• Journal of Life Science
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• v.8 no.6
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• pp.687-694
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• 1998

Enzyme electrophoresis was used to estimate genetic diversity and population structure of Chimaphila japonica Miq. in Korea. The percent of polymorphic loci within the enzymes was 48.7%. Genetic diversity at the species level and at the population level was high (Hes=0.278 ; Hep=0.222, respectively), whereas the extent of the population divergence was relatively low ( $G_{ST}$ =0.079). $F_{IS}$ , a measure of the deviation from random mating within the 7 populations, was 0.355. An indirect estimate of the number of migrants per generation (Nm=2.61) indicates that gene flow is high among Korean populations of the species. In addition, analysis of fixation indices revealed a substantial heterozygosity deficiency in some populations and at some loci. Factors contributing to the high levels of genetic dive-rsity found in the entire species of C. japonica include wide distribution, long-lived perennials, ability to regenerate due to rhizomatous spread, outcrossing induced by animal vectors, and occasional pollen dispersal by wind.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.207-210
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• 2003

This study was designed to investigate the antioxidative effect of glasswort (Salicornia herbacea L.) grown in closed sea beach. To compare antioxidant effects of glasswort plant parts, dried ground leaves, stems, and roots of glasswort were exploited for investigation of antioxidant activity Antioxidant activity for the samples was investigated by Rancimat and TBA method. The oxidative stability determined by the Rancimat technique showed a variation in antioxidative index (AL) between the different plant parts, ranging from 1.0 to 3.6. Oxidative stability from ground stem sample of glasswort harvested in the closed sea beach was the highest, and followed by leaf and root. Stem had higher oxidative stability than ascorbic acid. Antioxidatiue effects of glasswort were increased in dose-dependent manners, and antioxidant activity by addition of glasswort with same amount to 4% oil was similar to the activity of ascorbic acid. Specially, 8~10% glasswort addition to oil showed similar antioxidative effect to 1% $\alpha$-tocopherol.

• Korean journal of applied entomology
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• v.8
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• pp.11-18
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• 1969

식물 생장 조절제로서 phthalamic acid와 그 유도체를 사용하여 추락답을 개량하기 위한 예비 시험을 실시하여 다음과 같을 결과를 얻었다. 1) 아래 7종의 phthalamic acid 및 그 유도체를 합성 또는 정제하여 공시약제로 하였으며 합성품의 수율은 $87-92\%$였다. (표 1) A. Phthalamic acid B. Phthalanilic acid C. N- (o-Chlorophenly)-phthalamic acid D. N-(p-Chlorophenyl)-phthalamic acid E. N- (3,4-Dichlorophenyl)-phthalamic acid F. Sodium-N- (m-tolyl)-phthalamate (Duraset) G. Sodium-N-(1-naphthyl)-phthalamate (Alanap) 2) Wheat straight growth test에서 공시약제는 10ppm 및 20ppm의 농도에서 Control보다 월등한 생장 촉진효과를 보였으며 특히 흥미있는 것은 phthalamic acid 유도체가 phthalamic acid 자체보다 더 좋은 효과를 보였다. (표4, 그림 1) 3) 수도 종자의 발아 시험 결과 초장은 phthalamic acid 유도체가 적시 phthalamic acid 자체보다 좋았으며 기중 Alanap. 3,4-dichlorophenyl phthalamic acid 및 Duraset가 가장 좋았으나 10-100ppm 범위내의 농도에 거의 영향없었다. (표 5) 근의 생육은 일반적으로 약제의 종류에 따라 상이할 뿐 아니라 초장의 생육보다 더욱 약제에 민감하였다. 근장은 phthalamic acid, phthalanilic acid, (p-chlorophenyl)phthalamic acid, 3,4-dichlorophenyl phthalamic acid가 Control 보다 약간 좋은 효과를 보였고, Alanap은 매우 불량하였다. (표 6) 근수는 (p-chlorohhenyl) phthalamic acid만 Control에 비해 우수하였고 나머지 약제는 대체로 근수를 감소시키거나 Control과 비슷한 효과를 보였다. (표 7) 또한 농도가 증가함에 따라 근수는 감소하였으며, Alanap, (o-chlorophenyl) phthalamic acid는 근단에 심한 약해가 일어났다. 4) 전근시험에서 근수는 공시약제에 의하여 증가되었으나 50-200ppm의 농도에서 별 영향이 없었다.(표 8, 그림 2) 근장은 농도가 증가함에 따라 감소되는 영향이었으나 공시약제에는 상이한 효과를 보였다. 5) 이상 결과에서 p-chlorophenyl phthalamic acid 및 3,4-dichlorophenyl phthalamic acid가 수도용 식물생장조절제로서 실용적 개발의 가능성을 보였다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.14 no.3
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• pp.25-31
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• 1977

Fe V spinels were prepared by sintering the well-ground stoichiometric mixtures of Fe O and V O at 1,10$0^{\circ}C$ under H -CO atmosphere. The activation energy for electrical conduction decreases with increasing amount of iron. The tendency of activation energy depending on the amount of iron contained clarifies that the electrical condction of the spinel is mainly due to electron hopping between Fe and Fe ions at B sites. In the experiment for negative resistance characteristics, the threshold voltage (Vth) for the samples is related to ambient temperature, thickness and raising rate of applied voltage. Vth decreases as temperature increases while Vth increases linearly with thickness and Vth increases linearly with the raising rate of applied voltage in semi-logarithmic scale. These results lead to a conclusion that current paths mainly formed by thermal breakdown are ascribed to the negative resistance phenomena. Applying this property, these vanadium iron spinels may be used for switching elements.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1656-1658
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• 2003

고전압 대전류 시스템에 사용하는 스위치의 기본 요구조건은 저가, 긴 수명, 적은 지터와 대용량 그리고 seal-off 형태로 쉽게 설치하여 운전하는 것이다. 본 논문은 고전압 대전류용 Seal-off TVS (Triggered Vacuum Switch)를 개발하는 것을 목적으로 하고있다. 제작한 TVS는 양전극과 음전극이 교대로 고정된 간격으로 각각 3개의 전극으로 배열되어 있으며 전극은 사다리꼴 모양으로 되어있고 트리거 시스템과 개스를 흡수하는 게터가 내부에 설치되어 있다. 제작한 스위치 내부는 약 $10^{-7}$ torr의 진공상태를 유지하고 있으며 세라믹 챔버를 사용하여 Seal-off 상태로 설계, 제작하였다. TVS의 에너지 최고 전달량은 74 C 이며 30 kV, 100 kA, $1{\sim}2$ ms의 스위치를 제작하여 시험을 하였다. 스위치 시험 장치는 200 ${\mu}F$, 22 kV 6개를 병렬로 연결한 커패시터 뱅크와 160 ${\mu}H$의 인덕터와 0.2 ${\Omega}$의 저항을 이용하여 시험 장치를 구성하였다. 본 논문은 제작한 스위치의 전기적인 특성 시험한 결과에 대하여 논하고자 한다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.227-227
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• 2010

동력 전달을 위한 구동 부품에 대한 내마모성 개선을 통한 에너지 효율 및 부품의 수명 향상에 대한 사회적 관심이 급증하고 있다. 특히, 최근에는 자동차용 구동부품에 저마찰 내마모 특성이 우수한 Mo-N-Cu 나노복합체 박막에 대한 연구가 활발하게 진행되고 있다. 본 연구에서는 Mo-N-Cu 나노복합체 박막을 마그네트론 스퍼터링 증착법을 활용하였고, 이때 Mo 및 Cu 타겟을 적용하여 동시에 증착하였다. 진공 챔버의 진공도는 $5{\times}10^{-6}\;Torr$ 이하의 초기 진공도를 확보한 이후, 알곤 및 질소 가스를 주입하여 공정 압력이 5 mTorr 수준이 되도록 하였다. 이때 N2/(Ar+N2) = 0.5를 유지하였다. Mo-N-Cu 박막내에 Cu 함량 변화를 위해 Mo 캐소드는 D.C. 1 kW로 고정하고 Cu 캐소드에 R.F. 파워를 0, 40, 60, 80 W로 변화하였다. 박막의 두께는 증착시간을 변화하면서 $1\;{\mu}m$ 이상이 되도록 하였다. Cu 캐소드에 인가된 파워의 변화에 따라 Mo-N-Cu 박막내 Cu 함유량은 10 at.%까지 변화되는 것을 EDX 분석을 통해 확인하였다. 또한 증착된 Mo-N-Cu 박막의 표면 및 단면에 대한 FE-SEM 분석을 통하여 전형적인 주상구조를 지닌 MoN 박막에서 Cu 함량이 증가할수록 Mo-N-Cu 박막의 결정성을 방해하는 것을 확인하였다. 또한 XRD 분석을 통하여 박막의 결정 구조 분석을 하였고, Nano Indentor를 통하여 30 GPa 수준의 고경도를 지닌 박막이 형성됨을 확인하였다. 박막의 내마모 특성 평가를 위해 ball-on-disk 트라이보미터를 활용하여 마찰계수 평가를 수행하였고, Cu 함유량의 변화에 따라 마찰계수가 MoN 박막의 경우 0.8에서 Cu 함량이 5 at.%에서 0.15로 급격하게 낮아짐을 확인하였다.

• Korean Journal of Materials Research
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• v.15 no.11
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• pp.705-710
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• 2005

NIL (nanoimprint lithography) technique has demonstrated a high potential for wafer size definition of nanometer as well as micrometer size patterns. During the replication process by NIL, the stiction between the stamp and the polymer is one of major problems. This stiction problem is moi·e important in small sized patterns. An antistiction layer prevents this stiction ana insures a clean demolding process. In this paper, we were using a TCP (transfer coupled plasma) equipment and $C_4F_8$ as a precursor to make a Teflon-like antistiction layer. This antistiction layer was deposited on a 6 inch silicon wafer to have nanometer scale thicknesses. The thickness of deposited antistiction layer was measured by ellipsometry. To optimize the process factor such as table height (TH), substrate temperature (ST), working pressure (WP) and plasma power (PP), we were using a design of experimental (DOE) method. The table of full factorial arrays was set by the 4 factors and 2 levels. Using this table, experiments were organized to achieve 2 responses such as deposition rate and non-uniformity. It was investigated that the main effects and interaction effects between parameters. Deposition rate was in proportion to table height, working pressure and plasma power. Non-uniformity was in proportion to substrate temperature and working pressure. Using a response optimization, we were able to get the optimized deposition condition at desired deposition rate and an experimental deposition rate showed similar results.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.2
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• pp.80-103
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• 2002

To screen the effective materials for hair loss treatment, several natural extracts were tested using in vivo and in vitro test models. Firstly, all test materials were applicated onto the back skin of C57BL／6 mouse and then hair growth pormoting effect were measured using hair growth index As a result, Polygonum muitifiorum Thunb and Terrninalia chebula Retz. showed potent hair growth promoting effect, ranking as 1.5-2.0 of hair growth index. However, there were no plant extracts, which have remarkable potential of growth promotion of human hair dermal papilla cells cultured in vitro. In the experiments of 5${\alpha}$-reductase type Ⅱ inhibition assay, Morus alba L., Chaenomelis Fructus, Saussureae Radix, Angelicae Gigantis Radix, Polygonum multifiorum Thunb, and Angelica dahurica (Fischer) Bentham et Hooker f. showed effective potential to inhibit the activity of 5${\alpha}$-reductase type Ⅱ. To investigate the possible involvement of effects of several plant extracts on the gene expression of growth factors in human hair dermal papilla cells, RT-PCR analyses were performed. As a consequences, Mentha haplocalyx Briq., Cimicifuga foetida L., Eclipta prostrata (L.) L., Pinus densiflora S. et. Z, and Polygonum muitifiorum Thunb revealed the regulatory roles on the expression of growth factors such as IGF-I, KGF, HGF and VEGF in the dermal papilla cells. Another test for inhibition of microbial such as P. acne and P. ovale were also carried out to find whether these plant extracts have anti-microbial activities. Morus alba L. and Chaenomelis Fructus showed anti-microbial effects on Propionibacterium acnes, which is believed as a pathogen of acne. Together, these results showed several plant extracts can be used for hair growth promotion.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.2
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• pp.94-102
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• 2024

The exact mechanism of sialolith formation has yet to be determined. Recurrence of sialolithiasis is rare, affecting only 1%-10% of patients. The current study presents a case of recurrent stones that occurred twice on the right submandibular gland 6 months postoperative and 7 months after reoperation in a 48-year-old female patient. The stones were analyzed using histology, scanning electron microscopy, energy dispersive spectroscopy, and transmission electron microscopy (TEM). The first stone showed a three-layered structure with a poorly mineralized peripheral multilayered zone, highly mineralized middle layer, and the central nidus. The stones were composed of Ca, C, O, Cu, F, N, P, Si, Zn, and Zr. In TEM, compact bi-layered bacterial cell membrane was found on the peripheral layer and the central nidus of the stone as well as exosomes in the central nidus. The results demonstrated the essential components of sialolith formation, including bacteria, inflammatory exosomes, and exfoliated salivary epithelial cells that cooperatively underwent the pathogenetic progresses of central nidus formation, induction of compact zone calcification of the middle layer, and repeated subsequent deposition in the peripheral multilayer zone. The rapid recurrence could have resulted from residual pieces of a sialolith acting as the nidus of bacterial infection.

• Journal of Forest and Environmental Science
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• v.40 no.3
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• pp.196-209
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• 2024

This study aimed to develop a mixed plantation strategy, with Sal (Shorea robusta) as the primary tree species, along with four associated and two naturally grown tree species. Using a randomized complete block design (RCBD), the field experiment involved a control group (mono plantation) and three mixed plantation groups, each replicated four times, totaling 80 replicates (40 in 2019 and 40 in 2020). Survival rate, height and collar diameter growth of seedlings were recorded in both mono and mixed plots in July 2021. Statistical analyses, including one-way ANOVA on means from three replicate plots (p<0.05) and a Tukey HSD test, were conducted to assess differences between treatments. Significant differences in survival rates were found among mono plantations, with T_Mono04 showing the highest survival rate (88% to 91%). However, there were no significant differences in survival rates among seedlings in mixed plantations. Notably, survival rates were lower in mono plantations compared to mixed plantations. Mono plantations showed significant differences in height growth across both 2019 and 2020 plots, with T_Mono05 achieving the highest height growth (101.1 cm to 123.6 cm). Similarly, mixed plantations showed significant differences in height growth, with T_Mixed7 displaying the most substantial growth (116.4 cm to 138.2 cm). Overall, mixed plantations showed greater height growth compared to mono plantations. Significant variations in collar diameter growth were noted in both the 2019 and 2020 mono plantation plots, with T_Mono01 showing the highest growth (10.2 mm to 11.1 mm). Similarly, among mixed plantations, a significant difference in collar diameter growth was observed, with T_Mixed4 exhibiting the highest growth (10.4 mm to 13.1 mm). Overall, mixed plantations showed higher collar diameter growth compared to mono plantations. The findings suggest that planting Sal trees alongside compatible associated and naturally grown tree species in the Sal forests is preferable over establishing mono plantations.