• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.200-208
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• 2004

Effects of cucumber and tomato seed germination by previous leaf and root vegetables (cabbage, radish, welsh onion, lettuce) residue in soil were tested in pot condition. Overall, suppression effect of welsh onion residue was the greatest in 4 tested crop residue and followed by radish, cabbage and lettuce, but lettuce residue didn't have effect on cucumber seed germination. Suppression were maintained ca. 20 days but after the time point, growth of cucumber and tomato were enhanced. Enhancing effect of welsh onion residue was the greatest in 4 tested crops residues and followed by radish, cabbage and lettuce. As a conclusion, residue of welsh onion, radish and cabbage were suppressed the germination of cucumber and tomato seeds but enhanced growth after 20 days of treatment. To verify the effective concentration of residue on suppression of germination and growth of radicle of cucumber and tomato, plant extract of welsh onion, radish, cabbage and lettuce were diluted as 5, 10, 17, 23, 35, 50, and $65\%$, and then tested. In low concentration treatment, 5, 10, 17, and $23\%$, all 4 crop extracts didn't suppress cucumber seed germination. High concentration of lettuce extract, 35, 50, and $65\%$, cucumber seed didn't germinate at all. In case of welsh onion extract, only $65\%$ treatment suppressed cucumber seed germination. In low concentration treatment, 17, and $23\%$, only the welsh onion extract suppressed young radicle. In case of high concentration treatment, except $35\%$, all four crops extract suppressed cucumber radicle growth. In low concentration treatment, tomato seed germination was suppressed by lettuce extract only but in high concentration treatment, 35, 50, and $65\%$, all extracts suppressed germination. Especially higher than $50\%$ treatment, tomato seed didn't germinate at all. Radicle growth was highly suppressed in welsh onion and lettuce extract, higher than $23\%$ concentration. As conclusion, leaf and root vegetable extracts suppressed cucumber and tomato seed germination and in high concentration, also suppressed radicle growth.

• Analytical Science and Technology
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• v.6 no.2
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• pp.231-238
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• 1993

The thermal behavior of binder in multi-layer actuator has an effect on the properties of actuator. Binder burn-out process and thermal degradation mechanism of PNN-PZT/Acrylic binder were analyzed by FTIR, DSC, TGA. Binder was burnt out by two step. In oxygen atomsphere, thermal degradation was activated and final residue was minimized to 5%.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.610-610
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• 2013

그래핀을 구성하는 탄소 원자는 모두 표면에 존재하기 때문에, 맞닿아 있는 물질에 따라 그래핀의 물리적 특성에 민감한 영향을 미치기도 한다. 본 연구에서는 라만분광법과 원자 힘 현미경(atomic force microscopy, AFM)을 이용하여 통상적인 열처리 조건에서 그래핀에 탄화수소가 흡착될 수 있는 가능성을 탐구하였다. 산소가 없는 조건에서 열처리된 그래핀으로부터 D, G, 2D 봉우리와 겹쳐지는 폭이 넓은 새로운 라만 봉우리들이 관찰되었다. 열처리 시간, 온도 및 진공도에 따른 라만 스펙트럼의 변화와AFM에 의해 확인된 표면의 구조 변화로부터 새로이 관찰된 라만 봉우리는 탄화수소의 탄화에 의해 그래핀의 표면에 형성된 비결정성 탄소물질(amorphous carbon)임을 확인하였다. 기계적 박리법과 화학기상증착법으로 시료를 준비할 때 사용된 폴리머 잔유물이 열처리 과정에서 탄화수소를 배출하는 것으로 판단된다. 이 연구는 그래핀 소자의 작동에 있어서 환경적인 효과를 이해하고 탄화에 의해 그래핀 표면에 만들어진 비결정질 탄소를 정량화하는데 도움을 줄 것이다.

• Journal of the Korean Society of Radiology
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• v.83 no.5
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• pp.1003-1013
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• 2022

Biliary atresia is an unknown etiology of extrahepatic bile duct obstruction with a 'fibrous ductal remnant,' which represents the obliterated ductal remnant in the porta hepatis. The sonographic 'triangular cord' (TC) sign has been reported to indicate a fibrous ductal remnant in the porta hepatis. In this review, we discuss the correlations among surgicopathological and sonographic findings of the porta hepatis and the definition, objective criteria, diagnostic accuracy, and differential diagnosis of the TC sign in biliary atresia.

• Journal of Conservation Science
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• v.27 no.3
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• pp.301-312
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• 2011

Epoxy resin has superior durability and adhesive strength and proper physical strength so that it is used to diversity materials for multi-purposes. However epoxy resin is hardly removed after hardening specially once it is applied to artefacts, it is difficult to remove them under re-conservation. This paper is an experimental study on removing epoxy resin applied to iron objects using Nd:YAG laser cleaning system. Tests conducted in this study investigated how increasing laser energy and pulses would give effect on samples. The samples were prepared in a way that epoxy resin, itself pure and one which was mixed with pigment and they were applied to iron coupons and corroded iron coupons respectively. As a result of experiment, pure epoxy resin applied to corroded iron coupons was ablated at high laser energy but epoxy resin applied to iron coupons and mixing with pigment were not ablated but discolored and bubbled due to laser-induced heat generation. Results of FT-IR showed no component alteration of shifted resins and no residues on the surfaces ablated by laser irradiation. From SEM-EDS for removed surfaces, the debris from epoxy resin and melting iron was observed. Therefore, this study demonstrated the possibilities and limitations for laser cleaning to remove epoxy resin from iron objects.

• Elastomers and Composites
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• v.36 no.4
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• pp.225-236
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• 2001

In order to improve the properties of the copolymer and the terpolymer that was used as removal-type pressure sensitive adhesive(PSA), we synthesized quaterpolymer with the variation of the types of monomer, initiator, and solvent, and concentration, the monomer/solvent ratio, reaction temperature and time. and determined the properties of this adhesive: the viscosity, molecular weight, conversion, solid content and structure of polymer. The prepared polymer was crosslinked by changing the type of crosslinking agent and concentration, and then we investigated the characteristics or adhesive such as peel adhesion, shear adhesion, heat resistance, weathering resistance and peel adhesion to aging. The optimum performance of RA/2- EHA/MMA/2-HEMA as a PSA were obtained when benzoyl peroxide was used as an initiator with the reactant mixture consisted of 80% BA and 2-EHA, 15%, MMA, and 5% 2-HFMA. The optimum reaction temperature and time were $80^{\circ}C$ and 8 hours, respectively. For BA/2-EHA/MMA/AA, the optimum performance was obtained when the polymerization was performed at the monomer composition of 80% BA/2-EHA, 15% MMA, and 5% AA. BPO was used as initiator and the optimum reaction temperature and time were identical to those of BA/2-EHA/MMA/ 2-HEMA. Isocyanate and melamine were used to crosslink BA/2-EHA/MMA/2-HEMA and BA/2-EHA/MMA/AA, respectively. No effect on the type of cross-linking agent on the peel adhesion was observed with aging. The quarterpolymers crosslinked with melamine left residues on the counter surface after weathering resistance test, while the polymers crosslinked with isocyanate did not.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.3
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• pp.295-305
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• 1994

Greenhouse and laboratory studies were conducted to investigate the allelopathic potential of alfalfa and vetch residues on soybean and corn using various extract concentrations (0, 5, 10, 15 and 20%, w/v) and residue rates (0, 0.25, 0.5, 0.75 and 1%, w/w). Aqueous extracts of alfalfa (Medicago sativa L.) and vetch (Vicia spp.) exhibited an allelopathic effect on soybean and corn seed germination, seedling length and weight. The degree of inhibition significantly increased as the aqueous extract concentration increased. Alfalfa and vetch 20% extracts reduced soybean seed germination, seedling length and weight by 35%, 57%, 32% and 15%, 42%, 25% respectively, when compared to control. Corn germination, seedling length and weight was inhibited by 20%, 23%, 38% by alfalfa and 19%, 18%, 35% by 20% vetch extracts. Alfalfa and vetch extracts inhibited secondary root formation and branching as the extract concentration increased. Alfalfa and vetch 20% extracts inhibited by 41% and 32% secondary root numbers, respectively as compared to control. It was found that the aqueous extract of alfalfa resulted in greater reduction in germination, seedling length and weight of soybean than that of vetch. Alfalfa and vetch 1% residue rate inhibited soybean plant height by 30% and 10%, leaf area by 31% and 23%, and dry weight by 18% and 1%, nodule number by 27% and 20% also. Alfalfa and vetch residue significantly enhanced plant height, leaf area and dry weight of corn. The maximum stimulation occurred with 0.25% and 1% of alfalfa and vetch residue rates, respectively. Plant height, leaf area, and dry weight increased by 23%, 59%, 58% and 17%, 52%, 94% with alfalfa and vetch residues of 0.25% and 1%, respectively. This study demonstrates that there is an allelopathic potential resulting from alfalfa and vetch residues on soybean growth and yield. It also suggests that these residues may affect crop growth and development due to the inhibitory or stimulatory effects of allelochemicals existing in the residue.

• Journal of the Korean Chemical Society
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• v.52 no.2
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• pp.133-139
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• 2008

A new sensitive and selective spectrophotometric method for determination of trace amounts of cadmium using a polyvinyl chloride membrane containing bis-(2-ethylhexyl)phthalate as a solid phase extraction medium was investigated. Bis-(2-ethylhexyl)phthalate has used as a plasticizer. Cd(II) in an aqueous solution was trapped on the membrane in the form of colorful Cd (II)-I- - MG complexes (which MG is malachite green) and the cadmium complex was concentrated in the membrane. The absorbance of the green membrane was measured at 629 nm using a spectrophotometer, and then, the concentration of the cadmium was calculated using a calibration curve, which expressed the relationship between the Cd(II) concentration and the membrane absorbance after coloring for 25 min. The calibration curve was linear in the range of 10-760 μgL-1 cadmium in the test solution. The detection limit based on the 3Sbl criterion was 1.8199 μgL-1 and the relative standard deviations (RSD) were less than 4 % (n=5). The proposed method has been successfully applied to the determination of trace amounts of cadmium in the Tadjan River water sample (Sari-Iran), and the mean value of 28.7 μgL-1 was obtained.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.23-23
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• 2011

Chemical-Mechanical Planarization (CMP) 공정이란 화학적 반응 및 기계적인 힘이 복합적으로 작용하여 표면을 평탄화하는 공정이다. 이러한 CMP 공정은 반도체 산업에서 회로의 고집적화와 다층구조를 형성하기 위하여 도입되었으며 반도체 제조를 위한 필수공정으로 그 중요성이 강조되고 있다. 특히 최근에는 Inter-Level Dielectric (ILD)의 형성과 Shallow Trench Isolation (STI) 공정에서실리콘 산화막을 평탄화하기 위한 CMP 공정에 대해 연구가 활발히 이루어지고 있다. 그러나 CMP 공정 후 scratch, pitting corrosion, contamination 등의 Defect가 발생하는 문제점이 존재한다. 이 중에서도 scratch는 기계적, 열적 스트레스에 의해 생성된 패드의 잔해, 슬러리의 잔유물, 응집된 입자 등에 의해 표면에 형성된다. 반도체 공정에서는 다양한 종류의 실리콘 산화막이 사용되고 gks이러한 실리콘 산화막들은 종류에 따라 경도가 다르다. 따라서 실리콘 산화막의 경도에 따른 CMP 공정 및 이로 인한 Scratch 발생에 관한 연구가 필요하다고 할 수 있다. 본 연구에서는 scratch 형성의 거동을 알아보기 위하여 boronphoshposilicate glass (BPSG), plasma enhanced chemical vapor deposition (PECVD) tetraethylorthosilicate (TEOS), high density plasma (HDP) oxide의 3가지 실리콘 산화막의 기계적 성질 및 이에 따른 CMP 공정에 대한 평가를 실시하였다. CMP 공정 후 효율적인 scratch 평가를 위해 브러시를 이용하여 1차 세정을 실시하였으며 습식세정방법(SC-1, DHF)으로 마무리 하였다. Scratch 개수는 Particle counter (Surfscan6200, KLA Tencor, USA)로 측정하였고, 광학현미경을 이용하여 형태를 관찰하였다. Scratch 평가를 위한 CMP 공정은 실험에 사용된 3가지 종류의 실리콘 산화막들의 경도가 서로 다르기 때문에 동등한 실험조건 설정을 위해 동일한 연마량이 관찰되는 조건에서 실시하였다. 실험결과 scratch 종류는 그 형태에 따라 chatter/line/rolling type의 3가지로 분류되었다 BPSG가 다른 종류의 실리콘 산화막에 비해 많은 수에 scratch가 관찰되었으며 line type이 많은 비율을 차지한다는 것을 확인하였다. 또한 CMP 공정에서 압력이 증가함에 따라 chatter type scratch의 길이는 짧아지고 폭이 넓어지는 것을 확인하였다. 본 연구를 통해 실리콘 산화막의 경도에 따른 scratch 형성 원리를 파악하였다.

• Resources Recycling
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• v.22 no.2
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• pp.71-77
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• 2013

Electronic products such as appliances, computers, and cellular phones have printed circuit boards (PCBs) in common and the PCBs in the waste electronic products contain valuable metals and organic resins. In Korea, recovery and recycling of the organic resins as well as the valuable metallics from the wastes are required indeed as the most of resources are being imported from abroad. In this article, the patents and papers for the recycling of organic residues from the waste PCBs were collected and analyzed. The open patents of USA (US), European Union (EP), Japan (JP), and Korea (KR) and SCI journals from 1979 to 2012 were investigated. The patents and journals were collected using key-words and filtered by the definition of the technology. The patents and journals were analyzed by the years, countries, companies, and technologies and the technical trends were discussed in this paper. It is showed sluggish relatively activity of published papers and patent applications for polymer manufacturing technology in local and abroad.