• 한국표면공학회지
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• 제49권3호
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• pp.265-273
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• 2016

The effects of surface modification by nitric acid on the pre-treatment of electroless copper plating were investigated. Copper was electroless-plated on the nitric acid treated graphite activated by a two-step pre-treatment process (sensitization + activation). The chemical state and relative quantities of the various surface species were determined by X-ray photoelectron spectroscopy (XPS) after nitric acid modification or pre-treatment. The acid treatment increased the surface roughness of the graphite due to deep and fine pores and introduced the oxygen-containing functional groups (-COOH and O-C=O) on the surface of graphite. In the pre-treatment step, the high roughness and many functional groups on the nitric acid treated graphite promoted the adsorption of Sn and Pd ions, leading to the uniform adsorption of catalyst ($Pd^0$) for Cu deposition. In the early stage of electroless plating, a lot of tiny copper particles were formed on the whole surface of acid treated graphite and then homogeneous copper film with low variation in thickness was formed after 30 min.

• 한국환경복원기술학회지
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• 제15권5호
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• pp.145-153
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• 2012

To obtain basic information for evaluating resistance of soil acidification for growth, net photosynthesis, $N_2$ fixation rate and nutrient status of Alnus firma and Alnus hirsuta seedlings grown in brown forest soil acidified with $H_2SO_4$ or $HNO_3$ solution were investigated (control (pH=5.9), LN (pH=5.0; Low levels of Nitric acid), HN (pH=4.0; High levels of Nitric acid), LS (pH=5.0; Low levels of Sulfuric acid), and HS (pH=4.0; High levels of Sulfuric acid)). The shoot dry weight of Alnus firma and Alnus hirsuta and the root dry weight of Alnus hirsuta seedlings grown in the HN, LS and HS were significantly less than that of the seedlings grown in the control. The Chlorophyll a/b ratio in leaves of Alnus firma at LN, LS and HS was significantly lower than that of control. The concentration of N in leaves of Alnus hirsuta at HS was significantly higher than that of control. The net photosynthetic rate of Alnus firma and Alnus hirsuta seedlings at LN and HN was higher than that of control. Based on the results, we concluded that the negative effects of soil acidification due to sulfate deposition are greater than those of soil acidification due to nitrate deposition on growth, net photosynthesis and $N_2$ fixation rate of Alnus firma more than Alnus hirsuta.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1443-1450
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• 2016

The objective of the current study was to investigate the effects of dietary ${\omega}-6/{\omega}-3$ polyunsaturated fatty acid (PUFA) ratios on lipid metabolism in goslings. One hundred and sixty 21-day-old Yangzhou geese of similar weight were randomly divided into 4 groups. They were fed different PUFA-supplemented diets (the 4 diets had ${\omega}-6/{\omega}-3$ PUFA ratios of 12:1, 9:1, 6:1, or 3:1). The geese were slaughtered and samples of liver and muscle were collected at day 70. The activities and the gene expression of enzymes involved in lipid metabolism were measured. The results show that the activities of acetyl coenzyme A carboxylase (ACC), malic enzyme (ME), and fatty acid synthase (FAS) were lower (p<0.05), but the activities of hepatic lipase (HL) and lipoprotein lipase (LPL) were higher (p<0.05), in the liver and the muscle from the 3:1 and 6:1 groups compared with those in the 9:1 and 12:1 groups. Expression of the genes for FAS (p<0.01), ME (p<0.01) and ACC (p<0.05) were higher in the muscle of groups fed diets with higher ${\omega}-6/{\omega}-3$ PUFA ratios. Additionally, in situ hybridization tests showed that the expression intensities of the high density lipoprotein (HDL-R) gene in the 12:1 and 9:1 groups were significantly lower (p<0.01) than that of the 3:1 group in the muscle of goslings. In conclusion, diets containing lower ${\omega}-6/{\omega}-3$ PUFA ratios (3:1 or 6:1) could decrease fat deposition by inhibiting fat synthesis in goslings.

• 공업화학
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• 제20권5호
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• pp.536-541
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• 2009

플라즈마 중합 아크릴산 필름을 원격 플라즈마 방식으로 Si과 KBr 기판 위에 증착하였다. 플라즈마 출력, 반응 압력, 간접 플라즈마 방식이 필름의 성장속도, 화학적 구조 및 화학 결합 상태 등에 미치는 영향을 조사하였다. 화학 구조와 화학적 상태는 FT-IR, XPS 분석과 curve fitting 기법으로 분석하였다. 플라즈마 출력에 따른 필름의 성장속도는 100 W에서 포화값을 보이지만, 압력에 대해서는 300 mtorr에서 최대값을 나타내었다. 플라즈마 출력을 높이거나 압력을 낮추면 단위 입자들에게 가해지는 에너지 값(W/FM)이 증가하여 아크릴산 분자의 파괴가 촉진되었다. XPS curve fitting 분석 결과, W/FM값이 커질수록 카르복실 COO 결합은 감소하지만 에테르 C-O 결합과 카보닐 C=O 결합은 증가하여 서로 반대의 경향을 보임을 확인하였다.

• 한국식품영양학회지
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• 제20권3호
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• pp.245-252
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• 2007

This study investigated the effects of conjugated linoleic acid(CLA) on the fat deposition, triglyceride levels and the expression of stearoyl-CoA desaturase 1(SCD1) in the livers of male ICR mice that were fed with either soybean oil or beef tallow supplemented with CLA. Mice weighing $25{\sim}30$ g were divided into four groups; soybean oil(SBO), and SBO supplemented with 1% CLA(SBOC), beef tallow(BT) and BT supplemented with 1% CLA(BTC). Each group consisted of 10 mice that were fed the experimental diets for 4 weeks. The experimental diets consisted of 64% carbohydrate, 20% protein, and 16% fat in terms of their contributions to total calories. All other nutrients were identical in the diets. Triglyceride measurements were completed using a kit. Fatty acid compositions were analyzed in the liver using gas chromatography. The levels of SCD1 expression were analyzed by RT-PCR in the liver. No significant differences were found for food intake level, body weight and food efficiency among the experimental groups. However, the weights of epididymal fat pads and plasma triglyceride levels were significantly lower in SBOC and BTC(p<0.05) compared to the SBO and BT groups. These effects were similar in the CLA supplemented groups. The expression level of SCD1 gene and ${\Delta}9$ desaturase index were not significantly different, regardless of the fat used for CLA supplementation. Based on these results, addition of CLA showed decreasing effects on the fat depots weight and the concentration of triglyceride regardless of the fat sources. The SCD1 gene expression and ${\Delta}9$ desaturase index were not influenced by the types of fats with respect to the CLA effects.

• 한국표면공학회지
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• 제55권2호
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• pp.102-119
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• 2022

Gold plating is used as a coating of connecter in printed circuit boards, ceramic integrated circuit packages, semiconductor devices and so on, because the film has excellent electric conductivity, solderability and chemical properties such as durability to acid and other chemicals. As increasing the demand for miniaturization of printed circuit boards and downsizing of electronic devices, several types of electroless gold plating solutions have been developed. Most of these conventional gold plating solutions contain cyanide compounds as a complexing agent. The gold film obtained from such baths usually satisfies the requirements for electronic parts mentioned above. However, cyanide bath is highly toxic and it always has some possibility to cause serious problems in working environment or other administrative aspects. The object of this investigation was to develop a cyanide-free electroless gold plating process that assures the high stability of the solution and gives the excellent solderability of the deposited film. The investigation reported herein is intended to establish plating bath composition and plating conditions for electroless gold plating, with thiomalic acid as a complexing agent. At the same time, we have investigated the solution stability against nickel ion and pull strength of solder ball. Furthermore, by examining the characteristics of the plated Au plating film, the problems of the newly developed electroless Au plating solution were improved and the applicability to various industrial fields was examined. New type electroless gold-plating bath which containing thiomalic acid as a complexing agent showing so good solution stability and film properties as cyanide bath. And this bath shows the excellent stability even if the dissolved nickel ion was added from under coated nickel film, which can be used at the neutral pH range.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 센서 박막재료
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• pp.11-14
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• 2001

We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 30[mN/m]. LB layers of Arac. 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. The 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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1506-1507
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• 1998

Stearic acid LB films was deposited by LB technique. The deposition status of LB films were verified by UV absorbance which was increased in proportion to the number of layers. And, I-V characteristics were measured to investigate the response properties between LB films and organic gases using the distance of electrodes. The current was increased with the applied voltage but decreased as increasing the distance of electrodes. The conductivity of stearic acid LB films using the distance of electrodes was $10^{-8}$[S/cm], which corresponds to that of the semiconductor.

• 한국응용과학기술학회지
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• 제17권4호
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• pp.226-232
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• 2000

Polyimide is a well-known organic dielectric material, which has not only high chemical and thermal stability but also good electrical insulating and mechanical properties. In this research, we have synthesized a polyamic acid(PAA), which is a precursor of the polyimide. To obtain the optimum conditions of polyamic acid alkylamine salt(PAAS) Langmuir-Blodgett(LB) film deposition, the ${\pi}-A$ isotherms were examined by varying subphase temperature, barrier moving speed and spreading amount of solution. Film formation was verified by measuring transfer ratio, absorption of UV/vis spectra and scanning electron microscope(SEM) images.

• Bulletin of the Korean Chemical Society
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• 제17권4호
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• pp.342-347
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• 1996

Voltammetric determination of phenol derivatives, such as phenol, o-, m-, and p-cresols was studied with a β-Cyclodextrin (β-CD) modified-carbon paste electrode composing of the graphite powder and Nujol oil. Phenol derivatives were chemically deposited via the complex formation with β-CD by immersing the CME into a sample solution. The resulting surfaces were characterized with cyclic and differential pulse voltammetry. Treating the CME with 1 M nitric acid for five sec after a measurement could regenerate the electrode surface. Linear sweep and differential pulse voltammograms were recorded for the above system to optimize the experimental parameters for analysing the phenol derivatives. In this case, the detection limit for phenols was 5.0×10-7M for 25 min of the deposition time with differential pulse voltammetry. The relative standard deviation was ±5.2% of 3.0×10-6M (four repetitions). The interference effect of the following organic compounds was also investigated; Bezoic acid, hippuric acid, o-, m-, and p-methylhippuric acid. Adding the organic compounds into the sample solution reduces the peak current of the phenols to about 25%.