Results 91 to 100 of about 87,639 (320)

The sequestration of phosphate by iron phases in the sediments from Lake Rotorua, New Zealand [PDF]

open access: yes, 2007
A sequential extraction method was used to determine which dominant sedimentary mineral phase was involved in phosphorus retention in the sediments of Lake Rotorua and to verify the importance of iron phases in the role as a phosphorus sink. The observed
Mangan, Carmel Mary
core  

SQUID-SIMS is a useful approach to uncover primary signals in the Archean sulfur cycle [PDF]

open access: yes, 2014
The Agouron Institute and National Aeronautic and Space Administration Exobiology Award NNX09AM91G supported this work.Many aspects of Earth's early sulfur cycle, from the origin of mass-anomalous fractionations to the degree of biological participation,
Guan, Yunbin   +19 more
core   +1 more source

Local Structures of Se and Br in Cretaceous–Paleogene Boundary Sediments and Concentration Effects of Ferrihydrite Originating From Impact Ejecta

open access: yesGeological Journal, EarlyView.
Chemical states of Se and Br atoms in the KPg boundary sediments from Stevns Klint were studied using XAFS spectroscopy. The high concentrations of Se4+ could become an index of the degree to which the global environment was soiled with dust and ash derived from impact ejecta or volcanic eruptions.
Kei‐ichiro Murai   +5 more
wiley   +1 more source

Electrochemical study on Surface Oxidation of Natural Pyrite in Ferric Sulfate Solution

open access: yesInternational Journal of Electrochemical Science, 2019
Surface oxidation of natural massive pyrite in 0.5 M sulfuric acid solutions with different ferric concentrations was investigated. The electrode of natural pyrite was made and its behavior was measured using cyclic voltammetry (CV), linear sweep ...
Guobao Chen, Hongying Yang
doaj   +1 more source

Pyrite-type cobalt phosphosulphide bifunctional catalyst for aqueous and gel-based rechargeable zinc-air batteries

open access: yes, 2020
Pyrite-type cobalt phosphosulphide bifunctional catalyst for aqueous and gel-based rechargeable zinc-air ...
S Sampath (13464078)   +2 more
core  

Pyrite oxidation under initially neutral pH conditions and in the presence of Acidithiobacillus ferrooxidans and micromolar hydrogen peroxide [PDF]

open access: yes, 2012
Hydrogen peroxide (H2O2) at a micromolar level played a role in the microbial surface oxidation of pyrite crystals under initially neutral pH. When the mineral-bacteria system was cyclically exposed to 50 μM H2O2, the colonization of Acidithiobacillus ...
Lin, C., Ma, Y.
core   +1 more source

Apatite in Carbonatite Preserving Primary Magmatic, Post‐Magmatic Overgrowth, and Post India‐Asia Collision‐Related Hydrothermal Alteration: Evidenced From U–Pb Isotope and Trace Element Geochemistry

open access: yesGeological Journal, EarlyView.
U–Pb isotope and trace element geochemistry of apatite from carbonatites of Peshawar Plain Alkaline Igneous Province, western Himalaya shows Permo‐Carboniferous magmatism, an additional magmatic pulse during Cretaceous, and post‐magmatic hydrothermal/metasomatism during Oligocene. ABSTRACT U–Pb isotope and trace element geochemistry of apatite combined
Mehboob ur Rashid   +9 more
wiley   +1 more source

The German Soil Systematics and the Rationale Behind Its Revision

open access: yesJournal of Plant Nutrition and Soil Science, EarlyView.
ABSTRACT Background The German Soil Systematics is a pedogenetic classification based on the morphological expressions of pedogenic processes and has been developed over several stages since 1952. The system has successfully been in use for soil classification and soil survey for almost 70 years.
Einar Eberhardt   +3 more
wiley   +1 more source

Influence of Ca2+ and Mg2+ on Pyrite Flotation at Different Slurry Temperatures

open access: yesKuangchan zonghe liyong
This is an article in the field of mineral processing engineering. Through single mineral flotation test, solution chemistry calculation, Zeta potential detection, XPS detection, the influence and regulation mechanism of Ca2+ and Mg2+ on the flotation of
Xin WANG   +4 more
doaj   +1 more source

Quantifying user variability in the traditional X‐ray ice‐rafted‐debris counting technique

open access: yesJournal of Quaternary Science, EarlyView.
ABSTRACT The flux of icebergs is most commonly constrained in the palaeo‐record by manually counting gravel clasts in sediment core X‐ray images—a trusted method in Quaternary science and palaeoceanography for nearly 40 years. In this study, we explore the reproducibility (user consistency and between‐user variability) of the traditional clast‐counting
Neil McDonald   +3 more
wiley   +1 more source

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