스프링클러 구리배관의 공식 파손 억제

서상희 ( Sang Hee Suh ),서영준 ( Youngjoon Suh ),이종혁 ( Jonghyuk Lee ),권혁상 ( Hyuksang Kwon ) 한국부식방식학회 2020 Corrosion Science and Technology Vol.19 No.2

The inhibition of pitting corrosion failure of copper sprinkler tubes in wet sprinkler systems was studied. First, an apparatus and technology for removing air in the sprinkler tubes by vacuum pumping and then filling the tubes with water were developed. Using this apparatus and technology, three methods for inhibiting the pitting corrosion of the copper sprinkler tubes installed in several apartment complexes were tested. The first one was filling the sprinkler tubes with water bubbled by high-pressure nitrogen gas to reduce the dissolved oxygen concentration to lower than 2 ppm. In the second method, the dissolved oxygen concentration of water was further reduced to lower than 0.01 ppm by sodium sulfite. In the third method, the sprinkler tubes were filled with benzotriazole (BTAH) dissolved in water. The third method was the most effective, reducing the failure frequency of the sprinkler tubes due to pitting corrosion by more than 80%. X-ray photoelectron spectroscopy analyses confirmed that a Cu-BTA layer was well coated on the inside surface of the corrosion pit, protecting it from corrosion. A potentiodynamic polarization test showed that BTAH should be very effective in reducing the corrosion rate of copper in the acidic environment of the corrosion pit.

아황산나트륨을 이용한 스프링클러 동배관 공식 부식 방지

서상희 ( Sang Hee Suh ),서영준 ( Youngjoon Suh ),권혁상 ( Hyuksang Kwon ) 한국부식방식학회 2017 Corrosion Science and Technology Vol.16 No.5

Inhibition of pitting corrosion of the copper sprinkler tubes by removing dissolved oxygen in water with sodium sulfite was studied on the wet sprinkler systems operated in 258 household sites. First, air in the sprinkler tubing was removed by vacuum pumping. The tube was then filled with sodium sulfite dissolved in water. Sodium sulfite was very effective in maintaining a very low dissolved oxygen concentration in water in the sprinkler tube for the observation period of six months. Water leakage from the copper sprinkler tube was reduced significantly by using sodium sulfite. Both pitting corrosion process and pitting corrosion inhibition mechanism were investigated by examining microscopical and structural aspects of corrosion pits formed in failed copper sprinkler tube. Pitting corrosion was caused by pressurized air as well as sediments such as sand particles in copper tubes through oxygen concentration cells. It was confirmed microscopically that growth of corrosion pits was stopped by reducing dissolved oxygen concentration to a very level by using sodium sulfite.

Nuclear Localization of Fibroblast Growth Factor Receptor 1 in Breast Cancer Cells Interacting with Cancer Associated Fibroblasts

Suh Jinyoung,김도희,Kim Su-Jung,Cho Nam-Chul,Lee Yeon-Hwa,Jang Jeong-Hoon,서영준 대한암예방학회 2022 Journal of cancer prevention Vol.27 No.1

Cancer-associated fibroblasts (CAFs) represent a major component of the tumor microenvironment and interplay with cancer cells by secreting cytokines, growth factors and extracellular matrix proteins. When estrogen receptor-negative breast cancer MDAMB-231 cells were treated with the CAF-conditioned medium (CAF-CM), Akt and STAT3 involved in cell proliferation and survival were activated through phosphorylation. CAFs secrete fibroblast growth factor 2 (FGF2), thereby stimulating breast cancer cell progression. Akt activation induced by CAF-CM in MDA-MB-231 cells was abolished when FGF2-neutralizing antibody was added. Treatment of MDA-MB-231 cells directly with FGF2 enhanced the phosphorylation of Akt and the FGF receptor (FGFR) substrate, FRS2α. These events were abrogated by siRNA-mediated silencing of FGFR1. In a xenograft mouse model, co-injection of MDAMB-231 cells with activated fibroblasts expressing FGF2 dramatically enhanced activation of Akt. Stable knockdown of FGFR1 blunted Akt phosphorylation in xenograft tumors. MDA-MB-231 cells co-cultured with CAFs or directly stimulated with FGF2 exhibited enhanced nuclear localization of FGFR1. Notably, FGF2 stimulation produced reactive oxygen species (ROS) accumulation in MDA-MB-231 cells, and FGF2-induced nuclear accumulation of FGFR1 was abrogated by the ROS scavenging agent, N-acetylcysteine.

15-Deoxy-Δ12,14-prostaglandin J2 Induces Epithelial-tomesenchymal Transition in Human Breast Cancer Cells and Promotes Fibroblast Activation

Jeehye Choi,Jinyoung Suh,김도희,나혜경,서영준 대한암예방학회 2020 Journal of cancer prevention Vol.25 No.3

In inflammation-associated carcinogenesis, COX-2 is markedly overexpressed, resulting in accumulation of various prostaglandins. 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is one of the terminal products of COX-2-catalyzed arachidonic acid catabolism with oncogenic potential. Epithelial-to-mesenchymal transition (EMT) is a process by which epithelial cells lose their polarity and adhesiveness, and thereby gain migratory and invasive properties. Treatment of human breast cancer MCF-7 cells with 15d-PGJ2 induced EMT as evidenced by increased expression of Snail and ZEB1, with concurrent down-regulation of E-cadherin. Nuclear extract from 15d-PGJ2-treated MCF-7 cells showed the binding of Snail and ZEB1 to E-box sequences present in the E-cadherin promoter, which accounts for repression of E-catherin expression. Unlike 15d-PGJ2, its non-electrophilic analogue 9,10-dihydro- 15d-PGJ2 failed to induce EMT, suggesting that the α,β-unsaturated carbonyl group located in the cyclopentenone ring of 15d-PGJ2 is essential for its oncogenic function. Notably, the mRNA level of interleukin-8 (IL-8)/CXCL8 was highly elevated in 15d-PGJ2-stimulated MCF-7 cells. 15d-PGJ2-induced up-regulation of IL-8/CXCL8 expression was abrogated by silencing of Snail short interfering RNA. Treatment of normal fibroblast with conditioned medium obtained from cultures of MCF-7 cells undergoing EMT induced the expression of activated fibroblast marker proteins, α-smooth muscle actin and fibroblasts activation protein-α. Co-culture of normal fibroblasts with 15d-PGJ2-stimulated MCF-7 cells also activated normal fibroblast cells to cancer associated fibroblasts. Taken together, above findings suggest that 15d-PGJ2 induces EMT through up-regulation of Snail expression and subsequent production of CXCL8 as a putative activator of fibroblasts, which may contribute to tumor-stroma interaction in inflammatory breast cancer microenvironment.

조직공정성이 종합병원 의사들의 직무만족, 전문직업몰입 및 조직몰입에 미치는 영향

고종욱 ( Jong Wook Ko ),서영준 ( Young Joon Seo ),서상혁 ( Sang Hyuk Suh ) 한국보건행정학회 2003 보건행정학회지 Vol.13 No.3

The purpose of this study is to investigate the impacts of distributive and procedural justice on job satisfaction, professional commitment and organizational commitment among hospital physicians. The sample of this study consisted of 185 physicians from 8 general hospitals located in Metropolitan area and Youngnam area in Korea. Data were collected using self-administered questionnaires with the response rate of 40.2% and analyzed using hierarchical regression technique. The results of this study showed that procedural justice had a direct impact on job satisfaction, professional commitment and organizational commitment among hospital physicians, whereas distributive justice had no significant impact. The results imply that hospital administrators should take measures to establish procedural justice to increase job satisfaction, professional commitment and organizational commitment among hospital physicians.

Optimization of soaking in aqueous ammonia pretreatment of canola residues for sugar production

유하영(Yoo, Hah-Young),김성봉(Kim, Sung Bong),이상준(Lee, Sang Jun),이자현(Lee, Ja Hyun),서영준(Suh, Young Joon),김승욱(Kim, Seung Wook) 한국신재생에너지학회 2011 한국신재생에너지학회 학술대회논문집 Vol.2011 No.11

Bioenergy production from lignocellulosic biomass and agriculture wastes have been attracted because of its sustainable and non-edible source. Especially, canola is considered as one of the best feedstock for renewable fuel production. Oil extracted canola and its agriculture residues are reuseable for bioethanol production. However, a pretreatment step is required before enzymatic hydrolysis to disrupt recalcitrant lignocellulosic matrix. To increase the sugar conversion, more efficient pretreatment process was necessary for removal of saccharification barriers such as lignin. Alkaline pretreatment makes the lignocellulose swollen through solvation and induces more porous structure for enzyme access. In our previous work, aqueous ammonia (1~20%) was utilized for alkaline reagent to increase the crystallinity of canola residues pretreatment. In this study, significant factors for efficient soaking in aqueous ammonia pretreatment on canola residues was optimized by using the response surface method (RSM). Based on the fundamental experiments, the real values of factors at the center (0) were determined as follows; 70?C of temperature, 17.5% of ammonia concentration and 18 h of reaction time in the experiment design using central composition design (CCD). A statistical model predicted that the highest removal yield of lignin was 54% at the following optimized reaction conditions: 72.68?C of temperature, 18.30% of ammonia concentration and 18.30 h of reaction time. Finally, maximum theoretical yields of soaking in aqueous ammonia pretreatment were 42.23% of glucose and 22.68% of xylose.

한약제의 장관흡수에 관한 생물약제학적 연구 : Effects of Bezoar on the Small intestinal Absorption of Baicalin in the Scutellariae Radix 우황이 황금중 Baicalin의 소장흡수에 미치는 영향에 관한 연구

서영준,김종갑 중앙대학교 약학연구소 1990 약학 논총 Vol.4 No.-

The interaction of bezoar on the small intestinal absorption of baicalin in the Scutellariae Radix were studied using Schanker's loop circulation method in comparison with dissolution rate and partition coefficient. The results obtained are as follows : 1. Dissolution rate of baicalin in the Scutellariae Radix approached to plateau on 60 minutes. 2. Absorption rate of baicalin in the Scutellaria radix in the small intesinal tract was increased within 90 minutes by coexistence of bezoar fractions but not influenced after 90 minutes.

Fiji의 醫療制度

徐榮浚 서울대학교병원부설 병원연구소 1986 병원연구 Vol.10 No.-

Philipines의 醫療制度

徐榮浚 서울대학교병원부설 병원연구소 1987 병원연구 Vol.11 No.-

원격지 모니터링을 위한 삼차원 위치 측정기의 개발

박강,서영준 明知大學校 産業技術硏究所 1999 産業技術硏究所論文集 Vol.18 No.-

In this paper, a 3D position measuring device that finds the 3D coordinates of an arbitrarily placed object using a camera and laser light is introduced. By positioning the laser light at a known location regarding to the camera, the distance from the camera and the object is calculated using a structured lighting scheme. The remaining two coordinates can be calculated using inverse perspective transformation after measuring the location of the laser light image that is projected on the image plane. The orientation of the camera is controlled by two stepping motors: pan and tilt motors. The angels of those motors are controlled by a PC through a parallel port, which enables the whole system can be built in Windows™ environment. The camera and the distance measuring system are calibrate an accurate position of the object. This 3D position measuring device can be used to acquire information that is necessary to monitor a remote place.