광섬유 Sagnac 간섭계를 이용한 초음파의 비접촉식 감지

이정주,장태성,이승석,김영길,권일범,이왕주,Lee, Jeong-Ju,Jang, Tae-Seong,Lee, Seung-Seok,Kim, Yeong-Gil,Gwon, Il-Beom,Lee, Wang-Ju 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.9

This paper describes a fiber optic sensor suitable for non-contact detection of ultrasonic waves. This sensor is based on a fiber optic Sagnac interferometer. Quadrature phase bias between two interfering laser beams in Sagnac loop is introduced by a polarization controller. A stable quadrature phase bias can be confirmed by observing the interferometer output versus phase bias. This method eliminates a digital signal processing for detection of ultrasonic waves using Sagnac interferometer. Interference intensity is affected by the frequency of ultrasonic waves and the time delay of Sagnac loop. Collimator is attached to the end of the probing fiber to focus the light beam onto the specimen surface and to collect the reflected light back into the fiber probe. Ultrasonic waves produced by conventional ultrasonic transducers are detected. This fiber optic sensor based on Sagnac interferometer is very effective for detection of small displacement with high frequency such as ultrasonic waves used in conventional non-destructive testing.

호피 시 착지방법에 따른 하지 강성도

이정주,손종상,김정윤,김영호,Lee, J.J.,Son, J.S.,Kim, J.Y.,Kim, Y.H. 대한의용생체공학회 2011 의공학회지 Vol.32 No.2

The purpose of the present study was to analyze the lower stiffness over the difference between soft and stiff landings during hopping. Five male subjects performed hopping on two legs at 2.5 Hz. During the experiments, 3D motion capture system was used to obtain the kinematic data and two force plates were synchronized to calculate the kinetic data. We determined lower extremity stiffness of the knee and ankle from kinetic and kinematic data. Leg stiffness was approximately 1.2-times significantly higher in stiff landing than in soft landing_ There was no significant difference in knee joint stiffness between soft and stiff landings. Ankle joint stiffness was approximately 1.34-times significantly higher in stiff landing than in soft landing. These results suggest that humans adjust lower extremity stiffness over the comparison of two different landing methods we evaluated.

대학에 대한 새로운 사회의 요구

이정주,Lee, Jeong-Ju 한국대학교육협의회 2004 大學敎育 Vol.127 No.-

우리의 가장 좋은 자원은 인적자원이다. 대학이 이 풍부한 인적자원을 지식근로자로 육성할 때 우리는 세계시장에서 다시 경쟁력을 회복할 수 있게 될 것이다. 청년실업문제는 노동정책의 문제가 아니라 대학교육 개혁의 문제로 인식되어야 하는 것이다.

자동차 브레이크 마찰재용 비침상형 육티탄산칼륨의 합성 연구

이정주,이나리,피재환,김종영,김정주,Lee, Jung Ju,Lee, Na-Ri,Pee, Jae-Hwan,Kim, Jong-Young,Kim, Jeong-Joo 한국재료학회 2017 한국재료학회지 Vol.27 No.3

We synthesized potassium hexatitanate, ($K_2Ti_6O_{13}$, PT6), with a non-fibrous shape, by acid leaching and subsequent thermal treatment of potassium tetratitanate ($K_2Ti_4O_9$, PT4), with layered crystal structure. By controlling nucleation and growth of PT4 crystals, we obtained splinter-type crystals of PT6 with increased width and reduced thickness. The optimal holding temperature for the layered PT4 was found to be ${\sim}920^{\circ}C$. The length and width of the PT4 crystals were increased when the nucleation and growth time were increased. After a proton exchange reaction using aqueous 0.3 M HCl solution, and subsequent heat treatment at $850^{\circ}C$, the PT4 crystal transformed into splinter-type PT6 crystals. The frictional characteristics of the friction materials show that as the particle size of PT6 increases, the coefficient of friction (COF) and wear amounts of both the friction materials and counter disc increase.

외상무홍채증과 동반된 무수정체안에서 흑색횡격막 인공수정체 삽입에 대한 장기 임상경험

이정주,이상준,김신동,Jung Joo Lee,M,D,Sang Joon Lee,M,D,Shin Dong Kim,M,D 대한안과학회 2008 대한안과학회지 Vol.49 No.2

`Purpose: This is a report on the long-term follow-up of patients who had received black diaphragm intraocular lens implantation after traumatic aniridia. Methods: This is a retrospective study on the long-term follow-up for more than 50 months of six patients who had received black diaphragm intraocular lens implantation after traumatic aniridia. Results: An improvement in visual acuity of more than two letters, according to the Snellan chart, occurred in three out of six eyes that were available for follow-up studies after an average period of 7 years and 8 months (50-115 months) after the operation, and no visual acuity decline groups were present. Early complications of black diaphragm intraocular lens implantation consisted of cystoid macular edema and transient intraocular pressure rise. The complications late occurred included bullous keratopathy in four eyes, glaucoma in three eyes, and exotropia in three eyes. We performed penetrating keratoplasty in two of the four eyes suffering from bullous keratopathy, and an Ahmed valve implantation in two of the three eyes suffering from glaucoma. There were signs of reduced visual acuity in four eyes due to complications of the surgery. Conclusions: The authors of this report recommend care in use of black diaphragm intraocular lens implantation, by studies done with an average follow-up period of 7 years and 8 months post operatively. Also reported were severe complications with this treatment such as bullous keratopathy and glaucoma.`

Clinicopathologic Changes in Children with Immunoglobulin A Nephritis and Henoch-Sch$\ddot{o}$nlein Purpura Nephritis after Cyclosporine A and Angiotensin-converting Enzyme Inhibitor Treatment

이정주,김용진,신재일,임현이,박세진,Lee, Jeong Ju,Kim, Yong-Jin,Shin, Jae Il,Yim, Hyunee,Park, Se Jin Korean Society of Pediatric Nephrology 2013 Childhood kidney diseases Vol.17 No.2

목적: IgA 신병증, HSP 신병증은 사구체의 메산지움에 IgA가 침착되는 대표적인 질환이다. 본 연구는 소아에서, 이 두 가지 질환에 대한 Cyclosporin A 의 임상적 및 병리학적 효과를 평가하기 위하여 시행되었다. 방법: 총 54명의 환자(IgA 신병증: Henoch-Sch$\ddot{o}$nlein purpura 신병증=36:18)를 대상으로 후향적으로 연구를 진행하였다. CsA는 5mg/kg/day 으로 투여하였으며, 투여 전, 후로 단백뇨의 양을 측정, 병리학적 변화를 조사하기 위해 신생검을 시행하였다. HSP 신병증 및 IgA 신병증의 신생검은 병리학적으로 각각 ISKDC 분류법, Oxford 분류체계(2009)로 구분하였다. 결과: 혈청 단백/크레아티닌 비는 치료 전후로 $3.7{\pm}1.5$에서 $0.6{\pm}0.4$으로 호전되었고(P<0.001), 총 54명 중 32명의 환자(59.2%)에서 CsA 치료 1년 후 단백뇨의 관해를 보였다. 신생검의 병리학적 소견은 호전되거나, 또는 치료 전후로 유지되는 양상을 보였으며, CsA로 인한 합병증은 없었다. 결론: CsA 는 IgA의 사구체 침착을 특징으로 하는 IgA 신병증, HSP 신병증 환자에서 단백뇨 감소효과 및 말기신부전으로의 진행을 예방하는 데에 효과적인 것으로 사료된다. Purpose: To investigate the clinicopathologic effects of cyclosporine A (CsA) in children with diseases characterized by mesangial immunoglobulin A deposits such as immunoglobulin A nephropathy (IgAN) and Henoch-Sch$\ddot{o}$nlein purpura nephritis (HSPN). Methods: We retrospectively reviewed the clinicopathologic outcomes of 54 children (IgAN, 36; HSPN, 18) treated with CsA. The starting dose of CsA was 5 mg/kg per day, and it was administered in 2 divided doses. The degree of proteinuria and pathologic changes in renal biopsies were evaluated before and after CsA treatment. Results: The mean protein to creatinine ratio decreased from $3.7{\pm}1.5$ to $0.6{\pm}0.4$(P <0.001), and 32 (59.2%) children achieved complete remission of proteinuria after 1-year CsA treatment. Among the 54 children, 24 maintained normal renal function and 25 exhibited microscopic hematuria or proteinuria at the end of CsA treatment. In the HSPN group, 3 children whose initial biopsies indicated class IIIb disease showed class II disease on follow-up, and the follow-up biopsies of 2 children who had class II disease indicated the same class II disease. In the IgAN group, cortical tubular atrophy occurred in 1 child, and no child with IgAN had cortical interstitial fibrosis or tubular atrophy after 1-year CsA treatment. No significant complications were found in the children treated with CsA. Conclusion: Our findings indicate that CsA treatment is effective and beneficial in reducing massive proteinuria and preventing progression to end-stage renal failure in children with glomerular diseases characterized by IgA deposits, such as IgAN and HSPN, within 1 year of treatment.

간유(肝兪).중완(中脘)의 대계(大?) 약침(藥鍼)이 급성 산화적 간손상에 미치는 효과

이정주,문진영,Lee Jeong-Joo,Moon Jin-Young 경락경혈학회 2003 대한침구의학회지 Vol.9 No.1

Objectives : Circii Herba has been used as a natural drug for the treatment of stress digestive system disease. The aim of this study is to investigate the role of Circii Herba aqua-acupuncture solution (CHAS) in experimental oxidative liver injury. Methods : In order to investigate the effects of CHAS on acute liver injury, male ICR mice were pretreated with CHAS(0.2 ml/mouse/day) at the loci of BL18 and CV12 for 6days, starved for 24hrs, and administerated acetaminophen(500 mg/kg, i.p.). After acetaminophen administeration, mice were sacrificed, and the liver was removed, rinsed with ice-cold $1.15{\%}$ KCI buffer, and homogenized at $4^{\circ}C$. Fractions(fraction Ⅰ, Ⅱ, Ⅲ) were isolated by differential centrifugation. Lipidperoxide, total SH, and glutathione(GSH) levels were measured in the Fraction Ⅰ. In addition, activities of hepatic enzyme, such as catalase, glutathione peroxidase(GSH-Px) were measured in the Fraction Ⅱ, and glutathione S-transferase(GST) was measured in the Fraction Ⅲ. Results : In vivo treatment of CHAS(BL18 and CV12) showed effective inhibition of acetaminophen induced lipid peroxidation, and showed elevations of total SH, GSH level, catalase, GSH-Px, GST activities. Conclusions : These results suggested that CHAS might suppress the formation of oxidative metabolites, and prevent acetaminophen induced hepatotoxicity.

수재해 정보관리 및 서비스를 위한 공간, 비공간 정보 자료 개념 설계

이정주,김동영,정영훈,황의호,채효석,Lee, Jeong-Ju,Kim, Dong-Young,Jung, Young-Hun,Hwang, Eui-Ho,Chae, Hyo-Sok 한국농공학회 2016 한국농공학회논문집 Vol.58 No.2

This study conducted a basic design of system and interface which provide both of spatial and non-spatial data for water hazard information management. This helps to decide directions of the future integrated water hazard information platform and possible technical examinations of the web-based system for the realization of the prototype. For user friendly system, this study did a survey to investigate the data format, service environment, image processing level and visualization type that users prefer. Also, authorization range was set up by type of the user group. In the water hazard information platform, the data and analysis algorithm were classified by the fields. Furthermore, the platform was consisted with six block systems according to the function and the interface and designed to flexibly mount or modify the additional functions. For a basic design of the data exchange method and protocols, a prototype was constructed by using the spatial information web service technology. The portal service system to visualize and provide spatial data was designed by the WMS/WFS type of OGC standard interface and the FTP/HTTP interface type through open source GIS software for server environment.

이차전지(二次電池) 제조공정(製造工程)스크랩으로부터 고효율(高效率) 親環境(친환경) 코발트(Co)와 리튬(Li)의 회수(回收)에 관(關)한 연구(硏究)

이정주,정진도,Lee, Jeong-Joo,Chung, Jin-Do 한국자원리싸이클링학회 2010 資源 리싸이클링 Vol.19 No.6

리튬이차전지 양극스크랩으로부터 코발트와 리튬을 회수하기위해 물리적 전처리, 침출, 용매추출 및 회수실험을 행하였다. 실험재료로 제조공정에서 발생되는 코발트계 양극스크랩을 사용하여 단위공정별 최적조건을 구하였다. 물리적전처리 최적조건은 온도 $500{\sim}550^{\circ}C$, 파쇄날 회전속도 1000rpm이었으며, 침출 최적조건은 300rpm, 2M $H_2SO_4$, 2.5M $H_2O_2$, $95^{\circ}C$이었다. D2EHPA(bis(2-ethylhexyl) phosphoric acid) 와 PC88A를 각각 알루미늄과 코발트의 추출제로 사용하여 분리.정제하였으며, 코발트는 염기성시약을 사용하여 $Co(OH)_2$로, 리튬은 탄산나트륨 및 LiOH를 사용하여 탄산리튬($LiCO_3$)으로 회수하였다. $Co(OH)_2$는 열처리를 하여 삼산화코발트($Co_3O_4$)로 만들고 분쇄기를 사용하여 10 ${\mu}m$정도의 입자를 만들었다. 최적조건에서 코발트와 리튬 회수율은 99%이상, 리튬회수율은 99%이상이었으며, 삼산화코발트의 순도는 99.98%이상이었다. A study on the recovery of cobalt and lithium from Lithium Ion Battery(LIB) scraps has been carried out by a physical treatment - leaching - solvent extraction process. The cathode scraps of LIB in production were used as a material of this experiment. The best condition for recovering cobalt from the anode scraps was acquired in each process. The cathode scraps are dissolved in 2M sulfuric acid solution with hydrogen peroxide at $95^{\circ}C$, 700 rpm. The cobalt is concentrated from the leaching solution by means of a solvent extraction circuit with bis(2-ethylhexyl) phosphoric acid(D2EHPA) and PC88A in kerosene, and then cobalt and lithium are recovered as cobalt hydroxide and lithium carbonate by precipitation technology. The purity of cobalt oxide powder was over 99.98% and the average particle size after milling was about 10 lim. The over all recoveries are over 95% for cobalt and lithium. The pilot test of mechanical separation was carried out for the recovery of cobalt from the scraps. The $Co_3O_4$ powder was made by the heat treatment of $Co(OH)_2$ and the average particle size was about 10 ${\mu}m$ after grinding. The recovery was over 99% for cobalt and lithium each other and the purity of cobalt oxide was over 99.98%.

세제 농도에 따른 세척력과 세제성분의 잔류

이정주,김유겸,Lee, Jung-Ju,Kim, You-Kyum 한국섬유공학회 2011 한국섬유공학회지 Vol.48 No.2

Selected standard methods for washing machines: agitating type; horizontal drum type. Market detergents: standard powder detergent; powder detergent; liquid detergents. Standard soiled clothes composed of five types, including the various contaminants from the actual life of soiled clothes, respectively. When washing with the standard course for a washing machine and using the standard, recommended amount of detergent product, the detergency for the agitating-type washing machine and standard soiled clothes increased by approximately 25%, on average, compared to the case of -30% use, and increased by 2% compared to the case of +60% use, respectively. When the horizontal drum-type washing machine was used, detergency increased by approximately 28%, on average, compared to -30% use, and increased by 12% compared to +100% case. Accordingly, the detergency when using the standard amount of detergent increased by approximately 27% on average, and increased by approximately 7% compared to the cases of +60%~+100% use. Moreover, the residue of the detergent components was extremely small, but proportional nonetheless to detergent concentration.