• Journal of the Korean GEO-environmental Society
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• v.6 no.3
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• pp.17-23
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• 2005

In Korea, the production of reclaimed concrete materials has been increased due to the increase in the concrete structures taken down every year. The reclaimed concrete materials have been reused as road materials. However, the studies on their mechanical and environmental properties have been very limited. The recycled rate of the materials is currently low in Korea. This paper presents the investigation of mechanical and environmental properties of the reclaimed concrete materials, as well as the comparisons with those of gravel. For the evaluation of the mechanical and environmental characteristics, following tests were conducted on both reclamed materials and gravel; liquid limit, plasticity index, CBR, sand equivalent test, abrasion test, pH test, and column leaching test. The test results showed that the reclaimed concretes satisfy the requirements for use as roadbase, subbase, and subgrade materials, except base materials. The pH of reclaimed concrete materials was less than 11 and the leaching test results satisfied the regulatory requirement of Waste Management Act in Korea. Based on the investigations, it appears that the reclaimed concrete materials are environmentally safe and applicable for use as road materials.

• Journal of the Korean Solar Energy Society
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• v.33 no.1
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• pp.15-23
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• 2013

In this study, thermodynamic performance of R435A is examined both numerically and experimentally in an effort to replace HFC134a used in the refrigeration system of domestic water purifiers. Even though HFC134a is used predominantly in such a system these days, it needs to be phased out in the near future in Europe and most of the developed countries due to its high global warming potential. To solve this problem, cycle simulation and experimental measurements are carried out with a new refrigerant mixture of 20%R152a/80%RE170 using actual domestic water purifiers. This mixture is numbered and listed as R435A by ASHRAE recently. Test results show that the system performance with R435A is greatly influenced by the amount of charge due to the small internal volume of the refrigeration system of the domestic water purifiers. With the optimum amount of charge of 21 to 22 grams, about 50% of HFC134a, the energy consumption of R435A is 11.8% lower than that of HFC134a. The compressor discharge temperature of R435A $8^{\circ}C$ lower than that of HFC134a at the optimum charge. Overall, R435A, a new long term environmentally safe refrigerant, is a good alternative for HFC134a requiring little change in the refrigeration system of the domestic water purifiers.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.2
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• pp.109-117
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• 2009

In this study, thermodynamic performance of R430A is examined both numerically and experimentally in an effort to replace HFC134a used in the refrigeration system of domestic water purifiers. Even though HFC134a is used predominantly in such a system these days, it needs to be phased out in the near future in Europe and most of the developed countries due to its high global warming potential. To solve this problem, cycle simulation and experimental measurements are carried out with a new refrigerant mixture of 76%R152a124% R600a using actual domestic water purifiers. This mixture is numbered and listed as R430A by ASHRAE recently. Test results show that the system performance with R430A is greatly influenced by the amount of charge due to the small internal volume of the refrigeration system of the domestic water purifiers. With the optimum amount of charge of 21 to 22 grams, about 50% of HFC134a, the energy consumption of R430A is 13.4% lower than that of HFC 134a. The compressor dome and discharge temperatures and condenser center temperature of R430A are very similar to those of HFC134a at the optimum charge. Overall, R430A, a new long term environmentally safe refrigerant, is a good alternative for HFC134a requiring little change in the refrigeration system of the domestic water purifiers.

• Journal of the Korea Furniture Society
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• v.27 no.1
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• pp.8-14
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• 2016

Increasing concerns of environment need to make change furniture field to more environmentally friendly approach, such as reuse of by-products from wooden products. As it is, the methods of recycling wood for industrial purposes have the advantage of productivity and adaptability. However, the industrial way is required a certain production facility of processing wooden by-products and has possible hygienic problems due to contaminated sources. Many designers have developed their own methods for reuse of wood in unique and artistic ways. Even so, because of confined sources, it could be not enough supply. Therefore, I developed the design methodology utilizing wooden by-products from S Design Company to relieve former ways' problems. The design suggestion took materials from a safe and abundant source. The wooden leftover pieces were connected together with epoxy clay, so previous process traces of furniture are remained as a decorative factor. Moreover, the synthesized material was able to be processed by ordinary woodworking facilities without additional installations. In doing so, console table focused on a commercial purpose and dining table for an artistic objective were successfully fabricated as final suggestions. In consideration of the proposal using wooden furniture leftovers, diverse recycling designs should be investigated for future reference.

• Mycobiology
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• v.45 no.4
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• pp.240-254
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• 2017

Cereal grains are the most important food source for humans. As the global population continues to grow exponentially, the need for the enhanced yield and minimal loss of agricultural crops, mainly cereal grains, is increasing. In general, harvested grains are stored for specific time periods to guarantee their continuous supply throughout the year. During storage, economic losses due to reduction in quality and quantity of grains can become very significant. Grain loss is usually the result of its deterioration due to fungal contamination that can occur from preharvest to postharvest stages. The deleterious fungi can be classified based on predominance at different stages of crop growth and harvest that are affected by environmental factors such as water activity ($a_w$) and eco-physiological requirements. These fungi include species such as those belonging to the genera Aspergillus and Penicillium that can produce mycotoxins harmful to animals and humans. The grain type and condition, environment, and biological factors can also influence the occurrence and predominance of mycotoxigenic fungi in stored grains. The main environmental factors influencing grain fungi and mycotoxins are temperature and $a_w$. This review discusses the effects of temperature and $a_w$ on fungal growth and mycotoxin production in stored grains. The focus is on the occurrence and optimum and minimum growth requirements for grain fungi and mycotoxin production. The environmental influence on aflatoxin production and hypothesized mechanisms of its molecular suppression in response to environmental changes are also discussed. In addition, the use of controlled or modified atmosphere as an environmentally safe alternative to harmful agricultural chemicals is discussed and recommended future research issues are highlighted.

• Journal of the Korean GEO-environmental Society
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• v.6 no.1
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• pp.15-21
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• 2005

In this study, the utilization of coal-ash and phosphogypsum was considered as the evapotranspiration final landfill cover(ET cover) material. Cover material considered was the mixture of the weathered granite soil, coal-ash and phosphogypsum and so we sequentially performed the leaching test, column test and field model test to investigate the environmental effects of mixtures of coal-ash and phosphogypsum. In the leaching test, all materials had lower heavy metal concentration than the regulated threshold values. The column test and the review of related regulations were carried out to determine the optimum mixing ratio(OMR) and OMR was soil(4):coal-ash(1): phosphogypsum(1) on the volume base, which was applied to field model test. Field model tests were continued from February to June, 2004 in the soil box that was constructed with cement block. It was verified that coal-ash and phospogypsum mixed with soil was safe environmentally and the mixture of both wastes could improve the water retention capacity of cover materials.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.2
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• pp.41-50
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• 2021

The asphalt pavement industry has introduced the warm-mix asphalt (WMA) as a mean of energy saving and environmentally safe technology, because the WMA mixture can be mixed and compacted at 30℃ lower than conventional hot-mix asphalt (HMA) at 160℃ or higher. The implementation of WMA can be a good option for paving operations for rural road in remote place, not only due to energy saving and environmental issues, but also lower working temperature. Using WMA technology, the cooled-down asphalt mixture can be still compacted to meet the quality requirement in narrow winding rural road in remote places. Therefore, this study is designed to evaluate engineering properties of WMA binders and concretes, which were prepared for rural road pavement. The objective of the study was to evaluate and suggest proper fundamental properties level of the WMA concrete for rural road pavement. The kinematic viscosity test result indicated that the WMA binders used in this study were effective for compaction at lower temperature, i.e., at 115℃, compared to the HMA binder. According to strength property analyses, it was found that the WMA concrete was acceptable for rural road pavement even though it was compacted at 30℃ lower level. Since the deformation strength (SD) of 3.2 MPa was found to satisfy rutting and cracking resistance minimum guidelines, this value was suggested as a minimum SD value for rural road pavement, considering lack of maintenance program for rural area.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.20 no.3
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• pp.307-319
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• 2022

60+ Years of nuclear power generation has led to a significant legacy of radioactively contaminated land at a number of nuclear licenced "mega sites" around the world. The safe management and remediation of these sites is key to ensuring there environmental stewardship in the long term. Bioremediation utilizes a variety of microbially mediated processes such as, enzymatically driven metal reduction or biominerialisation, to sequester radioactive contaminants from the subsurface limiting their migration through the geosphere. Additionally, some of these process can provide environmentally stable sinks for radioactive contaminants, through formation of highly insoluble mineral phases such as calcium phosphates and carbonates, which can incorporate a range of radionuclides into their structure. Bioremediation options have been considered and deployed in preference to conventional remediation techniques at a number of nuclear "mega" sites. Here, we review the applications of bioremediation technologies at three key nuclear licenced sites; Rifle and Hanford, USA and Sellafield, UK, in the remediation of radioactively contaminated land.

• Nutrition Research and Practice
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• v.17 no.4
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• pp.762-779
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• 2023

BACKGROUND/OBJECTIVES: Mediterranean diet is an environmentally friendly and healthy diet model. The diet offers many vegetables, fruits, nuts, and olive oil to consumers. In addition, it provides moderate amounts of fish and chicken, smaller quantities of dairy products, red meat, and processed meat. The Mediterranean diet has a high anti-inflammatory and antioxidant content, and it causes many physiological changes that can provide a physical performance advantage. This study examined the effects of a 15-day menu, which was planned using foods with a low acid load within the Mediterranean diet rules, on the exercise performance, lactate elimination, anthropometric measurements, and body composition. SUBJECTS/METHODS: Fifteen professional male athletes between the ages of 13 and 18, who were engaged in ski running, were included in the experimental study. Dietary intervention was applied for 15 days. The athlete performances were evaluated by applying the vertical jump test, hand grip strength, 20 meters shuttle run test, and Borg fatigue scale. After the shuttle run test (every 3 min for 30 min), blood was drawn from the finger, and the lactate elimination time was calculated. Performance and lactate measurements, body analysis, and anthropometric measurements were taken before and after dietary intervention. RESULTS: The vertical jump height and hand grip strength increased after the intervention (P < 0.05). The test duration, total distance, the number of shuttles, and maximum oxygen consumption parameters of the shuttle run test increased (P < 0.05). After the intervention, the athletes' perceived fatigue scores decreased in several stages of the shuttle run test (P < 0.05). The lactate elimination time and athlete's body composition were similar in repeated measurements (P > 0.05). In the last measurements, the upper middle arm circumference decreased while the height of the athletes increased (P < 0.05). CONCLUSIONS: These results show that the Mediterranean diet is a safe and feasible dietary approach for aerobic performance and strength increase.

• The Plant Pathology Journal
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• v.39 no.6
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• pp.600-613
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• 2023

Fusarium oxysporum is the main pathogen causing Fusarium basal rot in onion (Allium cepa L.), which incurs significant yield losses before and after harvest. Among management strategies, biological control is an environmentally safe and sustainable alternative to chemical control. In this study, we isolated and screened bacteria for antifungal activity against the basal rot pathogen F. oxysporum. Isolates 23-045, 23-046, 23-052, 23-055, and 23-056 significantly inhibited F. oxysporum mycelial growth and conidial germination. Isolates 23-045, 23-046, 23-052, and 23-056 suppressed the development of Fusarium basal rot in both onion seedlings and bulbs in pot and spray inoculation assays. Isolate 23-055 was effective in onion seedlings but exhibited weak inhibitory effect on onion bulbs. Based on analyses of the 16S rRNA and rpoB gene sequences together with morphological analysis, isolates 23-045, 23-046, 23-052, and 23-055 were identified as Bacillus thuringiensis, and isolate 23-056 as Bacillus toyonensis. All five bacterial isolates exhibited cellulolytic, proteolytic, and phosphate-solubilizing activity, which may contribute to their antagonistic activity against onion basal rot disease. Taken together B. thuringiensis 23-045, 23-046, 23-052, and 23-055 and B. toyonensis 23-056 have potential for the biological control of Fusarium basal rot in onion.