scholarly journals Linking crystal structure with temperature-sensitive vibrational modes in calcium carbonate minerals

2014 ◽  
Vol 16 (33) ◽  
pp. 17634-17639 ◽  
Author(s):  
Ben Xu ◽  
Kristin M. Poduska
Keyword(s):  
Crystal Structure ◽  
Calcium Carbonate ◽  
Temperature Sensitive ◽  
Vibrational Modes ◽  
Temperature Dependent ◽  
Carbonate Minerals ◽  
Structure Packing

Crystal structure packing arrangements could provide a generalizable approach to track either temperature-dependent or crystallinity-related effects in IR-active solids.

Crystal structure and temperature-dependent properties of Na2H4Ga2GeO8 – a novel gallogermanate

2020 ◽  
Vol 75 (9-10) ◽  
pp. 805-813
Author(s):  
Irma Peschke ◽  
Lars Robben ◽  
Christof Köhler ◽  
Thomas Frauenheim ◽  
Josef-Christian Buhl ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Decomposition Temperature ◽  
Spectroscopic Techniques ◽  
Charge Balance ◽  
Temperature Dependent ◽  
Raman Spectroscopic ◽  
Debye Temperatures ◽  
Diffraction Lattice ◽  
Temperature Dependent Properties ◽  
Balance Structure

AbstractSynthesis, crystal structure and temperature-dependent behavior of Na2H4Ga2GeO8 are reported. This novel gallogermanate crystallizes in space group I41/acd with room-temperature powder diffraction lattice parameters of a = 1298.05(1) pm and c = 870.66(1) pm. The structure consists of MO4 (M = Ga, Ge) tetrahedra in four-ring chains, which are connected by two different (left- and right-handed) helical chains of NaO6 octahedra. Protons coordinating the oxygen atoms of the GaO4 tetrahedra not linked to germanium atoms ensure the charge balance. Structure solution and refinement are based on single crystal X-ray diffraction measurements. Proton positions are estimated using a combined approach of DFT calculations and NMR, FTIR and Raman spectroscopic techniques. The thermal expansion was examined in the range between T = 20(2) K and the compound’s decomposition temperature at 568(5) K, in which no phase transition could be observed, and Debye temperatures of 266(11) and 1566(65) K were determined for the volume expansion.

Effect of Ion Migration of Multiple Copper-Zinc Alloy on the Crystal Structure of Calcium Carbonate Scale

2010 ◽  
Vol 96 ◽  
pp. 35-40 ◽  
Author(s):  
Yan Ding ◽  
Jun Ping Meng ◽  
Xu Hong Zhang ◽  
Li Juan Wang ◽  
Qing Guo Tang
Keyword(s):  
Crystal Structure ◽  
Calcium Carbonate ◽  
Zinc Ion ◽  
Ion Concentration ◽  
Zinc Alloy ◽  
Heating Process ◽  
Ion Migration ◽  
Heat Transfer Efficiency ◽  
Copper Zinc ◽  
Calcium Carbonate Scale

Multiple copper-zinc alloy was used to treat water in order to restrict the formation of hard scale during heating process. Trace amounts of metal ions were dissolved from the alloy under the action of tiny battery corrosion, which took part in the crystallization of calcium carbonate crystal. The ion migration rules and its effect on the crystal structure of water scale were studied. The ICP test results show that after immersion in the water for 20 min, the zinc ion concentration increased to 0.35 mg•L-1 compared with contrast group. The simulating experiment of the scale crystal growth demonstrated that the calcium carbonate scale after treated with the alloy showed a transformation from calcite to aragonite, and the ratio of calcite to aragonite changed from 1:0.125 to 1:2.30. Meanwhile, the heat transfer efficiency was increased to 2.19%.

scholarly journals Crystal Structure Dependence of Antiferromagnetic Coupling in FE/SI Multilayers

1995 ◽  
Vol 384 ◽  
Author(s):  
R. P. Michel ◽  
A. Chaiken ◽  
M. A. Wall
Keyword(s):  
Crystal Structure ◽  
Magnetic Coupling ◽  
Antiferromagnetic Coupling ◽  
Temperature Dependent ◽  
Layered Systems ◽  
Metal Insulator ◽  
Structure Dependence ◽  
Metallic Conductor ◽  
Metal Metal ◽  
Cscl Structure

ABSTRACTRecent reports of temperature dependent antiferromagnetic coupling in Fe/Si multilayers have motivated the generalization of models describing magnetic coupling in metal/metal multilayers to metal/insulator and metal/semiconductor layered systems. Interesting dependence of the magnetic properties on layer thickness and temperature are predicted. We report measurements that show the antiferromagnetic (AF) coupling observed in Fe/Si multilayers is strongly dependent on the crystalline coherence of the silicide interlayer. Electron diffraction images show the silicide interlayer has a CsCl structure. It is not clear at this time whether the interlayer is a poor metallic conductor or a semiconductor so the relevance of generalized coupling theories is unclear.

scholarly journals Temperature Dependence of Electrical Properties and Crystal Structure of 0.29Pb(In1/2Nb1/2)O3–0.44Pb(Mg1/3Nb2/3)O3–0.27PbTiO3Single Crystals

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Qian Li ◽  
Yun Liu ◽  
Andrew Studer ◽  
Zhenrong Li ◽  
Ray Withers ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Electrical Properties ◽  
Dielectric Permittivity ◽  
Neutron Diffraction ◽  
Electrical Measurement ◽  
Temperature Dependent ◽  
Electromechanical Properties ◽  
Polar Order

We characterized the temperature dependent (~25–200°C) electromechanical properties and crystal structure of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3single crystals usingin situelectrical measurement and neutron diffraction techniques. The results show that the poled crystal experiences an addition phase transition around 120°C whereas such a transition is absent in the unpoled crystal. It is also found that the polar order persists above the maximum dielectric permittivity temperature at which the crystal shows a well-defined antiferroelectric behavior. The changes in the electrical properties and underlying crystal structure are discussed in the paper.

On the Crystal Structure and Temperature Dependent Spectroscopy of the UV-C Emitting Phosphor Sr3(BO3)2:Pr3+,Na+

2021 ◽  
Vol 230 ◽  
pp. 117765
Author(s):  
Jan-Niklas Keil ◽  
Christian Paulsen ◽  
Rainer Pöttgen ◽  
Thomas Jüstel
Keyword(s):  
Crystal Structure ◽  
Temperature Dependent ◽  
Uv C

Temperature Dependent Raman Scattering in CsTiOAsO4 Single Crystal

1995 ◽  
Vol 398 ◽  
Author(s):  
A.R. Guo ◽  
C.-S. Tu ◽  
Ruiwu Tao ◽  
R.S. Katiyar ◽  
Ruyan Guo ◽  
...  
Keyword(s):  
Soft Mode ◽  
Low Frequency ◽  
High Mobility ◽  
Vibrational Modes ◽  
Frequency Range ◽  
Temperature Dependent ◽  
Higher Symmetry ◽  
Phonon Spectra ◽  
Symmetry Structure ◽  
Increasing Temperature

ABSTRACTThe longitudinal (LO) and transverse (TO) A1 vibrational modes have been measured between 30-1200 cm−1 as a function of temperature (30–1240 K) for CsTiOAsO4 (CTA). The frequencies for all corresponding Raman components shifted to lower frequencies on increasing the temperature, however, there is no typical soft-mode like behavior observed in the measured frequency range. The relative intensities of the low frequency bands increase dramatically with increasing temperature due to high mobility of Cs+ ion. A higher symmetry structure taking place above 940K has been confirmed by changes in the phonon spectra.

scholarly journals Mutations affecting the tRNA-splicing endonuclease activity of Saccharomyces cerevisiae.

Genetics ◽  
1988 ◽  
Vol 118 (4) ◽  
pp. 609-617
Author(s):  
M Winey ◽  
M R Culbertson
Keyword(s):  
Growth Defect ◽  
Temperature Sensitive ◽  
Gene Products ◽  
Endonuclease Activity ◽  
Temperature Dependent ◽  
Direct Role ◽  
Trna Splicing

Abstract Two unlinked mutations that alter the enzyme activity of tRNA-splicing endonuclease have been identified in yeast. The sen1-1 mutation, which maps on chromosome 12, causes temperature-sensitive growth, reduced in vitro endonuclease activity, and in vivo accumulation of unspliced pre-tRNAs. The sen2-1 mutation does not confer a detectable growth defect, but causes a temperature-dependent reduction of in vitro endonuclease activity. Pre-tRNAs do not accumulate in sen2-1 strains. The in vitro enzyme activities of sen1-1 and sen2-1 complement in extracts from a heterozygous diploid, but fail to complement in mixed extracts from separate sen1-1 and sen2-1 haploid strains. These results suggest a direct role for SEN gene products in the enzymatic removal of introns from tRNA that is distinct from the role of other products known to affect tRNA splicing.

Oxygen Spectroscopy and Polarization-Dependent Imaging Contrast (PIC)-Mapping of Calcium Carbonate Minerals and Biominerals

2014 ◽  
Vol 118 (28) ◽  
pp. 8449-8457 ◽  
Author(s):  
Ross T. DeVol ◽  
Rebecca A. Metzler ◽  
Lee Kabalah-Amitai ◽  
Boaz Pokroy ◽  
Yael Politi ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Carbonate Minerals

Temperature-Dependent Vibrational Modes in Sodium Nitrite

1968 ◽  
Vol 174 (3) ◽  
pp. 946-952 ◽  
Author(s):  
M. K. Barnoski ◽  
J. M. Ballantyne
Keyword(s):  
Sodium Nitrite ◽  
Vibrational Modes ◽  
Temperature Dependent

scholarly journals Lactococcal Plasmid pNP40 Encodes a Novel, Temperature-Sensitive Restriction-Modification System

2004 ◽  
Vol 70 (9) ◽  
pp. 5546-5556 ◽  
Author(s):  
Jonathan O'Driscoll ◽  
Frances Glynn ◽  
Oonagh Cahalane ◽  
Mary O'Connell-Motherway ◽  
Gerald F. Fitzgerald ◽  
...  
Keyword(s):  
Restriction Enzymes ◽  
Temperature Sensitive ◽  
Temperature Dependent ◽  
Modification System ◽  
Restriction Modification System ◽  
Naturally Occurring ◽  
Low Copy Number ◽  
Encoding Genes ◽  
Restriction Modification ◽  
Specific Mrna

ABSTRACT A novel restriction-modification system, designated LlaJI, was identified on pNP40, a naturally occurring 65-kb plasmid from Lactococcus lactis. The system comprises four adjacent similarly oriented genes that are predicted to encode two m5C methylases and two restriction endonucleases. The LlaJI system, when cloned into a low-copy-number vector, was shown to confer resistance against representatives of the three most common lactococcal phage species. This phage resistance phenotype was found to be strongly temperature dependent, being most effective at 19°C. A functional analysis confirmed that the predicted methylase-encoding genes, llaJIM1 and llaJIM2, were both required to mediate complete methylation, while the assumed restriction enzymes, specified by llaJIR1 and llaJIR2, were both necessary for the complete restriction phenotype. A Northern blot analysis revealed that the four LlaJI genes are part of a 6-kb operon and that the relative abundance of the LlaJI-specific mRNA in the cells does not appear to contribute to the observed temperature-sensitive profile. This was substantiated by use of a LlaJI promoter-lacZ fusion, which further revealed that the LlaJI operon appears to be subject to transcriptional regulation by an as yet unidentified element(s) encoded by pNP40.

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