• Journal of Korean Ophthalmic Optics Society
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• v.13 no.2
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• pp.1-7
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• 2008

Purpose: This study was performed to evaluate the changes of lens morphology and tear stability during wearing soft contact lenses (SCLs) which were kept in drying condition like dry eye or became to be dried due to heedless care. Method: SCLs having different water content, thickness or material were rehydrated after being dehydrated artificially 2 or 4 times, and estimated their diameter and radius. Furthermore, the changes of tear film break-up time (TBUT) during SCL wearing were also measured. Result: Due to the dryness, the diameter of both 70% water content SCL and 59% water content SCL decreased, but the decrement was larger in 59% water content SCL. The more 59% water content SCL was dehydrated, the more its radius changed. However, the radius of 70% water content SCL did not change by 2 times dehydration and increased greatly by 4 times dehydration. The reduction of diameter of -1.00 D SCL was greater than that of -9.00 D SCL. Moreover, the radius of -1.00 D SCL increased depending on the frequency of dehydration but that of -9.00 D SCL did not changed. The diameter and radius changes of lotrafilcon B, silicone hydrogel lens, were less than those of hilafilcon B, copolymer of HEMA and N-vinyl pyrrolidone. TBUT during wearing SCLs decreased by wearing dehydrated SCLs. Conclusion: The diameter and radius of dehydrated SCLs as well as TBUT during wearing them were changed in spite of rehydration, which would be the important cause of uncomfortable feeling when people wore dehydrated SCL. The changes of SCL morphology and TBUT differed according to the water content, lens thickness and material.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.373-382
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• 1984

Processing conditions of retort pouched fried mackerel fish meat paste and quality stability during storage were investigated. The reasonable amounts of added ingredients to the frozen mackerel meat paste were $10\%$ of corn starch, $1\%$ of soybean protein, $1.5\%$ of sodium chloride, $0.6\%$ of monosodium glutamate, $0.3\%$ of alcoholic extract of red pepper, and $0.1\%$ of sodium erythorbate as an antioxidant and also added water corresponding to $10\%$ of the frozen mackerel meat paste. After grinding the defrosted mackerel fish meat paste with ingredients, the meat paste was molded in bar type and fried in soybean oil at $170-180^{\circ}C$ for 3 minutes. The fried mackerel meat paste was cooled, vacuum-packed in laminated plastic film bag (polyester/polyvinylidene chloride/unoriented polypropylene : $12{\mu}m/15{\mu}/50{\mu}m,\;14{\times}19cm$) and finally sterilized at $120^{\circ}C$ for 20 minutes in a hot water circulating retort. The pH, volatile basic nitrogen, moisture content, water activity, color, thiobarbituric acid value, peroxide value, texture and viable bacterial count of products were examined during 100 days of storage at $25{\pm}3^{\circ}C\;and\;5^{\circ}C$. The results showed that products could be preserved in good condition for 100 days at $25{\pm}3^{\circ}C$. Judging from sensory evaluation, the quality of products was not inferior to that of market products.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.161-170
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• 2020

There is systematic spatial variations in environmental properties due to sensitive reaction to external conditions at plastic greenhouse occupied 99.2% of domestic agricultural facilities. In order to construct 3 dimensional distribution of temperature, relative humidity, CO₂ and illuminance, measurement matrix as 3 by 3 by 5 in direction of width, height and length, respectively, dividing indoor space of greenhouse was designed and tested at experimental site. Linear regression analysis was conducted to evaluate optimal estimation method in terms with horizontal and vertical variations. Even though sole measurement point for temperature and relative humidity could be feasible to assess indoor condition, multiple measurement matrix is inevitably required to improve spatial precision at certain time domain such as period of sunrise and sunset. In case with CO₂, multiple measurement matrix could not successfully improve the spatial predictability during a whole experimental period. In case with illuminance, prediction performance was getting smaller after a time period of sunrise due to systematic interference such as indoor structure. Thus, multiple sensing methodology was proposed in direction of length at higher height than growing bed, which could compensate estimation error in spatial domain. Appropriate measurement matrix could be constructed considering the transition of stability in indoor environmental properties due to external variations. As a result, optimal measurement matrix should be carefully designed considering flexibility of construction relevant with the type of property, indoor structure, the purpose of crop and the period of growth. For an instance, partial cooling and heating system to save a consumption of energy supplement could be successfully accomplished by the deployment of multiple measurement matrix.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.761-778
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• 2017

The need of the underground space for the infrastructures in urban area is increasing, and especially the demand for shallow tunnels increased drastically. It is very important that the shallow tunnel in the urban area should fulfill not only its own safety conditions but also the safety condition for the adjacent structures and the surrounding sub-structure. Most of the studies on the behavior of shallow tunnels concentrated only on their behaviors due to the local deformation of the tunnel, such as tunnel crown or tunnel sidewall. However, few studies have been performed for the behavior of the shallow tunnel due to the deformation of the entire tunnel. Therefore, in this study the behavior of the surrounding ground and the stability caused by deformation of the whole tunnel were studied. For that purpose, model tests were performed for the various ground surface slopes and the cover depth of the tunnel. The model tunnel (width 300 mm, height 200 mm) could be simulationally deformed in the vertical and horizontal direction. The model ground was built by using carbon rods of three types (4 mm, 6 mm, 8 mm), in various surface slopes and cover depth of the tunnel. The subsidence of ground surface, the load on the tunnel crown and the sidewall, and the transferred load near tunnel were measured. As results, the ground surface subsided above the tunnel, and its amount decreased as the distance from the tunnel increased. The influence of a tunnel ceased in a certain distance from the tunnel. At the inclined ground surface, the wider subsidence has been occurred. The loads on the crown and the sidewall were clearly visible, but there was no effect of the surface slope at a certain depth. The load transfer on the adjacent ground was larger when the cover depth (on the horizontal surface) was lager. The higher the level (on the inclined surface), the wider and smaller it appeared. On the shallow tunnel under inclined surface, the transfer of the ambient load on the tunnel sidewall (low side) was clearly visible.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.359-370
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• 2009

Arsenic and heavy metals leached out as a result of oxidation of tailings exposed to the surface pose a serious environmental contamination of mine areas. This study investigated how arsenic behavior is controlled by a variety of processes, such as oxidation of sulfides and formation or alteration of secondary minerals, based on mineralogical methods. The study was carried out using the tailing samples obtained from Nakdong mine located in Jeongseongun, Gangwondo. After separating magnetic and non-magnetic minerals using pretreated tailing samples, each mineral sample was classified according to their colors and metallic lusters observed by the stereoscopic microscope. Subsequently, the mineralogical properties were determined using various instrumental analyses, such as x-ray diffractometer (XRD), energy dispersive spectroscopy (EDS), and electron probe micro analyzer (EPMA). The literature review confirmed that various ore minerals were identified in the Nakdong ore deposits. In this study, however, there were observed a few original ore minerals as well as secondary and/or tertiary minerals newly formed as a result of weathering including oxidation. In particular, we did not recognize pyrrhotite which has been known to originally exist in a large abundance, but peculiarly colloform-type iron (oxy)hydroxides were identified, which indicates most of pyrrhotite has been altered by rapid weathering due to its large reactivity. In addition, a secondary scorodites filling the fissure of weathered primary arsenopyrites were identified, and it is speculated that arsenic is immobilized through such a alteration reaction. Also, we observed tertiary iron (oxy)hydroxides were formed as a result of re-alteration of secondary jarosites, and it suggests that the environment of tailing has been changed to high pH from low pH condition which was initiated and developed by oxidation reactions of diverse primary ore minerals. The environmental change is mainly attributed to interactions between secondary minerals and parental rocks around the mine. As a result, not only was the stability of secondary minerals declined, but tertiary minerals were newly formed. As such a process goes through, arsenic which was immobilized is likely to re-dissolve and disperse into surrounding environments.

• Journal of Mushroom
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• v.11 no.3
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• pp.137-144
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• 2013

This study was carried out to investigate storage stability of harvested mushroom in developed varieties of button mushroom through identification of quality change during 35 days. The mushroom harvested up to $2^{nd}$ flush mushroom was stored on different storage temperature(4, 7, $10^{\circ}C$) and weight, length, thickness, color of pileus and stipe in fruit body was tested every 7 days. The morphological trait and color of stipe in fruit body were influenced by harvesting period and storage temperature. On the morphological traits of fruit body, mushroom harvested at $2^{nd}$ flush showed smaller difference than those at $1^{st}$ flush and mushroom stored at $4^{\circ}C$ indicated more difference than ones at the other temperature. Mostly color of pileus in brown button mushroom had lower ${\Delta}E$ (color difference) than white mushroom during storage period. The color of pileus of fruit body in white mushroom had low ${\Delta}E$ at $4^{\circ}C$ whereas that of brown mushroom was low at $10^{\circ}C$. The safe period of storage based on the L value is 7 days under a specified environmental condition. 'Seolgang' was stored for 14 days as good quality of mushroom, 'Saedo' had best quality after harvesting and 'Seojeong' was most stable during storage change in white mushroom varieties.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.331-337
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• 2016

Several foundation soil conditions below a homogeneous sand slope were assumed and slope stability analyses were conducted to determine the soil condition, in which a stabilizing pile can be used to increase the factor of safety against sliding. The assumed heights of the sand slope were 5m and 10m. For a 5m slope height, a stabilizing pile can be used in the foundation soil with a $15^{\circ}$ internal friction angle and a cohesion of 10kPa. For a 10m slope height, a stabilizing pile can be used in the foundation soil with a $20^{\circ}$ internal friction angle and a cohesion of 10kPa and a stabilizing pile can be used in the foundation soil with a $0^{\circ}$ internal friction angle and 40kPa, 45kPa and 50kPa of cohesion. According to the analysis results of stabilizing pile-reinforced foundation soil, the length of the stabilizing pile and magnitude of the maximum bending moment were strongly affected by the internal friction angle of the foundation soil. The lengths of stabilizing pile, for an internal friction angle of $0^{\circ}$ were 4.6, 8.0 times greater than those with an internal friction angle of $5^{\circ}$. The magnitude of the maximum bending moment of the stabilizing pile for an internal friction angle of $0^{\circ}$ was 24.6 times greater than that for an internal friction angle of $5^{\circ}$. Practically, a stabilizing pile cannot be used for foundation soil with an internal friction angle of $0^{\circ}$. Considering the results derived from this study, the effects of a stabilizing pile can be maximized for soft foundation soil that is embanked with a slow construction speed.

• Food Science and Preservation
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• v.12 no.4
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• pp.329-335
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• 2005

Storage quality characteristics of low fat salad dressing with spirulina($0.28\%$) was evaluated. After 2 wks of storage, viscosity decreased according to the prolonged storage time. After 8 wks storage, emulsion stability decreased to $30\%$, which was $25\%$ of freshly made dressing. The fat globule size distribution was not different from that of control until one month of storage, but after 75 days of storage, the fat globule size distribution pattern changed into the increase of larger size($15{\sim}2.0\;{\mu}m$: $11.4\%$ for control, $30.1-32.3\%$ for 75 days of storage). Hunter color of L value decreased, whereas a and b value increased according to the prolonged storage time. TBARS value at 8 wks of storage was increased upto $10\%$ for storage at $5^{\circ}C$ and $15\%$ for storage at $10^{\circ}C$. Antioxidant activity of salad dressing decreased according to the storage temperature and time: $IC_{50}$ values of DPPH radical scavenging activity of 8 wk storage was 157.4 mg/mL at $5^{\circ}C$ and 194.6 mg/mL at $10^{\circ}C$. Total microbial number of salad dressing was increase to 7.9 log(CFU/mL), but E. coli was not detected Based on present condition, low temperature storage was favorable for better quality of spirulina salad dressing.

• Food Science and Preservation
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• v.25 no.1
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• pp.145-154
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• 2018

The purpose of this study was to investigate the ability of natural antioxidants as stabilizers for meat by-products to prevent lipid oxidation. The white internal organs were evaluated using different treatments: no antioxidant (control), ascorbic acid (T1), Artemisiacapillaris Thunb. (T2), Opuntia (T3), Schisandra chinensis (T4), and Saururuschinensis (Lour.) Baill (T5). Antioxidant activities were analyzed by measuring DPPH contents, superoxide anion radical levels, nitrate scavenging activities, and total polyphenol contents. T1 and T2 showed higher antioxidant activities and total polyphenol contents (p<0.05). Additionally, changes in physicochemical properties (pH, color, volatile basic nitrogen [VBN], and thiobarbituric acid reactive substances [TBARS]) and microbiological aspects in white internal organs processed with antioxidants were investigated. As storage time increased, the CIE $a^*$ and $b^*$ values of the white internal organs processed with natural antioxidants were decreased (p<0.05), and CIE $L^*$ values were low, particularly for the T3 sample relative to that in the control. Moreover, the pH, VBN, and TBARS values of samples T2-T5 were increased after 7 days of storage, but showed low values compared with those of the control (p<0.05). Moreover, compared with the control group, the treatments showed antimicrobial effects. Our results indicated that these natural antioxidants could be used as lipid oxidation stabilizers of meat by-products during storage and that Artemisiacapillaris Thunb. and Opuntia may have applications as natural antioxidants in the meat by-product industry.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1687-1698
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• 2021

This study is to produce multiple layers of liposomes in a supercritical state and encapsulates active ingredients in order to stably encapsulate thermodynamically unstable active ingredients. In order to form a liposome in a supercritical state, a mixed surfactant development including vegetable-derived hydrogenated phosphatidyl choline and their delivative, hydrogenated sucrose distearate was synthesized as high purity. It describes a manufacturing method of injecting liquid carbon dioxide into a reactor to create a supercritical state and stirring to produce a giant liposome, and adding and loading genistein and quercetin. The HLB of the mixed lipid complex (SC-Lipid Complex) was 12.50, and multiple layers of liposome vesicles were formed even at very low concentrations. This surfactant had a specific odor with a pale yellow flake, the specific gravity was 0.972, and the acid value was 0.12, indicating that it was synthesized with high purity. As a result of the emulsifying capacity experiment using 20 wt% capric/capric triglyceride and triethylhexanoin using SC-Lipid Complex, it was found to have 96.2% emulsifying power. SC LIPOSOME GENISTEIN was confirmed that a multi-layer liposome vesicle was formed through a transmission electron microscope (Cryo-TEM) for the supercritical liposome encapsulated with genistein. The primary liposome particle size in which genistein was encapsulated was 253.9 nm, and the secondary capsule size was 18.2 ㎛. Using genistein as the standard substance, the encapsulation efficiency of supercritical liposomes was 99.5%, and general liposomes were found to have an efficiency of 93.6%. In addition, the antioxidant activity experiment in which quercetin was sealed was confirmed by the DPPH method, and it was found that the supercritical liposome significantly maintained excellent antioxidant activity. In this study, thermodynamically unstable raw materials were sealed into liposomes without organic solvents in a supercritical state. Based on these results, it is expected that it can be applied to various forms such as highly functional skincare cosmetics, makeup cosmetics, and scalp protection cosmetics.