• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.1
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• pp.83-91
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• 2011

Hemicelluloses are useful materials for papermaking and other biotechnological applications. To recover and further utilize the hemicelluloses, this study carried out the pre-extraction of the hemicelluloses from Korean mixed hardwoods chips using hot water and sodium hydroxide solution at various temperature and time conditions. Through the hot water pre-extraction, the wood components of 22% was extracted and the 35% of the hemicelluloses which were contained in the original wood chips were dissolved into the pre-extractives. The yield of the pre-extractives was more significantly influenced by the pre-extraction temperature than the time. The pre-extractives with the yield of 30% could be obtained by alkali pre-extraction and alkali concentration was the most important factor. It had lower hemicellulose content but high molecular weight, compared with the hot water pre-extractives.

• Textile Coloration and Finishing
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• v.31 no.2
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• pp.88-97
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• 2019

In this study, when printed on a nylon material, the color strength and fastness are lower than that of a polyester material, and the nylon material shrinks due to heat and pressure, resulting in poor design and poor compatibility. To overcome this problem, we investigated the possibility of transfer DTP by adding pre-treatment process to nylon transfer DTP process. For the basic study of pre-treatment preparation, we used pure nylon material which is not compounded and dispersion ink and transfer paper applied to existing PET transfer DTP. Pre-treatment preparations were classified into three types of acryl-base polymer and pre-treated with nylon and then applied to transfer DTP to confirm their color strength and fastness. The color strength of the pre-treated nylon material increased and poly-methyl-acrylate amulsion pre-treatment showed the best color at $210^{\circ}C$, 1.5m/min and 0.3MPa. The nylon material pre-treated with washing, friction, and light fastness was judged to be more excellent and stable.

• Journal of Korean Elementary Science Education
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• v.31 no.1
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• pp.109-124
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• 2012

Developing pedagogical content knowledge (PCK) has been emphasized for teacher's professionalism and it should be done from systematic teacher training courses. In this study, we investigated changes of elementary pre-service teachers' PCK of science teaching and motivational strategies before and after a training course. For the analysis of pre-service teachers' PCK, their lesson plans, surveys, and interviews were collected. According to the results, in the beginning of the semester, pre-service teachers in the experimental group usually used didactic or combination of didactic and inquiry teaching strategies and a few pre-service teachers used inquiry or discovery teaching strategies when making lesson plans. However, at the end of the semester many pre-service teachers used inquiry teaching strategies in their lessons which included activities of asking students' prior knowledge, conducing experiments, finding conclusion, and comparing teachers' explanations with students' explanations. Regarding motivational strategies, in the beginning of the semester they focused using activities to create student's emotional interest in science lesson but at the end they used other strategies to create positive atmosphere for learning, capture intellectual interest in science, and connect science to students' everyday lives. The changes in pre-service teachers' PCK in the experimental group was meaningful because there was less change in pre-service teachers' PCK in the control group. This study implies the need for effective professional development programs for developing pre-service teachers' PCK.

• Journal of Korean Elementary Science Education
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• v.38 no.1
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• pp.31-42
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• 2019

Through the criticism and evaluation of different classes teaching the same lesson topic, this study compared the viewpoints by two ways between two groups including pre-service and experienced teachers. Through free-style criticism, this study analyzed the differences between pre-service and experienced teachers' areas of attention. Through criteria-based analysis, the study analyzed the judgement of each area and the criteria of each judgement. The results of the study found that pre-service teachers criticised more limited areas, but somewhat more positive than their experienced teacher counterparts. Also, pre-service teachers did not observe thoroughly whether or not the teacher was well-informed of the science content, the sequence of curriculum, and whether or not meaningful interaction had occurred. As well as, pre-service teachers were not actually feel importance of student-oriented lessons, and they could not look room and materials are useful to students on students' sides. Additionally, pre-service teachers thought highly of lessons which were connected to other subjects rather than connected to daily life. Therefore, to notice diverse areas in the class, pre-service teachers need to criticise lessons using a diverse criterion. Also, pre-service teachers realized simple questions and that mechanical group activities are not always effective and that they need to think how to improve meaningful interaction. Moreover, they have to perceive that an inquiry-oriented student-lead approach is very important. Lastly, pre-service teachers have to closely consider the room efficiency and materials available to the students, and they must internalize that science class has to be connected with daily life.

• The Mathematical Education
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• v.60 no.1
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• pp.61-76
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• 2021

The purpose of this study is to analyze the errors and difficulties which pre-service secondary teachers shows during the task modification in consideration of the cognitive demand and to provide significant implications to the pre-service teacher education program related to the modification of the mathematical tasks. In the pursuit of this purpose, tasks were selected from perpendicular bisector units and 24 pre-service teachers were asked to modify the tasks to higher and lower level tasks. After the modification activities, opportunities for reflection and modification were provided. The findings from analysis are as follows. Pre-service teachers had a difficulty to distinguish between PNC tasks and PWC tasks. Also, We identified the interference phenomena that pre-service teachers depended on the apparent elements of the task. Pre-service teachers showed a tendency to overlook the learning objectives and learning hierarchy during the task modification, and to focus on some types of task modification. However, pre-service teachers were able to have meaningful learning opportunities and extend the category of tools to technology including Geogebra through self-reflection and correction activities on task modification. The above results were summed up and we presented the implications to the task modification program in the pre-service secondary teacher education.

• The Journal of Internal Korean Medicine
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• v.30 no.1
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• pp.212-227
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• 2009

Objective : Membranous nephropathy (MN) is one of the most commonest forms of glomerular disease in man and the most frequent cause of the adult idiopathic nephrotic syndrome. Some investigators recommend no treatment, while others propose aggressive therapy, including prednisolone plus an immunosupressant such as chlorambucil or cyclophosphamide. But a more effective way to treat MN is not defined yet. This study was to evaluate the effects of Patriniae Radix extract (PRE) on the MN induced by cBSA in mice. Methods : Mice were divided into 4 groups. The first group (normal) was injected with saline. The second group (control) was treated with cBSA (10 mg/kg i.p) only. The third group, named PRE-2S0, was treated with cBSA (10 mg/kg i.p) and PRE (250 mg/kg, p.o). The fourth group, PRE-500, was treated with cBSA (10mg/kg i.p) and PRE (500mg/kg, p.o). After cBSA and PRE treatment for 4 weeks, we measured change of body weight, 24hrs proteinuria, serum albumin, total cholesterol, triglyceride, BUN, creatinine, IgG, IgA, IgM, $TNF-\alpha$, $IL-1\beta$, and $IFN-\gamma$ levels and the mRNA expression of $IFN-\gamma$, IL-6, and IL-10. The morphologic changes of renal glomeruli were also observed with a light microscope and an electron microscope. Results : The levels of 24 hrs proteinuria and serum triglyceride. BUN. IgG. $TNF-\alpha$, and $IL-1\beta$ significantly decreased in both PRE groups, while the level of serum albumin significantly increased in both PRE groups. The mRNA expression of IL-10 in splenocytes considerably increased in both PRE groups. The mRNA expression of $IFN-\gamma$ and IL-6 in splenocytes considerably increased in both PRE group. In histological findings of kidney tissue, thickening of GBM decreased in both PRE groups. Conclusions : The present study suggests that PRE is effective when treating mice with MN induced by cBSA. More clinical data and studies are to be done for efficient application.

• Journal of Life Science
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• v.29 no.1
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• pp.37-44
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• 2019

Leaves of Sasa quelpaertensis Nakai are used in folk medicine for their anti-inflammatory, antipyretic, and diuretic properties. To ensure efficient utilization of S. quelpaertensis leaf, we previously reported a preparation method for phytochemical-rich extract (PRE) using the leaf residue, which was produced after hot water extraction. This study was undertaken to evaluate the hypouricemic potential of S. quelpaertensis leaf PRE in potassium oxonate (PO)-induced hyperuricemic mice. The administration of PRE significantly reduced serum uric acid (UA), blood urea nitrogen (BUN), and serum creatinine levels and increased urine UA and creatinine levels in the PO-induced hyperuricemic mice. It also reduced liver UA levels and xanthine oxidase (XA) activity. A histological analysis revealed that PRE administration protected against PO-induced liver damage, pointing to anti-inflammatory and cytoprotective effects in PO-induced hyperuricemic mice. We analyzed the transcriptome response to PRE administration in PO-induced hyperuricemic mice using RNA sequencing (RNA-Seq) in kidney tissues. The administration of PRE mainly enriched genes involved in mediating immune and inflammatory responses and the metabolic pathway. A Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the metabolic pathway, purine metabolism, and antibody biosynthesis were the major pathways altered in the PRE and PO groups. These results suggest a potential role for PRE in the prevention and treatment of hyperuricemia with inflammation.

• Food Science and Preservation
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• v.9 no.3
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• pp.277-281
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• 2002

To decrease the rot of onion bulb during storage in simple house, later cultivar 'Changnyeungdaego' was dried after harvest on the field, ventilation house and non-ventilation house during 1 to 3days in 1997 and 1998. The maximum air temperature during pre-drying maintained highest in the non-ventilation house and lowest in the field, especially higher than 41.6$^{\circ}C$ at second and third day in 1997 and second day in 1998 on the non-ventilation house. Water content of onion bulbs showed 90.3∼89.5% at harvest and reduced 0.3∼l.8% in 1997, 0.2∼2.6% in 1998 after pre-drying, the rate of reduction was highest on the field and lowest on the ventilation house. Mean of maximum air temperature was 39.2$^{\circ}C$ in 1997 and 37.1$^{\circ}C$ in 1998 and relative humidity was 79.3% and 72.7% in July of 1997 and 1998, 78.2% and 79.1% in August of 1997 and 1998 during storage on the simple house after pre-drying. Rotting ratio of onion bulb showed higher in 1998 than 1997, but rotting appeared earlier 1997 than 1998. Total rotting rate as influenced by place and days of pre-drying was the lowest on the ventilation house, and highest on the non-ventilation. As the days of pre-drying increase, rotting rate of onion bulbs were lower. As above results, 1 or 2days of pre-drying on the ventilation house and 2 or 3days of pre-drying on the field were recommended to decrease the rotting onion bulb during storage.

• The Research Journal of the Costume Culture
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• v.11 no.1
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• pp.66-74
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• 2003

This study is to improve the worst lightfastness of a natural dye. To modify the fiber surface, low temperature oxygen plasma was carried out on silk fabric. The result is followed below after the examination of surface shape, dyeability, color change, UV absorbent influence and lightfastness. 1. When electric discharge outputs are 60W, 80W and 100w, and processing times are 10minutes, 20minutes and 40minutes, the etching effect of surface increased as electric discharge outputs and processing times increased. 2. When examined UV absorbent for 5hours, 10hours, 20hours, 40hours and 80hours, the value changes of E are 1.47, 2.51, 2.91, 3.71, 4.51 and 5.31 in case of Al pre-mordanting/ prasma 80W, 20min./ UVabsorbent 5% (100:1), 2.31, 2.47, 3.84, 3.90, 3.61 and 4.42 in case of Al pre-mordanting/prasma 80W, 20min.1 UV absorbent 5% (o.w.f.). The lightfastness decreased when UV absorbent increased. 3. Dyeability of the samples pre-treated with five different methods was in the following order: plasma processing for 20minutes at 60W/Al pre-mordanting > Al pre-mordanting > plasma processing for 20minutes at 60W > Al after-mordanting. non mordanting Plasma treatment had superior effect on dyeability. 4. When UV absorbent was applied in fabric, the sample under higher electric discharge out puts showed more effective in improving lightfastness.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.259-262
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• 2009

The influence of pre-strain in low-cycle fatigue behavior of Fe-18Mn-0.05Al-0.6C TWIP steel was studied by conducting axial strain-controlled tests. As-received plates were deformed by rolling with reduction ratios of 10 and 30%, respectively. A triangular waveform with a constant frequency of 1 Hz was employed for low cycle fatigue test at the strain amplitudes in the range of ${\pm}0.4{\sim}{\pm}0.6$ pct. The results showed that low-cycle fatigue life was strongly dependent on the amount of pre-strain as well as the strain amplitude. Increasing the amount of prestrain, the number of reversals to failure was significantly decreased at high strain amplitudes, but the effect was negilgible at low strain amplitudes. A new model for predicting fatigue life of pre-strained body has been devised adding a correction term of ${\Delta}E_{pre-strain}$ to the energy-based fatigue damage parameter.