• Title/Summary/Keyword: Expanded area ratio

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Characteristic of Light Weight Mortar using Waste Expanded Polystyrene and Expanded Polystyrene Beads (폐 발포폴리스티렌과 발포폴리스티렌 비드를 활용한 경량 모르타르의 특성)

  • Kang, Suk-Pyo;Hwang, Byoung-Il
    • Journal of the Korea Institute of Building Construction
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    • v.17 no.5
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    • pp.393-401
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    • 2017
  • This study presents an evaluation of basic properties of light weight mortar with expanded polystyrene bead(EPB) and waste expanded polystyrene(WEP) by varying replacement rations. In order to evaluate the basic properties of the light weight mortar with EPB and WEP, unit weight, compressive strength, flexural strength, water absorption ratio, thermal conductivity and distribution of polystyrene (EPB and WEP) in hardened mortar were performed. As a result, unit volume, compressive strength, bending strength, water absorption and thermal conductivity of light weight mortar were increased, but area distribution of polystyrene decreased with increasing the replacement ratio of WEP.

Does acellular dermal matrix expand in response to tissue expander inflation?

  • Yang, Chae Eun;Park, Kwang Hyun;Lee, Dong Won;Lew, Dae Hyun;Song, Seung Yong
    • Archives of Plastic Surgery
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    • v.46 no.1
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    • pp.34-38
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    • 2019
  • Background Acellular dermal matrices (ADMs) have recently become widely used in breast reconstruction, but the correlation between the final expander volume and the surface area of the ADM is not well understood. In this study, the expansion of the surface area of ADM and the expander volume was studied retrospectively in cases of acellular dermis-assisted tissue expander breast reconstruction. Methods Twenty cases of immediate breast reconstruction using an ADM-assisted tissue expander from January 2015 to December 2015 were evaluated. In all 20 cases, CGCryoDerm was used as the matrix, with a thickness of 1-3 mm. No slit incisions were made. Finally, the proportional increase in the area of the fully expanded ADM was compared to that of the tissue expander volume. Results The proportional increase in the ADM surface area was calculated to be from 1.1 to 2.46, with a mean value of 1.7. Additionally, under the assumption that the expander had a spherical shape, the increase in its radius (the cube root of its volume) was assessed. The range of the proportional increase in the expander radius was 1.1 to 2.24, with a mean value of 1.66. The proportional increase in the radius of the expanded ADM surface area ranged from 1.04 to 1.34, with a mean ratio of 1.28. Conclusions The results of this study confirmed that the ADM expanded when the tissue expander was inflated. However, the ADM expanded to a lesser extent than the tissue expander, indicating that the muscle and other tissues expanded more than the ADM when the tissue expander was inflated.

Performance Improvement Study of Propeller Propulsion Efficiency and Cavitation for the 8800TEU Class Container (8800TEU급 컨테이너선 프로펠러 추진효율 및 캐비테이션 성능향상 연구)

  • Ahn, Jong-Woo;Kim, Gun-Do;Kim, Ki-Sup;Park, Young-Ha;Ahn, Hae-Seong;Jung, Young-Jun;Yoon, Ji-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.6
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    • pp.453-460
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    • 2017
  • In order to investigate propulsion efficiency and cavitation characteristics for expanded area ratio variation of the 8800TEU class container propeller, a series of performance tests were conducted at Large Cavitation Tunnel (LCT) and Towing Tank (TT) in KRISO. The cavitation test of the existing propellers (KP1029 & KP1030) was conducted using FRP model ship in LCT. On the basis of LCT test results, it was required to design propeller with better propulsion efficiency and cavitation performance. Two propellers (KP1171 & KP1172) with decreased expanded area ratio were designed on the basis of KP1029 propeller. The new design propellers showed higher efficiency than KP1029 and reasonable cavitation performance. In the future, they will be applied as the standard propeller for the propeller design of the large container ship. Through the performance test and prediction results for the new design propellers, it is thought that high-load propeller with better propulsion efficiency and cavitation performance will be developed constantly.

An Experimental Study on Beam Strengthening of RC Buildings with Expanded Steel Plates in Rural Area (농어촌 지역 RC건축물 보의 철판망 보강에 관한 실험 연구)

  • Kim, Yoon IL;Hong, Si Hyun
    • Journal of the Korean Institute of Rural Architecture
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    • v.7 no.1
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    • pp.121-128
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    • 2005
  • This experimental study was conducted to investigate beam strengthening of RC buildings with expended steel plate(ESP) in rural area. Nine test specimens were manufactured, whose variables were tensile steel ratio and the amount and the shape of expanded steel plate. The test results indicated that strengthened beams with ESP showed the improvement of flexural strength of 50%~90%, and the beam strengthening of U type was excellent for shear reinforcement as well as flexural reinforcement, more over, the honeycomb shape of ESP and anchor bolts for development of ESP were very effective.

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Stabilization of Rhizosphere pH during Tomato Cultivation Using Expanded Rice Hull Substrate (양액재배용 평연화 왕겨 배지의 근권 pH 안정화)

  • 임상현;김경희;전신재;유근창
    • Journal of Bio-Environment Control
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    • v.10 no.2
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    • pp.95-100
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    • 2001
  • In countries that consumes rice as a main staple, rice hulls are natural resources composed of a large amount of organic compounds and high uniformity in size. Rice hulls are expanded to get rid of a defect in untreated rice hulls and to be used as a hydroponic substrate. Research on rice hulls is continuing for the agricultural application. This research was conducted to stabilize rhizosphere pH of the expanded rice hull substrates because of high pH caused by repeated use in ERH(expanded ride hull) substrates and without increasing the cost of developing new substrates. Sphagnum peatmoss (pH 3.0-4.0) wee mixed with the expanded rice hull substrate in the ratio of 10% (v/v), and this ratio kept the pH range of 6.0 to 6.5 in the root area of tomato plants during growth and at the time of harvest of tomato fruits. Also absorbtion of nutrients was highly increased. The yield increased from 1,051 to 1,266 kg per tomato plant which were harvested by two clusters.

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How Much Development Can a Rail Station Lead? A Case Study of Hong Kong

  • Xue, Charlie Qiuli;Sun, Cong
    • International Journal of High-Rise Buildings
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    • v.7 no.2
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    • pp.95-109
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    • 2018
  • Since the concept was first introduced in the 1970s, transit-oriented-development (TOD) has greatly expanded in East Asian cities such as Hong Kong. Rail stations are built together with clusters of residential-commercial towers and government services to form a new style of living - a "rail village." This paper examines the composition, scale, spatial form, organization and operation of several typical rail villages in Hong Kong. The cases range across those planned from the mid-1990s to 2015. Based on the analysis of the rail village composition, the paper derives a development ratio to indicate the density, effectiveness and efficiency of a rail village catchment area. The ratio provides a useful and direct figure for the comparison of different stations, cities and development modes.

A Study on the Functional Space Configuration and Area Distribution of Rural Public Health Center (농어촌 보건소의 기능별 공간구성 및 면적배분에 관한 연구)

  • Cho, Heeyoung;Yoon, Sohee;Kim, Suktae
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.22 no.1
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    • pp.51-61
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    • 2016
  • Purpose: To improve and establish functions for public health centers in rural public, an analysis will be done on arrangement plan and area by function for public health centers in farming and fishing villages. After finding out this relationship and architectural characteristics, spatial organization and area ratio for providing efficient medical service and the relationship between the two will be examined. Methods: 8 of them were selected and site visit and interview with the person in charge were conducted to investigate the current status. The drawings collected for analysis were input as CAD data and schematized. The relationship between the arrangement type and area for the public health centers in farming and fishing villages was analyzed and based on this, an analysis was done on agricultural scale and characteristics, and putting these analyzed results together, an appropriate method of improvement was proposed for spatial organization by function for public health centers in farming and fishing villages and to provide efficient service. Results: Firstly, the Plan types found in the public health centers in farming and fishing villages could be classified into three including single-type, multiple-type and radial-type. Secondly, according to an analysis of areas by function, in the case of treatment function, there was a difference in the area ration for selective treatment. This ratio is considered to be greatly influenced by the project each public health center focuses on. Thirdly, I could become aware of the relationship between spatial organization and area ratio based on the analysis of arrangement and area derived above. Implication: As the data to refer to in future research on spatial organization for public health centers, if the object of analysis becomes more expanded and investigated, it will be utilized in detail for spatial planning of public health centers, thereby being expected to contribute to more efficient and qualitatively enhanced medical service provided by public health centers.

Longitudinal Thermal Dispersion Enhancement by Oscillating Flow in a Grooved Channel (그루브 채널에서 왕복 유동에 의한 열확산 촉진에 관한 연구)

  • Kim, Seo-Young;Kim, Su-Hyeon;Kang, Byung-Ha
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.10 s.241
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    • pp.1075-1082
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    • 2005
  • The characteristics of longitudinal dispersion enhancement by the flow oscillation are numerically studied according to various groove geometries in a 2-D channel in the present study. The length of expanded section l$_{1}$/h$_{1}$ is varied from 0 to 8.75. The oscillating flow condition is given at both side ends, i.e., u = Asin ($2{\pi}ft$) The non-dimensional temperatures at both side ends are set to zero. The bottom and top walls are adiabatic. The local heat sources are located at the middle of the groove wall. In order to solve the governing equations, the SIMPIER algorithm is employed. The present results indicate that maximum longitudinal thermal dispersion can be achieved when the area ratio of the expanded section to the contracted section in the grooved channel becomes 1.

A Study on the Layout and External Space of High School in Gyeongnam Area (경남지역 고등학교의 교사배치와 외부공간 구성실태에 관한 연구)

  • Yang, Kum-Suek
    • Journal of the Korean Institute of Rural Architecture
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    • v.10 no.3
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    • pp.19-26
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    • 2008
  • The purpose of this study is to clarify the actual condition of external space general high schools newly established or planned in Gyeongnam from 2001 starting the 7th curriculum to 2006. The results of analysis about site plan type, composition state of external space and area ratio of its composition of each high school facilities are as follows: 1) In facilities arrangement of high schools, it shows diverse forms of arrangement from existing uniform straight type, however, most of schools do not being against the simple in their external space. 2) Comparing to traditional high school facilities, it occurs various types of plane and the area is somewhat expanded in the school with same class size, however, it needs to improve facility standards in its reality to deal with the change of future educational environment actively.

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Performance analysis of hubless rim-driven thruster based on the number of blades: a CFD approach (날개수에 따른 허브리스 림 추진기의 성능 분석 : CFD를 이용한 접근)

  • Hyoung-Ho KIM;Chang-Je LEE
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.60 no.1
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    • pp.80-86
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    • 2024
  • We analyzed the performance of hubless rim propellers based on the number of blades, maintaining a fixed pitch ratio and expanded area ratio, using computational fluid dynamics (CFD). Thrust coefficient, torque coefficient and efficiency according to the number of blades were analyzed. In addition, the pressure distribution on the discharge and suction sides of the blade was analyzed. As the advance ratio increases, the thrust coefficient decreases. The highest thrust was shown when the advance ratio was lowest. For the three, four, five and six-blades, the torque coefficient tended to decrease as the advance ratio increased. In the case of seven and eight-blades, the torque coefficient tended to increase as the advance ratio increased. The maximum efficiency was found when the advance ratio was 0.8. When the three-blade, it showed high efficiency at all advance ratios. A high pressure distribution was observed at the leading edge of the discharge blade, and a low pressure distribution was observed at the trailing edge. Applying a hubless rim-driven thruster with the three-blade can generate higher thrust and increase work efficiency.