The following results were obtained by conducting a flow experiment. The experiment with air volume showed that the ducts with 3 shapes in the same cross-sectional area were large in the order of circular duct, square duct, and flexible duct. As a result of measuring the pressure value by duct shape to determine the cause of the difference between the flow rate and the air volume value by duct, the negative pressure was large in the order of circular duct, square duct, and flexible duct. in the countercurrent test, In the case of circular ducts, the deviation was high, In the case of Flexible ducts, the mild increase in the countercurrent is judged to be the difference in pressure and friction received by shape.
PURPOSES : The process of extracting and recovering an asphalt binder from an asphalt mixture is harmful to the human body and can affect the properties of the asphalt binder owing to the presence of residual solvent quantities. This study was conducted to determine the properties of aged asphalt binders based on rejuvenator content without extracting and recovering the asphalt binders using RAP mortar.
METHODS : After extracting and recovering aged binders from waste asphalt, a rejuvenator was added at a certain rate to evaluate the physical and rheological properties of the binder based on the added amount.
RESULTS : When the rejuvenator content was greater than necessary, the absolute viscosity was not properly measured owing to the behavior of the rejuvenator. The phase angle was measured to be almost 90°, thus indicating that it acted as a liquid . In addition, the shear strain and nonrecovery compliance also increased significantly.
CONCLUSIONS : If an excess rejuvenator quantity was added to the aged binder, the absolute viscosity was not properly measured, the phase angle was measured to be almost 90°, and the shear strain increased significantly. It is also necessary to conduct the same tests on different types of RAPs to ensure that the results of this study are reasonable.
To enhance the efficacy of Abeliophyllum distichum leaves, extracts were prepared using different solvents for hydrolytic enzyme-treated Abeliophyllum distichum leaves. Physicochemical quality and antioxidant activity were measured. Soluble solids, reducing sugar, ascorbic acid, flavonoids, and polyphenols contents showed the lowest values in the control without enzyme treatment. However, they showed high contents in ethanol extract. In the case of enzyme treatment, their values were higher than those of the control. In particular, verbascoside content increased about 220 times more than that of the control group when treated with enzymes and extracted with 50% ethanol. pH was lowered upon enzymatic treatment. Regarding DPPH radical scavenging activity, for enzyme-free, 25% ethanol extract showed the highest activity among extracts with different solvents. For cellulase and pectinase-treated leaves, water extract showed the highest DPPH radical scavenging activity among extracts with different solvents. For leaves treated with enzyme combination, 50% ethanol extract showed the highest DPPH radical scavenging activity among extracts with different solvents. Regarding ABTS radical scavenging activity, it was generally higher in the 50% ethanol extract than in the water extract and 25% ethanol extract. In particular, verbascoside content was increased when the extract was prepared by co-treatment with enzymes and 50% ethanol.
In this study, to improve the performance of kitchen range hoods, a comparative analysis of air volume and noise is conducted using three ducts by changing shapes. It was found that the difference in air volume was caused by the pressure difference received by each shape. The noise data can be found to be no more than 60dB overall, except for the second tier of A-type. The difference when connecting the circular, square, and flexible ducts was judged to be due to some laboratory noise, and it was found that there was no difference.
This study investigated the quality characteristics and antioxidant effects of rice cookies containing different percentage of freeze-dried plum powder (3%, 5%, 6%, and 12%). The density of the dough and the thickness of the rice cookies from the control group and the additive group were not significantly different. The pH value of the dough, its moisture content and spread factor, as well as the Hunter’s L and b values of the rice cookies significantly decreased as the amount of dried plum powder added increased. However, the sweetness, hardness, thickness, Hunter’s a value, total polyphenol, total flavonoid and anthocyanin contents, DPPH and ABTS free radials scavenging activity, and ferric reducing antioxidant power of the rice cookies significantly increased as the amount of dried plum powder added increased. Overall, the results of this study showed that adding dried plum power enhanced the antioxidant activities and quality characteristics of rice cookies.
PURPOSES : In this study, a system is investigated and developed to remove fog by injecting air onto a road using high-pressure air generated by turbo blowers installed on both edges of the road without using artificial chemicals.
METHODS : A test device was constructed on a scaled road measuring 5 m long. A 225 kW class turbo blower was used to supply air. An air injection nozzle was installed to allow high-pressure air supplied from the turbo blower to be sprayed vertically from the edge of the road and horizontally from the surface of the road. Ten micro humidifiers were used to generate fog.
RESULTS : Experimental results show that when ground fog occurs on the road, spraying air only in the vertical direction cannot effectively remove the fog. However, when vertical and horizontal nozzles are used simultaneously, both ground fog and flowing fog are removed effectively.
CONCLUSIONS : A system for removing fog by spraying air jet is constructed, and fog is generated using a micro humidifier. Results from the fog removal performance test show that the system effectively removes fog.
This study investigated the quality characteristics and antioxidant activity of Yanggaeng prepared with various amounts of watermelon radish flesh (WRF) powder, in ratios of 0 (control), 2.5, 5, 7.5, and 10% of the cooked white bean paste. The proximate composition, pH, sugar content, Hunter’s color values, texture analysis, and antioxidative activities of Yanggaeng were examined. Increasing the amount of WRF in the Yanggaeng tended to increase the crude ash, carbohydrate, sugar, total polyphenol, total flavonoids, and anthocyanin contents, a value, DPPH and ABTS radical scavenging activities, with decreasing the moisture and crude protein contents, L and b values, and pH. Texture measurement scores in terms of springiness, chewiness for Yanggaeng showed that 2.5% or 5.0% group was higher than those of the control group. Hardness was higher in the sample groups than in the control group. In conclusion, the results show that Yanggaeng with up to 7.0% added WRF powder can be developed as products, and there is a possibility of developing health functional snack products using WRF powder.
PURPOSES : This study was conducted to prevent road thinning ice caused by abnormal weather conditions.
METHODS : The appropriate amount of de-icer spread rate was verified by presenting the appropriate amount of snow removal agent spraying criteria for the thickness of the water film, owing to abnormal weather phenomena (fog, frost), and applying the standards to the site. Furthermore, we present a method to utilize residual salt, by quantifying the surface state changes according to the amount of deicer.
RESULTS : Precautionary spread experiments to prevent road thin ice caused by abnormal weather conditions, indicated no freezing from 7.6g/m2 at 2℃-4℃ but 11.1g/m2 was suggested as a step higher considering external environmental variables. The amount of spraying was presented in two sections of rainfall(freezing rain). It is 17.7g/m2 at 0-7℃, 33.3g/m2 at -7~ -15℃, and 44.4g/m2 and 51.1g/m2 at non-urban, respectively.
CONCLUSIONS : The criteria were divided into air temperature and road temperature standards, so that they could be distributed according to the temperature standards that meet the conditions, and the criteria presented were confirmed to be effective in preventing road thinning ice. If the road manager adopts Safety Line, which is suggested by utilizing the amount of residual salt on the road, it is believed that it can help determine the additional deicer.
PURPOSES : The purpose of this study is to evaluate the asphalt binder properties using FTIR analysis.
METHODS : To investigate the chemical properties of asphalt binders, FTIR tests were performed. Recently, FTIR was used for quantification under various aging conditions. Three scans were averaged for each sample within the wavenumber range of 4000 to 400 cm-1, at a resolution of 4 cm-1 (default Simatech software settings). To determine the oxidation of the extracted asphalt binder and the remaining TCE solution in the extracted asphalt binder, the penetration test was adopted and compared. To track the changes in the chemical composition of the aged bitumens, the ATR spectrum of each sample was analyzed, both qualitatively and quantitatively. The qualitative analysis involved identifying characteristic absorption peaks for the functional group of interest, such as polymer components, carbon and sulfur oxidation products, and polar aromatics.
RESULTS : The asphalt binder is easily oxidized in air during FTIR testing. To reduce the oxidization of the asphalt binder, the asphalt binder must avoid air contact to measure constant results. Sometimes, the extracted asphalt binder has a residual solvent (TCE), which affects the evaluation of the extracted asphalt binder rheology, such as absolute viscosity and penetration testing. To solve this problem, the research team adopted the FTIR test method. First, the TCE was scanned with FTIR to obtain the chemical characteristics of TCE. After that, the extracted asphalt binder was scanned and the FTIR spectra were compared with those of TCE. If there is a TCE in the extracted asphalt binder, a typical peak was found in the spectrum. Thus, it is possible to estimate the content of the TCE remaining in the extracted asphalt binder via the FTIR test method.
CONCLUSIONS : It is possible to evaluate the aging of asphalt binder through FTIR analysis used for the analysis of the chemical structure of asphalt. In addition, during FTIR analysis, the sample is required to avoid air contact to obtain accurate results. FTIR analysis was conducted to confirm whether the solvent (TCE) remained in the extracted asphalt binder and it was confirmed that the penetration increased by a factor of two when the solvent remained. This suggests that it is difficult to control the quality of the asphalt mixture by controlling the amount of recycled additive, as well as the aging of the extracted asphalt binder.