연소합성을 이용한 저온형 고체산화물 연료전지용 나노구조 세리아계 전해질 제조

조승환,김종호,김도경,Jo, Seung-Hwan,Kim, Jong-Ho,Kim, Do-Kyung 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.12

Gadolinia-doped ceria nanopowder was prepared by glycine-nitrate combustion method with different glycine/nitrate mixing ratio. The characteristics of the synthesized powder were investigated by X-ray diffraction method, transmission electron microscopy, thermal gravity, differential thermal analysis and thermo-mechanical analysis. The smallest powder was obtained with glycine/nitrate ratio 1.00 and the lowest organic and water vapor contained powder was made with glycine/nitrate ratio 1.75. According to dilatometry, fast densification was occurred around $1000^{\circ}C$ and shows full density over $1300^{\circ}C$. Finally near-fully dense ceria electrolyte was fabricated with conventional sintering technique. Glycine-nitrate process yields fine nanopowders which enable low temperature sintering and fabrication of fully dense and nanostructured oxide electrolyte.

원기둥의 종횡비가 저온의 순수물속에 잠겨있는 등온수직원기둥에 의해 야기되는 자연대류 열전달에 미치는 영향

조승환,이진호,유갑종 대한기계학회 1989 대한기계학회 춘추학술대회 Vol.- No.-

Experimental Study of In-Flight Deployment of a Multicopter from a Fixed-Wing UAV

조승환,이병주,오장진,송정규,이창민,김승균,석진영 한국항공우주학회 2019 International Journal of Aeronautical and Space Sc Vol.20 No.3

This study reports the experimental results for the in-flight launch of a multicopter from a fixed-wing UAV for a potential cooperative mission. As the cruise conditions of a fixed-wing UAV are harsh for a small multicopter, this study proposes a guidance strategy for agile attitude re-initialisation. Moreover, restraint and deployment apparatus is devised for the fixed-wing UAV and the quadcopter. The performance of the proposed approach is verified through ground and flight experiments. During the flight tests, the multicopter was successfully deployed from the fixed-wing UAV in flight; the multicopter recovered its attitude and performed subsequent missions: waypoint navigation and automatic landing assuming a close support mission.

Synthesis and Reaction of 1,5,3,7-Diazadiphosphocine-1,5-Dicarboxylic Acids

조승환,송주현,이도훈,이용균,박유미,최순규,한정태,정대일,Cho, Seung-Hwan,Song, Ju-Hyun,Lee, Do-Hun,Lee, Yong-Gyun,Park, Yu-Mi,Choi, Soon-Kyu,Hahn, Jung-Tai,Jung, Dai-Il Korean Society of Life Science 2007 생명과학회지 Vol.17 No.7

본 연구는 MRI 조영제나 새로운 생리활성 물질을 개발키 위해 paraformaldehyde와 hypophosphorous acid를 아미노산인 glycine 혹은 glutamic acid와 함께 반응시켜 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphos-phocme-1,5-diacetic acid 1 와 3,7-dihydrexy-3,7-dioxoperhydre-1,5,3,7-diazadiphos-phocme-1,5-di- (2-glutaric acid)3을 합성하였다. 그러나 aspartic acid에 의한 2-[5-(1,2-dicarboxy-ethyl)-3,7-dihydroxy-3,7-dioxo-315.715-[1,5,3,7]diazadiphosphocan-1-yl]-succinic acid 2는 얻지 못했다. 합성 된 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-dia-zadiphosphocine-1,5-diacetic acid 1을 산 촉매에 의한 에스테르화반응시켜 화합물 3,7-dihydroxy-3,7-dioxoper-hydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid methyl ester 4, 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-dia-zadiphosphocine-1,5-diacetic acid ethyl ester 5, 그리고 3,7-dihyoxy-3,74dioxoperhyo-1,5,3,7-diazadiphosphocine-1,5-diacetic acid propyl ester 6을 합성하였다. 계속해서 다양한 반응을 통해 새로운 화합물을 합성할 것이며 생리활성검색도 실시할 예정이다. In order to synthesize new bioactive compounds and contrasting agents, reactions of glycine and glutamic acid as an animo acid with paraformaldehyde and hypophosphorous acid were executed. Products are 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid 1 and 3,7-dihydroxy-3,7- dioxoperhydre-1,5,3,7-diazadiphosphocine-1,5-di-(2-glu taric acid) 3. 2-[5-(1,2-Dicarboxyethyl)-3,7-dihydroxy-3,7-dioxo-315.715-[1,5,3,7] diazadiphosphocan-1-yl]-succinic acid 2 by using aspartic acid was not obtained. Esterification of 3,7- dihydroxy-3,7-dioxoperkydro-1,5,3,7-diaza-diphosphocine-1,5-diacetic acid 1 by treatment of methanol, ethanol, and propanol were executed. 3,7-Dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid methyl ester 4, 3.7-dihydroxy-3,7-dioxoperhydro-1,5,3,f-diazadiphosphocine-1.5-diacetic acid ethyl ester 5, and 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid propyl ester 6 were respectively synthesized in good yields. Continuously, we will try synthesis of novel compounds and evaluation of biological activity.

백서 두개골에서 키토산 코팅 티타늄 플레이트 이식이 골 형성에 미치는 영향

조승환,임원봉 한국키틴키토산학회 2019 한국키틴키토산학회지 Vol.24 No.4

In order to improve the success of internal fixation in hip fracture, various treatments were applied to titanium surface in plate. Although there have been a lot of trial to handle the surface of titanium with various material so that the bone and the plate could be tightly combined, they have still failed to maintain the osteoinctivities in the past. Therefore, the purpose of this study is to investigate the possibility of improvement the osteoinctivity when the surface of titanium plate was coated with chitosan, and confirmed that the coated material stayed on. Using the calvarial defect model in rats, the study on the bone regeneration of the chitosan coated titanium plate was carried out. The chitosan coating led a rough surface on the titanium plate and fit bone formation between titanium plate and defected bone when the plate were implanted in the rat’s calvaria. In addition, the implantation of chitosan coated titanium plate led the new bone formation in the defected rat’s calvaria, significantly. In conclusion, the chitosan coated titanium plate developed in this study led the fit bone formation between titanium plated and defected bone by increased osteoinductivity, and it shows possibilities for clinical use in hip fracture.

The Correlation between the Fracture Types and the Complications after Internal Fixation of the Femoral Neck Fractures

조승환,이상홍,이현준 대한고관절학회 2016 Hip and Pelvis Vol.28 No.1

Purpose: This study aims to determine the correlation between the fracture patterns and the complications in patients with femoral neck fracture treated with internal fixation. Materials and Methods: The study comprises 45 patients with femoral neck fracture treated with multiple screws or compression hip screw between May 2008 and April 2012. The mean age was 48 years at the time of the surgery and the mean duration from initial injury to surgery was 20 hours. The fracture patterns were identified according to the anatomical location, the Garden classification and the Pauwels classification. The occurrence of nonunion and avascular necrosis were reviewed with clinical results including Harris hip score and Lunceford hip function test. The correlation between the fracture pattern and occurrence of complications were analyzed. Results: Fracture site union was achieved in 40 hips with the average union time of 17 weeks. Five nonunions occurred which showed high likelihood to occur in subcapital type, displaced (Garden stage III or IV) and Pauwels type III fractures (P<0.05). Avascular necrosis was developed in 10 hips which was mostly in subcapital type and Pauwels type III fracture but no statistical significance was found (P>0.05). The mean Harris hip score was 91 points, and Lunceford functional results were excellent in 15 hips, good in 24, fair in 4 and poor in 2. Conclusion: There was high risk of nonunion in subcapital type fracture, displaced fracture (Garden stage III and IV) and vertically oriented fracture (Pauwels type III). Careful attention is needed in these fracture types.

상수도수 불화사업을 위한 각 지역별 음용수의 불소농도에 대한 비교조사연구

조승환,신승철 ( Seung Hwan Cho,Seung Chul Shin ) 대한예방치과·구강보건학회 1995 大韓口腔保健學會誌 Vol.19 No.2

복합운동프로그램에 참여한 뇌성마비 청소년의 신체구성, 등속성 근력 및 운동기능의 변화

조승환,이운용,이대택 대한운동사협회 2009 아시아 운동학 학술지 Vol.11 No.3

[INTRODUCTION] The purpose of this study was to investigate the changes of body composition, isokinetic muscular strength, and motor function in cerebral palsy participating combined exercise program. [METHOD] Eight men volunteered for this study (15.4±1.6 yrs, 154.9±6.7 cm, 46.6±9.4 kg, 19.2±9.4 %Fat) and they were more than 13 year old who could communicate and exercise by themselves. They performed walking and weight bearing exercise 3 times a week for 8 weeks. Then after 4 weeks, they participated the exercise program again. Body composition for BIA and isokinetic muscular strength for Biodex were measured. Motor function for Gross Motor Function Measures(GMFM) were also measured. [RESULT] Body composition did not significantly differed between before and after exercise (p>.05). Isokinetic muscular strength; Knee extensor and flexor muscular strength and GMFM were significantly different between before and after exercise (p<.05). [CONCLUSION] Combined exercise program affected isokinetic muscular strength and motor function but did not seem to affect the body composition. In other words, walking and muscular strength combined exercise affected to cerebral palsy youth in isokinetic muscular strength and motor function only. [서론] 본 연구의 목적은 뇌성마비 청소년의 복합 운동프로그램 참여에 따른 신체구성, 등속성 근력 및 운동기능에 미치는 영향을 살펴보는 데 있다. [방법] 피험자(n=8명, 나이: 15.4±1.6세, 키: 154.9±6.7cm, 몸무게: 46.6±9.4kg, %Fat: 19.2±9.4%)는 뇌성마비 진단을 받은 13세 이상 중등학교 특수 학급 학생이었다. 이들에게는 8주간 주3회 60분씩 개인별 체력 수준에 맞추어 유산소 운동과 근력강화 운동을 병행하였고 운동 4주후 개인 체력 수준에 맞추어 강도가 재설정 되었다. 피험자의 신체구성은 생체전기저항 방법을 이용하여 측정했고, 등속성 근력은 등속성 운동장비(Biodex Pro4)를 이용하여 측정했다. 운동기능은 대동작기능평가(Gross Motor Function Measures)방법 중 걷기와 관련된 4·5영역을 평가하였다. [결과] 걷기와 근력 복합운동이 뇌성마비 청소년의 신체구성에는 영향을 미치지 못했다(p>.05). 반면 등속성 근력 분석 결과 좌우측 슬관절 신전과 굴곡 최대 근력과 운동기능 변화에서는 효과가 있는 것으로 나타났다(p<.05). [결론] 뇌성마비 청소년에게 걷기와 근력 복합운동이 등속성 근력과 운동기능에 제한적으로 효과가 있는 것을 알 수 있었다.

[시] 호주머니 외 4편

조승환 문예운동사 2009 문예운동 Vol.- No.101

Clinical Outcomes of Total Hip Arthroplasty for Displaced Femoral Neck Fractures in Patients 80 Years of Age and Older Selected by Clinical Frailty Score

조승환,Se Hwan Lee,윤선중 대한고관절학회 2020 Hip and Pelvis Vol.32 No.3

Purpose: The utility of total hip arthroplasty (THA) for the treatment of displaced femoral neck fractures in elderly patients (≥80 years of age) remains controversial as a patient’s general condition is an essential factor impacting recovery. This study aims to determine if THA is a valuable option for appropriately selected elderly patients. Materials and Methods: All patients underwent cementless THA using a direct lateral approach with a rectangular stem. Eighty-two patients ≥80 years of age underwent THA due to a displaced femoral neck. Clinical frailty scale (CFS) scores <5 were indicated for THA. The modified Harris hip score (mHHS), visual analogue scale (VAS), and patient satisfaction were used to assess outcomes. Results: Nine of 82 patients died in the study period with another underlying disease. One, a 90-year-old male with pneumonia expired in the intensive care unit at 7-day postoperatively, while the other eight died due to causes unrelated to THA. Of the remaining 73 patients: (i) mean mHHS score increased to 80.57±21.36 at 1- year postoperatively; (ii) VAS was 2.3±0.9 points six-months postoperatively; and (iii) 78.7% of patients reported that they were very satisfied or satisfied 1-year postoperatively. The number of perioperative complications was 10.8% (9 hips) without the need for revision surgery. Conclusion: The use of THA in patients ≥80 years of age with low CFS scores (<5) described here yielded favorable results and a relatively low rate of complications. However, a well-controlled comparative study or randomized trial is required to further refine selection criteria for THA in this patient population.