• Title/Summary/Keyword: Large strains

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Deformations of Cantilever Strips and Beam with Small Elastic Strains (작은 탄성 변형률 하의 고정-자유 지지된 스트립과 보의 변형)

  • 호광수;박기철;임세영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.4
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    • pp.572-582
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    • 1989
  • Elastic deformations of an infinitely long strip and a beam loaded by uniform pressure upon their upper surfaces, with the fixed-free end dondition, are considered within the range of small strains. All local governing equations are satisfied up to first order in strains, and to take into account the higher order terms neglected in the local governing equations, the overall equilibrium is imposed exactly up to the leading order. The success of the approach relies upon the semi-inverse method and the decomposition of deformations in which the classical linear theory guides the solution. The solution bridges the gap between the two extremes-the classical solutions valid only for infinitesimal deformations and the solutions form the technical theories for deformations with large rotations. The solutions may be used to confirm the technical theories and to verify numerical solutions obtained from finite element analysis.

Strain Measurement and Failure Detection of Reinforced Concrete Beams Using Fiber Otpic Michelson Sensors (광섬유 마이켈슨 센서에 의한 RC보의 변형률 측정 및 파손의 검출)

  • Kwon, Il-Bum;Huh, Yong-Hak;Park, Phi-Lip;Kim, Dong-Jin;Lee, Dong-Chun;Hong, Sung-Hyuk;Moon, Hahn-Gue
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.3 no.3
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    • pp.223-236
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    • 1999
  • The need to monitor and undertake remidial works on large structures has greatly increased in recent years due to the appearance of widespread faults in large structures such as bridges and buildings, etc, of 20 or more years of age. The health condition of structures must be monitored continuously to maintenance the structures. In order to do in-situ monitoring, the sensor is necessary to be embedded in the structures. Fiber optic sensors can be embedded in the structures to get the health information in the structures. The fiber sensor was constructed with $3{\times}3$ fiber couplers to sense the multi-point strains and failure instants. The 4 RC (reinforced concrete) beams were made to 2 of A type, 2 of B type beams. These beams were reinforced by the reinforcing bars, and were tested under the flexural loading. The behavior of the beams was simultaneously measured by the fiber optic sensors, electrical strain gages, and LVDT. The states of the beams were interpreted by these all signals. By these experiments, There were verified that the fiber optic sensors could measure the structural strains and failure instants of the RC beams, The fiber sensors were well operated until the failure of the beams. It was shown that the strains of the reinforcing steel bar can be used to monitor the health condition of the beams through the flexural test of RC beams. On the other words, the results were arrived that the two strains in the reinforcing bar measured at the same point can give the information of the structural health status. Also, the failure instants of beams were well detected from the fiber optic filtered signals.

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Genogroup position of aquabirnavirus GC-1 isolated from rockfish Sebastes schiegeli in Korea

  • Joh, Seong-Joon;Lee, Youn-Jeong;Song, Chang-Sun;Kang, Shien-Young;Mo, In-Pil;Heo, Gang-Jun
    • Korean Journal of Veterinary Research
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    • v.48 no.3
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    • pp.287-293
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    • 2008
  • The cDNA of the aquabirnavirus, GC-1 isolated from rockfish Sebastes schlegeli in Korea, was synthesized using the reverse transcriptase-polymerase chain reaction. The nucleotide and deduced amino acid sequences were determined from cDNA of the VP2-NS-VP3 coding region of genome segment A. The nucleotide sequences of the segment A were 3,086 base pairs (bp) in length and contained large open reading frame (ORF) and terminal sequences. The large ORF was comprised of 2,916 bp nucleotides and composed of 972 deduced amino acid sequences. Pairwise comparisons were made with other aquabirnavirus sequences published previously. The study of genetic relationships between GC-1 and aquabirnaviruses in the large ORF and VP2 coding regions demonstrated that the GC-1 has the nearest genetic relationship with the marine birnaviruses (MABV strains), and the GC-1 and MABV strains can be clustered as the same genogroup. GC-1 can be included in MABV, which is the 7th genogroup of family Aquabirnaviridae.

Modelling of strains in reinforced concrete flexural members using alpha-stable distribution

  • Rao, K. Balaji;Anoop, M.B.;Kesavan, K.;Balasubramanian, S.R.;Ravisankar, K.;Iyer, Nagesh R.
    • Computers and Concrete
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    • v.11 no.5
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    • pp.411-440
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    • 2013
  • Large fluctuations in surface strain at the level of steel are expected in reinforced concrete flexural members at a given stage of loading due to the emergent structure (emergence of new crack patterns). This has been identified in developing deterministic constitutive models for finite element applications in Ibrahimbegovic et al. (2010). The aim of this paper is to identify a suitable probability distribution for describing the large deviations at far from equilibrium points due to emergent structures, based on phenomenological, thermodynamic and statistical considerations. Motivated by the investigations reported by Prigogine (1978) and Rubi (2008), distributions with heavy tails (namely, alpha-stable distributions) are proposed for modeling the variations in strain in reinforced concrete flexural members to account for the large fluctuations. The applicability of alpha-stable distributions at or in the neighborhood of far from equilibrium points is examined based on the results obtained from carefully planned experimental investigations, on seven reinforced concrete flexural members. It is found that alpha-stable distribution performs better than normal distribution for modeling the observed surface strains in reinforced concrete flexural members at these points.

Studies on the outbreak cause of inner tissue browning and malformed symptoms on fruiting body of Agaricus brazilensis (신령버섯(Agaricus brazilensis) 기형증상의 발생원인 및 조직내 갈변에 관한 연구)

  • Jhune, Chang-Sung;Yun, Hyung-Sik;Park, Yun-Jung;Weon, Hang-Yeon;Yoo, Young-Bok;Lee, Chan-Jung;Chung, Jong-Chun;Kong, Won-Sik
    • Journal of Mushroom
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    • v.7 no.4
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    • pp.168-172
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    • 2009
  • We attempted to isolate the bacterial strains from the fruiting bodies of Agaricus brazilensis and determined their effects on browning and distortions of mushrooms. No bacterial strains were isolated when the middle of browning regions of A. brazilensis were used. Total 125 bacterial strains were obtained from the surface of browning regions and classified into 17 different genera and 29 species by using MIDI methods. Most common genus were Pseudomonas (26), Yersinia (29), and Cedecea (29). High lytic activity were detected when Pseudomonas strains were tested, while relatively low lytic activity were observed with both Yersinia and Cedecea strains.Therefore, we believed the distortion of mushroom could be the result of bacterial infections. Also, the development of brownish color was detected in large number of A. brazilensis strains only by incubation at 4C, suggesting no specific correlation between bacterial strains and brownish color development. Also, it is considered that the development of brownish color can be the normal changes of A. brazilensis.

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Genetic Diversity of Agrobacterium vitis Strains in Korea (국내 포도나무 혹병(Agrobacterium vitis) 균주의 유전적 다양성)

  • Kim, Jong-Kun;Choi, Jae-Eul;Kang, Hee-Wan
    • Research in Plant Disease
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    • v.13 no.3
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    • pp.137-144
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    • 2007
  • Fifty nine strains of Agrobacterium vitis, the causal agent of crown-gall disease on grapevine, originating from different geographical regions and 16 grapevine cultivars including 35 Kyoho cultivar of Korea, were characterized by PCR polymorphic analysis using Universal Rice Primer(URP). Of 12 URP primers, primers URP1F, URP2R, URP2F, and URP4R, URP17R were available for detecting PCR polymorphic bands among the A. vitis strains. PCR polymorphic bands produced by primers URP2F and URP17R were profiled to 12 strain types. A. vitis strains originated from Kyoho cultivar of grapevine showed relatively simple genetic diversify of the four PCR types, while the A. vitis strains originated from other grapevine cultivars and type culture strains showed various genetic diversity with 8 types. Unweighted Pair-Group Method with Arithmetic mean(UPGMA) cluster analysis using the URP-PCR polymorphic bands showed 59.4. vitis strains are genetically clustered into large seven groups.

A riboprinting scheme for identification of unknown Acanthamoeba isolates at species level

  • Kong, Hyun-Hee;Chung, Dong-Il
    • Parasites, Hosts and Diseases
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    • v.40 no.1
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    • pp.25-31
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    • 2002
  • We describe a riboprinting scheme for identification of unknown Acanthamoeba isolates at the species level. It involved the use of PCR-RFLP of small subunit ribosomal RNA gene (riboprint) of 24 reference strains by 4 kinds of restriction enzymes. Seven strains in morphological group I and III were identified at species level with their unique sizes of PCR product and riboprint type by Rsa 1. Unique RFCP of 17 strains in group II by Dde I. Taq I and Hae III were classified into: (1) four taxa that were identifiable at the species level. (2) a subgroup of 4 taxa and a pair of 2 taxi that were identical with each other. and (3) a species complex of 7 taxa assigned to A. castellanii complex that were closely related. These results were consistent with those obtained by 18s rDNA sequence analysis. This approach provides an alternative to the rDNA sequencing for rapid identification of a new clinical isolate or a large number of environmental isolates of Acanthamoeba.

Evaluation of White-rot Fungi for Biopulping of Wood

  • Kang, Kyu-Young;Sung, Jung-Suk;Kim, Dae-Young
    • Mycobiology
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    • v.35 no.4
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    • pp.205-209
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    • 2007
  • Ergosterol involves in fungal cell growth as a major component in fungal cell membranes. It can be an indicator that shows the fungal activity, and its content depends on the fungal strains, culture, growth conditions and so on. In this study, fungal activities and growth patterns of three white-rot fungi strains isolated in Korea were evaluated by determination of ergosterol contents during the incubation. Wood decay test and chemical analyses of wood were also performed to verify the relationship between fungal activity and wood degrading capacity of white-rot fungi for 60 days. In the results of experiments, it is considered that the test strains selectively degrade large amount of lignin in wood at the early stage of decay. Especially, Phanerochaete chrysosporium showed the best capability on selective degradation of lignin among the test fungi. It is suggested that the determination of ergosterol content in the fungal culture during the incubation is the simple and effective screening method of white-rot fungi for the application to biopulping of wood.

A Study on the Strain Analysis by Image Processing Technique (화상처리기법을 이용한 변형율해석에 관한 연구)

  • 백인환;신문교
    • Journal of Advanced Marine Engineering and Technology
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    • v.12 no.4
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    • pp.32-45
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    • 1988
  • The scanning moire method, in which the master grating is replaced by the scanning line of television camera and in which the moire pattern is obtained by thining out some scanning line, is discussed by the sampling theory. It is determined also by the sampling theory that relationship between the fringe pattern. The programs that analyze the strain by the scanning moire method have been developed. For the simulation model in which we are able to calculate analytically the distribution of strains, the scanning moire method is discussed. It is shown that the small strains and the large strains are analyzed from the same picture by the thinning out technique and that the accuracy of analysis is improved by change of the phase in the thinning out technique.

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Six Newly Recorded Fungal Taxa from Freshwater Niche in Korea

  • Lim, Hyo Jin;Nguyen, Thuong T.T;Lee, Hyang Burm
    • Mycobiology
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    • v.49 no.2
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    • pp.105-121
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    • 2021
  • Six interesting fungal strains were isolated during a survey of fungal diversity associated with freshwater; these strains were designated as CNUFC YJW2-22, CNUFC MSW11-6-2, CNUFC HRS5-3, CNUFC MSW242-6, CNUFC DMW2-2, and CNUFC CPWS-1. Based on a polyphasic approach including phylogenetic analyses of internal transcribed space (ITS), large subunit (LSU), beta-tubulin (BenA), and calmodulin (CaM) gene sequences, morphological analyses, the six strains were found to be identical to Acremonium guillematii, Cadophora novi-eboraci, Lectera nordwiniana, Mycoarthris corallina, Talaromyces siamensis, and Tetracladium globosum, respectively. To our knowledge, these are the first records of the rare Lectera, Mycoarthris, and Tetracladium genera in Korea, and the first reports of A. guillematii, C. novi-eboraci, L. nordwiniana, M. corallina, T. siamensis, and Te. globosum in a freshwater environment.