800㎿급 발전소 복수기의 최적 운전점 및 운전방법에 대한 연구

장철호(Cheol-Ho Jang),홍은기(Eun-Kee Hong),황광원(Kwang-Won Hwang),윤린(Rin Yun) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.5

Along with the recent construction of a 800㎿ thermal power plant it is necessary to check the soundness of the current operation of the condenser, and to investigate the effects of vacuum level of it on the turbine efficiency for the power plant. In this study, the performances of the condenser and the turbine for the 800㎿ thermal power plant were tested based on the ASME PTC 6 and ASME PTC 12.2 with the variation of the vacuum level. When the condenser vacuum levels were 719.91 ㎜Hg, 724.5 ㎜Hg, and 729.6 ㎜Hg, the turbine efficiencies were 47.36%, 47.47%, and 47.55%, respectively. From the regression analysis of the present data, it was estimated that the optimal vacuum point is between 729 ㎜Hg and 731 ㎜Hg. When this optimal point is to be applied to the condenser, the profit of 5.5 billion won/year is expected based on the '09 caloric cost.

The Antioxidant Effect of the Rhaponticum uniflorum Extracts on the Oxidative Stress in H₂O₂ induced Human Keratinocytes

So Hee Ahn,Won Yeoung Choi,Ji Won Jeong,Geon Woo Park,Su Yeon Kang,Eun Jeong Kim,Su Rim Sin,Eun Seo Jang,Gye Won Lee,Young Ho Cho 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

In this study, To investigate the antioxidant activities of Rhaponticum uniflorum extracts (RUE), we assessed scavenging activities on DPPH, ABTS radicals, and reducing power. The DPPH and ABTS radical scavenging activities (SC50) of RUE were 96.97±1.19 μg/mL and 31.26±0.13 μ g/mL, respectively, and the reducing power significantly increased dose-dependent manner. To study the antioxidant effecters of RUE in H₂O₂ induced human keratinocytes, expression of Nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were determined by Western blot and qRT-PCR. RUE induced the expression of HO-1, a critical target enzyme of Nrf2, in a concentration-dependent manner. The expression of HO- 1 mRNA was also induced in H₂O₂-treated HaCaT cells but no significant difference in the level of HO-1 mRNA was observed. Taken together, these results suggest that RUE may be useful as a potential ingredient for anti-aging products.

Sophora flavescens의 뿌리에서 유래한 Cholinesterase 저해 화합물

장원희, 트란홍광, 김장훈, 양서영, 김영호 충남대학교 약학대학 의약품개발연구소 2021 藥學論文集 Vol.36 No.-

Searching for cholinesterase inhibitory compounds from natural products is important to de- velop therapeutic agents for Alzheimer’s disease. Our previous research on the chemical components of Sophora flavescens roots resulted in the isolation of twelve flavonoids, kushenol E (1), maackiain (2), 8-prenylkaemperol (3), 8-prenylnaringenin (4), kushenol L (5), kushenol A (6), kushenol C (7), kushenol B (8), sophoraflavanone G (9), kushenol H (10), isoxanthohumol (11) and kurarinone (12) and their structures were elucidated by spectroscopic methods. Inhibitory effect of cholinesterase were tested using the Ellman's method. Most flavonoid compounds showed good inhibitory activities on cholinesterases. Kushenol E (1) and sophoraflavanone G (9) showed good inhibitory activities on acetylcholinesterase with IC50 values of 3.75 and 4.14 μM and butyrylcholinesterase with IC50 values of 2.00 and 0.75 μM, respectively. In addition, a kinetic analysis revealed that kushenol E (1) was non-competitive inhibitor with Ki value of 0.77 μM on acetylcholinesterase and 0.16 μM on butyrylcholinesterase, whereas sophoraflavanone G (9) was mixed type inhibitior with Ki value of 9.42 μM on acetylcholinesterase and 0.81 μM on butyrylcholinesterase. These findings suggest that flavonoid compounds from S. flavescens roots are potential cholinesterase inhibitors.

Bone-supported pendulum을 이용한 상악대구치 원심이동

장용걸,박호원,이주현,서현우 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.3

상악 대구치의 원심이동이 요구되는 경우, 구외견인, Wilson distalizing arches, 가철식 스프링 장치 그리고 Schwarz plate-type 장치 등을 사용 할 수 있다. 그러나 이러한 전통적인 대구치의 원심이동 장치들로 치료에 성공하기 위해서는 환자의 협조가 필수적이기 때문에 많은 소아치과 의사들은 환자 의존성을 최소화하고 임상가가 통제 할 수 있는 장치들로 전환하고 있다. 이 중 가장 일반적인 것이 pendulum 장치인데, 고정원이 되는 전방치아의 원하지 않는 이동과 고정원 소실, 그리고 구개부 고정원이 좋지 않은 경우 원하는 정도의 구치부 원심이동을 얻기 어렵다는 단점이 있다. 이와 같은 전통적인 pendulum의 단점을 해결하고자, SAS(Skeletal Anchorage System)를 pendulum에 접목하여 골에서 직접 지지를 얻는 변형된 형태의 pendulum, 즉 bone supported pendulum을 제작하여 장착 시킨 후 주기적인 관찰을 시행하였다. 본 증례는 혼합치열기 환자를 대상으로 bone supported pendulum을 사용하여 안정된 고정원 유지, 원치 않는 치아이동의 최소화 및 양호한 상악 대구치 원심이동 등을 관찰하였기에 이를 보고하는 바이다. To distalize the maxillary molars. the traditional techniques such as extra-oral traction. Wilson distalizing arches. removable spring appliances and Schwarz plate-type appliances have been used. But, these need considerable patient cooperation. For minimal patient compliance. many practitioners use the pendulum appliances. Several clinical studies demonstrated pendulum is effective molar distalization appliance in the growing patient(using the premolars and the palate as anchorage). But unfortunately, maxillary anterior teeth also shift mesially as the molar moves distally. As a result anchorage loss is occurred. To overcome these disadvantages, we used bone-supported pendulum, combined the conventional pendulum with Skeletal Anchorage System(SAS). The miniscrew was implanted in the anterior paramedian region of the median palatal suture, which has comparatively sufficient bone thickness and is low risk to damage on the dental follicles. We report three cases, using bone-supported pendulum for the maxillary molar distalization in children. After treatment, we find out anchorage stability, minimal unfavorable anterior tooth movement and sufficient molar distalization.

구강에서 채취한 혐기성 세균에 대한 서양산 고추냉이(Horseradish, Armoracia rusticana) 뿌리 추출물의 항균효과

장용걸,박호원,신일식,이주현,서현우 大韓小兒齒科學會 2010 大韓小兒齒科學會誌 Vol.37 No.2

서양산 고추냉이 (Horseradish, Armoracia rusticana)의 주성분인 allylisothiocyanate(AIT)는 각종 세균에 대한 살균 효과로 주목받고 있다. 이전 연구들을 통해 구강내 다양한 세균 및 진균류에 대한 항균성이 입증되었으나 근단내 병소를 유발하는 혐기성 세균에 대한 연구는 미진한 실정이다. 본 연구에서는 사람의 근단 병소에서 직접 분리한 E. faecalis와 F. nucleatum에 대한 서양산 고추냉이 뿌리 추출물의 항균활성을 표준균주와 비교해보고 이를 대표적인 항균제인 클로르헥시딘과 비교하여 다음과 같은 결론을 얻었다. 1. 서양산 고추냉이 뿌리 추출물은 E. faecalis 임상 분리균주에 대하여 표준균주와 같거나 약간 높은 농도에서 항균효과를 나타냈고, 625.0~1,250.0 μg/ml의 농도에서 클로르헥시딘 (7.8~15.6 μg/ml)과 대등한 항균효과를 가지는 것으로 나타났다. 2. 서양산 고추냉이 뿌리 추출물은 F. nucleatum 임상 분리균주에 대하여 표준균주와 같거나 약간 높은 농도에서 항균효과를 나타냈고, 78.1~312.5 μg/ml의 농도에서 클로르헥사딘 (7.8~15.6 μg/ml)과 대등한 항균효과를 가지는 것으로 나타났다. 이번 연구로 표준균주 뿐만 아니라 구강에서 직접 분리한 혐기성 세균에 대한 서양산 고추냉이 뿌리 추출물의 항균성을 확인할 수 있었고, 추후 근관 세척제나 소독제로 서양산 고추냉이 뿌리 추출물을 이용할 수 있는 가능성을 보여주었다. Objective : The aim of this study was to determine the antimicrobical effect of horseradish root extracts against Enterococcus faecalis and Fusobacterium nucleatum isolated from oral cavity compared with reference strain, and compared with that of chlorhexidine. Method : Horseradish root extracts and chlorhexidine were sequentially diluted and tested against anaerobes(E. faecalis, F. nucleatum) isolated from children's oral cavity. The microbes were anaerobically incubated and the minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC) were detected. Results: 1. Horseradish root extracts showed antimicrobial effect against E. faecalis isolated strain at same or slightly higher concentration compared with MIC of reference strain. 2. 625.0~1.250.0 ㎍/ml horseradish root extracts showed similar antimicrobial effect with chlorhexidine(7.8~15.6 ㎍/ml). 3. Horseradish root extracts showed antimicrobial effect against F. nucleatum isolated strain at same or slightly higher concentration compared with MIC of reference strain. 4. 78.1~312.5 ㎍/ml horseradish root extracts showed similar antimicrobial effect with chlorhexidine(7.8~15.6 ㎍/ml). Conclusions : The results of this study confirm that horseradish root extracts has antimicrobial effect against anaerobes isolated from oral cavity as well as reference strain. And we found the potential of horseradish root extracts as a canal irrigant or disinfectant.

IMT-2000 기지국용 이중 편파를 위한 광대역 단일 소자 안테나 설계 및 특성 개선

장원호,박주성,태재훈,이윤현 한국항행학회 2002 韓國航行學會論文誌 Vol.6 No.3

본 논문에서는 편파 다이버시티 특성을 갖는 이중 편파(Dual-Polarization)방식의 INT-2000(1.885㎓-2.17㎓)기기국용 안테나에 사용할 수 있도록 기존 Folded Dipole안테나의 특성을 개선하였다. 제작된 안테나는 PCB기판에 몰디드 다이폴 안테나 구조에 적층 형태를 갖는 마이크로 스트립 안테나로서 각 단자별 반사게수가 -20㏈ 이하, 이중 편파 구조에서 중요한 규격인 단자간 분리도는 -20㏈ 를 가지며, 이들은 전 대역에서 약 7 dBi 이상의 특성을 보였다. Design and characteristic improvement of existing folded dipole antenna is presented to adopt W-CDMA(1.885~2.170 ㎓) wideband antenna radiators. The antenna structure has +/- 45 degrees dual polarization. In order to overcome the narrow bandwidth and low gain characteristic typical of the microstrip antenna, double layered structure was employed. The antenna achieved below -20 ㏈ reflection coefficients each ports. -20 ㏈ of port isolation, above 7 dBi of gain, providing evidence that the proposed design can be used in the W-CDMA service frequency band antenna.

四鹽化炭素로 肝障害를 誘導한 家兎에서의 抗結核劑의 排泄에 關한 硏究

元章喜,權昌鎬 慶熙大學校 1984 論文集 Vol.13 No.-

The drug metabolism of several antituberculosis was investigated in liver injuried rabbits. Antituberculosis drugs which used on this experiment were Rifampicin, Isoniazide and Pyrazinamide. The results were as follows. 1. Activities of sGOT and sGPT of rabbits induced liver injury by CCl_4 were increased (in sGOT, from 48.9 ± 1.48 units/ml to 370 ± 19 units/ml and in sGPT, from 42.5 ± 1.22 units/ml to 386 ± 32 units/ml) after the lapse of 24 hours from CCl_4 administration and then they were decreased gradually with the lapse of time (in sGOT, to 310 ± 25 units/ml and in sGPT, to 285 ± 26 units/ml after the lapse of 72 hours from CCl_4 administration). 2. The rifampicin which cxcreted mainly through bile at a small dose administration was excreted in urine at a large dose administration. 3. Each antituberculosis drugs which administrated on this experiment was excreted more quantity in urine of CCl_4 pretreated rabbits as compared with normal rabbits. particularly, Rifampicin was excreted far more quantity in urine of CCl_4 pretreated rabbits all the time. 4. From the above results, it was recognized that many notice about use of Antituberculosis drugs to liver injuried body must be required.

위성방송 수신을 위한 대수주기 마이크로스트립 안테나에 대한 연구

장원호,진재선,이윤현 한국항행학회 2003 韓國航行學會論文誌 Vol.7 No.2

본 연구에서는 이동하면서 BS/CS 대역의 무궁화 3호 위성 신호를 수신할 수 있도록 42도 이상의 틸팅각을 갖는 새로운 구조의 패치안테나에 대해 제시하였다. 본 안테나의 구조는 패치 다이폴을 직렬 배열한 대수 주기형 안테나와 개구결합을 이용한 급전 구조로 이루어 졌다. 테이퍼드 슬롯에 8개의 직렬 패치 다이폴이 수직으로 놓여짐으로써 각 패치 다이폴에 직렬 급전이 된다. 직렬 급전된 패치 다이폴의 방사는 BS/CS 대역에서 메인 빔의 방향이 73? ~ 42?를 형성하였고, 이득은 9.31~11.03 dBi로 측정되었다. 32개의 엘레멘트를 4×8로 적절히 배열하면 24 dBi이상의 이득과 40-48도 내외의 앙각이 형성되어, 무궁화 3호 위성의 이동체 탑재용 안테나에 적용이 가능하다. In this study, we provide a single element log-periodic antenna that the feeding networks and array structures are aperture coupled and series dipole array type. We made the antenna for direct receiving the Moogoongwha satellite broadcasting signal. The transmission power was able to feed the patch dipole in series due to lay perpendicularly 8 series patch dipole on tapered slot. The patch dipole radiation pattern which fed in series power, make the main beam direction up 37°~42° within the BS/CS bandwidth. The main beam gain was measured 9.31~11.03 dBi. Using 32 elements to array the elements properly, we acquire 4×8 array structure on limited PCB board. As a result, it has been found that the new planar DBS antenna structure have high gain over 10dBi and acceptable elevation angle over 42 degree, and we can apply this result to commercial DBS reception antenna manufacturing.

ETACS와 CDMA 디지털 셀룰라 시스템이 공존하는 환경에서 Interference Canceller System의 설계 및 구현

장원호,홍주석,이윤현 한국항행학회 2002 韓國航行學會論文誌 Vol.6 No.4

본 논문에서는 인접한 대역에 ETACS와 CDMA 방식의 디지털 셀룰라 시스템이 공존하는 중국 상해 지역의 간섭환경에서 기존의 간섭제거장비보다 이를 효과적으로 개선할 수 있는 Interference Canceller Systern(ICS)을 설계하고, 개발된 부품들을 통해 구현하였다. 구현된 ICS는 무선 채널환경의 변화에 안정적이면서 인접한 대역의 ETACS와 CDMA방식의 디지털 셀룰라 시스템 간에 약 29dB이상의 간섭 제거 성능을 보유한 시스템임을 확인하였다. In this paper, we provide the Interference Canceller Systems(ICS) in the wireless environments in the presence of co-existing ETACS and CDMA digital cellular systems to effectively cancel the interference than the established canceller systems. We proved the enhanced cancelling performances more than 29 dB cancellation characteristics between co-existing ETACS and CDMA digital cellular systems and the stabilized system characteristics in the rapidly changing wireless circumstances.

개에 발생한 만성 승모판폐쇄부전증에 대한 Pimobendan 치료 1례

장재임,전형규,최호정,이영원,송근호 忠南大學校 獸醫科大學 附設 動物醫科學硏究所 2006 動物醫科學硏究誌 Vol.14 No.-

A 11-year-old intact male maltese dog with respiratory distress, cyanosis and coughing was referred to the Veterinary Medical Teaching Hospital of Chungnam National University. Loud holosystolic murmur with a palpable precordial thrill was heard at the left apex region by auscultation. Left sided cardiac enlargement and mitral regurgitated flow were detected by thoracic radiography and echocardiography, respectively. Clinical signs were improved by treatment of diuretics, ACE inhibitor and pimobendan.