• Title/Summary/Keyword: different height

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Effect of Anode Gas Channel Height on Gas Diffusion and Cell Performance in a Molten Carbonate Fuel Cell (용융탄산염 연료전지 연료극 기체 유로 높이에 따른 가스 확산 및 단전지 성능 변화 연구)

  • Lee, Jung-Hyun;Kim, Do-Hyung;Kim, Beum-Ju;Kang, Seung-Won;Lim, Hee-Chun
    • Transactions of the Korean hydrogen and new energy society
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    • v.20 no.6
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    • pp.479-484
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    • 2009
  • The effect of anode gas channel height on gas diffusion and cell performance in a 100 $cm^2$ class molten carbonate single cell is investigated. Single cell separators with three different channel height are used. The effect of the gas channel height on the distribution of the reactive gas concentration is evaluated by the two-dimensional concentration diffusion equation. The overpotential caused by concentration drop with different channel height is estimated by the voltage decay related to diffusion of reactants, well known as concentration polarization, using limiting current density. The estimation could have the possibility to identify the reactant mass transfer polarization in the complicate factors of the overall electrodes.

Effect of Drainpipe Height and Media Composition on Growth and Yield of Soilless Cultivated Cut Rose in Container Culture (절화장미 용기재배 시 배수구 높이, 배지조성이 생육과 수량에 미치는 영향)

  • Choi, Gyeong-Lee;Cho, Myeong-Whan;Cheong, Jae-Woan;Roh, Mi-Young;Rhee, Han-Cheol
    • Journal of Bio-Environment Control
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    • v.19 no.4
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    • pp.240-245
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    • 2010
  • The objective of this study was to determine the effect of different height of drainpipe and growing media soilless cultivated cut rose in container culture. Two experiment were to examine the effect of the drainpipe height and media composition on yield and quality of cut rose, Four different drainpipe height (0, 3, 6, 9 cm) were treated to determine of optimal container type. Yield was the highest at 3 cm drainpipe height, but quality was not significantly affected by drainpipe height. Survival rate of rose was 100%, 100%, 92%, and 92%, respectively. Two different drainpipe height (0, 3 cm) and 7 media composition (pure coir and pelite, and mixed with two media 3 : 1, 2 : 1, 1 : 1, 1 : 2, 1 : 3 v/v) was treated to determine of media composition related to drainpipe height. The supply of nutrient solution was controlled by the signal of water potential at -5 kPa using frequency domain reflectometry (FDR) sensor in mixed coir with pelite 3 : 1, 1 : 1, 1 : 3 (v/v), respectively. Irrigation frequency reduced in high ratio of coir media and 3 cm height of drainpipe. Quality of cut rose except for flower weight and yield until 2nd harvest was not significantly affected by drainpipe height, but yield after 3rd was higher at 3 cm than 0 cm height of darinpipe. In the media composition, yield and qulity of cut rose was increased at high ratio of coir media.

Preparation of Diamond Thin film for Electric Device and Crystalline Growth (전자 디바이스용 다이아몬드 박막의 제조 및 결정성장 특성)

  • Kim, Gru-Sik;Park, Soo-Gil;Son, Won-Keun;Fujishiama, Akira
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1720-1723
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    • 2000
  • Boron doped conducting diamond thin film were grown on Si substrate by microwave plasma chemical vapor deposition from a gaseous feed of hydrogen, acetone/methanol and solid boron. The doping level of boron was controlled from 0ppm to $10^4$ppm (B/C). The Si substrate was tilted ca. 10$^{\circ}$ to make Si substrate have different height and temperature. Experimental results show that same condition but different temperature of Si substrate by height made different crystalline of diamond thin film. There were appeared 3$\sim$4 step of different crystalline morphology of diamond. To characterize the boron-doped diamond thin film, Raman spectroscopy was used for identification of crystallinity. To survey surface morphology, microscope was used. Grain size was changed gradually by different temperature due to different height. The Raman spectrum of film exhibited a sharp peak at 1334$cm^{-1}$, which is characteristic of crystalline diamond. The lower position of diamond film position, the more non-diamond component peak appeared near 1550$cm^{-1}$.

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A study on the Characteristics of Structural Proportion of Pillar and 'Kong-po' in 'Main Hall of Royal Palace(正殿)' of the Royal Palace (궁궐(宮闕) 정전(正殿)에서 기둥과 공포의 구조적(構造的) 비례특성(比例特性)에 관한 연구(硏究))

  • Park, Eon-Kon;Choi, Hyo-Sik
    • Journal of architectural history
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    • v.14 no.1 s.41
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    • pp.71-87
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    • 2005
  • 4 royal palaces are currently remained from capital city (Seoul) of 'Cho-Sun(朝鮮)' period. In these palaces, 'Main hall of Royal Palace(正殿)' is the center of the Royal Palaces. The 'Main hall of Royal Palace' of the Royal Palace was the best building of that time. Therefore there were many studies about the 'Main hall of Royal Palace'. But these studies were individual studies of these 'Main hall of Royal Palace'. Therefore, this study is to analyze and compare 4 'Main hall of Royal Palace' of the Royal palaces. It is to study the proportion regarding the Diameter of the pillar, the Height, the pillar and pillar Interval's Distance, and the arrangement of 'Kong-Po(bracket sets)'. With these studies, it is to prove that the 'Main hall of Royal Palace' is the building which high construction technique of this time is expressed. Result of this study is as followings; First, the proportion of pillar height(H) to its diameter(D) average from H=8.0 to 8.5D. Only the Myeong-Jeong-Jeon omitted the 'Go-Ju(高柱)' in the 'Toi-Kan (退間)' to place Ea-Jwa(御座). Second, Second, the proportion of diameter of the pillar of 'Eoi-Bu-Pyeong-Ju(外部平柱)' and 'Nae-Jin-Go-Ju(內陣高柱)' average D1(Diameter of 'Eoi-Bu-Pyeong-Ju') =0.91D2 (Diameter of 'Nae-Jin-Go-Ju'). In regards to the height, the single floor 'Main hall of Royal Palace' and double floor 'Main hall of Royal Palace' seems to be different. The height proportion of the double floor 'Main hall of royal palace' is H1(Height of 'Eoi-Bu-Pyeong-Ju')=0.34H2(Height of 'Nae-Jin-Go-Ju') and single floor 'Main hall of Royal Palace' has a proportion of H1=0.62H2. Third, in Geun-Jeong-Jeon, with the proportion of height and diameter of the pillar, interval's distance between pillars and diameter, the pillar interval distance and height, of 'Ea-kan(御間)' from the 'Toi-Kan' is different from 'Main hall of Royal Palace'. This is because the structure of 'Toi-Kan' of Geun-Jeong-Jeon is not stable. In order to reinforce this, 'Gui-Go-Ju(隅高柱)' of the Geun-Jeong-Jeon jut out $4{\sim}7%$ more compared to In-Jeong-Jeon. Fourth, when comparing double floor 'Main hall of royal palace' of Geun-Jeong-Jeon and In-Jeong-Jeon, based on distance of 'Eoi-Bu-Pyeong-Ju' and 'Nae-Jin-Go-Ju' of lower level, the 'Sang-Bu-Pyeong-Ju(上部平柱)' of Geun-Jeong-Jeon jut out $4{\sim}7%$ more compared to the In-Jeong-Jeon and also It becomes thicker. Fifth, the arrangement of 'Kong-Po' on the front row of 'Gan(間)' had to do with the change of side 'Gan'. Even though the Geun-Jeong-Jeon and the In-Jeong-Jeon were double floors, the arrangement of the 'Kong-Po' is different because the number of side bay is different.

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The effect of sleeve pattern on the ease of blouse -On sleeve cap height and sleeve length- (소매의 형태가 Blouse의 여유감에 미치는 영향 -소매산과 소매길이를 중심으로-)

  • 정혜락
    • Journal of the Korean Home Economics Association
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    • v.24 no.2
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    • pp.1-11
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    • 1986
  • The subject, in the blouses that sleeve caps and sleeve lengthes are different from, did sensory test by right arm movement and both arms movement. This sensory test which is used in fabric good, is Shef's. RESULTS : 1) The ease of bust size is very significant by cap height, at 5%, 1% level by sleeve length. 2) The front area of arm hole is affected by cap height, sleeve length movements more than the back and the under area of arm hole are 3) Sleeve width is affected by cap height, sleeve length both arms movement. That is, they should be designed according to the use because they affect the ease of blouse very much. Especially bust size should be considered with sleeve pattern because the ease bust becomes different with sleeve pattern.

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A Numerical Study on Flow Characteristics Around Rectangular Cylinder with Different Width-to-height Ratios (종횡비 변화에 따른 사각실린더 주위의 유동 특성에 관한 수치적 연구)

  • Park, Yong-Gap;Son, Chang-Min
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.8
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    • pp.523-529
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    • 2010
  • We investigate two-dimensional laminar flow around rectangular cylinders placed in a uniform stream. Numerical simulations are performed, using finite volume method, in the ranges of $50{\leq}Re{\leq}150$ and $0.1{\leq}W/H{\leq}1.0$, where Re and W/H are the Reynolds number and the width-to-height ratio, respectively. The immersed boundary method is used to handle the rectangular cylinder in a rectangular grid system. Comparisons with the previous results show good agreement in Strouhal number, drag and lift coefficient. The present study reports the detailed information of flow structure at different width-to-height ratios in the ranges of $50{\leq}Re{\leq}150$.

Influence of specimen height on the shear behavior of glass beads in the direct shear test

  • Young-Ho Hong;Yong-Hoon Byun;Jong-Sub Lee
    • Geomechanics and Engineering
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    • v.34 no.4
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    • pp.461-472
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    • 2023
  • A box scale affects the shear behavior of soils in the direct shear test. The purpose of this study is to investigate the scale effect on the shear behavior of dilative granular materials by testing specimens of different heights placed in a type C shear box. Experimental tests were performed on specimens composed of glass beads with different heights and equal initial void ratios. Results showed that the peak friction and dilation angles linearly increased with the specimen height; however, the residual friction angle remained relatively constant. Similarly, the shear stiffness increased with the specimen height, rapidly reaching its peak state. Height does not have a significant effect on the total volume changes; nevertheless, a high aspect ratio can be assumed to result in global and homogeneous failure. The results and interpretations may be used as reference for recommending shear box scale in direct shear tests.

The Effect of Keyboard Height on the Muscle Activity of the Upper Trapezius Muscle

  • Lee, Jun-Cheol;Baek, Hong-Seok
    • International journal of advanced smart convergence
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    • v.8 no.2
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    • pp.211-217
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    • 2019
  • This study is designed to reduce worker fatigue, improve efficiency and provide a functional working environment based on previous studies that pain occurs in the shoulder area, especially the upper trapezius muscle, when the keyboard height is not appropriate. In this study, the height of the keyboard is four, the height of the elbow and desk is the same height, the height of the desk is 3cm lower than the elbow, the height of the desk is 6cm high, and the height is 9cm high. When working on the keyboard, the wrist and forerunner were organized into four groups of 10 people so that the height was different for each group. When the height of the keyboard is given in various ways compared to the height of the elbow of the subject, it is verified whether there is a difference in the RMS (Root Mean Square) of the upper trapezius muscle. The results of this study showed that the muscle activity of the upper trapezius muscle cap was significant only in the left and right keyboard height -4cm, 0cm, +4cm, +8cm group, but the difference in muscle activity was not significant in the rest group. The first study will require a study of the control of the factors affecting the tension of the subjects, the measurement of muscle activity against various muscles, and whether the length of the shoulder and fingertips of the subject affect muscle activity according to the keyboard type.

Variation of Atmospheric Concentrations of Organochlorine Pesticides (OCPs) and Polychlorinated Biphenyls (PCBs) at Different Height (대기 중 유기염소계 살충제(OCPs)와 PCBs의 높이별 농도 변화)

  • Chun, Man-Young;Choi, Min-Kyu;Yeo, Hyun-Gu
    • Environmental Analysis Health and Toxicology
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    • v.23 no.3
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    • pp.201-211
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    • 2008
  • This study was performed to find the atmospheric concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) at four different heights (l0, 50, 150 and 1,500 cm) using low volume polyurethane foam (PUF) plug air sampler in semi-rural area. ${\alpha}-/{\beta}-/{\gamma}-HCH$ with low molecular weights and Koa (octanol-air partitioning coefficient) in OCPs were similarly high concentrations at all heights, but the other OCPs (p,p'-DDE, p,p'-DDD, p,p'-DDT, Heptachlor epoxide, ${\gamma}$-CHL, ${\alpha}$-CHL, Trans-nonachlor) with high molecular weights and Koa decreased with increasing heights. However, the concentrations of PCBs increased with increasing height.

A Study on the Daylight Distribution Analysis in different Height of Roller Shade in a Small Office (Roller Shade 높이 조절에 따른 사무소 건축물의 주광유입분포 분석에 관한 연구)

  • Lim, Ji-Sun;Kim, Yu-Sin;Choi, An-Seop
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.10a
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    • pp.17-20
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    • 2008
  • Available daylight in inside offers comfortable view environment, and psychological and physical advantages to people in the room. But, it has a problem of an excessive direct sunlight. This study analyzed daylight distribution characteristic by roller shade systems with a Mock-up test. With three 1/2 Scale Mock-up rooms, we performed a test of daylight distribution performance in different shade height of each room through the different height of roller shade. systems. This research will be used as a fundamental study for automated roller shade systems.

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