• Title/Summary/Keyword: surface reactivity

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A Correlation Study on Surface Contamination of Semiconductor Packaging Au Wire by Components of Rinse (반도체 패키지용 Au Wire의 표면처리용 린스 성분에 따른 표면오염 비교 연구)

  • Ha-Yeong Kim;Yeon-Ryong Chu;Jisu Lim;Gyu-Sik Park;Jiwon Kim;Dahee Kang;Yoon-Ho Ra;Suk Jekal;Chang-Min Yoon
    • Journal of Adhesion and Interface
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    • v.25 no.2
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    • pp.63-68
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    • 2024
  • In this study, the contamination of gold(Au) wire according to the types of rinse applied for surface treatment in the wire bonding process is investigated and confirmed. For the surface treatment, rinses containing silicon(Si) or those based on organic materials are mainly employed. To identify their effects, surface treatment is conducted on Au wire using two types of rinse at a 1.0 wt% concentration, referred to as Si-including and Oil-based rinse-coated Au wire. Subsequently, a simulation experiment is performed to verify the reactivity of dust containing Si components that could occur in the semiconductor process. Through optical microscopy (OM) and scanning electron microscopy(SEM) analysis, it is observed that a larger amount of dust is adsorbed on the surface of Si-including rinse-coated Au wire compared with the Oil-based rinse-coated Au wire. This is attributed that the rinse containing Si components is relatively polar, causing polar interactions with dust, which also has polarity. Therefore, it is expected that using a rinse without Si components can reduce contamination caused by dust, thereby decreasing the defect rate in the practical wire bonding process.

Theoretical Study on the Reaction Mechanism of Azacyclopropenylidene with Epoxypropane: An Insertion Process

  • Tan, Xiaojun;Wang, Weihua;Li, Ping
    • Bulletin of the Korean Chemical Society
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    • v.35 no.9
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    • pp.2717-2722
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    • 2014
  • The reaction mechanism between azacyclopropenylidene and epoxypropane has been systematically investigated employing the second-order M${\o}$ller-Plesset perturbation theory (MP2) method to better understand the reactivity of azacyclopropenylidene with four-membered ring compound epoxypropane. Geometry optimization, vibrational analysis, and energy property for the involved stationary points on the potential energy surface have been calculated. It was found that for the first step of this reaction, azacyclopropenylidene can insert into epoxypropane at its C-O or C-C bond to form spiro intermediate IM. It is easier for the azacyclopropenylidene to insert into the C-O bond than the C-C bond. Through the ring-opened step at the C-C bond of azacyclopropenylidene fragment, IM can transfer to product P1, which is named as pathway (1). On the other hand, through the H-transferred step and subsequent ring-opened step at the C-N bond of azacyclopropenylidene fragment, IM can convert to product P2, which is named as pathway (2). From the thermodynamics viewpoint, the P2 characterized by an allene is the dominating product. From the kinetic viewpoint, the pathway (1) of formation to P1 is primary.

Effect of Absorbed Metal Ion Concentration by After-treated Mordanting on the Color and Fastness in Human Hair and Wool Fiber Dyed with African Marigold Petals Extract (아프리칸 매리골드(Tagetes erecta L.) 꽃 추출물(抽出物)로 염색(染色)한 모발(毛髮)과 양모섬유 염색(羊毛纖維 染色)에서 후매염(後媒染)에 의해서 흡착(吸着)된 금속(金屬)이온 농도(濃度)가 색상(色相)과 견뢰도(堅牢度)에 미치는 영향(影響))

  • Kim, Kyung-Sun;Jeon, Dong-Won
    • Journal of Fashion Business
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    • v.10 no.5
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    • pp.45-57
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    • 2006
  • In the previous study, african marigold petals extract was valued as an excellent natural yellow dye because of its distinguished reactivity with various mordants and color fastness. In this study, we were studied on effect of absorbed metal ion by after-treatment of mordants on the color and fastness in human hair and wool fiber dyed with african marigold petals extract because the proteinic and cellulosic fiber were very well dyed. The dyed human hair showed better dyeing ability in the color fastness than wool fiber on tests of light, wash and perspiration. The absorbed metal ion concentration of mordanted human hairs were 1 or 5 times higher than wool fibers. However, excess of absorbed metal ion haven't consistent effect on K/S and surface color. Human hairs dyed using african marigold extract and mordanted with Al, Sn, Cu and Fe were showed various reddish yellow color groups and good dyeing ability on african marigold extract.

Effect of SiC Particles Size on the Densification of $Al_2O_3-SiC$ Composite During Pressureless Sintering ($Al_2O_3-SiC$ 복합재료의 상압소결시 치밀화에 미치는 SiC 원료분말의 크기영향)

  • 채기웅
    • Journal of the Korean Ceramic Society
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    • v.36 no.11
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    • pp.1261-1265
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    • 1999
  • Effect of SiC particle size of the densification of Al2O3-SiC composite during pressureless sintering was investigated. Two types of SiC powders having average particle size of 0.15${\mu}{\textrm}{m}$ and 3${\mu}{\textrm}{m}$ were used. Densification rate of the specimen containing 0.15${\mu}{\textrm}{m}$ SiC particles was slower than that of the specimen containg 3${\mu}{\textrm}{m}$ SiC particles. Although the relative density of the specimen containing 0.15${\mu}{\textrm}{m}$ SiC particles was below 90% of theoretical density after sintering at 155$0^{\circ}C$ the complete closure of open pores occurred. Therefore full densification could be obtained by subsequent HIP. On the other hand in the specimen containing 3${\mu}{\textrm}{m}$ SiC particles the complete closed pore was observed at 95% of theoretical density. Such a fast pore closure in the specimen containing 0.15${\mu}{\textrm}{m}$ SiC particles is likely to occur as a result of dense reaction layer formation on the specimen surface which is attributed to the high reactivity of small size particles with sintering atmosphere.

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Gas Reaction Characteristics of Waste Oyster Shell Sorbent

  • Jung, Jong-Hyeon;Shon, Byung-Hyun;Kim, Hyun-Gyu;Yoo, Kyung-Seun;Choung, Young-Hean;Choi, Suck-Gyu;Kim, Young-Sik
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2005.06a
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    • pp.365-370
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    • 2005
  • The objective of this study is to develop the sorbent of oyster shell, which can remove gaseous acid pollutants emitted from the incinerator and power plants. The physicochemical properties of prepared absorbents have been measured using ICP and BET Also, this study is to investigate the Hydration/calcination reaction in the fixed bed reactor. Thus, the results could be summarized as follows. Oyster shell can be used in powder type without former processing. It should be also noted that sulfation reactivity of oyster sample increases to about 5 times by calcination/hydration reaction due to the increase of specific surface area and pore volume. From these experiments, we have found that both $SO_2$ and $NO_x$ in simulated flue gas can be effectively removed by use of oyster absorbent.

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Production of Characterization of Monoclonal Antibody to Glycoprotein D Antigen of Herpes simplex Virus Type 2

  • Choi, Young-Sook;Kim, Tae-Un;Lee, Inyung-Hoan;Cho, Myung-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.11 no.2
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    • pp.173-178
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    • 2001
  • A monoclonal antibody (mAb) to the glucoprotein D (gD) of Herpes simplex virus type 2 (HSV-2) was successfully generated by hybridoma technology and characterized. The mAb, SKS2v, recognized a gD antigen with an apparent molecular mass of 60kDa in a Western blot analysis. The isotype was determined by a sandwich ELISA to be IgG2a. HSV-2 exhibited major antigens of 36, 43, 46, 47, 60, 69, 81, 96, 109, 112, 159, and 227 kDa among 25 protein profiles in SDS-PAGE, and among these antigens, those of 60, 112, 125, and 227 kDa were immunodominant in a Western blot analysis using antisera, thereby indicating that they play a role in inducing neutralizing antibodies in HSV-2 infection. When reacted with Vero cells infected with HSV-1 and HSV-2 SKSv2 showed a reactivity to the surface of the infected cells, and a gD antigen of 60 kDa appeared to be expressed in both types of HSV.

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경구투여 백신 후보물질로서의 Helicobacter pylori 외막 단백질의 조사

  • 박형배;최태부
    • Microbiology and Biotechnology Letters
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    • v.25 no.2
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    • pp.129-136
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    • 1997
  • Helicobacter pylori is a spiral-shaped, microaerophilic human gastric pathogen causing chronic-active gastritis in association with duodenal ulcer and gastric cancer. To investigate the possibility of H. pylori outer membrane proteins (OMPS) as the oral vaccine antigens, sarcosine-insoluble outer membrane fraction has been prepared from H. pylori NCTC 11637. The major OMPs having apparent molecular masses of 62 kDa, 54 kDa and 33 kDa were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), which were identified as urease B subunit (UreB), heat shock protein (Hsp54 kDa) and urease A subunit (UreA), respectively. Minor protein bands of 57 kDa, 52 kDa, 40 kDa, 36 kDa and 31 kDa were also observed. The antigenicity of H. pylori OMPs and antigenic cross-reactivity among the strains were determined by immunoblot analysis using anti-H. pylori OMPs antisera or intestinal lavage solutions. The results showed that UreB, Hsp54 kDa, UreA and 40 kDa proteins vigorously stimulated mucosal immune response rather than systemic immunity. From this results, these proteins seemed to be useful as the antigen candidates for the oral vaccine. The immunoblotting results with surface proteins from eight isolated H. pylori strains were similar to that of H. pylori NCTC 11637. The IgA which had been arised from oral administration of H. pylori OMPs, was able to bind H. pylori whole-cells.

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Detection of PCB77 by Indirect Competitive Enzyme-linked Immunosorbent Assay in Sea Sediment Samples

  • Chen, Han-Yu;Zhuang, Hui-Sheng;Yang, Guang-Xin
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.922-926
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    • 2013
  • 3,3',4,4'-Tetrachlorobiphenyl (IUPAC PCB77) is one of seven indicative polychlorinated biphenyls (PCBs) in the surface sediments. The current study presents a novel polyclonal antibody for the determination of the PCB77 using indirect competitive enzyme-linked immunosorbent assay. Under optimum conditions, PCB77 was determined within the concentration range of 0.01-100 ${\mu}g\;L^{-1}$, with a detection limit of 0.057 ${\mu}g\;L^{-1}$. The assays were tested for their cross-reactivity profiles using 3 selected congeners and 4 Aroclor products. The assays were highly specific for coplanar PCB congeners, but less specific for Aroclor1248. The spiked recoveries from five sediment samples were 86%-114% for PCB77 from ELISA, which were satisfactory. The current study demonstrated that the developed antiserum and immunoassay procedure can be used to detect PCB77 in environmental samples. The results of the sediment analysis were confirmed by conventional GC/ECD.

Decomposition of Carbon Dioxide Using Sr Ferrites with Various Compositions (다양한 조성의 Sr 페라이트를 이용한 CO2분해 반응 특성)

  • 신현창;최정철;정광덕;최승철
    • Journal of the Korean Ceramic Society
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    • v.40 no.2
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    • pp.191-197
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    • 2003
  • Sr ferrites with various compositions were applied to the decomposition of $CO_2$ to mitigate the greenhouse effect. In the reduction reaction of Sr ferrites up to 80$0^{\circ}C$, starting temperature was lower with increasing of Sr content in Sr ferrite. However, the reactivity was higher with decreasing Sr content. In the $CO_2$ decomposition reaction with reduced Sr ferrites, the amount of CO and C were depended on the ratio of Sr and Fe in Sr ferrite. With increasing Sr content. larger amount of C were deposited on the surface of ferrite. Therefore, in order to apply Sr ferrites for the decomposition of $CO_2$, it is necessary to control the ratio of Sr and Fe according to the conditions used.

Isolation and Characterization of Vaccine Candidate Genes Including CSP and MSP1 in Plasmodium yoelii

  • Kim, Seon-Hee;Bae, Young-An;Seoh, Ju-Young;Yang, Hyun-Jong
    • Parasites, Hosts and Diseases
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    • v.55 no.3
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    • pp.255-267
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    • 2017
  • Malaria is an infectious disease affecting humans, which is transmitted by the bite of Anopheles mosquitoes harboring sporozoites of parasitic protozoans belonging to the genus Plasmodium. Despite past achievements to control the protozoan disease, malaria still remains a significant health threat up to now. In this study, we cloned and characterized the full-unit Plasmodium yoelii genes encoding merozoite surface protein 1 (MSP1), circumsporozoite protein (CSP), and Duffy-binding protein (DBP), each of which can be applied for investigations to obtain potent protective vaccines in the rodent malaria model, due to their specific expression patterns during the parasite life cycle. Recombinant fragments corresponding to the middle and C-terminal regions of PyMSP1 and PyCSP, respectively, displayed strong reactivity against P. yoelii-infected mice sera. Specific native antigens invoking strong humoral immune response during the primary and secondary infections of P. yoelii were also abundantly detected in experimental ICR mice. The low or negligible parasitemia observed in the secondary infected mice was likely to result from the neutralizing action of the protective antibodies. Identification of these antigenic proteins might provide the necessary information and means to characterize additional vaccine candidate antigens, selected solely on their ability to produce the protective antibodies.