Chemical Procedures for Rhenium Extraction from Geological Samples: Optimising the Anion Resin Bead Clean‐up Step

2020 ◽  
Vol 44 (2) ◽  
pp. 231-242 ◽  
Author(s):  
Gang Yang ◽  
Aaron Zimmerman ◽  
Nicole C. Hurtig ◽  
Svetoslav V. Georgiev ◽  
Vineet Goswami ◽  
...  
Keyword(s):  
Geological Samples ◽  
Resin Bead ◽  
Anion Resin

Bence-albee after 25 years: A new superior α-factor correction procedure for the quantitative analysis of oxides and silicates

1992 ◽  
Vol 50 (2) ◽  
pp. 1744-1745
Author(s):  
John T. Armstrong
Keyword(s):  
Quantitative Analysis ◽  
Electron Microprobe ◽  
Binary Systems ◽  
Correction Procedure ◽  
Geological Samples ◽  
The Past ◽  
Large Matrix ◽  
Computational Speed ◽  
Microprobe Data ◽  
Geological Sciences

One of the most cited papers in the geological sciences has been that of Albee and Bence on the use of empirical " α -factors" to correct quantitative electron microprobe data. During the past 25 years this method has remained the most commonly used correction for geological samples, despite the facts that few investigators have actually determined empirical α-factors, but instead employ tables of calculated α-factors using one of the conventional "ZAF" correction programs; a number of investigators have shown that the assumption that an α-factor is constant in binary systems where there are large matrix corrections is incorrect (e.g, 2-3); and the procedure’s desirability in terms of program size and computational speed is much less important today because of developments in computing capabilities. The question thus exists whether it is time to honorably retire the Bence-Albee procedure and turn to more modern, robust correction methods. This paper proposes that, although it is perhaps time to retire the original Bence-Albee procedure, it should be replaced by a similar method based on compositiondependent polynomial α-factor expressions.

Quantitative Analysis Of X-Ray Images From Geological Materials

1990 ◽  
Vol 48 (2) ◽  
pp. 244-245
Author(s):  
J. M. Paque ◽  
R. Browning ◽  
P. L. King ◽  
P. Pianetta
Keyword(s):  
Quantitative Analysis ◽  
Bulk Composition ◽  
Principal Component ◽  
Analytical Description ◽  
Bulk Sample ◽  
Geological Samples ◽  
X Ray ◽  
Software And Hardware ◽  
And Storage ◽  
Insight Into

Geological samples typically contain many minerals (phases) with multiple element compositions. A complete analytical description should give the number of phases present, the volume occupied by each phase in the bulk sample, the average and range of composition of each phase, and the bulk composition of the sample. A practical approach to providing such a complete description is from quantitative analysis of multi-elemental x-ray images.With the advances in recent years in the speed and storage capabilities of laboratory computers, large quantities of data can be efficiently manipulated. Commercial software and hardware presently available allow simultaneous collection of multiple x-ray images from a sample (up to 16 for the Kevex Delta system). Thus, high resolution x-ray images of the majority of the detectable elements in a sample can be collected. The use of statistical techniques, including principal component analysis (PCA), can provide insight into mineral phase composition and the distribution of minerals within a sample.

Stabilization of pH in Solid-matrix Hydroponic Systems

HortScience ◽  
1993 ◽  
Vol 28 (10) ◽  
pp. 981-984 ◽  
Author(s):  
Jay Frick ◽  
Cary A. Mitchell
Keyword(s):  
Seed Yield ◽  
Seed Oil ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Solid Matrix ◽  
Resin Bead ◽  
Resin Beads ◽  
Hydroponic Systems ◽  
Ethanesulfonic Acid ◽  
Substrate Ph

2-[N-morpholino] ethanesulfonic acid (MES) buffer or Amberlite DP-1 (cation-exchange resin beads) were used to stabilize substrate pH of passive-wicking, solid-matrix hydroponic systems in which small canopies of Brassica napus L. (CrGC 5-2, genome: ACaacc) were grown to maturity. Two concentrations of MES (5 or 10 m m) were included in Hoagland 1 nutrient solution. Alternatively, resin beads were incorporated into the 2 vermiculite: 1 perlite (v/v) growth medium at 6% or 12% of total substrate volume. Both strategies stabilized pH without toxic side effects on plants. Average seed yield rates for all four pH stabilization treatments (13.3 to 16.9 g·m-2·day-1) were about double that of the control (8.2 g·m-2·day-1), for which there was no attempt to buffer substrate pH. Both the highest canopy seed yield rate (16.9 g·m-2·day-1) and the highest shoot harvest index (19.5%) occurred with the 6% resin bead treatment, even though the 10 mm MES and 12% bead treatments maintained pH within the narrowest limits. The pH stabilization methods tested did not significantly affect seed oil and protein contents.

Rapid decomposition of geological samples by ammonium bifluoride (NH 4 HF 2 ) for combined Hf‐Nd‐Sr isotope analyses

2021 ◽  
Author(s):  
Gábor Újvári ◽  
Urs Klötzli ◽  
Monika Horschinegg ◽  
Wencke Wegner ◽  
Dorothee Hippler ◽  
...  
Keyword(s):  
Geological Samples ◽  
Sr Isotope ◽  
Rapid Decomposition ◽  
Ammonium Bifluoride ◽  
Isotope Analyses

scholarly journals Prehistorical Obsidian Sources in the Island of Lipari (Aeolian Islands)

2020 ◽  
Vol 6 (1) ◽  
pp. 393-402
Author(s):  
Maria Clara Martinelli ◽  
Mauro Coltelli ◽  
Marco Manni ◽  
Letizia Bonizzoni ◽  
Alessandra Guglielmetti ◽  
...  
Keyword(s):  
Fission Track ◽  
Scientific Research ◽  
Raw Material ◽  
Neolithic Period ◽  
Study Analysis ◽  
Geological Samples ◽  
Aeolian Islands ◽  
Methodological Aspects ◽  
And Diffusion ◽  
Age Determinations

AbstractThis research project concerns the study, analysis and dating of obsidian flows on the island of Lipari, in relation to the population of the Aeolian Islands, during the Neolithic period.The collection, processing and diffusion of Lipari obsidian characterise the Neolithic population of Lipari and the entire Mediterranean. By improving the knowledge of supply methods in the territory, it will be possible to formulate hypotheses on the chronology of the sources, the ways of collecting the raw material and on the mobility of the Neolithic communities in the Aeolian Islands. The scientific research is divided into two main topics: the first concerns the analytical and methodological aspects of archaeological and geological studies of Lipari obsidian; the second, the formation of obsidian at Lipari, their sources and lithological characteristics. Throughout the duration of this study we will perform new age determinations of Neolithic obsidian artefacts and geological samples, directly with the method of fission track, and indirectly dating paleo soils using the radiocarbon method.

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