타타늄의 열처리 조건에 따른 동전위 양극분극특성 및 표면 미세구조 변화

주동현,이용렬,정영화,양홍서,박상원,이도재,송호준,박영준 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.2

The corrosion resistance of metallic implants is essential for successful implant osseointegration. Moreover, the implant surface should have appropriate surface roughness for the attachment of the osteoblast and collagen fibrils. When titanium is exposed to air a thermodynamically very stable oxide film is formed at once. This oxide is very thin and yet it protects the metal from corrosion instantaneously. However, the oxide would not be ideal, and it would be supposed that the state of oxide film would be various by the different conditions when it is formed. The objective of this study was to evaluate the electrochemical properties and surface microstructural changes of titanium after passivation treatment or exposure to high heat (in vacuum or in air). ASTM grade 2 commercially pure titanium (Ti) disks of 10㎜ diameter were wet ground and polished with 240 and 600 grit SiC, and then ultrasonically cleaned with distilled water and ethanol. Cleansed as-received samples (As-R group) were passivated with 30% nitric acid solution at 50℃ for 15 minutes to make the Pas group. The Std-V samples were made by treating the Ti disks in vacuum quartz tube (10^-8 Torr) at 530℃ for 40 min for stress relieving, followed by annealing at 700℃ for 90 min, and then slow cooling to room temperature. The Std-A samples undergo identical procedure as the Std-V group except that it is done in air. For 530℃-V samples, Ti disks were heated at 530℃ for 40 minutes and slow cooled to room temperature. The 1000℃-V samples were produced by heating Std-V specimens again at 1000℃ for 2 hr, followed by cooling to room temperature. 530℃-A and 1000℃-A samples were also prepared. Potentiodynamic anodic polarization measurement, SEM, AFM and XRD analysis were performed to evaluate the effects of the various treatments. The difference in the mean values of E_corr between groups showed statistically significant difference (P<0.05), but that of I_corr did not show significance (P>0.05). When Ti surface was passivated there was a shift of corrosion potential (E_corr) in the noble direction and a lower corrosion current density (I_corr) value. Std-A samples showed most noble E_corr value among the tested groups. 530℃-V samples showed more noble E-corr than other tested groups except Std-A group. 1000℃-V samples showed more noble E-corr than those of Std-V sample. In the case of Std-, 530℃- and 1000℃-groups, -A sub-groups showed better corrosion resistant characteristics than -V sub-groups in regard to E-corr and I_corr values. In the SEM observations, the surfaces of the As-R samples showed only scratch line on smooth surface. In Pas samples, thick oxide layer covered the surface under high magnification observation. 530℃-A samples were covered by oxide granules, and Std-A samples had 25~50 nm-thick acicular oxides. The 1000℃-A samples were covered by coarse oxide crystals with a granule diameter of 0.1~0.6 μm having a gross appearance of milky white color, which was identified by XRD as a rutile. On the other hand, 1000℃-V samples showed an Widmansta¨tten structrue of which the orientation of the lattice is formed along crystallographic planes of the parent crystals. On the AFM observation, 530℃-A samples showed RMS roughness of 79.38 nm which is 5 times rougher than those of the As-R samples. Std-A sample had a roughness of 330.47 nm which is about 20-times rougher than that of the As-R sample. 1000℃-A samples were covered by coarse granular oxides and the roughness were about 0.56 μm. Vacuum sub-group samples showed a more smooth surface than air sub-group samples, and the oxide film was more dense. Due to variability of the surface treatment and heat treatment conditions, the process of the oxide formation seems to be affected thereby making the corrosion properties and surface micro-morphology different. However, more various electrochemical analysis together with surface analysis, and an investigation for the effects of those on the osteoblast cell adhesion and calcium phosphate apposition are needed for the improvement of the osseointegration rates of the titanium implants.

김치 용매획분이 고 콜레스테롤 식이를 섭취한 토끼의 심장, 신장 및 폐의 항산화 효소계 활성에 미치는 영향

전혜년,김현주,송영옥 부산대학교 김치연구소 2003 김치의 과학과 기술 Vol.9 No.-

김치의 용매획분중 in vitro에서 LDL 산화억제 활성이 강했고 in vivo에서 지질저하 효과가 있었던 디클로로메탄 획분, 에틸아세테이트 획분, 수용성 획분이 고콜레스테롤 식이를 섭취한 토끼의 심장, 신장, 그리고 폐에서 항산화 효소의 활성에 미치는 영향을 살펴보았다. 과산화물 함량은 심장이 가장 높고 신장이 가장 낮았으나, catalase와 GSH-pxghkf성은 심장이 낮았고, 신장은 높은 활성을 나타냈다. Catalase, GSH-px 및 SOD의 활성은 모든 장기에서 1% 콜레스테롤 식이를 섭취한 대조군에 비해 김치 용매획분군에서 낮았고 특히 디클로로메탄 획분군의 항산화효소 활성은 유의적으로 낮았다(p<0.05). 이러한 결과는 김치 용매획분은 심장, 신장 그리고 폐에 지방축적을 억제하는 효과가 있었고, 그로 인해 지질 유리기의 생성이 적어, 각 장기에서 유리기를 제거하는 항산화 효소의 활성이 낮은 것으로 생각된다. The effects of dichloromethane (CH_(2)Cl_(2)), ethylacetate (EtOAc) or water (H_(2)O) fraction of Korean cabbage kimchi on anti-oxidative enzyme activities of the heart, kidney and lung of rabbit fed 1% cholesterol diet for 16 weeks were studied. The amount of kimchi fraction added to the 100g of diet was 8.3mg of CH_(2)Cl_(2), 5.6mg of EtOAc, and 221.9mg of H_(2)O, which are equivalent to 5% of freeze-dried kimchi in the diet. Each group had 6 rabbits and rabbit was housed individually. Lipid peroxide values for the heart was the highest followed by lung and kindey. But the activities of catalase and GSH-px were the lowest in the heart and the highest in the kidney. Activities of anti-oxidative enzymes (catalase. GSH-px, Mn-SOD, Cu, Zn-SOD) of rabbits fed kimchi solvent fractions added diets were lower than those of the control which fed 1% cholesterol diet. Among kimchi groups, CH_(2)Cl_(2) group showed the lowest(p<0.05) enzymes activities. Lipid accumulation in these organs fed diets with kimchi solvent fractions, especially with CH_(2)Cl_(2) fraction, were lower than that of the control. Therefore, production of the lipid free radicals might be suppressed and the activities of anti-oxidative enzymes responsible for removing the free radicals seemed to be lowered in kimch frachoin-fed rabbits.

플라이애쉬 콘크리트의 特性에 미치는 굵은 骨材 最大値數의 影響에 관한 實驗的 硏究

김덕현,유영주,이상수,송하영,김을용 한밭대학교 2004 한밭대학교 논문집 Vol.21 No.-

In this study, the experiment was carried out to investigate and analyze the influence of coarse aggregate's maximum size and Fly Ash replacements ratio on the properties of concrete. The main experimental variables were water/cement ratio 45 and 65(%), maximum size of coarse aggregate 15, 25 and 40(mm), Fly Ash replacements ratio 0, 10, 20(%). According to the test results, the principal conclusions are summarized as follows. 1) The slump and flow of fresh concrete were found to be higher in the order of maximum size of coarse aggregate 15, 25 and 40(mm), also in the order of Fly Ash replacements ratio 0, 10, 20(%). 2) The compressive strength of hardened concrete were found to be lower in the order of maximum size of coarse aggregate 15, 25 and 40(mm). While, Fly Ash replacements ratio increases in age 7days, showed tendency that compressive strength increases together. but, age 28, 56(day) were showed opposite tendency.

Microcapsule을 이용한 생물학적 처리방법에 의한 오·폐수 중의 탈질소화에 관한 연구

이상호,최재선,송주영 國立 昌原大學校 産業技術硏究所 1996 産技硏論文集 Vol.10 No.-

Various experiments were conducted to test denitrification ability of immobilized Paracoccus denitrificans on calcium alginate microcapsules from synthetic waste water. Paracoccus denitrificans one of a typical denitrifying strain, showed good denitrification ability on both as a immobilized strain and as a strain itself. Calcium alginate microcapsule wall did'nt play a role to interrupt the diffusion rate of substrate in and product out. This system showed a possibility for the development of denitrifying apparatus if the immobilization technique could be improved.

Enzyme Immobilized Reactor Design for Ammonia Removal from Waste Water

Song, Ju-Yeong,Chung, Soo-Bae The Korean Society for Biotechnology and Bioengine 1997 Biotechnology and Bioprocess Engineering Vol.2 No.2

Removal of nitrogen compound from waste water is essential and often accomplished by biological process. To prevent washout and to develop an efficient bioreactor, immobilization of sutibal microorganisms could be sensible approach. Strains and permeabilized cell encapsulated in cellulose nitrate microcapsules and immobilized on polystyrene films were prepared by the method described in the previous study. In the wastewater treatment system, nitrification of ammonia component is generally known as rate controlling step. To enhance the rate of nitrification, firstly nitrifying strains Nitrosomonas europaea(IFO14298), are permeabilized chemically, and immobilized on polystyrene films and secondly oxidation rates of strain system and permeabilized strain system are compared in the same condition. with 30 minute permeabilized cells, it took about 25 hours to oxidize 70% of ammonia in the solution, while it took about 40 hours to treat same amount of ammonia with untreated cells. All the immobilization procedures did not harm to the enzyme activity and no mass transfer resistance through the capsule well was shown. In the durability test of immobilized system, the system showed considerable activity for the repeated operation for 90 days. With these results, the system developed in this study showed the possibility to be used in the actual waste water treatment system.

CHEMISTRY : Protective effect of arabinose and sugar beet pulp against high glucose-induced oxidative stress in LLC-PK1 cells

( Yeong Bok Song ),( Boh Kyung Kim ),( Mi Jin Choi ),( Yeong Ok Song ),( Eun Ju Cho ) 부산대학교 김치연구소 2012 김치의 과학과 기술 Vol.15 No.-

The protective effects of L-arabinose and sugar beet (SBP) on high glucose-induced oxidative stress were investigated using LLC-PK cells. Under the high glucose-induced cellular oxdative model, the treatment of 45 mM of glucose led to the decrease in cell viability and increase in lipod peroxidation_However. L-arabinose and SBP significantly inhibited the high glucose-induced cytotoxicity and lipid per-oxidation. In addition, the formation of nitric oxide(NO) was increased by the treatment of 45mM glu-cose. while the treatment of L-arabinose or SBP inhibited signigicantly the NO formation compared with high glucose-treated control. The superoxide anion production of groups treated whth L-arabinose or SBP was significantly lower than that of the control treated with high glucose. Futhermore. L-arabinose and SBP elevated the glucose uptake. resulting in lower glucose concentration compared with non-treated control. High glucose levels induced the overexpressions of bax. inducible NO synthase and cyclooxygen-ase-2. but L-arabinose or SBP treatrnent down-regulated the expressions of these genes. Arabinose and SBP also inhibited the expression of nuclear factor-kappa B induced by 45mM glucose in LLC-PK cells. In particular, arabinose exhibited stronger inhibitory activities on high glucose-induced oxdative stress than SBP did. These findings indicate that L-arabinose and SBP are promising antioxidative agents with protective activities against hyperglycemia.

구강질환과 감염성 심내막염

조주영 ( Ju Yeong Jo ),조수진 ( Su Jin Ju ),송희상 ( Hii Sang Song ) 조선대학교 치의학연구원 2014 Oral Biology Research (Oral Biol Res) Vol.38 No.2

Despite significant improvements in medical treatments, infective endocarditis remains a very serious health problem with considerable morbidity and mortality. Indeed, the frequency of severe endocarditis has increased in recent years, particularly in association with antibiotic-resistant pathogens. Accordingly, infective endocarditis constitutes a major challenge for clinicians and a considerable burden for the health-care system. In addition, dental disease has long been associated with increased prevalence of infective endocarditis. Many reports have demonstrated that antibiotics given before a dental procedure can reduce the risk of bacteremia from oral disease. Here, we review recent treatments for prophylaxis of infective endocarditis before dental procedure.

고도 이형성의 관상선종을 동반한 Gastritis Cystica Profunda

송영림 ( Song Yeong Lim ),박준용 ( Park Jun Yong ),김용범 ( Kim Yong Beom ),강기주 ( Kang Gi Ju ),김희선 ( Kim Hui Seon ),최대로 ( Choe Dae Lo ),윤호성 ( Yun Ho Seong ),이자영 ( Lee Ja Yeong ),김경호 ( Kim Gyeong Ho ),이진헌 ( Lee 대한소화기학회 2004 대한소화기학회지 Vol.43 No.1

Gastritis cystica profunda is usually characterized by hyperplastic and cystic dilatation of pseudopyloric gland with submucosal invasion. These lesions possess malignant histologic features as metaplastic and even dysplastic alteration can be observed, however they usually exhibit benign behavior. Macroscopically, gastritis cystica profunda may present as a submucosal tumor or as a polyp. In rare case, however, it can be found as a giant mucosal fold. The proposed pathogenesis of lesion relates to ischemia, chronic inflammation, and the presence of foreign body. Herein, we report a case of gastritis cystica profunda associated with high grade tubular adenoma in a patient without antecedent surgery. (Korean J Gastroenterol 2004;43:52-55)

김현승 시의 의식변화 연구

송주영 ( Song Ju-yeong ) 청람어문교육학회(구 청람어문학회) 2017 청람어문교육 Vol.0 No.61

이 글에서는 김현승이 유한적 존재로서의 자아를 탐구하고 그것을 극복하기 위해 무한한 내면의 순결성을 지향하며 유한적 존재의식과 무한한 정신세계를 양심적 삶으로 극복한 모습을 살펴보았다. 또한 영원한 자연의 순환적 논리에서 유한한 인간적 삶의 지향점을 모색하며 자아와 세계의 합일을 추구한 시인의 변증법적인 시적 변모를 밝히고자 하였다. 김현승 시세계의 기본적 흐름은 끊임없는 자기 탐구였다. 경건한 자아를 추구했던 시인으로 그의 시세계는 일관되게 자아를 탐구하는 것에서 출발하였다. 또 인간이 유한적 존재라는 사실을 자각하며 그 한계를 극복할 수 있는 무한한 내밀의 세계를 지향하였다. 내면이 들려주는 양심의 부름에 귀를 기울이며 유한한 시간을 극복하려고 노력하였다. 개인의 삶에서 더 나아가 시를 통해 사회 변화를 꿈꾸었으며 자신의 시가 작은 촛불처럼 미약하지만 세상을 따스하게 비출 수 있기를 바랐다. 시간이 흐를수록 자연에 대한 시각도 깊이 심화되었다. 초기에 하루의 시작을 이야기하던 시가 사계절의 변화를 바라보는 시각으로 변화하였다. 어둠을 밝히며 새벽을 노래하던 시인은 봄의 씨앗을 품고 있는 어머니와 같은 겨울의 대지를 예찬하였다. 봄의 완성보다 가을의 사색과 겨울의 시작을 노래하며 자연에 대한 심화된 인식을 통해 미래의 가능성을 꿈꾸는 시인의 면모를 보여주었다. This study set out to examine the ways that Kim Hyeon-seung overcame his finite consciousness of existence and infinite world of mind through a conscientious life by exploring his ego as a finite being and being oriented toward the purity of infinite inside to conquer it. It also aimed to shed light on the dialectical aspects of his poetry as he sought after the combination of his ego and the world by searching for the orientation of finite human life in the circular logic of eternal nature. The basic flow of his poetic world was a constant self-inquiry. His poetic world began with his consistent inquiry into his ego as a poet that pursued a reverent ego. He recognized the fact that human beings were finite and was oriented toward an infinite secret world to overcame the limitation. He tried to overcome finite time by listening to the calls of conscience from his inside. He dreamed of social changes through his poems beyond his personal life and hoped that his poems would shine warm light on the world even though their light might be weak like little candlelight. His viewpoint of nature deepened over time. He talked about the beginning of a day in his early poems and watched the seasonal changes in his later works. Singing about the dawn to light up darkness, the poet began to praise the earth of winter like a mother holding the seeds of spring inside. He was a poet that dreamed of possibilities of the future through his deepening perception of nature, singing about the thought of autumn and the beginning of winter rather than the completion of spring.

고정희 『눈물꽃』에 나타난 탈식민성 연구

송주영 ( Ju Yeong Song ) 현대문학이론학회 2016 現代文學理論硏究 Vol.0 No.65

이 논문은 고정희 다섯 번째 시집 『눈물꽃』에 있는 연작시를 중심으로 시에 나타난 탈식민성을 연구한 것이다. 현 시대에서 영토를 차지하는 제국주의의 모습은 사라졌지만 지배와 피지배의 논리는 여전히 존재한다. 우리 역사에서 무력을 바탕으로 권력을 장악했던 군부독재 정권 시절은 피지배층에 대한 착취와 억압이 합리화되는 사회였다. 그 어느 때보다도 가부장적 권위와 제국주의적 폭력이 만연하였다. 그러한 시 대상황을 비판적 시각에서 재현한 고정희 시를 탈식민주의적 관점에서 살펴보았다. 사이드(Edward W. Said)에 의하면 동양 식민지인의 모습은 서양 유럽인의 시각에 의해 형성되고 결정되었다. 주체가 지닌 우월감의 반대 현상으로 식민지인에게는 열등 감만이 주어진다는 것이다. 고정희는 지배층의 모략과 야욕을 재현하여 독자에게 상황 판단의 기회를 제공하였다. 지배세력이 피지배층을 기만하는 모습을 객관적으로 보여 줌으로써 우리가 주체에 의해 결정된 시선에 갇혀있는 것은 아닌지 성찰하도록 하였다. 곧 보이지 않는 문화적·정치적 억압의 모습을 뒤집어 재현하여 그 상황을 전유하도록 만드는 것이다. 그는 피지배층이 타자화된 정체성에서 벗어나 주체적 존재로서 일어서기를 바란다. 그래서 주검만 가득한 세상에서 새로운 생명탄생을 희망하며 서로 의 닫힌 마음을 열고 하나가 되기를 소망하였다. 고정희는 『눈물꽃』을 통해 타인의 시선에 갇혀 사는 마네킹 같은 존재들을 깨워 슬픔의 시대를 극복하고자 하였다. 또한 개벽천지를 위해 작두를 타는 헌신의 몸짓으로 우리의 진정한 모습을 성찰하고 현실을 냉철하게 직시하여 주체적 존재로 거듭날 것을 당부하였다. This thesis is a sthdy on postcoloniality shown on Go Jung-hee``s poem focusing on the serial poetry in her fifth poetical works Flower of Tears. In the present age, imperialism that fought over territory has vanished, but the logic of dominance and sub-ordinance still exists. South korea``s in the 1980s, when dictatorship dominated the society based on military force, exploitation and suppression toward the subjugated classes was justified. Patriarchal authority and violence of imperialism were more rampant than at any other time in Korean history. Go Jung-hee reproduced the situation of the era in a critical point of view. Therefore I looked at her poem in a perspective of post colonialism. According to Edward W. Said, the image of Oriental colonial people is formed and determined by the point of view of Western Europeans; on the contrary of the superiority of the subject, to the colonial people, only the sense of inferiority is given. Go Jung-hee provides readers the opportunity of estimating the situation by reproducing the scheme and ambition of the establishment. Objectively showing the establishment deceiving the subjugated class, she made us reflect on whether we are confined by the subject. In other words, by flipping the situation to reenact the cultural·political suppression, it makes us monopolize the situation. She wants the subjugated people to be freed from their selves as an object and stand up as independent selves. Therefore, in a world full only of dead bodies, she wished a new life to be born and desired everybody to open up their hearts and become one. Through Flower of Tears, Go Jung-hee woke up the people who lived their lives restricted by others`` eyes and tried to overcome the era of sorrow. She also asked us to self-examine ourselves and rationally face the reality with the devoted act of dancing on the blade of the straw cutter for the convulsion of nature