• Title/Summary/Keyword: Heat treatment condition

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A Study on Synthesis and Crystallization of a Benzimidazolone Pigment (Benzimidazolone계 안료의 합성 및 용매 결정화에 관한 연구)

  • Kim, Song Hyuk;Kim, Jae Hwan;Yang, Seok Won;Lee, Won-Ki;Jin, Young Eup;Park, Seong Soo
    • Applied Chemistry for Engineering
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    • v.26 no.2
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    • pp.159-164
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    • 2015
  • Pigment yellow 180 (P.Y.180), a kind of benzimidazolone, has been widely used in various industrial fields of ink, paint, plastics, toner, and color filter, etc. This is a high performing pigment that is a greenish yellow shade with excellent properties such as heat resistance, solvent resistance, acid resistance and alkali resistance. In this study, pigment compounds were synthesized using various coupling reaction temperature condition. The properties of samples crystallized under various solvents and temperature conditions using autoclave pressurizer were also investigated. The pigment crystallized using DMSO solvent treatment showed the improvements such as the increase of X-ray intensity ratios and particle size, high color strength, and enhanced dispersibility.

Flooding Stress-Induced Glycine-Rich RNA-Binding Protein from Nicotiana tabacum

  • Lee, Mi-Ok;Kim, Keun Pill;Kim, Byung-gee;Hahn, Ji-Sook;Hong, Choo Bong
    • Molecules and Cells
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    • v.27 no.1
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    • pp.47-54
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    • 2009
  • A cDNA clone for a transcript preferentially expressed during an early phase of flooding was isolated from Nicotiana tabacum. Nucleotide sequencing of the cDNA clone identified an open reading frame that has high homology to the previously reported glycine-rich RNA-binding proteins. The open reading frame consists of 157 amino acids with an N-terminal RNA-recognition motif and a C-terminal glycine-rich domain, and thus the cDNA clone was designated as Nicotiana tabaccum glycine-rich RNA-binding protein-1 (NtGRP1). Expression of NtGRP1 was upregulated under flooding stress and also increased, but at much lower levels, under conditions of cold, drought, heat, high salt content, and abscisic acid treatment. RNA homopolymer-binding assay showed that NtGRP1 binds to all the RNA homopolymers tested with a higher affinity to poly r(G) and poly r(A) than to poly r(U) and poly r(C). Nucleic acid-binding assays showed that NtGRP1 binds to ssDNA, dsDNA, and mRNA. NtGRP1 suppressed expression of the fire luciferase gene in vitro, and the suppression of luciferase gene expression could be rescued by addition of oligonucleotides. Collectively, the data suggest NtGRP1 as a negative modulator of gene expression by binding to DNA or RNA in bulk that could be advantageous for plants in a stress condition like flooding.

Studies on the Production and Properties of Chitinase Produced by Streptomyces sp. (방선균이 생산하는 Chitinase의 성질에 관한 연구)

  • 김광현;서정훈
    • Microbiology and Biotechnology Letters
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    • v.6 no.4
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    • pp.149-153
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    • 1978
  • A strain of Streptomyces sp producing chitinase was isolated from soil and its cultural condition and some properties of this enzyme were investigated. When 0.375 per cent of glucose was added to basal medium, this organism produced the most quantities of this enzyme after shaking culture at 3$0^{\circ}C$ for 48 hrs., while the production of the enzyme was repressed at the more concentration of glucose than that. The enzyme had a optimal pH of 7.0, optimal temperature of 5$0^{\circ}C$ and the activity of that was not decreased by heat treatment for 20 minute at 7$0^{\circ}C$. And then the activity was increased by Co$^{2+}$ but was slightly inhibited by Hg$^{2+}$, Ni$^{2+}$, Pb$^{2+}$.EX> 2+/.

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Analysis for Cause of Corrosion and Gas Leakage on LP-Gas Cylinder (LP가스 용기의 부식 및 가스누출 원인 분석)

  • Choi S. C.;Jo Y. D.;Kweon J. R.;Kim J. Y.
    • Journal of the Korean Institute of Gas
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    • v.5 no.1
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    • pp.52-59
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    • 2001
  • Factors to cause accidents were investigated through a systematic analysis of leakage accidents in welded LP-gas cylinder between 199 and 1999. As a result It was showed that most of leakage accident occurred at the pin-hole due to the localized corrosion on welded zone in cylinder. Accordingly, in this paper, we suggested that the problems of heat treatment condition in two-piece welded cylinder and substitute proposal for preventing the tearing of T zone in three-piece welded cylinder. Furthermore, corrosion rate on the weldment and base metal of welded LP-gas cylinder was evaluated using the electrochemical tests in acid rain and $3.5\%NaCl$ solution, Also, the poor adhesion and defects of film which was produced by electrostatic powder spray painting, while the LP-gas cylinder was manufactured, were analyzed using SEM(Scanning Electron Microscopy). And we proposed a optimum coating thickness of the cylinder.

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Compensatory Hyperhidrosis after Thoracoscopic Sympathectomy in Essential Hyperhidrosis (본태성 다한증 환자의 수술 후 발생하는 보상성 다한증)

  • Seo, Eui Kyo;Cho, Yong Eun;Yoon, Do Heum;Kim, Young Soo
    • Journal of Korean Neurosurgical Society
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    • v.30 no.4
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    • pp.486-492
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    • 2001
  • Objective : Essential hyperhidrosis is a pathological condition of excessive sweating beyond that required to cool the body, though poorly understood, originating from a dysfunction of the sympathetic nervous system. Thoracoscopic sympathectomy is the most popular treatment for upper limb hyperhidrosis, because it is a safe, effective, minimally invasive, and time-saving method. However, the common complication is the compensatory hyperhidrosis in other areas of the body, notably on the back, chest, abdomen, and buttocks. Compensatory hyperhidrosis is severe enough for some people, especially those living in a warm climate or engaging in heavy physical activities, to regret ever having had operation. The pathophysiological mechanisms underlying compensatory hyperhidrosis are incompletely understood, even though it is thought to be a truly compensatory feature related to thermoregulation of the body. Materials and Methods : we studied the clinical features of total 233 patients who were diagnosed as essential hyperhidrosis and treated with thoracoscopic sympathectomy or sympathicotomy from March 1992 to July 2000. Results : The success rate of thoracoscopic sympathetic surgery(sympathectomy or sympathicotomy) was 98.7%. The global rate of compensatory hyperhidrosis was 77% ; 84% in group T2, 3 sympathectomy, 76% in group T2 sympathectomy, 43% in group T2, 3 sympathicotomy and 59% in group T2 sympathicotomy. The rate of embarrassing or disabling compensatory sweating was significantly higher in T2 sympathectomy and in T2, 3 sympathectomy than in T2 sympathicotomy and T2, 3 sympathicotomy with significancy in statistic analysis(p<0.01). The precipitating factors of compensatory hiperhidrosis, including heat(warm weather), anxiety, stress, and exertion were noted. The compensatory hyperhidrosis was the main cause of patient dissatisfaction after thoracoscopic sympathectomy. Conclusion : The degree of compensatory hyperhidrosis is closely related to the extent of thoracic sympathectomy.

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Development of a Cost-Effective Process for the Fabrication of Single Grain $YBa_2Cu_3O_{7-y}$ Bulk Superconductors (단결정 $YBa_2Cu_3O_{7-y}$ 벌크 초전도체 제조를 위한 경제적 공정의 개발)

  • Park, Soon-Dong;Kim, Kwang-Mo;Jun, Byung-Hyuk;Han, Young-Hee;Kim, Chan-Joong
    • Progress in Superconductivity
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    • v.13 no.2
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    • pp.133-138
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    • 2011
  • To reduce the processing cost of the single grain REBCO (RE: Rare-earth elements) bulk superconductors, a cost-effective process should be developed. One possible way of developing the cost-effective process is the use of low-cost precursor powders. In this study, the single grain YBCO superconductors were fabricated using a home made powder. $YBa_2Cu_3O_{7-y}$ (Y123) powders were synthesized at $850-900^{\circ}C$ in air by the powder calcination method with repeated crushing and heat treatment steps. The processing parameters for the fabrication of single grain Y123 bulk superconductors, $T_{max}$ (maximum temperature), $T_p$ (peritectic temperature) and a cooling rate through $T_p$ were optimized. To enhance the flux pinning capacity of the single grain Y123 samples, $Y_2BaCuO_5$ (Y211) particles were dispersed in the Y123 matrix by adding $Y_2O_3$ powder to the calcined Y123 powder. Applying the optimized processing condition, the single grain Y123 superconductors with $T_c=91\;K$ and $J_c=1.5{\times}10^4\;A/cm^2$ at 2 T were successfully fabricated using a home made powder. The levitation forces and trapped magnetic field at 77 K measured using a Nd-B-Fe permanent magnet of 5300 G were 47 N and 3000 G, respectively, which are comparable to those obtained for the samples fabricated using a commercial grade Y123 powders.

Development of Antimicrobial Edible Film from Defatted Soybean Meal Fermented by Bacillus subtilis

  • KIM , HYUNG-WOOK;KIM, KYUNG-MI;KO, EUN-JUNG;LEE, SI-KYUNG;HA, SANG-DO;SONG, KYUNG-BIN;PARK, SANG-KYU;KWON, KI-SUNG;BAE, DONG-HO
    • Journal of Microbiology and Biotechnology
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    • v.14 no.6
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    • pp.1303-1309
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    • 2004
  • In order to extend shelf-life of the packaged or coated foods, an antibacterial edible film was developed. Antimicrobial activities of 9 bacteriocin-like substance (BLS)­producing strains were evaluated after growing them on defatted soybean meal medium (DSMM). Bacillus subtilis was selected among those, because it showed the biggest inhibition zone against 6 problem bacteria in food. The antimicrobial edible film, containing $0.32\%$ of BLS, was produced from the fermented soybean meal with B. subtilis at the optimum condition of pH 7.0-7.5 and $33^{\circ}C$ for 33 h. The antimicrobial activity of the film was over $50\%$ of the maximum activity after film production with heat treatment at $90^{\circ}C$ and pH adjustment to 9. When the soy protein film with BLS was applied on the agar media containing E. coli, the growth inhibition was much higher than the ordinary soy protein film. These results indicate that the soy protein film with BLS from B. subtilis can be used as a new packaging material to extend the shelf-life of foods.

Characteristics and Lytic Activity of Phage-Derived Peptidoglycan Hydrolase, LysSAP8, as a Potent Alternative Biocontrol Agent for Staphylococcus aureus

  • Yu, Jun-Hyeok;Lim, Jeong-A;Chang, Hyun-Joo;Park, Jong-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.29 no.12
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    • pp.1916-1924
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    • 2019
  • Outbreaks of staphylococcal food poisoning (SFP) causing serious human diseases and economic losses have been reported globally. Furthermore, the spread of Staphylococcus aureus with increased resistance to multiple antimicrobial agents has become a major concern in the food industries and medicine. Here, we isolated an endolysin LysSAP8, as one of the peptidoglycan hydrolases, derived from the bacteriophage SAP8 infecting S. aureus. This endolysin was tagged with a 6×His at the C-terminal of the target protein and purified using affinity chromatography. LysSAP8 demonstrated lytic activity against a broad spectrum of bacteria, which included a majority of the staphylococcal strains tested in this study as well as the methicillin-resistant S. aureus (MRSA); however, no such activity was observed against other gram-positive or gram-negative bacteria. Additionally, LysSAP8 could maintain bactericidal activity until 0.1 nM working concentration and after heat treatment at 37℃ for 30 min. The ability of LysSAP8 to lyse cells under varying conditions of temperature (4-43℃), pH (3-9), and NaCl concentrations (0-1,000 mM), and divalent metal ions (Ca2+, Co2+, Cu2+, Mg2+, Mn2+, Hg2+, and Zn2+) was examined. At the optimized condition, LysSAP8 could disrupt approximately 3.46 log CFU/ml of the planktonic cells in their exponential phase of growth within 30 min. In this study, we have suggested that LysSAP8 could be a potent alternative as a biocontrol agent that can be used to combat MRSA.

Development of composite catalyst for hazardrous gas treatment using the heat of aviary heating equipment (계사용 온풍기를 이용한 유해가스처리 복합촉매시스템 개발)

  • Jang, Hyun-Tae;Cha, Wang-Seog
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.10
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    • pp.2779-2785
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    • 2009
  • Among the livestock, chickens are raised because of the merit ingested protein in low-priced cost of production and are primary livestock increased the consumption of meat. The factors of influencing condition, odor is the most important factor. Odor substances are ammonia, amines, hydrogen sulfide and mercaptan which come from night soil. Livestock are prevented from rearing by means of these odor substances. Though the henhouse is heated using hot air type heater in the winter season, it is ventilated for the control of odor because of the increase of odor concentration. In the present work, composite catalytic system combined the existing facilities(hot air type heater) with catalytic system was developed, it could controled odor and hazardous gas using the oxidation/reduction reaction without extra operating cost. Moreover, the purpose of this work is to develop the catalysts which are cost competitive and can maximize energy efficiency. The catalysts are noble metal(Pt-Rh) and composite transition metal(Mn) type.

Preparation and Adsorption-photocatalytic Activity Evaluation of TiO2-Coconut Shell Powder Composite (TCSPC) (TiO2-Coconut Shell Powder Carbon 복합체 (TCSPC) 제조 및 흡착 광촉매 산화 활성 평가)

  • Lee, Min Hee;Kim, Jong Kyu
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.6
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    • pp.357-362
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    • 2015
  • A novel $TiO_2$-Coconut Shell Powder Composite (TCSPS), prepared by the controlled sol-gel method with subsequent heat treatment, was evaluated as an innovative photocatalytic absorbent for the removal of methylene blue. Optimal preparation conditions of TCSPC were obtained by a response surface methodology and a central composite design model. As compared with the results obtained from one-factor-at-a-time experiments, the values were approximated to the nearest condition of these values and the following experimental parameters were set as the optimum : $600^{\circ}C$ calcination temperature and 20 g of coconut shell powder loading amount.