• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.3
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• pp.403-407
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• 2005

A study was conducted to evaluate the effect of substitution of the flour with Lycium chinense powder on the characteristics of yellow layer cake. Physical properties including specific gravity, specific volume, cake index and color were measured. Also, the hardness change during 6 storage days at 22℃ were measured. Even though the specific gravity of batter decreased significantly with respective addition of 12%, 16% and 20% Lycium chinense powder, the specific volume of cakes did not show difference except the case of 20% addition. The addition of Lycium chinense powder did not influence on cakes' appearance negatively except that of 20% cake. The crust became darker as the level of Lycium chinense powder increased. The crumb color turned into dark orange with addition of Lycium chinense powder, and the intensity became stronger as the level of Lycium chinense powder increased. Both 4% and 8% Lycium chinense powder cakes were scored as same as control in moistness and softness. And they were favored as much as control.

• Journal of Surface Science and Engineering
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• v.45 no.3
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• pp.111-116
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• 2012

Oblique angle deposition (OAD) is a physical vapor deposition method which utilizes non-normal angles between the substrate and the vaporizing source. It has been known that tilting the substrate changes the properties of the film deposited on it, which was thought to be a result of morphological change of the film. In this study, OAD has been applied to prepare single and multilayer Al films by magnetron sputtering. The magnetron sputtering source of 4 inch diameter was used to deposit the films. Al films have been deposited on Si wafers and cold-rolled steel sheets. The multilayer films were prepared by changing the tilting angle upside down at each layer interval, which means that when the first layer was deposited at an angle of $+45^{\circ}$, the second layer was deposited at an angle of $-45^{\circ}$, and vice versa. The microstructure, surface roughness and reflectance of the films were investigated using a scanning electron microscope, a surface profiler and a spectrophotometer, respectively. The corrosion resistance was measured and compared using the salt spray test. The single layer film prepared at an oblique angle of $60^{\circ}$ prepared at other angles. However, for the multilayer films, the film prepared at an oblique angle of $45^{\circ}$ showed the most compact and featureless structure. The multilayer films were found to exhibit higher corrosion resistance than the single layer films.

• Journal of Hydrogen and New Energy
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• v.34 no.3
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• pp.283-291
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• 2023

The physical properties were analyzed for four gas diffusion layers, and gas diffusion electrodes (GDEs) for the cathode of high-temperature polymer electrolyte membrane fuel cell were fabricated through bar coating with three binder to carbon (B/C) ratios. Among them, The GDE from JNT30-A6P showed a significant change in secondary pore volume at a B/C ratio of 0.31, which had the largest pore volume among all GDEs. In the polarization curve, JNT30-A6P GDE showed the best membrane electrode assembly (MEA) performance with a peak power density of 384 mW/cm² at a a B/C ratio of 0.31. From the distribution of relaxation time analysis, the peak 1 corresponding to mass transfer resistance of oxygen reduction reaction (ORR) was significantly reduced in the JNT30-A6P GDE. This is the result that when the binder content decreased, the volume of the secondary pore increased, and the mass transfer resistance of ORR decreased, which played an essential role in the MEA performance.

• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.99-116
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• 1999

Wooden hollow core flush door is one of the main products of furniture manufacturing and woodworking industries. Warping and buckling of the door is serious problems in service. It has been reported that warping is caused by differences of physical and mechanical properties of face and back of skin panel for the door. This study focused on the prediction of warping and buckling phenomena of the flush door using numerical models. Predictions from the models were also compared with the experimental results obtained from the doors with plywood and hardboard skin panels under various environmental conditions. Three elastic constitutive models, so called elastic beam model, plate model and plate-buckling model, were employed to predict warping and buckling of the doors. It was observed that warping was more pronounced in low humidity condition than in high humidity condition. The plate model considering Poisson's effect was reliable to predict warping more closely than elastic beam model in low humidity condition. The plate-buckling model, however, was the best in the fitting of predictions with the experimental results under high humidity condition because buckling was developed in face and back of skin panel at that condition.

• Journal of the Korean Chemical Society
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• v.37 no.10
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• pp.867-873
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• 1993

Influences of crystallization time and $H_2O/Al_2O_3$ ratio of the reaction mixtures on the synthesis of AlPO$_4$-5 molecular sieve have been studied by X-ray powder diffraction, nitrogen adsorption, scanning electron microscope (SEM), and solid state $^{27}$Al magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. The degree of crystallinity of AlPO$_4$-5 follows a sigmoid pattem as crystallization time increases. The induction period is shorter than 1 h when the crystallization process is carried out at 150$^{\circ}$C. The conversion of reactants to product, AlPO$_4$-5, can be clearly observed, and all of the determined physical properties change abruptly after about 2 h. It is found that increase in $H_2O/Al_2O_3$ ratio of the reaction mixtures not only changes the crystal morphology from aggregates to hexagonal single crystals, but also results in the formation of longer AlPO$_4$-5 crystals.

• Fisheries and Aquatic Sciences
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• v.22 no.7
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• pp.15.1-15.8
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• 2019

Corexit 9500 is a dispersant commercially available in Nigeria that is used to change the inherent chemical and physical properties of oil, thereby changing the oil's transport and fate with potential effects on the environment. The aim of this study was to assess the biochemical (enzymes and electrolyte) toxicity of Corexit 9500 dispersant on the gills, liver and kidney of juveniles of Clarias gariepinus after exposure for 21 days. One hundred sixty fish were used without gender consideration. Range-finding tests were conducted over a 96-h period after acclimatisation of the test organisms in the laboratory. The test organisms (10/treatment) were exposed to Corexit 9500 in the following concentrations-0.00, 0.0125, 0.025 and 0.05 ml/l in triplicate. Twenty-one days later, fish was dissected. 0.5 g from each of the following organs-gills, liver and kidney tissues-was removed, homogenised and tested for enzymes [superoxide dismutase (SOD), catalase (CAT), alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP)], urea, creatinine and electrolytes (sodium ($Na^+$), potassium ($K^+$), chloride ($Cl^-$), bicarbonate ($HCO_3{^-}$)) following standard methods. In the gills, SOD and ALT to AST ratio were significantly lower than in control while the creatinine was significantly higher in the toxicant. In the kidney, creatinine was significantly higher in fish exposed to the toxicant. In the liver, ALP increased in the toxicant while urea was decreased. The mean electrolyte concentrations ($Na^+$, $K^+$, $Cl^-$ and $HCO_3{^-}$) increased significantly in the concentration of the toxicant (P < 0.05). The alterations observed in the activities of these electrolytes and enzymes indicated that Corexit 9500 interfered with transamination and metabolic functions of the fish.

• Textile Coloration and Finishing
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• v.34 no.2
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• pp.109-116
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• 2022

Tire codes are made of materials such as hemp, cotton, rayon, nylon, steel, polyester, glass, and aramid are fiber reinforcement materials that go inside rubber to increase durability, driveability, and stability of vehicle tires. The reinforcement of the tire cord may construct a composite material using tires such as automobiles, trucks, aircraft, bicycles, and fibrous materials such as electric belts and hoses as reinforcement materials. Therefore, it is essential to ensure that the adhesive force between the rubber and the reinforced fiber exhibits the desired physical properties in the rubber composite material made of a rubber matrix with reinforced fibers. This study is a study on the heat treatment conditions for improving the adhesion strength of the tire cord and the reinforced fiber for tires. The core technology of the drying process is a uniform drying technology, which has a great influence on the quality of the reinforcement. Therefore, the uniform airflow distribution is determined by the geometry and operating conditions of the dryer. Therefore, this study carried out a numerical analysis of the shape of a drying nozzle for improving the performance of hot air drying in a dryer used for drying the coated reinforced fibers. In addition, the flow characteristics were examined through numerical analysis of the study on the change in the shape of the chamber affecting drying.

• Textile Coloration and Finishing
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• v.30 no.2
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• pp.77-89
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• 2018

In the case of fiber/rubber composites for tire applications, the interfacial adhesion between fiber and rubber significantly affects the physical properties of the finished products. Generally, organic synthetic fibers used for tire cords are treated with resorcinol formaldehyde latex(RFL) primer on the surface of the fiber to improve the adhesion to rubber. Changes of adhesion between rubber and tire cords might weaken as temperature rises due to overheating of car engine and friction with road. In this study, the effects of temperature on the primer treated polyketone cord/rubber composites and the changes in interfacial adhesion were investigated. Polyketone cord/rubber composites were prepared after RFL solution treatment on the surface of polyketone fibers. After that, composites was thermally aged at different temperature conditions(60, 80, 100, $120^{\circ}C$) and times(1, 5, 10, 15days). The adhesion strength of polyketone cord/rubber composite treated with RFL primer was higher than untreated composite by more than 3 times. After heat aging, the adhesion strength of untreated polyketone cord/rubber composites increased while the RFL treated polyketone cord/rubber composites decreased somewhat.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.4
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• pp.9-17
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• 1994

It is well recognized recently that ultrasonic technique is one of the most widely used methods of nondestructive evaluation to characterize material properties of nonconventional engineering materials. Therefore it is very important to understand physical phenomenon on propagation behavior of elastic wave in these materials, which is directly associated with ultrasonic signals in the test. In this study, the theoretical analysis on multi-scattering of harmonic elastic wave due to the particulate with interface between matrix and fiber in metal matrix composites(MMCs) was done on the basis of Lax's quasi-crystalline approximation and extinction theorem. SiC particulate (SiCp) reinforced A16061-T6 composite material was chosen for this analysis. From this analysis, frequency dependences of phase velocity and amplitude attenuation of effective plane wave due to the change of volume fraction of SiC particulate were clearly found. It was also shown that the interface condition between matrix and fiber in MMCs gives a direct effect on the variation of phase velocity of plane wave in MMCs.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.24-32
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• 2015

National and international regulations on the exhaust gases of diesel engines are being strengthened, and a study of the combutsion engine and the post-porcessing system are in progress as a variety of ways. There are many techniques for the removal of nitrogen oxide like HC-SCR, LNT, Urea-SCR. And the technical development on the Urea-SCR owing to high conversion efficiency and fuel economy characteristics has being processed. This study investigated the physical/chemical properties of urea according to the change of the urea content, and were analysed the characteristic of exhaust gas. According to the increase of urea content, the contests of biuret aldehyde, phosphate content was increased and the changes of emission quantity of carbon monoxide, hydrocarbons and particulate matter in the exhaust gas was very slight. The emission quantity of NOx was decreased in accordance with increasing the urea content and it was shown to be more than 80 % in the urea solution having more than 30 wt%.