• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.339-340
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• 2002

Natural castor oil was chemically reconstructed to extend the carbon chains by means of iso-reaction so as to improve the rheological behavior, by way of increasing the viscosity index and decreasing the pour point. The rheological and tribological characteristics of the reconstructed castor oil were comparatively investigated with those of the natural castor oil and several other vegetable oils and a mineral oil. The friction and wear test results on a four-ball machine indicate that the chemically reconstructed castor oil has considerably improved rheological and tribological properties as compared with the natural castor oil. It shows a greatly increase viscosity index and largely decreased pour point, which makes it applicable to low temperature lubrication. The chemically reconstructed castor oil even shows better tribological behavior than pentaerythritol ester or di-iso-capryl sebacate. However, it is still needed to increase the oxidation stability of the reconstructed castor oil.

• 접착 및 계면
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• 제18권4호
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• pp.179-182
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• 2017

본 연구에서는 polycaprolactone diol, castor oil과 4,4'-methylene dicyclohexyl diisocyanate 를 소프트 도메인으로, dimethylol butanoic acid를 내부 유화제로, trimethylamine을 중화제로 사용하여 다른 분자량을 가지는 prepolymer를 기초로 castor oil 기반의 수분산 폴리우레탄을 성공적으로 합성하였다. 분자량 변화에 따른 기계적인 물성 변화(UTM), 표면의 친수성 확인(contact angle), castor oil 유무에 따른 표면개질 변화(FE-SEM) 등을 평가 분석하였다. Castor oil 기반의 수분산 폴리우레탄의 경우 표면 친수성 향상 및 개질 변화를 기대할 수 있으며, 다양한 접착제 분야에 적용될 유망한 후보 물질로 여겨질 수 있을 것으로 예상된다.

• BMB Reports
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• 제47권2호
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• pp.92-97
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• 2014

We have examined the effect of bithorax complex genes on the expression of castor gene. During the embryonic stages 12-15, both Ultrabithorax and abdominal-A regulated the castor gene expression negatively, whereas Abdominal-B showed a positive correlation with the castor gene expression according to real-time PCR. To investigate whether ABD-B protein directly interacts with the castor gene, electrophoretic mobility shift assays were performed using the recombinant ABD-B homeodomain and oligonucleotides, which are located within the region 10 kb upstream of the castor gene. The results show that ABD-B protein directly binds to the castor gene specifically. ABD-B binds more strongly to oligonucleotides containing two 5'-TTAT-3' canonical core motifs than the probe containing the 5'-TTAC-3' motif. In addition, the sequences flanking the core motif are also involved in the protein-DNA interaction. The results demonstrate the importance of HD for direct binding to target sequences to regulate the expression level of the target genes.

• KSBB Journal
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• 제14권6호
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• pp.696-701
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• 1999

본 연구에서는 lipase를 이용해서 ricinoleic acid를 대량생산하기 위해 피마자유의 완전가수분해 조건을 찾고자 하였다. 널리 알려진 lipase CR, lipase CC, lipase PP를 대상으로 피마자유의 가수분해의 가능성을 시험하고, 유기용매를 사용함으로써 가수분해도를 향상시킬 수 있음을 확인하였다. 일반적으로 lipase의 활성을 감소시키는 극성용매의 경우 피마자유의 가수분해에 있어서도 효소의 활성을 감소시켰고, 물과 섞이지 않는 hydrophobic solvent가 피마자유의 가수분해도를 크게 증가시키는 것을 확인하였다. 본 연구에서는 isopropyl ether의 효과가 가장 크며, 조건에 따라 가수분해도를 두 배 이상 증가시킨다는 것을 확인하였다. 그리고 유기용매를 사용함으로써 pH의 영향을 바꾸거나 감소시킬 수 있다는 사실도 확인하였다. 용매와 물의 부피비에 의해서 가수분해가 영향을 받는다는 사실과 특히 유기용매보다는 물의 양에 절대적으로 영향받는다는 사실을 발견하였다. 하지만, 물과 유기용매의 부피비와 함께 lipase와 피마자유의 무게비도 매우 중요하다는 것을 확인하였다. 30$^{\circ}C$에서 isopropyl ether를 사용할 경우 무게 비로 2 wt%일 때는 약 82%, 4 wt% 이상의 lipase CC나 lipase CR을 사용하면 피마자유가 완전히 가수분해되는 사실을 발견하였다.

• 대한약침학회지
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• 제25권2호
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• pp.71-78
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• 2022

Objectives: Post-term pregnancy is a condition associated with increased maternal and fetal complications. Administration of castor oil causes cervical stimulation by increasing the production of prostaglandins. We examined the effects of castor oil on cervical ripening and labor induction through a systematic review and meta-analysis. Methods: The search process was performed to obtain relevant articles from databases including Pubmed, Cochrane library, Scopus, Science direct, SID, Iran Medex, and Google Scholar using the English keywords of cervical ripening, post-term, castor oil, labor induction, Bishop score, and pregnancy considering all possible combinations without time constraints and their Persian equivalents from national databases. Results: A total of eight related articles from the 19 primary studies were extracted and systematically reviewed. According to a cumulative chart, the difference in the post-intervention Bishop score was statistically significant (standard mean difference [SMD]: 1.64, 95% confidence interval [CI]: 1.67-2.11, p = 0.001), indicating an effect of castor oil on increasing the Bishop score. In addition, the difference in labor induction was statistically significant after the intervention (odds ratio: 11.67, 95% CI: 3.34-40.81, p = 0.001), indicating an effect of castor oil on increasing the odds ratio of labor induction (experience of vaginal delivery). Conclusion: This meta-analysis showed that oral administration of castor oil is effective for cervical ripening and labor induction. Midwives should closely monitor pregnant women with prolonged labor and collaborate with obstetricians to employ castor oil as a safe intervention to induce cervical ripening and labor to prevent undue caesarean surgery.

• The Plant Pathology Journal
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• 제17권6호
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• pp.357-360
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• 2001

Gray mold was observed on leaves of castor bean grown in Woniu and Okcheon in Korea in October 2000. Symptoms developed in the form of spot and blight with sporulation of the causal fungi at the marginal or central parts of the leaves. A total of 25 isolates were obtained from the infected leaves of castor bean. Out of the 25 isolates, 5 isolates which originated from Woniu were identified as Botrytis cinerea, while 20 isolates from Okcheon were identified as Amphobotrys ricini based on morphological and cultural characteristics. Two isolates each of B. cinerea and A. ricini were tested for their pathogenicity to castor bean plants. Gray mold symptoms similar to those observed in the fields were induced on leaves of castor bean by artificial inoculation. This is the first report of gray mold in castor bean caused by B. cinerea and A. ricini in Korea.

• 대한화장품학회지
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• 제10권1호
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• pp.42-48
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• 1984

The comparative detergency of Sodium dodecyl sulfate (SDS) solution near the first critical micelle concentration (CMC) was measured by means of a 131 I-labelled castor oil as a soil. More than 95% radiochemical purity of 131 I-labelled castor oil was obtained using potassium lidide as a carrier. Polyester test fabric was soiled with 131 I-labelled castor oil, and washed in a conventional washing apparatus mounted on appropriate devices. Fabric radioactivities were measured before and after washing by a scintilation counter. Near the first CMC, the detergency of SDS was increased with decreasing of surface tension of SDS. It was also shown that 131 I-labelled castor oil was useful for studying the detergency of SDS.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2296-2302
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• 2018

Internally plasticized PVC was prepared via chemical reaction of azide PVC and alkynyl group containing castor oil methyl ester. The chemical structure of alkynyl group containing castor oil methyl ester and internally plasticized PVC was characterized with FT-IR and $^1H$ NMR. Properties of internally plasticized PVC, including thermal stability, tensile tests and resistance to extraction in different solvents, was investigated. The results showed that alkynyl group containing castor oil methyl ester, as internal plasticizer of PVC, not only decreased the $T_g$ of PVC from $84.6^{\circ}C$ to $41.6^{\circ}C$ efficiently, but also presented no plasticizer loss in five different solvents. The tensile tests showed that elongation at break and tensile strength of internally plasticized PVC was 353.8% and 18.1 MPa. The internally plasticized PVC has potential application in replacing the traditional PVC material in PVC products with high durability.

• 한국초지조사료학회지
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• 제12권4호
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• pp.232-238
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• 1992

To understand the basic information on the management and utilization of reed canarygrass (Phalaris arundinacea L.), four cultivars of Palaton. Venture, Castor and Frontier (control) were compared for growth characteristics, dry matter (DM) yield and nutritive value, 1990 to 1992. The reed canarygrass was harvested four times annually, at soiling stage. The average plant height at harvest was 60 cm in Frontier, 57 cm in Palaton and Venture, and 52 cm in Castor. Initial heading and heading date in 1990 were ca. 21 May and 29 May, respectively, regardless of cultivar. The highest yield (12.495 kg/ha) in 1990 was observed by Frontier. In 1991. Palaton. Venture and Frontier outyielded Castor significantly, and the yields of all cultivars in 1992 were not significant, ranged from 11,460 kg (Castor) to 12,298 kg/ha (Palaton). On an average for three years, Palaton (10,592 kg), Venturc (10,405 kg) and Frontier (1 1,277 kg/ha) produced more forages than Castor. In Frontier the percentage of DM distribution at first harvest (spring) was highest (32.4%). However, the distributions at third (summer) and fourth (autumn) harvest were high in Palaton and Venture, compared with Frontier. The nutritive value of reed canarygrass was not significantly different among cultivars, and the percentage of weeds was slightly high in Castor reed canarygrass.

• 청정기술
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• 제17권3호
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• pp.238-243
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• 2011

본 연구에서는 폴리우레탄을 위한 친환경 폴리올 합성을 위하여 피마자유 기반의 폴리올을 합성하였다. 피마자유의 2차 알콜에 다른 촉매 없이 무수말레산을 이용하여 카르복실기를 도입하고, 이를 1차 알콜로 전환하기 위하여 아미노알콜($H_2N$-R-OH) 유도체를 반응시켜 친환경 폴리올을 제조하였다. 다양한 비율의 피마자유와 무수말레산의 반응이 시험 되었으며, 전체 반응은 상대적으로 낮은 공정온도와 무촉매 반응을 기반으로 수행되었다. 긴 곁가지가 도입되어 유동성을 가지고 있는 피마자유 기반의 천연폴리올이 기존의 합성폴리올과 가장 우수한 상용성을 나타내었다.