• Title/Summary/Keyword: residual value

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A Study on the Vent Path Through the Pressurizer Manway and Steam Generator Manway under Loss of Residual Heat Removal System During Mid-loop Operation in PWR (가압경수로의 부분충수 운전중 잔열제거계통 기능 상실사고시 가압기와 증기발생기 Manway 유출유로를 이용한 사고완화에 관한 연구)

  • Y. J. Chung;Kim, W. S.;K. S. Ha;W. P. Chang;K. J. Yoo
    • Nuclear Engineering and Technology
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    • v.28 no.2
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    • pp.137-149
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    • 1996
  • The present study is to analyze an integral test, BETHSY test 6.9c, which represent loss of RURS accident under mid-loop operation. Both the pressurizer manway and the steam generator outlet plenum manway are opened as vent paths in order to prevent the system from pressurization by removing the steam generated in the core. The main purposes are to gain insights into the physical phenomena and identify sensitive parameters. Assessment of capability of CATHARE2 prediction can be established the effective recovery procedures using the code in an actual plant. Most of important physical phenomena in the experiment could be predicted by the CATHARE2 code. The peak pressure in the upper plenum is predicted higher than experimental value by 7 kPa since the differential pressure between the pressurizer and the surge line is overestimated. The timing of core uncovery is delayed by 500 seconds mainly due to discrepancy in the core void distribution. It is demonstrated that openings of the pressurizer manwey and the steam generator manway can prevent the core uncovery using only gravity feed injection. Although some disagreements are found in the detailed phenomena, the code prediction is considered reasonable for the overall system behaviors.

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Numerical Modeling of Circulation Characteristics in the Kwangyang Estuarine System (광양만 권역의 해수순환 수치모델 실험)

  • Kim, Baek Jin;Ro, Young Jae;Jung, Kwang Young;Park, Kwang Soon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.4
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    • pp.253-266
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    • 2014
  • The ECOM3D is used to study the circulation characteristics and density current from the Sumjin River runoff in the Kwangyang Estuarine System, South Sea, Korea. Annual mean value of $120m^3/s$ was imposed from the Sumjin River. The numerical model results in terms of tidal height, current and salinity field show satisfactory with skill scores over 90%. The current velocity showed the range of 1~2.5 m/s during flood and ebb phases. In particular, very strong flow occur in the narrow Channels of Noryang, Daebang and Changson exceeding over 2.0 m/s. The tidal residual currents in the various locations in the Kwangyang Estuary showed the range of 1~21 cm/s, The density-driven current through the Yeosu and Noryang Channels are about 12 cm/s and 4 cm/s, respectively. The current path through the Yeosu Channel is deflected toward west Bank. Based on budget analysis of the volume flux, the volume flux through the Yeosu Channel and the Noryang Channel were estimated to be 97.4 and $22.1m^3/s$ accounting for the 81.5% and 18.5% of total flux, respectively.

Seasonal Monitoring of Residual Veterinary Antibiotics in Agricultural Soil, Surface Water and Sediment Adjacent to a Poultry Manure Composting Facility (계분 퇴비화 시설 인근 농경지 토양, 지표수 및 저질토의 계절별 잔류 항생물질 모니터링)

  • Lee, Sang-Soo;Kim, Sung-Chul;Kim, Kwon-Rae;Kwon, Oh-Kyung;Yang, Jae-E.;Ok, Yong-Sik
    • Korean Journal of Environmental Agriculture
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    • v.29 no.3
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    • pp.273-281
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    • 2010
  • Concentration of antibiotics including a tetracycline group (TCs) of tetracycline (TC), chlortetracycline (CTC), and oxytetracycline (OTC), a sulfonamide group (SAs) of sulfamethoxazole (SMX), sulfathiazole (STZ), and sulfamethazine (SMT), an ionophore group (IPs) of lasalocid (LSL), monensin (MNS), and salinomycin (SLM), and a macrolide group (MLs) of tylosin (TYL) was determined from samples collected from the agricultural soil, stream water, and sediment. For the agricultural soil samples, the concentration of TCs had the highest value among all tested antibiotic's groups due to its high accumulation rate on the surface soils. The lower concentrations of SAs in the agricultural soils may be resulted from its lower usage and lower distribution coefficient (Kd) compared to TCs. The concentration of TCs in stream water was significantly increased through June to September. It would be likely due to soil loss during an intensive rainfall event and a reduction of water level after the monsoon season. A significant amount of TCs in the sediment was also detected due to its accumulation from runoff, which occurred by complexation of divalent cations, ion exchange, and hydrogen bonding among humic acid molecules. To ensure environmental or human safety, continuous monitoring of antibiotics residues in surrounding ecosystems and systematic approach to the occurrence mechanism of antibiotic resistant bacteria are required.

Use-friendly Active Packaging of Powdered Infant Formula in Single-serve Portion Augmented with Anti-oxidative Function (산화억제 가능성과 사용편의성을 가진 일회성 조제분유 포장)

  • Lee, Hye Lim;An, Duck Soon;Lee, Dong Sun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.25 no.3
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    • pp.95-99
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    • 2019
  • In the modified atmosphere packaging of powdered infant formula, the oxygen inside the package may cause its quality deterioration and needs to be minimized for quality preservation. A way of oxygen scavenger inclusion in the single-serve package without contacting the product was devised for removing oxygen residing initially and permeating through the seal layer during the storage. A polyethylene/pulp multi-layer porous filter bag of 5 × 7 cm containing 13 g of powdered infant formula was packaged in an 8 × 9 cm size aluminium laminated film package with a Fe-based oxygen scavenger of 1.8 g. After nitrogen flushed packaging, the active packages were stored at 30℃ for 254 days with periodical quality measurement. The active package could remove the initial residual oxygen of 1.4% completely and maintain absence of oxygen for the whole storage, which contributed to reduced oxidation observed in lower product peroxide value compared to that of the product in the control package. There was no influence of packaging treatment on content of 5-hydroxymethylfurfural, reaction product of initial nonenzymatic browning. The devised oxygen-scavenging single-serve package showed a potential to improve the preservation of infant formula powder and extend the shelf life.

INFLUENCE OF COOLING RATE ON THERMAL EXPANSION BEHAVIOR AND FLEXURAL FAILURE OF PFM SYSTEMS (도재 냉각방법의 차이가 금속-도재간 열팽창 양상과 결합력에 미치는 영향)

  • Lim, Ae-Ran;Lim, Ho-Nam;Park, Nam-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.28 no.1
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    • pp.165-191
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    • 1990
  • Although a number of studies have been performed to assure that residual stress caused by a mismatch of alloy porcelain thermal expansion can contribute to clinical failure of a ceramometal restoration, the interactive influence of cooling rate on the magnitude of thermal expansion difference and on bond strength between them have not been extensively analyzed. The objective of this study was to determine the influence of cooling rate and the number of firing cycles on the expansion mismatch and the flexural failure resistance of metal porcelain strip. Tested alloys included one Pd-Ag alloy, one Ni-Cr-Be alloy with two kinds of porcelain, Vita and Ceramco. Metal specimens were cast into rods with a height of 13mm and a diameter of 5mm. Subsequently, the castings were subjected to scheduled firing cycles without porcelain. And the porcelain specimens after being fired were trimmed into a bar with a final dimension of $5{\times}5{\times}25mm$. Thermal expansions of the alloys and porcelains were measured by using a push rod or a differential dialometer respecitvely. Porcelain glass transition temperatures and expansion values were derived alloy-porcelain pairs were assessed by comparing expansion values of the components at a porcelain glass transition temperature. Calculations were made using combinations of a Ni-Cr alloy or Pd-Ag alloy with each of two porcelain products. Metal-porcelain strip specimens were subjected to four point loading in an Instron testing machine until crack occured at the metal-cramic interface at the time of sharp decrease of load on recorder. On the basis of this study, the following conclusions may be stated: 1. Regardless of the kinds of ceramometal combinations, both of calculated and experimental data revealed that the double fired specimens exhibited a significantly lower flexural strength. 2. By the rise of the amount of mismatch, bond strength were decreased. 3. Thermal expansion value of Pd-Ag alloys were higher than that of Ni-Cr alloys. 4. Expansion curves of metal were proportional to the increase of temperature and were not affected by the experimental conditions, however porcelains did not show the same magnitude of metal, and a shift of the glass transition temperature to higher temperatures was observed when cooled rapidly 5. Alloy-porcelain thermal compatibility appeared more dependent on the porcelain than the alloy.

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Prognostic Evaluation of Tumor-Stroma Ratio in Patients with Early Stage Cervical Adenocarcinoma Treated by Surgery

  • Pongsuvareeyakul, Tip;Khunamornpong, Surapan;Settakorn, Jongkolnee;Sukpan, Kornkanok;Suprasert, Prapaporn;Intaraphet, Suthida;Siriaunkgul, Sumalee
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.10
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    • pp.4363-4368
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    • 2015
  • Background: The tumor-stroma ratio (TSR) represents the percentage of neoplastic cell components compared to the combined area of neoplastic cells and the surrounding tumor-induced stroma. A low TSR (predomination of stromal component) has been demonstrated to be an independent adverse prognostic factor in cancers of several organs. In cervical carcinoma patients, TSR has been evaluated in only one previous study with different histological types. The present study aimed to assess the prognostic value of TSR in early stage cervical cancer patients with adenocarcinoma histology only. Materials and Methods: Histological slides of patients with early stage (IB-IIA) cervical adenocarcinoma who underwent surgical treatment between January 2003 and December 2011 were reviewed. Patients who had received preoperative chemotherapy were excluded. TSR was categorized as low (<50%) and high (${\geq}50%$). Correlations between TSR and clinicopathological variables were evaluated. Prognostic values of TSR and other variables were estimated using Cox's regression. Results: Of 131 patients; 38 (29.0%) had low TSR and 93 (71.0%) had high TSR. The patients with low TSR had significantly higher proportions of deep cervical stromal invasion (outer third of wall, p=0.011; residual stroma less than 3 mm, p=0.008) and parametrial involvement (p=0.026). Compared to the patients with high TSR, those with low TSR tended to have lower 5-year disease-free survival rate (83.8% versus 88.9%) and overall survival rate (85.6% versus 90.3%), although the differences were not statistically significant. Low TSR was significantly associated with decreased overall survival in univariate analysis (HR 2.7; 95% CI 1.0-7.0; p=0.041), but not in multivariate analysis. TSR was not significantly associated with decreased disease-free survival. Conclusions: Low TSR is associated with decreased overall survival in patients with early stage cervical adenocarcinoma treated by surgery. However, it was not found to be an independent prognostic predictor in this study.

Genetic correlations between first parity and accumulated second to last parity reproduction traits as selection aids to improve sow lifetime productivity

  • Noppibool, Udomsak;Elzo, Mauricio A.;Koonawootrittriron, Skorn;Suwanasopee, Thanathip
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.3
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    • pp.320-327
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    • 2017
  • Objective: The objective of this research was to estimate genetic correlations between number of piglets born alive in the first parity (NBA1), litter birth weight in the first parity (LTBW1), number of piglets weaned in the first parity (NPW1), litter weaning weight in the first parity (LTWW1), number of piglets born alive from second to last parity (NBA2+), litter birth weight from second to last parity (LTBW2+), number of piglets weaned from second to last parity (NPW2+) and litter weaning weight from second to last parity (LTWW2+), and to identify the percentages of animals (the top 10%, 25%, and 50%) for first parity and sums of second and later parity traits. Methods: The 9,830 records consisted of 2,124 Landrace (L), 724 Yorkshire (Y), 2,650 LY, and 4,332 YL that had their first farrowing between July 1989 and December 2013. The 8-trait animal model included the fixed effects of first farrowing year-season, additive genetic group, heterosis of the sow and the litter, age at first farrowing, and days to weaning (NPW1, LTWW1, NPW2+, and LTWW2+). Random effects were animal and residual. Results: Heritability estimates ranged from $0.08{\pm}0.02$ (NBA1 and NPW1) to $0.29{\pm}0.02$ (NPW2+). Genetic correlations between reproduction traits in the first parity and from second to last parity ranged from $0.17{\pm}0.08$ (LTBW1 and LTBW2+) to $0.67{\pm}0.06$ (LTWW1 and LTWW2+). Phenotypic correlations between reproduction traits in the first parity and from second to last parity were close to zero. Rank correlations between LTWW1 and LTWW2+ estimated breeding value tended to be higher than for other pairs of traits across all replacement percentages. Conclusion: These rank correlations indicated that selecting boars and sows using genetic predictions for first parity reproduction traits would help improve reproduction traits in the second and later parities as well as lifetime productivity in this swine population.

Characteristics of Sediments in the Kanghwa Tidal Flat on the west coast of Korea (한국 서해 강화 갯벌의 퇴적물 특성)

  • Woo, Han Jun;Bahk, Jang Jun;Lee, Yeon Gyu;Je, Jong Geel;Choi, Jae Ung
    • Journal of Wetlands Research
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    • v.6 no.1
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    • pp.167-178
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    • 2004
  • The southern tidal flat of Kanghwa Island is one of the biggest flats on the west coast of Korea. Tide is typically a semidiurnal with maximum range of about 10m. The tidal flat receives large amount of sediments from Han River system. Surface sediments for sedimentary analyses were sampled at 83 stations in the study area in August 2003. The surface sediments consisted of five sedimentary facies. Generally, sandy mud sediments dominated in the southern tidal flat of Kanghwa Island, whereas sand sediments dominated in channel and subtidal zones of the western part of Kanghwa Island. The area of sandy mud sediment extended to eastward tidal flat compared to sedimentary facies in August 1997. Sedimentary facies analysis of three core sediments from the tidal flat to the south of the Kangwha Island revealed three sedimentary facies: trough-cross-bedded sand, laminated silt, and bioturbated silt. Distribution of the facies in the cores suggested that sedimentation rates has been generally high in the margin of main tidal channel, especially in the east of the Donggeum Island. Twelve-and-half-hour anchoring survey was carried out for measurements of hydrodynamic parameters at Yeomha channel near Choji Bridge(K1) and channel near Donggeum Island(K2) in June 2003. Residual flows indicated strong ebb-dominated tidal currents. Depth-integrated net suspended sediment loads for one tidal cycle were seaward movement with 309,217.9kg/m and 128,123.1kg/m at station K1 and K2, respectively. The higher value of net suspended sediment loads at station K1 suggested that lots of suspended sediments from Han River deposited in the eastern part of tidal flat.

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A Feasibility Study on the Application of Self-Shielded Flux Cored Arc Welding Process for the On-Site Steel Bridge Box Fabrication (교량용 강재 박스의 현장 제조시 셀프실드 플럭스코어드 아크용접의 적용 타당성에 대한 연구)

  • Hwang, Yong-Hwa;Koh, Jin-Hyun;Oh, Se-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.2
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    • pp.122-128
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    • 2005
  • A feasibility study on the application of self?shielded flux cored arc welding to the on-site SM520 steel bridge box fabrication for express trains and high way construction instead of gas-shield flux cored arc welding was conducted in terms of weld soundness, mechanical properties, toughness and microstructures. All welded specimens made with the self?shielded FCAW process were tested by magnetic particle and ultrasonic techniques and they were found to be sound. All multipass weld specimens made with both self-shielded and gas-shielded FCAW processes showed yield and tensile strengths of $462{\sim}549\;MPa$ and $548{\sim}640\;MPa$, respectively. The impact values of Charpy V-Notch weld specimens also met with the required value of 40J at $-20^{\circ}C$. The hardness values of the top area of weldments were higher than those of the bottom area because of higher residual stresses in the near surface. It was found that welding characteristics of SM520 steel by the on-site welding conditions with self-shielded FCAW showed almost equivalent to those by gas-shielded FCAW in terms of sound welds, mechanical properties and microstructure.

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Power Loss and Electro-Magnetic Characteristics of Ni-Cu-Zn Ferrites (Ni-Cu-Zn페라이트의 손실과 자성 특성)

  • Otsuki E.;Kim Jeong-Su
    • Proceedings of the Korean Institute of Resources Recycling Conference
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    • 2004.12a
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    • pp.3-11
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    • 2004
  • The power loss analysis was carried out for Ni-Cu-Zn ferrite samples with different content of NiO and ZnO. The power loss, Pcv decreases monotonically wi increasing temperature and attains to a certain value at around $100\~120$ degrees Celsius. The frequency dependence of Pcv can be explained by $Pcv\~f^n$', and n is independent of the frequency, f up to 1MHz. The Pcv decreases with an increase in ZnO/NiO. The Pcv was separated to hysteresis loss, Ph and residual loss, (Pcv-Ph). The temperature characteristics and compositional dependence of Pcv can be attributed to the Ph, while (Pcv-Ph) is not affected by both temperature and ZnO/NiO. By analyzing temperature and composition dependence of Ph and initial permeability, ${\mu}^i$ following equations could be formularized. $${\mu}_i{\mu}o=I_x\;^2/(K_1+bs_ol_s)\;\;\;\;(1)$$ $Wh=13.5(I_s\;^2/{\mu}_i{\mu}_o)\;\;\;\;(2)$$ Were ${\mu}_o$ is permeability of vacuum, $I_s$ saturation magnetization, $K_1$ anisotropy constant, $S_o$ internal heterogeneous stress, $I_s$, magnetostriction constant, b unknown constant. Wh hysteresis loss per one cycle of excitation (Ph: Wh*f). Steinmetz constant of Ni-Cu-Zn ferrites, $m=1.64\~2.2$ is smaller than the one of Mn-Zn ferrites, which suggests the difference of loss mechanism between these materials.

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