초발수 현상을 이용한 나노 잉크 미세배선 제조

손수정,조영상,나종주,최철진,Son, Soo-Jung,Cho, Young-Sang,Rha, Jong Joo,Cho, Chul-Jin 한국분말야금학회 2013 한국분말재료학회지 (KPMI) Vol.20 No.2

This study is carried out to develop the new process for the fabrication of ultra-fine electrodes on the flexible substrates using superhydrophobic effect. A facile method was developed to form the ultra-fine trenches on the flexible substrates treated by plasma etching and to print the fine metal electrodes using conductive nano-ink. Various plasma etching conditions were investigated for the hydrophobic surface treatment of flexible polyimide (PI) films. The micro-trench on the hydrophobic PI film fabricated under optimized conditions was obtained by mechanical scratching, which gave the hydrophilic property only to the trench area. Finally, the patterning by selective deposition of ink materials was performed using the conductive silver nano-ink. The interface between the conductive nanoparticles and the flexible substrates were characterized by scanning electron microscope. The increase of the sintering temperature and metal concentration of ink caused the reduction of electrical resistance. The sintering temperature lower than $200^{\circ}C$ resulted in good interfacial bonding between Ag electrode and PI film substrate.

LIGA 금형몰드를 이용한 Fe-Ni계 나노분말의 초미세 가스베어링 제조

손수정,조영상,김대종,김종현,장석상,최철진,Son, Soo-Jung,Cho, Young-Sang,Kim, Dae-Jung,Kim, Jong-Hyun,Chang, Suk-Sang,Choi, Chul-Jin 한국분말야금학회 2012 한국분말재료학회지 (KPMI) Vol.19 No.2

This paper describes the manufacturing process of tilting pad gas bearing with a diameter of 5 mm and a length of 0.5-1 mm for power MEMS (Micro Electomechanical Systems) applications. The bearing compacts with nanopowder feedstock were prepared by Ni-metal mold with 2-mold system using LIGA process. The effect of the manufacturing conditions on sintering properties of nanopowder gas bearing was investigated. In this work, Fe-45 wt%Ni nanopowder with an average diameter of 30-50 nm size was used as starting material. After mixing the nanopowder and the wax-based binders, the amount of powder was controlled to obtain the certain mixing ratio. The nanopowder bearing compacts were sintered with 1-2 hr holding time under hydrogen atmospheres and under temperatures of $600^{\circ}C$ to $1,000^{\circ}C$. Finally, the critical batch of mixed powder system was found to be 70% particle fraction in total volume. The maximum density of the sintered bearing specimen was about 94% of theoretical density.

Cone-Beam Computed Tomogram (CBCT)과 Adjusted 2D lateral cephalogram의 계측점 차이에 관한 비교 연구

손수정,전윤식,김민지,Son, Soo-Jung,Chun, Youn-Sic,Kim, Minji 대한치과보철학회 2014 대한치과보철학회지 Vol.52 No.3

목적: 본 연구에서는 CBCT (Cone-Beam Computed Tomogram)와 100%로 확대율을 보정한 조절된 측모 두부 방사선 규격 계측 사진(Adjusted 2D Lateral Cephalogram; 이하 Adj-Ceph)의 좌표값을 비교하여 차이가 있는 계측점들의 항목을 분석하여 기존의 2D 분석법을 CBCT 분석에 적용할 수 있는지 여부를 평가해보고자 하였다. 재료 및 방법: 성인 환자 50명의 CBCT 자료 50개와, 동일 환자의 측모 두부 방사선 규격사진을 100% 확대율로 보정한 자료(Adj-Ceph) 50개를 대상으로 하여, 수평축과 수직축의 좌표를 비교하였다. 계측점들의 위치와 좌우 중첩 여부에 따라 두개골 전방에 위치한 점들(group A), 두개 중후방에 위치한 점들(group B), 좌우 양측성 점들(group C), 치아부위 계측점들(group D) 네 그룹으로 나누어 분석 하였고, 좌표값에 유의한 차이가 있는지 분석하기 위하여 paired t-test를 시행하였다. 결과: 수평축(Y축)에서는 Group B (S, Ar, Ba, PNS), Group C (Po, Or, Hinge axis, Go), Group D (U1RP, U6CP, L6CP) 등 11개의 계측점에서 유의한 차이가 있었다. 수직축(Z축)에서는 전체 계측점에서 유의한 차이가 있었다(P<.01). 좌표값의 차이 분석 결과 수평축에서는 13개의 계측점에서 1 mm 이상의 유의한 차이가 있었다. 수직축에서는 Group B의 Sella를 제외한 전체 계측점에서 1 mm 이상의 유의한 차이가 있었다. 결론: CBCT 분석 시에는 기존의 측모두부방사선 규격사진의 분석법을 그대로 사용하기에는 어려움이 있다. 3D 분석법, 또는 수평축에서 13개의 계측점들이 보정되고, 수칙축 19개가 보정된 수정된 새로운 2D 분석법이 사용되어야 한다. Purpose: This study aims to investigate if 2D analysis method is applicable to analysis of CBCT by comparing measuring points of CBCT with those of Adjusted 2D Lateral Cephalogram (Adj-Ceph) with magnification adjusted to 100% and finding out at which landmarks the difference in position appear. Materials and methods: CBCT data and Adj-Ceph (100% magnification) data from 50 adult patients have been extracted as research objects, and the horizontal (Y axis) and vertical (Z axis) coordinates of landmarks were compared. Landmarks have been categorized into 4 groups by the position and whether they are bilaterally overlapped. Paired t-test was used to compare differences between Adj-Ceph and CBCT. Results: Significant difference was found at 11 landmarks including Group B (S, Ar, Ba, PNS), Group C (Po, Or, Hinge axis, Go) and Group D (U1RP, U6CP, L6CP) in the horizontal (Y) axis while all the landmarks in vertical (Z) axis showed significant difference (P<.05). As a result of landmark difference analysis, a meaningful difference with more than 1 mm at 13 landmarks were indentifed in the horizontal axis. In the vertical axis, significant difference over 1 mm was detected from every landmark except Sella. Conclusion: Using the conventional lateral cephalometric measurements on CBCT is insufficient. A new 3D analysis or a modified 2D analysis adjusted on 19 landmarks of the vertical axis and 13 of the horizontal axis are needed when implementing CBCT diagnosis.

열처리에 의한 다양한 컬러 담수양식진주의 색 향상 연구

손수정,서진교,박종완,Son, Soo-Jung,Seo, Jin-Gyo,Park, Jong-Wan 한국패류학회 2009 The Korean Journal of Malacology Vol.25 No.1

In this study, we conducted heat-treatment on freshwater cultured pearls at various conditions in other to improve their color. Also, after heat treatment, we used the UV-Vis, ED-XRF and SEM to investigate changes freshwater cultured pearls' color, composition and internal structure. UV-Vis analysis showed the reflectivity of samples increased at most heat-treatment conditions although the reflectivity decreased at a certain temperature and duration. At $100^{\circ}c$/8 h, $120^{\circ}c$/6 h and $140^{\circ}c$/4 h, the reflectivity increased highest. In proportion to reflectivity increase, freshwater cultured pearls' color was improved. Ca, Mn, Sr and other micro elements were found from ED-XRF analysis. However, changes in composition of elements were not detected. It was found that the content of Mn in freshwater cultured pearl is higher than other micro elements. From SEM analysis, aragonite's shape was shown in narce and some of the narce were condensed after heat treatment. 본 연구에서 우리는 다양한 컬러의 담수양식진주(화이트, 오렌지, 퍼플 등)을 사용하여, 담수진주의 컬러를 변화시켜 가치향상을 목적으로 다양한 온도 및 시간별로 열처리를 실시하였다. 진주의 손상을 최대한 막고 컬러를 향상시킬 수 있는 최적의 조건(온도 및 시간)을 정립하여, 그에 따른 진주의 컬러변화, 광택, 성분분석, 내부구조 등의 변화를 UV-Vis, ED-XRF, SEM 등을 사용하여 비교 관찰하였다. 결론적으로 우리는 열처리를 통하여 담수양식진주의 컬러와 광택 및 상품가치를 높일 수 있는 가장 적합한 조건을 제시하고자 하였다.

국내 Bi-modular charge system 개발현황

손수정(Soo-Jung Son),이원민(Won-Min Lee),권순길(Soon-Gil Gwon),정진영(Jin-Young Jung) 한국추진공학회 2019 한국추진공학회 학술대회논문집 Vol.2019 No.5

펜톨라이트를 이용한 수중폭발 실험

최걸기,정근완,손수정,김종철,이필승,Choi, Gulgi,Jung, Keunwan,Jung, Son Soo,Kim, Jong-Chul,Lee, Phill-Seung 대한화약발파공학회 2017 화약발파 Vol.35 No.3

폭약이 수중에서 폭발하면 공기 중에서 폭발하였을 때와는 다르게 폭발 이후 발생하는 가스의 영향에 대한 고려가 필요하다. 수중 폭발 시에는 폭발압력의 전파속도가 공기 중에서 폭발했을 때에 비하여 빠르고, 발생하는 가스 또한 확산되어 에너지를 소실하기 전 물에 의하여 버블의 형태로 갇히게 된다. 이 때 버블은 팽창과 수축을 반복하며 충격파를 만들어낸다. 이러한 일련의 현상을 연구하기 위하여 내부를 관측할 수 있는 실린더형 철재 수조를 제작하고 폭발 실험을 수행하였다. 본 연구에서는 탄체가 없는 소량의 펜톨라이트를 수중에서 폭발시켰고, 이 때 발생하는 충격파를 계측하고 발생된 가스버블의 거동을 관측하여 그 결과를 관찰하였다. When explosives explode in water, the effect of post-explosion gas after explosion should be considered, unlike explosion in the air. During explosion in water, the propagation velocity of the explosion pressure is faster than when the explosion occurs in the air. The generated gas is diffused and trapped in the form of bubbles by water before the energy is dissipated. At this time, the bubble expands and contracts, creating a shock wave. In order to investigate this series of phenomena, a cylinder type steel water tank capable of observing the interior was fabricated and explosion experiments were conducted. In this study, a small amount of shell-free pentolite was exploded in water. Experiments were performed to observe the behavior of the generated gas bubble as well as to measure the shock wave generated. We designed the experimental method of underwater explosion and examined the results.

일개 대학생의 단기 체중조절 프로그램이 치주건강에 미치는 영향: 사전연구

궁화수 ( Hwa Soo Koong ),손수정 ( Soo Jung Son ),박후섭 ( Hoo Seob Park ),서형석 ( Hyung Seok Seo ),황수정 ( Soo Jeong Hwang ) 한국치위생과학회 2015 치위생과학회지 Vol.15 No.4

Recent cross-sectional studies indicate that obesity is a risk factor for periodontal disease. This study was aimed to investigate whether the four-week weight control program including caloric restriction and exercise training could have an effect on periodontal health. Forty-one obese (body mass index [BMI] ≥25.0) and five overweight (23.0≤BMI<25.0) students participated in the weight control program. Anthropometric data and oral examination data were collected at the baseline and at the 27th day. BMI, waist hip ratio (WHR), and percent of body fat (PBF) of the subjects decreased significantly, but gingival index, sites with bleeding on probing (BOP), and sites with shallow pocket depth didn``t show the significant changes in paired t-test. There was no difference in the outcomes according to smoking, drinking alcohol, and sex. Nevertheless, PBF and sites with BOP (r=0.777) and WHR and sites with shallow pocket depth (r=0.444) showed positive correlations. PBF accounted for 58.9% of the variance in sites of BOP in regression analysis. We suggested that obesity might relate with periodontal health, although it was not clear whether weight control could influence on periodontal health directly.

차세대 핵융합로 블랑켓 재료의 국내외 개발 방향

조승연(Seungyon Cho),유인근(In-Keun Yu),손수정(Soo Jung Son) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

FUSION power offers the potential of an almost limitless source of energy for future generations but it also presents some formidable scientific and engineering challenges. Korea is one of participation countries in ITER project, and study on fusion material is also one of critical issues. A number of materials are necessary to construct the fusion reactor. Especially, structural materials for plasma facing and blanket require reliable properties under severe environments. As a basis on fusion study, material R&D is considerable of interest. Construction of ITER TBM and fabrication data are on progress for next generation nuclear fusion. In this conference, the present state and future prospects for fusion material study will be introduced.

천연감미료 스테비오사이드와 스테비올의 생체내, 시험관내 유전독성평가

오혜영(Hye Young Oh),한의식(Eui Sik Han),최돈웅(Don Woong Choi),김종원(Jong Won Kim),손수정(Soo Jung Son),엄미옥(Mi Ok Eom),강일현(Il Hyun Kang),강혁준(Hyuck Joon Kang),하광원(Kwang Won Ha) 대한약학회 1999 약학회지 Vol.43 No.5

The standard operation procedure of mouse lymphoma L5178Y tk+/- -3.7.2C gene mutation assay (MOLY) has been regarded as a sensitive In vitro mammalian cell gene mutation assay that is capable of detecting clastogens as well as mutagens. Using MOLY, one of natural sweetner, stevioside (5mg/ml) and its aglycon, steviol (340mcg/ml) were evaluated the mutagenicity. Stevioside and steviol did not induce mutagenicity in MOLY. On the other hand, stevioside (250mg/kg, B.W.) and steviol (200mg/kg, B.W.) were also evaluated their ability to induce mucronuclei in regenerating hepatocytes and bone marrow cells of ddY mice. From these results, stevioside and steviol did not induce any mutagenic effect both MOLY and In vivo micronucleus test.

자체 제작한 시험장에서의 GPR의 매설물 검출능력에 관한 측정

손수정,신병철 한국비파괴검사학회 2000 한국비파괴검사학회지 Vol.20 No.4

730MHz의 고정 주파수를 방사하는 3소자 안테나 방식의 GPR을 이용하여 자체 제작한 시험장 속에 매설된 다양한 시험편의 검출능력을 조사하였다. 여러 가지 상황에 대한 검출능력을 알아보기 위하여 매설물의 재질, 크기, 매설 깊이에 차이를 두어 실험을 수행하였다. 레이다파의 전파속도를 조절하여, B-scan상의 쌍곡선 패턴의 위치를 실제 매설한 깊이에 정확하게 위치하게 함으로써, 실험결과로부터 얻은 soil(dry)에서의 레이다파의 전파속도가 기존 data와 유사함을 확인하였다.