http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
FT 합성반응용 철촉매에 미치는 촉매특성에 미치는SiO<sub>2</sub> 첨가효과
천동현(Chun, Dong-Hyun),김학주(Kim, Hak-Joo),현순택(Hyun, Sun-Taek),양정훈(Yang, Jung-Hoon),이호태(Lee, Ho-Tae),양정일(Yang, Jung-Il),정헌(Jung, Heon) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.06
Precipitated iron-based catalysts are highly promising for the Fischer-Tropsch synthesis (FTS), in particular for the low temperature FTS below 280?C, because of their high activity and low cost. SiO₂ is an essential promoter for the precipitated iron-based catalysts to improve the attrition strength and physical stability. In this study, we carried out FTS over precipitated iron-based catalysts with and without SiO₂ in a fixed-bed reactor. The catalysts were prepared by a conventional co-precipitation method. In case of the catalysts with SiO₂, we used two comparative preparation methods, i.e., incorporation of SiO₂ before precipitation (denoted as precipitated SiO₂) and after precipitation (denoted as binder SiO₂), respectively. The addition of SiO₂ crucially affects both physico-chemical properties and catalytic peformance of precipitated iron-based catalysts.
천동일,Chun, Dong-il 대한족부족관절학회 2020 대한족부족관절학회지 Vol.24 No.1
Metatarsalgia is a generalized term used to describe forefoot pain. The possible etiologies can range from direct to indirect pathologies. Metatarsalgia has several causes. This paper evaluates the recent literature to provide an in-depth review of metatarsalgia after forefoot surgery.
SiO<sub>2</sub> 원료물질에 따른 Fischer-Tropsch 합성반응용 Fe계 촉매의 성능변화
천동현(Chun, Dong Hyun),김학주(Kim, Hak-Joo),현순택(Hyun, Sun-Taek),이호태(Lee, Ho-Tae),양정일(Yang, Jung-Il),양정훈(Yang, Jung Hoon),정헌(Jung, Heon) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06
Fe계 촉매는 FT(Fischer-Tropsch) 합성반응에 매우 유망한 촉매로 주목받고 있으며, 280?C 미만의 저온 FT 합성반응의 경우, 침전법이 Fe계 촉매의 가장 전형적인 제조방법으로 알려져 있다. Fe계 촉매에 첨가되는 조촉매로는 Cu, K, SiO₂ 등이 가장 대표적이며, 이 중에서 특히 구조 조촉매로 첨가되는 SiO₂는 Fe계 촉매의 기계적 강도를 향상시킬 뿐만 아니라, 촉매의 성능에도 크게 영향을 미치는 것으로 보고되고 있다. 본 연구에서는 침전법을 이용하여 저온 FT 합성반응용 Fe계 촉매를 제조하였고, 구조 조촉매로 첨가한 SiO₂의 원료물질에 따른 Fe계 촉매의 성능변화를 조사하였다. SiO₂의 원료물질로는 콜로이드 SiO₂와 분말 SiO₂를 이용하였으며, 분말 SiO₂를 이용한 촉매가 콜로이드 SiO₂를 이용한 촉매보다 다소 높은 CO 전환율 및 중질탄화수소 선택도를 나타내는 것을 확인하였다.
종골 길이와 너비의 상관관계를 이용한 종골 너비 추정에 관한 연구
천동일,황수강,조재호,최성우,김용범,원성훈,Chun, Dong-il,Hwang, Shu Chiang,Cho, Jae-ho,Choi, Sung-Woo,Kim, Yong Beom,Won, Sung Hun 대한족부족관절학회 2017 대한족부족관절학회지 Vol.21 No.2
Purpose: The purpose of this study was to determine the correlation and ratio between the calcaneal length and width for predicting the width of calcaneus. Materials and Methods: A total of 190 feet (190 patients) were included based on computed tomography scans. The length of calcaneus (CL) was measured on the line connecting the center of a circle tangent to the cortical margin in the anterior and posterior parts of the calcaneus in a sagittal plane (W1, W2). The width of the calcaneus was defined as the horizontal line of each part (W1, W2, W3) on the same axial plane. The relationship between the measurement was determined through a correlation analysis. The reliability was assessed based on intraclass correlation coefficients. Results: The CL and widths of calcaneus (W1, W2, W3) had a good positive correlation (r=0.848 [W1/CL], r=0.738 [W2/CL], r=0.769 [W3/CL]; p<0.001). The mean CL and widths ratios were 0.33 (W1/CL), 0.37 (W2/CL), and 0.37 (W3/CL). Using these ratios to estimate the widths by multiplying each ratio by the measured calcaneal length, we found a difference between the estimated calcaneal widths and the actual measured calcaneal widths values was 0.25 mm, 0.43 mm, and 0.16 mm. All measurements showed good-to-excellent inter- and intraobserver reliability. Conclusion: This study analyzed the correlation and ratio between the length and width of the calcaneus. The results will help orthopedic surgeons fixate screws in a stable manner to prevent iatrogenic injuries to the medial neurovascular structures of the calcaneus.
스포츠 손상에 의한 아킬레스건의 급성 분절 파열: 증례 보고
천동일,원성훈,이상현,조재호,Chun, Dong-Il,Won, Sung Hun,Lee, Sang Hyeon,Cho, Jaeho 대한족부족관절학회 2017 대한족부족관절학회지 Vol.21 No.2
Tendoachilles rupture has recently seen an increase in frequency, accounting for up to 40% of all tendon ruptures. However, an acute segmental rupture of the Achilles tendon is very rare with only one case caused by predisposing factors, such as steroid injection. In this report, we highlight an unusual clinical presentation of a segmental rupture of the Achilles tendon without any underling predisposing factor and without direct trauma. Herein, we discuss its mechanism. Twelve months after surgical repair with open technique, this patient became fully functional again in daily activity.
당뇨병성 족부 궤양 환자의 진단 1년 내의 절단율 및 위험 인자의 분석
천동일,전민철,최성우,김용범,노재휘,원성훈,Chun, Dong-Il,Jeon, Min Chul,Choi, Sung-Woo,Kim, Yong-Beom,Nho, Jae-Hwi,Won, Sung Hun 대한족부족관절학회 2016 대한족부족관절학회지 Vol.20 No.3
Purpose: This study investigates the amputation rate within 1 year after the diagnosis of diabetic foot ulcer and its associated risk factors. Materials and Methods: This study enrolled 60 patients with diabetic foot ulcer. The mean and standard deviation age was $64.4{\pm}12.8years$ (range, 32~89 years); the mean and standard deviation prevalence period for diabetes mellitus was $21.0{\pm}7.5years$ (range, 0.5~36 years). The amputation rate was evaluated by dividing the subjects into two groups - the major and minor amputation groups - within 1 year following the initial diagnosis of diabetic foot ulcer. Multivariate Cox proportional hazards regression analysis was used to identify the risk factors for amputation. Results: The total amputation rate of 38.3% (n=23) was comprised of the amputation rate for the major amputation group (10.0%) and rate for the minor amputation group (23.8%). There was a high correlation between peripheral artery disease (toe brachial pressure index <0.7) and amputation (hazard ratio [HR] 5.81, confidence interval [CI] 2.09~16.1, p<0.01). Nephropathy was significantly correlated with the amputation rate (HR 3.53, CI 1.29~9.64, p=0.01). Conclusion: Clinicians who treat patients with diabetic foot complications must understand the fact that the amputation rate within 1 year is significant, and that the amputation rate of patients with peripheral artery disease or nephropathy is especially high.