투사형 전조등의 광학적 분석

성희진,홍사용,류지욱 公州大學校 基礎科學硏究所 1999 自然科學硏究 Vol.8 No.-

투사형 전도등의 특성을 조사하기 위해 광선 추적법으로 광학계를 분석하고 그 결과를 포물경 전도등과 비교하였다. 포물경 전도등의 경우 광학계가 단순한 장점이 있지만 광원의 일부분 만을 반사하며 실제 광원의 크기와 위치를 고려할 때 높은 수차가 불가피 했다. 투사형 전도등은 여러개의 광학부품 사용하는 복잡함과 전체적 길이가 길어지는 단점이 있지만 포물경 전도등 보다 40%이상의 빛을 더 활용하며 전체적인 수차도 상당히 줄일 수 있었다. 그러나 투사형 전도등 광학계의 성능은 비구면 렌즈의 형태에 매우 민감한 것으로 나타났다. To investigate characteristics of the projection type headlights for automobiles, we used ray tracing methods and compared the results with those from parabolic type headlights. The parabolic type headlights are simple but have two limits: first, they require large apertures. To reflect 50% of a source light, the aperture must be 4 times of focal length and to have more reflected light, apertures must grow geometrically. second, a parabolic mirror have large aberration when a source is away from a focus, since output of a headlight cannot be divergent, a source should locate far side from a mirror and moreover a light source has a finite size, large aberration is unavoidable. The projection type headlights have many optical components and longer depth compared with parabolic types, but their apertures can be made small. Advantage of using a ellipsoidal mirror is to reduce beam divergence by half and displace a focal position to another focal point, so that spherical aberration free and short focal length aspherical lens can be placed in proper position. In our study, we adopt a commercially available aspheric lens and the results were quite good compared with those from parabolic types but not optimal since output experienced total reflection at an aspheric lens. We found to improve performance of headlights, proper design of an aspheric lens was crucial.

돈사폐수를 이용한 Polyhydroxyalkanoates의 생산

조경숙,류희욱,박창호 이화여자대학교 생명과학연구소 1996 생명과학연구논문집 Vol.7 No.-

돈사페수를 발효기질로 이용한 생분해성 고분자, polyhydroxyalkanoates(PHA)의 생산이 가능하였다. 균주로는 질소 혹은 인 등의 비탄소 영양원의 제한 없이도 PHA의 생산이 가능한 Azotobacter vinelandii UWD를 이용하였고 돈사폐수배지에서의 PHA 생산특성을 glucose 합성배지에서의 특성과 비교하였다. A. vinelandii uwd균주는 탄소원으로 glucose와 alkanoates가 함유된 배지에서 alkanoates를 우선적으로 소비하여 주로 생장을 하고, glucose 소비단계에서는 생장보다는 PHA를 생산하는 diauxic growth를 하였다. 돈사폐수 원액을 배지로 사용할 경우 UWD 균주의 건조균체량과 PHA함량이 낮았는데(0.91 g/L,37 wt%). 이는 돈사폐수 중에 함유되어 있는 acetate, propionate, butyrate 및 valerate 등과 같은 높은 농도의 alkanoates가 세포생장을 저해하기 때문이었다. 증류수로 50% 희석한 배지(총 생산 균체 건중량 2.02g/L)를 사용하는 것이 바람직한 것으로 밝혀졌다. 50% 희석 돈사폐수 배지에 glucose를 3% 첨가하면 건조균체량은 9.40g/L로 현저하게 증가하였으며, 균체내 PHA 함량은 58.3%, PHA 생산속도는 0.11g/(L·h)이었다. Glucose 합성배지에서 합성된 PHA는 poly-β-hydroxybutyrate(PHB)의 형태이었고, 돈사폐수 배지로부터는 copolymer인 poly-β-hydroxybutyrate-co-β-hydroxyvalerate, P(HB-co-HV)를 2-8mol% 합성할 수 있었다. 돈사폐수배지를 이용하여 PHA를 생산하는 동안 배지의 염도를 대략 50% 정도 제거가 가능하였다. Biodegradable polymer, polyhydroxyalkanoates(PHA), could be produced using swine wastewater (SW)as a fermentation substance. Azotobacter vinelandii UWD was able to produce PHA without limiting non-carbon nutrients such as nitrogen and phosphorous. Production characteristics of strain UWD in SW medium were compared with those in glucose sythetic medium In the synthetic medium containing glucose and alkanoates as carbon sources. A vinelandii UWD grew diauxically, first by using alkanoates and then by using glucose to produce biomass and PHA. Using raw SW medium, cell mass production was small(0.91 g/L)and PHA content was 37 wt% because cell growth was inhibited by alkanoates such as acetate, propionate, butyrate, and valerate contained in SW. Use of two-fold diluted SW as fermentation medium was desirable for PHA production. When 3% of glucose was added to the two-fold diluted SW, dry cell mass increased to 9.40 g/L, and the PHA content and PHA production rate were 58.3 wt% and 0.11g/(L·h), respectively. When grown in SW media A. vinelandii UWD formed PHA copolymers containing β-hydroxybutyrate and β-hydroxyvalerate(HV), and HV content in the copolymer was 2-8mol% whereas homopolymer of poly-β-hydroxybutyrate was produced in the glucose synthetic medium. Approximately 50% of salinity in the medium was reduced after PHA production using SW medium.

폐탄광 배수에 의한 주변 화천 오염 실태 조사

조경숙,장용근,류희욱 崇實大學校 生産技術硏究所 1996 論文集 Vol.26 No.1

The survey was carried out to investigated the contamination of streams by the acid mine drainage originates from abandoned coal mines and coal refuse piles. The physico-chemical characteristics such as pH, sulfate and elements concentrations of waters and sediments in streams were analyzed, and the microbial activities in the sediments were evaluated by measuring dehydrogenase activities. In sites contaminated by the acid mine dranage, the pH of waters adn sediments declined to acid from neutral due to the accumulation of sulfate. Dehyfrogenase activities ranged from 12 to 170 ㎍-TPF·g-dry soil-¹·24h-¹in the contaminated sites, whereas teh uncontaminated sites had activities of 1,176-4,259 ㎍-TPF·g-dry soil-¹·24h-¹. Dehydrogenase activities were significantly affected by low pH of sediments, indicating that high strength of sulfate inhibited microbial activities. The concentrations of heavy matals such as Pb and Fe in contaminated sediment (37-46 ppm Pb; 46,000 ppm Fe) were much higher than those in the uncontamnated sediments. concentration of Al in the contaminated water acidfied by the abandoned coal drainage was in range of 11 to 42 ppm. compared with those in the uncontaminated sediments, the concentrations of Mn, Mg and Ca in contaminated sediments were low because of the leaching of them from soil to water by acidfied stream water.

돈사폐수를 이용한 Polyhydroxyalkanoates의 생산

조경숙,박창호,류희욱 이화여자대학교 환경문제연구소 1997 이화환경연구 Vol.1 No.-

돈사폐수를 발효기질로 이용한 생분해성 고분자, polyhydroxyalkanoates(PHA) 의 생산이 가능하였다. 균주로는 질소 혹은 인 등의 비탄소 영양원의 제한 없이도 PHA 의 생산이 가능한 Azotobacter vinelandii UWD 를 이용하였고 돈사폐수배지에서의 PHA 생산특성을 glucose 합성배지에서의 특성과 비교하였다. A. vinelandii UWD 균주는 탄소원으로 glucose와 alkanoates 가 함유된 배지에서 alkanoates를 우선적으로 소비하여 주로 생장을 하고, glucose소비단계에서는 생장보다는 PHA를 생산하는 diauxic growth 를 하였다. 돈사폐수 원액을 배지로 사용할 경우 UWD 균주의 건조균체량과 PHA 함량이 낮았는데(0.91g/L, 37wt%), 이는 돈사폐수 중에 함유되어 있는 acetate, propionate, butyrate 및 valerate등과 같은 높은 농도의 alkanoates가 세포생장을 저해하기 때문이었다. 증류수로 50% 희석한 배지(총 생산 균체 건중량 2.02g/L)를 사용하는 것이 바람직한 것으로 밝혀졌다. 50% 희석돈사폐수 배지에 glucose를 3% 첨가하면 건조균체량은 9.40g/L로 현저하게 증가하였으며, 균체내 PHA 함량은 58.3%, PHA 생산속도는 0.11g/(L·h)이었다. Glucose 합성배지에서 합성된 PHA는 poly-β-hydroxybutyrate(PHB)의 형태이었고, 돈사폐수 배지로부터는 copolymer인 poly-β-hydroxybutyrate-co-β-hydroxyvalerate, P(HB-co-HV)를 2-8mol%합성할 수 있었다. 돈사폐수배지를 이용하여 PHA를 생산하는 동안 배지의 염도를 대략 50% 정도 제거가 가능하였다. Biodegradable polymer, polyhydroxyalkanoates(PHA), could be produced using swine wastewater (SW) as a fermentation substance. Azotobacter vinelandii UWD was able to produce PHA without limiting non-carbon nutrients such as nitrogen and phosphorous. Production characteristics of strain UWD in SW medium were compared with those in glucose synthetic medium. In the synthetic medium containing glucose and alkanoates as carbon sources. A. vinelandii UWD grew diauxically, first by using alkanoates and then by using glucose to produce biomass PHA. Using raw SW medium, cell mass production was small (0.91g/ L) and PHA content was 37wt% because cell growth was inhibited by alkanoates such as acetate, propionate, butyrate, and valerate contained in SW. Use of two-fold diluted SW as fermentation medium was desirable for PHA production. When 3% of glucose was added to the two-fold diluted SW, dry cell mass increased to 9.40g/L, and the PHA content and PHA production rate were 58.3wt% and 0.11g(L·h), respectively, When grown in SW media A. vinelandii UWD formed PHA copolymers containing β-hydroxybutyrate and β-hydroxyvalerate (HV), and HV content in the copolymer was 2-8mol% whereas homopolymer of poly-β-hydroxybutyrate was produced in the glucose synthetic medium. Approximately, 50% of salinity in the medium was reduced after PHA production using SW medium.

Gas holdup and mass transfer of mycelial fermentation broths in a bubble column bioreactor with a radial gas sparger

Ryu,Hee Wook 崇實大學校 生産技術硏究所 1995 論文集 Vol.25 No.2

The gas holdup and mass transfer characteristics in fermentation broths of Rhizopus oligosporus have been determined in a bubble column with a radial gas sparger. The addition of antifoam agent during the course of fermentation exhibits a significant effect on gas holdup and mass transfer properties of fermentation broths. The correlations for gas holdup and mass transfer coefficients in slug flow regime of the mycelial fermentation broths and carboxymethyl cellulose(CMC) solutions as the simulated fermentation broths in the bubble columns have been proposed. Also, a flow regime map in the bubble columns of the mycelial fermentation broths and CMC solutions has been proposed.

HDAC6 deacetylates p53 at lysines 381/382 and differentially coordinates p53-induced apoptosis

Ryu, Hyun-Wook,Shin, Dong-Hee,Lee, Dong Hoon,Choi, Junjeong,Han, Gyoonhee,Lee, Kang Young,Kwon, So Hee Elsevier 2017 Cancer letters Vol.391 No.-

<P><B>Abstract</B></P> <P>HDAC6-selective inhibitors represent promising new cancer therapeutic agents, but their precise mechanisms of action are not well understood. In particular, p53's role in HDAC6 inhibitor-induced effects has not been fully elucidated. In this study, we show that an HDAC6-selective inhibitor, A452, increased wild-type p53 levels by destabilizing MDM2, but decreased mutant p53 by inducing MDM2 and inhibiting Hsp90-mutant p53 complex formation. Interestingly, HDAC6 levels inversely correlated with p53 acetylation at lysines 381/382 associated with p53 functional activation. A452 blocked HDAC6 nuclear localization, resulting in increased levels of acetylated p53 at Lys381/382. HDAC6 bound to the C-terminal region of p53 via its deacetylase domain. A452 disrupted the HDAC6-Hsp90 chaperone machinery via Hsp90 acetylation and degradation. Furthermore, it chemosensitized cancer cells to the Hsp90 inhibitor 17-AAG. Overall, silencing of HDAC6 showed similar effects. These findings suggest that the anticancer action of HDAC6 inhibitors requires p53 and Hsp90 and targeting of HDAC6 may represent a new therapeutic strategy for cancers regardless of p53's mutation status.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HDAC6 deacetylates p53 at lysine 381/382. </LI> <LI> A452 increases wild-type p53 levels by destabilizing MDM2. </LI> <LI> A452 decreases mutant p53 levels by inhibiting Hsp90-mutp53 complex formation. </LI> <LI> HDAC6 levels inversely correlate with p53 acetylation. </LI> <LI> A452 disrupts HDAC6-Hsp90 chaperone machinery via Hsp90 acetylation and degradation. </LI> </UL> </P>

Production of retinoids from recombinant E. coli harboring engineered mevalonate pathway

Hee-Jeong JANG,Hee-Kyoung RYU,Sook-Hee LEE,Chong-long WANG,Shah ASAD ALI,Jung-Hun KIM,Jong-Wook SONG,Seo-Hee KANG,Seon-Won KIM,Deok-Kun OH 한국생물공학회 2009 한국생물공학회 학술대회 Vol.2009 No.10

Refinement of Low-Grade Clay by Microbial Removal of Sulfur and Iron Compounds Using Thiobacillus ferrooxidans

RYU, HEE WOOK,CHO, KYEOUNG SUK,CHANG, YONG KEUN,KIM, SANG DONE,MORI, TADAHIRO 이화여자대학교 생명과학연구소 1995 생명과학연구논문집 Vol.6 No.-

The refinement of low-grade clay, of which impurities are mainly sulfur and iron compounds, is required because of the recent shortage of high-grade clayfor manufacturing of structural ceramics. The major impurity compound com\ntained in the low-grade clay we treated was identified as pyrite by X-ray power diffraction and inductively coupled plasma analyses. The well-firmed crystals of pyrite had a framboidal form of 1㎛-20㎛ diameter. The microbial removal of pyrite form the low-grade clay was investigated by using a sulfur and iron-oxidizing bacterium, Thiobacillus ferrooxidans. About 82-90% of the pyrite was removed in 5-12 d for pulp densities up to 70%(w/v). The removal rate of pyrite ranged from 270 to 914 mg-pyritic sulfur/l·d deconcentration (S): r(mg-pyritic sulfur/l·h)=1.96×10_-2(mg-pyritic sulfur/l). The logarithm of the amount of oxidizied pyrite per unit volume and the final pH in the reaction medium were fuond to have a liner relationship which could be expressed as pH=2.43-0.55log[FeS_2(mM)]. With the refined clay no red color due to the presence of pyritic was developed after firing, and its whiteness was similar to that of high-grade clay.

Poly(hydroxybutyrate-co-hydroxy-valerate) from swine waste liquor by Azotobacter vinelandii UWD

Ryu,Hee Wook,Cho,Kyung-Suk,Goodrich,Philip R,Park,Chang-Ho 이화여자대학교 환경문제연구소 1997 이화환경연구 Vol.1 No.-

Application of engineered bacterial whole mevalonate pathway for β-carotene production in E. coli

Hee-Jung Jang,Sook-Hee Lee,Chong-Long Wang,Hee-Kyoung Ryu,Asad Ali Shah,Jong-Wook Song,Amitabha Das,Seon-Won Kim 한국생물공학회 2008 한국생물공학회 학술대회 Vol.2008 No.10