수분산 에폭시 경화물의 물성에 관한 연구

양석우,김강열 한국공업화학회 2006 한국공업화학회 연구논문 초록집 Vol.2006 No.1

The System of City Planning and Development in North Korea: Focused on Development of Kaesong Industrial Complex (KIC)

양석우,곽동화 대한건축학회 2014 Architectural research Vol.16 No.3

South and North Korea, the divided nations on the Korean peninsula, began with the same modern city planning system, but following the adoption of different national ideologies—capitalism and socialism—, they established their own city planning system and developed their cities accordingly. However, the process of planning and developing a joint city of Kaesong Industrial Complex (KIC) led to the recognition about the need to bridge the differences and prepare for future joint development. This study examines North Korea’s city planning system by comparing the two Koreas’ systems, and identify the characteristics of North Korea’s city planning system through a case analysis of the KIC. By comparing two cases, we found two distinct characteristics of North Korea’s. The one is a tool for realizing ideologies and maintaining national system. The other one is that it is ideology-oriented system for the supreme leader and party while South Korea has control-oriented system for the public. We analyze the KIC case based on four pillars: planning system, development system and procedure, master plan, and use behaviors. Result of analysis shows that in KIC there are many socialistic features as we mentioned above in terms of planning system, urban design & structure, and use behavior even though a private enterprise-Hyundai Asan, in South Korea led the whole process. This study is meaningful in that it identifies the specific characteristics of North Korea’s city planning focusing on the KIC and is expected to serve as a baseline material to set the future direction for North Korea’s development.

성형안과의 소개

양석우 대한의사협회 2017 대한의사협회지 Vol.60 No.9

Fabrication of $YBa_{2}Cu_{3}O_{7-x}$-Ag Composite Superconductors by Pyrophoric Synthetic Method

양석우,김찬중,홍계원,신형식,Yang, Seok-U,Kim, Chan-Jung,Hong, Gye-Won,Sin, Hyeong-Sik Materials Research Society of Korea 1998 한국재료학회지 Vol.8 No.12

$YBa_2$$Cu_3$$O_{7-y}$ (123) 초전도체에서 은 입자의 미세분산을 얻고자 말릭산을 사용한 발화합성과 고상반응법으로 123와 123-Ag 복합 초전도분말을 제조하였다. 발화합성분말을 원료로 사용할 시 마이크론 미만의 미세한 123 분말과 은 분말의 복합체를 얻을 수 있었다. 원료로 사용된 산화은($Ag_2O$) 분말은 발화합성과정 중금속 은으로 환원되었다. 원료분말에 첨가된 금속 은에 의한 반응 물질간의 확산 촉진으로 123상이 단시간내에 생성되었고 입자성장도 촉진되었다. 발화합성법으로 제조한 시편은 기계적 혼합공정으로 제조한 시편에 비해 은 입자들은 미세하게 분산시킬 수 있어서 초전도체의 임계전류밀도가 향상되었다. To obtain fine dispersion of Ag particles in $YBa_2$$Cu_3$$O_{7-y}$ (123) superconductors, 123 samples were made by pyrophoric synthetic method using malic acid and the subsequent solid- state reaction. As the pyrophoric synthetic powder was used as a precursor material, fine 123 powder of submicron size was produced in a short reaction time. The added $Ag_2$O was converted to metallic Ag during Pyrophoric reaction and it accelerated both the formation of 123 phase and the grain growth via the enhanced mass transfer. The Ag particles of the sample sintered using the pyrephoric synthetic powder were more finely dispersed in the 123 matrix, compared to those of the sample sintered using the mechanically mixed powder, attributing to the improvement of the superconducting properties.

발화합성법에 의한 YBa₂Cu₃O_6+x 초전도 선재의 제조

양석우,이영민,김영순,박정식,김찬중,홍계원,신형식,Yang, Suk-Woo,Lee, Young-Min,Kim, Young-Soon,Park, Jeong-Shik,Kim, Chan-Joong,Hong, Gye-Won,Shin, Hyung-Shik 한국공업화학회 1998 공업화학 Vol.9 No.7

$YBa_2Cu_3O_{6+x}(Y123)-Ag$ 초전도 선재를 0/20 wt%의 은(Ag)을 첨가한 발화합성분말과 고상반응분말을 사용하여 플라스틱 압출법으로 제조하였다. 플라스틱 압출법은 분말제조, 플라스틱 paste 제조, 다이 압축, binder 소각 및 소결공정을 포함한다. 양질의 초전도체를 제조하려면 원료물질이 균질하고 미세한 분말이어야 한다. 0/20 wt%를 첨가한 $Y_2O_3-BaCO_3-CuO$ precursor 분말을 발화합성(PS)법과 고상반응(MM)법으로 제조하였다. 원료분말이 Y123 초전도상으로 전이되는 생성속도를 공기중에서 여러온도와 시간별로 반응시켜 알아보았다. 발화합성법으로 제조한 분말이 고상반응법으로 제조한 분말보다 Y123상으로 빠르게 전이되었다. 이것은 PS법으로 제조한 분말이 미세한 크기와 균질한 화학적 조성으로 인해 Y123상으로 빠른 전이를 한 것이기 때문이다. 플라스틱 압출법으로 제조한 Y123-Ag 초전도 선재의 임계전류밀도($J_c$)는 원료분말의 특징에 따라 $150{\sim}230A/cm^2$값을 나타내었다. 은을 20 wt.% 첨가한 발화합성분말로 제조한 선재의 $J_c$는 $230A/cm^2$이었다. $YBa_2Cu_3O_{6+x}(Y123)-Ag$ high-Tc superconducting wires were fabricated by plastic extrusion technique using pyrophoric synthetic and mechanical mixing powder with and without Ag addition(20 wt.%). This method involves powder preparation, plastic paste making, die extrusion, binder burn-out and the sintering process. In order to fabricate a good-quality superconducting body, it is required to use homogeneous and fine-size power as a starting materials. $Y_2O_3-BaCO_3-CuO$ precursor powders with/without Ag addition were prepared both by pyrophoric synthetic(PS) and mechanical mixing(MM) method of raw powders. The formation kinetics of the powder mixtures into Y123 phase was investigated at various temperatures and times in air atmosphere. The powder prepared by PS method was more easily converted into a Y123 phase than the MM powder. The fine size and good chemical homogeneity of the powder prepared by PS method is attributable to the fast formation into a Y123 phase. The critical current density($J_c$) of the Y123-Ag superconducting wires made by plastic extrusion method were in the range of $150A/cm^2{\sim}230A/cm^2$. depending on the charateristics of starting material powders. $J_c$ of the wire prepared by pyrophoric synthetic powder with 20 wt.% Ag addition was $230A/cm^2$.

다량의 안와첨주위 목재이물 및 누공의 치험 1예

양석우,김연덕,김경락 대한안과학회 2004 대한안과학회지 Vol.45 No.8

Purpose: A diagnosis of wooden intraorbital foreign bodies is common and their removal is often necessitated after complications become manifested. In case of operation, it is difficult to find and remove wooden foreign bodies completely. We have experienced a case of retained multiple intraorbital foreign bodies removed by the secondary operation. We report this case with a literature review. Methods: A 39-year-old man visited our clinic complaining of diplopia, exophthalmos, and limitation of eyeball movement. He had fallen down and had a lacerated wound. Right after primary closure, he experienced strabismus, orbital cellulitis, and abscess. Several months later, he had a soft mass in the operated lower lid, and two wooden intraorbital foreign bodies were found. MRI detected granuloma and cellulitis near the cavernous sinus. Results: More than ten intraorbital wooden foreign bodies were surgically removed. After the surgery exophthalmos and diplopia were improved, and limitation of eyeball movement disappeared. The MRI findings were also improved. Conclusions: Intraorbital wooden foreign bodies should be diagnosed with a thorough history taking and radiologic exam, due to a number of potential complications, such as orbital cellulitis, abscess, and diplopia. Furthermore, they should be removed in consideration that they can move spontaneously into the deep interior of the orbit. 목적 : 목재에 의한 안와내 이물은 수상 당시 진단이 이루어지지 않아 합병증이 발생한 후에 진단되는 일이 흔하고, 수술 시에도 이물의 발견과 제거가 불충분한 경우가 많다. 저자들은 2차례 반복된 수술에 의해 제거된 다량의 안와내 목재 이물 치험 1예를 보고한다. 대상과 방법 : 우상안검 열상을 입은 39세 남자환자가 사시, 봉와직염 등의 합병증으로 치료받던 중, 우하안검 연부종괴가 발생하였다. 연부종괴 절제술 중 나무조각이 발견되어 제거하였으나 술후 지속적으로 절개부위에서 고름이 흘러나와 안와 전산화 단층촬영을 시행하였고, 육아종이 여전히 줄지않은 소견을 보였다. 본원 전원 후 실시한 자기공명촬영에서 안와첨 주위 육아종에 둘러싸인 이물질이 관찰되었다 결과 : 안와내 이물질과 육아종 제거술을 시행하여 십수개의 목재이물을 제거하였다. 술후 안구돌출, 부종, 고름배출 등의 임상증상은 개선되었고, 컴퓨터 단층촬영상 육아종 소견이 보이지 않았다. 결론 : 잔류된 안와내 목재이물은 안와 깊은 곳까지 이동할 수 있으므로 철저한 병력 청취와 방사선 검사를 통해 정확한 진단과 세심한 제거가 시행되어야 한다.

비소세포 폐암종에서 Cyclin D1, p21 및 p53단백의 발현과 예후와의 관계

양석우,조상호,양우익,정우희,안철민,이두연 대한병리학회 1999 Journal of Pathology and Translational Medicine Vol.33 No.12

수분산 에폭시 수지 모르타르를 이용한 콘크리트 구조물의 적용성에 관한 연구

양석우,김강열 한국공업화학회 2006 한국공업화학회 연구논문 초록집 Vol.2006 No.1

Formation Kinetics and Characterization of Y1Ba2Cu6+x - Ag powders prepared by pyrophoric synthetic technique

양석우,김영순,박정식,신형식,김찬중,홍계원 ( Suk Woo Yang,Young Soon Kim,Jeong Shik Park,Hyung Shik Shin,Chan Joong Kim,Gye Won Hong ) 한국공업화학회 1995 한국공업화학회 연구논문 초록집 Vol.1990 No.3

Do Helper T Cell Subtypes in Lymphocytic Thyroiditis Play a Role in the Antitumor Effect?

양석우,강성호,김경래,최인홍,장항석,오영륜,홍순원 대한병리학회 2016 Journal of Pathology and Translational Medicine Vol.50 No.5

Background: Papillary thyroid carcinoma (PTC) is frequently accompanied by lymphocytic thyroiditis (LT). Some reports claim that Hashimoto’s thyroiditis (the clinical form of LT) enhances the likelihood of PTC; however, others suggest that LT has antitumor activity. This study was aimed to find out the relationship between the patterns of helper T cell (Th) cytokines in thyroid tissue of PTC with or without LT and the clinicopathological manifestation of PTC. Methods: Fresh surgical samples of PTC with (13 cases) or without (10 cases) LT were used. The prognostic parameters (tumor size, extra-thyroidal extension of PTC, and lymph node metastasis) were analyzed. The mRNA levels of two subtypes of Th cytokines, Th1 (tumor necrosis factor α [TNF-α], interferon γ [IFN-γ], and interleukin [IL] 2) and Th2 (IL-4 and IL-10), were analyzed. Because most PTC cases were microcarcinomas and recent cases without clinical follow-up, negative or faint p27 immunoreactivity was used as a surrogate marker for lymph node metastasis. Results: PTC with LT cases showed significantly higher expression of TNF-α (p = .043), IFN-γ (p < .010), IL-4 (p = .015) than those without LT cases. Although the data were not statistically significant, all analyzed cytokines (except for IL-4) were highly expressed in the cases with higher expression of p27 surrogate marker. Conclusions: These results indicate that mixed Th1 (TNF-α, IFN-γ , and IL-2) and Th2 (IL-10) immunity might play a role in the antitumor effect in terms of lymph node metastasis.