pH-Dependent Sorption of Chlorinated Guaiacols on Estuarine Sediments:  The Effects of Humic Acids and TOC

1997 ◽  
Vol 31 (1) ◽  
pp. 188-193 ◽  
Author(s):  
Jennifer L. Gundersen ◽  
William G. MacIntyre ◽  
Robert C. Hale
Keyword(s):  
Humic Acids ◽  
Estuarine Sediments ◽  
Chlorinated Guaiacols ◽  
Ph Dependent

A BIOSEQUENCE OF SOILS OF THE ROUGH FESCUE PRAIRIE – POPLAR TRANSITION IN SOUTHWESTERN ALBERTA

1966 ◽  
Vol 3 (4) ◽  
pp. 457-471 ◽  
Author(s):  
J. F. Dormaar ◽  
L. E. Lutwick
Keyword(s):  
Organic Matter ◽  
Humic Acids ◽  
Exchange Capacity ◽  
Soil Profiles ◽  
Exchangeable Cation ◽  
Spectral Pattern ◽  
Ph Dependent ◽  
Physical And Chemical ◽  
Rough Fescue ◽  
Populus Spp

A biosequence of soil profiles, ranging from Black through various stages of Dark Gray to Eluviated Dark Gray Chernozems and a Degraded Brown Wooded soil, is found under a sequence of vegetation ranging from rough fescue prairie (Festuca scabrella association) to encroaching poplar (Populus spp.) and fir trees (Pseudotsuga taxifolia (Poir.) Britt.) in the Porcupine Hills of southwestern Alberta. Samples were gathered to establish the differential physical and chemical changes that have occurred in the soils over an 80-year period.Increased eluviation accompanied a reduction in the percentage of exchangeable calcium but it remained the dominant exchangeable cation in all horizons. Most of the exchange capacity arises from the organic matter. The exchange sites are mainly pH-dependent. The changes in the organic matter, because of the encroachment of trees, are more strikingly evident than are the changes in the mineral matter.Infrared absorption spectra of electrodialyzed humic acids display a conspicuous change in spectral pattern between 2 500 and 1 800 cm−1. There are indications of increased acidity and increased aromaticity in the humic acids of the B horizon as eluviation progresses.

scholarly journals Striking analogies and dissimilarities between graphene oxides and humic acids: pH-dependent charging and colloidal stability

2020 ◽  
Vol 306 ◽  
pp. 112948 ◽  
Author(s):  
Etelka Tombácz ◽  
Ildikó Y. Tóth ◽  
Krisztina Kovács ◽  
Erzsébet Illés ◽  
Márta Szekeres ◽  
...  
Keyword(s):  
Humic Acids ◽  
Colloidal Stability ◽  
Graphene Oxides ◽  
Ph Dependent

Ammonium uptake in carrot cell structures is influenced by pH-dependent cell aggregation

1995 ◽  
Vol 95 (3) ◽  
pp. 415-422
Author(s):  
Henry-York Steiner ◽  
Donald K. Dougall
Keyword(s):  
Cell Aggregation ◽  
Ammonium Uptake ◽  
Cell Structures ◽  
Carrot Cell ◽  
Dependent Cell ◽  
Ph Dependent

The Reaction of Thiol Compounds with the Vitamin-K Dependent Clotting Factors

1969 ◽  
Vol 21 (03) ◽  
pp. 573-579 ◽  
Author(s):  
P Fantl
Keyword(s):  
Prothrombin Time ◽  
Vitamin K ◽  
Anaerobic Conditions ◽  
Clotting Factors ◽  
Thiol Compounds ◽  
Aerobic Conditions ◽  
One Stage ◽  
Factor Ii ◽  
Ph Dependent ◽  
The One

SummaryTreatment of human and dog oxalated plasma with 0.2 to 1.0 × 10−1 M 2.3-dithiopropanol (BAL) or dithiothreitol (DTT) at 2–4° C for 30 min results in the reduction of the vitamin-K dependent clotting factors II, VII, IX and X to the respective-SH derivatives. The reaction is pH dependent. Under aerobic conditions the delayed one stage prothrombin time can be partly reversed. Under anaerobic conditions a gradual prolongation of the one stage prothrombin time occurs without reversal.In very diluted plasma treated with the dithiols, prothrombin can be converted into thrombin if serum as source of active factors VII and X is added. In contrast SH factors VII, IX and X are inactive in the specific tests. Reoxidation to active factors II, VII, IX and X takes place during adsorption and elution of the SH derivatives. The experiments have indicated that not only factor II but also factors VII, IX and X have active-S-S-centres.

Tracing Estuarine Sediments by Neutron Activation

1977 ◽  
Author(s):  
Richard M. Ecker ◽  
John F. Sustar ◽  
William T. Harvey
Keyword(s):  
Neutron Activation ◽  
Estuarine Sediments

ROLE OF ADDED PHOSPHOGYPSUM AND HUMIC ACIDS IN THE KINETIC RELEASE OF SALT FROM SALT AFFECTED SOIL (SALINE – SODIC)

2020 ◽  
pp. 15-27
Keyword(s):  
Electrical Conductivity ◽  
Humic Acids ◽  
Release Rate ◽  
Release Kinetics ◽  
Sodium Adsorption Ratio ◽  
Salt Affected Soil ◽  
Two Factors ◽  
Dissolved Ions ◽  
Kinetic Release

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt-affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second-factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.

Peculiarities of the Influence of Humic Acids on the Development of Plankton Algae

2011 ◽  
Vol 47 (1) ◽  
pp. 97-104
Author(s):  
V. A. Medved' ◽  
P. D. Klochenko ◽  
O. V. Vasilenko ◽  
T. A. Vasilchuk
Keyword(s):  
Humic Acids
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