• Title/Summary/Keyword: Barcelona model

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Numerical analysis of FEBEX at Grimsel Test Site in Switzerland (스위스 Grimsel Test Site에서 수행된 FEBEX 현장시험에 대한 수치해석적 연구)

  • Lee, Changsoo;Lee, Jaewon;Kim, Geon-Young
    • Tunnel and Underground Space
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    • v.30 no.4
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    • pp.359-381
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    • 2020
  • Within the framework of DECOVALEX-2019 Task D, full-scale engineered barriers experiment (FEBEX) at Grimsel Test Site was numerically simulated to investigate an applicability of implemented Barcelona basic model (BBM) into TOUGH2-MP/FLAC3D simulator, which was developed for the prediction of the coupled thermo-hydro-mechanical behavior of bentonite buffer. And the calculated heater power, temperature, relative humidity, total stress, saturation, water content and dry density were compared with in situ data monitored in the various sections. In general, the calculated heater power and temperature provided a fairly good agreement with experimental observations, however, the difference between power of heater #1 and that of heater #2 could not captured in the numerical analysis. It is necessary to consider lamprophyre with low thermal conductivity around heater #1 and non-simplified installation progresses of bentonite blocks in the tunnel for better modeling results. The evolutions and distributions of relative humidity were well reproduced, but hydraulic model needs to be modified because the re-saturation process was relatively fast near the heaters. In case of stress evolutions due to the thermal and hydraulic expansions, the computed stress was in good agreement with the data. But, the stress is slightly higher than the measured in situ data at the early stage of the operation, because gap between rock mass and bentonite blocks have not been considered in the numerical simulations. The calculated distribution of saturation, water content, and dry density along the radial distance showed good agreement with the observations after the first and final dismantling. The calculated dry density near the center of the FEBEX tunnel and heaters were overestimated compared with the observations. As a result, the saturation and water content were underestimated with the measurements. Therefore, numerical model of permeability is needed to modify for the production of better numerical results. It will be possible to produce the better analysis results and more realistically predict the coupled THM behavior in the bentonite blocks by performing the additional studies and modifying the numerical model based on the results of this study.

A comparative study for design of boundary combined footings of trapezoidal and rectangular forms using new models

  • Luevanos-Rojas, Arnulfo;Barquero-Cabrero, Jose Daniel;Lopez-Chavarria, Sandra;Medina-Elizondo, Manuel
    • Coupled systems mechanics
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    • v.6 no.4
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    • pp.417-437
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    • 2017
  • This paper shows a comparative study for design of reinforced concrete boundary combined footings of trapezoidal and rectangular forms supporting two columns and each column transmits an axial load and a moment around of the axis X (transverse axis of the footing) and other moment around of the axis Y (longitudinal axis of the footing) to foundation to obtain the most economical combined footing. The real soil pressure acting on the contact surface of the footings is assumed as a linear variation. Methodology used to obtain the dimensions of the footings for the two models consider that the axis X of the footing is located in the same position of the resultant, i.e., the dimensions is obtained from the position of the resultant. The main part of this research is to present the differences between the two models. Results show that the trapezoidal combined footing is more economical compared to the rectangular combined footing. Therefore, the new model for the design of trapezoidal combined footings should be used, and complies with real conditions.

Elevated PIVKA-II is Associated with Early Recurrence and Poor Prognosis in BCLC 0-A Hepatocellular Carcinomas

  • Wang, Bei-Li;Tan, Qi-Wen;Gao, Xing-Hui;Wu, Jiong;Guo, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6673-6678
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    • 2014
  • Background: To investigate the prognostic value of serum PIVKA-II (prothrombin induced by the absence of vitamin K or antagonist-II) in BCLC (Barcelona Clinic Liver Cancer) 0-A hepatocellular carcinoma (HCC) patients after curative resection. Materials and Methods: Preoperative sera were collected from 140 patients with BCLC 0-A HCCs undergoing curative resection during 2011-2012 in Zhongshan Hospital. Follow-up ended on November 2013. ELISA was used to detect the serum concentrations of preoperative PIVKA-II. The prognostic value of PIVKA-II and other clinicopathological factors was analyzed by the Kaplan-Meier method and the multivariate Cox proportional hazards model. Results: During follow-up, 39 of 140 patients suffered recurrence and the 1-year recurrence rate was 27.9%. The high-PIVKA-II expression group had lower 1-year time to progression (TTP) compared with the low-expression group (54.8% vs 20.2%, p<0.001). Patients with high preoperative PIVKA-II expression showed a relatively higher risk of developing postoperative recurrence than those with low expression in the low-recurrence-risk subgroups, including ${\alpha}$-fetoprotein ${\leq}400ng/mL$ (45.4% vs 16.7%; p=0.006), tumor size ${\leq}5cm$ (54.2% vs 18.1%; p<0.001), single tumor (56.0% vs 19.1%; p<0.001), absence of satellite lesions (53.3% vs 19.8%; p=0.001), absence of vascular invasion (52.6% vs 14.9%; p=0.002), and Edmondson stage I/II (60.9% vs 20.3%; p<0.001). PIVKA-II was the strongest independent prognostic factor for TTP (hazard ratio, 2.877; 95% CI 1.524-5.429; p=0.001). Conclusions: Elevated PIVKA-II is associated with early recurrence of BCLC 0-A HCC after curative resection and can be considered a novel prognostic predictor.

Prognostic Value of Biochemical Response Models for Primary Biliary Cholangitis and the Additional Role of the Neutrophil-to-Lymphocyte Ratio

  • Yoo, Jeong-Ju;Cho, Eun Ju;Lee, Bora;Kim, Sang Gyune;Kim, Young Seok;Lee, Yun Bin;Lee, Jeong-Hoon;Yu, Su Jong;Kim, Yoon Jun;Yoon, Jung-Hwan
    • Gut and Liver
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    • v.12 no.6
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    • pp.714-721
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    • 2018
  • Background/Aims: Recently reported prognostic models for primary biliary cholangitis (PBC) have been shown to be effective in Western populations but have not been well-validated in Asian patients. This study aimed to compare the performance of prognostic models in Korean patients and to investigate whether inflammation-based scores can further help in prognosis prediction. Methods: This study included 271 consecutive patients diagnosed with PBC in Korea. The following prognostic models were evaluated: the Barcelona model, the Paris-I/II model, the Rotterdam criteria, the GLOBE score and the UK-PBC score. The neutrophil-to-lymphocyte ratio (NLR) was analyzed with reference to its association with prognosis. Results: For predicting liver transplant or death at the 5-year and 10-year follow-up examinations, the UK-PBC score (areas under the receiver operating characteristic curve [AUCs], 0.88 and 0.82) and GLOBE score (AUCs, 0.85 and 0.83) were significantly more accurate in predicting prognosis than the other scoring systems (all p<0.05). There was no significant difference between the performance of the UK-PBC and GLOBE scores. In addition to the prognostic models, a high NLR (>2.46) at baseline was an independent predictor of reduced transplant-free survival in the multivariate analysis (adjusted hazard ratio, 3.74; p<0.01). When the NLR was applied to the prognostic models, it significantly differentiated the prognosis of patients. Conclusions: The UK-PBC and GLOBE scores showed good prognostic performance in Korean patients with PBC. In addition, a high NLR was associated with a poorer prognosis. Including the NLR in prognostic models may further help to stratify patients with PBC.

Prognostic Significance of Preoperative Serum Alpha-fetoprotein in Hepatocellular Carcinoma and Correlation with Clinicopathological Factors: a Single-center Experience from China

  • An, Song-Lin;Xiao, Ting;Wang, Li-Ming;Rong, Wei-Qi;Wu, Fan;Feng, Li;Liu, Fa-Qiang;Tian, Fei;Wu, Jian-Xiong
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4421-4427
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    • 2015
  • Objectives: To investigate the prognosis significance of preoperative serum alpha-fetoprotein (AFP) and the correlation with clinicopathological factors of hepatocellular carcinoma (HCC) patients who underwent hepatectomy. Materials and Methods: Clinicopathological data of retrospective analysis were collected for 251 HCC patients undergoing hepatectomy in this study. According to preoperative AFP level, patients were categorized into AFP-negative (0-20ng/mL) and AFP-positive (>20 ng/mL) groups for Kaplan-Meier analysis and Cox proportional hazard regression modeling. Results: The results demonstrated that increased AFP was associated with longer prothrombin time (PTs), liver capsule invasion, low grade differentiation, and late Barcelona Clinic Liver Center (BCLC) stage. Moreover, the female patients had a greater prevalence of increased preoperative AFP than male patients [284.8 (3.975-3167.5) vs (3.653-140.65); Z-2.895, p=0.004]. The 1-, 3-, and 5-year recurrence-free survival (RFS) rates were 78.1, 57.5, and 40.6 % in the AFP-negative group and 61.8, 37.7, and 31.4 %, respectively, in the AFP-positive group (log-rank test 8.312, p=0.004). The 1-, 3-, and 5-year overall survival (OS) rates were 94.4, 83.8, and 62.3% in the AFP-negative group and 87.2, 60.0, and 36.7%, respectively, in the AFP-positive group. The difference was statistically significant (log-rank test, 16.884, p=0.000). Cox proportional-hazards model identified preoperative AFP to be an independent prognostic predictor of overall survival. Conclusions: Preoperative serum AFP is an independent predictor of prognosis among HCC patients following surgical resection. Female patients have a higher preoperative AFP than their male counterparts.

Population genetic structure of Sedum polytrichoides (Crassulaceae): Insights into barriers to gene flow (바위채송화(돌나물과)집단의 유전적 구조: 유전자 이동과 물리적 장벽에 관한 통찰)

  • Chung, Mi Yoon;Lopez-Pujol, Jordi;Chung, Myong Gi
    • Korean Journal of Plant Taxonomy
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    • v.46 no.4
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    • pp.361-370
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    • 2016
  • An area comprising Juwangsan National Park and its adjacent mountains (southeastern Korean Peninsula) is a good model system for testing the effects of physical barriers to gene flows in plant populations. We predicted that plant species consisting of isolated populations are genetically more differentiated than those that are rather continuously distributed. Most populations of Sedum polytrichoides occur in four isolated valleys, and we assessed the genetic variability and structures using twelve allozyme loci in ten populations. We also compared the present results to earlier findings pertaining to the two co-occurring herbs Hylotelephium ussuriense (${\equiv}$ Sedum ussuriense) (growing only in the four isolated valleys) and S. kamtschaticum (rather continuously distributed). We found moderate levels of within-population genetic variation in S. polytrichoides ($H_{e}=0.112$). Estimates of among-population divergence in S. polytrichoides were also moderate ($F_{ST}=0.250$) and, as expected, very similar to that of H. ussuriense (0.261) but considerably higher than the variation in S. kamtschaticum (0.165). An analysis of molecular variance (AMOVA) revealed that S. polytrichoides and H. ussuriense had higher percentages of among-valley variation (19% each) than S. kamtschaticum (4%). Most of this variation, as also indicated by the STRUCTURE program, was due to differences in genetic profiles between the two central valleys. We concluded that the genetic differences observed between species (S. kamtschaticum vs. S. polytrichoides and H. ussuriense) are mainly due to differences in their distribution within the study area.