• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.210-216
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• 2008

Leuconostoc mesenteroides SM isolated from a raw carrot was used for the fermentation of carrot juice (CJ). Lactic acid fermentation of CJ was performed at $25^{\circ}C$ for 24 hr with $0{\sim}20%$ sucrose concentration, resulting in the production of mucilage. The fermented CJ showed the complete conversion of sugar into dextran after fermentation for 24 hr in the presence of sucrose below 15% concentration. With 15% sucrose, the fermented CJ had pH 3.8, 0.9% acidity, consistency index of $3.5\;Pa{\cdot}s^n$. After cold storage for 3 weeks, fermented CJ showed slight increase in acidity and relatively constant value in pH; however, the consistency index, red color value and viable cell counts were slightly decreased for 3 weeks. The ${\beta}-carotene$ content in CJ was drastically decreased by lactic acid fermentation for 24 hr, indicating $72\;{\mu}g/mL$ as compared to $142\;{\mu}g/mL$. The fermented CJ had improved body texture, red color and stability without sedimentation.

• Korean Journal of Metals and Materials
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• v.46 no.2
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• pp.65-68
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• 2008

Generally CCM (cold crucible melting) is not suitable for melting glass. However, in this study we described the quantitative relationship between the basic property of glass and power balance, the power absorption in the melt, the losses in the coil and the cold crucible, for melting glass in CCM. The dependence of power balance on the applied frequency and the electric conductivity has been found. Above 300 kHz, the glass (B) contained alkali ion which has the low resistance $3.0{\Omega}{\cdot}cm$ at $900^{\circ}C$ and $1.36{\Omega}{\cdot}cm$ at $1,100^{\circ}C$ was melted easily and 60% of the overall power was absorbed in the melt and 30% and 10% of the overall power was lost in the cold crucible and coil respectively. Under the same condition, the glass (A) contained non-alkali ion was not melted easily and 50% of the overall power was absorbed in the melt and 40% and 10% of the overall power was lost in the cold crucible and coil respectively. In conclusion, the small absorbed power of the overall power in melt prevented a successful melting as for glass A, and the successful melting depends on the relative size of the absorbed power in melt irrespective of the melting volume. Hence, as typical for direct induction heating method(CCM), the successful melting strongly depended on the chosen working frequency based on electric conductivity of glass, power balance and the control of the critical power which was absorbed in melt.

• Transactions of Materials Processing
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• v.7 no.2
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• pp.158-167
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• 1998

Hot restoration mechanism flow stress and stain of the Al2024 composites reinforced with 1,8,15,36, and $44{\mu}m\;SiC_p$(10 vol. %) were studied by hot torsion tests. The hot restoration mechanism of all the composites was found to be dynamic recrystallization(DRX) at $320^{\circ}C$ while that of the composites reinforced with 1 and $8{\mu}m\;SiC_p$ was found to be dynamic recovery(DRX) at $480^{\circ}C$. It was found that the Al2024 composite with $15{\mu}m\;SiC_p$ showed the highest flow stress(${\sim}$223 MPa) at $320^{\circ}C$ under a strain rate of 1.0/sec. Also the highest flow strain of the composites was obtained at $430^{\circ}C$. The com-posites reinforced with 1 and $8{\mu}m\;SiC_p$ showed lower flow stress and higher flow strain at $480^{\circ}C$ than those of the composites reinforced with 15, 36, and $44\;{\mu}m\;SiC_p$ These result were discussed in relation to the transition of the hot restoration mechanism. $DRX{\leftrightarrow}DRV$. The dependence of flow stress on strain rate and temperature was attempted to fit with the hyperbolic sine equation ($\dot{\varepsilon}=A[sinh({\alpha}{\cdot}{\sigma}_p]^n$ exp(-Q/RT)and Zener-Hollomon parameter($Z=\;\dot{\varepsilon}\;exp(Q/RT))$.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.5
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• pp.527-535
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• 2015

As a new technical approach, a hydraulic and magnetic clamp device was attempted to realize a magnetic clamp crane system that uses 8 simultaneously actuating individual hydraulic cylinders. Through this approach, a Sr type of ferritic permanent magnet ($SrO{\cdot}6Fe_2O_3$), not the previously employed electro-magnet, was utilized for the purpose of lifting and transporting the heavy weighted and oversized curved steel plates used for manufacturing the ships. This study is aimed at manufacturing and developing the hydraulic magnetic clamp prototype, which is composed of three main parts - the base frame, cylinder joint, and magnet joint - in order to safely transport such curved steel plates. Furthermore, this research was pursued to conduct a performance evaluation as to the prototype manufacture and acquire the planned quantity value and the development purpose items. The most significant item for a performance evaluation was estimated for the magnetic adhesive force (G) and in this process, a ferritic permanent magnet (Sr type) with 3700~4000 G of residual induction (Br) and 2640/2770 Oe of coercive force (Hc) was utilized. In addition, other relevant items such as hoist tension (kN), transportation time (sec), and the applied load (Kgf) exerted on the hydraulic cylinders were also evaluated in order to acquire the optimum quantity value. As a result of the evaluation, the relevant device turned out to be suitable for safely transporting the curved steel plates.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1284-1289
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• 2007

The Biological Activated Carbon (BAC) process in the water treatments represents a kind of biofiltration process which capabilities of bacteria to remove organic matters are maximized. It enables to eliminate organic matters and effectively reduce microbial regrowth potentials. As attached bacteria employ natural organic matter as a substrate, they are significantly dependent on indigenous microorganisms. In this study, characteristics of bacterial community by culturable and unculturable Methods have been conducted in a pilot plant using SAC in water treatment process at the downstream of the Nakdong River. Based on the results, HPC and bacterial- production for coal-based activated carbon material were $1.20{\sim}56.2{\times}l0^7$ cfu/g and $1.2{\sim}3.7\;mgC/m^{3}h$, respectively, in the SAC process. The highest level of attached bacteria biomass and organic carbon removal efficiency was found in the coal-based activated carbon. The genera Pseudomonas, Flavobacterium, Alcaligenes, Acilzetobacter, and Spingomonas were identified for each activated carbon material. Pseudomonas vesicularis was the dominant species in the coconut- and coal-based materials, where as Pseudomonas cepacia was the dominant species in the wood-based material. The Scanning Electron Microscope (SEM) observation of the activated carbon surface also found the widespread distribution of rod form and coccus. The community of attached bacteria was investigated by performing Fluorescent in situ hybridization (FISH) analysis. a group was dominant in coal, wood and coccunt-based materials, ${\alpha},\;{\beta}\;and\;{\gamma}$ group ranged from 27.0 ${\sim}$ 43.0%, 7.1 ${\sim}$ 22.0%, 11.3 ${\sim}$ 28.6%, respectively. These results suggest that a group bacterial community appears to be regulated removal efficiency of organic material in water treatment process.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.140-145
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• 2017

This study was conducted to find out the effects of $CO_2$ fertilization (1,000ppm) on the quality and storability of 'Maehyang' strawberry fruits. Qualities such as firmness, soluble solid, and acidity of strawberry fruits showed higher numbers in those treated with $CO_2$ fertilization compared to those after harvest. Strawberry fruits were stored at $8^{\circ}C$; MA condition using $20,000cc{\cdot}m^{-2}{\cdot}day^{-1}{\cdot}atm^{-1}$ OTR (oxygen transmission rate) films and conventional condition using unsealed PE box stored for 20 and 10 days, respectively. Fresh weight loss rate was less than 1.0% in MA storage regardless of $CO_2$ fertilization treatment. Concentrations of oxygen, carbon dioxide, and ethylene in OTR films did not show any significant difference between $CO_2$ fertilization treatment and control (nontreatment) during storage. $CO_2$ fertilization treatments maintained higher firmness after storage regardless of storage methods, but soluble solid, acidity, and surface color did not differ among the treatments. Visual quality and off-flavor based on sensory evaluation was the highest in $CO_2$ fertilization treated strawberry and stored at a MA condition, and was the lowest in $CO_2$ fertilization treated strawberry and those stored in a conventional condition, respectively. The fungal incidence rate of strawberry fruits showed less in $CO_2$ fertilization treatment than control during both MA and conventional storage. These results suggest that $CO_2$ fertilization can improve firmness, increase visual quality after harvest and storage at $8^{\circ}C$, and the MA storage method enhances the shelf-life of 'Maehyang' strawberry fruits.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.7-14
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• 1981

Secondary amines are known as one of the precursors of nitrosamines which are potent carcinogenic compounds for human being and animals. In this study, trimethylamine and dimethylamine contents of salted, hot-air dried and sun dried samples of two commercial fishes, mackerel pike and seerfish were analyzed and quantitatively compared at three different temperature conditions. The formation of both secondary amines was more rapid at$10^{\circ}C\;and\;15^{\circ}C\;than\;at\;2^{\circ}C$. Residual amounts of trimethylamine oxide of salted samples were relatively higher than those of the other samples. Trimethylamine contents of hot-air dried mackerel pike and sun dried seerfish were relatively higher than those in the other samples, while those of salted samples were comparatively lower than those of others. Dimethylamine contents of hot-air dried samples were higher than those of the other samples, whereas those of salted samples were comparatively lower than those of the other samples.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.403-408
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• 2010

This study was carried out to investigate the physiological responses of $Rhododendron$ $mucronulatum$ Turcz. and $R.$ $indicum$ (L.) Sweet seedlings with 0%, 35%, 55% and 75% shading of full sunlight in polyethylene film house. The shading treatments were performed during the late growth season for each species (from Sept. 9 to Nov. 5, 2008). The shading treatment was effective in reducing the daily temperature by 0.9 to $1.7^{\circ}C$ during September and by 0.8 to $1.7^{\circ}C$ during October. Before the shading treatments, the water content of $R.$ $mucronulatum$ and $R.$ $indicum$ amounted to 68.5% and 66.3%, respectively. The water contents of two species after 75% shading treatment period decreased to 66.2% (3.4% reduction) and 65.9% (0.6% reduction), respectively. Notably, both species had a similar tendency indicating less reduction rate of water content with 75% shading. $R.$ $indicum$ showed higher photosynthetic capacity with higher level of shading, and its photosynthetic capacity reached the highest level ($9.63{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). On the other hand, shading-treated $R.$ $indicum$ showed higher intercellular $CO_2$ concentration, stomatal conductance and transpiration rate (55% shading > 35% shading > 75% shading) than non-treated ones. In addition, non-treated seedlings showed higher water use efficiency than treated ones. In particular, it was found that the leaf color of $R.$ $mucronulatum$ turned equivalent to purple under full sunlight, while its leaf color kept equivalent more to green with higher level of shading, as evidenced even in naked eyes. According to comprehensive analysis using Munsell Color Chart on potential leaf color variations of $R.$ $mucronulatum$ depending on the level of shading, it was found that relatively many leaf colors under full sunlight were equivalent to R (red) and Y (yellow) chart, while relatively many leaf colors with higher level of shading were equivalent to G (green) and Y chart, where the latter still showed green color.

• Journal of Food Hygiene and Safety
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• v.20 no.2
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• pp.83-88
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• 2005

This study was conducted to estimate the contents of heavy metals including lead, cadmium, zinc, copper as well as iron status(serum iron, total iron binding capacity, feritin etc)in blood samples of middle school students(n=300). The contents of heavy metals were determined using the GF-AAS (Graphite furnace Atomic Absorption Spectrophotometer). The microwave digestion method and dilution method were compared. The dilution method showed the better recovery and detection limit than microwave digestion method. The values of toxic metals in whloe blood of boys & girls were 3.46 & 3.05 for Pb,0.063 & 0.065 for Cd respectively (ug/dL). Also the values of trace metals in serum of boys & girls were 105.9 & 92.6 for Zn, 98.3 & 99.0 for Cu respectively (ug/dL). The prevalence of iron deficiency was $7.5\%$ in 146 boys and $14.3\%$ in 156 girls. The mean values of lead in girls were higher in iron deficiency, iron deficiency anemia and anemia groups than normal group. The mean values of lead and zinc were higher in boys compared to those in girls(P<0.05), the mean values of cadmium and copper in boys were similar to those in girls. Our results of toxic metals such as Pb & Cd showed lower to CDC's(Centers for Disease Control) blood lead levels of concern for children, 10 ug/dL.

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.124-131
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• 2015

Radiation exposure to humans can be caused by the gamma rays emitted from natural radioactive elements(such as uranium, thorium and potassium and any of their decay products) of Naturally Occurring Radioactive Materials(NORM) or Technologically Enhanced Naturally Occurring Radioactive Materials(TENORM) added consumer products. In this study, assume that activity of radioactive elements is $^{238}U$, $^{235}U$, $^{232}Th$ $1Bq{\cdot}g^{-1}$, $^{40}K$ $10Bq{\cdot}g^{-1}$ and the gamma rays emitted from these natural radioactive elements radioactive equilibrium state. In this study, reflected End-User circumstances and evaluated annual exposure dose for products based on ICRP reference voxel phantoms and ICRP Recommendation 103 using the Monte Carlo Method. The consumer products classified according to the adhere to the skin(bracelet, necklace, belt-wrist, belt-ankle, belt-knee, moxa stone) or not(gypsum board, anion wallpaper, anion paint), and Geometric Modeling was reflected in Republic of Korea "Residential Living Trend-distributions and Design Guidelines For Common Types of Household.", was designed the Room model($3m{\times}4m{\times}2.8m$, a closed room, conservatively) and the ICRP reference phantom's 3D segmentation and modeling. The end-user's usage time assume that "Development and Application of Korean Exposure Factors." or conservatively 24 hours; in case of unknown. In this study, the results of the effective dose were 0.00003 ~ 0.47636 mSv per year and were confirmed the meaning of necessary for geometric modeling to ICRP reference phantoms through the equivalent dose rate of belt products.