• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.287-292
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• 2012

Light effects on temperature dependence of safflower oil oxidation and tocopherol degradation were studied. Safflower oil was oxidized at 20, 40, 60, or $80^{\circ}C$ for 30, 30, 15, and 6 days, respectively, in the dark or under light. Oil oxidation was evaluated with peroxide value (POV) and conjugated dienoic acid (CDA) value, and tocopherols were monitored by HPLC. Safflower oil consisted of palmitic, stearic, oleic, and linoleic acids at 7.3, 2.0, 14.2, and 76.6%, respectively, with tocopherols at 1157.1 mg/kg. Peroxide and CDA values of safflower oil increased while tocopherol contents decreased with the oxidation time and temperature. Light increased and accelerated the oil oxidation and tocopherol degradation. Temperature dependence of the oil oxidation and tocopherol degradation was higher in the dark rather than under light. The results suggest that temperature control could be more essential in the dark rather than under light with regard to the oxidative stability of safflower oil.

• Journal of the Korean Society for Precision Engineering
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• v.5 no.3
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• pp.63-70
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• 1988

This paper presents the development of a microcomputer-aided design program for a SISO control system. The program has been written in GWBASIC language which is suitable for Intel 80861 CPU with 640KB memory. By utilizing this program, sampling time, the number of bits for the A/D and D/A converter, and the stability for the digital control system can be determined. To demonstrate the utility of this program, a microcomputer controlled precision temperature control system has been employed as an example.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.151-152
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• 2004

An acceleration technique combined with the discrete ordinates method which has been widely used in the solution of neutron transport phenomena is applied to the solution of radiative transfer equation. The self-adjoint form of the second order radiation intensity equation is used to enhance the stability of the solution, and a new linearization method is developed to avoid the nonlinearity of the material temperature equation. This new acceleration method is applied to the well known Marshak wave problem, and the numerical result is compared with that of a non-accelerated calculation

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.282-287
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• 1987

This paper presents the development of a microcomputer-aided design program for a digital control system. The program has been written in GWBASIC language which is suitable for Intel 8086II CPU with 640KB memory. By utilizing this program, sampling time, the number of bits A/D and D/A converter, and the stability for the digital control system carl be determined, To demonstrate the utility of this program, a microcomputer controlled precision temperature control system has been employed as an example.

• Current Research on Agriculture and Life Sciences
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• v.28
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• pp.9-15
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• 2010

Extraction Efficiency of colorants from sorghum and its storage stability were examined according to the various extracting and storage conditions in this study. The obtained results were as follows ; The absorbance values of extracted colorants were increased with increasing extract time and temperature. The extraction at pH 4 extract was most efficient among the various pH conditions. In the juice extractor system, the amount of extracted colorant was more in distilled water pre-treatment than pH 5, but it was more in pH 5 in the long time pre-treatment above 20 hour. The color of extract solutions changed through variation of the pH. Its color changed from light yellow to heavy yellow finally red ton by pH increasing. The Methionine addition gave an effect on the storage stability of colorant solution and then had better storage stability. And so it delayed the color change up to storge period 18th day and the stabilizing effect was revealed in order of Methionine 10mmol-addition>20mmol-addtion>non-addtion.

• Fisheries and Aquatic Sciences
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• v.18 no.1
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• pp.21-26
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• 2015

Seasoned laver Pyropia spp. is a traditional Korean seafood that has gained popularity worldwide because of its unique taste, texture, and health benefits. It is prepared by roasting a sheet of dried laver, to which vegetable oils have been applied, at an ultra-high temperature (UHT) of $300^{\circ}C$. Therefore, the oxidative stability of the oils is the most important factor in determining the shelf life of seasoned laver products. In this study, we investigated changes in the thermal oxidative stability of six major vegetable oils (sesame, perilla, sunflower, rice bran, canola, and olive) during the seasoned laver processing. The oxidation induction time of each oil from the seasoned laver products was decreased compared with the fresh oil. These results indicate that the UHT treatment ($300^{\circ}C$, 10 s) induced thermal oxidation of the oils. Among the six seasoned laver oils, the induction times of olive (OL, 8.02 h) and sesame (SE, 5.31 h) oils were significantly higher than the other oils. The acid values (AVs) of OL and SE oils from the seasoned laver were 0.49 and 0.79, respectively. On the other hand, perilla oil had the overall worst thermal oxidative properties (induction time: 0.35 h, AV: 2.82). Our results provide useful information about seasoned laver products for researchers or manufactures.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2171-2176
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• 2007

The 3-omega (3-${\omega}$) method is utilized to measure the thermal conductivity of nanofluids. A metal line heater on a silicon nitride membrane bridge structure is microfabricated by a bulk silicon etching method. Localized measurement of the thermal conductivity within the nanofluids droplet is possible by the fabricated 3-${\omega}$ sensor. Time varying AC temperature amplitudes and thermal conductivities are measured to check the stability of the nanofluids containing multi-wall carbon nanotubes (MWCNTs). Stabilities of MWCNT nanofluids prepared with different chemical treatments are compared. Acid treated MWCNT showed best dispersion stability in water while MWCNTs dispersed in water with surfactants such as Gum Arabic and Sodium dodecyl benzene sulfate showed clear sign of gravity dependence.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.217-222
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• 2000

A large Pc structure building is system that consisted of bearing wall and slab joint. It has general structure stability from unity thar each members tied at joint. The strength of mortar that packing in joint among panels is important to internal force in entire building system. Do, if we could get early strength estimation with microwave. It would bring good construction planning, reduce construction time, and judge building stability and so on. The purpose of this study is to develop early estimation method for making better quality control and constructing good PC panel structure. The results of this study were as follows :1) With sealed molds, reduced moisture volatilization to more than 60% and enlarged 30% accelerated compressive strength than before one. 2) To get more accelerated strength, we should control maximum temperature difference to $30^{\circ}C$ downward 3)Interrelation with 7-day and 28-day strength were 0.831,0.902, and it is above than before one

• Journal of Powder Materials
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• v.1 no.1
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• pp.4-14
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• 1994

The effects of Ce on the mechanical alloying behavior and the thermal stability of Al-8wt.%Fe were investigated. The steady states of Al-8wt.%Fe and Al-8wt.%Fe-4wt.%Ce powders with 1.5 wt.% stearic acid as a process control agent were reached after mechanical alloying for 1000 minuties and 1300 minuties respectively at the conditions of the impeller revolving velocity of 300 rpm and the ball to powder input ratio of 50 : 1. The hardness of Al-8wt.%Fe specimen hot extruded and isothermally aged at various temperatures for up to 1000 hours decreased rapidly at 50$0^{\circ}C$ and its high temperature ultimate tensile strength began to decrease at 40$0^{\circ}C$ with increasing aging time. The decrease in the hardness and ultimate tensile strength of the specimen were reduced substantially by addition of Ce. It was thought to be due to the formation of thermally stable A14Ce and All3Fe3Ce intermetallic compounds.

• Journal of the Korean Wood Science and Technology
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• v.24 no.3
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• pp.5-11
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• 1996

It has been reported that acetylation reduces the sorption of wood, thereby increasing the stability of the acoustic and dimensional properties of wood under conditions of changing humidity. Bamboos used for making a Korean traditional flute were acetylated and their dimensional properties were evaluated by measuring Weight Percent Gain and thickness swelling in water. Before acetylation bamboos were vacuum-dried to 3~6% at $50{\sim}80^{\circ}C$ without degradation. The optimum reaction temperature and time for bamboo acetylation were found to be $120^{\circ}C$ and 8 hours, respectively.