scholarly journals Characterization of Ferrihydrite-Soil Organic Matter Coprecipitates by X-ray Diffraction and Mössbauer Spectroscopy

2008 ◽  
Vol 42 (21) ◽  
pp. 7891-7897 ◽  
Author(s):  
Karin Eusterhues ◽  
Friedrich E. Wagner ◽  
Werner Häusler ◽  
Marianne Hanzlik ◽  
Heike Knicker ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
X Ray Diffraction ◽  
X Ray

Influence of soil organic matter on sulfate retention in two Podzols in Quebec, Canada

1999 ◽  
Vol 79 (1) ◽  
pp. 103-109 ◽  
Author(s):  
F. Courchesne ◽  
J.-F. Laberge ◽  
A. Dufresne
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Ammonium Oxalate ◽  
X Ray Diffraction ◽  
Weighted Mean ◽  
Fine Silt ◽  
Mineral Horizon ◽  
Organic C ◽  
X Ray

The role of soil organic matter (OM) on SO4 retention was investigated by comparing OM content, SO4 retention, and the distribution of Fe, Al and Si compounds in OM-poor (Grands-Jardins, PGJ) and OM-rich (Hermine, HER) Podzols from Québec, Canada. At both sites, four pedons were sampled by horizon; soil pH in H2O, organic C, phosphate-extractable SO4 and, sodium pyrophosphate, acid ammonium oxalate and dithionite-citrate-bicarbonate (DCB) extractable Fe, Al and Si were measured for each mineral horizon. The mineralogy of the clay (<2 µm) and fine silt (2–20 µm) fractions of selected horizons was determined by X-ray diffraction (XRD) and infrared spectroscopy (IR). Weighted mean organic C and pyrophosphate extractable Fe and Al contents were significantly higher in the HER than in the PGJ sola, while the PGJ soils were richer in amorphous inorganic Al. No trends were observed for inorganic Fe compounds. Chemical dissolution and IR allowed the identification of short-range ordered aluminosilicates, probably allophane, in the OM-poor and slightly acidic to neutral PGJ soils. These materials were absent from the OM-rich and acidic HER soils. Phosphate extractions showed that the weighted mean native SO4 content was five times higher in the PGJ than in the HER soil. Finally, native SO4 was strongly related to inorganic Fe, Al and Si (associated with allophane) at PGJ but only to inorganic Fe at HER. These results indicate that OM indirectly affects SO4 sorption through the influence organic substances exerts on the nature and distribution of pedogenic Fe, Al and Si compounds, such as allophane, in Podzolic profiles. Key words: Organic matter, sulfate, imogolite, allophane, silica, Podzol

EFFECT OF SOIL ORGANIC MATTER OXIDATION ON THE COLLAPSE OF VERMICULITE

1985 ◽  
Vol 65 (3) ◽  
pp. 593-597 ◽  
Author(s):  
N. M. MILES ◽  
M. SCHNITZER ◽  
C. R. DE KIMPE
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Key Words ◽  
Mixed Layer ◽  
Ir Spectrum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Matter Oxidation ◽  
Ir Spectrophotometry ◽  
Complete Collapse

Oxidation of organic matter with H2O2 produced substantial amounts of NH3 which was then fixed by vermiculite, causing partial or complete collapse and converting the mineral to a mica-like product. The collapse of the mineral was indicated by shifts in the 001 spacing from 1.476 to 1.030 nm and the appearance of a well-defined band at 1430 cm−1 in the IR spectrum, indicative of the presence of NH4+ in the interlayer positions of the clay. Our data suggest that: (a) the transformation of vermiculite to mica during H2O2 oxidation may result in underestimation of the vermiculite content of soils by XRD, and (b) the wide occurrence of mixed-layer minerals in soils may in part have resulted from the fixation of NH3 liberated from the microbial mineralization of organically bound N. Key words: Ammonia, X-ray diffraction, IR spectrophotometry, mixed-layer minerals, H2O2 pretreatment

CHARACTERIZATION OF ORGANIC MATTER FOR THE BIOENERGY GENERATION BY X-RAY DIFFRACTION

2021 ◽  
Author(s):  
Aysla Caroline Sousa Oliveira ◽  
Gabriela Morais da Costa ◽  
Julie Brenda Santos da Silva ◽  
Glauber Cruz
Keyword(s):  
Organic Matter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bioenergy Generation

Characterization of Mycelium-Like Material Formed During Drying of Salt Stock Prunes

1994 ◽  
Vol 57 (9) ◽  
pp. 817-819
Author(s):  
ROBIN Y.-Y. CHIOU ◽  
WEN-CHING TZENG ◽  
KUO-FONG HUANG
Keyword(s):  
Organic Matter ◽  
Sodium Chloride ◽  
Citric Acid ◽  
Diffraction Analysis ◽  
Diffraction Pattern ◽  
X Ray Diffraction ◽  
X Ray

Material with the appearance of mold mycelium was formed on salt stock prunes during drying. The moisture-free mycelium-like material consisted of 98.5 to 98.7% sodium chloride (NaCl), 1.67% organic matter and 0.165% acidity expressed as citric acid. X-ray diffraction analysis of the material revealed a diffraction pattern similar to that of NaCl. Formation of the material was dependent upon the efficiency and extent of drying. However, the material was not observed on deskinned salt stock prunes subjected to drying.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Synthesis and characterization of TiN / Ti / AISI 410 coatings

2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama
Keyword(s):  
Synthesis And Characterization ◽  
Photoemission Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Columnar Grains ◽  
Tin Thin Films ◽  
Steel Aisi ◽  
Interacting Surfaces ◽  
Stainless Steel Aisi

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified.  Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

New Coordination Compounds of Fe(III) with Organic Ligands

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihaela Flondor ◽  
Ioan Rosca ◽  
Doina Sibiescu ◽  
Mihaela-Aurelia Vizitiu ◽  
Daniel-Mircea Sutiman ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Complex Compounds ◽  
Organic Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Chemical Analysis ◽  
Structural Formulae ◽  
Paramagnetic Properties

In this paper the synthesis and the study of some complex compounds of Fe(III) with ligands derived from: 2-(4-chloro-phenylsulfanyl)-1-(2-hydroxy-3,5-diiodo-phenyl)-ethanone (HL1), 1-(3,5-dibromo-2-hydroxy-phenyl)-2-phenylsulfanyl-ethanone(HL2), and 2-(4-chloro-phenylsulfanyl)-1-(3,5-dibromo-2-hydroxy-phenyl)-ethanone (HL3) is presented. The characterization of these complexes is based on method as: the elemental chemical analysis, IR and ESR spectroscopy, M�ssbauer, the thermogravimetric analysis and X-ray diffraction. Study of the IR and chemical analysis has evidenced that the precipitates form are a complexes and the combination ratio of M:L is 1:2. The central atoms of Fe(III) presented paramagnetic properties and a octaedric hybridization. Starting from this precipitation reactions, a method for the gravimetric determination of Fe(III) with this organic ligands has been possible. Based on the experimental data on literature indications, the structural formulae of the complex compounds are assigned.

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