• Tribology and Lubricants
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• v.18 no.5
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• pp.319-323
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• 2002

Polyol esters were synthesized by condensation reaction of polyols (PE and DiPE) and linear acids such as valeric acid, caproic acid, heptylic acid and caprylic acid. The structures of polyol esters were confirmed by gas chromatography. Hot tube test was used test was used to measure thermal stability of polyol esters and its thermal properties depended on the structure of acid moiety contained in polyol esters.

• Membrane Journal
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• v.25 no.3
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• pp.216-222
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• 2015

The method measuring LEP (liquid entry pressure) was optimized to evaluate the wettabilities of hydrophobic membranes which might affect long-term durability of membrane in MD (membrane distillation) process. Conductivity of the permeate was monitored to measure the LEPs of PE (polyethylene) and PVDF (polyvinylidene di-fluoride) hollow fiber membranes from highly concentrated synthetic feed water of 20 wt% NaCl. Holding time over 5 min and the ratio of membrane area to the tank volume more than $10m^2/m^3$ were required to ensure LEP value.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.6 no.1
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• pp.41-46
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• 2000

The level of plasticizer such as diethyl phthalate (DEP), di-n-propyl phthalate (DprP), di-n-butyl phthalate (DBP), di-n-pentyl phthalate (DPP), butylbenzyl phthalate (BBP), di-(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP) and di-(2-ethylhexyl) adipate (DEHA) was determined in disposable sanitary gloves. Samples of disposable sanitary gloves were taken at retail shops, and their overall extractions in carbon tetrachloride were measured, after establishment of soxhlet appratus in 6 hours. All of 8 samples of disposable sanitary gloves at retail shops were polyethylene (PE). All of the manufactures was voluntarily labelled their boxes of gloves in line Korea Food Code. The level of phthalate esters and DEHA in all of 8 samples were not exceed the detection limit. The detection limits of DEP, DprP, DBP, DPP, BBP, DEHP, DCHP and DEHA were 1.8, 1.9, 1.3, 1.1, 0.9, 0.7, 2.1 and 0.8 mg/L, respectively.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.377-377
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• 2006

Alkoxyamine and thiocarbonyl thio end capped polyethylene (PE) chains were synthesized using a direct and simple approach consisting in reacting di(polyethylenyl)magnesium (PE-Mg-PE) chains with a range of nitroxides and disulfides of thiocarbonyl thio compounds. PE-Mg-PE compounds were prepared by a catalyzed chain growth reaction of ethylene on nbutyloctylmagnesium (BOMg) with a neodymocene complex $(C_{5}Me_{5})_{2}NdCl_{2}Li(OEt_{2})_{2}$. Complete characterizations confirm the introduction of the desired end groups. The controlled radical polymerization (NMP and RAFT) of butyl acrylate mediated by these functional polyethylenes was successful.

• Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.14-21
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• 2006

The aim of this study was to investigate in vivo toxicity and effects of two phthalate esters (PEs), di-n-butylphthalate (DBP) and di-2-ethylhexyl phthalate (DEHP), on the immune system of the bagrid catfish, Pseudobagrus fulvidraco. Groups of experimental fish were subjected to daily intraperitoneal injections of 300 or 1000 mg $kg^{-1}$ of DBP or DEHP for 3 days, and the cellularity and functional activity of phagocytes were measured in the spleen and pronephros (head kidney). The number of spleen leukocyte cells increased significantly (p<0.05) in response to low and high doses of DEHP and DBP, respectively; however, the cellularity of the pronephros was more susceptible to higher dose of DEHP than DBP. Nonspecific immunity, as determined by the phagocytic index (PI) and phagocytic capacity (PC), was significantly depressed by DEHP at 1000 $1000mg\;kg^{-1}\;day^{-1}$ in the pronephros at 3 days after injection. Furthermore, significantly (p<0.05) increased levels of serum glutamic oxaloacetate transaminase (GOT) and glutamic pyruvate transaminase (GPT) indicated marked hepatic dysfunction in immunosuppressed fish. Treated fish showed a significant reduction in total serum protein but no significant alteration in lysozyme activity. These results demonstrate the sensitivity of the fish immune response for predicting PE-induced immunotoxicity.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.479-485
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• 2001

A study of the levels of phthalate and adipate esters, which are suspected as endocrine disruptors, in food packaging wraps and packaged foods were carried out. Among 11 wrap samples, 8 household wraps purchased at retail markets were polyvinyl chloride(PVC) and polyethylene(PE), while 3 commercial wraps at wholesale markets were PVC. All of 51 selected food samples, such as 12 samples of vegetable, 11 samples of fruit, 6 samples of bread and rice cake, 4 samples of meat and poultry, 4 samples of fish and 14 samples of side dish, packaged with commercial PVC wraps containing adipate esters were purchased at retail markets. The level of di-(2-ethylhexyl) adipate(DEHA) and diisononyl adipate(DINA) was from 2.2 to 17.9% and from 4.2 to 22.3% in household PVC wraps, respectively. In the commercial PVC wraps, the level of DEHA showed from 18.3 to 22.5%, while other phthalate esters were not detected. The phthalate and adipate esters were not detected in PE wraps. The level of DEHA in packaged foods, such as vegetable, fruit, bread and rice cake, meat and poultry, fish and side dish, were determined up to $8.2\;{\mu}g/cm^2,\;17.4\;{\mu}g/cm^2,\;31.0{\mu}g/cm^2,\;8.3\;{\mu}g/cm^2,\;2.1\;{\mu}g/cm^2$ and $92.3\;{\mu}g/cm^2$, respectively. The results suggested that migration levels of DEHA in foods were closely related to the fat content, wrapping condition of food and stroage time and temperature.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.89-89
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• 2009

높은 소수반송자 수명(life-time)을 가지는 고품위 실리콘 기판은 고효율 실리콘 이종접합 태양전지 제작을 위한 중요 요소 기술 중 하나이다. 본 연구에서는 n-type c-Si 기판을 이용한 고효율 실리콘 이종접합 태양전지제작을 위해 hot water oxidation(HWO) 공정을 이용하여 고품위 실리콘 기판을 제작하였다. 실리콘 기판의 특성 분석은 Qusi-steady state photoconductance (QSSPC)를 이용하여 소수반송자 수명을 측정하였으며, 기판의 면저항 및 wetting angle을 측정하여 공정에 따른 특성변화를 분석하였다. Saw damage etching 된 기판을 웨이퍼 표면으로부터 particle, 금속 불순물, 유기물 등의 오염을 제거하기 위해 $60{\sim}85^{\circ}C$로 가열된 Ammonia수, 과산화수소수($NH_4OH/H_2O_2/H_2O$), 염산 과산화수소수($HCL/H_2O_2/H_2O$) 및 실온 희석불산(DHF) 중에 기판을 각각 10분 정도씩 침적하여, 각각의 약액 처리 후에 매회 10분 정도씩 순수(DI water)에서 rinse하여 RCA 세정을 진행한 후 HWO 공정을 통해 기판 표면에 얇은 산화막 을 형성시켜 패시베이션 해주었다. HF를 이용하여 자연산화막을 제거시 HWO 공정을 거친 기판은 매끄러운 표면과 패시베이션 영향으로 기판의 소수 반송자 수명이 증가하며, 태양전지 제작시 접촉저항을 감소시켜 효율을 증가 시킬수 있다. HWO 공정은 반응조 안의 DI water 온도와 반응 시간에 따라 life-time을 측정하여 진행하였으며, 이후 PE-CVD법으로 증착된 a-Si:H layer 및 투명전도 산화막, 금속전극을 증착하여 실리콘 이종접합 태양전지를 제작하였다.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.82-90
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• 2013

An Optical Network-on-Chip(ONoC) based on silicon photonics is one of promising technology for next generation exascale computing architectures. Recent active researches on ONoC focus on improving bandwidth further and avoiding path collisions by using wavelength division multiplexing (WDM). However, the number of wavelengths used for the WDM increases linearly as the number of Processing Element (PE) increases in existing ONoCs which adopt centralized routing architecture. The problem will also arises growing cost of optical devices such as light switches and light sources and limits the scalability of ONoC due to the sinal loss caused by interference of distinct light sources. In this paper, we proposes a distributed routing architecture for ONoC which is based on 2D-mesh structure using WDM technique and present a method that minimize the required number of wavelengths exploiting the connectivity of communication. In comparison with existing centralized routing architectures, results show reduction by 56% of the number of wavelengths and 21% of the number of optical switches in $8{\times}8$ networks.

• Journal of Mushroom
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• v.11 no.2
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• pp.77-81
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• 2013

To develop a new cultivar of king oyster mushroom(Pleurotus eryngii), G09-21 as parental strain was selected by the method of Di-mon crossing between monokaryotic strain ASI 2824-21 derived from ASI 2824(Keunneutari No. 2) and dikaryotic strain ASI 2887(Aeryni 3). The Pe21-53(G09-21-10 x ASI 2844-9) was shown the best cultural characteristics, selected to be a new cultivar and designated as 'Seolsong'. The 'Seolsong' was distinctly formed incompatibility line in the confrontation growth of parental strains Keunneutari No. 2, Aeryni 3 and ASI 2844. Analysis of the genetic characteristics of the new cultivar 'Seolsong' showed a different DNA profile as that of the control strains, Keunneutari No. 2, Aeryni 3 and ASI 2844, when RAPD(Random Amplified Polymorphic DNA) primer URP4 was used. The optimum temperature and pH arrange for mycelial growth were $25{\sim}30^{\circ}C$ and pH 5~8, respectively. This new cultivar 'Seolsong' of fruiting body production per bottle was about $131.4{{\pm}}43.1$ g which is about 102% quantity compared to that of other cultivar Keunneutari No. 2. And also the stipe is thick and long, but the number of available stipe is few. Particularly, it was tolerant of high moisture above 90% during the growth period after primodia formation. We therefore expect that this new strain will save of labor and cost of cultivation by without culling work.

• Nuclear Engineering and Technology
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• v.56 no.10
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• pp.4184-4194
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• 2024

New technologies in polymer synthesis and pipe extrusion equipment have led to the commercialization of high-performance, large-diameter, thick-wall high density polyethylene (HDPE) pipes. They have been used in the field of seawater transport and cooling to replace metal pipes, due to their advantages of high corrosion resistance and extensibility. Connection of HDPE pipe is important as it determines the safety of the entire piping system. Butt fusion welding is commonly used for HDPE pipe connection but may cause the formation of weak points in the welded joints, interfering the reliability of the pipeline system in the application of nuclear power plants. At present, there is a lack of research on evaluating the performance of welded joint for large-diameter thick-wall HDPE pipes made by butt fusion-welding. The purpose of this study is to investigate the influence of three different butt fusion-welding processes, i.e., single low pressure (SLP), single high pressure (SHP) and dual low pressure (DLP), by evaluating the performance of their welded joints, including characterizing tensile strength, extensibility, crystallinity and hardness. In specific, a thick-wall HDPE pipe with OD of 812.8 mm and wall thickness of 74 mm which is certified for nuclear safety class was used for study. Representative specimen from the outer, middle and inner part across the wall of the main pipe body and welded joints were taken for testing. Different test methods and specimens were designed to assess the feasibility of evaluating the welding performance from different welding process. The results showed that the mechanical properties of different locations of the welded joints were different, and the tensile strength and fracture energy of the middle part of the joint were lower than that of the inner and outer parts, which could be caused by the difference in the crystallinity and thickness of the melting zone influenced by welding processes, as can be seen from the analysis of DSC test and morphology observation. Hardness testing was conducted on the section of the welded joints, and it revealed that the micromechanical properties of the welded joints in the region of the heat-affected zone were enhanced significantly, which may be due to the annealing effect caused by welding process. In summary, The DLP process resulted in the best extensibility of the welded joints among three processes, suggesting that the joining pressure from welding process plays an important role in affecting the extensibility of the welded joints.