Electropulsing Treatment on Enhancement of Electrical Conductivity of Screen-Printed Ag Wire

Ju‑Won Park,Howook Choi,Hwangsun Kim,Simoon Sung,Hye‑Jin Jeong,Il Kim,Jaeseok Gong,Sung‑Tae Hong,Heung Nam Han 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

The effect of high electric current density on the sintering of Ag wires manufactured by screen printing is evaluated throughelectrical resistivity analysis and microstructure observation. Different forms (continuous and pulsed) of electric currentwith different current densities are applied to the specimens. Conventional heat treatment is also performed as a controlgroup to examine the athermal effect of electropulsing treatment. Compared to the conventional heat treatment, the resistivityis reduced more under the electropulsing treatment with continuous current for the same temperature and treatment time.Also, the process time of electropulsing treatment can be reduced by applying a pulse form of high density current insteadof continuous current without losing the benefit of enhanced reduction of resistivity. The microstructural observationsobtained from high angle annular dark field scanning transmission electron microscope and a digital precession instrumentclearly show that necking connecting the crystals is formed more firmly under electric current. In addition, the temperaturechange of Ag wire and substrate is calculated according to the change of the resistivity when the electric current is appliedto confirm the reliability.

법랑모세포 분화와 법랑질 형성과정에서 OD314, Apin protein의 발현 및 기능

박종태,최용석,김흥중,정문진,오현주,신인철,박주철,손호현 대한치과보존학회 2006 Restorative Dentistry & Endodontics Vol.31 No.6

본 연구에서는 법랑모세포 분화와 법랑질 형성에 연관이 있는 OD314 일명 Apin protein의 기능을 밝힐 목적으로, in-situ hybridization에 의한 OD314 mRNA 발현과 법랑모세포 세포주에서 OD314 enamel matrix protein의 발현, 그리고 OD314 유전자를 과발현/억제시킬 수 있는 construct를 제작한 후 법랑질 형성 중에 OD314의 기능을 알아보고자 RT-PCR를 시행하여 다음과 같은 결과를 얻었다. 1. OD314 mRNA는 발생중인 상아모세포보다 법랑모세포에서 강하게 발현되었다. 2. Tuftelin은 석회화 결정이 형성되는 14일까지 발현이 지속되고, 그 이후부터 점차 감소하였다. Amelogenin과enamelin은 7일부터 그 발현이 점점 감소하였다. 3. U6-OD314 siRNA construct를 이용하여 transfection한 법랑모세포 세포주는 OD314와 tuftelin,MMP2 mRNA 발현이 감소하였으며, CM-OD314를 transfection하여 OD314의 과발현을 유도한 경우에는 OD314와 MMP20 mRNA의 발현이 뚜렷이 증대되었다. 이 결과는 OD314가 법랑모세포의 분화와 법랑질의 형성 그리고 석회화 과정에 중요한 역할을 하는 새로운 인자임을 시사한다. This study was aimed to elucidate the biological function of OD314 (Apin protein), which is related to ameloblast differentiation and amelogenesis. Apin protein, calcifying epithelial odontogenic (pindborg) tumors (CEOTs)-associated amyloid, were isolated from CEOTs, and has similar nucleotide sequences to OD314. We examined expression of the OD314 mRNA using in-situ hybridization during tooth development in mice. Expression of OD314 and several enamel matrix proteins were examined in the cultured ameloblast cell line up to 28 days by reverse transcription-polymerase chain reaction (RT-PCR) amplification. After inactivation and over-expression of the OD314 gene in ameloblast cell lines using U6 vector-driven RNA interference and CMV-OD314 construct, RT-PCR were performed to evaluate the effect of the OD314 during amelogenesis. The results were as follows: 1. In in-situ hybridization, OD314 mRNAs were more strongly expressed in ameloblast than odontoblast. 2. When ameloblast cells were cultured in the differentiation and mineralization medium for 28 days, the tuftelin mRNA expression was maintained from the beginning to day 14, and then gradually decreased to day 28. The expressions of amelogenin and enamelin were gradually decreased according to the ameloblast differentiation. 3. Inactivation of OD314 by U6-OD314 siRNA construct down-regulated the expression of OD314, MMP-20, and tuftelin, whereas over-expression of OD314 by CMV-OD314 construct up-regulated the expression of OD314 and MMP-20 without change in tuftelin. These results suggest that OD314 is considered as an ameloblast-enriched gene and may play the important roles in ameloblast differentiation and mineralization.

국내에서 생산 판매되는 담배 각초에 존재하는 알칼로이드 함량과 주류연의 연기성분 비교 연구

박병주,신주식,임흥빈 충북대학교 연초연구소 2006 煙草硏究 Vol.20 No.-

국내에서 시판되고 있는 69종의 궐련담배 각초를 재료로 하여 궐련담배 각초에 함유되어 있는 alkaloid 함량을 측정하고 궐련담배 주류연의 tar 및 nicotine 함량을 측정하여 비교분석한 결과는 다음과 같다. 1. 국내에서 시판되고 있는 귈련담배는 tar와 nicotine의 함량이 각각 5 mg, 0.5 mg 수준인 담배가 가장 많았다. 2. 국내에서 시판되는 궐련담배 각초 alkaloid 성분의 평균함량은 nicotine 15.7±1.8 mg/g, nornicotine 432±182 μg/g, anabasine 63±28 μg/g, myosmine 52±17 μg/g이었다. 3. Alkaloid 성분 중 nornicotine 함량은 타사 제품에 비해 A사와 군소업체 제품담배에서 유의하게 높았다. 4. 국내에서 시판되는 궐련담배 각초에 존재하는 nicotine의 주류연으로의 이행율은 10 % 이하였다. This study was carried out to compare alkaloids contents existed in tobacco shred, with major components in tobacco smoke from 69 cigarette brands being on sale in Korea. Alkaloids and cigarette smoke components were analysed by gas chromatography. Cigarette brands with the level of tar 5 mg/cig and nicotine 0.5 mg/cig in mainstream smoke were major in Korea. Mean values of nicotine, nornicotine, anabasine, and myosmine contents existed in tobacco shred from 69 cigarette brand were 15.6 ± 1.9 mg/g, 431 ± 187 ug/g, 62 ± 28 ug/g, 53 ± 16 ug/g, respectively. Nornicotine contents existed in tobacco shred of cigarette brands manufactured by A company and some small companies were relatively higher than that other three major companies. Direct transfer rates of nicotine from shred to mainstream smoke in most cigarette being on sale in Korea was lower than 10%. These results indicates that alkaloids contents in tobacco shred from cigarette have something to do with cigarette smoke components and this analysis have to fulfil periodically in order to obtain a basic information for quality evaluation of cigarette smoke in connection with smoking and healths.

국내에서 생산 판매되는 담배 각초에 존재하는 보습제 함량 비교

박병주,임흥빈,이학수 충북대학교 연초연구소 2006 煙草硏究 Vol.20 No.-

This study was carried out to compare humectant contents existed in tobacco shred from 69 cigarette brands being on sale in Korea. Humectant in tobacco shred were extracted by AOAC official method and analysed by gas chromatography. Mean value of glycerol, propylene glycol, and triethylene glycol contents from 69 cigarette brands were 13.6 ± 4.5 mg/g, 6.5 ± 2.6 mg/g, and 0.8 ± 0.2 mg/g, respectively. Humectant contents existed in tobacco shred of cigarette brands manufactured by small tobacco companies were relatively lower than that of the other four major tobacco companies in Korea. These results indicates that humectant contents in tobacco shred from cigarette have to determine periodically in order to give a basic information for quality evaluation of cigarette smoke in connection with smoking and healths, because it plays an important role the formation toxic cigarette smoke components. 본 실험은 국내에서 시판되고 있는 69종의 궐련담배 각초를 재료로 하여 실시하였다. 궐련담배 각초에 함유되어 있는 보습제의 함량을 측정하고 궐련담배 주류연의 tar 및 nicotine 함량을 측정하여 비교분석한 결과는 다음과 같다. 1. 국내에서 시판되는 귈련담배 각초 보습제 성분의 평균함량은 glycerol 13.6±4.5 mg/g, propylene glycol 6.5±2.6 mg/g, triethylene glycol 0.8±0.2 mg/g이었다. 2. 군소업체 귈련담배 각초에 존재하는 보습제 함량은 대규모업체에 비해 상대적으로 매우 낮은 수준을 유지하고 있었다

법랑모세포 분화와 성숙과정에서 OD314의 발현

박주철,안성민,김흥중,정문진,박민주,신인철,손호현 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.5

법랑모세포는 법랑질을 형성하고 유지하는 세포로, 법랑질의 유기기질을 분비하고 법랑질 석회화 과정에도 관여한다. 치아 발생과정에서 법랑모세포의 분화는 순차적인 상피-간엽 상호작용에 의하여 조절되나, 분화나 성숙과정의 정확한 기전은 아직까지 잘 알려져 있지 않다. 최근에 상아모세포에서 처음 발견된 OD314가 치아 발생과정에서 상아질을 형성하는 상아모세포 뿐 아니라 법랑모세포에도 발현된다고 하였다. 이에 본 연구에서는 생쥐 하악 전치의 다양한 시기의 법랑모세포를 이용하여, 형태학적 분석과 in-situ hybridization에 의한 OD314 mRNA의 발현 그리고 OD314 항체를 이용한 면역조직화학적 분석을 통하여 OD314 유전자의 법랑 모세포 분화와 성숙과정에서의 역할을 연구하여 다음과 같은 결과를 얻었다. 1. 형태학적으로 법랑모세포는 분화 단계에 따라 분비 전단계 법랑모세포, 분비기 법랑모세포, 성숙기의 평탄끝 법랑모세포와 성숙기의 주름끝 법랑모세포로 구분되었다. 2. OD314 mRNA는 분비기의 법랑모세포에서부터 발현되기 시작하여 법랑모세포가 성숙해갈 수록 그 발현이 증가하였다. 3. OD314 단백질은 분비 전단계의 법랑모세포에서는 발현되지 않고, 분비기의 법랑모세포에서는 세포질에 전체적으로 발현되었다. 성숙기의 평탄끝 법랑모세포와 주름끝 법랑모세포에서는 세포의 근심과 원심끝단에 OD314 단백질이 강하게 발현되었다. 이상의 결과를 종합하여 OD314는 법랑모세포의 분화와 성숙과정에서 세포질 내부에서 특징적인 역할을 하는 것으로 사료된다. Ameloblasts are responsible for the formation and maintenance of enamel which is an epithelially derived protective covering for teeth. Ameloblast differentiation is controlled by sequential epithelial-mesenchymal interactions. However, little is known about the differentiation and maturation mechanisms. OD314 was firstly identifled from odontoblasts by subtraction between odontoblast/pulp cells and osteoblast/dental papilla cells, even though OD314 protein was also expressed in ameloblast during tooth formation. In this study, to better understand the biologcal function of OD314 during amelogenesis, we examined expression of the OD314 mRNA and protein in various stages of ameloblast differentiation using in-situ hybridization and immunohistochemistry. The results were as follows : 1. The ameloblast showed 4 main morphological and functional stages referred to as the presecretory, secretory, smooth-ended, and ruffle-ended. 2. ○D314 mRNA was expressed in secretory ameloblast and increased according to the maturation of the cells. 3. OD314 protein was not expressed in presecretory ameloblast but expressed in secretory ameloblast and maturative ameloblast. OD314 protein was distributed in entire cytoplasm of secretory ameloblast. However, OD314 was localized at the proxiamal and distal portion of the cytoplasm of smooth- ended and ruffle-ended ameloblast. These results suggest that ○D314 may play important roles in the ameloblast differentiation and maturation.

다공성 활성탄의 표면 개질 및 이산화티탄 고정

주창식,박흥재,정갑섭 한국환경과학회 2003 한국환경과학회지 Vol.12 No.9

For the purpose of surveying any possibility of anchoring titanium dioxide on activated carbons to promote their activities as catalysts and/or adsorbents, two activated carbons were oxidized with ammonium peroxydisulfate and followed by anchoring titanium dioxide. The anchoring of titanium dioxide on the oxidized activated carbons were performed via the adsorption of tetrabutyltitanate, hydrolysis with deionized water, and calcination. The effect of oxidizing and anchoring treatment on the surface element composition, surface area, and pore texture were analyzed by XPS, BET and TPD. The oxidation of activated carbons with ammonium peroxydisulfate introduced carboxyl groups on the surface of activated carbons and these carboxyl groups promoted the anchoring of titanium oxide on the activated carbons. However, the treatments affected the surface area and the porosity of activated carbons.

지속적 농업발전을 위한 유기농업전략

박흥식,정순재,오주성,최성관 東亞大學校 大學院 1999 大學院論文集 Vol.24 No.-

The economic impact on the environment and human health caused by conventional chemical intensive agriculture is causing scientist to re-assess the development of agricultural systems. Pesticides and processed chemical fertilizers have been shown to becausing environmental disruption which will nudermine the resource base on which agriculture production depends. The rise of sustainale agriculture, integrated pest management, organic agriculture, and other forms of alternative agriculture are a result of varmers and researchers searching for new solutions to the problem of food production which does not endanger the all important agriculture are a result of farmers and researchers endanger the all important agriculture resource base. Organic agriculture is one approach which has been developing more quickly in recent years with increasing consumer purchasing power. Organic agriculture has shown itself to be sa or more profitable, and in many cases as productive as conventional agricultural methods on some crops. Further development of organic agriculture, and low-input agriculture will require further modification of policies which overwhelmingly support high imput, chemical intensive agriculture.

Fractal 차원에 의한 표면경화면과 마찰면의 형태해석

문병주,조연상,옥철호,박흥식,전태옥 동아대학교 생산기술연구소 2001 生産技術硏究所硏究論文集 Vol.6 No.1

The determination of surface middleography is believed to be extremely important in the areas of contact mechanics, adhesion and friction. In order to describe middleography of various rubbed and hardened surface, the wear test was carried out under different experimental conditions in dry friction. And fractal descriptors was applied to rubbed and hardened surface of laser modified steel with image processing system. These descriptors to analyze surface structure are fractal dimension. Surface fractal dimension can be determined by sum of intensity difference of surface pixel. middleography of rubbed and hardened surface can be effectively obtained by fractal dimensions.

관행농법과 유기농법의 비교연구

오주성,박흥식,정순재,정원복,진동호 東亞大學校 大學院 2000 大學院論文集 Vol.25 No.-

This study focuses on Comparative of conventional Agriculture and Organic Farming Among various kinds of environmentally sound farming practices the organic and Conventional Agriculture practices are chosen for this study. The main objective of this study is to evaluate the technological systems of organic farming practice in order to find the possibility of extending such technological system to the general farmers. Compared with the general farming practices, the organic farming requires many special technologies. Among them, technologies relating to compost making, pest, insect and weed control are different from those fo general farming practices. New technologies for the improvement of organic farming practices are developed or and imported from abroad by the organic farming association. As far as technology development for the organic farming, many research organizations between the goals of technology development of the conventional and organic farming system. In other words, land productivity of the organic farming technological system is lower than that of the conventional farming technological system.

WMT를 이용한 인터넷 방송국 구축

김홍식,이영진,조재영,주영훈,박주연,송선아 인제대학교 기초과학연구소 2000 자연과학 Vol.4 No.-

WMT(Windosw Media Technologies)는 Microsoft에서 만든 인터넷 또는 인트라넷상에서 고품질의 오디오/비디오를 실시간으로 전송하여 주는 멀티미디어 스트리밍 기술이다. WMT는 대부분의 로컬 및 스트리밍 멀티미디어 파일 형식을 지원하기 때문에 개발자들은 어떤 웹 어플리케이션이나 사이트에라도 오디오와 비디오 방송을 구축할 수 있다. WMT에 포함된 Windows Media Encoder, Windows Media On Demand Producer등을 이용하고 전용서버를 설치하여 on-Demand방송이나 실시간 인터넷 방송을 구축할 수 있다. WMT is the multimedia streaming technology which transfer the audio and video on Internet or Intranet. Because WMT supports almost styles of local and streaming multimedia file, some developers build the radio and video broadcasting system at any web applications and sites. This paper shows the method of develop the realtime internet broadcastion system with WMT.