Dry etching of polydimethylsiloxane using microwave plasma

Hwang, Sung Jin,Oh, Dong Joon,Jung, Phill Gu,Lee, Sang Min,Go, Jeung Sang,Kim, Joon-Ho,Hwang, Kyu-Youn,Ko, Jong Soo IOP 2009 JOURNAL OF MICROMECHANICS AND MICROENGINEERING - Vol.19 No.9

<P>This paper presents a new polydimethylsiloxane (PDMS) dry-etching method that uses microwave plasma. The applicability of the method for fabricating microstructures and removing residual PDMS is also verified. The etch rate of PDMS was dominantly influenced by the gas flux ratio of CF<SUB>4</SUB>/O<SUB>2</SUB> and the microwave power. While the PDMS etch rate increased as the flux ratio of CF<SUB>4</SUB> was increased, the etch rate decreased as the flux ratio of O<SUB>2</SUB> was increased. The maximum etch rate of 4.31 µm min<SUP>−1</SUP> was achieved when mixing oxygen (O<SUB>2</SUB>) and tetrafluoromethane (CF<SUB>4</SUB>) at a 1:2 ratio at 800 W power. The PDMS etch rate almost linearly increased with the microwave power. The ratio of the vertical etch rate to the lateral etch rate was in a range of 1.14–1.64 and varied with the gas fluxes. In consideration of potential applications of the proposed PDMS etching method, array-type PDMS microwells and network-type microprotrusion structures were fabricated. The contact angle was dramatically increased from 104° (non-etched PDMS surface) to 148° (etched PDMS surface) and the surface was thereby modified to be superhydrophobic. In addition, a thin PDMS skin that blocked holes and PDMS residues affixed in nickel microstructures was successively removed.</P>

트레드밀 운동시 흡기근 테이핑이 폐활량에 미치는 영향

김민지,신수영,송월섭,조수진,최동락,황미진,황진규,박진현,김경,Dennis W. Fell 대구대학교 특수교육재활과학연구소 2011 再活科學硏究 Vol.29 No.1

이 연구는 트레드밀 운동과 키네시오 테이핑의 효과에 따른 폐활량의 변화를 알아보기 위해 26명의 비흡연자가 참가하였으며 키네시오 테이핑을 적용하지 않은 그룹과 키네시오 테이핑을 적용한 두 그룹으로 무작위로 배정하고 각 군들을 주 3회 6주간의 트레드밀 훈련을 실시하였다. 실험 전과 후, 스파이로미터를 사용하여 키네시오 테이핑의 적용 따른 폐활량 변화 효과를 측정하였다. 이 연구의 결과를 종합해보면 키네시오 테이핑을 적용 그룹에서 적용하지 않은 그룹에 비해 FVC, FEV1에서 유의한 증가를 보였다. 이러한 결과는 건강한 성인에서 키네시오 테이핑을 적용한 경우 키네시오 테이핑을 적용하지 않고 트레드밀 운동을 한 경우보다 폐활량의 향상에 효과적이라고 생각되어진다. The purpose of this study was to investigate the variation of vital capacity(VC) according to the effects of kinesio taping with treadmill exercise. Twenty-six non-smokers were participated in this research and these subjects were randomly assigned into two groups. To measure the VC variation effects of kinesio taping, spirometer was used. The collected data were analyzed statistically by using a paired Mauchly test and repeated measure ANOVA. The results of this study were as follows; A group: treadmill with kinesio taping B group: treadmill without kinesio taping. Between A and B, there were significant differences. In the case of A group, there was 11.66% increase of VC, during 3 weeks experiment(p<.01). In the case of B group, there were significant differences, 3.35% increase of VC, during 3 weeks taping intervention(p<.01). After 6 weeks experiment, the improvement of VC shown a significant difference with intergroup (p<.05). From this result, it was revealed that treadmill exercise with kinesio taping was effective to improve VC to healthy adult than treadmill exercise without kinesio taping.

비복신경이식을 이용한 긴 거리의 말초신경 결손부 수복

이종호,이세영,김명진,이은진,안강민,김성민,최원재,명훈,황순정,서병무,최진영,정필훈 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.2

The surgery of oral and maxillofacial area poses the risk of cranial nerve damage such as trigeminal nerve or facial nerve. Inferior alveolar nerve is prone to damage in the third molar extraction, implant installation, orthognathic surgery, open reduction and rigid fixation, and tumor ablation surgery. On the other hands,facial nerve is likely to be damaged or sacrificed with trauma or parotidectomy. In case of inferior alveolar nerve injury, the incidence is reported to be about 1.3%. The nerve function will almost recover in minimal damage, but it won't recover at last in total damage of a part of nerve unit. In latter cases, nerve regeneration in intended by allograft as nerve substitute or various route of merve condit. But the recovery with autograft is believed to be most relialbe mrthod in the rapair of long-span(longer than 15㎜)nerve defect. We have performed autologous sural nerve graft in the repair of nerve defect, which is caused by resection of benign or malignant tumor. Hereby we report the method of nerve harvesting, recovery of defected peripheral nerve and the complications of donor site with the discussion of sural nerve anatomy.

하치조신경 및 설신경 손상 평가를 위한 한국인 정상 성인의 하순-이부 및 혀의 감각 조사

이종호,이세영,송승일,이은진,안강민,김성민,명훈,황순정,서병무,최진영,정필훈,김명진 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.2

In the head and neck area, there are so many sensory nerves, which are sometimes injuried iatrogenically or inadvertently so that involved patients complained of the loss of sensations. In such cases, it is important to judge the degree of injuries and regeneration of nerve for better diagnosis and treatment. Seddon and Sunderland's classification, which is commomly used, is focused on histological change and nerve conduction. As times goes by, it is difficult to access patient's sensory disturbance by this method. Until now, so many methods such as contract threshold, direction, two-point discrimination, pin prick, thermal discrimination and current perception threshold have been introduced for sensory evaluation. However, there hasn't been enough information regarding each methodology nor integrated standard methodology for the measurement. the purpose of this study is to get Korean adult normative sensory values of lower lip,chin and tongue using modified methods of contact thershold, ditection, two point discrimination, pin prick, thermal discrimination and assess degree of regeneration of sensory nerve damage.

서울의 PPNG 발생 빈도(1991-1992)

김재홍,윤기범,박평원,김영진,전경민,김영태,김중환,곽호,구상완,송민석,유옥,지혜구,김동원,문상은,박영립,정승호,성범진,성순제,엄주용,황정열,이기홍,이주협,전태진 대한화학요법학회 1994 대한화학요법학회지 Vol.12 No.1

The prevalence of PPNG among pretreated gonorrhea cases isolated at the STD clinic of Choong-Ku Public Health Center in Seoul has been studied and reported annually since 1981. In 1991, 123 strains of N.gonorrhoeae were isolated, among which 58(47.1%) were PPNG. In 1992, 98 starains of N.gonorrhoeae were isolated, among which 51(52.0%) were PPNG. In all, 109(49.3%) strains were found to be PPNG among 221 strains isolated between 1991-1992. The prevalence of PPNG in Seoul showed increased tendency till 1989, thereafter, it has been stationary or slightly decreasing.

저농도 이산화탄소 포집용 흡착제 개발 및 최적조건에 관한 연구

이주열 ( Ju Yeol Lee ),박덕신 ( Duck Shin Park ),조영민 ( Young Min Cho ),권순박 ( Soon Park Kwon ),황윤호 ( Yoon Ho Hwang ),송형진 ( Hyung Jin Song ),이상봉 ( Sang Bong Lee ) 한국유화학회 2012 한국응용과학기술학회지 Vol.29 No.1

본 논문은 다양한 시설내에 적은 농도의 CO2 제거를 위한 선택적 CO2 흡수능력을 향상시킨 흡착제의 효율평가에 관한 것이다. 직경 4mm의 구형 흡착제는 시판용 제올라이트에 첨가제, 물, 바인더, LiOH를 섞어 제조하였다. 칼럼테스트에서 400분 이내에 90% 이상의 CO2흡착효율을 나타내었고, 흡착필터모듈 흡착능력을 평가하기 위해 회분식과 연속식타입의 챔버테스트가 시행되었다. 회분식테스트에서 30분 이내에 약 92%의 CO2가 제거되는 것을 확인하였다. 연속식테스트에서 30분 이내 70%의 CO2가 제거효율을 보였으며, 2,500ppm 이상의 CO2가 제거되는 것을 확인하였다. 재현성테스트를 수차례 수행한 결과 15일동안 1,000ppm 이상의 CO2가 연속적으로 제거됨을 보였다. TGA 분석법을 이용한 흡착량 분석에서 흡착제 g당 5.0mmol의 CO2를 흡착하는 것으로 나타났다. 본 연구에서 개발된 흡착제는 상온에서 저농도 CO2 실내환경에 적용가능한 것으로 판단된다. In this study, CO2 adsorbent was developed for removing low concentration of CO2 in multiple-use facilities. The efficiency of the adsorbent which was improved selective CO2 adsorption capabilities was evaluated. The pellet type adsorbent was modified from a commercial zeolite with mixing LiOH, binder, additives, and H2O. Column tests showed over 90 % of CO2 was adsorbed within 400min. Chamber tests including batch and continuous types were performed for evaluating the adsorbent module. By batch tests, it was evaluated that about 92 % of CO2 was removed within 30 min. By continuous tests, 70% of CO2 was removed within 30 min. It was analyzed that over 2,500 ppm of CO2 was continuously removed as shown chamber tests. The reproducibility tests repeatedly performed for 15 days shows that over 1,000 ppm of CO2 was continuously removed. Adsorption capacity of the developed adsorbent was 5.0mmol CO2/g adsorbent which was analyzed by TGA. It was estimated that the modified adsorbent was applicable to low CO2 concentration and low temperature of indoor environment.

원산지별 감초추출물의 항산화활성 증가를 위한 효율적인 추출조건 탐색

하지훈 ( Ji Hoon Ha ),이혜미 ( Hye Mi Lee ),권순식 ( Soon Sik Kwon ),김해수 ( Hae Soo Kim ),김문진 ( Moon Jin Kim ),전소하 ( So Ha Jeon ),정유민 ( Yoo Min Jeong ),황준필 ( Jun Pil Hwang ),박종호 ( Jong-ho Park ),최영기 ( Yung-key 대한화장품학회 2013 대한화장품학회지 Vol.39 No.4

본 연구에서는 한국 및 중국산 감초(Glycyrrhiza uralensis), 그리고 우즈베키스탄산 감초(Glycyrrhiza glabra)를 대상으로 추출용매, 추출온도, 추출시간 등 추출조건별 추출물을 제조하고 이들 추출물들의 추출 수율과 항산화 활성을 비교하여 최적의 추출조건을 선정하였다. 항산화 활성 중 자유 라디칼(1,1-phenyl-2-pic-rylhydrazyl, DPPH) 소거활성은 85% 에탄올로 60 ℃에서 6 h 동안 추출한 조건에서 한국 감초로부터 얻은 추출물이 가장 높은 활성(46.05%)을 나타내었다. 루미놀 발광법을 이용한 추출물들의 총 항산화능 측정 실험과 피부 광노화에 중요한 ¹O₂으로 유도된 세포막 손상에 대한 추출물들의 세포 보호 효과를 측정한 실험 모두에서도 위의 조건에서 가장 높은 항산화 활성을 나타내었다. 특히, 한국 감초는 τ₅₀이 116.4 min으로 비교 물질인(+)-α-tocopherol (28.5 min)보다 약 4 배나 높은 세포 보호 효과를 나타내었으며, 추출 수율은 18.75%로 우즈베키스탄 및 중국 감초보다 각각 1.2 배 및 2.5 배의 추출 수율을 나타내었다. 따라서, 본 연구 결과는 항산화 소재로 화장품에 응용하기 위하여 감초로부터 추출물을 얻기 위한 최적의 조건은 85% 에탄올로 60 ℃에서 6시간 동안 추출하는 것임을 보여주었다. In this work, licorice extracts were prepared using various extraction conditions such as extraction solvent, temperature, and time from Glycyrrhiza uralensis (G. uralensis) produced in Korea and China and Glycyrrhiza glabra (G. glabra) in Uzbekistan. The optimum extraction condition was selected from the extraction yields and antioxidative activities of extracts. Korea licorice extracts showed the highest free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scav-enging activity (46.05%) under the extraction condition of 85% ethanol at 60 ℃ for 6 hours. The prominent ROS (reactive oxygen species) scavenging activity using luminol-dependent chemiluminescence assay and the cellular protective effect against ¹O₂ induced cellular membrane damage were also shown from the extracts obtained from the same condition. Especially, Korea G. uralensis extracts exhibited the higher prominent protective effect (τ₅₀ = 116.4 min) than (+)-α-tocopherol (τ₅₀ = 28.5 min) and the extraction yield of Korea licorice extract was 18.75%, which is 1.2 times and 2.5 times higher than that of Uzbekistan and China, respectively. These results indicate that the extraction condition of 85% ethanol at 60 ℃ for 6 hours is optimal to prepare licorice extracts, which can be applicable as antioxidative cosmetic materials.

평양 남정리 53호분 출토 토제칠기의 보존 및 제작기법 연구 : 토제칠이배, 토제칠반, 토제칠안

황현성,임수경,김희진,이태진,고민정,윤은영 국립중앙박물관 2013 고고학지 Vol.19 No.-

본고는 일제 강점기 조사 미등록 유물 정리사업의 일환으로 수행한 평양 남정리 53호분 출토 토제칠이배, 토제칠반, 토제칠안에 관한 연구이다. 남정리 출토 유물은 소지가 목심이 아닌 토제라는 것과 칠이배와 칠반을 얹은 칠안이 함께 출토되었다는 점에서 주목할 만하다. 토제칠이배 및 칠반 그리고 칠안의 보존처리를 통해 이들의 형태와 문양 등에 대해 알 수 있었다. 또한 칠기에 사용된 붉은색 안료의 성분을 분석하여 안료의 주성분이 진사(HgS)였음을 확인하였다. 이번 연구에서 기존에 잘 알려지지 않았던 한반도 내 위치한 낙랑의 토제칠기에 관해 살펴볼 수 있었으며 이러한 제작방법이 한나라 고유의 문화인지 아니면 재지세력이 한나라의 영향을 받아 현지화한 문화의 산물인지에 대해 생각해 볼 수 있는 기회라 생각된다. This research paper examines the lacquered pottery cup, plate and table unearthed from Tomb No. 53 at Namjeong-ri in Pyongyang, which were under conservation treatment as a part of the Project of Unregistered Artefacts Uncovered in the Japanese Colonial Era. It is very rare to have a lacquered pottery cup and plate, lying on a lacquered pottery table, as a set of grave goods. In particular, they are not wooden but pottery items. Through conservation treatment for lacquered pottery cup, plate and table, it was possible to find out their shapes and decoration patterns. The resulting analysis of the red pigment used indicates that cinnabar (HgS) is the main element. This research is significant because it examines lacquered pottery wares produced in Lelang, which has rarely been conducted. Further research will need to prove whether their production techniques were in the unique Chinese Han style or were produced by indigenous craftsmen who adopted the Chinese Han technique.

Ipriflavone 투여가 백서의 실험적 치아이동 후 치주조직의 재형성에 미치는 영향

민지현,조진형,이기헌,황현식 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.5

본 연구는 치아이동 후 ipriflavone 투여가 치주조직의 재형성, 나아가 치아회귀 억제에 미치는 영향을 알아보기 위하여 시행되었다. 웅성 백서 72마리를 대상으로 상악 좌우측 제1, 2구치 사이에 교정용 고무밴드를 끼워 제1, 2구치를 3주간 이동시킨 다음, 교정용 고무밴드 제거 1일 전부터 매일 체중 kg당 50 mg 또는 400 mg의 ipriflavone을 투여한 실험군과 ipriflavone을 투여하지 않은 대조군으로 구분하였다. 교정용 고무밴드를 제거함으로써 회귀가 나타나기 시작한 날로부터 5일 간격으로 15일까지 각각 실험동물을 희생시켜가며 치아회귀 거리를 계측하는 한편 치주조직 재형성 소견을 관찰하였다. Ipriflavone을 투여하고 치아회귀를 관찰한 결과 용량에 관계없이 대조군에 비하여 적은 양의 회귀를 나타내었으며 시간 간격에 따른 치아회귀를 관찰한 결과 대부분의 회귀가 5일째 나타난 대조군과 달리, 늦게 그리고 점진적으로 나타나는 양상을 보였다. Ipriflavone을 투여하고 조직소견을 관찰한 결과 대조군에 비하여 치조골연이 매끄러운 양상을 보였으며 시간 간격에 따른 조직소견을 관찰한 결과 대조군에 비하여 치주인대 재배열이 빠르게 나타나는 양상을 보였다. 이상의 결과는 ipriflavone의 투여가 치주조직의 재형성을 통하여 회귀를 억제함으로 교정적 치아이동 후 보정에 도움이 될 수 있음을 시사하였다. Objective: The purpose of this study was to examine the effect of ipriflavone on periodontal reorganization and prevention of relapse following tooth movement. Methods: Orthodontic rubber bands were inserted between the first and second maxillary molars of 27 white male rats for 3 weeks for experimental tooth movement. From one day before the removal of orthodontic rubber band, ipriflavone was administered 50 or 400 mg/kg daily in each experimental group whereas carboxymethyl cellulose solution was administered in the control group. They were sacrificed at the 5, 10, and 15th day from the day of removal of orthodontic rubber bands. The amount of relapse was evaluated by measuring the interdental space, and the extent of periodontal reorganization was compared through histological examination. Results: In case of ipriflavone administration, the amount and velocity of relapse was less and slower compared to the control group. In addition, the ipriflavone group showed more rapid periodontal reorganization compared to the control group. Conclusions: The results of the present study suggest that ipriflavone administration can be used effectively in the prevention of relapse following orthodontic tooth movement through the acceleration of periodontal reorganization.

황산염을 함유한 생석회와 화학첨가제 혼합토의 팽창특성

민덕기,황광모,정진형 울산대학교 2003 공학연구논문집 Vol.34 No.1

최근 많이 건설중인 도로에서 연약지반을 노상토로 사용하게 될 경우, 공학적으로 많은 문제점이 발생되기 때문에 생석회, 시멘트 등의 여러 가지 화학첨가제를 첨가하여 지반을 개량하게 된다. 특히 생석회에 의한 토질안정처리공법에서 주된 반응은 생석회와 흙 사이에 장기간에 걸쳐 일어나는 포졸란 반응이며, 산성화된 우수 및 공장의 폐수로 오염된 토양 속의 황산염과 결합하여 토질안정처리의 많은 문제점이 발생되고 있다. 도로의 기층재료로 사용된 생석회 혼합토는 흙 속의 황산염과 반응하여 Ettringite, Thaumasite, Gypsum과 같은 팽창성 반응생성물을 생성하여, 도로의 균열 등 악영향을 미친다. 따라서, 본 연구에서는 생석회와 화학첨가제(CaCl₂, CaSO₄, Fe₂O₃)를 혼합하여 산성화된 우수나 공장지대의 오염된 폐수 속에 포함된 황산염에 대한 영향을 조사하였다. 연구결과, 황산염은 생석회 혼합토의 팽창특성을 변화시키는 것으로 나타났다. 팽창특성은 간극수의 pH가 낮을수록 팽창성이 증가하였으며, CaSO₄를 첨가한 생석회 혼합토의 팽창성이 큰 것으로 나타났다. 팽창성의 증가는 황산염과 반응하여 생성된 침상의 Ettringite의 생성에 기인한 것임을 확인할 수 있었다. Lime has been extensively utilized to stabilize the weak and soft compressible clay deposits. It has been recently reported that the presence of sulphate causes abnormal volume changes in lime-stabilized soils. Volume change in lime-stabilized soils can take place due to ettringite, thaumasite, and gypsum, which are complex calcium-silicate-hydroxide-sulphate-carbonate-hydrate minerals. Sulphate compounds cause a variety of serious geotechnical hazards such as swell pressure and damages to light structures and pavements. This paper discusses the influence of sulphate on sulplus soil specimens treated with lime and chemical additives(CaCl₂, CaSO₄, Fe₂O₃). The main objective of this paper is to estimate the physical behavior of lime-treated sulplus soils after curing periods of up to 60 days. The physical and mechanical characteristics were explained by means of a laboratory study. The formation of sulphate compounds due to soil-lime and sulphate reactions were identified by X-Ray Diffraction(XRD) and Scanning Electron Microscope(SEM). The results showed that the sulphate increased swelling properties of soils. Theswelling properties development is probably related to the needle-like crystals which were able to be observed by SEM.