Nuclear Technology Research Articles

Study on early hydration and pore structure evolution of cement paste containing graphene oxide

Graphene oxide (GO) significantly enhances cement hydration. This study investigates the effects of GO on the early hydration and pore structure evolution of cement paste by examining its impact on the setting time and mechanical properties of cement-based materials. In situ monitoring of the hydration process and microstructural changes was conducted using low-field nuclear magnetic resonance technology. The findings reveal that GO's nucleation effect accelerates cement hydration, reducing the setting time and increasing both the hydration rate and degree. Moreover, hydration products utilize GO as a template, leading to adjusted morphologies and enhanced interlinking of C–S–H gels. This results in a marked reduction in porosity and a denser microstructure within the cement paste. Consequently, the early mechanical properties of the cement paste are improved, with a significant increase in flexural strength observed at 72 hours. These results suggest that GO, which is cost-effective, size-controllable and suitable for mass production, holds great potential for applications in cement-based materials.

The Effect of Nanofluid Coolant and Thorium-added Fuel on Burnup Dependent Isotopic Compositions in VVER-1000 Reactor

Recently, the use of nanofluids has gained importance in studies aimed at increasing reactor efficiency while also addressing safety concerns in nuclear technology. Various studies have investigated the effects of adding nanoparticles of different types and proportions to the coolant water on the thermal and neutronic characteristics of power reactors using conventional UO2 fuels. Given the abundance of thorium compared to uranium, research on thorium-based fuels has become increasingly significant. In this study, the criticality and isotope changes in a VVER-1000 reactor loaded with 5% ThO2 and 95% UO2 by mass as fuel, and 0.1% by volume of Al2O3, CuO, and TiO2 nanoparticles as the coolant, were investigated. Neutronic analysis was performed using the MCNP5 and MONTEBURNS2.0 codes. The analysis results indicated that the operational lifespan of the reactor with only water coolant and thorium-based fuel was shortened due to the presence of nanoparticles. Furthermore, it was observed that while there was no significant change in the amount of fissile 235U and fertile 238U isotopes, the consumption of fertile 232Th isotope in the reactor increased with the insertion of nanoparticles into the coolant.

Enhancement of Co(II) removal via coupling of electrosorption and electrodeposition using asymmetric electrode from wastewater

The growing demand for nuclear energy and the promotion of nuclear technology applications will generate large quantities of cobalt-containing wastewater. The efficient removal of cobalt from radioactive wastewater is of great significance for the resource regeneration and environmental protection. However, conventional removal methods are constrained by the poor removal efficiency and slow removal kinetics. Herein, the sulfonated polyether ether ketone coated activated carbon fibers (anode)/activated carbon fibers (cathode) asymmetric electrodes was proposed to boost the Co(II) electrosorption performance. The experimental results showed that compared to traditional symmetric electrodes, the theoretical maximum electrosorption capacity (116.19 mg·g−1) had an exceptional enhancement of 69 %. The voltage and initial pH of the solution had an undeniable impact on the efficiency of cobalt electrosorption. Furthermore, more than 75 % of Co(II) was rapidly immobilized within 3 h. The kinetic fitting indicated that the electrosorption process was more appropriately described by pseudo-second-order kinetic model. The Co(II) removal efficiency was up to 80 % under the conditions of coexistence with Na+, Mn2+, Ni2+, Zn2+, Sr2+, and Cs+. More importantly, it combines two synthetic mechanisms of electrosorption and electrodeposition to realize the purification of cobalt-containing wastewater. Overall, considering the fast and highly-efficient cobalt removal performance and innate economy, the asymmetric electrosorption for cobalt removal provides new insights into the treatment of cobalt-containing wastewater.

Microstructure and radiation shielding characteristics of PVA fiber-reinforced ultra-high performance concrete

The application of nuclear technologies simulates the development of radiation shielding materials. Traditional heavy-weight concrete used for radiation shielding is limited in practical construction due to the poor mechanical properties and durability. This study developed a PVA fiber-reinforced ultra-high performance concrete (UHPFRC) with magnetite as heavy aggregates used for radiation shielding. Due to the scientific skeleton design, UHPFRC exhibits superior mechanical properties, with compressive strength and flexural strength reaching up to 121.9 MPa and 23.2 MPa, respectively. The microstructure of UHPFRC was investigated in detail and the results revealed that the incorporation of PVA fibers refined the pore structure of UHPFRC. The interfacial transition zone between magnetite aggregates and cementitious matrix in UHPFRC was much denser than that in traditional concrete due to the low water to binder ratio. The gamma and neutron radiations shielding capacity of UHPFRC were evaluated by the combination of actual measurement and simulation. By introducing light nuclei and refining the pore structure, the incorporation of PVA fibers improved the neutron radiation shielding capabilities of UHPFRC by 5.1%.

A Sociotechnical Readiness Level Framework for the Development of Advanced Nuclear Technologies

The Technology Readiness Level (TRL) scale was initially developed by the National Aeronautics and Space Administration in the 1970s and is now widely used in space, nuclear, and other complex technology sectors in the United States and beyond. The TRL scale is particularly useful for determining where the extrapolation of untested subsystems or features could produce technical risk, cause expensive redesigns, or act as a roadblock to technology development. In this paper, we propose the development of a sociotechnical readiness level or SRL, premised on the understanding that the successful development and eventual use of a technology requires achieving not only full technological readiness but also anticipating, prioritizing, and addressing societal concerns that may arise during the course of development of a technology. Failures to anticipate and address societal factors in the early stages of technology development have led to high-profile delays, and in some cases, ultimate failures of nuclear technology projects. The sociotechnical readiness scale, which conceptually draws on the design research and science and technology studies scholarship, centers on the principles of equity and environmental justice in technology design and emphasizes the need for social engagement during the process of technology development. Nowhere is such an approach to technology development more vital or needed than for the long-term management of spent nuclear fuel.

Lithium Neutron Cross Sections During the Manhattan Project and the Quest for the H-Bomb

Neutron cross sections of the stable lithium isotopes 6Li and 7Li were of interest in the 1940s and 1950s in part because of their reactions, which form tritium using moderated neutrons on 6Li and higher-energy neutrons on either isotope. Lithium remains of interest today for use as a blanket and shielding material in fusion reactors, where it can be used to breed tritium for a self-sustaining fuel cycle. During the Manhattan Project, the resonance in the 6Li(n,t) reaction was discovered and later became important for enhancing tritium production for nuclear technologies. The dominant natural isotope 7Li was and remains of interest because of the expense of enriching 6Li. It has been oft reported that the 1954 Castle Bravo nuclear test had a yield twice as large as expected because the nuclear explosive device designers had not properly accounted for the benefits from the 7Li isotope in the fuel; we note that this explanation is false.

Radioactive Attenuation Using Different Types of Natural Rocks.

Humans benefit from nuclear technology, but it also generates nuclear radiation that is bad for both the environment and human health. The serious issue of radiation leakage affects many technological applications. Shielding is required to protect both users and the environment from negative side effects. This work describes the radioactive attenuation properties of some natural rocks, such as claystone, bentonitic claystone, bentonitic shale, sandstone, and basalt using a NaI(Tl) detector. The mass attenuation coefficients μm of these rocks at various photon energies, half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP) were determined. The validation of obtained values of μm was carried out against the theoretical calculations from the XCOM program, and the correlation factor and relative deviation between the two methods were evaluated. It was noted that basalt samples exhibit superior shielding parameters when compared to other rock samples. Also, the concentrations of naturally occurring radioactive elements (238U, 226Ra, 232Th, and 40K) were measured, allowing for the calculation of environmental hazard indices and assessment of attenuation (%) efficiency for certain natural rocks, such as bentonite, sandstone, and basalt. The results revealed that increasing the thickness of Basalt-AZ from 1.5 cm to 2 cm results in an approximate 11% rise in attenuation percentage, with values reaching 77.12%, 67.2%, 67.65%, and 59.8% for NMA-U, IAEA-Th, IAEA-Ra, and IAEA-K, respectively.

Evaluation of pore characteristics evolution and damage mechanism of granite under thermal-cooling cycle based on nuclear magnetic resonance technology

During the development process of deep geothermal energy (Hot dry rock, HDR), the high-temperature granite matrix in the wellbore needs to withstand thermal-cooling cycles, easily leading to wellbore instability and collapse. Considering the actual drilling engineering using different types of drilling fluid, thermal-cooling cycle experiments (cycles of 1, 2, 4, 8, 12 times) of granite were conducted using natural, water, and liquid nitrogen (LN2) cooling methods. Based on the low-field nuclear magnetic resonance measurement, the development and evolution of pore size, quantity, and distribution under different cooling ways and thermal cycles were studied, and the changes in rock mechanical parameters under different cooling methods and thermal cycling conditions were quantified. Then, the rock damage coefficients based on the variation patterns of different types of pores were calculated, and a quantitative relationship was established among T2 spectrum, pore, and mechanical damage. Finally, the proton weighting method was used to analyze the changes in the internal bearing area of rocks, revealing the deterioration mechanism of rock mechanical properties under different cooling ways and thermal cycling conditions. The results showed that the porosity increased with thermal cycles during the thermal-cooling cycle treatment, and the growth rate was first fast and then slow. Under the same number of thermal cycles, the groundwater cooling porosity was the highest, followed by LN2 and natural cooling. The relationship between T2 spectral area and rock damage was established on this basis, and the rock damage value increased with thermal cycles in an exponential function, and the proportion of large pores significantly affected the pore damage. A relationship (positively proportional linear) between pore damage and the mechanical degradation coefficient of high-temperature cooling cycle granite and a method for predicting rock degradation through pore damage were established, the deterioration mechanism of rock mechanical properties under thermal cycle treatment was revealed.

High-performance PEEK composite materials research on 3D printing for neutron and photon radiation shielding

With the rapid advancement of nuclear energy technology, addressing technical challenges in the field of radiation shielding, particularly achieving lightweight and efficient shielding against neutron and multiple radiation types, remains a formidable task. To address the aforementioned issues, this study investigates the 3D printing performance of polyether ether ketone (PEEK) composite materials for shielding against both neutron and photon multibeam radiation. High-content 3D printing filament is developed, with simultaneous shielding capabilities against neutron and photon radiation. This research successfully accomplishes the high-density 3D printing of PEEK shielding composites with increased concentrations of boron carbide(B4C), tungsten(W), and both materials. The experimental results indicate that 3D printed specimens of B4C/W/PEEK, a neutron and photon shielding composite material, exhibit excellent mechanical properties. Importantly, the radiation shielding composite 3D function parts achieves effective shielding against muitibeam radiation and weight reduction compared to traditional radiation shielding materials.

Optimism and pessimism in nuclear technology promises : the legacies of three European EPR projects

Les mégaprojets dans une série de secteurs, y compris l’énergie nucléaire, souffrent souvent de « pathologies » telles que des retards quasi chroniques, des dépassements de budget et l’incapacité à tenir leurs promesses. S’appuyant sur le concept de promesse technoscientifique et sur la controverse entre les spécialistes des mégaprojets concernant le principe dit de la main cachée, cet article remet en question la notion quelque peu simpliste de suroptimisme comme cause première des pathologies des mégaprojets dans le secteur nucléaire. Il examine la promesse de l’EPR (European Pressurised Reactor) de génération III comme exemple pour illustrer les rôles complexes de l’optimisme et du pessimisme dans la gouvernance des mégaprojets et la construction des promesses technoscientifiques, en se concentrant sur les premières phases de justification et de planification des projets. Les conclusions soulignent la nécessité et les risques de l’optimisme, la difficulté de juger - ex ante - si l’optimisme et le pessimisme produisent des impacts sociétaux souhaitables au vu des impacts à long terme des mégaprojets, et la nécessité de formes institutionnalisées de pessimisme afin de contenir l’excès d’optimisme et de garantir la robustesse des promesses technoscientifiques. Le long héritage des cycles de promesses dans le secteur nucléaire a des conséquences considérables sur la construction actuelle des promesses, comme le montre l’émergence de la promesse du petit réacteur modulaire, en partie en réaction aux difficultés considérables, façonnées par la dynamique spécifique optimisme-pessimisme, rencontrées par les projets de la Génération III, y compris ceux de l’EPR en Europe.

China's nuclear power in the context of decarbonization of the global energy industry

The global structure of energy resource consumption is analyzed. It is shown that the total consumption of energy resources in the 20th century increased almost 15 times and amounted to about 118 PWh in 2000. Of these, more than 80% were fossil (natural) energy carriers, 13 % were renewable energy sources and more than 6 % were nuclear power. This trend has continued for many years. Renewable energy sources and nuclear power are projected to dominate the growth of global energy consumption, meeting on average more than 90 % of the additional demand. China ranks first in the world in terms of GDP and the rate of development of the electric power complex, as well as in terms of production volume and the rate of development of nuclear power. The structure of electricity generation by fuel type in countries (TOP 5, 2021) with high energy consumption has been analyzed. It is shown that the main players in this market are three countries: China (30 %), USA (13 %) and India (6 %). The volume of electricity production in China is almost three times larger than in the EU countries and almost 7 times larger than in Russia. The structure of nuclear energy and China's achievements in this field are considered. It is shown that in the context of nuclear technologies (creation of fourth-generation reactors, development of technologies close to the full closed cycle of nuclear waste processing) China is already ready to significantly expand the scope of nuclear energy. Special attention is paid to the safety of nuclear facilities operations. The main problem China will face is the absence of an insurmountable barrier between civilian and military use of such technologies. This poses a serious threat to the ecology and life safety of the country. In the long term, nuclear power must also solve the problem of safe, long-term disposal of radioactive waste. It is shown that in the future China needs to re-examine its nuclear program in the context of cooperation with International Nuclear Security Organizations.

P-191 Pronuclear transfer overcomes embryonic developmental arrest in Padi6-deficient mice

Abstract Study question Can pronuclear transfer (PNT) overcome embryonic developmental arrest (EDA) observed in the created Padi6-/- mouse model? Summary answer Applying PNT significantly improved the blastocyst rate of Padi6-/- zygotes, indicating its potential in overcoming female-related infertility. What is known already Various components of the subcortical maternal complex (SCMC), including peptidyl arginine deiminase 6 (PADI6), play a crucial role in early embryonic development and female fertility. Recent studies have revealed that mutations in PADI6 can result in EDA and thus female infertility, which is hard to overcome by current available treatment methods. The PNT technique, designed to replace compromised cytoplasm with a healthy counterpart, has been proposed to overcome specific female-related infertility indications. The Padi6-/- mouse displaying EDA, offers a valuable model to investigate the efficacy of PNT to overcome female-related infertility. Study design, size, duration From April 2022 to December 2023, an experimental study was conducted with CRISPR/Cas9 created Padi6 knockout mice. For fertility evaluation, Padi6-/- and Padi6+/- females were paired with wildtype males. Next, 30 wildtype and 25 Padi6-/- oocytes were collected for parthenogenetic activation. A total of 81, 54 and 145 zygotes were collected from wildtype, Padi6+/- and Padi6-/- females, respectively, for evaluating embryonic development and the effectiveness of PNT in overcoming EDA. Participants/materials, setting, methods The C57BL/6J Padi6-/- mouse model was established by introducing Padi6 c.1577_1578insT with CRISPR/Cas9. Female mice aged 6-12 weeks underwent ovarian hyperstimulation and mated with wildtype males. Oocytes were parthenogenetically activated with SrCl2 in presence of Cytochalasin D, and checked for 2-cell and blastocyst rates. PNT treatment was applied by transferring the 2PN from Padi6-/- to wildtype enucleated zygotes using electrofusion, and the efficiency was evaluated in terms of embryonic developmental potential. Main results and the role of chance After mating Padi6-/- female mice with wild-type males, no offspring could be obtained. In contrast, Padi6+/- females exhibited normal fertility, yielding an average of 7.3 offspring per litter. In addition, Padi6-/- males are also fertile. Twenty-eight wildtype oocytes (n = 30) survived parthenogenetic activation, with 85.71% (24/28) reaching the 2-cell stage, and 75% (18/24) subsequently forming blastocysts. In contrast, all Padi6-/- oocytes (n = 25) survived after activation, but only 20% (5/25) reached the 2-cell stage (P < 0.0001), with none progressing to blastocyst (P = 0.0039). Regarding zygote development, 82.14% (46/56) of wildtype zygotes and 98.14% (53/54) of Padi6+/-embryos reached the 2-cell stage, showing blastocyst rates of 95.65% (44/46) and 100% (53/53) respectively. For zygotes obtained from Padi6-/- females, 72.50% (87/120) of them progressed to the 2-cell stage (P = 0.1908, vs wildtype), but only 4.60% (4/87) reached blastocysts (P< 0.0001, vs wildtype), exhibiting the EDA phenotype. Following PNT to wildtype cytoplasm (n = 25), 23 reconstructed PNT zygotes were obtained. Of these, 91.30% (21/23) reached the 2-cell stage (P = 0.4924, vs wildtype), and 85,71% (18/21) developed to the blastocyst stage (P = 0.3151, vs wildtype), which is equivalent to the wildtype zygotes. Limitations, reasons for caution This study is limited by the small sample size of the PNT, which will still be extended. Next to the blastocyst rate, additional assessment methods such as multi-omics analyses will be employed to assess the efficiency and safety of PNT treatment. Wider implications of the findings This study provides further insight into the potential of the nuclear transfer technology for female-related infertility issues due to cytoplasmic incompetence. For couples experiencing recurrent EDA after ICSI due to inferior oocyte quality, PNT still offers them the possibility of having genetically related children. Trial registration number Not applicable

A Comparison of Quality and Reliability of YouTube Videos About the MRI Technique and Its Various Aspects.

The Magnetic Resonance Imaging (MRI) machine is a subset of nuclear magnetic resonance imaging technology that produces images of the body using magnetic field gradients. The MRI Machine has two components: the computer-based control centre room and the adjacent MRI machine room where the patient undergoes the scan. This study aimed to assess the quality and reliability of YouTube videos about MRI machines, MRI scans, and MRI claustrophobia and compare the quality and reliability of the videos among different types of uploaders. Methodology: The YouTube Search Algorithm and a Google Sheets questionnaire were used to evaluate 10 videos that satisfied the inclusion criteria of the study. The video analytics included were title, number of views, likes and dislikes, comments, duration, source, and content. The quality of each video was established using the Global Quality Score (GQS), Reliability Score, and Video Power Index (VPI), where each quantifier went through statistical analysis using SPSS software, version 21.0 (IBM Corp., Armonk, NY) to determine if there was any significance. In order to determine statistical differences between the groups, the Kruskal-Wallis test was used on the quantifiers GQS, reliability score, and VPI to generate p-values. The p-valuefor VPI is 0.467, GQS is 0.277, and reliability is 0.316. All the p-values are greater than 0.05, showing that there is no statistical support for any significant difference between the groups in their VPI, GQS and reliability scores. YouTube videos with high-quality and reliable information on MRI machines, MRI procedures, and claustrophobia, especially those uploaded by clinicians and hospitals, can provide correct information, helping patients decide to undergo these procedures and alleviate claustrophobia.

Uranium quantification in radioactive waste drums using In-Situ Object Counting System (ISOCS) for safeguards purposes

For the peaceful use of nuclear energy, materials, and technology, various methods have been developed for safeguards purposes. Among them, the In-Situ Object Counting System has demonstrated its usefulness and reliability in various nuclear material verification activities, due to its capability of operating without standard materials. In the present study, the performance of In-Situ Object Counting System for uranium quantification was evaluated using an experimental drum at KEPCO NF as well as low-level radioactive waste drums at the Korea Radioactive Waste Agency. The results showed that In-Situ Object Counting System could quantify uranium in radioactive waste drums, with a relative error ranging from −1 to −67 % compared with destructive assay results. This study also examined, using the Monte Carlo N-particle transport 6.2 code, the factors that affect uncertainty in uranium quantification: geometrical conditions, spectrum quality, heterogeneity, and the self-shielding effect. These findings could prove useful in efforts to optimize the In-Situ Object Counting System as a tool for nuclear material verification in the safeguards context.

Reinforcement Learning-Based Control Sequence Optimization for Advanced Reactors

The last decade has seen the development and application of data-driven methods taking off in nuclear engineering research, aiming to improve the safety and reliability of nuclear power. This work focuses on developing a reinforcement learning-based control sequence optimization framework for advanced nuclear systems, which not only aims to enhance flexible operations, promoting the economics of advanced nuclear technology, but also prioritizing safety during normal operation. At its core, the framework allows the sequence of operational actions to be learned and optimized by an agent to facilitate smooth transitions between the modes of operations (i.e., load-following), while ensuring that all safety significant system parameters remain within their respective limits. To generate dynamic system responses, facilitate control strategy development, and demonstrate the effectiveness of the framework, a simulation environment of a pebble-bed high-temperature gas-cooled reactor was utilized. The soft actor-critic algorithm was adopted to train a reinforcement learning agent, which can generate control sequences to maneuver plant power output in the range between 100% and 50% of the nameplate power through sufficient training. It was shown in the performance validation that the agent successfully generated control actions that maintained electrical output within a tight tolerance of 0.5% from the demand while satisfying all safety constraints. During the mode transition, the agent can maintain the reactor outlet temperature within ±1.5 °C and steam pressure within 0.1 MPa of their setpoints, respectively, by dynamically adjusting control rod positions, control valve openings, and pump speeds. The results demonstrate the effectiveness of the optimization framework and the feasibility of reinforcement learning in designing control strategies for advanced reactor systems.

Strength and Fractal Characteristics of Artificial Frozen–Thawed Sandy Soft Soil

In regions with sandy soft soil strata, the subway foundation commonly undergoes freeze–thaw cycles during construction. This study focuses on analyzing the microstructural and fractal characteristics of frozen–thawed sandy soft soil to improve our understanding of its strength behavior and stability. Pore size distribution curves before and after freeze–thaw cycles were examined using nuclear magnetic resonance technology. Additionally, fractal theory was applied to illustrate the soil’s fractal properties. The strength properties of frozen remolded clay under varying freezing temperatures and sand contents were investigated through uniaxial compression tests, indicating that soil strength is significantly influenced by fractal dimensions. The findings suggest that lower freezing temperatures lead to a more dispersed soil skeleton, resulting in a higher fractal dimension for the frozen–thawed soil. Likewise, an increase in sand content enlarges the soil pores and the fractal dimension of the frozen–thawed soil. Furthermore, an increase in fractal dimension caused by freezing temperatures results in increased soil strength, while an increase in fractal dimension due to changes in sand content leads to a decrease in soil strength.

FPGA implementation and measurement of cusp-flattop hybrid filter shaping method for nuclear instruments

In the field of nuclear technology applications, digital multi-channel pulse amplitude analysis technology plays an indispensable role in information acquisition due to its high precision and sensitivity. However, the challenge of pulse pileup can compromise the accuracy of measurement results in this technology. While conventional filter shaping and pulse pileup processing methods can extract nuclear pulse feature information under mild pileup conditions, severe pileup can notably degrade spectral counting rate and resolution. This paper introduces a designed two-channel pulse pileup rejection method, termed the cusp-flattop hybrid filter forming algorithm, leveraging the unique features of cusp, such as high forming speed and minimal interference from pulse pileup. The two channels simultaneously process the collected signals and utilize their differences for data filtering and rejection. This approach enhances information content, improves data processing quality, and boosts the signal-to-noise ratio. Compared to three methods—three trapezoidal filter shaping algorithms, the triangle trapezoidal pulse shaping algorithm, and the pulse width discrimination algorithm—our proposed method refines the shaping threshold of pulse pileup rejection. It accurately distinguishes and extracts effective pulse amplitudes even under severe pileup conditions, generating energy spectrum results while accounting for counting rate and resolution. Building on this, we construct a digital multichannel pulse amplitude analysis system based on FPGA (Field Programmable Gate Array) and use a national standard alloy sample, YSBS41346, for testing. The system can generate energy spectrum correctly, consistent with the actual sample content. We evaluate the system's performance by comparing the peak counting rate and resolution of the energy spectrum generated by the cusp-flattop hybrid filter forming algorithm and the trapezoidal forming algorithm. A high peak counting rate represents the maximum nuclear pulse data captured by the system, while low resolution indicates more valid data after pileup rejection. Through testing, the peak counting rate reaches 12843cps, with a resolution of 6.68%, marking a significant improvement over the trapezoidal pulse forming algorithm. The system demonstrates satisfactory performance and operational effectiveness, aligning with the design objectives and presenting innovative and practical applications.

Crystallite Size Effect on Photoluminescence of Combustion-Derived Gd2O3 Nanoparticles

Rare earth oxides are considered materials that are commonly used in high performance luminescent devices, magnets, catalysts and various other practical applications such, as electronics, magnetism, nuclear technology, optics and catalysis. Using [Formula: see text] nanoparticles synthesised by combustion route and calcinated at various temperatures (600[Formula: see text]C, 800[Formula: see text]C, 1000[Formula: see text]C, and 1200[Formula: see text]C), we have investigated its phosphors nature in this study. We evaluated the phase purity and grain size distributions from the powder X-ray diffraction patterns of all the samples. This was done using the Rietveld refinement and the FW[Formula: see text]/[Formula: see text]M technique. Our observation of the [Formula: see text] nanoparticles grain size distribution was made possible using transmission electron microscopy pictures and HRSEM images. The photoluminescence spectrum of [Formula: see text] nanoparticles showed emission in the region near-band-edge blue and green emission. To detail the photoluminescence behavior, the excitation, emission spectra and CIE 1976 plot were recorded and the CIE coordinates were found to be [Formula: see text] as well as [Formula: see text] that look like blue. The use of phosphors nature is enabled by studying the impact of grain size and the linear dependent behaviour of [Formula: see text] nanoparticles.

Research on the capillary absorption capacity of concrete of different particle sizes after high temperature based on nuclear magnetic resonance technology

Concrete is subjected to thermal stress and thermal loading in a high temperature environment, resulting in the expansion and contraction of internal pores, which adversely affects the stability and durability of concrete structures. To explore the effects of temperature and aggregate particle size on the capillary absorption capacity of concrete, the capillary absorption tests were carried out on the specimens with aggregate particle sizes of 1.25–2.5 mm, 2.5–5.0 mm and 5.0–10 mm after high temperature treatment at 300 °C, 400 °C and 500 °C.In this paper, The capillary absorption coefficient was measured by mass change method, and the migration change law and spatial distribution of water during capillary absorption were monitored by NMR technology, the changes in water content in different pores during water absorption were calculated by nuclear magnetic resonance T2 spectroscopy, and a method for calculating the capillary absorption coefficient based on T2 spectra was proposed. The results showed that the capillary absorption coefficient of the samples without high-temperature treatment decreased with increasing of particle size. The capillary absorption coefficient increases at 300 °C and decreases slightly at 400 °C. At 500 °C, the capillary absorption coefficient increases dramatically. This shows that at 500 °C, the durability of concrete is drastically affected. The capillary absorption coefficient calculated based on the T2 spectrum is linearly related to the results of the traditional weighing method. In this paper, the fractal geometry theory and regarding methods are used to deduce the relationship between the average capillary rise height and t12DT, and the rise rate is related to the pore structure. And the correctness of the model was verified by MRI. This study can provide theoretical guidance for the safety assessment of concrete structures after high temperature exposure.

Generation and transcriptomic characterization of MIR137 knockout miniature pig model for neurodevelopmental disorders

BackgroundNeurodevelopmental disorders (NDD), such as autism spectrum disorders (ASD) and intellectual disorders (ID), are highly debilitating childhood psychiatric conditions. Genetic factors are recognized as playing a major role in NDD, with a multitude of genes and genomic regions implicated. While the functional validation of NDD-associated genes has predominantly been carried out using mouse models, the significant differences in brain structure and gene function between mice and humans have limited the effectiveness of mouse models in exploring the underlying mechanisms of NDD. Therefore, it is important to establish alternative animal models that are more evolutionarily aligned with humans.ResultsIn this study, we employed CRISPR/Cas9 and somatic cell nuclear transplantation technologies to successfully generate a knockout miniature pig model of the MIR137 gene, which encodes the neuropsychiatric disorder-associated microRNA miR-137. The homozygous knockout of MIR137 (MIR137–/–) effectively suppressed the expression of mature miR-137 and led to the birth of stillborn or short-lived piglets. Transcriptomic analysis revealed significant changes in genes associated with neurodevelopment and synaptic signaling in the brains of MIR137–/– miniature pig, mirroring findings from human ASD transcriptomic data. In comparison to miR-137-deficient mouse and human induced pluripotent stem cell (hiPSC)-derived neuron models, the miniature pig model exhibited more consistent changes in critical neuronal genes relevant to humans following the loss of miR-137. Furthermore, a comparative analysis identified differentially expressed genes associated with ASD and ID risk genes in both miniature pig and hiPSC-derived neurons. Notably, human-specific miR-137 targets, such as CAMK2A, known to be linked to cognitive impairments and NDD, exhibited dysregulation in MIR137–/– miniature pigs. These findings suggest that the loss of miR-137 in miniature pigs affects genes crucial for neurodevelopment, potentially contributing to the development of NDD.ConclusionsOur study highlights the impact of miR-137 loss on critical genes involved in neurodevelopment and related disorders in MIR137–/– miniature pigs. It establishes the miniature pig model as a valuable tool for investigating neurodevelopmental disorders, providing valuable insights for potential applications in human research.