scholarly journals Nanomechanics of organic-rich shales: the role of thermal maturity and organic matter content on texture

2016 ◽  
Vol 11 (4) ◽  
pp. 775-787 ◽  
Author(s):  
Sara Abedi ◽  
Mirna Slim ◽  
Franz-Josef Ulm
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Thermal Maturity

Threshold water content beyond which hydrophobic soils become hydrophilic: The role of soil texture and organic matter content

Geoderma ◽  
2013 ◽  
Vol 209-210 ◽  
pp. 177-187 ◽  
Author(s):  
E.S. Vogelmann ◽  
J.M. Reichert ◽  
J. Prevedello ◽  
C.O.B. Consensa ◽  
A.É. Oliveira ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Content ◽  
Soil Texture ◽  
Organic Matter Content ◽  
Matter Content

scholarly journals Searching for the Correlation Between the Activity of Urease and the Content of Nickel in the Soil Samples: The Role of Metal Speciation

2020 ◽  
Vol 20 (4) ◽  
pp. 1904-1911
Author(s):  
Paweł Miśkowiec ◽  
Zofia Olech
Keyword(s):  
Organic Matter ◽  
Urease Activity ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Total Content ◽  
Matter Content ◽  
Soil Samples ◽  
Soil Urease ◽  
Positive Correlations

Abstract The purpose of this study was to verify the correlation between the activity of urease and the content of nickel in soil of temperate climate in relation to the land management. Moreover, the metal speciation was taken into account in order to search for the above-mentioned correlation. Arable lands, forested lands, and wastelands were analyzed. The basic soil parameters were determined such as pH, clay fraction content, and organic matter content. The speciation of nickel was studied by using BCR (Bureau Communitaire de Reference) sequential extraction procedure and flame atomic absorption spectrometry, while the urease activity was determined spectrophotometrically. The pseudo-total content of Ni in every sample was below 30 mg kg−1 of dry soil. The dominant form of nickel in the soil samples was the residual form. Although the urease activity varied slightly between the samples, the differences turned out to be statistically insignificant. However, the highly positive correlations between the urease activity, organic matter content, and the pseudo-total content of Ni were found and discussed. Moreover, the positive correlations between the urease activity and two geochemical forms of nickel, namely, active and residual form, were confirmed. The results of performed experiments prove that the method of land management does not significantly affect either the topsoil urease activity or the nickel distribution in the case of the extensive agriculture and forestry. However, the existence of at least two forms of the active soil urease was proposed. The first one―contained in the soil solution or loosely adsorbed on the soil particulates and the second one―strongly adsorbed onto the clay minerals. Also the complex role of the organic matter in protecting urease from external factors was presented. Finally, it was postulated that the nickel content in soil may be the indicator of the soil urease activity.

scholarly journals Role of rumen protozoa in nitrogen digestion in sheep given two isonitrogenous diets

1986 ◽  
Vol 56 (2) ◽  
pp. 407-419 ◽  
Author(s):  
K. Ushida ◽  
J. P. Jouany ◽  
P. Thivend
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Nitrogen Sources ◽  
Matter Content ◽  
Diaminopimelic Acid ◽  
Digestible Organic Matter ◽  
The Mean ◽  
Phase Retention ◽  
Microbial N

1. The effect of protozoa on digestion in the rumen was studied using either defaunated or faunated sheep.2. Six wethers, each fitted with rumen and simple duodenal cannulas, were given two isonitrogenous diets containing either lucerne (Medicago sativa) hay (diet L) or sodium hydroxide-treated wheat straw (diet S). The diets were given in eight equal portions per day at 3-h intervals. The mean intake of dry matter, 53 g/kg body-weight0.75per d, was similar for the two diets and each diet had a similar digestible organic matter content. Diet L promoted a large protozoal population and was rich in nitrogen sources of low rumen-degradability, while diet S supported a smaller protozoal population and was rich in rumen-degradable N.3. Digesta flow at the duodenum was estimated by means of a dual-marker technique using chromium-mordanted lucerne hay and polyethylene glycol as markers. The microbial flow at the duodenum was estimated using diaminopimelic acid (DAPA), nucleic-acid purine bases (PB) and35S incorporation simultaneously. The different microbial markers were compared in the defaunated sheep. Protozoal N contribution was estimated in faunated sheep.4. Defaunated sheep had lower rumen ammonia concentrations and molar proportions of butyric acid than faunated sheep, but they had higher molar proportions of propionic acid.5. Rumen organic matter digestion was reduced by defaunation, but this decrease was compensated for by increased intestinal digestion.6. There was a net increase of N flow (approximately 10 g/d) between mouth and duodenum in defaunated sheep. This was explained by increases in both microbial and dietary N flows from the rumen compared with faunated sheep.7. The influence of protozoa on solid- and liquid-phase retention times in the rumen is discussed, as well as the protozoal contribution to microbial N flow in the duodenum of faunated sheep.

Organic Matter Chlorination Rates in Different Boreal Soils: The Role of Soil Organic Matter Content

2012 ◽  
Vol 46 (3) ◽  
pp. 1504-1510 ◽  
Author(s):  
Malin Gustavsson ◽  
Susanne Karlsson ◽  
Gunilla Öberg ◽  
Per Sandén ◽  
Teresia Svensson ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Organic Matter Content ◽  
Boreal Soils

scholarly journals Variasi Morfologi dan Kelimpahan Kepiting Uca spp. di Kawasan Mangrove, Tuban-Bali

2017 ◽  
Vol 4 (2) ◽  
pp. 236
Author(s):  
Yuli Krisnawati ◽  
I Wayan Arthana ◽  
Ayu Putu Wiweka Krisna Dewi
Keyword(s):  
Organic Matter ◽  
Organic Matter Content ◽  
Road Construction ◽  
Strong Relationship ◽  
Matter Content ◽  
Fiddler Crabs ◽  
Toll Road ◽  
Mangrove Area ◽  
Uca Lactea

Fiddler crabs (Uca spp.) are one of the mangrove fauna that has an important role of food chain within the scope of mangrove, which is as a deposit eater. The mangrove area in Kampoeng Kepiting has been damaged due to reclamation for Bali Mandara toll road construction, which can interfere the survival/existence of Fiddler crabs. Therefore, it is necessary to do a research concerning the abundance of Fiddler Crabs in Kampoeng Kepiting mangrove area. The aim of this study is to determine the type and abundance of Fiddler crabs and to discover the coherency among Fiddler Crabs abundance in the manner of c-organic matter content in Kampoeng Kepiting area. Fiddler crabs samples were carried out using 1×1 meter quadrant transect by digging as deep as 30 cm. The abundance of Fiddler crabs was analyzed under the Krebs equation. The results from this study indicate Fiddler crabs were found in Kampoeng Kepiting area ,i.e. Uca demani, Uca coarctata, Uca dussumieri, Uca bellator, Uca lactea perplexa, Uca tetragonon, Uca chlorophthalmus crassipes, Uca lactea annulipes, Uca triangularis, and Uca vocans. The highest Fiddler crabs abundance were found at station 4 which is 72±4,2 ind/m2, whilst the abundance of Fiddler crabs (Uca spp.) at station 5 is (33±1,2 ind/m2). The c-organic matter content has a strong relationship with the abundance of Fiddler crabs in Kampoeng Kepiting mangrove area (r = 0,91). This study shows that mangrove conditions in Kampoeng Kepiting are still able to support Fiddler Crabs (Uca spp.) existence.

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

Sign in / Sign up

Export Citation Format

Share Document