Sorption of Polyfluoroalkyl Surfactants on Surface Soils: Effect of Molecular Structures, Soil Properties, and Solution Chemistry

2020 ◽  
Vol 54 (3) ◽  
pp. 1513-1521 ◽  
Author(s):  
Sandra Mejia-Avendaño ◽  
Yue Zhi ◽  
Bei Yan ◽  
Jinxia Liu
Keyword(s):  
Soil Properties ◽  
Solution Chemistry ◽  
Molecular Structures ◽  
Surface Soils

scholarly journals Assessing the amount of soil organic matter and soil properties in high mountain forests in Central Anatolia and the effects of climate and altitude

2017 ◽  
Vol 63 (No. 5) ◽  
pp. 199-205 ◽  
Author(s):  
Göl Ceyhun
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Properties ◽  
Arid Regions ◽  
Climatic Factors ◽  
Central Anatolia ◽  
High Mountain ◽  
Mountain Forests ◽  
Surface Soils ◽  
Semi Arid

The objectives of this study were to determine the amounts of soil organic matter (SOM) stored within surface soils of high mountain forests and how the SOM amounts are affected by aridity and altitude in semi-arid regions of Central Anatolia. Various climate and altitude conditions of Central Anatolia were included in this study, and SOM amounts were found to be higher in the surface soils of northern Anatolia forests. Our results showed that altitude, climatic factors, and tree species were the most important factors affecting the amount of SOM and other soil properties. SOM, pH, bulk density and available water content differed significantly depending on the altitude and climatic factors in the study areas. As the altitude increased in semi-arid regions, the aridity decreased and the amount of SOM increased.

The hydrology of Vertosols used for cotton production: I. Hydraulic, structural and fundamental soil properties

Soil Research ◽  
2003 ◽  
Vol 41 (7) ◽  
pp. 1255 ◽  
Author(s):  
R. W. Vervoort ◽  
S. R. Cattle ◽  
B. Minasny
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Soil Depth ◽  
Sharp Decrease ◽  
Clay Content ◽  
Structural Development ◽  
Cotton Production ◽  
Surface Soils ◽  
Eastern Australia ◽  
Water Retention Properties

This paper describes the hydraulic, structural and fundamental soil properties for 23 Vertosol horizons from 18 sampling sites in New South Wales and southern Queensland. At each site a combination of infiltration measurements and soil sampling was conducted. Samples were collected for determination of the soil water characteristic, shrink–swell relationships, and fundamental soil properties such as particle size distributions, pH, electrical conductivity (EC), exchangeable cations (Ca2+, Mg2+, K+, Na+), extractable P contents, extractable sulfate and Fe contents, and CaCO3 and total C contents. Large cores were sampled, impregnated with resin, and sectioned for image analysis. The program SOLICON v2.1 was used to calculate structural form parameters from the images. Measured hydraulic conductivities of the surface soils were large compared with earlier reported research for Vertosols. However, a sharp decrease in hydraulic conductivity occurred with depth in the profiles, which is assumed to be due to increased bulk densities and exchangeable sodium percentages (ESP). The data also indicated a general north–south trend in the structural development of these Vertosols. Surface soils from the northern areas, such as the Gwydir and Namoi valleys, exhibited more porous structural forms, and as a result, greater average hydraulic conductivities. This appears to be due to differences in ESP, clay content and the mineralogical suite of the clay; surface samples with smaller ESPs and larger proportions of smectitic clay tended to have the greatest values of hydraulic conductivity. Other fundamental soil properties such as extractable Fe and P contents, and CaCO3 content, were found to have little or no correlation to the hydraulic or structural properties of these Vertosols, while differences in measured shrink-swell and water retention properties were largely a function of soil depth. The database developed has given an overview of the hydraulic properties of Vertosols used for cotton production in south-eastern Australia.

Extractable Fe in the surface horizons of a range of soils from Queensland

Soil Research ◽  
1990 ◽  
Vol 28 (2) ◽  
pp. 259 ◽  
Author(s):  
JO Skjemstad ◽  
HVA Bushby ◽  
RW Hansen
Keyword(s):  
Organic Matter ◽  
Soil Properties ◽  
Soil Ph ◽  
Clay Content ◽  
Surface Soils ◽  
Soil Weathering ◽  
Extraction Procedures ◽  
Weathering Processes ◽  
Mobile Component ◽  
Extractable Iron

The levels of iron and aluminium extracted from 36 surface soils by pyrophosphate, oxalate and dithionite are compared with a number of other soil properties. Correlations suggest that aluminium released by these extraction procedures is largely associated with organic matter while only a small fraction of the iron released is in this form. Significant correlations between soil pH and the negative logarithms of both oxalate (r = 0.715) and pyrophosphate (r = 0.959) extractable iron in soils with >20% clay content indicate that pH is the most significant factor in determining the level of ferrihydrite and iron/organic matter complexes in surface soils. The significance of these relationships in terms of soil weathering processes is discussed. Further, the data suggest that pyrophosphate extractable iron is a useful indicator of the most active, mobile component of iron in surface soils.

scholarly journals Synthesis, Characterization and Solution Chemistry of trans-Indazoliumtetrachlorobis(Indazole)Ruthenate(III), a New Anticancer Ruthenium Complex. IR, UV, NMR, HPLC Investigations and Antitumor Activity. Crystal Structures of trans-1-Methyl-Indazoliumtetrachlorobis-(1-Methylindazole)Ruthenate(III) and its Hydrolysis Product trans-Monoaquatrichlorobis-(1-Methylindazole)-Ruthenate(III)

1996 ◽  
Vol 3 (5) ◽  
pp. 243-260 ◽  
Author(s):  
Kari-Georg Lipponer ◽  
Ellen Vogel ◽  
Bernhard K. Keppler
Keyword(s):  
Antitumor Agents ◽  
Ruthenium Complex ◽  
Hydrolysis Product ◽  
Order Rate Constant ◽  
Solution Chemistry ◽  
Molecular Structures ◽  
Physiological Conditions ◽  
Cell Dimensions ◽  
Competitive Products ◽  
Hydrolysis Of

Besides intensive studies into the synthesis of the complex trans-Hlnd[RuCl4(ind)2] (Ind = indazole) 1, which differs remarkably from the usual method for the complexes of the HL[RuCl4L2] - type, competitive products and hydrolysis of this species are described. Stability and pseudo-first-order rate constant under physiological conditions of complex 1 in comparison with the analogous imidazole complex trans-Hlm[RuCl4(im)2] (Im = imidaZole) ICR were examined by means of HPLC, UV and conductivity measurements (Kobs.(1) = 1.55 × 10-4s-1; Kobs.(ICR) = 9.10 × 10-4s-1). An attempt was made to elucidate the bonding conditions in 1 by studying the reactions of Ru(lll) and the two N-methyl isomers of indazole. It can be expected that bonding in the unsubstituted ligand should occur via the N2 nitrogen. The molecular structures of the complex trans-H(1-Melnd)[RuCl4(1-Melnd)2] × 1H2O (1-Melnd = 1-methylindazole) 6 and its hydrolysis product in aqueous solution [RuCl3(H2O)(1-Melnd)2]7 were determined crystallographically. After anisotropic refinement of F values by least squares, R is 0.053 for 6 and 0.059 for 7. Both complexes crystallize with four molecules in a unit cell of monoclinic symmetry. The space group is P2.1/n for 6 with cell dimensions a = 10.511Å, b = 13.87Å, c = 19.93Å, and β = 98.17° and C2/c for 7 with a = 19.90Å, b = 10.94Å, c = 8.490Å and β = 96.74° The fact that the aqua species 7 could be isolated after dissolving 6 in a water/acetone solution confirmed the theory of many Ru(lll) complexes being initially transformed, under physiological conditions, into aqua complexes in a first and often rate-determining hydrolysis step. Compounds 1 and ICR are potent antitumor agents which exhibit activity against a variety of tumor cells and experimental tumor models in animals, including autochthonous colorectal tumors. Clinical studies with 1 are in preparation.

SPECTRAL DIFFERENTIATION OF SURFACE SOILS AND SOIL PROPERTIES

Soil Science ◽  
1993 ◽  
Vol 155 (4) ◽  
pp. 283-293 ◽  
Author(s):  
T. L. COLEMAN ◽  
P. A. AGBU ◽  
O. L. MONTGOMERY
Keyword(s):  
Soil Properties ◽  
Surface Soils

The effect of phosphate buffering capacity and other soil properties on North Carolina phosphate rock dissolution, availability of dissolved phosphorus and relative agronomic effectiveness

1997 ◽  
Vol 37 (8) ◽  
pp. 1037 ◽  
Author(s):  
A. M. Babare ◽  
R. J. Gilkes ◽  
P. W. G. Sale
Keyword(s):  
North Carolina ◽  
Soil Properties ◽  
Phosphate Rock ◽  
Relative Effectiveness ◽  
Buffering Capacity ◽  
Available P ◽  
Surface Soils ◽  
Agronomic Effectiveness ◽  
North Carolina Phosphate Rock ◽  
P Buffering Capacity

Summary. The dissolution of North Carolina phosphate rock (NCPR) in soil was investigated in a laboratory study using surface soils sampled from 28 permanent pasture sites. The relationships between phosphorus (P) dissolved, P availability and various soil properties were investigated using simple and multiple linear regression and the findings related to the relative effectiveness of NCPR for pasture production at the sites. The extent of dissolution of NCPR was positively correlated to P buffering capacity (r2 = 0.42). Phosphorus buffering capacity and titratable acidity together accounted for 72% of the variance in dissolution. Bicarbonate-extractable P (‘available’ P) generally increased as dissolution increased. However, the increase in available P was consistently lower for soils with higher P buffering capacity. The proportion of dissolved P that was available also decreased with increasing P buffering capacity (r2 = 0.63). Consequently, the increase in available P was highest for soils with very low to low P buffering capacity. This suggests that the effectiveness of NCPR as a fertiliser may be more closely related to the availability of dissolved P, than to the amount of NCPR dissolved in a soil. Consistent with this laboratory finding, the agronomic effectiveness of NCPR relative to superphosphate measured in the field tended to decrease with increasing P buffering capacity. The agronomic effectiveness of NCPR was comparable with superphosphate only at certain sites, and with some noted exceptions, most of these had surface soils with very low to low P buffering capacity. The high relative effectiveness of NCPR at these sites was mostly attributed to the loss of superphosphate by leaching. Since NCPR dissolves much more slowly than superphosphate, only a small amount of the P applied as NCPR would be lost during leaching events. Slow dissolution of the remaining NCPR probably supplied a small amount of dissolved P over an extended period of time, and due to the low P buffering capacity, much of this was available to plants.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

Scanning tunneling microscopy (STM) of DNA and RNA

1989 ◽  
Vol 47 ◽  
pp. 34-35
Author(s):  
Patricia G. Arscott ◽  
Gil Lee ◽  
Victor A. Bloomfield ◽  
D. Fennell Evans
Keyword(s):  
Molecular Structures ◽  
Inorganic Materials ◽  
Resolving Power ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Form And Function ◽  
Dna And Rna ◽  
Calf Thymus ◽  
And Function ◽  
The Relationship

STM is one of the most promising techniques available for visualizing the fine details of biomolecular structure. It has been used to map the surface topography of inorganic materials in atomic dimensions, and thus has the resolving power not only to determine the conformation of small molecules but to distinguish site-specific features within a molecule. That level of detail is of critical importance in understanding the relationship between form and function in biological systems. The size, shape, and accessibility of molecular structures can be determined much more accurately by STM than by electron microscopy since no staining, shadowing or labeling with heavy metals is required, and there is no exposure to damaging radiation by electrons. Crystallography and most other physical techniques do not give information about individual molecules.We have obtained striking images of DNA and RNA, using calf thymus DNA and two synthetic polynucleotides, poly(dG-me5dC)·poly(dG-me5dC) and poly(rA)·poly(rU).

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