• Title/Summary/Keyword: Ac

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Adsorption Efficiency of Coal Based GACs and Evaluation of Economic Efficiency (석탄계 활성탄별 흡착능 및 경제성 평가)

  • Choi, Dong-Hoon;Son, Hee-Jong;Park, Jin-Sik;Moon, Choo-Yeun;Ryu, Dong-Choon;Jang, Seong-Ho;Kwon, Ki-Won;Kim, Han-Soo
    • Journal of Environmental Science International
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    • v.22 no.2
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    • pp.205-213
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    • 2013
  • This is made of domestic and foreign coal activated carbon of five species, physicochemical adsorption efficient about sterilize products and micro harmful substances and is a result of the economic evaluation. The most well-developed micropores bed volume 123,409 of AC-1 activate carbon appeared to be the best next AC-2, AC-3, AC-4, AC-5 followed by activated carbon was investigated. PFOA and PFOS in the BV 96,000 when evaluating foreign types of adsorption activated carbon adsorption capacity was greater when more than PFOA, PFOS showed that the adsorption well. The economic evaluation of activated carbon usage in chloroform (CUR) was most excellent as a AC-1 4.3 g/day, the next AC-2, AC-3, AC-4, AC-5 there are two types of foreign economic order appears to have appeared, but the current domestic market when applying the price AC-1, AC-3, AC-2, AC-4, AC-5 order was investigated.

Mechanical Properties of SiCp/AC8A Composites Fabricated by Pressureless Metal Infiltration Process (무가압함침법으로 제조한 SiCp/AC8A 복합재료의 기계적 성질)

  • 김재동;고성위;김형진
    • Composites Research
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    • v.15 no.3
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    • pp.1-10
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    • 2002
  • The effect of size of SiC particles and additive Mg content on the mechanical properties and wear characteristics were investigated for the SiCp/AC8A composites fabricated by pressureless infiltration process. Results showed that the hardness and the bending strength increased with decreasing the size of SiC particle. By increasing the Mg content the hardness of SiCp/AC8A composites increased due to the hard reaction products, however the bending strength decreased by formation of coarse precipitates and high porosity level. The SiCp/AC8A composites exhibited about 6 times higher wear resistance compared with AC8A alloy at high sliding velocity and as increasing the particle size, wear resistance was improved. The major wear mechanical of SiCp/AC8A composites exhibited the abrasive wear at low to high sliding velocity whereas AC8A alloy showed adhesive and melt wear at high sliding velocity.

Introduction of Maize Transposable Elements, Ac and Ds into the Genome of a Diploid Potato Species (옥수수 전위유전자 Ac 및 Ds의 2배체종 감자 Genome 내로의 도입)

  • 김화영;임용표
    • Korean Journal of Plant Tissue Culture
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    • v.27 no.1
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    • pp.39-45
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    • 2000
  • Two maize transposable elements, immobilized Ac (iAc) and Ds, have been introduced into the genome of a diploid potato clone (Solanum tuberosum Group Phureja clone 1.22). The iAc is a modified Ac that is supposed to be unable to transpose but is expected to trans-activate the transposition of a Ds that is unable to transpose by itself. When the leaf and stem explants of in vitro shoots of the clone 1.22 were inoculated with Agrobacterium tumefaciens strains harboring binary vectors containing the iAc and the Ds, calli were formed from the explants on media containing 50 mg/L of kanamycin, and shoots were regenerated from the calli. The regenerated shoots formed roots when cultured on media containing 100 mg/L of kanamycin, whereas untransformed shoots did not form roots on the same media. The PCR amplification of the DNA's from the transgenic plants confirmed that the iAc and the Ds elements were introduced into the potato genome of 1.22.

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Adenylyl Cyclases in Mycobacteria (마이코박테리아의 adenylyl cyclase)

  • Jeon, Han-Seung;Ko, In-Jeong;Oh, Jeong-Il
    • Journal of Life Science
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    • v.21 no.3
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    • pp.473-479
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    • 2011
  • Adenylyl cyclase (AC) catalyzes the formation of cyclic AMP (cAMP) from ATP. The cAMP produced by AC serves as a secondary messenger in a variety of signal transduction pathways, and controls various cellular functions in many organisms. ACs can be grouped into six classes based on their primary amino acid sequences. Eukaryotes and mycobacteria contain only members of class III AC. The catalytic cyclase domains of class III AC are active as dimers: mammalian ACs, which are composed of a single polypeptide with two catalytic cyclase domains, form the active site as a result of intramolecular dimerization of the catalytic cyclase domains. In contrast, mycobacterial ACs function as homodimers, since their polypeptides contain a single catalytic cyclase domain. Six amino acids are required for the catalytic activity of class III AC - two aspartate residues, a lysine-aspartate pair and an arginine-asparagine pair. 16 ACs belonging to the class III were identified in Mycobacterium tuberculosis H37Rv, and their characteristics are reviewed.

Proteomic and Phenotypic Analyses of a Putative Glycerol-3-Phosphate Dehydrogenase Required for Virulence in Acidovorax citrulli

  • Kim, Minyoung;Lee, Jongchan;Heo, Lynn;Lee, Sang Jun;Han, Sang-Wook
    • The Plant Pathology Journal
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    • v.37 no.1
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    • pp.36-46
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    • 2021
  • Acidovorax citrulli (Ac) is the causal agent of bacterial fruit blotch (BFB) in watermelon, a disease that poses a serious threat to watermelon production. Because of the lack of resistant cultivars against BFB, virulence factors or mechanisms need to be elucidated to control the disease. Glycerol-3-phosphate dehydrogenase is the enzyme involved in glycerol production from glucose during glycolysis. In this study, we report the functions of a putative glycerol-3-phosphate dehydrogenase in Ac (GlpdAc) using comparative proteomic analysis and phenotypic observation. A glpdAc knockout mutant, AcΔglpdAc(EV), lost virulence against watermelon in two pathogenicity tests. The putative 3D structure and amino acid sequence of GlpdAc showed high similarity with glycerol-3-phosphate dehydrogenases from other bacteria. Comparative proteomic analysis revealed that many proteins related to various metabolic pathways, including carbohydrate metabolism, were affected by GlpdAc. Although AcΔglpdAc(EV) could not use glucose as a sole carbon source, it showed growth in the presence of glycerol, indicating that GlpdAc is involved in glycolysis. AcΔglpdAc(EV) also displayed higher cell-to-cell aggregation than the wild-type bacteria, and tolerance to osmotic stress and ciprofloxacin was reduced and enhanced in the mutant, respectively. These results indicate that GlpdAc is involved in glycerol metabolism and other mechanisms, including virulence, demonstrating that the protein has pleiotropic effects. Our study expands the understanding of the functions of proteins associated with virulence in Ac.

Speed and Position Control of AC Servo System using SIMTool (SIMTool을 이용한 AC 서보 시스템의 속도 및 위치제어)

  • Ji, Jun-Keun;Lim, Young-Ha
    • Proceedings of the KIEE Conference
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    • 2003.10b
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    • pp.184-186
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    • 2003
  • In this paper, speed and Position control of AC servo system using SIMTool of Realgain company is introduced. "AC Servo-Designer"system, including CEMTool/SIMTool S/W, RG-DSPIO board, AC servo driver and AUTOTool program, is used in this research. "AC Servo-Designer"system can use SIMTool blocks to Because design and implement various controller in short time, speed and position controller of AC servo system are easily designer and implemented according to control objectives.

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Design of Speed Controller for AC Servo System by Rapid Design System using DSP (DSP 사용 고속설계제어기에 의한 AC 서보시스템의 속도제어기 설계)

  • Ji Jun-Keun
    • Proceedings of the KIPE Conference
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    • 2004.07a
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    • pp.177-181
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    • 2004
  • In this paper design of speed controller for AC servo system by rapid design system(RG-01D) using DSP of Realgain company is introduced. 'AC Servo-Designer' system, including CEMTool/SIMTool S/W, RG-DSPIO board, AC servo driver and AUTOTool program, is used in this research. Because 'AC Servo-Designer' system can use SIMTool blocks to design and implement various controller in short time, speed controller for AC servo system is easily designed and implemented according to control objectives.

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A PWM Buck AC-AC Converter with Instantaneous Compensation for Voltage Sag and Surge (전압 Sag와 Surge에 대한 순시보상 기능을 갖는 PWM Buck AC-AC 컨버터)

  • Choi Nam-Sup
    • Proceedings of the KIPE Conference
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    • 2001.07a
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    • pp.197-200
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    • 2001
  • This paper presents a PWM buck AC-AC converter with instantaneous compensation for input voltage sag and surge. The presented converter use commercial IGBT modules and its output voltage is regulated so as to remain constant AC output voltage. The feedforward control technique is also proposed to establish instantaneous duty level change whereby stable output voltage will be retained. This paper show the characteristics and control algorithm of the converter through various PSPICE simulations.

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Extraction, purification and properties of anti-complementary polysaccharide from Arecae Pericarpium (대복피로부터 항보체 활성다당의 추출, 정제 및 그 특성)

  • Kwon, Kyung-Sup;Shin, Kwang-Soon;Cho, Hong-Yon;Yang, Han-Chul
    • Applied Biological Chemistry
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    • v.35 no.4
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    • pp.308-314
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    • 1992
  • To examine the characteristics of anti-complementary compounds from Arecae Pericarpium (the pericarps of Areca catechu) which showed the highest activity during our screening procedures, the extraction and purification were performed. AC-1 fraction from Arecae Pericarpium was purified by hot water extraction, methanol reflux, ethanol precipitation, dialysis and lyophilization. This compound had total sugar 48.2%, uronic acid 14.6% and protein 36.8%. Rhamnose, arabinose, mannose and galactose were found in sugar components. By cetavlon (cetyltrimethylammonium bromide) treatment AC-1 was fractionated to AC-2, AC-3 and AC-4. Among them, AC-2 showed the highest activity and yield. By periodate oxidation, AC-2 was deactivated, but had no change in activity by pronase digestion. Moreover active fractions, AC-2-IIIa and AC-2-IIIc isolated from AC-2 by two successive column chromatography using DEAE-Toyopearl $650C(Cl^-form)$ and Sephadex G-100. AC-2-IIIa was mainly made up of rhamnose, mannose, galactose and glucose, and AC-2-IIIc, mannose, galactose and glucose. These both polysaccharides were identified as homogeneous by gel filtration of Sepharose CL-4B and electrophoresis, and molecular weights of them were 120,000 and 15,000, respectively.

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Comparison of Attenuation Correction Methods for Brain SPECT Ima (Brain SPECT 영상의 Attenuation Correction 방법들에 대한 비교)

  • Jo, Jin U;Kim, Chang Ho;Na, Soo Kyung;Lee, Gui Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.16 no.2
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    • pp.120-125
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    • 2012
  • Purpose : The purpose of this study was to compare count between Chang's method and CT-based attenuation correction (AC-CT) among the attenuation correction (AC) methods for non-attenuation correction (AC-non) images of Brain SPECT (Single Photon Emission Computed Tomography). Materials and Methods : We injected $^{99m}Tc$ 37Mbq in a Hoffman 3D phantom filled with distilled water in the phantom study, and injected intravenously $^{99m}Tc$-HMPAO 740Mbq in a normal volunteer in the patient study, and then obtained Brain SPECT images with Symbia T6 of Siemens and conducted quantitative brain analysis. Transverse images to which each method was applied were rebuilt at the same position, and 6 regions of interest (ROI) were drawn on each of Slice No. 10, 20 and 30 and then the counts of AC-non, AC-CT and Chang's method were compared. Results : The mean counts of AC-non, AC-CT and Chang's method were $4606.8{\pm}511.3$, $16794.6{\pm}2429.4$, and $8752.6{\pm}896.5$, respectively, in the phantom study and $5460.8{\pm}519.6$, $15320{\pm}1171.6$ and $12795{\pm}1422.1$, respectively, in the patient study. In the phantom study, the ratio of AC-CT to AC-non was 3.70 and the ratio of Chang's method to AC-non was 1.92, and in the patient study, they were 2.85 and 2.38, respectively. Conclusion : From this study, we found that AC-CT makes higher AC than Chang's method. In addition, when Chang's method was used, AC in the patient study was higher than that in the phantom study. These results need to be considered also in other examinations.

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