• Journal of environmental and Sanitary engineering
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• v.19 no.3 s.53
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• pp.52-57
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• 2004

Content of chlorine in s쇼rene-DVB copolymer was decreased as crosslink increased and it is because as crosslink increased $1\%,\;2\%,\;5\%\;and\;10\%$ DVB content increased and crosslink density increased and cavity was reduced. Functional group of resin almost disappeared as C-C1 peak around $700cm^{-1}$ was substituted with 1-aza-12-C-4 macrocyclic ligand and new peak of C-N around $1020cm^{-1}$ appeared, so it was confirmed that styrene-DVB copolymer and ligand were compounded. As crosslink increased in the analysis of element contents, it resulted in the reduction of nitrogen content and it is because as crosslink increased, it led to the reduction of chlorine content in the process of substitution reaction and it affected macrocyclic ligand substituted. Form of functional synthetic resin showed distortion of its particles as macrocyclic ligand was introduced to styrene-DVB copolymer and hydrogen of ligand caused substitution with chlorine element of styrene molecule.

• Korean journal of food and cookery science
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• v.32 no.5
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• pp.656-663
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• 2016

Purpose: This study was aimed to compare the nutritional content of the life stages of Tenebrio molitor. Methods: Nutritional element analysis comprised 12 minerals, 18 amino acids, 4 vitamins, and 12 fatty acids in larval, pupal, and adult stages. Nutritional element content was expressed as a percentage of 100 g of sample and determined in raw and freeze-dried samples to assess the food value of the insect. Results: Moisture, crude protein, and crude fat contents in raw samples were 63.5%, 23.19%, and 3.96%, respectively. Moisture content was significantly higher in the adult stage than in larval and pupal stages, whereas crude fat and crude ash contents were lower. Mineral composition of the mealworm showed K, P, and Mg in decreasing order of content, with no differences among life stages. Total amino acid content increased from adult, pupal to larval stages, in order with each stage's growth, without difference in amino acid composition. Seventy-six to 78% of total fatty acid corresponded to unsaturated fatty acids, with oleic acid as the most abundant. In addition, fatty acid content was high in the adult stage, and clear differences were observed between life stages. Finally, vitamins B1 and B3 showed similar content between life stages, whereas vitamin B2 showed a higher content the adult than larval and pupal stages. A higher folate content was observed in pupal and adult stages than in the larval stage. Although freeze-dried samples showed a higher nutritional content than raw samples, both samples were similar in composition and content between life stages, suggesting the suitability of freeze-dried samples for use as food materials. Conclusion: These results may provide a basis for more diversified industrial applications of the Tenebrio molitor.

• Journal of Magnetics
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• v.18 no.3
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• pp.365-369
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• 2013

Coal ash is known to contain a noticeable amount of valuable elements, including transition metals and lanthanides. Therefore it is quite actual problem to extract them for metallurgy and other applications. This paper presents the results of high gradient magnetic and mechanical separation, microscopy, element analyses and optical spectroscopy of brown coal ash taken from the combustion camera and chimney-stalk of Angren thermal power station. The separated magnetic fraction was 3.4 wt.%, where the content of Fe in ferrospheres increased to 58 wt.%. The highest contents of Fe and rare earth elements were found in the fine fractions of $50-100{\mu}m$. Optical absorption spectroscopy of water solutions of the magnetic fractions revealed $Fe^{2+}$ and $Fe^{3+}$ ions in the ratio of ~1:1. The separated coal ash could be used for cleaning of technological liquid waste by means of the high gradient magnetic field.

• Korean Journal of Human Ecology
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• v.24 no.2
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• pp.297-325
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• 2015

The purpose of this research is to analyze content elements of Housing area in 2013 middle school Technology Home Economics textbooks 1 and 2, total of 22 according to 2009 revised curriculum. The analysis method was content analysis, focusing on contents of main text, tables & figures, reading material, and activity materials by their content elements. This research will contribute in obtaining suggestion for the post curriculum/textbook development and helping teachers to perform a lesson. The results are as follows. First, Housing area included 1 to 4 content elements per each units, from 2 chapters and 6 units. The content elements stated in Home economics curriculum were total of 16 which consists of 'the meaning of housing,' 'housing types,' 'family forms,' 'family life style cycle,' 'life style,' 'neighboring environment,' 'co-living values,' 'air environment,' 'heat environment,' 'light environment,' 'acoustic environment,' 'space division,' 'circulation', 'effective use of space,' and 'sustainable dwelling practice.' All of these components are dealt with in every textbooks. Second, the numbers of content elements provided in each textbooks were the same, however they showed difference in their contextual aspect. Some contents need supplemental material for their lacking content element. Others need proper understanding of the concept because some showed different contents from the appropriate content elements. Third, repetitions in content elements were observed, the contents of 'co-living values' in textbook 1 and 'sustainable dwelling practice' in textbook 2 were similar in terms of eco-friendly housing, co-housing and universal housing. These two content elements should be merged as one next curriculum, or should be stated together in one subunit.

• The Journal of the Korea Contents Association
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• v.11 no.7
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• pp.100-109
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• 2011

This thesis is a content analysis on whether the proportion of structural element and theme association of television news imagery is different, depending on the historical background, and on what it means, which can be the index of scene-based and realistic report. Most researches of television news are horizontal studies of the same period, making light of vertical studies reflecting the change of age. Therefore, This study analyzed 729 items composed of 11,945 shots extracted from MBC Newsdesk from 1987, to 2007, the samples of which were extracted by systematic random sampling with five years' interval. This content analysis found out that there was high proportion of scene-based and realistic report such as 'sound-bite', 'event footage', 'direct matching' in the year 1987, 2007, and high proportion of 'corroboration shot', 'file footage', 'indirect reference', 'literal matching only' in the year 1997, which revealed the fact that reality-based report had not been faithfully accomplished in 1997.

• International Journal of Concrete Structures and Materials
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• v.19 no.1E
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• pp.33-39
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• 2007

The magnitude and distribution of hydration heat of concrete structures are related to the thermal properties of each component of the concrete, the initial temperature, the type of formwork, and the ambient temperature of exposed surfaces. Even though the reinforcing steel bar has completely different thermal properties, it has been excluded in the thermal analysis of the concrete structures for uncertain reasons. In this study, finite element analysis was performed on the concrete structures reinforced with steel bars in order to investigate the effect of reinforcing steel bars on the temperature and stress distribution due to the heat of hydration. As the steel content increased, the maximum temperature and the difference in the internal-external temperature decreased by 32.5% and 10.0%, respectively. It is clearly shown that the consideration of the influence of reinforcing steel bars in the heat of hydration analysis is necessary to obtain realistic solutions for the prediction of the maximum temperature and stresses of concrete structures.

• Computers and Concrete
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• v.18 no.6
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• pp.1097-1112
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• 2016

Fire loading causes a critical collapse of RC (Reinforced Concrete) Structures since the embedded steels inside are relative week against high elevated temperature. Several numerical frameworks for fire resistance have been proposed, however they have limitations such as unstable convergence and long calculation period. In the work, 2-D nonlinear FE technique is proposed using Galerkin method for RC structures under fire loading. Closed-form element stiffness with a triangular element is adopted and verified with fire test on three RC slabs with different fire loading conditions. Several simulations are also performed considering fire loading conditions, water contents, and cover depth. The proposed numerical technique can handle time-dependent fire loading, convection, radiation, and material properties. The proposed technique can be improved through early-aged concrete behavior like moisture transport which varies with external temperature.

• Structural Engineering and Mechanics
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• v.62 no.1
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• pp.21-31
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• 2017

Engineered Cementitious Composite (ECC) is a special class of the new generation of high performance fiber reinforced cementitious composites (HPFRCC) featuring high ductility with relatively low fiber content. In this research, the mechanical performance of ECC beams will be investigated with respect to the effect of slag and aggregate size and amount, by employing nonlinear finite element method. The validity of the models was verified with the experimental results of the ECC beams under monotonic loading. Based on the numerical analysis method, nonlinear parametric study was then conducted to evaluate the influence of the ECC aggregate content (AC), ECC compressive strength ($f_{ECC}$), maximum aggregate size ($D_{max}$) and slag amount (${\phi}$) parameters on the flexural stress, deflection, load and strain of ECC beams. The simulation results indicated that when increase the slag and aggregate size and content no definite trend in flexural strength is observed and the ductility of ECC is negatively influenced by the increase of slag and aggregate size and content. Also, the ECC beams revealed enhancement in terms of flexural stress, strain, and midspan deflection when compared with the reference beam (microsilica MSC), where, the average improvement percentage of the specimens were 61.55%, 725%, and 879%, respectively. These results are quite similar to that of the experimental results, which provides that the finite element model is in accordance with the desirable flexural behaviour of the ECC beams. Furthermore, the proposed models can be used to predict the flexural behaviour of ECC beams with great accuracy.

• Journal of the Korean GEO-environmental Society
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• v.15 no.8
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• pp.51-58
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• 2014

In this research, the composite grounds including original clay and soil-cement were constructed for conducting uniaxial compression test. Strength and deformation properties were analysed using results of laboratory tests with variations of water content of clay, replacement ratio and cement content. Numerical simulation using 3D distinct element method was conducted for soil cement. For strength of composite ground that contains more than cement contents of 15 %, it is more effective to increase cement content than increase of replacement ratio. Strength and elastic modulus of composite ground could be predicted by regression equations using uniaxial compression strength of clay, cement content of soil cement and replacement ratio. For strength and elastic modulus of soil cement, which is most important things for predicting final strength and elastic modulus of composite ground, numerical simulation using the distinct element method adapted bonding model could be used to verify laboratory test, and predict strength and elastic modulus.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.54.1-54
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• 2000