• 한국태양에너지학회 논문집
• /
• 제22권4호
• /
• pp.51-61
• /
• 2002

Analysis of thermodynamic design data of double effect solar absorption heat pump system for heating has been done to find the property of Libr-water + ethylene Glycol mixture for working fluid by computer simulation. Derived thermodynamic design data. enthalpy based coefficient of performance and flow ratio for possible combinations of operating temperature for water - LiBr and Ethylene Glycol mixture (H2O: CHO ratio 10:1 by mole) by computer simulation. The obtained results, COP and mass flow ratio of the water-lithium bromide-ethylene glycol system, are compared with data for the water-Libr pair solution.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
• /
• pp.691-694
• /
• 2004

The effects of polymer-cement ratio and antifoamer content on the setting time and durability of high-fluidity polymer-modified mortars using redispersible polymer powder are examined. As a result, the setting time of the polymer-modified mortars using redispersible polymer powder tend to delayed with increasing polymer-cement ratio, regardless of the antifoamer content. The water absorption and chloride ion penetration depth of the high-fluidity polymer-modified mortars using redispersible polymer powder decrease with increasing polymer-cement ratio and antifoamer content. The water absorption and chloride ion penetration improvement is attributed to the improved bond between cement hydrates and aggregates because of the incorporation of redispersible polymer powder.

• 한국수소및신에너지학회논문집
• /
• 제23권5호
• /
• pp.448-454
• /
• 2012

In this paper, a three-dimensional hydrogen absorption model is applied to a thin double-layered annulus ZrCo hydride bed and validated against the temperature evolution data measured by Kang et al. The present model reasonably captures the bed temperature evolution behavior and the 99% hydrogen charging time. The equilibrium pressure expression for hydrogen absorption on ZrCo is derived as a function of temperature and the H/M atomic ratio based on the pressure-composition isotherm data given by Konishi et al. In addition, this present model provides multi-dimensional contours such as temperature and H/M atomic ratio in the thin doublelayered annulus metal hydride region. This numerical study provides fundamental understanding during hydrogen absorption process and indicates that efficient design of the metal hydride bed is critical to achieve rapid hydrogen charging performance. The present three-dimensional hydrogen absorption model is a useful tool for the optimization of bed design and operating conditions.

• 한국건설순환자원학회논문집
• /
• 제8권4호
• /
• pp.506-513
• /
• 2020

본 연구에서는 무기계 혼화재료인 제올라이트 및 활성 황토를 혼입한 모르타르의 역학적 특성, 흡수율, NOx 저감 성능을 평가하였다. 제올라이트 및 활성 황토는 결합재로서 시멘트의 대체재로 사용되었으며 치환율은 각 20, 30%로 설정하였다. 각 배합의 압축강도 및 휨강도를 평가한 결과, Plain 배합에서 가장 높은 강도가 평가되었다. 제올라이트 및 활성 황토의 혼입율이 증가할수록 강도가 낮아지는 경향이 나타났다. 또한 활성 황토와 제올라이트 혼입 배합간의 강도 차이는 미미한 수준으로 나타났다. 흡수율을 평가하기 위해 기존의 배합의 물-결합재 비를 낮추고 활성 황토 및 제올라이트의 치환률을 25%로 설정한 배합을 설계하였다. 제올라이트 혼입 배합에서 가장 높은 흡수율이 평가되었으며, 나머지 두 배합 간에 흡수율의 차이는 매우 적었다. 광촉매 코팅의 유무를 고려한 NOx 저감 성능을 평가한 결과, 동일 배합이라 하더라도 광촉매를 코팅함에 따라 뚜렷한 NOx 농도 저감이 나타났다. 또한 제올라이트 및 활성 황토는 다공성 성질을 갖기 때문에 Plain 배합 보다 높은 NOx 감소 성능을 나타내었다. 활성 황토 배합의 경우 흡수율은 제올라이트 배합보다 낮은 값을 나타내었지만, 제올라이트 혼입 배합보다 뛰어난 NOx 저감 성능이 나타났다.

• 한국농공학회지
• /
• 제11권1호
• /
• pp.1604-1615
• /
• 1969

본(本) 실험(實驗)은 cement mortar를 고산용액에 침지(浸漬)시켜 산(酸)의 작용(作用)에 의(依)한 모르타르의 부식(腐蝕)이 모르타르의 물리적성질(物理的性質)에 미치는 영향(影響)을 구명(究明)하여 보다 내산성(耐酸性) 모르타르 또는 콘크리트의 배합설계(配合設計)에 기초자료(基礎資料)를 제시(提示)하고저 시도(試圖)하였던 바 그 결과(結果)를 요약(要約)하면 다음과 같다. 가. 공시체(供試體)는 5cm 입방체(立方體)의 모르타르로서 그 배합비(配合比)(중량(重量))는 1:1, 1:3, 1:5, 1:7, 1:10의 5종(種)을 제작(製作) 사용(使用)하였다. 나. 물리시험(物理試驗)에서는 재령(材令) 7일(日), 28일(日), 3개월(個月), 6개월(個月)의 압축강도시험(壓縮强度試驗)과 5시간(時間) 자비(煮沸)의 흡수율시험(吸水率試驗)을 하였다. 다. 산성시험(酸性試驗)에서는 0.1N-Hcl 용액(溶液)을 사용(使用)하고 7일간격(日間隔)으로 감량(減量)을 7주간(週間) 계속측정(繼續測定)하였다. 라. 물리적(物理的) 제성질(諸性質)인 배합비(配合比), w/c/비(比), 흡수율(吸水率), 압축강도(壓縮强度) 및 밀도간(密度間)의 상호관계(相互關係)는 다음식(式)으로 표시(表示)되었다. 1. 배합비(配合比)와 흡수율(吸水率)과의 관계(關係) Y=1.036X+13.53 여기서 Y : 흡수율(吸水率)(%), X: 배합비(配合比) 2. 배합비(配合比)와 w/c 비(比)와의 관계(關係) Y=0.214+0.204X 여기서 Y:w/c 비(比), X: 배합비(配合比) 3. w/c 비(比)와 흡수율(吸水率)과의 관계(關係) Y=5.01X+12.53 여기서 Y: 흡수율(吸水率)(%) X: w/c비(比) 4. 밀도(密度)와 흡수율(吸水率)과의 관계(關係) Y=50.6-0.0176X 여기서 Y: 흡수율(吸水率)(%) X: 밀도(密度)($kg/m^3$) 5. 밀도(密度)와 w/c 비(比)와의 관계(關係) Y=5.46-0.0024X 여기서 Y: w/c비(比) X: 밀도(密度)($kg/m^3$) 마. 7주간(週間) 0.1N-HCl 용액(溶液)에 침지후(浸漬後) 감량(減量)의 범위(範圍)는 배합비(配合比) 1:1에서 20.4%(最小), 1:10에서 9%(最大)이였다. 바. 감량(減量)과 물리적(物理的) 제성질(諸性質)과의 관계(關係)는 다음식(式)으로 표시(表示)되었다. 1. 감량(減量)과 배합비(配合比)와의 관계(關係) Y=8.59X+8.63 여기서 Y: 감량(減量)(%) X: 배합비(配合比)

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
• /
• pp.485-488
• /
• 2003

The results of an experiment on the sound absorption of the porous concrete using recycled aggregates and its influence on the compressive strength are reported in this paper. The content of recycled aggregate of 0, 10, 30, 50 and 70%, and the design void ratio of 30 percent for a given size of aggregate were used. In the compressive strength, an aggregate of the size of 5~13mm is much higher strength than that of the 13~20mm, In sound absorption experiment, the sound absorption ratio was is subjected to decreased as the content of recycled aggregates was increased. As a result, Porous concrete using recycled aggregates and by-products sufficiently have the performance of sound absorption.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
• /
• pp.62-65
• /
• 2003

In this study, to confirm corrosion of reinforced concrete affected by carbonation, chloride ion diffusion, absorption ratio, air permeability, measured carbonation velocity coefficient, chloride ion diffusion coefficient, absorption coefficient, air permeability coefficient. Corrosion velocity under environment of complex deterioration. And than compared corrosion velocity with these coefficients. As the results of this study, the correlation coefficient between chloride ion diffusion coefficients and absorption coefficient was revealed that it is very high. As well, an increase in carbonation, chloride ion diffusion also increases corrosion velocity. It showed that corrosion velocity was affected by the carbonation, chloride ion diffusion, absorption ratio, air permeability. Generally, data on the development of these coefficient made with none, organic B, organic A, inorganic B, and inorganic A is shown. It showed that coating of surface prevent steel bar from deteriorating.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2003년도 학술.기술논문발표회
• /
• pp.103.2-108
• /
• 2003

The purpose of this study is to understand the Physical characteristics of cement mortar about humidity control on indoors and wall crack restraint. Experiments were conducted on the strength, water absorption coefficient, drying-shrinking crack, length change, cracks of mortar plaster bases according to mixture rate by mixing cellulose fiber and diatomite into cement mortar. The excellent tensile & bending reinforcement efficiency of cellulose fiber and void filling ability of diatomite proved to be suppressing cracks of cement. And diatomite seems to improve moisture-protection efficiency of cement mortar because of its high water absorption ratio and slow drying speed.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 하계학술대회 논문집
• /
• pp.5-8
• /
• 2000

The population density of excited species in dc, rf and laser ablation plume plasmas has been measured using laser absorption spectroscopy. It was shown that, when the plasma was modulated by on and off with, the sensitivity and signal to noise (S/N) ratio became high. For example, the atomic O(3$^{5}$ S$^{o}$ $_2$) Population density, No* in $O_2$/He mixtures was obtained by the highest S/N ratio at a frequency of 2.7kHz. In a 20Torr room air, the lowest No* level to be detectable was shown to be an order of 10$^{7}$ cm$^{-3}$ . The population densities of resonance Ar(1S$_2$) and Xe(1S$_4$) levels were also measured in barrier discharges and laser ablation plasmas.

• 한국표면공학회지
• /
• 제32권3호
• /
• pp.297-302
• /
• 1999

In situ measurement of infrared absorption spectra has been performed during low-temperature plasma-enhanced chemical vapor depositiion of silicon-oxide films using tetramethoxysilane as a silicon source. Several absorption bands due to the reactant molecules are clearly observed before deposition. In the plasma, these bands completely disappear at any oxygen mixing ratio. This result shows that most of the tetramethoxysilane molecules are dissociated in the rf plasma, even C-H bonds. Existence of Si-H bonds in vapor phase and/or on the film surface during deposition has been found by infrared diagnostics. We observed both a decrease in Si-OH absorption and an increase in Si-O-Si after plasma off, which means the dehydration condensation reaction continues after deposition. The rate of this reaction is much slower than the deposition ratio of the films.