• Journal of the Korea Concrete Institute
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• v.25 no.1
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• pp.73-80
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• 2013

Polymer cement slurry (PCS) made from organic polymer dispersion and cement has good adhesion to steel, waterproofness and acid resistance due to being of polymer films formed in cement slurry. The purpose of this study is to evaluate the mix design conditions at early curing age of PCS-coating material effected on improvement in bond strength of coated rebar. The test pieces are prepared with two types of polymer dispersions such as St/BA and EVA, four polymer-cement ratios, two types of cement, four coating thicknesses and three curing ages, and tested for the bond strength test. From the test results, in general, bond strength of PCS-coated rebar is better than that of uncoated rebar and epoxy-coated rebar. It is also high bond strength at curing ages of 7-day or less, and coating thicknesses of $75{\mu}m$ and $100{\mu}m$. The maximum bond strength of PCS-coated rebar at curing age of 3-hour is almost same as that of curing age of 1-day and 7-day. The maximum bond strength of PCS-coated rebar with ultra high-early strength cement and St/BA at polymer-cement ratio of 80%, and coating thickness of $100{\mu}m$ is about 1.52 and 1.58 times respectively, the strength of uncoated rebar and epoxy-coated rebar. It is apparent that the curing age, coating thickness, type of polymer and cement are very important factors to improve the bond strength of PCS-coated rebar to cement concrete. We can have basic information that PCS-coated rebar with curing age at 3-hour and coating thickness of $100{\mu}m$ can replace epoxy-coated rebar.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.9
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• pp.1278-1284
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• 2000

An experiment was performed to evaluate different methods for preserving shrimp by-products and to determine their chemical composition. In the first experiment three ratios of shrimp by-product (SBP) to molasses (6:1, 4:1 and 3:1, wet weight), and to cassava root meal (3:1, 2:1 and 1:1, wet weight of shrimp by-product and air-dry weight of cassava root meal) were investigated. The pH of the SBP ensiled with molasses at a ratio of 3:1, and with cassava root meal at a ratio of 1:1, decreased during the first week to below 4.5 and remained low up to day 56 of ensiling, whereas the pH of the mixtures with higher ratios of SBP remained above 7.0, and the material deteriorated rapidly. The dry matter decreased initially in all treatments but then increased slightly from day 28 in the treatment where shrimp by-product was ensiled with cassava root meal at a ratio of 1:1. The crude protein (CP) and ammonia-N $(NH_3-N)$ contents of the preserved shrimp by-product material ensiled with molasses at a ratio of 3:1 increased significantly one week after ensiling. The CP content then remained constant, while the $NH_3-N$ concentration continued to increase up to 56 days after ensiling. When SBP was ensiled with cassava root meal at a ratio of 1:1 the CP content of the silage increased significantly up to 21 days after ensiling and then decreased back to the original level after 56 days, whereas $NH_3-N$ increased markedly up to 14 days and then remained fairly constant up to 56 days. However, the $NH_3-N$ content was significantly higher when SBP was ensiled with cassava root meal than with molasses. A balance experiment was carried out, arranged as a double Latin-square and including 6 F1 (Large White ${\times}$ Mong Cai) castrates fed randomly one of three diets based on cassava root meal, rice bran, and fish meal (FM) or shrimp by-product ensiled with molasses (SBEMO) or with cassava root meal (SBECA) as the main protein source. Apparent organic matter and CP digestibilities were significantly (p<0.001) higher for the fish meal diet than for the two shrimp by-product diets, although CP digestibility in SBEMO and SBECA was similar (p>0.05). N-retention was significantly higher for the fish meal diet than for the SBEMO diet, which in turn was significantly higher than for the SBECA diet (p<0.01). It can be concluded that shrimp by-product can be preserved by ensiling with molasses at a ratio of 3:1 or with cassava root meal at a ratio of 1:1. Nutrient digestibility and N-retention of diets based on these shrimp by-product silages were lower than for similar diets based on fish meal, probably due to their high chitin content and inferior amino acid balance.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.111-116
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• 2020

Total polyphenol contents, flavonoid contents, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activities of ethanol extracts of 20 herbal plants (sage, turmeric, mace, bayleaf, fenugreek, oregano, blackpepper, whitepepper, clove, marjoram, cinnamon, coriander, basil, dillseed, mustard, cadamon, thyme, celery, rosemary, cumin) were analyzed for the screening of high flavonoid-containing plant resource. Thyme extract, showing the highest flavonoid content and a high degree of antioxidant activity, was selected as a bioactive cosmetic material. The total polyphenols and flavonoids contents of thyme extracts were measured as 6.90 mg chlorogenic acid equivalent (CAE)/100 g and 1.71 mg naringin equivalent (NE)/100 g, respectively, and DPPH radical scavenging activities was 90%. Among the tested organic solvents, hexane gave the highest extraction yield. Thus hexane was selected as the most suitable solvent for the extraction of thyme. Response surface method was used to obtain optimized extraction conditions for thyme: reaction temperature of 35.9 ℃, raw material to hexane ratio of 1.63:25 (w/v), and reaction time of 192 min. These predicted extraction conditions was validated by a total flavonoid extraction experiment showing a value equivalent to 96.3% of the predicted total flavonoid content. It is expected that the optimized solvent extraction conditions could be used for the production of flavonoid using thyme.

• Analytical Science and Technology
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• v.17 no.6
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• pp.481-488
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• 2004

Solvent extraction of Ni(II) into a chloroform by using salen[N,N'-Bis (salicylidene)-ethylenediamine] as a ligand has been studied. Salen was synthesized from ethylenediamine and salicylaldehyde by simple condensation reaction in an ethanol. Salen formed a 1 : 1 complex with Ni(II) and its extraction constant was $10^{5.12}$. For the determination of Ni(II) in sea water samples, some experimental conditions such as pH of solution, amount of salen, acid type and concentration for back extraction, extraction time, and influence of foreign ions were optimized by using a synthetic sea water. The sea water of which the composition was similar to a natural sea water was synthesized in this laboratory. Trace Ni(II) was extracted into the chloroform in the weak basic solution above pH 8. And the nickel could be quantitatively extracted with the concentration of salen higher than $1.2{\times}10^{-4}mol/L$. This concentration was more than 180 times of Ni(II) in the solution with a mole ratio. Real samples of Korean coastal sea water were analyzed under optimized conditions. Even though Ni(II) was not detected in these samples. Recoveries more than 98% were obtained in the samples which 40 ng/mL of Ni(II) was spiked. And detection limit of proposed method was 1.3 ng/mL. From these results, it could be known that salen of this type would be applied for the determination of trace metals as an organic chelating reagent.

• Journal of Animal Environmental Science
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• v.15 no.2
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• pp.155-160
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• 2009

This study was carried out to investigate the feasibility of Multi Process of Aerobic Digestion (MPAD) for recycling of swine manure slurry as fertilizer. MPAD consisted of three kinds of difference process which are thermophilic aerobic oxidation (TAO) system, lime solidification system, and reverse osmosis (R/O) membrane system. TAO system was studied well previously for decade. The chemical composition of the lime-treated solid fertilizer was as like that organic matter 17.4%, moisture 34.1%, N 0.9%, P 1.7%, K 0.3%, Ca 12.7%, and which was expected to be useful as acid soil amendment material. The concentrated liquid material produced by R/O membrane system was also expected as a good fertilizer for crops production and soil fertility improvement.

• Applied Chemistry for Engineering
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• v.30 no.3
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• pp.384-388
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• 2019

In winter season, the snow and ice accretion on the bottom of the high speed railway rolling stock and boogie part has fallen at a high speed from the ballast section (gravel section for the transmission of the rolling stock load received by sleepers and fixing sleepers), causing the gravel to be scattered, thereby damaging the railway rolling stock structures and facilities. In order to solve these problems, the gravel scattering prevention net, manual de-icing, and movable hot air machine were used, but their efficiency was low. For the more efficient de-icing than ever before, an optimum material for de-icing fluid for high speed railway rolling stock was developed by evaluating the ice melting capacity, kinematic viscosity, evaporation of the material used as a chemical de-icing fluid. Four kinds of organic acid salts (sodium formate, sodium acetate, potassium formate and potassium acetate) and two different alcohols (propylene glycol, glycerol) were used as evaluation materials. Potassium formate, potassium acetate, and propylene glycol had similar ice melting capacities in the indoor test, but the propylene glycol showed the best ice melting capacity in spraying the system simulation test. This is because the kinematic viscosity of propylene glycol was 2.989029 St, which is higher than those of other materials therefore, it could stay longer on the ice and de-icing. In addition, potassium formate and potassium acetate were difficult to be used since the crystals precipitated and adversely affected the appearance of the rolling stock. The propylene glycol is the most optimum as an de-icing fluid for the high speed railway rolling stock.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.301-307
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• 2010

This study evaluates quality of Nuruk, which is a source material of Takju, collected in Daegu and Gyeongbuk and investigates fermentation characteristics of Takju made of it. Totally 7 types of Nuruk were examined and their pH and titratable acidity were 5.4~5.9 and around 0.1%, respectively. Saccharifying activity was high in D, F, G, A and E Nuruk by recording over 300 mg%. Lactic acid bacteria count was the highest in G Nuruk with $3.78\times10^8$ and yeast and total microbe count recorded the highest levels, $3.78\times10^8$ and $3.47\times10^8$, respectively in B Nuruk. When quality characteristics of Takju made of each type of Nuruk were compared, alcohol content was the highest in G Nuruk by recording 19.0% and titratable acidity was 0.44~0.86% in all samples. Hunter's color, brown color and turbidity showed different levels according to types of Nuruk and all lactic acid bacteria, yeast and total microbe counts were the highest in A and E Nuruk. For alcohol components, E and G Nuruk showed high fusel oil content levels and methanol and fusel oil contents of all samples were suitable as standards, respectively. The total organic acid content was the highest in B Nuruk at about 4,000 mg% and it was 2,000 mg% and around 1,000 mg% in A, E, F and G Nuruk and C and D Nuruk, respectively. The content of total free amino acid was the highest in B Nuruk at 3,676 mg% and it was observed to be 1,890, 1,676 and 1,531 mg% in G, E and C Nuruk in that order, respectively. Sensory preference of subjects in their 20s was high overall in G and C Nuruk and that of those in their 40s was high in F and C Nuruk. From all of these results, the types of Nuruk largely affected quality and components of Takju and an appropriate method to consider useful purpose is needed.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.77-84
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• 1976

The preservation efficiency, quality and utilization of silage from 3 species of pumpkins (Mammoth pumpkin, Queensland blue pumpkin, Korean pumpkin) without and with 10, and 20% wheat bran additive were studied in this experiment. Silages were analysised and tested the chemical composition, pH and quality of silages between at 40-60 days and egg performance were carried out with mammoth pumpkin silage without additive. The results were summaried as follows. 1. The losses of all silage ware lower and similar as about 15% at 6 monthes following after silage-making but all raw pumpkins were spoilaged during the winter storaging. 2. The moisture content of silages were higher as about 97% in mammoth pumpkin silage, 94% in Queensland pumpkin silage and 91% in Korean pumpkin silage without additive and all nutrient content of silage without and with additive were depended on its content of raw silage material of pumpkins and wheat bran. The contents of moisture and N-free extract were slightly decrease but not significantly difference during the silaging and other contents were not so much changed. 3. Good quality of silage were made from all pumpkins with and without additive. Organic acid contents were 2.09-2.93% of lactic acid, 0.68-1.71% of acetic acid and 0% of butyric acid and it was pH 3.8-4.0 in silages. 4. Feed intakes, egg production and quality of egg were showed good result in 5.0 and 7.5% silage feeding group as D.M. base for egg performance. (P<0.01) 5. It was concluded that good quality of silage were made from pumpkins with and without wheat bran additive and it was suggested that poor quality feedstuff may be improved it feeding value by extended palatability with pumpkin additive silage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.248-253
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• 2017

This study was conducted to analyze the anti-oxidant activity of green juice containing barley sprouts. The specimens used in the experiments were supplied byCSJ company located in Jincheon-gun, Chungbuk province. Polyphenol and flavonoid was detected in Huttuynia cordata Thunb fermentation sprout juiceat $1.075{\pm}0.174mg/mL$ and $2.736{\pm}0.187\;quercetin\;mg/mL$, in organic dandelion at $1.048{\pm}0.173mg/mL$ and $2.685{\pm}0.245\;quercetin\;mg/mL$, kan andRakat $1.013{\pm}0.083mg/mL$ and $3.624{\pm}0.237\;quercetin\;mg/mL$, broccoli blending juice at $1.494{\pm}0.255mg/mL$ and $3.826{\pm}0.286\;quercetin\;mg/mL$, and barley sprouts at $1.043{\pm}0.220mg/mL$ and $1.990{\pm}0.223\;quercetin\;mg/mL$, respectively.Antioxidant activity testing revealed the electron donating ability of Huttuynia cordata Thunb fermentation sprout juice for DPPH was 81.97%. Moreover, the free radical scavenging ability measured by ABTS assay showed that the activity was increased in the order of broccoli blending juice, Huttuynia cordata Thunb fermentation sprout juice, organic dandelion, 'kan andRak', barley sprout, and thatthe effects were similar to those of ascorbic acid at $100{\mu}g/mL$. Statistical processing is using SPSS 24, analysis of distributed layout and Duncan's multiple range (p<0.05). Therefore, the use of functional assistance material of products in the future indicates that it is worth a healthy functional drink.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.777-784
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• 2016

This study aimed to evaluate the quality characteristics of wheat-Makgeolli (WM), a traditional Korean cereal alcoholic drink, using three varieties of wheat, namely Jokyoung (JK), Baegjoong (BJ) and Keumkang (KK). Samples of WM brewed from 100%, 85% and 70% milling rates of the three Korean wheat cultivars were analyzed for alcohol, pH, coloring degree, total acids, soluble solid, free sugars, and organic acids. As the milling rates in wheat decreased, total sugar content in WM increased while the pH of all samples decreased. The WM exhibited 0.95~1.27% in acidity, $10.2{\sim}12.5^{\circ}Brix$ in total sugar, and 14~16% in alcohol content. The most organic acids in WM was lactic acid, ranging in all the samples from 85.3~650.3 mg%. The results showed that BJ under a 70% milling rate had the highest reducing sugar contents and 15.97% in alcohol content. The carbohydrate content increased with the milling rate of wheat. Resulting in a positive correlation between carbohydrate content of wheat and total acids, reducing sugars (p<0.001), and alcohol content (p<0.05) in WM. Total sugar content is positively correlated with alcohol and reducing sugar content (p<0.001). Considering the yield, the milling rates will be adjusted to raw material prices.