Nuclear Magnetic Resonance of GdCo<sub>3</sub>

Bubble column reactors are considered the reactor of choice for numerous applications including oxidation, hydrogenation, waste water treatment, and Fischer-Tropsch (FT) synthesis. They are widely used in a variety of industrial applications for carrying out gas-liquid and gas-liquid-solid reactions. In this paper, the computational fluid dynamics (CFD) model is used for predicting the gas holdup and its distribution along radial and axial direction are presented. Gas holdup increases linearly with increase in gas velocity. Gas bubbles tends to concentrate more towards the center of the column and follows a wavy path.

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“…So it is clear that the gas follows a certain wavy flow pattern. Similar results are also reported by Joshi et al (2002).…”

Section: Resultssupporting

confidence: 91%

Axial and Radial Gas Holdup in Bubble Column Reactor

Wagh¹,

Ansari²,

Kene³

2014

Bulletin of the Korean Chemical Society

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“…All Co-moments are antiparallel to the Er-moments so we find B hf ¼ þ2:3; þ6:5; and À9:6 T for 3b-, 6c-, and 18h-Co respectively. Neglecting transferred and dipolar fields one has B hf ¼ A s m s þ A 0 m 0 with spin (orbital) moment m s ðm 0 Þ and the corresponding coupling constants A s ¼ À13 T=m B and A 0 ¼ 65 T=m B [2]. The unusual positive sign of B hf is, thereby, due to an unquenched orbital momentum.…”

mentioning

confidence: 99%

“…Nuclear magnetic resonance (NMR) of 57 Co has been reported for R ¼ Y; Gd, and Nd [1][2][3] but the work concentrated on low temperatures. Here, we extend our previous work on ErCo 3 [4] and focus on the temperature dependence of the Co sublattice magnetizations.…”

mentioning

confidence: 99%

Metamagnetic phase transitions in ErCo3 investigated with microscopic methods

Pieper¹,

Niki²,

Seto³

et al. 2004

Journal of Magnetism and Magnetic Materials

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“…However, the anisotropy of the Gd 3+ ion in GdCo 3 is negligible, since the 4f shell is half filled and there is no orbital contribution to the magnetic moment. GdCo 3 is a collinear ferrimagnet with a uniaxial anisotropy along the c-axis from low to high temperature [18,21]. The difference of anisotropy between Tb 3+ and Gd 3+ ions is expected to give rise to different magnetic properties between Nd 1-x Gd x Co 3 and Nd 1-x Tb x Co 3 .…”

Section: Discussionmentioning

confidence: 99%

“…These results imply that in the Gd-or Tb-rich samples, the anisotropy or the EMD is almost independent of temperature. In fact, in GdCo 3 the c-axis anisotropy was reported from 4.2 K to room temperature [18] and in TbCo 3 the angle θ between the EMD and c-axis exhibits a small change, i.e. θ varies from 80° to 90° from 5 K to room temperature [15,19].…”

Section: Originalmentioning

confidence: 99%

Crystal structure and magnetic properties of mixed compounds Nd_1–xR_xCo₃ (R = Gd, Tb)

Ouyang

Rao²,

Liu

et al. 2005

Physica Status Solidi (b)

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The biosynthesis of the volatiles 2,5‐ and 2,6‐diisopropylpyrazine (2 and 3, resp.) released by the myxobacteria Nannocystis exedens subsp. cinnabarina (Na c29) and Chondromyces crocatus (strains Cm c2 and Cm c5) was studied. Isotopically labeled precursors and proposed pathway intermediates were fed to agar plate cultures of the myxobacteria. Subsequently, the volatiles were collected by use of a closed loop stripping apparatus (CLSA), and incorporation into the pyrazines was followed by GC/MS analysis. [2H8]Valine was smoothly incorporated into both pyrazines clearly establishing their origin from the amino acid pool. The cyclic dipeptide valine anhydride (16) – a potential intermediate on the biosynthetic pathway to branched dialkylpyrazines – was synthesized containing 2H1 labels in specific positions. Feeding of [2H16]‐16 and [2H12]‐16 in both valine subunits mainly resulted in the formation of pyrazines derived from only one labeled amino acid, whereas only traces of the expected pyrazines with two labeled subunits were found. To investigate the origin of nitrogen in the pyrazines, a feeding experiment with [15N]valine was performed, resulting in the incorporation of the 15N label. The results contradict a biosynthetic pathway via cyclic dipeptides, but rather point to a pathway on which valine is reduced to valine aldehyde. Its dimerization to 2,5‐diisopropyldihydropyrazine 36 and subsequent oxidation results in 2. The proposed biosynthetic pathway neatly fits the results of earlier labeling studies and also explains the formation of the regioisomer 2,6‐diisopropylpyrazine 3 by isomerization during the first condensation step of two molecules valine aldehyde. A general biosynthetic pathway to different classes of pyrazines is presented.

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Nuclear Magnetic Resonance of GdCo₃

Cited by 16 publications

References 5 publications

Axial and Radial Gas Holdup in Bubble Column Reactor

Axial and Radial Gas Holdup in Bubble Column Reactor

Metamagnetic phase transitions in ErCo3 investigated with microscopic methods

Crystal structure and magnetic properties of mixed compounds Nd_1–xR_xCo₃ (R = Gd, Tb)

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Nuclear Magnetic Resonance of GdCo3

Cited by 16 publications

References 5 publications

Axial and Radial Gas Holdup in Bubble Column Reactor

Axial and Radial Gas Holdup in Bubble Column Reactor

Metamagnetic phase transitions in ErCo3 investigated with microscopic methods

Crystal structure and magnetic properties of mixed compounds Nd1–xRxCo3 (R = Gd, Tb)

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Product

Resources

About

Nuclear Magnetic Resonance of GdCo₃

Crystal structure and magnetic properties of mixed compounds Nd_1–xR_xCo₃ (R = Gd, Tb)