• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1153-1159
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• 2007

The vibration analysis is necessary at the design stage to improve crew's life on board and to prevent the vibration troubles of the hull structures and main machineries prior to the construction. Especially, if high vibration problems occur on the global structures like the hull girder and the deckhouse after construction, it takes lots of time, labor and cost to cure them and thus accurate analysis of global vibration should be performed from the design stage. In this study, some factors for the global vibration analysis have been investigated and the way to be applied to the analysis has been suggested.

• Nuclear Engineering and Technology
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• v.52 no.3
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• pp.477-484
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• 2020

The control rod drive mechanism needs to be debugged after reactor fresh fuel loading. It is of great importance to monitor the subcriticality of this process accurately. A modified method was applied to the subcriticality monitoring process, in which only a single control rod cluster was fully withdrawn from the core. In order to correct the error in the results obtained by Neutron Source Multiplication Method, which is based on one point reactor model, Monte Carlo neutron transport code was employed to calculate the fission neutron distribution, the iterated fission probability and the neutron flux in the neutron detector. This article analyzed the effect of a coarse mesh and a fine mesh to tally fission neutron distributions, the iterated fission probability distributions and to calculate correction factors. The subcriticality before and after modification is compared with the subcriticality calculated by MCNP code. The modified results turn out to be closer to calculation. It's feasible to implement the modified NSM method in large local reactivity addition process using Monte Carlo code based on 3D model.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.5
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• pp.509-515
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• 2008

The vibration analysis is necessary at the design stage to improve crew's life on board and to prevent the vibration troubles of the hull structures and main machineries prior to the construction. Especially, if high vibration problems occur on the global structures like the hull girder and the deckhouse after construction, it takes lots of time, labor and cost to cure them and thus accurate analysis of global vibration should be performed from the design stage. In this study, some factors for the global vibration analysis have been investigated and the way to be applied to the analysis has been suggested.

• The Plant Pathology Journal
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• v.28 no.1
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• pp.87-92
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• 2012

$Tomato$ $spotted$ $wilt$ $virus$ (TSWV)-infected $Capsicum$ $annuum$ plants were collected from open fields during June to July in 2010. The TSWV isolates were designated as Gneung, Ghang-Kjj, Gchang-Njc, Ghae, and Pap. The nucleotide sequence of the nucleocapsid protein (N) and movement protein (NSm) of the five isolates was determined. The pathogenicity of the five isolates was determined on 14 $C.$ $annuum$ cultivars two times by using mechanical inoculation. The five isolates induced different response: Both Gneung and Gchang-Kjj did not infect any of the cultivars in the 2nd trial, while Gchang-Njc, Ghae and Pap infected 11, 6 and 13 of 14 cultivars, respectively. The five isolates also were tested on $Solanum$ $lycopersicum$ breeding line TGC09-71 and three $Nicotiana$ species. $S.$ $lycopersicum$ showed a similar response to the five isolates as did $C.$ $annuum$. Both Gchang-Njc and Ghae infected systemically all three $Nicotiana$ species tested. While both Pap and Gneung did not infect any of the $Nicotiana$ species tested. In conclusion, five TSWV isolates induced different infection spectra in $C.$ $annuum$ cultivars, $Nicotiana$ species and an $S.$ $lycopersicum$ breeding line. Amino acid sequence analysis of the NSm gene could not support or explain the different infection spectra of the five isolates. This study indicated that various isolates must be used as virus inocula for evaluation of $C.$ $annuum$ and $S.$ $lycopersicum$ cultivars in breeding programs for TSWV resistance.

• Steel and Composite Structures
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• v.22 no.6
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• pp.1337-1358
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• 2016

The current study focuses on the assessment and interface response of reinforced concrete elements with composite materials (carbon fiber reinforced polymers-CFRPs, glass fiber reinforced polymers-GFRPs, textile reinforced mortars-TRM's, near surface mounted bars-NSMs). A description of the transfer mechanisms from concrete elements to the strengthening materials is conducted through analytical models based on failure modes: plate end interfacial debonding and intermediate flexural crack induced interfacial debonding. A database of 55 in total reinforced concrete columns (scale 1:1) is assembled containing elements rehabilitated with various techniques (29 wrapped with CFRP's, 5 wrapped with GFRP's, 4 containing NSM and 4 strengthened with TRM). The failure modes are discussed together with the performance level of each technique as well as the efficiency level in terms of ductility and bearing/ bending capacity. The analytical models' results are in acceptable agreement with the experimental data and can predict the failure modes. Despite the heterogeneity of the elements contained in the aforementioned database the results are of high interest and point out the need to incorporate the analytical expressions in design codes in order to predict the failure mechanisms and the limit states of bearing capacities of each technique.

• Structural Engineering and Mechanics
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• v.83 no.4
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• pp.415-433
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• 2022

Eighteen (18) (120×300×2200 mm) beams were prepared and tested to evaluate the shear strength of Glass Fiber Reinforced Concrete (GFRC) beams with no shear reinforcement, and evaluate the effectiveness of various innovative strengthening systems to increase the shear capacity of the GFRC beams. The test variables are the amount of discrete glass fiber (0.0, 0.6, and 1.2% by volume of concrete) and the type of longitudinal reinforcement bars (steel or GFRP), the strengthening systems (externally bonded (EB) sheet, side near-surface mounted (SNSM) bars, or the two together), strengthening material (GFRP or steel) links, different configurations of NSM GFRP bars (side bonded links, full wrapped stirrups, side C-shaped stirrups, and side bent bars), link spacing, link inclination angle, and the number of bent bars. The experimental results showed that adding the discrete glass fiber to the concrete by 0.6%, and 1.2% enhanced the shear strength by 18.5% and 28%, respectively in addition to enhancing the ductility. The results testified the efficiency of different strengthening systems, where it is enhanced the shear capacity by a ratio of 28.4% to 120%, and that is a significant improvement. Providing SNSM bent bars with strips as a new strengthening technique exhibited better shear performance in terms of crack propagation, and improved shear capacity and ductility compared to other strengthening techniques. Based on the experimental shear behavior, an analytical study, which allows the estimation of the shear capacity of the strengthened beams, was proposed, the results of the experimental and analytical study were comparable by a ratio of 0.91 to 1.15.

• Research in Plant Disease
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• v.29 no.3
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• pp.286-294
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• 2023

Biological and molecular characterization of a Korean isolate of Orthotospovirus chrysanthinecrocaulis (formerly known as chrysanthemum stem necrosis virus, CSNV) isolated from Chrysanthemum morifolium was determined using host range and sequence analysis in this study. Twenty-three species of indicator plants inoculated mechanically CSNV-Kr was investigated for determination of host range. CSNV-Kr induced various local and systemic symptoms in the inoculated plant species. CSNV-Kr could not infect three plant species and induced symptomless in systemic leaves in Nicotiana tabacum cultivars, though the plant samples reacted positively with the antiserum to CSNV by double-antibody sandwich-enzyme-linked immunosorbent assay. The complete genome sequence of CSNV-Kr was determined. The L RNA of CSNV-Kr consists of 8,959 nucleotides (nt) and encodes a putative RNA-dependent RNA polymerase. The M RNA of CSNV-Kr consists of 4,835 nt and encodes the movement protein (NSm) and the glycoprotein precursor (Gn/Gc protein). The S RNA of CNSV-Kr consists of 2,836 nt and encodes NSs protein and N protein. The Gn/Gc and N sequence of CSNV-Kr were compared with those of previously published CSNV isolates originating from different countries at nucleotide and amino acid levels. The Gn/GC sequence of CSNV-Kr shared 98.8-99.5% identity with CSNV isolated from other countries and the N sequence of CSNV-Kr shared 98.8-99.6% identity. No particular region of variability could be found in either grouping of viruses. All of the CSNV isolates did not show any relationship according to geographical origins and isolation hosts, suggesting no distinct segregation of the CSNV isolates.

• Microbiology and Biotechnology Letters
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• v.34 no.3
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• pp.257-264
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• 2006

An aerobic submerged membrane bioreactor (MBR) treating ammonium wastewater was studied in respect of nitrification characteristics and distribution of nitrification bacteria over a period of 350 days. MBR was fed with ammonium concentration of 500-1000 mg $NH_4-N/L$ at a nitrogen load of $1-2kg\;N/m^3{\cdot}d$. Overall ammonium oxidation rate increased with dissolved oxygen (DO) concentration, temperature, and sludge retention time (SRT). Under a higher concentration of free ammonia ($NH_3-N$) due to the decrease of ammonium oxidation rate, the nitrite ratio ($NO_2-N/NO_x-N$) in the effluent increased. The sudden collapse of nitrification efficiency accompanied by sludge foaming and the increase of sludge volume index (SVI) was observed unexpectedly during the operation. At the later stage of operation, additional carbon source was fed to the MBR and resulted in twice higher value of SVI and the decrease of ammonium oxidation rate. In fluorescence in situ hybridization (FISH) analysis, genus Nitrosomonas which is specifically hybridized with probe NSM156 was initially the dominant ammonia oxidizing bacteria and the amount of Nitrosospira gradually increased. Nitrospira was the dominant nitrite oxidizing bacteria during whole operational period. Significant amount of Nitrobacter was also detected which might due to the high concentration of nitrite maintained in the reactor.

• Ocean and Polar Research
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• v.35 no.1
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• pp.1-14
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• 2013

Shoreline data of the barrier islands in Nakdong River Estuary for the last three decades were assembled using six sets of aerial photographs and seven sets of satellite images. Canny Algorithm was applied to untreated data in order to obtain a wet-dry boundary as a proxy shoreline. Digital Shoreline Analysis System (DSAS 4.0) was used to estimate the rate of shoreline changes in terms of five statistical variables; SCE (Shoreline Change Envelope), NSM (Net Shoreline Movement), EPR(End Point Rate), LRR (Linear Regression Rate), and LMS (Least Median of Squares). The shoreline in Jinwoodo varied differently from one place to another during the last three decades; the west tail has advanced (i.e., seaward or southward), the west part has regressed, the south part has advanced, and the east part has regressed. After the 2000s, the rate of shoreline changes (-2.5~6.7 m/yr) increased and the east advanced. The shoreline in Shinjado shows a counterclockwise movement; the west part has advanced, but the east part has retreated. Since Shinjado was built in its present form, the west part became stable, but the east part has regressed faster. The rate of shoreline changes (-16.0~12.0 m/yr) in Shinjado is greater than that of Jinwoodo. The shoreline in Doyodeung has advanced at a rate of 31.5 m/yr. Since Doyodeung was built in its present form, the south part has regressed at the rate of -18.2 m/yr, but the east and west parts have advanced at the rate of 13.5~14.3 m/yr. Based on Digital Shoreline Analysis, shoreline changes in the barrier islands in the Nakdong River Estuary have varied both temporally and spatially, although the exact reason for the shoreline changes requires more investigation.

• Journal of Microbiology and Biotechnology
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• v.25 no.10
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• pp.1751-1760
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• 2015

Mucin2 (MUC2), an important regulatory factor in the immune system, plays an important role in the host defense system against bacterial translocation. Probiotics known to regulate MUC2 gene expression have been widely studied, but the interactions among probiotic, pathogens, and mucin gene are still not fully understood. The aim of this study was to investigate the role of MUC2 in blocking effects of probiotics on meningitic E. coli-induced pathogenicities. In this study, live combined probiotic tablets containing living Bifidobacterium, Lactobacillus bulgaricus, and Streptococcus thermophilus were used. MUC2 expression was knocked down in Caco-2 cells by RNA interference. 5-Aza-2'-deoxycytidine (5-Aza-CdR), which enhances mucin-promoted probiotic effects through inducing production of Sadenosyl-L-methionine (SAMe), was used to up-regulate MUC2 expression in Caco-2 cells. The adhesion to and invasion of meningitic E. coli were detected by competition assays. Our studies showed that probiotic agents could block E. coli-caused intestinal colonization, bacteremia, and meningitis in a neonatal sepsis and meningitis rat model. MUC2 gene expression in the neonatal rats given probiotic agents was obviously higher than that of the infected and uninfected control groups without probiotic treatment. The prohibitive effects of probiotic agents on MUC2-knockdown Caco-2 cells infected with E44 were significantly reduced compared with nontransfected Caco-2 cells. Moreover, the results also showed that 5-Aza-CdR, a drug enhancing the production of SAMe that is a protective agent of probiotics, was able to significantly suppress adhesion and invasion of E44 to Caco-2 cells by upregulation of MUC2 expression. Taken together, our data suggest that probiotic agents can efficiently block meningitic E. coli-induced pathogenicities in a manner dependent on MUC2.