• 전기화학회지
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• 제3권2호
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• pp.85-89
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• 2000

Lithium ion Battery(LIB)의 음극 활물질로써 리튬을 대체하기 위한 노력으로 phenol resin을 탄화시킨 탄소재료를 사용하였다. Phenol resin을 소성하면 축합반응을 일으키면서 탄화되어 무정형 탄소가 된다. 무정형 탄소는 층간거리가 넓어 리튬의 삽입과 탈리가 용이하지만 탄소간의 결합력이 약하여 구조적 붕괴가 일어난다. 이러한 문제를 해결하기 위해 세공형성제로서 $ZnCl_2$를 사용하였다. $ZnCl_2$는 생성된 물질에서 3차원적 망상구조로 성장하는 개방세공을 형성하는 세공형성제로서 뿐만 아니라, 벌크 첨가제가 도핑된 느슨한 구조를 형성하는 미세세공 형성제로서 작용하였다. SEM을 통해서 구조적 차이를 알 수 있었으며, XRD분석으로 층간의 거리를 알 수 있었다. CV측정을 통해 두 가지 샘플에 대한 산화와 환원 반응의 차이를 알아보았다.

• 한국환경과학회지
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• 제27권2호
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• pp.109-122
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• 2018

This study was conducted to investigate the removal characteristics of heavy metals and sulfate ion from acid mine drainage by porous zeolite-slag ceramics (ZS ceramics) that was prepared by adding wood flour as pore-foaming agent while calcining the mixtures of natural zeolite and converter slag. The batch test showed that the removal efficiency of heavy metals by pellet-type porous ZS ceramics increased as the particle size of wood flour was decreased and as the weight mixing ratio of wood flour to ZS ceramics was increased. The optimal particle size and weight mixing ratio of wood flour were measured to be $75{\mu}m$ and 7~10%, respectively. The removal test with the porous ZS ceramics prepared in these optimal condition showed very high removal efficiencies: more than 98.4% for all heavy metals and 73.9% for sulfate ion. Relative to nonporous ZS ceramics, the increment of removal efficiency of heavy metals by porous ZS ceramics with $75{\mu}m$ and 10% wood flour was 5.8%, 60.5%, 36.9%, 87.7%, 10.3%, and 57.4% for Al, Cd, Cu, Mn, Pb, and Zn, respectively. The mechanism analysis of removal by the porous ZS ceramics suggested that the heavy metals and sulfate ion from acid mine drainage are eliminated by multiple reactions such as adsorption and/or ion exchange as well as precipitation and/or co-precipitation.

• The Plant Pathology Journal
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• 제24권2호
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• pp.202-206
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• 2008

Antifungal activity of Korean and Chinese lichen-forming fungi (LFF) was evaluated against plant pathogenic fungus of Colletotrichum acutatum, causal agent of anthracnose on hot pepper. This is the first attempt to evaluate antifungal activity of LFF, instead of lichen thalli, against C. acutatum. Total 100 LFF were isolated from the lichens with discharged spore method or tissue culture method. Among the 100 isolates, 8 LFF showed more than 50% of inhibition rates of mycelial growth of the target pathogen. Especially, Lecanora argentata was highly effective in inhibition of mycelial growth of C. accutatum at the rate of 68%. Antifungal activity of other LFF was in the order of Cetrelia japonica (61.4%), Ramalina conduplicans (59.5%), Umbilicaria esculenta (59.5%), Ramalina litoralis (56.7%), Cetrelia braunsiana (56.5%), Nephromopsis pallescensn (56.1%), and Parmelia simplicior (53.8%). Among the tested LFF, 61 isolates of LFF exhibited moderate antifungal activity against the target pathogen at the inhibition rates from 30 to 50%. Antifungal activity of the LFF against C. acutatum was variable at the species level rather than genus level of LFF. This study suggests that LFF can be served as a promising bioresource to develop novel biofungicides.

• 한국미생물·생명공학회지
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• 제18권3호
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• pp.221-226
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• 1990

Bacillu circulans F-2를 포함한 B.circulans의 prophage와 bacteriocin을 검출하기 위하여, mitomycin C를 처리하고 전자현미경상, plaque 형성능(plaque-forming activity), 세균세포살균능(killing activtiy)을 실험했다. killing activity 양성균으로부터 서당밀도균배원심(sucrose gradient centrifugation)을 통해 bacteriophage-like particle의 존재를 확인하였다. 이들 입자들은 형태학적으로 phage tail 또는 T4 phage와 닮은 구조를 가지고 있었다.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.385-389
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• 2012

The application of microorganisms in the field of construction material is rapidly increasing worldwide; however, almost all studies that were investigated were bacterial sources with mineral-producing activity and not with organic substances. The difference in the efficiency of using bacteria as an organic agent is that it could improve the durability of cement material. This study aimed to assess the use of biofilm-forming microorganisms as binding agents to increase the compressive strength of cement-sand material. We isolated 13 alkaliphilic biofilmforming bacteria (ABB) from a cement tetrapod block in the West Sea, Korea. Using 16S RNA sequence analysis, the ABB were partially identified as Bacillus algicola KNUC501 and Exiguobacterium marinum KNUC513. KNUC513 was selected for further study following analysis of pH and biofilm formation. Cement-sand mortar cubes containing KNUC513 exhibited greater compressive strength than mineral-forming bacteria (Sporosarcina pasteurii and Arthrobacter crystallopoietes KNUC403). To determine the biofilm effect, Dnase I was used to suppress the biofilm formation of KNUC513. Field emission scanning electron microscopy image revealed the direct involvement of organic-inorganic substance in cement-sand mortar.

• 환경위생공학
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• 제8권1호
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• pp.129-138
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• 1993

The marked spread of the cockraches of recent years has raised a great social problem in urban areas. The cockroach have to remove1 because transmit a disease to human as pest insect, but particulars are not yet reported on biological control agent for the cockroach removal. This study was tried for the first time on biological control for the cockroach removal. The obtained results were as follows : 1. The isolated were spore-forming bacillus 1098 strain in soil. The No. 109(TH 109) strain of the among spore-forming bacillus was showed the poisonous against Cockroach. 2. The biological characteristics and flagella antigenicity of the strain is similar to Bacillus thur-ingiensis subsp. indiana. 3. TH 109 strain have the delta-endotoxin of cuboid shap. 4. This delta-endotoxin of product by TH 109 strain was toxic to the cockroach(Blattella gemzanica. L).

• Mycobiology
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• 제33권3호
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• pp.158-162
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• 2005

The immunomodulatory effect of aqueous extract of Inonotus obliquus, called as Chaga, was tested on bone marrow cells from chemically immunosuppressed mice. The Chaga water extract was daily administered for 24 days to mice that had been treated with cyclophosphamide (400 mg/kg body weight), immunosuppressive alkylating agent. The number of colony-forming unit (CFU)-granulocytes/macrophages (GM) and erythroid burst-forming unit (BFU-E), increased almost to the levels seen in non-treated control as early as 8 days after treatment. Oral administration of the extract highly increased serum levels of IL-6. Also, the level of $TNF-{\alpha}$ was elevated by the chemical treatment in control mice, whereas was maintained at the background level in the extract-treated mice, indicating that the extract might effectively suppress $TNF-{\alpha}$ related pathologic conditions. These results strongly suggest the great potential of the aqueous extract from Inonotus obliquus as immune enhancer during chemotherapy.

• 한국세라믹학회지
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• 제52권6호
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• pp.403-409
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• 2015

Porous alumina ceramics are involved in many industrial applications due to the exceptional properties of these products. This study addresses the preparation of porous alumina ceramics using hollow microspheres as a pore-forming agent and slip casting as a green-body-forming technique. A uniform distribution of pores is a basic requirement of a porous material. This study investigates three different slurry systems, i.e., as-prepared alumina slurry, alumina slurry electrostatically dispersed by hydrochloric acid (HCl), and slurry dispersed by the commercial dispersant 'Darvan C-N'. At a low viscosity, the hollow microspheres in the slurry tend to float, which causes a non-uniform pore distribution. To avoid this phenomenon, the viscosity of the slurry was increased to the extent that the movement of hollow microspheres ceased in the slurry. As a result, a uniform pore distribution was achieved.

• Journal of Ginseng Research
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• 제25권2호
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• pp.63-67
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• 2001

We previously reported that acidic polysaccharide from Panax ginseng induced the proliferation lymphocytes and the generation of activated killer cells. Here we found that polysaccharide (PG-75) precipitated with 75% EtOH from water extract of Panax ginseng also has both in vitron and in vivo hematopoietic activities. In vitro studied with bone marrow cells from BALB/c mouse revealed that PG-75 had direct effect on hematopoietic colony-forming cell(CFC) growth, increased granulocyte macrophage-colony forming cell numbers by 1.59 fold over than non-treated. the ability of PG-75 to modulate hematopoiesis in vivo was evaluated the bone marrow and spleen celluarity, granulocyte-macrophage progenitor cells. BALB/c female mice were administered G-75 intraperitoneally, PG-75 was found to significantly increase the number of BM cells, spleen cells, GM-CFU on 3 hours after injection. PG-75 was also able to induce significant augmentation of GM-CSF and IFN-${\gamma}$, production in sera. These studies illustrate than PG-75 has hematopoietic activities and that this agent may be useful in the prevention and/or treatment of radio- or chemotherapy-associated myelosuppression.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.38-39
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• 2018

Foame concrete was used to reduce insulation problems and interlayer noise in slab. There have been no studies on the physical properties of foaming agents using foamed concrete,Only the physical properties of foamed concrete mixed with foam agent. It is judged that the density and distribution of Foams will be changed when the pressre is changed when the bubble is formed. In this study to investigate the changes of Foam density and the physical performance of foamed concrete by changing the pressure during Foam formation.