배·급수 시스템에서 부식방지제의 적용 평가 연구

우달식,문정기,구성은,최종헌,김주환,문광순 대한상하수도학회 2003 상하수도학회지 Vol.17 No.5

This study evaluated the effect of the corrosion inhibitors on the corrosion control performance in drinking water distribution system. A phosphate-zinc based inhibitor formulated was for the efficient corrosion control in drinking water distribution system. In a continuous-circulation test, 99% reduction in corrosion rate was achieved. The optimum concentration of the corrosion inhibitor was found to be 2.2㎎ PO₄/L. The effect of the corrosion inhibitor was significant for the pipes of carbon steel, galvanized steel and copper, but less for that of stainless steel. The corrosion inhibitor can be an effective cure for corrosion and red water problems by prevention the old pipes from further corrosion. Tap water in Mokpo and Kwangyang were more corrosive than the water in the rest of 4 other regions(Seoul, Pohang, Pusan, Puyeo). Tap water in Pusan was high in various ionic concentrations in general. The corrosion inhibitor reduced the corrosion rate by 76-94%, depending on the origin of the tap water.

트랙타 부착 대형이앙기 개발 및 재배적 실용성

박성태,장익주,정창화,김상열,김재현,문헌팔,양세준,김순철 한국국제농업개발학회 2002 韓國國際農業開發學會誌 Vol.14 No.3

쌀 생산비를 줄이고 대경지 규모화 영농에 적응할 수 있는 농기계 개발을 목적으로 연구개발한 대규모 경지적응 트랙터 부착 대형벼이앙기의 구성과 특징 및 개발시작기의 재배적 실용성 평가결과를 요약정리하면 다음과 같다. 1. 트랙터 부착 12조 대형벼이앙기는 크게 바퀴자국 제거로타리, 문짝형 정지판, 이앙장치부 등으로 구성되어 있다. 2. 트랙터 부착 12조 이앙기는 트랙터 동력을 이용하여 로타리, 정지 및 이앙작업이 동시에 이루어 질 수 있도록 개발하였다. 3. 바퀴자국을 없애는 날은 기존의 로타리 날을 교체하면 되도록 반달형 날로 제작하였다. 4. 이앙기는 이동시는 접을 수 있도록 설계 제작되어 대형화가 가능하므로 기존 6조 승용이앙기에 비하여 이앙작업 능력이 1.5배 이상이었다. 5. 트랙터 부착 대형벼이앙기는 트랙터와 같은 큰 동력원을 이용할 수 있으므로 측조시비기, 긴매트모 탑재 등 다양한 작업기 및 기능을 추가로 부착 가능하도록 설계되었다. 6. 트랙터 부착 대형벼이앙기는 어린모 및 중묘이앙시 결주율은 3.0∼4.3%로 기계이앙기 결주 허용범위 5% 미만이었다. 하지만 무경운 논에서는 이앙작업은 가능하나 부묘율이 다소 높은 점은 보완이 필요하다. To develop a labor saving rice cultivation technology, a new tractor attached rice transplanter has been developed for large scale farming and its field performance was evaluated. The rice transplanter consists of three major parts such as rotary for removing tractor tire furrow, door-shaped soil leveling plate and transplanting equipment. The rice transplanter is operated using the power of the tractor and performs rotary, harrow and seedling transplanting simultaneously. A half moon shaped rotary blade was found to be very efficient to remove tire furrow developed during seedling transplanting and the original rotary blade can be replaced easily with existed rotary blade. The seedling transplanting part of the transplanter was designed to fold into small size and the transplanting efficiency of the transplanter was found to be 1.5 times higher than that of the conventional riding type six row transplanter. Since the transplanter is operated through a strong power of the tractor, the additional attachment such as fertilizer application apparatus and long mat rice seedling carrier is possible. Based on the field performance of the transplanter, although the missing hill percentage showed roughly with 3.0∼4.3% for 10-day and 30-day old seedlings but the percentage is less than 5% which is maximum missing hill permit in the transplanting rice. Seedling transplanting in no-tillage field condition is acceptable but floating seedling percentage is still high and thus further technology improvement for minimizing floating seedling percontage is needed.

원격탐사를 위한 병렬계산 기법

김형중,장태정,김희원,김형수,이정문,장순자 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

원격탐사에 사용되는 편미분방정식을 고속으로 풀기 위한 기법을 프로그래밍하고 성능을 향상시킬 수 있는 방법을 제시했다. 미지수가 30만개 이상되는 복소수(non-Hermitian) 행렬의 해를 구하는 프로그램을 작성했다. 이 프로그램은 C와 PVM에 기반을 두고 있다. 수렴속도를 향상시키기 위해 대각 스케일링을 이용했다. 통신속도의 개선을 위해 데이터 압축 기법을 이용했다. 수렴속도를 측정 제시함으로써 실제 문제 적용에 참고할 수 있다. Network-based computing with cluster of personal computers or workstations recently has become an important and successful technique. Network-based computing enables fast computation and resolves short of storage with computers on the desks. Cluster of inexpensive computers offers them aggregated computing power and storage to challenge very large-scale problems. Iterative solvers are used for the large sparse linear systems. Preconditioners accelerate the rate of convergence of the iterative solvers. However, parallelization accelerate the rate of convergence of the iterative solvers. However, parallelization of preconditioners is far from satisfaction so far. Thus, the simplest diagonal scaling is a good alternative for improved convergence and easy parallelization. In order to reduce communication overhead, a data compression technique is considered. Data communication time can be reduced at the cost of convergence rate. MATLAB simulation result is given in this paper. This method is effective to cluster of computers connected through slow networks.

기종성 방광염을 동반한 기종성 신우신염 1예

김선두,김순제,이길도,김정수,김지훈,윤호상,송종오,문언수 대한노인병학회 2000 Annals of geriatric medicine and research Vol.4 No.3

工業敎育大學 敎育改善에 관한 硏究(Ⅲ)

宋周鎬,李昌岬,洪元杓,孟琦錫,任洪彬,李廷玟,李載元,李來烈,權五憲,金振淳,李文洙 충남대학교 공업교육연구소 1982 論文集 Vol.5 No.1

This paper aims at providing a concrete plan to improve technical and vocational teacher education in the College of Industrial Education of Chungnam National University. It is intended to propose a practical four-year regular and short-term course. Also, the estimated required facilities is included in this study as well as their management. The main conclusions and recommendations are summarized as follows; 1) The numbers of students enrollment should be reduced to 220 students which is the approximate number of future demand. 2) In order to offer to the students a broader education and to cope with the increase/decrease in demand of technical and vocational teacher within a specific field, the 8 department existing at the present (Department of Architecture Engineering Education, Civil Eng. Educ., Metallurgical Eng. Educ., Mechanical Eng. .Educ., Electrical Eng. Educ., Electronic Eng. Educ., Industrial Chemistry Educ. and Industrial Technology Educ.) would be combined into 5 (Department of Construction Engineering Education, Mechanical Eng. Educ., Electrical Eng. Educ., Industrial Chemistry Educ. and Industrial Technology Educ.). 3) The short-term course program is recommened to provide additional training and education to those candidates who already have experience in technical fields to meet an occasional demand. 4) It is necessary to add the Teaching Profession Section in the administrative organization of the College.

Lidocaine, Thrombin, Epinephrine 의 항균효과

김진우,이동건,전혜선,김승준,김석찬,안중현,김치홍,권순석,김영균,김관형,문화식,신완식,송정섭,박성학 대한감염학회 2005 감염과 화학요법 Vol.37 No.6

목적 : 기관지내시경 검사에서 흔히 사용되는 국소마취제인 lidocaine과 내시경시 지혈목적으로 사용되는 thrombin과 epinephrine이 각종 균주에 미치는 항균효과에 대해 알아보고자 하였다. 재료 및 방법 : 균주는 가톨릭대학교 성모병원에서 2004년 3월부터 2004년 9월까지 임상검체 에서 동정된 S. aureus, S. pneumoniae, K. pneumoniae, P. aeruginosa 각각 42, 42, 42, 43주를 대상으로 하였다. Lidocaine, thrombin, epinephrine 감수성 검사는 National Committee for Clinical Laboratory Standards (NCCLS, 2002)의 기준에 따랐다. 결과 : Lidocaine은 S. aureus, S. pneumoniae, P. aeruginosa에서 MIC_(50), MIC_(90) 모두 20,000 ㎍/mL 이었다. K. pneumoniae는 각각 10,000 ㎍/mL이었다. Thrombin은 S. aureus와 P. aeruginosa에서 MIC50 500 lU/mL 과 MIC_(90) 500 IU/mL 이상이었고, K. pneumoniae에서는 MIC_(50)과 MIC_(90)이 모두 500 lU/mL이상이었으나 S. pneumoniae에서는 MIC_(50)과 MIC_(90)은 125 IU/mL이었다. Epinephrine은 K. pneumoniae, S. pneumoniae에 대한 MIC_(50), MIC_(90)가 모두 >500 ㎍/mL이었고, S. aureus와 P. aeruginosa에 대한 MIC_(50), MIC_(90)가 모두 500 ㎍/mL이었다. 결론 : 기관지 내시경 검사에서 흔히 쓰이는 lidocaine, thrombin, epinephrine 등의 약제들이 호흡기 질환의 흔한 병원균인 S. aureus, S. pneumoniae, K. pneumoniae, P. aeruginosa 균주들에 대해 항균 효과가 있을 수 있어 세균배양검사에 영향을 미칠 수 있겠다. Background : We performed this stody to find out about antimicrobial effect of lidocaine which is commonly used local anesthetic, and thrombin and epinephrine used for hemostasis during bronchoscopic procedures. Materials and Methods : The microorganisms that were cultured from specimens obtained during bronchoscopy were Staphylococcus aureus (n=42), Streptococcus pneumoniae (n=42), Klebsiella pneumoniae (n=42), and Pseudomonas aeruginosa (n=43) collected from St. Mary's Hospital, from March to Sep 2004 were used for susceptibity testing. Susceptibility to lidocaine, thrombin, and epinephrine were tested according to the National Committee for Clinical Laboratory Standards. Result : MIC_(50) and MIC_(90) of lidocaine for S. aureus, S. pneumoniae, P. aeruginosa were all 20,000 ㎍/mL and that for K. pneumoniae were 10,000 ㎍/mL. MIC_(50) and MIC_(90) of thrombin for both S. aureus and P. aeruginosa was 500 IU/mL and above 500 IU/mL, respectively; that for K. pneumoniae were all above 500 IU/mL and for S. pneumoniae they were 125 IU/mL, MIC_(50) and MIC_(90) of epinephrine for K. pneumoniae and S. pneumoniae were above 500 ㎍/mL; that for S. aureus and P. aeruginosa were 500 ㎍/mL. Conclusion : We observed possible antimicrobial effect of lidocaine, thrombin, and epinephrine in vitro against pathogens such as S. aureus, S. pneumoniae, K. pneumoniae, P. aeruginosa, which are common respiratory microorganisms. The use of these agants could affect the result of bacterial culture.

Comparing Chewable and Manual Toothbrushes for Reducing Dental Plaque: A Pilot Study

( Moon-jin Jeong ),( Hye-sun Shin ),( Soon-jeong Jeong ),( Do-seon Lim ) 한국치위생과학회 2017 치위생과학회지 Vol.17 No.3

This study aimed to compare the effectiveness of chewable toothbrush and manual toothbrush and provide basic data for recommendation of the chewable toothbrush in specific groups and situations. A total of 20 subjects participated in this study (rolling method, 10; non-rolling method, 10). After professional prophylaxis, participants used the manual toothbrush to brush their teeth for 3 minutes. After a 7-day wash-out period, participants used the chewable toothbrush according to the manufacturer`s instructions. Pre- and post-plaque indexing of the teeth was performed. The dental plaque index was assessed using the Turesky Modification of the Quigley-Hein Plaque Index (TMQHPI) for amount of plaque and Silness-Loe Plaque Index (SLPI) for plaque thickness. The difference between pre- and post-dental plaque index was analyzed using a paired t-test and the Wilcoxon signed-rank test. The Mann-Whitney U test was also used to compare the dental plaque index reduction rates. The dental plaque index differed significantly between the chewable toothbrush and the manual toothbrush. The TMQHPI reduction rate was significantly different between the rolling and non-rolling method groups for the manual toothbrush but not the chewable toothbrush. The difference in SLPI reduction rate between the rolling and non-rolling method groups was significant for the manual toothbrush but not for the chewable toothbrush. Differences in the dental plaque index reduction rates between the chewable and manual toothbrushes were not significant in the non-rolling method group. The results of this study showed higher reduction rates in dental plaque with manual toothbrush use than with chewable toothbrush use. However, the non-rolling method group did not show statistically significant differences according to toothbrush type. The present study showed that a chewable toothbrush can be an alternative to a manual toothbrush for individuals who have difficulty using the generally recommended rolling method.

Effect of Pycnogenol on Skin Wound Healing

Jeong, Moon-Jin,Jeong, Soon-Jeong,Lee, Soo-Han,Kim, Young-Soo,Choi, Baik-Dong,Kim, Seung-Hyun,Go, Ara,Kim, Se Eun,Kang, Seong-Soo,Moon, Chang-Jong,Kim, Jong-Choon,Kim, Sung-Ho,Bae, Chun-Sik Korean Society of Microscopy 2013 Applied microscopy Vol.43 No.4

This study was carried out to investigate the effects of pycnogenol (PYC) on the cutaneous wound healing of the mice. The wounds were extracted on days 1, 3, 5, and 7 post-injury for histomorphometrical analysis including wound area, infiltrating inflammatory cells, wound contracture including collagen deposition. As the result, the wound area of PYC-treated group was larger than the control group on days 1 to 7. Inflammatory cells in the PYC-treated wounds were decreased at day 1 compared to the control wound tissue. From day 3 to 7, there was no significant difference between the control and the PYC-treated skin wounds. Though the degree of contraction in the PYC-treated group was lower than that of the control group from days 1 to 5, but appeared significantly higher on day 7. Compared to the control group, collagen accumulation in the PYC-treated group was higher than that of the control group from days 5 to 7. From this result, it may support the possibility that PYC would be useful agent for early inflammatory response and matrix remodeling phase of the skin wounds.

Perfluoropolymer Surface for Shock-free Homeotropic Alignment of Smectic Liquid Crystals

Jeong, Soon Moon,Kim, Jin Ki,Shimbo, Yoshio,Araoka, Fumito,Dhara, Surajit,Ha, Na Young,Ishikawa, Ken,Takezoe, Hideo WILEY-VCH Verlag 2010 ADVANCED MATERIALS Vol.22 No.1

<B>Graphic Abstract</B> <P>Perfect homeotropic alignment of smectic liquid crystals is demonstrated using an amorphous perfluoropolymer as an alignment layer (see figure). The hydrophobic surface of the perfluoropolymer allows rapid recovery to the homeotropic orientation from the damaged layer structure caused by mechanical shock— for example pressing with tweezers— or crystallization. <img src='wiley_img/09359648-2010-22-1-ADMA200901777-content.gif' alt='wiley_img/09359648-2010-22-1-ADMA200901777-content'> </P>

Bright, wind-driven white mechanoluminescence from zinc sulphide microparticles embedded in a polydimethylsiloxane elastomer

Jeong, Soon Moon,Song, Seongkyu,Joo, Kyung-Il,Kim, Joonwoo,Hwang, Sung-Ho,Jeong, Jaewook,Kim, Hyunmin The Royal Society of Chemistry 2014 ENERGY AND ENVIRONMENTAL SCIENCE Vol.7 No.10

<P>A variety of mechanoluminescent (ML) materials have recently reinvigorated studies of luminescence activated by mechanical stress, but few practical applications have been demonstrated due to the destructive nature of the process. To overcome these shortcomings, elastico-mechanoluminescent (elastico-ML) materials, which generate luminescence under elastic deformation, have been suggested with a view to their use in practical devices. However, the weak brightness and limited white colour expression of these materials must be resolved before they can be employed in practical applications. Here, we report a wind-driven ML device that produces significant brightness and emits warm/neutral/cool white light over a range of colour temperatures from zinc sulphide (ZnS) microscopic particles embedded in a polydimethylsiloxane (PDMS) composite. Harnessing wind-activated mechanoluminescent devices in practical displays or lighting systems could pave the way to new environmentally friendly lights, which reduce energy waste and promote sustainability.</P> <P>Graphic Abstract</P><P>Harnessing wind-driven mechanoluminescence (ML) in practical displays or lighting systems could pave the way to new environmentally friendly lights based on wind motion, to cut down energy waste and promote sustainability. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c4ee01776e'> </P>