Effect of Ti Addition on the Microstructure and High-Temperature Oxidation Property of AlCoCrFeNi High-Entropy Alloy

Gi‑Su Ham,Young‑Kyun Kim,Young Sang Na,Kee‑Ahn Lee 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.1

This study investigated the effect of Ti addition on microstructure and high-temperature oxidation property of AlCoCrFeNihigh-entropy alloy. Ti content was controlled at 0 at% and 1 at%. The two alloys were found to have BCC single phase, andthe average grain sizes of Ti0.0 and Ti1.0 were 47.3 μm and 49.7 μm, respectively, showing similarity. The EDS mappingof the inside of grains found that both alloys were characterized to be divided into Al-Ni element rich region and Cr–Feelement rich region. As a result of high-temperature oxidation test at 1100 °C, oxidation weight gains were measured atTi0.0: 0.75 mg/cm2 and Ti1.0: 0.17 mg/cm2, respectively. The results indicate that Ti addition largely improved high temperatureoxidation resistance of AlCoCrFeNi HEA. Ti1.0 alloy, in particular, showed remarkably more excellent 1100 °Chigh-temperature oxidation resistance than other previously reported major ones such as NiCrAl and FeCrAl. In the surfaceand cross-section observations after oxidation tests, both alloys were found to have Al2O3oxides mostly. While the Ti0.0material was observed to have Al2O3spallation macroscopically, the Ti1.0 alloy showed Al2O3spallation only in some localareas. In addition, a unique result was found in AlCoCrFeNiTix(x=0,1) alloy that BCC → FCC phase transformation was accelerated,and FCC phase layer was formed in the surficial area where Al element had been depleted due to high-temperatureoxidation. Moreover, as Ti was added, the thickness of FCC layer induced by high-temperature oxidation decreased. Basedon the results, it was also discussed on how to improve the high-temperature oxidation resistance of AlCoCrFeNiTixHEA.

소포체 스트레스에 의한 대식세포의 세포사멸 : caspase 11의 잠재적 역할 a potential implication of caspase 11

정상원,김용찬,이혜영,백상기,김영상,강광일 충남대학교 생물공학연구소 2004 생물공학연구지 Vol.10 No.1

Apoptosis is caused by a set of previously latent proteases, the caspases, which cleave several hundred cellular substrates. It has been established that there are two basic signaling pathways to caspases activation. One is initiated by engagement of cell surface death receptors (extrinsic pathway). The other is provoked by perturbation of the mitochondrial membrane promoted by physical or chemical stress agents (intrinsic pathway). Recent studies point to the endoplasmic reticulum (ER) as a third subcellular compartment implicated in apoptotic cell death. The ER regulates protein synthesis, protein folding and trafficking, cellular responses to stress and intracellular calcium (Ca^(++)) levels. Alterations in Ca^(++) homeostasis and accumulation of misfolded proteins in the ER cause ER stress that ultimately leads to apoptotic cell death. Prolonged ER stress is linked to the pathogenesis of several different neurodegenerative disorders. However, ER stress-mediated cell death pathway in macrophage has not been studied well. Here, we demonstrate evidence for the thapsigargin-induced cell death and the potential contribution of caspase-11 which could be induced by ER stress in macrophage.

제주 성상 S/S MTr #1 행원 풍력단지 전압해석

김상준(Sang-Jun Kim),조민호(Min-Ho Cho),윤기갑(Gi-Gab Yoon),장상옥(Sang-Ok Jang),안정식(Jeong-Shik Ahn) 대한전기학회 2003 대한전기학회 학술대회 논문집 Vol.2003 No.11

골다공증의 위험인자 : 아산시 지역 주민을 대상으로

김용배,장원기,황보영,김화성,안규동,이병국,이용진,이남수,이상건,이상범,이상우,이선정,이성수 순천향대학교 2006 Journal of Soonchunhyang Medical Science Vol.12 No.1

Objective : As the average lifespan of human increases, osteoporosis and osteoporosis-related fractures have become major health care problems. Despite recent advances in medical treatment, few studies have assessed the recognition of osteoporosis in general adults. This study examined the recognition of osteoporosis and analyzed the relating factors. Method : A population-based sample of 1086 adults in Asan-city, Korea was investigated with questionnaires and height, weight, Information regarding the general characteristics(gender, age, economic state), lifestylef exercise, smoking, alcohol),medical history(progestin, GH, steroid, calcitonin, PTH), demographic parameter, obesity, stress, and family history was collected through an interview using a structural questionnaire. The level of obesity was measured by the body mass index(BMI). BMD(Bone mineral density) at the lumbar spine and femoral neck was measured by dual energy X-ray absorptiometry. Osteoporosis was considered to be T-score below -2.5. Results : The prevalence of osteoporosis increased progressively with age, decreased with BMI and predominant in women by the result of x^(2) -test, T-test. Age, weight, BMI were significantly correlated with osteoporosis by the result of Pearson correlation ana1ysis(P<0.05). And age, gender, BMI, family history of osteoporosis were proved to be significant risk factors of osteoporosis by the result of multiple logistic regression(P<0.05). Conclusion : These results suggest that age, gender, BMI might be the most important risk factors of osteoporosis. And the history taking about family history of osteoporosis is helpful for diagnosing osteoporosis.

녹동균 세포외막 단백질 백신 CFC-1-101의 안정성 및 면역원성 검토 : 임상 제 Ⅰ/Ⅱa상 시험

장인진,김익상,유경상,임동석,김형기,신상구,장우현,박완제,이나경,정상보,안동호,조양제,안보영,이윤하,김영지,남성우,김현수 대한감염학회 1998 감염 Vol.30 No.3

목적 : 제일제당에서는 녹농균의 세포외막 단밸질을 유효성분으로 하는 백신인 CFC-101을 개발하였으며, 동물시험에서 이 백신의 안전성과 유효성을 입증하였다. 본 연구에서는 이 녹농균 백신의 인체에 대한 안전성과 면역원성을 평가하는 동시에 인체 접종시의 최적 투여 용량을 결정하기 위하여 제 I/Ⅱa상 임상시험을 수행하였다. 방법 : 건강한 성인 남자를 피험자로 선별하여 각 용량군에 백신투여자 6명, 위약투여자 2명을 배정하였다. 백신 투여군은 0.25mg, 0.5mg 또는 1.0mg 용량의 녹농균 백신을 7일 간격으로 3회에 걸쳐 근육주사 하였으며, 위약 투여군에게는 세포외막 단백질을 제외한 동일한 성분을 투여하였다. 백신접종 후 국소적 또는 전신적인 반응의 발생여부를 관찰하고, 혈액시료를 체취하여 백신의 역가와 유효성을 검정하였다. 결과 : 녹농균 백신 CFC-101은 모든 접종자에서 양호한 내약성을 보였다. 또한 0.5mg 과 1.0mg 백신 투여군에서는 100%의 항체양전율을 나타내었다. 생성된 항체는 녹농균 세포외막단백질에 특이성을 보였고, 녹농균 감염에 대해 방어효능이 있었다. 결론 : 이와같은 결과로부터 이 녹농균 백신은 인체에 안전하게 투여할 수 있으며, 높은 항체 생성능으로 감염방어 효능을 보이고 0.5mg과 1.0mg이 최적용량인 것으로 판단되었다. Background : We developed a Pseudomonas aeruginosa outer membrane protein(OMP) vaccine CFC-101, and the prophylactic efficacy of which has been demonstrated in animal models. In order to evaluate the safety and immunogenicity of the P. aeruginosa vaccine, we carried out a phase I/Ⅱa clinical trial in healthy male volunteers. Methods : Groups of eight volunteers, including two placebo subjects, were vaccinated intramuscularly with three doses of 0.25, 0.5 or 1.0 mg of the vaccine at one week intervals. Sings of systemic and local reactions observed after vaccination were recorded for each vaccinee for 5 days. Physical examinations were performed on days 0, 1, 7, 8, 14, 15, 21, and 42, and clinical laboratory tests were done on days 0, 3, and 21. Blood samples for assay of serum antibody levels were obtained up to 42 days after the first vaccination. Results : The vaccine was generally well tolerated by all vaccinees, showing no significant side effects. In the three dosage groups, all vaccinees, except one receiving the 0.25 mg dose, showed significant elevation in serum IgG antibody titers against the vaccine proteins, indicating 100% seroconversion in 0.5 and 1.0 mg groups. The human antibodies induced by the vaccine were specific for P. aeruginosa OMPs, as confirmed by western blot analysis and immunoprecipitation assays. The capacity of the human antisera to enhance opsonophagocytic killing activity by polymorphonuclear leukocytes and to confer protection against P. aeruginosa infections indicates that the antibodies elicited by the vaccine have protective efficacy. Conclusion : We conclude that the P. aeruginosa OMP vaccine is safe and effective for human use and its optimal dose to be 0.5 or 1.0 mg.

보조자극분자를 이용한 암치료

장미라,윤희령,성인옥,정상원,김용찬,손정희,이혜영,강광일,백상기,김영상 충남대학교 생물공학연구소 2002 생물공학연구지 Vol.8 No.1

Tumor cells express tumor-associated antigen which can be target to the cytotoxic Tlymphocytes. CTL precursor activation requires antigen recognition and cytokine help from Th cells. In this pathway, the cross-presentation mechanism, professional antigen presenting cells first pick up tumor antigen and present the antigen to Th cells. Another pathway is to activate CTL precursor by the direct priming. The tumor cells, however, lack costimulatory signal, which is required for full activation. The lymphocytes recognized specific antigen without costimulatory signal resulted in anergy. Tumor cells engineered to express the costimulatory molecules are better immunogen and induce antitumor immunity. We will discuss the recent progress in tumor therapy using the costimulatory molecules on the basis of the direct priming mechanism.

本草綱目 수재藥材의 식물분류학적 고찰 : Entries in the Part of Fruit 果部編

성정숙,문성기 慶星大學校 1999 論文集 Vol.20 No.2

The plant entries in the part of fruits in Ben Cao Gang Mu <Bon-cho-kang-mok(本草綱目)> was classified according to the protocols of Engler. Total numbers of plant written in chinese names were 126. Among them only 104 entries were able to be identified by elucidation of several references. They were classified as 2 divisions, 5 classes, 26 orders, 38 families, 66 genera, 92 species with 6 varieties. Other 22 entries were unable to be classified because of their ambiguities in name.

韓國詩의 純粹性과 參與性에 關한 硏究 : 韓國 現代詩를 中心으로

成耆兆 단국대학교 대학원 1980 學術論叢 Vol.4 No.-

The contemporary poetry is an another world created through the poets. For an organized reality of life or nature potencially exists as a material of poem, out it is not a poem itself. The contemporary poetry which is a different world created through the poets, a cryst allization which is accomplished through their own experiments, must be dealt with a very pure crystallization composured through media, letters, and such a poem must be written in prder to contribute human beings and to lead us into the truth. Poetry is accomplished by a poet's wise views and developed sensibility, based on our atmost aims; the ideal and mental values of human beings. So far as a poetry is intended to the explanation of whole life, even it is created by a poet's sensibility, both of scientific and moral method muet not be ignored at all for the poetry world. Here, the sensual function, a manifestation of ethics and consciousness is availably included the in intelligence and rationality of the poets. So a true poem mustbe based on a real poetical thought which is flourished from the poet's phlosophy, intelligence and emotion, and a poem is able to called as a poet's recomposured thought. It is ture that a poem has to beincluded the poetical truth becasseit exists for the human beings bymaking the original meaning of lfe renew and reforming the individuals through its rhythmical poetiic dictions. The poetical truth, an art's value must be come throughim pressions, and only an arrangement of letters, at the same time, is nothing but a vacant monologue. The traditional essence of poetry-accepted, expressed and stimulated by sensibility-is composured various elements including the intelligence and rationality. Among the various elements, only two of them (one is the pure function of he contmeporary poetry, and the other is the social function of the contemporary poet) are dealt with inthis thesis: in the one, the rhythmical instructional and pictorial elements of poetry are studied, and in the other, every potencial questions of pure and participating poetry are studied with many examples of the Korean contemporary poetry; by explaining the poetical and refusal elements on the participation because the social function is required the poetical participation to society. We can easily appreciate that the poems composured by the poets, who adhete to only the purity of Korean poetry ad turn away their attentions to the reality used to be intended to the very idolenee and at last lost theiraffections from the leader becauseit is ignored the the poets' philosophy, and that the poets who try to proted participating poetry mostly fall into a vacant realm of thought by emphasizing the non-elemental essences which are apart from the original literary essences. In the contemporary poetry of Korea, it is true that there is a profound wall and sturggle between the purity and participation of poetry. It is ture that a well composured lyric poem alone has its own poetic value, and a participating poetry is also valuable with itself. The more variety in literature, the better. And a poem becomes great only when it is appeared with various meaning. Here we are really acquired poets and poems in which the purity with the aesthetic values and theprofound philo ophical though of impressions would be accomplished in the field of Korean contemporary poetry.

대나무 섬유소를 이용한 섬유보강 콘크리트의 역학적 특성

류현기,권용주,신상용 忠州大學校 2009 한국교통대학교 논문집 Vol.44 No.-

This study is a experiment on the mechanical properties of concrete according to the fiber additional quantity of bamboo. The experiment and analysis results are as the following. The slump as a quality of the concrete not to harden showed to decrease more remarkably for a slump value than the plain according to the increment of cellulose additional rate. Air quantity showed to increase only in 0.2% fiber additional rate and to get out of KS allowable error of bad air content in 0.4% and 0.6%, and capacity mass by unit showed a reverse tendency against air quantity according to the change of cellulose additional quantity. Compression intensity as a quality of hardening concrete showed collectively a tendency to decrease in the remnant past days except only 0.6% at the standard past day 愀8 and the initial 3 days. Pulling intensity showed to increase more than the plain in all past days according to the change of fiber additional quantity of bamboo, and bending intensity also showed to be higher revelation intensity than the plain in the measurement result at the standard past day 28. In the result of length change rate, we can find the bigger the cellulose additional rate as a special quality increased, the more it decreased according to the pass of the past day.

憲法委員會

成基宅 중앙대학교 법학대학 1974 法政論叢 Vol.18 No.-