• Journal of the Korean Geosynthetics Society
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• v.10 no.4
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• pp.113-121
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• 2011

River sand has generally used for the backfill material of underground power cables. The thermal resistivity of it has $150^{\circ}C$-cm/Watt in wet condition and more than double in dry condition. The final goal of this study is to find the backfill material which has a small change in thermal resistivity with various water contents, for example thermal resistivity is $50^{\circ}C$-cm/Watt and $100^{\circ}C$-cm/Watt in wet and dry conditions respectively. In this study it is presented that the comparison of thermal resistivity using stone powder, crush rock, weathered granite soil and Jumunjin sand as well as river sand in the needle method regarding water content, dry unit weight and particle size distribution. As a result, the thermal resistivity of a material is minimized when they have maximum dry unit weight at optimum moisture content and maximum density by appropriately mixing materials for particle size distribution. Therefore thermal resistivity characteristics should be considered two factors: one is the difference between natural dry condition and dry state after optimum moisture content, and the other is the difference between unit weight of raw material and maximum dry density.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1339-1347
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• 2008

The objective of this study was to determine the effects of green tea probiotics on growth performance, meat quality and immune response in finishing pigs, and to assess the possibility of substituting green tea probiotics for antibiotics in diets of finishing pigs. This green tea probiotics is made by mixing green tea powder and excipients (defatted rice bran and wheat bran) and fermenting the mixture with beneficial bacteria. A total of 90 crossbreed "Landrace$\times$Yorkshire" finishing pigs with an average body weight of $72.5{\pm}2.5kg$ were assigned to 5 dietary treatments in a completely randomized design. Each treatment had 3 replications with 6 pigs per replication. The five dietary treatments were control, antibiotic (0.003% chlortetracycline added) and 0.1, 0.5 and 1.0% of green tea probiotics. There were no significant differences in final body weight, daily weight gain, daily feed intake and feed conversion ratio in the green tea probiotics and antibiotic treatments (p>0.05). Crude protein content was significantly increased in the 0.1 and 1.0% green tea probiotics treatment groups (p<0.05) and there was no significant difference in crude fat content of the meat among the treatments. The TBA value of meat was significantly lowered with 0.5 and 1.0% green tea probiotics treatments compared to that of controls and statistically similar to the antibiotic treatment after 3 weeks of storage (p<0.05). The growth of spleen cells stimulated with Con A (0.1 and $1.0{\mu}g/ml$) was significantly increased with 1.0% green tea probiotics treatment compared to that of the control treatment (p<0.05). The growth of spleen cells stimulated with LPS (1.0, 3.0 and $10{\mu}g/ml$) was significantly increased in the 0.5% green tea probiotics group compared to the antibiotic group (p<0.05). In Con A ($1.0{\mu}g/ml$) medium, IL-6 production of spleen cells was significantly increased with 1.0% green tea probiotics treatment compared to that of the control (p<0.05). In LPS ($10.0{\mu}g/ml$) medium, TNF-${\alpha}$ production of spleen cells increased significantly in all green tea probiotics treatment groups compared to that of the control (p<0.05). Finally it can be summarized that addition of green tea probiotic has a positive effect similar to antibiotic and 0.5% is the suitable dietary supplementation dose for finishing pig production.

• Journal of the Korea Institute of Building Construction
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• v.18 no.5
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• pp.447-453
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• 2018

Since 1960, Korea the town center was developed intensively due to rapid industrial development. As a result of the development, the population was concentrated in urban areas and the green area was decreased. Due to the decrease of the green area, the circulation system of the rainwater was changed, hence the rainwater was not introduced into the groundwater., On the other hand, the water on the surface of the road was changed into the water for flowing to the river and evaporation. The changes in the water flow cause many problems, and the depletion of the groundwater does not create an environment in which microorganisms and plants can live. in Korea, permeable pavement construction is increased to solve these problems, but existing pavement blocks have many problems. The pores of the permeable block are clogged due to the accumulation of dust or whitening phenomenon, and the permeability is lost. In this study, the solution of the problems of existing permeable block were suggested by using polymer and artificial permeable pipe, and strength, permeability and service life are increased, The relationship between the substitution rate of the polymer and the mixing ratio of the artificial permeable pipe was analyzed.

• Resources Recycling
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• v.14 no.4 s.66
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• pp.22-33
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• 2005

Four sheet-shaped and one soft-shaped self-sealing waterproof materials were prepared to recycle some GRT(Ground Rubber Tires). Their physical properties were tested to consider characteristics of them. The self-sealing waterproof materials were consisted of GRT/super absorbent polymer(SAP)/binder and mold by a hot press after mixing with a batch-typed internal mixer. The average size of GRT particles was -40 mesh, SAPs were commercial GE-500F and poly(AM-SAS-AA) prepared in this work. Binders were PU. EVA, LDPE, SBR, and poly(2-EHA). And PU film was attached to improve the properties of waterproof materials. Characteristics of self-sealing waterproof materials consisted of by GRT/GE-500F/EV-600/PU film and GRT/GE-500F/SBR(vulcanization)/PU film among the developed self-sealing waterproof materials were similar to the commercial products. And properties of the soft-shaped self-sealing waterproof materials consisted of by GRT/GE-500F/Po1y(2-EHA) and CRT/Poly(AM-SAS-AA)/poly(2-EHA) were improved within from four times to twenty times compared to the one oi the commercial products.

• Journal of Aquaculture
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• v.10 no.2
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• pp.143-151
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• 1997

A six week feeding trial was conducted to determine the amount of fish meal analog (FMA) that can be replacing fish meal protein (FM) in Korean Rockfish. Seven experimental diets were formulated on isonitrogenous 52% crude protein and isocaloric basic 16.8KJ/g diet. Also, foreign commercial fish meal analog (CFMA) and attractants (ATT) were tested in this experiment. Percentage of the graded level of replacement of FM by FMA/CFMA on the basis of crude protein were as following : Diet 1, 100%FM ; Diet by 2, 60%FM : 40% CFMA ; Diet 3, 60%FM : 40$ CFMA+ATT ; Diet 4, 80%FM : 20%FMA ; Diet 5, 80%FM : 20% FMA+ATT ; Diet 6, 60%FM : 40%FMA+ATT ; Diet 7, 40%FM : 60% FMA+ATT. The FMA was made by mixing six animal protein source such as th blood meal, squid liver powder, meat and bond meal, leather meal, feather meal, poultry by-product and 3 essential amino acids (Met, Lys, Ile). Weight gain, feed efficiency, specific growth rate and protein efficiency ratio of fish fed diets 4, 5 and 6 were not significantly different (P>0.05) from those of fish fed the control (100% FM), while those of fish fed diets 2 and 3 were significantly lower (P<0.05) than those of fish fed the diet 6. There was no significant ATT effects in this study (P>0.05). Significant differences were found in hepatosomatic index, hemoglobin and condition factor. Therefore, these, results indicated that FMA can be used up to 40% as a substitute of fish meal protein in Korean Rockfish diets.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.2
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• pp.143-148
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• 2016

The aim of research is inducing the optimum proportion of fly ash(FA) and blast furnace slag(BS) for ternary cement. In this research, hence, the fundamental properties of mortar mixtures were evaluated depending on various proportion of FA and BS. The results of the experiment, within the scope of the study, obtained the following conclusions. Flow of the mixtures was increased with addition of binary supplementary cementitious material(SCM), and especially, portion of FA. The air content of the mixtures was increased with addition of binary SCMs, while it was decreased with increased FA content. In the case of unit mass, increased value was obtained due to the increased air content within 25 to 45% of binary SCM content, while it was increased within 65 to 100% of binary SCM up to only 20% of FA content and decreased more than 20% of FA because of the low density of FA. The setting time of the mixtures was delayed with addition of binary SCM and FA. In the case of compressive strength, at 91-day age, the highest value was obtained with 25 and 45% of binary SCM with the proportion of FA to BS of 40 to 60. Therefore, based on the compressive strength, it is considered that the binary SCM content of 25 and 45% with the proportion of FA to BS of 2 : 3 is the most favorable conditions in this research scope.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.255-262
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• 2020

Blended cement with fly ash and bottom ash from Circulating Fluidized Bed Combustor boiler(CFBC) burned at a low temperature, can be high heat of hydration and abnormal setting caused by higher volumn contents of Fe₂O₃, free-CaO, SO₃. In this study, the ground CFBC bottom ash powder mixed with blast furnace slag was used as substitute activator of gypsum and recycled iron slag was produced from mix and pulverized by ball mill to increase the recycling rate. The effect on compressive strength of cements with the mixture of original and hydrated bottom ash mixtures with BFS with small water, respectively, was analyzed, and it was found that the hydrated bottom ash activator was more effective in initial strength development. To improve the initial strength of blended cement, an activator mixed with a blast furnace slag and bottom ash mixing ratio of 5:95 and 10:90, respectively, the slag cement by about 6%, and it was analyzed to develop an initial strength similar to gypsum as a conventional activator.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.2
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• pp.283-299
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• 2017

The leakage of tunnel causes the long-term durability of the structures such as concrete lining to deteriorate. The cause of durability degradation can be various substances contained in groundwater such as chloride, sulphate, water, and gas. In this study, a series of test were carried out to determine the watertightness performance and the resistance to salt water of the spray-applied membrane used as non-structural rock support or as a waterproof material for tunnels. As a result, it was found that the penetration of water could occur in a specimen, and the reason was that the internal pores generated by the mixing of the liquid polymer and the powder material and the internal pores were connected by the water pressure. The tensile strength of the test specimens immersed in distilled water and saline water was found to be reduced to less than half of the tensile strength in normal condition. In addition, The elongation was measured to be higher in distilled water than in salt water. However, this result will require further investigation.

• Food Science and Preservation
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• v.24 no.8
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• pp.1188-1194
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• 2017

Gochujang, a traditional Korean food, is fermented by mixing red pepper powder, various grain, meju and salt. Changes in the kind of ingredients and fermentation method could increase health functionalities. In this study, in vivo anti-colitis effects of gochujang prepared with mixed grains, bamboo salt baked 3 times and meju starters on DSS-induced colitis in C57BL/6 mice were studied. We prepared gochujang prepared with mixed grains (MG), bamboo salt, and Aspergillus oryzae (A) and Baccillus subtilis (B) mixed starters (MG-AB) and gochujang prepared with MG, bamboo salt and A, B and Lactobacillus plantarum (L) mixed starters (MG-ABL). MG-AB and MG-ABL significantly increased body weight and colon length compared to the control (p<0.05). MG-ABL showed significantly decreased interleukin-6 (IL-6) expression in serum compared to the control and MG-AB group (p<0.05). MG-ABL also regulated mRNA and protein levels of pro-apoptotic Bcl-2-associated X protein (Bax) and anti-apoptotic B-cell lymphoma-2 (Bcl-2) in the mice colon tissue (p<0.05). Therefore, MG-ABL exhibited the increased anticolitis effects by inhibiting damage of colon tissue, probably by regulating a pro-inflammatory cytokine of IL-6 and regulated apoptosis related genes. These results indicated that gochujang changed with good ingredients and starters had colitis preventive effects and might be due to active compounds in mixed grain and bamboo salt, and produced by L during the fermentation of gochujang.

• Resources Recycling
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• v.19 no.1
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• pp.33-39
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• 2010

The spheric sintered body with $6{\pm}2mm$ diameter was manufactured in a rotary kiln at $1125^{\circ}C$/15 min using green body formed by pelletizing the batch powder composing of coal bottom ash produced from power plant and dredged soil by 70:30, wt%. And the physical properties of sintered body (BD) were analyzed to confirm the possibility for applying to an absorbent to restore a contaminated soil. The sintered body had a giant pore above 100 ${\mu}m$ and a fine pore below 10 ${\mu}m$, and bulk density was 1.4. Also its specific surface area, porosity and void proportion were $12.0m^2/g$, 30.1% and 38.2% respectively. The crushed body (BD-C), produced by crushing a BD specimen into an irregular shape with a aspect ratio of about 2, was similar to BD specimen at bulk density and pore size distribution. But it had superior values of specific surface area, porosity and void proportion compared with BD specimen owing to a decreased apparent volume due to conversion of closed pore existed at interior of BD to open pore during a crushing process. The IEP of sintered body occurred at about pH=5, so the optimum pH condition of reacting aqueous solution could be known before bonding a microbe to the sintered body. Hence, the optimum void proportion and porosity of an absorbent can be obtained by appropriate mixing a BD with BD-C from the base data calculated in this study.