연마방법에 따른 금속의 활택도에 관한 연구 - Atomic Force Microscope를 이용한 -

박원규,우이형,최부병,이성복,Park Won-Kyu,Woo Yi-Hyung,Choi Boo-Byung,Lee Sung-Bok 대한치과보철학회 2003 대한치과보철학회지 Vol.41 No.1

The surface of metals should be as smooth as possible for optimum comfort, oral hygiene, low plaque retention, and resistance to corrosion. In this study five specimens of each precious metal(type III gold alloy, ceramic gold alloy, and Ag-Pd alloy) were divided into five groups according to finishing and polishing procedures : group 1(sandblaster), group 2(group 1+stone), group 3(group 2+brown rubber), group 4(group 3+green rubber), and group 5(group 4+rouge). Six specimens of each non-precious metal(Co-Cr alloy, Ni-Cr alloy, and Co-Cr-Ti alloy) were divided into six groups: group 1(sandblaster), group 2(group 1+hard stone), group 3(group 2+electrolytic polisher), group 4(group 3+brown hard rubber point), group 5(group 4+green hard rubber point), and group 6(group 5+rouge). Considering factors affecting the rate of abrasion, the same dentist applied each finishing and polishing procedure. In addition, the surface roughness of enamel, resin, and porcelain was evaluated. The effect of finishing and polishing procedures on surface roughness of precious and non-precious metals, enamel, resin, and porcelain was evaluated by means of Atomic Force Microscope(AutoProbe CP. Park Scientific Instruments, U.S.A.) that can image the three dimensional surface profile and measure average surface roughness values of each sample at the same time. The obtained results were as follows : 1. According to finishing and polishing procedures, the surface roughness of type III gold alloy, ceramic gold alloy, and Ag-Pd alloy was decreased in the order of group 1, 2, 3, 4, and 5 (P<0.01). 2. According to finishing and polishing procedures. the surface roughness of Co-Cr alloy, Ni-Cr alloy, and Co-Cr-Ti alloy was decreased in the order of group 1, 2, 3, 4, 5, and 6 (p<0.01). 3. There was not statistically significant difference in the surface roughness among three metals of precious metals in group 1 but was significant difference in group 2, 3, 4, and 5 (P<0.05). 4. There was not statistically significant difference in the surface roughness among three metals of non-precious metals in all groups. 5. When the surface roughness of the smoothest surface of each metal, enamel. porcelain, and resin was compared, porcelain was the smoothest and the surface roughness was decreased in the order of Ni-Cr alloy. Co-Cr alloy. Co-Cr-Ti alloy, resin. Ag-Pd alloy, ceramic gold alloy type III gold alloy, and enamel (P<0.01). The results of this study indicate that the finishing and polishing procedures should be carried out in a logical, systematic sequence of steps and the harder non-precious metals may be less resistance to abrasion than are the softer precious metals.

洛東江 流城의 水質에 關한 硏究 (I)

박원규,박영규,서종덕,Won Kyu Park,Yung Kyu Park,Jong Duck Suh 대한화학회 1969 대한화학회지 Vol.13 No.4

The results of water analysis for 10 stations in the main Naktong and 11 stations in the tributaries from March to December 1968 are as follows: The water quality of the Naktong River Basin is generally the frist class of water, especially the tributaries, Hwang river, Nam river, Milyang river, Naesongchun, Hoechun, Wichun and Panbyunchun were dissolved in less than 100 mg/l as the amount of the total ion of the main component. In comparison with river discharge, the amount of the total ion of the main component is decreased in June and July, because of the river discharge is increased in those periods. According to the measurement of the conductivity and the hardness, the better water quality is distinguished by the following order: lower part of river (Namji), middle part of river (Waegwan), upper part of river (Yean). The conductivity of Kumho river, Tongchon is higher than the middle part of the main river and Nam river, Chongam is smaller than lower part of the main rivller. The variation of the amount of the total ion of main component in the basin is mainly effected by $HCO_3^-, SO_4^{-2}, Cl^-, Ca^{+2}$. The relationship between $[K^+]\;and\;[C^l-]\;and\;[Na^+]\;and\;[Cl^-]\;are\;[K^+]=0.04\;[Cl^-]+1.7\;mg/l,\;[Na^+]=0.06\;[Cl^-]$ mg/l .The main river was much contaminated by Kumho river and C.O.D. at Gang-chung, Kumho river in June was recorder over the standard about 7 times.

고집광 태양광 발전 기술

박원규,박경호,전동환,박상혁,Park, Won-Gyu,Park, Gyeong-Ho,Jeon, Dong-Hwan,Park, Sang-Hyeok 한국광학회 2012 광학과 기술 Vol.16 No.1

용융법과 졸겔법으로 제조된 Cordierite 계 유리와 겔의 결정화 거동

박원규,Park, Won-Gyu 배재대학교 공학연구소 1997 공학논문집 Vol.1 No.1

코디어라이트(2MgO.$2Al_2 O_3$.$5SiO_2$)계 유리와 겔을 일반 용융법과 졸겔법으로 제조하여 그 결정화 거동을 비교하여 보았다. 졸겔법으로 제조되는 겔의 치밀화 온도는 $810^{\circ}C$이었으며, IR결과 용융유리와 같은 구조를 가짐을 알 수 있었다. 겔의 결정화 개시온도는 $965^{\circ}C$이었으며, 핵형성제로서 10wt%의 $TiO_2$를 첨가한 용융유리의 $978^{\circ}C$ 보다 낮았다. 겔로부터의 결정상의 변화는 스피넬, $\beta$-석영고용 결정에서 $\alpha$-코디어라이트결정으로, 핵형성제로서 $TiO_2$를 넣은 용융유리에서는 (Mg,Al)TiOn 고용결정상과 $\beta$-석영고용결정에서 $\alpha$-코디어라이트로 전이하여감을 알 수 있었다. 핵형성제를 첨가한 용융유리의 결정화는 핵형성제로부터의 체적결정화였으며, 첨가하지 않은 경우는 $\beta$-석영고용결정으로부터의 표면결정화에 의해 결정화가 일어났으며, 겔로부터의 결정화는 치밀화과정에서 미립자사이에 생겨난 계면으로부터의 표면핵형성에 의한 내부 결정화과정을 거쳐 일어남을 알 수 있었다. The crystallization behaviours of cordierite gel derived from sol-gel method and glass prepared from conventional melting method with or without $TiO_2$ as nucleants are compared. The densification temperature of gel is $810^{\circ}C$ and its chemical structure identified by IR analysis is same as that of glass melted by conventional method. The beginning crystallization temperature of gel is $965^{\circ}C$ lower than that of melted glass with 10wt% $TiO_2$, which is $978^{\circ}C$. The crystalline phases developed from gel during heat treatment are identified as spinel, $\beta$-quartz solid solution and $\alpha$-cordierite crystal and crystalline phases in case of glass are (Mg,Al)TiOn and $\beta$-quartz solid solution and $\alpha$-cordierite crystal, respectively. The crystallization in melted glass with nucleants occurs through bulk crystallization and in case of that without nucleants surface crystallization occurs, while the crystallization in gel is internal crystallization from interface between particles formed after densification.

자기 연마법에 의한 질화 규소계 세라믹 파이프 내면의 경면 연마 특성에 관한 연구

박원규,타케오시무라,Park, Won-Gyu,Shinmura, Takeo 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.1

Results ar presented of a new process for internal precision finishing of slender fine ceramic pipes using a magnetic field generated by a permanent magnets. For finishing the interior surface of a long pipe, a new type of finishing equipment was developed which can be very easily used in an industrial surrounding. In general, the pipe is so slender that a conventional finishing tool is hardly inserted into the pipe deeply, being impossible to finish. Therefore, a new technology has been considered to finish inside of a slender ceramic pipe by a simple technique. In this experimental, Magnetic Abrasive Machining is applied for the inner surface of silicon nitride fine ceramic pipe using ferromagnetic particles mixed with chromium-oxide powder. It is shown the initial roughness of 2.6㎛ Ry(0.42㎛ Ra) in the inside surface can be precisely finished to the roughness of 0.1㎛ Ry(0.01㎛ Ra). This paper discusses the outline of the processing by the application of magnetic abrasive machining and a few finishing characteristics.

아미드옥심화 PAN 나노섬유 웹의 중금속 흡착 특성

박원규,장미화,양혜연,최창남,Park, Won-Kyu,Jang, Mi-Hwa,Yang, Hye-Youn,Choi, Chang-Nam 한국섬유공학회 2007 한국섬유공학회지 Vol.44 No.6

In order to prepare the heavy metal adsorbent, PAN nano fiber web was prepared by electro spinning and subsequently amidoximated with hydroxyl amine. The diameter of fiber depended on the polymer concentration and the applied voltage. The average diameter increased with an increase of the polymer concentration and decreased with the applied voltage. Both the prepared nano fiber web and PAN fiber for weaving were amidoximated by the reaction of PAN with hydroxylamine. The formation of amidoxime groups was identified by FT-IR spectra and elemental analyses. The degree of amidoximation of PAN nano fiber was increased with increasing temperature. Amidoximated PAN nano fiber web had an excellent adsorption capacity for heavy metal ions, especially $Cu^{+2}$, compared with the amidoximated PAN fiber for weaving due to the relatively large specific surface area.

조경용 탄성포장의 재료 배합비에 따른 결합력과 탄성분석

박원규,Park, Won-Kyu 한국조경학회 2010 韓國造景學會誌 Vol.38 No.5

탄성포장은 보행자의 만족감이 매우 높아 수요가 지속적으로 증가할 것으로 예상되나, 탄성포장의 재료 배합기준 즉, 합성고무 칩(EPDM chip)과 폴리우레탄 바인더의 적정배합기준이 미비하여 시공 시 많은 시행착오를 겪고 있는 실정이다. 따라서, 본 연구는 조경용 탄성포장의 폴리우레탄 바인더 배합비에 따른 결합력과 반발탄성의 변화를 실험을 통해 분석하고, 이를 바탕으로 적정한 재료배합 비율을 제시하고자 하였으며, 실험결과는 다음과 같다. 인장실험에서는 시료 B와 시료 C가 바인더 배합비율과 인장강도 간에 강한 양의 상관관계가 있는 것으로 나타나, 배합비율이 증가하면 인장강도가 증가한다는 것을 알 수 있다. 경도실험에서는 시료 A,시료 B,시료 C모두 바인더 배합비율과 경도 간에 통계적으로 상관관계가 없는 것으로 나타나, 탄성포장재의 경도는 바인더의 배합비율에 따라 달라지지는 않는 것으로 판단된다. 반발탄성실험에서는 시료 A와 시료 B가 배합비율과 반발탄성 간에 강한 음의 상관관계가 있는 것으로 나타나, 배합비율이 증가하면 반발탄성이 낮아진다는 것을 알 수 있다. 실험결과를 바탕으로 적정배합비율을 분석해 보면 인장강도의 경우, 인장강도의 증가가 둔화되거나 오히려 감소하는 배합비율 포인트는 20%이며, 반발탄성의 경우, 반발탄성이 급격하게 감소하는 배합비율 포인트는 22%이다. 따라서 두가지 요인을 감안할 때, 적정 배합비는 20~22% 사이로 판단된다. 본 연구의 결과는 조경용 탄성포장 시공 시 결합력과 탄성을 제고할 수 있는 재료배합의 지침을 제공할 수 있을 것으로 기대된다. The demand for elastic pavement, providing comfort for pedestrians is expected to increase continuously but the lack of a standard for materials mixing ratio, that is, the optimal mixing ratio between ERDM chip and polyurethane binder, is still in a trial and error stage. This study aimed at recommending an optimal mixing ratio for elastic landscape pavement through a coherence and resilience test depending on ratio. The test result is outlined as follows. In a tensile strength test, samples B and C indicated a close positive relationship between the binder mixing ratio and tensile strength, indicating that the higher the mixing ratio the higher the tensile strength. In a hardness test, none of samples A, B or C indicated a statistical interrelationship between the binder mixing ratio and hardness. That is, the hardness of the elastic pavement material remained unchanged, irrespective of the binder mixing ratio. In a resilience lest, Samples A and B indicated a close negative interrelation between mixing ratio and resilience, indicating that the higher the mixing ratio, the lower the resilience. Upon analyzing the optimal mixing ratio based on test results, an increase in tensile strength began to slow at a 20% mixing ratio, while resilience began to reduce rapidly at 22%, Thus the optimal range for a mixing ration appeared to be 20~22%. The outcome of this study could to provide guidance for improving the elasticity and stability of elastic pavement.

특발성비후성두개경막염: 증례 보고

박원규,변우목,김동석,Park, Won-Gyu,Byeon, U-Mok,Kim, Dong-Seok 대한영상의학회 2003 대한영상의학회지 Vol.49 No.4

특발성비후성두개경막염은 다른 영역의 질환을 배제함으로써 얻을 수 있는 매우 드문 질환이다. 53세 남자가 1개월간의 지속적인 두통과 우안 시력 감소를 주소로 내원하였다. 우측 해 변동 내의 종괴 및 양측 전두엽 부문의 비후된 경막 모두 MR 관상면 T1 강조영상에서 뇌회색질과 동등한 신호강도, T2 강조영상에서 저신호강도를 보였으며, 조영증강후 T1 강조영상에서 양측 선두엽 부분의 경막은 미만성으로 두껍고 비교적 강한 조영증강을 보였으나 해면동내 종괴는 조영증강되지 않았다. 저자들은 수술로 확진된 특발성비후성두개경막염 1예를 경험하였기에 그 방사선학적인 소견을 보고하고자 한다. Idiopathic hypertrohpic cranial pachymeningitis is rare, and is essentially a diagnosis of exclusion. A 53-year-old man presented with headache and visual loss in the right eye, first experienced a month earlier. MR images depicted a mass in the right cavernous sinus. At T1-wighted imaging, both the mass and the thickened dura mater present in both fromted lobes were isointense, while at while T2-weighted imaging, the signal intensity of both the mass and the dura mater was low. After the injection of contrast medium, pachymeningeal enhancement was obserbed. We report the radiologic findings in a case of idiopathic hypertrophic cranial pachymeningitis, confirmed surgically and pathologically.

우리나라 건축물에 사용된 목재 수종의 변천

박원규,이광희,Park, Won-Kyu,Lee, Kwang-Hee 한국건축역사학회 2007 건축역사연구 Vol.16 No.1

We investigated the changes in the species of the woods used for Korean ancient and historic architectures, which include prehistoric excavated relics and existing wooden buildings in South Korea. The species data were collected from various sources such as excavation and repair reports, journal papers, and a few unpublished documents. We divided the building Periods as Paleolithic, Neolitic, Bronze Ages, Iron Age/Three Kingdoms, Koryo, Joseon (early, middle, late) and modem periods. In prehistoric periods, hardwoods were major species. Oak (Quercus spp.) woods dominated (94 percent in average); the others (5%) were Juglans mandshurica, Platycarya strobilacea, Castanea crenata, and few softwoods(1%). During Iron Age and Three Kingdom periods, oaks remained as a major species (57%) and others Platycarya strobilacea(21%), Castanea crenata(13%), and Pinus spp. (6%). The oak woods decreased in Koryo period and they occupied only 1.1%. Instead of oaks, pine (Pinus spp., 71%) and Zelkova serrata (22%) dominated in Koryo. In early and middle Joseon periods, pine woods (73%) remain as a major species and the others were oaks (14%) and Zelkova serrata (9%). As late Joseon came, the pine woods occupied more than 88%. In the late 19th and early 20th centuries, a few boreal species such as larch (Larix spp.) and spruce (Picea spp.), which grow in cold area, were found. We believe they were transported from northern Korea. The existing buildings in Korea are mainly from Joseon period and a few from late Koryo periods. During these periods, pine woods were used for most buildings. For such reason, pine woods were known as 'representative materials for historic buildings'. but earlier times, broad-leaved trees, i.e., oak and Zelkova woods were major materials. The changes in building materials resulted from both climate and human impacts. The dry climate and disturbed forests induce more pines in the mountains. We also compared the wood qualities of the species and found that Zelkova woods were superior ones and deserved more planting for future demands in the repair for historic buildings.

공동주택단지 외부공간의 친환경 수준에 따른 주민의 거주만족도와 친환경 의식 비교 연구 - 광주광역시 아파트 단지를 대상으로 -

박원규,임선화,Park, Won-Kyu,Im, Sun-Hwa 한국주거학회 2009 한국주거학회 논문집 Vol.20 No.6

This study focused on the analysis of residential satisfaction and environment awareness depending on the environment-friendly level on the outdoor space of the housing complexes. The purpose of this study is to present basic materials of the environment-friendly outdoor space planning of housing complexes. The major findings of the study are as follows. First, the results of the comparative analysis of the satisfaction of the outdoor space of apartment complexes show that the complexes with the most application of environment-friendly elements had higher residential satisfaction. But there was no meaningful statistical difference between the complexes with the higher level of application of the environment-friendly elements and the complexes with medium level of application. Secondly, according to a comparative analysis, the overall residential satisfaction of the apartment complexes was the same as the residential satisfaction of the outdoor space. Thirdly, the results of the correlative analysis of residential satisfaction and environmental awareness showed that the satisfaction of the apartment complexes decreases as the awareness of the environment-friendly apartment complex increases. The results of this study can be used as basic materials for environment-friendly outdoor space planning of apartment complexes.