• Journal of Environmental Science International
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• 제26권12호
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• pp.1307-1319
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• 2017

In this study, we investigated the impact of different initial data on atmospheric modeling results using the Weather Research and Forecast (WRF) model. Four WRF simulations were conducted with different initialization in March 2015, which showed the highest monthly mean $PM_{10}$ concentration in the recent ten years (2006-2015). The results of WRF simulations using NCEP-FNL and ERA-Interim were compared with observed surface temperature and wind speed data, and the difference of grid nudging effect on WRF simulation between the two data were also analyzed. The FNL simulation showed better accuracy in the simulated temperature and wind speed than the Interim simulation, and the difference was clear in the coastal area. The grid nudging effect on the Interim simulation was larger than that of the FNL simulation. Despite of the higher spatial resolution of ERA-Interim data compared to NCEP-FNL data, the Interim simulation showed slightly worse accuracy than those of the FNL simulation. It was due to uncertainties associated with the Sea Surface Temperature (SST) field in the ERA-Interim data. The results from the Interim simulation with different SST data showed significantly improved accuracy than the standard Interim simulation. It means that the SST field in the ERA-Interim data need to be optimized for the better WRF simulation. In conclusion, although the WRF simulation with ERA-Interim data does not show reasonable accuracy compared to those with NCEP-FNL data, it would be able to be Improved by optimizing the SST variable.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제44권1호
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• pp.31-36
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• 2011

This study developed a normal temperature-circulatable retort-sterilized crab analog (RSCA) with a long shelf-life by retort sterilization. We examined the optimum sterilization conditions and quality characteristics of the RSCA. A central composite design for response surface methodology (RSM) was adopted to optimize of the retort sterilization. The central composite design consisted of 11 samples: four factorial points, four star points, and three central points. The sterilization temperature and $F_0$-value for retort sterilization were the independent variables, and the shearing force, whiteness, and sensory score for texture were the dependent variable. The RSM analysis of the multiple response optimization for the RSCA using the Minitap statistical programing gave an $F_0$-value of 3.3 min. at $117.5^{\circ}C$. The RSM analysis also indicated that the sterilization temperature during retort sterilization was the most influential factor, while the $F_0$-value had little effect on the quality of the RSCA. The moisture, pH and volatile basic nitrogen contents of the RSCA product were 73.1%, 7.3 and 17.2 mg/100 g, respectively, and viable cells count was >18 CFU/g. And sensory quality characteristics of this RSCA was similar to those of a commercial crab analog.

• KSBB Journal
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• 제28권2호
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• pp.65-73
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• 2013

This study aimed to investigate the enzymatic hydrolysis of mannitol using Viscozyme$^{(R)}$ L, Celluclast$^{(R)}$ 1.5 L, Saczyme$^{(R)}$, Novozym$^{(R)}$, Fungamyl$^{(R)}$ 800 L, Driselase$^{(R)}$ Basidiomycetes sp., and Alginate Lyase, and to optimize of reaction conditions for production of reducing sugar. Response surface methodology (RSM) based on central composite rotatable design was used to study effects of the independent variables such as enzyme (1-9% v/w), reaction time (10-30 h), pH (3.0-7.0) and reaction temperature ($30-70^{\circ}C$) on production of reducing sugar from mannitol. The coefficient of determination ($R^2$) of $Y_1$ (yield of reducing sugar by Viscozyme$^{(R)}$ L) and $Y_3$ (yield of reducing sugar by Saczyme$^{(R)}$) for the dependent variable regression equation was analyzed as 0.985 and 0.814. And the p-value of $Y_1$ and $Y_3$ showing 0.000 and 0.001 within 1% (p < 0.01), respectively, was very significant. The optimum conditions for production of reducing sugar with Viscozyme$^{(R)}$ L were 9.0 % (v/w) amount of enzyme, 30.0 hours of reaction time, pH 4.5 and $30.0^{\circ}C$ of reaction temperature, and those with Saczyme$^{(R)}$ were 9.0% (v/w) of amount of enzyme dosage, 30.0 h of reaction time, pH 7.0 and $30.0^{\circ}C$ of reaction temperature, consequently, the predicted reducing sugar yields were 22.5 and 27.9 mg/g-mannitol, respectively.

• Membrane Journal
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• 제11권1호
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• pp.38-49
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• 2001

The surface of polyimide membrane was modified by plasma treatment using Ar and NH~. and the permeability and selectivity for the mixture gas $(CO_2/N_2=20/80 vol%)$ were measured. The per¬meation experiments were performed by a variable volume method at $30^{\circ}$C and total pressure of 5 atm, The effect of the plasma conditions such as treatment time, power input, gas flow rate and pressure in the reactor on the transport Dwperties of modified membranes was investigated. The surface of the plasma treated membrane was analyzed by means of FTlR - ATH, ESCA and AFM. The dependences of the wettability and the etching on plasma treatment time were investigated by use of the contact angle and the weight loss measurement. Measurements of gas pcnneability characteristic were performed using both dry and wet membranes. The effects of experimental conditions such as temperature on the membrane performance were studied.

• Fisheries and Aquatic Sciences
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• 제25권3호
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• pp.175-186
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• 2022

Sea mustard (Undaria pinnatifida), an important edible seaweed belonging to the brown algal family of Alariaceae, contains copious physiologically active substances. It has long been popular in Korea as a food and is frequently consumed in the form of soup. It is also commercially available as a home meal replacement. In this study, we developed a seasoning key base with a high degree of sensory preference from sea mustard using the extrusion cooking process. Extrusion cooking conditions were optimized through response surface methodology. Barrel temperature (X₁, 140℃-160℃) and screw speed (X₂, 158-315 rpm) were set as independent variables, and overall preference was determined as the dependent variable (Y, points). An optimal condition was obtained at X₁ = 148.5℃ and X₂ = 315 rpm, and the dependent variable (Y, overall acceptance) was 7.95 points, similar to the experimental value of 7.81. Umami taste had a relationship with the overall acceptance of sea mustard seasoning. In the electronic nose and tongue, increased sourness and umami intensities were associated with the highest sensory score. The samples were separated well by each characteristic via principal component analysis. Collectively, our study provides imperative preliminary data for the development of various seasonings using sea mustard.

• Korean Journal of Remote Sensing
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• 제37권2호
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• pp.211-220
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• 2021

Land Surface Temperature (LST) is one of the useful parameters to diagnose the growth and development of crop and to detect crop stress. Unmanned Aerial Vehicle (UAV)-based LST (LSTUAV) can be estimated in the regional spatial scale due to miniaturization of thermal infrared camera and development of UAV. Given that meteorological variable, type of instrument, and surface condition can affect the LSTUAV, the evaluation for accuracy of LSTUAV is required. The purpose of this study is to evaluate the accuracy of LSTUAV using LST measured at ground (LSTGround) under various meteorological conditions and growth phases of garlic crop. To evaluate the accuracy of LSTUAV, Relative humidity (RH), absolute humidity (AH), gust, and vegetation index were considered. Root mean square error (RMSE) after minimizing the bias between LSTUAV and LSTGround was 2.565℃ under above 60% of RH, and it was higher than that of 1.82℃ under the below 60% of RH. Therefore, LSTUAV measurement should be conducted under the below 60% of RH. The error depending on the gust and surface conditions was not statistically significant (p-value < 0.05). LSTUAV had reliable accuracy under the wind speed conditions that allow flight and reflected the crop condition. These results help to comprehend the accuracy of LSTUAV and to utilize it in the agriculture field.

• Journal of the Korean Solar Energy Society
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• 제31권1호
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• pp.37-43
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• 2011

In this paper, the optimized doping condition of crystalline silicon solar cells with $156{\times}156\;mm^2$ area was studied. To optimize the drive-in temperature in the doping process, the other conditions except variable drive-in temperature were fixed. These conditions were obtained in previous studies. After etching$7\;{\mu}m$ of the surface to form the pyramidal structure, the silicon nitride deposited by the PECVD had 75~80nm thickness and 2 to 2.1 for a refractive index. The silver and aluminium electrodes for front and back sheet, respectively, were formed by screen-printing method, followed by firing in 400-425-450-550-$850^{\circ}C$ five-zone temperature conditions to make the ohmic contact. Drive-in temperature was changed in range of $830^{\circ}C$ to $890^{\circ}C$to obtain the sheet resistance $30{\sim}70\;{\Omega}/{\box}$ with $10\;\Omega}/{\box}$ intervals. Solar cell made in $890^{\circ}C$ as the drive-in temperature revealed 17.1% conversion efficiency which is best in this study. This solar cells showed $34.4\;mA/cm^2$ of the current density, 627 mV of the open circuit voltage and 79.3% of the fill factor.

• Clean Technology
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• 제15권4호
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• pp.245-252
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• 2009

Profiles development of melt spinning process of poly(lactic acid) (PLA) was simulated via a numerical method and the radial temperature distribution was calculated using finite difference method. The spinning speed ranged from 1 km/min to 5 km/min was analyzed and the effect of spinning conditions on the radial temperature distribution was investigated. At low spinning speed, the difference between PLA and poly(ethylene terephthalate) (PET) was relatively small. As the spinning speed increased, the difference in velocity profile became prominent. PLA showed a slower spinning speed than PET and solidified more slowly. The temperature difference between the core and surface of the PLA filament reached 4.6 K, which was less than that of PET filament with a difference of 10.4 K. The radial temperature difference increased with increasing the cooling-air velocity and the spinning temperature.

• Journal of the Korean Society for Heat Treatment
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• 제24권3호
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• pp.127-132
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• 2011

The silicon-containing Diamond-like Carbon (Si-DLC) film as an low friction coefficient coating has especially treated a different silicon content by plasma-enhanced chemical vapor deposition (PECVD) process at $500^{\circ}C$ on nitrided-STD 11 mold steel with (TMS) gas flow rate. The effects of variable silicon content on the Si-DLC films were tested with relative humidity of 5, 30 and 85% using a ball-on-disk tribometer. The wear-tested and original surface of Si-DLC films were analysed for an understanding of physical and chemical characterization, including a changing structure, via Raman spectra and nano hardness test. The results of Raman spectra have inferred a changing intra-structure from dangling bonds. And high silicon containing DLC films have shown increasing carbon peak ratio ($I_D/I_G$) values and G-peak values. In particular, the tribological tested surface of Si-DLC was shown the increasing hardness value in proportional to TMS gas flow rate. Therefore, at same time, the structure of the Si-DLC film was changed to a different intra-structure and increased hardness film with mechanical shear force and chemical reaction.

• Journal of the Korean Wood Science and Technology
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• 제39권1호
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• pp.75-85
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• 2011

The main purpose of this study is to evaluate the potential of producing bioethanol from yellow poplar ($Liriodendron$ $tulipifera$) wood chips by oxalic acid pretreatment and to examine the pretreatment conditions by response surface methodology (RSM). Based on $2^3$ factorial design, adjusted variables were reaction temperature ($^{\circ}C$), residence time (min), and acid loading (g/g), and a series of distinct 15 experimental conditions was organized with duplication at central point (total 16 performances). After pretreatment, simultaneous saccharification and fermentation (SSF) was subjected on solid fraction with yeast strain $Pichia$ $stipitis$. Maximum ethanol yields of the most samples were measured at 72 hours and applied to RSM as a dependent variable. 9.7 g/${\ell}$ of ethanol was produced from the solid pretreated at $180^{\circ}C$ for 40 min with 0.013 g/g of oxalic acid loading. According to the response surface methodology, it was determined that the temperature is the most governing factor via statistic analysis.