• 한국조경학회지
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• 제35권5호
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• pp.46-55
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• 2007

This study was carried out to analyze both the root structure and the fine root phytomass of the vertical and horizontal distribution of Zelkova serrata Makino. which was transplanted in the reclaimed land from the sea in Gwangyang, Jeonnam, South Korea. The base ground was reclaimed land from the sea. $Z_1$ of the planting ground was filled to a $100{\sim}150cm$ thickness with the improved soil instead of the reclaimed soil from the sea, $Z_2$ of the planting ground was covered to a $20{\sim}30cm$ thickness with the improved soil and $Z_3$ of the planting ground was mounded to 120cm thickness with the improved soil on the reclaimed land from the sea. In addition, $Z_4,\;Z_5\;and\;Z_6$ of the planting grounds were at the large-sized mound on the reclaimed land from the sea. $Z_4$ of the planting ground was located at the lowest level, $Z_5$ planting ground was located at the slope and $Z_6$ planting ground was located at the top of the large-sized mound. The large-sized mounds contain 3 layers, the base layer was reclaimed land from the sea and the second layer was mounded to a $200{\sim}300cm$ thickness with the desalinized soil from the sea on the base layers and the finally layers were mounded to a $80{\sim}120cm$ thickness with improved soil on the second layer. The planting grounds $Z_3,\;Z_4,\;Z_5\;and\;Z_6$ developed roots such as tap roots, lateral roots and heart roots. However, in $Z_1\;and\;Z_2$ roots development were inhibited. The fine-root phytomass of the 6 planting ground types was as follows: $113.5g\;DM/m^2$ for $Z_5$, $105.5g\;DM/m^2$ for $Z_4$, $88.3g\;DM/m^2$ for $Z_3$, $81.0g\;DM/m^2$ for $Z_6$, $73.0g\;DM/m^2$ for $Z_2$, $43.3g\;DM/m^2$ for $Z_1$. The vertical distribution of the fine root phytomass decreased from the upper to the deeper soil profiles in the 6 mound types. The fine root phytomass was $43.3{\sim}71.8%$ in a $0{\sim}20cm$ thickness of soil layer and it decreased according to the distance from the nearest trees. The root growth in the improved soil was better than in the reclaimed soil from the sea. However, root growth decreased more in the disturbed soils even though the planting grounds contained the improved soils. The retarded development of roots and the spatial distribution patterns of the fine root phytomass were closely connected to the reclaimed soil from the sea. In the disturbed soil, the soil hardness and alkalic cation($Na^+,\;K^+,\;Ca^{2+},\;Mg^{2+}$). were high and the soil water was lacking. We suggest that the construction of planting grounds and the improvement of bad soil are necessary for the proper and effective growth of landscaping plants.

• Journal of Radiation Protection and Research
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• 제48권4호
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• pp.184-196
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• 2023

Background: Radiation protection is crucial in various fields due to the harmful effects of radiation. Shielding is used to reduce radiation exposure, but gamma radiation poses challenges due to its high energy and penetration capabilities. Materials and Methods: This work investigates the radiation shielding properties of polyvinylidene fluoride (PVDF) samples containing different weight fraction of tungsten carbide (WC), tungsten trioxide (WO₃), and tungsten disulfide (WS₂). Parameters such as the mass attenuation coefficient (MAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Z_eff), and macroscopic effective removal cross-section for fast neutrons (Σ_R) were calculated using the Phy-X/PSD software. EpiXS simulations were conducted for MAC validation. Results and Discussion: Increasing the weight fraction of the additives resulted in higher MAC values, indicating improved radiation shielding. PVDF-xWC showed the highest percentage increase in MAC values. MFP results indicated that PVDF-0.20WC has the lowest values, suggesting superior shielding properties compared to PVDF-0.20WO₃ and PVDF-0.20WS₂. PVDF-0.20WC also exhibited the highest Z_eff values, while PVDF-0.20WS₂ showed a slightly higher increase in Z_eff at energies of 0.662 and 1.333 MeV. PVDF-0.20WC has demonstrated the highest Σ_R value, indicating effective shielding against fast neutrons, while PVDF-0.20WS₂ had the lowest Σ_R value. The Monte Carlo N-Particle Transport version 5 (MCNP5) simulations showed that PVDF-xWC attenuates gamma radiation more than pure PVDF, significantly decreasing the dose equivalent rate. Conclusion: Overall, this research provides insights into the radiation shielding properties of PVDF mixtures, with PVDF-xWC showing the most promising results.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.676-684
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• 1998

Baculovirus transfer and expression vectors with Hyphantria cunea nuclear polyhedrosis virus (HcNPV) were constructed. An initial transfer vector, pHcEV, constructed using HcNPV was previously reported (Park et al. 1993. J. Kor. Soc. Viral. 23: 141-151). Herein, the size of the vector was properly reduced, and a functionally perfect vector was constructed and named pHcEV-IV (6.7 kb). The vector has a 2.2-kb HcNPV DNA sequence in the 5'-flanking region of the vector's polyhedrin gene promoter. The 1.8-kb HcNPV DNA sequence, poly A signal sequence, T3 primer sequence, and 13 multicloning site sequences, in order, were ligated in front of the translation start codon of the polyhedrin gene. The cloning indicating marker lacZ gene was inserted into the pHcEV-IV, named pHcEV-IV-lacZ, and transferred into the wild-type virus. Recombinant expression virus, lacZ-HcNPV, was constructed by replacing the lacZ gene in the pHcEV-IV-lacZ with the polyhedrin gene of the wild-type virus. The recombinant virus was isolated from blue plaques that produce $\beta$-galactosidase without polyhedra. The lacZ gene insertion was confirmed by Southern hybridization analysis. The expression of the lacZ gene in Spodoptera frugiperda cells infected with the lacZ-HcNPV was examined by SDS-PAGE and colorimetric assay. One 116-kDa LacZ protein band appeared on the PAGE. The production rate of the $\beta$-galactosidase was approximately 50 international units (IU) per min per ml between 2 to 5 days postinfection (p.i.). The highest activity occurred at five days p.i. was 170 IU/min/$m\ell$. The enzyme activity first appeared about 20 h p.i. as measured by colorimetric assay.

• 한국의류학회지
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• 제45권2호
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• pp.356-375
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• 2021

The Generation Z (Gen-Z) consumer has a unique beauty-consuming behavior that is distinct from the previous generations. This study aims to identify the meaning of makeup rituals based on the theoretical framework of the ritual concept. In-depth interviews were conducted with fifteen females in their mid-teens to early 20s. The results showed that Gen-Z has different types of makeup ritual scripts for both ordinary days and special days, which are constantly being re-written and revised based on the experience accumulated. In addition, there are various types of ritual artifacts that play an important role in Gen-Z's makeup ritual, and that they provide psychological comfort and satisfaction. The importance of DIY (Do It Yourself), collecting, and independent brands is emphasized. The role of Gen-Z in the makeup ritual was expanding from a creator for her own ritual to a collaborator for peers' rituals, and sometimes the expansion goes beyond the direct relationships to virtual ones through SNS (Social Network Service). The Gen-Z cohort is found to be a member of beauty knowledge network through which they learn, share, and create the know-how and shopping skills.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2591-2599
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• 2021

The effect of thermal aging at 475 ℃ and 750 ℃ of Z3CN20.09M cast duplex stainless steel (CDSS) on microstructure, mechanical and intergranular corrosion properties were investigated by transmission electron microscope (TEM), nano indenter, scanning electron microscope (SEM) and corrosion fatigue test system. The result indicated that the spinodal decomposition and G precipitated were occurred after aged at 475 ℃, as well as sigma precipitated at 750 ℃. The microstructure degeneration of ferrite was saturated after aged for 2000h and 200 h at 475 ℃ and 750 ℃ respectively. The mechanical properties, intergranular corrosion resistance and corrosion fatigue lives were continuing deteriorated with increasing the aging time at both temperatures. The difference of the degeneration mechanisms of Z3CN20.09M CDSS aged at 475 ℃ and 750 ℃ was analyzed.

• Restorative Dentistry and Endodontics
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• 제34권2호
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• pp.145-153
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• 2009

본 연구에서는 측정장치의 compliance유무가 복합레진의 중합수축응력 측정에 미치는 영향을 알아보았다. 변위센서, cantilever load cell과 부궤환 (negative feedback) 시스템을 적용하여 compliance를 허용하는 것과 허용하지 않는 두 가지 모드로 중합수축응력의 측정이 가능한 stress-strain analyzer를 제작하였다. 한 종의 flowable (Filtek Flow: FF) 복합레진과 두 종의 universal hybrid (Z100: Z1 and Z250: Z2) 복합레진이 사용되었다. Load cell의 끝과 base plate에 고정된 직경 3.0 mm의 금속 막대에 silane을 처리하였다. 1.0 mm의 거리로 고정한 두 개의 금속 막대 사이 에 복합레진을 적용한 후 광중합을 하였다. 복합레진의 수직 중합수축률과 중합수축응력을 10 분 동안 기록하였고 인장탄성계수도 구하였다. 통계처리는 일원분산분석과 paired t-test를 시행하였고 95% 유의수준에서 Tukey's test로 사후 검정하였다. 측정된 중합수축 응력은 재료와 compliance의 유무에 따라 큰 차이를 보였다. Compliance를 허용한 모드에서 중합수축응력은 FF: 3.11 (0.13)이 가장 컸으며 Z1: 2.91 (0.10), Z2: 1.94 (0.09) Mpa의 순서였다. 측정장치의 compliance를 허용하지 않은 경우에는 Z1 17.08 (0.89)이 가장 컸고 FF: 10.11 (0.29), Z2: 9.46 (1.63) MPa의 순이었다. 또한 Z1, Z2, FF의 인장탄성계수는 각각 2.31 (0.18), 2.05 (0.20), 1.41 (0.11) GPa 이었다. 중합수축응력은 compliance mode에서는 복합레진의 수직 중합수축률이 주요 영향 요인이었으며, compliance를 배제한 모드에서는 탄성계수의 효과가 지배적이었다.

• 전력전자학회논문지
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• 제18권4호
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• pp.322-332
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• 2013

Conventional single-phase series quasi Z-source voltage compensator can not compensate for voltage sag less than 50% that frequently occurs in the industrial field. In this study, single-phase series quasi Z-source voltage sag-swell compensator which can compensate the voltage variation of entire range is proposed. The proposed system is composed of two quasi Z-source AC-AC converters connected in series with output terminal stage. Voltage sag less than 50% could be compensated by the intersection switching control of the upper converter duty ratio and of the upper converter duty ratio. Also the compensation voltage and its flowchart for each compensation mode are presented for entire sag-swell region. To confirm the validity of the proposed system, a DSP(DSP28335) controlled experimental system was manufactured. As a result, the proposed system could compensate for the voltage sag/swell of 20% and 60%. Finally, voltage compensation factor and THD(Total Harmonic Distortion) according to voltage variation and load change were measured, and voltage quality shows a good results.

• 수산해양기술연구
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• 제29권2호
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• pp.162-167
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• 1993

Wilbrink 본뜨기에서 모우드 라킹 현상과 소모적 궤적의 두 경우에 대한 일반화차원 D 하(n)을 수치 해석적으로 계산하였다. 투닝변수 z=0.03, 소모변수 b=0.9, k 하(d)=0.272313668의 값으로 주어진 소모적 Wilbrink 본뜨기에서 모우드 라킹현상의 경우에는 n～20일 때 D 하(-20) =0.924202의 값을 갖으며, 소모적궤적에서는 D 하(-20) =0.63292와 D 하(+20) =1.89877의 값으로 주어진다. 이때의 값들은 n$\longrightarrow$$\infty$감에 따라 Circle 본뜨기의 D 하($\pm$$\infty$) 값들과 근사적으로 일치한다.

• 한국잠사곤충학회지
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• 제51권2호
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• pp.185-190
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• 2013

2011년부터 수입되어 사육 유통되는 슈퍼밀웜의 국내 샘플들은 형태 분류학적 검토를 통하여 Zophobas atratus란 종으로 밝혀졌고, Z. morio란 학명은 이 종의 동물이 명임이 확인되었다. 이 외래종은 자원 관리측면에서 국명을 '아메리카왕거저리'로 신칭하였다. 이 종과 형태적으로 유사한 자생종 P. valgipes 및 사육종 T. molitor와 DNA 바코드 분석 결과, Zophobas atratus와 P. valgipes는 평균 21.4%, Zophobas atratus와 Z. morio는 20.9%의 염기분화율을 보여 DNA 바코드로 쉽게 종 동정할 수 있음을 확인하였다. Z. atratus의 국내집단은 모두 동일 일배체형을 갖고 있어 국외의 동일 지역 개체군이 국내로 유입된 것으로 추정된 반면에 Z. molitor는 동일 사육집단 내에서도 두 개의 종내 집단이 뚜렷이 구분되고 서로의 염기 분화율이 1.17 ~ 2.19%로 갭을 형성한 것으로 보아 국내 Z. molitor 사육개체들은 서로 다른 지역 집단이 혼입되어 대량 사육에 이용되어진 것으로 추정된다. 이번 연구를 통하여 분석된 상업적으로 도입, 이용되는 2종의 거저리류의 분류학적 기초 정보가 국내 곤충자원 관리를 위하여 유용하게 이용될 것으로 판단된다.

• 한국재료학회지
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• 제11권3호
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• pp.197-202
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• 2001

교류구동형 플라즈마 표시소자의 보호막으로 사용되는 MgO의 특성향상을 위하여 기존의 MgO에 양이온이 등전적으로 치환될 수 있는 ZnO를 소량 첨가하여 고주파 마그네트론 스퍼터링 방법으로 $Mg_{1-x}$Z $n_{x}$O박막을 성장시키고 박막의 전기적, 광학적 특성을 조사하였다. ZnO농도가 0.5 at%, 1at%인 $Mg_{1-x}$Z $n_{x}$O 박막을 보호막으로 갖는 PDP 테스트 판넬을 제작하고 ZnO의 첨가가 소자의 방전전압과 메모리 이득에 미치는 영향을 살펴보았다. ZnO농도가 0at%, 0.5 at%, 1at%인 $Mg_{1-x}$Z $n_{x}$O 박막의 광투과율은 ZnO 첨가에 따라 변화를 보이지 않으나 유전상수는 다소 증가하는 경향을 보였다. ZnO의 농도가 0.5 at%인 $Mg_{1-x}$Z $n_{x}$O 박막을 보호막으로 갖는 PDP 소자의 방전개시전압과 방전유지 전압이 MgO 박막을 보호막으로 갖는 소자에 비해 20V까지 낮아졌고, 결과적으로 메모리계수는 다소 증가하였다. ZnO농도가 0.5 at%, 1at%인 $Mg_{1-x}$Z $n_{x}$O 박막을 보호막으로 갖는 소자에서 ZHO의 첨가에 비례하여 방전세기 (플라즈마 밀도)가 증가하였다.도)가 증가하였다.도)가 증가하였다.