• 제목/요약/키워드: strain-life

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Morphological and Phylogenetic Analyses Reveal a New Species of Genus Monochaetia Belonging to the Family Sporocadaceae in Korea

  • Seong-Keun Lim;Kallol Das;Soo-Min Hong;Sang Jae Suh;Seung-Yeol Lee;Hee-Young Jung
    • Mycobiology
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    • 제51권2호
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    • pp.87-93
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    • 2023
  • The fungal strain belonging to the genus Monochaetia of the family Sporocadaceae was isolated from hairy long-horned toad beetle (Moechotypa diphysis) during the screening of microfungi associated with insects from Gangwon Province, Korea. The strain KNUF-6L2F produced white, light brown to dirty black surface, and olivaceous green colonies with the higher growth, while the closest strain M. ilicis KUMCC 15-0520T were light brown to brown, and M. schimae SAUCC 212201T light brown to brown toward center. The strain KNUF-6L2F produced shorter (5.7-14.0 ㎛) apical appendages than M. ilicis (6.0-24.0 ㎛), but similar to M. schimae (7.0-12.5 ㎛). Three median cells of KNUF-6L2F were light brown to olivaceous green, whereas brown and olivaceous cells were observed from M. ilicis and M. schimae, respectively. And the strain KNUF-6L2F produced larger conidiogenous cells than M. ilicis and M. schimae. Additionally, phylogenetic analyses based on molecular datasets of internal transcribed spacer (ITS) regions, translation elongation factor 1-alpha (TEF1α), and β-tubulin (TUB2) genes corroborated the strain's originality. Thus, the strain is different from other known Monochaetia species, according to molecular phylogeny and morophology, hence we suggested the new species Monochaetia mediana sp. nov. and provided a descriptive illustration.

대도시 단독가구 여자노인의 생활의 질 향상을 위한 연구 - 가족.소비.주거생활을 중심으로- (Quality of Life of Elderly Women Living alone or with the Spouse -With a focus on the family consumer and hosing life-)

  • 제미경
    • 가정과삶의질연구
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    • 제13권4호
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    • pp.101-114
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    • 1995
  • The purpose of this study was to investigate the factors which influenced the quality of life of elderly women living alone or with the spouse. A survey using interview was administered to 221 elderly women living in Seoul and Pusan The major findings were as follows: 1) The family life satisfaction of elderly women was determined by the quality of relationship with her eldest son's wife shared activities financial strain and location. The determinants of consumer life satisfaction were financial strain materialism tenure and the number of income sources, Housing life satisfaction was influenced by the convenience of neighborhood facilities tenure and housing structure type. 2) The quality of relationship with her eldest son's wife social activities financial strain tenure and the reason for independent household formation explained the variance of the life satisfaction about 29% by using a stepwise multiple regression method.

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유지시간 효과를 고려한 12Cr 내열강의 열피로 및 저주기 피로 특성 (Thermal-Mechanical and Low Cycle Fatigue Characteristics of 12Cr Heat Resisting Steel with Hold Time Effects)

  • 하정수;고승기;옹장우
    • 한국자동차공학회논문집
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    • 제3권1호
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    • pp.1-12
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    • 1995
  • Isothermal and thermal-mechanical fatigue characteristics of 12Cr heat resisting steel used for high temperature applications were investigated including hold time effects. Isothermal low cycle fatigue test at $600^{\circ}C$ and in-phase, out-of-phase thermal-mechanical fatigue test at 350 to $600^{\circ}C$ were conducted using smooth cylindrical hollow specimen under strain-control with total strain ranges from 0.006 to 0.015. Regardless of thermal-mechanical and isothermal fatigue tests, cyclic softening behavior was observed and much more pronounced in the thermal-mechanical fatigue tests with hold times due to the stress relaxation during the hold time. The phase difference between temperature and strain in thermal-mechanical fatigue tests resulted in significantly shorter fatigue life for out-of-phase compared to in-phase. The differences in fatigue lives were dependent upon the magnitudes of plastic strain ranges and mean stresses. During the hold time in the strain-controlled fatigue tests, the increase in the plastic strain range and the stress relaxation were observed. It appeared that the increase in plastic strain range per cycle and the introduction of creep damage made important contributions to the reduction of thermal-mechanical fatigue life with hold time, and the life reduction tendency was more remarkable in the in-phase than in the out-of-phase thermal-mechanical fatigue. Isothermal fatigue tests performed under the combination of fast and slow strain rates at $600^{\circ}C$ showed that the fatigue life decreased as the strain rate and frequency decreased,especially for the low strain ranges.

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버섯(P. eryngii spp.) 추출물의 항산화 활성과 총 페놀함량 (Antioxidant Activity and Total Phenolic Compounds off P. eryngii spp. Extracts)

  • 지희연;김규현;공원식;김선림;김진애;정일민;김정태
    • 한국작물학회지
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    • 제50권spc1호
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    • pp.216-219
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    • 2005
  • This objective of this study was to determined the activity of antioxidants of DPPH, SOD and total phenolic compounds in mushroom(P. eryngii spp.) extract. The antioxidant acitivity using DPPH showed that strain No. 2007$(31.78\%)$ and strain No.2014$(27.45\%)$ were the highest DPPH inhibition. Among the thirteen mushroom examined, strain No. 2014$(58.30\%)$ and strain No. 2010$(57.19\%)$ had the highest SOD activity. The highest total phenol content were in strain No.2013$(1465.03{\mu}g/g)$ and strain No.2005$(1401.09{\mu}g/g)$. Our study suggest that it may be possible to improve mushroom with high natural antioxidant.

Mean Stress를 고려한 11.7Cr-1.1Mo강의 고온저주기 피로특성에 관한 연구 (A Study of Low Cycle Fatigue Characteristics of 11.7Cr-1.1Mo Heat Resisting Steel with Mean Stress)

  • 홍상혁;홍춘희;이현우
    • 한국자동차공학회논문집
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    • 제14권3호
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    • pp.133-141
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    • 2006
  • The Low cycle fatigue behavior of 11.7Cr-1.1Mo heat-resisting steel has been investigated under strain-controlled conditions with mean stresses at room temperature and $300^{\circ}C$. For the tensile mean stress test, the initial high tensile mean stress generally relaxed to zero at room temperature, however, at $300^{\circ}C$ initial tensile mean stress relaxed to compressive mean stress. Low cycle fatigue lives under mean stress conditions are usually correlated using modifications to the strain-life approach. Based on the fatigue test results from different stain ratio of -1, 0, 0.5, and 0.75 at room temperature and $300^{\circ}C$, the fatigue damage of the steel was represented by using cyclic strain energy density. Total strain energy density considering mean stress indicated well better than not considering mean stress at $300^{\circ}C$. Predicted fatigue life using Smith-Watson-Topper's parameter correlated fairly well with the experimental life at $300^{\circ}C$.

Rahnella aquatilis Strain AY2000 Produces an Anti-Yeast Substance

  • Ryu, Eun-Ju;Kim, Han-Woo;Kim, Byung-Woo;Kwon, Hyun-Ju;Kim, Kwang-Hyeon
    • Journal of Microbiology and Biotechnology
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    • 제16권10호
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    • pp.1597-1604
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    • 2006
  • To screen for an anti-yeast substance (AYS), many bacteria were isolated from soil and a strain AY2000 was selected. The strain AY2000 was identified as Rahnella aquatilis by morphology, biochemical properties, and 16S r-RNA nucleotide sequence analyses. The strain AY2000 showed anti-yeast activity against Candida albicans and Saccharomyces cerevisiae, whereas R. aquatilis ATCC33071 as a type strain did not show the activity against the yeasts under the same condition. The growth of yeast cell was significantly inhibited by AYS produced by the strain AY2000, as shown by optical density and MTT assay. The minimum inhibitory concentration (MIC) of the AYS against S. cerevisiae and C. albicans at $28^{\circ}C\;was\;20{\mu}g/ml\;and\;60{\mu}g/ml$, respectively. The MIC of AYS against hyphae of C. albicans at $37^{\circ}C\;was\;600{\mu}g/ml$. Scanning electron microscopic analysis revealed that yeast cells treated with AYS had an irregular form with a wrinkled and rough surface.

Nb 첨가 오스테나이트계 내열 스테인리스강의 열기계적 피로 수명 및 변형 거동 (Endurance Life and Deformation Behavior under Thermo-mechanical Fatigue of Nb-added Heat Resistant Austenitic Stainless Steel)

  • 오용준;박중철;양원존
    • 대한금속재료학회지
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    • 제49권7호
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    • pp.541-548
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    • 2011
  • Thermomechanical fatigue (TMF) behavior of heat resistant austenitic stainless steel was evaluated in the temperature range from 100$^{\circ}C$ to peak temperatures of 600 to 800$^{\circ}C$; The fatigue lives under TMF conditions were plotted against the plastic strain range and the dissipated energy per cycle. In the expression of the inelastic strain range versus fatigue life, the TMF data obtained at different temperature ranges were located close to a single line with a small deviation; however, when the dissipated energy per cycle, calculated from the area of the stress-strain hysteresis loops at the half of the fatigue life, was plotted against the fatigue life, the data showed greater scattering than the TMF life against the inelastic strain range. A noticeable stress relaxation in the stress-strain hysteresis curve took place at the peak temperatures higher than 700$^{\circ}C$, but all specimens in this study exhibited cyclic hardening behavior with TMF cycles. Recrystallization occurred during the TMF cycle concurrent with the formation of fine subgrains in the recrystallized region, which is considered to cause the cyclic hardening of the steel.

Isolation and Phosphate-Solubilizing Characteristics of PSM, Aeromonas hydrophila DA33

  • Song, Ok-Ryul;Lee, Seung-Jin;Lee, Mi-Wha;Choi, Si-Lim;Chung, Soo-Yeol;Lee, Young-Gyun;Choi, Yong-Lark
    • Journal of Life Science
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    • 제11권2호
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    • pp.63-69
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    • 2001
  • bacterium having high abilities to solubilize in-organic phosphate was isolated from cultivated soils. The strain was identified as Aeromonas hydrophila DA33, based on the physiological and biochemical properties. The optimum temperature and initial pH to solubilize insoluble phosphate in sucrose minimal medium were 3$0^{\circ}C$ and pH 5.0, respectively. In these conditions, phosphate-solubilizing activities of the strain against two types of insoluble phosphate were quantitatively determined. When glucose was used for carborn source, the strain had a marked mineral phospahte solubilizing activity. Inorganic phospahte solubilization was directly related to the pH drop by the strain. Analysis of the culture medium confirmed the production of gluconic acid as the main organic acid released by Aeromonas hydrophila DA33.

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Draft Genome Sequence of Weissella koreensis Strain HJ, a Probiotic Bacterium Isolated from Kimchi

  • Seung-Min Yang;Eiseul Kim;So-Yun Lee;Soyeong Mun;Hae Choon Chang;Hae-Yeong Kim
    • 한국미생물·생명공학회지
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    • 제51권1호
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    • pp.128-131
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    • 2023
  • Here we report the draft genome sequence of Weissella koreensis strain HJ and genomic analysis of its key features. The genome consists of 1,427,571 bp with a GC content of 35.5%, and comprises 1,376 coding genes. In silico analysis revealed the absence of pathogenic factors within the genome. The genome harbors several genes that play an important role in the survival of the gastrointestinal tract. In addition, a type III polyketide synthase cluster was identified. Pangenome analysis identified 68 unique genes in W. koreensis strain HJ. The genome information of this strain provides the basis for understanding its probiotic properties.

변형률 에너지법을 이용한 Inconel 617의 저주기피로 수명 예측 (Prediction of Low Cycle Fatigue Life for Inconel 617 using Strain Energy Method)

  • 김덕회;김기광;김재훈;이영신;박원식
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.285-290
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    • 2004
  • Low cycle fatigue tests are performed on the Inconel 617 that be used for a hot gas casing. The relation between strain energy density and numbers of cycles to failure is examined in order to predict the low cycle fatigue life of Inconel 617. The life predicted by the strain energy method is found to coincide with experimental data and results obtained from the Coffin-Manson method. Also the cyclic behavior of Inconel 617 is characterized by cyclic hardening with increasing number of cycle at room temperature.

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