• Journal of Plant Biotechnology
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• 제36권1호
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• pp.38-44
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• 2009

Two low temperature induced genes designated as SLTI66 and SLTI629 encoding KS-type dehydrin were heterologously expressed in E coli and A. thaliana. E coli cells expressing SLTI66 and SLTI629 protein grew better with iron stress compared to the control cells. Ectopic expression of SLTI629 conferred tolerance to iron stress in Arabidopsis but SLTI66 did not. Arabidopsis plants expressing SLTI66 showed enhanced tolerance to freezing and drought stress compared to those of wild type and SLTI629 lines. We propose that SLTI66 and SLTI629 play a different role as a protector against osmotic and metal stresses.

• Journal of Welding and Joining
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• 제33권1호
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• pp.54-60
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• 2015

Laser-arc hybrid welding has been considered as an effective pipe girth welding process since early 2000's. Tolerance for fit-up offsets such as gap and edge misalignment is one of most important requirements in pipe girth laser-arc hybrid welding, and several approaches using parameter optimization, a laser beam scanning and an arc oscillation have been tried. However the required offset tolerance has not been fully accomplished up to now and laser-arc hybrid welding has not been widely applied in pipeline construction than expected, despite of its high welding speed and deep penetration. In this study, internal welding was adopted to ensure the offset tolerance and sound back bead. The effect of welding parameters on bead shape was investigated at the flat position. Also tolerances for gap and edge misalignment were verified as 0.5 mm and 2.0 mm, respectively. The position welding trials were conducted at several welding positions from the flat to the overhead position in a downward direction. With the fixed welding speed, arc current for gas metal arc welding current and laser output power, adequate welding voltages for gas metal arc welding were suggested for each position.

• Bulletin of the Korean Chemical Society
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• 제7권1호
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• pp.12-15
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• 1986

Lead tolerance of $Pt/Al_2O_3$ catalysts was evaluated for CO oxidation depending on the properties of the alumina supports and base metals added as promoter. Among the four different alumina supports, the support with a large macropore volume (0.45 cc/g) and 5% Ce has shown the best resistence to lead poisoning. Most of the base metals added to the Pt-catalysts were found to be ineffective for improving lead resistence, but boron has shown an excellent lead tolerence, although it decreases the initial catalytic activity.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.93-94
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• 2006

A novel production method for porous metal components has been developed by applying powder space holder (PSH) method to metal powder injection molding (MIM) process. The PSH-MIM method has an industrial competitive advantage that is capable of net-shape manufacturing the micro-sized porous metal products with complicated shapes and controlled porosity and pore size. In this study, the small impeller with homogeneous micro-porous structure was manufactured by the PSH-MIM method. The effects of combinations in size and fraction of PMMA particle on dimensional tolerance and variation of sintered porous specimens were investigated. It was concluded that the PSH-MIM method could manufacture commercially microporous metal components with high dimensional accuracy.

• KSBB Journal
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• 제16권1호
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• pp.54-60
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• 2001

저품위 광석으로부터 유가 금속을 회수하기 위한 생물용출법의 적용에 있어 미생물의 활성은 매우 중요하며, 제련미생물은 금속이온에 대해 어느 정도 내성을 가지고 있어야 한다. 본 연구에서는 대표적인 제련미생물인 Thiobacillus ferrooxidans의 철산화속도에 미치는 단독 혹은 혼합 금속이온의 영향을 조사하여, T. ferrooxidans의 금속이온에 대한 내성 특성을 조사하였다. 생장 배지에 $Zn^{2+}$, $Cu^{2+}$, $Ni^{2+}$, 및 $Cd^{2+}$를 단독으로 첨가한 경우(첨가농도범위, $Zn^{2+}$ 60g/L이하, $Cu^{2+}$, $Ni^{2+}$, 및 $Cd^{2+}$ 6 g/L 이하)에는 T. ferrooxidans에 의한 철산화속도는 금속이온의 첨가량에 크게 저해 받지 않았다. $Zn^{2+}$를 제외한 $Cu^{2+}$, $Ni^{2+}$, 및 $Cd^{2+}$의 2 성분 혹은 3 성분의 혼합금속이온을 첨가한 경우에는 T. ferrooxidans의 철산화 활성에 대한 혼합 금속이온의 저해 효과는 최대 50% 정도로 크게 나타나지는 않았다. 그러나, $Zn^{2+}$을 타 금속이온과 2 성분 혹은 3 성분을 혼합하여 생장 배지에 첨가한 경우에는 T. ferrooxidans의 철산화 활성 저해에 대한 혼합 금속이온의 상승 효과가 큰 것을 밝혔다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 1998년도 제38회 춘계학술발표대회
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• pp.43.1-43.1
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• 1998

• 한국환경과학회지
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• 제23권1호
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• pp.61-68
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• 2014

This study attempted to utilize various groundcover plants in phytoremediation, using shade plants, which often have a high shade tolerance for shade urban space. Liriope platyphylla was grown in soil containing three of heavy metals, Zn, Cd, and Pb under four different concentrations (0, 100, 250 and 500 mg/kg) to determine the heavy metal accumulation characteristics and removing from soil. Total amounts of accumulated Zn in L. platyphylla were increased in accordance with increasing elevated Zn concentrations in soil, but the difference was not significant between Zn250 and Zn500. Cd accumulation, sharply increased in Cd100 and Cd250, but was reduced in Cd500. Increased Pb concentration in soil resulted a continuous increase in the total amounts of Pb accumulated in L. platyphylla. The total content of Zn in soil decreased by almost 50% in Zn100, almost 33% in Zn250 and 20% in Zn500 through growth of L. platyphylla over a period of 7 months. In the case of Cd, the concentration in soil, was decreased with 10% in Cd100, 10% in Cd250 and 33% in Cd500 through growth of L. platyphylla over a period of 7 months. This results indicate that more Cd was removed by planting L. platyphylla, compared to Zn or Pb.

• Journal of Plant Biotechnology
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• 제42권4호
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• pp.409-413
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• 2015

본 연구는 토양에 오염된 중금속을 제거하기 위한 식물정화공정에 사용할 식물체를 개발하기 위해 $TgMTP_1$ 유전자를 CaMV35S 상시 발현 할 수 있도록 Ti-plasmid 벡터를 구축하여 형질전환식물을 육성하였다. 유전자가 도입된 형질전환 애기장대에서 TgMTP유전자를 과발현하는 호모 TG-116 (T3 generation) 계통을 육성하여 그 특성을 조사하였다. 호모계통으로 육성한 TG-116 계통은 callus 및 식물체에서 중금속에 대한 저항성을 보였다. 특히 RT-PCR 및 Western 분석에서 유전자의 발현은 잎에서 높게 나타났으며, Ni 흡수 및 축적이 많이 일어났다. 따라서 MTP1 유전자가 발현되어 액포에 중금속을 축적하는 실험결과를 활용한다면 식물정화공정에 사용할 수 있는 다양한 유전자원으로 기대할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제31권8호
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• pp.1045-1059
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• 2021

Various abiotic stressors like drought, salinity, temperature, and heavy metals are major environmental stresses that affect agricultural productivity and crop yields all over the world. Continuous changes in climatic conditions put selective pressure on the microbial ecosystem to produce exopolysaccharides. Apart from soil aggregation, exopolysaccharide (EPS) production also helps in increasing water permeability, nutrient uptake by roots, soil stability, soil fertility, plant biomass, chlorophyll content, root and shoot length, and surface area of leaves while also helping maintain metabolic and physiological activities during drought stress. EPS-producing microbes can impart salt tolerance to plants by binding to sodium ions in the soil and preventing these ions from reaching the stem, thereby decreasing sodium absorption from the soil and increasing nutrient uptake by the roots. Biofilm formation in high-salinity soils increases cell viability, enhances soil fertility, and promotes plant growth and development. The third environmental stressor is presence of heavy metals in the soil due to improper industrial waste disposal practices that are toxic for plants. EPS production by soil bacteria can result in the biomineralization of metal ions, thereby imparting metal stress tolerance to plants. Finally, high temperatures can also affect agricultural productivity by decreasing plant metabolism, seedling growth, and seed germination. The present review discusses the role of exopolysaccharide-producing plant growth-promoting bacteria in modulating plant growth and development in plants and alleviating extreme abiotic stress condition. The review suggests exploring the potential of EPS-producing bacteria for multiple abiotic stress management strategies.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.483-489
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• 2008

Nine newly isolated mushroom strains were tested to assess both their zinc tolerance and potential for zinc removal from an aqueous solution. Four strains of ectomycorrhizal fungi, namely Clavariadelphus truncatus (T 192), Rhizopogon roseolus (T 21), Lepista nuda (T 373), and Tricholoma equestre (T 174), along with five strains of white rot fungi, Lenzites betulina (S 2), Trametes hirsuta (T 587), Ganoderma spp. (T 99), Polyporus arcularius (T 438), and Ganoderma carnosum (M 88), were investigated using zinc-amended solid and liquid media. Their biosorption properties were also determined. The colony diameter and dry weight were used as tolerance indices for fungal growth. C. truncatus and T. equestre were not strongly inhibited at the highest concentrations of (225 mg/l) zinc in solid media. The most tolerant four strains with solid media, C. truncatus, G carnosum, T. hirsuta, and T. equestre, were then chosen for tolerance tests in liquid media. An ectomycorrhizal strain, C. truncatus, was also detected as the most tolerant strain in liquid media. However, the metal-tolerant strains demonstrated weak activity in the biosorption studies. In contrast, the highest biosorption activity was presented by a more sensitive strain, G. carnosum. In addition, seven different biosorbent types from G. carnosum (M 88) were compared for their Zn (II) biosorption in batch experiments.