• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.85-87
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• 1990

Silicon nitride film was deposited on a silicon wafer using a laser CVD(LCVD) technique, which is based on direct photolysis of $SiH_4/NH_3$ gas mixture by ArF laser beam(${\lambda}=193\;nm$). The refractive index of deposited SiN film is 1.9 at the temperature of $300^{\circ}C$, pressure of 5 torr. The breakdown field strength of LCVD SiN film was 10MV/cm. In IR spectrum, the absorption peak of Si-H, N-H, and Si-N is detected and it is shown that hydrogen is included in SiN film. From analysis of absorption band. it is calculated that density of Si-H, N-H bond is higher than $5{\times}10^{22}cm^{-3}$. LCVD MIS capacitor and PECVD MIS capacitor have injection-type hysteresis but it is known that hysteresis loss of LCVD MIS capacitor is smaller than that of PECVD MIS capacitor. It means that Interface state density of LCVD capacitor is smaller than that of PECVD capacitor. In addition, the flatband voltage($V_{FB}$) of LCVD is smaller than that of PECVD capacitor. And it means that fixed charged density($Q_{FIX}$) of LCVD capacitor is smaller than that of PECVD MIS capacitor.

• 한국전자파학회논문지
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• 제16권8호
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• pp.810-814
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• 2005

TEM 셀 내에 있는 혈액에 대한 삽입 손실과 반사율을 측정하여, 원하는 혈액 흡수 SAR(Specific Absorption Rate) 선택에 따른 TEM셀 입력 전력을 구하였다. 혈액 세포는 피부 세포와 함께 전자파 영향을 연구하기 위한 기준 세포이다. 따라서 SAR에 따른 혈액 세포에 인가할 전력 산출은 정확해야 함은 물론 타당성이 있어야 한다. 이 연구에서는 g당 혈액 세포가 받는 전력을 산출하기 위해 50 g의 혈액을 이용하여 전달 전력 감소를 측정하였다. 측정된 데이터로부터 휴대폰 전자파 생체 흡수율 SAR 0.8, 1.6, 3, 4 mW/g에 해당하는 TEM셀 입력 전력을 계산하였다. 이 연구 결과는 배양 세포의 전자파 방사 장치에 응용함을 목적으로 하고 있다.

• 한국식품영양과학회지
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• 제33권9호
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• pp.1566-1572
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• 2004

냉동 반죽 제조시 azodicarbonamide(ADA) 첨가량을 달리하여 만든 냉동 반죽의 물성에 미치는 영향인 farinogram, amylogram, extensogram을 비교 조사하였고, 냉동 반죽의 품질을 결정하는 2차 발효 시간, 빵 제품의 pH, 수분 함량, 비용적 및 경도에 미치는 영향을 -20$^{\circ}C$ 냉동고에서 제조 직후부터 12주까지 저장하면서 비교 조사하였다. ADA 첨가량이 증가할수록 farinogram에서 반죽의 흡수율, 안정도와 강력도는 증가하고, 흡수 시간과 약화도는 감소하였으며, amylogram에서 호화 개시 온도와 최고 점도는 증가하고, 최고 점도시 온도는 감소하였다. 또한 extensogram에서는 발효시간 45분에서 면적, 신장도와 저항비는 증가하고, 저항도는 감소되었다. 냉동 반죽 제빵법으로 만든 냉동 반죽은 같은 냉동 저장 기간에서 ADA 첨가량이 증가할수록 2차 발효시간, 수분 함량 및 경도 값은 감소하였으며, pH, 비용적은 증가하였다.

• Archives of Plastic Surgery
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• 제37권5호
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• pp.671-675
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• 2010

Purpose: In order to maintain corrected nasal tip projection, strong support is important. Authors used calvarial bone graft method for this purpose. Patients were followed up about permanency of the bone graft for a long time. Methods: From 1995 to 1998, author performed calvarial bone graft on 30 adult patients with secondary cleft lip and nose deformity. Patients were observed for 34 months. There were no specific complications, and results were satisfactory. We could confirm the permanence of the calvarial bone graft in 3 patients by photography and radiologic studies for 10 years follow-up. Results: None of the patients showed size change or displacement. But the portion of graft facing the tip was absorbed resulting in loss of tip projection and short nose in two patients. One patient had fracture on the middle of the graft. This caused depression from lower portion of the dorsum to the tip. Conclusion: Despite of autogenous grafts such as calvarial bone, absorption of the bone may occur when compressed with tension for a long period. And the graft in the nasal tip not having any contact with the nasal bone may cause absorption of the graft.

• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.907-916
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• 2020

This research was conducted to investigate the linear expansion and resistance properties of a composite board (com-ply). This board was made of medium-density fiberboard (MDF) laminated using avocado (Persea americana), mahogany (Swietenia mahogani), and pine (Pinus merkusii) veneers. These three types of veneers were laminated on both surfaces of the MDF using adhesives, namely, epoxy and isocyanate. Glue (250 g·m^-2) was spread on the surface, followed by cold press for 3 h with an applied pressure of 15 kg·cm^-2. The research result revealed that com-ply exhibited an increased dimensional stability compared with MDF, indicated by reduction in water absorption, thickness swelling, and linear expansion. The com-ply made of the pine veneer and isocyanate adhesive exhibited high density, water absorption, thickness swelling, and screw withdrawal load. The com-ply that exhibited the strongest resistance to drywood termite attacks was the one made of the mahogany veneer and isocyanate adhesive. Moreover, the com-ply that exhibited the biggest weight loss (3.6 %) was made of the pine veneer and epoxy adhesive. The results of this research may facilitate in manufacturing com-ply using the selected veneer and adhesive without the application of hot press.

• 한국분말재료학회지
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• 제23권1호
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• pp.38-42
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• 2016

$BaTiO_3$-coated Fe nanofibers are synthesized via a three-step process. ${\alpha}-Fe_2O_3$ nanofibers with an average diameter of approximately 200 nm are first prepared using an electrospinning process followed by a calcination step. The $BaTiO_3$ coating layer on the nanofiber is formed by a sol-gel process, and a thermal reduction process is then applied to the core-shell nanofiber to selectively reduce the ${\alpha}-Fe_2O_3$ to Fe. The thickness of the $BaTiO_3$ shell is controlled by varying the reaction time. To evaluate the electromagnetic (EM) wave-absorbing abilities of the $BaTiO_3@Fe$ nanofiber, epoxy-based composites containing the nanofibers are fabricated. The composites show excellent EM wave absorption properties where the power loss increases to the high frequency region without any degradation. Our results demonstrate that the $BaTiO_3@Fe$ nanofibers obtained in this work are attractive candidates for electromagnetic wave absorption applications.

• The Korean Journal of Pain
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• 제14권1호
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• pp.26-31
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• 2001

Background: Sympathetic blocks with local anesthetics are used to differentiate sympathetically- maintained pain (SMP) from sympathetically-independent pain (SIP). However, systemic lidocaine is also used in the management of neuropathic pain. Therefore, there may be possibility of a false positive response in relieving their pain by systemic absorption of lidocaine following a diagnostic sympathetic block in patients with SIP. In this study, we measured the plasma lidocaine concentrations after a stellate ganglion block (SGB) using three volumes of 1% lidocaine. Methods: This prospective, crossover study was performed in 3 patients who experience sudden hearing loss and in 4 volunteers. Each person received SGB three times using three different volumes (6 ml, 12 ml and 16 ml) of 1% lidocaine at one week intervals. SGB was performed using a 23 G butterfly needle via a paratracheal approach by two persons. Two ml of venous blood was obtained from a prepared contra-lateral sided venous route at 1, 3, 5, 7, 10, 20 and 60 min after SGB. Plasma lidocaine level was analyzed by immunoassay. Results: Mean plasma lidocaine concentrations correlated well with the volumes of 1% lidocaine used in SGB; larger volumes showed higher concentrations (P < 0.01). Mean peak plasma concentrations were $1.08{\pm}0.18$ in 6 ml, $1.90{\pm}0.47$ in the 12 ml and $2.74{\pm}0.67{\mu}g/ml$ in the 16 ml groups (P < 0.01). The mean time to reach peak plasma concentration was not significantly different between the three groups. Conclusions: The peak plasma lidocaine concentrations in SGB using large volume were found to be similar to that of IV lidocaine infusion in the management of neuropathic pain. These data suggest that diagnostic sympathetic block may result in many false positive responses for SMP. Part of its effect may be related to systemic local anesthetic absorption and not to a sympathetic block. Therefore, physicians may be required to use optimal volumes and minimal concentration of local anesthetic in diagnostic sympathetic block procedures and also make a careful assessment of the performance of a permanent sympathetic block.

• Journal of Nutrition and Health
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• 제38권1호
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• pp.40-47
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• 2005

This study was performed to determine the effect of three different concentrations of soy-isoflavones on calcium and phosphorus balance in either sham-operated or ovariectomized female rats. Seventy-two 16-week old Sprague-Dawley rats underwent sham operation or bilateral ovariectomy. They were provided diets containing different levels of soy iso-flavones for 6 weeks: 50 ppm (Jow isoflavone intake; LI) , 250 ppm (medium isoflavone intake; MI) and 500 ppm (high isoflavone intake; HI). The subsequent fecal and urinary excretions of calcium and phosphorus were then measured. In the sham-operated rats, body weight gains and food efficiency ratio of the MI and HI groups were significantly lower than the control group while food intake was not different. However, there was no significant difference in the ovariectomized rats. The fecal excretion of calcium was significantly lower in the LI, MI and HI groups than the control group in sham operated rats, and significantly lower in the HI group than the control group in ovariectomized rats. Also, apparent ab-sorption rate of calcium and phosphorus did not show any significant difference among groups. Urinary excretion of calcium and phosphorus was significantly lower in the HI group than the LI group in the sham-operated rats. Urinary excretion of calcium was significantly higher in the control ovariectomized rats than in the control sham-operated rats. Retention of calcium and phosphorus did not show any significant difference in both groups. From the above result, we see that isoflavone intake increases calcium retention through an increase in calcium absorption and also suppresses the increase of calcium excretion in urine in ovariectomy. Therefore, it is suggested that isoflavone intake is recommended for menopausal women who experience sharp bone loss due to the decrease in estrogen honnone.

• BMB Reports
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• 제42권1호
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• pp.47-52
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• 2009

Alanine racemase catalyzes the interconversion of L-alanine and D-alanine and plays a crucial role in spore germination and cell wall biosynthesis. In this study, alanine racemase produced by Bacillus anthracis was expressed and purified as a monomer in Escherichia coli and the importance of lysine 41 in the cofactor binding octapeptide and tyrosine 270 in catalysis was evaluated. The native enzyme exhibited an apparent $K_m$ of 3 mM for L-alanine, and a $V_{max}$ of $295\;{\mu}moles/min/mg$, with the optimum activity occurring at $37^{\circ}C$ and a pH of 8-9. The activity observed in the absence of exogenous pyridoxal 5'-phosphate suggested that the cofactor is bound to the enzyme. Additionally, the UV-visible absorption spectra indicated that the activity was pH independece, of VV-visible absorption spectra suggests that the bound PLP exists as a protonated Schiff's base. Furthermore, the loss of activity observed in the apoenzyme suggested that bound PLP is required for catalysis. Finally, the enzyme followed non-competitive and mixed inhibition kinetics for hydroxylamine and propionate with a $K_i$of $160\;{\mu}M$ and 30 mM, respectively.

• 한국지구과학회지
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• 제30권1호
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• pp.40-48
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• 2009

지각내에서 지진파의 감쇠기구는 매질 고유의 흡수와 에너지의 산란에 의하여 조정된다. 한반도 남부에서 전체 감쇠로부터 산란과 고유의 에너지 손실량을 분리하여 추정했다. 전체감쇠를 고유 Q와 산란 Q로 분리하기 위하여, 단일 후방산란된 coda Q와 다중산란 이론의 관계로부터 유도되는 공식이 사용되었다. Q는 주파수 대역 1.5-20Hz 범위내에서 고유 Q가 산란 Q보다 훨씬 작은 것으로 나타났다. 이것은 한반도 지각내에서 고유 흡수에 의한 에너지 손실이 산란효과에 의한 손실보다 더욱 크다는 것을 의미한다. 1.5-3Hz범위의 고유 Q를 제외하고는 고유 Q와 산란 Q가 지진학적으로 활동적인 다른 지역에 비하여 큰 것으로 나타났다.