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>

알루미나이드 확산코팅된 스테인레스 합금의 내산화 및 내삭마 특성

황철홍,이효민,오정석,황동현,황유석,이종원,최정묵,박준식,Hwang, Cheol Hong,Lee, Hyo Min,Oh, Jeong Seok,Hwang, Dong Hyeon,Hwang, Yu Seok,Lee, Jong Won,Choi, Jeong Mook,Park, Joon Sik 한국분말재료학회 (*구 분말야금학회) 2021 한국분말재료학회지 (KPMI) Vol.28 No.5

Stainless steel, a type of steel used for high-temperature parts, may cause damage when exposed to high temperatures, requiring additional coatings. In particular, the Cr₂O₃ product layer is unstable at 1000℃ and higher temperatures; therefore, it is necessary to improve the oxidation resistance. In this study, an aluminide (Fe₂Al₅ and FeAl₃) coating layer was formed on the surface of STS 630 specimens through Al diffusion coatings from 500℃ to 700℃ for up to 25 h. Because the coating layers of Fe₂Al₅ and FeAl₃ could not withstand temperatures above 1200℃, an Al₂O₃ coating layer is deposited on the surface through static oxidation treatment at 500℃ for 10 h. To confirm the ablation resistance of the resulting coating layer, dynamic flame exposure tests were conducted at 1350℃ for 5-15 min. Excellent oxidation resistance is observed in the coated base material beneath the aluminide layer. The conditions of the flame tests and coating are discussed in terms of microstructural variations.

Effects of Chungkookjang Extract on Growth Hormone Secretion from GH3 Mouse Pituitary Cell and Growth Hormone Receptor Signaling Pathway

Sun Il Choi(최선일),Ji Eun Kim(김지은),In Sik Hwang(황인식),Hye Ryun Lee(이혜련),Young Ju Lee(이영주),Hong Joo Son(손홍주),Dong Seob Kim(김동섭),Kyu Min Park(박규민),Dae Youn Hwang(황대연) 한국생명과학회 2012 생명과학회지 Vol.22 No.9

뇌하수체 전엽에서 성장호르몬의 생산과 분비는 세포의 분열과 분화 그리고 이동을 조절하는 몇 가지 천연물질에 의해 유도된다. 따라서 발효과정을 통해 제조된 청국장이 성장호르몬의 대사에 미치는 영향을 평가하기 위하여 성장호르몬 분비능과 반응성을 뇌하수체 세포와 성장호르몬 표적세포에서 관찰하였다. 6가지 종류의 콩 품종으로 제조된 청국장 추출물 중에서, 대원, 대풍, 태광의 3종류 청국장 추출물은 5 mg/ml 농도에서 GH3 세포로부터 성장호르몬의 분비를 촉진하였다. 비록 세포 생존능은 이러한 추출물에 의해 유의적인 변화가 유도되지 않았으나, 성장호르몬의 분비량은 청국장 추출물의 농도에 의존적으로 증가하였다. 또한 성장호르몬의 표적 기관으로부터 유래된 MG63과 HepG2 세포는 GH3로부터 수집된 조건적 배양액에 의해 유의적으로 활성화되었다. 또한 이러한 세포에서 STAT5 발현은 대원 청국장 추출물을 처리 후, 15분 혹은 30분부터 세포질에서 유의적으로 증가하였으며, p-STAT5는 핵에서 30분 혹은 60분부터 증가하였다. 따라서 이러한 결과는 3가지 종류의 청국장 추출물은 성장호르몬의 분비를 촉진시키며, 청국장의 조건적 배양액은 성장호르몬 표적세포에서 신호전달을 유도함을 제시하고 있다. The production and secretion of growth hormone (GH) in the anterior pituitary gland can be induced by several natural products to control cell proliferation, differentiation, and migration. To investigate whether Chungkookjang (CKJ) produced by the fermentation process affects GH-related metabolism, the secretion and the response of GH were observed in pituitary cells and GH target cells. Among six CKJs manufactured by different strains of glycine max, only three CKJs, including Daewon (DW), Daepung (DP), and Taegwang (TG), induced GH secretion from GH3 cells at 5.0 mg/ml concentration. There were no significant changes detected in the viability of any of the cells treated with these CKJs. In addition, the increase in GH secretion from the GH3 cells was dependent on the concentration of the three types of CKJs. The proliferation of cell lines, including MG63 and HepG2 cells, that originated from those derived from the GH target organs was significantly activated by treatment with the GH-containing conditional medium (GCM) harvested from the three CKJ-treated GH3 cells, although their induction rate was different from each other. In these cells, p-STAT5 was maximally translocated into the nucleus of MG63 cells 30 min after DW treatment, while it was translocated in HepG2 cells at 60 min. These results suggest that these three types of CKJ could enhance the secretion of GH, as well as the GCM-derived response, in the two target organs.

실내 환경디자인 가치평가체계에 관한 연구 : 디자인 과정중 평가단계의 시스템의 관점을 중심으로

황세민,신동진 진주여자전문대학 1993 論文集 Vol.16 No.-

본 연구는 실내 환경디자인의 올바른 평가를 통해 환경의 변화주체인 인간의 가치실현과 추구를 기본으로 하고 있다. 주된 논의는 실내 환경디자인의 해결안을 시스템적 관점하에서 지적하고 그 방법으로 인간의 기본적 인지과정을 이해하여 인간과 실내환경사이에 연관성을 토대로 보편적인 준거를 마련하는데 있다. 목적으로는 시스템적 관점으로 디자인 접근을 시도함으로서 인간 주변 환경에 전반적인 향상에 있다. 연구 과정을 보자면 다음과 같다. 1. 연구의 목적과 방향을 기술하였고 2. 시스템적 관점의 이론적 배경을 살펴보고 그를 통한 환경에 대한 인간의 인지과정을 이해한다. · 인간의 자극-반응과정과 정보처리과정을 통하여 가치평가체계의 보편적 근거를 마련하였다. · 환경에 의한 인간의 행태와 심리변화를 이해하여 디자인에 이용할 수 있는 가능성을 발견하였다. · 이는 체계적인 가치평가에 있어 주요 요소가 됨을 알았다. 3. 시스템적 기준에 의한 체계와 미학적 접근을 통해 가치평가기준을 정립하고자 했다. · 환경심리 행태론과 정보이론 등의 이론을 통해 가치기준을 위한 근거를 마련하였다. · 이러한 가치체계는 인간으로 하여금 실내환경에 대한 우선순위를 깨닫게 함으로서 보다 효율적 사용에 대한 적극성을 갖게 한다. 실내환경디자인은 공간에 존재하는 물리적 심리적 등의 모든 환경적 요소와 인간의 관계 속에서 출발한다. 그렇기 때문에 디자인을 하는 입장에서의 자세는 바로 이러한 환경적 요소의 관계성을 깊이 이해하고 통합하는데 중점을 두어야 하고 이 또한 올바른 평가에 의해 적극적인 디자인이 추출될 수 있게 하여야 한다. This study was carried to evaluate interior design for the achievement of human value. The main issue of this study was discussed in the systematic approach for the solution of interior design. The research method was based on the cognitive science and human behaviors. And the purpose of this thesis is to improve on human environments. The organization of this study can be briefly described as follows. The first, the purpose and directions of this study was described. The second, the value Evalution Systems(VES) was built, though the analysis of cognitive processes of human behavior. And I find the possibility of the application in the design process. And the third, though the systematic and aestetic approach, I established the references of the evalution for design value. As a result, all of environmental designer must consider that the interior design is based on the environmental facors of human behavior.

경화제 주입에 의한 치핵치료의 후유증

이동식,심민철,김재황 대한대장항문학회 1997 Annals of Coloproctolgy Vol.13 No.3

자궁내막증 백서모형에서 Danazol과 Decapeptyl의 치료효과에 관한 연구

황선보,이민석,심재현,김동훈,배한익 동국대학교 경주대학 1996 東國論集 Vol.15 No.-

본 연구의 목적은 장간막에 자궁내막 조직을 자가이식하여 수술적으로 유도된 자궁내막증 백서모형에서 자궁내막증의 치료를 위해 danazol과 decapetyl의 치료효과를 평가하는 것이다. 백서(n=48)들은 무작위적으로 정상대조군(n=12)과 수술적으로 유도된 자궁내막증군(n=36)으로 구분하였다. 후자는 비치료군과, danazol 치료군과 decapeptyl 치료군으로 세분하였다(각 군의 n=12). Danazol(8mg/일)은 수술후 4째주부터 구강을 통해 투여되었다. Decapeptyl(0.2mg/2주)은 근주하였다. 처음투약후 10일, 20일, 40일, 60일째에 각군의 2마리의 쥐를 희생시켰다. 저자들은 자궁내막증 이식체와 난소의 크기를 측정하여 다음의 결론를 얻었다. 1. 자궁내막증 이식체의 크기는 비치료군에 비해(3.91±1.08mm) danazol 치료군과 decapeptyl치료군에서 (각각2.28±0.17mm 과 2.78±0.97mm), 현저히 감소되었다(p<0.01). 2. danazol과 decapeptyl 두 치료군에서 장기치료가 단기치료보다 자궁내막증 이식체의 크기를 감소시키는데 더 효과적이었다(p<0.01). 3. 난소의 크기는 정상대조군과, 비치료군과 decapeptyl 치료군에서 유의하게 차이를 보이지 않은데 반해(각각 4.46±0.85mm, 4.77±0.82mm과 4.97±0.92mm), danazol 치료군에서는 유의하게 감소하였다(3.97±0.63mm) (p<0.63mm). 백서모형에서 수술적으로 이식된 자궁내막조직의 성장과 발달은 자궁내막증의 병인 이해와 신약개발에 유용한 연구모델을 제공할 수 있을 것 이다. The purpose of this study was to surgically induce endometriosis in the rat by autotransplanting endometrial tissue to the mesentery and to evaluate the efficacy of danazol and decapeptyl for the treatment of endometriosis. Rats(n=48) were randomly assigned to normal control group(n=12) and surgically induced endometriosis group(n=36). The latter was further divided into the untreated, danazol treated and decapeptyl treated groups (n=12 for each group). Danazol(8mg/day) was orally administrated from 4weeks after operation. Decapeptyl(O.2ml/2weeks) was injected intramuscularly. Two rats of each group are sacrificed on the 10th, 20th, 40th, 60th, 80th and lOOth day after the first drug administration. We measured sizes of endometriotic implants and ovaries. The results were as follows; 1. The sizes of endometriotic implants were significantly decreased(P<O.Ol) in the danazol and decapeptyl treated groups (2.28±O.71mm and 2.78±O.89mm, respectively) compared with untreated group(3.91±l.08mm). 2. Long term treatment was more effective than short term treatment in decreasing the size of endometriotic implants in both danazol and decapeptyl treated groups(P<O.Ol). 3. The size of ovaries was not significantly different among the normal control, untreated and decapeptyl treated groups(4.65±O.83mm, 4.77±O.82mm and 4.97±O.92mm, respectively) but was significantly decreased(P<O.Ol) in the danazol treated group(3.97±O.63mm). The successful growth and development of surgically transplanted endometrial tissue in the rat may offer an useful research model that can be used to understand pathogenesis of endometriosis and to explore new drug therapies.

두개안면골 골절 및 결손에 있어서 모상건막하 두개골막피판의 적용

황민효,선 욱,김동일,최 준,백세민 大韓成形外科學會 1994 Archives of Plastic Surgery Vol.21 No.5

Technological advances in reconstructive surgery have aroused a wide spread reappraisal of anatomy and anatomical concepts. Mamy useful new flaps, such as the fasciocutaneous flap, have been introduced as a result. However subgaleal flaps have not been widely used, and there is little anatomical information published to guide tha surgeon in designing such a flap. The advantages of the subgaleal flaps are multiple pedicle, good vascularity and easier management, support the split and full thickness skin graft, thin and supple, gliding nature and minimal donor morbidity. The subgaleal flap has been used as an isolated flap in a variety of prospective cases such as defects or fractures of cranial floor frontal sinus or orbit, nasal or midface reconstruction, soft tissue contouring in massive facial trauma. We have used the subgaleal pericranial flaps in 3 cases with craniofacial fracutres or deformities and acquired satisfying results.

주의력결핍/과잉행동장애와 양극성장애 공존 환아군과 주의력결핍/과잉행동장애 환아군의 비교연구

정동선,하규섭,정희연,구훈정,황준원,김붕년,신민섭,조수철,홍강의 大韓神經精神醫學會 2006 신경정신의학 Vol.45 No.6

Objective : Attention deficit hyperactivity disorder (ADHD) is frequently comorbid with a variety of psychiatric disorders. Among them, bipolar disorder (BPD) has especially attracted growing interest. This is partly due to the fact that early onset BPD has been frequently misdiagnosed as ADHD because of symptomatic overlap. The aim of the present study is to find the differences in demographic data and clinical features of ADHD+BPD and ADHD in children and adolescents. Method : Children and adolescents patients participating in the present study have been enrolled at the child psychiatric clinic since 2004. 14 patients meeting the DSM-IV chteria for ADHD+BPD and 19 patients meeting the criteria for ADHD and 15 healthy comparison subjects were recruited. All groups were evaluated through the Schedule for Affective disorders and Schizophrenia for School-Age Children-Present and Life Time version-Korean version (K-SADS-PL-K). Demographic data and clinical charactehstics of the subjects were also collected. Parents were asked to complete the Child Behavior Check List(CBCL) and the Toddler Temperamental Scale (TTS) clinical ratings were obtained using the Young Mania Rating Scale(YMRS), the Children's Depression Iventory (CDI) and the Dupaul ADHD scale. Clinical variables between ADHD+BPD and ADHD were analyzed using the Mann-Whitney U test. YMRS, CDI, Dupaul ADHD scale (inattention and hyperactivity), CBCL, and TTS among the three groups were analyzed using the Kruskal-Wallis test with post-hoc Mann-Whitney U test. Results : 1) ADHD+BPD group had an earlier onset age of ADHD than ADHD group 2) ADHD+BPD group had more co-morbid psychiathc disorders than ADHD group. 3) Compared to ADHD group, ADHD+BPD had more psychiathc family history, especially mood disorders. 4) ADHD+BPD group had prodromal symptoms such as irritability, anger dyscontrol and academic dysfunction, compared to ADHD group who rarely showed prodromal symptoms. 5) ADHD+BPD group had higher ADHD scores than the ADHD group in the Dupaul ADHD inattentive scale. 6) In global functions of CBCL, ADHD+BPD group showed more impaired functions at home and school than ADHD group. 7) In Attention diagnostic system (ADS), ADHD+BPD group had more omission and commission errors than ADHD group, especially in the visual system. 8) In the subtests of the IQ profile, ADHD+BPD group had lower arithmetic and block design scores than ADHD group. Conclusion : Clinicians have to rule out underlying bipolarity in children and adolescents with ADHD who show earlier age of onset and severe clinical features. Bipolarity should be explored intensively in ADHD children and adolescents who have early onset of symptoms and severe functional impairment.

용액분산촉진 초임계 공정을 이용한 라이소자임 나노 입자의 제조 및 그 특성

김동현,박희준,강선호,전승욱,김민수,이시범,박정숙,황성주 한국약제학회 2005 Journal of Pharmaceutical Investigation Vol.35 No.2

The micron or nano-sized lysozyme as a model protein drug was prepared using solution enhanced dispersion by supercritical fluid (SEDS) process at various conditions (e.g., solvent, temperature and pressure) to investigate the feasibility of pulmonary protein drug delivery. The lysozyme particles prepared were characterized by laser diffraction particle size analyzer, scanning electron microscopy (SEM) and powder X-ray diffractometry (PXRD). The biological activity of lysozyme particles after/before SEDS process was also examined. Lysozyme was precipitated as spherical particles. The precipitated particles consisted of 100 -200 nm particles. Particle size showed the precipitates to be agglomerates with primary particles of size 1 - 5 μm. The biological activity varied between 38 and 98% depending on the experimental conditions. There was no significant difference between untreated lysozyme and lysozyme after SEDS process in PXRD analysis. Therefore, the SEDS process could be a novel method to prepare micron or nano-sized lysozyme particles, with minimal loss of biological activity, for the pulmonary delivery of protein drug.

속도추정에 의한 유도전동기의 벡터제어에 관한 연구

김동희,정경채,김민희,황돈하,이달해 嶺南大學校 工業技術硏究所 1994 工業技術硏究所論文集 Vol.22 No.1

Recently, the vector controlled induction motors are widely used in the industrial AC servo system requiring high accuracy and fast response. However, in the conventional vector control, by using of speed sensors for speed information of the motor, the system design has been restricted. This paper proposes te vector control system based on speed estimation controls motor speed by estimating angular speed of secondary flux linkages from voltage equations of induction motor without speed and voltage sensor. To stabilize the control system for estimation, the ??-axis flux keeps to zero by the compensation control method with state feedback. In addition, the whole control system is designed to be controlled by software in microcomputer. Computer simulations domonstrates that the control characteristics of the proposed vector control system based on speed estimation are satisfactory in both dynamic performance and accuracy.