• Economic and Environmental Geology
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• v.36 no.6
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• pp.537-543
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• 2003

As pyrite is commonly associated with arsenopyrite, the use of pyrite including arsenopyrite for medicine requires close attention on arsenic toxicity. The toxicity was reduced by traditional processing operations include heating and quenching in vinegar. To verify the scientific effects of this process, pyrite containing many crystals of arsenopyrite was processed at temperatures from 45$0^{\circ}C$ to 85$0^{\circ}C$ and through as many as 5 processing cycles. Arsenopyrite completely disappeared when processed only once at $650^{\circ}C$ while it remained even after 5 processing cycles at 45$0^{\circ}C$. Arsenic was most abundant in medicinal mineral samples processed at 45$0^{\circ}C$ and sharply decreased when processed at $650^{\circ}C$ or 85$0^{\circ}C$ And arsenic extraction test in water was carried out from the processed pyrite medicine on the assumption that pyrite medicines with the lowest As metal content would be most desirable. Arsenic were most abundant in water extracted from medicinal mineral samples processed at 45$0^{\circ}C$ and sharply decreased when processed at $650^{\circ}C$ or 85$0^{\circ}C$. But the extracted As concentrations in water exceeded drinking water standards even when processed at 85$0^{\circ}C$. Increasing temperature promoted elimination of arsenopyrite and reduction of As in medicinal minerals and the extraction solutions. But the effects of processing cycles at the same processing temperature were not clear. Heating temperature is more important than number of processing cycles for the removal of arsenic, and it is necessary to heat pyrite to over $650^{\circ}C$ to remove it.

• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.152-163
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• 1999

It is required to analyze the controlled response of air temperature in greenhouse according to control techniques for precise control. In this study, a mathematical model was established for air heating of greenhouse with hot-water heating system The parameters of the model were decided by regression analysis using reference data measured at the greenhouse being heated In the simulation for the digital control of air temperature in the greenhouse, the mathematical model to evaluate the control performances was used. Tested control methods were ON-OFF contpol, p control, rl control and PID control. The mathematical model represented by inside air temperature ( T$_{i}$), hot-water temperature (T$_{w}$) in heating pipe and outside air temperature (T$_{o}$) was expressed as a following discrete time equation ; T$_{i}$($textsc{k}$＋1)＝ 0.851.T$_{i}$($textsc{k}$)＋0.055.T$_{w}$($textsc{k}$)＋0.094.T$_{o}$($textsc{k}$) Control simulations for various control methods showed the settling time, the overshoot and the steady state nor as follows; infinite time, 3.5$0^{\circ}C$, 3.5$0^{\circ}C$ for ON-OFF control : 30min 2.37$^{\circ}C$, 0.51$^{\circ}C$ for P control; 21min, 0.0$0^{\circ}C$, 0.23$^{\circ}C$ for PI control; 18min 0.0$0^{\circ}C$, 0.23$^{\circ}C$ for PID control, respectively. PI and PID controls appeared to be optimal control methods. There was no effect of differential gain on the heating process but much effect of integral gain on it.on it.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.114-118
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• 1986

The study was conducted to find out the gene effects on litter size and birth weights in mice with 362 progenies from full-diallel crosses of four lines of BALB/c, CBA, C3H and C57BL. The progenies were farrowed at the Experimental Animal Farm, College of Agriculture, Kyungpook National University in November, 1984, and data were analyzed into general combining ability, specific combining ability and reciprocal effects with Griffing's model. General combining ability effects estimated in line-crosses were -0.4163~0.3337 for litter size and -0.0356~0.0894 for birth weights. However, no significant differences were observed in general combining ability effects on litter size and birth weights. Specific combining ability effects estimated in line-crosses were -1.0388~1.7913 for litter size and -0.1144~0.1343 for birth weights. However, the specific combining ability effects for litter size and birth weights appeared to be insignificant. The reciprocal effects, which appeared to be significant, were -2.26 from BALB/c ${\times}$ C3H, 1.84 from CBA ${\times}$ C57BL and -1.50 from BALB/c ${\times}$ CBA for litter size. For birth weights, the reciprocal effects were estimated -0.26 from CBA ${\times}$ C57BL, 0.15 from BALB/c ${\times}$ CBA and -0.15 from BALB/c ${\times}$ C57BL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.741-746
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• 2004

Drying of raw ginseng root down to 35% moisture content required for extrusion process. There were two kinds of pre-treatments of raw ginseng root which were chopping and whole-root ginseng before frying at 80, 100 and 12$0^{\circ}C$. Drying rate and physicochemical properties of dried ginseng were evaluated to determine optimum drying temperature for extrusion process. Drying time at 8$0^{\circ}C$ to decrease to 35% moisture was 6.5 hr and ginsenoside content in dried ginseng at 8$0^{\circ}C$ was lower than that of dried ginseng at 100 and 12$0^{\circ}C$. Drying time at 100 and 12$0^{\circ}C$ to decrease to 35% moisture was 5.5 and 3.5 hr and redness of dried ginseng powder was 5.20 and 7.23 respectively. Browness and redness of dried ginseng extract from 75% ethylene were significantly increased with the increase in drying temperature. Ginsenosides Rb1, Rb2, Rc, Rd, Rg1 and total saponin were also increased with the increase in drying temperature from 8$0^{\circ}C$ to 10$0^{\circ}C$, however, those were not significantly different with drying temperature at 100 and 12$0^{\circ}C$. Drying temperature for extrusion process can be optimal at 10$0^{\circ}C$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.407-410
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• 2000

(M $n_{l-x}$M $g_{l-x}$)F $e_{2+x}$ $O_4$(x=0.0, 0.025, 0.1, 0.2) for NTC(negative temperature coefficient) thermistor was prepared by calcining at 80$0^{\circ}C$ and sintering at from 1100 to 130$0^{\circ}C$ with 5$0^{\circ}C$ intervals while x was varied from 0.0 to 0.025, 0.1 and 0.2. The best linear property was obtained in the based specimen sintered at 120$0^{\circ}C$ with x=0.1 composition. Thermistor parameter, $B_{25~85^{\circ}C}$, was in the range of 5000~ 7300 [K]. Temperature coefficient of resistance, $\alpha$$_{25^{\circ}C}$, was -5.2 %/$^{\circ}C$. The results showed the possibility that Mn-Ni-Co based thermistor could be substituted by the composition used in this study was confirmed.med.d.

• Korean Journal of Microbiology
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• v.31 no.2
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• pp.105-112
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• 1993

Plesiomonas shigelloides distributed in the aquatic systems was isolated and identified in this study and compared with the c1inica] isolates in view of their physiological characteristics, Biochemica] charactristics of the isolates of P. shigelloides one sample taken from Gupo and two samples taken from Mu]gum, were studied. However, none was isolated in Haeundae, Dadaepo, Kangdong and Nakdong estuary. The isolated bacteria had an optimum growth condition in peptone water of $25~35^{\circ}C$, pH 7.5-8.0 and 1% NaCI concentration. The cell grew most properly on the selective enrichment media which were made from adding inositol to peptone water. DNase was s]owly produced and the results were different from those of other studies. The components of the fatty acid were 3% of 3-hydroxy]ated fatty acid containing $C_{12}~C_{18}$. 0-10% cyclopropane ($C_{17:0}$), 25~30% hexadecanoic acid ($C_{16:0}$), 32~43% hexadecenoic acid ($C_{16:1}$), 1~2% octadecanoic acid ($C_{16:0}$), and 9~14% octadecenoic acid ($C_{18:1}$). Bacterio]ogica] characteristics, susceptibility of antibiotics, and the components of fatty acid of the c1inica] isolates were similar to those of the strains isolated from the aquatic systems. The strains isolated from c1inica] sources degraded lactose more fast than those isolated from the aquatic systems. There existed resistant bacteria to chlorampenicol in the strains from patients, but there were no resistant bacteria in the strains from the aquatic systems. The components of fatty acid of the clinical isolates were 0~2% $C_{17:0 cyclo}$ and 2~3% $C_{18:0}$, but those of the strains from the aquatic systems were 2~10% and 1~2%, respectvely, which showed the quantitative difference between both components.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1015-1021
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• 2010

In this study, the effect of the C/SiC composition ratio on the impact damage of a reaction sintered SiC (RS-SiC) plates was evaluated. An impact test was conducted by using an air gun. The impacter used was a steel ball with a diameter of 2 mm, and the impact velocities were 113, 122, and 180 m/s. The RS-SiC plates were $20\times20\times3$ mm with different C/SiC composition ratios. The ring crack diameters damaged by a steel ball were determined using SEM images. It was observed that the maximum diameter increased with increasing impact velocity, and it rapidly changed with increasing C/SiC composition ratio because of the effect of residual Si and the variation flexural strength. Cone cracks were formed in the case of C/SiC composition ratios of 0.4~0.5, this indicated that the impact damage changed from a ring crack to a cone crack in this critical range of C/SiC composition ratios. The C/SiC composition ratio of 0.3 was determined to be the optimal ratio for the RS-SiC manufacturing process.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.525-532
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• 1995

The periods of germination and seedling emergence, epidermal cell size and the activities of peroxidase and amylase of 6 rice cultivars were examined to clarify the response to 3 temperature conditions, constant temperatures of 27$^{\circ}C$ and 17$^{\circ}C$ and alternating temperature of 24/1$0^{\circ}C$, in the dark condition. The periods of germination and seedling emergence were increased and the germination was delayed greater than the seedling emergence under 17$^{\circ}C$ and 24/l$0^{\circ}C$, compared with 27$^{\circ}C$. Lengths of epidermal cell of coleoptile and first leaf were reduced, but the widths were increased in the 17$^{\circ}C$ and 24/1$0^{\circ}C$, compared with 27$^{\circ}C$. The activities of peroxidase in the emerging shoots and amylase in the germinating seeds were reduced in 17$^{\circ}C$ and 24/1$0^{\circ}C$. There were significant correlations between peroxidase activities and the widths of epidemal cell of first leaf and between amylase activities and periods of germination. Varietal differences of all observations were remarkable in 17$^{\circ}C$ and 24 /1$0^{\circ}C$.

• Nuclear Engineering and Technology
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• v.16 no.2
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• pp.58-63
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• 1984

Paper electrophoretic separation of octahedrally bonded (Ruc $l_{6}$ )$^{3-}$ has been carried out by using the specially designed migration apparatus. The supporting electrolyte solutions are as follows: 0.1M-HCl $O_4$, 0.05 M-HCl+0.09M-KCl, 0.1M-HCl, 5$\times$10$^{-3}$ M-NTA, 0.01M-HCl, 0.01M-HCl $O_4$, 0.01M-citric acid, 0.01M-K $H_2$P $O_4$+0.01M-N $a_2$HP $O_4$, 0.05M-borax, 0.025M-N $a_2$C $O_3$+0.025M-NaHC $O_3$, 0.01M-N $a_3$P $O_4$, 0.01M-NaOH and 0.1 M-NaOH. The (Ruc $l_{6}$ )$^{3-}$ appears in 2 to 4 peaks and is found in several chemical species such as (RuCl ($H_2O$)$_{5}$ )$^{2+}$, cis and trans (RuC $l_2$($H_2O$)$_4$)$^{1+}$, (RuC $l_3$($H_2O$)$_3$)$^{0}$ , (RuC $l_4$($H_2O$)$_2$)$^{1-}$, (RuC $l_{5}$ ($H_2O$))$^{2-}$ and (RuC $l_{6}$ )$^{3-}$. The retention value has been found to be highest in the 0.025M-N $a_2$C $O_3$+0.025M-NaHC $O_3$ electrolyte solution.n.

• Analytical Science and Technology
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• v.5 no.3
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• pp.319-325
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• 1992

Plasma are melting method was used in making Mo-1.17 Ti-0.18 Zr-0.06 C ingot having over 99% of the theoretical density. Oxygen content herewith, decreased from the origin of 830ppm to 40ppm. After cold rolling of Mo alloy by 50%, the recrystallization behaviors were studied in the temperature range from $800^{\circ}C$ to $2100^{\circ}C$ for 1 hr isochronical holding time and also at $1400^{\circ}C$, $1500^{\circ}C$, $1600^{\circ}C$ for varying isothermal holding time 0 to 108000sec. The complete recrystallization temperature of Mo was $1400^{\circ}C$ but that of Mo alloy was $1700^{\circ}C$. 50%-1 hr recrystallization temperature of Mo alloy sheet was about $1500^{\circ}C$ and when compared to Mo there was an increase of over $300^{\circ}C$. The activation energy of recrystallization of Mo alloy sheet was 508kJ/mol.