• Title/Summary/Keyword: Sulfates

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Hydro/solvothermal synthesis, crystal structure, and thermal behaviour of piperazine-templated nickel(II) and cobalt(II) sulfates

  • Kim, Chong-Hyeak;Park, Chan-Jo;Lee, Sueg-Geun
    • Analytical Science and Technology
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    • v.19 no.4
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    • pp.309-315
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    • 2006
  • Two piperazine-templated metal sulfate complexes, $(C_4N_2H_{12})[Ni(H_2O)_6](SO_4)_2$, I and ($C_4N_2H_{12}$) $[Co(H_2O)_6](SO_4)_2$, II, have been synthesized by hydro/solvothermal reactions and their crystal structures analyzed by single crystal X-ray diffraction methods. Complex I crystallizes in the monoclinic system, $P2_1/n$ space group, a=12.920(3), b=10.616(2), $c=13.303(2){\AA}$, ${\beta}=114.09(1)^{\circ}$, Z=4, $R_1=0.030$ for 3683 reflections; II: monoclinic $P2_1/n$, a=12.906(3), b=10.711(2), $c=13.303(2){\AA}$, ${\beta}=114.10(2)^{\circ}$, Z=4, $R_1=0.032$ for 4010 reflections. The crystal structures of the piperazine-templated metal(II) sulfates demonstrate zero-dimensional compound constituted by diprotonated piperazine cations, metal(II) cations and sulfate anions. The structures of complex I and II are substantially isostructural to that of the previously reported our piperazine-templated copper(II) sulfate complex $(C_4N_2H_{12})[Cu(H_2O)_6](SO_4)_2$. The central metal(II) atoms are coordinated by six water molecules in the octahedral geometry. The crystal structures are stabilized by three-dimensional networks of the $O_{water}-H{\cdots}O_{sulfate}$ and $N_{pip}-H{\cdots}O_{sulfate}$ hydrogen bonds between the water molecules and sulfate anions and protonated piperazine cations. Based on the results of thermal analysis, the thermal decomposition reactions of the complex I was analyzed to have three distinctive stages whereas the complex II proceed through several stages.

Effects of Various Kinds of Calcium sulfates on the Early Hydration of Belite-rich Cement (여러 가지 석고에 따른 Belite-rich Cement 초기 수화의 영향)

  • 조현태;정재현;황인수;송종택;조계홍
    • Journal of the Korean Ceramic Society
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    • v.37 no.5
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    • pp.438-443
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    • 2000
  • This dissertation is focused on the study over the improvement for the early strength of belite-rich cement(BRC). For this purpose, the initial hydration behaviors according to addition of different calcium sulfate types were evaluated. From the observations by XRD, DSC and SEM, the BRC II and III with the addition of natural anhydrate and flue gas desulphurization(FGD) gypsum, respectively, formed much ettringite after 7 days more than the BRC I with the addition of chemical gypsum. The compressive strength of the BRC II and III developed outstandingly due to the formation of calcium aluminate hydrate within pores of hardened BRC paste. Especially, in the case of BRC III adding FGD with low impurities, the early as well as long term compressive strengths were shown very high, compared with other specimens.

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Strength Improvement of Lime-treated Soil with Chloride and Sulphate (생석회와 첨가제에 의한 해성퇴적토의 강도개선)

  • 민덕기;황광모;박근호
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.227-232
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    • 1999
  • In this paper, a laboratory investigation was carried out to estimate the strength improvement of quicklime mixture for the effective use of surplus soils, and the shear strength with curing time was estimated at the content of lime. The effect of strength improvement has been established through the change of lime content with chlorides and sulfates from the samples taken at Samsan region, Ulsan. The test results indicated that the presence of calcium sulphate encouraged the efficiency of lime stabilization, and increased shear strength. Furthermore, it is necessary for inquiring into the relationship between the characteristics of strength and the chemical components.

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Experimental Study on Deterioration Characteristics under Combined Exposure Conditions of Chlorides and Sulfates (염화물 및 황산염 복합환경 하에서의 열화특성에 관한 실험적 연구)

  • 오병환;인광진;강의영;김지상;서정문
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.771-776
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    • 2001
  • Test results on the deterioration process of concrete under single and combined attacks of chloride penetration have been obtained. After test period of 52 weeks, it is found that the internally penetrated chloride ion contents are less in the single attacks of chloride than the combined attacks of chloride and sulfate. Both the diffusion coefficients and surface chloride concentration derived form the chloride profiles showed a time dependence. Also the performance of fly ash-blended cements was observed to be better than plain cements in retarding chloride attack. However it should be needed that improved chloride diffusion model for the combined deterioration process.

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Experimental Study of Chlorides Ion Diffusion Characteristics under Combined Condition of Chlorides and Sulfates (염해 및 황산염의 복합작용에 따른 염소이온 확산특성의 실험적 연구)

  • 오병환;김선우;정상화;서정문
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.413-418
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    • 2000
  • The test results on the deterioration process of concrete under single and combined action of chloride penetration have been obtained. Within the test period of 15 weeks, it is seen that the internally penetrated chloride ion contents are slightly less in the combined action of NaCI and $Na_2SO_4$ than the single action of NaCI. Also the theoretical prediction of chloride penetration based on measured diffusion coefficient agress well with the test data of single deterioration process but disagress with that of combined process. Therefore it should be needed that improved chloride diffusion model for the combined deterioration process.

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Reaction Processes of the Formation of Mg-Al Spinel by a Thermal Decomposition of a Mixed Sulfate Hydrate (복합 황산염 수화물의 열분해에 의한 Mg-Al 스피넬의 생성반응)

  • 박홍채;오기동
    • Journal of the Korean Ceramic Society
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    • v.23 no.6
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    • pp.71-75
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    • 1986
  • The forming reaction processes of magnesium aluminate spinel by a thermal decomposition of sulfate hydrate were studied with DTA, TG. SEM and X-ray powder diffraction methods. The hydrous salt composed of the mixture of the two compounds of $MgSO_4$ $6H_2O$ and ${AL_2}({SO_4})_17H_2O_3$ in which both sulfates were crystalline. On heating the hydrous slat the crystalline magnesium and aluminum sulfate anhydride to amorphous alumina magnesium sulfate anhydride decomposed to amorphous magnesia and these amorphous oxides reacted completely each other to form a spinel at $1000^{\circ}C$ The apparent activation energy of forming reaction of spinel was 36.5 kcal/mole($900^{\circ}C$~$1000^{\circ}C$) The crystallite size of spinel obtained at $1000^{\circ}C$ after 1 h was 380$\AA$.

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Isolation and Characterization of Marinobacter sp. KS-1, which Produces a Chondroitin Sulfate-like Mucopolysaccharide

  • Lee, Dae-Sung;Kim, Kyung-Suk;Lee, Myung-Suk;Kim, Young-Mog
    • Fisheries and Aquatic Sciences
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    • v.13 no.3
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    • pp.210-215
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    • 2010
  • In an effort to isolate a bacterium producing chondroitin sulfate (CS), a marine bacterium, KS-1, which produces mucopolysaccharides, was isolated from seawater and identified as Marinobacter sp. based on analyses of its morphological and biochemical traits and 16S rDNA sequence. Agarose-gel electrophoresis showed that the KS-1 strain produces a CS-like mucopolysaccharide. Structural analysis using Fourier transform infrared spectroscopy revealed that the structure of the CS-like mucopolysaccharide produced by Marinobacter sp. KS-1 is similar to that of dermatan sulfate (CS B). However, the molecular mass of the CS-like mucopolysaccharide is higher than that of standard chondroitin sulfates. Considering the above results, we conclude that the Marinobacter sp. KS-1 produces a CS-like mucopolysaccharide that differs somewhat from CS B in molecular mass.

Preliminary studies on the sulfur isotopes and geochemistry of the urban precipitation in Korea

  • Jang, Jae-Ho;Lee, In-Sung;Kim, Gue-Buem
    • Proceedings of the KSEEG Conference
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    • 2003.04a
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    • pp.237-237
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    • 2003
  • Preliminary studies on the seasonal variations in abundance of stable isotopes were carried out on the snow and rainwater samples from urban area. Stable isotopes and other geochemical data as a tool for characterizing the seasonality and source of pollutants were examined in study areas, especially to trace the sources of sulfate in precipitation and to distinguish sulfates of natural and anthropogenic origin. (omitted)

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