[논문]반응성 골재의 입자 크기와 입도가 모르타르의 알칼리-실리카 반응 팽창에 미치는 영향

전쌍순,이효민,진치섭 釜山大學校生産技術硏究所 2003 生産技術硏究所論文集 Vol.62 No.-

골재의 알칼리-실리카 반응성을 판정하는 방법으로 모르타르 바 법 (Mortar-Bar method) 이 일반적으로 사용되고 있다. 본 연구에서는 알칼리 골재 반응성을 판정하는 모르타르 바 법 중에서 촉진시험법인 ASTM C 1260 시험방법을 이용하여 반응성 골재를 판별하고l 판별된 반응성 골재의 입자 크기와 입도가 모르타르의 알칼리-실리카 반응 팽창에 미치는 영향에 관하여 검토하였다. 그 결과I 반응성 골재의 입자 크기 및 입도에 상관없이 반응성 골재의 총표면적이 커질수록 팽창률도 증대하여,알칼리-실리카 반웅에 의한 팽창과 반웅성 골재의 총표면적과의 사이에는 상관관계가 있는 것을 확인할 수 있었다.

메타카오린의 포조란 효과에 의한 콘크리트 내 알칼리-실리카 반응 억제 효과

이효민,전쌍순,황진연,진치섭,윤지해,옥수석 한국광물학회 2004 광물과 암석 (J.Miner.Soc.Korea) Vol.17 No.3

알카리-실리카반응은 시멘트 내의 알칼리와 화학적으로 불안정한 반응성 골재와의 화학반응으로서, 그 결과 콘크리트의 팽창과 균열을 발생하는 작용이다. 본 연구에서는 우수한 포조란반응 특성을 나타내는 새로운 광물혼화재로 부각되고 있는 메타카오린의 알칼리-실리카반응 억제 효과에 대하여 연구하였다. 다양한 치환율로 메타카오린을 혼합한 모르타르 공시체를 제작하여, 알칼리-실리카 반응성 시험(ASTM C 1260), 압축강도 시험 및 유동성 시험을 실시하고, 시멘트 수화물에서의 구성성분 변화에 대한 XRD 정량분석을 실시하였다. 그 결과, 메타카오린의 혼합은 시멘트 페이스트내의 가용 포트랜다이트의 함량을 급속히 감소시키는 빠른 포조란반응 및 수화반응 특성을 나타내어, 알칼리-실리카 반응에 의한 팽창을 억제하고 우수한 압축강도를 발현하는 것으로 나타났다. 시멘트에 메타카오린의 혼합에 의한 알칼리-실리카 반응에 의한 팽창억제는 치환율 15% 이상, 즉 시멘트 페이스 내의 가용 포트랜다이트 함량이 약 10% 이하가 될 경우 효과적이다. 메타카오린의 혼합에 의한 알칼리-실리카 반응에 의한 팽창 억제는 유해성이 높은 알칼리-칼슘-실리카 겔의 형성이 억제된 결과와 포조란 효과에 의한 치밀하고 균질한 시멘트 페이스트 형성으로 인한 알칼리 용액의 침투가 억제된 결과에 의한 것으로 생각된다. 15% 이상의 메타카오린의 혼합은 보통의 모르타르보다 높은 초기강도를 발현하였으며, 후기강도는 전 치환율 범위에서 보통의 모르타르 이상의 아주 우수한 강도를 나타내었다. 강도발현 특징은 메타카오린에 의한 빠른 포조란반응 및 수화특성을 반영하고 있다. Alkali-silica reaction (ASR) is a chemical reaction between alkalies in cement and chemically unstable aggregates and causes expansion and cracking of concrete. In the present study, we studied the effects of metakaolin, which is a newly introduced mineral admixture showing excellent pozzolainc reaction property, on the inhibition of ASR. We prepared mortar-bars of various replacement ratios of metakaolin and conducted alkali-silica reactivity test (ASTM C 1260), compressive strength test and flow test. We also carefully anal zed the mineralogical changes in hydrate cement paste by XRD qualitative analysis. The admixing of metakaolin caused quick pozzolanic reaction and hydration reaction that resulted in a rapid decrease in portlandite content of hydrated cement paste. The expansion by ASR was reduced effectively as metakaolin replaced cement greater than 15%. This resulted in that the amounts of available portlandite decreased to less than 10% in cement paste. It is considered that the inhibition of ASR expansion by admixing of metakaolin was resulted by the combined processes that the formation of deleterious alkali-calcium-silicate gel was inhibited and the penetration of alkali solution into concrete was retarded due to the formation of denser, more homogeneous cement paste caused by pozzolanic effect. Higher early strength (7 days) than normal concrete was developed when the replacement ratios of metakaolin were greater than 15%. And also, late strength (28 days) was far higher than normal concrete for the all the replacement ratios of metakaolin. The development patterns of mechanical strength for metakaolin admixed concretes reflect the rapid pozzolanic reaction and hydration properties of metakaolin.

Xylan 분해균주인 Bacillus stearothermophilus의 오탄당 이용

이효선,조쌍구,최용진 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.4

강력한 xylan 분해 토양 분리균인 Bacillus stearothermophilus의 xylan 분해 주 산물인 xylose와 arabinose등의 pentose 이용과 pentose이용에 미치는 glucose와 기타 maltose 및 cellobiose 등의 효과를 분석하였다. 본 균주는 유일 탄소원으로 glucose를 가장 효율적으로 이용하였으며 다음으로 xylose와 ribose와 같은 pentose 그리고 maltose 등의 이당류도 잘 이용하였으나 glycerol은 전혀 이용하지 못하였다. 또한 glucose와 pentose 또는 xylooligomer와의 혼합 탄소원을 첨가했을 때도 B. stearothermophilus는 glucose를 우선적으로 이용하는 순서적 이용(sequential utilization) 현상과 더불어 전형적인 diauxic growth 양상을 나타내었다. 이에 비해 maltose와 pentose 혼합기질의 경우는 동시이용(co-utilization) 현상을 보였고 cellobios와 pentose 혼합물은 순서적 이용, 그리고 xylose와 arabinose의 pentose 혼합 탄소원인 경우는 두 탄소원을 동시에 이용하였다. 이와 같은 B. stearothermophilus의 탄소원 이용 특성은 glucose 대사관련 주요 효소인 hexokinase의 구성적 생산(constitutive production)과 이에 반한 ^D-xylose isomerase, ^D-xylulokinase 및 ^L-arabinose isomerase 등의 pentose 대사 주 관련 효소의 유도 생산(induced production)과 관계되는 효소 생산 조절 기작 내지는 inducer exclusion 현상을 비롯한 catabolite regulatory mechanism에 기인하는 것으로 설명할 수 있었다. Bacillus stearothermophilus, a potent xylanolytic bacterium isolated from soil, was tested for the strain's strategies of pentose utilization and the evidence of substreate preferences. The strain metabolized glucose, xylose, ribose, maltose, cellobiose, sucrose, arabinose and xylitol. The efficacy of the sugars as a carbon and energy source in this strain was of the order named above. The organism, however, could not grow on glycerol as a sole growth substrate. During cultivation on a mixture of glucose and xylose or arabinose, the major hydrolytic products of xylan, B. stearothermophilus displayed classical diauxic growth in which glucose was utilized during the first phase. On the other hand, the pentose utilization was prevented immediately upon addition of glucose. Cellobiose was preferred over xylose or arabinose. In contrast, maltose and pentose were co-utilized, and also no preference on between xylose and arabinose. Enzymatic studies indicated that B. stearothermophilus possessed constitutive hexokinase, a key enzyme of the glucose metabolic system. While, the production of ^D-xylose isomerase, ^D-xylulokinase and ^D-arabinose isomerase essential for pentose phosphate pathway were induced by xylose, xylan, and xylitol but repressed by glucose. Taken together, the results suggested that the sequential utilization of B. stearothermophilus would be mediated by catabolite regulatory mechanisms such as catabolite inhibition or inducer exclusion.

[논문]재생골재의 광물학적 및 화학적 특성과 동결융해 저항성

전쌍순,이효민,진치섭 釜山大學校生産技術硏究所 2003 生産技術硏究所論文集 Vol.62 No.-

급속한 산업화와 인구증가 및 대량소비에 따른 페기물에 의하여 초래되는 지구 환경오염을 위한 사회시스템의 구축이 필요함을 암시한다고 볼 수 있다. 본 연구에서는 지금까지 주로 저급재료로 사용되던 재생골재의 구성광물,화학조성 및 물리화학적 특성과 알칼리-골재 반응성 여부를 조사하고, 재생굵은골재의 대체율에 따른 콘크리트 강도와 동결융해 저항성을 검토하여 재생골재의 재활용을 위한 기초자료를 제시하고자 한다. 본 연구에 사용된 재생골재는 천연골재에 비교하여 공학적 기초 물성치에서 현저히 큰 차이는 나타내지 않았으며, 이를 사용한 재생콘크리트의 공학적 특성도 보통 콘크리트의 기준에 근접하는 것으로 나타났다.

쇄석 골재의 광물학적 및 화학적 특성과 알칼리-실리카 반응성

전쌍순,박현재,이효민,진치섭 釜山大學校生産技術硏究所 2002 生産技術硏究所論文集 Vol.61 No.-

본 연구에서는 쇄석 골재의 광물학적 및 화학적 특징과 알칼리-실리카 반응에 대한 골재의 유해 가능성을 연구하였다. 이를 위하여 알칼리-실리카 반응을 유발하는 광물들의 포함여부 및 이에 따라 잠재적으로 조기 열화현상을 유발할 수 있는 암석을 유형별(화성암, 변성암, 퇴적암 및 탄산염암)로 골재를 수집하였다. 암종 별로 선별하여 수집한 골재 내의 알칼리 반응성 유해 물질 존재 여부 확인 X선 회절분석(XRD)과 편광현미경에 의한 광물학적 방법을 사용하였다. 알칼리-실리카 반응성 유무해 판단을 ASTM C 227의 Mortar-Bar 시험방법에 의해 평가 분석하였고, 주 화학성분은 X선 형광분석기(XRF)로 실시하였다. In Korea, due to the shortcomings of natural aggregates and increasing needs of crushed stones, it is necessary to examine the alkali-silica reaction of the crushed stones. The purpose of this study is to analyze petrographic, chemical properties and alkali-silica reaction of crushed stones. This study was performed to investigate the alkali-silica reaction of crushed stones using chemical analysis, physical properties, XRD, XRF and mortar-bar method. As a result, most of test aggregates didn't show any reaction, but many test aggregates have common deleterious mineral. Therefore, there exists the possibility of chemical reaction in petrographic point of view.

Inhibitory Effects of Naringenin and Its Novel Derivatives on Hyaluronidase

Sun-Hee Moon,Kee-Tae Kim,Na-Kyoung Lee,Ye-Sun Han,Seung-Yeol Nah,Ssang Goo Cho,Yong-Sun Park,Hyun-Dong Paik 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.1

Naringenin is a bioactive flavanone containing antioxidative, anti-inflammatory, and anticarcinogenic properties. The inhibitory effects on hyaluronidase of naringenin and its novel derivatives were evaluated. Among these flavonoids at 200 μM concentration, 7-O-butyl naringenin had the highest inhibitory effect on hyaluronidase with 44.84%. In addition, For naringenin at concentrations of 0, 150, and 190 μM, the apparent Michaelis constants (appKm) were calculated to be 0.60±0.02, 0.43±0.02, and 0.41±0.01 ㎎/㎖ of substrate, respectively; for 7-O-butyl naringenin at 0, 20, and 30 μM concentrations, those were 0.44±0.03 and 0.27±0.03 ㎎/㎖, respectively. The Vmax values at 150 and 190 μM naringenin were 0.59±0.02 and 0.56±0.01 ㎎/㎖/min, respectively; and those at 20 and 30 μM 7-O-butyl naringenin were 0.50±0.02 and 0.33±0.02 ㎎/㎖/min, respectively. However, the slopes of each inhibitory reaction were not significantly different. Therefore, naringenin and 7-O-butyl naringenin were shown to be uncompetitive inhibitors. These results demonstrate the potential use of 7-O-butyl naringenin as an anti-inflammatory substance.

ASTM C 227과 ASTM C 1260에 따른 쇄석 골재의 알칼리-골재 반응성

잔쌍순(Jun, SSang Sun),이효민(Lee, Hyomin),진치섭(Jin, Chi Sub),황진연(Hwang, Jin Yeon),이진성(Lee, Jin Sung) 한국콘크리트학회 2003 한국콘크리트학회 학술대회 논문집 Vol.2003 No.5

Induction of Apoptotic Cell Death by Synthetic Naringenin Derivatives in Human Lung Epithelial Carcinoma A549 Cells

Lee, Eung-Ryoung,Kang, Yong-Jin,Choi, Hye-Yeon,Kang, Geun-Ho,Kim, Jung-Hyun,Kim, Bong-Woo,Han, Ye Sun,Nah, Seung-Yeol,Paik, Hyun-Dong,Park, Yong-Sun,Cho, Ssang-Goo Pharmaceutical Society of Japan 2007 Biological & pharmaceutical bulletin Vol.30 No.12

<P>Although flavonoids, which are both qualitatively and quantitatively one of the largest groups of natural products, exhibit a variety of beneficial health effects, the exact molecular mechanism of the cellular activities is still not fully explained and there currently exists a lack of evidence for any relationship between the structure–activity relationship and apoptosis-inducing activity. In order to determine the importance of the OH group or substitution of the 5 or carbon-7 in the diphenylpropane skeleton of flavonoids, we originally synthesized several modified naringenin derivatives, including 7-<I>O</I>-benzyl naringenin (KUF-1) and 7-<I>O</I>-(MeO-<SMALL>L</SMALL>-Leu-<SMALL>D</SMALL>-Pro-carbonylmethyl) naringenin (KUF-7). Treatment with KUF-1 or KUF-7 resulted in significant apoptosis-inducing effects concomitant with chromatin condensation, caspase activation, and intracellular ROS production. Our data indicate that originally synthesized naringenin derivatives, KUF-1 and KUF-7 differentially regulate the apoptosis of A549 cells <I>via</I> intracellular ROS production coupled with the concomitant activation of the caspase cascade signaling pathway, thereby implying that hydroxylation or substitution at Carbon-7 is critical for the apoptosis-inducing activity of flavonoids.</P>

Induction of apoptotic cell death by synthetic naringenin derivatives in human lung epithelial carcinoma A549 cells

Lee, Eung-Ryoung,Kang, Yong-Jin,Choi, Hye-Yeon,Kang, Geun-Ho,Kim, Jeong-Hyun,Kim, Bong-Woo,Han, Ye Sun,Nah, Seung-Yeol,Paik, Hyun-Dong,Park, Yong-Sun,Cho, Ssang-Goo 충남대학교 형질전환복제돼지연구센터 2007 논문집 Vol. No.10

Although flavonoids, which are both qualitatively and quantitatively one of the largest groups of natural products, exhibit a variety of beneficial health effects, the exact molecular mechanism of the cellular activities is still not fully explained and there currently exists a lack of evidence for any relationship between the structure-activity relationship and apoptosis-inducing activity. In order to determine the importance of the OH group or substitution of the 5 or carbon-7 in the diphenylpropane skeleton of flavonoids, we originally synthesized several modified naringenin derivatives, including 7-O-benzyl naringenin (KUF-1) and 7-0-(MeO-L-Leu-D-Pro-carbonylmethyl) naringenin (KUF-7). Treatment with KUF-1 or KUF-7 resulted in significant apoptosisinducing effects concomitant with chromatin condensation, caspase activation, and intracellular ROS production. Our data indicate that originally synthesized naringenin derivatives, KUF-l and KUF-7 differentially regulate the apoptosis of A549 cells via intracellular ROS production coupled with the concomitant activation of the caspase cascade signaling pathway, thereby implying that hydroxylation or substitution at Carbon-7 is critical for the apoptosis-inducing activity of flavonoids.

Regulation of apoptosis by modified naringenin derivatives in human colorectal carcinoma RKO cells

Lee, Eung-Ryoung,Kang, Yong-Jin,Kim, Hyun-Jeong,Choi, Hye-Yeon,Kang, Geun-Ho,Kim, Jung-Hyun,Kim, Bong-Woo,Jeong, Hyo-Soon,Park, Yong-Sun,Cho, Ssang-Goo Wiley Subscription Services, Inc., A Wiley Company 2008 Journal of cellular biochemistry Vol.104 No.1

<P>Flavonoids are micronutrients that are widely detected in foods of plant origin and have been ascribed pharmacological properties. Several biological functions of flavonoids have been thus far identified, whereas there currently exists a lack of evidence to support the relationship between the structure-activity relationship and apoptosis-inducing activity. In an attempt to determine the importance of the OH group or substitution of the 5- or 7-carbon in the diphenylpropane skeleton of flavonoids, we selected 14 different flavonoids with different structures, particularly with regard to the 5- or 7-carbon, and found that naringenin treatment caused a slight decrease in the cell viability of the human colorectal carcinoma RKO cells. Next, in order to characterize the effects of specific substitutions of the 7-carbon of naringenin on apoptosis-regulatory activities, and in an attempt to develop anti-proliferative flavonoid derivatives that would be more effective against colon cancer, we originally synthesized several modified naringenin derivatives (MNDs) including 7-O-benzyl naringenin (KUF-1) and 7-O-(m-metoxybenzyl) naringenin (KUF-2). Treatment with KUF-1 or KUF-2 resulted in significant apoptosis-inducing effects concomitant with losses in mitochondrial membrane potential, caspase activation, intracellular ROS production, and sustained ERK activation. Our data show that KUF-1 or KUF-2 regulate the apoptosis of RKO cells via intracellular ROS production coupled with the concomitant activation of the ERK signaling pathway, thereby implying that hydroxylation or substitution at C7 is critical for the apoptosis-inducing activity of flavonoids. J. Cell. Biochem. 104: 259–273, 2008. © 2007 Wiley-Liss, Inc.</P>