• The Korean Journal of Ecology
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• v.9 no.1
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• pp.19-24
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• 1986

Effects of temperature, pH, light-and-dark and degree of oxygen supply on germination of Papaver somniferum L. seeds were investigated. The optimum temperature of the germination was 2$0^{\circ}C$, but the germination was decreased as temperatures changed to the upper and lower. The largest elongation of both radicle and hypocotyl also occurred at 2$0^{\circ}C$. The best germination occurred at pH 7 but this decreased suddenly the above and below of that pH value. Although no effect of light-and-dark on the germination was, this was restricted under limited. oxyten supply in terms of underwater germination as compared with abovewater one.

• Korean Journal of Materials Research
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• v.16 no.5
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• pp.318-322
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• 2006

Short-term high temperature degradation test was conducted on Hastelloy X, a candidate tube material for high temperature gas-cooled reactors (HTGR), to evaluate the variation of microstructure and mechanical property in air at $1050^{\circ}C$ during 2000 h. The dominant oxide layer was Cr-oxide and a very shallow Cr-depleted region was observed below the oxide layer. At the beginning of degradation, the island shape $M_6C$ precipitate (M=Mo-rich, Fe, Ni, Cr) was observed in matrix region. After 2000 h degradation, precipitate shape was changed to the chain shape and increased amount of precipitate. These results influenced mechanical property of the specimen which exposed in high temperature. Yield strength was decreased from 115MPa to 89 MPa after 24 h and 2000 h exposure, respectively.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.12
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• pp.1588-1595
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• 2000

Natural convection heat transfer in an enclosure with an opening in the right veritcal wall and a heat source at the bottom surface is investigated using a holographic interferometric technique. The effects of the opening length, divider length attached to the top wall, and heater temperature on the temperature distribution are examined. The opening length as well as the divider length greatly affects the degree of inflow and outflow of air. In the case of small opening length, the opening doesnt affect much the upward warm air flow resulting in the symmetric temperature distribution .The upward flow in hindered by the divider resulting in the decrease of heat transfer from the heater region to the upper region. The longest divider shows the highest temperature in the lower region of enclosure. In the case of large opening length, the inward cold flow moves the upward flow to the left direction. Among the cases of different divider length, the case of H(sub)d=0.25H shows the highest temperature in the lower region of enclosure.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.7
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• pp.532-536
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• 2011

The silicon nitride films were prepared by chemical vapor deposition using inductively coupled plasma. During the deposition, the substrate was heated at $150^{\circ}C$ and power 1,000 W. To evolution low temperature manufacture, we have studied the role of source gases, $SiH_4$, $NH_3$, $N_2$, and $H_2$, to produce Si-N and N-H bond in a-SiNx:H film growth. $SiH_4$, $NH_3$, and $N_2$ flow rate fixed at 100, 10, and 10 sccm, $H_2$ flow rate varied from 0 to 10 sccm by small scale. To get the electrical characteristics, we makes MIM structure, and analysis surface bonding state. Experimental data show that Si-N and N-H bond is increased and hence electrical characteristics is showed 3 MV/cm breakdown-voltage, and leakage-current $10^{-7}\;A/cm^2$.

• Journal of the Korean Ceramic Society
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• v.24 no.5
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• pp.500-506
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• 1987

In order to synthesize monodispersed spherical silica fine particles, we investigated the reaction of hydrolysis of 0.05∼4.0 mole Si(OC2H5)4-0.01∼7.60mole NH3 -0.24∼38.40 mole H2O-2.62∼16.88mole C2H5OH systems. The range of the composition of solution which spherical silica particles were formed was enlarged according to an increase in concentration of Si(OC2H5)4. Larger particles were obtained at higher molar ratios of Si(OC2H5)4/C2H5OH, NH3/H2O and H2O/Si(OC2H5)4 and at a lower reaction temperature.

• Journal of Aquaculture
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• v.3 no.1
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• pp.79-88
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• 1990

In order to obtain the basic data fir the effective seed production of sea squirt, Halocynthia roretzi(Drasche), the influence of water temperature and light intensity on spawning induction, egg development and seed settling were investigated during the Period from December 24, 1906 to February 24, 1987. The maximum number of eggs spawned was obtained at $14^{\circ}C$. The relationships between the water temperature (T, $^{\circ}C$) and the required time (h, hour) in each egg developmental stage were given as follows : Up to 8 cell 1/h =0.0147 T-0.0069(.=0.9816), Up to 32 cell 1/h =0.0100 T-0.0017(r=0.9672), Up to early tadpole 1/h =0.0043 T+0.0024(r=0.9913), Up to hatching larva 1/h =0.0021 T-0.0021 (r=0.9898). The highest rate of seed attachment was obtained at $14^{\circ}C$ of water temperature.

• Journal of the Korean Ceramic Society
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• v.37 no.6
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• pp.545-551
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• 2000

Sintering behaviors of the glass-alumina composites for low firing temperature were investigated as a function of the particle size of glass frit. The system of glass frit was Pb-B-Si-Al-O. The median particle sizes of the glass frits were 2.72$\mu\textrm{m}$, 2.67$\mu\textrm{m}$ and 1.33$\mu\textrm{m}$, which were prepared with changing ball-milling times as 24 h, 48 h and 96 h. The glass-alumina composites showed maximum density at certain temperature, and further heating led to dedensification behaviors, so called over-firing. The sintering temperature, which showed maximum density, raised from 425$^{\circ}C$ to 475$^{\circ}C$ with increase of particle size of glass frit from 1.33$\mu\textrm{m}$ to 2.72$\mu\textrm{m}$. Especially, the over firing behaviors, which were occurred at high sintering temperatures, were greatly increased with decrease of particle size of glass frit.

• The Korean Journal of Malacology
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• v.31 no.1
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• pp.1-8
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• 2015

This study was conducted to investigate the effects of elevated water temperature (WT) on biochemical and immunological factors in the hemolymph of the abalones, Haliotis discus hannai and H. discus discus. The abalone were exposed to various WT; 20, 22, 24, 26 and $28^{\circ}C$ for 4 days. In the control and $20^{\circ}C$, total-protein (TP), glucose and calcium (Ca) in hemolymph of H. discus discus were higher than the values in H. discus hannai. The values of magnesium (Mg), alkaline phosphatase (ALP) and lysozyme in H. discus hannai were similar to the H. discus discus in the control. There were no significant alterations in TP, glucose and Mg levels of hemolymph in H. discus hannai and H. discus discus by WT increases. The values of Ca, ALP and lysozyme were increased in H. discus hannai exposed to the high temperature (26 and $28^{\circ}C$) compared to control, while the values in H. discus discus were not significant difference between the WT groups. The phenoloxidase (PO) activity was increased in hemolymph of H. discus hannai exposed to high temperature (${\geq}24^{\circ}C$) compared to the control (P < 0.05). These physiological and immunological parameters were significantly changed in H. discus hannai. However, these parameters in H. discus discus were barely altered at the high WT (P < 0.05). These results suggested that H. discus hannai is considered to be more sensitive than H. discus discus at the high WT.

• Journal of Welding and Joining
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• v.26 no.6
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• pp.54-58
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• 2008

Laser welding with AZ61 filler wire was carried out to improve formability though reduction of porosity and formation of under fill bead. Optimum welding condition and mechanical properties of butt joint for $400{\times}500{\times}1.3mm$ magnesium sheets were studied. Optimal welding conditions of laser power, welding speed, and defocusing length are 1000W, 3m/min, and 2mm, respectively. Results of tensile test indicated that both tensile strength and elongation of specimens welded with filler wire were improved at room temperature because of reduction of porosity and under-filled bead formation in addition to the precipitation hardening and microstructure refinement by Al-Mn and Mg-Al-Zn precipitates. At elevated temperature of $200{\sim}350^{\circ}C$, fracture location of tensile specimen was shifted from weld metal to base metal, indicating less softening of weld metal than base metal.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.65-72
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• 2019

This study investigated the effects of temperature ($50^{\circ}C$, $55^{\circ}C$, and $60^{\circ}C$) and time (12 and 24 h) on the cookery properties of sous-vide (SV) processed pork loin. As an indicator of cookery properties, cooking loss, expressible moisture (EM), pH, differential scanning calorimetry (DSC), shear force, total plate count (TPC) and CIE color were measured and compared with fresh (FC) and cooked control (CC, $75^{\circ}C$ for 30 min). SV treatments at $50^{\circ}C$ showed higher tenderness and lower cooking loss comparing to CC. DSC result indicated that thermal transition of collagen was a key factor affecting the cooking loss and shear force of meat. In comparison of CC, risks of insufficient pasteurization and uncooked color generation were not shown in SV processed meat. Therefore, the results indicated that SV had a potential advantage to produce tender and moist meat, and the best SV condition of pork loin was estimated at $50^{\circ}C$ for 24 h.