• Journal of the Korean Institute of Gas
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• v.15 no.4
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• pp.7-14
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• 2011

Using 20 L spherical explosion vessel and differential scanning calorimeter (DSC), an experimental investigation was carried on explosion characteristics and thermal decomposition of some reactive organic dust. As the result, the minimum explosion concentration of Benzoyl peroxide (BPO), Phthalic anhydride (PA) and 1-Hydroxybenzotriazol (HBT) exist between 10 and 15 g/$m^3$, which indicates that their explosion sensitivity are high. The maximum Kst values of HBT, PA and 97 % BPO are 251, 146 and 80 [$bar{\cdot}m/s$], respectively and the explosion severity of HBT is the explosion class of St-2. The flame velocity was also calculated from the combustion time of dust and flame arrival time to estimate the flame propagation characteristics in a closed vessel. The decomposition temperature and heat of decomposition reaction for 97 % BPO and HBT are $107^{\circ}C$ (1025 J/g), $214^{\circ}C$ (1666 J/g), respectively and it was found that these low decomposition temperature and high released heat affect the explosion characteristics.

• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.20-25
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• 2008

This study was conducted to develop the industrial producing technology of sprout vegetables using the cut twigs of woody plants. We have cut the twigs of wild mulberry tree on 13 April,2006 to examine the sprouting rate as affected by the storage conditions on relative humidity of $40{\sim}50%$ and $80{\sim}90%$ under $4{\sim}6^{\circ}C$ temperature. And we have also investigated the sprouting growth following those storage period of twigs cut with $1{\sim}3$ buds. The longer storage periods, the less survival rate of wild mulberry twigs cut. The sprouting rate of cut twigs gathered on the day which had not stored at low temperature was 97.4%. And The sprouting rate at the relative humidity of $40{\sim}50%$ after storing at low temperature for 122 days were 34.2%, and that of at $80{\sim}90%$ relative humidity was 85.7%. The longer storage periods, the more the number, length and width of sprouts. Therefore, the twigs of a wild mulberry trees cut with $1{\sim}3$ buds were able to produce the sprout vegetables under the condition of temperature $4{\sim}6^{\circ}C$ and relative humidity $80{\sim}90%$.

• Journal of Aquaculture
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• v.6 no.3
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• pp.159-171
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• 1993

The effects of environmental factors (density, light, temperature) and live food on growth and survival rate of zoea and mysis of fleshy shrimp, Penaeus chinensis, were examined. The percent survival rates at the culture densities of 200 and 300 larvae per liter were significantly higher than that of 500 larvae per liter (p< 0.05). The percent survival rates at the culture densities of 100, 200, 300 and 500 larvae per liter were $90.3^{ab},\;95.2^a,\;94.3^a\;and\;86.7^b\%$ (p< 0.05). The effects of light conditions with diatom premix diet showed that continuous light was the best for the survival rate, $96.5\%$. Natural light and continuous darkness showed the survival rates $79.0\%\;and\;4.3\%$, respectively. On the rearing temperature, the survival rates were $97.3\%\;at\;19^{\circ}C\;and\;96.7\%\;at\;22^{\circ}C$ with little difference but the higher temperature resulted in faster growth. The survival rate was $51.6\%;at\;25^{\circ}C$ thus showing significant decrease compared to $19^{\circ}C\;and\;22^{\circ}C$. At this temperature the growth was also suffered. With regard to dietary value of live food, both the best survival rate and the fastest growth were obtained when 6 mixed species of diatom (A. normaii, C. simplex, N closterium, P. tricornutum, S. costatum and T. weissflogii) were provided. When single species was supplied the best survival rate $(82.1\%)$ was obtained with S. costatum, but the other species resulted in much inferior survival rates $(below\;80.0\%)$ and poor growth.

• Fire Science and Engineering
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• v.26 no.2
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• pp.84-89
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• 2012

For the safe handling of n-nonanol, this study was investigated the explosion limits of n-nonanol in the reference data. The flash points and AITs (autoignition temperatures) by ignition delay time were experimented. As a results, the lower and upper explosion limits of n-nonanol recommended 0.8 Vol.% and 6.1 Vol.%, respectively. The lower flash points of n-nonanol by using closed-cup tester were experimented $94{\sim}97^{\circ}C$. The lower flash points of n-nonanol by using open cup tester were experimented $103{\sim}104^{\circ}C$. This study measured relationship between the AITs and the ignition delay times by using ASTM E659-78 apparatus for n-nonanol. The experimental AIT of n-nonanol was $270^{\circ}C$.

• Applied Biological Chemistry
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• v.45 no.2
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• pp.108-113
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• 2002

The compositions of essential oils isolated from the aerial parts of Chrysanthemum boreale and C. indicum by steam distillation were analyzed by GC and GC-MS. Ninty-four components were identified in the essential oil from C. boreale, with camphor (15.40% as GC peak area), cir-chrysanthenol (14.11%), ${\alpha}-thujone$ (13.27%), 1,8-cineole (4.16%), ${\alpha}-pinene$ (3.80%), ${\beta}-caryophyllene$ (3.58%), gremacrene D (2.69%), camphene (2.40%), umbellulone (2.24%) and ${\beta}-pinene$ (2.00%) as the major constituents. In the oil from C. indicum, the major constituents among 80 components identified were germacrene D (16.50%), camphor (10.04%), ${\alpha}-thujone$ (6.40%), ${\alpha}-pinene$ (4.50%), ${\alpha}-cadinol$ (3.97%), camphene (3.82%), ${\beta}-pinene$ (3.67%), zingiberene (3.64%), cis-chrysanthenol (3.45%), piperitone (3.09%), 1,8-cineole (2.61%) and chrysanthenone (2.42%). The oil from C. boreale, although similar to that from C. indicum in many respects, contained proportionately higher levels of camphor, cis-chrysanthenol, ${\alpha}-thujone$, 1,8-cineole and umbellulone, while that from C. indicum contained higher levels of germacrene D, ${\beta}-caryophyllene$, ${\alpha}-cadinol$, zingiberene, cis-chrysanthenol and piperitone.

• Journal of the Korean Society of Food Culture
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• v.10 no.3
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• pp.133-137
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• 1995

The objectives of this study were to determine the chemical composition of persimmon pickles and microorganisms associated with the manufacture of persimmon pickles. Moisture content was 80.04% and sugar content was 13.72%, but crude ash content was 4.26% which meant some of sodium chloride in soaking solution were permeated into fresh persimmon. Soluble tannin and total vitamin C contents were decreased from 635.45 mg% and 34.53 mg% to 81.04 mg% and 23.76 mg%, respectively. Free sugars contained in persimmon pickles were glucose, fructose and sucrose, 17 kinds of free amino acids were detected including glutamic acid (24.97 mg%), aspartic acid (24.02 mg%) and leucine (22.33 mg%). Microorganisms asociated with the manufacture of persimmon pickles were identified as Bacillus subtilis, B. cereus, B. pumilus, B. thuringiensis, Candida glabrata, C. guilliermondi and Hansenula cnomala, especially C. glabrata was the strain which caused the swelling of vacuum packages of persimmon pickles in retail stores.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.397-400
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• 2009

This paper describes ASIC design of Multimedia application SoC platform based RISC processor with BTB(Branch Target Buffer). For performance enhancement of platform, we use a simple branch prediction scheme, BTB structure, that stores a target address for branch instruction to remove pipeline harzard. Also, the platform includes a number of peripheral such as VGA controller, AC97 controller, UART controller, SRAM interface and Debug interface. The platform is designed and verified on a Xilinx VERTEX-4 FPGA using a number of test programs for functional tests and timing constraints. Finally, the platform is implemented into a single ASIC chip which can be operated at 100MHz clock frequency using the Chartered 0.18um process. As a result of performance estimation, the proposed platform shows about 5~9% performance improvement in comparison with the previous SoC Platform.

• Electrical & Electronic Materials
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• v.10 no.2
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• pp.97-104
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• 1997

In this paper, in order to investigate the behavior of charged particles on (Sr.Ca)TiO$_{3}$ ceramics with paraelectric properties, the characteristics of electrical conduction and thermally stimulated current was measured respectively. As a result, the conduction mechanism is divided into three regions having different mechanism as the current increased. The region I below 200[V/Cm] shows the ohmic conduction. The region B between 200[V/cm] and 2000[V/cm] can be explained by the Poole-Frenkel emission theory, and the region III above 2000[V/cm] is dominated by the tunneling effect. The three peaks of TSC were obtained at the temperature of -20[.deg. C], 20[.deg. C] and 80[.deg. C], respectively. The origins of these peaks are that the .alpha. peak observed at -20[.deg. C] looks like to be ascribed to the ionization excitation from donor level in the grain, and the .alpha.' peak observed at 20 [.deg. C] appears to show up by hopping conduction of the trapped carrier of border between the oxidation layer and the grain, and the .betha. peak observed at 80[.deg. C] seems to be resulted from hopping conduction of existing carrier in the trap site of the border between the oxidation and second phase.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.27-32
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• 2005

We propose an effective and environmentally friendly dry stripping method using a supercritical carbon dioxide ($SCCO_2$) system modified by a single and multiple cosolvents to remove ion-implanted photoresist and residue from a wafer surface at three different temperatures (97, 148, $200^{\circ}C$) and pressures (200, 300, 400 bar). After high dose of ion implantation the photoresist was not easily removed by using pure $SCCO_2$, but swollen. The $SCCO_2$ system modified by single cosolvents and multiple cosolvents mixed with aprotic solvents could not effectively remove the heavy organics, but swell them. However, the $SCCO_2$ system modified with multiple cosolvent (5%, v/v) composed of DMSO and DIW showed high removal efficiency for ion-implanted photoresists at $97^{\circ}C$ and 200 bar for 30 min (about 80%). In this study it has been shown that the dry stripping method using $SCCO_2$ system modified with multiple cosolvents could replace either plasma ashing or acid and solvent wet bench method and dramatically reduce accompanied chemical usage and disposal.

• Korean Journal of Crystallography
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• v.12 no.2
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• pp.97-101
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• 2001

Phillipsite-type zeolite powders were synthesized from domestic coal fly ash by hydrothermal reaction with 2.0 M-3.5M NaOH solution at $80^{\circ}C{\sim}120^{\circ}C$ for 24 h. The properties of zeolite were investigated by XRD, SEM and IR spectroscopy. The effects of chemical composition of fly ash, reaction temperature and NaOH concentration on the zeolite synthesis were well appeared on IR spectra. It is found that the $TO_4$(T=Si, Al) tetrahedra have a well ordered structure as the $SiO_2$ content, synthesis temperature and NaOH concentration become high.