• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.477-480
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• 2003

This study discusses the fundamental properties of cement mortar with the kinds and adding ratio of stabilizing agent of recycled water. According to the results, fluidity and air content hardly make difference by the kinds and adding ratio of stabilizing agent. When recycled water is used, setting time is shortened slightly in comparison with plain mortar because of an increase of fine particle. And it is similar to the use of recycled water in the case of A, Band D(stabilizing agent), but shortened significantly in the case of C. Also, it does not show difference with variation of the adding ratio, but as the adding ratio increases, it approach to the value of plain mortar. When recycled water is used, compressive strength is similar to plain concrete, and it shows the larger value in order of D, C and A. As the adding ratio of stabilizing agent increases, it decreases at 3days, but increases at 7 and 28days. However, at the adding ratio of 0.5%, it decreases, instead. Length change ratio by drying shrinkage increases in the case of B in comparison with plain mortar, but is similar to plain mortar in the other stabilizing agent. As the adding ratio of stabilizing agent increases, it decreases, however, increases at the adding ratio of 0.5%

• 설비공학논문집
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• 제13권8호
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• pp.692-700
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• 2001

Flow boiling heat transfer coefficients(HTCs) of R22, R134a, R407C, and R410A were measured experimentally for a horizontal plain and a microfin tube. Experimental apparatus was composed of 3 main parts: a refrigerant loop, a water loop and a water-glycol loop. The test section in th refrigerant loop was made of a copper tube of 9.52 mm outer diameter and 1 m length for both tubes. The refrigerant was heated by passing hot water through an annulus surrounding the test section. Tests were performed at a fixed refrigerant saturation temperature of $5^{\circ}C$ with mass fluxes of 100~300 kg/$m^2$s. Test results showed that at similar mass flux the flow boiling HTCs of R134a were similar to those of R22 for both plain and microfin tube. HTCs of R407C were similar to those of R22 for a plain tube but lower than those of R2 by 25~48% for a microfin tube. And HTCs of R410A were higher than those of R2 by 20~63% for a plain tube and were similar to those of R22 for a microfin tube. In general, HTCs of a microfin tube were 1.8~5.7 times higher than those of a plain tube.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1303-1314
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• 2021

The purpose of this study is to compare preferences of consumers between food items made from modified cassava flour and plain flour using sensory tests. This study is a qualitative research with an experimental approach and four food items, namely streamed brownies, cookies, fried mushrooms, and seasoning flour have been used for the study. Each of these food items are made from modified cassava flour and plain flour. Panelists wore blindfolds and tasted the food items except the seasoning flour. Based on the data analysis, the panelists have different preferences towards the four food items. The result of the paired Wilcoxon test showed that there is not any different preference in terms of taste of steamed brownies made from mocaf or plain flour, while there is a significant difference in terms of color, aroma, texture, and appearance between the steamed brownies made from mocaf and plain flour. Consumers decide to buy products made from mocaf because these products use local flour and are gluten-free. This article describes the customer's preference based on sensory analysis between products made from mocaf and ones made from plain flour. The result can be used as the basis for developing food items made from local flour and alternative food for customers allergic to gluten.

• Clinics in Shoulder and Elbow
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• 제24권1호
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• pp.15-20
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• 2021

Background: The presence of an acromial spur implies a rotator cuff disorder due to impingement between the acromial spur and the rotator cuff. The purpose of the study was to observe acromial spurs using ultrasonography and to compare measurements between plain radiographs and sonograms. Methods: We retrospectively enrolled 51 consecutive patients with acromial spurs, which were interpreted on preoperative plain radiographs (supraspinatus outlet view and 30° caudal tilt) and preoperative sonograms. The ultrasonography transducer was held vertically and continuously moved laterally, which corresponded to the long axis of the long head of the biceps. The distance from the most distal margin of the original acromion to the most projected point of the acromial spur was measured. Results: No significant difference was found between the plain radiograph and ultrasonography measurements (p=0.186). A moderate to strong correlation was detected between the ultrasonography and supraspinatus outlet-view measurements (r=0.776, p=0.000). Conclusions: Anteriorly projected acromial spurs were well-visualized by ultrasonography. No discrepancy in acromial spur length was detected between the use of plain radiography (supraspinatus outlet view and 30° caudal-tilt view) and ultrasonography. The correlation coefficients between the plain radiography and ultrasonography measurements exceeded 0.7.

• 한국건설순환자원학회논문집
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• 제4권4호
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• pp.117-124
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• 2009

본 연구에서는 FA 다량 치환 콘크리트의 품질 개선 및 기타 품질 향상을 목적으로 선행 연구에서 개발된 조강형 혼화제(GA)로 FA 다량 치환 콘크리트의 품질 향상 가능성을 평가하였다. 실험은 우선 FA 15%를 치환한 배합에 나프탈렌계 혼화제(이하 NA)를 사용한 것을 Plain으로 하였고, FA 20, 25% 및 30%를 치환한 경우, GA를 사용하여 콘크리트의 제반특성을 Plain과 비교 실험 하였다. 굳지 않은 콘크리트 특성으로 유동성은 GA를 사용할 경우 저하하므로 그 사용량을 증가시켜주어야 하는데, 단 W/B 60%의 경우는 Plain 보다 슬럼프 로스가 약 35~70 mm 감소하여 유리한 것으로 나타났다. 공기량은 FA 사용량 증가에 따라 FA에 포함된 미연소탄분의 AE제 흡착작용에 기인하여 감소함으로서 AE제 사용을 비례적으로 증가시켜 주어야함을 알 수 있었다. 블리딩은 FA 20%에서 블리딩 발생량이 가장 적게 나타나 블리딩 저감 효과를 기대할 수 있었다. 경화 콘크리트의 특성으로 응결시간은 GA를 사용한 경우 Plain과 동등한 수준으로 나타나, 응결 지연현상을 줄일 수 있는 것으로 판단된다. 압축강도는 W/B 및 양생온도와 관계없이 GA를 사용한 경우 Plain과 동등한 강도 발현을 확인 할 수 있었으나, FA 30% 치환한 경우는 사용상에 주의가 필요할 것으로 사료된다. 동결융해 저항성은 Plain보다 초기 값이 작게 나타났으나, 전반적으로 큰 차이가 아니기 때문에 내동해성 문제가 없을 것으로 판단된다. 촉진 중성화는 GA를 사용함에 따라, FA를 다량 사용할 경우 단점으로 지적되는 중성화 취약에 대한 문제는 어느 정도 해결 할 수 있을 것으로 분석되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 봄 학술발표회 논문집
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• pp.119-123
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• 1993

Axial load-strain relationships of confined concrete with spiral reinforcement were investigated. The main variables were compressive strength of concrete, spacing of hoop reinforcement, and specimen height of plain concrete. The program included tests of eleven confined specimens, and twelve plain specimens, but for all specimens no longitudinal reinforcement was provided. Load-strain curves of confined and plain concrete specimens are reporeted.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1990년도 봄 학술발표회 논문집
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• pp.116-121
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• 1990

Baxed on the results tested by various researchers, a complete stress-strain relation of plain and confined concrete is proposed. The peak strength and the corresponding strain are calculated by using the Mohr-Coulomb theory and elastic tri-axial constitutive relation. A parametric study was conducted to assess the influence of the plain concrete strength, the degree of confinement, the shape of the section, and the tie configuration for the square section. According to this model, the behavior of concrete section is predicted, and compared with experimental data and other proposed models on circular and square sections. A good agreement between theoretical and experimental results is observed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 추계 학술논문 발표대회
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• pp.85-86
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• 2016

Recently damages caused by the additional costs and degradation in durability combined deterioration due to plain concrete deterioration has occurred. In particular, in the case of the finish that is not exposed to the outside air in the concrete to respond to the harsh environment (freeze-thawing, calcium laying, etc.), to establish a quality control way for the process and the concrete mix design for it.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 추계학술발표대회 논문집
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• pp.64-69
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• 2001

In general, laminate effective orthotropic thermal conductivities are dependent on fiber and matrix material properties, fiber volume fraction and fabric geometric parameters. This paper deals with the predicting method of the transverse and the in-plane thermal conductivities of plain weave fabric composites based on the three dimensional series-parallel thermal resistance network. Thermal resistance network was applied to unit cell model that characterizes the periodically repeated pattern of plain weave. Also, an experiment apparatus is setup to measure the thermal conductivities of composite material. The numerical and experimental results of carbon/epoxy plain weave are compared.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.93-99
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• 2005

단공 분사기와 선회형 분사기의 두 가지 연료분사기에 대해 2상 유동 수치해석을 수행하였다. 단공 분사기의 경우, 캐비테이션 모델을 적용하여 압력조건에 따른 유출계수, 캐비테이션 발생 영역 크기와 정도를 계산하여 분석하였으며, 실험결과와도 비교하였다. 선회형 분사기에서는 VOF모델을 적용하여 두 가지 형상에 대해 공기코어의 크기, 분무각, 그리고 벽 압력 분포 등을 실험결과와 비교했다.