• Mass Spectrometry Letters
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• 제9권1호
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• pp.1-16
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• 2018

Microfluidic technologies hold high promise and emerge as a potential molecular tool to facilitate the progress of fundamental and applied biomedical researches by enabling miniaturization and upgrading current biological research tools. In this review, we summarize the state of the art of existing microfluidic technologies and its' application for characterizing biophysical properties of individual cells. Microfluidic devices offer significant advantages and ability to handle in integrating sample processes, minimizing sample and reagent volumes, and increased analysis speed. Therefore, we first present the basic concepts and summarize several achievements in new coupling between microfluidic devices and mass spectrometers. Secondly, we discuss the recent applications of microfluidic chips in various biological research field including cellular and molecular level. Finally, we present the current challenge of microfluidic technologies and future perspective in this study field.

• Applied Microscopy
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• 제50권
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• pp.15.1-15.6
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• 2020

Sample preparation including dehydration and drying of samples is the most intricate part of scanning electron microscopy. Most current sample preparation protocols use critical-point drying with liquid carbon dioxide. Very few studies have reported samples that were dried using chemical reagents. In this study, we used hexamethyldisilazane, a chemical drying reagent, to prepare plant samples. As glandular trichomes are among the most fragile and sensitive surface structures found on plants, we used Millingtonia hortensis leaf samples as our study materials because they contain abundant glandular trichomes. The results obtained using this new method are identical to those produced via critical-point drying.

• 한국산학기술학회논문지
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• 제5권4호
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• pp.309-314
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• 2004

네일 파일(nail file)을 제조할 때 재료는 강판(두께 0.5㎜)을 사용하고 가공방법은 외형형상을 만들고 Φ 0.8-Φ 1.0㎜의 구멍을 약 300여개 뚫어 완성한다. 이들의 가공방법은 에칭(etching)에 의존하여 제조원가의 33%를 에칭비가 차지하고 있으므로 제조원가의 상승원인이 되고 에칭시 부식제(etching reagent)의 잔류도 환경 친화적이 못되며 재료가 강판이기 때문에 제품에 녹(rust)이 생기므로 이들의 문제점을 해결하고자 다음과 같이 연구개발을 수행하였다. 제품의 녹 방지를 할수 있는 적합한 재질 선택 방법을 고찰하고, 에칭 가공방법을 사용하지 않고 금형을 이용한 프레스 가공으로 교체하기 위하여 프레스 스탬핑시의 스트립 레이아웃(strip layout)기법을 연구개발하고, 금형 부품 중에서 작업 중 절손이 빈번한 보통의 표준펀치를 퀼형의 펀치로 개발 하므로써 프로그레시브 퍼퍼레이팅 금형(progressive perforating die)을 개발하게 되었다.

• 한국수소및신에너지학회논문집
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• 제6권2호
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• pp.75-84
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• 1995

SPE-composites which was prepared with impregnation-reduction method for hydroen production were investigated with morphological and electrochemical analysis. As Pt reagent's concentration increased, Pt loadings increased. However, reductant's concentration had a little effect on Pt loadings. By the morphological analysis, it was found that Pt was deposited inside of SPE. Furthermore, with electrochemical analysis, we found that Pt loading, electricity, roughness factor and active surface area were $2.05mg/cm^2$, 14.20 mC, 21.55, $10.51cm^2/mg$ respectively at reducing agent concentration 0.05 mol/L. Therefore, we found the deposited Pt inside of SPE would give an effect on electrical characteristics of SPE-composites.

• 한국환경보건학회지
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• 제27권4호
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• pp.9-14
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• 2001

This study was performed to develop the modified FGD(Flue Gas Desulfurization) process which can eliminate the possibility of generating secondary pollutants. Limestone was regenerated by adding ammonium hydroxide and carbon dioxide, and reusing it as a absorbent in FGD gypsum Process. A series of the new or modified FGD process which include desulfurization and regeneration limestone from CaSO$_3$. 1/2H20 and CaSO4 . 2H2O, were carried out under various experimental conditions. The results showed that the optimum injection ratio for regeneration of limestone was 0.3 ml/min of CO2 flow rate, 2 ml of NH4OH per 0.01 M of regent grade CaSO4 . 2H20O and the optimum regeneration temperature was 50. The increaser was the number of times of limestone regeneration, the faster was the breakthrough point of desulfurization at the desulfurination process which the regenerated limestone was used. Then the efficiency of desulrurization was decreased. This study can be confirmed the possibility for reuse of regenerated limestone due to the similarity of desulfurization characteries both reagent grade calcium carbonate and regenerated calcium carbonate. Finally, it appeared that the new technology using regenerated 1imestone can be applied to the FGD process.

• Journal of the Korean Wood Science and Technology
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• 제23권2호
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• pp.37-46
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• 1995

The substitution of carboxymethylated hydroxyl group in pulp revealed more hydrophilic than hydroxyl group. And then fibers were more flexible, swell more which leads to better conformation between fibers in turn this raise paper strength. In this paper, we tried to chemical modifyings of recycled fiber, OCCs(old corrugated containers). Many researchers have examined chemical modification of papermaking fiber by partial carboxymethylation(PCM) using a organic solvent processes. We made modified PCM processes adapted waters m replace of the organic solvent. Our testings for the optimum conditions on the new method, conditions as reaction time, temperature, liquor ratios were designed likely plant system. Freenesses(SR$^{\circ}$) were increased following on carboxyl content of the samples. Handsheets of untreated samples and partial carboxymethylated OCCs were made by optimum conditions on different concentrations of the reagent. As results, maximum 25% strength increasing effects were obtained by the new method.

• 약학회지
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• 제3권1호
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• pp.48-50
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• 1957

The micro-assay methods of vanillin have been shown quite few, though several methods have been introduced for determination. A new sensitive micro-determination of vanillin, applying the yellow color reaction of vanillin and anillin, is shown in this paper. The absorption maximum of the yellow coloring matter, 4-Oxy-3-methoxy-henzal aniline, was 435 mu. The one dimensional ascending paper chromatographic method is applyed for isolation of vanillin from the mixed sample. The microdetection of vanillin is studied only in this paper. Vanillin was detected by the yellow spot on paper trip by the coloring reagent of aniline after several hours paper strip chromatographic at the following condition; paper strip ................ 2.5 X 35cm Whatman Filter Paper No.2 developing Solvent ......... petroleum-benzene-methanol n-butanol-water coloring agent ............. aniline. The Rf-value on petroleum benzene and methanol was 0.63 and that on n-butanol and water was 0.90. The minimum detectable amount of vanillin by this method was 10 micrograms. It is recommendable, if interference substances as aromatic aldehydes present, that the application of this aniline reaction and Foline Denis reaction on the same paper chromatogram is appreciable.

• Archives of Pharmacal Research
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• 제17권4호
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• pp.231-235
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• 1994

Fluorenecarboxaldehyde hydrazone 9FCH)was synthesized as a new fluorescent reagent for the determination of acidity. FCH had no fluorescence in itself, however, it strongly fluoresced under acidic conditions at excitation maximum of 392 nm and emission maximum of 447 nm, respectively. It showed good correlation with pH in the range from pH 0.60 to pH 3.60 in strong acids. As an application, the acidity of gastric juice in rats and humans was determined. In comparision with pH-metry, the acidity measured by the developed method showed generally increased values of about 0.7-1.3 unit and 0.8-1.2 unit in rats and humans, respectively. However, these results had statistically close correlation with those of pH-metry and the correlation coefficients were 0.887 in rats and humans between two methods.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1033-1034
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• 2006

Metallic compound of ternary Al-B-C system was prepared by mechanical alloying (MA) using Al, boron and graphite powders as starting materials. MA was carried out using Spex 8000 mixer/mill for 50 hours in an argon atmosphere without process control reagent such as methyl alcohol. The MA powders obtained were heat-treated in vacuum at the temperature of 873 and 1273 K for 5 hour. Pure ternary Al-B-C compound was obtained in the chemical content of Al:B:C=55:27:18. The ternary compound obtained in this study has a new phase whose crystal structure is not identified yet.

• 약학회지
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• 제4권1호
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• pp.43-46
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• 1959

A new quantitiative analytical method of prussic acid by "Microdiffusion analysis" was studied. HCN-Glucoside of ARMENIACA was hydrolysed with KOH in out-room of unit, and then concentrated sulfuric acid was poured in order to liberate the HCN gas. The liberated gas was absorbed into nickel sulfate solution of inner room of unit quantitatively. The excess of nickel sulfate was determined by EDTA Reagent using MX-indicator. By this method, the following results were obtained: (1) It was needed more than 4 hours, in order to hydrolyse completely at $50^{\circ}C$, but could be shortened to 3 hrs. at $^60{\circ}C$. (2) It was completely absorbed into nickel sulfate solution after 30min.