• KSBB Journal
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• 제15권3호
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• pp.299-306
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• 2000

발광미생물 (luminescent bacteria)인 P. phosphoreum을 이용한 수계의 환경독성물질로 지정된 ethane, benzene, phenol류에 chlorine이 치환된 l47~의 독성강도를 생체발광의 50%저하시키 는 독성농도인 ECso값을 통한 생물학적 정량을 하였을 때 phenol) benzene) ethane 의 순서로 독성깅도가 높게 산출되 어졌으며, 특히 지환된 chlo괴ne의 수가 증가할수록 독성강도가 강하다는 것을 알 수 있었다. 또한 산출된 ECso값을 이용허여 독성물질들의 물려화학적 parameter특성인 octan이(water 분할계 수 (log P), 용해도 (log S) 및 solvatochromic parameter의 떤관쟁 을 QSAR 모탤링하였으며 실힘을 통하지 않고, 독성의 독성강도 를 예측할 수 있는 회기식을 다음과 같이 산출하였다. $log EC_{50} =2.48 + 0.914 log S(n=9 R2=85.5% RE=0.378) log EC_{50}=0.35 - 4.48 Vi/100 + 2.84 \pi^* +9.46{\beta}m-4.48am (n =14 R2=98.2% RE=0.012) log EC_{50} =2.64 -1.66 log P(n=5, R2=98.8% RE=0.16) log EC_{50}=3.44 -1.09 log P(n=9 R2= 80.8% Re=0.207)$. QSAR 모델은 QSAR 검증식을 통하여 확인된 다중회기식을 이용함으로 실험하지 않은 독성물 질이 갖는 물리화학적인 특성을 대입하여 log Eeso값을 예측할 수 있으므로 경제적, 시간적으로 이익을 얻을 수 있는 모델이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.37-38
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• 2007

This paper reports the characteristics of piezoelectric microspeakers that are audible in open air with high quality piezoelectric AlN thin film according to the materials properties. When we use a tensile-stressed silicon nitride diaphragm as a supporting layer, the Sound Pressure Level (SPL) is relatively small. However, the SPL of the fabricated microspeakers that have compressive-stressed composite diaphragm show higher output pressure than those of tensile-stressed diaphragm. It produces more than 60dB from 100Hz to 15kHz and the highest SPL is about 100dB at 9.3kHz with 20 Vpeak-to-peak sinusoidal input biases and at 10 mm distances from the fabricated microspeakers to the reference microphone.

• Journal of Animal Science and Technology
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• 제50권4호
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• pp.485-498
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• 2008

본 연구는 희토의 첨가가 비육돈의 생산성, 면역관련 혈액학적 지표, 육질특성 및 분내 유해가스발생 함량에 미치는 영향에 대해 알아보기 위하여 시험을 실시하였다. 3원 교잡종 비육돈 64두를 공시하였으며, 시험 개시시 체중이 65.42±1.16kg 이었고, 10주간 사양시험을 실시하였다. 시험설계는 1)Antibiotic free diet (NC), 2)NC diet+6 weeks 44ppm of tylosin/4 weeks 22ppm of tylosin(PC) 3)NC diet+100ppm of RE(RE1) 및 4)NC diet+200ppm of RE (RE2)로 4개 처리를 하여 처리당 4반복, 반복당 4두씩 완전임의 배치하였다. 사양시험 기간 동안 일당증체량, 일당사료섭취량 및 사료효율은 처리구간에 유의적인 차이가 없었다(P>0.05). 건물 및 질소 소화율은 RE2처리구가 다른 처리구와 비교하여 높게 나타났으며(P<0.05). 에너지소화율은 RE2처리구가 NC 및 RE1처리구와 비교하여 높은 소화율을 나타내었다(P<0.05). WBC 수준은 6주에서 RE1처리구가 NC 및 RE2처리구와 비교하여 높은 함량을 나타내었다(P<0.05). 배최장근의 명도를 나타내는 L*값은 희토를 첨가한 RE1 및 RE2처리구가 NC처리구와 비교하여 높게 나타났으나(P<0.05), a* 값은 PC처리구가 RE1처리구와 비교하여 유의적으로 높았다(P<0.05). 근내지방 내 지방산 조성에 있어서 total MUFA는 RE2처리구가 다른 처리구와 비교하여 높은 함량을 나타내었으며(P<0.05), total UFA는 RE2처리구가 PC처리구와 비교하여 높았다(P<0.05). 등지방 내 지방산 조성에 있어서 Total SFA는 PC처리구가 희토를 첨가한 RE1 및 RE2처리구와 비교하여 높은 함량은 나타내었다(P<0.05). Total UFA/SFA는 희토를 첨가한 RE1 및 RE2처리구가 PC처리구와 비교하여 높게 나타났다(P<0.05). 분내 유해가스 물질의 발생 함량에 있어서 암모니아(NH3)는 희토를 첨가한 RE1 및 RE2 처리구가 NC 및 PC처리구와 비교하여 낮은 함량을 나타내었다(P<0.05). 결론적으로, 본 시험의 결과 비육돈에 희토의 첨가는 영양소 소화율, 육질특성, 지방산조성 및 분내 유해가스 함량에 영향을 미치는 것으로 사료된다.

• 한국산림과학회지
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• 제97권5호
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• pp.547-551
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• 2008

The study aimed to develop a cryopreservation method for long-term storage using mature somatic embryo of Japanese larch. In this study, desiccation treatments significantly affected re-induction rates of embryogenic tissue (ET) from dried somatic embryos. In the effect of different dehydration temperature and duration on the re-initiation ET. the highest frequency was shown when somatic embryos were dehydrated at $25^{\circ}C$ for 2 (45.5%) or 1 day (43.3%), respectively. In addition, low temperatures [$4^{\circ}C$, 2 days (44.2%) or 3 days (43.5%)] were marked higher ET initiation. After that, the initiation value was declined with dehydration duration. For comparison of different relative humidity on re-induction frequency of ET, the best re-induction (43.5%) was obtained from somatic embryos pre-dried at $(NH_4)_2SO_4$ (RH 79%). Both $Na_2HPO_4$ (RH 97%) and $Na_2CO_3$ (RH 88%) treatments were showed the similar rate, 34.6, 34.2%, respectively. However the lowest rate (19.6%) was observed in distilled water (RH 100%). In comparison of the various storage temperatures and duration of the dried somatic embryos, the highest frequency (66.9%) of re-initiation was obtained when somatic embryos were cryopreserved for one day. However, the frequency was gradually decreased as the time length of storage increased regardless of types of storage. None of ET re-initiated when stored at $4^{\circ}C$ for 1, 2 and 84 days.

• 한국의류학회지
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• 제40권3호
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• pp.566-573
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• 2016

Sustainability in fashion cannot ignore fashion attributes required for the design of rapidly changing and innovative products. This study examines "Re-Birth Design" development and provides a means to apply academic and industry perspectives to the investigation of Re-Birth fashion product development. This study defines "Re-Birth Design" as stock that has been designed and launched through distribution channels, subsequently returned unused, then improved and reborn into a new product for redistribution. This study analyzed specific cases. We selected 100 designs for Re-Birth from 11 brands of "K" fashion company in Korea, to be successfully sold in 2014. These cases are used in the analysis and are categorized into design types. As a result of the analysis, "Re-Birth Design" had five levels: Level 1. Changes in supplementary materials such as adding or removing decoration, Level 2. Changes in patterns or materials (changes within the product), Level 3. Partial changes in design (leading to a new design), Level 4. Complete deconstruction and rebirth of the design, and Level 5. Complete deconstruction followed by the use of the design source for a new product that is not a garment. This study analyzed products owned by brands, as well as successful cases of Re-Birth designs that reused existing resources, reduced energy consumption, and increased environmental and economic efficiency by recreating new products that could be resold.

• Nuclear Engineering and Technology
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• 제56권3호
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• pp.1013-1021
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• 2024

A series of experiments were performed to produce a fuel source for a molten salt reactor (MSR) through pyroprocessing technology. A simulated LiCl-KCl-UCl₃-NdCl₃ salt system was prepared, and the U element was fully recovered using a liquid cadmium cathode (LCC) by applying a constant current. As a result, the salt was purified with an UCl₃ concentration lower than 100 ppm. Subsequently, the U/RE ingot was prepared by melting U and RE metals in Y₂O₃ crucible at 1473 K as a surrogate for RE-rich ingot product from pyroprocessing. The produced ingot was sliced and used as a working electrode in LiCl-KCl-LaCl₃ salt. Only RE elements were then anodically dissolved by applying potential at - 1.7 V versus Ag/AgCl reference electrode. The RE-removed ingot product was used to produce UCl₃ via the reaction with NH4Cl in a sealed reactor.

• 대한한의학회지
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• 제31권5호
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• pp.64-81
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• 2010

Objectives: The object of this study was to observe the suppressive effects of Yijintang-gamibang (YJGMB), Yijintang being traditionally used in the Korean Medicine for treating various digestive diseases, on the rat reflux esophagitis (RE) as compared with omeprazole, a well-known proton pump inhibitor. Methods: Three different dosages of YJGMB, 50, 100 and 200 mg/kg, were orally pretreated once a day for 28 days before pylorus and forestomach ligation. Seven groups of 8 rats each were used in the study. Six hrs after pylorus and forestomach ligation, changes to the stomach and esophagus lesion areas, gastric volumes, acid and pepsin outputs, invasive lesion percentages, fundic mucosa, esophageal submucosa and total thicknesses were measured by histomorphometry. The results were compared with omeprazole 10 and 30 mg/kg treated groups in which the effects on RE were already confirmed. Results: As results of pylorus and forestomach ligation, marked increases of esophageal and gastric mucosa lesion areas, gastric volumes, acid outputs, pepsin outputs were observed with histopathological changes of RE, such as hemorrhages, ulcerative lesions and edematous changes on the esophageal and fundic mucosa. However, these pylorus and forestomach ligation induced RE were dose-dependently inhibited by treatment of 50, 100 and 200 mg/kg of YJGMB. YJGMB 50 mg/kg showed similar suppressive effects as 30 mg/kg of omeprazole, but more favorable effects were observed as compared with omeprazole 10 mg/kg. Conclusion: The results suggest that YJGMB showed favorable suppressive effects on the RE induced by pylorus and forestomach ligation. It is therefore expected that YJGMB will show favorable effects on RE as corresponds to the suggestion of traditional Korean medicine. However, more detailed mechanism studies should be conducted in future with the screening of the biological active chemical compounds in herbs.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.255-255
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• 2016

Resistive random access memory (ReRAM)는 낮은 동작 전압, 빠른 동작 속도, 고집적화 등의 장점으로 인해 차세대 비휘발성 메모리 소자로써 많은 관심을 받고 있다. 최근에 ReRAM 절연막으로 NiOx, TiOx, AlOx TaOx, HfOx와 같은 binary metal oxide 물질들을 적용하는 연구가 활발히 진행되고 있다. 특히, HfOx는 안정적인 동작 특성을 나타낸다는 점에서 ReRAM 절연막 물질로 적합하다고 보고되고 있다. ReRAM 절연막을 형성할 때, 물리 기상 증착 방법 (PVD)이나 화학 기상 증착법 (CVD)과 같은 방법이 많이 이용된다. 이러한 증착 방법들은 고품질의 박막을 형성시킬 수 있는 장점이 있다. 하지만, 높은 온도에서의 공정과 고가의 진공 장비가 이용되기 때문에 경제적인 문제가 있으며, 기판 또는 금속에 플라즈마 손상으로 인한 문제가 발생할 수 있다. 따라서 이러한 문제점들을 개선하기 위해 용액 공정이 많은 관심을 받고 있다. 용액 공정은 공정과정이 간단할 뿐만 아니라 소자의 대면적화가 가능하고 공정온도가 낮으며 고가의 진공장비가 필요하지 않은 장점을 가진다. 따라서 본 연구에서는, 용액공정을 이용하여 HfOx 기반의 ReRAM 제작하였고 $25^{\circ}C$와 $85^{\circ}C$에서 ReRAM의 동작특성에 미치는 compliance current의 영향을 평가하였다. 실험 방법으로는, hafnium chloride (0.1 M)를 2-methoxyethanol에 충분히 용해시켜서 precursor를 제작하였다. 이후, p-type Si 기판 위에 습식산화를 통하여 300 nm 두께의 SiO2 절연층을 성장시킨 후, 하부전극을 형성하기 위해 electron beam evaporation을 이용하여 10/100 nm 두께의 Ti/Pt 전극을 증착하였다. 순차적으로, 제작된 산화물 precursor를 이용하여 Pt 위에 spin coating 방법으로 1000 rpm 10 초, 6000 rpm 30초의 조건으로 두께 35 nm의 HfOx 막을 증착하였다. 최종적으로, solvent 및 불순물을 제거하기 위해 $180^{\circ}C$의 온도에서 10 분 동안 열처리를 진행하였으며, 상부 전극을 형성하기 위해 electron beam evaporation을 이용하여 Ti와 Al을 각각 50 nm, 100 nm의 두께로 증착하였다. ReRAM 동작에서 compliance current가 미치는 영향을 평가하기 위하여 compliance current를 10mA에서 1mA까지 변화시키면서 측정한 결과, $25^{\circ}C$에서는 compliance current의 크기와 상관없이 일정한 메모리 윈도우와 우수한 endurance 특성을 얻는 것을 확인하였다. 한편, $85^{\circ}C$의 고온에서 측정한 경우에는 1mA의 compliance current를 적용하였을 때, $25^{\circ}C$에서 측정된 메모리 윈도우 크기를 비슷하게 유지하면서 더 우수한 endurance 특성을 얻는 것을 확인하였다. 결과적으로, 용액공정 방법으로 제작된 ReRAM을 측정하는데 있어서 compliance current를 줄이면 보다 우수한 endurance 특성을 얻을 수 있으며, ReRAM 소자의 전력소비감소에 효과적이라고 기대된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.215-220
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• 2002

Epoxy-coated re-bar was partly used to the structures and put to practical use, but were not economical and appeared to have defects such as the diminishing of long term bond strength between concrete. The study of polymer cement slurry coated re-bar was started in order to complement the defect of epoxy coated re-bar, and ever since the basic properties appeared to be excellent. But, study of bond properties embedded in concrete specimens was insufficient until now. This study attempts to examine the possibility of improving the bond strength of polymer cement slurry coated re-bar between concrete specimens in accordance with ACI Code and KS Code through pull-out test of 150mm$\times$150mm$\times$150mm substrates with polymer cement slurry coated re-bar having polymer cement ratios of 50%, 75% and 100%, coating thickness 250${\mu}{\textrm}{m}$, 450 ${\mu}{\textrm}{m}$ and with curing ages of 3, 7 and 28 days. High strength concrete was designed having a compressive strength of 500kgf/cm2 as specified. Practical bond length ranges of 55 and 85mm were applied to each of specimen. The bond strength of polymer cement slurry coated re-bar using St/BA-1 and St/BA-2 was compared to that of plain re-bar. The results of this study showed that the bond strength of 55mm bond length was much higher than that of 85mm bond length.

• 한국의류산업학회지
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• 제24권2호
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• pp.241-248
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• 2022

This study aims to provide basic data to suggest guidelines for re-education and work improvement of modelists based on the analysis of the current status of modelist work and education. A survey was conducted from January 4 to May 15, 2020, targeting 44 people working in pattern, pattern CAD, and grading in domestic apparel companies. Descriptive statistical analysis and frequency analysis using SPSS 25 were employed to analyze the status of work type, work difficulties, and re-education. For pattern production, the rate of using pattern CAD for business was high. It was found that companies mainly use YUKA CAD (63.8%), and branded companies use pattern CAD (100%). It was found that 3D CAD is mostly employed by vendors (88.9%), and CLO (90%) is mainly used. Regarding difficulties in pattern making, it was found that they experienced difficulties with stretchable materials owing to the amount of shrinkage and sagging of the fabric. The work problem was the lack of requisite working hours owing to the volume of work. Regarding future re-education, 63.6% of the total respondents indicated that they required a course related to pattern correction and material. Moreover, it was found that re-education was necessary to upgrade technology and acquire new knowledge, however, information on re-education was insufficient.