperature effect of the scintillation crystal has to be taken into account for the temperature compensation of the whole detector. After the overall temperature compensation of the SiPM-GAGG(Ce) detector, the average drift rates of 662 keV for 137Cs, 1 173 keV and 1 332 keV for 60Co and 59.5 keV for 241Am peak channel sites are reduced to 0.37%, 0.37%, 0.36% and 0.57%, which is a significant compensation effect. In the absence of temperature compensation, the 137Cs energy resolution varies from 8.08% at -20 ℃ to 14.58% at 40 ℃. After compensating for the temperature effect of the SiPM-GAGG(Ce) detector, the137Cs energy resolution changes from 8.36% at -20 ℃ to 9.29% at 40 ℃. The stability of the energy resolution is significantly improved. The temperature compensation system has the advantages of low noise, small size and freely customisable temperature characteristic curves. It effectively solves the problem of significant differences in the driving voltage of SiPM from different manufacturers and the compensation of temperature effects after coupling the 8×8 SiPM array with Φ2 in×2 in GAGG(Ce) crystals, and significantly improves the stability of the γ spectrometry system.
Tungsten has been considered as a potential candidate material for the application of plasma-facing components in magnetic confinement fusion reactors. Fusion neutrons introduce severe displacement damage into the first-wall materials along with a high amount of helium which is detrimental to the desirable material properties. Ion beam implantation combined with positron annihilation spectroscopy is a well-adopted method to investigate the irradiation damage in materials without any induced radioactivity. In this study, two separate tungsten samples were individually irradiated with 9.1 MeV Au5+ ions to a dose of 2.5 × 1014 ions/cm2 and 130 keV He ions to a dose of 1 × 1016 ions/cm2 with the intention to investigate the evolution of vacancy-type defects in the absence and presence of helium. The irradiated samples were subjected to isochronal annealing and characterized using positron annihilation Doppler broadening spectroscopy. The evolution of vacancy-type defects during different stages of annealing was investigated using defect-sensitive positron S-parameter. An increase in S-parameter due to the presence of vacancy-type defects was observed upon irradiation in both samples. The S-parameter variations with respect to the temperature showed different stages of vacancy annealing corresponding to stage III from 473 K to 673 K where the migration and clustering of mono-vacancies occurs, stage IV from 673 K to 973 K due to the growth of nano-voids and stage V from 973 K to 1273 K due to the dissociation of nano-voids. Complete recovery of irradiation-induced defects occurred in both samples at 1273 K. Both the samples showed similar vacancy annealing stages and no signature on the formation and growth of He-vacancy clusters or He bubbles was observed in the present study.
The red palm weevil Rhynchophorus ferrugineus infest more than nearly 40 palm species around the world. They damage the internal tissues of palms by the larval stage which is the serious stage. Nanoparticles represent a new generation of environmental remediation technologies that can provide cost-effective solution to some of the most challenging environmental clean-up problems. They also help to produce new pesticides. Nanochitosan is used to control the red palm weevil larvae and adults. The results show that it affects the mortality percentage of R. ferrugineus larvae. The mortality percentage increased by increasing the time and concentrations of nanochitosan, since 100% mortality was obtained at the concentration 80000 ppm after (15–20) days time interval. The percentage of mortality of R. ferrugineus female and male showed that the most effective concentration of nanochitosan was 20000 ppm, where 100% mortality was obtained in time interval 10–20 days. In addition, nanochitosan affects the biology of red palm weevil by decreasing pupation percentage, emergence percentage, pupal duration number of eggs/female, hatchability percentage and longevity of males and females as compared to the control. LC50 and Lc25 of nanochitosan disturbs the total protein and total carbohydrates. The activity of enzymes (protease, invertase and amylase) of larvae and adult (males and females) was disordered. We conclude that nanochitosan can be used as a control tool to the red palm weevil.
Medical physics. Medical radiology. Nuclear medicine, Nuclear engineering. Atomic power
Rebekah Hermsmeier, Xiaodong Xing, Timur V. Tscherbul
We explore the quantum dynamics of nuclear spin relaxation in cold collisions of $^1Σ^+$ molecules with structureless atoms in an external magnetic field. To this end, we develop a rigorous coupled-channel methodology, which accounts for rotational and nuclear spin degrees of freedom of $^1Σ^+$ molecules, their interaction with an external magnetic field, as well as for anisotropic atom-molecule interactions. We apply the methodology to study collisional relaxation of the nuclear spin sublevels of $^{13}$CO molecules immersed in a cold buffer gas of $^4$He atoms. We find that nuclear spin relaxation in the ground rotational manifold of CO occurs extremely slowly due to the absence of direct couplings between the nuclear spin sublevels. The rates of collisional transitions between the $N=1$ nuclear spin states of CO are generally much higher due to the direct nuclear spin-rotation coupling between the states. These transitions obey selection rules, which depend on the values of space-fixed projections of rotational and nuclear spin angular momenta for the initial and final molecular states. For some initial states, we also observe a strong magnetic field dependence, which can be understood using the first Born approximation. We use our calculated nuclear spin relaxation rates to investigate the thermalization of a single nuclear spin state of CO$(N=0)$ immersed in a cold buffer gas of He. The calculated nuclear spin relaxation times ($T_1\simeq 0.5$ s at $T=1$ K) display a steep temperature dependence decreasing rapidly at elevated temperatures due to the increased population of rotationally excited states, which undergo nuclear spin relaxation at a much faster rate. Thus, long relaxation times of $N=0$ nuclear spin states in cold collisions with buffer gas atoms can only be maintained at sufficiently low temperatures ($kT\ll 2B_e$), where $B_e$ is the rotational constant.
In empirical software engineering, benchmarks can be used for comparing different methods, techniques and tools. However, the recent ACM SIGSOFT Empirical Standards for Software Engineering Research do not include an explicit checklist for benchmarking. In this paper, we discuss benchmarks for software performance and scalability evaluation as example research areas in software engineering, relate benchmarks to some other empirical research methods, and discuss the requirements on benchmarks that may constitute the basis for a checklist of a benchmarking standard for empirical software engineering research.