• The Korean Journal of Food And Nutrition
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• v.35 no.6
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• pp.417-425
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• 2022

The purpose of this study was to investigate the antioxidant activities, quality characteristics, and storage stability of perilla oil mayonnaise (PM) with different levels of onion powder (OP) from 0 to 3%. As the amount of OP increased, the L, a, and b values increased, but pH decreased (p<0.05). The addition of OP raised viscosity (p<0.05). The addition of OP to PM proportionally increased the total phenolic content, and antioxidant activities as measured by DPPH and ABTS radical scavenging activity, and FRAP assay. When compared to PM without OP, PM that contained OP had a peroxide value that was almost 1.94 times lower. The emulsion stability was between 97.62 to 94.92% in the PM without OP and PM with OP groups was 99.60% for 12 weeks. This study showed that the inclusion of OP in PM has the potential to inprove its quality, antioxidant activities, and storage stability.

• Explosives and Blasting
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• v.40 no.4
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• pp.1-14
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• 2022

To review the appropriateness of current regulations on the simple explosive storage facility, the effects of internal explosion on the structural stability of the standard storage facility were analyzed by means of both FEM analyses and field experiments. As a result, it was found that the explosion-proof performance of the existing storage structure was not sufficient for 15 kg of emulsion-type explosive. Thus, an alternative method of splitting explosives was tested by conducting sympathetic detonation experiments. This method worked properly as expected, and the proper amount of splitted explosive was determined according to the test results. In addition, a storage structure with open ceiling was found to be very effective because explosion pressure was released so rapidly that the damage of the facility could be reduced significantly. Hence, such a structural pattern was proposed as a new design scheme for simple explosive storage facility.

• Advances in concrete construction
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• v.15 no.6
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• pp.419-430
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• 2023

In this study, the effect of two types of aggregates (fly ash aggregate and shale aggregate) on the density, strength, and durability of preplaced lightweight aggregate concrete (PLWAC) was studied. The results showed that the 7 - 28 days strength of concrete prepared with fly ash aggregates (high water absorption rate) significantly increased, which could attribute to the long-term water release of fly ash aggregates by the refined pore structure. In contrast, the strength increase of concrete prepared with shale aggregates (low water absorption rate) is not apparent. Although PLWAC prepared with fly ash aggregates has a lower density and higher strength (56.8 MPa @ 1600 kg/m³), the chloride diffusion coefficient is relatively high, which could attribute to the diffusion paths established by connected porous aggregates and the negative over-curing effect. Compared to the control group, the partial replacement of fly ash aggregates (30%) with asphalt emulsion (20% solid content) coated aggregates can reduce the chloride diffusion coefficient of concrete by 53.6% while increasing the peak load obtained in a three-point bending test by 107.3%, fracture energy by 30.3% and characteristic length by 103.5%. The improvement in concrete performance could be attributed to the reduction in the water absorption rate of aggregates and increased energy absorption by polymer during crack propagation.

• Clean Technology
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• v.16 no.2
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• pp.73-79
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• 2010

Vinyl acetate(VAc) was dispersion-polymerized using supercritical carbon dioxide that has many environmental advantages. To get poly(vinyl acetate) (PVAc) of larger molecular weights from conventional emulsion polymerization, VAc was polymerized at temperatures between 333.15 and 343.15 K and pressures between 20 and 40 MPa with initiator (0.5 ~ 5% of monomer) and silicone-based stabilizer (1 ~ 10% of monomer) for 2 ~ 50 hr. The resulting PVAc was analyzed to see the variations in the yield and the molecular weight. The final product of this research, PVA (poly(vinyl alcohol)), was prepared from PVAc by saponification. The effect of saponification conditions on the yield and the molecular weight of polymer were also studied.

• Resources Recycling
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• v.32 no.2
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• pp.33-42
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• 2023

Metal emulsions have been studied for several decades as a method of increasing the efficiency of the steelmaking process. This study was performed using a water model, observable at room temperature, to compensate for the disadvantages of the high-temperature experiment, the results of which are difficult to observe visually. As a substitute for metal-in-slag emulsions, experiments were conducted by dropping distilled water into silicone oil and comparing the results with the results of a calculation by momentum balance equations. The descending velocity of the water droplet decreased as the diameter of the droplet and viscosity of the fluid (silicon oil) increased. To simulate the descending velocity of a water droplet in silicon oil under stirring conditions, the flow rate of the fluid (silicon oil) was measured by particle image velocimetry (PIV) methods. The calculation of the descending velocity of the water droplet was in good agreement with the measured values, with and without stirring a viscous silicone oil.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.3
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• pp.601-607
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• 2024

The discharge of oily wastewater into water bodies and soil poses a serious hazard to the environment and public health. Various conventional techniques have been employed to treat oil-water mixtures and emulsions; Unfortunately, these approaches are frequently expensive, time-consuming, and unsatisfactory outcomes. Porous materials and adsorbents are commonly used for purification, but their use is limited by low separation efficiencies and the risk of secondary contamination. Recent advancements in nanotechnology have driven the development of innovative materials and technologies for oil-contaminated wastewater treatment. Nanomaterials can offer enhanced oil-water separation properties due to their high surface area and tunable surface chemistry. The fabrication of nanofiber membranes with precise pore sizes and surface properties can further improve separation efficiency. Notably, novel technologies have emerged utilizing nanomaterials with special surface wetting properties, such as superhydrophobicity, to selectively separate oil from oil-water mixtures or emulsions. These special wetting surfaces are promising for high-efficiency oil separation in emulsions and allow the use of materials with relatively large pores, enhancing throughput and separation efficiency. In this study, we introduce a facile and scalable method for fabrication of superhydrophobic-superoleophilic felt fabrics for oil/water mixture and emulsion separation. AlN nanopowders are hydrolyzed to create the desired microstructures, which firmly adhere to the fabric surface without the need for a binder resin, enabling specialized wetting properties. This approach is applicable regardless of the material's size and shape, enabling efficient separation of oil and water from oil-water mixtures and emulsions. The oil-water separation materials proposed in this study exhibit low cost, high scalability, and efficiency, demonstrating their potential for broad industrial applications.

• IMMUNE NETWORK
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• v.23 no.2
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• pp.16.1-16.19
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• 2023

Bacillus Calmette-Guerin (BCG) vaccine is the only licensed vaccine for tuberculosis (TB) prevention. Previously, our group demonstrated the vaccine potential of Rv0351 and Rv3628 against Mycobacterium tuberculosis (Mtb) infection by directing Th1-biased CD4⁺ T cells co-expressing IFN-γ, TNF-α, and IL-2 in the lungs. Here, we assessed immunogenicity and vaccine potential of the combined Ags (Rv0351/Rv3628) formulated in different adjuvants as subunit booster in BCG-primed mice against hypervirulent clinical Mtb strain K (Mtb K). Compared to BCG-only or subunit-only vaccine, BCG prime and subunit boost regimen exhibited significantly enhanced Th1 response. Next, we evaluated the immunogenicity to the combined Ags when formulated with four different types of monophosphoryl lipid A (MPL)-based adjuvants: 1) dimethyldioctadecylammonium bromide (DDA), MPL, and trehalose dicorynomycolate (TDM) in liposome form (DMT), 2) MPL and Poly I:C in liposome form (MP), 3) MPL, Poly I:C, and QS21 in liposome form (MPQ), and 4) MPL and Poly I:C in squalene emulsion form (MPS). MPQ and MPS displayed greater adjuvancity in Th1 induction than DMT or MP did. Especially, BCG prime and subunit-MPS boost regimen significantly reduced the bacterial loads and pulmonary inflammation against Mtb K infection when compared to BCG-only vaccine at a chronic stage of TB disease. Collectively, our findings highlighted the importance of adjuvant components and formulation to induce the enhanced protection with an optimal Th1 response.

• Journal of the Korean Society for Heat Treatment
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• v.37 no.1
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• pp.16-22
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• 2024

The conventional degreasing process involves removing oil and contaminants at temperatures above 80℃, resulting in excessive energy consumption, increased process costs, and environmental issues. In this study, we aimed to find the optimal degreasing conditions for the pre-treatment process of electro-galvanizing cold-rolled steel sheets, conducted efficiently at room temperature without the need for a separate heating device. To achieve this, we developed a room temperature degreasing solution and a brush-type degreasing tool, aiming to reduce energy consumption and normalize the decrease in degreasing efficiency caused by temperature reduction. Alkaline degreasing solution were prepared using KOH, SiO₂, NaOH, Na₂CO₃, and Sodium Lauryl Sulfate, with KOH and NaOH as the main components. To enhance the degreasing performance at room temperature, we manufactured additives including sodium oleate, sodium stearate, sodium palmitate, sodium lauryl sulfate, ammonium lauryl sulfate, silicone emulsion, and EDTA-Na. Room temperature additives were added to the alkaline degreasing solution in quantities ranging from 0.1 to 20 wt.%, and the uniformity of degreasing and the adhesion of the galvanized layer were evaluated through Dyne Test, T-bending Test, OM, SEM, and EDS analyses. The results indicated that the optimal degreasing solution composition consisted of NaOH (30 g/L), Na₂CO₃ (30 g/L), SLS (6 g/L), and room temperature additives (≤1 wt%).

• Animal Bioscience
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• v.37 no.7
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• pp.1277-1288
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• 2024

Objective: This study was aimed to investigate the effect of fresh and dried hydrolyzed Cordyceps militaris (CM) mushroom with proteolytic enzymes; bromelain (CMB), flavorzyme (CMF), and mixture of bromelain: flavorzyme (CMBF) on quality properties of spent hen chicken. Methods: Mushroom extract (CME) were combined with three proteolytic enzyme mixtures that had different peptidase activities; stem bromelain (CMB), flavorzyme (CMF), and mixture of stem bromelain:flavorzyme (CMBF) at (1:1). The effect of these hydrolysates was investigated on spent hen breast meat via dipping marination. Results: Hydrolyzation positively alters functional properties of CM protease. in which bromelain hydrolyzed group (CMB) displayed the highest proteolytic activity at 4.57 unit/mL. The antioxidant activity had a significant increment from 5.32% in CME to 61.79% in CMB. A significantly higher emulsion stability index and emulsification activity index compared to CME were another result from hydrolyzation (p<0.05). Texture properties along with the shear force value and myofibrillar fragmentation index were notably improved under CMB and CMBF in fresh condition. Marination with CM mushroom protease that was previously hydrolyzed with enzymes was proven to also increase the nucleotide compounds, indicated by higher adenosine 5'-monophosphate (AMP) and inosine 5'-monophosphate (IMP) in hydrolysate groups (p<0.05). The concentration of both total and insoluble collagen remained unchanged, meaning less effect from CM protease. Conclusion: This study suggested the hydrolyzation of CM protease with bromelain or a mixture of bromelain:flavourzyme to significantly improve functional properties of protease and escalate the taste-related nucleotide compounds and texture profiles from spent hen breast meat.

• Applied Chemistry for Engineering
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• v.35 no.4
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• pp.329-334
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• 2024

To improve the UV absorbance and emulsion stability of sunscreen creams prepared using refined seabuckton oil, experimental conditions were designed utilizing the central composite design model-response surface methodology (CCD-RSM). The amount of surfactant, emulsification time, and thickener amount were chosen as independent variables, and the experiment was carried out after the reaction values of ESI, MDS, and UV absorbance at 290 nm were determined. The main effect and interaction effect, which have the most influence on the response value, were analyzed through the F-value and P-value of the regression equation coefficient calculated through RSM, and the statistical significance of the coefficient was evaluated through the P-value. The optimal emulsification conditions using RSM were calculated as follows: amount of surfactant (4.39 wt%), emulsification time (25.42 min), and amount of thickener (1.24 wt%). At these conditions, the reaction value was calculated as ESI (98.5%), MDS (32.9 nm), and UV absorbance (2.73). As a result of conducting an actual experiment under the calculated optimal conditions, the average error rate was measured as ± 2.7%