Technical Support Research Articles

Adaptive group sample with central momentum contrast loss for unsupervised individual identification of cows in changeable conditions

Individual identification is the basis for accurate breeding and management of dairy cows. Most of the studies on individual identification of dairy cows focused on closed data sets. Meanwhile, the training process requires lots of manual labeling data as support. Aiming at solving the above shortcomings, an unsupervised cow individual identification model named AC-Cowid (Adaptive Group Sample-Central Momentum Contrastive loss-Cowid) was proposed. The innovation of the model lied in the novel sampler and loss function. Adaptive Group Sampler made up for the sampling imbalance problem in the current samplers. The sampler would self-update with model optimization. The central constraint term in Central Momentum Contrastive loss made the updated features more inclined to the cluster center, effectively solved the discomfort of Contrastive loss to cow image data. Feature similarity matching was adopted to meet the challenge of data conversion from a closed set to an open and changeable set. The unsupervised training reduced the workload of manual data labeling. The CMC-1 and mAP index of the final model were 99.50 % and 77.90 %, respectively. Ablation and hyper-parameter experiments proved the effectiveness of the proposed method. The comparison experiment tested eight unsupervised methods and five supervised algorithms in the state-of-the-art. The mAP and CMC-1 of the proposed method was the best among the comparison algorithms. Above all, the proposed method was 4.60 % and 5.38 % higher on mAP and CMC-1 compared with the best algorithm in supervised learning. This study could provide technical support for individual identification of cows in large-scale cattle farms.

Remaining useful life prediction method for jointless track circuits based on multivariate feature fusion and nonlinear Wiener process

Abstract Predicting the Remaining Useful Life (RUL) of track circuits is essential to ensure the safe and reliable operation of high-speed railways. In response to the challenges faced by current machine-learning-based RUL prediction methods, which struggle to represent the uncertainty in the probability distribution of RUL predictions, this paper suggests a hybrid-driven method for estimating remaining life. Firstly, the track circuit Health Index (HI) is constructed by feature dimensionality reduction and fusion of the original multivariate monitoring data through Kernel Principal Component Analysis (KPCA) and Autoencoder (AE); Secondly, the degraded state of the rail circuit is modelled using a nonlinear Wiener degradation model. Finally, the principle of First Hitting Time (FHT) is used to derive the Probability Density Function (PDF) of the anticipated RUL. The efficacy and superiority of the approach presented in this paper are validated by experimental research on the track circuit monitoring dataset. The method enhances forecast accuracy and reduces prediction uncertainty, offering robust technical support for track circuit maintenance decision-making.

Digital Inclusion Strategy in Modern Cultural Industries through the Prism of Digital Divide

The purpose of the article is to reveal the features of digital inclusion in modern cultural industries of Ukraine and to outline promising strategies for overcoming the digital divide. Research methodology. The analytical method, the method of analysis and synthesis, the dialogical method, the typological method, the systematic method, the method of comparative analysis and the method of scientific generalisation are applied. Scientific novelty. The problem of digital inclusion in the cultural industry has been studied; the theory of digital inclusion in foreign scientific works is considered; the peculiarities of digital inclusion in modern cultural industries of Ukraine were revealed; promising measures on which the strategy for overcoming the digital divide should be based are outlined. Conclusions. The strategy of digital inclusion of cultural industries in Ukraine should be based on a set of measures aimed at overcoming the digital divide, which includes, first of all: providing high-speed Internet to as large a part of the population as possible; all kinds of assistance in the process of improving the digital literacy of potential consumers of a cultural product / service; provision of high-quality technical support; creation of specialised applications and online content, according to the specifics of the activities covered by each cultural industry. Potential forward-looking steps include providing ongoing support to users, reducing professional jargon and offering interpretive resources, and ensuring that technology and training are offered to all users on an equal basis, not just those confident enough to seek help. The study revealed that at the current stage in Ukraine, only libraries not only offer the Internet, but also provide a range of training services from basic digital literacy to the skills needed to use certain services (audio/video streaming service, file sharing services, online platforms), devices and applications that are currently actively used in the system of cultural industries (for example, applications of augmented reality in museum, exhibition activities, performing arts).

A factor analysis based automatic optimization method of vibration sensor points for ship acoustic reconstruction

To address the challenge associated with optimizing the number and positioning of accelerometer points in ship acoustic reconstruction, factor analysis is applied to the automatic optimization of accelerometer position in this work according to the source independence of ship’s underwater radiated noise. Based on the numerical simulation method that calculates the vibration noise response under specific operation conditions, the minimum number and the optimal position of the accelerometers can be obtained through the factor analysis and multi-parameter comprehensive evaluation method. The results of acoustic reconfiguration and testing are compared using one test cabin as a validation object to verify the effectiveness of the proposed method. The results show that the automatic optimization algorithm can improve the reconstruction accuracy concerning the uniform distribution method. The error is reduced from 15.46% (1.5 dB) to 8.35% (0.8 dB), and the correlation coefficient is improved from 0.86 to 0.89. The semi-automatic optimization method is slightly lower in terms of errors and correlation coefficients compared to the automatic optimization algorithm. After increasing the number of monitoring positions for automatic optimization, the acoustic reconstruction accuracy is further improved, while the average error is reduced to 7.37% (0.7 dB) and the correlation coefficient is improved from 0.89 to 0.92. The experimental results are proximate to the conclusions of the simulation calculation. Even under the circumstance of multi-factor noise interference, the correlation coefficient of multi-position automatic optimization can still reach 0.8, in comparison with the uniform distribution method, the error is reduced from 32.49% (3.4 dB) to 25.94% (2.6 dB). The proposed method effectively captures the dynamic characteristics of complex structures and their impact on underwater radiated noise, and the integration of factor analysis can prominently enhance the computational efficiency, thereby providing technical support for engineering applications to the ship acoustic reconstruction.

Exploring global perspectives on the use of computer-based simulation in pharmacy education: a survey of students and educators

Background: Increasing student numbers and logistical challenges in pharmacy education limit patient counselling and clinical placement opportunities. Computer-based simulation (CBS) offers scalable, interactive learning but faces integration barriers.Objective: To explore global perceptions of CBS implementation in pharmacy education among educators and students. Methods: An online cross-sectional survey was developed based on literature review and expert feedback. The survey was distributed globally through academic pharmacy organisations, social media, and the authors’ networks. It included 20 questions targeting pharmacy educators and students.Results: Responses from 152 educators across 38 countries and 392 students from 46 countries, spanning six WHO regions (AFRO, AMRO, EMRO, EURO, SEARO, and WPRO) were analysed using descriptive and inferential statistics. The majority of educators (90.1%, n = 137) and students (84.2%, n = 330) expressed comfort with using CBS and implementing it in their curriculum. Despite this, CBS was perceived as underutilised by 53.5% (n = 81) of educators and 63.7% (n = 250) of students. Students valued CBS for enhancing communication and problem-solving skills, while educators highlighted its relevance to community pharmacy practice. Both groups supported CBS use in assessments. All educators (100%) identified workload reduction as a key priority, hoped CBS could assist in this area. Educators also reported barriers such as financial constraints (56.6%, n = 86) and insufficient technical support (53.3%, n = 81). On the other hand, students were less optimistic about institutional support, with only a few (7.4%, n = 29) believed institutional leaders would actively support CBS adoption. Regional differences emerged, with SEARO (Southeast Asia) and AFRO (Africa) showing the lowest CBS usage rates. Educators in SEARO, AFRO, and EMRO (Eastern Mediterranean) raised concerns about technical support, while those in SEARO, AFRO, and WPRO (Western Pacific, including Australia, New Zealand, and Singapore) expressed financial concerns. Educators in AFRO and WPRO, however, reported being 100% comfortable with using CBS.Conclusion: Both students and educators recognised the potential of CBS in pharmacy education, with strong support for its integration. Addressing barriers such as educator workload, financial constraints, and technical support is crucial for broader adoption. Improved resource allocation and targeted training for educators are essential to effectively incorporate CBS into the pharmacy curriculum.

Improving Text Classification in Agricultural Expert Systems with a Bidirectional Encoder Recurrent Convolutional Neural Network

With the rapid development of internet and AI technologies, Agricultural Expert Systems (AESs) have become crucial for delivering technical support and decision-making in agricultural management. However, traditional natural language processing methods often struggle with specialized terminology and context, and they lack the adaptability to handle complex text classifications. The diversity and evolving nature of agricultural texts make deep semantic understanding and integration of contextual knowledge especially challenging. To tackle these challenges, this paper introduces a Bidirectional Encoder Recurrent Convolutional Neural Network (AES-BERCNN) tailored for short-text classification in agricultural expert systems. We designed an Agricultural Text Encoder (ATE) with a six-layer transformer architecture to capture both preceding and following word information. A recursive convolutional neural network based on Gated Recurrent Units (GRUs) was also developed to merge contextual information and learn complex semantic features, which are then combined with the ATE output and refined through max-pooling to form the final feature representation. The AES-BERCNN model was tested on a self-constructed agricultural dataset, achieving an accuracy of 99.63% in text classification. Its generalization ability was further verified on the Tsinghua News dataset. Compared to other models such as TextCNN, DPCNN, BiLSTM, and BERT-based models, the AES-BERCNN shows clear advantages in agricultural text classification. This work provides precise and timely technical support for intelligent agricultural expert systems.

Numerical simulation of fluid flow characteristics and ultrasonic cavitation performance in novel-designed stirred tank sonoreactor

A novel-designed stirred tank sonoreactor was developed to well solve large-scale dispersion of nanoparticles in liquid phase system. The fluid flow characteristics and ultrasonic cavitation performance in the sonoreactor were numerically simulated by CFD method. By comparing the pressure, cavitation bubble and velocity distribution under different situations, it is found that larger ultrasonic amplitude, relatively smaller ultrasonic frequency, higher saturated vapor pressure and lower viscosity of liquid medium are beneficial to ultrasonic cavitation. Besides, the acoustic flow action is strengthened with the increase of ultrasonic frequency and decrease of gas-liquid mixture's average density. For the designed sonoreactor, it is critical that high-frequency transducers should be determined near the bottom and upper region of the kettle, and large-amplitude transducers can be confirmed in the middle position. The research findings will provide theoretical and technical supports for developing state-of-the-art sonoreactors and optimizing ultrasonic process parameters in the industrialized preparation of nanocomposites.

Two factors facilitate the cost-effective and harmless cementation of rare earth slags through MICP technology: Carbonic anhydrase bacteria and endogenous calcium ions

Microbially induced carbonate precipitation (MICP), a solidification/stabilization technique that doesn't interfere with recycling and can reduce the migration of pollutants, has been employed to cement rare earth slags (RES). Currently, the MICP process of the urease/carbonic anhydrase pathway has attracted considerable attention. However, the MICP process of the urease pathway may produce high concentrations of ammonia, which can cause secondary contamination; the addition of a calcium source (calcium chloride) may increase the cost of the treatment process. In this study, two factors, carbonic anhydrase bacteria and endogenous calcium ions (Ca²⁺), facilitated the MICP technology to cost-effectively and harmlessly cement RES and stabilize contaminants. The findings indicated that strain Z1 could utilize endogenous Ca²⁺ to cement the RES, thereby enhancing its unconfined compressive strength, reducing the disintegration rate, radiation dose, and wind erosion intensity, and facilitating the stabilization of heavy metals and radionuclides. In comparison to the CK group, the leaching concentrations of Cu2+, Pb2+, Zn2+, Cd2+, Th(Ⅳ), and U(Ⅵ) in the C1 group were reduced by 42.37 %, 20.20 %, 18.77 %, 22.53 %, 12.32 %, and 23.66 %, respectively. The treatment effect can be further enhanced by adding exogenous Ca2+. This study's findings can help reduce the potential environmental risks in the long-term sequestration of RES, while also providing technical support for the sustainable development of the rare earth industry.

Health status assessment of pump station units based on spatio-temporal fusion and uncertainty information

An effective health status assessment (HSA) for pump station units (PSUs) is crucial for accurately determining their real status and providing technical support for safe operational decisions. Due to the limitations of existing data-driven HSA methods, which primarily focus on the temporal dependencies of monitoring signals and fail to explore the complex interconnections among signals comprehensively. Moreover, when constructing performance degradation indices based on linear differences, these methods do not effectively integrate heterogeneous signals, resulting in an incomplete and inaccurate assessment of the overall system degradation. This paper proposes a real-time comprehensive HSA method for PSUs based on multi-source heterogeneous uncertainty information. Initially, a health benchmark model (HBM) is built using CrossGNN, which possesses cross-scale and cross-variable interaction capabilities, to precisely capture the temporal dependencies and dynamic relationships among variables in monitoring signals. Subsequently, key measurement points that reflect the operational status of the PSUs are identified through correlation analysis to establish multi-source evaluation indices. Then, considering the uncertainty in signal changes, a novel health degradation index (HDI) is developed using Mahalanobis distance (MD) and the Gaussian Cloud Model (GCM) to analyze changes in unit status. Furthermore, a weighting calculation method based on the non-dominated sorting genetic algorithm (NSGA-II) is proposed to establish a real-time comprehensive health index (RCHDI) for a thorough assessment of PSUs status. Finally, the effectiveness of the proposed method is validated through a case study using data from a pump station in the South-to-North Water Diversion Project in China. The results show that, compared to other studies, the proposed method significantly improves the stability and smoothness of the state assessment curve, with increases of 21.5% and 47.1% respectively, providing a new perspective for comprehensively assessing the health status of PSUs.V

Modeling for Formation of Microdroplets Prepared by Pulsated Orifice Ejection Method

Abstract This study investigated the preparation of metallic microdroplets by pulsed orifice ejection method. Computational fluid dynamics simulations, combined with volume-of-fluid model, were employed to analyze the jet break-up and droplet formation behaviors of various metallic materials within a certain Weber number (We) range. An energy-based physical model under inlet boundary conditions was established to precisely control the generation of droplets. The results indicate that the break-up state of metal jets is significantly influenced by material properties within the range that We=12~24, which makes the materials exhibiting higher surface tension and density relatively favorable to the production of mono-sized microdroplets. Moreover, the break-up behavior of the jet is closely related to the ratio of volume force to surface tension (Bond number). And the proposed model effectively predicts the properties of droplets. This research provides theoretical guidance and technical support for the precise preparation of metallic microdroplets.

Multiphysics Field Coupled to a Numerical Simulation Study on Heavy Oil Reservoir Development via Electromagnetic Heating in a SAGD-like Process

Conventional thermal recovery methods for heavy oil suffer from significant issues such as high water consumption, excessive greenhouse gas emissions, and substantial heat losses. In contrast, electromagnetic heating, as a waterless method for heavy oil recovery, offers numerous advantages, including high thermal energy utilization, reduced carbon emissions, and volumetric heating of the reservoir, making it a focus of recent research in heavy oil thermal recovery technologies. This paper presents a numerical simulation study of electromagnetic heating for heavy oil recovery, using a heavy oil block in the Bohai Bay oilfield in China as a case study. Firstly, a multiphysics field coupled to a mathematical model was established, considering the impact of the temperature on the heavy oil viscosity, the threshold pressure gradient of non-Darcy flow, and the dielectric properties of the reservoir, along with heat dissipation from overlying and undercover sandstone and gravitational effects on fluid flow. Secondly, a numerical simulation method for the coupled multiphysics fields was developed, and the convergence and stability of the numerical simulation method were tested. Finally, a sensitivity analysis based on the numerical simulation results identified the factors affecting heavy oil production. It was found that electromagnetic heating significantly enhances heavy oil production, and the threshold pressure gradient greatly influences the prediction of heavy oil production. Moreover, heat dissipation from the overlying and undercover sandstone severely reduces cumulative oil production. When the production well is located below the electromagnetic heating antenna, larger well spacing results in higher cumulative heavy oil production. Higher heavy oil production is achieved when the antenna is positioned at the center of the reservoir for the studied cases. Power has a big effect on increasing heavy oil production, but its influence diminishes as power increases. There exists an optimal range of electromagnetic frequencies for maximum cumulative production, and higher water saturation leads to poorer electromagnetic heating efficiency. This study provides a theoretical foundation and technical support for the numerical simulation technology and development plan optimization of heavy oil reservoirs subjected to electromagnetic heating.

Performance and mechanism of triethanolamine-triisopropanolamine corrosion inhibitor to deterioration of reinforced concrete under the coupling effect of freeze-thaw cycles and chloride attack

The purpose of this study is to propose an efficient and economical organic triethanolamine-triisopropanolamine corrosion inhibitor (OTTCI) to reduce the corrosion of steel in reinforced concrete. The influence of OTTCI on corrosion of steel in reinforced concrete under the coupling effect of freeze-thaw cycles and chloride attack (FTCs-CA) were characterized by electrochemical impedance spectroscopy (EIS), dynamic electrode potential (PDP), mechanical properties (mass loss rate (M), compressive strength (fn) and relative dynamic elastic modulus value (Pi)), capillary water absorption (CWA), bubble spacing coefficient (BSC) and scanning electron microscope (SEM). The inhibition mechanism of OTTCI was also analyzed and summarized. The results displayed that the dosage of OTTCI delayed the degradation of reinforced concrete under FTCs-CA. After 150 cycles, the M value of specimens with 1.0 % OTTCI reduced by 66.31 % compared to that of specimens without OTTCI, the Pi value increased by 51.9 %, and the polarization resistance and corrosion inhibition efficiency reached 2744.19 Ω cm2 and 92.88 %, respectively. In addition, OTTCI significantly reduced the CWA value and porosity. After 150 cycles, the CWA and porosity with 1.0 % OTTCI decreased by 60.1 % and 54.54 % respectively. The capillary water absorption coefficient increased linearly with the increase of FTCs-CA. SEM tests illustrated that OTTCI inhibited the development of internal cracks and macropores in concrete and promoted the formation of hydrated calcium silicate gels and calcite. The application of this study not only provides a new method to alleviate the deterioration of reinforced concrete, but also offers theoretical and technical support for further investigate on the deterioration characteristics of reinforced concrete in harsh environments.

Application of phase space file secondary computation method in cell dose distribution

Phase space files can store the particle information in one or more planes of radiation particles simulated by the Monte Carlo (MC) method. The secondary calculation method based on phase space files is commonly used to improve the efficiency of MC simulations. However, it is still unclear whether phase space files are applicable for microdosimetric evaluations. In this study, voxel-type and mesh-type monolayer cell population models of different sizes were constructed, and phase space files of secondary electrons generated by photons with different initial energies were obtained using the MC software -- PHITS. The overall average dose caused by the secondary electron phase space files in the region of interest and their microdosimetric distribution within cells were calculated and compared with the results caused by the initial photons under the same geometric conditions. The results showed that the adoption of secondary electron phase space files had almost no impact on the evaluation of macroscopic average dose, with deviations lower than 3% compared to the overall dose caused by the initial photons in the Petri dish. For microdosimetric distributions of the voxel-type model and the two different morphologies of mesh-type cell models, with a macroscopic accumulated dose of 1 mGy, the relative deviation of the cell dose distribution generated by the initial photons and the phase space files was below 10% and the total computation time of phase space files was below 2% of initial photon's. For accumulated doses of 10, 50, and 100 mGy, the relative deviation of the cell nucleus specific energy obtained by secondary electrons and initial photons was greater than 10%. As the size of the culture dish increased, the differences in cell dose distributions also increased, with the root mean square error (RMSE) and coefficient of variation (Cv) of dose distributions both exceeding 30%. In conclusion, this study assessed the effectiveness of the secondary calculation method utilizing phase space files for dose evaluation at the cellular scale. This research offers essential technical support and theoretical foundations for the utilization of this approach in microdosimetric investigations at the cellular level.

Synthesis and Fabrication of Metal Cation Intercalation in Multilayered Ti3C2Tx Composite CNF Electrode for Asymmetric Coin Cell Supercapacitors.

Ti3C2Tx has attracted considerable attention from researchers in energy storage due to its unique structure and beneficial surface functional group characteristics. Recent studies have focused extensively on developing Ti3C2Tx composites to create potential electrode materials for energy storage applications. Carbon nanofiber is often combined with Ti3C2Tx to produce high-performance functional nanocomposites, effectively harnessing the unique properties of Ti3C2Tx nanosheets while ensuring exceptional electrochemical behavior. This work employs an ultrasonication method to prepare a Na-Ti3C2Tx/CNF electrode. Establishing a stable interlayer structure between Ti3C2Tx nanosheets and cationic metal intercalation materials is crucial for expanding the interlayer spacing of Ti3C2Tx and creating multidirectional stable ion transport channels. Consequently, this process exposes more active sites that are accessible to ions. At a current density of 1 A g-1, the resulting Na-Ti3C2Tx/CNF demonstrates an impressive specific capacitance of 680.2 F g-1. Notably, the asymmetric supercapacitor assembled with Na-Ti3C2Tx/CNF as the positive electrode and activated carbon as the negative electrode exhibits remarkable cyclic retention of 83.1% and the Coulombic efficiency of 90.5% after 10,000 cycles at 10 A g-1, a wide voltage window of 1.5 V, a high energy density of 102.5 W h kg-1, and a power density of 2963.7 W kg-1. The fabricated coin cell ASC devices, which include glowing red light-emitting diodes, were demonstrated in practical applications. The optimization strategy for developing Na-Ti3C2Tx/CNF provides essential technical support for integrating Na-Ti3C2Tx/CNF into the next generation of portable and adaptable wearable electrochemical energy storage devices.

Variable-energy cocktail beam technology for investigating synergistic damage in nuclear materials on LEAF platform

This study addresses the critical issue of synergistic radiation damage in structural materials of fusion reactors, focusing on the interaction between the displacement defects and transmutation-produced hydrogen and helium. These effects are simulated and investigated by employing the advanced multi-beam ion implantation capabilities of the LEAF (Low Energy high intensity highly charged ion Accelerator Facility) platform. Firstly, high-intensity cocktail beams, such as “4He+ and 56Fe14+" and “4He+ and 58Ni15+", are generated and characterized successfully. Then, a complex radiation environment is mimicked within the fusion reactors by applying variable-energy irradiation. Secondly, similar penetration depths for different ions, which are crucial for studying synergistic effects, are obtained by precisely controlling the energy of the cocktail beams through the innovative energy modulation system of the LEAF platform. Finally, the post-irradiation analyses, performed by using the transmission electron microscopy (TEM) and nanoindentation, revealed distinct microstructural changes and alterations in material properties, providing insights into the degradation mechanisms under irradiation. This work not only generates diverse and high-intensity “cocktail” ion beams but also achieves rapid energy switching of the beams. Further, the work is expected to pave the way for the implementation of a novel multi-beam irradiation technique in advanced heavy-ion linear accelerators, and also to provide innovative experimental methods and technical support for studying the synergistic effects of nuclear materials.

Exploring the Challenges of Online Learning in Nigerian Higher Education

This study examines the challenges faced by lecturers in Nigerian higher education institutions when adopting and using e-learning platforms. Through virtual interviews conducted with 12 university lecturers across six regions, the research identifies several key obstacles: unreliable internet connectivity, frequent power outages, and limited access to technological resources. Additionally, inadequate training and institutional support are noted as significant barriers. Thematic analysis was employed to analyze the qualitative data, revealing patterns and common themes related to these challenges. The study suggests that improving internet and power infrastructure, along with enhancing training and technical support, are crucial strategies for overcoming these issues. The findings emphasize the need for targeted interventions to create a more supportive environment for e-learning, aiming to improve the educational experience for both lecturers and students.

Citizens’ Perception of Digital Public Services: A Case Study among Romanian Citizens

Digital transformation has become a topic of interest since public institutions digitalize their processes to improve efficiency, while citizens wish to solve their issues through online platforms. Even if this topic is a priority, the Digital Economy and Society Index reveals that digital public services from UE are under 30% development and implementation. This paper presents the current research made on digital public services and the perspective of Romanian citizens on the adoption of these platforms. The authors conduct bibliometric research to highlight the current progress and concerns. Furthermore, a quantitative analysis is made to determine the perception of Romanian citizens on digital public services and the factors that influence their decision to use them instead of traditional methods. According to the bibliometric analysis, 23 countries showed a raised interest for digital public services after 2020, which was a crucial moment that pushed digitalization among public institutions. Although Romanian citizens are aware of the benefits brought by digital public services, they encounter issues in terms of lack of information and technical support, knowledge, data security, and the complexity of these platforms. Therefore, the government should implement an integrated approach that considers cultural values as well as reliable and accessible digital solutions.

SOFTWARE-DEFINED SDR RADIO SYSTEM

The article presents software, which is one of the types of computer system support, along with technical (hardware), mathematical, informational, linguistic, organizational, methodological and legal support.

Effects of load and high temperature on uniaxial compressive properties of desert sand concrete

In order to explore the influence of load and high temperature on the uniaxial compressive properties of desert sand concrete (DSC), the axial compressive strength test of desert sand concrete after different loads and temperatures was carried out, and the stress-strain curve was measured. The influence of load level, temperature grade and cooling method on the mass loss rate, ultrasonic velocity and uniaxial compressive performance of desert sand concrete after high temperature was analyzed. The results show that as the temperature increases, the mass loss rate of desert sand concrete gradually increases, the axial compressive strength gradually decreases, the peak strain increases significantly, the stress-strain curve tends to be flat, and the elastic modulus decreases continuously. The "pseudoplastic platform" near the axial compressive strength of the stress-strain curve of desert sand concrete after high temperature is more obvious. Based on the two-stage constitutive model of concrete, the constitutive model of desert sand concrete considering the influence of temperature and load level is established. The research results can provide technical support for the performance evaluation of desert sand concrete after high temperature.

ELSMOR - towards European Licensing of Small Modular Reactors:Methodology recommendations for light-water small modular reactors safety assessment.

Decarbonization of energy production is key in today's societies and nuclear energy holds an essential place in this prospect. Besides heavy-duty electricity production, other industrial and communal needs could be served by integrating novel nuclear energy production systems, among which are low-power nuclear devices, like small modular reactors (SMRs). The ELSMOR (towards European Licensing of Small Modular Reactors) European project addresses this topic as an answer to the Horizon 2020 Euratom NFRP-2018-3 call. The consortium includes 15 partners from eight European countries, involving research institutes, major European nuclear companies and technical support organizations. The 3.5-year project, launched in September 2019, investigates selected safety features of light-water (LW) SMRs with focus on licensing aspects. Providing a comprehensive compliance framework that regulators can adopt and operate, the licensing process of such SMRs could be optimized, helping their deployment. In this prospect, as a result of ELSMOR's work, this article gives an overview of the specific issues that LW-SMRs may bring about in the different domains of nuclear safety, in terms of: •Methodological standpoints: safety goals, safety requirements, safety principles (defence-in-depth implementation);•Main safety functions of reactivity control, decay heat removal and confinement management;•Severe accident management;•Other safety issues particular to SMRs: use of shared systems; performing of multi-unit probabilistic safety assessment (PSA); spent fuel management, transport and disposal management. In this article, adequate methodologies are developed to deal with these issues and to help assess the safety of LW-SMRs. This work gives a precious synthesis of the safety assessment issues of LW-SMRs and of the associated methodologies developed in the context of the ELSMOR European project.