Characterization of Thermal Evolution of Pores and Fluids in Shales Using NMR 2D Measurement

Hydrolyzed ZrCl4 and ZrO2 · nH2O have been used as starting compounds in a time-differential perturbed-angular correlation (TDPAC) investigation on the stabilization and thermal evolution of the metastable tetragonal form of ZrO2. This phase, of quadrupole parameters very similar to those reported for the high temperature tetragonal form, emerges at moderate temperatures previous to the monoclinic phase, when starting from hydrolyzed ZrCl4 and from ZrO2 · 2H2O treated previously at 673 K. Though in all cases zirconia appears initially as an amorphous compound characterized by unique hyperfine parameters, two different precursors have been observed to exist immediately previous to the occurrence of either the monoclinic or the metastable tetragonal crystal phases. Each of them exhibits a quadrupole frequency identical with and an asymmetry parameter higher than the ones characterizing the forthcoming corresponding crystal phases. A crystallization enthalpy of (33 ± 5) kJ/mol has been determined for the formation of the metastable tetragonal phase out of its precursor.

Download Full-text

Coupled Zircon-Rutile U-Pb Chronology: LA ICP-MS Dating, Geological Significance and Applications to Sediment Provenance in the Eastern Himalayan-Indo-Burman Region

Geosciences ◽

10.3390/geosciences9110467 ◽

2019 ◽

Vol 9 (11) ◽

pp. 467 ◽

Cited By ~ 1

Author(s):

Laura Bracciali

Keyword(s):

Thermal Evolution ◽

Secondary Growth ◽

Sediment Provenance ◽

Good Precision ◽

Combined Application ◽

Geological Processes ◽

Icp Ms ◽

Wide Range ◽

Isotopic Characterization

U-Pb dating by LA ICP-MS is one of the most popular and successful isotopic techniques available to the Earth Sciences to constrain timing and rates of geological processes thanks to its high spatial resolution, good precision (absolute U/Pb age resolution of ca. 2%, 2s), rapidity and relative affordability. The significant and continuous improvement of instrumentation and approaches has opened new fields of applications by extending the range of minerals that can be dated by this method. Following the development and distribution to the community of good quality reference materials in the last decade, rutile U-Pb thermochronology (with a precision only slightly worse than zircon) has become a commonly used method to track cooling of deep-seated rocks. Its sensitivity to mid- to low-crustal temperatures (~450 °C to 650 °C) is ideal to constrain exhumation in active and ancient orogens as well as thermal evolution of slow-cooled terranes. Recrystallization and secondary growth during metamorphism and the presence of grain boundary fluids can also affect the U-Pb isotopic system in rutile. A growing body of research focusing on U-Pb dating of rutile by LA ICP-MS is greatly improving our understanding of the behavior of this mineral with regards to retention of radiogenic Pb. This is key to fully exploit its potential as a tracker of geological processes. The latest developments in this field are reviewed in this contribution. The combined application of U-Pb zircon and rutile chronology in provenance studies, particularly when complemented by lower-T thermochronometry data, allows the isotopic characterization of the sources across a wide range of temperatures. The benefits of applying detrital zircon-rutile U-Pb chronology as a coupled provenance proxy are presented here, with a focus on the Eastern Himalayan-Indo-Burman region, where a growing number of successful studies employs such an approach to help constrain river drainage and basin evolution and to infer feedback relationships between erosion, tectonics and climate.

Download Full-text

Sol-gel Synthesis and Characterization of Lithium and Cerium Codoped Perovskite

Journal of Materials and Applications ◽

10.32732/jma.2020.9.1.17 ◽

2020 ◽

Vol 9 (1) ◽

pp. 17-24

Author(s):

Katarina Mužina ◽

Marija Tkalčević ◽

Filip Brleković ◽

Ivana Katarina Munda ◽

Vilko Mandić ◽

...

Keyword(s):

Photocatalytic Activity ◽

Thermal Evolution ◽

Sol Gel ◽

Thermo Gravimetric Analysis ◽

Calcium Nitrate ◽

Gravimetric Analysis ◽

X Ray ◽

Sol Gel Synthesis ◽

Thermally Treated

Perovskites are an important group of ceramic materials with a structural formula ABO3 and wide array of potential applications in electronics, superconductors, catalysis, etc. CaTiO3, by which the whole group was named for, is particularly significant due to its use in catalysis, but its photocatalytic activity is limited by a large band gap value (~3.5 eV). A possible solution is the substitution of A and B cations with foreign cations which causes the alteration of properties, including photocatalytic efficiency. The aim of this work was the sol-gel synthesis of lithium and cerium codoped CaTiO3, characterization of the prepared gel and ceramics obtained by its thermal treatment. Samples of codoped perovskite, Ca1-xLixCexTiO3, where x = 0, 0.01, 0.02, 0.03 and 0.04, were prepared and characterized using powder X–ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), differential thermal and thermo-gravimetric analysis (DTA-TGA), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Photocatalytic activity was evaluated through the study of methylene blue photocatalytic degradation. XRD analysis showed that the prepared samples consisted of calcium nitrate and titanium chelate. In accordance with the established thermal evolution path, all samples were thermally treated at 500 °C for 2 hours. Beside perovskite, Ca2Ti2O6 appeared as a secondary phase in all thermally treated samples. SEM analysis of thermally treated samples showed the presence of agglomerates of irregular morphology and the decrease of primary particles size with the increase of dopants concentration. The sample with x=0.04 showed an increased photocatalytic activity.

Download Full-text

Microscopic Characterization of the Thermal Evolution of Stainless Steel Coatings Sputter-deposited onto WC Particles

Microscopy and Microanalysis ◽

10.1017/s1431927608089320 ◽

2008 ◽

Vol 14 (S3) ◽

pp. 39-40 ◽

Cited By ~ 2

Author(s):

C.M. Fernandes ◽

A.M.R. Senos ◽

M.T. Vieira

Keyword(s):

Thermal Evolution ◽

Nanocrystalline Structure ◽

Sputter Deposition ◽

Wet Milling ◽

Metallic Elements ◽

Metallic Binder ◽

Powder Particles ◽

Sputter Deposited ◽

Stainless Steel Coatings

The hardmetal composites are generally produced from powders of tungsten carbide (WC) and of metal elements, belonging to group 8-10 of the periodic table, which are mixed together by wet milling. News processes, alternatives to milling, have been developed, aiming a higher uniformity of the metallic binder distribution in WC based composites, together with other technological benefits. One of those methods consists of the sputter deposition of metal binder onto the WC powder leading to powder particles coated with the metallic elements. The particles coating showed to be chemically and morphologically very uniform and possesses a nanocrystalline structure and improved surface properties, such as powder's flowability, pressing behaviour, sinterability and thermal reactivity.

Download Full-text

Characterization of Residual Kerogens and the Pores in Shale Rocks During Thermal Evolution

10.3997/2214-4609.201903011 ◽

2019 ◽

Author(s):

J.B. Xu ◽

B. Cheng ◽

Y. Zhang ◽

X. Zhang ◽

Z.W. Wei ◽

...

Keyword(s):

Thermal Evolution

Download Full-text

Structural Characterization of the Thermal Evolution of Tetrahedrally Coordinated Amorphous Carbon Films

MRS Proceedings ◽

10.1557/proc-498-55 ◽

1997 ◽

Vol 498 ◽

Cited By ~ 1

Author(s):

L. J. Martinez-Miranda ◽

J. P. Sullivan ◽

T. A. Friedmann ◽

M. P. Siegal ◽

N. J. DiNardo

Keyword(s):

Thermal Evolution ◽

Periodic Structures ◽

Structural Features ◽

Carbon Films ◽

Interface Roughness ◽

X Ray ◽

Film Density ◽

Angle Scattering ◽

Post Deposition

ABSTRACTWe present the results of a post-deposition annealing structural study on amorphous tetrahedrally-coordinated carbon (a-tC) films on Si(100) prepared by pulsed-laser deposition. Films as-deposited and post-annealed at 200, 300, 400, 500 and 600 °C, respectively, are studied using combined x-ray reflectivity and low-angle scattering measurements. The scans are fit to the Fresnel equations to obtain values for average film density, film and interface thickness, and film and interface roughness. We observe a correlation between the evolution of film density, roughness and the spacing of quasi-periodic structures in the films as a function of annealing temperature. We relate the evolution of these structural features with previous measurements of the resistivity and the observed stress release in these films.

Download Full-text

Characterization of oxygen passivated iron nanoparticles and thermal evolution to γ-Fe2O3

Journal of Materials Science ◽

10.1023/b:jmsc.0000035328.99440.8d ◽

2004 ◽

Vol 39 (15) ◽

pp. 4877-4885 ◽

Cited By ~ 20

Author(s):

T. C. Rojas ◽

J. C. Sánchez-López ◽

J. M. Greneche ◽

A. Conde ◽

A. Fernández

Keyword(s):

Iron Nanoparticles ◽

Thermal Evolution

Download Full-text

Morphological Characterization of Mycobacteriophage R1

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051281 ◽

1974 ◽

Vol 32 ◽

pp. 254-255

Author(s):

B. L. Soloff ◽

T. A. Rado

Keyword(s):

Carbon Source ◽

Stationary Phase ◽

Growth Phase ◽

Minimal Medium ◽

Morphological Characterization ◽

Logarithmic Growth Phase ◽

Complete Lysis ◽

Lysogenic Culture ◽

Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

Download Full-text