Coating with boron nitride on SiC fiber using atomic substitution

Woo‑Seong Tak,Jin‑Uk Hwang,Young‑Keun Jeong,Woo‑Sik Kim 한국세라믹학회 2020 한국세라믹학회지 Vol.57 No.2

To increase the mechanical properties of ceramic matrix composite, it is important that formation of lubricant layer for crack deflection between matrix and fiber. Therefore, we fabricated uniform boron nitride (BN) lubricant layer using atomic substitution method. Silicon carbide (SiC) fiber surface was modified with amine groups using (3-amonipropyl)triethoxysilane to coat SiC fiber with BN as a solid lubricant. Then, surface was coated with graphene oxide (GO). Boric acid powder was supplied to the GO-coated fibers and the samples were heat-treated at 1200–1400 ℃ under N2 and NH3 atmospheres. An uniform BN layer could be coated on SiC fiber with 10 nm-1.11 μm. Crystallinity and thickness of BN layer could be controlled by reaction temperature. It was also confirmed that crystalline BN formed under process conditions of higher than 1400 ℃.

중ㆍ고년여성의 하지 근 기능과 요부 및 대퇴근 횡단면적의 상관관계

김창근,이수경,권영우,박정배 한국체육대학교 체육과학연구소 2001 국제학술대회논문집 Vol.20 No.1

The purpose of the present study was to investigate the relationship between isokinetic muscle function and muscle cross-sectional area (CSA). Twelve women participated in the present study, divided young (n=6, 23.7±1.9 year) and elderly women (n=6, 60.3±6.8 year). Isokinetic strength (power, strength, endurance) and CSA (psoas major and thigh muscles) measured with dynamometer and computerized tomograph, respectively. Cross-sectional area of psoas major muscle in elderly group revealed markedly smaller than in young group, but thigh muscle was not the case. Muscle CSA in young women correlated between power and endurance and psoas major muscle, as well as between muscle strength and CSA of thigh muscle. But no correlation occurred between strength and cross sectional area, except endurance which was highly correlated between CSA and endurance. In conclusion, aging decreases muscle function and CSA. Partially muscle strength correlated with muscle CSA in young women, but no correlation occurred in elderly women. Further study needed to elucidate the exact mechanism related to aging muscle with muscle density and neuromuscular function.

지문과 정신분열증

우숙희,정국동,최송표,조근자,양은진,김수일,박경란,이영호,김원식 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Fingerprint patterns of 333 schizophreniacs who met with the diagnostic criterias of International Pilot Study of Schizophrenia except items associated with chronicity in exclusion criteria were studied, and the following results were obtained. 1. The frequency distribution of the fingerprint patterns in the 333 schizophreniacs was ulnar loop, whorl, twinned loop, arch, radial loop in order in both control and schizophrenia groups. 2. Finger ridge counts of both sexes were decreased significantly in schizophrenia group. 3. Dissociation of fingerprint pattern in the schizophrenia group was 51.1%, which was far greater than 6.25% of control group. Number of dissociation was greatest in the thumb, followed by index, middle, ring, and little finger in order. According to the above results, it is considered that both the number of finger ridges and degree of dissociation of fingerprint patterns were closely related with schizophrenia. Analysis of fingerprints and palmprints with the aid of chromosomal analysis would contribute the early diagnosis and prevention of schizophrenia.

편마비 환자의 건측에 적용한 고유수용성 신경근 촉진법이 환측 근 긴장도에 미치는 영향

우영근,조규행,유은영 한국전문물리치료학회 2002 한국전문물리치료학회지 Vol.9 No.2

The purpose of this study was to investigate the effect of proprioceptive neuromuscular facilitation (PNF) approach on the spasticity of affected side in patients with hemiplegia, Three subjects with hemiplegia participated in this study. In single-subject research design (a multiple baseline across individuals) was employed in this study. The intervention program including PNF to the unaffected side was introduced for 30 minutes each day during each intervention phase. Muscle tone of affected side was measured with Tone Assessment Scale, and active hip abduction distance of affected side was taken with the subject supine. And then the muscle tone and the hip abduction distance were measured again 30 minutes later following the intervention. The results showed that the PNF application had some beneficial effects on both muscle tone and active hip abduction. This results suggests that PNF application to non-paretic limb can be effective in reducing muscle tone and improving hip abduction range on paretic limb in persons with hemiplegia. However, further research is needed to prove the effect of PNF application on functional improvement.

薏苡仁의 投與가 마우스의 細胞性 및 體液性 免疫機能에 미치는 影響

우영은,김형균,송봉근,이언정 한국한의학연구원 1996 한국한의학연구원논문집 Vol.2 No.1

Coicis Semen is one of the oriental medicine that has been used for the treatment of the disease such as pulmonary abscess, periappendicular abscess and wart since ancient times. However, the mechanism of the action of the drug is not well studied. This study was done to investigate the effects of Coicis Semen on the host defense mechanism. Effects of Coicis Semen on the immune responses were analyzed by measuring the contact gypersensitivity, hemagglutinin, hemolysin and rosette formation, cytotoxicity, and reactive oxygen intermidiates production. As the results, water extract of Coicis Semen administration enhanced the antibodies (hemagglutinin and hemolysin) formation and the appearance of rosette forming cells of the spleen. Also Coicis Semen increased the allogeneic immune response in the mouse, showed cytotoxic activity against human leukemia cell line(K562) and decreased the contact hypersensitivity against dinitroflurobenzene. Also administration of Coicis Semen slightly increased NK cell activity and enhanced the production of such reactive oxygen intermidiates as superoxide and hydrogen peroxide from the macrophages in vivo and in vitro. The above results demonstrate that Coicis Semen has enhancing effects on cellular and humoral immune responses against disease.

공동주택 유지관리 FCI 모니터링에 관한 연구

범성우,정영한,박태근 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

After the 1980' s governmental housing business policy was vigorously attained, demand of apartment housing is still on the increase, but systematic maintenance is not following this current incerase trend. A promotion about the realization on the importance of maintenance due to life-time degradation of apartment housing and a plan of life-long practice of maintenance established together with longterm stratergy for maintance upkeep must be imperative. Purpose of this study presents application plan about FCI from rifle cycle viewpoint of building. Expect that is used laying plan that is middle part of a song miracle in actuality and expense arbor in the mountains of longtimer line plan of apartment house. As administration subject establishes well-timed repair time and more strategic budget, may behave better maintenance.

구조용 데크플레이트를 사용한 연속 합성슬래브 부모멘트 영역의 균열거동

양근혁,고영우,정헌수 대한건축학회 2005 大韓建築學會論文集 : 構造系 Vol.21 No.1

The objective of this study W3" to evaluate the flexural cracking behavior in the negative moment region of continuous composite slabs reinforced with structural steel decking Main experimental variables were slab thickness and top bar ratio The slabs were tested in 2 continuous span with fixed-ends to get easy access to the negative moment region Also, Based on the distribution of interfacial bond stresses along a segment between two adjacent cracks was assumed as sin function, a simple method for predicting the spacing and width of cracks was suggested Results showed that crack spacing and width m the negative moment region of composite slabs depend mainly on the top bar ratio rather than slab thickness The predictions obtained from the proposed method arc m good agreement With experimental results

임대아파트 장기수선 대체안 검토를 위한 CAFM 시스템 개발

정영한,박태근,김광우,김창덕,김옥규,황영삼,박홍석 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

In the case of rental apartment. the special Quality continuously preservation administration business consist and saves up Long-term Maintenance expense voluntarily. Because business surrounding that this can control preservation administration business whole is possible. administration of repair work is easy. Do system development that introduce technique for long-term strategy establishment in CAFM by purpose. Estimation of system to develop is as following: Can reduce time that take in LCC calculation because approach automatically to information of necessary facility in LCC calculation and know repair time as is easy. It is possible that execute selection of item that is examined in long-term maintenance plan as efficient and correct. Priority injection of budget by facility deteriorated degree is consisted preferentially using FCI.

Neutral Protease를 이용한 닭 간 단백질 가수분해물의 산업적 이용에 관한 연구

박숙영,김우정,이근택 강릉대학교동해안지역연구소 1990 東海岸硏究 Vol.1 No.2

영양학적으로 매우 우수한 부존자원이라 할 수 있는 닭 간의 단백질을 protease인 Neutrase를 이용하여 효소적으로 가수분해를 하였다. 가수분해시의 최적조건을 파악하기 위하여 온도, 시간, pH 및 효소 첨가량 (E/S ratio) 의 조건을 검토하고 수분과 기름의 흡수성, 유화활성, 점도등의 기능성을 조사하였다. 아울러 다시료 비교법에 의한 관능검사를 시행하였다. Neutrase를 이용하여 닭 간 단백질을 가수분해 시켰을 때 온도 50℃, pH 6.0에서 최대활성을 나타내었고, 효소의 첨가량이 증가할 수록 가수분해도는 증가하였다. 수분과 기름의 흡수성과 유화활성도는 반응시간이 지날수록 감소하였고 점도는 증가하였다. 동결건조된 닭 간 단백질 가수분해물의 냄새와 색깔에 대한 관능평가에서는 썩은내와 역겨운 냄새만이 1% 범위에서 유의성이 있었다. 또한 효소적 가수분해는 닭 간 단백질 가수분해물의 색을 붉은색이 감소하는 대신 좀더 밝고, 녹색을 띠도록 하였다. Chicken liver is a potential valuable source of nutrients. Chicken liver protein was enzymatically hydrolyzed using a kind of protease, Neutrase. In order to determine the optimum conditions of hydrolysis process, the parameters of reaction temperature, time, pH, and enzyme to substrate ratio (E/S ratio) were investigated. To evaluate the functional properties of hydrolysate, water and oil absorption capacity, emulsifying capacity and viscosity were measured. Sensory tests by multiple comparison test were also carried out. The optimum condition for the hydrolysis were 50℃ and pH 6.0 and degree of hydrolysis incrased with increasing E/S ratio. Water and oil absorption and emulsifying capacity were decreased and viscosity was increased during hydrolysis. The sensory evaluation of odor and color of freeze-dried chicken liver protein hydrolysates showed a significant increase in 'spoiled' and 'nauseous' (p < 0.01). It was also found that the proteolytic hydrolysis caused the color of chicken liver protein hydrolysates to be brighter, less redish and more greenish.

고주파 마그네트론 스퍼터링 방법에 의해 MgO(100) 기판위에 증착된 (Pb, La) TiO_3 박막의 제작과 특성연구

張志根,張鎬廷,金敏寧,嚴于鎔 단국대학교 1995 論文集 Vol.29 No.-

Pyroelectric (Pb, La) TiO_3 (PLT) thin films have been prepared on Pt coated MgO(100) substrate by RF magnetron sputtering method in an atmosphere of mixed gas of Ar and O_2. PLT file deposited at 580℃ showed perovskite single phase with prominent C-axis orientation perpendicular to the substrate surface. The full width at half maximum (FWHM) of the PLT film was 0.45 degree indicating good crystallinity. From the RHEED observation, the PLT film showed spotty pattern, indication a single crystal phase with rough film surface. The relative dielectric constant(ε_r) and dielectric loss(tanδ) of the perovskite PLT film deposited at 580℃ were 75 and 0.006 at 1kHz, respectively. From the hysterisis loop analysis using sawyer-tower circuit, the remanent polarization(P_r) and coercive field(E_c) were about 10μC/㎠ and 160kV/㎝, respectively.