• Title/Summary/Keyword: Physical chemistry

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Solvent-Free Synthesis of Some1-Acetyl Pyrazoles

  • Thirunarayanan, Ganesamoorthy;Sekar, Krishnamoorthy Guna
    • Journal of the Korean Chemical Society
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    • v.57 no.5
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    • pp.599-605
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    • 2013
  • Some N-acetyl pyrazoles including 1-(3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-$^1H$-pyrazole- 1-yl) ethanones have been synthesised by solvent free cyclization cum acetylation of chalcones like substituted styryl 3,4- dichlorophenyl ketones using hydrazine hydrate and acetic anhydride in presence of catalytic amount of fly-ash: $H_2SO_4$ catalyst. The yield of these N-acetyl pyrazole derivatives are more than 75%. The synthesised N-acetyl pyrazoline derivatives were characterized by their physical constants and spectral data.

A Study on the Mixture of Detergents (혼합세제에 관한 연구)

  • Choe, Koang-Hoon;Kwon, Sun-Ja;Lee, Ki-Chang;Hwang, Yong-Hyun
    • Journal of the Korean Applied Science and Technology
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    • v.4 no.1
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    • pp.73-75
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    • 1987
  • Linear alkylbenzene sulfonate (LAS) from the mixture of anionic and nonionic detergents (containing amide type and alkylphenoxy polyethanol type) is identified by Fourier transform infrared spectrometer, separated using physical properties (solubility) and determined by nuclear magnetic resonance spectroscopy.

Activation Enthalpies for Plastic Deformation

  • Chang-Hong Kim;Tai-Kyue Ree
    • Bulletin of the Korean Chemical Society
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    • v.1 no.1
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    • pp.39-44
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    • 1980
  • Activation energies for plastic deformation calculated from traditional phenomenological equations have been criticized frequently since the values are different by authors, and also by experimental conditions. The reasons of different activation enthalpies are clarified in this study. Our method for calculating activation enthalpies based on the authors' theory of plastic deformation was presented and discussed. The method was applied to various cases of alloys, the calculated activation enthalpies are listed and compared with the activation energies obtained by the traditional methods in order to show the reasonableness of our method. The physical meaning of the activation enthalpies which we found was clarified.

Species Selective Spectroelectrochemistry Employing Derivative Absorbance Signals

  • Zhang, Chaojiong;Park, Su-Moon
    • Bulletin of the Korean Chemical Society
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    • v.10 no.3
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    • pp.302-308
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    • 1989
  • Species selective spectroelectrochemistry (SSSE) is described by relating the derivative absorbance (dA/dt) signals with electrochemical currents for conventional transient electrochemical experiments. Expressions relating the currents with the dA/dt signals were obtained. From these expressions, physical constants such as coefficients and molar absorptivities of electrogenerated species can be determined. By obtaining both derivative absorbance and current signals concurrently and comparing them, one can perform the SSSE experiments. The utility of the SSSE in sorting out electrochemical information is demonstrated.

Low-Temperature SCR of NO over Physical Mixture of MnO2 and Metal-Loaded Activated Carbon (MnO2와와 금속담지활성탄의 물리적 혼합물을 이용한 NO의 저온 선택적 촉매 환원 반응)

  • Choi, Jong Cheol;Cho, Chul-Hoon;Jeong, Kwang-Eun;Jeon, Jong-Ki;Yim, Jin-Hyeong;Park, Young-Kwon
    • Applied Chemistry for Engineering
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    • v.19 no.1
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    • pp.92-97
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    • 2008
  • Selective catalytic reduction (SCR) of NO with ammonia was carried out over the physical mixture of $MnO_2$ and K or Cu-loaded activated carbons (AC) at low temperature. Introduction of oxygen affected positively the reduction of NO. Metal-impregnated AC showed significantly enhanced catalytic activity. Without water, the mixed catalyst of $MnO_2$ and K-loaded AC exhibited the best activity in the reduction of NO at $120^{\circ}C$. On the contrary, the activities of all the catalysts were significantly diminished in the presence of water. The mixed catalyst of $MnO_2$ and Cu-loaded AC treated with nitric acid and heat (1 : 1, w/w) exhibited the better activity for the reduction of NO than each single catalyst in presence of water.

Efficient use of ferrate(VI) for the remediation of wastewater contaminated with metal complexes

  • Sailo, Lalsaimawia;Pachuau, Lalramnghaki;Yang, Jae Kyu;Lee, Seung Mok;Tiwari, Diwakar
    • Environmental Engineering Research
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    • v.20 no.1
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    • pp.89-97
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    • 2015
  • Remediation of wastewater contaminated with metal(II)-complexed species (Cu(II)-NTA (NTA: nitrilotriacetic acid), Cu(II)-EDTA (EDTA: ethylenediamine tetraacetic acid) and Cd(II)-EDTA is attempted using the potential applicability of ferrate(VI). Kinetics of pollutant degradation is obtained with the removal of ferrate(VI) studied at wide range of pH (8.0-10.0) and the concentration of metal(II)-complexed species (0.3 to 15.0 mmol/L) employing a constant dose of ferrate(VI) i.e., 1.0 mmol/L. Pseudo-first-order and pseudo-second-order rate constants were obtained in the reduction of ferrate(VI) which was then employed to obtain the overall rate constants of the pollutant degradation. The mineralization of NTA and EDTA was obtained with the change in TOC (total organic carbon) values collected by the ferrate(VI) treated pollutant samples. Decrease in pH and molar pollutant concentrations was greatly favored the percent mineralization of NTA or EDTA by the ferrate(VI) treatment. The treated pollutant samples were filtered and subjected for AAS (atomic absorption spectrophotometric) analysis to assess the simultaneous removal of copper and cadmium from aqueous solutions at the studied pH as well at the elevated pH 12.0. Results show that an enhanced removal of cadmium or copper was achieved at pH 12.0. Overall, ferrate(VI) possesses multifunctional application in wastewater treatment as it oxidizes the degradable impurities and removes metallic impurities by coagulation process.

Impact of Air Convection on H3PO4-Activated Biomass for Sequestration of Cu (II) and Cd (II) Ions

  • Girgis, Badie S.;Elkady, Ahmed A.;Attia, Amina A.;Fathy, Nady A.;Abdel Wahhab, M. A.
    • Carbon letters
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    • v.10 no.2
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    • pp.114-122
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    • 2009
  • Crushed, depitted peach stones were impregnated activated with 50% $H_3PO_4$ followed by pyrolysis at $500^{\circ}C$. Two activated carbons were produced, one under its own evolved gases during pyrolysis, and the second conducted with air flow throughout the carbonization stage. Physicochemical properties were investigated by several procedures; carbon yield, ash content, elemental chemical analysis, TG/DTG and FTIR spectra. Porosity characteristics were determined by the conventional $N_2$ adsorption at 77 K, and data analyzed to get the major texture parameters of surface area and pore volume. Highly developed activated carbons were obtained, essentially microporous, with slight effect of air on the porous structure. Oxygen was observed to be markedly incorporated in the carbon matrix during the air treatment process. Cation exchange capacity towards Cu (II) and Cd (II) was tested in batch single ion experimental mode, which proved to be slow and a function of carbon dose, time and initial ion concentration. Copper was up taken more favorably than cadmium, under same conditions, and adsorption of both cations was remarkably enhanced as a consequence of the air treatment procedure. Sequestration of the metal ions was explained on basis of the combined effect of the oxygen functional groups and the phosphorous-containing compounds; both contributing to the total surface acidity character.

Study on the Peel off Style Low Viscosity Epoxy and Separation Media for a Moving Historic Sites (유구 이전 전용 저점도형 에폭시와 박리제에 관한 연구)

  • Han, Won-Sik;Hong, Tae-Kee;Park, Gi-Jung;Lim, Sung-Jin;Wi, Koang-Chul
    • Journal of Conservation Science
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    • v.24
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    • pp.37-42
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    • 2008
  • Stability of the moving historic sites have something to do with the degree of easiness of work as well as physical property of polymer product. These agents should be able to use without the effect of outer environments like water or low temperature and must have stability during progress of working the peel off Urethane pre-product from Epoxy surface. So, we synthesized low viscosity epoxy resin and hardener with best physical quality and separation media for the moving of historical sites. These products have very good tension strength, adhesion strength, low viscosity and various physical properties that the users want. Particularly, separation media products have good separation of Urethane pre-products surface and Epoxy final product surface.

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