• 제목/요약/키워드: large area cell

검색결과 383건 처리시간 0.027초

두피 및 사지에 다발성 섬유종을 동반한 결절성 경화증 (A Case of Tuberous Sclerosis with Multiple Fibroma on Scalp and Extremity)

  • 김형석;정희선;신극선;이상엽;송지선
    • Archives of Plastic Surgery
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    • 제35권3호
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    • pp.341-344
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    • 2008
  • Purpose: Tuberous sclerosis is an autosomal dominant multisystemic neurocutaneous syndrome characterized by the development of multiple hamartoma distributed through the body, skin, brain, heart, kidney, and lung. The classic triad is seizure, mental retardation, and facial angiofibroma. We experienced a case of a tuberous sclerosis associated with the facial lesion and multiple masses on scalp, forehead, and right lower extremity. Methods: This a 34-year-old male patient had subependymal giant cell astrocytoma in brain and multiple angiomyolipoma in both kidneys. Tangential excision with razor blade and dermabrasion were done on the centrofacial area. We excised other lesions and the mass on scalp was excised and covered with split thickness skin graft. Results: The histopathological finding revealed that the facial lesion was angiofibroma and the others were multiple fibroma. Conclusion: In our case of tuberous sclerosis, we chose the tangential excision to remove the large nodules of angiofibroma, and then dermabrasion was used to smooth the final contour. The patient appeared to have a good results from this treatment modality. But, tuberous sclerosis is an disease that needs long term follow-up to check up the recurrence of skin problem.

CDMA/TDMA 기반 무선 원격계측 시스템용 모뎀의 VLSI 구조 설계 (A VLSI Architecture Design of CDMA/TDMA Modem Chipsets for Wireless Telemetry Systems)

  • 이원재;이성주;이서구;정석호;김재석
    • 대한전자공학회논문지SD
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    • 제41권5호
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    • pp.107-114
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    • 2004
  • 본 논문에서는 CDMA 및 TDMA 기술을 기반으로 하는 무선 원격계측 시스템용 모뎀에 적합한 최적 하드웨어 구조 및 VLSI 설계에 대해서 제시한다. 무선 원격계측 시스템은 계측이 필요한 다수의 지점에 소형 무선계측기(RT: Remote Terminal)를 설치하고, 설치된 무선계측기로부터 계측데이터를 무선으로 수집하기 위해 제안된 시스템이다. 무선 원격계측 시스템은 계측데이터를 전송하기 위한 다수의 RT와 RT로부터 데이터를 수집하는 1개의 CU(Central Unit)로 구성된다. 본 논문에서는 이러한 RT와 CU용 모뎀에 적합한 최적 하드웨어 구조를 제안하였고, 제안된 구조를 Verilog HDL로 설계 및 검증하였다. Verilog HDL로 설계된 모뎀은 Synopsys/sup TM/툴을 이용하여 게이트 수준으로 합성되었고, 합성결과 RT 및 CU용 모뎀은 0.6㎛ 공정에서 각각 약 27K 게이트와 222K 게이트의 하드웨어 복잡도를 가졌다. 제안된 모뎀은 Altera/sup TM/ FPGA로 구현 및 검증되었다.

Calcitonin Transport through Skin Using Iontophoresis

  • Kim, Kyung-Min;Oh, Seaung-Youl
    • Journal of Pharmaceutical Investigation
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    • 제41권1호
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    • pp.9-17
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    • 2011
  • The objective of this work is to study transdermal delivery of calcitonin using iontophoresis and to evaluate various factors which affect the transdermal transport. We have studied the effect of polarity, current density, drug concentration, penetration enhancers (isopropyl myristate [IPM] and ethanol) and laser treatment on transdermal flux and the results were compared. We also investigated the iontophoretic flux from microemulsions containing calcitonin together with oleic acid (OA) or IPM. In vitro flux study was performed at $33^{\circ}C$, using side-by-side diffusion cell and full thickness hairless mouse skin. Anodal delivery at pH 3.0 was much larger than cathodal and passive delivery, due to the positive charge of calcitonin. Cumulative amount delivered (CUM) by cathodal or passive delivery was close to zero for 10 hours. The pretreatment of skin by neat IPM markedly increased the CUM anodically. CUM increased as the current density, drug concentration or the duration of IPM treatment increased. Microemulsion containing IPM or oleic acid was prepared and the phase diagram was constructed. CUM also increased when IPM was incorporated into a microemulsion. OA microemulsion showed similar enhancing effect to IPM microemulsion. The delivery of calcitonin from 70% (v/v) ethanol aqueous solution showed a large increase in flux. Laser treatment of skin before flux experiment exhibited about 2 fold increase in total calcitonin amount transported for 12 hours, when compared to that delivered by IPM microemulsion. Based on these results, we have evaluated the possibility of delivering enough amount of calcitonin to reach the therapeutic level. The data suggest that it is highly possible to deliver clinically effective amount of calcitonin using iontophoresis patch with small area (<10 $cm^2$).

2016년 1월 23일~25일에 발생한 서해안 대설 발달 메커니즘 분석 (Analysis of the West Coast Heavy Snowfall Development Mechanism from 23 to 25 January 2016)

  • 이재근;민기홍
    • 대기
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    • 제28권1호
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    • pp.53-67
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    • 2018
  • This study examined the lake effect of the Yellow Sea which was induced by the Siberian High pressure system moving over the open waters. The development mechanism of the convective cells over the ocean was studied in detail using the Weather Research and Forecasting model. Numerical experiments consist of the control experiment (CTL) and an experiment changing the yellow sea to dry land (EXP). The CTL simulation result showed distinct high area of relative vorticity, convergence and low-level atmospheric instability than that of the EXP. The result indicates that large surface vorticity and convergence induced vertical motion and low level instability over the ocean when the arctic Siberian air mass moved south over the Yellow Sea. The sensible heat flux at the sea surface gradually decreased while latent heat flux gradually increased. At the beginning stage of air mass modification, sensible heat was the main energy source for convective cell generation. However, in the later stage, latent heat became the main energy source for the development of convective cells. In conclusion, the mechanism of the west coast heavy snowfall caused by modification of the Siberian air mass over the Yellow Sea can be explained by air-sea interaction instability in the following order: (a) cyclonic vorticity caused by diabatic heating induce Ekman pumping and convergence at the surface, (b) sensible heat at the sea surface produce convection, and (c) this leads to latent heat release, and the development of convective cells. The overall process is a manifestation of air-sea interaction and enhancement of convection from positive feedback mechanism.

CuInGaSe2 단일 타겟을 이용한 대면적 CIGS 스퍼터링 박막의 특성 (Characteristics of large-area CIGS thin films fabricated by sputtering CuInGaSe2 single target)

  • 김태원;김영백;송상인;박재철
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.125.2-125.2
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    • 2011
  • CuInGaSe2 (CIGS)을 포함한 Chalcopyrite계 물질은 직접천이형 반도체이면서, ${\sim}1{\times}10^5cm^{-1}$ 이상의 광흡수계수를 보이며, 조성제어를 통한 밴드갭 조절이 가능해 차세대 고효율 박막태양전지재료로 매우 주목받고 있다. 최근, CIGS 박막태양전지 제조를 위해 CIGS 흡수층의 여러 가지 박막제조 공정들이 개발되고 있으나, 동시증착법과 소위 2단계법이라 일컬어지는 금속 전구체 스퍼터링 증착 후 셀렌화 공정을 가장 대표적인 공정이라 말 할 수 있다. 동시증착법은 실험실 수준의 소면적 셀에서 20%에 가까운 높은 효율의 CIGS 박막태양전지 제조에 성공하였음에도 불구하고, 상용화를 위한 대면적 셀 제조를 위해 해결해야 할 문제들이 아직 남아있다. 또한, 2단계법의 경우는 스퍼터링 공정을 기반으로 대면적 셀 제조에는 용이하나, CIGS/Mo 계면에서의 Ga 응집현상의 발생 및 셀렌화 공정에 사용되는 독성가스($H_2Se$)의 문제 등이 남아 있어 새로운 시각에서의 접근 방법이 요구되고 있다. 본 연구에서는 CIGS 4성분계 단일 타겟을 사용, RF 스퍼터링 공정을 통해 $200{\times}200mm^2$ 기판 위에 CIGS 박막을 제조하여 그 특성을 분석하였다. XRD 분석결과, 동시증착법에서 일반적으로 관찰되는 CIGS/Mo 계면에서의 $MoSe_2$ 상의 존재는 관찰되지 않았으며, CIGS 단일상의 다결정 박막이 제조되었음을 알 수 있었다. 또한, CIGS 박막제조 후, RTA 공정을 통해 CIGS 박막의 결정성이 향상됨을 관찰 할 수 있었으며, SIMS 분석결과, Mo층의 공정 조건에 따라 CIGS/Mo 계면에서의 금속원소 (In, Ga, Mo)의 상호확산이 크게 억제됨을 알 수 있었다. 그 외의 특성평가 결과들을 통하여 CIGS 4성분계 단일 타겟을 사용한 CIGS 박막태양전지 제조의 유용성에 대해 논의하고자 한다.

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순수 에탄올을 이용한 재발된 좌골부위 압박궤양의 경화요법적 치료 (Treatment of Recurrent Ischial Pressure Sore Using Sclerotherapy with Absolute Ethanol)

  • 송훈;박상근;김종환;홍인표
    • Archives of Plastic Surgery
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    • 제33권5호
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    • pp.627-631
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    • 2006
  • Purpose: Ischial region is common site of pressure sore as well as greater trochanteric area. In general, ischial pressure sore associated with a large subcutaneous bursa often requires radical surgical treatment. The authors performed sclerotherapy using absolute ethanol which was considered as an alternative in treating recurrent ischial pressure sore. Methods: From may 2005 to February 2006, 11 ischial pressure sore patients were treated sclerotherapy using absolute ethanol. The authors performed sclerotherapy using absolute ethanol in 11 patients in whom the ischial sore has recurred despite of multiple radical surgical treatment. The patients' original disorders were spinal cord injury in 9 patients, cerebral palsy in 1 patient and giant cell tumor in thoracic vertebrae 1 patient. Results: Recurrence of pressure sore was not found in any patient during the follow-up period. The swap of the bursa taken before the surgery was germ cultured and compared with the discharge from an end of the inserted drain tube. The germ cultured results after the surgery were tested negative in all patients. Conclusion: This method involves causing the bursa to become scarred and closing it up by sterilizing, fixing, and denaturing by the pharmacologic effect of absolute ethanol instead of surgical excision of the bursa. We felt that aforementioned treatment modality may be considered as an alternative in treating recurrent ischial pressure sore.

Silicone Implant 삽입 후에 발생한 안와내 거대 낭종 (Large Intraorbital Cyst after Silicone Implant Insertion: A Case Report)

  • 하상욱;이혜경;유원민;탁관철
    • Archives of Plastic Surgery
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    • 제33권5호
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    • pp.659-662
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    • 2006
  • Purpose: Alloplastic implants, such as methylmethacrylate, Teflon, silicone, Supramid are commonly used to cover the floor defect and to prevent reherniation of the displaced orbital tissue in orbital floor fracture. Silicone implant has been used for reconstruction of orbital wall defects because of pliability, advantage of carving and chemically inert nature. However, silicone implant also has complications including infection, extrusion, pain, dystopia and tissue reaction. Cyst formation around the silicone implant is a very rare complication. According to many reports, cysts around alloplastic implant in an orbital area are mostly hemorrhagic cysts consisted of blood breakdown product with fibrous capsule cell in histologic examination. Methods: The authors report atypical case and successful treatment of intraorbital hemorrhagic cyst around silicone implant of a 37-year-old male patient. Results: Preoperative symptoms of diplopia, exophthalmos, proptosis, vertical dystopia and ectropion of lower eyelid were resolved after surgical removal of implants with surrounding capsule. Conclusion: Clinical suspicion of plastic surgeon is important in diagnosis of intraorbital cyst of patients who have history of silicone implantation and computed tomography is the standard tool of diagnosis. During the operation, caution must be taken on delivering the whole capsule of intraorbital cyst along with silicone implant to prevent recurrence of the cyst.

18% 효율 Cu(In,Ga)Se2 박막태양전지용 ZnSnO 버퍼층의 원자층 증착법 및 분석 (Characterization of Atomic-Layer Deposited ZnSnO Buffer Layer for 18%- Efficiency Cu(In,Ga)Se2 Solar Cells)

  • 김선철;김승태;안병태
    • Current Photovoltaic Research
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    • 제3권2호
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    • pp.54-60
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    • 2015
  • ZnSnO thin films were deposited by atomic layer deposition (ALD) process using diethyl zinc ($Zn(C_2H_5)_2$) and tetrakis (dimethylamino) tin ($Sn(C_2H_6N)_4$) as metal precursors and water vapor as a reactant. ALD process has several advantages over other deposition methods such as precise thickness control, good conformality, and good uniformity for large area. The composition of ZnSnO thin films was controlled by varying the ratio of ZnO and $SnO_2$ ALD cycles. The ALD ZnSnO film was an amorphous state. The band gap of ZnSnO thin films increased as the Sn content increased. The CIGS solar cell using ZnSnO buffer layer showed about 18% energy conversion efficiency. With such a high efficiency with the ALD ZnSnO buffer and no light soaking effect, AlD ZnSnO buffer mighty be a good candidate to replace Zn(S,O) buffer in CIGSsolar cells.

Fabrication of Crystalline $ZrO_2$ Nanotubes by ALD

  • 김현철;;유현준;김명준;양윤정;이선희;신현정
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2011년도 춘계학술발표대회
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    • pp.241.1-241.1
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    • 2011
  • Numerous possible applications for $ZrO_2$ nanotubes exist such as for catalyst support structures, for sensing or for applications as a solid state electrolyte. Especially, because of a large specific surface area, high efficiency for solid oxide fuel cell (SOFC) application at low temperature can be expected for nanotublar structures in even small size. A zirconium precursor, Tetrakis (ethylmethylamino) zirconium, TEMAZr and $H_2O$ oxidant were used to deposit$ZrO_2$ thin films on an anodized aluminum oxide (AAO) templates having sub-100nm cylindrical pores by atomic layer deposition (ALD) in the temperature range of 150~250$^{\circ}C$. The crystalline structures of as-prepared and post-annealed $ZrO_2$ nanotubes were characterized by x-ray diffraction and high-resolution transmission electron microscopy. The as-prepared samples at $150^{\circ}C$ and $200^{\circ}C$ were showed amorphous, whereas a mixed phase of tetragonal, monoclinic and amorphous polymorph was observed at $250^{\circ}C$. In the bulk, zirconia remains monoclinic phase up to $1,175^{\circ}C$, however, $ZrO_2$ nanotubes were showed tetragonal phase upon post thermal treatments merely at $400^{\circ}C$. This trend may be indicative of high-curvature surfaces of nanotubes and thereby the presence of intrinsic compressive strain. The amount of amorphous structures in the mixed phase as well as as-grown $ZrO_2$ nanotubes were also gradually decreased by subsequent heat treatment.

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전류 궤적 영상의 특징과 트리모델을 이용한 태양광 전력 인버터의 고장진단 (Fault Diagnosis of Solar Power Inverter Using Characteristics of Trajectory Image of Current And Tree Model)

  • 황재호
    • 전자공학회논문지CI
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    • 제47권4호
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    • pp.102-108
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    • 2010
  • 태양광 발전 시스템은 태양 전지에 의해 태양 에너지를 직류로 변환하며 이 직류를 인버터에 의해 일반 가정에서 사용되는 교류로 변환한다. 최근 태양광 발전 시스템의 전력량이 증가하는 추세이므로 대전력을 전송하는 3상 시스템에 관한 연구가 중요하다. 본 논문에서는 태양광전지의 계통연계 시스템의 3상 PWM 인버터의 스위치 개방이 발생했을 경우, 이를 간단히 검출하고 식별하는 방법을 제안한다. 제안 방법은 $\alpha\beta$ 평면에서 전류 벡터의 궤적 영상의 패턴을 특징으로 하여 정상상태와 각각의 고장 상태를 결정하여 트리로 분류한다. 트리 구성을 위한 고장패턴은 21개로 하였으며 고장 패턴트리의 결정을 위한 분류 파라메터는 모양, 영역, 분산각, 벡터각으로 하였다. 각 고장에 대하여 제안방법의 성능을 평가한 결과 모든 고장요소를 정확히 분류하여 패턴 트리를 구성하였다.