• Journal of the Korean Applied Science and Technology
• /
• v.34 no.1
• /
• pp.152-162
• /
• 2017

A hydrophilic coating solution was prepared by adding a silane coupling agent and a nano-inorganic oxide in aqueous surfactant solution to increase the efficiency of photovoltaic power generation due to the introduction of antifogging and antifouling properties on the glass surface of the solar cell module. Addition of $Ludox^{(R)}$, a nano-inorganic oxide, to 1% hydrophilic coating solution showed improved hydrophilicity and excellent antifogging effect regardless of $Ludox^{(R)}$ concentration. However, the antifouling effect on the glass surface was showed only when Ludox was added more than 10%. In the case of addition of 0.7% of hydrolyzed TEOS at pH 4, the antifogging effect was maintained as a result of the steam test as well as the antifouling effect even after the coated glass surface was rubbed 100 times with a wet Kimwipe. In addition, from the surface roughness ($R_q$) calculated using AFM data, the higher surface roughness with irregular surface shape was obtained with the higher concentration of TEOS. The addition of 0.7% of TEOS showed relatively high surface roughness and well organized surface condition which can help to improve transmittance of light. In conclusion, $Ludox^{(R)}$ is not required only for the antifogging property. However, at least 10% of Ludox should be added to show antifouling effect and 0.7% of TEOS should be added for good durability.

• Journal of the Korean Chemical Society
• /
• v.59 no.1
• /
• pp.36-44
• /
• 2015

This article describes synthesis and electrochemical properties of layer-by-layer self-assembled multilayer film composed of polyaniline (PANi), graphene oxide (GO) and phytic acid (PA), whereby the GO was electrochemically reduced to ERGO, resulting in $(PANi/ERGO/PANi/PA)_{10}$ film electrode. Especially, we examined the possibility to improve the volumetric capacitive property of $(PANi/ERGO)_{20}$ film electrode via combining a spherical hexakisphosphate PA nanoparticle into the multilayer film that would dope PANi properly and also increase the porosity and surface area of the electrode. The electrochemical performances of the multilayer film electrodes were investigated using a three-electrode configuration in 1 M $H_2SO_4$ electrolyte. As a result, the $(PANi/ERGO)_{20}$ electrode showed the volumetric capacitance of $666F/cm^3$ at a current density of $1A/cm^3$, which was improved to the volumetric capacitance of $769F/cm^3$ for the $(PANi/ERGO/PANi/PA)_{10}$ electrode, in addition to the cycling stability maintained to 79.3% of initial capacitance after 1000 cycles. Thus, the electrochemical characteristics of the $(PANi/ERGO)_{20}$ electrode, which was densely packed by ${\pi}-{\pi}$ stacking between the electron-rich conjugate components, could have been improved through structural modification of the multilayer film via combining a spherical hexakisphosphate PA nanoparticle into the multilayer film.

• Food Science and Preservation
• /
• v.21 no.1
• /
• pp.146-150
• /
• 2014

The feasibility of incorporating jujube powder as a value-added food ingredient in cookies was investigated. The amount of jujube powder added (0~20%) was found to have significantly affected the cookie quality (p<0.05). Furthermore, the pH ranged from 6.16 to 6.69, and moisture content gradually increased from 4.11% to 4.76%, while the spread ratio and loss rate have significantly decreased with the increasing levels of the powder added (p<0.05). Lightness decreased; however, the redness and yellowness, as well as hardness, have significantly increased with the higher amount of jujube powder in the formulation (p<0.05). In addition, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was significantly increased (p<0.05) without remarkable differences between the control and 5% sample, and 15% and 20% sample (p>0.05). The consumer acceptance test indicated that the addition of jujube powder of up to 10% had a favorable effect on the consumer preferences in general. Based on the overall observation, the cookies with 5~10% jujube powder is recommended for taking advantage of the functional properties of jujube powder without sacrificing the sensory quality.

• Food Science and Preservation
• /
• v.24 no.2
• /
• pp.266-273
• /
• 2017

This study was carried out to investigate the quality characteristics and antioxidative activity of bread containing lotus leaf powder (in ratios of 0, 1, 2, and 3% of the total flour). The pH of dough and bread were decreased as the concentration of lotus leaf powder increased. The volume of dough during fermentation did not show significant difference between 1% lotus leaf powder containing dough and control. The weight of bread increased by addition of lotus leaf powder. The volume, specific volume and baking loss rate of the bread decreased as lotus leaf powder levels increased. Redness and yellowness of the inner crumb were decreased by the addition of lotus leaf powder, but lightness was increased. 2,2-diphenyl-1-picrylhydrazyl-radical scavenging activity and total polyphenol contents were increased significantly as the concentration of lotus leaf powder increased. The overall acceptability of bread containing 1% lotus leaf powder showed no significant difference compared with control. The result exhibited that adding the lotus leaf powder into the bread increased antioxidant activity, and the highest quality improvement was obtained by incorporating 1% (w/w) lotus leaf powder into the bread formula.

• Journal of Life Science
• /
• v.25 no.8
• /
• pp.936-941
• /
• 2015

The principal objective of this fundamental research was to analyze the physicochemical changes and sensory properties of Dolsan leaf mustard pickles (DMP) for the development of low-salt pickles in order to contribute to the diversification of food. The DMPs were stored at −2℃ for 90 days, with salinity maintained at 1.63% to 1.85%. The pH was decreased during storage, and the acidity was gradually increased for up to 60 days of storage, after which it was increased rapidly to 1.10. The L-values (lightness) from the stems were decreased during storage. The a-values (greenness) were increased, while the b-values (yellowness) were decreased. It was shown that the DMP had a progressive browning phenomenon and the number of lactic acid bacteria gradually decreased. The sensory evaluation showed that crunchy textures were decreased and touch textures were increased at 30 days. Therefore, Dolsan leaf mustard is suitable as a material for low-salt pickles during storage for 90 days. The results of the analysis of the physicochemical and sensory properties indicate that the optimal storage for DMP was maintained for up to 30 days.

• Elastomers and Composites
• /
• v.36 no.1
• /
• pp.44-51
• /
• 2001

To see the effect of chemical surface modification, the carbon black surfaces were treated with three types of chemicals (KOH, $H_3PO_4$, and benzene). Vulcanization and mechanical properties of a styrene-butadiene rubber (SBR) were investigated depending on the chemical treatments. The surface free energy increased considerably with the treatments by both the acid (HCB) and base (KCB), but only a slight increase was observed for benzene treatment(BCB). The BCB showed the highest level of the London dispersive component. The vulcanization reaction was found to be faster in the order of KCB-SBR> BCB-SBR> VCB-SBR(virgin) > HCB-SBR. The difference in minimum and maximum torque of rheocurve, representing the degree of crosslinking, was found to be higher for the BCB-SBR compared to those of VCB-SBR, KCB-SBR, and HCB-SBR. The BCB-SBR and KCB-SBR showed the improved tensile and dynamic mechanical properties. A linear relationship was found to exist between the London dispersive component of surface free energy and mechanical properties.

• Applied Chemistry for Engineering
• /
• v.29 no.5
• /
• pp.541-548
• /
• 2018

In this work, the $N_2O$ decomposition catalyst and reaction characteristics to control the $N_2O$ removal were described. Experiments were carried out by using Rh as an active metal catalyst on various supports and the $Rh/CeO_2$ catalyst with $CeO_2$ support showed the best activity for the $N_2O$ decomposition when it was prepared under the constant heat treatment condition ($500^{\circ}C$-4 hr). $H_2-TPR$ and XPS analyzes were performed to confirm the effect of the physical and chemical properties of the catalyst on $N_2O$ decomposition. As a result, it was found that the increase of the oxygen transfer capacity of the catalyst due to the increase of both the redox property and $Ce^{3+}$ amount affected the decomposition reaction of $N_2O$. In addition, the future work will include a treatment process capable of decomposition $N_2O$ and NO under the condition that $N_2O$ and NO are simultaneously generated and its characteristics of $N_2O$ decomposition reaction.

• Culinary science and hospitality research
• /
• v.20 no.4
• /
• pp.1-13
• /
• 2014

This study aims to determine the physicochemical and sensory qualities of yogurt dressing prepared with mulberry juice(0, 10, 20, 30 and 40%). As the amount of organic acid added with mulberry juice increased, malic acid, acetic acid and citric acid contents increased, while tartaric acid content decreased. The viscosity of the control group(5033.33 cP) was higher than that of the others(3043.33~736.67 cP). The pH of the control group(3.38) was lower than that of the others(3.38~3.45). The sweetness of the control group(15.80) was lower than that of the others(16.30~16.83). As for the colors, L value decreased significantly, whereas a value and b value increased significantly with more mulberry juice added. DPPH radical scavenging activity of the control group was 8.61%, whereas that of yogurt dressing samples with mulberry juice ranged from 21.98~50.65%. The sensory property results showed that yogurt dressing with 20% mulberry juice added group had the highest value in terms of color, taste, mouth feel and overall acceptability. Overall, the result of this study indicates that the yogurt dressing containing 20% of mulberry juice was most preferred among the groups.

• Journal of Animal Science and Technology
• /
• v.46 no.6
• /
• pp.937-946
• /
• 2004

Duroc is widely used to improve the meat quality and productivity. To elucidate the phylogenetic relation and the sequence specificity for the maternal property, the complete sequence of mitochondrial genome was determined and the population diversity of Duroc was investigated in this study. The length of mtDNA tested is 16,584-bp. There are several insertion/deletion mutations in the control region and coding regions for tRNA and rRNA, respectively, but not in peptide-coding regions. Four peptide-coding genes(COⅡ, COⅢ, ND3 and ND4) showed incomplete termination codon sequences such as T--, and two(ND2 and ND4L) did alternative initiation codons(AIC), respectively. Especially, the initiation codon sequences of ND2 gene were polymorphic in this population. Polymorphisms were detected in 11-bp duplication motif within control region as well as ND2 and CYTB. Variation patterns observed from the tests on three mtDNA regions were linked completely and then two haplotypes obtained from combining the data dividing this population. Duroc mtDNA is observed at the European pig cluster in the phylogenetic tree, however, the results from the population analyses supported previous opinions. This study suggests that the breed Duroc was mainly originated from the European pig lineage, and Asian lineage was also used to form the pig breed Duroc as maternal progenitors.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.1
• /
• pp.113-119
• /
• 2005

This study was performed to evaluate the effects of the addition of medicinal herb extracts on shelf-life and quality of seasoning beef. The pH of seasoning beef treated with medicinal herbs was more stable than those without medicinal herbs. The moisture content of non-treated group decreased than that of group treated with medicinal herbs. The shear forces of seasoning beef revealed that non-treated group and other group treated with medicinal herbs were higher than those with medicinal herb extracts less than 0.5% adding medicinal herb extracts. As the storage time increased, the redness of group treated with 2.0% medicinal herbs was most stable among the seasoning beef color. The increase of TBA value was observed as the storage period increased. The total bacterial count of non-treated group was detected to 10$^{8}$ CFU/g, but that of group with medicinal herbs was counted from 10$^4$ CFU/g to 10$^{5}$ CFU/g at 6 days of storage time. The sensory evaluation indicated that the changes of group treated with various concentration of medicinal herbs were scored relatively higher than that of non-treated groups.