• Journal of Conservation Science
• /
• v.31 no.4
• /
• pp.443-455
• /
• 2015

To verifying the stability of Natural pigments for Dancheong which is available on the market was carried out as light resistance and gas corrosion test. In this particular case, we will confirm the characteristics of the only pigments except of Dancheong technique and influence of substance. Medium using for coloring are animal glue and synthetic resin that widely used for Dancheong in currently. Selected to artificial light source is a xenon arc lamp, contaminated gas is nitrogen dioxide gas in experiment. Degree of degradation of pigment were compared by measuring the degree of color change. The result of light resistance test, mineral pigments were good; color is green and blue type, soil pigments also good; color is yellow ocher, white clay, red clay etc. Gamboge, unghwang, cinnabar, red lead were confirmed not good. The result of gas corrosion test, most of the natural pigments were good condition except the red lead. Generally, animal glue samples had better than a synthetic resin samples.

• Advances in concrete construction
• /
• v.5 no.6
• /
• pp.575-586
• /
• 2017

The disposal of polythene waste and fly ash is causing serious threat to the environment. Aim of this study is to decrease environmental pollution by using polythene waste and fly ash in concrete. In this study, cement was partially replaced with 0%, 5%, 10%, 15% and 20% fly ash (by weight) and plastic waste was added in shredded form at 0.6% by weight of concrete. The specimens were prepared for the concrete mix of M25 grade and water to cementitious material ratio (w/c) was maintained as 0.45. Fresh concrete property like workability was examined during casting the specimens. Hardened properties were found out by carrying out the experimental work on cubes, cylinders and beams which were cast in laboratory and their behavior under test were observed at 7 & 28 days for compressive strength and at 28 days for density, flexural strength, dynamic modulus of elasticity, abrasion resistance, water permeability and impact resistance. Overall results of this study show that addition of 0.6% (by weight of the concrete) plastic waste with 10% (by weight of cement) replacement of cement by fly ash result an improvement in properties of the concrete than conventional mix.

• Journal of the Society of Naval Architects of Korea
• /
• v.58 no.1
• /
• pp.32-39
• /
• 2021

Korean coastal fishery suffers from profitability degradation due to a decrease in fisheries resources, pollution in coastal waters, fuel coast increase, and market opening for aquaculture products. The next generation Korean fishing vessel aims at the improvement of energy efficiency, enhancement of crew welfare, and safety. These purposes can be accomplished by adopting a new standard hull form with improved resistance performance and a modernized residence facility on the deck. In order to improve resistance performance, this study attempts to optimize design variables for stern flaps for three kinds of fishing vessels - coastal multi-purpose, coastal trap, and dredged nets. A series of model tests for these fishing vessels was carried out in the towing tank of Pusan National University. The results indicate that for some cases, the stern flap caused the stern trim of the vessel to decrease, leading to the resistance reduction.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.05a
• /
• pp.65-66
• /
• 2023

Recently, the importance of improving air quality has been greatly highlighted due to environmental problems such as indoor air pollution, and efforts are being made to improve indoor air quality not only in Korea but also around the world. In this situation, this study aims to study the physical properties of cement boards using pearlite with excellent physical adsorption performance due to micropores in materials, expanded graphite that is widely used as a flame retardant to prevent heat transfer in the event of a fire. The experimental items are bending fracture load and impact resistance. The bending destruction load at the fiber mixing rates 1, 2, 3, and 4 (%) did not meet the standard 140N, but the bending destruction load at 5% was 168.2N, and the impact resistance of the fiber mixing rates 1 and 2 (%) could not be measured due to cracks and damage, and the impact resistance at 3, 4, and 5 (%).

• Journal of Life Science
• /
• v.9 no.3
• /
• pp.314-327
• /
• 1999

This study was investigated to isolate identify the total bacteria and fungi from the indoor air of work-place of the shoes, paint, stainless steel, and plastic industries. The number of bacterial colonies on the nutrient agar plates were calculated by the open petridish method for 30 minutes in indoor air of work-places at the autumn and winter. The isolated bacteria were identified by Gram stain and biochemical test using API Staph and API 20E kits. The isolated fungal colonies were identified by gross appearance of the giant colonies and microscopic examination of their spore and hyphal characteristics on the slide culture method. The minimum inhibitory concentration (MIC) of several antibiotics against isolated bacteria was determined by the microdilution method with Mueller-Hinton broth. The 70-400 colonies in autumn and 54-236 colonies in winter were isolated from the indoor air of work-places of several industry. The isolation rates of Gram positive cocci, Gram positive bacilli, Gram negative bacilli, and Gram negative cocci were 46.3%, 19.8%, 17.3%, and 16.1%, respectively. In Gram positive cocci, the most strains were identified as Aerococcus spp, Micrococcus spp, and Staphylococcus spp. In Gram positive and negative bacilli, and Gram negative cocci were identified as Bacillus spp, Pseudomonas spp, and Neisseria spp, respectively. The frequently isolated fungi were Aspergillus spp, Penicillium spp and Rhizopus spp, respectively. The frequently isolated Aerococcus spp, Micrococcus spp, and Staphylococus spp were highly resistance against ampicillin, erythromycin, methicillin, and tetracycline. These results arouse our attention to microbiologic pollution in the indoor air of work-places of industries.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.05a
• /
• pp.805-810
• /
• 2003

It is the real circumstance in the country that not only the data and special books but also people who have an expert knowledge are short of the field of the study about plastic wastes, so that to build the Database carrying out gathering info of that is the present question obviously. The business on recycling plastic, for some reason or other, is one of the best ways as called bright prospect industry to prevent environmental pollution and obtain economical outcome by using limited resources. Plastic wastes with construction industry especially using Polymer may have a good effect on the environment and human beings and have a fine view to produce functional and Eco-friendly concrete as well. In this study, Chemical resistance and Water Absorption test in Polymer concrete using bentonite as a shrinkage control agent was made an experiment by comparing with influence on concrete strength and used to offer some valuable data about Polymer concrete.

• Journal of the Korea Convergence Society
• /
• v.8 no.11
• /
• pp.141-149
• /
• 2017

This study was to investigate the sanitary microbiological aspects of Cheonho Reservoir and its antibiotic resistance in the natural environment to contribute to the public healthcare improvement. Groups of coliforms, were counted at three sites of the Cheonho Reservoir in July and September 2013, and the isolates were identified according to the water pollution process test standards. Antibiotic resistance was evaluated using the Korea National Institute of Health's standard antibiotic susceptibility test. The average coliform counts in Cheonho Reservoir were $2.0{\times}10^3CFU/mL$, 41% of which were identified as Escherichia coli(E. coli). Antibiotic resistance rate in E. coli isolated from Cheonho reservoir was highest in Ampicillin 31.3%, Ticarcillin 25.0%, Cefaxolin and Cefoxitin 18.8% respectively. Convergence multiple resistance patterns, 38,5% presented resistance to 4 durgs, 6 drugs resistance were 7.7%. The more than 2 drugs resistance were 92.3%. Cheonho Reservoir is a public park that accessible to the citizens, further convergence studies are needed to develop sanitary microbiological management practices and study antibiotic resistance of the reservoir.

• Journal of the Korean Geotechnical Society
• /
• v.32 no.3
• /
• pp.29-37
• /
• 2016

SSG (self-healing smart grouting) method, which is developed recently, has the characteristics such as an improvement of durability and waterproofing, prevention of leaching and pollution. In this study, we performed several tests such as gel-time measurement, uniaxial compression test, permeability test, fish poison test and chemical resistance test to compare the engineering properties of SSG with the other chemical grouting method (LW, SGR). As results of tests, the SSG method has low possibility of groundwater and ground pollution caused by leaching, furthermore, it has advantages like long/short term waterproofing, strength and durability. Therefore the SSG method can be applicable in the fields as an alternative of existing chemical grouting methods with problems.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.10a
• /
• pp.841-846
• /
• 2002

As growing of industrialization and increasing of population. the quantities of waste are rapidly growing in the earth. It cause some problems such as the waste of natural resources and environmental pollution. In this context, recycling waste glass as a material of concrete has a great advantage environmentally and economically. On that score, other contries have start recycling waste glass widely and accoumulatig the technology of manufacturing equipment and construction. However, few studies have been done in this country. Therefore, this study was conducted freeze-thaw resistance test and neutralization reaction test to analyze the durability properties of steel fiber reinforced concrete containing waste glass as fine aggregate and containing industrial by-products(Fly ash).

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.05b
• /
• pp.493-496
• /
• 2005

The Re-mi-con sludge water has been investigated because of environmental pollution and disposal cost. So, sludge water is partially reused as mixing water. However, if sludge water is reused too much that would influence the quality of concrete. KS specification limits the amount of sludge content up to 3$\%$ of cement weight. In this study, the effect of re-mi-con sludge on the characteristics of concrete is compared to raise the reuse ratio of re-mi-con sludge. From the test results, as blending ratio of re-mi-con sludge increases, workability is decreases. However, the re-mi-con sludge water have a minor effect on the strength development, the drying shrinkage and the resistance of freeze and thawing. Also, the existing model codes of drying shrinkage do not coincide with the test results of this study.