The Lower Miocene Macelj sandstones from the western part ofHrvatsko Zagorje, are green in colour with variable amounts o f glauconitic grains. This paper presents the results of mineralogical ...andsome petrological analysis of three charactersitic samples of thesesandslones.The natural sandstone samples were analysed by polarisingmicroscope and by X -ray poweled diffraction (XRD). After separation,the pure or almost pure glauconitic materials were analysed by XRD,chemical analysis and thermal analysis (TG, DTA and DTG). Theresults show variation, not only in the glauconitic material of thesandstone samples, but also within individual samples. The amount ofsmeclite layers varies from < 5% to approximately 40% de pending onthe degree of order and the stage of glauconitic evolution. This is indicatedby the contents o f K, AI, Fe , adsorbed water and cationexchange capacity as well as XRD powder patterns.
As part of the study of interaction of the Ba
2
RCu
3O
6+z (
R=lanthanides and Y) superconductor with SrTiO
3 buffer, phase equilibria of the subsystem,
R
2O
3–TiO
2–CuO (
R=Nd, Y, and Yb), have been ...investigated in air at 960
°C. While the phase relationships of the two phase diagrams with smaller
R (Y and Yb) are similar, substantial differences were found in the Nd
2O
3–TiO
2–CuO system, partly due to different phase formation in the binary
R
2O
3–TiO
2 and
R
2O
3–CuO systems.
R
2CuTiO
6 and
R
2Cu
9Ti
12O
36 were the only ternary phases established in all the three diagrams.
R
2Cu
9Ti
12O
36 belongs to the perovskite-related AC
3(B
4)O
12 family which is cubic
Im3. Depending on the size of
R
3+,
R
2CuTiO
6 crystallizes in two crystal systems:
Pnma (
R=La–Gd), and
P6
3cm (
R=Dy–Lu). The structure and crystal chemistry of the
Pnma series of
R
2CuTiO
6 (
R=La, Nd, Sm, Eu, and Gd) are discussed in detail in this paper. Patterns for selected members of
R
2CuTiO
6 have also been prepared and submitted for inclusion in the Powder Diffraction File (PDF).
Phase diagram of the Y
2O
3–CuO–TiO
2 system prepared in air at 960
°C
CRYSTMET is a database of critically evaluated crystallographic data for metals (including alloys, intermetallics and minerals) and associated bibliographic, chemical and physical information. Also ...included are simulated powder diffraction patterns for all of the entries. The database currently contains almost 70000 entries and covers the literature exhaustively from 1922 to the present. The database is available on CD‐ROM with search/analysis software for use on personal computers. This software can be used with any database in the appropriate format; currently CRYSTMET and the ICSD databases are available. This paper describes the database content, the procedures used in its construction, the software made available to the user and a number of potential uses for the data.
In using infrared or infrared‐enhanced photography to examine gunshot residue (GSR) on dark‐colored clothing, the GSR particles are microscopically examined directly on the fabric followed by the ...modified Griess test (MGT) for nitrites. In conducting the MGT, the GSR is transferred to treated photographic paper for visualization. A positive reaction yields an orange color on specially treated photographic paper. The examiner also evaluates the size of the powder pattern based on the distribution of nitrite reaction sites or density. A false‐positive reaction can occur using the MGT due to contaminants or dyes that produce an orange cloud reaction as well. A method for enhancing visualization of the pattern produced by burned and partially unburned powder is by treatment of the fabric with a solution of sodium hypochlorite. In order to evaluate the results of sodium hypochlorite treatment for GSR visualization, the MGT was used as a reference pattern. Enhancing GSR patterns on dark or multicolored clothing was performed by treating the fabric with an application of 5.25% solution of sodium hypochlorite. Bleaching the dyes in the fabric enhances visualization of the GSR pattern by eliminating the background color. Some dyes are not affected by sodium hypochlorite; therefore, bleaching may not enhance the GSR patterns in some fabrics. Sodium hypochlorite provides the investigator with a method for enhancing GSR patterns directly on the fabric. However, this study is not intended to act as a substitute for the MGT or Sodium Rhodizonate test.
The influence of the magnetic state of a ferromagnetic wire substrate on the morphology of deposited nickel obtained by electrolysis has been studied. It has been demonstrated using statistical ...analysis that in the course of nickel electrodeposition without external magnetic field the dimensional characteristics of the arising dendritic structures are affected significantly by the residual magnetization of the substrate. When in the course of Ni electrodeposition even a weak dc magnetic field is applied perpendicularly to the wire axis, nearly identical structures are formed; that is, the system “forgets” its previous magnetic state. The magnetic properties of the substrate were visualized using powder patterns.
Noise spectroscopy has previously been demonstrated to provide broad-bandwidth excitation with minimal applied RF field strengths. Nonetheless, its application to broadline solid-state NMR ...spectroscopy has appeared limited by the need to have unrealistically short probe- and receiver-recovery times after pulses. In this Communication, we explain theoretically and demonstrate experimentally that accurate lineshapes can be observed in2H solid-state NMR spectroscopy even where the probe ringdown time greatly exceeds the required time between sampled data points. Moreover, accurate lineshapes can be observed to ±125 kHz using RF fields as weak as a few hundred hertz.
Reference X-ray powder patterns and the crystal structures of the lanthanide compounds, BaR2ZnO5, in which R = La, Nd, Sm, Eu, Gd, Dy, Ho, Y, Er, or Tm, were determined by the X-ray Rietveld ...refinement technique. A structural trend was confirmed for this series of compounds. The compounds with smaller ionic radii (R = Sm, Eu, Gd, Dy, Ho, Y, Er, or Tm) are isostructural to the orthorhombic "green phase" (BaY2CuO5). R is seven-fold coordinated inside a monocapped trigonal prism. These prisms share edges to form wave-like chains parallel to the long b-axis. The BaR2ZnO5 compounds which contain larger size R (La and Nd) crystallise in the tetragonal space group I4/mcm. The structure consists of ZnO4 tetrahedra (instead of planar CuO4 groups as found in BaR2CuO5) with 10-fold coordinated bicapped square prismatic Ba and 8-fold coordinated bicapped trigonal prismatic R ions between them. The lattice parameters for each group of compounds are given. 24 refs.
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