SELENIUM DISTRIBUTION IN CANADIAN SOIL PROFILES

1974 ◽  
Vol 54 (1) ◽  
pp. 63-68 ◽  
Author(s):  
M. LÉVESQUE
Keyword(s):  
Organic Carbon ◽  
Soil Profiles ◽  
Organic Carbon Content ◽  
Surface Layers ◽  
Parent Materials ◽  
Podzolic Soils ◽  
Marked Accumulation ◽  
Relationship Of ◽  
The Relationship ◽  
Combined Data

The distribution of selenium (Se) in 54 Canadian soil profiles was examined according to horizon in the profile, and to soil properties. Apart from the organic surface layers, the Podzolic B horizons had the highest Se values (0.52 ppm), and so displayed a marked accumulation. The Luvisolic and Gleysolic B horizons also showed some accumulation. The Se content of parent materials was generally low (0.10 ppm). Simple correlation analyses of the combined data (irrespective of horizon) indicated that Se distribution was closely associated with both organic carbon and NH4-oxalate extractable Fe and Al. When the data were arranged according to genetic groupings, this association remained true only for Podzolic B horizons. Multiple regression analyses revealed that the predominant factors involved in the Se distribution were the Se content of parent materials, and the organic carbon content of the upper horizons, in that order, except for Podzolic soils. Clay had little or no influence on the Se distribution. In spite of the relationship of Se to parent materials, the contribution by atmospheric contaminants to the Se enrichment of soils could remain important.

Keterkaitan parameter nilai pH, C-organik, N-Total, C/N dan alofan pada beberapa Andisols di Jawa Barat

SoilREns ◽  
2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Rina Devnita ◽  
Mahfud Arifin ◽  
Ridha Hudaya ◽  
Ade Setiawan ◽  
Apong Sandrawati
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Total Nitrogen ◽  
Soil Analysis ◽  
Volcanic Eruptions ◽  
Soil Parameters ◽  
Organic Carbon Content ◽  
Ph Values ◽  
Relationship Of ◽  
The Relationship

The correlation of chemical parameters and soil mineralogy one to another in Andisols were interesting to be studied, to increase the understanding of soil reactions, nutrient availability and soil mineral content. Andisols from three locations and derived from three different volcanic eruptions namely G. Tangkuban Parahu, G. Patuha and G. Tilu, with andesite, andesite-basalt and basalt parent materials respectively, were examined the correlation of several soil parameters. The values of pH, organic carbon, total nitrogen, C/N and allophane content were obtained from the soil analysis of every horizon of the soil profiles at each site. Correlation analyses were used to see the relationship of the parameters. The results showed a negative correlation between pH and organic carbon (r = -590 *). The soil pH values were positively correlated with the amount of allophane (r = 0.687 *). The pH values were correlated positively with imogolite content (r = 0.356 *). The pH values were negatively correlated with organic carbon (r = -0.590 *). The organic carbon content was negatively correlated with depth (r = - 0.582 *). The organic carbon content was negatively correlated with allophane (r = 0.707 *). Total nitrogen values were negatively correlated with increasing depth (r = -0.531 *).Keywords: Mt. Tangkuban Parahu, Mt. Patuha, Mt. Tilu, andesit, andesit-basalan, alophane

scholarly journals Contact-deformation mechanism of boundary friction

2020 ◽  
Vol 164 ◽  
pp. 14004
Author(s):  
Alexandr Dykha ◽  
Volodymyr Kukhar ◽  
Viktor Artiukh ◽  
Maxim Aleksandrovskiy
Keyword(s):  
Experimental Studies ◽  
Deformation Mechanisms ◽  
Internal Stresses ◽  
Stress And Strain ◽  
Relative Deformation ◽  
Contact Deformation ◽  
Surface Layers ◽  
Friction Units ◽  
Relationship Of ◽  
The Relationship

Research was conducted to determine the effect of lubricants on stress and strain in the contact of metal surfaces. Experiments were carried out on the introduction of a fixed and moving indenter in contact with a dry and lubricated surface.The steel spherical specimen was pressed into a lubricated and dry metal surface. The microstructures of the structure of the surface layer are studied under various conditions of deformation. The diagrams of the relative deformation of the surface layers are constructed. The mechanism of the formation and distribution of internal stresses for dry and greased contact is described. Experimental studies of the introduction of a moving steel indenter into a lubricated surface have been carried out. The relationship of the deformation mechanisms of lubricated surfaces with their wear resistance is determined. The results obtained are recommended for predicting the durability of lubricated friction units according to the criterion of contact strength.

First Pan-Arctic Assessment of Dissolved Organic Carbon Concentration in Permafrost-Region Lakes

2020 ◽  
Author(s):  
Lydia Stolpmann ◽  
Anne Morgenstern ◽  
Julia Boike ◽  
Michael Fritz ◽  
Ulrike Herzschuh ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Permafrost Region ◽  
Organic Carbon Content ◽  
Soil Organic Carbon Content ◽  
Doc Concentration ◽  
Deposit Type ◽  
Relationship Of ◽  
Global Carbon

<p>Permafrost-region lakes are dynamic landscape systems and play an important role for climate change feedbacks. Lake processes such as mineralization and flocculation of DOC, one of the main carbon fraction in lakes, contribute to the global carbon cycle. These processes are in focus of climate research but studies have been limited in geographic extent. We synthesized published datasets and unpublished datasets from the author team totaling 1,691 water samples from 1,387 lakes across the Subarctic and Arctic in permafrost regions of Alaska, Canada, Siberia, and Greenland to provide first insights for linkages between DOC concentration to the basin. In our synthesis, we find regional differences in DOC concentration of permafrost-region lakes. We focussed on relations between lake DOC concentration and latitude, permafrost zones, ecoregions, lake surrounding deposit type, and ground ice classification of each lake basin. Additionally, we analysed the lake surrounding soil organic carbon content from 0-100 cm depth and 0-300 cm depth. Individual lake DOC concentrations of our dataset range from below detection limit assigned to 0 mg L<sup>-1</sup> (North Slope, Alaska) to 1,130 mg L<sup>-1</sup> (Yukon Flats, Alaska). We found regional median lake DOC concentrations of 18.8 mg L<sup>-1</sup> (Greenland, n=25), 12.2 mg L<sup>-1</sup> (Alaska, n= 1,135), 9.6 mg L<sup>-1</sup> (Siberia, n=252), and 7.2 mg L<sup>-1</sup> (Canada, n=279). Lakes in the isolated permafrost zone had the highest median DOC concentration compared to lakes in the sporadic, discontinuous, and continuous permafrost zones. Our synthesis shows increasing lake DOC concentration with decreasing latitude and, due to a larger availability of biomass and organic carbon, a significant relationship of lake DOC concentration and ecoregion of the lake. We found higher lake DOC concentrations in boreal permafrost sites compared to tundra sites. About 22 % of lakes in our dataset are located in regions with ice-rich syngenetic permafrost deposits (yedoma). Because yedoma contains large amounts of organic carbon, we assumed to find higher DOC concentrations in yedoma lakes compared to non-yedoma lakes. Our analysis shows a significant relationship of lake DOC concentration and surrounding deposit type but not a higher DOC concentration in yedoma lakes compared to non-yedoma lakes. Finally, we found a relationship of soil organic carbon content from 0-100 cm depth and lake DOC concentration. In contrast, a comparison of soil organic carbon content from 0-300 cm depth and lake DOC concentration shows no significant correlation. This was also found for ground-ice content and lake DOC concentration. Our dataset of lakes across the Arctic shows that the DOC concentration of a lake strongly depends on its environmental properties. This dataset will be fundamental to establish a pan-Arctic lake DOC pool for estimations of the impact of lake DOC on the global carbon cycle and further on climate change.</p>

scholarly journals Species Abundance and Body Size Relationship of Bird Assemblages at Selected Sites in Western Sarawak

2020 ◽  
Vol 3 (2) ◽  
pp. a18-25
Author(s):  
AHMAD FITRI AZIZ ◽  
CHARLIE JUSTIN MERGIE LAMAN
Keyword(s):  
Body Size ◽  
Regression Line ◽  
Species Abundance ◽  
General Rule ◽  
Bird Assemblages ◽  
Energy Equivalence ◽  
Average Body Mass ◽  
Relationship Of ◽  
The Relationship ◽  
Combined Data

The Energy Equivalence Rule (EER) is an unresolved issue in ecology. This rule states that the amount of energy used for each species in a population is independent of its body size. A study on the relationship between abundance and body size of bird assemblages was conducted in Western Sarawak. Abundance data of bird assemblages from seven selected sites in Western Sarawak were used to produce a regression line of log absolute species abundance versus log average body mass. Data from all selected sites were combined to represent bird assemblages in Western Sarawak and the slope produced was -0.216. The slopes obtained for each site were 0.808, -0.080, -0.258, -0.067, -0.161, -0.072 and -0.237, respectively. Statistical analysis shows that the slope of combined data did not differ significantly from -0.75, as expected under the EER. Thus, this study shows that the EER can be applied as a general rule of community structure of bird assemblages in Western Sarawak.

The effect of Aeolian accessions on soil development on granitic-rocks in south eastern Australia. III. Micromorphological and geochemical evidence of weathering and soil development

Soil Research ◽  
1988 ◽  
Vol 26 (1) ◽  
pp. 33 ◽  
Author(s):  
CJ Chartres ◽  
PH Walker
Keyword(s):  
Fine Sand ◽  
Soil Development ◽  
Granitic Rocks ◽  
Soil Profiles ◽  
The West ◽  
Parent Materials ◽  
Podzolic Soils ◽  
Swelling Clays ◽  
Eastern Australia ◽  
Red Earth

Micromorphological, mineralogical and chemical data show that clay illuviatidn, clay decomposition and strong weathering of biotite and feldspars to clay mineral$ have all been significant processes of soil development in three red podzolic soils and one red earth. Decomposition of biotite and illuviation of swelling clays into fissures in the saprolite and C horizons appear to have aided the physical fragmentation of the granitic parent materials. Disruption of illuvial features by faunal activity and shrink-swell processes in the upper B horizons accentuate apparent illuvial clay maxima in the B3 and C horizons. Low clay contents in the A horizons of the red podzolic soils examined result from ehviation and clay decomposition, whereas the higher fine sand contents of these horizons result, in part, from the deposition of aeolian transported materials. Substantial aeolian deposition at another site has led to the development of a red earth. The deposition of greater amounts of aeolian material to the soils to the west of Canberra has led to the development of complex, polycyolic soil profiles in comparison to the profiles investigated towards the coast.

The relationship of soil organic carbon to 210Pbex and 137Cs during surface soil erosion in a hillslope forested environment

Geoderma ◽  
2013 ◽  
Vol 192 ◽  
pp. 59-67 ◽  
Author(s):  
Mengistu T. Teramage ◽  
Yuichi Onda ◽  
Hiroaki Kato ◽  
Yoshifumi Wakiyama ◽  
Shigeru Mizugaki ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Surface Soil ◽  
Relationship Of ◽  
The Relationship

scholarly journals Contact-deformation mechanics of the interaction of lubricated surfaces

2019 ◽  
Vol 1 ◽  
pp. 15-20
Author(s):  
A Dykha ◽  
S Posonsky1
Keyword(s):  
Wear Resistance ◽  
Experimental Studies ◽  
Deformation Mechanisms ◽  
Internal Stresses ◽  
Relative Deformation ◽  
Contact Deformation ◽  
Surface Layers ◽  
Deformation Mechanics ◽  
Relationship Of ◽  
The Relationship

The questions of the influence of the lubricant on the conditions of deformation in the contact of solids are considered. The steel spherical specimen was pressed into a greased and dry metal surface. The microstructures of the structure of the surface layer are studied under various conditions of deformation. The diagrams of the relative deformation of the surface layers are constructed. The mechanism of the formation and distribution of internal stresses for dry and greased contact is described. Experimental studies of the introduction of a moving steel indenter into a lubricated surface have been carried out. The relationship of the deformation mechanisms of lubricated surfaces with their wear resistance is determined.

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