Results 281 to 290 of about 5,243,021 (356)
Some of the next articles are maybe not open access.
Effect of humic acids on batch anaerobic digestion of excess sludge
Water Research, 2019Xiaodi Hao, Mark van Loosdrecht
exaly +2 more sources
Soil Science, 1959
Summary Paper and column chromatography using partition and ion‐exchange conditions, high‐ and low‐voltage paper electrophoresis, and gelatine‐gel diffusion have all been used in an attempt to fractionate humic acids, but only limited success is recorded.
C. B. COULSON +2 more
openaire +2 more sources
Summary Paper and column chromatography using partition and ion‐exchange conditions, high‐ and low‐voltage paper electrophoresis, and gelatine‐gel diffusion have all been used in an attempt to fractionate humic acids, but only limited success is recorded.
C. B. COULSON +2 more
openaire +2 more sources
Nature, 1963
THE idea that humic acids are heteropolycondensates1 of phenolic substances with or without the participation of amino-acids is now widely accepted. Three possible sources of the phenols are postulated: (1) phenolic materials such as flavonoids leached from the plant debris; (2) phenolic units formed during the decomposition of lignin; (3) phenolic ...
A, BURGES +4 more
openaire +2 more sources
THE idea that humic acids are heteropolycondensates1 of phenolic substances with or without the participation of amino-acids is now widely accepted. Three possible sources of the phenols are postulated: (1) phenolic materials such as flavonoids leached from the plant debris; (2) phenolic units formed during the decomposition of lignin; (3) phenolic ...
A, BURGES +4 more
openaire +2 more sources
Plant and Soil, 1972
An explanation has been advanced for the previously reported observation that alkaline hydrolysis of humic acids will release amino acids that are resistant to acid hydrolysis. It is thought that under the alkaline conditions oxidation of N-phenyl-amino acids to the more readily hydrolysed quinonimines occurs.
T. J. Piper, A. M. Posner
openaire +1 more source
An explanation has been advanced for the previously reported observation that alkaline hydrolysis of humic acids will release amino acids that are resistant to acid hydrolysis. It is thought that under the alkaline conditions oxidation of N-phenyl-amino acids to the more readily hydrolysed quinonimines occurs.
T. J. Piper, A. M. Posner
openaire +1 more source
Humic and fulvic acids as biostimulants in horticulture
Scientia Horticulturae, 2015Pierluigi Mazzei, Alessandro Piccolo
exaly +2 more sources
Tetrahedron, 1967
Abstract The action of water and acids on “humic acid” (HA) is described, and it is concluded that HA is a complex of a polycyclic aromatic “core” responsible for the ESR spectrum which is attached to polysaccharides, proteins, relatively simple phenols and metals.
M.V. Cheshire +4 more
openaire +1 more source
Abstract The action of water and acids on “humic acid” (HA) is described, and it is concluded that HA is a complex of a polycyclic aromatic “core” responsible for the ESR spectrum which is attached to polysaccharides, proteins, relatively simple phenols and metals.
M.V. Cheshire +4 more
openaire +1 more source
Tetrahedron, 1967
Abstract Alkaline solutions of “humic acid” (HA) isolated from some eighty different soils and peats give ESR spectra indicative of the presence of remarkably stable semiquinone ion radicals. The type of spectrum is largely determined by the pH of the soil but not by the age of the soil or the nature of the plant cover, and the examination of the HA ...
N.M. Atherton +3 more
openaire +1 more source
Abstract Alkaline solutions of “humic acid” (HA) isolated from some eighty different soils and peats give ESR spectra indicative of the presence of remarkably stable semiquinone ion radicals. The type of spectrum is largely determined by the pH of the soil but not by the age of the soil or the nature of the plant cover, and the examination of the HA ...
N.M. Atherton +3 more
openaire +1 more source
Tetrahedron, 1971
Abstract The synthesis is described of quinones containing α-amino acid ester substituents and the structure of the products is established by NMR and mass spectroscopic techniques. Hydrolysis of the products with 6N HCl has been studied; the products behave as vinylogous amides but the release of nitrogen in the form of amino acid is low ...
P.A. Cranwell, R.D. Haworth
openaire +1 more source
Abstract The synthesis is described of quinones containing α-amino acid ester substituents and the structure of the products is established by NMR and mass spectroscopic techniques. Hydrolysis of the products with 6N HCl has been studied; the products behave as vinylogous amides but the release of nitrogen in the form of amino acid is low ...
P.A. Cranwell, R.D. Haworth
openaire +1 more source
, 2020
Integrated management of soil organic matter and nutritional status of crop plants is essential to sustain the production of organic farming systems. Thus, a 2–year field experiment was conducted to examine the effects of soil additions (192 kg N ha–1 ...
H. Saudy +3 more
semanticscholar +1 more source
Integrated management of soil organic matter and nutritional status of crop plants is essential to sustain the production of organic farming systems. Thus, a 2–year field experiment was conducted to examine the effects of soil additions (192 kg N ha–1 ...
H. Saudy +3 more
semanticscholar +1 more source
Electrochemical degradation of humic acid
Science of The Total Environment, 2000The treatment of natural water for drinking water production goes through the degradation of humic substances. In this study, humic acid, extracted from a peat area located at the margins of the Mogi Guaçu River at São Paulo State, Brazil, was used to perform electro-oxidation essays in order to evaluate the possibilities of electrochemical methods in ...
A J, Motheo, L, Pinhedo
openaire +2 more sources