• Resources Recycling
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• v.21 no.5
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• pp.79-87
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• 2012

With the increasing size and universalization of lithium-ion batteries, the development of cathode materials has emerged as a critical issue. The energy density of 18650 cylindrical batteries had more than doubled from 230 Wh/l in 1991 to 500 Wh/l in 2005. The energy capacity of most products ranges from 450 to 500Wh/l or from 150 to 190 Wh/kg. Product developments are focusing on high capacity, safety, saved production cost, and long life. As Co is expensive among the cathode active materials $LiCoO_2$, to increase energy capacity while decreasing the use of Co, composites such as $LiMn_2O_4$, $LiCo_{1/3}N_{i1/3}Mn_{1/3}O_2$, $LiNi_{0.8}Co_{0.15}Al_{0.05}O_2$, and $LiFePO_4$-C (167 mA/g) are being developed. Furthermore, many studies are being conducted to improve the performance of battery materials to meet the requirement of large capacity output density such as 500Wh/kg for electric bicycles, 1,500Wh/kg for electric tools, and 4,000~5,000Wh/kg for EV and PHEV. As new cathodes active materials with high energy capacity such as graphene-sulfur composite cathode materials with 600 Ah/kg and the molecular cluster for secondary battery with 320 Ah/kg are being developed these days, their commercializations are highly anticipated.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.3
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• pp.82-88
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• 2005

This study was carried out to investigate on the change of NaCl content during the food waste composting and on the safety of food waste compost(FWC) manufactured by the non-stirrer sealed fermenter. Plant culture test with pepper crop was also performed to see the effect of FWC, which was produced by the G co. ltd., on the growth of peper and migration of NaCl in soil. The culture test was performed at the farmland in Chungnam National University. The results were as follows; the NaCl content was gradually accumulated during food waste composting process, probably through water evaporation. Sodium concentration was, however, remarkably decreased at the final stage due to the desalting effect by water which was concentrated on the ceil of the fermentor. The analysis of chemical properties and humidity parameters on the food waste compost revealed that the product is quite a good qualified one. More than 0.5 tons of FWC application on red pepper cultivation caused diminished effect on the yield and the accumulation of salts on soil.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.86-92
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• 2000

This study was conducted to determine the optimal mixing ratio of the paper mill sludge(PMS) and pig manure(PM). Since the former contains lots of total carbon and low nitrogen, it was used as carbon source. Also, dried paper mill sludge(DPMS) was added to the mixture to control the water content. The treatments was composed of four as follows, PMS-100(PM 0%+PMS 80%+DPMS 20%), PMS-85(15+65+20), PMS-70(30+50+20), and PMS-55(45+35+20). The mixtures were composted under aerobic condition in $1.25m^3$ static piles. The piles were aerated for 15 minutes per day and turned over the mixture once a week at the early stage of composting. To estimate the maturity of composts, the changes of physico-chemical properties such as temperature, pH, C/N ratio and color were monitored every week. The 25-30 and 55-60% as optimal condition of C/N ratio and moisture content were respectively recommended for effective composting by the evaluation of the changes of phsico-chemical properties for materials taken from compost files during the composting period. When the 30 and 45% of PM were mixed with PMS, the maturity time at least demanded to the stable state were shortened and the qualify of the final product was improved in a view of nutritional components.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.4
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• pp.132-140
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• 2006

This investigation into unfermented soybeans, which were left from the soybeans used to make cheongguk-jang, was conducted to find out its availability of the application to the environmental-friendly fertilizers. The test of cultivating lettuce, using 1/5000a Wagner pot, was carried out inside the affiliated farm glasshouse, belonged to University of Chung-Nam National. The results showed that in the category of leaf length, the control and cheongguk-jang soybeans treatment plot had similar outcomes and in the category of the extract of the cheongguk-jang soybeans, it increased by about 26~33%. And in the categories of width and number of leaves it showed that the extract treatment increased by about 9~20%, in compared to the control. Finally, in the category of fresh weight, the results showed that cheongguk-jang soybean and the extract of the cheongguk-jang soybean effectively increased by about 9~27%, and that pig manure compost treatment plot with the extract of the cheongguk-jang soybean also significantly increased by about 26%, compared to the control. Accordingly, the unfermented soybean left in the production of cheongguk-jang and the extract of the cheongguk-jang soybean are considerably appeared to be valuable environmental-friendly fertilizers.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.4
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• pp.61-70
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• 2019

This study aimed to investigate the physicochemical characteristics of fish meal, bone meal, and sesame oil cake, which are readily available by-products from agriculture and fisheries, during the process of liquid fertilizer fermentation, and to examine the effects of liquid fertilizer application on seed germination and growth of tomatoes. During processing the fermentation for liquid fertilizers by using fish meal, bone meal, and sesame oil cake liquid fertilizers, the pH of the fertilizer increased in the order of bone meal > fish meal > sesame oil cake, and the concentration increased rapidly up to 30 days in all types of liquid fertilizer. The nitrogen content of the liquid fertilizers increased as fermentation progressed in the order of fish meal > bone meal > sesame oil cake. The phosphorus content increased as fermentation progressed and the highest was 1.0 % in the liquid fertilizer of sesame oil cake. The germination rate and its index of radish seeds were compared for different dilutions of each of the liquid fertilizers. Excluding the 10-fold dilution of the fish meal and oil cake liquid fertilizer, all the treatment groups showed a germination rate ≥ 95 % and the germination index tended to increase with dilution rate of liquid fertilizers. For responses of tomato growth, there were no significant differences among the liquid fertilizer treatment groups; however, the organic content, microbial density, and microbial biomass C in the soil were higher than chemical fertilizer treatment. These results demonstrated that there were differences in the characteristics of liquid fertilizers depending on the materials used, and that liquid fertilizer can be used for nutrition management for the organic crop cultivation.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.4
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• pp.71-81
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• 2019

This research was conducted to improve availability of agricultural by-products, national natural resources that could be used as fertilizer source, by estimating the amount of production and collecting main contents of fertilizer substances from previous studies and data, in order to be used as basic data to investigate national resources that could be used as alternatives for imported oil-cakes in the future. Conversion factor was used to estimate annual production of agricultural by-products for main 34 crop types in 2018. For total agricultural by-products, rice straws accounted at 50.3% for the highest proportion, followed by 8.7% of rice husks, showing that by-products from rice harvest accounted at 59.0% for all by-products. Further, there were listed the contents of fertilizer substances (nitrogen, phosphoric acid, potash) in 40 types of by-products from agricultural areas. The average contents of nitrogen, phosphoric acid, and potash in agricultural by-products were 1.43%, 0.59%, and 1.90%, respectively. As a result of estimating the annual nitrogen supply amount from 26 agricultural by-products in 2018, it was found that it could supply 44,911 tons of nitrogen. The investigated by-products contained fertilizer substances such as nitrogen, phosphoric acid, and potash, but the contents were lower compared to castor oil-cake used as main component of organic fertilizer. Therefore, resource management plan needs to be established for efficient use of by-products because time, location, and nutrient content of agricultural by-product production were extremely different. Research on fertilizer and manure using agricultural by-products need to be conducted to develop and distribute alternatives for imported oil-cakes.

• Korean Journal of Materials Research
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• v.25 no.2
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• pp.75-80
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• 2015

The carbon dioxide($CO_2$) released while producing building materials is substantial and has been targeted as a leading contributor to global climate change. One of the most typical method to reducing $CO_2$ for building materials is the addition of slag and fly ash, like pozzolan material, while another method is reducing $CO_2$ production by carbon negative cement development. The MgO-based cement was from the low-temperature calcination of magnesite required less energy and emitted less $CO_2$ than the manufacturing of Portland cements. It is also believed that adding reactive MgO to Portland-pozzolan cements could improve their performance and also increase their capacity to absorb atmospheric $CO_2$. In this study, the basic research for magnesia cement using $MgCO_3$ and magnesium silicate ore (serpentine) as main starting materials, as well as silica fume, fly ash and blast furnace slag for the mineral admixture, were carried out for industrial waste material recycling. In order to increase the hydration activity, $MgCl_2$ was also added. To improve hydration activity, $MgCO_3$ and serpentinite were fired at $700^{\circ}C$ and autoclave treatment was conducted. In the case of $MgCO_3$ as starting material, hydration activity was the highest at firing temperature of $700^{\circ}C$. This $MgCO_3$ was completely transferred to MgO after firing. This occurred after the hydration reaction with water MgO was transferred completely to $Mg(OH)_2$ as a hydration product. In the case of using only $MgCO_3$, the compressive strength was 3.5MPa at 28 days. The addition of silica fume enhanced compressive strength to 5.5 MPa. In the composition of $MgCO_3$-serpentine, the addition of pozzolanic materials such as silica fume increased the compression strength. In particular, the addition of $MgCl_2$ compressive strength was increased to 80 MPa.

• Resources Recycling
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• v.15 no.5 s.73
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• pp.17-25
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• 2006

Al-MCM-48 was used as a catalyst to decompose high density polyethylene(HDPE). Catalytic activity of Al-MCM-48 was compared with those of Al-MCM-41, Beta, and ZSM-5. Catalytic decomposition rate over Al-MCM-48 was much higher than at of non-catalytic pyrolysis only. Compared to other catalysts, Al-MCM-48 revealed the little higher activation energy value. The progressive deactivation behavior of the catalysts has also studied. ZSM-5 and Al-MCM-48 showed slower deactivation rates than Al-MCM-41 and Beta. Pyrolysis coupled with gas chromatographic separation and flame ionization detection (Py-GC/ FID) was also performed to assess the characteristics of pyrolysis products. ZSM-5 gave a higher fraction of gaseous products ($C_1-C_4$). Al-MCM-41 and Beta produced mainly $C_5-C_{12}$ products. The selectivity to oil product ($C_5-C_{22}$) obtained with Al- MCM-48 is higher an that with the other catalysts employed in this study.

• Resources Recycling
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• v.17 no.5
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• pp.66-75
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• 2008

Using a pinus koraiensis and pinus rigida which are normally being discarded in South Korea, the optimal condition of producing charcoals has been studied to develop activated carbons which can be recycled as a higher value-added product. A study on manufacture of activated carbons from a discarded timber consists of two processes, the production process of charcoals from a discarded timber by low temperature pyrolysis process and the production process of activated carbons from the charcoals by chemical activation reaction. This study deals with the production process of charcoals from a discarded timber by low temperature pyrolysis process. As a results of experiment, it was investigated that charcoals produced through drying at $150^{\circ}C$ for 6hr and pyrolysis process at $500^{\circ}C$ for 1hr had the highest values in physical properties such as iodine number and BET surface area. Furthermore, through observing SEM images, the maximum development of porosity had been founded in this condition. It was confirmed that values of physical properties on using a pinus koraiensis are superior to the ones when using a pinus rigida. When charcoals were produced from a pinus koraiensis in this condition, BET surface area was approx. $640m^2/g$.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.91-91
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• 2003

시험은 대조구 0%와 남은 음식물에 Protein의 요구량 수준을 각각 높인 10%, 20%, 30%, 40%, 대조구에 녹차 부산물(GTB) 첨가구 1.0%, 남은 음식물 30% + 녹차 부산물 (GTB) 1.0%로 총 7처리 4반복으로 하였으며, 반복당 6수씩 개체별로 사양 실험을 실시하고, 산란율, 난중, 난각두께, 난황색, Thiobarbituric acid (TBA) 및 관능검사 등을 측정한 결과는 다음과 같다. 1. 산란율은 남은 음식물 10%, 20% 및 40% 첨가구에서 각각 82.65%, 81.54% 및 82.27%로 높게 나타났으나 남은 음식물 30%첨가구는 75.34%로 낮게 나타났으며 통계적 유의차를 보였다 (P<0.05). 대조구가 72.87%가 가장 낮게 나타났으며 (P<0.05), 주령별로는 주령이 증가할수록 산란율이 다소 감소하는 경향을 보였다. 2. 난중은 전 처리구중 가장 높은 경향을 보인 것은 남은 음식물 30% + GTB 1%처리구가 63.78로 높은 경향을 보였다. 가장 낮은 난중은 남은 음식물 10%처리구가 60.02로 나타났다 (P<0.05). 3. 산란량은 전 처리구에서 남은 음식물 30% + GTB 1%가 52.53g으로 높게 나타났고, 가장 낮은 산란량을 보인 것은 대조구가 45.32g으로 가장 낮게 나타났으며 통계적 유의차를 보였다 (P<0.05). 4. 사료 요구율은 남은 음식물 20%첨가구가 2.86으로 높게 나타났으며, 낮은 요구율은 남은 음식물 10%첨가구가 2.47으로 낮게 나타났으며 통계적 유의차를 보였다 (P<0.05). 전 처리구간에서 사료 요구율은 주령이 증가할수록 요구율이 증가하는 경향을 보였다. 5. 콜레스테롤은 대조구 + GTB 1.0%첨가구가 13.923으로 높게 나타났다. 가장 낮은 콜레스테롤은 남은 음식물 40%처리구가 12.003으로 낮게 나타났다. 남은 음식물을 첨가한 처리구가 난황 내 콜레스테롤 함량이 낮아지는 경향을 보였으나 남은 음식물 30%첨가구가 12.835로 높은 수치를 보였으며 통계적 유의차는 나타나지 않았다 (P>0.05). 6. TBA가 가장 높은 처리구간은 1주에는 남은 음식물 40%첨가구가 3.205로 높게 나타났으며 2주에는 남은 음식물30%첨가구가 3.275로 높게 나타났다. 마지막 주에는 3.947로 높게 나타났다. 이 결과로 볼 때 남은 음식물을 첨가한 처리구가 대체적으로 산패도가 높게 나타나는 경향을 보였으며 통계적 유의차는 나타나지 않았다 (P>0.05).