• Title/Summary/Keyword: 재생 및 보존

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Performance Characteristics of Organic Rankine Cycle Using Medium Temperature Waste Heat with Different Working Fluids (중온 배기열을 이용한 유기랭킨사이클 작동유체별 성능특성)

  • Kwon, Dong-Uk;Heo, Ki-Moo;Yoon, Sung-Hoon;Moon, Yoon-Jae;Yoo, Ho-Sun;Lee, Jae-Heon
    • Plant Journal
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    • v.10 no.2
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    • pp.38-47
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    • 2014
  • Renewable Portfolio Standards was introduced into the system in Korea in 2012. Interest in the unutilized and renewable energy sources is increasing. and these being actively investigated. An organic rankine cycle has emerged as an alternative in order to take advantage of bio-gas engine heat of sewage treatment plants whose capacity is 1500 kW. The organic rankine cycle power system was simulated by a simulator which is a commercial program of power plant design and performance analysis. The biogas engine is operated by $460^{\circ}C$ and 2.7 kg/s flow rate in the sewage treatment plant. Working fluids(R-601a, R-123, R-245fa) are selected to use in ORC power system in this temperature range. It was the isopentane that is the best performance among three working fluids. It could be obtained net power of 163.1 kW and efficiency of 13.66% from isopentane in the simulation.

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Transforming a Buffer Green into an Urban Park as Multi-functional Green Infrastructure - A Case of the Buffer Green of Sinmae Market in Daegu, Korea - (입체적 도시기반시설로서 완충녹지의 공원화 계획 - 대구광역시 신매시장 완충녹지 공원화 계획을 사례로 -)

  • Kim, Miyeun;Min, Byoungwook
    • Journal of the Korean Institute of Landscape Architecture
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    • v.49 no.2
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    • pp.101-112
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    • 2021
  • In Korea, efforts have been made continuously to improve the environment of traditional markets concerning the issues of urban regeneration. In particular, many old cities and traditional markets face a lack of parking spaces. As a solution to this, attempts are being made to prepare underground parking spaces by designing urban planning facilities in three-dimensional ways and utilizing the upper part as a more meaningful space. This study is about the master plan to use the upper green area while creating an underground parking lot at 571 Sinmae-dong, Suseong-gu, Daegu. This green area was defined as a space with dual values, 'defensive green space' that needs to be ecologically protected, and 'active cultural space' where walking flows to the market and various events are concentrated. Three specific design strategies to balance these values were presented. First, to prevent indiscriminate occupation and damage by people and maintain a healthy green environment, securing the maximum amount of undivided green space in the site was suggested. Second, a space layout and a topography and planting patterns that can overcome the morphological characteristics of narrow and long-shaped sites enable the experience of abundant green spaces. Third, providing space to strengthen the connections with nearby urban facilities such as Sinmae Market and Gosan Library can also intensively accommodate cultural activities in various cities. This study has academic significance in providing implications for urban regeneration projects with similar contexts in the future.

A CASE REPORT OF A DENTIGEROUS CYST TREATED BY MARSUPIALIZATION (조대술을 이용한 함치성 낭종의 치험례)

  • Jun, Eun-Min;Kim, Tae-Wan;Kim, Hyun-Jung;Nam, Soon-Hyeun;Kim, Young-Jin
    • Journal of the korean academy of Pediatric Dentistry
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    • v.34 no.3
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    • pp.473-480
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    • 2007
  • The dentigerous cyst originates through alteration of stellate reticulum after amelogenesis has completed, with accumulation of fluid between the layers of the reduced enamel epithelium or between this epithelium and the tooth crown. Its incidence is relatively high on 10s or 20s of age and it is always related to the unerupted crown. Generally, it has no symptom, however, if the cyst is large or accompanied with pus formation, swelling and pain may occur. In radiographic findings, it shows impacted crown surrounded by well defined unilocular radiolucent lesion and occasionally displacement of adjacent teeth or root resorption. The goal of treatment is complete elimination of abnormal tissue preserving the tooth involved in the cyst. Enucleation and marsupialization are commonly used for the treatment. Marsupialization is the procedure which removes the partial portion of the cystic wall and connects with the oral mucosa. As the pressure in the cyst decreases, bone regeneration takes place in the defect area and cystic wall converts into normal mucosa. This procedure, however, is the most conservative procedure which allows the protection of adjacent important structures. If the eruption space is sufficient, then inducing the eruption of the permanent tooth in the cyst is also possible. In following cases, dentigerous cyst was diaganosed after clinical and radiographic examination. Marsupialazation was done to remove the cyst and induce the tooth, which was in the cyst, to erupt into the oral cavity.

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The Value and Change of the Forest Village Bugundang in Itaewon, Seoul (서울 이태원 부군당(府君堂) 마을 숲의 변천과 가치)

  • Kim, Hai-Gyoung;Kim, Young-Soo
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.31 no.2
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    • pp.58-69
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    • 2013
  • This research try to review about individuals' living culture place by record to before process of transition and modify of Bugundang village's forest in Itaewon. A result is as follows. First, Itaewon Bugundang is located in highest site of center building of twon forest, it has been preserve by double fence and taboo subject. Physical element of village forest is a factor which give sanctity of Buhundang. Second, it is connecting Namsan and Yongsan Family Park as green space. Also Itaewon Bugundang isolated from the current residential area. but in the past, the main beliefs and rituals of its area are responsible for a diverse community where public service was strong. Itaewon Bugundang have played a role presenting a local taboos and social norms. Therefore, these elements of the local community have the traditional cultural values. Third, Zelkova and Kalopanax pictus need to be preserved the value by the Seoul Metropolitan Government. Fourth, components of Bugundang are built by Hwajucheong, Dangjigi house, seonangdan, monument, fence, masonry and various trees. And the function and role of each of these elements remains as traditional culture. And the structural features of historic architectural properties has the value as a registered cultural properties. Fifth, due to these features, the traditional landscape of Itaewon bugundang play a role succeeding disappearing traditional culture and is worth as a potentially valuable landscape elements. This study has significance to the excavation community tradition disappearing landscape and excavation of candidate new tradition.

Silicon thin films and solar cells by HWCVD (열선 화학 기상 증착법에 의한 실리콘 박막 및 태양전지 특성)

  • Kim Sang-Kyun;Lee Jeong Chul;Jeon Sang Won;Lim Chung Hyun;Ahn Sae Jin;Yun Jae Ho;Kim Seok Ki;Song Jinsoo;Park S-J;Yoon Kyung Hoon
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.06a
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    • pp.205-208
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    • 2005
  • 최근 열선 화학 기상 증착법(HWCVD)은 낮은 온도에서 TFT용 Poly Si 중착을 할 수 있다는 점과 실리콘 박막을 빠른 속도로 증착할 수 있다는 점에서 각광을 받고 있다. 본 연구에서는 HWCVD를 이용하여 태양전지를 제조하고 그 특성을 평가하였다. 조건에 따른 실리콘 박막의 특성 변화를 알기 위해 corning glass 및 실리콘 wafer에 다양한 조건에서 단위 박막(intrinsic layer)을 증착하였고 이 결과를 바탕으로 p/i/n 구조의 태양전지를 제조하였다. Ta 열선 온도는 1700-2000도였고 가스 원료인 $SiH_4$와 수소의 비율을 조절하면서 그 영향을 관찰하였다. 태양전지의 경우 p충과 n충은 PECVD로 증착하였으며 단위박막 및 태양전지 i충 증착시 기판과 열선간의 거리는 7cm, 기판 온도는 $200^{\circ}C$$250^{\circ}C$로 고정하였고 작업압력은 30mTorr였다. 단위 박막 특성 평가를 위해 암/광 전도도, SEM, Raman Scattering, FT-IR등을 사용하였으며 태양전지 특성 평가를 위해 I-V 및 Spectral response를 측정하였다. 열선 온도가 증가함에 따라 증착속도 및 결정화 분율은 증가하였다. 특히 비정질에서 결정질로 전이되는 구간은 매우 좁았으며 여러 분석 방법에서 일치되는 결과를 보였다. $SiH_4$ 유량이 늘어날수록 비정질이 결정질로 바뀌는 열선 온도가 증가하였으며 기판 온도가 낮을 경우 또한 결정으로 바뀌는 열선 온도가 증가하였다. 태양전지의 경우 열선 온도가 증가함에 따라 $V_{oc}$ 및 W가 낮아졌으며 $J_{sc}$, 는 증가하는 경향을 보였으며 결정질 비율이 증가하는 것을 관찰할 수 있었다. 이러한 경향은 quantum efficiency 결과에서도 확인할 수 있었다.용을 반복하면서 석재 내부와 외부의 암석 및 결정에 균열과 미세열극 등이 생성되어 석재 자체의 구조적 안정성에 영향을 주고 있다. 따라서 감은사지 석탑은 지리적 환경 차이로 인해 일반적인 환경의 석조물들과는 다른 형태의 풍화양상을 보이고 있어서 풍화양상 및 풍화형태에 대한 정확한 연구와 이해를 바탕으로 보존대책이 마련되어야 한다.되었다. 이런 모든 시편들을 각 탈염방법에 따라 탈염처리한 후 XRD와 SEM-EDS으로 분석한 결과 인철광과 침철광은 어떠한 변화도 보이지 않았고, 다만 적금광으로 동정된 시편만이 잔존하지 않았다. 철기 제작별 $Cl^-$ 이온 추출량과 탈염효과에 대한 비교 실험은 이온 크로마토그래피 분석 결과와 마찬가지로 단조 철제유물이 주조 철제보다 $Cl^-$ 이온을 많이 가지고 있었으며, 탈염 처리 후에는 $Cl^-$ 이온은 전혀 발견되지 않았다. 이상의 결과 $K_2CO_3$와 Sodium 용액은 탈염처리에서 가장 적합한 탈염처리 용액으로 알수가 있었으며 특히 어떠한 탈염 용액으로 유물을 처리한다 해도 철제유물에 생성된 부식물은 제거되지 않는다는 것을 알게 되었다. 따라서 보존처리자는 유물 표면의 부식 상태만을 보고 처리하기 보다는 철기제작물로 고려하여 처리하는 것이 필요하다. 또한 금속에 부식을 야기시키는 $Cl^-$ 이온과 부식물을 완전하게 제거하여 탈염처리를 하는 것이 유물 부식을 최대한 지연시킬 수 있는 것이라 생각된다.TEX>$88\%$)였다.(P=0.063). 결론: 본 연구에서는 MTHFR C/T & T/T 유전자 다형성이 위암의 발생과 그 위치에 대해 관련이 있는 것으로 여겨지고, 흡연력, 음주력과는 관련이 없는 것으로 여겨진다.험이 커지는 경향을 보였으나, 나이 및 병기, 종양의 크기, MD-BED $Gy_{10}$ 등의 예후 인자를 보정한 다변

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Cancer Stem Cells and the Tumor Microenvironment (암줄기세포와 종양 미세환경에 대한 고찰)

  • Soo-Yeon Woo;Hee-Seon Choi;Kanghee Yoo;Junseo Kim;Yeolhee Yoon;Seungyeon Lee;Jaehyuk Choi;Kyeongho Kim;Kangjun Lee;Seunghyeon Hwang;Dongjun Lee
    • Journal of Life Science
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    • v.34 no.6
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    • pp.418-425
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    • 2024
  • Solid tumors are heterogeneous populations of multiple cell types. While the majority of the cells that comprise cancer are unable to divide, cancer stem cells have self-renewal and differentiation properties. Normal stem cell pathways that control self-renewal are overactivated in cancer stem cells, making cancer stem cells important for cancer cell expansion and progression. Dick first proposed the definition of cancer stem cells in acute myeloid leukemia, according to which cancer stem cells can be classified based on the expression of cell surface markers. Cancer stem cells maintain their potential in the tumor microenvironment. Multiple cell types in the tumor microenvironment maintain quiescent cancer stem cells and serve as regulators of cancer growth. Since current cancer treatments target proliferative cells, quiescent state cancer stem cells that are resistant to treatment increase the risk of recurrence or metastasis. Various signals of the tumor microenvironment induce changes to become a tumor-supportive environment by remodeling the vasculature and extracellular matrix. To effectively treat cancer, cancer stem cells and the tumor microenvironment must be targeted. Therefore, it is important to understand how the tumor microenvironment induces reprogramming of the immune response to promote cancer growth, immune resistance, and metastasis. In this review, we discuss the cellular and molecular mechanisms that can enhance immunosuppression in the tumor microenvironment.

Alveolar ridge preservation using granulation tissue for esthetic implant restoration on maxillary anterior tooth (상악 전치부의 심미적 임플란트 수복을 위한 육아 조직(Granulation tissue)을 이용한 치조제 보존술)

  • Lee Chang Kyun
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.32 no.1
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    • pp.16-22
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    • 2023
  • Esthetic factors are very important in the success of maxillary anterior implant restoration. However, achieving esthetic results is difficult, especially in cases where periodontitis has resulted in severe alveolar bone loss. In the case of maxillary anterior teeth, the alveolar ridge resorption that begins immediately after tooth extraction interferes with the esthetic implant restoration. Therefore immediate implant placement can be performed to minimize the alveolar ridge resorption. However, in severe bone loss cases, immediate implant placement could result in esthetic failure, and this result might cause irreparable problems. We can also perform alveolar ridge preservation and then place implants later. On JCP published in 2019, there is the consensus of European academy of periodontology on the extraction socket management and the timing of implant placement. This consensus states that alveolar ridge preservation should be considered when there is severe labial bone loss in an esthetically important area such as maxillary anterior region. On performing the alveolar ridge preservation, we cannot obtain the primary wound closure, so secondary wound healing is induced with open membrane technique or soft tissue grafting should be performed for primary wound closure. However, the secondary wound healing can have a negative impact on bone regeneration, and soft tissue grafting such as FGG or CT graft can be burdensome for both patients and dentists. On the other hand, by using the granulation tissue in the extraction socket, primary closure can be achieved without soft tissue grafting. Also some studies have shown that granulation tissue in periodontal defects contains stem cells that may help in tissue regeneration. Based on this, implant restorations were performed on maxillary anterior teeth with severe alveolar bone loss by alveolar ridge preservation using granulation tissue. In spite of the severe bone defect of the extraction socket, relatively esthetic results could be obtained in implant restorations.

취장 외분비기능 부전에서 합성 단백 분해효소 억제 물질에 대한 취조직 재생 및 기능 변동 연구

  • 김경환
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1993.04a
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    • pp.84-84
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    • 1993
  • 취장 외분비 기능 부전은 임상적으로 영양결핍, 발육부전, 지방변동을 유발하나 이의 치료로는 결려된 소화효소 보충 등 보존적 요법만 시행될 뿐 근본적인 치료법은 없는 실정이다. 지난해 과제는 합성 단백분해 억제물질인 Camostat이 취장의 비대와 중식을 일으키며 또한 단백분해 효소분비를 증가시킴을 보고한 바 있다. 이를 토대로 최근 보고된 실험적 취장 외분비기능 부전 모델을 이용하여 camostat의 효과를 검색하고자 하였으며 아울러 이를 CCK효과와 비교하였다. 실험동물로는 몸무게 200 g 안팎의 수컷 Sprague-Dawley계 흰쥐를 사용하였으며 취장기능 부전은 oleic acid (25 $\mu$/100 g bw)를 취관내 주입하여 유발하였다. Camostat은 200 mg/kg씩 위내 투여(i.g.)하였으며 CCK(CCK-8)는 5 $\mu\textrm{g}$/kg씩 하루 2회 피하주사하였고 투여기간은 각각 3, 7, 14 일간으로 하였다. 각 약물 투여 후 취장 외분비 기능과 조직학적 검색을 실시하여 다음과 같온 결과를 얻었다. 1. Oleic acid의 취관내 주입으로 흰쥐의 취장 무게, 조직내 효소단백 함량 및 효소분비량이 현저히 감소되었고 조직학적으로 심한 위축과 섬유화를 관찰할 수 있었으며 이는 주입 후 기간이 지남에 따라 계속 진행하였다. 2. 취장기능 부전 유발 흰쥐에서 camostat 처치로 조직내 효소단백 함량 및 효소분비가 증가 되었으며 이는 14일간 처치군에서 뚜렷하였다. 3. 취장 기능부전 유발 횐쥐에서 camostat 처치는 조직학적으로 기능적인 외분비 조직이 유지되었으며 이는 3일군에서 특히 뚜fut하였다. 4. 취장기능부전 유발 횐쥐에서 CCK 처치효과는 camostat 처치효과와 비슷하였다. 이상의 결과로 보아 oleic acid 주입은 취장기능부전 연구에 유용한 실험모델로 생각되며 합성 단백 분해 효소 억제제인 Camostat은 취장외분비 기능 부전의 진행을 억제하고 어느정도 그 기능을 호전시킬 수 있으며 이는 CCK유리에 기인한다고 생각한다.

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Development of Flash Memory Management Algorithm (플래쉬 메모리 관리 알고리즘 개발)

  • Park, In-Gyu
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.38 no.1
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    • pp.26-45
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    • 2001
  • The Flash memory market: is an exciting market that has quickly over the last 10 years. Recently Flash memory provides a high-density. truly non-volatile, high performance read write memory solutions, also is characterized by low power consumption, extreme ruggedness and high reliability. Flash memory is an optimum solution for large nonvolitilc storage operations such as solid file storage, digital video recorder, digital still camera, The MP3 player and other portable multimedia communication applications requiring non-volatility. Regardless of the type of Flash memory, Flash media management software is always required to manage the larger Flash memory block partitions. This is true, since Flash memory cannot be erased on the byte level common to memory, but must be erased on a block granularity. The management of a Flash memory manager requires a keen understanding of a Flash technology and data management methods. Though Flash memory's write performance is relatively slow, the suggested algorithm offers a higher maximum write performance. Algorithms so far developed is not suitable for applications which is requiring more fast and frequent accesses. But, the proposed algorithm is focused on the justifiable operation even in the circumstance of fast and frequent accesses.

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Stability of periodontally compromised teeth after splint and non-surgical therapy: two cases followed-up for 1 to 3 years (Splint 및 비외과적 치주치료를 통하여 치주질환에 이환된 치아의 안정화 증례 보고)

  • Kim, Yeon-Tae;Park, Ye-Sol;Kim, Do-Hyung;Jeong, Seong-Nyum;Lee, Jae-Hong
    • Journal of Dental Rehabilitation and Applied Science
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    • v.34 no.4
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    • pp.338-344
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    • 2018
  • This article describes cases of applying non-surgical treatment including scaling and root planing, occlusal adjustment and tooth splinting of periodontally compromised lower anterior incisors Clinical and radiographic evaluations were performed over a 1-3-year period. All clinical parameters and radiographic bone levels improved in both cases. Dramatic regeneration of alveolar bone and lamina dura were observed on radiographic images, and no specific complications occurred during the follow-up period. Within the limitations of this study, these cases demonstrated the possibility of tooth rescue through non-surgical treatment and splinting of periodontally compromised teeth typically considered for extraction.