Results 1 to 10 of about 32,992 (301)

Macromolecular changes of humic substances induced by interaction with organic acids

European Journal of Soil Science, 1996
Summary Two different humic materials, one from a forest soil and the other from wormcasts, were used to study the influence of mineral and organic acids on the conformational properties of humic substances. The macromolecular changes were followed by low pressure gel permeation chromatography after titrating ...
PICCOLO A, NARDI, SERENELLA, CONCHERI, GIUSEPPE   +2 more
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The Crystalline State of Macromolecular Substances

Angewandte Chemie International Edition in English, 1974
AbstractUnlike low molecular weight substances, high polymers do not crystallize completely. However long the crystallization process is continued, they still consist of a mixture of crystalline and non crystalline regions. In the undrawn material, these regions form larger units which are known as spherulites.
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SORPTION AND CHROMATOGRAPHY OF MACROMOLECULAR SUBSTANCES

Russian Chemical Reviews, 1961
CONTENTS I. Introduction 612 II. Elution chromatography 613 III. Frontal chromatography 614 IV. New chromatographic methods 615 V. Polyelectrolytes 616 VI.
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Synthesis of Macromolecular Substances by Addition Polymerization

2001
As already explained, polymerization reactions can proceed by various mechanisms and can be catalyzed by initiators of different kinds. For addition polymerization of single compounds, initiation of chains may occur via radical, cationic, anionic, or so-called coordinative-acting initiators, but some monomers will not polymerize by more than one ...
Dietrich Braun, Harald Cherdron, Helmut Ritter   +2 more
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Chapter 49 Macromolecular substances and plastics

1975
Publisher Summary This chapter discusses macromolecular substances and plastics. In industry, gel permeation chromatography (GPC) serves as a method for characterizing and analyzing new polymeric products and for controlling the quality of standard products (Harmon).
M. Kubín, J. Čoupek
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On the mechanism of collapse of monolayers of macromolecular substances II. Cellulose acetate

Journal of Colloid and Interface Science, 1980
Abstract The phenomenon of collapse of monolayers of cellulose acetate, describable according to the Prout-Tompkins law, that is as a phenomenon of nucleation and growth with interference during growth, was studied. Ellipsometric measurements and measurements made by optical and electronic microscopy confirm the above mechanism.
Piero Baglioni, Gabriella Gabrielli, Giulio G.T. Guarini   +2 more
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Clearance of macromolecular and particulate substances from the cerebrospinal fluid system of the rat

Journal of Neurosurgery, 1979
✓ Arachnoid villi in the intracranial dural sinuses constitute the principal sites for absorption of proteins and particulates from the cerebrospinal fluid (CSF) system. Although arachnoid villi in the rat are morphologically less complex than those found in other mammals, their resistance to CSF outflow, as assessed by a graded series of constant flow
J D, Mann, A B, Butler, R N, Johnson, N H, Bass   +3 more
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A new phenomenon in flow birefringence of solutions of macromolecular substances

Journal of Polymer Science, 1953
AbstractMeasurements on flow birefringence of solutions of polyvinyl chloride in cyclohexanone revealed that the angle of orientation increases with decreasing concentration of the solution. That this surprising effect was not due to constructional or experimental errors was demonstrated by results obtained with polystyrene, which were in agreement ...
E. J. Arlman, W. Boog, D. J. Coumou
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Macromolecular material (humic substance) in the water column and sediments

Marine Chemistry, 1992
Abstract The progress during the past 10–15 years in the studies of organic macromolecules (humic substances, HS) in seawater and sediments is reviewed. The review describes the advances in the characterization of seawater and sedimentary HS, HS formation models, studies on the geochemical role of marine HS, and future research needs.
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Affinity Chromatography of Macromolecular Substances on Adsorbents Bearing Carbohydrate Ligands

1981
Publisher Summary This chapter provides information on the methods for preparing affinity adsorbents having carbohydrate ligands and illustrates the use of these adsorbents for the purification of representative, macromolecular substances. Affinity chromatography is possible because of the stereospecific interactions that can occur between the ...
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