• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.2
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• pp.159-166
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• 2018

In this study, the internal structural design, dynamic characteristics and load analyses of the small scaled rotor blade required for LCH(Light Civil Helicopter) main rotor wind tunnel test were carried out. The test is performed to evaluate the aerodynamic performance and noise characteristics of the LCH main rotor system. Therefore, the Mach-scale technique was appled to design the small scaled blade to simulate the equivalent aerodynamic characteristics as the full scale rotor system. It is necessary to increase the rotor speed to maintain the same blade tip speed as the full scale blade. In addition, the blade weight, section stiffness, and natural frequency were scaled according to the Mach-type scaling factor(${\lambda}$). For the design of skin, spar, torsion box, which are the main components of the blade, carbon and glass fiber composite materials were adopted, and composite materials are prepreg types that can be supplied domestically. The KSec2D program was used to evaluate the section stiffness of the blade. Also, structural loads and dynamic characteristics of the Mach scale blade were investigated through the comprehensive rotorcraft analysis program CAMRADII.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1211-1219
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• 2012

In this study, extracts from Caragana sinica flowers and leaves were tested for antioxidant and angiotensin converting enzyme inhibitory activities, along with xanthine oxidase, tyrosinase, elastase, and astringent effects. Total phenolic compounds of acetone extracts from Caragana sinica flowers and leaves were the highest at 3.42 and 2.98 mg/g, respectively, when various extraction solvents were used. Optimal conditions for extraction of phenolic compounds from Caragana sinica leaves and flowers were 70% ethanol for 18 hr. DPPH scavenging activities were the highest in 70% ethanol extracts of Caragana sinica. ABTS radical cation decolorization values of 70% ethanol extracts were higher than those 60% ethanol extracts at 74%. Antioxidant protection factor was 1.2 PF in 70% ethanol extracts from Caragana sinica flowers and leaves. TBARS was lower than that of control (0.54 ${\mu}M$) in all sections. Angiotensin converting enzyme inhibitory activity of Caragana sinica flower extract was 80~90% at a phenolic concentration of 0.2~1.0 mg/mL, whereas xanthin oxidase inhibitory activity of Caragana sinica leaf extract was higher than that of flower extract. Tyrosinase inhibitory activity, which is related to skin-whitening, was above 20%, whereas elastase inhibitory activity related to anti-wrinkle effect was above 50% at a phenolic concentration of 0.8 mg/mL. Astringent effects of Caragana sinica flower and leaf extracts were higher than tannic acid as a control at an equivalent concentration. This result suggests that extracts from Caragana sinica flowers and leaves are suitable as functional foods having anti-hypertension, anti-gout, and medicinal cosmetic activities, including whitening and anti-wrinkle effects.

• Journal of Radiation Protection and Research
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• v.24 no.4
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• pp.205-213
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• 1999

Effective dose conversion coefficients from unit activity radionuclides contaminated on the ground surface were calculated by using MCNP4A rode and male/female anthropomorphic phantoms. The simulation calculations were made for 19 energy points in the range of 40 keV to 10 MeV. The effective doses E resulting from unit source intensity for different energy were compared to the effective dose equivalent $H_E$ of previous studies. Our E values are lower by 30% at low energy than the $H_E$ values given in the Federal Guidance Report of USEPA. The effective dose response functions derived by polynomial fitting of the energy-effective dose relationship are as follows: $f({\varepsilon})[fSv\;m^2]=\;0.0634\;+\;0.727{\varepsilon}-0.0520{\varepsilon}^2+0.00247{\varepsilon}^3,\;where\;{\varepsilon}$ is the gamma energy in MeV. Using the response function and the radionuclide decay data given in ICRP 38, the effective dose conversion coefficients for unit activity contamination on the ground surface were calculated with addition of the skin dose contribution of beta particles determined by use of the DOSEFACTOR code. The conversion coefficients for 90 important radionuclides were evaluated and tabulated. Comparison with the existing data showed that a significant underestimates could be resulted when the old conversion coefficients were used, especially for the nuclides emitting low energy photons or high energy beta particles.

• Korean Journal of Human Ecology
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• v.11 no.3
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• pp.273-285
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• 2002

Three materials for sport underwear were manufactured by order for study, and among them, suitable material in order to perform an experiment on the effect of wearing was adopted. The results are as follows: The result of wearing an experimental clothes for sports manufactured as a foundation-type underwear for sports showed that if the same compositional materials were applied, laminating material had higher rate than that of others in the amount of sweat. Concerning relative humidity in clothes and the amount of sweat absorbed in clothes among the two kinds of materials which were produced by laminate, material 2(nylon+modal) was statistically exerts higher influence on the amount of sweat. The humidity in clothes keeps the optimal condition of 59.8%, and breast part showed the highest relative humidity. The material 2(nylon+modal) showed the highest comfortableness, the sense of warmth, humidity and voluminousness, and the sense of pressure. Follow-up survey revealed that in case of material 2, higher amount of sweat than that of the group objects in its early phase, and the amount of sweat varies from individuals. The temperature in clothes of folded parts of experimental clothes and maximum surface temperature was equivalent to that of average skin. With the lapse of time, the weight decreased of 11.03% in maximum, and 3.12% in minimum. The amount of change in the girth was greater in part of body frame than that of limbs, and especially, navel and waist part showed high decrease, and upper breast, breast and the largest part of abdomen showed relatively low decrease. The above experiment revealed that materials for suitable to the underwear for sports for loss of weight by an exercise should be made of doubled-nylon and modal, along with the laminate processing, which heightens the amount of sweat. Thus, wearing an experimental wear gave satisfaction in the view of the beauty of appearance as it did not discharge flowing secretion to the outside at the time of exercise.

• Journal of Radiation Protection and Research
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• v.39 no.4
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• pp.159-167
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• 2014

In Korea, July 2012, the law as called 'Act on Safety Control of Radioactive Rays Around Living Environment' was implemented to control the consumer product containing Naturally Occurring Radioactive Material (NORM), but, there are no appropriate database and effective dose calculation system. The aim of this study was to develop evaluation technique of the exposure dose with the use of the consumer products containing NORM and to understand the characteristics of the exposed dose according to the radiation type and energy. For the evaluate of exposure dose, the ICRP reference phantom was simulated by the MCNPX code based on Monte Carlo method, and the minimum, medium, maximum energy of alphas, betas, gammas from the representative NORM of Uranium decay series were used as the source term in the simulation. The annual effective doses were calculated by the exposure scenario of the consumer product usage time and position. Short range of the alpha and beta rays are mostly delivered the dose to the skin. On the other hand, the gamma rays mostly delivered the similar dose to all of the organs. The results of the annual effective dose with $1Bq{\cdot}g^{-1}$ radioactive stone-bed and 10% radioactive concentration were employed with the usage time of 7 hours 50 minute per day, the maximum annual effective dose of alphas, betas, gammas were calculated 0.0222, 0.0836, $0.0101mSv{\cdot}y^{-1}$, respectively.

• Food Science and Preservation
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• v.15 no.3
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• pp.456-460
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• 2008

Santalum album has been used as a folk medicine for treatment of skin diseases, inflammation, gonorrhea, gleet, and cystitis in India and other Asian countries. In a search for possible bioactive agents from natural sources, we found that the various solvent extracts of S. album showed significant antioxidative effect in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity test and moderate other biological functions submitted to the several bioassay systems for whitening and cytotoxicity evaluations. Among the tested extracts displayed DPPH radical scavenging activity, and the 70% acetone extract showed the most potent activity with an $IC_{50}$ value of $18.6\;{\mu}g/ml$, more potent than a positive control, L-ascorbic acid ($IC_{50}$, $28.7\;{\mu}g/mL$). Also, anti-lipid peroxidation, tyrosinase inhibitory, and cytotoxic effects were determined in each experiment. Total phenolic content of 70% acetone extract was found to be 117.1 mg equivalent of gallic acid per g of extract. Previous phytochemical investigation reveals the presence of phenolic compounds. The results indicate that S. album possess potential antioxidant activity and phenolic constituents are responsible for this capacity.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.261-266
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• 2015

To quantitatively evaluate the total phenolics, total flavonoids, and antioxidant capacity in the leaves, bulbs, and roots of fresh Allium hookeri, they were extracted using various solvents including water, aqueous methanol (20, 40, 60, and 80%; v/v), and absolute methanol. The leaves had the highest levels of total phenolics (240.4-276.6 mg gallic acid equivalents/100 g) and total flavonoids (9.7-34.1 mg catechin equivalents/100 g). The highest antioxidant capacities of 78.7- 103.4 mg vitamin C equivalents (VCE)/100 g, 24.4-59.0 mg VCE/100 g, and 1,798.8-2,169.7 mg VCE/100 g in the leaves were also observed using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC) assays, respectively. The total phenolics had a higher linear correlation with antioxidant capacity than the total flavonoids. In general, 60% (v/v) aqueous methanol extract had higher levels of total phenolics and flavonoids, and higher antioxidant capacity than any other solvents used. This study suggested that A. hookeri might be a good source of phenolics and antioxidants.

• Journal of Life Science
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• v.32 no.5
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• pp.348-354
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• 2022

The leaves, stems, seeds, and roots of Dendropanax morbifera have been used since ancient times as folk medicines for the treatment of headaches, skin diseases, infectious diseases, and other ailments. This study investigated the antioxidant, alcohol metabolism, and hepatoprotective effects of D. morbifera leaf and stem water extracts. The total polyphenol content of the D. morbifera leaf and stem water extracts was 49.56 mg tannic acid equivalent (TAE)/g, and the 1,1-diphenyl-2-picrylhydrazy (DPPH) radical scavenging activity of the D. morbifera leaf and stem water extracts was 84.09% at 1,000 ㎍/ml concentration. The effects of D. morbifera leaf and stem water extracts on alcohol metabolism were determined by measuring the generation of reduced nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH). The ADH and ALDH activities of D. morbifera leaf and stem water extracts were increased in a dose-dependent manner at 37.68% and 41.67%, respectively, at a 1,000 ㎍/ml concentration. The D. morbifera leaf and stem water extracts showed significant protective effects against tacrine-induced cytotoxicity in HepG2 cells at 50 ㎍/ml. Based on our results, we concluded that D. morbifera leaf and stem water extracts may be used as major pharmacological agents, such as antioxidants, alcohol metabolism, and anti-hepatitis remedies.

• Journal of Life Science
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• v.28 no.11
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• pp.1369-1378
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• 2018

Prunus mume Siebold & Zucc., a member of the Rosaceae family (called Maesil in Korea), has been widely distributed in East Asia, e.g. Korea, Japan and China, and its fruit has been used as a traditional drug and health food. In this study, we evaluated physicochemical properties and physiological activities of condensed Prunus mume juice treated with pectinase (PJ). The values of total acidity, pH, sugar contents, turbidity moisture content of the PJ were 35.81%, 2.73, $54.36^{\circ}Brix$, 2.75 and 51.32%, respectively. The PJ had effective DPPH radical scavenging activity, reducing power effect, $H_2O_2$ scavenging activity and ${\beta}$-carotene bleaching effect. DPPH radical scavenging activities of PJ was 46.31%; their reducing power ($OD_{700}$) was 1.80; $H_2O_2$ scavenging activity of PJ was 91.62%; and ${\beta}$-carotene bleaching effect of PJ was 73.02%. Also, PJ showed effective levels of ${\alpha}$-glucosidase inhibition activity. The cell viability was measured by SRB assay. The PJ significantly decreased the cell viability of mouse melanoma cells (B16) and human melanoma cells (SK-MEL-2 and SK-MEL-28) in a dose-dependent manner, however, there was no effect on human keratinocyte HaCaT. In morphological study, PJ-treated SK-MEL-2 cells showed distorted and shrunken cell masses. Total polyphenol contents and total flavonoid contents of PJ were 588.31 mg% (gallic acid equivalent) and 860.45 mg% (rutin equivalent). The antiproliferative effect of PJ seems to be associated with the antioxidant activity of its flavonoid and polyphenol contents. In conclusion, PJ may be beneficial in development of a functional food material.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.225-232
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• 2014

Purpose : The purpose of this study was to evaluate the surface and superficial dose for patients requiring postmastectomy radiation therapy(PMRT) with different treatment techniques. Materials and Methods : Computed tomography images were acquired for the phantom(I'mRT, IBA) consisting of tissue equivalent material. Hypothetical chestwall and lung were outlined and modified. Five treatment techniques(Wedged Tangential; WT, 4-field IMRT, 7-field IMRT, TOMO DIRECT, TOMO HELICAL) were evaluated using only 6MV photon beam. GafChromic EBT3 film was used for dose measurements at the surface and superficial dose. Surface dose profiles around the phantom were obtained for each treatment technique. For superficial dose measurements, film were used inside the phantom and analyzed superficial region for depth from 1-6mm. Results : TOMO DIRECT showed the highest surface dose by 47~70% of prescribed dose, while 7-field IMRT showed the lowest by 35~46% of prescribed dose. For the WT, 4-field IMRT and 7-field IMRT, superficial dose were measured over 60%, 70%, and 80% for 1mm, 2mm, and 5mm depth, respectively. In case of TOMO DIRECT and TOMO HELICAL, over 75%, 80%, and 90% of prescribed dose was measured, respectively. Surface and superficial dose range were uniform in overall chestwall for the 7-field IMRT and TOMO HELICAL. In contrast, Because of the dose enhancement effect with oblique incidence, The dose was gradually increased toward the obliquely tangential angle for the WT and TOMO DIRECT. Conclusion : For PMRT, TOMO DIRECT and TOMO HELICAL deliver the higher surface and superficial doses than treatment techniques based linear accelerator. It showed adequate dose(over 75% of prescribed dose) at 1mm depth in skin region.