Magnetic Vertical Structure of Soil as a Result of Transformation of Iron Oxides During Pedogenesis. The Case Study of Soil Profiles from Slovakia and Ukraine

2017 ◽  
pp. 103-125
Author(s):  
Maria Jeleńska ◽  
Beata Górka-Kostrubiec ◽  
Sylwia K. Dytłow
Keyword(s):  
Iron Oxides ◽  
Vertical Structure ◽  
Soil Profiles

scholarly journals Evaluation of Magnetic Separation Efficiency on a Cassiterite-Bearing Skarn Ore by Means of Integrative SEM-Based Image and XRF–XRD Data Analysis

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 390 ◽  
Author(s):  
Markus Buchmann ◽  
Edgar Schach ◽  
Raimon Tolosana-Delgado ◽  
Thomas Leißner ◽  
Jennifer Astoveza ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Iron Oxides ◽  
Separation Efficiency ◽  
Analysis Data ◽  
Gangue Mineral ◽  
Data Partition ◽  
Local Regression ◽  
Separation Processes ◽  
Magnetic Separator

Image analysis data obtained from scanning electron microscopy provided data for a detailed evaluation of the separation efficiency for various processes involving the beneficiation of particulate materials. A dry magnetic separation by a drum type magnetic separator served as a case study to visualize effects of processing of a skarn ore with a high content of cassiterite as ore mineral (~4 wt%). For this material, iron oxides and silicates are the main gangue mineral groups. Based on the obtained data, partition curves were generated with the help of local regression. From the partition curves, the separation efficiency was evaluated and the relevant particle properties deduced. A detailed analysis of the bias of the quantitative mineralogical data is presented. This bias was monitored and further analyzed in detail. Thorough analysis of feed and products of magnetic separation enabled identification of the most important factors that control losses of cassiterite to the magnetic product, namely the association with iron oxides and particle sizes below ~40 µm. The introduced methodology is a general approach applicable for the optimization of different separation processes and is not limited to the presented case study.

Application of target detection algorithms to identification of iron oxides using ASTER images: a case study in the North of Semnan province, Iran

2014 ◽  
Vol 8 (9) ◽  
pp. 7321-7331 ◽  
Author(s):  
Majid Rahimzadegan ◽  
Behnam Sadeghi ◽  
Manuchehr Masoumi ◽  
Siamak Taghizadeh Ghalehjoghi
Keyword(s):  
Iron Oxides ◽  
Target Detection ◽  
Detection Algorithms ◽  
The North ◽  
Semnan Province

scholarly journals Lidar signal simulation for the evaluation of aerosols in chemistry transport models

2012 ◽  
Vol 5 (6) ◽  
pp. 1543-1564 ◽  
Author(s):  
S. Stromatas ◽  
S. Turquety ◽  
L. Menut ◽  
H. Chepfer ◽  
J. C. Péré ◽  
...  
Keyword(s):  
Optical Properties ◽  
Vertical Structure ◽  
Simulation Software ◽  
Lidar Signal ◽  
Transport Models ◽  
Signal Simulation ◽  
Level 1 ◽  
Dust Events ◽  
Level 2

Abstract. We present an adaptable tool, the OPTSIM (OPTical properties SIMulation) software, for the simulation of optical properties and lidar attenuated backscattered profiles (β') from aerosol concentrations calculated by chemistry transport models (CTM). It was developed to model both Level 1 observations and Level 2 aerosol lidar retrievals in order to compare model results to measurements: the level 2 enables to estimate the main properties of aerosols plume structures, but may be limited due to specific assumptions. The level 1, originally developed for this tool, gives access to more information about aerosols properties (β') requiring, at the same time, less hypothesis on aerosols types. In addition to an evaluation of the aerosol loading and optical properties, active remote sensing allows the analysis of aerosols' vertical structures. An academic case study for two different species (black carbon and dust) is presented and shows the consistency of the simulator. Illustrations are then given through the analysis of dust events in the Mediterranean region during the summer 2007. These are based on simulations by the CHIMERE regional CTM and observations from the CALIOP space-based lidar, and highlight the potential of this approach to evaluate the concentration, size and vertical structure of the aerosol plumes.

Redox-active antibiotics enhance phosphorus bioavailability

Science ◽  
2021 ◽  
Vol 371 (6533) ◽  
pp. 1033-1037 ◽  
Author(s):  
Darcy L. McRose ◽  
Dianne K. Newman
Keyword(s):  
Iron Oxides ◽  
Microbial Growth ◽  
Antibiotic Production ◽  
Phosphorus Limitation ◽  
Redox Cycling ◽  
Reductive Dissolution ◽  
Phosphorus Acquisition ◽  
Redox Active ◽  
Life On Earth

Microbial production of antibiotics is common, but our understanding of their roles in the environment is limited. In this study, we explore long-standing observations that microbes increase the production of redox-active antibiotics under phosphorus limitation. The availability of phosphorus, a nutrient required by all life on Earth and essential for agriculture, can be controlled by adsorption to and release from iron minerals by means of redox cycling. Using phenazine antibiotic production by pseudomonads as a case study, we show that phenazines are regulated by phosphorus, solubilize phosphorus through reductive dissolution of iron oxides in the lab and field, and increase phosphorus-limited microbial growth. Phenazines are just one of many examples of phosphorus-regulated antibiotics. Our work suggests a widespread but previously unappreciated role for redox-active antibiotics in phosphorus acquisition and cycling.

First evidence of Pleistocene ochre production from bacteriogenic iron oxides. A case study of the Upper Palaeolithic site at the San Teodoro Cave (Sicily, Italy)

2020 ◽  
Vol 123 ◽  
pp. 105221
Author(s):  
Vittorio Garilli ◽  
Gerlando Vita ◽  
Valeria La Parola ◽  
Massimiliana Pinto Vraca ◽  
Renato Giarrusso ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Upper Palaeolithic ◽  
Bacteriogenic Iron Oxides
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