• 한국도로학회논문집
• /
• 제18권4호
• /
• pp.29-35
• /
• 2016

PURPOSES : The new waste management policy of South Korea encourages the recycling of waste materials. One material being recycled currently is tire-derived fuel (TDF) ash. TDF is composed of shredded scrap tires and is used as fuel in power plants and industrials plants, resulting in TDF ash, which has a chemical composition similar to that of the fly ash produced from coal. The purpose of this study was to evaluate the properties of an asphalt concrete mix that used TDF ash as the mineral filler. METHODS : The properties of the asphalt concrete were evaluated for different mineral filler types and contents using various measurement techniques. The fundamental physical properties of the asphalt concrete specimens such as their gradation and antistripping characteristics were measured in accordance with the KS F 3501 standard. The Marshall stability test was performed to measure the maximum load that could be supported by the specimens. The wheel tracking test was used to evaluate the rutting resistance. To investigate the moisture susceptibility of the specimens, dynamic immersion and tensile strength ratio (TSR) measurements were performed. RESULTS : The test results showed that the asphalt concrete containing TDF ash satisfied all the criteria listed in the Guide for Production and Construction of Asphalt Mixtures (Ministry of Land, Infrastructure and Transport, South Korea). In addition, TDF ash exhibited better performance than that of portland cement. The Marshall stability of the asphalt concrete with TDF ash was higher than 7500 N. Further, its dynamic stability was also higher than that listed in the guide. The results of the dynamic water immersion and the TSR showed that TDF ash shows better moisture resistance than does portland cement. CONCLUSIONS : TDF ash can be effectively recycled by being used as a mineral filler in asphalt, as it exhibits desirable physical properties. The optimal TDF ash content in asphalt concrete based on this study was determined to be 5%. In future works, the research team will compare the characteristics of asphalt concrete as function of the mineral filler types.

• 한국도로학회논문집
• /
• 제14권4호
• /
• pp.9-18
• /
• 2012

PURPOSES : This study evaluated the field applicability and laboratory performance of warm-mix asphalt (WMA) as an alternative technology in asphalt pavement. METHODS : The pilot road using two different types of WMA mixture and one HMA mixture was constructed in Waegwan-Seokjeok road construction site and the mixtures were sampled at the asphalt plant for laboratory testings. The field applicability was assessed in environmental aspects, such as $CO_2$ emission, and in aspects of constructibility using the existing equipment and procedure, i.e., thickness and density measurement. The laboratory testings included the moisture susceptibility test by AASHTO T283, dynamic modulus test, triaxial repeated load permanent deformation test, and the fatigue test. RESULTS : The temperatures for production and compaction of WMA were $20{\sim}30^{\circ}C$ lower than those for HMA and therefore, the noxious gas emission were significantly reduced. The field density of WMA pavements was similar or better than that of HMA pavement. From the laboratory testings, it was found that WMA mixtures exhibit comparable performance to HMA mixture in moisture susceptibility, permanent deformation, and fatigue performance. CONCLUSIONS : With these results, it would be concluded that WMA could replace the existing HMA technology without any significant issue. To support this conclusion, it is necessary to track the long-term performance of WMA in pilot road.

• 수산해양기술연구
• /
• 제47권4호
• /
• pp.435-442
• /
• 2011

In an attempt to respond to the increase in international oil prices and reduce operating expenses, ship remodeling was carried out on a 740ton class tuna purse seiner. To strengthen the competitiveness of the fisheries industry by improving vessel performance, a bulbous bow was newly equipped. The slipway and rudder area were also lengthened and enlarged with the propeller and main engine remained unchanged. To reduce the hull resistance, a circle type bulbous bow was attached on the hull behind bow thruster and thus the cost for exchanging electrical equipment for bow thruster was reduced. The new rudder area was expanded 15% more than the old one within the extent that the existing mechanical control part and rudder stock were not changed. To prevent fishing net damage and stabilize wake field, slipway was lengthened to the optimal position. All of the new design of remodeling parts went through the model tests in towing tank and CWC. Besides resistance test, all of necessary model test results were delivered for hydrodynamic character for the modified ship. The maneuvering simulation to verify that the remodeled ship satisfies the IMO rules was performed in both zigzag and turning tests. The estimated resistance with new bulbous bow and lengthened stern was reduced by 4.8% in the 2-dimensional analysis and 17.4% in the 3-dimensional analysis in comparison of conventional ship. The average reduction of resistance was estimated about 10%. Maneuvering character of modified hull form was found to satisfy all regulations under IMO. The remodeling of tuna purse seiner can not only improve fishing performance but also contribute to reduction of operating cost by saving energy for the fisheries industry.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제20권1호
• /
• pp.19-24
• /
• 2010

Bumblebees are widely used to pollinate crops in greenhouses and fields. Here, we investigated whether different wake-up treatments during a short period of 1~3 days just before indoor rearing has any effects on oviposition and colony development of $CO_2$-treated Bombus ignitus queens and artificially hibernated B. terrestris queens The wake-up regimes were defined as 16L for 1 day (16L-1), 16 L per day for 3 days (16L-3), 24L for 1 day (24L-1), or 24D for 1 day (24D-1). Among these wake-up treatments, the oviposition rate and preoviposition period of B. ignitus queens reared at 24L-1 were 16.7~25.1% higher and 1.0~3.5 days shorter than other wake-up treatments. B. terrestris queens reared at 24L-1 also showed the best results for egg-laying characteristics, which were 8.9~18.8% higher for oviposition and 0.6~3.5 days shorter for preovipostion period than other wake-up treatments. Furthermore, B. terrestris queens reared at 24L-1 were 17.5% and 13.8% higher in rate of colony foundation and queen production, respectively, than other wake-up treatments. These results show that the most favorable wake-up treatment just before rearing for egg-laying and colony developmental characteristics of B. ignitus and B. terrestris queens was 24L-1. Overall, our findings indicate that a wake-up treatment just before rearing was effective for colony initiation and colony development of bumblebee queens.

• Asian-Australasian Journal of Animal Sciences
• /
• 제31권9호
• /
• pp.1393-1400
• /
• 2018

Objective: This study was carried out to assess the haplotype diversity and population dynamics in cattle populations of Ethiopia. Methods: We sequenced the complete mitochondrial cytochrome b gene of 76 animals from five indigenous and one Holstein Friesian${\times}$Barka cross bred cattle populations. Results: In the sequence analysis, 18 haplotypes were generated from 18 segregating sites and the average haplotype and nucleotide diversities were $0.7540{\pm}0.043$ and $0.0010{\pm}0.000$, respectively. The population differentiation analysis shows a weak population structure (4.55%) among the populations studied. Majority of the variation (95.45%) is observed by within populations. The overall average pair-wise distance ($F_{ST}$) was 0.049539 with the highest ($F_{ST}=0.1245$) and the lowest ($F_{ST}=0.011$) $F_{ST}$ distances observed between Boran and Abigar, and Sheko and Abigar from the indigenous cattle, respectively. The phylogenetic network analysis revealed that all the haplotypes detected clustered together with the Bos taurus cattle and converged to a haplogroup. No haplotype in Ethiopian cattle was observed clustered with the reference Bos indicus group. The mismatch distribution analysis indicates a single population expansion event among the cattle populations. Conclusion: Overall, high haplotype variability was observed among Ethiopian cattle populations and they share a common ancestor with Bos taurus.

• 한국기계가공학회지
• /
• 제19권7호
• /
• pp.89-97
• /
• 2020

Container vessels continue to grow in size, led by global shipowner. Large ships can be loaded more cargo at a time, reducing the cost of transportation per teu. this eventually leads to economies of sale, in which the production cost per unit decreases with increasing output. in accordance with the 70th Convention of the Marine Environment Protection Committee of the International Maritime Organization, as of January 1, 2020, MARPOL Annex VI Regulation 14.1.3 will be effective. All vessels must be meet these criteria to reduce Sox emissions and reduce NOx emissions by reducing the content of manned sulfur oxides from 3.5% to less than 0.5%, otherwise IACS Member States Entry to the port is denied. in order to do that need to LNG storage tank. in this study characteristic of the material after line heating (600℃,700℃,800℃,900℃) of 9% Ni steel used in the manufacture of LNG fuel tank of ship were verified using by mechanical test. In the heating method by line heating. The initial properties of steel are changed by variables such as temperature, time, speed. The experimental data of line heating presented in this paper confirmed that the initial change of 9% Ni steel could be minimized.

• 복식문화연구
• /
• 제26권2호
• /
• pp.140-156
• /
• 2018

The purpose of this study is to review and establish the three concepts of upcycling, zero-waste fashion design, and regional sustainability through a review of domestic and international case studies. Furthermore, it will provide the theoretical basis for using upcycling as a regional sustainability practice to create zero-waste fashion design. To conduct an empirical study, we systematized the stages of the survey on waste resources in Changsin-dong, the sourcing and utilization of waste resources, the design-planning stage, and the co-production with pattern and sewing masters as a suggested practice for regional sustainability. Through this study, we propose the possibility of regional sustainability by developing and sharing the method of zero-waste fashion design. The conclusion of the study as follows: First, upcycling fashion designs can be extended to a regional sustainability practice by taking the characteristics of social design into account. Second, by providing a design development process and methodology suitable for regional sustainability application, it is helpful to revitalize regional upcycling fashion brands and communities by providing data for upcycled fashion branding. Third, as part of the revitalization project for the Chang-shin and Soongin areas that started in 2014, using the region's economic, cultural, and environmental characteristics to make and sell high-value, upcycled fashion products will contribute to social and economic achievements and aid in solving regional problems.

• Smart Structures and Systems
• /
• 제24권4호
• /
• pp.541-552
• /
• 2019

Construction development and greenhouse gas emissions have globally required a strategic management to take some steps to stain and maintain the environment. Nowadays, recycled aggregates, in particular ceramic waste, have been widely used in concrete structures due to the economic and environmentally friendly solution, requiring the knowledge of recycled concrete. Also, one of the materials used as a substitute for concrete cement is wollastonite mineral to decrease carbon dioxide (CO2) from the cement production process by reducing the concrete consumption in concrete. The purpose of this study is to investigate the effect of wollastonite on the mechanical properties and durability of conventional composite concrete, containing recycled aggregates such as compressive strength, tensile strength (Brazilian test), and durability to acidic environment. On the other hand, in order to determine the strength and durability of the concrete, 5 mixing designs including different wollastonite values and recovered aggregates including constant values have been compared to the water - cement ratio (w/c) constant in all designs. The experimental results have shown that design 5 (containing 40% wollastonite) shows only 6.1% decrease in compressive strength and 4.9% decrease in tensile strength compared to the control plane. Consequently, the use of wollastonite powder to the manufacturing of conventional structural concrete containing recycled ceramic aggregates, in addition to improving some of the properties of concrete are environmentally friendly solutions, providing natural recycling of materials.

• 한국환경과학회지
• /
• 제28권3호
• /
• pp.385-392
• /
• 2019

This study investigated the relationship among seven species of trichoderma through the identification of strains collected in Korea. The phylogenetic tree among the collected strains was classified into four groups. The trichoderma strains isolated in this way showed inhibitory effect on the fusarium wilt which is parasitic to cotyledon stem..The invisibility of J9, J10, J13 and J16 strains were higher in comparison with other strains in vitro test stand, and their spore production level was also higher. In the aluminum ring tests, it showed that the yield of the spores in J9, J10 and J13 were more than any other strain. As a result conducting the port test for cucumbers, the plant lengths of J13 were larger than the control plot, and the root lengths of all strains, except for J2 were longer than the control plot, and the root weights of J1, J9, J10, J13 and J16 were larger than the control plot. The disease severity for the fusarium wilt showed the smallest values at J13 and J16 in comparison with the control plot, and the control values of J13 and J16 were higher than other strains.

• 한국환경과학회지
• /
• 제30권12호
• /
• pp.1101-1111
• /
• 2021

In this study, among the W-S-R(Wiper-Signal-Rainfall) relationship methods used to produce sensor-based rain information in real time, we sought to produce actual rainfall information by applying machine learning techniques to account for the effects of wiper operation. To this end, we used the gradient descent and threshold map methods for pre-processing the cumulative value of the difference before and after wiper operation by utilizing four sensitive channels for optical sensors which collected rain sensor data produced by five rain conditions in indoor artificial rainfall experiments. These methods produced rainfall information by calculating the average value of the threshold according to the rainfall conditions and channels, creating a threshold map corresponding to the 4 (channel) × 5 (considering rainfall information) grid and applying Optima Rainfall Intensity among the big data processing techniques. To verify these proposed results, the application was evaluated by comparing rainfall observations.