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임광희,허욱,이길성,박제웅,김선규,양인영 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-
Ultrasonic NDE of composite laminates is usually analyzed on the backwall echoes of the specimen. In the inspection of actual composite structures, the back surface of the part was curved or contained complex geometry and did not provide a usable backwall echo. In this work, a one-sided pitch-catch setup was used in the detection and evaluation of flaws and material anomalies in solid composite laminates. Two miniature potted Rayleigh wave transducers (for generating surface waves in contact mode on steel) were joined head-to-head and used in the pitch-catch mode on the surface of composites. The pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave to fiber orientation of the CFRP composites, including low level porosity, ply waviness, and cracks.
Effects of LEP, GYS1, MYOD1, and MYF5 polymorphisms on pig economic traits
Park, Sang-Je,Ha, Jeongim,Kim, Il-Suk,Kwon, Seul Gi,Hwang, Jung Hye,Park, Da Hye,Kang, Deok Gyeong,Kim, Tae Wan,Kim, Sam Woong,Kim, Chul Wook Walter de Gruyter GmbH 2015 Annals of animal science Vol.15 No.3
<B>Abstract</B><P> In the present study, we examined the effect of single nucleotide polymorphisms (SNPs) of leptin (LEP), skeletal muscle glycogen synthase (GYS1), myogenic differentiation 1 (MYOD1), and myogenic factor 5 (MYF5) genes on economic trait association in pigs. LEP/HindIII, MYOD1/DdeI, MYF5/FokI, and GYS1/FokI genotypes were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) from 466 pigs comprised of Duroc, Landrace and Yorkshire breeds. The LEP/HindIII polymorphism differed significantly with respect to average daily gain (ADG) in Duroc pigs (P<0.05). However, the GYS1/FokI polymorphism was not significantly associated with any trait. The MYOD1/DdeI polymorphism was significantly associated with both ADG and meat percentage (MP) in Duroc pigs, and ADG, backfat thickness (BFT) and feed efficiency (FE) in Landrace pigs, whereas the MYOD1/DdeI polymorphism was not significantly associated with any trait in Yorkshire pigs. In addition, the MYF5/FokI polymorphism revealed a close relationship with ADG in Duroc pigs. In conclusion, we believe that the SNPs within LEP, MYOD1 and MYF5 in certain pig breeds play important roles as potential genetic markers for economic traits of pigs.</P>
Je-Woong Park,Do-Jung Kim,Young-Sub Kweon,Kwang-Hee Im,David K. Hsu,Sun-Kyu Kim,In-Young Yang 한국비파괴검사학회 2009 한국비파괴검사학회지 Vol.29 No.3
Composite wood materials are very sensitive to water and inspection without any coupling medium of a liquid is really needed to wood materials due to the permeation of coupling medium such as water. However, air-coupled ultrasound has obvious advantages over water-coupled experimentation compared with conventional C-scanner. In this work, it is desirable to perform contact-less nondestructive evaluation to assess wood material homogeneity. A wood material was nondestructively characterized with non-contact and contact modes to measure ultrasonic velocity using automated data acquisition software. We have utilized a proposed peak-delay measurement method. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. The variation of ultrasonic velocity was found to be somewhat difference due to air-coupled limitations over conventional scan images. However, conventional C-scan images are well agreed with increasing the resin-infiltrated time as expected. Finally, we have developed a measurement system of an ultrasonic velocity based on data acquisition software for obtaining ultrasonic quantitative data for correlation with C-scan images.
Park, Je-Woong,Kim, Do-Jung,Kweon, Young-Sub,Im, Kwang-Hee,Hsu, David K.,Kim, Sun-Kyu,Yang, In-Young The Korean Society for Nondestructive Testing 2009 한국비파괴검사학회지 Vol.29 No.3
Composite wood materials are very sensitive to water and inspection without any coupling medium of a liquid is really needed to wood materials due to the permeation of coupling medium such as water. However, air-coupled ultrasound has obvious advantages over water-coupled experimentation compared with conventional C-scanner. In this work, it is desirable to perform contact-less nondestructive evaluation to assess wood material homogeneity. A wood material was nondestructively characterized with non-contact and contact modes to measure ultrasonic velocity using automated data acquisition software. We have utilized a proposed peak-delay measurement method. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. The variation of ultrasonic velocity was found to be somewhat difference due to air-coupled limitations over conventional scan images. However, conventional C-scan images are well agreed with increasing the resin-infiltrated time as expected. Finally, we have developed a measurement system of an ultrasonic velocity based on data acquisition software for obtaining ultrasonic quantitative data for correlation with C-scan images.
Park, Je Woong,Yang, In Young,Im, Kwang Hee,Hsu, David K.,Song, Sung Jin,Kim, Hak Joon,Cho, Young Tae Trans Tech Publications, Ltd. 2007 Materials science forum Vol.566 No.-
<P>In particular, CFRP (carbon fiber reinforced plastics) composite materials have found wide applicability because of their inherent design flexibility and improved material properties. CFRP composites were manufactured from uni-direction prepreg sheet in this paper. However, impacted composite structures have 50-75% less strength than undamaged structures. It is desirable to perform nondestructive evaluation to assess material properties and part defect in order to ensure product quality and structural integrity of CFRP. In this work, a CFRP composite material was nondestructively characterized and a pitch-catch technique was developed to measure impacteddamaged area using an automated-data acquisition system. Also one-sided mode was performed to scan defect both manual contact measurement and an immersion tank. It is found a pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave to subtle flaw conditions in the composite, including fiber orientation, low level porosity, ply waviness, and cracks. The paper describes the depth of the sampling volume with the head-to-head miniature Rayleigh probes and also ultrasonic C-scan images are acquired experimentally using one-sided measurement and a conventional scanner.</P>
Influence of Ultrasonic Waves on the Stacking Orientation in Carbon Fiber/Epoxy Composite Laminates
JE-WOONG PARK,DO-JUNG KIM,DAVID K. HSU,YOUNG-HWAN SEO,KWANG-HEE IM 한국해양공학회 2008 韓國海洋工學會誌 Vol.22 No.4
In this study, an investigation of shear wave ultrasonic technique was carried out to detect stacking orientation error for CF/Epoxy quasi-isotropy composite laminates. The ultrasonic shear wave is particularly sensitive to ply orientation and layup sequence in the CF/Epoxy composite laminates. In the manufacturing of composite laminates, it is important that layup errors be detected in samples. In this work, an effortwas made to develop shear wave techniques that can be applied to composite laminates. During testing the most significant problem is that the couplant conditions do not remain the same because of its changing viscosity. The design and use of a shear wave transducer would greatly alleviate the couplant problem. A pyramid of aluminum, with isosceles triangle (two 45o angles) sides, was made in generate shear waves, using two longitudinal transducers based on an ultrasonic-polarized mechanism. A signal splitter was connected to the pulser jack on apulser/receiver and to the longitudinal transducers. The longitudinal transducers were mounted with mineral oil, and the shear transducer was mounted with burnt honey on the bottom as a receiver. The shear wave was generated at a maximum and a minimum based on the ultrasonic-polarized mechanism. Results show it is feasible to measure layup error using shear wave transducers on a stacking of prepregs in composites.
Park, Sang-Je,Kim, Young-Hyun,Lee, Sang-Rae,Choe, Se-Hee,Kim, Myung-Jin,Kim, Sun-Uk,Kim, Ji-Su,Sim, Bo-Woong,Song, Bong-Seok,Jeong, Kang-Jin,Jin, Yeung-Bae,Lee, Youngjeon,Park, Young-Ho,Park, Young Il Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.11
BCS1L gene encodes mitochondrial protein and is a member of conserved AAA protein family. This gene is involved in the incorporation of Rieske FeS and Qcr10p into complex III of respiratory chain. In our previous study, AluYRa2-derived alternative transcript in rhesus monkey genome was identified. However, this transcript has not been reported in human genome. In present study, we conducted evolutionary analysis of AluYRa2-exonized transcript with various primate genomic DNAs and cDNAs from humans, rhesus monkeys, and crabeating monkeys. Remarkably, our results show that AluYRa2 element has only been integrated into genomes of Macaca species. This Macaca lineage-specific integration of AluYRa2 element led to exonization event in the first intron region of BCS1L gene by producing a conserved 3' splice site. Intriguingly, in rhesus and crabeating monkeys, more diverse transcript variants by alternative splicing (AS) events, including exon skipping and different 5' splice sites from humans, were identified. Alignment of amino acid sequences revealed that AluYRa2-exonized transcript has short N-terminal peptides. Therefore, AS events play a major role in the generation of various transcripts and proteins during primate evolution. In particular, lineage-specific integration of Alu elements and species-specific Alu-derived exonization events could be important sources of gene diversification in primates.