• The Journal of Engineering Geology
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• v.26 no.3
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• pp.383-392
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• 2016

This study is to evaluate the physical and mechanical properties on the Ipseok-dae columnar joints of Mt. Mudeung National Park. For these purposes, physical and mechanical properties as well as discontinuity property on the Mudeungsan tuff, measurement of vibration and local meteorology around columnar joints, and ground deformation by self-weight of columnar joints were examined. For the physical and mechanical properties, average values were respectively 0.65% for porosity, 2.69 for specific gravity, 2.68 g/cm³ for density, and 2411 m/s for primary velocity, 323 MPa for uniaxial compressive strength, 81 GPa Young's modulus, and 0.25 for Poisson's ratio. For the joint shear test, average values were respectively 3.15 GPa/m for normal stiffness, 0.38 GPa/m for shear stiffness, 0.50 MPa for cohesion, and 35° for internal friction angle. The JRC standard and JRC chart was in the range of 4~6, and 1~1.5, respectively. The rebound value Q of silver schmidt hammer was 57 (≒ 90 MPa). It corresponds 20% of the uniaxial compressive strength of intact rock. The maximum vibration value around the Ipseok=dae columnar joints was in the range of 0.57 PPV (mm/s)~2.35 PPV (mm/s). The local meteorology of surface temperature, air temperature, humidity, and wind on and around columnar joints appeared to have been greatly influenced the weather on the day of measurement. For the numerical analysis of ground deformation due to its self-weight of the Ipseok-dae columnar joints, the maximum displacement of the right ground shows when the ground distance is approximately 2 m, while drastically decreased by 2~4 m, thereafter was insignificant. The maximum displacement of the middle ground shows when the ground distance is approximately 0~2 m, while drastically decreased by 3~10 m, thereafter was insignificant. The maximum displacement of the left ground shows when the ground distance is approximately 5~6 m, while drastically decreased by 6~10 m, thereafter was insignificant.

• Progress in Medical Physics
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• v.16 no.2
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• pp.82-88
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• 2005

In this study, the physical compensator made with the high density material, Cerrobend, and the electronic compensator realized by the movement of a dynamic multileaf collimator were analyzed in order to verify the properness of a design function in the commercial RTP (radiation treatment planning) system, Eclipse. The CT images of a phantom composed of the regions of five different thickness were acquired and the proper compensator which can make homogeneous dose distribution at the reference depth was designed in the RTP. The frame for the casting of Cerrobend compensator was made with a computerized automatic styrofoam cutting device and the Millennium MLC-120 was used for the electronic compensator. All the dose values and isodose distributions were measured with a radiographic EDR2 film. The deviation of a dose distribution was $\pm0.99 cGy\;and\;\pm1.82cGy$ in each case of a Cerrobend compensator and a electronic compensator compared with a $\pm13.93 cGy$ deviation in an open beam condition. Which showed the proper function of the designed compensators in the view point of a homogeneous dose distribution. When the absolute dose value was analyzed, the Cerrobend compensator showed a $+3.83\%$ error and the electronic compensator showed a $-4.37\%$ error in comparison with a dose value which was calculated in the RTP. These errors can be admtted as an reasonable results that approve the accuracy of the compensator design in the RTP considering the error in the process of the manufacturing of the Cerrobend compensator and the limitation of a film in the absolute dosimetry.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.213-220
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• 2014

This study was conducted to evaluate the effects of high n-3 or n-6 diet on free fatty acid profile and meat quality traits of pork loin. The 20 heads of commercial $Landrace{\times}Yorkshire{\times}Duroc(LYD)$ crossbreed pigs ($90.9{\pm}2.4BWkg$) were divided into four groups by added fat and oils, such as 5% tallow (Control), 5% linseed oil (T1), 5% safflower oil (T2), and mixture of linseed oil (2.5%) + safflower oil (2.5%) (T3), then reared 4 weeks. Pork loins were taken after slaughter, then sliced in 2 cm thickness and put in low-density polyethylene (LDPE) bag for analysis. T1 showed significantly high concentration of linolenic acid ($2.35{\pm}0.21%$) (p<0.05). The total amount of saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA) and poly-unsaturated fatty acid (PUFA) was significantly high in T1 ($36.05{\pm}1.18%$), C ($22.60{\pm}2.11%$) and T2 ($47.80{\pm}1.29%$), respectively (p<0.05). However, the ratio of n-6:n-3 was significantly low in T1 ($11.57{\pm}0.90$) than that of T2 ($37.56{\pm}12.51$) (p<0.05). There was no signigicant difference in lightness, redness, pH, water holding capacity and cooking loss between treatments (p>0.05). However, the yellowness of T2 was significantly higher than others (p<0.05). From those results, it was considered that feeding high n-3 and n-6 fatty acid diet to pig enables modify fatty acid profile of pork without any side effect on meat quality.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.3
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• pp.41-48
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• 2021

This study aimed to develop an alternative organic fertilizer to castor oil cake-based fertilizers. To assess the nutrient effect of the developed fermented mixed organic fertilizers, the yield of lettuce and soil characteristics after growth were analyzed and compared to those of a trial using a mixed expeller cake fertilizer. Two fermented mixed organic fertilizers, FA and FB, each containing 5.0% nitrogen, 2.6% phosphate, and 1.4% potassium, were produced by mixing different ratios of rice bran, dried distillers grains, sesame oil meal, and fish meal. This study was conducted with six trials: untreated, mixed expeller cake fertilizer, and the fermented mixed organic fertilizers FA and FB. Based on the amount of nitrogen fertilization (70 kg ha^-1) on the lettuce, the fermented mixed organic fertilizers FA and FB were applied at 100% and 150%, respectively, and the mixed oil cake was applied at 100%. As the amount of treatment increased, there was no significant difference except the number of leaves in FA treatment. The yields from the FA100 and FB100 treatments were 38.2 and 40.8 Mg ha^-1, respectively, which was not significantly different from that of the mixed expeller cake fertilizer treatment at 38.3 Mg ha^-1. In addition, the nitrogen uptake and utilization efficiency of the lettuce were not significantly different between mixed expeller cake fertilizer and fermented mixed organic fertilizer treatments. Analysis of the chemical properties of the soil after the trial showed that he mixed expeller cake fertilizer treatment showed the lowest pH. There were no significant differences in electrical conductivity, content of soil organic matter, available phosphate, and exchangeable cation among the fertilizer treatments. However, the bacterial and actinomyces density was higher in the soil from the fertilizer trials than in the non-fertilizer trials. These results indicated that the two tested fermented mixed organic fertilizers had nourishing effects and soil characteristics that were similar to those of the mixed expeller cake fertilizer. Thus, farmers can use these fermented mixed organic fertilizers as alternatives to castor oil cakes for the cultivation of organic lettuce.

• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.83-92
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• 2023

This study was established to investigate the site environment of mixed forests in Korea and to estimate the growth and yield of stands using national forest resources inventory data. The growth of mixed forests was derived by applying the Chapman-Richards model with diameter at breast height (DBH), height, and cross-sectional area at breast height (BA), and the yield of mixed forests was derived by applying stepwise regression analysis with factors such as cross-sectional area at breast height, site index (SI), age, and standing tree density per ha. Mixed forests were found to be growing in various locations. By climate zone, more than half of them were distributed in the temperate central region. By altitude, about 62% were distributed at 101-400 m. The fitness indexes (FI) for the growth model of mixed forests, which is the independent variable of stand age, were 0.32 for the DBH estimation, 0.22 for the height estimation, and 0.18 for the basal area at breast height estimation, which were somewhat low. However, considering the graph and residual between the estimated and measured values of the estimation equation, the use of this estimation model is not expected to cause any particular problems. The yield prediction model of mixed forests was derived as follows: Stand volume =-162.6859+6.3434 ∙ BA+9.9214 ∙ SI+0.7271 ∙ Age, which is a step- by-step input of basal area at breast height (BA), site index (SI), and age among several growth factors, and the determination coefficient (R²) of the equation was about 96%. Using our optimal growth and yield prediction model, a makeshift stand yield table was created. This table of mixed forests was also used to derive the rotation of the highest production in volume.

• Korean Journal of Environmental Biology
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• v.26 no.4
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• pp.279-291
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• 2008

The seasonal distribution pattern of the Bivalvia samples collected from 12 stations in Gamak Bay in April, July, September and November from 2001 to 2006. A total of 28 species (226.72$\pm$196.20 ind. m$^{-2}$) were identified. The COD has decreased from 3.30 mg L$^{-1}$ to 1.89 mg L$^{-1}$ level on average and especially, the COD of sediment has decreased from 21.51 mg g-dry$^{-1}$ to 16.99 mg g-dry$^{-1}$ level on average. Therefore, water quality level of Gamak Bay was improved from level 3 to 2. The dominant species over 1.0 percentages were composed of the total 13 species, and they occupied 96.75% of the total density of the Bivalvia. Major dominant species was Musculista senhousia 100.38 ind. m$^{-2}$ (22.16%), Moerella rutila 69.00 ind. m$^{-2}$ (15.23%), Theorafragilis 49.70 ind. m$^{-2}$ (10.97%), Mytilus edulis 42.18 ind. m$^{-2}$ (9.31 %), and Raphia undulata 40.99 ind. m$^{-2}$ (9.05%). This area could be divided into three groups by the cluster analysis based on the total species composition.

• Journal of the Korean Applied Science and Technology
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• v.34 no.2
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• pp.244-253
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• 2017

The aim of this study was to investigate the bioactivity and antioxidant activity of peel from Gardenia jasminoides Ellis fructus (GJE). We were separated into GJE peel. After that, we determined anthocyanin. GJE peel were extracted by 70% methanol, distilled water (DW) and ethyl acetate (EA) three solvents. To investigate by the solvent extract of total phenol content and value as a functional food ingredient of GJE peel through nitrogen oxide scavenging activity, antioxidant activity, reducing power and lipid peroxidation inhibition were performed. Solvent extract bioactivity of increasing concentrations (0.2, 0.4, 0.6 mg/mL) were significantly increased (p<0.05). GJE peel extracts showed lower activity than positive control (ascorbic acid, BHA, trolox). The total phenol contents of GJE peel extracts were highest in EA extract. However, the order of total phenol content of the solvent in the GJE peel and the results of analysis of various physiological activities were inconsistent. Considering the extraction yield and various physiological activities, it is expected to be effective when extracted from 70% methanol and DW extract. The results suggest that GJE peel is highly expected to be useful as a functional foods and natural antioxidant.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.327-334
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• 2014

Light intensity is one of the most important requirements for plant growth, affecting growth, development, survival, and crop productivity. Sunlight is the main energy source on Earth which is energy used by photosynthesis to convert light energy to chemical energy. In this study, the light use efficiency and photosynthetic characteristics of high-quality rice cultivars were evaluated after shading on ripening stage. For the study, we treated of three levels of shade (0, 50 and 70%) on rice at ripening stage and two levels of nitrogen (9 and 18 kg/10a) used three high yielding rice cultivars, such as Boramchan, Hopum, and Honong. The shade was given for the respective plots from heading up to harvesting. We were performed to determine growth survey, SPAD and chlorophyll fluorescence every 10 days interval after shading on ripening stage. At harvest stage, grain yield and yield components were determined. Results of analysis of the results representing the maximum photosynthetic efficiency of PSII, Fv/Fm, and SPAD were decreased by depending on the time at full sunlight. But shade treatments were not changed and a significant difference among cultivars did not appear. Compared with the full sunlight, shade treatments significantly delayed ripening rate and decreased rice quality of cultivated rice. Therefore, rice yield, can be reduced in proportion to the shading density is apparent, the rate of decrease was not observed difference between varieties, when protected from light 70%, and decreased to less than 50%. The adverse effects of low light intensity on the yield and yield components were not able to significantly minimize by the nitrogen level.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.332-340
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• 2009

In this study, the thermal insulation effectiveness of the greenhouse insulators by the installation methods was investigated to find the right installation way of the insulation materials. Physical properties of the insulators such as thickness, air transmissivity, apparent density, ultraviolet rays cutoff ratio, reflectance, thermal conductivity, moisture absorptivity were evaluated and the insulation ability of the insulators were measured by the module experiments. For the same insulator, the insulation ability of the case with the outward direction of the black colored face, i.e., with the inward direction of the white colored face, was better than that of vice versa. The case of the black colored both surfaces was better than the case of the white colored both surfaces. For aluminium reflection material, the case with the outward direction of the lustre face, i.e., with the inward direction of the non-lustre face, was better than that of vice versa. For the same material with the inner thin polyethylene foam (or polyester) and the chemical wool, the case with the outward direction of the inner thin polyethylene foam (or polyester), i.e., with the inward chemical wool, was better than that of vice versa. Addition of the inner thin polyethylene foam increased the insulation effect very much.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.8
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• pp.950-955
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• 2007

Non-point source control system which had been designed only for oil-water separation in the fields of oil refinery and garage was upgraded in this research for the removal of runoff pollutants in impervious urban area. Pollutants including oil from driveway and bridge were eliminated by two types of pathway in the system. One is the coalescence mechanism that the oil droplets in the runoff come into contact with each other in the spiral buoyant media surface and form larger coalesced droplets of oil that are carried upstream to the oil layer. The other is the precipitation that solids in runoff were settled by gravity in the system. In this research, coalescing characteristics of oil and water separation were investigated through image analyses, and efficiencies of the non-point source control system were evaluated using dust in driveway and waste engine oil. Media made of high density and high molecular weight polyethylene was indeterminate helical shape and had sleek surface by analysing SEM photographs and BET. Surface area and specific gravity of media which were measured directly were 1,428 $mm^2$ and 45.3 $kg/m^3$ respectively. From the image analyses of the oil droplets photographs which were taken by using microscope, it was proved clearly that the coalescence was the main pathway in the removal of oil from the runoff. Finally, the performances of the non-point source control system filled up with the media were suspended solid $86.6\sim95.2%$, $COD_{Cr}$, $87.3\sim95.4%$, n-Hexane extractable materials $71.8\sim94.8%$ respectively.