• Title/Summary/Keyword: analytical properties

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Fabrication of Gold Nanostructures Using Electrochemical Deposition Integrated with Solution Process (용액 공정을 접목한 전기화학 증착 기법을 활용한 금 나노 구조체 제작)

  • Jihee Kim;Donghyeon Kim;Mijeong Kang
    • Journal of the Korean Electrochemical Society
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    • v.27 no.3
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    • pp.81-87
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    • 2024
  • Nanomaterial electrodes are used to improve the analytical performances of electrochemical measurements in biological and chemical field. Frequently used methods for fabricating metal nanostructures are solution processing and electrodeposition. In the solution process, it is possible to control the characteristics (e.g., direction) of metal growth by using capping agents, thereby fabricating nanoparticles of specific structures. In the electrodeposition, the electrode surface and the deposited metal atoms are in direct contact. Each process has its own limitation as well, and many studies are conducted to overcome such limitation. In this paper, we report an integration of the two fabrication methods and the characteristics, such as structural and electrochemical properties, of the fabricated electrodes. Lastly, we discuss the possibility of using the fabricated nanostructured electrode as a sensor.

Comparison of Cleaning Performance of CFC 113 and the Alternatives (CFC 113과 대체세정제의 세정성능 비교)

  • Row, Kyung Ho;Choi, Dai-Ki;Lee, Youn Yong
    • Analytical Science and Technology
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    • v.6 no.5
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    • pp.521-530
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    • 1993
  • According to the Montreal Protocol, CFC 113, one of the ozone-depleting substances, will be prohibited to use as a cleaning solvent essentially in the electronic industry. Therefore, the development of the alternative cleaning solvents to CFC 113 is being accelerated. A number of the alternative cleaning solvents are avialable on the market. The alternatives of Axarel 32(DuPont), Cleanthru 750H(KAO Chemical), and EC-Ultra(Petroferm) are chosen for the comparison of cleaning performance with CFC 113. The test methods for measuring the cleaning performance were composed of the measurement of the physical properties, the experiments on the material compatibility with cleaning solvents, the measurement of the evaporation rate, and finally the experiments of the removal efficiency. Normally the basic physical properties of the alternatives had higher boiling points, viscosity and surface tension, which were quite different to those of CFC 113. In terms of solubility of rosin-based flux, the solubilities of abietic acid (nonpolar organic) were similar, but those of the activator (polar organic) in the alternatives were better than CFC 113. The evaporation of the alternatives was very slow, compared to CFC 113, which had much lower boiling point. All the cleaning solvents showed the good material compatibility with FR4 and Cu-coated PCB. The better removal efficiencies of abietic acid were obtained when using the ultrasonic mechanical energy over the dipping method. The experiments also indicated the very slow-eavaporating solvent was not desirable with the dipping cleaning method, and the differences in the removal efficiency of the alternatives with the ultrasonic cleaning method were negligible. Among the alternatives, the overall cleaning performances were obsorved as almost similar. Before selecting the ultimate cleaning solvent, the application of cleaning machine, environmental issues, and economics are simultaneously considered with the cleaning performance.

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Spectrophotometric Determination of Soil Chemical Properties Using Soiltek® KA-P Spectrophotometer (Soiltek KA-P 분광광도계률 사용한 토양 화학적 성질의 분광학적 분석)

  • Hyun, Hae-Nam;Oh, Sang-Sil;Koo, Bon-Jun;Kang, Ho-Jun
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.2
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    • pp.127-138
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    • 2000
  • To enable rapid and convenient soil test, new soil analytical methods, which require only one instrument, UV/Vis spectrophotometer, were developed and named "Soiltek KA-P spectrophotometric methods". The Soiltek$^{(R)}$ KA-P spectrophotometric method was compared with standard method of RDA in analytical capability for soil chemical properties. Using the 78 soils collected from upland, paddy, orchard, and vinyl house soils, soil organic matter, exchangeable K, Ca, and Mg. CEC, available $SiO_2$, and nitrate were analyzed by the two methods. The color stability(ratio of the absorbance at elapsed time t to the absorbance at time t=0) of organic matter. Ca, Mg, and available $SiO_2$ decreased to about 2% within one hour. However, that of exchangeable K, CEC, and nitrate remained constant. The results obtained with Soiltek$^{(R)}$ KA-P spectrophotometric method showed highly significant correlation with those measured by the standard method of RDA($R^2$ >0.9501), in which the slopes were near unity of $1.0{\pm}0.05$. The standard deviation values of organic matter, exchangeable K, Ca, and Mg, CEC, available $SiO_2$, and nitrate were apparently lower than ${\pm}1.8gkg^{-1}$, ${\pm}0.05cmol^+kg^{-1}$, ${\pm}0.18cmol^+kg^{-1}$, and ${\pm}0.13cmol^+kg^{-1}$, ${\pm}1.0cmol^+kg^{-1}$, ${\pm}5.0mgkg^{-1}$, and ${\pm}10.0mgkg^{-1}$, respectively. All the measurements showed coefficients of variation of less than 7~17% and were within the confidence level of 95%, which means both the methods are precise. Considering the relative simplicity, low cost, precision and accuracy, the proposed Soiltek$^{(R)}$ KA-P spectrophotometric methods could be recommended as an alternative to standard method.

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Antioxidant Properties of Different Parts of Red and Black Adzuki Beans (적두 및 흑두의 부위별 항산화 특성)

  • Lee, Lan-Sook;Choi, Eun-Ji;Kim, Chang-Hee;Sung, Jung-Min;Kim, Young-Boong;Kum, Jun-Seok;Park, Jong-Dae
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.8
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    • pp.1150-1156
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    • 2015
  • The objective of this study was to investigate the polyphenolic compounds found in different parts of red and black adzuki beans and to determine the contribution of polyphenolic compounds to the antioxidant properties of adzuki beans. Total polyphenolic and proanthocyanidin contents were studied and their antioxidant activities were determined by ferric reducing antioxidant power, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt assay. The highest total polyphenolic content was found in seed coats (26.1~33.9 mg/g), followed by whole beans (6.9~8.0 mg/g) and dehulled beans (3.3~3.4 mg/g). The highest total proanthocyanidin content was also found in seed coat with 26.5~30.7 mg/g. Moreover, seed coats exhibited the highest antioxidant activity regardless of analytical methods. Antioxidant activity was positively and significantly correlated with total polyphenolic content with the exception of dehulled beans, in which there was no correlation with total polyphenolic content. In particular, the highest correlation was found between DPPH and total polyphenolic content (r=0.945, P<0.01) in whole beans.

A Study on the Influences of the Estimation of Areas and Fees for Rental Facilities Affiliated with Subway Stations: A Case of Seoul Subway Lines 5 and 6 (지하철 역사 내 임대시설 적정 면적 및 임대료 산정에 영향을 미치는 변수에 관한 연구: 서울 지하철 5호선, 6호선을 사례로)

  • Jang, Jae Min;Lee, Kyung Chul;Gim, Tae-Hyoung Tommy
    • Journal of the Korean Society for Railway
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    • v.19 no.3
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    • pp.380-387
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    • 2016
  • Considering that the Seoul subway sector is expected to see extension of lines, addition of stations, and changes of operating companies, a review is needed to identify ways to eliminate or minimize financial deficits in its operation. As for deficits from the operation, additional businesses for extra income have been suggested as alternatives, but inasmuch as Western urban development (that of the subway containment area) may not be applicable to Korean settings, a practical alternative is to maximize income by efficient use of rental facilities that are located inside station properties. This alternative requires the estimation of appropriate facility size and rent for each station; few, however, have addressed this topic. At this juncture, this study aimed to draw an equation for estimating the sizes and rents of station properties by reflecting characteristics of lines and locations; a case study was performed for Subway Lines 5 and 6. Analytical findings are that rental facility sizes and rental incomes are affected mainly by the subway ridership and transport revenues, whereas the influence of ground-level commercial activity is relatively weak. A particularly great influence was found to be the value of apartment housing in areas through which the subway lines run. Stations on Line 5, which runs through areas of high-value housing, were assigned smaller facility sizes and higher rents than those on Line 6, which covers areas with relatively low housing value. The equation suggested in this study would make possible more practical feasibility studies when the need arises to estimate sales of new or extended facilities affiliated with stations.

Synthesis, Physico-Chemical and Biological Properties of Complexes of Cobalt(II) Derived from Hydrazones of Isonicotinic Acid Hydrazide (Isonicotinic Acid Hydrazide의 Hydrazone으로부터 유도된 코발트(II) 착물의 합성, 물리-화학 및 생물학적 성질)

  • Prasad, Surendra;Agarwal, Ram K.
    • Journal of the Korean Chemical Society
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    • v.53 no.1
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    • pp.17-26
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    • 2009
  • Hydrazones of isonicotinic acid hydrazide, viz., N-isonicotinamido-furfuralaldimine (INH-FFL), N-isonicotnamido-cinnamalidine (INH-CIN) and N-isonicotnamido-3',4',5'-trimethoxybenzaldimine (INH-TMB) were prepared by reacting isonicotinic acid hydrazide with respective aromatic aldehydes, i.e., furfural, cinnamaldehyde or 3,4,5-trimethoxy-benzaldehyde. A new series of fifteen complexes of cobalt(II) with these new hydrazones, INH-FFL, INH-CIN and INH-TMB, were synthesized by their reaction with cobalt(II) salts. The infrared spectral data reveal that hydrazone ligands behave as a bidentate ligand with N, O donor sequence towards the $Co^{2+}$ ion. The complexes were characterized on the basis of elemental analysis, magnetic susceptibility, conductivity, infrared and electronic spectral measurements. Analytical data reveal that the complexes have general composition [Co($L)_2X_2]\;and\;[Co(L)_3](ClO_4)_2$ where L= INH-FFL, INH-CIN or INH-TMB and X = $Cl^-,{NO_3}-,\;NCS^-\;or\;CH_3COO^-.$ The thermal behaviour of the complexes were studied using thermogravimetrictechnique. Electronic spectral results and magnetic susceptibility measurements are consistent with the adoption of a six-coordinate geometry for the cobalt(II) chelates. The antimicrobial properties of cobalt(II) complexes and few standard drugs have revealed that the complexes have very moderate antibacterial activities.

The Sorption Properties of Cs on the Surface of Artificially Weathered Illite (인위적으로 풍화시킨 일라이트 표면의 Cs 흡착 특성)

  • Kim Yeongkyoo;Lee Eun Jung
    • Journal of the Mineralogical Society of Korea
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    • v.17 no.3
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    • pp.235-243
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    • 2004
  • Illite has been known to adsorb Cs preferentially to other alkali cations, especially at lower Cs concentration due to the frayed edge site. This frayed edge site was only verified by isotherm experiments, but not by other analytical methods. To investigate the Cs sorption properties on the surface of illite, artificially weathered illite with increasing frayed edge sites was reacted with Cs at different solution concentrations. The illite was weathered f3r 1 hour, 2 days, 14 days in 0.001 M HCl solution. With increasing reaction time, increasing amount of K in solution was observed, indicating formation of frayed edges by weathering, which was also verified by XRD, SEM, and TEM analysis. Original and weathered illites were converted to the homoionic Na form and reacted with $10^{-3}$ / ~ $10^{-7}$ M CsCl solutions for 24 hour. The aspect of Cs sorption was clearly distinguished around $10^{-5}$ M Cs concentration. The relative Cs amount sorbed on illite at low concentration (<10$^{-5}$ M) was higher than high concentration and increased with decreasing Cs concentration. In general, the amount of sorbed Cs increases with increasing weathering time and this trend is more noticeable at lower concentration while not much differentiated with weathering time at high concentration. These results indicate that the selective Cs sorption site exists in illite at low concentration, known as frayed edge site, and the number of those sites increases with weathering time.

Analytical Studies on the Composition of Oil and Protein in the Seed of Thornless Chinese Pepper Zanthoxylum schinifoilum var. inermis Nakai (민산초나무 종실(種實)의 유지(油脂) 및 단백질조성(蛋白質組成)에 관한 연구(硏究))

  • Yoon, Han-Kyo;Kim, Chi-Moon
    • Korean Journal of Agricultural Science
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    • v.3 no.2
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    • pp.170-176
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    • 1976
  • In order to analyze the composition of fatty acid in the seed oil. and amino acid in the seed protein of wild thornless chinese pepper tree; Zanthoxylum schinifolum var. inermis Nakai. GLC method and amino acid autoanalyzer were applied. respectively. while the general composition of the seed and physico-chemical properties of the seed oil were also determined by A. O. A. C. method. The results obtained were summarized as follow The content of oil, protein and ashes were 47.05%, 20.14% and 3.1%, respectively. The content of sulfur and cyan compound in the seed were 0.02% and 0.00005%, respectively, which were far below than allowed guantity by food regulation. Therefore, it is considered to be safe for edible purpose. The iodine absorption number obtained was 145.2, which might be belonged to drying oil. The physico-chemical properties of the seed oil such as acid value, saponification number and refractive index showed the characteristics of an unsaturated high molecular fatty acid compound. The seed oil was composed of 34.8% of oleic acid, 25.1% of linoleic acid and 26.1% of linolenic acid, which accounts for more than 80% of essential fatty acid. Therefore, it could be used as an edible oil. Seventeen kinds of amino acids were anayzed from seed protein. Among them comparatively high content of threonine, valine, methionine, isoleucine, leucine and phenylalanine were observed. As a non-essential amino acid, glutamic acid was found as high as 4.985%. From these results the seed of thornless Chinese pepper would be good for oil and protein source.

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Analytical Studies on the Fatty acids and Amino acids Composition of Pinus Koraiensis seed (잣나무 종실(種實)의 지방산(脂肪酸) 및 Amino산(酸) 조성(組成)에 관한 연구(硏究))

  • Kim, Chi Moon;Yoon, Han Kyo
    • Korean Journal of Agricultural Science
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    • v.2 no.2
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    • pp.469-474
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    • 1975
  • In order to analyse the composition of fatty acid in the seed oil and amino acid in the seed protein of Pinus Koraiensis seed, GLC method was applied, while the general composition of the seed and physico-chemical properties of the seed oil were also determined by A. O. A. C. method. The results obtained were summarized as follows: 1. Oil content of the seed was high as 70.25 percent, and comparatively high content of protein (16.4%) and ashes (2.34%) were observed. 2. The seed oil seemed to be belonged semi-drying oil based on the iodine absorbtion. number (108.93). The physical and chemical properties of seed oil such as acid value, saponification number and refractive index showed the composition of unsaturated high molecular fatty acid. 3. The seed oil was composed of high molecular fatty acid, 36.6 percent of oleic acid and 46.7% of linoleic acid, totaling more than 80 percent. Therefor it was good quality as an edible oil. 4. In the amino acid analysis of seed protein 16 Kinds of amino acid were determined, among them essential amino acid like lysine, methionine, threonine, phenylalanine, leucine, isoleucine and valine were abundant. From the results it was considered that the seed is good guality as a protein source.

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Temperature-Dependency Thermal Properties and Transient Thermal Analysis of Structural Frames Exposed to Fire (온도의존성 열특성 계수를 고려한 화재에 노출된 철근콘크리트 골조의 해석적 연구)

  • Han, Byung-Chan;Kwon, Young-Jin;Kim, Jae-Hwan;Shin, Yeong-Soo;Choi, Eun-Gyu
    • Journal of the Korea Concrete Institute
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    • v.19 no.3
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    • pp.283-292
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    • 2007
  • A research projects is currently being conducted to develop a nonlinear finite element analysis methods for predicting the structural behavior of reinforced concrete frame structures, exposed to fire. As part of this, reinforced concrete frames subjected to fire loads were analyzed using the nonlinear finite-element program DIANA. Two numerical steps are incorporated in this program. The first step carries out the nonlinear transient heat flow analysis associated with fire and the second step predicts the structural behavior of reinforced concrete frames subjected to the thermal histories predicted by first step. The complex features of structural behavior in fire conditions, such as thermal expansion, plasticity, cracking or crushing, and material properties changing with temperature are considered. A concrete material model based on nonlinear fracture mechanics to take cracking into account and plasticity models for concrete in compression and reinforcement steel were used. The material and analytical models developed in this paper are verified against the experimental data on simple reinforced concrete beams. The changes in thermal parameters are discussed from the point of view of changes of structure and chemical composition due to the high temperature exposure. Although, this study considers codes standard fire for reinforced concrete frame, any other time-temperature relationship can be easily incorporated.