• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.13.1-13.8
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• 2017

Background: Oronasal/antral communication, loss of teeth and/or tooth-supporting bone, and facial contour deformity may occur as a consequence of maxillectomy for cancer. As a result, speaking, chewing, swallowing, and appearance are variably affected. The restoration is focused on rebuilding the oronasal wall, using either flaps (local or free) for primary closure, either prosthetic obturator. Postoperative radiotherapy surely postpones every dental procedure aimed to set fixed devices, often makes it difficult and risky, even unfeasible. Regular prosthesis, tooth-bearing obturator, and endosseous implants (in native and/or transplanted bone) are used in order to complete dental rehabilitation. Zygomatic implantology (ZI) is a valid, usually delayed, multi-staged procedure, either after having primarily closed the oronasal/antral communication or after left it untreated or amended with obturator. The present paper is an early report of a relatively new, one-stage approach for rehabilitation of patients after tumour resection, with palatal repair with loco-regional flaps and zygomatic implant insertion: supposed advantages are concentration of surgical procedures, reduced time of rehabilitation, and lowered patient discomfort. Cases presentation: We report three patients who underwent alveolo-maxillary resection for cancer and had the resulting oroantral communication directly closed with loco-regional flaps. Simultaneous zygomatic implant insertion was added, in view of granting the optimal dental rehabilitation. Conclusions: All surgical procedures were successful in terms of oroantral separation and implant survival. One patient had the fixed dental restoration just after 3 months, and the others had to receive postoperative radiotherapy; thus, rehabilitation timing was longer, as expected. We think this approach could improve the outcome in selected patients.

• 전기전자학회논문지
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• 제16권4호
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• pp.283-289
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• 2012

이 논문에서 Trench Power MOSFET의 스위칭 성능을 향상시키기 위한 Separate Gate Technique(SGT)을 제안하였다. Trench Power MOSFET의 스위칭 성능을 개선시키기 위해서는 낮은 gate-to-drain 전하 (Miller 전하)가 요구된다. 이를 위하여 제안된 separate gate technique은 얇은(~500A)의 poly-si을 deposition하여 sidewall을 형성함으로서, 기존의 Trench MOSFET에 비해 얇은 gate를 형성하였다. 이 효과로 gate와 drain에 overlap 되는 면적을 줄일 수 있어 gate bottom에 쌓이는 Qgd를 감소시키는 효과를 얻었고, 이에 따른 전기적인 특성을 Silvaco T-CAD silmulation tool을 이용하여 일반적인 Trench MOSFET과 성능을 비교하였다. 그 결과 Ciss(input capacitance : Cgs+Cgd), Coss(output capacitance : Cgd+Cds) 및 Crss(reverse recovery capacitance : Cgd) 모두 개선되었으며, 각각 14.3%, 23%, 30%의 capacitance 감소 효과를 확인하였다. 또한 inverter circuit을 구성하여, Qgd와 capacitance 감소로 인한 24%의 reverse recovery time의 성능향상을 확인하였다. 또한 제안된 소자는 기존 소자와 비교하여 어떠한 전기적 특성저하 없이 공정이 가능하다.

• 한국태양에너지학회 논문집
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• 제29권1호
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• pp.18-23
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• 2009

We intend to describe a 12kW building-integrated photovoltaic system which was applied into the south wall of a new building. This study showed the results that were appeared from describing the PV module manufacture and installation process, and performing generation performance analysis of BIPV system. From the result we confirmed that the generation performance of the BIPV system was changed by season. The performance ratio(PR) was about 83.6% in winter and it means that performance of this BIPV system was so good in that season. On the other hand, the PR in summer was about 75.0% dropped about 8%. It was believed that the change was influenced by the reduction of solar radiation irradiated into the PV modules by installation position and rainy spell in summer. And we also confirmed that low irradiation condition is cause of the additional loss in the total PV system. In this case, the efficiency ratio of PCS drops significantly at low input loads and the average conversion efficiency of PCS in summer was 76.4% decreased about 10% from 86% in winter.

• Applied Science and Convergence Technology
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• 제23권5호
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• pp.248-253
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• 2014

Air Gap Membrane Distillation (AGMD) is one of several technologies that can be used to solve problems fresh water availability. AGMD exhibits several advantages, including low conductive heat loss and higher thermal efficiency, due to the presence of an air gap between the membrane and condensation wall. A previous study by Bhardwaj found that the condensation surface properties (materials and contact angle) affected the total collected fresh water in the solar distillation process. However, the process condition differences between solar distillation and AGMD might result in different condensation phenomena. In contrast, N. Miljkovic showed that a hydrophobic surface has higher condensation heat transfer. Moreover, to the best of our knowledge, there is no study that investigates the effect of condensation surface properties in AGMD to overall process performance (i.e. flux and thermal efficiency). Thus, in this study, we treated the AGMD condensation surface to make it hydrophobic or hydrophilic. The condensation surface could be made hydrophilic by immersing and boiling plate in deionized (DI) water, which caused the formation of hydrophilic aluminum hydroxide (AlOOH) nanostructures. Afterwards, the treated plate was coated using hexamethyldisiloxane (HMDSO) through plasma-enhanced chemical vapor deposition (PECVD). The result indicated that condensation surface properties do not affect the permeate flux or thermal efficiency significantly. In general, the permeate flux and thermal efficiency for the treated plates were lower than those of the non-treated plate (pristine). However, at a 1 mm and 3 mm air gap, the treated plate outperformed the non-treated plate (pristine) in terms of permeate flux. Therefore, although surface wettability effect was not significant, it still provided a little influence.

• 조명전기설비학회논문지
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• 제22권12호
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• pp.47-55
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• 2008

전력수요의 증가와 도심지역의 확대로 주거지역에 새로운 변전소를 건설하거나, 기존 변전소에 변압기 증설이 필요하다. 그러나 변전소의 변압기 소음으로 인한 불만이 증가하고 있다. 지금까지 한전에서는 변압기의 소음전달을 차단하기 위하여 옥외 변전소의 경우에는 방진패드 설치, 다양한 방음벽 설치, 변압기 본체 밀폐 등을 시행하여 왔으며, 옥내 변전소의 경우에는 방음문, 방음서터 및 풍도형 방음장치 설치 등을 시행하여 왔다. 그러나 현재의 소음 저감대책은 만족할 정도에 이르지 못하는 실정이다. 따라서 변압기 자체의 소음발생 억제에 대한 근본적인 대책이 요구되고 있다. 본 연구에서는 변압기 외함의 보강제 사이를 강판으로 막아 변압기 외함에서 방출되는 소음을 차단하기 위한 차음판 기술을 개발하였다. 차음판을 변압기 외함에 적용하기 위하여 변압기 외함의 진동 특성과 차음판의 적용에 따른 음의 감쇄를 해석하고, 실변압기에 차음판을 적용하여 소음의 저감효과를 측정하여 약 11[dB]의 소음저감 효과를 확인하였다.

• 한국작물학회지
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• 제47권2호
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• pp.132-136
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• 2002

The rice straw managements are essential for maintaining soil fertility as well as reducing chemical fertilizer application in paddy field. A field experiment was conducted on moderately well draining alluvial paddy soil to investigate the decomposition pattern of rice straw. The mesh bags containing the rice straw harvested in the previous year were placed at soil surface and buried into around 10cm depth and recovered periodically for determining the straw decomposition. Pot experiments were conducted to investigate the fates of N released from $^{15}$ N-labeled rice straw under different levels of N fertilizer application. The overall decomposition patterns of rice straw were similar for the two incorporation depths in transplanted paddy field. The straw incorporated at transplanting date showed weight loss of about 50%, 70% and 90% after 2 months, 5 months, and 2 years, respectively. The decompositions of straw cell wall components showed somewhat different pattern. The decompositions of cellulose and silica were similar to that of dry weight while the decomposition of lignin was slower than that of cellulose and silica. N was released from rice straw 42% and 65 % of the initial N after one month and after five months, respectively. P release was faster than N release. Recoveries of rice straw-$^{15}$ N by rice plants were 10.2, 13.4 and 14.9% in 0, 120 and 240 mg N pot$^{-1}$ , respectively. Soil recoveries of rice straw $^{15}$ N were 17.3, 20.6 and 18.9% in 0, 120 and 240mg N pot$^{-1}$ , respectively.

• The Korean Journal of Physiology and Pharmacology
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• 제16권6호
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• pp.437-446
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• 2012

Ulcerative colitis is an inflammatory bowel disease (IBD) characterized by recurrent episodes of colonic inflammation and tissue degeneration in human or animal models. The contractile force generated by the smooth muscle is significantly attenuated, resulting in altered motility leading to diarrhea or constipation in IBD. The aim of this study is to clarify the altered contractility of circular and longitudinal smooth muscle layers in proximal colon of trinitrobenzen sulfonic acid (TNBS)-induced colitis mouse. Colitis was induced by direct injection of TNBS (120 mg/kg, 50% ethanol) in proximal colon of ICR mouse using a 30 G needle anesthetized with ketamin (50 mg/kg), whereas animals in the control group were injected of 50% ethanol alone. In TNBS-induced colitis, the wall of the proximal colon is diffusely thickened with loss of haustration, and showed mucosal and mucular edema with inflammatory infiltration. The colonic inflammation is significantly induced the reduction of colonic contractile activity including spontaneous contractile activity, depolarization-induced contractility, and muscarinic acetylcholine receptor-mediated contractile response in circular muscle layer compared to the longitudinal muscle layer. The inward rectification of currents, especially, important to $Ca^{2+}$ and $Na^+$ influx-induced depolarization and contraction, was markedly reduced in the TNBS-induced colitis compared to the control. The muscarinic acetylcholine-mediated contractile responses were significantly attenuated in the circular and longitudinal smooth muscle strips induced by the reduction of membrane expression of canonical transient receptor potential (TRPC) channel isoforms from the proximal colon of the TNBS-induced colitis mouse than the control.

• 한국가스학회지
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• 제24권4호
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• pp.56-61
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• 2020

수소의 액화에는 예냉 에너지, 상변화 에너지, 수소 변환열 제거 등 다량의 에너지가 요구되어진다. 본 논문의 목적은 예냉공정에 필요한 에너지로 LNG냉열로 액체질소를 제조하여 사용하는 LNG냉열 간접 이용 방식과, Cold box의 단열에 냉공기를 이용하는 새로운 에너지절약 공정을 제안하여 수소액화 수율을 향상시키고자 하였다. 분석 결과를 보면, LNG냉열 간접이용 방식은 에너지 절약과 함께 액체수소 플랜트의 안전성을 제공하는 장점을 갖는다. 새로운 Cold box 단열 방식은 외벽 철판 3mm/우레탄폼 20cm/공기 5cm/우레탄폼 20cm/설비의 구조일 때 현재 펄라이트 단열에 비교하여 열유입량이 약 35%~50%가 감소하게 된다. 또한 냉공기 보다 온도가 높은 설비는 냉각의 효과를 얻게 된다. 수소액화 플랜트의 공정에 본 결과를 적용한다면 액체 수율이 50% 내외로 크게 향상되는 효과를 제공하게 된다.

• Archives of Plastic Surgery
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• 제34권4호
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• pp.448-454
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• 2007

Purpose: The objective of this study was to evaluate the outcomes of using the free flap in the reconstruction of maxillary defects. Methods: 27 consecutive cases of maxillary reconstruction with free flap were reviewed. All clinical data were analyzed, including ideal selection of flap, time of reconstruction, recurrence of cancer, postoperative complications, flap design, and follow-up results. The main operative functional items, including speech, oral diet, mastication, eye globe position and function, respiration, and aesthetic results were evaluated. Results: Among the 24 patients who underwent maxillary reconstruction with the free flap, 14 patients underwent immediate reconstruction after maxillary cancer ablation, and 10 patients underwent delayed reconstruction. There occurred 1 flap loss. Recurrences of the cancer after the reconstruction happened in 2 cases. Postoperative complications were 3 cases of gravitational ptosis of the flap, 2 cases of the nasal obstruction, and 1 case of fistula formation. Out of 27 free flaps, there were 15 latissimus dorsi myocutaneous flaps, 5 radial forearm, 4 rectus abdominis myocutaneous flaps, 1 scapular flap, 2 fibula osteocutaneous flap, respectively. Flaps were designed such as 1 lobe in 9 cases, 2 lobes in 9 cases, and 3 lobes in 5 cases. Among the 14 patients who had intraoral defect or who had palatal resection surgery, 2 patients complained the inaccuracy of the pronunciation due to the ptosis of the flap. It was corrected by the reconstruction of the maxillary buttress and hung the sling to the upper direction. All of the 14 patients were able to take unrestricted diets. In 6 patients who had reconstruction of inferior orbital wall with rib bone graft, they preserved normal vision. Aesthetically, most of the patients were satisfied with the result. Conclusion: LD free flap is suggested in uni-maxilla defect as the 1st choice, and fibular osteocutaneous flap and calvarial bone graft to cover the larger defect in bi-maxilla defect.

• 한국진공학회지
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• 제7권2호
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• pp.155-160
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• 1998

256M DRAM급에 해당하는 0.25$\mu\textrm{m}$의 회로선 폭을 가공하기 위해 Arc layer & DUV resist 사용이 필수적이다. Poly-Si 식각시 Arc layer 적용여부 및 resist 종류에 따른 차이 를 TCP-9408 etcher(Lam Research Co.)에서 $Cl_2/O_2, Cl_2/N_2, Cl_2$/HBr 3가지 gas chemistry 를 변화시키면서 조사하였다. 동일한 식각 조건에서 DUV resist사용의 경우에 I-line resist 에 비해 식각 profile이 profile이 positive하고 CD gain도 크게 나왔다. 이것은 resist손실에 의한 polymer생성의 증가가 식각시 측벽 보호막을 강화시키기 때문이다. Arc layer 적용의 경우 Arc layer 식각시 생기는 fluorine계 polymer가 poly-Si 식각시 mask역할을 하므로 CD gain이 증가하는 것으로 나타났다. Gas chemistry에 의한 영향은 $Cl_2/O_2$의 경우가 식각 시 polymer형성을 촉진시켜 positive profile 및 CD gain을 초래하였다. $Cl_2$/HBr의 경우에는 profile이 vertical 하였고 CD gain도 거의 없었다. 또한 dense pattern 과 isolated pattern 사이의 profile 및 CD 차이도 가정 작게 나타났다. HBr gas 사용이 식각시 pattern density 에 따른 측벽 보호막 형성의 불균일성을 최소화 시켜 양호한 특성을 보여주었다.