• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.361-373
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• 2016

This study tested the antioxidant activities and anti-aging effects of an extract of Orostachys japonicus, a herb used as a folk remedy for cancer for a long time. To assess the antioxidant activities of the Orostachys japonicus extract (OJE), the total polyphenol content was confirmed to have a high caffeic acid equivalent weight of 12 g by dry weight of 100g OJE and the total flavonoid content was confirmed that the quercetin equivalent of 1.7 g by dry weight of 100g OJE. DPPH free radical scavenging activity was confirmed a high scavenging activity of 79.7% at a concentration of 1%. To confirm the anti-aging effect of OJE, MMP-1 expression was decreased in $25{\mu}L/mL$ and $50{\mu}L/mL$ similar to control. In a clinical experiment, a group of subjects who used a cosmetic product containing OJE showed a significant increase in the amount of skin moisture from the forehead, left cheek, and chin. The experimental group showed a significant increase in the amount of skin sebum from the chin and maintaining pH balance of normal skin, As a result, the OJE demonstrates the efficacy of natural cosmetic material as antioxidant and anti-aging.

• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2365-2370
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• 2009

A working electrode in dye-sensitized solar cells was fabricated using $TiO_2$ colloidal sol prepared from titanium isopropoxide used as a starting material by applying the sol-gel method. The effect of aging times and temperatures on physical and chemical properties of $TiO_2$ sol particles was systematically investigated. Results showed that the crystallinity and average particle size of $TiO_2$ colloidal sol can be successfully controlled by the adjustment of aging time and temperature. The conversion efficiency of the repetitive dry coating films fabricated using the dried $TiO_2$ colloidal sol particles and hydroxypropyl cellulose binder (15%) was 10.31% with a high transparency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.36-41
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• 2003

This paper presents the results of power spectra using the fundamental and low frequency harmonic components of leakage current waveform to study aging on contaminated EPDM insulator(was serviced during 1997-2001, region Pohang, korea) under salt fog conditions. Experiments have been conducted in the chamber salt fog and at the 16KVrms. The salt contents adjusted as 0g,25g,50g and 75g per liter of deionized water. The onset of dry-band arcing on polymer insulators could be determined by signal processing the low frequency harmonics components. A correlation has been found between the fundamental and low harmonic components of power spectra on leakage current. Where aging could be associated with an increase in the level of both the fundamental and low frequency harmonics components of leakage current. Surface aging for contaminated EPDM insulators occurred when the fundamental component of leakage current was greater then some level On the other hand, when the polymer insulator approached failure, the fundamental component of leakage current reached relatively high values and low frequency harmonics components of the leakage current trended to decrease. The results suggest that both the fundamental and low frequency harmonics of leakage current can be used as a tool to determine both the beginning of aging and before flashover, end of life EPBM insulator in salt fog.

• Journal of the Korean Home Economics Association
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• v.8 no.1
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• pp.100-119
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• 1970

In finding an improved and generalized method of making Jung-pyun, a type of scientific experimental cookey has been attempted with the use of yeast in place of Korean native rice wine named "Takju" The result is shown as follows; 1. Starta prepared with yeast and rice powder was mixed again with fresh rice powder as fermenting and aging agents in Jung-pyum making. 2. Recommendable methods of starta making are shown as follows; a. Recipe Rice powder--Certain amount Yeast--1% Sugar--10% Water--65%(by volume) b. Temperature and Time of Fermentation Temperature--30$^{\circ}C$ Time--20 hrs. 3. Recommendable method of dough making are shown as follows; a. Recipe Starta--Certain amount Rice powder--Two times the starta(2-3 times) Sugar--10% Water--50%(by volume) b. Temperature and Time of Aging Temperature--35$^{\circ}C$ Time--3 hrs. (3-4 hrs) 4. Steaming Time 25-30 min.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.715-720
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• 2003

The chief factors for the penetration and diffusion of chloride ions in concrete are water-cement ratio(W/C), aging, curing conditions, chloride ions concentration of given environment., wet and dry conditions and etc. In this study, of these factors effect of curing conditions such as standard and outdoor curing on the characteristics of chloride ions diffusion in concrete were researched when environmental factors for the penetration and diffusion of chloride ions were constant. For this purpose, the voltages passing through the diffusion cell were measured by using accelerated test method using potential difference, and then diffusion coefficients of chloride ions by using Andrade's method were estimated for 44%, 49.5% and 60% of w/c, respectively. As a result., according to curing conditions correlation among diffusion coefficients of chloride ions, W/C and aging were concluded through multiple regression model.

• Applied Biological Chemistry
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• v.14 no.2
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• pp.165-169
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• 1971

From both breast and leg muscle of 12 week-old broiler chicken held for aging in slushed ice and dry chilling at $33-35^{\circ}F$., myosin, actomyosin and other nitrogenous fractions were extracted with KCl-phosphate buffer for various periods from 1 hr. to 25 hr. post-mortem. The changes in extractable nitrogen occurred mainly as a result of decrease in extractability of myosin and to some extent, increase in extractability of actomyosin. Changes in stroma, sarcoplasmic and NPN fractions were small. Myosin extractability decreased rapidly during the first 3 hr. post-mortem and then reduced Continuously in both leg muscle and breast muscle during wet chilling. The decrease of myosin extractability in leg muscle was much more than that in breast muscle, and then the extractability increased after 17 hr. post-mortem in dry chilling. Actomyosin was extracted at low consistent level in wet chilling, while it increased considerably after 17 hr. post-mortem in dry chilling. The tendency was similar in both breast and leg muscle.

• Journal of Powder Materials
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• v.26 no.6
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• pp.471-476
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• 2019

Additively manufactured metallic components contain high surface roughness values, which lead to unsatisfactory high cycle fatigue resistance. In this study, high cycle fatigue properties of selective laser melted Ti-6Al-4V alloy are investigated and the effect of dry-electropolishing, which does not cause weight loss, on the fatigue resistance is also examined. To reduce the internal defect in the as-built Ti-6Al-4V, first, hot isostatic pressing (HIP) is conducted. Then, to improve the mechanical properties, solution treatment and aging are also implemented. Selective laser melting (SLM)-built Ti64 shows a primary α and secondary α+β lamellar structure. The sizes of secondary α and β are approximately 2 ㎛ and 100 nm, respectively. On the other hand, surface roughness Ra values of before and after dry-electropolishing are 6.21 ㎛ and 3.15 ㎛, respectively. This means that dry-electropolishing is effective in decreasing the surface roughness of selective laser melted Ti-6Al-4V alloy. The comparison of high cycle fatigue properties between before and after dry-electropolished samples shows that reduced surface roughness improves the fatigue limit from 150 MPa to 170 MPa. Correlations between surface roughness and high cycle fatigue properties are also discussed based on these findings.

• Food Science of Animal Resources
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• v.39 no.2
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• pp.266-275
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• 2019

Although the production of dry-aged beef has been increasing, most purveyors are unaware of the changes in quality that ensue after completion of the aging period and do not adhere to specific guidelines for its packaging and storage. The objective of this study was to investigate the storage stability of vacuum-packaged dry-aged beef based on changes in microbial, physicochemical, and sensory properties during refrigeration at $4^{\circ}C$ for 21 d. The total aerobic bacterial count exceeded 6 Log CFU/g at approximately day 11 and significantly increased after day 14. Freshness indicators such as pH and volatile basic nitrogen content were acceptable until day 14 and 21, respectively. Based on the evaluation of overall sensory acceptability, the dry-aged beef was acceptable until 14 d without any sensory deterioration. Therefore, vacuum-packaged dry-aged beef could be stored for 11 d at $4^{\circ}C$ without any adverse effect on its microbial and sensory quality.

• The Journal of the Korean dental association
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• v.12 no.7
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• pp.521-526
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• 1974

This observation was carried out to investigate the inorganic constituents of dental calculus of varying locations and different ages. Supragingival calculus was obtained from 540 patients with the periodontal disease. The results were as follows : 1. The weight loss rate in ashing by aging was the highest in the 2nd decade (63.7%) and followed in order by 3rd decade (60.8%), seventh decade 959.8%), fourth decade (55.9%), sixth decade (52.6%) and fifth decade (43.2%). 2. The weight loss rate by ashing was more prominent in the buccal surfaces of the upper posterior teeth (62.0%) than in the lingual surface of the lower anterior teeth (59.7%). 3. The difference in contents of the inorganic constituents by sex was not remarkable. (male, Ca:373.0 P:333.9, female, Ca: 380.2, P: 339.6 ㎍/mg dry weight) 4. In the dry calulus, contents of the inorganic constituents were as follows: Ca:325.8 P:269.10 Mg:1.21 Na:8.44 K:1.32, Zn:0.67 ㎍/mg. 5. The Ca/P ratio was the lowest in the upper anterior region (1.11) and the highest in the lower posterior region (1.29) and the average was 1.20.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10c
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• pp.145-150
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• 1998

This study deals with the effect on performance of epoxy resign mortar mixed special cement for surface control and maintenance of aging concrete construction. The test of main property of epoxy resign in this study are the evaluation on the adhesive strength between substrate and epoxy resign mortar under the environment of wet or concrete substrate surface. We gained the test results of good adhesive strength over 15 kgf/$\textrm{cm}^2$ under the wet and dry condition of concrete surface.