Prediction of Grain Structure of Thin Bronze Slab Produced by Horizontal Continuous Casting

Yong‑You Kim,Hee‑Soo Kim 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.2

The grain structure of a thin bronze slab produced by horizontal continuous casting was investigated using heat-transfercalculation and cellular automaton (CA). The composition of the bronze was Cu–22wt%Sn, which has been widely used inKorean history. The solid form of Cu–22wt%Sn was assumed as a single phase for simplicity. To simulate the macrostructureof the alloy, the heat transfer in the horizontal continuous casting was calculated as a steady-state one-dimensional lumpedsystem. The CA was used for simulating the grain structure. Since the temperature profile was in the steady state, the cellinformation was shifted along the casting direction at a rate of one cell per time step during the simulation. The grainswere nucleated at the slab surface and grown as columnar grains. The effects of the process parameters, such as initial melttemperature and casting speed, on the grain structure of the slab were investigated. It was found that the casting speed is acritical factor determining the angle between the columnar grains and the casting direction.

부산시 용호동 정책이주단지 주거공간의 내·외부 변용 특성에 관한 연구

김용운(Kim, Yong-Woon),유재우(You, Jae-Woo) 대한건축학회 2014 대한건축학회 학술발표대회 논문집 Vol.34 No.2

소목(Caesalpinia sappan) 추출물의 Streptococcus mutans에 대한 성장, 산생성, 부착 및 비수용성 글루칸 합성 억제에 미치는 영향

유용욱,유현희,김윤정,유미선,서세정,이황,이흥수 대한구강보건학회 2003 大韓口腔保健學會誌 Vol.27 No.2

Streptococcus mutans is known as the causative bacterial playing the most important role in forming plaque and it is being noticed as major causative bacteria of dental caries. Therefore, development of more effective, substantial and safe preventive agent against dental caries and periodontal disease is honestly required. The present study was designed to investigate the effect of chloroform extract(CE), n-butanol extract(BE),methanol extract(ME) and water extract(WE) of Caesalpinia on the growth, acid production, adhesion, and insoluble glucan synthesis of Streptococcus mutans. The CE, BE, ME and WE decreased the growth and acid production of S.mutans than that of control, especially, the ME was more effective than other extracts. The effect of CE, BE, ME and WE on the adherences to saliva-coated hydroxyapatite bead(S-HA) were evaluated. At the concentration of 2,000 ㎍/㎖, the CE showed 32% rate of bacterial adherence to S-HA, whereas, other extracts of the same concentration producedgreater than 50% rate. The CE and BE were significantly decreased the reduction rates of water insoluble glucan formation from sucrose by crude glucosyltransferase of S.mutans. Thus, the application of C. sappan can be considered a useful and a practical method for the prevention of dental caries.

급성 구강감염부위에서 Staphylococcus lugunensis 의 특성

유용욱,이미성,차정단,김기경,신상희,문상은,김강주 원광대학교 생명공학연구소 1999 생명공학연구소보 Vol.6 No.1

Staphylococcus lugdunensis (S. lugdunensis) is a newly identified pathogenic species of coagulase negative staphylococci and an occasional but not rare cause of severe infections, such as infective endocarditis after dental extraction, bacteremia, osteomyelitis, peritonitis, and soft tissue infections. As antibiotic use increased, resistance rapidly developed. Some strains have plasmids related to antibiotic resistance. To characterize S. lugdunensis in acute oral infection, S. lugdunensis was isolated from the patients with acute oral abscess, osteomyelitis, and normal persons. Antibiotic resistance, in vitro cellular toxicity, in vivo virulence, δ-like hemolysin activity, and synergistic hemolysis on sheep blood agar plates were investigated. The dot blot analysis and Southern blot analysis of staphylococcal DNA was performed with δ-hemolysin gene probe of Staphylococcus aureus. (S. aureus) Staphylococcal DNA was cloned, nucleotide sequence was analysed, and homology was compared with other sequence in Gene Bank. S. aureus, S. lugdunensis, Staphylococcus cohnii (S. cohnii), and other coagulase negative staphylococci (CNS) were isolated from the patients with acute oral infection. The isolation ratio of S. lugdunensis in the patients with infection was higher than that of healthy persons, but the isolation ratio of S. aureus in the patients with infection was similar to that of healthy persons. S. lugdunensis from the patients with acute oral infection showed the resistance to penicillin, methicillin, cephalothin, and clindamycin. S. lugdunensis in the patients had cellular toxicity in vitro and virulence in vivo. All strains of S. lugdunensis had δ-like hemolysin activity against rabbit erythrocytes. Four of the six strains of S. lugdunensis gave synergistic hemolysis with S. aureus on sheep blood agar plates. In dot blot analysis, all strains of S. lugdunensis showed the positive reaction with the probe of δ-hemolysin gene in S. aureus, but a 7.3 kb HindⅢ fragment was observed in the DNA of S. lugdunensis that gave synergistic hemolysis in a Southern blot analysis. The molecular size of partially purified δ-hemolysin was about 50 kd. The cloned fragments from the chromosomal DNA of S. lugdunensis showed the partial homology with the insulin receptor-related and dopamine receptor of humans. These results suggest that S. lugdunensis might be an important pathogen in acute oral infection and show some homology with eukaryotes.

병원과 그 외부환경에서 분리된 포도상구균의 항균제 감수성과 카드뮴 저항성비교

김은숙,문상은,김강주,유용욱,정수진,김신무,문영희 원광대학교 생명공학연구소 1995 생명공학연구소보 Vol.3 No.1

It has been reported that Stratococcus aures(S. aureus) causes outbreaks of infection. To investigate the nosocomial infection, one hundred strains of S. aureus were isolated from the nasal cavity of the personnel and the environment in the dental clinic at Chonbuk province in Korea, the nasal cavity of personnel in healthy students, and the disease site from the patients at the Wonkwang medical center and Jesus presbyterian medical center. S. aureus was identified by Gram stain, catalase test, mannitol fermentation test and coagulase test. After isolation, the strains were characterized by antibiotic resistance. The antibiotic susceptibility tests were performed according to the National Committee of Clinical Laboratory Standards. Cadmium-resistance testing was assayed by broth dilution using Mueller-Hinton containing 125 μM of cadmium. Plasmid DNA was isolated by boiling method. All isolate of S. aureus in this study showed the resistance to ampicillin and penicillin, and the susceptibility to vancomycin. The resistance ratio of cadmium in the disease site was higher than that of the healthy site. These results suggest that S. aureus in the hospital might show the resistance to ampicillin and penicillin, and vancomycin be a drug of choice in the nosocomial infection.

활성탄의 급여가 젖소 송아지의 성장 및 배설물의 Ammonia 함량에 미치는 영향

유선일,박덕섭,명윤아,이인덕,남명수,김용국 충남대학교 농업과학연구소 2007 농업과학연구 Vol.34 No.2

This study was carried out to investigate the influences of feed containing activated charcoal on the performances of calves The daily weight gain, feed intake, feed requirement and the content of ammonia in the excreta were measured. The experiment was conducted with 10 male calves for 30 days. Each were equally divided with treatment group and control group and for the treatment group's animal fed diets containing 1.0% activated charcoal. The daily weight gain of calves were decreased by 1.92% when they were fed activated charcoal(1.02㎏/day) compared to that of control calves(1.04㎏/day) and the daily feed intake of treatment group(2.86㎏/day) was 10.06% lower comparing to the control group(3.18㎏/day). In case of feed requirement, the result showed 8.2% lower in the treatment group(2.80㎏) than control group(3.06㎏). The content of ammonia in excreta was significantly lower for treatment group(0.33ppm) than control group (2.67ppm)(p<0.05), which showed more improvement for reducing ammonia content in the treatment group with 87.6%(p<0.05). 본 연구는 사료에 활성탄을 첨가했을 때 송아지의 일당 증체량, 사료 섭취량, 사료 요구율 및 배설물의 ammonia 함량에 미치는 영향을 규명하기위해 실시하였다. 홀스타인 수송아지 10두를 30일 동안 대조구, 시험구(활성탄 1%첨가)로 각5두 공시하여 시험하였으며, 실험 결과를 요약하면 다음과 같다. 송아지의 일당 증체량은 대조구(1.04kg/일)에 비하여 활성탄을 급여했을 때(l.02kg/일) 1.92% 감소하였고, 일당 사료 섭취량은 시험구(2.86kg/일)가 대조구(3.18kg/일)에 비해서 10.06% 낮았으나, 사료 요구율은 대조구(3.06kg/kg증체)에 비해 시험구(2.80kg/kg증체)에서 8.2% 낮은 결과를 나타내었다. 송아지 배설물의 ammonia 함량은 대조구의 2.67ppm에 비하여 시험구가 0.33ppm으로 87.6% 감소되는 개선효과를 보였다(p<0.05).

토끼의 Aflatoxin B₁중독증에 대한 인삼엑기스의 효과 : 임상, 생리적 및 병리학적 변화 Clinical, Physiological and Pathological Changes

김차용,변유성,문평일,정덕화,김종수 慶尙大學校 1987 論文集 Vol.26 No.1

Chinchilla 계통 1~1.5㎏ 되는 토끼 30마리를 5군 으로 나누어 체중㎏당 제 1군은 대조군으로서 Cornoil 0.3ml 씩 제 2군은 aflatoxin B? 0.03mg과 인삼 엑기스 8mg을 제 5군은 aflatoxin B? 0.06mg과 인삼엑기스 8mg을 3주동안 카테타로 경구 투여하여 임상, 혈액학적 및 병리학적 변화를 관찰하였다. 1.사료소비량 감소, 침울, 쇠약, 혼수, 체중증가율감소등과 같은 임상증상은 대조군을 제외한 전 처리군에서 독을 투여후 3일째 부터 전처리기간을 통하여 나타났으나 aflatoxin B? 단독처리군에서 인삼엑기스 혼합처리군보다 더 현저하게 나타났다. 2. 혈청 효소와 AST, ALT는 독물투여후 7일부터 인삼엑기스 혼합투여군 보다 aflatoxin B? 단독 투여군에서 높게 증가하였다. 3.전처리군에서 적혈수용적, 헤모글로빈농도는 영향을 받지 않았고, 혈장단백질은ㅇ 독물투여후 14일이후 aflatoxin B?단독 처리군에서 현저하게 감소하였다. 4. Aflatoxin B?과 인삼엑기스 혼합 투여군 보다 aflatoxin B? 단독투여군에서 간장의 공포변성,담관증생, 핵농축, 붕괴, hepatic fibrosis와 임파절 및 비장에서 현저한 임파양 세포의 소실을 나타내었다. The present study has been carried out to investigate the effectsof ginseng extract on induced chronic aflatoxicosis in rabits. Groups of rabbits were treated orally with aflatoxin B? and mixture of ginseng extract for 21 days with a dosage of 0.03mg, 0.06mg of the toxin and 0.03mg or o.o6mg of the toxin mixture of 8mg of ginseng extract or 0.3ml corn oil s place to per kg body weight. The results obtained were is follows. 1. Sings o toxicosis included reduction of feed consumption emaciation, decrese of body weight and coma revealed in both groups treated with 0.03mg pr 0.06,mg of aflatoxin B?/Kg/B.W than groups 4.5 after days 3. 2. In groups 2, 3(aflatoxin B? 0.03, 0.06mg), Activity of asparate aminotransferase(AST) and alanine aminotransferase (ALT)were increased sigificantly in dats7, 14 and 21. 3. In all groups, Mean values for packed cell volume(PCV)and hemogobin were unremarkasble, but plasma total protein were decreased in groups 2,3than 4,5 groups on days 14 and 21. 4. The rabits treated with aflatoxin B?(2,3 groups)showed markedly degenerative chasnges ranging from swelling and decreaseed granularity to marked vacuolation, hepatic necrosis, fibrosis and bile duct, Proliferation and depletion of lymphocytes in lymphocytes in lymphonde, spleen than groups 4,5.

Berberine의 항생제 내성 확색포도구균에 대한 항미생물 효과

김강주,차정단,김해경,유현희,유용욱,이동근 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.2

Antibiotic-resistant Staphylococcus aureus (S. aureus) emerged in many parts of the world and increased complex clinical problems. Therefore, new agents are needed to treat the antibiotic-resistant S. aureus. Some natural products are candidates of new antibiotic substances. Previous reports showed that the extract of Coptidis Rhizoma and Phellodendri Cortex have antimicrobial effects. The main antibacterial substance of Coptidis Rhizoma and Phellodendri Cortex is berberine. In this study, we examined the antimicrobial activity of berberine to antibiotic-resistant S. aureus. We isolated the 13 strains of antibiotic-resistant S. aureus from the oral cavity of healthy children in a preschool, and investigated the antimicrobial activity of berberine. We examined the effects of berberine on the level of resistance to antibiotic-resistant S. aureus. We observed that the invasion of S. aureus into human gingival fibroblasts was blocked by berberine. Berberine inhibited the growth of antibiotic-resistant S. aureus as a dosw dependent maner. Minimum inhibitory concentration (MIC) of berberine against antibiotic-resistant S. aureus was 50∼100㎍/㎖. The inhibition of S. aureus invasion was depended on the concentration of berberine in human gingival fibroblasts. The MIC of ampicillin against antibiotic-resistant S. aureus was 32㎍/㎖. However, the MIC of ampicillin against antibiotic-resistant S. aureus in the presence of 50㎍/㎖ berberine was 1㎍/㎖. These data indicate that the combination with berberine and β-lactam antibiotics resulted in the synergistic reaction. These results suggest that the berberine may have the antimicrobial activities to antibiotic-resistnat S. aureus, and the mechanism may be the inhibition of growth and intracellular invasion, and alteration of antibiotic-resistance level of antibiotic-resistant S. aureus.

비호지킨 림프종의 임상적 고찰

김태원,조은택,조기섭,정재용,허재봉,장영,박유환,정춘해 조선대학교 1995 The Medical Journal of Chosun University Vol.20 No.1

A retrospective clinical and histologic study of 30 non-Hodgkin's lymphomas diagnosed at the Department of Hemato-oncology of the Chosun University from January 1989 to December 1993 is presented. Among total 30 cases whose sexes were mentioned, male were 18 and female were 12 and the ratio is 1.5:1. The peak incidence of non-Hodgkin's lymphoma was found in the third decade. The case distributions by Working formulation were summarized in table 3. The most common histopathologic type of non-Hodgkin's lymphoma was the diffuse large cell type of intermediate grade. The presenting symptoms at the time of first visit to the hospital were summarized in table 4. The most common symptoms were palpable mass. Lymph node enlargements were found in 87 %, and most frequently on cervical area(35%). The incidence of primary nodal lymphoma is more frequent than extranodal lymphoma, 1.2:1. The most common primary site of extranodal lymphoma is the gastrointestinal tract. In the laboratory findings, the data of hemoglobin and hematocrit were summarized in table 8, 9, Values of hemoglobin and hematocrit of female patients greater than those of male patients. The results of the immunophenotypings of nodal and extranodal lymphoma indicates that the B-cell lymphoma are predominant(B:T=1.4:1). The clinical stage was Ⅱ in 9 cases(30%) Ⅲ in 9 cases(30%), Ⅳ in 8 cases(26.7%), Ⅰin 4 cases(13.3%), 28 cases were treated with CHOP regimen. Among them, 17 cases(60.8%) achieved a complete remission. 5 cases had a partial response. The most frequent toxicities were toxic hepatitis.

참치 뼈를 이용한 Hydroxyapatite 세라믹 복합체의 합성 및 생체 친화성(제3보) : 인공체액에서의 Hydroxyapatite 세라믹 복합체간의 결합의 전자현미경 관찰 SEM Photographs of Bonding Properties between Hydroxyapatite Ceramics Composites in the Simulated Body Fluid

김세권,최진삼,이창국,변희국,전유진,이응호,박인용 대전산업대학교 반도체기술연구소 1999 半導體技術硏究所報 Vol.1 No.-

참치 뼈에서 추출한 hydroxyapatite를 출발물질로 여러 가지 세라믹 복합체를 제조하여 인공체액에서의 hydroxyapatite 복합체간의 화학결합을 조사하였다. hydroxyapatite 복합체들은 인공체액에서 4주 후부터 화학 결합성질을 나타내었다. 결합강도는 bioglass가 가장 강하게 나타났으며, 조성에 따른 의존성은 관찰할 수 없었다. 인공체액에서 복합체들은 이들의 경계면에서 불균일 핵생성 및 성장에 의해 화학적 결합으로 이루어졌다. Chemical bonding was investigated in the simulated body fluid of several selected hydroxyapatite-containing composites. The hydroxyapatite-containing composites chemically bonded with each other in the simulated body fluid after 4 weeks. Bioglass was strongly bonded in the simulated body fluid, but bonding strength was not depended on composition. Their composite bodies were chemically bonded by heterogeneous nucleation and growth at the interfaces of the specimens in the simulated body fluid.