• Title/Summary/Keyword: RCC

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Evaluation of Creep-Fatigue Damage of KALIMER Reactor Internals Using the Elastic Analysis Method in RCC-MR

  • Koo, Gyeong-Hoi;Bong Yoo
    • Nuclear Engineering and Technology
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    • v.33 no.6
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    • pp.566-584
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    • 2001
  • In this paper, the progressive deformation and the creep-fatigue damage for the conceptually designed reactor internals of KALIMER(Korea Advanced Liquid MEtal Reactor) are carried out by using the elastic analysis method in the RCC-MR code for normal operating conditions including the thermal load, seismic load (OBE) and dead weight. The maximum operating temperature of this reactor is 53$0^{\circ}C$ and the total service lifetime is 30 years. Thus, the time- dependent creep and stress-rupture effects become quite important in the structural design. The effects of the thermal induced membrane stress on the creep-fatigue damage are investigated with the risk of the elastic follow-up. To calculate the thermal stress, detailed thermal analyses considering conduction, convection and radiation heat transfer mechanisms are carried out with the ANSYS program. Using the results of the elastic analysis, the progressive deformation and creep-fatigue damages are calculated step by step using the RCC-MR in detail. This paper ill be a very useful guide for an actual application of the high temperature structural design of the nuclear power plant accounting for the time-dependent creep and stress-rupture effects.

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An ICCP Application Method for an Error Decrease of the Power Control Communication System (전력제어 통신 시스템의 에러 감소를 위한 ICCP 적용 방안)

  • 김종빈;정래성
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.40 no.9
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    • pp.349-357
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    • 2003
  • Because of capacity of the electric power equipment grew larger and the electric power system was complicated, it was required a protocol to process data without the errors in order to supply the high quality and stable electric power. However, HDLC and TCP/IP communication protocol using between Seoul EMS and Kwangju RCC (or between RCC and SCC) is decreasing reliability by the delay of speed and the occurrence of errors. In this paper, we applied ICCP(Inter-Control Center Communication Protocol) communication protocol in order to improve them and implemented an electric power communication system for remote control of the electric power equipment. Also, we modified program for error correction and implemented the system using the most suitable BLT. The errors were more decreased in case of ICCP protocol than HDLC protocol and TCP/IP protocol applied to the electric power communication system.

Earthquake response of roller compacted concrete dams including galleries

  • Karabulut, Muhammet;Kartal, Murat Emre
    • Structural Engineering and Mechanics
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    • v.72 no.2
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    • pp.141-153
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    • 2019
  • The effect of galleries on the earthquake behavior of dams should be investigated to obtain more realistic results. Therefore, a roller compacted concrete (RCC) dam with and without galleries are examined under ground motion effects. For this purpose, Cine RCC dam constructed in Aydın, Turkey, is selected in applications. The optimal mesh around galleries is investigated to obtain the most realistic results. Two-dimensional finite element models of Cine RCC dam with and without galleries are prepared by using ANSYS software. Empty and full reservoir conditions were taken into account in the time-history analyses. Hydrodynamic effect of the reservoir water was taken into account considering two-dimensional fluid finite elements based on the Lagrangian approach. It is examined that how principle stresses and displacements change by height and during earthquake. The dam-foundation-reservoir interaction was taken into consideration with contact-target element pairs. The displacements and principle stress components obtained from the linear analyses are compared each other for various cases of reservoir water and galleries. According to numerical analyses, the effect of galleries is clear on the response of RCC dam. Besides, hydrodynamic water effect obviously increases the principle stress components and horizontal displacements of the dam.

Spontaneously Regressed Rathke's Cleft Cyst

  • Lee, Chaejin;Park, Seong-Hyun
    • Journal of Korean Neurosurgical Society
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    • v.62 no.6
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    • pp.723-726
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    • 2019
  • We report two rare cases of spontaneously regressed Rathke's cleft cyst (RCC). A 52-year-old woman presented with headache. A pituitary hormone study was normal. Brain magnetic resonance imaging (MRI) showed a $0.45-cm^3$ cystic sellar lesion. The cyst was hyperintense on T1-weighed imaging and hypointense on T2-weighted imaging without rim enhancement, comparable to a RCC. Six months later, brain MRI showed no change in the cyst size. Without any medical treatments, brain MRI 1 year later revealed a spontaneous decrease in cyst volume to $0.05cm^3$. A 34-year-old woman presented with headache and galactorrhea lasting 1 week. At the time of the visit, the patient's headache had disappeared. Her initial serum prolactin level was 81.1 ng/mL, and after 1 week without the cold medicine, the serum prolactin level normalized to 11.28 ng/mL. Brain MRI showed a RCC measuring $0.71cm^3$. Without further treatments, brain computed tomography 6 months later showed a spontaneous decrease in cyst volume to $0.07cm^3$. Another 6 months later, brain MRI revealed that the cyst had remained the same size. Neither patient experienced neurological symptoms, such as headache or visual disturbance, during the period of cyst reduction. The RCCs in both patients underwent spontaneous regression without any medical treatment during a period of 6 months to 1 year. Although spontaneous regression of a RCC is rare, it is still possible and a sufficient follow-up period should be considered.

Thymoquinone Suppresses Migration of Human Renal Carcinoma Caki-1 Cells through Inhibition of the PGE2-Mediated Activation of the EP2 Receptor Pathway

  • Park, Geumi;Song, Na-Young;Kim, Do-Hee;Lee, Su-Jun;Chun, Kyung-Soo
    • Biomolecules & Therapeutics
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    • v.29 no.1
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    • pp.64-72
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    • 2021
  • Renal cell carcinoma (RCC) is likely to metastasize to other organs, and is often resistant to conventional chemotherapies. Thymoquinone (TQ), a phytochemical derived from the seeds of Nigella sativa, has been shown to inhibit migration and metastasis in various cancers. In this study, we assessed the effect of TQ on the migratory activity of human RCC Caki-1 cells. We found that treatment with TQ reduced the proteolytic activity of matrix metalloproteinase-9 (MMP-9) in Caki-1 cells. TQ significantly repressed prostaglandin E2 (PGE2) production, its EP2 receptor expression as well as the activation of Akt and p38, the wellknown upstream signal proteins of MMP-9. In addition, treatment with butaprost, a PGE2 agonist, also induced MMP-9 activity and migration/invasion in Caki-1 cells. Moreover, pharmacological inhibitors of PI3K/Akt and p38 remarkably attenuated butaprost-induced Caki-1 cell migration and invasion, implying that activation of PI3K/Akt and p38 is a bridge between the PGE2-EP2 axis and MMP-9-dependent migration and invasion. Taken together, these data suggest that TQ is a promising anti-metastatic drug to treat advanced and metastatic RCC.

Adrenal Metastasis from Renal Cell Carcinoma Regressed with Allergen-removed Rhus verniciflua Stokes;A Case Report (알러젠 제거 옻나무 추출물 투여로 소퇴된 신세포암 유래 부신전이암 1례)

  • Jeong, Ui-Min;Jeong, Jong-Soo;Jung, Hyun-Sik;Park, Jae-Woo;Yoon, Seong-Woo
    • The Journal of Internal Korean Medicine
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    • v.29 no.2
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    • pp.529-534
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    • 2008
  • Renal cell carcinoma(RCC) is one of the major malignant renal cell tumors. Although RCC can metastasize to almost every organ, the most common metastatic sites are the lung parenchyma, the bones, the liver, and the brain. Adrenal metastasis from RCC is extremely rare. Adrenal metastasis from RCC shows poor prognosis, with little benefit from chemotherapy, radiation therapy, hormone therapy or immunotherapy. In this report, we describe a case of an RCC patient who showed lung and adrenal metastasis. The patient underwent left nephrectomy and chemotherapy(sunitinib), which were not effective. He refused further conventional medical treatment, and instead started treatment with Traditional Korean Medicine using allergen-removed Rhus verniciflua Stokes. After about 3 months of this treatment, the size of the adrenal tumor had decreased significantly with good performance status. Further study will be needed to demonstrate the tumor regression effect of allergen-removed Rhus verniciflua Stokes on patients with metastatic renal cell carcinoma.

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A method on integrity evaluation with high reliability for superheater structure in a supercritical thermal power plant (초임계압 화력 과열기 구조의 고신뢰도 건전성 평가 방법)

  • Lee, Hyeong-Yeon;Ju, Yong-Sun;Choi, Hyun-Sun;Won, Min-Gu;Huh, Nam-Su
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.16 no.1
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    • pp.65-73
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    • 2020
  • Integrity evaluations on a platen superheater were conducted as per ASME Section VIII Division 2(hereafter 'ASME VIII(2)') which was originally used for design with implicit consideration of creep effects. A platen superheater subjected to severe loading conditions of high pressure and high temperature at creep regime in a supercritical thermal plant in Korea was chosen for present study. Additional evaluations were conducted as per nuclear-grade high-temperature design rule of RCC-MRx that takes creep effects into account explicitly. Comparisons of the two results from ASME VIII(2) and RCC-MRx were conducted to quantify the conservatism of ASME VIII(2). From present analyses, it was shown that the design evaluation results exceeded allowable limits of RCC-MRx for the plant design conditions although limits of ASME VIII(2) were satisfied regardless of operation time, which means that design as per ASME VIII(2) might be potentially non-conservative in case of operation in creep range. A high-temperature design evaluation program as per RCC-MRx, called 'HITEP_RCC-MRx' has been used and it was shown that pressure boundary components can be designed reliably with the program especially for the loading conditions of long-term creep conditions.

Aberrant Methylation of the 1p36 Tumor Suppressor Gene RIZ1 in Renal Cell Carcinoma

  • Ge, Peng;Yu, Xi;Wang, Zi-Cheng;Lin, Jian
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.4071-4075
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    • 2015
  • Background: Retinoblastoma protein-interacting zinc finger gene 1(RIZ1) functions as a tumor suppressor. Hypermethylation-mediated RIZ1 silencing has been reported in several cancers, but not in renal cell carcinoma (RCC) yet. Materials and Methods: We examined the RIZ1 expression and methylation in a panel of RCC cell lines and 50 primary tumors using semiquantitative/quantitative polymerase chain reaction (PCR), methylation specific PCR, and bisulfite sequencing genomic. We also explored the relationship between methylation status of RIZ1 and clinicopathological features in RCC patients. Results: RIZ1 expression was down-regulated or lost in OS-RC-2, 769-P, Caki-1, 786-O and A498 RCC cell lines. Restored expression of RIZ1 was detected after addition of 5-aza-2'-deoxycytidine with/without trichostatin A, suggesting that DNA methylation directly mediates its silencing. The RIZ1 expression was significantly reduced in RCCs compared to adjacent non-malignant renal samples (P<0.001). Aberrant methylation was detected in 15 of 50 (30%) RCCs and in 2 of 28 (7%) adjacent non-malignant renal samples (P=0.02). No statistically significant correlation between methylated and unmethylated cases with regard to age, gender, pathological stage and grade was observed. Conclusions: RIZ1 expression is down-regulated in human RCC, and this down-regulation is associated with methylation. RIZ1 methylation may play a role in renal carcinogenesis.

Effect of Different Organic Fertilizers on Performance and Disease Occurrence in Seedling 'Niitaka' Pear Trees (유기질 비료의 시용이 '신고' 배 실생묘의 생육 특성과 병 발생률에 미치는 영향)

  • Li, Xiong;Kim, Wol-Soo;Choi, Hyun-Sug
    • Korean Journal of Organic Agriculture
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    • v.18 no.1
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    • pp.55-62
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    • 2010
  • The study was conducted to investigate effects of different organic fertilizers on 'Niitaka' pear tree performances in a controlled greenhouse. The four 'Niitaka' pear seedling trees per treatment were grown in a greenhouse for 6 months. Each pot was filled with control, rice bran (RB), coffee bran compost (CBC), and the mixture (RCC) of RB + CBC + chitin incubated compost (CIC). Each pot was filled with 1:1:1 (v/v/v) of soil : sand : fertilizer, and control, RB, CBC, CIC, and RCC were applied as treatments. Root fresh weights and root activities were increased by all the organic fertilizers, especially by RCC. RCC treated trees had the highest tree height and thickest tree trunk, and all organic fertilized trees showed increased tree growth compared to the control. The more diseased and damaged degrees on the leaf by spider mites increased leaf falling rates on all the treatments. The reduced diseased and healthy leaves were found on RCC treated trees that had better tree performance. Also, all the organic fertilized trees seemed to prevent the occurrence of disease in the leaf. Therefore, the organic fertilizer applications could be a good strategy to obtain better tree performance and maintain healthy seedlings in the nursery market or young organic pear orchard.

Optimum Compaction Test of Roller Compacted Concrete Pavement (롤러전압 콘크리트포장의 적정 다짐실험 방안 고찰)

  • Chung, Gun Woo;Lee, Seung Woo
    • International Journal of Highway Engineering
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    • v.17 no.3
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    • pp.27-33
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    • 2015
  • PURPOSES : To ensure appropriate RCC properties with sufficient strength development and workability, it is necessary to secure a proper level of consistency. It is also necessary to secure maximum dry density, which is an important factor for increasing the interaction of aggregate interlocking, leading to an augmentation of RCC strength. On the other hand, the dry density of RCC can be changed owing to the compaction conditions, water content, and particle size distribution. A Proctor test and a modified Proctor test were used for determining the optimum water content needed to achieve maximum dry density with different amounts of compaction energy. A Vebe test, on the other hand, was used for checking the level of consistency, which is important for producing a workable mixture. METHODS : To confirm the degree of compaction at various particle sizes, RCC mixtures with different sand/aggregate ratios were evaluated. The Proctor test and modified Proctor test were applied to these mixtures to check the effect of the aggregate gradation and compaction energy on the maximum dry density and optimum water content. During each test, three specimens were produced for all types of water content under each aggregate gradation. A compaction curve and the optimum water content and maximum dry density for each aggregate gradation were then obtained for both tests. The range of water content for the appropriate consistency of each aggregate gradation was determined through a Vebe test. The optimum water content was then evaluated based on this range. RESULTS : The compaction test results show that the modified Proctor test provides a higher maximum dry density and lower optimum water content compared with the standard Proctor test. For the modified Proctor test, two cases of aggregate gradation (s/a = 30% and 70%) had the optimum water contents outside of the appropriate water content range. For the standard Proctor test, on the other hand, none of aggregate gradations provided the optimum water content within the desired range. CONCLUSIONS : The modified Proctor test should be used for an RCC mixture design because it can provide adequacy between maximum dry density and consistency. Moreover, the compaction roller has become highly developed for higher compaction energy.