• Title/Summary/Keyword: U+box

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Study on Filling Capacity of Self-Consolidating Concrete for Modular LNG Storage Tank (모듈형 LNG 저장탱크용 자기 충전 콘크리트의 충전 성능평가 실용화 연구)

  • Lee, Dong Kyu;Lee, Keon Woo;Choi, Myoung Sung
    • Journal of the Korean Society of Safety
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    • v.33 no.6
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    • pp.50-57
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    • 2018
  • The purpose of this study is to evaluate the practical application of the self consolidating concrete for the steel concrete pannel (SCP) in module LNG storage tank proposed in the previous research. We evaluated the physical properties and filling performance of developed concrete for the SCP module. First, a slump flow test was conducted to evaluate the performance of the proposed guidelines for the filling test. As a result, all of the concrete used showed satisfactory performance. Based on the results of the previous study, it was found that the reliability of the required time measured by the $T_{500}$ test and the rheometer results measured before and after pumping was 0.94 which means the separation and blocking should not occur. The L-box test and the U-box test were conducted before and after pumping. All of the guidelines suggested showed satisfactory performance. SCP module for LNG storage tanks was fabricated on actual size scale to evaluate the practical application at the final site. As a result, it was confirmed that satisfactory filling performance was obtained in all the specimens.

Investigating the combination of natural and crushed gravel on the fresh and hardened properties of self-compacting concrete

  • Moosa Mazloom;Mohammad Ebrahim Charmsazi;Mohammad Hosein Parhizkari
    • Structural Monitoring and Maintenance
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    • v.11 no.1
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    • pp.1-18
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    • 2024
  • Self-compacting concrete is widely used around the globe today due to its special and unique properties. This study examines the effect of natural and crushed gravel combinations in different percentages in short-and long-term properties of concrete. The best utilized sand had a fineness modulus of 2.7. In the mentioned mix designs, silica fume was used with 0 and 7% of the weight of the cement. In order to check the properties of fresh and hardened concrete, 9 and 5 test types were performed, respectively. The carried out tests were slump flow, V-funnel, J-ring, L-box, U-box and column segregation for fresh concrete, and compressive, tensile and flexural strengths for hardened concrete. A mix with only 100% natural gravel was considered as the control mix. According to the results, the control mix design and the one containing 100% crushed gravel with silica fume were the best in fresh and hardened concrete tests, respectively. Finally, using the optimization method, a mix design with 25% natural gravel, 75% crushed gravel and silica fume was introduced as the best mix in terms of the results of both fresh and hardened concrete tests.

MIRIS 우주관측카메라 FM Dewar 설계

  • Cha, Sang-Mok;Mun, Bong-Gon;Jeong, Ung-Seop;Lee, Dae-Hui;Nam, Uk-Won;Park, Yeong-Sik;Lee, Chang-Hui;Park, Seong-Jun;Lee, Deok-Haeng;Ga, Neung-Hyeon;Han, Won-Yong;Park, Jang-Hyeon;Seon, Gwang-Il;Yang, Sun-Cheol;Park, Jong-O;Lee, Seung-U;Lee, Hyung-Mok;Matsumoto, Toshio
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.40.2-40.2
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    • 2010
  • MIRIS 우주관측카메라는 과학기술위성 3호의 주탑재체로서 $0.8{\sim}2.0{\mu}m$의 근적외선영역에서 우주배경복사와 우리은하 평면의 Pa-$\alpha$ survey 관측을 목적으로 한다. 이러한 임무를 수행하기 위해 MIRIS 우주관측카메라에는 MCT(HgCdTe) IR 검출기가 사용되고 6개의 필터를 장착할 수 있는 필터휠이 설계되었으며, 열잡음을 줄이고 원하는 SNR을 얻기 위해 모두 100K 이하로 냉각이 요구된다. 효과적인 냉각 및 저온유지를 위해서 외부의 열을 1차적으로 차단하는 Cryostat 외부용기와 100K 이하로 냉각되는 내부 Cold Box의 이중구조를 가지는 Dewar가 설계 되었다. 내부 Cold Box의 냉각은 소형 stirling cooler로 이루어지고 외부의 열 유입량이 Cooler의 냉각용량을 넘지 않도록 설계하였다. Cryostat 외부용기는 radiation cooling으로 냉각되어 200K 이하의 온도를 유지하며 내부 Cold Box로의 열유입을 최소화하기 위해 GFRP(Glass Fiber Reinforced Plastic) 단열 지지대와 MLI(Multi Layer Insulation)가 사용된다. 또한 100K으로 냉각시 필터고정부와 Cold Box 구조에서 일어날 수 있는 구조적인 피로도를 줄이고 열변형에 의한 문제를 방지하기 위한 고려가 설계에 포함되었다. FM(Flight Model)은 고진공 환경의 우주공간에서 문제가 발생하지 않도록 설계되었다. 또한 EQM 진동시험결과를 토대로 발사환경에서 발생하는 강한 진동을 견딜 수 있도록 FEM(Finite Elements Method) 구조해석을 통하여 필터고정부에 flexible structure 설계와 완충제를 추가하고 필터휠 구동부와 harness 고정부 및 cooler 지지부를 비롯한 전체 구조물에서 충분히 진동을 극복할 수 있도록 설계하였다.

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Analysis of the monopole antenna characteristcs of handy phone using Finite Difference Time Domain(FDTD) Method (시간영역 유한차분법을 이용한 휴대용 전화기의 모노폴 안테나 특성해석)

  • 손영수;윤현보
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.6 no.3
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    • pp.3-14
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    • 1995
  • The broadband input impedance, the input power and the radiation pattern of the monopole antenna attached to the handy phone operated at 800MHz are calculated by using the Finite Difference Time Domain(FDTD) Method. For the FDTD analysis of frequency characteristics of monopole antenna, the handy phone is modeled with the geometry that the monopole antenna is connected to a conducting box, and the modified FDTD algorithm[11] used the thin wire appproximation method and the Maxwell's integral equation from the original Yee algorithm is applied for the analysis of the wire structure. Also, by means of finding the current distribution directly from circumferencial magnetic filelds around the monopole antenna and the conducting box, the radiation pattern is calculated to observe the influence of the conducting box, and is compared with the results of the known mothod for the FDTD calculation of radiation pattern, For the experiments, the handy phone of which full length including antenna is .lambda. $\lambda$/2 is manufactured and we confirm that all computation results are agree well with the mea- sured values.

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Determination of La in $U_3Si/Al$ Spent Nuclear Fuel by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry (Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry에 의한 $U_3Si/Al$ 사용후핵연료 중 La의 분리 및 정량)

  • Han, Sun Ho;Choi, Kwang Soon;Kim, Jung Suk;Jeon, Young Shin;Park, Yang Soon;Jee, Kwang Yong;Kim, Won Ho
    • Analytical Science and Technology
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    • v.13 no.5
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    • pp.601-607
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    • 2000
  • Lanthanum has been used as one of the burnup monitor in spent nuclear fuel. $U_3Si/Al$ spent nuclear fuel contains small amount of La in high concentration of U and Al. Therefore, chemical separation of La is required to remove matrix elements. At first, ion chromatography (IC) and inductively coupled plasma systems were installed in radiation shielded glove box to handle the radioactive samples. Retention behavior of uranium, aluminum, lanthanum and some interesting fission products (Sr, Zr, Y, Mo, Ru, Pd, Rh, Cs, Ba, Ce, Pr, Nd, Sm, Eu and Cd) was investigated using the CG10 column and ${\alpha}$-HiBA eluent. As all elements were eluted earlier than lanthanum in 0.2 M ${\alpha}$-HiBA eluent, a portion of U and Al was directly passed to waste using a three way valve between the column and the nebulizer. Thus it was possible to determine the lanthanum in a high concentration of U and Al matrix. Retention time of La was about 12 minutes in this separation condition. Optimum range for the determination of La in $U_3Si/Al$ spent nuclear fuel was $1-10{\mu}g/L$ (ppb) with this system and detection limit was $0.25{\mu}g/L$ in case of $200{\mu}L$ of sample volume.

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Control of Seed-borne Infection of Ustilago nuda and Pyrenophora graminea on Barley (맥류(麥類)에 발생(發生)하는 Ustilago nuda 및 Pyrenophora graminea에 대한 종자(種子) 소독(消毒)에 관한 연구(硏究))

  • Lee, Du-Hyung
    • The Korean Journal of Mycology
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    • v.8 no.2
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    • pp.89-94
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    • 1980
  • Effects of seed disinfectants on loose smut (Ustilago nuda) and leaf stripe (Pyrenophora graminea) of barley were investigated in field tests. For these experiments, seed samples carrying natural infection of Ustilago nuda and Pyrenophora graminea were used and the following fungicides were used: Baytan, Baytan U, Benlate T, Busan 30, KAC-7703, P 242, Panoctine, Sisthane Ec, Sisthane Wp, Sisthane Ds, Sodium Omadine, Terracoat Zn, Vitathiram and Zinc Omadine, respectively. Results have shown that Sisthane and Benlate T have equal effect to Vitathiram against Ustil­ago nuda and Pyrenophora graminea. Baytan U was effective against loose smut but inferior to leaf stripe of barley. P 242 was effective against leaf stripe but inferior to loose smut of barley. Busan 30 have shown moderately inferior effect to Vitathiram against loose smut and leaf stripe of barley. A mild inhibition of seed germination and seedling growth of barley, naked barley and wheat seeds was observed when high concentration of Sisthane and Baytan U were treated in seedling box placed in green house conditions, but no symptom observed in field conditions.

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Molecular Cloning and Analysis of Phosphate Specific Transport (pst) Operon from Serratia marcescens KCTC 2172 (Serratia marcescens KCTC 2172로부터 pst operon의 클로닝 및 해석)

  • Lee, Seung-Jin;Lee, Yong-Seok;Lee, Sang-Cheol;Park, In-Hye;Ahn, Soon-Cheol;Choi, Yong-Lark
    • Journal of Life Science
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    • v.19 no.5
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    • pp.566-572
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    • 2009
  • A recombinant plasmid, pDH3, was obtained from the genomic library of Serattia marcescens KCTC 2172, and several recombinant subclones constructed from pDH3. The nucleotide sequence of a 5,137 bp segment, pPH4, was determined and three open reading frames were detected. The three ORFs encoded the phosphate specific transport (pst) operon, which was pstC, pstA, and pstB, with the same direction of transcription. Comparison of the pst operon of S. marcescens with that of other organisms revealed that the genes for pstS and phoU were missing. A potential CRP bonding site and pho box sequence was found in the upstream of the putative promoter at the regulatory region. Analysis of the nucleotide sequence showed that homology in amino acid sequences between the PstC protein and Yersinia sp., Vibrio sp., and Pseudomonas sp. were 49, 37 and 33%, respectively. The PstA protein and Yersinia sp., Vibrio sp., and Pseudomonas sp. showed homologies of 64, 51, and 47%, respectively. PstB protein and Methanocaldococcus sp., E. coli, and Mycoplasma sp. showed homologies of 60, 50, and 48%, respectively. The pst genes could be expressed in vivo and positively regulated by cAMP-CRP. The E. coli strain harboring plasmid pPH7, with pst genes, increased with the transport of phosphate.

A Study on Food Service for School Children -Provided by Dong Duck Elementary School in Daegu- (학교급식(學校給食)에 관(關)한 조사연구(調査硏究) -대구 동덕국민학교를 중심(中心)으로-)

  • Song, Wha-Sop
    • Journal of Nutrition and Health
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    • v.6 no.3
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    • pp.47-63
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    • 1973
  • This study concerns the nutritional status of food in a lunch-box and the school lunch program provided for Dong Duck Elementary School Pupils in Daegu. Two hundred andsix pupils were randomly selected as a sample. The nutrients contained in a lunch-box and school lunch menu were analyzed according to the Food Composition Table. Nutrients and cost of the Dong Duck Elementary School Lunch were compared to the average nutrient contents of food in a lunch-box of o pupil. In addition, comparisons between the Recommended Daily Allowances of nutrients for Korean children aged from 9 to 11 (4th, 5th, and 6th grade) and that of the contained nutrients in the average lunch-box were conducted. The average nutrients contained in the lunch-box compared with the Recommended Daily Allowances are: Calorie 77.41% (542.60ca1), Protein 73.60% (16.93gr), Fat 33.95% (3.95gr), Calcium 27.85% (111.39mg), Ferret 80.30% (2.65mg), Vitamin A 10.09% (100.93 I.U.), Vitamin Bl 70.27% (0.27mg), Vitamin B2 88.37% (0.38mg), Vitamin C 15.40% (3.45mg). All of the nutrients in the lunch-box fall far below the Recommended Daily Allowances for the 9-11 age group. The average nutrients of staple food in the lunch-box compared with the side-dishes were found to contain Calorie 90.80%, Protein 50.32%, Fat 58.27%, Calcium 37.07 %, Ferret 53.96%, Vitamin A 0.0028%, Vitamin B1 78.11%, Vitamin B2 21.09%. The nutrients of food contained in the Dong Duck Elementary School Lunch Program compared with the Recommended Daily Allowances were: 1. The Protein, Fat, Ferret, Vitamin B1 and Vitamin B2 content was generally satisfactory. 2. Calcuim, Vitamin A and Vitamin C were lower than the Recommended Daily Allowances. 3. The Calorie content was generally lower for the 9-11 age group. The per pupil cost of the lunch-box was 41.87 won which includes the cost of staple food 16.92 won and side-dishes 24.95 won, whereas the school lune Provided by Dong Duck Elementary School Costs 35 won per pupil. Questionnaires were sent to four hundred parents (through their children) to find out their attitude toward the school lunch program. 390(97.50%) of them were returned and 7 of them dia not answer at all. Therefore, these were eliminated from the samlpe. Among 185 parents whose children were eating the school lunch; 172 parents (92.97% ) would pay 40 won for the proposed new school lunch program whereas only 13 parents (7.03%) did not want it. Among 198 parents whose children were not having the school lunch, 58 parents (29.29%) would agree to have the lunch for their children at the cost of 35 won with the proposed new school lunch program equivalent to 40 won. 126 parents (63.63%) could not agree to have their children being the school lunch because of their financial difficulty (74 parents 58.72%). The rest of parents (52 parents 41.28%) raised other reasons which were minor problems. Among the tatal of 383 parents, 309 parents (80.68%) would agree to gave school lunch for their children if the cost of the proposed new school lunch program would be 35 won to 40 won and if minor problems concerning the school lunch program are solved. Sixty parents (15.66% ) raised questions about the school lunch program concerning sanitary problems, taste of bread, and the quantity of lunch. Among 383 parents, 358 parents answered and 25 parents did not. When school officer asked if the parents would help during the school lunch hour, 101 parents indicated they could not help at all, but 177 parents, replied they could help. Among 177 parents, 40 parents of them could share their time from one or two hours everyday except Saturday and 107 parents could serve 1 to 3 days per week. Through this study, it is evident that further investigation should be done of the school lunch program which can be provided 35 won with the proposed new school lunch program. The parents participation in the school lunch program would be improved the understanding between school and parents as well as insure better nutrition and sanitation for the children.

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Determinants of U. S. Theatrical Animation Box Office Performance (미국 극장용 애니메이션 흥행 결정요인 연구: 100대 흥행 애니메이션을 중심으로)

  • Kuem, Hyun Soo;Park, Su Kyeong;Han, Seo Yeon;Hong, Seon Yeong;Chon, Bum Soo
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.597-607
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    • 2013
  • This research examined factors in determining the success of theatrical U.S. animation movies. Based on movie characteristics and content factors, this study explore determinants of the success for animation movies. The results are follows: firstly, the success of animation movies were determined by some factors such as production expenses, the way of producing animation movies, sequential movies and viewer ratings. Secondly, there differences between the success in the U.S. and other countries. Although the success of animation movies in the U.S. were more production related factors, those in other countries were more quality related factors.

The Evaluation of Thermal Performance of Vacuum Glazing by Composition and the Pillar Arrangement through Test Method of Thermal Resistance (단열성 시험 방법을 통한 진공유리의 구성 및 필러 배치에 따른 열 성능 평가)

  • Cho, Soo;Kim, Seok-Hyun;Eom, Jae-Yong
    • Journal of the Korean Solar Energy Society
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    • v.35 no.1
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    • pp.61-68
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    • 2015
  • The advanced counties effort to the supplement of the zero energy buildings for the global building energy saving. In the middle of the development of passive technology, the government has to effort to the energy saving of buildings by enhanced performance of the window thermal insulation. By the method of enhanced performance of window thermal insulation, the use of vacuum double glazing saves the energy consumption in building. This glazing has low U-value(heat transmission coefficient) than normal double glazing. The vacuum glazing enhanced thermal insulation performance by vacuum space of between the glass and glass. For this vacuum glazing, pillar maintain the space between glass and glass. But this structure cause the raising the heat transmission coefficient in pillar approaching glass. This study confirmed the U-value by the test method of thermal resistance for windows and doors. Also this study confirmed the variation of heat transmission coefficient by the structure of vacuum glazing. And this study measured the surface temperature of the vacuum glazing about pillar approaching glass and vacuum space in cool chamber and hot box. That result, this study confirmed U-value of $0.422W/m^2{\cdot}K$ of vacuum glazing. Also this study confirmed U-value of $0.300{\sim}0.422W/m^2{\cdot}K$ by various the structure of vacuum glazing. And this study confirmed the heat flow in pillar approaching glass.