• Resources Recycling
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• v.30 no.6
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• pp.68-75
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• 2021

This study aims to investigate the manufacturing process of calcium chloride-based special cement, i.e., CCA (calcium chloro aluminate, C₁₁A₇·CaCl₂), which uses limestone, by using one type of random industrial by-product, domestic coal ash, cement kiln dust. The manufacturing process of was examined in detail, and the results suggested that the amount of CCA synthesized increased with an increase in the firing temperature. The manufacturing process of CCA was investigated at 1200℃, which was determined as the optimum firing temperature. The results showed that in general, the amount of CCA synthesized tended to increase with an increase in the firing time; however, the clinker melted when the firing time was more than 30 min, thereby suggesting that a firing time of less than 20 min would be suitable for the clinkering process. The optimal firing conditions for manufacturing CCA were obtained as follows: heating rate of 10 ℃/min, firing temperature of 1200 ℃, and holding time of 20 min. The results also suggest that manufacturing CCA will be easier when high chlorine-containing cement kiln dust is used.

• Korean Chemical Engineering Research
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• v.57 no.3
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• pp.400-407
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• 2019

Oxy-combustion with a circulating fluidized bed (Oxy-CFBC) technology has been paid attention to cope with the climate change and fuel supply problem. In addition, Oxy-CFBC technology as one of the methods for carbon dioxide capture is an eco-friendly that can reduce air pollutants, such as $SO_2$, NO and CO through a flue gas recirculation process. The newly developed $100kW_{th}$ pilot-scale Oxy-CFBC system used for this research has been continuously utilizing to investigate oxy-combustion characteristics for various fuels, coals and biomasses to verify the possibility of fuel diversification. The anthracite is known as a low reactivity fuel due to a lot of fixed carbon and ash. Therefore, this study aims not only to improve combustion efficiency of an anthracite, but also to capture carbon dioxide. As a result, compared to air-combustion of sub-bituminous coal, oxy-combustion of anthracite could improve 2% combustion efficiency and emissions of $SO_2$, CO and NO were reduced 15%, 60% and 99%, respectively. In addition, stable operating of Oxy-CFBC could capture above 94 vol.% $CO_2$.

• Biomedical Science Letters
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• v.28 no.3
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• pp.170-177
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• 2022

In mountainous regions, wild herbs which can also be edible in nature for humans and animals possess a wide array of biologically diversified properties. It is because of the fact that due to the cold weather of mountains; they are enriched in certain kinds of phytochemicals such as anti-oxidants, anti-inflammatory and many more. One such kind of an herb is Aster scaber (AS) in Korean. It is a widely cultivated culinary herb in Korean peninsula and used as a side dish in Korean culinary cuisine. In view of its extensive use in cuisine, we geared to unravel the anti-oxidant and anti-inflammatory effects of AS in murine alveolar macrophage cell line (MH-S). 2,2'-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assays revealed a dose dependent (7.8~1,000 ㎍/mL) inhibition of oxidation by AS 70% ethanol (ASE) extract as compared to Trolox and Ascorbic acid respectively. Nitric oxide assay (NO) showed a dose dependent decrease (5~40 ㎍/mL) in MH-S cells with ASE when stimulated with Coal Fly Ash (CFA). Moreover, this dose for NO reduction was also found to be least cytotoxic for cells as determined by cellular viability (MTT) assay. The gene expression of pro-inflammatory mediators (iNOS and COX-2) and cytokines (IL-6 and IL-1β) and were also dose dependently inhibited by ASE in MH-S cells through RT-PCR. Therefore, in light of these findings, AS exhibited a strong anti-oxidant and anti-inflammatory agent. These results also justify the extensive use of this mountainous herb in culinary practices for beneficial effects on human health.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.532-539
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• 2011

The physical and chemical properties of the dried low rank coals (LRCs) before and after the surface treatment using ozone and ammonia were characterized in this study. The contents of moisture, volatiles, fixed carbon and ash consisting of dried LRCs before the surface treatment were about 2.0, 44.8, 44.9 and 8.9%, respectively. Also, it was composed of carbon of 62.66%, hydrogen of 4.33%, nitrogen of 0.94%, oxygen of 27.01% and sulfur of 0.09%. The dried LRCs was surface-treated with the various dry methods using gases such as ozone at room temperature, ammonia at $200^{\circ}C$ and then the dried LRCs before and after the surface treatment were characterized by the various analysis methods such as FT-IR, TGA, proximate and elemental analysis, caloric value, ignition test, adsorption of $H_2O$ and $NH_3-TPD$. As a result, the oxygen content increased and the calorific value, ignition temperature and the contents of carbon and hydrogen relatively decreased because the oxygen-contained functional groups were additionally generated by the surface oxidation with ozone which plays a role as an oxidant. Also, its $H_2O$ adsorption ability got higher because the hydrophilic oxygen-contained functional groups were additionally generated by the surface oxidation with ozone. On the other hand, it was confirmed that the dried LRCs after the surface treatment with $NH_3$ at $200^{\circ}C$ have the decreased oxygen content, but the increased calorific value, ignition temperature and contents of carbon and hydrogen because of the decomposition of oxygen-contained functional groups the on the surface. In addition, the $H_2O$ adsorption ability was lowered bucause the surface of the dried LRCs might be hydrophobicized by the loss of the hydrophilic oxygen-contained functional groups. It was concluded that the various physico-chemical properties of the dried LRCs can be changed by the surface treatment.

• Journal of Mushroom
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• v.16 no.3
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• pp.147-154
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• 2018

This study was aimed to improve the productivity and income of mushroom farming by developing a new casing material as a substitute for clay loam casing soil, which is becoming more difficult to acquire. When the new casing materials were used for the stable production of button mushroom (Agaricus bisporus), a 1:1 mixture of clay loam and button mushroom media obtained after harvest supported 13% greater mycelial growth ($32.0kg/3.3m^2$). This material was better than clay loam soil in preventing contamination with environmental compounds and pests. The use of an inexpensive 1:1 mixture of peat moss and coco peat resulted superior mycelial growth with 4% better yield ($32.9kg/3.3m^2$) compared with conventional clay loam soil. Advantages of these casing materials included ready availability and improved productivity. Mixtures of peat moss + coco peat + zeolite (50%:30%:20%) and coco peat + coal ash (75%:25%) could substitute for conventional casing soil. Additionally, the novel mixtures containing material obtained after cultivation might be used to produce organic fertilizer.