• Journal of Life Science
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• v.25 no.4
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• pp.433-440
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• 2015

Several studies suggest that regular consumption of walnuts may have beneficial effects against oxidative stress-mediated disease such as cancer. The present study reports the total phenolic and flavonoid contents, together with the antioxidant and antibacterial activities of several solvent extracts (methanol, n-hexane, ethyl acetate, n-butanol, and water) obtained from walnut (Juglans regia L.) green husk. MIC (minimal inhibitory concentration) values of the walnut extracts for 8 human pathogenic bacteria strain were determined using agar dilution method. Antioxidant activity of extracts were assessed using DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)) assays, EC₅₀ of DPPH and ABTS scavenging activities, and determination of total phenolic and flavonoid content and its correlation with DPPH and ABTS scavenging capacities. Among the six extracts, ethyl acetate extract (EtOAc Ex) showed the highest antimicrobial activity at 3.2 mg/ml of MICs against Staphylococcus aureus SG511. Total flavonoids and polyphenol contents of EtOAc Ex were 42.48 mg of quercetin equivalents (QE)/g and 223.25 mg of gallic acid equivalents (GAE)/g respectively. The highest antioxidative potential was shown by the sample extracted with EtOAc Ex (EC₅₀=13.43 μg/ml for DPPH and EC₅₀=41.83 μg/ml for ABTS radical scavenging activity assay). These results showed that J. regia green husk extracts can be used as an easily accessible source of natural antibacterial agents and natural antioxidants.

• Journal of Life Science
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• v.26 no.8
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• pp.955-962
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• 2016

Fish-meat gel is an intermediate product used in a variety of surimi-based seafood. One of the most-used raw materials of fish-meat gel is Alaska Pollock due to its high-quality meat in terms of gel strength and texture. However, increasing demand for fish-meat gel, along with overexploitation of the wild catch Alaska Pollock, has put the industry in need of low-cost sustainable alternative sources for fish-meat gel. Pagrus major (PM) is a widely aquacultured fish known for having white meat that is low in fat. The current study compares the quality of fish-meat gel prepared from aquacultured PM to that of high and mid-grade Alaska Pollock fish-meat gel. Gels were compared in terms of gel strength, texture, color, and protein pattern. Results indicated that fish-meat gels prepared from PM were superior to Alaska Pollock fish-meat gels with regard to gel strength, hardness, springiness, chewiness, cutting strength, and breaking force. In addition, although not matching in quality, PM exhibited a cohesiveness, whiteness, and expressible moisture content comparable to Alaska Pollock of both grades. Protein pattern analysis also showed that PM and Alaska Pollock fish-meat gels had similar protein profiles before and after gel preparation. Therefore, P. major is suggested as a potential substitute for Alaska Pollock in fish-meat gel production.

• Journal of Life Science
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• v.20 no.7
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• pp.1134-1142
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• 2010

This study was carried out to investigate the effects of powders of autoclaved soy flour and doenjang fermented using Bacillus subtilis DJI on lipid profiles and antioxidative activities of rats fed a high cholesterol diet. Sprague-Dawley male rats weighing 200~210 g were divided into four groups: normal diet group (N), high cholesterol diet group (HC), autoclaved soy flour and high cholesterol diet group (SHC), and doenjang and high cholesterol diet group (DHC). The serum ALT, AST and ALP activities of the SHC and DHC groups were lower than those of the HC group, but exerted no significant change on serum LDH activity. Serum triglyceride, total cholesterol and LDL-cholesterol levels were markedly decreased by autoclaved soy flour and doenjang administration, while the serum HDL-cholesterol level was higher in groups given autoclaved soy flour and doenjang administration. The GSH-Px and catalase activities in liver elevated by a high cholesterol diet were significantly decreased by autoclaved soy flour and doenjang administration (p<0.05). Liver GSH levels of the SHC and DHC groups were significantly decreased compared to the HC group (p<0.05). Liver TBARS level was significantly decreased in the DHC group fed with doenjang powder compared with those of the HC group (p<0.05). These results suggest that soy flour and doenjang may reduce levels of serum cholesterol and prevent oxidative stress by stimulating antioxidative systems in rats fed a high cholesterol diet.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.188-198
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• 2016

In soybeans, responses of high temperature according to shift of sowing dates during the growing season was explored using the crop model, CROPGRO-soybean. In addition, it analyzed impact on change of sowing dates affects yield potential of soybean under future climate scenario (2041-2070). In Jeonju and Miryang during 1981-2010, if sowing at 15 or ten days ahead from 10 June, namely in shorten of the sowing day (i.e. when sown on 25 or 30 May), the yield potential reduced. However, the yield potential increased when sown 5 June. In the case of delay of sowing day (i.e. when sown on 15 or 20 June), reduction of yield potential in the average -5% was higher than increase in the average +2%. In particular, the relative changes for shorten of the sowing day or delay of the sowing day do not be shown in normal years which high temperatures did not abnormally occur during the growing season from 2003 to 2010 except when sown on 25 May. In abnormal years which high temperatures occurred during the critical period, especially R5 to R7, shorten of the sowing day affected to the increase of yield potential in Miryang, while the yield potential decreased in Jeonju except when sown on 5 June. However, delay of the sowing day influenced on the reduction of yield potential both in two sites. In future climate scenario of Representative Concentration Pathway (RCP) 8.5 during from 2041 to 2070, the increase and decrease of yield potential for shorten of the sowing day were +10/-9% for RCP 8.5 of Jeonju, and +14/-9% for RCP 8.5 of Miryang, respectively. Additionally, it showed +10/-17% for RCP 8.5 in Jeonju, and +10/-29% for RCP 8.5 in Miryang, respectively in the increase and decrease of yield potential for delay of the sowing day.

• Journal of Korean Home Economics Education Association
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• v.31 no.1
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• pp.137-149
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• 2019

This study described the status of snack intake and personality of middle school students, determined the differences in snack intake and personality according to gender and grade levels, and examined the effect of snack intake on personality. Data were collected from a self-reported survey from students of a middle school in Gwangju city and 717 questionnaires used for the analyses. The data were analyzed for frequency, percentage, mean, standard deviation, Cronbach's α, t-test, ANOVA, Duncan test, and multiple regression analysis using SPSS/PC 18.0 program. The results obtained were as follows. First, as for the snack intake frequency, '1~2 times per a day' had the largest number of responses(42.3%), followed by 'sometimes'(37.6%), '2~3 times per a day'(12.6%), 'never'(7.5%). As for the reason of snack intake, 'habitually'(27.3%) had the largest number of responses, followed by 'insufficient amount of meal'(21.0%), 'skipping meals'(13.6%), and 'stress relief'(8.2%). Mean score of agreeableness was the highest(3.64) among the personality components followed by Openness/intellect(3.42), Extraversion(3.36), Conscientiousness(3.15), and Emotional Stability(3.09) on the 5-point scale. Second, there were statistically significant differences in Emotional Stability depending on the gender. There were statistically significant differences in Extraversion, Agreeableness, and Openness/intellect by the grade level. Third, fruit intake frequency had statistically significant influence on Extraversion(β=.134). Intake frequency of bread(β=-.099), fruit(β=.142), ice cream(β=.092), and rice cake(β=.090) had statistically significant influence on Agreeableness. Intake frequency of bread(β=.105), drink(β=-.113), fruit(β=.113), and flour-based food(β=-.126) had statistically significant influence on Emotional Stability. Intake frequency of fruit(β=.106) and milk(β=.110) had statistically significant influence on Openness/intellect. Intake frequency of fruit had statistically positive influence on all the personality components. Intake frequency of rice cake had statistically positive influence on two personality components. Intake frequency of drinks had statistically negative influence on Emotional Stability. The outcomes indicate that snack intake affects the personality of adolescents.

• Journal of the Korea Institute of Building Construction
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• v.9 no.4
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• pp.55-61
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• 2009

Recently, the number of high-rise buildings being built in Korea by major construction companies for residential and commercial use has been increasing. When constructing a high-rise building, it is necessary to apply massive amounts of concrete to form a mat foundation that can withstand the huge load of the upper structure. However, it is of increasing concern that due to limitations in terms of the amount of placing equipment, available job-sites and systems for mass concrete placement in the construction field, it is not always possible to place a great quantity of concrete simultaneously in a large-scale mat foundation, and for this reason consistency between placement lift cannot be secured. In addition, a mat foundation Is likely to crack due to the stress caused by differences inhydration heat generation time. To derive a solution for these problems, this study provides test results of a hydration heat crack reduction method by applying placement lift change and setting time control with a super retarding agent for mass concrete in a large-scale mat foundation. Mock-up specimens with different mixtures and placement liftswere prepared at the job-site of a newly-constructed high-rise building. The test results show that slump flow of concrete before and after adding the super retarding agent somewhat Increases as the target retarding time gets longer, while the air content shows no great difference. The setting time was observed to be retarded as the target retarding time gets longer. As the target retarding time gets longer, compressive strength appears to be decreased at an early stage, but as time goes by, compressive strength gets higher, and the compressive strength at 28 days becomes equal or higher to that of plain concrete without a super retarding agent. For the effect of placement lift change and super retarding agent on the reduction of hydration heat, the application of 2 and 4 placement lifts and a super retarding agent makes it possible to secure consistency and reduce temperature difference between placement lifts, while also extending the time to reach peak temperature. This implies that the possibility of thermal crack induced by hydration heat is reduced. The best results are shown in the case of applying 4 placement lifts.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1673-1680
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• 2016

The purpose of this study was to examine how customer orientation (CO) reduces employee stress to customers (CSS). As emotional labor strategies [surface acting (SA) and deep acting (DA)] may mediate a role between CO and CSS, we verified multiple parallel mediator roles of SA and DA between CO and CSS. Our survey was administered to 323 school foodservice employees in Daegu and Gyeongbuk. The results show that CO increased DA but did not decrease SA, and SA had a positive effect on CSS while DA did not influence CSS. These results did not support the parallel multiple mediator model. We conducted post-hoc model modification and proposed the serial multiple mediator model as a modified model. As a result, CO increased DA, DA reduced SA, and SA showed a positive relation with CSS. This double mediating effect through DA and SA between CO and CSS was significant. Based on these results, we found that CO did not have a direct effect on SA and CSS. DA did not directly reduce CSS while CO reduced SA and CSS through DA indirectly. DA had a negative effect on CSS through SA indirectly. Finally, implications and limitations of this are discussed.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.478-484
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• 2012

This study was carried out to investigate the plant growth and ion absorbance balance of various native plants affected by the NaCl concentration (0, 100, 200, 300 mM). Carex blepharicarpa, Carex lenta, Carex matsumarae, Carex sendaica, Iris pseudacorus L., Sedum oryzifolium Makino, Sedum polytrichoides Hemsl., and Typha angustifolia L. were used in this experiment. Carex blepharicarpa, Carex lenta, Carex matsumarae, and Iris pseudacorus L. were tolerant of salinity at the NaCl concentration of 200 mM. The root growth of Carex sendaica and Typha angustifolia L. was suppressed at the NaCl concentration of 100 mM, expecially the root growth responded more sensitively than the upper growth to salinity. The K absorbance of Carex sendaica decreased according to the NaCl application, and the Na/K rate value was 3 at the NaCl concentration of 300 mM. The K, Ca, and Mg absorbance of Typha angustifolia L. decreased at the NaCl concentration of 200~300 mM, and the Na/K rate value was 0.8 at the NaCl concentration of 300 mM. The plant growth of Sedum oryzifolium Makino and Sedum polytrichoides Hemsl. was suppressed at the NaCl concentration of 100~200 mM. The K, Ca, and Mg absorbance of Sedum oryzifolium Makino decreased at the NaCl concentration of 200~300 mM, and Sedum polytrichoides Hemsl. was unaffected by the NaCl application. The Na/K value was 1 in both plants. Therefore, Carex blepharicarpa, Carex lenta, Carex matsumarae, and Iris pseudacorus L. were tolerant plants of salinity at the NaCl concentration of 200 mM considering the plant growth and ion absorbance balance. Especially, the Carex plants were expected to expanding use by the proven tolerance of salinity. The root growth of Carex sendaica, Sedum oryzifolium Makino, Sedum polytrichoides Hemsl., and Typha angustifolia L., was suppressed at the NaCl concentration of 100 mM, but there was no distinct tendency of ion absorbance in leaves according to the NaCl application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.111-118
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• 2010

Stress due to excess water is one of the most limiting factor for soybeans to high yield under wet climates. This study aimed to identify the photosynthetic responses of soybeans to waterlogged growing condition with 5 soybean varieties by waterlogging for 10 days at V5 and R2 stage, respectively. Chlorophyll fluorescence decreased more rapidly at R2 stage waterlogging than at V5 stage waterlogging in all soybean tested varieties. The degree of recovery was much more in Pungsannamulkong and Muhankong( 95～97% of control) than in Jangyeobkong and Myungjunamulkong at 5 days after waterlogging. Photosynthetic rate, transpiration and stomatal conductance were also increased more rapidly in Pungsannamulkong and Muhankong than in Jangyeobkong and Myungjunamulkong after waterlogging irrespective of waterlogging stages. As the result of multiple regression analysis in order to identify the effects of stomatal conductance and transpiration to the photosynthetic rate, the R2 value of stomatal conductance in control and waterlogging treatment was 0.7293 and 0.7582, respectively. If the transpiration, another dependent variable, was added to the regression formula, there was not so big difference in the variation of photosynthetic rate. This result means that if just one factor of them(the stomatal conductance and transpiration) be measured in the case of waterlogged condition, the changes of photosynthetic rate can be estimated.

• Economic and Environmental Geology
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• v.46 no.1
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• pp.51-61
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• 2013

Researches on the oil recovery enhancement using the nanotechnology has recently been studied in the United States. The previous researches has focused mainly on the flow characteristics of nanoparticles in porous media, and the stability of the nano-emulsion itself. However, the analysis did not deal with the size effects between a nano-emulsion and the pore size which has an important role when nano-emulsion flows in the porous media. In this research, nano-based emulsion was fabricated which is able to be applied for the enhanced oil recovery techniques and its characteristics was analyzed. In addition, in order to identify the characteristics of nano-emulsions flowing through the porous media, the size effect was analysed by filtering test. According to the results, when the emulsion was fabricated, SCA(Silane Coupling Agent) or PVA(Poly Vinyl Alcohol) are added to improve the stability of emulsion. As the ratio of the decane to water increased, the viscosity of emulsion and the droplet size also increased. For the filtering test at the atmospheric conditions, the droplet did not go through the filter; only the separated water from the emulsion was able to be filtered. This phenomenon occurred because the droplet was not able to overcome the capillary pressure. At the filtering test by suction pressure, most of the emulsion was filtered over the filter size of $60{\mu}m$. However, the ratio of filtration was rapidly degraded at less than $45{\mu}m$ filters. This is caused due to deformation and destruction of the droplet by strong shear stress when passing through the pore. The results from the study on the basic characteristic of nano-emulsion and filtering test will be expected to play as the important role for the fabrication of the stable nano-emulsion or the research on the recovery of residual oil in porous media.