• Journal of Forest and Environmental Science
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• v.10 no.1
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• pp.38-48
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• 1994

This study was carried out to estimate drying schedule of Fagaceae four species grown in Kangwon-Do by oven-drying at $100^{\circ}C$ which aimed to elucidate the characteristics such as current moisture content, drying process, initial check, collapse and internal check during drying. The results were summerized as follows ; Current moisture content of each board showed a rapid drying curve with the hight initial moisture content of board and species with the high initial moisture content took long to do drying. Appearance of checks for Quercus variabilis were extremely severe and estimated schedule was $T_5-C_2$. The shrinkage rate of grain direction was in the order of tangential direction > radial direction > longitudial direction and the shrinkage rate of oven-drying at $100^{\circ}C$ was bigger than normal shrinkage rate.

• Journal of the Korean Chemical Society
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• v.37 no.10
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• pp.867-873
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• 1993

Influences of crystallization time and $H_2O/Al_2O_3$ ratio of the reaction mixtures on the synthesis of AlPO$_4$-5 molecular sieve have been studied by X-ray powder diffraction, nitrogen adsorption, scanning electron microscope (SEM), and solid state $^{27}$Al magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. The degree of crystallinity of AlPO$_4$-5 follows a sigmoid pattem as crystallization time increases. The induction period is shorter than 1 h when the crystallization process is carried out at 150$^{\circ}$C. The conversion of reactants to product, AlPO$_4$-5, can be clearly observed, and all of the determined physical properties change abruptly after about 2 h. It is found that increase in $H_2O/Al_2O_3$ ratio of the reaction mixtures not only changes the crystal morphology from aggregates to hexagonal single crystals, but also results in the formation of longer AlPO$_4$-5 crystals.

• KSBB Journal
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• v.16 no.4
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• pp.430-434
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• 2001

Microorganisms of livestock wastewater were microscopically examined to identify bacillus types with optimal absorbance at 630 nm. Growth cuties of microorganisms at various levels of livestock wastewater (5, 10, 20, 30, 40, 50%) and different temperatures (20$\^{C}$ , 37$\^{C}$) were prepared to determine dilution at which microorganisms did not grow within 1 hour of inoculation, regardless of levels and temperatures. Heat treatment of livestock wastewater at 10 0$\^{C}$ for 2 minutes was good enough to inhibit the growth of microorganisms at 20$\^{C}$ and 37$\^{C}$. A good linear relationship was obtained between levels of livestock wastewater and absorbance at 630 nm (R=98.88%) and dry cell weight (98.98%). The dry cell weight of microorganisms in livestock wastewater was 0.375 g/L.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.4
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• pp.373-386
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• 2014

This paper concerns the deformation behavior of tunnels crossing weak zone during excavation. A three dimensional finite element model was adopted in order to conduct a parametric study on the orientation of weaj zone in terms of strike and dip angle relative to the tunnel longitudinal axis. The results of the analyses were then analyzed so that the tunnel displacements in terms of the ratios between the crown settlement and springline displacement can be related to the orientation of the weak zone. The results indicate that the displacement ratios between the tunnel crown and springline tend to quantitatively change when a weak zone exists near or ahead of the tunnel suggesting that the displacement ratios can be effectively used to predict the weak zone during tunnelling. Practical implications of the findings are discussed.

• Elastomers and Composites
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• v.42 no.3
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• pp.168-176
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• 2007

When the rubber vulcanizates reinforced with carbon black or silica are subjected to cyclic loading from its virgin state, the stress required on reloading is less than that on the initial loading. This stress softening phenomenon is referred to as the Mullins effect. The strain energy function of rubber vulcanizates was investigated using theory of pseudo-elasticity incorporated damage parameter that Ogden and Roxburgh have proposed to describe the damage-induced stress softening effect in rubber-like solids. The quasi-static cyclic loading test was performed using the NR-SBR vulcanizates reinforced with carbon black, and then the effect of a damage parameter to stress-strain curve in reloading and subsequent reloading paths was studied. The strain energy function of the rubber vulcanizates with a different filler content was also evaluated.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.3
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• pp.171-180
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• 2010

Analysis on the temporal variation of the stratification is carried out by using the continuous water temperature and salinity data observed in the coastal monitoring buoy in Mikawa Bay, Japan. The main analysis results are as follows. The stratification pattern have an obvious and dominant 1-year period variation and the occurrence frequency (days) are exponentially decreased as the stratification intensity (SI) defined as the density difference between surface and bottom layers linearly increases. The frequency distribution function of the SI is presumably close to the log-normal function type or exponential function type. From the water temperature and salinity scatter diagram analysis, the line and loop type patterns are shown in the bottom and surface layers, respectively. In addition, the analysis of the SI estimation show that the error bound in case of using the weekly-monitoring data is about 4.45 times greater than that in case of using the continuous (daily) monitoring data.

• The Korean Journal of Mycology
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• v.34 no.1
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• pp.34-38
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• 2006

To assess the effects of proton beam on radiation sensitivity of the basidiospore and mycelium of oyster mushroom (Pleurotus ostreatus), the $D_{10}$ values and $L_{50}$ (lethal 50%) values were analysed. By the proton beam radiation, the survival rate and germination rates increased at the dose of $10\;Gy{\sim}100\;Gy$ and then decreased significantly over 500 Gy. $L_{50}$ values of basidiospore and mycelium of Pleurotus ostreatus were over 500 Gy and 400 Gy, respectively. $D_{10}$ values were calculated from linear regression formulae ($D_{10}\;=\;-1/slope(b)$, y = a + bx) as 750 Gy and 1,250 Gy, respectively. Based on our experiment, the optimum dose of proton beam as a mutation source would be between from 500 Gy to 750 Gy for basidiospores and from 400 Gy to 1000 Gy for mycelium of oyster mushroom.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.169-175
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• 2006

Potentiometric biosensor using flow injection analysis system was developed to determine citrate concentration in foods. Biosensor system consisted of sample injector, peristaltic pump, enzyme reactor, carbonate ion selective solid-state electrode, reference electrode, detector, and recorder. Enzyme reactor was prepared with immobilized citrate lyase and oxaloacetate decarboxylase. Carbonate ions produced through enzyme reactions of citrate were potentiometrically detected by ion selective electrode. Optimum conditions for biosensor system were investigated. Interference effect of major sugars and organic acids was less than 5% on citrate biosensor system. Citrate concentrations in fruit juices were determined by biosensor and gas chromatography. No significant difference was observed between two analytical methods. Results indicate citrate biosensor is useful in determining citrate concentration in foods.

• Journal of the Korean Electrochemical Society
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• v.8 no.3
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• pp.130-134
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• 2005

To the best knowledge, the formation and characterization of InSb nanowires have not been reported yet in spite of its good characteristics as a III-V compound semiconductor. The nanowire arrays were potentiostatically electrodeposited in a mixing solution of indium chloride, antimony chloride, citric acid, and potassium citrate according to our previous work on the electrodeposition of the stoichiometric InSb films. The electrical properties of nanowire arrays were measured by semiconductor parameter analyzer, and the microstructural analysis of the nanowires was conducted by employing XRD. Our experimental results indicate that the InSb nanowires have a highly preferred orientation of (220) direction and also exhibit electrical characteristics of n-type semiconductors which we, however, similar to semi-metals mainly due to their narrow band-gap and high electron mobility.

• Journal of the Korean Electrochemical Society
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• v.8 no.3
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• pp.135-138
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• 2005

We investigated the electrochemical formation of a stoichiometric III-V compound semiconductor of InSb from an aqueous citric solution. Under an? optimized electrochemical condition, not like other research results, the electrodeposited InSb are satisfied exactly with the stoichiometry. Furthermore it retains the inherent characteristics of III-V compound semiconductor, InSb without heat treatment. EPMA, XPS and XRD were employed for confirmation of its composition/stoichiometry, chemical state, and crystallographic orientation, respectively.