• Korean Journal of Food Science and Technology
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• v.54 no.1
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• pp.94-102
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• 2022

Defatted soybean, larvae of brown mealworm (Tenebrio molitor), and powdered pupae of silkworm (Bombyx mori) were fermented in solid and liquid forms using Aspergillus oryzae and Bacillus subtilis. The protein degradation rate (NDR) through solid fermentation was the highest in the fermented soybean control sample (54.69±6.54%), followed by silkworm pupae (34.82±5.99%) and brown mealworm larvae (30.54±3.80%). When these edible insects were fermented in liquid form, solid extraction yield was 37.73-46.88%, and protein yield was 47.47-63.02%. NDR of fermented liquid form products increased to 58.90, 52.62, and 50.13% for soybean, brown mealworm larvae, and silkworm pupae, respectively. SDS-PAGE of the liquid fermented products confirmed that microbial fermentation decomposed higher-molecular-weight proteins into small polypeptides. In vitro digestibility of liquid forms of edible insects increased by 1.26 to 1.53 times after fermentation. The protein solubility, foaming ability, and foam stability of liquid-fermented edible insects all tended to increase through fermentation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.121-127
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• 2024

In this study, the applicability of replacing DG(Desulfurized Gypsum) from oil refinery with CCCMs(Carbon dioxide Conversion Capture Materials) as an ALC(Auto-claved LIghtweight Concrete) raw material was examined, and basic properties of ALC was measured. The main chemical components of DG and CCCMs were CaO and SO₃, and an increase in LOI(Loss of ignition) due to mineral carbonation reaction was verified. The crystalline phases of CCCMs were CaCO₃, CaSO₄, Ca(OH)₂, and CaSO₄·2H₂O. When DG, a raw material for ALC production, was replaced with CCCMs, foaming height, pore shape, absolute dry gravity, and compressive strength results measured similar for all binders. In addition, the formation of tobermorite which is main crystalline phase of ALC was shown for all specimens in microstructural analysis.

• Applied Chemistry for Engineering
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• v.35 no.3
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• pp.239-247
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• 2024

When a fire occurs on a naval vessel, rapid suppression and control are essential to mitigate potential human and material losses. Due to the nature of naval vessels, the risk of fuel fires is significant, making the use of aqueous film-forming foam (AFFF) crucial for effective fire suppression. Additionally, the possibility of fires occurring within compartments on the vessel must also be considered. Understanding the trajectory and application range of AFFF in such environments is vital, necessitating the design of firefighting systems tailored to compartmental conditions. In this study, an analysis was conducted to investigate the feasibility of applying spray height and angle for AFFF using computational fluid dynamics (CFD) methodology as a validation tool. Based on these findings, CFD analysis results applicable to compartment environments on naval vessels were obtained. These results will serve as the foundation for the development of firefighting systems capable of promptly responding to fuel fires within naval vessel compartments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.97-104
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• 2002

Protein hydrolysate was prepared as a natural flavor stock from the sharp toothed eel (Muraenesox cinereus) mince using com-mercially available proteolytic enzymes, Alcalase, Neutrase, Protamex, and Flavourzyme. A 6 hr hydrolysis of mince, to which water of the equal weight of the mince was added, with $2\%$ (w/w, protein weight) Elavourzyme at $50^{\circ}$ yielded a hydrolysate of the highest acceptability. Removing the access lipid in liquified hydrolysate (not dehydrated) after enzyme hydrolysis, five times repetitive extraction using n-hexane (liquified hydrolysate : n-hexane=4 : 1, v/v) was effective, resulting in less than $1\%$ lipid content of the dehydrated-hydrolysate. The amino acid composition of the hydrolysate (prepared with Flavourzyme) was similar to that of the starting material. Hydrolysis led to an increase in concentration of not only total free amino acid but also free amino acid such as serine, glutamic acid, alanine, and methionine responsible for umami taste, especially up to about 40 times for methionine. Major free amino acids in amount were leucine, phenylalanine, valine, alanine, and isoleucine and they comprised about half of the total free amino acids, Moisture adsorption, fat adsorption, emulsifying capacity, and foaming capacity of the hydrolysate were 870.1 $\pm$ $7.9\%$, 352.0$\pm$ $5.3\%$, 50.3 $\pm$ $1.2\%$, and $87.5\pm$ $2.5\%$, respectively, and solubility was 83$\~$$84\%$ at acid pH range of 2$\~$4.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.73-84
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• 2018

Recently, the importance of flame retardation treatment technology has been emphasized due to the increase in urban fire accidents and fire damage incidents caused by building exterior materials. Particularly, in the utilization of wood-based building materials, the flame retarding treatment technology is more importantly evaluated. An Intumescent system is one of the non-halogen flame retardant treatment technologies and is a system that realizes flame retardancy through foaming and carbonization layer formation. To apply the Intumescent system, composite material was prepared by using Ethylene vinyl acetate (EVA) as a matrix. To enhance the flame retardant properties of the Intumescent system, a nano-clay was applied together. Composite materials with Intumescent system and nano - clay technology were processed into sheet - like test specimens, and then a new structure of cross laminated timber with improved flame retardant properties was fabricated. In the evaluation of combustion characteristics of composite materials using Intumescent system, it was confirmed that the maximum heat emission was reduced efficiently. Depending on the structure attached to the surface, the CLT had two stages of combustion. Also, it was confirmed that the maximum calorific value decreased significantly during the deep burning process. These characteristics are expected to have a delayed combustion diffusion effect in the combustion process of CLT. In order to improve the performance, the flame retardation treatment technique for the surface veneer and the optimization technique of the application of the composite material are required. It is expected that it will be possible to develop a CLT structure with improved fire characteristics.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.256-262
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• 2011

Amine can undergo irreversible reactions by $O_{2}$ and high temperature in amine scrubbing process and these phenomena are called "degradation". Degradation causes not only a loss of valuable amine, but also operational problems such as foaming, corrosion and fouling. In this study, using various chemical absorbents(MEA; monoethanolamine, AMP; 2-amino-2-methyl-1-propanol, DAM; 1,8-diamino-p-menthane), we examined the following variable. I) loading ratio of $CO_{2}$ at $50^{\circ}C$ and $120^{\circ}C$, ii) concentration variation and initial degradation rate constant of absorbent in $CO_{2}$ and $CO_{2}/O_{2}$ system, and iii) effect of degradation by $O_{2}$. The $CO_{2}$ loading of 20 wt% DAM was 400% and 270% higher than that of 20 wt% MEA and AMP at 50, respectively and was the largest the difference of $CO_{2}$ loading between absorption $(50^{\circ}C)$ and regeneration $(120^{\circ}C)$ condition. The initial degradation rate constant of 20 wt% DAM was $2.254{\times}10^{-4}cycle^{-1}$ which was slower than that of MEA $(2.761{\times}10^{-4}cycle^{-1})$ and AMP $(2.461{\times}10^{-4}cycle^{-1})$ in $CO_{2}$ system. Also, it was increased 30% by $O_{2}$ that effects on the degradation by $O_{2}$ was less than 100% increased. these degradation reactions was able to identify by formation of new peak in GC and FT-IR spectrum analysis.

• Korean Journal of Agricultural Science
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• v.11 no.2
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• pp.223-232
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• 1984

The influences of some factors involved in removing glucose from egg white by the glucose oxidase system be fore drying were investigated. And the properties between foams prepared from raw and enzyme-treat ed egg white was compared. The results obtained we re summarized as follows; 1. The dianisidine method was found to be suitable for the measurement of egg white glucose in the range up to 100ug/ml. 2. The optimal pH of glucose oxidase activity on glucose was found to be a bout 5.0, and thats activity was most stable in the pH range of about 4.0~5.0 when that enzyme was treat ed for 30 minute at $50^{\circ}C$. 3. The optimal temperature for glucose oxidase reaction on glucose was found to be about $20^{\circ}C$, and that enzyme activity was s table up to $50^{\circ}C$. 4. The removing rate of glucose from egg white with glucose oxidase was influenced by the enzyme concentration, pH and oxygen addition, and the react ion time of the desugarization was about 10 hour sunder the conditions of 0.5% hydrogen peroxide, pH 7.0 and $26^{\circ}C$. 5. All of the each egg white treated with glucose oxidase, glucose oxidase+pancreatin, glucose oxidase+trypsin showed highly foaming ability than that of natural egg white(control), but thats foam stability, on the contrary, was reversed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.4
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• pp.345-352
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• 1985

To characterize the protein from arrowroot leaf, proteins were extracted and separated from arrowroot leaf, then its amino acid composition and functional properties were studied. Protein in arrowroot leaf was consisted of 18.5% albumin, 33.5% globulin, 34.0% glutelin, 6.2% protamine and 7.8% insoluble residues. The rates of precipitation of proteins which extracted with water, 1M NaCl, and 0.015N NaOH as a solvent were 84.7% (at pH 3.0), 76.4% (at pH 2.5) and 86.4% (at pH 4.0), respectively. The extracted proteins were separated up to about 90% by organic solvents such as ethanol and acetone at 80% concentration, Composition of arrowroot leaf protein concentrates were: $1{\sim}2%$ moisture, $59{\sim}67%$ protein, $4{\sim}8%$ ash and $5{\sim}6%$ (dialyzed concentrates) or $1{\sim}2%$ (acetone-treated ones) lipid. Main amino acids of the concentrates were aspartic acid, glutamic acid and glycine. Solubility profile of the concentrates according to pH was typical. The minimum solubility (below pH 5.0) of acetone extracted protein concentrates was lower than that of unextracted ones, whereas the reverse was true for pH value above this region. Bulk density, water and fat absorption of the concentrates were attributable to correlation to the treatment of acetone. And the bulk density of the concentrates was negatively correlative to both water and fat absorption. Emulsifying and foaming properties were not varied with the treatment of acetone.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.388-395
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• 2016

This paper explores the photocatalytic sensitivity of cement mortar incorporated with recycled $TiO_2$ from waste water sludge. Basically, $TiO_2$ cluster sank down slowly to the bottom of cement mortar specimen before setting and hardening process. This leads the mismatch of $TiO_2$ concentration on the top and the bottom faces of a specimen. This poorly dispersed $TiO_2$-cement mortar naturally exhibits poor NOx removal efficiency especially on the top of cementitious structure. In architectural engineering application such as building or housing structures, one can simply filp over from the bottom so that more $TiO_2$ concentrated surface can be placed outward into the air. However, in highway pavement case, this could not be applicable due to in-situ installation of concrete pavement. Hence, the dispersion of $TiO_2$ cluster inside the cementitous material is getting important issue onto road construction application. To elaborate this issue, according to our results, silica fume, high-ranged water reducer, viscosity agent, blast furnace slag were not enhanced much of dispersion characteristics of $TiO_2$ cluster. The combination of foaming agent and accelerator of hardening with viscosity agent and small grain size of fine aggregate may help the dispersion of $TiO_2$ inside cementitious materials. Even though the enhanced dispersion were applied to the specimen, NOx removal efficiency doest not change much for the top surface of the specimen. This concurrently affected by the presence of tiny air voids and the dispersion of $TiO_2$ in that these voids could easily adsorbed NOx gas with the aid of large surface area.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.347-355
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• 2021

During the earthquake, for multi-story structure, if the first floor is soft, the deformation will concentrate on that floor causing a serious damage to the column members which might leads to the collapse of the whole structure like Piloti structure during the Pohang earthquake in Korea. According to the 2016 National Disaster Management Research Institute's "Investigation of Seismic Reinforcement and Cost Analysis of Domestic Non-seismic Buildings", the rate of seismic resistance of private reinforced concrete buildings was 38.3 %. Among them, it was reported that the seismic-resistance ratio of the two to five-story structures was less than 50 %. Accordingly, the government is trying to improve the seismic rate through support projects, but the conventional seismic reinforcement methods are still expensive, and emergency construction is difficult. Therefore, in this study, the field applicability was evaluated by improving the reinforcement method using Velcro, which was developed through the research project of the Ministry of Land, Transport and Maritime Affairs in 2014. In order to improve the performance of the Velcro reinforcement method, introducing the initial tension of Velcro using high foaming rigid urethane filling between the Velcro and concrete of the columns was applied. Additionally, an experiment was conducted to evaluate the ductility of Velcro specimen from the concrete confinement effect. As a result, the ductility of the Velcro specimen was improved compare to Normal specimen. However, the energy dissipation capacity of VELCRO2 is better than VELCRO1, yet the maximum ductility of those two specimens did not show a significant difference. Therefore, the improvement of the internal filler material is still needed to have a better maximum ductility.