• International Journal of Highway Engineering
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• v.13 no.3
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• pp.31-38
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• 2011

As the percentage of permeable ground is reduced due to the increased impermeable roads of major cities, a heat island phenomenon can be dominantly observed, resulting in increased temperature. In addition, rainfall that would have been naturally absorbed and retained by the permeable ground is overflowed due to large volumes of run-off water, resulting in more sewer failures and increased erosion. In terms of permeable pavement system, block paving has been used anywhere as well as provides many years of service. The permeable block paving is an effective alternative to the more traditional asphalt or plain concrete for minor roads; furthermore, it looks a lot better than other pavements. In this study, the functional drainage evaluation of block paving was carried out, considering the usage of experimental sludge and wheel tracking test, in order to simulate the field condition of roads.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.131-139
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• 2021

This study assessed the use of zeolite with high absorption performance in landscape paving concrete as a substitute for aggregate. The absorption performance and strength properties of paving concrete were investigated according to the replacement rate of the zeolite coarse aggregate, and the mechanical properties were investigated through strength tests. The absorption rate of the zeolite aggregate was 14%, which is 2.5 times higher than that of general aggregate. When zeolite coarse aggregate is applied to paving concrete, the absorption rate increases according to the replacement rate. The absorption rate was 5.2% at a replacement rate of 50%, which was 42% higher than that of general paving concrete. The compressive strength increased to 20% of the replacement rate and decreased at a higher replacement, but all the strengths in the construction standard code were satisfied. The flexural strength satisfied the code up to a replacement rate of 10%, but the strength decreased with increasing replacement rate, and the splitting tensile strength was greater than that of paving concrete using general aggregate up to a 20% replacement rate. Overall, zeolite coarse aggregate can be applied as a substitute.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.63-69
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• 2015

The aim of this study was to investigate the deformation of packaging materials used for ready-to-eat (RTE) foods after the retort process and microwave heating. From the multilayer films consisting of polyethylene terephthalate (PET), polyamide (PA), and cast polypropylene (CPP) in a stand-up pouch form used for RTE foods, some deformation of the CPP layer, which was in direct contact with the food, was observed after the retort process and microwave heating. The damage was more severely caused by microwave heating than by the retort process. This may be attributed to diverse factors including the non-uniform heating in a microwave oven, the sorption of oil into the packaging film, and the different characteristics of food components such as viscosity, salt and water content. The development of heat-resistant packaging materials and systems suitable for microwave heating of RTE foods is required for the safety of consumers.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.413-420
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• 2011

An experiment was conducted to suggest the road pavement material combining wooden chip crushed from little useful roots and branches from logging sites or wood waste from construction sites with urethane resin. For the specimen, the mass ratio of urethane resin to construction wood waste chip/lumber waster chip was set to three different levels of 0.5, 0.75, and 1.0, which was measured, mixed with mixer, and molded; 7 days after, tensile strength test, elasticity test using golf balls and steel balls, permeability coefficient measurement, and flammability test were executed. As the result, the tensile strength of the specimen at the dry state in the air exhibited the range of 0.2-1.1MPa, and there was no change after 7 days of aging. When submerged in water, however, the strength was partially diminished; the diminishing rate was greater for less urethane resin usage, and therefore it appears desirable to set the mass ratio of resin to the wood waste chip over 0.75 to consider the moisture intrusion by precipitation and such. As the result of elasticity test, the GB and SB coefficients of the specimen using wood waste chips and urethane resin were measured to be low at below 20%, exhibiting excellent elasticity as road pavement material. Also, the permeability coefficient was over 0.5mm/sec for specimens of all combinations, exceeding the standard value required after construction for permeable pavement material, and the flammability of wood-type pavement material was evaluated to have no practical issues.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.41-48
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• 2011

Warm-mix asphalt(WMA) technology has been developed to allow asphalt mixtures to be produced and compacted at a significantly lower temperature. The WMA technology was identified as one of means to lower emissions for $CO_2$ and has been spread so quickly in the world. Recently, two innovative WMA additives has been developed to reduce mixing and paving temperatures applied in asphalt paving process in Korea. Since the first public demonstration project in 2008, many WMA projects have successfully been constructed in national highways. In 2010, the WMA field trial was conducted on new national highway construction under Dae-Jeon Regional Construction Management Administration. The two different WMA loose mixtures(WMA and WMA-P) and a HMA mixture were collected at the asphalt plant to evaluate their mechanical performance in the laboratory. The Third-scale Model Mobile Loading Simulator(MMLS3) was adopted to evaluate rutting resistance and moisture damage under different traffic and environmental conditions. In this study, plant-produced WMA mixtures using two WMA additives along with the conventional hot mix asphalt(HMA) mixtures were evaluated with respect to their rutting resistance and moisture susceptibility using MMLS3. Based on the limited laboratory test results, plant-produced WMA mixtures are superior to HMA mixtures in rutting resistance and the moisture susceptibility. The WMA additive was effective for producing and compacting the mixture at $30^{\circ}C$ lower than the temperature for the HMA mixture.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.1
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• pp.43-50
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• 2013

This study investigated the effect of functional MA films (FMA) masterbatched by zeolite powder treated with 1 N HCl solution and anti-fogging agent (CA) on the freshness extension of 'Fuji' Apples. Preference, weight loss, total ascorbic acid, sugar content, acidity, change of gas composition in package were evaluated during storage at $15^{\circ}C$. After 150 days of storage, the weight loss of LLDPE film (control, L) apples was 0.4%, and that of apple in FMA film (CA) was 1.1%. Total ascorbic acid content of apples in control after 150 days was 2.09 mg%, and those of apple in FMA film was 2.94 mg%. The titratable acidity of apple in FMA film was higher than that in control, while soluble solids content of packages was lower than that in control after 150 days. Ethylene gas adsorbability in control package was 192.2 ppm and those in FMA film was 165.6 ppm. Overall, apples in FMA film was better than that of control. It was verified that apples packed with LLDPE film(control) lasted about 130 days, while those with FMA film lasted about 170 days. Also, FMA film treated with anti-fogging agent achieved no significant effect on freshness extension compared to non-treated film, but quality of 'Fuji' Apples was improved by anti-fogging agent when compared to that of non-treated anti-fogging agent.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.07a
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• pp.65-70
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• 1999

벼 재배의 생력화를 위하여 현재 국내에는 벼 직파 재배 기술이 확대 보급되고 있다. 기존 벼 직파 재배 기술은 직파유형에 따라 차이가 있지만 발아율 및 입모율, 도복, 잡초방제, 종자손실 및 유동, 포장준비 및 재배관리에 많은 문제점들이 있어 이를 획기적으로 개선할 수 있는 방안이 절실한 실정이다. 벼 펠렛 종자를 이용한 파종은 현행 직파 재배의 여러 문제점들을 해결할 수 있을 뿐만 아니라 입모율 향상, 초기생육촉진 및 초기 병충해 방제, 시비기술의 혁신을 기할 수 있어 안정적 직파 재배 기술을 확립할 수 있을 것으로 보인다. (중략)

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1308-1314
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• 1999

The effects of modified atmosphere(MA) packaging and coating on the quality of mushroom (Agaricus bisporus) were investigated. Whole mushrooms(100 g) were packed with polyvinyl chloride(PVC) film wrap, PD941 and PD961 film bags and were stored in a chamber at $12^{\circ}C$ and 80% RH for 6 days. Gas composition of packages, respiration rate, weight loss, color and maturity index of MA packaged mushrooms were examined. The wrap packaged mushrooms showed different level of internal $CO_2$ concentrations among water washed, chitosan coated and $CaCl_2$ coated subgroups significantly at 5% level. The maximum $CO_2$ concentration of PD941 and PD961 packages for all coated showed $4.1{\sim}4.7%$ and $10.4{\sim}11.7%$, respectively, for the first day. PD961 package showed the lowest $O_2$ concentration compared to other groups. There were no significant respiration rate differences between wrap packed and PD941 packaged. Respiration rate of water washed. chitosan coated and $CaCl_2$ coated in PD961 packaged was 192 mg, 226 mg and 245 mg, respectively. Maturity index of PD961 packaged were not significantly different among the water washed, chitosan and $CaCl_2$ coated packages. Chitosan coating showed a negative effect on color change of mushrooms. The weight loss of 961 packaged was lower $(7.0{\sim}8.0%)$ that those of wrap packaged and PD941 packaged.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.545-550
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• 2016

The main purpose of this study is to analyze and evaluate the feasibility of ligthweight pavement system with pile foundation on soft soil by laboratory small chamber test. In order to verify the stability of lightweight pavement system, the 1/30 scaled downed model system was tested at lab. The soft soil condition was simulated and group piles for skin friction resistance were used. Within the limited lab test, the settlements of pavement system were 0.86 mm for Case A, 0.70 mm for Case B, and 0.50 mm for Case C. The converted maximum settlement differential settlement were 25.8 mm and 10.8 mm. These values meet the inside of specification of Bridge Design Guide in Korea. The use of lightweight pavement systems on soft soils could be an alternative construction method on soft soils to reduce the challenges of conventional design and constructions.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.739-742
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• 2014

This study investigated the effect of perforation by the Indian meal moth (Plodia interpunctella) larvae on various flexible food-packaging films, in relation to their thickness and type. Among the various flexible packaging films, polyethylene (PE), aluminum foil (AF), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) were selected for this study due to their wide usage in food packaging. Based on their thickness, film penetration by P. interpunctella larvae was measured as in following order: PP, $20{\mu}m$; AF, $9{\mu}m$; PET, $12{\mu}m$; PP, $30{\mu}m$; PS, $30{\mu}m$; PE, $40{\mu}m$; PE, $35{\mu}m$; PS, $60{\mu}m$; and PET, $16{\mu}m$. P. interpunctella larvae rapidly penetrated through the packaging films regardless of their thickness and type. In particular, it was observed that PP of $20{\mu}m$ and PS of $30{\mu}m$ were completely penetrated by P. interpunctella larvae within 72 h, rendering thin PP and PS films less valuable as anti-insect packaging films. Our results show that the perforations by P. interpunctella larvae were observed in the thin films. These results imply that each packaging film has a marginal thickness against the perforations by P. interpunctella larvae.