• Title/Summary/Keyword: Scale-up

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Turbulent Enhancement of the Cooling System of Nuclear Reactor by Large Scale Vortex Generation in a Nuclear Fuel Bundles (원자로 연료봉내 대형 와유동에 의한 원자로 냉각제 시스템의 난류 증진)

  • 전건호;박종석;최영돈
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.11
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    • pp.1004-1011
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    • 2000
  • Experimental and computational studies were carried out to confirm the turbulent enhancement of the cooling system of nuclear reactor by large scale vortex generation in nuclear fuel bundle. The large scale vortex motions were generated by rearranging the inclination angles of mixing vanes to the coordinate directions. Axial development of mean and turbulent velocities in the subchannels were measured by the 2-color LDV system. Eddy diffusivity heat flux model and $k-varepsilon$ model were employed to analyze the turbulent heat and fluid flows in the subchannel. The turbulence generated by split mixing vanes has small length scales so that they maintain only about $10 D_H$ after the spacer grid. On the other hand, the turbulences generated by the large scale vortex continue more and remain up to $25 D_H$after the spacer gird.

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Effect of Alloying Elements of Si, Mn, Ni, and Cr on Oxidation of Steels between 1050℃ and 1200℃ in Air (강의 대기 중 1050~1200℃의 산화에 미치는 합금원소 Si, Mn, Ni, Cr의 영향)

  • Lee, Dong Bok
    • Korean Journal of Metals and Materials
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    • v.50 no.4
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    • pp.300-309
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    • 2012
  • Low-carbon steels and a stainless steel were oxidized isothermally and cyclically between $1050^{\circ}C$ and $1200^{\circ}C$ for up to 100 min in air to find the effect of alloying elements of Si, Mn, Ni, and Cr on their oxidation. The most active alloying element of Si was scattered inside the oxide scale, at the scale-alloy interface and as internal oxide precipitates beneath the oxide scale. Manganese, which could not effectively improve the oxidation resistance, was rather uniformly distributed in the oxide scale. Nickel and chromium tended to present at the lower part of the oxide scale. Excessively thick porous scales formed on the low-carbon steels, whereas thin but non-adherent scales containing $Cr_2O_3$ formed on the stainless steel.

A Study on the Face Image to Color of Make-up (색채 메이크업에 의한 얼굴이미지 연구)

  • Song, Mi-Young;Park, Oak-Reon;Ha, Jong-Kyung
    • Fashion & Textile Research Journal
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    • v.7 no.5
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    • pp.527-534
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    • 2005
  • The purpose of this research is to study face images according to color of make-up was made by computer graphic simulation. The various facial images can be helpful for choosing suitable make-up color planning. In order to find out the differences of face images by make-up color, three different foundations and seven eye-shadows, six lips were applied on the round face model. Make-up Image Scale was used the scale of seven point modified the S-D method. Data were analyzed by Varimax perpendicular rotation method, Duncan's Multiple Range Test, Three-way ANOVA. As the result of make-up image perception analysis, a factor structure was divided into mildness, modernness, elegance, unique. The factor of mildness, modernness, unique affected on the foundation color. Foundation color was found out to be influential variable to distinguish color perception abilities. Also, the foundation, eye-shadow, lip color were influenced interactively on the perception of elegance factor. Pink color was important color, influenced on the mildness factor. Gray and purple color were influenced on the modernness factor. Mildness factor was perceived as the most bright foundation but unique factor was perceived as the most dark foundation. Then, the foundation, eye-shadow, lip color were influenced interactively on the perception of facial images. The results can be effectively applied to today's marketing and color design management which is focused on the product's emotional image in customer's mind.

The Politics of Scale: The Social and Political Construction of Geographical Scale in Korean Housing Politics (스케일의 정치: 한국 주택 정치에서의 지리적 스케일의 사회적.정치적 구성)

  • Ryu, Yeon-Taek
    • Journal of the Korean Geographical Society
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    • v.42 no.5
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    • pp.691-709
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    • 2007
  • This paper investigates the social and political construction of geographical scale in conjunction with Korean housing politics. Recently, attention has been drawn to the issue of the social and political construction of geographical scale. Spatial scales have increasingly been regarded as socially constructed and politically contested rather than ontologically pregiven or fixed. The scale literature has paid attention to how different spatial scales can be used or articulated in social movements, with an emphasis on 'up-scaling' and 'scales of activism' rather than 'down-scaling' and 'scales of regulation.' Furthermore, the scale literature has focused on the aspect of empowerment. However, it is worthwhile to examine how scale-especially 'down-scaling' and 'scales of regulation'-can be used not only for marginalizing or excluding unprivileged social groups, but also for controlling the (re)production of space, including housing space. Under a regulatory regime, the Korean central government gained more control over the (re)production of housing space at geographical multi-scales by means of 'jumping scales,' specifically 'down-scaling.' The Korean central government has increasingly obtained the capacity to 'jump scales' by using not only multiscalar strategies for housing developments, but also taking advantage of various scales of institutional networking among the central and local governments, quasi-governmental institutions, and Chaebols, across the state. Traditionally, scale has been regarded as an analytical spatial unit or category. However, scale can be seen as means of inclusion(and exclusion) and legitimation. Choosing institutions to include or exclude cannot be separated from the choices and range of spatial scale, and is closely connected to 'scale spatiality of politics.' Facilitating different forms of 'scales of regulation,' the Korean central government included Chaebols and upper- and middle-income groups for the legitimization of housing projects, but excluded local-scale grassroots organizations and unprivileged social groups as decision-makers.

Scale, Untranslatability, Cultural Translation, and World Literature

  • Kim, Youngmin
    • Journal of English Language & Literature
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    • v.64 no.3
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    • pp.469-481
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    • 2018
  • When literatures and cultures encounter their counterparts in terms of the big data or statistics of a new reconfiguration in the cognitive map, the tangential points of the borderland will be reduced to what Mitchell calls "a mere abstraction on a map," which nevertheless will provide a vast interstitial zone of "intersections, competition, and exclusions." This zone will be the dynamic vortex for the aesthetics, politics, and ethics of cultural translation. The translated discourse will engage in carrying across the disturbing region of untranslatability and demonstrate how the literary texts of world literature reveal enriching but threatening human experience. This dynamic border of vortex will construct the translational space of world literature, transcending the fragmentary untranslatable nature of the hybrid convergence of the ethnic, racial, cultural and national intermixtures and constructing what Pascal Casanova terms "The World Republic of Letters." In this paper, I will demonstrate how the very concept of scale is related to literary space as well as how distance creates a poetics of literary landscapes which looks ahead of world literature. Also, I will attempt to find the possibility to relate the "micro-scale" with the "macro-scale," and to construct the scale politics of representation. "Glocalization" is a convenient theoretical tool for the double movement of the up-scale and down-scale.

Scaleup of Electrolytic Reactors in Pyroprocessing (Pyroprocessing 공정에 사용되는 전해반응장치의 규모 확대)

  • Yoo, Jae-Hyung;Kim, Jeong-Guk;Lee, Han-Soo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.7 no.4
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    • pp.237-242
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    • 2009
  • In the pyroprocessing of spent nuclear fuels, fuel materials are recovered by electrochemical reactions on the surface of electrodes as well as stirring the electrolyte in electrolytic cells such as electrorefiner, electroreducer and electrowinner. The system with this equipment should first be scaled-up in order to commercialize the pyroprocessing. So in this study, the scale-up for those electrolytic cells was studied to design a large-scale system which can be employed in a commercial process in the future. Basically the dimensions of both electrolytic cells and electrodes should be enlarged on the basis of the geometrical similarity. Then the criterion of constant power input per unit volume, characterizing the fluid behavior in the cells, was introduced in this study and a calculation process based on trial-and-error methode was derived, which makes it possible to seek a proper speed of agitation in the electrolytic cells. Consequently examples of scale-up for an arbitrary small scale system were shown when the criterion of constant power input per unit volume and another criterion of constant impeller tip speed were respectively applied.

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Intermediate Term Follow Up for R3 Sympathicotomy in Palmar Hyperhidrosis (수장부 다한증에서의 제3번 늑골 위 교감 신경(R3) 차단술의 중기 결과)

  • 손국희;김광호;백완기;김정택;김현태;김영삼;윤용한
    • Journal of Chest Surgery
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    • v.37 no.6
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    • pp.530-535
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    • 2004
  • Background: Thoracoscopic R3 (above the third rib)sympathicotomy has been performed as an effective method in treating palmar hyperhidrosis because it is effective in eliminating the symptoms of hyperhidrosis and has lower degree of compensatory hyperhidrosis than that of sympathectomy. Most of the results published were based on the short-term follow up. So we evaluated the intermediate term follow up results of the R3 sympathicotomy. Material and Method: From April 1999 to August 2001, ninety-four patients with palmar hyperhidrosis had been treated by R3 sympathicotomy at the Inha University Hospital. Follow-up study was completed for 76 patients (male 38, female 38) and average follow-up period were 25$\pm$9.1 (15∼50) months. The sympathetic trunk passing above the upper border of third rib was divided by electric cautery. The patient's satisfaction after surgery was estimated using the analogue scale from score 0 to 100 (100 means perfect satisfaction). Result. The scale of patient's satisfaction immediately after operation was 92.36$\pm$9.93. After 15 months, the scale of satisfaction was decreased to average 71.80$\pm$20.24 and it is statiscally significant. The cause of dissatisfaction were compensatory hyper-hidrosis and recurrence of symptom. The degree of sweating immediately after operation was mean 0 and after 15 months it increased to mean 1.5. The degree of the compensatory hyperhidrosis immediately after operation was mean 1 and it increased to mean 5 after 15 months. Conclusion: R3 sympathicotomy has excellent therapeutic results immediately after operation but therapeutic effectiveness is becoming to decrease 15 months after operation. The common causes of dissatisfaction are compensatory hyperhidrosis and recurrence of hyperhidrosis.

Production of Foamed Glass by Using Hydrolysis of Waste Glass(III) - Heat Treatment for Stabilization and Scale-up Test - (폐유리의 가수분해 반응에 의한 발포유리의 제조(III) - 안정화 열처리공정 및 Scale-up Test -)

  • Lee, Chul-Tae;Um, Eui-Heum
    • Applied Chemistry for Engineering
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    • v.17 no.1
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    • pp.73-81
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    • 2006
  • Heat treatment condition for the stabilization of foamed glass block through the foaming process of the hydrolized waste glass was investigated and scale-up test for the manufacturing of foamed glass was also attempted for the actual foaming process. Proper heat treatment condition was quenching from the foaming temperature to $550{\sim}600^{\circ}C$ for stabilization, and then annealing from stabilization temperature to $200^{\circ}C$ and holding up at $200^{\circ}C$ for removal thermal stress, and then annealing to the room temperature with cooling speed of $0.3^{\circ}C/min$. Through this heat treatment conditions, foamed glass block with size of $250mm{\times}250mm{\times}90mm$ was produced successfully. The properties of this foamed glass block showed density of $0.28{\pm}0.06g/cm^3$, thermal conductivity of $0.048{\pm}0.005kcal/hm^{\circ}C$, moisture absorption of $0.5{\pm}0.09vol%$, linear expansion coefficient of $(8.6{\pm}0.2){\times}10^{-6}m/m^{\circ}C$($400^{\circ}C$), flexural strength of $15.0{\pm}0.6kg/cm^2$, and compression strength of $39.5{\pm}0.6kg/cm^2$.

Strain Improvement and Bioprocess Optimization for Enhanced Production of Haluronic Acid(HA) in Bioreactor Cultures of Streptococcus zooepidemicus (히알루론산 생산성 향상을 위한 Streptococcus zooepidemicus 균주 개량 및 발효조 배양공정 최적화)

  • Kim, Soo Yeon;Chun, Gie-Taek
    • Microbiology and Biotechnology Letters
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    • v.48 no.3
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    • pp.344-357
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    • 2020
  • Strain improvement and bioprocess development were undertaken to enhance hyaluronic acid(HA) production by Streptococcus zooepidemicus cells. Using a high-yielding mutant strain, statistical medium optimization was carried out in shake flask cultures, resulting in 52% increase in HA production (5.38 g/l) at the optimal medium composition relative to the parallel control cultures. For sufficient supply of dissolved oxygen (DO), which turned out to be crucial for enhanced production of HA, agitation system and speed were intensively investigated in 5 L bioreactor cultures. Increase in oxygen mass transfer coefficient (kLa) through increment of agitation speed (rpm) and 35% expansion of diameter of the newly-designed impellers showed significantly positive effects on HA production. By installing an expanded Rushton-turbine impeller for efficient break-down of sparged air, and an extended marine impeller above the Rushton-turbine impeller for efficient mixing of the air-born viscous fermentation broth, maximum amount of HA (9.79 g/l) was obtained at 450 rpm, 1.8 times higher level than that of the corresponding flask culture. Subsequently, the possibility of bioprocess scale-up to a 50 L bioreactor was investigated. Despite almost identical maximum HA production (9.11 vs 9.25 g/l), the average HA volumetric productivity (rp) of the 50 L culture turned out only 74% compared to the corresponding 5 L culture during the exponential phase, possibly caused by shear damages imposed on the producing cells at the high stirring in the 50 L culture. The scale-up process could be successfully achieved if a scale-up criterion of constant oxygen mass transfer coefficient (kLa) is applied to the 50 L pilot-scale bioreactor system.

The follow-up study on patients of Amyotrophic lateral sclerosis after 1 year (근위축성 측삭경화증 환자 1년 후 추적 조사)

  • Kim, Hyun-Sik;Song, Bong-Kuen;Park, Man-Yong;Lim, Na-Ra;Kim, Sung-Ha;Kim, Sung-Chul
    • Journal of Pharmacopuncture
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    • v.13 no.1
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    • pp.121-128
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    • 2010
  • Objectives : This study was to investigate the effects of Oriental medical treatment on ALS. Methods : We investigated 12 ALS patients which were admitted to Gwang-Ju O.M.hospital for 3 months and follow-up at 8 months after discharge. All patients were treated by SAAM-acupuncture, herb medication, Bee venom Pharmacopuncture therapy, Needle-embedding therapy, etc and after discharge self-therapy at home. We evaluated patients using the Amyotrophic lateral sclerosis Functional Rating Scale-Revised(ALSFRS-R), Medical Research Council (MRC) Scale. Results : After 1 month, mean ALSFRS-R score of patients was $29.08{\pm}7.99$, 2 months $28.70{\pm}7.17$, 3 months $28.16{\pm}8.23$, 1 year $21.33{\pm}9.93$ and mean MRC Scale of patients was $25.34{\pm}8.45$, 2 months $25.34{\pm}8.45$, 3months $21.56{\pm}9.20$. But in both cases, the variation was not statistically significant. Conclusions : We think that the results of this case be a pilot study that proves the effect of Oriental Medical treatment on ALS.