• Title/Summary/Keyword: CO tolerance

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Design of a Cascaded H-Bridge Multilevel Inverter Based on Power Electronics Building Blocks and Control for High Performance

  • Park, Young-Min;Ryu, Han-Seong;Lee, Hyun-Won;Jung, Myung-Gil;Lee, Se-Hyun
    • Journal of Power Electronics
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    • v.10 no.3
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    • pp.262-269
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    • 2010
  • This paper proposes a practical design for a Cascaded H-Bridge Multilevel (CHBM) inverter based on Power Electronics Building Blocks (PEBB) and high performance control to improve current control and increase fault tolerance. It is shown that the expansion and modularization characteristics of the CHBM inverter are improved since the individual inverter modules operate more independently, when using the PEBB concept. It is also shown that the performance of current control can be improved with voltage delay compensation and the fault tolerance can be increased by using unbalance three-phase control. The proposed design and control methods are described in detail and the validity of the proposed system is verified experimentally in various industrial fields.

Improved Thermal Stability of a Novel Acidophilic Phytase

  • Byung Sam Son;So Hyeong Kim;Hye-Young Sagong;Su Rin Lee;Eun Jung Choi
    • Journal of Microbiology and Biotechnology
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    • v.34 no.5
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    • pp.1119-1125
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    • 2024
  • Phytase increases the availability of phosphate and trace elements by hydrolyzing the phosphomonoester bond in phytate present in animal feed. It is also an important enzyme from an environmental perspective because it not only promotes the growth of livestocks but also prevents phosphorus contamination released into the environment. Here we present a novel phytase derived from Turicimonas muris, TmPhy, which has distinctive structure and properties compared to other previously known phytases. TmPhy gene expressed in the Pichia system was confirmed to be 41 kDa in size and was used in purified form to evaluate optimal conditions for maximum activity. TmPhy has a dual optimum pH at pH3 and pH6.8 and exhibited the highest activity at 70℃. However, the heat tolerance of the wildtype was not satisfactory for feed application. Therefore, random mutation, disulfide bond introduction, and N-terminal mutation were performed to improve the thermostability of the TmPhy. Random mutation resulted in TmPhyM with about 45% improvement in stability at 60℃. Through further improvements, a total of three mutants were screened and their heat tolerance was evaluated. As a result, we obtained TmPhyMD1 with 46.5% residual activity, TmPhyMD2 with 74.1%, and TmPhyMD3 with 66.8% at 80℃ heat treatment without significant loss of or with increased activity.

Factors Affecting Interpersonal Tolerance and Intolerance (대인 간 관용과 불관용에 영향을 주는 요인)

  • Joeng, Ju-Ri
    • Korean Journal of Culture and Social Issue
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    • v.28 no.3
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    • pp.307-329
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    • 2022
  • This study aimed to explore factors which can predict interpersonal tolerance and intolerance. Specifically, the study examined whether tolerance and intolerance would be explained by demographic variables, social desirability, empathy (cognitive empathy and affective empathy), fear of compassion for others, social trust, and zero-sum belief. Participants in the study were 445 adults (218 males and 227 females) who completed an online survey. Data were analyzed by using hierarchical regression analyses to control the effects of demographic variables and social desirability. The results indicated that tolerance was explained by gender, subjective socioeconomic status, social desirability, cognitive empathy, and social trust. In addition, intolerance was predicted by social desirability, fears of compassion for others, and zero-sum belief. It means that the constructs of tolerance and intolerance are distinct, and different factors predict tolerance and intolerance, respectively. Therefore, it would be necessary to develop realistic ways to promote tolerance and to prevent intolerance at the same time in order to achieve co-existence in a multicultural and diverse society.

Inhibitory Action of the Ginseng Total Saponin on the Nalbuphine-Induced Tolerance and Withdrawal Syndrome

  • Kim, Dong-Hyun;Yoo, Hwan-Soo;Jang, Choon-Gon;Kang, Jong-Seok;Kim, Dong-Sup;Choi, Ki-Hwan;Jang, So-Yong;Oh, Sei-Kwan
    • Journal of Ginseng Research
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    • v.29 no.2
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    • pp.86-93
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    • 2005
  • This study was undertaken to determine the antagonism of the ginseng total saponin (GTS) on the development of nalbuphine-induced tolerance and physical dependence. GTS is blown to have antinarcotic action with a dose of 100mg/kg (i.p.) in rats. STS significantly inhibits the development of nalbuphine-induced physical dependence as well as the tolerance. The level of pCREB was elevated in the striatum by the chronic treatment with nalbuphine or GTS, how-ever, the elevation of pCREB was inhibited by the GTS co-treatment. It has been suggested that NMDA receptor and/or NO is involved in the penomena of opioid dependence and withdrawal. However, the level of nNOS and NR1 was not modulated by the treatment with nalbuphine or GTS on the cortex, hippocampus and striatum in the rat brain. These results suggest that the GTS could be used to ameliorate the nalbuphine tolerance and withdrawal symptoms.

Sanitation and Tissue Residue Problems in High Quality Pork - Review -

  • Lee, M.H.;Ryu, P.D.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.2
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    • pp.233-243
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    • 1999
  • Food safety or sanitation are terms broadly applicable to procedures designed to ensure that food quality is high and free of factors which may adversely affect human health. These factors include zoonotic diseases and acute and chronic effects of ingesting natural and human-made xenobiotics. Use of drugs in animal production for the treatment and control of animal diseases, to promote growth rate, and to improve feed conversion efficiency has expanded year by year, thus increasing the possibilities for occurrences in animal products of residues harmful to humans. Governmental agencies have made efforts to control or prevent residue problems. The Korean Food and Drug Administration (KFDA) is charged with the responsibility of establishing tolerances for veterinary drugs, pesticides, and mycotoxins and other non-pharmaceutical substances. The Department of Veterinary Service is responsible for establishing guidelines regarding withdrawal times of drugs, approval of drugs, their uses, and sanitation enforcement of livestock products. The authors describe the toxicological basis for the establishment of tolerance levels for xenobiotics and the pharmacokinetic basis for establishing withdrawal time for veterinary drugs. The regulatory tolerance levels of chemicals in pork and swine feed, Korean regulations on the use of feed additives, rapid residue test methods, the National Residue Program, and the Food Animal Residue Avoidance Databank are discussed. Rapid EIA methods that are under development for the screening of live animals are described These methods predict tissue residues from an examination of blood samples taken from pigs before they are slaughtered.

SSR (Simple Sector Remapper) the fault tolerant FTL algorithm for NAND flash memory

  • Lee, Gui-Young;Kim, Bumsoo;Kim, Shin-han;Byungsoo Jung
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.932-935
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    • 2002
  • In this paper, we introduce new FTL(Flash Translation Layer) driver algorithm that tolerate the power off errors. FTL driver is the software that provide the block device interface to the upper layer software such as file systems or application programs that using the flash memory as a block device interfaced storage. Usually, the flash memory is used as the storage devices of the mobile system due to its low power consumption and small form factor. In mobile system, the state of the power supplement is not stable, because it using the small sized battery that has limited capacity. So, a sudden power off failure can be occurred when we read or write the data on the flash memory. During the write operation, power off failure may introduce the incomplete write operation. Incomplete write operation denotes the inconsistency of the data in flash memory. To provide the stable storage facility with flash memory in mobile system, FTL should provide the fault tolerance against the power off failure. SSR (Simple Sector Remapper) is a fault tolerant FTL driver that provides block device interface and also provides tolerance against power off errors.

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Effects of Ru/C Catalyst on the CO Tolerance of Anode and Durability of Membrane in PEMFC (PEMFC에서 전극의 CO 내성 및 막 내구성에 미치는 Ru/C 촉매의 영향)

  • Sim, Woo-jong;Kim, Dong-whan;Choi, Seo-hee;Kim, Ki-joong;Ahn, Ho-Geun;Jung, Min-chul;Park, Kwonpil
    • Korean Chemical Engineering Research
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    • v.46 no.2
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    • pp.286-290
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    • 2008
  • Small amounts of CO in reformate fuel gas effectively block platinum catalysts by strong adsorption on the platinum surface at the operation temperature of $60{\sim}80^{\circ}C$ in PEMFC. To oxidate CO, Ru/C layer (CO filter) was placed between Pt/C layer and GDL (gas diffusion layer) in this study. Ru/C filter provided good CO-tolerant PEMFC anode, but decreased the performance of unit cell about 10% at 0.6 V due to mass transfer resistance from Ru/C filter thickness and increase of charge transfer resistance. Membrane degradation is one of the most important factors limiting the life-time of PEMFCs. Membrane durability would be dependent on the electrode catalyst type. It seemed that Ru catalyst layer would shorten the life time of PEMFC as enhanced the fluoride emission rate of membrane in acceleration test.

A Signal Processing Software Technique for the Tolerance of the 4 Axis Strain-gauge Sensors applied to the Military Weapon System (군 무기체계에 적용되는 4 축 스트레인-게이지의 오차에 대한 신호처리 소프트웨어 기법)

  • Young-Jun Lee;Chong-Ho Yi
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.1
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    • pp.185-194
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    • 2023
  • The 4-axis strain-gauge, which is widely applied to military weapon systems, is operated in poor temperature and vibration conditions, tolerance may increase and malfunctions may occur. To improve this, this paper proposes a signal-processing software technique for the tolerance of the 4-axis strain gauge applied to a military weapon system. First, the tolerance of the strain-gauge and the signal processing circuit according to the ambient temperature were evaluated and analyzed. Second, a software technique for processing the dead zone and offset area that can improve the tolerance of the strain-gauge is proposed. The experimental results applying the software technique confirmed that it operated normally in the temperature test and operation test. Therefore, the proposed software technique is valid and can be used as useful information to improve tolerance due to ambient temperature and vibration when designing a system using a strain-gauge.