• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.498-500
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• 1992

In this paper, we described a evaluating technique of deposition status of LB films by quartz crystal. As a deposited material for this experiments, arachidic acid and stearic acid were used. We observed the deposition status of LB films on the surface of quartz crystal. The experimental results showed that Y type H films are deposited according to frequency shift, deposition ratio, and SEM photographs etc.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.349-352
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• 1999

We have investigated the electrical characteristics of arachidic acid($C_{20}$), stearic acid(C_{18} and palmitic acid($C_{16}$) Langmuir-Blodgett(LB) films because the fatty acid systems have a same hydrophilic group and a different hydrophobic one (alkyl chain length). In this work, fatty acid systems were used as LB films and the status of the deposited films were confirmed by evaluating the capacitance and I-V characteristics. The conductivity of $C_{20}$, C_{18} and $C_{16}$ LB films obtained from I-V characteristics were about 5x $10^{15}$, 3x $10^{14}$ and 9x $10^{14}$[S/cm], espectively. These results have shown the insulating materials and could control the conductivity by changing the length of alkyl chain. Also, we have confirmed that the barrier height of fatty acid systems were about 1.32- 1.40[eV] and the relative dielectric constant were about 2.9~4.2. These values were almost the same ones obtained from dielectric characteristics.

• Journal of the Korean Society of Food Culture
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• v.12 no.2
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• pp.189-193
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• 1997

A study was conducted to investigate the effects of deodorizing temperature on physicochemical characteristics, fatty acid and triglyceride (TG) composition, and to estabilish the optimal deodorizing conditions in corn oil. Acid value (AV) of $240^{\circ}C$ treating group was showed 0.065 as the lowest level, the AV range was $0.08{\sim}0.09$ at $250{\sim}270^{\circ}C$. Lovibond total color was 24 as the lowest level, peroxide values (POV) were zero at $240{\sim}270^{\circ}C$ range. But POV was showed 0.42 meg/kg oil at $235^{\circ}C$, according to the optimal deodorizing temperature for the complete removal of peroxides was required more than $240^{\circ}C$. On the other hand, inclose of deodorizing temperature was conducted to the increase of saturated fatty acid content as myristic, palmitic, stearic and arachidic acid etc. Change of TG composition at treated group more than $250^{\circ}C$ was reliable, $S_3$ type TG was appeared. As a result, high temperature deodorizing was induced the undesirable influence at the physicochemical properties in deodorized corn oil.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.4
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• pp.525-528
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• 2009

In this study, phytosterol content and fatty acid composition of grape seeds from fourteen different cultivars produced in Korea were determined. Although the total phytosterol contents depended upon the cultivars, the major phytosterol was $\beta$-sitosterol (64.9$\sim$119.3 mg/100 g) in all samples. The fatty acid composition of the grape seeds were analyzed as palmitic (16:0, 6.8$\sim$16.8%), palmitoleic (16:1, 0.1$\sim$0.2%), stearic (18:0, 4.7$\sim$5.2%), oleic (18:1, 16.6$\sim$26.1%), linoleic (18:2, 16.6$\sim$20.1%), linolenic acid (18:3, 0.3$\sim$0.5%) and arachidic acid (20:0, 0.3$\sim$0.5%). Campbell early, the mainly produced and consumed cultivar in Korea, contained relatively high phytosterol content compared to other samples and high proportion of unsaturated fatty acids. Therefore, the seeds from Campbell early might be used for functional oil production and as food ingredients.

• Polymer(Korea)
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• v.24 no.1
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• pp.90-96
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• 2000

Organic electroluminescent (EL) device was fabricated with Alq$_3$ as an emitting material and PDPMA ultra thin film prepared by Langmuir-Boldgett technique as a polymer hole transport layer. A stable condensed PDPMA monolayer was obtained using arachidic acid as a surface active material. The thickness and absorbance of PDPMA LB film increased line-arly with the layer numbers. The organic multilayered device consisted of ITO/PDPMA LB film (19 layers)/Alq$_3$/Al emitted green light with brightness of 2500 cd/m$^2$ at a DC 14 V Especially, the drive voltage of EL device having PDPMA LB film of 15 layers exhibited the value as low as 4 V. The effects of thickness control and molecular orientation in the PDPMA LB film on EL performance were discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11b
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• pp.27-32
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• 2004

Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuir-films. MDC flowing across monolayers is analyzed using a rod-like molecular model. A method for determining the dielectric relaxation time ${\tau}$ of floating 'monolayers on the water surface is presented. MDC floing across monolayers is analyzed using a rod-like molecular model. It is revealed that the dielectric relaxation time ${\tau}$ of monolayers in the isotropic polar orientational phase is determined using a liner relationship between the monolayer compression speed a and the molecular area Am. Compression speed a was about 30,40,50mm/min. LB layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film.The physicochemical properties of the LB films were examined by UV absorption spectrum, SEM and AFM. The structure of manufactured device is Au/Arachidic acid/Al, the number of accumulated layers are 3~9. Also, we then examined of the MIM device by means of I-V characteristic of the device is measured from -3 to +3[V]. The insulation property of a thin film is better as the distance between electrodes is larger.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1843-1845
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• 1999

We have investigated the dielectric characteristics of palmitic acid(PA), stearic acid (SA) and arachidic acid(AA) Langmuir-Blodgett(LB) films because these fatty acid systems have a same hydrophilic group and a different hydrophobic one (alkyl chain length). In this work. fatty acid systems were used as LB films and the status of the deposited films was confirmed by evaluating the transfer ratio. the UV absorption and the capacitance. Also, the dielectric characteristics such as the frequency-capacitance characteristics and the dielectric dispersion and absorption characteristics of PA, SA and AA through-plane were measured. The relative dielectric constants of PA, SA and AA LB films were about $2.6\sim4.6$, $2.4\sim4.1$ and $2.2\sim3.8$, respectively. That is, the relative dielectric constants were decreased in proportion to the chain length of methylene group. And, the dielectric dispersion and absorption of each fatty acid LB films have arisen from spontaneous polarization of dipole polarization in the range of $10^4\sim10^5[Hz]$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.419-422
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• 1998

There are lots of researches which are using quratz crystal in order to apply it to sensors, for example, mass detect sensor, humidity sensor, gas sensor, etc. We tried to apply quartz crystal to the sensor using the resonant frequency and the resistance properties. Four kinds of fatty acid which are having the same head group are coated at the surface of quartz crystal, the shift of the resonant frequency and the resistance are observed according to length of the tail group. Myristic acid$(C_{14})$, palmitic acid$(C_16)$, stearic acid$(C_{18})$, and arachidic acid$(C_{20})$ were coated by Langmuir-Blodgett(LB) technique. As results, the resonant frequency shift was observed linearly. However, there are some difference compared with Sauerbrey's equation. It can be explained by the effect of the temperature property and/or humidity. On the other hand, the shift of the resistance was observed nonlinearly.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.93-97
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• 1987

The seeds cf Pinus Koraiensis mere studied for their moisture, total lipids and ash contents and fatty acid composition. The seeds contained ca. 3.6% moisture, 70.4% purified total lipids and 2.5% ash. The proximate composition of the seeds was not influenced by the sampling rears (1984 and 1985). Twenty-one fatty acids ranged from myristic to arachidic acids were identified in the seed lipids. The seed lipids contained linoleic acid (47.9%), oleic acid (28.4%) and 5, 9, 12-18:3(11.1%) as major fatty acids and 5,9,12-18:3, 5,11-20:2 and 5,11,14-20:3 as 5-olefinic nonmethylene-interrupted polyenoic acids. The sampling Tears also had no effect on the fatty acid composition of the seed lipids.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.95-95
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• 2020

The groundnut (Arachis hypogaea L.), also known as peanut, is a high amount of good-quality vegetable oil in seeds cultivated worldwide. The aim of this study was to evaluate and analyze oil composition of 83 groundnut accessions collected from 7 countries include Korea and Philippines. Total oil contents were recovered by Soxhlet extraction and the fatty acid compositions were analyzed by using gas chromatography. Total oil contents of 83 groundnut accessions showed a significant variability among the entire domain of collections and rangerd from 44.59 to 57.58 %. The averages of palmitic and stearic acid were 11.36 and 3.39 % ranged from 8.77 to 13.65 %, and 1.88 to 7.22 %, respectively. Oleic and linoleic acid showed a wide variation which ranged from 40.32 to 61.67 %, and 22.54 to 41.99 %, respectively. Arachidic acid was ranged from 0.93 to 2.42 %. Significant negative correlation was observed between oleic and linoleic acid.