Thermal-hydraulic and load following performance analysis of a heat pipe cooled reactor

Jiao Guanghui,Xia Genglei,Wang Jianjun,Peng Minjun 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.5

Heat pipe cooled reactors have gained attention as a potential solution for nuclear power generation in space and deep sea applications because of their simple design, scalability, safety and reliability. However, under complex operating conditions, a control strategy for variable load operation is necessary. This paper presents a twodimensional transient characteristics analysis program for a heat pipe cooled reactor and proposes a variable load control strategy using the recuperator bypass (CSURB). The program was verified against previous studies, and steady-state and step-load operating conditions were calculated. For normal operating condition, the predicted temperature distribution with constant heat pipe temperature boundary conditions agrees well with the literature, with a maximum temperature difference of 0.4 K. With the implementation of the control strategy using the recuperator bypass (CSURB) proposed in this paper, it becomes feasible to achieve variable load operation and return the system to a steady state solely through the self-regulation of the reactor, without the need to operate the control drum. The average temperature difference of the fuel does not exceed 1 % at the four power levels of 70 %,80 %, 90 % and 100 % Full power. The output power of the turbine can match the load change process, and the temperature difference between the inlet and outlet of the turbine increases as the power decreases.

Optimal fertilizer application for Panax notoginseng and effect of soil water on root rot disease and saponin contents

Xia, Pengguo,Guo, Hongbo,Zhao, Hongguang,Jiao, Jie,Deyholos, Michael K.,Yan, Xijun,Liu, Yan,Liang, Zongsuo The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.1

Background: Blind and excessive application of fertilizers was found during the cultivation of Panax notoginseng in fields, as well as increase in root rot disease incidence. Methods: Both "3414" application and orthogonal test designs were performed at Shilin county, Yunnan province, China, for NPK (nitrogen, phosphorus, and potassium) and mineral fertilizers, respectively. The data were used to construct the one-, two-, and three-factor quadratic regression models. The effect of fertilizer deficiency on root yield loss was also analyzed to confirm the result predicted by these models. A pot culture experiment was performed to observe the incidence rate of root rot disease and to obtain the best range in which the highest yield of root and saponins could be realized. Results: The best application strategy for NPK fertilizer was $0kg/667m^2$, $17.01kg/667m^2$, and $56.87kg/667m^2$, respectively, which can produce the highest root yield of 1,861.90 g (dried root of 100 plants). For mineral fertilizers, calcium and magnesium fertilizers had a significant and positive effect on root yield and the content of four active saponins, respectively. The severity of root rot disease increased with the increase in soil moisture. The best range of soil moisture varied from 0.56 FC (field capacity of water) to 0.59 FC, when the highest yield of root and saponins could be realized as well as the lower incidence rate of root disease. Conclusion: These results indicate that the amount of nitrogen fertilizer used in these fields is excessive and that of potassium fertilizer is deficient. Higher soil moisture is an important factor that increases the severity of the root rot disease.

Ontogenetic Expression of Lpin2 and Lpin3 Genes and Their Associations with Traits in Two Breeds of Chinese Fat-tailed Sheep

Jiao, Xiao-Li,Jing, Jiong-Jie,Qiao, Li-Ying,Liu, Jian-Hua,Li, Liu-An,Zhang, Jing,Jia, Xia-Li,Liu, Wen-Zhong Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.3

Lipins play dual function in lipid metabolism by serving as phosphatidate phosphatase and transcriptional co-regulators of gene expression. Mammalian lipin proteins consist of lipin1, lipin2, and lipin3 and are encoded by their respective genes Lpin1, Lpin2, and Lpin3. To date, most studies are concerned with Lpin1, only a few have addressed Lpin2 and Lpin3. Ontogenetic expression of Lpin2 and Lpin3 and their associations with traits would help to explore their molecular and physiological functions in sheep. In this study, 48 animals with an equal number of males and females each for both breeds of fat-tailed sheep such as Guangling Large Tailed (GLT) and Small Tailed Han (STH) were chosen to evaluate the ontogenetic expression of Lpin2 and Lpin3 from eight different tissues and months of age by quantitative real-time polymerase chain reaction (PCR). Associations between gene expression and slaughter and tail traits were also analyzed. The results showed that Lpin2 mRNA was highly expressed in perirenal and tail fats, and was also substantially expressed in liver, kidney, reproductive organs (testis and ovary), with the lowest levels in small intestine and femoral biceps. Lpin3 mRNA was prominently expressed in liver and small intestine, and was also expressed at high levels in kidney, perirenal and tail fats as well as reproductive organs (testis and ovary), with the lowest level in femoral biceps. Global expression of Lpin2 and Lpin3 in GLT both were significantly higher than those in STH. Spatiotemporal expression showed that the highest levels of Lpin2 expression occurred at 10 months of age in two breeds of sheep, with the lowest expression at 2 months of age in STH and at 8 months of age in GLT. The greatest levels of Lpin3 expression occurred at 4 months of age in STH and at 10 months of age in GLT, with the lowest expression at 12 months of age in STH and at 8 months of age in GLT. Breed and age significantly influenced the tissue expression patterns of Lpin2 and Lpin3, respectively, and sex significantly influenced the spatiotemporal expression patterns of Lpin3. Meanwhile, Lpin2 and Lpin3 mRNA expression both showed significant correlations with slaughter and tail traits, and the associations appear to be related with the ontogenetic expression as well as the potential functions of lipin2 and lipin3 in sheep.

An Improved Result on Stability Analysis of Delayed Load Frequency Control Power Systems

Shiyu Jiao,Jianwei Xia,Zhen Wang,Xiangyong Chen,Jing Wang,Hao Shen 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.4

This paper investigates the stability of power systems with load frequency control considering time delays(constant and time-varying delays). A new criterion for ensuring the stability of the system is proposed on the basisof Lyapunov stability theory and a further strengthened inequality. Finally, taking a single-area load frequencycontrol scheme with the proportional-integral controller as an example, according to the stability criterion obtained,the relationship between the maximum allowable delay and the gain of proportional-integral controller is discussed. Besides, in case studies, the effectiveness of our method is also demonstrated.

Simple Synthesis of Multi-Halogen Pyrazino[1,2-a]indole-1,8(2H,5aH)-diones

Rui-Xia Yang,Yu-Cheng Zhao,Ling-Bin Kong,Sheng-jiao Yan,Jun Lin 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.10

A concise and efficient one-pot synthesis of multi-halogen pyrazino[1,2-a]indole-1,8(2H,5aH)-dione (MHPID) derivatives by the reaction of an enamino ester with multi-halogen benzoquinone derivatives is described. MHPIDs 3a–3d were obtained with good yields (78–83%) by refluxing enamino esters 1a and 1b and tetrahalogen-1,4-benzoquinones 2a and 2b for 24 h without the use of catalysts. Compounds 3e–3p were also obtained with excellent yields (69–92%) via the reaction of the phenyl-substituted enamino esters 1c–1h with tetrahalogen-1,4-benzoquinones 2a and 2b in CH3CN catalyzed by Cs2CO3. These two protocols are efficient and effective for the synthesis of MHPIDs.

Contribution Rate of Influent Factors Affecting Soil Moisture and its Scale Effect in Loess Plateau,China

Feng Jiao,Zhang Zhe,Ning-Xia Liang 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Diaporthe taoicola and D. siamensis, Two New Records on Citrus sinensis in China

( Meng Jiao Cui ),( Xin Wei ),( Peng Liang Xia ),( Ji Ping Yi ),( Zhi He Yu ),( Jian Xin Deng ),( Qi Li Li ) 한국균학회 2021 Mycobiology Vol.49 No.3

Two Diaporthe species isolated from fruit of Citrus sinensis in China were characterized based on morphology and multilocus phylogeny of ITS, tef1, and tub2 gene sequences. The phylogeny indicated that the two species match Diaporthe taoicola and D. siamensis. A critical examination of phenotypic characteristics confirmed the phylogenetic results. Diaporthe taoicola was morphologically characterized by producing Alpha conidia with tapering toward both ends. Meanwhile, D. siamensis produced cylindrical or ellipsoidal Alpha conidia with two oil drops. Pathogenicity tests revealed that both species were pathogenic to fruit of C. sinensis. To our knowledge, the two species were firstly reported on Citrus sinensis in China.

Anisotropic In-plane Resistivity and Magnetoresistance of the Detwinned BaFe2As2

Lin Jiao,Zong Fa Weng,Xue Yan Tang,Lu Kai Guo,Tian Shang,Lin Yang,Hui Qiu Yuan,Yu Ying Wu,Zheng Cai Xia 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.3

We have measured the electrical resistivity and the magnetoresistance of detwinned BaFe2As2single crystals in fields up to 16 Tesla. The temperature dependence of the resistivity shows acounterintuitive anisotropic behavior in the ab-plane, likely arising from the effect of the nematicsusceptibility. Little magnetoresistance is observed at temperatures above the structural/magnetictransition, below which a huge in-plane magnetoresistance with an anisotropy is detected.

Function of Global Regulator CodY in Bacillus thuringiensis BMB171 by Comparative Proteomic Analysis

( Ming Xia Qi ),( Fei Mei ),( Hui Wang ),( Ming Sun ),( Ge Jiao Wang ),( Ziniu Yu ),( Yeon Ho Je ),( Ming Shun Li ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.2

CodY is a highly conserved protein in low G+C gram-positive bacteria that regulates genes involved in sporulation and stationary-phase adaptation. Bacillus thuringiensis is a grampositive bacterium that forms spores and parasporal crystals during the stationary phase. To our knowledge, the regulatory mechanism of CodY in B. thuringiensis is unknown. To study the function of CodY protein in B. thuringiensis, BMB171codY- was constructed in a BMB171 strain. A shuttle vector containing the ORF of cry1Ac10 was transformed into BMB171 and BMB171codY-, named BMB171cry1Ac and BMB171codY-cry1Ac, respectively. Some morphological and physiological changes of codY mutant BMB171codY-cry1Ac were observed. A comparative proteomic analysis was conducted for both BMB171codY-cry1Ac and BMB171cry1Ac through two-dimensional gel electrophoresis and MALDI-TOF-MS/MS analysis. The results showed that the proteins regulated by CodY are involved in microbial metabolism, including branched-chain amino acid metabolism, carbohydrate metabolism, fatty acid metabolism, and energy metabolism. Furthermore, we found CodY to be involved in sporulation, biosynthesis of poly-β-hydroxybutyrate, growth, genetic competence, and translation. According to the analysis of differentially expressed proteins, and physiological characterization of the codY mutant, we performed bacterial one-hybrid and electrophoretic mobility shift assay experiments and confirmed the direct regulation of genes by CodY, specifically those involved in metabolism of branched-chain amino acids, ribosomal recycling factor FRR, and the late competence protein ComER. Our data establish the foundation for in-depth study of the regulation of CodY in B. thuringiensis, and also offer a potential biocatalyst for functions of CodY in other bacteria.

Small Solitary Ground-Glass Nodule on CT as an Initial Manifestation of Coronavirus Disease 2019 (COVID-19) Pneumonia

Tianyi Xia,Jiawei Li,Jiao Gao,Xunhua Xu 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.5

The 2019 novel coronavirus (2019-nCoV) outbreak in Wuhan, Hubei Province, China in 2019 led to large numbers of people being infected and developing atypical pneumonia (coronavirus disease 2019, COVID-19). Typical imaging manifestations of patients infected with 2019-nCoV has been reported, but we encountered an atypical radiological manifestation on baseline computed tomography (CT) images in three patients from Wuhan, China infected with the 2019-nCoV. Surprisingly, the only similar CT finding was a solitary sub-centimeter ground-glass nodule adjacent to bronchovascular bundles, which could be easily overlooked. In addition, the follow-up images in these patients showed how COVID-19 pneumonia evolved from these small nodules. The radiologic manifestation of the three cases will expand contemporary understanding of COVID-19.