• Journal of the Korea Institute of Building Construction
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• v.24 no.2
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• pp.193-202
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• 2024

This research delves into the evaluation of the suitability of ultrasonic pulse velocity as a diagnostic tool for early detection of frost damage in concrete. The investigation involves the measurement of compressive strength and ultrasonic pulse velocity concerning the depth of freezing for individual mortar specimens, followed by an analysis of their microstructure and their interrelation. The findings indicate a consistent decrease in both compressive strength and ultrasonic pulse velocity with increasing freezing depth. Furthermore, a correlation between compressive strength and ultrasonic pulse velocity concerning the depth of early frost damage is established. Consequently, the study asserts the potential of utilizing the ultrasonic pulse velocity method for early detection of frost damage in concrete, with prospects for quantifying the depth of damage through further research endeavors.

• Journal of Conservation Science
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• v.35 no.3
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• pp.197-208
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• 2019

Biological damages of wooden cultural properties are closely related to the preservation of the environment; these damages can be accelerated because of rapid climate change. Therefore, to preserve cultural properties, it is important to understand environmental characteristics. This study aims to investigate the status of termite damage and the characteristics of major environmental factors such as micro-meteorology, meso-meteorology, and local-meteorology of the Josadang shrine in the Seonamsa temple at Suncheon. Damage was confirmed by visual observation and the response of the termite detection dog at the north-west corner. Also another damage was observed by the termite detection dog at the north-east corner. These pillars had lower surface temperature and higher moisture content compared with the pillars in the front. The mean temperature of the entire time was similar for the meteorologies; however, the relative humidity differed. High relative humidity, greater than 70%, was observed frequently. In particular, it was determined that the termite activity days were the most inside the Josadang shrine. The statistical analysis confirmed that there was a difference between the meteorology events through the F ratio. In addition, the difference of environmental factors with relative humidity and temperature was identified more great difference in relative humidity through the t-statistics of temperature and relative humidity. And then relative humidity was confirmed most great in the difference of meso-meteorology and local-meteorology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.545-550
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• 2019

The frequency of natural disasters and the scale of damage are increasing due to the abnormal weather phenomenon occurring all over the world. As a result, as the hydrological aspect of the urban watershed changes, the increase in impervious area leads to serious domestic flood damage due to increased rainfall. In order to minimize the damage of life and property, domestic flooding prediction system is needed. In this study, we developed a flood nomogram capable of predicting flooding only by rainfall intensity and duration. This study suggests a method to set the internal water immersion alarm criterion by analyzing the characteristics of the flooding damage in the flooded area in the metropolitan area where flooding is highly possible and the risk of flooding is high. In addition, based on the manhole and the pipe, the water level was set as follows under the four conditions. 1) When manhole overflows, 2) when manhole is full, 3) when 70% of the pipe is reached, and 4) when 60% of the pipe is reached. Therefore, it can be used as a criterion and a predictive measure to cope with the pre-preparation before the flooding starts, through the rainfall that causes the flooding and the flooding damage.

• Magazine of the Korean Society of Agricultural Engineers
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• v.23 no.4
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• pp.41-45
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• 1981

This study is to be surveyed the rural environmental conditions such as housing, water works, sewerage, road and farm road, land utilization, natural conservation and sightseeing, public damage and disaster, and rural water requirement through the 50 villages (10995 home unit) The brief results summarized in this study are as follows. 1.Modernization of rural housing, toilet room and arrangement of dust materials are getting better than before l0yrs. 2.Water works are highly improved but sewerage problem is still in the serious problems. 3.Rood achievement is quite good but farm road is in still insufficiency 4.Utilization of land resources should be maximaized but land conservation is still insufficient condition and farm land is getting polluted. 5.Natural environmental conservation is much more improved but landscape is still insufficient. 6.Public damages such as water pollution, air pollution, and others are getting greater and greater but meteorological damage should be decreased. 7.Watershed condition is getting better and better but because of the large requiriment of the water use for the crops, agricultural water use should be needed much more than before l0yrs.

• Environmental Mutagens and Carcinogens
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• v.19 no.1
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• pp.34-38
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• 1999

Fumonisin B1 is a secondary metabolite of Fusarium moniliforme, a contaminant of corn and corn product. Fumonisin B1 has been shown to be responsible for major toxicological effects of the fungus in rats, horses, and pigs. Fumonisin B1 induced λ DNA fragmentation, which was increased with incubation time, reducing agent NADPH and metal ion (Cu2+). The DNA damage was inhibited by dimethyl sulfoxide (DMSO) or mannitol as radical scavenger for free radicals. DNA fragmentation, induced by fumonisin B1 in the presence of 1 mM NADPH and 0.1 mM CuCl2, was inhibited by 100 mM DMSO. By the in vitro reaction of fumonisin B1 with supercoiled plasmid pBR322 DNA, plasmid DNA was relaxed, eventually linearized in the agarose gel electrphoresis. From rifampicin sensitive E. coli CSH138 in bacterial mutagenesis system, the rifampicin resistant E. coli mutants were obtained by fumonisin B1. These results suggest that fumonisin B1 may be a possible environmental mutagen in bacterial mutagen assay system.

• KOMUNHWA
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• no.64
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• pp.111-131
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• 2004

Academic museum have to prevent damage about a microorganisms(bacteria, fungi) and damage in current facilities and environmental condition, and an exhibition or garnered relics and are so, analysis checks maintenance environmental condition of an academi

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.63-67
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• 2003

Mercury, one of the most diffused and hazardous organ-specific environmental contaminants, exists in a wide variety of physical and chemical states. Although the reports indicate that the mercury induces a deleterious damage, little has been known from the investigations of its effects in living organisms. The purpose of this study is to evaluate the effects of mercury chloride and ionizing radiation. Prepubertal male F344 rats were administered mercury chloride in drinking water throughout the experimental period. Two weeks after whole body irradiation, organs were collected to analyze the induced injury. Serum levels of GOT, GPT, ALP, and LDH were checked in the experimental groups and the hematological analysis was accomplished in plasma. In conclusion, the target organ of mercury chloride seems to be urinary organs and the pattern of damage induced by mercury differs from that by irradiation.

• Earthquakes and Structures
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• v.7 no.3
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• pp.385-400
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• 2014

Pounding damage to bridges and buildings is observed in most major earthquakes. The damage mainly occurs in reinforced concrete slabs, e.g. building floors and bridge decks. This study presents the results from pounding of reinforced concrete slabs. A parametric investigation was conducted involving the mass of the pendulums, the relative velocities of impact and the geometry of the contact surface. The effect of these parameters on the coefficient of restitution and peak impact acceleration is shown. In contrast to predictions from numerical force models, it was observed that peak acceleration is independent of mass. The coefficient of restitution is affected by the impact velocity, total participating mass and the mass ratio of striker and struck block.

• Journal of the Speleological Society of Korea
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• no.88
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• pp.26-30
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• 2008

The black pollution that was able to include green pollution to appear for the intensity of light by an illumination institution is what after all I cannot ignore, and it may be said that chase thing damage by the isolation action that is white pollution done a long story in this outside a certain range by air quality change, dried present situation is really the environmental disruption by development and a damage phenomenon. If I am replaced in winker and I install a sensor light in the outlet by addition and use the electricity illumination that I installed for a tourist in the cave, it is expected that I can be available all the time that it is possible for electricity reduction more than the present and watches tourist passage plan private business Electric illumination in the cave for the environmental save in the cave because it is possible for more electricity reduction to be particularly off-season than on-season.

• Computers and Concrete
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• v.20 no.6
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• pp.689-704
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• 2017

The paper presents experimental and numerical investigations of prefabricated composite structural building reinforced concrete slabs with the insulating material for a residential building construction. The building slabs were composed of concrete and expanded polystyrene. In experiments, the slabs in the full-scale 1:1 were subjected to vertical concentrated loads and failed along a diagonal shear crack. The experiments were numerically evaluated using the finite element method based on two different constitutive continuum models for concrete. First, an elasto-plastic model with the Drucker-Prager criterion defined in compression and with the Rankine criterion defined in tension was used. Second, a coupled elasto-plastic-damage formulation based on the strain equivalence hypothesis was used. In order to describe strain localization in concrete, both models were enhanced in the softening regime by a characteristic length of micro-structure by means of a non-local theory. Attention was paid to the formation of critical diagonal shear crack which was a failure precursor.