• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.487-490
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• 2008

Temperature programmed oxidation (TPO) is used to characterize coke species deposited on commercial nickel catalyst, C11-PR during propane pre-reforming. Propane pre-reforming performed under various condition, S/C from 1.5 to 2.5 and temperature from $350^{\circ}C$ to $450^{\circ}C$. There are three kinds of coke species detected by TPO: (i) reactive coke, (ii) coke deposited on metal site and (iii) coke deposited on acid support. Coke deposited on metal and support are minimized although reactive coke is generated at temperature of $400^{\circ}C$ and S/C of 2.0. Reactive coke is expected to remove easily below temperature of $200^{\circ}C$. Therefore, optimized pre-reforming condition for propane is $400^{\circ}C$ and S/C of 2.0.

• 한국표면공학회지
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• 제43권6호
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• pp.309-314
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• 2010

The numerical study for the effect of various factors that affect the temperature distribution of the process glass installed above the large rectangular heater plate was carried out. For the calculation, heat flux, distance between heat source and process glass plate, effect of vacuum condition and convection in a chamber were considered as important factors. The results showed that the temperature gradient on the glass was increased at the natural convection because of the buoyancy force increases due to the heated air. Also, the more heat flux and distance between the heater plate and glass increases, the more increasing the temperature gradient was. In the case of isothermal heating wall, the temperature variation was smaller than the uniform heat flux condition.

• Restorative Dentistry and Endodontics
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• 제19권1호
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• pp.27-44
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• 1994

The purpose of this study was to determine the effects of pH, temperature and time on the synthesis of hydroxyapatite(HAP) by spontaneous precipitation under relatively physiologic condition. Specimens were obtained from aqueous system with various pH, temperature and experimental time. Chemical composition, crystallographic structure and crystallinity of the synthetic HAP were evaluated by Infrared spectroscopy and powdered X-ray diffraction method. The following results were obtained. 1. No precipitate was obtained under pH 5.5. 2. All the specimens were concluded as HAP except one that was obtained under the condition of pH 6.5, $25^{\circ}C$ and 1 day. It was concluded as dicalcium phosphate dihydrate(DCPD). 3. The crystallinity of HAP was enhanced by increases in pH, temperature and time of the preparation. But, the crystallinity of the synthetic HAP was lower than that of the mineral HAP. 4. Intermediates such as DCPD and octacalcium phosphate were formed on the process of the synthesis of HAP.

• 오토저널
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• 제9권3호
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• pp.55-65
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• 1987

This paper presents the method of piston temperature measurement and its data under various engine operating conditions. In case of high speed engine, the thermocouple wires must be guided from moving piston to stationary place with carful attention. for this purpose L_LINK SYSTEM was made and assembled to a passenger car engine on the test bench and then the piston temperature was successfully measured. The tested engine speed ranged from 1,000 to 4,000 rpm with 500 rpm increments. Not only the effects of engine speed and load on the piston temperature but those of spark timing, detonation, coolant temperature and Reynolds number based on inlet air condition were studied form the measurement obtained by this L_LINK SYSTEM.

• Journal of Applied Biological Chemistry
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• 제44권2호
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• pp.84-86
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• 2001

Capsaicin synthesis by suspension cultured cells of Jalapeno pepper (Capcicum annuum L.) was assessed in vitro under various conditions including temperature (23 and $30^{\circ}C$), light intensity (with light and without light), and shaking speed (110 and 200 rpm). Capsaicin production increased, while the cell biomass growth decreased possibly due to the production of a secondary metabolite. Capsaicin synthesis was primarily affected by light condition. Cells cultivated at 110 rpm and $23^{\circ}C$ under light condition yielded the highest fresh weight, while those cultivated under the same condition, but without light resulted in the lowest cell mass. Capsaicin content in cells of 18-day-old pepper grown at 110 rpm and $23^{\circ}C$ under light was 0.125% of the cell mass. However, without light treatment, the capsaicin content in cells at the same shaking speed and temperature increased up to 169%, indicating no light is favored in the capsaicin synthesis by Jalapeno pepper. Increasing the shaking speed from 110 to 200 rpm without light enhanced the capsaicin synthesis. Results of this study demonstrate that light condition is the limiting factor in the synthesis of capsaicin in tissue-cultured Jalapeno pepper cells.

• 한국주조공학회지
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• 제25권6호
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• pp.226-232
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• 2005

Contact material is widely used in the field of electrical parts. Ag-CdO material has a good wear resistance and stable contact resistance. In order to establish optimizing heat treatment condition, rolling temperature and oxidation process, we studied the microstructure of Ag-CdO material with various conditions. The experimental procedure were melting using high frequency induction, heat treatment, rolling and internal oxidation. And we experimented on difference process, Post-oxidaion. In this study, we obtained the optimizing heat treatment condition was $700^{\circ}C$ for 15 min. and the optimizing rolling temperature was $730^{\circ}C$. In investigation of the microstructure of oxidized material, coarse oxide and depleted oxidation layer existed. The hardness was average Hv 70. When we used Post-oxidation, oxides were finer than prior process and depleted oxidation layer did not exist. The hardness of Post-oxidation material was average Hv 80. And the optimizing rolling temperature was $800^{\circ}C$.

• 한국주조공학회지
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• 제11권4호
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• pp.331-337
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• 1991

Various test specimens were prepared by austempering low alloyed Mo-Ni-Cu ductile iron blocks of high graphite nodule count at 270, 320 or $370^{\circ}C$ for 0.5, 1, 3 or 9hrs. Tensile test, CVN impact test and plane-strain fracture toughness test(compact tension specimen of 50mm W) were done for each heat treatment condition at room temperature. X-ray diffractometer and optical microscope were used to investigate the change of microstructure and relationships between microstructure and test results. The highest retained austenite volume percent at each austempering temperature was corresponded to the highest mechanical property. The highest elongation value of 17%, U.T.S. value of 1,600 MPa or $K_{IC}$ value of 90MPa${\surd}$m were reached at each optimum condition. The best heat treatment condition for fracture toughness were 3hrs' holding time combined with the austempering temperature of 270 and $320^{\circ}C$, and 1hr's of $370^{\circ}C$.

• 한국재료학회지
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• 제26권5호
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• pp.235-240
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• 2016

Appropriate thermo-mechanical properties of nickel-based superalloys are achieved by heat treatment, which induces precipitation and solid solution hardening; thus, information on the temperature ranges of precipitation and dissolution of the precipitates is essential for the determination of the heat treatment condition. In this study, thermal analyses of nickel-based superalloys were performed by differential scanning calorimetry method under conditions of various heating rates of 5, 10, 20, or 40K/min in a temperature range of 298~1573K. Precipitation and dissolution temperatures were determined by measuring peak temperatures, constructing trend lines, and extrapolating those lines to the zero heating rate to find the exact temperature under isothermal condition. Determined temperatures for the precipitation reactions were 813, 952, and 1062K. Determined onset, peak, and offset temperatures of the first dissolution reaction were 1302, 1388, and 1406K, respectively, and those values of the second dissolution reaction were 1405, 1414, and 1462K. Determined solvus temperature was 1462K. The study showed that it was possible to use a simple method to obtain accurate phase transition temperatures under isothermal condition.

• KIEAE Journal
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• 제6권1호
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• pp.57-62
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• 2006

Korean Traditional houses has been evolved and developed in many years, adopting the natural environment to control exterior conditions. These control method are various passive system of using natural materials, considering micro climate, building lay out, and these system are more natural and ecological to make the comfortable indoor climate than active systems of the present houses. This study aims to analyzed control performance of outdoor environment of five Korean traditional houses during the summer and winter. These houses are varied with lay out and floor plan to reflect the way of control for environmental condition, surveyed the reverberation time and sound level difference between rooms of the main living room and other main floored room, master room and kitchen. Especially air temperature and humidity have been measured simultaneously in each rooms to compare with outdoor condition. As a result, the variation of air temperature and humidity of most rooms are considerably static while condition of outdoors are much varied, it is showed that indoor climate has been controled with traditional soiled walls.

• 한국초전도ㆍ저온공학회논문지
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• 제14권1호
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• pp.38-43
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• 2012

In the extreme conditions of launch vehicle in a space, such as cryogenic temperature and low-gravity environment, the mass gauging of remaining propellants becomes a difficult problem. Pressure-volume-temperature (PVT) method is one of the attractive mass gauging methods under low-gravity due to its simplicity and reliability. PVT gauging experiment with various mass flow rates of helium injection is carried out with the experimental apparatus creating cryogenic homogeneous condition as the condition of low-gravity. Experimental results are analyzed by a novel PVT gauging analysis method which considers all instantaneous changes of pressure and temperature in the ullage volume with small time intervals. It is observed that the gauging error from the novel PVT gauging analysis is -0.11% with 2 slpm mass flow rate of helium injection.