• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.34-45
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• 2016

Global warming and climate change have been caused by combustion of fossil fuels. The greenhouse gases contributed to the rise of temperature between $0.6^{\circ}C$ and $0.9^{\circ}C$ over the past century. Presently, fossil fuels account for about 88% of the commercial energy sources used. In developing countries, fossil fuels are a very attractive energy source because they are available and relatively inexpensive. The environmental problems with fossil fuels have been aggravating stress from already existing factors including acid deposition, urban air pollution, and climate change. In order to control greenhouse gas emissions, particularly CO2, fossil fuels must be replaced by eco-friendly fuels such as biomass. The use of renewable energy sources is becoming increasingly necessary. The biomass resources are the most common form of renewable energy. The conversion of biomass into energy can be achieved in a number of ways. The most common form of converted biomass is pellet fuels as biofuels made from compressed organic matter or biomass. Pellets from lignocellulosic biomass has compared to conventional fuels with a relatively low bulk and energy density and a low degree of homogeneity. Thermal pretreatment technology like torrefaction is applied to improve fuel efficiency of lignocellulosic biomass, i.e., less moisture and oxygen in the product, preferrable grinding properties, storage properties, etc.. During torrefacton, lignocelluosic biomass such as palm kernell shell (PKS) and empty fruit bunch (EFB) was roasted under an oxygen-depleted enviroment at temperature between 200 and $300^{\circ}C$. Low degree of thermal treatment led to the removal of moisture and low molecular volatile matters with low O/C and H/C elemental ratios. The mechanical characteristics of torrefied biomass have also been altered to a brittle and partly hydrophobic materials. Unfortunately, it was much harder to form pellets from torrefied PKS and EFB due to thermal degradation of lignin as a natural binder during torrefaction compared to non-torrefied ones. For easy pelletization of biomass with torrefaction, pellets from PKS and EFB were manufactured before torrefaction, and thereafter they were torrefied at different temperature. Even after torrefaction of pellets from PKS and EFB, their appearance was well preserved with better fuel efficiency than non-torrefied ones. The physical properties of the torrefied pellets largely depended on the torrefaction condition such as reaction time and reaction temperature. Temperature over $250^{\circ}C$ during torrefaction gave a significant impact on the fuel properties of the pellets. In particular, torrefied EFB pellets displayed much faster development of the fuel properties than did torrefied PKS pellets. During torrefaction, extensive carbonization with the increase of fixed carbons, the behavior of thermal degradation of torrefied biomass became significantly different according to the increase of torrefaction temperature. In conclusion, pelletization of PKS and EFB before torrefaction made it much easier to proceed with torrefaction of pellets from PKS and EFB, leading to excellent eco-friendly fuels.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.551-557
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• 2007

This paper describes a study on the permeability reduction of the riverbed ground during urban railway tunnel construction. The research is mainly concentrated on the study of the grouting or injection methods among permeability reduction methods which can be adapted in the riverbed ground. Firstly, the various grouting methods are theoretically reviewed and compared based on the previous research papers and case study results. It is also evaluated the grouting methods in view of a safe construction of the river crossing railway tunnel. Baced on the literature review and previous construction data, the design technology of grouting methods considering the long term hydro-geological behaviour in the riverbed, is suggested. Two injection methods namely, Natural Durable Stabilizer(N.D.S) and Space-Multi Injaction Grouting(S.M.I) methods, are introduced as new approach methods which can be adopted to modify the riverbed ground. In order to evaluate the ground that grouted and modified by the N.D.S and S.M.I method, the pilot test programmes including the field and laboratory permeability tests, are carried out in the river crossing tunnel construction sites. The results obtained from pilot test programme, are also reviewed. In conclusion, the grouting efficiency of the S.M.I method using the non-alcalimeter silica sol is better than that of NDS method using cement. In addition, it hopes that the research results are contributed to develop the grouting design technology.

• Applied Chemistry for Engineering
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• v.30 no.2
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• pp.145-150
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• 2019

In this study, we used extracts obtained from five different solvents (water, ethanol, hexane, ethyl acetate, butanol) of Achyranthes japonica (AJ) and also AJ fermented with Lactobacillus plantarum (LP) to confirm effects on the anti-inflammatory activity in RAW264.7 cells. Experiments of measuring nitric oxide (NO) and cytokine production were performed in lipopolysaccharide (LPS)-induced RAW264.7 cells, and the expression of both cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) was observed by a western blot method. The cytotoxicity of RAW264.7 was confirmed by the cell counting kit (CCK) assay at a concentration of $100{\mu}g/mL$, which has no toxicity. As a result of the inhibition of NO production, the inhibition rate of AJ-LP extracted with ethanol samples was about 74% higher than that of using the control group. Interleukin-6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and Interleukin-$1{\beta}$ (IL-$1{\beta}$), which are inflammatory cytokines, also showed an excellent efficacy with inhibition rates of about 57, 70, and 74%, respectively. Comparing to the results of COX-2 and iNOS expression in the AJ group, the inhibition rate of 20-hydroxyecdysone was the highest than others. On the other hand, the COX-2 expression level of AJ-LP group decreased about 16% compared to that of the control group, and the iNOS expression level was also decreased about 7%. These results suggest that the extract of AJ fermented from L. plantarum can be used as an anti-inflammatory natural material.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.599-608
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• 2020

This study aims to investigate the performance and satisfaction of occupational therapists at the Dementia Relief Center for health care of the elderly in local communities, and to provide basic data necessary for role establishment by checking occupational therapists' tasks according to the priority. The subjects of this study were occupational therapists in dementia care centers in the Honam area and Gwangju Metropolitan City, who were surveyed via mail and e-mail. The survey had a total of 54 items covering the general characteristics of the therapists and current state of the centers (n=8), performance and satisfaction with the service areas and task content of the centers (n=45), and tasks that were considered important (one short-answer question). It was found that occupational therapists at the Dementia Relief Center were mainly carrying out the "Dementia Prevention Management Projects", which provided the programs for the patients, and they showed the highest satisfaction. Although the 'MMSE-DS' is occupational therapists' own area with high performance and satisfaction, it was not assigned to the occupational therapists at the Dementia Relief Center, indicating that the role was insufficient. The tasks related "administrative works and strengthening community capacities" showed low performance and satisfaction, but they are essential for the operation of the Dementia Relief Center and the management of the patients, so the plans to increase the occupational therapists' performance should be established. The categories of projects that occupational therapists consider important were also consistent with those they had to perform. It means the occupational therapists at the Dementia Relief Center recognized their unique roles. In this context, to establish the role of occupational therapist at the Dementia Relief Center, it is necessary to amend the operating guidelines based on the performance, satisfaction, and priorities of the projects, and to develop the curriculums and programs that can improve the tasks with insufficient performance and low satisfaction.