• Journal of the Microelectronics and Packaging Society
• /
• v.11 no.1
• /
• pp.21-28
• /
• 2004

We have demonstrated the applicability of dry film photoresist (DFR) in photolithography process for fine pitch solder bumping on the polytetrafluoroethylene (PTFE/Teflon ) printed circuit board (PCB). The copper lines were formed with 100$\mu\textrm{m}$ width and 18$\mu\textrm{m}$ thickness on the PTFE test board, and varying the gaps between two copper lines in a range of 100-200$\mu\textrm{m}$. The DFRs of 15$\mu\textrm{m}$ thickness were laminated by hot roll laminator, by varying laminating temperature from $100{\circ}C$ to 15$0^{\circ}C$ and laminating speed from 0.28-0.98cm/s. We have found the optimum process of DFR lamination on PTFE PCB and accomplished the formation of indium solder bumps. The optimum lamination condition was temperature of $150^{\circ}C$ and speed of about 0.63cm/s. And the smallest size of indium solder bump was diameter of 50$\mu\textrm{m}$ with pitch of 100$\mu\textrm{m}$.

• The Journal of Korean Society for Radiation Therapy
• /
• v.30 no.1_2
• /
• pp.49-63
• /
• 2018

Purpose : The purpose of this study is investigating the changes of treatment plan and comparing skin dose with or without the skin flash. To investigate optimal applications of the skin flash, the changes of skin dose of each plans by various thicknesses of skin flash were measured and analyzed also. Methods and Material : Anthropomorphic phantom was scanned by CT for this study. The 2 fields hybrid IMRT and the 6 fields static IMRT were generated from the Eclipse (ver. 13.7.16, Varian, USA) RTP system. Additional plans were generated from each IMRT plans by changing skin flash thickness to 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm and 2.5 cm. MU and maximum doses were measured also. The treatment equipment was 6MV of VitalBeam (Varian Medical System, USA). Measuring device was a metal oxide semiconductor field-effect transistor(MOSFET). Measuring points of skin doses are upper (1), middle (2) and lower (3) positions from center of the left breast of the phantom. Other points of skin doses, artificially moved to medial and lateral sides by 0.5 cm, were also measured. Results : The reference value of 2F-hIMRT was 206.7 cGy at 1, 186.7 cGy at 2, and 222 cGy at 3, and reference values of 6F-sIMRT were measured at 192 cGy at 1, 213 cGy at 2, and 215 cGy at 3. In comparison with these reference values, the first measurement point in 2F-hIMRT was 261.3 cGy with a skin flash 2.0 cm and 2.5 cm, and the highest dose difference was 26.1 %diff. and 5.6 %diff, respectively. The third measurement point was 245.3 cGy and 10.5 %diff at the skin flash 2.5 cm. In the 6F-sIMRT, the highest dose difference was observed at 216.3 cGy and 12.7 %diff. when applying the skin flash 2.0 cm for the first measurement point and the dose difference was the largest at the application point of 2.0 cm, not the skin flash 2.5 cm for each measurement point. In cases of medial 0.5 cm shift points of 2F-hIMRT and 6F-sIMRT without skin flash, the measured value was -75.2 %diff. and -70.1 %diff. at 2F, At -14.8, -12.5, and -21.0 %diff. at the 1st, 2nd and 3rd measurement points, respectively. Generally, both treatment plans showed an increase in total MU, maximum dose and %diff as skin flash thickness increased, except for some results. The difference of skin dose using 0.5 cm thickness of skin flash was lowest lesser than 20 % in every conditions. Conclusion : Minimizing the thickness of skin flash by 0.5 cm is considered most ideal because it makes it possible to keep down MUs and lowering maximum doses. In addition, It was found that MUs, maximum doses and differences of skin doses did not increase infinitely as skin flash thickness increase by. If the error margin caused by PTV or other factors is lesser than 1.0 cm, It is considered that there will be many advantages in with the skin flash technique comparing without it.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2004.11a
• /
• pp.101-102
• /
• 2004

The observed means and standard divisions of the egg texture per generation in korean native chickens were as follow. The egg shell strength, the egg shell thickness and the egg shell colour were 3.8$\pm$0.2~4.2$\pm$0.1 kg/$\textrm{cm}^2$, 356.4$\pm$4.9~368.8$\pm$6.5${\mu}{\textrm}{m}$ and 47.0$\pm$1.7~50.0$\pm$3.3％. The regression coefficients were -0.03~0.03 kg/$\textrm{cm}^2$, -0.84~4.40${\mu}{\textrm}{m}$ and -0.88~-0.36％ respectively.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.2124-2125
• /
• 2011

금속의 비저항 측정방법은 4단자 방법, van der Pauw 방법, Four-Point Probe(FPP) 방법, eddy current 방법 등이 있다. 이들의 측정방법은 다르지만 동일한 시료에 대해 평가한 비저항은 측정 불확도 범위 내에서 일치하여야 한다. 이에 따라 균질한 비자성 금속(STS 316)을 선정한 후 비저항을 평가한 결과 4단자와 van der Pauw 방법에 의한 비저항(도전율)은 각각 75.86 ${\mu}{\Omega}{\cdot}cm$(2.273 %IACS)과 75.84 ${\mu}{\Omega}{\cdot}cm$(2.273 %IACS)로서 거의 동일한 결과를 나타냈으며, Four Point Probe(FPP) 방법은 75.91 ${\mu}{\Omega}{\cdot}cm$(2.271 %IACS), eddy current 방법은 76.63 ${\mu}{\Omega}{\cdot}cm$(2.25 %IACS)으로 나타났다.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.5
• /
• pp.33-39
• /
• 1998

The BST (Ba$_{1-x}$ Sr$_{x}$TiO$_{3}$)(50/50) thin film has been grown by RF magnetron reactive sputtering and its characteristics such as crystallization, surface roughness, and electrical properties have been investigated with varying the film thickness. The crystallization and surface roughness of BST thin film are investigated by using XRD and AFM, respectively The BST thin film anealed at 800.deg. C for 2 min has pure perovskite structure and good surface roughness of 16.1.angs.. We estimate that the thickness and dielectric constant of interface layer between BST film and electrode are 3nm and 18.9, respectively, by measuring the capacitance with various film thickness. As the film thickness increases form 80nm to 240nm, the dielectric constant at 10kHz increases from 199 to 265 and the leakage current density at 200kV/cm decreases from 0.682.mu.A/cm$^{2}$ to 0.181 .mu.A/cm$^{2}$. In the case of 240nm-thick BST thin film, the charge storage density and leakage current density at 5V are 50.5fC/.mu.m$^{2}$ and 0.182.mu.A/cm$^{2}$, respectively. The values indicate that the BST thin film is a very useful dielectric material for the DRAM capacitor.or.

• Proceedings of the KIEE Conference
• /
• 2007.04b
• /
• pp.37-39
• /
• 2007

금속의 전기 비저항 측정방법은 일반적으로 4단자, van der Pauw, Four-Point Probe(FPP), eddy current 방법 등이 있다. 이들의 측정방법들은 각각 다르지만 동일한 시료에 대한 전기 비저항 측정값은 거의 같은 결과를 나타내어 야 한다. 금속 전기 비저항의 정밀측정에 대한 연구를 위하여 비자성 금속인 STS 316 시료를 선정하여 측정한 결과 4단자와 van der Pauw 방법으로 측정된 비저항은 각각 $75.86{\mu}g\Omega{\cdot}cm$(2.273 %IACS), $75.80{\mu}g\Omega{\cdot}cm$(2.275 %IACS)이며, 측정 불확도는 0.25 %로서 거의 동등한 결과를 나타냈고, Four Point Probe(FPP) 방법으로 측정된 비저항은 $75.36{\mu}g\Omega{\cdot}cm$(2.288 %IACS), 측정 불확도는 0.45 %, eddy current 방법으로 측정된 비저항은 $76.63{\mu}g\Omega{\cdot}cm$(2.25 %IACS), 측정 불확도는 0.64 %로 나타났다.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.280-281
• /
• 2007

본 논문에서는 생체 내에 삽입하거나 연속적으로 혈당을 모니터링하기 위하여 제작된 무효소 혈당세서의 바이오 패키징 및 특성 최적화에 관하여 고찰하였다. 3전극을 갖는 동일한 센서구조에서 sensitivity를 최대화하기 위해 평면형 백금전극을 사용한 센서, 메조포러스 구조가 작동전극에 형성된 센서, 메조포러스 구조가 작동전극과 보조전극에 형성된 무효소 혈당센서를 설계, 제작하고 비교하였다. 각각의 센서는 0.009${\mu}A$ $mM^{-1}cm^{-2}$, 5.46${\mu}A$ $mM^{-1}cm^{-2}$, 7.75${\mu}A$ $mM^{-1}cm^{-2}$의 sensitivity를 가졌다. 또한 생체 이식되었을 때 혈액 속에서 글루코스응답을 얻는 데에 있어 방해종인 Ascrobic Acid와 Acetaminophen의 반응을 최소화하고, 혈액 내의 단백질들이 전극에 엉겨 붙는 것을 막기 위해 생체 적합한 물질인 Nafion 을 패키징 멤브레인으로 적용하여 센서를 제작하였다. 이 센서는 0.36${\mu}A$ $mM^{-1}cm^{-2}$의 sensitivity를 가졌다.

• The Korean Journal of Mycology
• /
• v.38 no.2
• /
• pp.197-198
• /
• 2010

The morphological and ecological characteristics of Russula eburneoareolata Hongo is reported first time in Korea. The fungus was collected from the mixed forest of Fagaceae in the Gyeryongsan Mountain National Park. The pileus is champagne to ivory, convex then expanded and depressed in the center afterward, and 4 to 9 cm broad. Stipe is 3 to 6 cm long, 12 to 20mm thick and tapering below. Spores are $7-8{\times}6-7\;{\mu}m$, subspherical oval and warty with some connecting lines. Basidia are about $35-40{\times}10-11\;{\mu}m$ and four-spore bearing type.

• Journal of the Korean institute of surface engineering
• /
• v.32 no.1
• /
• pp.3-9
• /
• 1999

Pt thin film of about 7000$\AA$ thickness was deposited on the alumina substrate using DC Magnetron Sputter and the characteristics of the film for temperature sensor were investigated. When film of about 7000$\AA$ thickness was deposited at working gas pressure of $2.0{\times}10^{-3}$torr, sputtering power of 50W, substrate temperature of $350^{\circ}C$(Ts), sheet resistance(Rs), resistivity($\rho$) and temperature coefficient of resistivity(TCR) of the film were respectively 0.39$\Omega$/$\square$, 27.60$\mu\Omega$-cm and $3350 ppm/^{\circ}C$. When the film was annealed at $1000^{\circ}C$ for 240min in hydrogen ambient, Rs, $\rho$ and TCR were respectively 0.236$\Omega$/$\square$, 15.18$\mu\Omega$-cm and 3716 ppm/$3716 ppm/^{\circ}C$. When working gas of 15sccm oxygen and 100sccm Argon were used, Rs, $\rho$ and TCR were respectively 0.335$\Omega$/$\square$, 22.45$\mu\Omega$-cm and $3427 ppm/^{\circ}C$. When the film was annealed at $1000^{\circ}C$ for 240min, Rs, $\rho$and TCR were respectively 0.224/$\Omega$$\square$, 14$\mu\Omega$-cm and $3760 ppm/^{\circ}C$ and the characteristics of the film were much improved.

• Nutrition Research and Practice
• /
• v.13 no.4
• /
• pp.279-285
• /
• 2019

BACKGROUND/OBJECTIVES: Excessive production of reactive oxygen species (ROS) such as hydroxyl (${\cdot}OH$), nitric oxide (NO), and hydrogen peroxide ($H_2O_2$) is reported to induce oxidative stress. ROS generated by oxidative stress can potentially damage glial cells in the nervous system. Cordyceps militaris (CM), a kind of natural herb widely found in East Asia. In this study, we investigated the free radical scavenging activity of the CM extract and its neuroprotective effects in $H_2O_2$-induced C6 glial cells. MATERIALS/METHODS: The ethanol extract of CM ($100-1,000{\mu}g/mL$) was used to measure DPPH, ${\cdot}OH$, and NO radical scavenging activities. In addition, hydrogen peroxide ($H_2O_2$)-induced C6 glial cells were treated with CM at $0.5-2.5{\mu}g/mL$ for measurement of cell viability, ROS production, and protein expression resulting from oxidative stress. RESULTS: The CM extract showed high scavenging activities against DPPH, ${\cdot}OH$, and NO radicals at concentration of $1,000{\mu}g/mL$. Treatment of CM with $H_2O_2$-induced oxidative stress in C6 glial cells significantly increased cell viability, and decreased ROS production. Cyclooxygenase-2 and inducible nitric oxide synthase protein expression was down-regulated in CM-treated groups. In addition, the protein expression level of phospho-p38 mitogen-activated protein kinase (p-p38 MAPK), phospho-c-Jun N-terminal kinase (p-JNK), and phospho-extracellular regulated protein kinases (p-ERK) in $H_2O_2$-induced C6 glial cells was down-regulated upon CM administration. CONCLUSION: CM exhibited radical scavenging activity and protective effect against $H_2O_2$ as indicated by the increased cell viability, decreased ROS production, down-regulation of inflammation-related proteins as well as p-p38, p-JNK, and p-ERK protein levels. Therefore, we suggest that CM could play the protective role from oxidative stress in glial cells.