• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.320-327
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• 2005

Liquefaction characteristics of saturated sand under various dynamic loadings such as sinusoidal, wedge, increasing wedge and real earthquake loading are investigated focusing on the excess pore water pressure build up instead of liquefaction resistance strength in this paper. There are large differences between two types of earthquake loading - impact and vibration in liquefaction characteristics. The angle of phase change line of sinusoidal loading is very close to the vibration type, whereas the cumulative deviator stress and cumulative plastic strain are larger than two types of real earthquake loadings. On the other hand, the liquefaction characteristics of increasing wedge loadings are located in the range between vibration and impact earthquake loadings. It is concluded that the sinusoidal loading overestimates the resistance of soil under real earthquake loading. Based on results obtained, the increasing wedge loading can reflect the liquefaction behavior under real earthquake loadings more efficiently than sinusoidal loading based on equivalent uniform stress concept.

• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.320-324
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• 1997

The number of Vivrio vulnificus strain 29307 was assessed for oysters treated with acetic, lactic, citric, and alginic acids during storage at 15$^{\circ}C$. When oysters were dipped with 0.5% acetic, 0.5% lactic, or 0.5% citric acids for 3 min, V. vulnificus was not detected after 4 days of storage. V. vulnificus in the treatment of 3% alginic acid (AL) containing 2% acetic acid (AA) was not detected after 2 days of storage, while it was isolated in the controls for 4 days of storage. Based on these results, the combination of AL and AA was more effective for preventing the growth of V. vulnificus in oysters than the treatments of the acid alone.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.315-320
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• 1989

Bacteria utilizing naphthalene as a sole carbon source for growth were isolated and identified and code named as Acinetobacter calcoaceticus R-88, Pseudomonas testosteroni R-87 and Pseudomonas putida R-89. Among these isolates, A. calcoaceticus R-88 found most effective in utilizing naphthalene. The optimal pH, temperature and concentration of naphthalene was 7.0, $30^{\circ}C$ and 10mM, respectively. The strain degraded naphthalene to salicylic acid as an intermediate. And the strain showed to be resistant to ampicillin, tetracyclin, chloramphenicol and kanamycin. A. calcoaceticus R-88 harbored plasmid DNA which was believed to be involved in naphthalene degradation.

• Journal of Species Research
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• v.11 no.4
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• pp.310-320
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• 2022

As a subset study to discover indigenous prokaryotic species in Korea, we isolated 20 bacterial strains and assigned them to the phyla Actinobacteria, Bacteroidota, Firmicutes, and Proteobacteria. From the high 16S rRNA gene sequence similarity (≥98.7%) and formation of a robust phylogenetic clades, we determined that each strain belonged to independent, predefined bacterial species. There are no official reports of these 20 species in Korea; therefore, 7 strains of the Actinobacteria, 2 strain of the Bacteroidota, 3 strains of the Firmicutes, and 8 strains of the Firmicutes are described in Korea for the first time. Gram reaction, colony and cell morphology, basic biochemical characteristics, and isolation sources are also described in the species description section.

• Geomechanics and Engineering
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• v.11 no.4
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• pp.531-552
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• 2016

The greenschist in the Jinping II Hydropower Station in southwest China exhibits continuous creep behaviour because of the geological conditions in the region. This phenomenon illustrates the time-dependent deformation and progressive damage that occurs after excavation. In this study, the responses of greenschist to stress over time were determined in a series of laboratory tests on samples collected from the access tunnel walls at the construction site. The results showed that the greenschist presented time-dependent behaviour under long-term loading. The samples generally experienced two stages: transient creep and steady creep, but no accelerating creep. The periods of transient creep and steady creep increased with increasing stress levels. The long-term strength of the greenschist was identified based on the variation of creep strain and creep rate. The ratio of long-term strength to conventional strength was around 80% and did not vary much with confining pressures. A quantitative method for predicting the failure period of greenschist, based on analysis of the stress-strain curve, is presented and implemented. At a confining pressure of 40 MPa, greenschist was predicted to fail in 5000 days under a stress of 290 MPa and to fail in 85 days under the stress of 320 MPa, indicating that the long-term strength identified by the creep rate and creep strain is a reliable estimate.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.10
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• pp.1610-1616
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• 2020

Objective: This study was to evaluate the effect of husbandry systems and strains on cecum microbial diversity of Jingyang chickens under the same dietary conditions. Methods: A total of 320 laying hens (body weight, 1.70±0.15 kg; 47 weeks old) were randomly allocated to one of the four treatments: i) Silver-feathered hens in enrichment cages (SEC) with an individual cage (70×60×75 cm), ii) Silver-feathered hens in free range (SFR) with the stocking density of 1.5 chickens per ten square meters, iii) Gold-feathered hens in enrichment cages (GEC), iv) Gold-feathered hens in free range (GFR). The experiment lasted 8 weeks and the cecum fecal samples were collected for 16S rDNA high throughput sequencing at the end of experiment. Results: i) The core microbiota was composed of Bacteroidetes (49% to 60%), Firmicutes (21% to 32%) and Proteobacteria (2% to 4%) at the phylum level. ii) The core bacteria were Bacteroides (26% to 31%), Rikenellaceae (9% to 16%), Parabacteroides (2% to 5%) and Lachnoclostridium (2% to 6%) at the genus level. iii) The indexes of operational taxonomic unit, Shannon, Simpson and observed species were all higher in SFR group than in SEC group while in GEC group than in GFR group, with SFR group showing the greatest diversity of cecum microorganisms among the four groups. iv) The clustering result was consistent with the strain classification, with a similar composition of cecum bacteria in the two strains of laying hens. Conclusion: The core microbiota were not altered by husbandry systems or strains. The free-range system increased the diversity of cecal microbes only for silver feathered hens. However, the cecum microbial composition was similar in two strain treatments under the same dietary conditions.

• Journal of the Society of Naval Architects of Korea
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• v.54 no.4
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• pp.312-320
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• 2017

This paper deals with the development of structural test facility for the strength assessment of marine leisure boat built from carbon fiber reinforced plastics (CFRP) materials. The structural test facility consists of test jig, load application and control system, and data acquisition system. Test jig, and load application and control system are designed to accommodate various size and short span to depth ratios of single skin, top-hat stiffened and sandwich constructions in plated structural format such as square and rectangular shapes. A lateral pressure load, typical and important applied load condition to the plates of the hull structure for marine leisure boat, is simulated by employing a number of hydraulic cylinders operated automatically and manually. To examine and operate the structural test facility, five carbon/epoxy based FRP square plates having the test section area of $1m^2$, which are part of CFRP marine leisure boat hull, are prepared and they are subjected to monotonically increasing lateral pressure loads. In the test preparation, considering the symmetry of the plates geometry, various strain gauges and linear variable displacement transformer are used in conjunction with data acquisition system utilizing LabVIEW. From the test observation, the responses of the CFRP hull structure of marine leisure boat are understood by obtaining load to deflection and strain to load curves.

• Korean journal of applied entomology
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• v.35 no.4
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• pp.315-320
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• 1996

The effects of 2-arnino-3-methyIimidazo[4,5-fq]u inoline (IQ), 2-amino-6dimethyl-dipyrido[l,2-a;3',2'-d] imidazole (Glu-P-1) and aflatoxin B1 (AFBI) on the mitotic recombinations and somatic chromosome mutations were investigated using the transgenic Drosophila bearing a chimeric gene consisting of a promoter region of Drosophila actin 5C gene and rat DNA polymerase $. For investigating mitotic recombinations and the somatic chromosome mutations, the heterozygous (mwhl+) strain possessing or lacking transgene pol P was used. The spontaneous frequency of small mwh spots, due to deletion or nondisjunction etc., in the non-transgenic w strain and the transgenic plpol $1-130 strain was 0.351 and 0.606, respectively. The spontaneous frequency (0.063) of large mwh spots, arising mostly from somatic recombination between the centromere and the locus mwh, in the transgenic plpol $1-130 strain, was about three times higher than that (0.021) of the non-transgenic w strain. The mutant clone frequencies of two types induced by two heterocyclic mines (IQ and Glu-P-1) and AFBl in the transformant pbol PI-130 were two or three times higher than those in the host strain w. These mean that rat DNA polymerase P participates at least in the somatic chromosome mutations and mitotic recombination processes. And the present results suggest that the transgenic Drosophl!~ used in this study can be used as a hypersensitive, in vivo short-term assaying system for various environmental mutagens.

• Journal of Sensor Science and Technology
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• v.20 no.5
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• pp.322-328
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• 2011

There are many ways to detect the heart rate non-invasively such as ECG, PPG, strain gauge, and pressure sensor. In this paper, the pulse wave measurement system using bipolar biased head on mode of the Hall sensor is proposed for measuring the radial artery pulse. TMS320F2812 was used to implement the proposed system and a portable wireless network(zig-bee) was used to show the experimental result. It was confirmed from experiment that the performance of the implemented system was more stable and faster than PPG sensor or piezoelectric film pressure sensor.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.320-323
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• 2004

In general, polymer concrete has more excellent mechanical properties and durability than Portland cement concrete, but very sensitive to heat and has large deformations. In this study, the long-term creep behaviors was predicted by the short-term creep test, and then the characteristic of creep of recycled-PET polymer concrete was defined by material and experimental variables. The error in the predicted long-term creep values is less than 5 percent for all polymer concrete systems. The filler carry out an important role to restrict the creep strains of recycled PET polymer concrete. The creep strain and specific on using the CaCO3 were less than using fly-ash. the creep increases with an increase in the applied stress, but not proportional the rate of stress increase ratio. The creep behavior of polymer concrete using recycled polyester resin is not a linear viscoelastic behavior.