• The KSFM Journal of Fluid Machinery
• /
• v.15 no.1
• /
• pp.58-63
• /
• 2012

Three dimensional unsteady numerical calculations were performed to investigate unsteadiness of the tip leakage flow in an axial compressor. The first stage of the four-stage low-speed research axial compressor was examined. Since this compressor has a relatively large tip clearance, the unsteadiness of the tip leakage flow is induced. Through the results from the unsteady calculations, the process of the induced unsteady tip leakage flow was investigated. It was shown that the leakage flow that occurred at a rotor blade tip clearance affected the pressure distribution on the pressure side near the tip of the adjacent blade, thus caused the fluctuation of the pressure difference between the pressure side and suction side. Consequently, the unsteady tip leakage flow was induced at the adjacent rotor blade. The unsteady feature of the tip leakage flow was changed as the operating point was moved. The interface between the tip leakage flow and the main flow only affected the trailing edge region at the design point whereas the interface influenced up to the leading edge at the low flow rate point. As the flow rate decreased, additionally, it was seen that the vortex size of the tip leakage flow increased and the relatively large length scale disturbance occurred. On the other hand, using frequency analysis, it was shown that the unsteadiness was not associated with the rotor speed and was about 40% of the blade passing frequency. This feature was explained in the rotor relative frame of reference, and the frequency decreased as the flow rate decreased.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.2
• /
• pp.417-421
• /
• 2004

A normal prion protein (PrPc) is converted to a protease resistant isoform (PrPsc) by an apparent self-propagating activity in bovine spongiform encephalopathies (BSE), which is a neurodegenerative disease. The cDNA encoding bovine PrP open reading frame (ORP) in Korean cattle was cloned by polymerase chain reaction (PCR). The cloned cDNA had a length of 795 base pairs which coded for a protein of 264 amino acid residues with a calculated molecular mass of 28.6 kDa. Identities of 90, 90, 79 and 78% on nucleotide and 94, 94, 84, and 84% on amino acid sequence were shown to PrP genes from sheep, goat, human, and mouse, respectively. The cloned DNA was ligated into the pQE30 expression vector and transformed into E. coli M15. The PrP was expressed by induction with isopropyl-$\beta$-D-thiogalactoside (IPTG) and purified on the Ni-NTA affinity column. High specific activities of the recombinant PrP were observed in the fraction of pH 5.8 eluate and showed a molecular mass of-29 kDa on SDS-PAGE and Western blot analysis.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.12
• /
• pp.2192-2198
• /
• 2016

The myeloid-specific IgA Fc receptor ($Fc{\alpha}R$) is a cell surface molecule on immunocytes that provides a fundamental connection between humoral and cellular immunity. In this study, the full-length cDNA sequence of swine $Fc{\alpha}RI$ ($swFc{\alpha}RI$) was isolated and characterized and found to contain a 792-base-pair open reading frame, encoding a 264-amino-acid transmembrane glycoprotein with a predicted molecular mass of 29.4 kDa. The $swFc{\alpha}RI$ shares high amino acid sequence homology (>50%) with its counterparts from cattle, seal, and horse. Rosetting analysis confirmed that COS-7 cells transfected with an $swFc{\alpha}RI$ expression plasmid was able to combine with chicken erythrocytes sensitized with porcine IgA, but not IgG.

• Fisheries and Aquatic Sciences
• /
• v.13 no.3
• /
• pp.224-230
• /
• 2010

Growth hormone (GH) is known as one of the main osmoregulators in euryhaline teleosts during seawater (SW) adaptation. Many of the physiological actions of GH are mediated through insulin-like growth factor-I (IGF-I), and the GH/IGF-I axis is associated with osmoregulation of fish during SW acclimation. However, little information is available on the response of fish IGF-II to hyperosmotic stress. Here we present the first cloned IGF-I and IGF-II cDNAs of marine medaka, Oryzias dancena, and an analysis of the molecular characteristics of the genes. The marine medaka IGF-I cDNA is 1,340 bp long with a 257-bp 5' untranslated region (UTR), a 528 bp 3' UTR, and a 555-bp open reading frame (ORF) encoding a propeptide of 184 amino acid (aa) residues. The full-length marine medaka IGF-II cDNA consists of a 639 bp ORF encoding 212 aa, a 109 bp 5' UTR, and a 416 bp 3' UTR. Homology comparison of the deduced aa sequences with other IGF-Is and IGF-IIs showed that these genes in marine medaka shared high structural homology with orthologs from other teleost as well as mammalian species, suggesting high conservation of IGFs throughout vertebrates. The IGF-I mRNA level increased following transfer of marine medaka from freshwater (FW) to SW, and the expression level was higher than that of the control group, which was maintained in FW. This significantly elevated IGF-I level was maintained throughout the experiment (14 days), suggesting that in marine medaka, IGF-I is deeply involved in the adaptation to abrupt salinity change. In contrast to IGF-I, the increased level of marine medaka IGF-II mRNA was only maintained for a short period, and quickly returned a level similar to that of the control group, suggesting that marine medaka IGF-II might be a gene that responds to acute stress or one that produces a supplemental protein to assist with the osmoregulatory function of IGF-I during an early phase of salinity change.

• Journal of Korean Society of Steel Construction
• /
• v.19 no.1
• /
• pp.67-78
• /
• 2007

In this study, we performed an investigation on the variations in the structural capacity of steel plate walls with various infill plate details. Five three-story plate walls with thin web plates were tested. Parameters for the test specimens were the connection details between the moment frame and infill plates, such as weld and bolt connections, the location and length of weld connection, and coupling wall. Regardless of the details of infilled steel plate, the steel plate wall specimens showed excellent initial stiffness, strength, and energy dissipation capacity. However, the wall with bolt-connected infill plates showed slightly low deformation capacity. This result showed that for workability and cost efficiency,various wall details can be used in practice without causing a significant decrease in the structural capacity of steel plate walls. A method for making projections on strength and energy dissipation capacity of steel plate wall specimens with various details was developed.

• Journal of Plant Biotechnology
• /
• v.36 no.4
• /
• pp.407-414
• /
• 2009

A cDNA clone encoding phytocystatin was isolated from Brassica rapa seedlings, through rapid amplification of cDNA ends (RACE). This gene (name as Brcpi1; GenBank accession no.: EF079953) had a total length of 881 bp with an open reading frame of 609 bp, and encoded predicted polypeptide of 203 amino acid (aa) residues including a putative N-terminal signal peptide. Other relevant regions found its sequence included the G and PW conserved aa motifs, and the consensus LARFAV sequence for phytocystatins and the reactive site QVVAG. The BrCPI1 protein shared 95, 94, 81, 80 and 78% identity with other CPI proterins isolated from Brassica oleracea (BoCPI-1), Arabidopsis thaliana (AtCY SB), Glycine max (GmCPI), Oryza sativa (OsCYS-2) and Zea may (ZmCPI) at amino acid level, respectively. Southern blot analysis showed that Brcpi1 was a low copy gene. Expression pattern analysis revealed that Brcpi1 was a tissue-specific expressing gene during reproductive growth and strongly expressed at mature seedling stages. Furthermore, overexpression of Brcpi1 in transgenic Arabidopsis was enhanced tolerance to salt and cold stresses. Meanwhile the juvenile seedling of Brcpi1 transgenic plants was not affected by various concentrations ABA in MS medium. Taken together, the results showed that Brcpi1 functioned as a cysteine protease inhibitor and it exhibited a protective agent against diverse types of abiotic stress, which induced this gene in a tissue- and stress-specific manner.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.21 no.3
• /
• pp.459-464
• /
• 2012

The point of impact, the shot group, and the flight traces depend on the combination of unique features which decide moving traces of the arrow (paradox of the archer, length of the arrow shaft, weight, angle of the feather, and spline of the arrow shaft). The more dense the impact points in the shot group and the earlier elimination of paradox of the archer, the higher assessment is given for the product. However, there is no way to objectively assess the efficiency and quality of the arrow, and there is no numeric data to be used as the basis for comparison with other products. Although capturing the images of flying arrow using a high-speed motion picture camera is possible, we are limited to observation from specific view angle only. Hence, the criteria for efficiency and quality assessment are mostly based on subjective opinions of experts or hunters, or review on consumers' remarks. In this paper, we propose a hardware composition that are based on three detection frames consisting of line lasers and photo diode arrays without the high-speed motion picture camera. Predicated on measured coordinates data, a nobel method for the archer's paradox measurement, a key parameter that determine the arrow's trajectory, and corresponding numerical analysis model is proposed.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.27 no.4
• /
• pp.241-248
• /
• 2007

Cytokinins are essential plant hormones that play crucial roles in various aspects of plant growth and development. By using mRNA differential display, we isolated a cytokinine-inducible cDNA encoding pathogenesis-related (PR) 4 from Arabidopsis amp1 mutant. The full-length PR4 cDNA, designated AtPR4, contains an open reading frame of 212 amino acids with calculated molecular mass of 22,900 Da and isoelectric point (pI) of 7.89. Genomic DNA blotting showed that the Arabidopsis genome has one copy of AtPR4. AtPR4 mRNA was induced by cytokinin and NaCl, but decreased by SA or JA treatment. PR proteins are induced in response to pathogen attack. Thus the AtPR4 gene isolated in this study may be a useful candidate for genetic engineering of forage crops for increased tolerance against pathogen.

• The Mathematical Education
• /
• v.29 no.1
• /
• pp.21-34
• /
• 1990

This is a study on an instruction of estimation for error correction in the calculation with a computer or a calculator. The aim of this study is to survey a new aspect of calaulation teaching and the teaching strategy of estimation and finally to frame a new curriculum model of estimation instruction. This research required a year and the outcomes of the research can be listed as follows: 1. Social utilities of estimation were made clear, and a new trend of calculation teaching related to estimation instruction was shown. 2. The definition of estimation was given and actual examples of conducting an estimation among pupils in lower grades were given for them to have abundant experiences. 3. The ways of finding estimating values in fraction and decimal fraction were presented for the pupils to be able to conduct an estimation. 4. The following contents were given as a basic strategy for estimation. 1) Front-end strategy 2) Clustering strategy 3) Rounding strategy 4) Compatible numbers strategy 5) Special numbers strategy 5. In an instuction of estimation the meaning, method. and process of calculation and calculating algorithm were reviewed for the cultivation of children's creativity through promoting their basic skill, mathematical thinking and problem-solving ability. 6. The following contents were also covered as an estimation strategy for measurement 1) Calculating the sense of quantity on the size of unit. 2) Estimating the total quantity by frequent repetition of unit quantity. 3) Estimating the length and the volume by weighing. 4) Estimating unknown quantity based on the quatity already known. 5) Estimating the area by means of equivalent area transformation. 7. The ways of instructing mental computation were presented. 8. Reviews were made on the curricular and the textbook contents concerning estimation instructions both in Korea and Japan. and a new model of curriculum was devised with reference to estimation instruction data of the United States.

• The Plant Pathology Journal
• /
• v.16 no.3
• /
• pp.151-155
• /
• 2000

A cDNA (Oslls1) encoding Lls1-homologue of maize was isolated from cDNA library of rice (Oryza sativa cv. Ilpum). The 2,138 bp of full length Oslls1 clone contains an open reading frame of 1,623 nucleotides encoding 575 amino acid residues. The deduced amino acid sequence of Oslls1 has a high level of homology with chlorophyll a oxygenases of Arabidopsis thaliana (67%) and Marchantia polymorpha (65%). Southern blot analysis of genomic DNA indicates the existence of a small gene family for Oslls1 in the rice genome. The expression of Oslls1 mRNA was induced in leaves and germinating seeds. Treatment of $H_2O$$_2$significantly down-regulated Oslls1 expression. The expression of Oslls1 mRNA was consititutively down-regulated in the blm, a rice mutant exhibiting spontaneous necrotic lesions. These results suggest that this Oslls1 gene may be involved incell death mechanisms in the blm mutant of rice.