Fly Ash를 이용한 고령토벽돌의 소결 특성

이진욱,이성민,김형태,최의석,이용석,Lee, Jin-Uk,Lee, Sung-Min,Kim, Hyung-Tae,Choi, Eui-Seok,Lee, Yong-Seok 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.12

고령토질 벽돌에 대한 fly ash의 첨가가 소결온도에 미치는 영향과 그에 따른 물성의 변화를 관찰하였다. Fly ash로는 탄소 8∼9%의 무연탄 연로 재를 사용하였고 고령토 등의 국산 천연원료를 이용하여 실험을 하였다. Fly ash와 고령토 등의 4종의 원료를 5가지의 혼합비로 조합하여 혼합, 성형하고 각각 1050${\circ}C$, 1100${\circ}C$, 1150${\circ}C$, 1200${\circ}C$의 온도로 소성하였다. 소성온도가 증가함에 따라 모든 시편에서 흡수율은 낮아지고 압축 강도는 증가하였다. 소성온도가 1100${\circ}C$ 이하인 경우 fly ash의 함량이 증가함에 따라 흡수율은 증가하고 강도가 감소하였다. 이에 비하여 소성온도가 1150${\circ}C$ 이상인 경우 흡수율은 소성온도가 낮은 경우와 유사한 경향을 보였으나 강도는 증가하였다. The effect of fly ash addition to the kaolin block has been investigated. The addition affected the firing temperature and physical properties such as water absorption and compressive strength. The starting materials were from korea natural resources and the fly ash were from the power plant using coal as fuel, containing free carbon of 8∼9 wt%. The starting natural materials were mixed with 5 different proportions of fly ash, pressed and then sintered at 1050, 1100, 1150 and 1200${\circ}C$. With sintering temperature, water absorption decreased and compressive strength increased. When specimens were sintered at the temperature lower than 1100${\circ}C$, water absorption increased and strength decreased with fly ash content. In contrast, when sintering was done at the temperature higher than 1150${\circ}C$, water absorption increased with fly ash content similarly but strength was improved.

Y₂O₃가 1 wt% 첨가된 AlN 세라믹의 전기절연성에 미치는 TiO₂ 첨가의 효과

이진욱,이원진,이성민,Lee, Jin-Uk,Lee, Won-Jin,Lee, Sung-Min 한국전기전자재료학회 2016 전기전자재료학회논문지 Vol.29 No.12

The effects of $TiO_2$ addition on the electrical insulation of AlN ceramics with 1 wt% $Y_2O_3$ as a sintering aid have been investigated. Some of $TiO_2$ has reacted with AlN powders and transformed to fine TiN particles during sintering, which was uniformly dispersed along grain boundaries of AlN. At a high electrical field (500 V/mm), the resistivity of AlN ceramics with $TiO_2$ addition of 0.2 wt% increased about 1000 times from $3{\times}10^{10}{\Omega}cm$ to $3.1{\times}10^{13}{\Omega}cm$. Based on the impedance spectroscopy measurement, it was found that $TiO_2$ addition increased dramatically electrical resistivity of AlN grains much more than that of grain boundaries. Thus, $TiO_2$ was believed to dissolve inside AlN grains to suppress ionic conduction of Al vacancies. This suppressed ionic conduction by Ti incorporation into AlN grains seems to contribute to more electrically insulating AlN ceramics.

Helicobacter pylori의 감수성과 숙주 연령과의 상관성 연구

이진욱,김승희,박탄우,김옥진,Lee, Jin-Uk,Kim, Seung-Hee,Park, Tan-Woo,Kim, Okjin 대한수의학회 2007 大韓獸醫學會誌 Vol.47 No.1

Helicobacter pylori (H. pylori) is an important bacterial pathogen that causes chronic gastritisand is associated with gastroduodenal ulcer disease, adenocarcinoma of the distal stomach, and gastricH. pylori infection associated with host agehave not been well-defined in human. To evaluate the difference in host susceptibility to infection in relationto age of acquisition of H. pylori infection, we designed an experiment involving inoculation of H. pyloriATC 43504 at different ages of Mongolian gerbils. H. pylori was inoculated at 5 weeks and 18 monthsof age, as representatives of early and late infection, respectively. Animals were sacrificed 1 week and 4weeks after challenge, and the stomach was removed from each animal for bacterial culture, histologicalexamination, and polymerase chain reaction test. 5 week-old gerbils revealed infection andmaintained continuously its infection until 4 weeks. However, old gerbils did not maintained H. pyloriinfection. These data suggest the insusceptibility of H. pylori in old Mongolian gerbils and the importanceof animal ages for successful animal experimental infection. Also, the results demonstrated that earlyinfection of H. pylori increases its host susceptibility, as compared to the case with later infection, possiblybecause of differences in host gastric mucosal factors and imunologic responses.

Helicobacter pylori의 in vivo 연구를 위한 ethanol-pretreating animal model의 개발

이진욱,김승희,박탄우,김옥진,Lee, Jin-Uk,Kim, Seung-Hee,Park, Tan-Woo,Kim, Okjin 대한수의학회 2006 大韓獸醫學會誌 Vol.46 No.4

A stable and reliable Helicobacter pylori (H. pylori) infection animal model would be necessary for evaluating vaccine efficacy and helpful for understanding the pathological mechanism of the organism. The aim of the present study is to investigate the effect of ethanol treatment prior to H. pylori inoculation on associated gastric mucosal injury and to establish ethanol-pretreating animal model to study H. pylori infection. Male Mongolian gerbils were used for the study. H. pylori was orally inoculated after 12 h fasting. 3 h prior to H. pylori inoculation, a group of gerbils was orally treated with absolute ethanol, 60% and 40% ethanol respectively. Another group of animals was treated either with H. pylori culture media alone or with different concentrations of ethanol plus culture media. Gerbils were killed 4 or 8 weeks after H. pylori inoculation. The colonization of H. pylori was confirmed by both histological examination and rapid urease test. Mucosal damage was evaluated grossly and histologically according to the criteria. The colonization of H. pylori and pathological changes in gastric mucosa of the animals were also observed. Although no significant change to the gastric mucose was observed in the animals treated either with H. pylori culture media alone or with different concentrations of ethanol plus culture media, persistent H. pylori infection was seen in the mucosa and mucosal leucocyte infiltration and severe epithelial damage was observed in the Helicobacter and ethanol + Helicobacter groups after 4 weeks. The gross and histological scores were higher in the ethanol + Helicobacter than in the Helicobacter alone group. As the results, ethanol-pretreatment with 60% concentration induced severe pathogenic changes by H. pylori infection in 5 weeks-old Mongolian gerbils. These results suggested that ethanol-pretreatment before H. pylori inoculation could increase the severity of gastric mucosal inflammation and enhance the colonization of H. pylori. The established ethanol-pretreating animal model would contribute to screen new drugs against H. pylori and be used as an useful tool for various animal experiments with H. pylori strains.

Helicobacter pylori의 병원성 비교를 위한 gerbil의 수침구속스트레스 모델

이진욱,김옥진,Lee, Jin-Uk,Kim, Ok-jiu 대한수의학회 2004 大韓獸醫學會誌 Vol.44 No.4

Helicobacter pylori (H. pylori)-infection is an important pathogen of stomach cancer after chronic gastritis and ulceration in the stomach and duodenum. However, the virulences of H. pylori strains have not been well-defined between clinical isolates. This study was designed to establish water-immersion-restraint stress (WIRS) model in mongolian gerbil for comparison of pathogenicity of H. pylori strains. To determine an optimal duration time for WIRS model in gerbil, 5-week-old Mongolian gerbils were divided into different groups by WIRS duration time. After graded duration of WIRS, the macroscopic ulcer index (UI) was measured with the stomach and duodenum of sacrificed animal. There were no significant differences between male and female in same duration group. However, the UI increased significantly in a time-dependent fashion. The group of 6 hours-WIRS animals showed severe hemorrhage and ulceration in their stomach and duodenum. On the other hand, the very mild lesions induced in 2 hours-treated animals. Therefore, we determined an optimal duration time for WIRS model in gerbil as 4 hours. Thereafter, we evaluated whether this WIRS model in gerbil could be used as an useful tool for in vivo comparison of pathogenicity of H. pylori strains by enhancement of pathological severity in H. pylori-infected gerbils. Mongolian gerbils were divided into H. pyloriinfected and PBS-inoculated groups. Thereafter, they were divided again into 4 hours-WIRS and no WIRS subgroups. After treatment, the severity of pathological changes was evaluated in a same manner with previous duration-determining experiment. When the animals were exposed to WIRS, the UI was significantly higher in the infected group than in the uninfected group. These results suggested that the established gerbil-WIRS model in this study enhanced effectively the severity of pathogenic changes in the H. pylori-infected Mongolian gerbils and could be used as an useful tool for in vivo comparison of pathogenicity of H. pylori strains.

CCTV를 이용한 강우입자분포 및 강우강도 산정

이진욱,김현준,변종윤,백종진,전창현,Lee, Jin-Uk,Kim, Hyeon-Jun,Byeon, Jong-Yun,Baek, Jong-Jin,Jeon, Chang-Hyeon 한국수자원학회 2022 물과 미래(한국수자원학회지) Vol.55 No.6

Helicobacter pylori 감염이 비스테로이드성 소염제에 위한 위장관 손상에 미치는 영향

이진욱(Jin-Uk Lee),김옥진(Okjin Kim) 한국실험동물학회 2004 Laboratory Animal Research Vol.20 No.4

The action of non-steroidal anti-inflammatory drug (NSAID) on the Helicobacter (H.) Pylori infected mucosa is a matter of debate. Some authors consider them to cause additive iatrogeny while others attribute a purportedly protective action to them. The aim of the present study is to investigate the effect of NSAID administration prior to H. pylori inoculation on associated gastrointestinal injury. Mongolian gerbils were used for the study, since they have been reported to be a suitable model for H. pylori-associated gastric mucosal injury, including gastric cancer. We used indomethacin as a potent NSAID. Gerbils were divided into indomethacin (20 ㎎/㎏)-inoculated and CMC-administrated groups. Thereafter, after 6 hours later, they were divided again into following subgroups-H. pylori-inoculated and PBS-inoculated animals. Gerbils were sacrificed 4 or 6 weeks after H. pylori inoculation and gastrointestinal damage was evaluated grossly and histologically. In the controls (CMC+PBS) and the group of indomethacin alone (I+PBS), no significant change to the gastrointestinal mucosa was observed. However, severe gastrointestinal epithelial damage was observed in the group of indomethacin administration preceding H. pylori-inoculation (I+Hp). In the group of CMC administration preceding H. pylori-inoculation (CMC+Hp), mild epithelial changes was observed. These results suggested that the administration of NSAID preceding H. pylori infection could promote the progression of gastrointestinal mucosal damages.

포스터발표 : 환경분석 ; 미세유동칩 시스템 내에 고정화된 T. cutaneum의 생물학적 활성 측정

이진욱 ( Jin Uk Lee ),이종원 ( Jong Won Lee ),전경미 ( Kyong Mi Chon ),권복순 ( Bok Soon Kwon ),김인수 ( In S. Kim ),조재원 ( Jae Weon Cho ) 대한상하수도학회 2005 공동춘계 학술발표회 논문집 Vol.2005 No.-

U-turn 설치를 위한 적정 폭원

이진욱(Lee, Jin-Uk),김기혁 대한교통학회 2009 대한교통학회 학술대회지 Vol.60 No.-

Helicobacter pylori 감염에 대한 indomethacin 투여의 영향

이진욱(Jin-Uk Lee),김옥진(Okjin Kim) 한국실험동물학회 2004 Laboratory Animal Research Vol.20 No.3

본 연구자은 NSAIDs가 H pylori 병증 발현에 영향을 미치는 것으로 추론하고 H. pylori 감염 양태가 사람과 가장 유사한 실험동물 모델인 Mongolian gerbil을 사용하여 확인실험을 실시한 결과, NSAIDs의 일종인 indomethacin익 투여가 H. pylori 감염에 의한 위장관 손상을 심화시키는 것을 확인하였다. 이러한 결과는 H. pylori 감염 환자들에서 NSAIDs의 복용은 제한되어져야함을 시사한다. This study was designed to find out the effects of indomethacin on Helicobacter pylori (H. pylori)induced gastrointestinal injuries. We used Mongolian gerbils which have been reported as a most optimal laboratory animal to study H. pylori ill vivo. To determine an optimal indomethacin concentration for oral administration, 5-week-old Mongolian gerbils were divided into different indomethacin concentrations. After graded concentrations of indomethacin, the gross and histological lesion scores were measured with the stomach and duodenum of sacrificed animals. The gross lesion scores in the stomachs of sacrificed animals increased in a concentration-dependent fashion. We determined an optimal indomethacin concentration in gerbil as 40 ㎎/㎏ body weight. We evaluated the effects of indomethacin on H. pylori-induced gastrointestinal injuries. Mongolian gerbils were divided into H. pylori-infected and PBS-treated groups. Thereafter, after 1 week later, they were divided again into following subgroups-20 ㎎/㎏ indomethacin-administrated and 40 ㎎/㎏ indomethacintreated and PBS-treated animals. After per oral treatment, the severity of pathological changes was evaluated in a same manner with previous indomethacin concentration-determining experiment. When the animals were exposed to indomethacin, the gross and histological lesion scores were higher in the infected groups than in the uninfected groups. These results suggested that indomethacin could induce the enhancement of H. pylori-induced gastrointestinal injuries.