Thermal Expansion Behavior of Thermally Expandable Microspheres Prepared by Suspension Polymerization Using P(AN-MMA-MAA) Core/Shell

Hyun Tae Kim,Ashok Kumar Jaladi,Yong Jin Lee,Duk Keun An 대한화학회 2020 Bulletin of the Korean Chemical Society Vol.41 No.2

Thermally expandable microspheres (TEMs) have widespread industrial applications. In this study, high heat resistant and largely expandable TEMs have been synthesized by suspension polymerization. Microspheres were prepared with acrylonitrile (AN) as the main monomer. Initial thermomechanical analysis of TEMs containing AN and methyl acrylate (MA) showed good thermal expansion, leading to the investigation of the polymerization using various monomers at variable weight ratios. TEMs with co-polymer AN, methyl methacrylate (MMA), and methacrylic acid (MAA) were investigated for the first time. They displayed wider heating range and larger expansion rate than the microspheres with MA monomer. The effect of varying amounts of monomer ratios on the thermal expansion behavior is discussed.

Quantitative Synthesis of Aldehydes from Weinreb Amides Using Lithium Diisobutyl-<i>t</i>-Butoxyaluminum Hydride (LDBBA)

An, Jae Sung,Shin, Won Kyu,An, Duk Keun Wiley Blackwell (John Wiley Sons) 2015 Bulletin of the Korean Chemical Society Vol.36 No.12

허혈성 심질환에서 나타나는 황상화지수, 사이토카인 및 염증지표의 변화

전상훈,안지훈,방덕원,온영근,현민수,김성구,권영주 순천향대학교 의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.3

..

허혈성 심질환에서 나타나는 항산화지수, 사이토카인 및 염증지표의 변화

전상훔,안지훈,방덕원,온영근,현민수,김성구,권영주 순천향대학교 교수학습개발센터 2004 Journal of Soonchunhyang Medical Science Vol.10 No.3

Purpose : As diet habits change and the elderly popuation increases conronary artery disease(CAD) has also increased. Recent ongoing studies on varous inflammatory indexes in acute coronary syndrome(ACS) are underway. Several study results have shown that total antioxidant status(TAS) was remarkably lower in unstable angina than in chronic stable angina and levels of interleukin-(IL-6), C-reactive protein(CRP), monocyte chemoattractant protein-1(MCP-1), P-selectin were reported to be elevated in unstable angina and acute myocardial infarction(AMI). In our study, we studied and compared the level changes of cytokines and inflammatory indexes that play important roles inside the blood vessel. Methods : Study subjects were patients who were admitted and underwent coronary angiography at the cardiology department in Soonchunhyang university hospital. Subjects were divided into 4 groups, a control group, a stable angina and unstable angina group and an acute myocardial infarction group. The clinical findings, TAS, inflammatory cytokines(P-selectin, MCP-1, IL-6), anti-inflammatory cytokines(IL-10), Homocysteine and CRP levels in each group were measured and compared. Results : The total number of study participants was 86 patients, with 26 patients in the control group, 21 patients with stable angina, 15 patients with unstable angina, and 24 patients with AMI. There were significant differences in the TAS among the 4 grouops. 1.7±0.51 mmol/L, 1.6±0.60 mmol/L, 1.4±0.20 mmol/L, 1.4±0.29 mmol/L respectively. IL-6 levels also showed a significant difference between groups, averaging 0.8±2.47 pg/ml, 2.7±3.77 pg/ml, 6.8±10.63 pg/ml, 10.9±17.43 pg/ml respectively. Homocysteine levels averaged 8.0±2.47 pg/ml, 6.8±10.63 pg/ml, 10.9±17.43 pg/ml restectively. Homocysteine levels averaged 8.0±1.0 μmol/L in the control group, 14.3±5.14 μmol/L in patients with stable angina, 16.0±4.66 μmol/L in patients with unstable angina, and 17.3±10.08 μmol/L in AMI patients. Conclusion : Compared to the control group, the TAS levels were significantly lower in patients with unstable angina and AMI. there was no difference between the control group and those with stable angina. IL-6 and homocysteine levels were also higher in patients with unstable angina and AMI. Therefore we concluded that measurements of TAS, IL-6 and homocysteine are useful in measuring the inflammatory index of coronary artery diseases and may be important factors in predicting the states and prognosis of cardiovascular disorders.

가막만 모자반 군락지 어류군집의 종조성 및 계절변동

윤호섭,안윤근,최상덕,Yoon, Ho-Seop,An, Yun-Keun,Choi, Sang-Duk 해양환경안전학회 2011 해양환경안전학회지 Vol.17 No.1

Species composition and seasonal variation of fish assemblages in Sargassum beds in Gamak Bay was determined using fish samples collected monthly by a surrounding net from October 2008 to September 2009. A total of 21 species, 582 individuals and 5,345.1 g of fishes were collected during the study period and Perciformes accounted for 47.6 % of the total number of species. Takifugu niphobles, Engraulis japonicus and Lateolabrax japonicus predominated in number, accounting for 55 % of the total number of individuals. Higher number of species and individuals occurred in June and in September-October. Species were grouped into three by cluster analysis: A) dominant species such as Leiognathus nuchalis and Takifugu niphobles, B) fish collected mainly in spring such as Sebastes inermis, Chaenogobius heptacanthus, Pterogobius zonoleucus, Pholis nebulosa, and Trachyrhamphus serratus, and C) fish collected mainly in autumn such as Engraulis japonicus, Lateolabrax japonicus, and Hyporhamphus sajori. 가막만 모자반 군락에서 2008년 10월부터 2009년 9월까지 월별로 두릿그물로 어류를 채집하여 어류의 종조성 및 계절변동을 분석하였다. 조사기간 동안 21종 582 개체, 5,345.1 g의 어류가 채집되었으며, 출현한 어종 중 복섬(Takifugu niphobles), 멸치(Engraulis japonicus)와 농어(Lateolabrax japonicus)가 전체 개체수의 55 %를 차지하였다. 12월과 1월에는 어류가 채집되지 않았고, 봄에 수온이 상승하며 증가하여 출현종수와 채집량이 6월에 높았고, 7월과 8월에는 감소하였으나, 9월과 10월에는 높은 값을 보였다. 종간 유사성을 집괴분석한 결과 3개의 무리로 구분되었다. A 그룹에는 출현기간이 비교적 긴 우점종인 주둥치(Leiognathus nuchalis)와 복섬(Takifugu niphobles)이, B 그룹에는 봄에 주로 출현한 볼락(Sebastes inermis), 살망둑(Chaenogobius heptacanthus), 흰줄망둑(Pterogobius zonoleucus), 베도라치(Pholis nebulosa), 거물가시치(Trachyrhamphus serratus), C 그룹에는 가을에 주로 출현한 멸치(Engraulis japonicus), 농어(Lateolabrax japonicus), 학공치(Hyporhamphus sajori)가 포함되었다.

Catalytic hydroboration of aldehydes and ketones with sodium hydride: Application to chemoselective reduction of aldehydes over ketones

Shin, Won Kyu,Kim, Hanbi,Jaladi, Ashok Kumar,An, Duk Keun Elsevier 2018 Tetrahedron Vol.74 No.43

<P><B>Abstract</B></P> <P>Sodium hydride-promoted catalytic hydroboration of aldehydes and ketones with pinacolborane (HBpin) was examined, and 10 mol% of NaH was found to cause the HBpin to participate in hydroboration in a convenient and efficient manner at mild reaction conditions. Further chemoselective hydroboration of aldehyde over ketone functionality was also analyzed. In addition, no hydroboration was observed form ester, acyl chloride, amide, nitrile, alkene, alkyne, alkyl halide and epoxide functional groups indicate that present system (HBpin, NaH) is highly selective for aldehydes and ketones.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

개불과 넙치의 혼합 사육시 성장과 사육환경의 변화

김용구,박일웅,안윤근,배애란,최상덕 國立麗水大學校 環境問題硏究所 2004 環境硏究論文集 Vol.6 No.-

This present study was conducted to determine the effects of sea water quality and sediment quality on growth and body composition in poly culture system, Paralichthys olivaceus and Urechis unicinctus. The seawater temperature of the experimental groups was ranges of 17.1~23.8℃, the lowest in 0 day and the highest in 70 day. The concentration of COD was 1.2~1.6㎎/ℓ, DIN 6.19~28.89㎎/ℓ in the D group. Mean IL concentration was 5.42~5.07% and it was maximum in 0 day and relatively minimum 70day. The concentration of AVS was 0.36~0.22㎎/g-dry, COD 4.36~4.08㎎/g-dry in the D group. Growth and feed intake of fish were affected by diets and feeding frequencies(P<0.05). There were differences at all experimental groups especially C group and control group but A, B group and C, D group were not difference. The lowest increased body weight was observed 4.7g in the D experimental group and the highest experimental group was observed 8.6g in the C group.

살조개, Protothaca jedoensis 초기치패의 저질 및 먹이생물별 성장

김정(Jung KIM),추부관(Bu Gwan Chu),장선익(Sun Ik JANG),한종석(Jong Seok HAN),라성주(Sung Ju RHA),안윤근(Yun Keun AN),윤호섭(Ho Seop YOON),최상덕(Sang Duk CHOI) 전남대학교 수산과학연구소 2011 수산과학연구소논문집 Vol.19 No.-

In order to obtain the basic information for artificial seedling production of venus clam, Protothaca jedoensis, growth and survival rate were investigated by substratum composition on spat collection, and species and concentration of food organisms during spat stage. The optimal substratum for spat collection was the sand size (Ø0.5-2 ㎜) showing that the highest growth and survival rate of spat were 493.2±0.4 ㎛, 13.0±0.9 %, respectively. As for spat rearing by four species of food organism (phytoplankton), Isochrysis galbana, Chaetoceros calcitrans, Monochrysis lutheri, and Pavlova lutheri were used singularly and the mixture of the four species was used. The highest growth and survival rates were observed in the Isochrysis galbana (1644.2±0.8 ㎛, 79.7±2.3 %), and followed by mixture group, Chaetoceros calcitrans, Monochrysis lutheri, and Pavlova lutheri. In the concentration of the four mixed food organisms on spat rearing, the highest growth and survival rates were observed in the concentration of 1×104 cells/㎖ (1637.0±1.0 ㎛, 75.0±0.9 %), and followed by 2×104 cells/㎖, 4×104 cells/㎖, and 0.5×104 cells/㎖. 살조개, Protothaca jedoensis의 인공종묘생산 기술개발을 목적으로 생물학적 기초자료를 얻고자 저질입도별 채묘 및 치패사육에서 먹이생물의 종류와 농도에 따른 성장과 생존율을 조사하였다. 저질입도별 채묘에서 최적 채묘기질은 극조립사(Ø0.5-2㎜)로 가장 높은 성장(493.2±0.4㎛)과 생존율(13.0±0.9%)을 보였다. 먹이생물별 치패사육에서 Isochrysis galbana가 가장 높은 성장(1644.0±0.8㎛)과 생존율(79.7±2.3%)을 보였으며, 혼합구, Chaetoceros calcitrans, Monochrysis lutheri, Pavlova lutheri 순으로 나타났다. 먹이생물(혼합) 농도별 치패사육에서 1×104cells/㎖가 가장 높은 성장((1637.0±1.0㎛)과 생존율(75.0±0.9%)을 보였으며, 2×104cells/㎖, 4×104cells/㎖, 0.5×104cells/㎖ 순으로 나타났다.

Protection and Preservation of Clithon retropictus, Level II Endangered Species Declining due to Development Projects Carried out in its Habitat

Sang Duk Choi,Hong il Jeon,No Yun Myeong,Sung Min Choi,Cheol Lee,Yun Keun An 한국환경생물학회 2018 환경생물 : 환경생물학회지 Vol.36 No.2

Clithon retropictus has been protected by the Ministry of Environment as an endangered species since 1998 and has been listed on the state red list of endangered species category II. It is viewed as a representative for all endangered species in the northeastern coastal waters of Korea. Most of the habitats of C. retropictus have been found to be in an unstable state because of development projects such as road construction, small stream development, irrigation for securing agricultural water, and flood prevention. These habitats are damaged by small stream maintenance projects and development, and the risk of damage is increasing and active efforts are needed in order to protect them. Although the Ministry of Environment is striving to preserve this endangered species, the habitat of C. retropictus is still facing external threats because it spreads to only a small area at high densities. Therefore, in order to protect the habitat of C. retropictus, a level II endangered species, it is urgent to make an effort to minimize habitat damage and to take measures for its protection.

가막만의 모자반군락이 수질환경에 미치는 영향

안윤근 ( Yun Keun An ),조주현 ( Ju Hyon Cho ),윤호섭 ( Ho Seop Yoon ),박일웅 ( Il Woong Park ),김윤설 ( Yun Seol Kim ),김호진 ( Ho Jin Kim ),최상덕 ( Sang Duk Choi ) 한국수산학회 2009 한국수산과학회지 Vol.42 No.3

We determined the influence of Sargassum beds on the water quality in Gamak Bay, Korea. Water temperature and salinity range from 3.3 to 23.4℃ and from 29.6 to 33.7 psu, respectively. Dissolved oxygen was 10.45mg L-1 in the Sargassum bed and 9.23mg L-1 in the control. Chlorophyll-a was 3.90μg L-1 in the Sargassum bed and 2.21μg L-1 in the control. Chemical oxygen demand were 1.14mg L-1 in the Sargassum bed and 1.43mg L-1 in the control. Total nitrogen were 0.038mg L-1 in the Sargassum bed and 0.067 mg L-1 in the control. Total phosphorus were 0.043mg L-1 in the Sargassum bed and 0.072mg L-1 in the control. Multivariate statistical analysis was used to analyze data. Water temperature was highly positively correlated with DO(p<0.01). T-N was highly positively correlated with T-P(p<0.01).