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        검색결과 13

        1.
        2023.11 구독 인증기관·개인회원 무료
        Due to the necessity of isolating spent nuclear fuel (SNF) from the human life zone for a minimum of 106 years, deep geological disposal (DGD) has emerged as a prominent solution for SNF management in numerous countries. Consequently, the resilience of disposal canisters to corrosion over such an extended storage period becomes paramount. While copper exhibits a relatively low corrosion rate, typically measured in millimeters per million years, in geological environment, special attention must be directed towards verifying the corrosion resistance of copper canister welds. This validation becomes inevitable during the sealing of the disposal canister once SNFs are loaded, primarily because the weld zone presents a discontinuous microstructure, which can accelerate both uniform and localized corrosion processes. In this research, we conducted an in-depth analysis of the microstructural characteristics of copper welds manufactured by TIG-based wire are additive manufacturing, which is ideal for welding relatively large structures such as a disposal canister. To simulate the welds of copper canister, a 12 mm thick oxygen-free plate was prepared and Y and V grooves were applied to perform overlay welding. Both copper welding zones were very uniform, with negligible defects (i.e., void and cracks), and contained relatively large grains with columnar structure regardless of groove types. For improving microstructures at welds with better corrosion resistance, the effect of preheat temperature also investigated up to 600°C.
        2.
        2023.05 구독 인증기관·개인회원 무료
        Since spent nuclear fuel (SNF) should be isolated from the human life zone for at least 106 years, deep geological disposal (DGD) is considered a strong candidate for SNF management in many countries. Therefore, a disposal canister should be nearly immune to corrosion in such a long-term storage environment. Even though copper has a low corrosion rate of a few millimeters per million years in geological environments, the corrosion resistance of the copper welds must be preferentially validated, which inevitably occurs during the sealing of the disposal canister after the SNF is loaded. This is because the weld zone is a discontinuous area of microstructure, which can accelerate uniform and localized corrosion. In this study, the microstructural characteristics of copper welds in different welding conditions such as friction stir welding, electron beam welding, cold spray, were analyzed, focusing on the formation of microstructure, which affects resistance to corrosion. In addition, the microstructure and corrosion properties of the copper weld zone manufactured by recent wire-based additive manufacturing (AM) technology were experimentally evaluated. From this preliminary test result, it was found that the corrosion characteristics of the welds produced by the AM process using wire are comparable to those of the conventional forged copper plate.
        3.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The goal of this study was to evaluate effects of various microbial and organic additives on chemical compositions, fermentation indices, and aerobic stability of barley silage. Youngyang barley harvested at 31.5% dry matter (DM), and ensiled into 20 L bucket silo for 0, 1, 3, 7, 48, and 100 d in quadruplicates with four additives following: sterile destilled water at 1% of fresh forage (CON); Lactobacillus plantarum at 1.2 x 105 cfu/g of fresh forage (CL); Lactobacillus buchneri at rate of 1.2 x 105 cfu/g fresh forage (LB); Fermented Persimmon Extract at 1% of fresh forage (FPE); and Essential Oil at 1% of fresh forage (EO). On 100 d of ensiling, CL and FPE silages had lower (p<0.05) DM than CON silage. Additionally, FPE silage had higher (p<0.05) crude protein than CON silage. All silages with additives, except EO, had higher (p<0.05) neutral detergent fiber (NDF) than CON silage. Silage treated with CL, LB, and FPE had lower in vitro DM digestibility than CON silage, and silages treated with LB and FPE had higher in vitro NDF digestibility (IVNDFD) on 100 d of ensiling. The PFE silage produced the highest (p<0.05) lactate during ensiling period, while LB silage produced the highest (p<0.05) acetate. All inoculated silages had higher (p<0.05) LAB count than control silage. Only CL silage had higher (p<0.05) yeast count than control silage, while the other silages were not differ compared to CON silage. The aerobic stability was higher (p<0.05) in LB and FPE silages than in CON silage. In conclusion, FPE could be an alternative additive to increase IVNDFD, fermentation indices, and aerobic stability of barley silage.
        4,000원
        4.
        2017.10 구독 인증기관·개인회원 무료
        At present, oak sawdust and rice bran are mainly used as the medium materials for bag cultivation of Lentinula edodes. This experiment was conducted to develop the optimum medium of ‘Nongjingo’, a new variety of Lentinula edodes. We investigated oak sawdust, oak fermented sawdust, poplar sawdust, and douglas fir sawdust as main materials, and rice bran and wheat bran as nutrient resources, respectively. The medium composition was consisted of main material 80%+nutrient 20% based on the volume ratio. Eight treatments of medium composition were tested. The period of mycelial incubation in ‘oak sawdust 40%+douglas fir sawdust 40%+rice bran 20% was 86 days (39 days in dark incubation and 47 days in browning) shortened up to 18 days compared to the control. The 1st yield of commercial fruiting bodies in this treatment was 48.1 g/bag which was 44.8% higher than that in control. We expect that the cultivation period of ‘Nongjingo’ will be shortened, and the yield increased in the medium replaced half of oak sawdust by douglas fir sawdust.
        5.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the kinematic and kinetic changes that may occur in the pelvic and spine regions during cross-legged sitting postures. Experiments were performed on sixteen healthy subjects. Data were collected while the subject sat in 4 different sitting postures for 5 seconds: uncrossed sitting with both feet on the floor (Posture A), sitting while placing his right knee on the left knee (Posture B), sitting by placing right ankle on left knee (Posture C), and sitting by placing right ankle over the left ankle (Posture D). The order of the sitting posture was random. The sagittal plane angles (pelvic tilt, lumbar A-P curve, thoracic A-P curve) and the frontal plane angles (pelvic obliquity, lumber lateral curves, thoracic lateral curves) were obtained using VICON system with 6 cameras and analyzed with Nexus software. The pressure on each buttock was measured using Tekscan. Repeated one-way analysis of variance (ANOVA) was used to compare the angle and pressure across the four postures. The Bonferroni's post hoc test was used to determine the differences between upright trunk sitting and cross-legged postures. In sagittal plane, cross-legged sitting postures showed significantly greater kyphotic curves in lumbar and thoracic spine when compared uncrossed sitting posture. Also, pelvic posterior tilting was greater in cross-legged postures. In frontal plane, only height of the right pelvic was significantly higher in Posture B than in Posture A. Finally, in Posture B, the pressure on the right buttock area was greater than Posture A and, in Posture C, the pressure on the left buttock area was greater than Posture A. However, all dependent variables in both planes did not demonstrate any significant difference among the three cross-legged postures (p>.05). The findings suggest that asymmetric changes in the pelvic and spine region secondary to the prolonged cross-legged sitting postures may cause lower back pain and deformities in the spine structures.
        4,000원
        6.
        2011.10 구독 인증기관·개인회원 무료
        The nematicidal activity of Phellodendron amurense rhizome-derived materials (methanol extract) toward Meloidogyne Spp. second-stage juveniles (J2) and these effects on Cucumis sativus and Cucumis melo. Results were compared with these of fosthiazate. J2 was examined using 24-well plate tests, pot bioassays (C. sativa and C. melo) and Field trials (C. melo). In 24-well plate test with J2, methanol extract of P. amurense exhibited 98.7% and 69.8% mortality at 0.25 and 0.125 mg/ml toward J2, respectively, whereas Fosthiazate showed 100% mortality at 1 mg/ml. In pot bioassays with J2, P. amurense rhizome methanol extract gave 79.5% and 57.4% mortality at 2ℓ/m2(1,000x) and 2ℓ/m2(2,000x)/3kg soil from C. sativa and 73.7% and 53.3% mortality at 2ℓ/m2(1,000x) and 2ℓ/m2(2,000x)/3kg soil from C. melo, respectively. In Field test at C. melo in greenhouse showed 55.1% and 26.9% mortality at 2ℓ/m2(1,000x) and 2ℓ/m2(2,000x) applied soil. P. amurense rhizome-derived materials, merit further study as potential root-knot nematode control agents because of their nematicidal activity.
        8.
        1998.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        5,700원
        9.
        1985.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to provide the basic data required for setting up the proper strategies to minimize the future marine pollution in the vicinity sea area of the Geoje Island, the general water quality parameters and dye diffusion experiment were carried out from January to March, 1983. Although TSS and COD level in the investigated sea area showed still slightly lower than the area of Seaside Industrial Complex Zones, seriously increasing due to the construction of heavy industrial plants. Dissolved oxygen showed more than 8 ppm, and inferred still enough for the reservation of the investigated sea area. The dye patches moved south-eastward with forming an elliptical shape and then turned slowly to the area of Kujora during flood tide, and it moved northwestward and then blocked the entrance of Jangseungpo during ebb tide, The diffusibility in the area may be assessed to be quite better than other coastal areas.
        4,000원
        10.
        2010.06 KCI 등재 서비스 종료(열람 제한)
        The present study was carried out to elucidate the effect of girdling on the quality and harvest date of the 'Shigyoku' grapes. Among girdled vines, the interval from full bloom to harvest date was 77 days; this was as much as seven days shorter in vines receiving a 20% girdling treatment. With regards to fruit characteristics, significant differences were observed in cluster length, berry number, and berry weight in vines that received girdling treatments. There were also significant differences in cluster weight; 468.2 g, 491.6 g and 504.9 g in the control group, 10% girdling group, and 20% girdling group, respectively. Thus, the use of girdling treatments is an effective approach to increasing cluster weight by 5% in the 10% girdling treatment and 8% in the 20% girdling treatment. The 10% girdling treatment showed significant difference in terms of titrable acidity; in fact, the overall titrable acidity was relatively high among all the girdling treatments. The concentration of anthocyanin increased in 20% girdling treatment, but there were no significant differences in anthocyanin concentration among girdling treatments. Berry color developed rapidly in vines that received girdling treatment.
        11.
        2002.09 KCI 등재 서비스 종료(열람 제한)
        고온-고압 상태에서 티탄철석 (FeTiO3)의 상변이에 대한 연구가 있었으나, 그 결과는 서로 일치하지 않고 있다. 특히, 티탄철석상과 페롭스카이트상의 상변이 경계는 담금방법에 의해 결정된 것으로 신뢰도에 의문이 제기되고 있다. 이러한 문제를 해결하기 위해, 고온-고압 현장상태에서 라지 볼륨 기기와 방사광을 이용하여 19 GPa와 700℃의 범위에서 X선 회절실험을 시행하였다. 이러한 실험결과, 페롭스카이트상은 상온에서 16 CPa 이상의 압력에서 안정하며, 15 CPa 근처에서 LiNbO3상으로 변이한다. 또한 이 두 고온-고압상은 500℃에서는 순간적인 상변이를 하고 있다. LiNbO3상은 각각 13 CPa 및 300'E와 10.8 GPa 및 400'E에서 티탄철석상으로 상변이 한다. 따라서 본 실험결과는 LiNbO3상은 고온-고압하에서 안정 영역을 확보하고 있으며, 페롭스카이트-티탄철석상경계는 이전에 발표된 결과와는 매우 다르다는 것을 지시해주고 있다.
        12.
        2001.04 서비스 종료(열람 제한)
        To improve the iron content of red pepper, we have transferred the entire coding sequence of the ferritin gene(Fpl) into Capsicum annuum (L. cv. Chungyang and Bukang) by Agrobacterium mediated transformation. Transformants were found to contain the Fp1 gene at up to three loci, increased distinct iron content changes. In transgenic plants, iron content was as much as 7-fold to 8-folds greater than that of their untransformed counterparts. Furthermore, the Rl progenies from transformant(A7, A8) co-segregated into a 15:1 ratio for both Kanamycin resistance and genotype of high iron.
        13.
        2000.09 KCI 등재 서비스 종료(열람 제한)
        MgO-페리클레이즈 단결정의 체적탄성률을 초음파 간섭법을 이용하여 측정하였는데 (100) 면과 (110)면에 대한 초음파속도 측정치로부터 계산된 값은 각각 163.2 GPa 와 162.6 GPa 이다. 이 계산에 이용된 MgO의 밀도는 동일 단결정을 분쇄하여 얻은 분말 시료를 X-선 회절법을 이용하여 결정하였다. 이러한 실험 결과를 기존의 값과 비교하였고, 이를 등온 체적탄성률로 변환하여 동일한 시료를 이용하여 시행된 에너지 분산 X-선 회절 실험 결과를 포함하는 실험 결과치와 비교하였다. 초음파 간섭법의 원리와 방법도 소개되었다.