Experimental Investigation on Critical Heat Flux in Bilaterally Heated Annulus with equal heat flux on both sides

Gui Miao,Guo Junliang,Kong Huanjun,Wu Pan,Shan Jianqiang,Peng Yujiao 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.9

A phenomenological study on CHF in a bilaterally heated annulus with equal heat flux on both sides was experimentally performed. The working fluid of the present test was R-134a. Variation characteristics of CHF and transition of CHF occurrence location were investigated under different pressure, mass flux and quality conditions. With the increase of critical thermodynamic quality, it was found that CHF first occurred on the outer surface of the annulus, then simultaneously occurred on both sides, and finally occurred on the inner surface at relatively high critical quality. After the CHF location transitioned to the inner rod, the sharp fall of CHF in the limiting critical quality region was observed. The critical quality corresponding to the CHF location transition decreased with the increase of mass flux and pressure. Besides, CHF in tube, internally heated, externally heated and bilaterally heated annuli were compared under the same hydraulic diameter conditions. The present study is conducive to improving the understanding of complicated CHF mechanism in bilaterally heated annulus, enriching the experimental database, and providing evidence for developing accurate CHF mechanism model for annuli.

Effect of Turbulent Fluctuation on Settling Behavior of Dredged Slurry in Sheared Condition

Miao-miao Song,Gui-zhong Xu,Jie Yin,Wei-juan Geng,Zhi-yan Zhou,Cheng-chun Qiu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.4

For the land shortage problem upon the city development in coastal areas, it is of great importance to improve the overall understanding of the settlement behavior of dredged slurry and determine the required site water storage capacity as well as the mechanical properties of the newly formed dredged slurry. This paper presents an experimental investigation on the effect of turbulent fluctuation on the settling behavior of dredged slurry in sheared condition via a self-developed testing apparatus namely double cylinder settling column. Test results showed that the settling velocity of the soil-water interface initially increased then decreased with the increasing rotation speed of the inner column. The interface would disappear and a stable suspended layer was observed when the rotation speed was greater than 20 rad/min, where water contents and grain composition were not changed over the depth. The particle content was closer to that of the original sample as the rotation speed kept increasing in the suspended layer. It was found that the stabilized flocs were gradually broken down by the turbulence effect existing in the sheared slurry. Moreover, the stabilized flocs were losing the stability gradually as the flowing velocity increased till 10 rad/min and the floc structure was broken down completely once the flowing velocity was greater than 20 rad/min.

A novel synthesis of spherical LiFePO4/C composite using Fe1.5P and mixed lithium salts via oxygen permeation

Gui-Xin Wang,Kangping Yan,Rui Liu,Miao Chen,Hanchang Kang,Xiuli Li 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.8

A novel route was designed to synthesize LiFePO4/C composites by using the Fe1.5P byproduct, mixed lithium salts, and permeated oxygen from air via a rheological phase method. The reaction process was investigated with various techniques. When the calcining time was increased from 10 to 30 h, the gradual formation of olivine structure was observed. The growth kinetics of the crystals was analyzed. SEM and TEM results indicated the as-synthesized LiFePO4 was constituted of small spheres covered with carbon particles. The discharge capacity of the LiFePO4/C composite prepared at ~700 oC for ~25 h could reach 139.7 mAh g−1 and still remained 130.2 mAh g−1 after 15 cycles at 0.2 C rate, comparable to that of the reported LiFePO4/C composite using conventional methods. Cyclic voltammogram confirmed the LiFePO4/C composite had a high purity and good lithium ion insertion/desertion redox behavior.

Optimized Medium Improves Expression and Secretion of Extremely Thermostable Bacterial Xylanase, XynB, in Kluyveromyces Lactis

( Yin Tie ),( Li Li Miao ),( Fei Fei Guan ),( Gui Li Wang ),( Qing Peng ),( Bing Xue Li ),( Guo Hua Guan ),( Ying Li ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.11

An extremely thermostable xylanase gene, xynB, from the hyperthermophilic bacterium Thermotoga maritima MSB8 was successful expressed in Kluyveromyces lactis. The response surface methodology (RSM) was also applied to optimize the medium components for the production of XynB secreted by the recombinant K. lactis. The secretion level (102 mg/l) and enzyme activity (49 U/ml) of XynB in the optimized medium (yeast extract, lactose, and urea; YLU) were much higher than those (56 mg/l, 16 U/ml) in the original medium (yeast extract, lactose, and peptone; YLP). The secretory efficiency of mature XynB was also improved when using the YLU medium. When the mRNA levels of 13 characterized secretion-related genes in the K. lactis cultured in YLP and YLU were detected using a semiquantitative RT-PCR method, the unfolded protein response (UPR)-related genes, including ero1, hac1, and kar2, were found to be up-regulated in the K. lactis cultured in YLU. Therefore, the nutrient ingredients, especially the nitrogen source, were shown to have a significant influence on the XynB secretory efficiency of the host K. lactis.

Performance evaluation of Accident Tolerant Fuel under station blackout accident in PWR nuclear power plant by improved ISAA code

Zhang Bin,Gao Pengcheng,Xu Tao,Gui Miao,Shan Jianqiang 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.7

The Accident Tolerant Fuel (ATF) is a new concept of fuel, which can not only withstand the consequences of the accident for a longer time, but also maintain or improve the performance under operating conditions. ISAA is a self-developed severe accident analysis code, which uses modular structures to simulate the development processes of severe accidents in nuclear plants. The basic version of ISAA is developed based on UO2eZr fuel. To study the potential safety gain of ATF cladding, an improved version of ISAA, referred to as ISAA-ATF, is introduced to analyze the station blackout accident of PWR using ATF cladding. The results show that ATF cladding enable the core to maintain a longer time compared to zirconium alloy cladding, thereby enhancing the accident mitigation capability. Meanwhile, the generation of hydrogen is significantly reduced and delayed, which proves that ATF can improve the safety characteristics of the nuclear reactor.

Effect of Salinity on Strength Behavior of Cement-treated Dredged Clay at High Initial Water Contents

Jie Yin,Wen-xia Han,Gui-zhong Xu,Ming-ming Hu,Yong-hong Miao 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.10

This paper presents the experimental investigation into the effect of salinity on the strength behavior of cement-stabilized dredged clays as fills at high initial water contents. One source of dredged clay was dredged from Baima Lake of China. Specimens were prepared having different porewater salinities by blending the air-dried clays with NaCl solution at different salt concentrations. The prepared saline dredged clay specimens were thereafter adjusted to different initial water contents and blended with cement with different amounts. Unconfined compression tests were performed on cement-stabilized dredged clay specimens after 28-day curing. All tested specimens show strain softening behavior where the axial strain corresponding to the peak stress varies with amount of cement. Stress-strain curve for the specimen with lower salinity lies above on that of higher one. Initial water content has a negative effect on the strength of cement-treated clays while cement has a positive effect on the development of strength for cement-treated dredged clays due to the pozzolanic reactions. The presence of salt has an adverse influence on the obtaining of strength for cement-treated dredged clays because salt can inhibit cement from generating C-S-H and C-A-H. Unconfined compressive strength almost linearly decreases with the increasing salinity. A quantitative expression was presented to calculate the unconfined compressive strength for cement-treated saline dredged clays concerning the effects for initial water content, porewater salinity and amount of cement.

EphB1 and Ephrin-B, New Potential Biomarkers for Squamous Cell/adenosquamous Carcinomas and Adenocarcinomas of the Gallbladder

Yuan, Yuan,Yang, Zhu-Lin,Miao, Xiong-Ying,Liu, Zi-Ru,Li, Dai-Qiang,Zou, Qiong,Li, Jing-He,Liang, Lu-Feng,Zeng, Gui-Xiang,Chen, Sen-Lin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.3

Squamous cell/adenosquamous carcinoma (SC/ASC) of the gallbladder are rare tumors and there are few clinical reports in the literature. Herein we report our clinical experience with 46 patients with SC/ASC and 80 with adenocarcinoma (AC). Expression of EphB1 and Ephrin-B in each tumor was determined using immunohistochemical methods for determination of correlations with prognosis. There was no difference in EphB1 and Ephrin-B expression between SC/ASC and AC tumors (P>0.05), but greater expression in those less than 3 cm in diameter, stage I or II (TNM stage), with no lymph node metastases, with no local invasion and treated with radical resection was apparent. Expression of EphB1 (P<0.05) and Ephrin-B (P<0.01) was higher in well differentiated than in poorly differentiated AC tumors. Kaplan-Meier survival analysis indicated that degree of differentiation, tumor diameter, lymph node metastases, local invasion, surgical approach and expression rate of EphB1 and Ephrin-B were closely related to the survival of SC/ASC (P<0.05) and AC patients (P<0.01). Patients with tumors that positive expressed EphB1 and Ephrin-B, whether it is SC/ASC ($P_{SC/ASC}$ =0.000) or AC ($P_{AC}$ =0.000 or $P_{AC}$ =0.002) had longer survival than those negative expression. Cox multivariate analysis indicated a negative correlation between expression of EphB1 or Ephrin-B and overall survival. Hence, EphB1 and Ephrin-B could be regarded as independent good prognostic factorsand important biological markers for SC/ASC and AC of gallbladder.

Rs7574865 polymorphism of STAT4 and risk of anti-tuberculosis drug-induced hepatotoxicity in Chinese Han

Guo Chen,Wei Mao,Shou‑Quan Wu,Yu Wang,Gui‑Yi Ji,Miao‑Miao Zhang,Qian‑Qian Liu,Jian‑Qing He 한국유전학회 2017 Genes & Genomics Vol.39 No.11

Anti-tuberculosis drug-induced hepatotoxicity (ATDH) is the most frequent, and potentially fatal adverse effect in the treatment of tuberculosis (TB). The rs7574865 polymorphism in the signal transducer and activator of transcription 4 gene (STAT4) was reported to be associated with drug-induced liver injury. However, there was no study aimed to this association in Chinese patients. The aim of this study was to investigate the influence of STAT4 polymorphisms on the susceptibility to ATDH in a Chinese Han population. A total of 280 TB patients with the prescription of anti-TB therapy, of Chinese Han origin, were enrolled. They were followed up for 3 months and demographic, clinical, laboratory and therapeutic data at each visit were collected. Two single nucleotide polymorphisms (SNPs) (rs7574865 and rs7582694) of STAT4 were genotyped with the MassARRAY platform. The associations between SNPs and ATDH risk were analyzed by logistic regression adjusting for confounding factors. A total of 24 patients were diagnosed with ATDH and considered as the case group, and 33 patients were lost to follow-up; the remaining 223 subjects without ATDH were considered as the control group. There was strong linkage disequilibrium (LD) between rs7574865 and rs7582694 ( r2 = 0.928 and D′ = 1). No significant association was found between SNPs or haplotypes of STAT4 and ATDH after correction for confounding factors. This prospective study is the first to investigate the association of genetic polymorphisms of STAT4 and ATDH in Chinese individuals. There was no significant association between the rs7574865 of STAT4 and ATDH in a Chinese Han population.