Layer-by-Layer Doping of Few-Layer Graphene Film

Gü,neş,, Fethullah,Shin, Hyeon-Jin,Biswas, Chandan,Han, Gang Hee,Kim, Eun Sung,Chae, Seung Jin,Choi, Jae-Young,Lee, Young Hee American Chemical Society 2010 ACS NANO Vol.4 No.8

<P>We propose a new method of layer-by-layer (LbL) doping of thin graphene films. Large area monolayer graphene was synthesized on Cu foil by using the chemical vapor deposition method. Each layer was transferred on a polyethylene terephthalate substrate followed by a salt-solution casting, where the whole process was repeated several times to get LbL-doped thin layers. With this method, sheet resistance was significantly decreased up to ∼80% with little sacrifice in transmittance. Unlike samples fabricated by topmost layer doping, our sample shows better environmental stability due to the presence of dominant neutral Au atoms on the surface which was confirmed by angle-resolved X-ray photoelectron spectroscopy. The sheet resistance of the LbL-doped four-layer graphene (11 × 11 cm<SUP>2</SUP>) was 54 Ω/sq at 85% transmittance, which meets the technical target for industrial applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2010/ancac3.2010.4.issue-8/nn1008808/production/images/medium/nn-2010-008808_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn1008808'>ACS Electronic Supporting Info</A></P>

인체기생 열두조충류의 형태비교 및 진단적 소견

임신영,강성구,양용상,백승한,류장근 THE KOREAN SOCIETY FOR BIOMEDICAL LABORATORY SCIEN 1998 Journal of biomedical laboratory sciences Vol.4 No.1

최근 우리 나라는 열두조충과 (Diphyllobothridae)에 속하는 조충류의 인체 감염예가 빈번하게 보고되고 있다. 이는 본 조충류의 감염매체인 어류를 날 것으로 생식할 기회가 많으며, 또한 본 조충류의 제1중간숙주인 물벼룩이 음료수를 통한 인체 감염이 원인일 것으로 추정되고 있다. 조충류의 진단은 충체에 있어 두적과 편절의 형태학적 특징을 감별하여 種의 분류와 진단을 하는 것이 기본적 순서가 될 것이나, 1차적으로 가능한 진단은 환자의 증상 참작과 분변으로부터 충란을 발견 감별하게 된다. 특히 광절열두조충류의 충란에 의한 種鑑別은 환자로부터 편절이나 충체의 확실한 감별을 위한 사전 정보를 가늠하는 뜻에서도 중요성이 있다. 이에 저자들은 환자의 치료와 함께 수집된 Diphyllobothrium latum, D. latum parvum 그리고 Spirometra erinacei의 편절과 충란을 재료로 형태 및 진단적 결과를 분석한 바 그 성적은 다음과 같다. 1. 환자의 분변에서 수집된 충란 50개씩을 각각 선택하여 형태와 크기에 대한 계측을 실시하였다. D. latum의 충란은 난개가 있고 난원형 또는 타원형의 모양으로 관찰되었으며 D. latum parvum은 D. latum에 비하여 더 난원형이면서 작게 관찰되었다. S. erinacei의 충란은 폭이 비대칭적이며 길쭉한 모양으로 관찰되었다. 2. D. latum, D. latum parvum 그리고 S. erinacei의 충란의 크기에서 충란의 평균 길이와 폭은 각각 61.4X41.7㎛, 55.9X41.4㎛ 그리고 66.7X36.4㎛이었다. 3. 각 조충의 편절을 고정한 다음, 첫째 포매하고 microtome으로 절편을 만들어 hematoxylin-eosin 염색을 실시하였고, 둘째 고정과 함께 semicon's aceto-carmine 염색표본을 작성하여 현미경 관찰을 한 결과 D. latum과 D. latum parvum은 생식선이 편절의 중앙선상에 위치하고 개구된 자궁구가 관찰되었다. 그리고 편절의 양측에 난황이 follicle로 관찰되었으며 전형적인 rosette모양을 형성하고 있었다. 그러나 D. latum parvum은 D. latum에 비하여 아주 작은 크기로 관찰되었다. S. erinacei의 편절은 자궁이 나선형으로 5∼7회 이상으로 말려서 관찰되었고 음경낭안에서 저정낭이 이어져 연결되고 있었다. 이로써 본 연구에서는 편절의 형태특징과 함께 충란 크기에 대한 계측과 분석을 하고자 하였으며, 공학현미경에 의한 계측치로 세 종류의 조충 감별에 유의한 참고치를 제기하는 바이다. Recently there have been frequent reports on human infection caused by the Diphyllobothridae in Korea. The adequate opportunities for Koreans to eat raw fish, the primary infection medium of cestodes and the human infection through drinking water by cyclops, the first intermediate host are believed to be main reasons for the infection. The first task of this study was to classify and diagnose the species by differentiating morphological characteristic between scolex and proglottids of cestodes. However, the initially available diagnosis was done with the patient's symptoms and the eggs obtained from his stool. It is important to differentiate the species by the eggs of Diphyllobothrium latum especially in that it can help get advance information for a more reliable analysis in the near future. The morphological and diagnostic results from proglottids and eggs of Diphyllobothrium latum, Diphyllobothrium latum parvum and Spirometra erinacei are as follows; In each kind of cestodes from the patient's stool, the shape and size of 50 eggs were measured. Eggs of Diphyllobothrium latum had an operculum and were ovoidal or ellipsoid to elliptical in shape. Eggs of Diphyllobothrium latum parvum were more ovoidal in shape and smaller in size than Diphyllobothrium latum. And eggs of Spirometra erinacei were asymmetrical in width and long and slender in shape. The average lengths and widths of Diphyllobothrium latum, Diphyllobothrium latum parvum and Spirometra erinacei were 61.4X41.7㎛, 55.9X41.4㎛ and 66.7X36.4㎛, respectively. After the segments of each cestode were fixed, embedding and hematoxylin-eosin dyeing on a microtome-made specimen were done. The micrographs of the semicon's aceto-carmine dyed specimen showed that Diphyllobothrium latum and Diphyllobothrium latum parvum had a centrally-located genital gland and an opened uterine pore. The yolks were observed on both sides of proglottids and had a typical rosette pattern. Yet, Diphyllobothrium latum parvum was shown smaller than Diphyllobothrium latum in the micrograph. Proglottids of Spirometra erinacei displayed that the uterus was rolled spirally more than five to seven times, and connected successively to the seminal vesicle in the cirrus sac. Shown above, this study was performed to measure the size of eggs and analyze the morphological characteristics of proglottids and provided the measurements of three types of cestodes obtained by a light microscope.

수돗물에서 동 배관의 부식특성에 관한 연구

심재주,신동호,최윤석,김정구,유승재 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.12

The corrosion behavior of copper in neutral aerated synthetic tap water was investigated using electrochemical methods, SEM and XPS. All potentiodynamic polarization curves showed active corrosion behavior, and the corrosion rate was more sensitive to flow velocity than Cl^(-) ion concentration and temperature. The result of potentiostatic test indicated that the current density decreased with increasing time regardless of Cl^(-) ion concentration and temperature in stagnant condition because copper compounds were formed uniformly on the surface. The EIS plot was changed from two time constants to three time constants with the formation of Cu₂O, and the charge transfer resistance (R_(ct)) was very large and increased with increasing immersion time. From all results, copper had good corrosion resistance in this potable water system.

유리폐기물과 하수슬러지 소각재의 고형화 처리연구

한상목,신대용,윤봉구,김승겸 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-

하수슬러지 소각재, 폐유리분말 및 고로슬래그의 고형화에 의하여 건자재를 제조하였다. 하수슬러지 소각재는 SiO_2와 Al_2O_3가 75 wt%, Fe_2O_3가 8.21 wt%, 폐유리분말은 SiO_2 71.4 wt%, Na_2O 14.43 wt% 및 CaO 9.32 wt%, 고로슬래그는 SiO_2 33.4 wt%, CaO 41 wt% 및 Al_2O_3 14.5 wt%를 함유하여 세라믹스 제조원료로 사용이 가능하였다. 하수슬러지를 800℃에서 2시간 하소한 무기질분말을 분쇄하여 하수슬러지 소각재를 제조하였다. 30∼70 wt%의 하수슬러지 소각재, 30∼70 wt%의 폐유리분말 및 10∼30 wt%의 고로슬래그를 혼함하여 950∼1,100℃에서 2시간 소성하여 시편을 제조하였다. 하수슬러지 소각재 첨가량이 감소하고 폐유리분말의 첨가량과 소성온도가 증가하면 부피비중과 압축강도는 증가하였으나 기공률과 흡수율은 감소하였다. 1,050℃에서 소성한 시편(No. 1, 3, 5 및 7)의 부피비중은 1.70∼1.83, 기공률과 흡수율은 0.3∼2.4% 및 0.1∼1.5%, 압축강도 272∼323 kgf/㎠을 나타내었다. 고로슬래그를 첨가하여 1,100℃로 소성한 시편(No. 8, 9, 및 10)의 부피비중은 1.82∼2.11 및 압축강도는 350∼671 kgf/㎠이었다. 하수슬러지 소각재, 고로슬래그 및 시편의 중금속출량은 매립지 침출수배출 허용기준치보다 낮아, 본 연구에서 제조한 시편은 주변 환경에 해가 없어 건자재로의 이용이 가능하였다. An experimental study for the constructional material by solidification using sewage sludge ash, waste glass powder and blast furnace slag was carried out in the senses of waste materials disposal and utilization. The reusability of sewage sludge ash, waste glass powder and blast furnace slag as a raw material in the manufacturing process of ceramics was highly expected because the chemical compositions of these waste materials were mostly SiO_2 and Al_2O_3. Sewage sludge ash was fabricated by calcined at 800℃ for 2 hours and obtained by the crushing. The mixture of 30∼70wt% of sewage sludge ash, 30∼70 wt% of waste glass powder and 10∼30 wt% of blast furnace slag were heated at 950∼1,100℃ for 2 hours. The density and the compressive strength of specimen increased with increasing the sintering temperature and decreasing the addition amount of sewage sludge ash, No. 1, 3, 5 and 7 specimens showed the bulk density of 1.70∼1.83, porosity of 0.3∼2.4%, water absorption of 0.1∼1.5% and compressive strength of 272∼323kgf/㎠. And, that of the No. 7 specimen heated at 1,100℃ increased with increasing the addition amount of blast furnace slag, and for No. 8, 9 and 10 specimens, bulk density was 1.82∼2.11 and compressive strength was 350∼671 kgf/㎠. An extraction test for specimen to detect toxic materials showed below the permitted standard of land-filling extractable heavy metal contents. It was founded that the specimen were useful for the constructional materials.

다운 증후군과 동반된 그레이브스병 1예

노혜정,신진호,김하영,김용성,백승훈,박병현,조정구 圓光大學校 醫科學硏究所 2005 圓光醫科學 Vol.20 No.1

프리텐셔너가 장착된 시트벨트 시스템의 관성잠김 안전버클 개발

탁태오,국민구,김대희,박재순,신승언,최석 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.A

To improve passenger safety, seat belt systems with pre-tensioner that tightens seat belt webbing using explosive just before collision are widely used these days. Even though seatbelt must not unlatched without passengers' operation. explosive power of pre-tensioner can cause unlocking of a buckle. To prevent the unlocking, an anti-g mass that blocks displacement of the release button has been attached to the buckle. In this study, the dynamics and statics of locking mechanism associated with operation of anti-g buckle has been theoretically investigated, and important design variables that affect the operation of anti-g buckle have been identified. Through the total seat belt system's dynamic simulation using force and displacement inputs obtained from seat belt sled test, design of the proposed anti-g buckle has been validated.

프리텐셔너가 장착된 시트벨트 시스템의 관성잠김 안전버클 개발

탁태오,국민구,김대희,박재순,신승언,최석 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.B

To improve passenger safety, seat belt systems with pre-tensioner that tightens seat belt webbing using explosive just before collision are widely used these days. Even though seatbelt must not unlatched without passengers' operation. explosive power of pre-tensioner can cause unlocking of a buckle. To prevent the unlocking, an anti-g mass that blocks displacement of the release button has been attached to the buckle. In this study, the dynamics and statics of locking mechanism associated with operation of anti-g buckle has been theoretically investigated, and important design variables that affect the operation of anti-g buckle have been identified. Through the total seat belt system's dynamic simulation using force and displacement inputs obtained from seat belt sled test, design of the proposed anti-g buckle has been validated.

국내에서 유행하는 HIV의 전파 경로에 따른 Subtype 분포

이주실,남정구,김성순,강춘,최병선,김옥진,박미선,성봉모,서순덕,전수경,변승옥,신영오,조해월 대한감염학회 2001 감염 Vol.33 No.5

Background : Previous data have been reported that subtype B is prevalent in South Korea, but neither the extent nor the proportion of subtypes could be evaluated. This study was designed to analyze the distribution of HIV-1 subtypes, temporal instructions and transmission dynamics between epidemiological groups. Methods : 1,280 Koreans had been diagnosed as HIV seropositive during the period 1985 to 2000. Among them, 134 individuals were selected for this molecular epidemiological study. 134 DNAs were isolated from uncultured or cultured peripheral blood mononuclear cells. V3-V5 (0.7 kb) fragment of HIV-1 env gene was amplified by nested polymerase chain reaction and was sequenced. Results : HIV-1 isolates from thirty-seven homosexuals were all subtype B (100%). On the other hand, 66 isolates from 94 heterosexuals were subtype B (70%) and 28 were non B subtypes (30% : 13 A, 4 C, 2 D, 8 E , 1 G). Only subtype B strains were isolated from 73 males who were infected with HIV inside Korea while 16 B and 20 non B subtype strains were isolated from 36 males who were HIV infected outside of Korea. However, B and non B strains were isolated half and half from females who were infected inside Korea except one. Conclusion : The HIV-1 subtype B strains are prevalent in Korea from the early HIV infection until present in both homo and heterosexuals. Non B strains have been transmitted from men who were infected outside Korea to their spouses and casual partners. So, we need further study to monitor subtype B and non B HIV transmission in epidemiological groups of Korea, (Korean J Infect Dis 33:311∼318, 2001)

모터구동형 안전벨트 리트랙터의 구동 메커니즘 설계

탁태오,박재순,국민구,김대희,신승언,최석 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.B

Motorized retractors enhance the safety of passengers by removing the slack of webbing and by holding upright driving position. Reliability of a driving mechanism that includes one-way clutch between the driving motor and webbing is directly linked to the safety of passenger. In this research, conditions for locking one-way clutch. and also conditions for sustaining locking are theoretically investigated. The operation of a motorized retractor under realistic conditions is simulated in order to validate the proposed retractor design.

모터구동형 안전벨트 리트랙터의 구동 메커니즘 설계

탁태오,박재순,국민구,김대희,신승언,최석 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.A

Motorized retractors enhance the safety of passengers by removing the slack of webbing and by holding upright driving position. Reliability of a driving mechanism that includes one-way clutch between the driving motor and webbing is directly linked to the safety of passenger. In this research, conditions for locking one-way clutch, and also conditions for sustaining locking are theoretically investigated. The operation of a motorized retractor under realistic conditions is simulated in order to validate the proposed retractor design.