• Proceedings of the Materials Research Society of Korea Conference
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• 2008.05a
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• pp.44.1-44.1
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• 2008

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.480-480
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• 2013

태양에너지는 신재생 에너지 중에서 무한한 에너지원으로서 태양에너지에 대한 활발한 연구가 이루어지고 있다. 그 중에서도 결정형 실리콘 태양전지에 대해 다양한 연구가 진행 중이다. 이러한 실리콘 태양전의 제작은 실리콘 식각 용액을 이용하여 기판의 절삭 손상된 부분을 식각한 후 텍스쳐링(texturing) 공정을 통해 표면의 흡수율을 높이고, 반면에 반사율을 감소시킨다. 텍스쳐링 공정이 끝난 후 도핑 공정을 통해 에미터(emitter)를 형성, 반사방지막을 증착, 기판의 전면과 후면에 페이스트를 바르고 스크린인쇄법으로 전극을 형성한 후 마지막으로 형성된 전극을 소성 공정을 통해 전극이 에미터와 접촉하면 태양전지가 완성된다. 하지만 텍스쳐링 공정을 통해 만들어진 피라미드 구조는 도핑공정을 하게 되면, 꼭짓점 부분의 균일한 도핑이 이루어지지 않는다. 이러한 균일하지 않은 공정으로 인해 전극 소성 공정에서 일부의 에미터층을 뚫어버리게 되므로 누설전류가 증가하게 된다. 그래서 본 논문에서는, 변환 효율을 개선시키기 위해 표면 구조와 반사방지막의 열처리 공정에 대한 연구를 하였다. 우선 피라미드 구조를 균일하게 만들었으며, 반사방지막 형성 후 열처리를 하여 소수 캐리어 수명을 증가시켰으며, 누설전류를 감소하였다. 균일한 도핑 및 전극 형성을 용이하게 하는 부드러운 피라미드 구조를 형성하기 위해 HND (HF：HNO3 : D.I wafer=5 : 100 : 100) 용액을 사용하여 식각하였다. 그 결과 직렬저항은 NHD용액을 사용하여 300초 동안 식각하였을 때 $1.284{\Omega}$ 낮아지는 결과를 얻을 수 있었으며, 도핑을 균일화하여 누설전류를 감소시킬 수 있었다.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.134-139
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• 2010

Mycobacterium tuberculosis (Mtb) is one of the most successful pathogens to infect one third of world population. Th1-mediated immunity against Mtb infection is known as critical to express mycobacteriostatic function but it is not sufficient to resolve the infection. In this study, to verify the possibility Mtb itself change the gene expression to survive against host immune response, expression pattern of selected H37Rv genes, 16S rRNA, acr, fbpA, aceA, and ahpC, during the course of infection was measured with absolute quantitation method using real-time RT-PCR. The total number of transcripts of 16S rRNA increased during the course of infection, which was coincide with the increasing CFU. The total number of fbpA transcripts per CFU, which encode typical secreted Mtb antigen, Ag85A, increased for 10 days of infection before decreasing. The number of transcripts of acr per CFU, which encode heat shock protein, ${\alpha}$-crystallin, increased during the infection, and ahpC and aceA, they both are enzymes produced in oxidative stressful condition, increased for 20 days and then slightly decreased on day 30. These findings are one of survival strategy of pathogen evading host immune response lead to persistent infection inside host cells.

• Journal of Life Science
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• v.14 no.3
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• pp.514-520
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• 2004

The antioxidative effects of fermented milk, mushroom extract and fermented milk containing its extract (Lentinus edodes, Ganoderna lucidum, and Pleurotus ostreatus) on the lipid peroxidation in the tissues of female Sprague-Dawley rats and on the DPPH ($\alpha,\alpha$' -diphenyl-$\beta$-picrylhydrazyl) radical donating ability were studied. The total concentrations of polyphenolic compound in Lentinus edodes, Ganoderma lucidum and Pleurotus ostreatus were 0.34, 0.20 and 0.34%, respectively. The DPPH donating abilities of mushroom extract, fermented milk, fermented milk containing its extract and BHT (butylated hydorxytoluene) as standard were 33.9, 34.9, 51.9 and 95.6%, respectively. Experimental diet groups were divided into five groups: the normal diet (ND), the cholesterol diet (CD), and cholesterol + fermented milk diet (CDFM), cholesterol + mushroom extract diet (CDME) and cholesterol + fermented milk containing mushroom extract diet (CDFMME). The concentrations of lipid peroxide in liver and its microsome were significantly lower in both CDFM and CDFMME groups than in the other groups. The kidney concentration of lipid peroxide was significantly higher in the CD group than in the ND group, but this rise were significantly decreased in the CDFM and CDFMME groups. Meanwhile, the concentrations of heart and spleen and their fractions were not significantly different among dietary groups. This study was suggested that the fermented milk diet containing mushroom extract effectively reduced the lipid peroxidation in liver and kidney of cholesterol-fed female rats.

• The Korean Journal of Mycology
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• v.18 no.2
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• pp.96-101
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• 1990

This study was conducted to select the promising antifungal microoganisms for biological control of wet bubble, Mycogone perniciosa. Ninty one isolates of fungi, 342 isolates of bacteria, and 556 actinomycetes were isolated from mushroom composts and soils, were subjected to primary screening test on agar medium base for their antimicrobial spectra. Among them, 12 bacteria and 71 actinomycetes were selected. Among the antibiotic producing microoganisms, 5 cultures were selected on the basis their antibiotic activities on casing soil with Benlate nontolerence M. perniciosa. Finally, AJ-117, AJ-136 and AK-139 were selected as microoganism with antifungal activity against two strains of M. perniciosa.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.334-338
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• 2007

The disinfection effects of trichloroisocyanuric acid (TICA), calcium hypochlorite (CH), and Bromochlorodimethylhydantoin (BCDMH) on various bacteria in aqueous suspension were comparatively characterized at various concentrations and exposure times of each disinfectant. When various bacteria cells ($10^8\;CFU/ml$) including Escherichia coli, Pseudomonas aeroginosa, Enterococcus faecalis, Bacillus cereus, Legionella pneumophila, and Staphylococcus aureus were exposed with a solution containing 8 ppm each of TICA, a 99% of the initial cells were killed in 60 sec, 368 sec, 372 sec, 506 sec, 812 sec, and 909 sec, respectively. In addition, the minimum exposure time required to kill 99% of E. coli ($10^8\;CFU/ml$) with 8 ppm of each TICA, BCDMH and CH was measured at 60 sec, 114 sec, and 7,100 sec, respectively. These comparative studies demonstrate that disinfection efficacy is highly variable depending on microbial species as well as disinfectant type, concentration, and exposure time.

• The Korean Journal of Mycology
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• v.33 no.2
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• pp.98-102
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• 2005

In 2003 to 2005, the root rot of Japanese angelica (Aralia elata) was surveyed in nursery beds of Korea, where incidence of the disease often reached up to 100%. Three isolates were obtained from the infected roots, and identified as Phytophthora cactorum on the basis of cultural, morphological characteristics and molecular analysis. The isolates were characterized by having markedly papillate and broadly ovoid deciduous sporangia. The optimum temperature for mycelium growth was at $25^{\circ}C$ on V8 juice agar. Pathogenicity of the isolates was confirmed by soil mixture inoculation. Approximately 900 bp of ITS rDNA was amplified from all 3 isolates and band pattern of restriction fragments observed by Alu I, Msp I, and Taq I digestion also supported the result of the morphological identification when compared with PhytID database.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.2
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• pp.133-138
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• 2015

This paper presents a performance improvement of gray level co-occurrence matrix(GLCM) based on the nonuniform quantization, which is generally used to analyze the texture of images. The nonuniform quantization is given by Lloyd algorithm of recursive technique by minimizing the mean square error. The nonlinear intensity levels by performing nonuniformly the quantization of image have been used to decrease the dimension of GLCM, that is applied to reduce the computation loads as a results of generating the GLCM and calculating the texture parameters by using GLCM. The proposed method has been applied to 30 images of $120{\times}120$ pixels with 256-gray level for analyzing the texture by calculating the 6 parameters, such as angular second moment, contrast, variance, entropy, correlation, inverse difference moment. The experimental results show that the proposed method has a superior computation time and memory to the conventional 256-level GLCM method without performing the quantization. Especially, 16-gray level by using the nonuniform quantization has the superior performance for analyzing textures to another levels of 48, 32, 12, and 8 levels.

• Journal of Dairy Science and Biotechnology
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• v.15 no.1
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• pp.11-20
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• 1997

This study was designed to carry out an observation on the growth inhibitory effect of fermented milk by the the lactic acid bacteria such as Lactobacillus bulgaricus, L. acidophilus and L. cormatus against pathogenic Escherichia coli O157:H7 were studied in vitro. The results of this study were as follows : The BL broth culture of L. bulgaricus, L. acidophilus and L. cormatus gave a similar extent of growth inhibitory effects against the pathogenic E. coli O157:H7 were after incubation time within 18 hours. The inhibitory effects of the fermented milk were observed on the survival time of pathogenic E. coli O167:H7 in the various fermented milk at 37${\circ}$C shaking water bath (70 rpm) were after incubation time between 140 and 200 minutes. These results indicated that major portion of growth inhibitory effects of fermented milk with various lactic acid bacteria against pathogenic E. coli O157:H7 was possible due to the acid, and minor portion to the other antibacterial substances.

• Applied Biological Chemistry
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• v.47 no.4
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• pp.373-378
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• 2004

In this study, established soil-borne Bacillus sp. FF-9 with strong antifungal activity was isolated for identification and to determine optimal culture condition. By using 16s rDNA sequencing method, FF-9 of the selected bacteria was identified as genus Bacillus sp., Bacillus sp. FF-9 was cultured at $30^{\circ}C$, for 24 h in the LB medium. Cell growth increased quickly after 6 h and the highest cell growth was indicated at 12 h. The most antifungal activity against Rhizoctoina solani AGII-II appeared at 18 h and the optimal temperature and pH were 30 and pH 8.0, respectively. A testing of carbon and nitrogen sources showed the highest antifungal activity at 1% lactose and 1% yeast extract Furthermore an addition of salt showed the most antibiotic activity in the 0.15% $K_2HPO_4$.