• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.05a
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• pp.236-237
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• 2001

In this study, experiments were carried out to measure the variations in the corrosion potential and current density of polarization curves with amorphous $Fe_{70}Cr_5Si_{10}B_{15}$ and $Co_{70}Cr_5Si_{10}B_{15}$ alloy ribbon. The results were particularly examined to identify the influences of corrosion potential including various conditions such as hydrochloric acid, temperature, salt, pH, and oxygen. The optimum conditions were established with variations including temperature, salt, pH, oxygen, corrosion rate, and resistance of corrosion potential. The mass tranfer coefficient(${\alpha}$) value was determined with the Tafel's slope for the anodic dissolution based on the polarization effect with optimum conditions. The second anodic current density peak and maximum passive current density were designated as the critical corrosion sensitivity($I_{r}/I_{f}$).

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.3
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• pp.107-113
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• 2009

The objective of this study is to investigate performance characteristics of a household refrigerator using a two-stage compression cycle. The performance of the two-stage compression cycle was measured by varying the compressor speed, condensing temperature, and evaporating temperature. The COP of the two-stage compression cycle was analyzed and then compared with that of the single-stage compression cycle. The optimum combination of compressor speeds for a low- and a high-stage was determined. The COP of the two-stage compression cycle using a PTC (parallel two-stage compression) method was 5.85% higher than that of a STC (serial two-stage compression) method at optimum operating conditions.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.128.2-128
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• 2003

Shoot blight was occurring on shoots of suckers of common lilac (Syringa vulgaris L.) growing in first author's apartment garden in May 2003. A species of Phytophthora was isolated from the lesions. The isolate did not sporulate on agar media but formed sporangia in water and also formed sex organs in single culture. Sporangia were semipapillate, ovoid obpyriform, measured 45.6-52.8 ${\times}$ 33.6-36.0$\mu\textrm{m}$. Sporagia were very variable in shape. Optimum temperature for mycelial growth was 25$^{\circ}C$. Oogonia were spherical and antheridia were paragynous. Optimum temp for mycelial growth was 25$^{\circ}C$. The isolate was identified as Phytopkhora citricola on the basis of the morphological characteristics and cardinal temperature.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.265-272
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• 1988

This experiment was carried to investigate the germination pattern in relation to temperatures and lights, and the emergence pattern in relation to seeding depths, lights and the alpha amylase activity of Youngia sonchifolia, Lactuca indica var. laciniata, Ixeris dentata var. albiflora and Ixeris polycephala. In Y. sonchifolia, the optimum germination temperature was $25^{\circ}C$, the optimum seeding depth to emerge was 0 mm and it could emerge in 0-5mm. In L. indica var. laciniata under cool storage, the optimum germination temperatures were $19^{\circ}C-28^{\circ}C$, the optimum seeding depth was 5mm and it could emerge in 0-20mm. In L. indica var. laciniata under room storage, the optimum germination temperature was $25^{\circ}C$ the optimum seeding depth was 5mm and it could emerge in 0-10mm. In I. dentata emerge was and 0mm and it could emerge in 0-5mm. In I. polycephla, the optimum temperatures were $16^{\circ}C-19^{\circ}C$, the optimum seeding depth to emerge was 0mm and it could emerge in 0-5mm. The alpha amylase activity was lower Y. sonchifolia, L. indica var. laciniata and I. dentata var. abiflora than barley cultivar Dongbor#1. And the increased pattern of alpha amylase activity was likely to it of germination rate.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.10
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• pp.505-509
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• 2004

The (Sr/sub 0.9/Ca/sub 0.1/)TiO₃(SCT) thin films are deposited on Pt-coated electrode(Pt/TiN/SiO₂/Si) using RF sputtering method at various substrate temperature. The optimum conditions of RF power and Ar/O₂ ratio were 140[W] and 80/20, respectively. Deposition rate of SCT thin film was about 18.75[Å/min]. The crystallinity of SCT thin films were increased with increase of substrate temperature in the temperature range of 100～500[℃]. The dielectric constant of SCT thin films were increased with the increase of substrate temperature, and changed almost linearly in temperature ranges of -80～+90[℃]. The current-voltage characteristics of SCT thin films showed the increasing leakage current as the substrate temperature increases.

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.619-623
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• 1989

The effects of temperature on yeast growth and ethanol production were investigated in batch cultures. The maximum specific growth rate of yeast was obtained at 36$^{\circ}C$ and the maximum specific production rate of ethanol was obtained at 33$^{\circ}C$. A mathematical model was employed to describe the temperature effects in ethanol fermentation and the parameters in the model were expressed as a function of temperature. Optimum temperature control strategy, from the simulation result, consists of starting the fermentation at high temperature and lowering the temperature as the fermentation proceeds.

• Journal of Welding and Joining
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• v.20 no.1
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• pp.69-75
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• 2002

This study investigated the effect of the system parameters on penetration depth measurement using infrared temperature sensing system. The distance from focusing lens to detector was varied to diminish the error in measuring weld bead width. The effect of bead surface shape on measured surface temperature profile was evaluated using specimen heated by electric resistance. The measuring distance from laser beam was changed to optimize the measuring point. The results indicated that the monitoring device of surface temperature using infrared detector array was applicable to real time penetration depth control.

• 한국도로학회:학술대회논문집
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• 2010.09a
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• pp.401-406
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• 2010

• 한국도로학회:학술대회논문집
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• 2005.11a
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• pp.127-132
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• 2005

• International Journal of Air-Conditioning and Refrigeration
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• v.6
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• pp.27-35
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• 1998

An experimental study was performed to investigate the optimum cycle of an inverter heat pump as a function of frequency. The performance of the inverter heat pump with the rated cooling capacity of 4,141 W(3,550kcal/h) was measured with a variation of frequency, indoor and outdoor temperature, and length of capillary tube in the psychrometric test room. As a base case, the inverter heat pump with the standard capillary length of l,000mm(optimum size for the frequency of 60Hz) and ASHRAE Test condition "A" was tested by varying frequency from 30Hz to 80Hz. Then, the optimum cycles were investigated by varying the length of capillary tube at each frequency level of 30, 60 and 80Hz. Based on the experimental data, the change of system characteristics between the optimum and the base case were analyzed for each selected frequency level. Generally, for low frequency level(30Hz), the longer length of the capillary tube compared with the standard size showed the higher energy efficiency ratio(EER), while for high frequency level(80Hz) the shorter length of the capillary tube showed the higher EER.