• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1996년도 추계 학술발표회
• /
• pp.468-472
• /
• 1996

A series of UV-curable polyurethane acrylate ionomer were synthesized from isophorone diisocyanate(IPDI), poly(tetramethylene ether glycol)(PTMG), 2,2-bis(hydroxymethyl)propionic acid (CMPA), triethylamine(TEA), 2-hydroxy ethyl acrylate (HEA), and dibutyl tin dilaurate (DBT) as a catalyst. 2,2-dimethoxy-2-phenyl acetophenone(DMPAP) was used as a photoinitiator. The films of UV-cured polyurethane acylate ionomer were prepared by casting the formulated materials onto a glass plate at room temperature and cured using a medium pressure mercury lamp (80 W/cm, max = 365nm). Effects of DMPA content, molecular weight of PTMG and degree of neutralization on the properties were invesigated. It is found that the storage modulus increased with increasing DMPA content. The glass transition temperature of sample A shifted to higher temperature as the content of DMPA was increased. Tensile modulus also increased with increasing DMPA content. Modulus and Tg decreased with increasing molecular weight of PTMG form 650 to 2000. With increasing the degree of nutralizaion, ionomers exhibited improved modulu.

• 대한설비공학회지:설비저널
• /
• 제12권3호
• /
• pp.189-197
• /
• 1983

In this study, the thermal environment of a certain building was investigated by using of concerned equipments and enquete sheets. The measured items were temperature, humidity, air flow and radiant heat, and thermal responses for the occupants were checked also, which are oriented to be used as basic data for environmental design. The results of this study are as followed. 1. The optimal room temperature was $24\~26.5^{\circ}C$ DBT in cooling season. 2. Under the condition from $50\%\;to\;70\%$ of relative humidity, the difference of relative humidity did not impact upon the feeling temperature. 3. In cooling season, the average clothing factor of occupants was 0.34 clo ; 0.49 clo for men and 0.25 clo for women. 4. The average working factor of occupants was $1.1\~1.3\;Met$ in that cooling season.

• 수산해양기술연구
• /
• 제26권3호
• /
• pp.265-274
• /
• 1990

한국 남해역에서 정기적인 해양 관측을 실시하고 있는 국립수산진흥원의 해양관측 정선이 외해쪽에만 치중되어 있어 연안수와 외해수간의 상호관계를 상세히 규명하기 어렵고 또한 해역에 따라서는 정선간의 간격이 커 복잡한 해황을 정확하게 파악하지 못하는 경우도 있다. 따라서 본 연구에서는 1986년 5월 23~25일간 부산수산대학교 실습선 402호를 이용하여 위와 같은 전선대 해역(제주도 동부 해역 부근)에서 자주 발생한다고 알려져 있는 수온역전 현상에 대해 DBT(Digital Momery Bathythermograph)를 사용하여 현장관측을 실시하여 보다 상세한 수온역전 구조와 그 발생 기구를 파악하고 부차적으로 이러한 수온역전 현상이 이 해역에 존재하고 있는 각 수괴들과 어떠한 관계가 있는가를 밝히고자 하였다. 그 결과, 총 67개 정점에서 수온역전이 출현한 정점은 39개이며, 그 출현빈도는 58.20%였다. 한정점에 수온역전 출현빈도는 한 개 층이 9개로서 13.42%, 두 개 층은 14개로서 20.80%, 세 개 층은 16개로서 23.88%로 나타났다. 수온역전은 대체로 수온약층 하의 수심인 40m 이심에서 일어났고 역전 수온 범위는 14~16$^{\circ}C$였다. 제주도 동부 해역에서 출현한 수온역전은 고온 고염의 쓰시마난류수가 저온 저염의 한국남안연안수 사이를 침투(intrusion)하여 생기는 수온역전과 저온 저염의 한국남안연안수가 고온 고염의 쓰시마난류수 사이를 침투하여 생기는 수온역전의 두 가지가 있다. 그리고 이러한 수온역전이 전선대에서 빈번히 발생함을 해양 관측을 통하여 구체적으로 밝혔다. 그리고 앞으로도 전선대에서 수온역전의 기구를 규명하여 각 수괴의 존재를 규명하는 문제로 계속적으로 연구해야 될 과제하고 생각한다.

• 한국식품과학회지
• /
• 제39권6호
• /
• pp.715-720
• /
• 2007

국내 유통되는 PVC제 랩 3건 및 병마개 가스킷 26종에 대한 부틸주석화합물의 재질 중 잔류량을 조사하였다. Mono-n-butyltin(MBI), di-n-butyltin(DBT) 및 tri-n-nutyltin(TBT)에 대하여 sodium tetraethylborate로 ethylation 유도체화 후 GC/MS-SIM으로 분석하였다. 분석법 검증결과 본 연구에서 사용한 분석방법의 검출한계는 $0.005\;{\mu}g/mL$였으며, $0.02-3.13\;{\mu}g/mL$의 농도범위에서 $R^2$ 값이 0.999 이상의 직선성, 90% 이상의 회수율을 확인할 수 있었다. 총 29건의 시료에 대하여 분석한 결과 모든 시료에서 부틸주석 화합물은 검출되지 않았다.

• 한국발생생물학회지:발생과생식
• /
• 제13권3호
• /
• pp.163-172
• /
• 2009

Some organotin compounds such as butyltins and phenyltins are known to induce impo-sex in various marine animals and are considered to be endocrine disruptors. In this study, the effect of organotins on follicular steroidogenesis in amphibians was examined using ovarian follicles of Rana dybowskii and Rana catesbeiana. Isolated follicles were cultured for 6 or 18 h in the presence and absence of frog pituitary homogenate (FPH) or various steroid precursors, and the levels of product steroids in the culture media oassay. Among the butyltin compounds, tributyltin (TBT) strongly and dose-dependently inhibited the FPH-induced synthesis of pregnenolone ($P_5$) and progesterone ($P_4$) by the follicles. TBT also strongly suppressed the conversion of cholesterol to $P_5$ and partially suppressed the conversion of $P_5$ to $P_4$. A high concentration of dibutyltin (DBT) also inhibited steroidogenesis by the follicles while monobutyltin and tetrabutyltin had negligible effects. The toxic effect of TBT or DBT was irreversible and a short time of exposure (30 min) was enough to suppress steroidogenesis. All the phenyltin compounds significantly inhibited FPH-induced $P_5$ synthesis by the follicles. The effective dose of 50% inhibition by diphenyltin was $0.04\;{\mu}M$ and those of monophenyltin and triphenyltin were $0.24\;{\mu}M$ and $0.3\;{\mu}M$, respectively. However, none of the phenyltin compounds significantly suppressed the conversion of $P_4$ to $17{\alpha}$-hydroxyprogesterone ($17{\alpha}$-OHP) (by $17{\alpha}$-hydroxylase), $17{\alpha}$-OHP to androstenedione (AD) (by $C_{17-20}$ lyase), or AD to testosterone by the follicles. Taken together, the data show that among the steroidogenic enzymes, P450scc in the follicles is the most sensitive to organotin compounds and that an amphibian follicle culture system can be a useful screening model for endocrine disruptors.

• Biomolecules & Therapeutics
• /
• 제28권1호
• /
• pp.83-91
• /
• 2020

Tryptamines are monoamine alkaloids with hallucinogenic properties and are widely abused worldwide. To hasten the regulations of novel substances and predict their abuse potential, we designed and synthesized four novel synthetic tryptamine analogs: Pyrrolidino tryptamine hydrochloride (PYT HCl), Piperidino tryptamine hydrochloride (PIT HCl), N,N-dibutyl tryptamine hydrochloride (DBT HCl), and 2-Methyl tryptamine hydrochloride (2-MT HCl). Then, we evaluated their rewarding and reinforcing effects using the conditioned place preference (CPP) and self-administration (SA) paradigms. We conducted an open field test (OFT) to determine the effects of the novel compounds on locomotor activity. A head-twitch response (HTR) was also performed to characterize their hallucinogenic properties. Lastly, we examined the effects of the compounds on 5-HTR1a and 5-HTR2a in the prefrontal cortex using a quantitative real-time polymerase chain reaction (qRT-PCR) assay. None of the compounds induced CPP in mice or initiated SA in rats. PYT HCl and PIT HCl reduced the locomotor activity and elevated the 5-HTR1a mRNA levels in mice. Acute and repeated treatment with the novel tryptamines elicited HTR in mice. Furthermore, a drug challenge involving a 7-day abstinence from drug use produced higher HTR than acute and repeated treatments. Both the acute treatment and drug challenge increased the 5-HTR2a mRNA levels. Ketanserin blocked the induced HTR. Taken together, the findings suggest that PYT HCl, PIT HCl, DBT HCl, and 2-MT HCl produce hallucinogenic effects via 5-HTR2a stimulation, but may have low abuse potential.

• 한국강구조학회 논문집
• /
• 제17권3호통권76호
• /
• pp.337-346
• /
• 2005

승용차 전용 조립식 고가도로 상부구조에 복합재료 바닥판을 적용하기 위하여 두 개의 사각형으로 이루어진 단위 모듈 단면이 개발되었으며, 설계된 단위 모듈 단면에 대해 두 가지의 적층형태로 각각 설계를 하여 성능을 비교하였다. 단위 모듈 및 2 연속 모듈 그리고 단위 모듈 5개를 접착제를 이용하여 부착한 바닥판 시스템에 대해 휨 거동 특성을 분석하고 설계하중 및 극한하중에 대한 바닥판의 사용성 및 구조안전성을 분석하기 위한 실험을 DBT와 LT로 설계된 실험체에 대해 각각 실시하였다. 또한 ABAQUS를 이용한 수치해석 결과와 실험 결과를 비교 분석하였으며, 실험 장치 및 방법과 파괴하중 및 파괴형상 등의 실험결과를 상세히 나타내었다. 구조실험결과 개발된 복합재료 바닥판은 승용차 전용 고가도로 바닥판으로 사용하기에 충분한 적용성과 효용성이 있음이 입증되었다.

• 환경생물
• /
• 제22권
• /
• pp.63-70
• /
• 2004

Tributyltin (TBT) and its degradation products, dibutyltin (DBT) and monobutyltin (MBT) were quantitatively determined in surface sediments and two molluscan species, Pacific oyster (Crassostrea gigas) and rock shell (Thais ctavigera), from Gwangyang Bay, Korea. Butyltin compounds were detectable in almost all sediment and biota samples. Tributyltin concentrations in surface sediment ranged<2∼33 ng g$\^$-1/, which is at a lower end of TBT concentrations in industrialized bays in Korea. However, TBT levels in sediments were related to boating activities around the bay. In biota samples, TBT concentrations were in the range of 178∼2,458 ng g$\^$-1/ toy oyster and 47∼236 ng g$\^$-1/ for rock shell. Relatively high TBT concentrations in biota were found near wharves for fisherboats and harbor areas. About 90∼100％ of the female T. clavigera displayed imposex, and relative penis length index of the imposexed-female was in the range of 20.9∼107.9％. Furthermore, TBT body residue had a significant positive relationship with degree of imposex in T. clavigera. Overall, TBT concentrations in Gwanyang Bay were much lower than other major bays in Korea.

• 한국환경과학회지
• /
• 제20권3호
• /
• pp.385-394
• /
• 2011

Organotin compounds (OTs), namely butyltins compounds (BTs) and phenyltin compounds (PhTs), were measured in surface and core sediments collected in Jeju harbor. The horizontal and vertical distribution was examined and the relationship between the concentration of OTs and organic matter content and particle size distribution was also studied. BTs were detected in significant concentrations in sediments inside Jeju harbor. PhTs were detected in very low concentrations, compared to BTs. The main species in BTs and PhTs were dibutyltin (DBT) and monobutyltin (MBT), monophenyltin (MPhT), respectively. In the relationships between the concentrations of total BTs and organic carbon content, the significant correlations ($r^2$=0.4898 in surface sediments, $r^2$=0.53 in one core sediments) and no correlation in another core sediments obtained, which is estimated that the distribution of BTs in sediments were affected by several factors, such as their physicochemical properties including organic carbon content, and a tide, etc. In the relationships between the concentrations of total BTs and particle size (mud, sand, and gravel) in sediments, the concentrations of total BTs were higher in the sediments with higher mud content, indicating that higher BTs were distributed with increasing sediments of fine granules.

• 상하수도학회지
• /
• 제25권4호
• /
• pp.527-534
• /
• 2011

In this research, the photocatalytic degradation of dibenzothiophene (DBT) in $TiO_2$ aqueous suspension has been studied. $TiO_2$ photocatalysts are prepared by a sol-gel method. The dominant anatase-structure on $TiO_2$ particles is observed after calcining the $TiO_2$ gel at $500^{\circ}C$ for 1hr. Photocatalysts with various transition metals (Nd, Pd and Pt) loading are tested to evaluate the effect of transition metal impurities on photodegradation. The photodegradation efficiencies with $TiO_2$ including Pt and Pd are higher than pure $TiO_2$ powder. Also we investigated the applicability of $H_2O_2$ to increase the efficiency of the $TiO_2$ photocatalytic degradation of dibenzothiophene. The degradation efficiency increases with increasing dosage of $H_2O_2$ in the range of 0.01M to 0.1M . The effect of pH is investigated; we obtained the maximum photodegradation efficiency at pH 5. In addition, the intermediate analysis found dihydroxyl -dibenzothiophene as a reaction intermediate of dibenzothiophene during the photodegradation.