• Title, Summary, Keyword: Chemical Analyses

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Metal Complexes of Sulfur-Containing Ligands (II). Synthesis and Properties of Platinum(II) Complexes of Dithiocarbamates (황함유 리간드의 금속착물(II). 디티오카바메이트류의 백금(II) 착물의 합성과 성질)

  • Chan-Woo Kim;Chang-Su Kim
    • Journal of the Korean Chemical Society
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    • v.37 no.8
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    • pp.717-722
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    • 1993
  • Reactions of [PtCl$_4$]$^{2-}$ with excess of dithiocarbamates in water lead to facile replacement of the chloro ligand by dithiocarbamato ligand to give [Pt(A)], [Pt(B)$_2$]Cl$_2$, [Pt(C)$_2$], and [Pt(D)(CH$_2$=CH$_2$)Cl]Cl. The complexes of platinum have been characterized by elemental analyses, infrared and UV-visible spectra, and conductivity measurements. Platinum(II)-dithiocarbamate complexes were soluble in polar solvents such as water, alcohol, acetone, dimethylformamide, and dimethylsulfoxide etc. The possible structure was proposed on the basis of elemental analyses and physical properties.

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Industrial Survey Analysis for Engineering Education of Civil, Chemical, and Electronics Engineering (토목, 화공, 전자 분야의 공학교육에 대한 산업체 설문조사 분석)

  • Kim Byoung-Il;Lee Euy-Soo;Park Jin-Woo
    • Journal of Engineering Education Research
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    • v.8 no.3
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    • pp.5-16
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    • 2005
  • In this study, several issues of engineering education of Korea were pointed out through the survey for industrial employees in the areas of civil, chemical and electronics engineering. For the area of civil engineering, a questionnaire based upon the outcomes of ABEEK(accreditation board for engineering education of Korea) was developed for the survey, and the replies from the survey were then analyzed. For the areas of chemical and electronics engineering, data obtained from the literature study were used for analyses. The results of analyses show that the level of engineering education is much lower than that of the industrial demand in the case of all three divisions. It shows the urgency in improvement of engineering education.

Surface Modification of PET Irradiated by Ultra-Violet (Part I) -Transformation of Chemical Structure and Surface Properties- (UV조사를 통한 PET의 표면개질 (제1보) -화학구조 변화 및 표면특성 변화-)

  • Choi Hae Young;Lee Jung Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.3_4
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    • pp.561-568
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    • 2005
  • The irradiation of Ultra-Violet (UV) is an efficient treatment for polymer to improve hydrophilic properties. 4-Channel PET knit fabrics were treated with UVA and UVC to develop functional and environment-friendly fabric. The fabric was treated with various treatment times and distances from UV lamps having different wavelength. FT-IR and XPS investigated the chemical changes. To confirm the change of surface properties, contact angle, surface energy and SEM were examined. The study of UV as a treatment for PET knit fabric shows significant changes in chemical and surface properties, which is proved by analyses. FT-IR and XPS analyses prove the augmentation of carboxylic, Hydrophilic groups on the surfaces treated by UV. The increase of water contact angle and surface energy means more water wettable and surface energy of PET film was substantially increased by UV irradiation time. The ageing after surface treatment had little influence on the surface energy of the irradiated PET film. SEM proves the surface modification of PET such as etching, bubble and crack. The negative effects are increased in accordance with increasing treatment time.

Sonochemical Synthesis of Amorphous Zinc Phosphate Nanospheres

  • Jung, Seung-Ho;Oh, Eu-Ene;Shim, Dae-Seob;Park, Da-Hye;Cho, Seung-Ho;Lee, Bo-Ram;Jeong, Yeon-Uk;Lee, Kun-Hong;Jeong, Soo-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.30 no.10
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    • pp.2280-2282
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    • 2009
  • Amorphous zinc phosphate nanospheres were prepared via a sonochemical route. Zinc phosphate nanospheres were uniform in shape with an average diameter of 210 nm. The average diameter of nanospheres could be controlled by changing the pH of a precursor solution. This sonochemical method is simple, facile, economical, and environmentally benign. Non-crystalline characteristics of as-prepared zinc phosphate nanospheres were confirmed by X-ray diffraction, transmission electron microscopy, and FT-IR spectroscopy analyses. We believe this technique will be readily adopted in realizing other forms of zinc phosphate nanostructures.

A Series of 3D Lanthanide Complexes Containing (La(III), Sm(III) and Gd(III)) Metal-organic Frameworks: Synthesis, Structure, Characterization and Their Luminescent Properties

  • Zhang, Huai-Min;Yang, Hao;Wu, Lan-Zhi;Song, Shuang;Yang, Li-Rong
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3777-3787
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    • 2012
  • Three kinds of 3D isomorphous and isostructural coordination polymers, namely, $\{[Ln_2(PDA)_3(H_2O)_3]{\cdot}0.25H_2O\}_{\infty}$ (Ln = La(1), Sm(2), and Gd(3)) ($PDA^{2-}$ = pyridine-2,6-dicarboxylate anion) have been synthesized under hydrothermal conditions and characterized by elemental analyses, IR spectroscopy, thermal analyses and single crystal X-ray diffraction. In these MOFs, Ln(III) centers adopt eight-coordinated and nine-coordinated with the $N_1O_7$ and $N_2O_7$ donor sets to construct distorted trianglar dodecahedron geometry and tricapped trigonal prism configurations, respectively. Based on the building block of tetranuclear homometallic $Ln_4C_4O_8$ unit (16-membered ring), 1-3 are connected into highly ordered 2D sheets via O-C-O linkers and further constructed into 3D architectures through hydrogen bonds. Crystallographic parameters suggest that the lanthanide contraction effect exist in these coordination polymers. Luminescent properties of the lanthanide-based MOFs (metal-organic frameworks) have been measured at room temperature, which reveal that they presenting ionselective characters toward certain metals, such as $Mg^{2+}$, $Cd^{2+}$ and $Pb^{2+}$ ions.

The Synthesis of Indigoid-Type Dyes Based on Isatin $\alpha-Chloride$ (Isatin $\alpha-chloride$에 의한 인디고계 염료의 합성)

  • Park, Soo-Youl;Shin, Seung-Rim;Shin, Joung-Il;Jun, Kun
    • Textile Coloration and Finishing
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    • v.19 no.3
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    • pp.6-11
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    • 2007
  • The indigoid-type dyes based on isatin $\alpha-chloride$ were synthesized and the dyes were discussed with relevance to the "H-chromophore" or "cross-conjugated chromophore". The color-changed properties of the dyes were also investigated by means of visible absorption spectra. The novel dyes from isatin $\alpha-chloride$ are of theoretical interest and such dyes can be used as continuous pH indicators in acid/base titrimetric analyses.

Chemical, Textural and Sensorial Attributes of Biltong Produced through Different Manufacturing Processes

  • Engez, Semih;Baskan, Pelin;Ergonul, Bulent
    • Food Science of Animal Resources
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    • v.32 no.3
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    • pp.263-267
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    • 2012
  • Six different types of biltong samples were manufactured from beef which was slowly frozen, quickly frozen or unfrozen. After marinating the samples according to the formulation used, meats were dried at two different temperatures ($28{\pm}1^{\circ}C$ or $42{\pm}1^{\circ}C$) until they lost half of their weights. Chemical, instrumental textural and sensorial analyses were done for determination of the most preferred sample and to compare the attributes of the samples with each other. It was found that, aw values of the samples were among 0.81 and 0.83, whereas water contents were changing among the values 39.64% and 45.37%. There were no significant differences determined among the protein contents of the biltong samples (p>0.05). Fat, ash and salt contents of the samples were among the values 1.32% and 2.07%, 5.30% and 6.06%, 2.68% and 3.30% respectively. Hardness of the samples were found between 34.81 N and 44.13 N and there was no significant difference observed among the hardness values of the biltong samples (p>0.05). As results of the analyses, it can be concluded that the highest flavor, color, tenderness and overall acceptability scores were obtained for the sample QF-LT which was made from quickly frozen beef and was dried at low temperature ($28{\pm}1^{\circ}C$) (p<0.05).

Seismic assessment and retrofitting of Pombalino buildings by pushover analyses

  • Meireles, Helena;Bento, Rita;Cattari, Serena;Lagomarsino, Sergio
    • Earthquakes and Structures
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    • v.7 no.1
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    • pp.57-82
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    • 2014
  • The heritage value of the mixed wood-masonry 18th century Pombalino buildings of downtown Lisbon is recognized both nationally and internationally. The present paper focuses on the seismic assessment of global response and retrofitting of a typical Pombalino building by nonlinear static analyses, performed by the research software Tremuri, which is able to model 3D configurations. The structure is modelled using nonlinear beams for masonry panels, while in case of the internal walls (frontal walls) an original formulation has been developed in order to take into account their specific seismic behaviour. Floors are modelled as orthotropic membrane finite elements: this feature allows to simulate the presence of both flexible and rigid diaphragms, being the first ones more representative of the original state while the second ones of retrofitted configurations. Seismic assessment has been evaluated by applying nonlinear static procedure and comparing the performance of different configurations (by considering various retrofitting strategies). Finally, assuming a lognormal cumulative distribution, fragility curves are obtained to be representative of Pombalino buildings: the most important application of such curves is for seismic risk and loss estimation analyses.

Analysis and Conservation of Historic Textiles - Theory and Practice - (섬유 문화재의 분석과 보존처리 - 이론과 실제 -)

  • Oh, Joon-Suk
    • Journal of the Korean Society of Costume
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    • v.58 no.5
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    • pp.211-231
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    • 2008
  • To conserve historic textiles, analyses of textile materials, pollutants and deterioration are prerequisite steps. Based upon analytical results, guides for conservation of historic textiles are established. In analyses of textile materials, pollutants and deterioration, there are chemical methods(burning, solubility and staining), physical methods(microscopy and density) and instrumental analysis(Fourier Transform Infrared Spectroscopy (FT-IR), Fourier Transform Raman Spectroscopy(FT-Raman), Gas Chromatography(GC), Mass Spectroscopy(MS), X-Ray Fluorescence (EDXRF, WDXRF), Energy Dispersive Spectroscopy(EDS), and X-Ray Diffraction(XRD), Tensile Testing Machine etc.). Combination of qualitative and quantitative analyses makes accurate diagnosis of textile condition possible. As examples of analyses and conservation of historic textiles, Chuninsan(19 century) similar to sunshade with handing down historic textile and golden decorative skirt(17 century) with excavated costume are taken.

Synthesis of Methylmethacrylate/acrylonitrile Organosol Copolymer

  • Ahn, Young-Ok
    • Journal of the Korean Chemical Society
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    • v.14 no.1
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    • pp.29-35
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    • 1970
  • Chacterization of MMA/AN organosol copolymer and subsequent comparison with the prior art latex copolymers has been accomplished. By means of NMR analyses, we found both types of copolymers to be random. The GPC analyses show that the organosol copolymers have a singnificantly broader MW spread than latex copolymers. This is due to the low MW stabilizer which is present as a physical mixture. As a result, the MW distribution is bimodal. Fractionation of a typical organosol copolymer yields a low MW(33,000-100,000), MMA rich fraction and a high MW (250,000-330,000), AN rich fraction. Solubility-wise, the organosol copolymers are readily soluble in the lacquer solvent MEK to give a colorless film. The prio rart copolymers, hewever, were imcompletely soluble and gave yellow, hazy film.

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