지르코니아 첨가된 보로실리케이트 유리의 결정화

심규인,김영환,임재민,최세영,Shim, Gyu-In,Kim, Young-Hwan,Lim, Jae-Min,Choi, Se-Young 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.6

Borosilicate glass was prepared in the composition of 81% $SiO_2$, 4% $Na_2O$, 2% $Al_2O_3$, 13% $B_2O_3$. The albite phase($NaAlSi_3O_8$) increased with the $ZrO_2$(0~10wt.%) addition. For measurement of glass transition temperature($T_g$), crystallization temperature($T_{c,max}$) measured by differential thermal analysis. The $T_g$ and $T_{c,max}$ were $510{\sim}530^{\circ}C$ $650{\sim}670^{\circ}C$, respectively. The crystallized glass was heated at various conditions(temperature, time). After nucleation at $550^{\circ}C$ for 2hours prior to crystal growth at $650^{\circ}C$ for 4hours, the resulting Vickers hardness, fracture toughness and bending strength were about $736H_v$, $1.0779MPa{\cdot}m^{1/2}$, and 493MPa, which were 17%, 45% and 149% higher than parent borosilicate glass, respectively. Crystal size and transmittance of crystallized borosilicate glass were analyzed by FE-SEM, EDX and UV-VIS-NIR spectrophotometer. Transmittance of crystallized borosilicate glass was decreased with increasing $ZrO_2$(wt%) at visible-range. The results prove that light-weight bulletproof can be fabricated by the crystallization of borosilicate glass.

금속유기화학증착법으로 사파이어 기판에 증착된 단층 SiO₂, TiO₂ 저반사막의 광 투과율, 내열성, 기계적 특성에 관한 연구

심규인,엄형우,강형,최세영,Shim, Gyu-In,Eom, Hyengwoo,Kang, Hyung,Choi, Se-Young 한국군사과학기술학회 2014 한국군사과학기술학회지 Vol.17 No.5

To improve sensing capability of infrared, heat-resistance and mechanical properties, the $SiO_2$ and $TiO_2$ anti-reflective layers were coated on sapphire substrate by MOCVD. The standard wavelength was 4,600nm, and the thickness of anti-reflective layers were 379 and 758nm in case of ${\lambda}/4$ and ${\lambda}/2$ of incident angle($65^{\circ}$), respectively. The $SiO_2$ and $TiO_2$ anti-reflective layers were coated 12.6 and 9.7nm/min of deposition rates by increasing oxygen pressure to set the ideal refractive index of 1.283. In case of $SiO_2({\lambda}/2)$ coating, the transmittance increased from 55.0 to 62.7%. The transmittance of $TiO_2({\lambda}/2)$ anti-reflective layer also increased from 55.0 to 64.8%. The flexural strength of $SiO_2({\lambda}/2)$ and $TiO_2({\lambda}/2)$ layer coated sapphire increased from 337.8 to 362.9 and 371.8MPa, respectively. The flexural strength at $500^{\circ}C$ of these materials also increased respectively to 304.5, 358.2MPa from 265.9MPa. From these results, we confirmed these materials can be used as transmission window of infrared light.

Development of Thin and Lightweight Bulletproof Windows Using Strengthened SLS Glass by Ion Exchange

심규인,박중구,김성환,안덕래,최세영 한국세라믹학회 2015 한국세라믹학회지 Vol.52 No.2

Soda-lime silicate (SLS) glass was strengthened by ion exchange for application of thin and lightweight bulletproof windows. The optimal conditions for ion exchanged SLS glass (thickness of 3 and 10 mm) at 480oC were 10 and 17 min, respectively. TheVickers hardness values of the strengthened SLS glass samples with thicknesses of 3 and 10 mm were 5.9 ± 0.22 and 6.7 ± 0.17GPa, respectively, which values were about 22% higher than those of parent SLS glass. By laminating a multilayer defense filmand polycarbonate sheet with ion exchanged SLS glass, we were able to make a thin and lightweight bulletproof window (24.25mm, 4.57 kg, 50.06 kg/m2, V50 901.8 m/s). As a result, the thickness of the bulletproof window was decreased by about 39% from40 to 24.25 mm. The light transmittance in the visible range satisfied the standard (over 76%) for bulletproof windows.

道德性 發達에 있어서 初期 놀이 活動의 意味

심규장(沈揆璋) 한국도덕교육학회 1990 道德敎育硏究 Vol.4 No.1

방탄소재 활용을 위한 SLS 유리 결정화의 효과

심규인,김태윤,최세영,Shim, Gyu-In,Kim, Tae-Yoon,Choi, Se-Young 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.1

For application of transparent bulletproof materials, the SLS(soda-lime-silicate) glass was heated by 2-step crystallization. The DTA curve for SLS glass revealed the nucleation and crystal growth temperature at about $575^{\circ}C$ and $675^{\circ}C$, respectively. The crystallized glass was heated at various conditions(temperature, time). As a result, the maximum nucleation and crystal growth rates were $3.8\times10^5/mm^3{\cdot}hr$ at $575^{\circ}C$ and 20.58nm/min at $680^{\circ}C$, respectively. The bending strength, fracture toughness and vickers hardness were 451.7MPa, $0.9388MPa{\cdot}m^{1/2}$, and $693.9H_v$ which were 201%, 31%, and 22% higher than parent glass, respectively. Surface image and transmittance of crystallized SLS glass were analyzed by optical microscopy and UV/VIS/NIR spectrophotometer. Transmittance of crystallized SLS glass at visible-range(200~800nm) was not changed.

금속유기화학증착법으로 사파이어 기판에 증착된 단층 SiO2, TiO2 저반사막의 광 투과율, 내열성, 기계적 특성에 관한 연구

심규인,엄형우,강형,최세영 한국군사과학기술학회 2014 한국군사과학기술학회지 Vol.17 No.5

To improve sensing capability of infrared, heat-resistance and mechanical properties, the SiO2 and TiO2 antireflectivelayers were coated on sapphire substrate by MOCVD. The standard wavelength was 4,600nm, and thethickness of anti-reflective layers were 379 and 758nm in case of λ/4 and λ/2 of incident angle(65˚), respectively. The SiO2 and TiO2 anti-reflective layers were coated 12.6 and 9.7nm/min of deposition rates by increasing oxygenpressure to set the ideal refractive index of 1.283. In case of SiO2(λ/2) coating, the transmittance increased from55.0 to 62.7%. The transmittance of TiO2(λ/2) anti-reflective layer also increased from 55.0 to 64.8%. The flexuralstrength of SiO2(λ/2) and TiO2(λ/2) layer coated sapphire increased from 337.8 to 362.9 and 371.8MPa,respectively. The flexural strength at 500℃ of these materials also increased respectively to 304.5, 358.2MPa from265.9MPa. From these results, we confirmed these materials can be used as transmission window of infrared light.

투명 방탄소재용 보로실리케이트 유리의 이온교환 강화

심규인,엄형우,최세영,Shim, Gyu-In,Eom, Hyengwoo,Choi, Se-Young 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.4

Transparent bulletproof windows play an important role in the munitions industry. The thickness of bulletproof windows including soda-lime silicate(SLS) glass, polyvinyl butyral, poly urethane, main defense(200MD), and safety film was reduced from 40mm to 29mm by adjustment of SLS glass laminated array. Borosilicate glasses generally have lower surface density and more excellent mechanical properties than SLS glass. Borosilicate glass was strengthened by ion exchange in the $KNO_3$ powder. The maximum mechanical properties were observed at $550^{\circ}C$ for 10min. The Vickers hardness, fracture toughness and 3-point bending strength of ion exchanged samples were about $775kg/mm^2$, $1.91MPa{\cdot}m^{1/2}$ and 764MPa each, which are about 27%, 149% and 249% higher than parent borosilicate glass, respectively. The penetration depth of K+ ion at $550^{\circ}C$ for 10min was $59.8{\mu}m$. As a result, the transparent bulletproof windows were predicted to be more lightweight by ion exchange of borosilicate glass. If the SLS glass for bulletproof windows is replaced by ion exchanged borosilicate glass, the bulletproof windows can be expected to be lightweight and thinner.

허브베어링 조립을 위한 최적 단조공정의 제안

심규하(G. H. Shim),김도균(D. G. Kim),최무호(M. H. Choi),김응주(E. Z. Kim),전만수(M. S. Joun) 한국소성가공학회 2012 한국소성가공학회 학술대회 논문집 Vol.2012 No.10

In this study, an optimized forging process for assembling hub bearing assembly is proposed. The shape of initial material is optimized to minimize forging load. The outer shape of inner race of the bearing is also improved not only to minimize forging load but also to reduce the total weight of the hub bearing assembly. The initial material with the inner race for rotary forging needs about 140 tons to be forged while the proposed design needs about 70 tons to be forged.

張載의 氣一元論에 對한 物理學的 理解

심규하 한국유교학회 2006 유교사상문화연구 Vol.27 No.-

張載는 萬物의 生滅 전 과정을 氣一元的 입장에서 糾明하였다. 그는 우주만물의 實體를 氣라고 闡明하고, 이 氣의 聚散작용에 의하여 우주만물의 生成과 消滅이 일어난다고 하였다. 그는 太虛, 氣, 萬物의 관계구조를 통하여 氣의 취산작용을 설명하고 있다. 이 세상은 모두 氣로 가득 차 있는데, 이 氣가 모이면 형체를 이루어 氣의 凝聚상태인 萬物이 되었다가 흩어지면 氣의 無形한 本然상태인 太虛로 돌아간다는 것이다.物理學은 구체적으로 드러나는 다양한 현상에 대한 통찰을 통하여 근원적인 법칙과 물질의 궁극적 본질을 탐구해 가는 學問이다. 따라서 물리학의 연구대상은 微細한 原子 속 素粒子에서부터 광활한 宇宙에 이르기까지 대단히 광범위하다. 이러한 물리학의 이론형성에 가장 중요한 비중을 차지하고 있는 개념은 ‘에너지’이다. 에너지는 相對性理論의 에너지-質量 等價原理가 알려지면서 우주 전체를 하나의 틀로 묶어 주는 槪念으로 자리 잡게 되었다. 質量을 가진 모든 物質들이 결국은 에너지의 변형이며, 더 나아가 우주의 모든 것들은 에너지의 어떠한 상태변화의 산물에 불과하다는 것이다. 그리고 에너지의 고유한 運動性과 그 基本的 相互作用을 통하여 우주만물의 끊임없는 변화가 가능한 것이다.장재의 기일원론은 관념적이고 주관적인 自覺을 통하여 萬物一體의 우주관을 확립하였다. 그러나 이러한 사상은 자칫 空虛한 주장으로 머물게 되어 일반인들을 啓導함에 있어서 다소 어려움이 있다. 따라서 만물의 본질과 변화의 문제에 대한 물리학의 성과를 통하여 모든 인간이 공유할 수 있는 객관적인 실증을 마련한다는 것은 우주자연에 대한 새로운 이해의 장을 마련할 수 있는 것이다.

Towards an understanding of teachers’ mediation in English language teaching in the primary schools.

심규남 한국초등영어교육학회 2009 초등영어교육 Vol.15 No.2

This small-scale study aims to investigate how primary teachers of English perceive their role as mediators with regard to English teaching. Thus, it examines the teachers’ current mediation principles and their perceived practice. This study also sets out to gain an in-depth understanding of further issues which emerged from the dissonance between the teachers’ beliefs and their perceived practice of mediation. In order to conduct the research, a mediation questionnaire was adopted from Williams and Burden (1997), and another open-ended questionnaire was constructed to obtain the qualitative data from 22 participants who are teachers of English and are in a Master’s degree program. The results of the study reveal that generally teachers hold and exercise their own beliefs regarding their role as mediators. However, they do not put some of their principles into practice. A number of significant factors were found to be responsible for this, these are: unfavorable teachers’ working conditions, dedication to the national curriculum, and their awareness of certain mediation principles. Some particular areas needing further investigation were identified in the last part of the study.