bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxygen consumption, locomotory‐respiratory coupling and exercise‐induced pulmonary hemorrhage in horses during the Paso Fino gait
Authors: Massie Shannon , Léguillette Renaud , Bayly Warwick , Sides Ray , Zuluaga‐Cabrera Angélica María
Published: November 2024

Background

Workload associated with the high frequency Colombian Paso Fino gait has not been evaluated.

Objectives

To determine the oxygen consumption (V̇O2), heart rate (HR), stride frequency: breathing ratio, and hematology associated with the Paso Fino gait, including whether exercise‐induced pulmonary hemorrhage (EIPH) occurs.

Animals

Eleven Paso Fino horses.

Methods

Prospective cohort study. Horses performed a standardized Paso Fino gait test across a wooden sounding board, simulating competition. V̇O2 and ventilatory parameters (tidal volume [VT]; peak inspiratory and expiratory airflows [PkV̇I, PkV̇E]; respiratory rate [RR], minute ventilation [V̇E]) were measured using a portable ergospirometry facemask. Heart rate was measured using electrocardiograms. Post‐exercise lactate, hematocrit, bicarbonate, pH, electrolytes, and biochemistry concentrations were measured. EIPH was assessed via tracheobronchoscopy. Four horses completed a secondary high‐intensity gallop to elicit peak V̇O2 for comparative purposes.

Results

Median [IQR] mean individual HR during the Paso Fino gait was 190 [178, 201] bpm. Relative V̇O2 measured 49.8 [48.4, 59.5] mL/(kg min; VT = 8.6 [8.0, 10.7] L; RR = 87.1 [75.4, 99.5] bpm; V̇E = 869 [740, 902] L/min; PkV̇I = 33.4 [32.7, 37.2] L/s; PkV̇E = 44.2 [40.3, 46.0] L/s). Horses took 2.8 [2.7, 2.9] strides/second and had a stride frequency: breathing ratio of 2.0 [1.8, 2.3]. Post‐exercise blood lactate concentration and hematocrit measured 2.7 mmol/L and 50% respectively. Three horses showed endoscopic evidence of Grade‐1 EIPH. The Paso Fino gait V̇O2 and HR equaled 79% V̇O2pk and 91% maximal HR, respectively, based on the high‐intensity gallop.

Conclusions and Clinical Importance

The Paso Fino gait represents submaximal exercise based on V̇O2 < V̇O2pk and blood lactate.
Transcriptional and Metabolomic Analyses Reveal That GmESR1 Increases Soybean Seed Protein Content Through the Phenylpropanoid Biosynthesis Pathway
Authors: Zhou Runnan , Wang Sihui , Li Jianwei , Yang Mingliang , Liu Chunyan , Qi Zhaoming , Xu Chang , Wu Xiaoxia , Chen Qingshan , Zhao Ying
Published: November 2024

Soybeans are an economically vital food crop, which is employed as a key source of oil and plant protein globally. This study identified an EREBP‐type transcription factor, GmESR1 (Enhance of Shot Regeneration). GmESR1 overexpression has been observed to significantly increase seed protein content. Furthermore, the molecular mechanism by which GmESR1 affects protein accumulation through transcriptome and metabolomics was also identified. The transcriptomic and metabolomic analyses identified 95 differentially expressed genes and 83 differentially abundant metabolites during the seed mid‐maturity stage. Co‐analysis strategies revealed that GmESR1 overexpression inhibited the biosynthesis of lignin, cellulose, hemicellulose, and pectin via the phenylpropane biosynthetic pathway, thereby redistributing biomass within cells. The key genes and metabolites impacted by this biochemical process included Gm4CL‐like, GmCCR, Syringin, and Coniferin. Moreover, it was also found that GmESR1 binds to (AATATTATCATTAAGTACGGAC) during seed development and inhibits the transcription of GmCCR. GmESR1 overexpression also enhanced sucrose transporter gene expression during seed development and increased the sucrose transport rate. These results offer new insight into the molecular mechanisms whereby GmESR1 increases protein levels within soybean seeds, guiding future molecular‐assisted breeding efforts aimed at establishing high‐protein soybean varieties.
Fact‐checking election‐campaign misinformation: Impacts on noncommitted voters' feelings and behavior
Authors: Prike Toby , Baker Joseph , Ecker Ullrich K. H.
Published: November 2024

Making misleading statements may benefit a politician, for example, during an election campaign. However, there are potentially also negative consequences; political misinformation can taint democratic debate, voters may be misled into forming false beliefs, and being fact‐checked may damage a politician's reputation. Previous research has found that correcting misleading statements made by established politicians reduces topical misperceptions, but hardly affects voter feelings and support. Here, we examined the impact of political misinformation and fact‐checking when politicians are unfamiliar. Participants (N = 406) were engaged in a simulated election campaign set in an unfamiliar country, featuring statements from fictional candidates. Participants indicated their feelings toward the candidates, cast a vote, and rated their belief in the fact‐checked statements. Misleading statements that were not corrected positively affected feelings toward and voting for (right‐leaning) politicians. Corrective fact‐checks had large effects, reducing belief in misinformation, and fact‐checked candidates were viewed much less favorably and attracted far fewer votes. This demonstrates that in the absence of strong pre‐existing attitudes, corrective fact‐checks can negatively impact misinformation‐spreading politicians who are not (yet) well known.
Policy compatibility: How anti‐smoking policy shapes state vaping policy innovation
Authors: Kim Seunghyun
Published: November 2024

Limited attention has been paid to how previous policies affect subsequent policy innovation. This article addresses this question by examining whether U.S. states with higher cigarette taxes are more likely to adopt e‐cigarette taxes and impose higher rates. The concept of policy compatibility, divided into normative and operational compatibility, is used to connect these policies. First, states with higher cigarette taxes are hypothesized to be more likely to adopt e‐cigarette taxes. This is because high cigarette tax rates indicate a preference for strong tobacco regulation, which is normatively compatible with regulating e‐cigarettes. States with high cigarette tax rates are also expected to choose high e‐cigarette tax rates. Such states, even if imposing higher e‐cigarette taxes, can maintain a similar or even larger price gap between cigarettes and e‐cigarettes, compared to those with low cigarette taxes. By doing so, they can not only reduce vaping effectively but also continuously provide smokers with a strong economic incentive to switch to e‐cigarettes. This indicates that such policies are operationally compatible with existing cigarette tax goals—reducing smoking and nicotine‐related health risks. The empirical findings support both hypotheses, offering insight into how past policies shape policy adoption.
Psychosocial characteristics of suicide deaths by regional types in Korea: An analysis based on population inflow and outflow
Authors: You Deuk‐Kweon
Published: November 2024

Introduction

This study aims to investigate the psychosocial characteristics of suicide deaths in Korea according to population inflow and outflow, and to identify high‐risk suicide groups by regional type in order to establish tailored suicide prevention plans for each region.

Methods

The analysis included 4193 suicide deaths from four regional types in Korea. The data source was a comprehensive survey of suicide deaths through police investigation records from the Korean government. The analysis involved collecting demographic variables, suicide‐related variables, and stress variables at the time of death for suicide deaths in each region and conducting cross‐analysis and multinomial logistic regression analysis.

Results

Across all regions, factors such as male gender, unemployment, hanging in one's own home, and mental health problems were prevalent. However, in population‐inflow urban areas, early‐middle age and economic problems were higher, in population‐outflow urban areas, late‐middle age and economic problems were more prominent. Additionally, in both inflow and outflow rural areas, there was a relatively higher proportion of old age and physical health problems.

Conclusions

This study is significant for confirming common and specific factors influencing suicide in each region, and for proposing considerations when formulating tailored suicide prevention plans for local communities.
Improving prescribing learning in problem‐based learning
Authors: Bull Stephanie , Sims Laura
Published: November 2024

Background

Prescribing errors are known to occur in clinical practice. To ensure prescribing competence, foundation doctors in the United Kingdom now need to pass a national Prescribing Safety Assessment (PSA). Medical students are requesting more prescribing learning. We propose that early year's problem‐based learning (PBL) sessions in medical curricula may be a place where more prescribing‐related material could be added to ensure preparedness to prescribe.

Approach

We modified existing PBL material by adding prescribing‐related tasks within the patient cases. To ensure relevancy, the prescribing tasks were blueprinted to the assessment structure of the PSA. An example task would be to tailor prescribing, advise on required monitoring and provide information about medication to the (fictional) patients.

Evaluation

Free text questionnaires were sent to second‐year medical students at two points in the academic year. Thirty‐eight of 244 participants responded. Students expressed perceived deficits in their prescribing education both within PBL and in other curriculum areas. Students desired more faculty‐led approaches to learning, yet acknowledged that the tasks introduced in PBL sessions, especially those that promoted use of clinical guidelines and national prescribing resources were useful.

Implications

Although students expressed a desire for increased faculty‐led learning on prescribing, the introduction of prescribing tasks into early‐year's PBL cases has a place. For example, tasks that promote students' use of prescribing and evidence‐based resources may build their confidence in using them throughout their medical degree and within the PSA assessment (where the formularies can be used by candidates).
Shaping competencies for culturally safe practice among medical students
Authors: Khanna Priya , Walke Emma , Bailie Jodie , Angelo Candace
Published: November 2024

Background

Limited evidence exists around authentic activities that can positively influence students' knowledge of and appreciation for the First Nations peoples' culture, impacts of colonisation and other determinants of health. A renewed Indigenous Health curriculum provided us with an opportunity to implement a cultural immersion for medical students to enhance their cultural awareness and competency.

Approach

Our approach towards the design and evaluation of cultural immersion was guided by three key frameworks—a strengths‐based approach towards curriculum design, Indigenous ways of knowing and being and immersions as transformative pedagogy.

Evaluation

Pre‐ and post‐immersion surveys were sent to 260 first‐year medical students in 2020 and 323 students in 2021 who were the participants. Response rates were 37% (2020) and 47% (2021). The data indicated significant improvements in students' knowledge of Indigenous cultural beliefs and history as well as confidence in working with Indigenous populations. Students' comments indicated their experiences varied on a continuum of four ways of ‘knowing’: reluctant, receiving, relating and reconstructing their beliefs. Their ways of ‘being’ varied across four levels: privileged, feeling discomforted, being humbled and agentic.

Implications

The study extends the limited evidence of theoretically informed interventions that have the potential to positively influence medical students' knowledge and appreciation of Indigenous history, culture and its impact of health outcomes. Cultural immersion experiences, when co‐designed with the community and in consideration with students' prior beliefs, are powerful tools to promote capabilities for working with Indigenous patients in culturally safe ways.
On the Effects of Substrate Temperature on Glass Internal Modification Using Femtosecond Laser Pulses
Authors: Hussein Rafid , Lei Shuting
Published: November 2024

The effects of substrate temperature on laser focal position and tear-drop morphology in laser internal modification of glass are investigated. A model is derived to predict the shift of the tear-drop at high substrate temperature. Femtosecond laser pulses are scanned inside borosilicate glass at room temperature, 150 °C, and 200 °C using a pulse energy of 4.5–18 µJ, a scanning speed of 5–20 mm/s, and a distance between lens and glass of 9.56–10.76 mm. Temperature effects are characterized by defining a height (width) gain ratio as the ratio between the tear-drop height (width) measured at high temperature to that measured at room temperature. Thermal expansion is simulated using a profile temperature acquired by a thermal camera and image processing. Results show that substrate temperature has a significant effect on self-focusing, and modifications at 200 °C show a relaxed discoloration compared to 150 °C and room temperature. Analytical predictions match the measurements of focal position in the distance of 9.56–9.96 mm at 200 °C where self-focusing is not significant while underestimating the measurements for the distance of 10.76 mm and 10.36 mm by 30–50 µm. At 200 °C, the tear-drop's gain ratio is increased when the pulse energy is increased in the range of 4.5–18 µJ. Within this pulse energy range and at 200 °C, the maximum width gain is 10–100% higher compared to the maximum height gain.
Experimental Investigation on the Chaos-to-Interwell Motion Transfer in a Bistable Beam-Slider Vibration Energy Harvester
Authors: Yu Liuding , Liu Shuyong , Guobiao Hu
Published: November 2024

Bistable structures are widely used for vibration energy harvesting due to their wide bandwidths and extraordinary performance. However, the dynamics of bistable structures are complicated, and inter-well, intra-well, chaotic, superharmonic, and subharmonic vibrations may coexist in some frequency ranges. Inter-well vibration is typically the most desired because of its large oscillation amplitude, which means more kinetic energy can be converted into electricity via different energy transduction mechanisms. In this study, a modified bistable beam-slider vibration energy harvester consisting of a cantilever beam and a movable slider on the beam is investigated experimentally. The slider can move along the beam under the combined effect of the inertial and magnetic forces. Moreover, magnetic nonlinearity is incorporated into the beam to achieve bistability instead of the linear or monostable configurations typically found in existing literature studies. The slider trajectory and the bistable cantilever beam time responses show that the slider can help the bistable beam system transfer from the chaotic to the inter-well vibration orbit. The results show that inter-well vibration can be maintained even with disturbance introduced with 3.92 m/s2 base excitation over the 15 Hz–18 Hz frequency range. The whole transfer process is self-regulating and does not require any external intervention. Therefore, the harvester we designed is self-adaptive, with a substantially broadened operating bandwidth.
Thermal Performance Optimization of Nano-Enhanced Phase Change Material-Based Heat Pipe Using Combined Artificial Neural Network and Genetic Algorithm Approach
Authors: Jose Jobin , Hotta Tapano Kumar
Published: November 2024

The present study focuses on the numerical investigation of nano-enhanced phase change material (Ne-PCM)-based heat pipes designed for electronic cooling applications. It uses both paraffin wax and n-eicosane as phase change materials (PCMs) that are combined with copper oxide (CuO) nanoparticles at different concentrations of 1%, 3%, 5%, and 7%. The heat input to the heat pipe ranges from 10 to 50 W in an increment of 10 W to simulate realistic operating conditions. The idea is to predict the heat pipe's thermal performance at various combinations of nanoparticles and PCMs and compare the same to the baseline case of deionized (DI) water (without PCM). The results show a constant drop in the evaporator temperature for the Ne-PCM-assisted heat pipes. Paraffin wax and n-eicosane exhibit maximum reductions of 2.86% and 1.94%, respectively, in evaporator wall temperature compared to using conventional DI water (without PCM). The thermal resistance of the heat pipe also decreases consistently with increasing the heat input for all cases, with the most significant reduction of 33.11% and 16.63% for paraffin wax–CuO- and n-eicosane–CuO-assisted heat pipes, respectively. The maximum evaporator heat transfer coefficients recorded are 257.79 W/m2K, 353 W/m2K, and 265.18 W/m2K for heat pipes using DI water (without PCM), paraffin wax–CuO, and n-eicosane–CuO, respectively. The nanoparticles act as a thermal conductivity enhancer and bring down the heat pipe's evaporator temperature with the addition of PCMs. Thus, the effective thermal conductivity of the Ne-PCM-based heat pipe is notably higher compared to heat pipes using DI water (without PCM). To understand the complex thermal behavior of the Ne-PCM-based heat pipes and to better predict their thermal performance, a predictive model has been developed using an artificial neural network (ANN). This model drives the genetic algorithm (GA) that considers the multivariable interaction of PCMs and nanoparticle concentrations to identify the optimal configuration and results in better thermal performance of the heat pipe. Thus, the combination of ANN and GA aids a useful approach for the effective prediction of the heat pipe's thermal performance. The outcomes of this study are useful for the development of sustainable solutions in electronic cooling applications.
Theoretical Analysis of Energy, Exergy, and Environmental-Related Aspects of Hydrofluoroolefin Refrigerants as Drop-In Alternatives for R134a in a Household Refrigerator
Authors: Kadhim Saif Ali , Al-Ghezi Moafaq K. S. , Ashour Ali M.
Published: November 2024

There are increasing trends to eliminate refrigerants with a high global warming potential (GWP) and use alternative environmentally friendly refrigerants in refrigeration systems. In this regard, this study presents a triple analysis of the energy, exergy, and environmental-related aspects of low-GWP hydrofluoroolefin refrigerants—R1234yf, R1234ze(E), and R1336mzz(Z)—as substitutes for the high-GWP R134a, which is used in a 200-liter household refrigerator having a 157 W cooling power. Pressure ratio, volumetric refrigeration capacity, power consumption, and coefficient of performance were studied as energy performance parameters. Exergy destruction rate and total exergy efficiency were studied as exergy performance parameters. Total equivalent warming impact was studied as an environmental performance parameter. All parameters were calculated under a condenser and ambient temperature of 30 and 40 °C, respectively, and a variable evaporator temperature of −5 to −30 °C. The outcomes revealed that R1234yf and R1234ze(E) give thermal performance close to R134a and higher environmental performance, while R1336mzz(Z) did not show thermal performance close to R134, nor did it show a clear improvement in environmental performance. R1234yf can be used as a direct replacement for R134a, but R1234ze(E) is considered a better alternative provided that the R134a compressor is replaced with a compressor with a higher displacement. The pure R1336mzz(Z) cannot be used in a refrigerator.
Design and Analysis of a Nuclear Hydrogen Production System by Methanol Reforming Using Light Water Reactor (LWR)
Authors: Liu Ruiyang , Peng Zhiyi , Yin Huaqiang , Zhang Huang
Published: November 2024

Hydrogen is a multiple energy carrier, which can help tackle various critical energy challenges and transition towards green and zero-carbon industries. There are numerous hydrogen production methods, including methane steam reforming, electrolysis of water, and the iodine-sulfur thermochemical cycle. These methods typically require a significant amount of electricity and heat, aligning well with the benefits of nuclear power. Nuclear energy is a reliable, low-carbon power source that generates high energy output. Nuclear reactors can produce a continuous supply of heat and electricity. It is necessary for the production of clean hydrogen, which reduces both infrastructure and hydrogen costs. Light-water nuclear reactors (LWRs) currently comprise over 80 percent of all commercial nuclear reactors worldwide. Improving their overall utilization capacity is crucial for enhancing the economics of commercial nuclear reactors. This study proposed utilizing a methanol steam reforming process technology for hydrogen production, which can be applied to LWR. The technology utilizes steam that produced from the light-water nuclear reactor to produce hydrogen. The steam is also a heat source for the methanol steam reforming hydrogen production reaction. It combines the steam with either pressure swing adsorption (PSA) or membrane separation purification technology to purify the hydrogen in the product gas, resulting in a reliable and high purity supply of hydrogen that could be 99.99%. This system for producing hydrogen using nuclear energy comprises a LWR combined with methanol hydrogen reforming. The study investigated outlet parameters of LWR and determined optimal reaction conditions for producing hydrogen through methanol reforming using nuclear energy. The process operates at temperatures between 200°C and 300°C and at pressures ranging from 1.0 MPa to 1.8MPa. The findings demonstrate the feasibility of hydrogen production from LWR. Additionally, the purification unit separates and purifies the hydrogen product gas to enhance hydrogen purity and minimize impurity effects on hydrogen equipment, thereby supporting the comprehensive use of nuclear energy and expanding the availability of hydrogen. This study compares the economic viability of two systems: a light water reactor combined with methanol reforming for hydrogen production and one that uses electrolysis of water for hydrogen production. Our findings indicate that methanol steam reforming using the light water reactor system is more cost-effective than water electrolysis using the same system. This study aims to design a hydrogen production system that is appropriate for use in a light water nuclear reactor and contributes to the effective utilization of nuclear energy.
A Single Channel Thermal-Hydraulic Calculation Module for PWR Pin-by-Pin Wise Coupled Calculation System
Authors: Li Zhigang , Pan Juejie , Xia Bangyang , Lu Wei , Zhao Wenbo , Qiang Shenglong
Published: November 2024

Due to the strong feedback effect between neutronics and thermal-hydraulics in the core of pressurized water reactors (PWR), neutronics and thermal-hydraulics coupling calculations are often used in the design and safety evaluation of PWR to provide more accurate results. The coupling calculation of neutronics and thermal-hydraulics at the full core pin-by-pin wise can provide more precise and precise coupling parameters, which is a hot research topic in the industry. How to advance the efficiency and accuracy of neutronics and thermal-hydraulics coupling calculations at the entire core pin by pin wise is a challenge in this research. Multiple digital reactor plans have been proposed worldwide, and one important task is to attempt to use the most advanced numerical simulation methods, high-precision calculation models, and ultra large-scale high-performance computing clusters to develop the new generation of digital reactor technology. In order to improve the efficiency of the pin-by-pin wise neutronics and thermal-hydraulics coupling calculation of the entire reactor core, this paper developed a two-phase thermal-hydraulic calculation module TH1D based on a single channel model, which can achieve thermal conductivity calculation of flat fuel and rod fuel, as well as two-phase thermal-hydraulic calculation of a single channel, and improve parameters such as fuel effective temperature, coolant temperature, moderator density, and void fraction for thermal feedback. And coupled it with the core fine mesh transportation calculation program CORCA-SPn to develop a PWR pin-by-pin wise neutronics and thermal-hydraulics coupling calculation program. The overall performance of TH1D was evaluated by conducting pin-by-pin wish neutronics and thermal-hydraulics coupling calculation on two typical PWR core: Hua-long Pressurized Reactor (HPR1000) and the Coupling benchmark of PWR with High Parameters (COPHP). Compared with the coupling program using the traditional sub-channel/multi-channel thermal-hydraulic calculation program CORTH/CORTH-R, the differences in thermal-hydraulic parameters between calculated by TH1D and the results of sub-channel/multi-channel program, as well as the differences in coupling calculation results, were compared. The following conclusions were drawn: 1) Through thermal-hydraulic simulation of a single channel containing a single plate or rod, TH1D showed good load performance compared to the reference results, with a relative deviation of less than 0.5% for all parameters; 2) the key result parameter deviation of the pin-by-pin wise coupling calculation using CORCA-SPn/TH1D is within an acceptable range, with the maximum keff deviation ≤ 250pcm and the maximum power weight deviation ≤ 1.88%; 2) The average efficiency of pin-by-pin wish coupling calculation is increased by 16 times (compared to CORTH) and 0.86 times (compared to CORTH-R), respectively.
Two-Phase Flow Distribution in 5 × 5 Rod Bundle During Boil-Off Process
Authors: Ueda Shota , Arai Takahiro , Ui Atsushi , Furuya Masahiro , Okawa Riichiro , Shirakawa Kenetsu , Yodo Tadakatsu
Published: November 2024

Boil-off may occur in light-water reactors with a stagnant core flow when a long period passes after the initiation of an accident. Improving the predictability of the two-phase mixture water level and void behavior during the boil-off process can effectively evaluate the long-term core coolability in accident progression analyses. Thus, this study investigated the void behavior transition during the boil-off process in a 5 × 5 heated rod bundle, which partially simulates the actual fuel assembly, at atmospheric pressure. Heat fluxes of 3, 6, and 9 kW/m2 were imposed to simulate the decay heat in long-term core cooling during an accident. The influence of collapsed water level on the distributions of void fraction, bubble chord length, and phase velocity was quantified using subchannel void sensors mounted within the rod bundle. The void fraction increased as the collapsed water level decreased because of the decrease in hydrostatic head. The measured three-dimensional distribution of phase velocity indicates the occurrence of inverse flow and the presence of global flow in the bundle during the boil-off process. The obtained results can contribute to the understanding of the multi-dimensional behavior of boil-off phenomena.
Effect of Pressure Acting on the Flaw Surface on Plastic Collapse Strength for Pipes With the Circumferential Surface Flaw
Authors: Machida Hideo
Published: November 2024

The Rules on Fitness-for-Service of Japan Society of Mechanical Engineers (the rules on FFS) stipulates the limit load evaluation method based on the plastic collapse strength as one of the fracture evaluation methods for pipes with circumferential flaws. However, since this evaluation method treats flaws as a decrease in thickness regardless of their location, the internal pressure acting on the flaw surface is not taken into consideration even when the flaws are on the inner surface of the pipe. The limit load evaluation methods that take into account the effect of the internal pressure acting on the flaw surface are derived, and compared the plastic collapse loads with and without considering the internal pressure acting on the flaw surface. When the flaw is shallow and its angle is small, the both plastic collapse loads are almost the same. However, when the flaw is deep and its angle is large, the plastic collapse load decreases due to the internal pressure acting on the flaw surface. Especially when the internal pressure is high, the impact is large. In the rules on FFS, the safety factor is taken into consideration in the evaluation of allowable stress, and the flaw depth is limited by a regulatory requirement when the flaw angle exceeds 60 degrees. Due to these, the impact of internal pressure acting on the flaw surface on collapse strength is negligible. If the flaw depth limitations are eliminated when the flaw angle exceeds 60 degrees or when accurate fracture strength has to be evaluated such as in reliability evaluation, the plastic collapse evaluation methods that take into account the effect of pressure acting on the flaw surface should be employed.
Evaluation of Component Cooling System Based on Optimization Algorithm in HPR1000
Authors: Yu Pei , Ting Hou , Yaguang Liu
Published: November 2024

Aiming at large design margin and low water temperature in winter of Component Cooling System in NPP, an innovative design method is provided, which can be used to determine the system configuration and operation scheme in the overall design stage. Firstly, based on the basic principle of system heat balance, the thermal evaluation model is established. Based on the guiding ideology of improving economy as much as possible under safety and operation conditions, an economic evaluation model is established. Then, based on the principle of optimization design, the multi-objective optimization algorithm and analysis program are developed; Finally, the above program is applied to deal with the multi-objective optimization problem, the scheme evaluation is realized. The optimization evaluation results of Component Cooling System HPR1000, which improves the economic efficiency of the power plant under construction. This method breaks through the traditional single line design process which is too dependent on design experience and insufficient quantitative analysis. In the adjustment of multi-disciplinary and multi variable design scheme and parameter optimization, the method of software decision-making and manual decision-making is adopted to shorten the design time and improve the accuracy.
Analysis on the Leakage Behavior of Cable Facility Using Gothic and Gothic 3D Models
Authors: Jia Ningxi , Liu Zhuo , Yuan Yidan
Published: November 2024

In this paper, the laminar leakage model in the leakage module of GOTHIC8.3 code is used to simulate the leakage behavior of Containment thermalAlhydraulic and aerosol Behavior in Light water rEactor (CABLE) test facility caused by penetration. First of all, the leakage rate factor is measured through the leakage rate test performed on the CABLE test facility under reference pressure and temperature. Then, a lumped parameter model and a distributed parameter model are established respectively for CABLE using GOTHIC8.3 code. Both models are modeled with the leakage module. Then, the leakage rate factor measured from the leakage rate test was used to analyze the leakage behavior in the GOTHIC8.3 distributed parameter model. Finally, two models are used to simulate the leakage rate test of CABLE facility, and the results are compared. Results indicate that the two models with the same leakage rate factor have the same total system leaking mass flow. Settings of different leakage surface affect the leaking mass flow position and the local leaking mass flow of cells in leakage surface, but the temperature and flow field distributions of containment vessel have little difference among the cases. With the advantages of the distributed parameter model, it can simulate the leakage behavior more accurately.
Oxidation Behavior and Tensile Property of Inconel 617 in the Simulation Environment of the Very-High-Temperature Reactor
Authors: Du Bin , Liu Zhiyong , Yin Huaqiang , Xiao Penghui , Zhang Huang , He Xuedong , Ma Tao
Published: November 2024

In this work, Inconel 617 was corroded at 950 °C up to 100 h in the impure helium and air atmospheres. The results show that the alloy oxidizes significantly more in air than impure helium, especially internally. There are two reasons for the difference in the oxidation of the alloy in the two atmospheres, one is the difference in the oxidizing gas content of the two, with air containing 21% O2 and only a small amount of H2O in the impure helium. The second is the occurrence of microclimatic reactions, which prompts the oxides that have been formed to occur reduction reaction. Differences in oxidation inevitably lead to differences in the tensile properties of the alloy. The results of the tensile tests shows that the yield strength (YS), ultimate tensile strength (UTS) and elongation (Elong) of Inconel 617 decreased from 309 MPa, 674 MPa, and 43.5% to 291 MPa, 649 MPa, and 39%, respectively, in the impure helium. In the air, the YS, UTS, and Elong of Inconel 617 were 299 MPa, 535 MPa, and 30%, respectively. One of the most important factors affecting degradation is oxidation, as elongated oxides (Al2O3) precipitating along the alloy grain boundaries can preferentially become the core of crack propagation and accelerate alloy failure. Therefore, to ensure the long-term safe operation of the reactor intermediate heat exchanger, the precipitation of excessive internal oxides from the alloy should be avoided as much as possible. controlling the CO content in helium is a simple and useful way to inhibit the oxidation of the alloy. A simple way to reduce the degree of oxidation of the alloy is to control CO in addition to minimizing the amount of oxygen and water in the helium.
Enabling Passive Scalar Wall Modelling in Large Eddy Simulation for Turbulent Flows at High Schmidt or Prandtl Numbers
Authors: Wong Kin Wing , Mickus Ignas , Grishchenko Dmitry , Kudinov Pavel
Published: November 2024

This study investigates near-wall diffusive flux modeling for passive scalar transport in turbulent flows with high Schmidt (Sc) or Prandtl (Pr) numbers. Under these conditions, the diffusion boundary layer becomes significantly thinner than the velocity boundary layer. Capturing the concentration boundary layer presents challenges due to additional scaling in the viscous-diffusive regime. For DNS, mesh resolution requirements to capture passive scalar behavior near the wall are more stringent than those for Kolmogorov scales in pure hydrodynamics investigations. Consequently, wall-resolved approaches in both RANS and WMLES demand excessive wall refinement, limiting their practicality for high Reynolds numbers and industrial applications. In this work, we focus on turbulent flow without an adverse pressure gradient.

Existing wall models fail to provide accurate estimates of wall diffusive flux for passive scalar transport at high Sc. This failure arises from the breakdown of the assumption of eddy diffusivity asymptotic behavior. Using such models for simulating surface processes (e.g., flow-accelerated corrosion) in RANS and WMLES can lead to non-negligible errors. Our study introduces a two-layer scalar diffusivity model to enhance wall modeling capabilities in passive scalar transport at high Sc or Pr numbers.
Design and Research of Radioactive Waste Gas Treatment System for Medical Isotope Test Reactor
Authors: Yongkang Zhang , Jinsong Zhang , Huiqing Yang , Li Chen , Yunming Chen
Published: November 2024

The radioactive activity concentration and gas composition of hydrogen-containing waste gas of medical isotope test reactor are very different from those of pressurized water reactor. The inert gas has higher radioactive activity concentration and contains a lot of nitrogen oxides. The difference of exhaust gas source term between test reactor and other reactor types and its cause and influence on design are analyzed. The reasonable emission control value is determined by reference to GB6249 and the site status. Based on the difference of the half-life of inert gas nuclides and the dynamic adsorption coefficient of activated carbon adsorption, the storage decay treatment of equal inert gas nuclides with short half-life (87Kr, 88Kr) and the retention adsorption treatment of 133Xe with relatively long half-life are adopted, giving full play to the advantages of the two processes, and greatly reducing the size and cost of equipment. The theoretical analysis and experimental demonstration of the effect of nitrogen oxides on the inert gas retention of activated carbon were carried out. The results showed that nitrogen oxides had no effect on the inert gas retention of activated carbon. Based on the analysis and demonstration of radioactive waste safety and system economy, the main equipment design and item classification are completed. At present, the design scheme has successfully passed the design review and safety analysis review.
Research on the Radiation Monitoring Methods in the Reactor Coolant Pressure Boundary Leakage of Nuclear Power Plant
Authors: Yang Zhenlei , Liu Chengmin , Jiang Tianzhi , Li Jin , Zhuo Xianglin , Zhu Hongliang , He Liang , He Zhengxi , Peng Jinqiu
Published: November 2024

Reactor coolant pressure boundary is one of the important protection barriers in nuclear power plant. The weak parts of reactor coolant pressure boundary, such as crack or fissure of the process pipeline, can present hidden troubles, and it can cause coolant leak and can produce a great threat to the safe operation for nuclear power plant, so it is necessary to pay attention to monitor the reactor coolant pressure boundary leakage.

With the increasing requirements on the quantitative monitoring level of reactor coolant pressure boundary coolant leakage, many kinds of radiation monitor methods (including the particulate iodine and noble gas radiation methods, 13N monitoring method and 18F monitoring method), have been conducted for the researchers. In this paper, the traditional particulate, iodine and noble gas radiation methods (short for PING monitoring methods) will be introduced in brief, including the basal principle, system design flow and so on. Because the monitoring objects of PING monitoring methods are corrosion products and fission products, it can only achieve qualitative monitor. The nuclear power plant operators pay more attention to the quantitative leakage condition, so 13N and 18F has attracted the attention of many researchers due to their existence form and their characteristic of positron-electron annihilation. Based on the advantages of 13N and 18F, the key technologies research has been carried out in Nuclear Power Institute of China. A full-range measurement method is proposed. More specifically, the radioactive activity measurement has been studied when nuclear power is greater than or equal to the set value (for example, 20%FP). In order to improve the accuracy of measurement, the coincidence detection and digital coincidence measurement technique has been adopted. By measuring the charge and time of the detectors’ output signals, the effective coincidence events based on time-to-digital converter (TDC) and high-speed ADC technology can be measured. In addition, the total gamma measurement method has been studied when nuclear power is less than the set value (for example, 20%FP). The digital multichannel pulse height analysis method has been studied. The energy spectra and linear fitting parameters are tested, the test results indicate that the measurement system has a good energy linearity. Through the above research, 13N and 18F monitoring methods have been proven to have advantages of quantitative monitoring compared with PING monitoring methods. At last, the recommended radiation monitoring methods of the reactor coolant pressure boundary leakage in nuclear power plant is given considering the advantages and disadvantages of different monitoring method.
Risk Assessment of the Integration of a Large-Scale Hydrogen Cogeneration Facility Into a VVER Power Plant
Authors: Diaz-Pescador Eduard , Viebach Marco , Gamaleja Florian , Hurtado Antonio
Published: November 2024

This manuscript presents the outcomes from the quantitative risk assessment (QRA) of the integration of a generic hydrogen cogeneration facility into the protected area of a reference nuclear power plant (NPP). The latter is Rivne NPP in Ukraine, and the hydrogen production plant (HPP) is assumed to use electricity from the NPP to operate in base-load mode.

The presented study applies HAZID technique to identify those postulated initiating events (PIEs) that lead to the worst-case scenario in the HPP and therefore major external hazard to the NPP, which is regarded as an hydrogen explosion. The study quantifies likelihood of occurrence of the two identified PIEs and potential accident scenarios. It evaluates as well the consequences of the worst-case scenario by means of empirical and analytical expressions in the process safety literature, together with conservative conditions.

The major external hazard is the storage facility due to the large hydrogen inventory. Nevertheless, storage is assumed outside of the NPP perimeter, and safety distances can be adjusted accordingly. In the electrolyser facility, a detonation of a hydrogen vapor cloud in the gas processing unit would only violate the 10 kPa criterion over the nearby standby diesel generators, under upper-bound conditions. An explosion of the buffer tank would have more severe consequences, requiring mitigation measures such as blast walls to ensure an adequate safety level under such conservative accidental conditions.
Exergy Analysis of a Small Modular Reactor Nuclear Power Plant Under Constant and Pure Sliding Pressure Operation
Authors: Wang Xin , Zhao Gang , Qu Xinhe , Yang Xiaoyong , Wang Jie
Published: November 2024

This study proposes a pure sliding pressure operation (SPO) scheme for a small modular reactor (SMR) nuclear power plant (NPP). The operation range considered is from 30 % to 100 % full power (FP). Subsequently, exergy analysis was conducted under constant pressure operation (CPO) as well as SPO. For this, a thermodynamic model of the SMR NPP had been established using EBSILON software, version 16.0. Exergy destruction and efficiency were estimated for the entire system and variable components. The results reveal that control valve throttling under CPO contributes significantly to turbine exergy destruction, accounting for 31.11 % at 30 %FP condition. This issue can be effectively avoided by implementing SPO. Among all components, the reactors have the highest exergy destruction, followed by the steam generators (SGs) and the turbine. Switching the secondary circuit to SPO results in exergy efficiency improvements of 0.16 %, 0.56 %, and 0.97 % at 90 %, 60 %, and 30 %FP conditions, respectively. Additionally, feed water pumps (FWPs) power consumption decreases by 10.29 %, 40.52 %, and 68.92 % respectively at 90 %, 60 % and 30 %FP conditions. However, there is little change in the exergy destruction of the primary circuit components. The research can serve as a valuable reference for optimizing the thermal performance of the NPP.
Thermal Cut-Off Energy for Accurate Analysis of Prismatic High-Temperature Gas-Cooled Reactor
Authors: Takeda Satoshi , Kitada Takanori , Yamamoto Akio , Yamaji Kazuya , Koike Hiroki , Asano Koji
Published: November 2024

In this study, the appropriate thermal cut-off energy for neutron transport calculations in High-Temperature Gas-cooled Reactor (HTGR) is investigated. The research employs the Monte Carlo calculation code MVP3.0 to evaluate the impact of changing thermal cut-off energy on the multiplication factor in the single fuel element geometries, focusing on variations in fuel and moderator temperatures at both the Beginning Of Life (BOL) and End Of Life (EOL). Up-scattering effect mainly caused by graphite used in HTGR as moderator has strong relation to the thermal cut-off energy. The findings show that when the thermal cut-off energy is set at 20 eV, the multiplication factor tends to be underestimated, especially at high fuel temperature. Furthermore, the study confirms that when the thermal cut-off energy is at or above 30 eV the variations in multiplication factors remain within approximately ±50 pcm.
An Iterational Physical Decoupling Method for Assessing the Safety of Deformed Fuel Channels
Authors: Zheng Junzheng , Lin Musen , Yang Xingtuan , Wang Dingqu , Li Songyang , Hao Wentao , Xiong Wei , Jiang Yueyuan
Published: November 2024

Irradiation during reactor operation causes continuous deformation in the fuel channels, resulting in narrowing of the control rod’s channels, which directly affects the safe insertion of the control rods. Faced with a multi-physics coupling scenario where the control rod is affected by flow resistance and channel resistance at the same time. This paper proposes a calculation scheme based on physical field decoupling and continuous iteration to calculate the rod dropping process in the deformed channels. Specifically, firstly, based on the empirical formula of the flow resistance, substitute the initial solution to estimate the flow resistance, and apply it to the control rod in the finite element method. Secondly, the finite element method is used to estimate the interaction force between the control rod and the channels, and then combining the flow resistance to obtain the time-velocity relationship (new solution). Thirdly, determine whether the iteration is terminated or return to the first step. Our study provides a solution to evaluate the safety of rod’s dropping process.