Results 221 to 230 of about 93,276 (264)

Chemical constituents of the antibiotic fraction ofArnebia nobilis

Experientia, 1969
Aus den Wurzeln vonArnebia nobilis wurden 4 antibiotisch wirksame Stoffe isoliert. Die Struktur von dreien wurde aufgeklart.
Y N, Shukla, J S, Tandon, D S, Bhakuni, M M, Dhar   +3 more
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Partial Purification of Aflatoxins by Simple Chemical Fractionation

Zentralblatt für Bakteriologie, Parasitenkunde, Infektionskrankheiten und Hygiene. Zweite Naturwissenschaftliche Abteilung: Allgemeine, Landwirtschaftliche und Technische Mikrobiologie, 1974
Summary A simple chemical fractionation procedure for the partial purification of aflatoxins, produced by a locally isolated Aspergillus flavus strain, was carried out. According to this procedure it was possible to isolate aflatoxin B free from other interfering compounds. Rf values, U.V.
M S, Tewfik, M, el-Khadem, Y A, Hamdi
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Chemical fractionations in meteorites—III. Major element fractionations in chondrites

Geochimica et Cosmochimica Acta, 1970
Abstract Some 20 elements, including the major constituents of chondritic matter, are fractionated among the several chondrite classes. We have tried to explain these fractionations on the assumption that they occurred in the solar nebula, starting from material of carbonaceous chondrite composition. 1. (1) Lithophile elements (Al, Ca, Cr, Hf, Mg,
J.W Larimer, Edward Anders
openaire   +1 more source

Relationships in component-fractional and chemical composition of crude oils

Chemistry and Technology of Fuels and Oils, 1987
Certain generalizations and calculation techniques were examined for determining the distribution of fractions and chemical compositions of crude oils within the limits of the standard boiling points. Distribution parameters were calculated on the basis of volume.
A. S. �igenson, D. M. Sheikh-Ali
openaire   +1 more source

Fractal-fractional Brusselator chemical reaction

Chaos, Solitons & Fractals, 2021
Abstract In this paper, we replace the classical differential operators with the fractal-fractional differential operators corresponding to the power law, exponential decay, and the generalized Mittag-Leffler kernels. These operators have two parameters created: the first is a fractal dimension and the second is a fractional order.
openaire   +1 more source

Chemical fractionation in the solar system

Journal of Radioanalytical Chemistry, 1977
The cosmochemical and geochemical history of planetary material is reflected in relative and absolute abundances of two groups of trace elements; siderophiles and volatiles. Many of these elements can be determined at the requires levels only by radiochemical neutron activation analysis.
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Optimal control in chemical fractionation problem

Russian Mathematics, 2012
We study a chemical fractionation process in a tower. This process is described by a system of first-order partial differential equations. We obtain necessary optimality conditions for the optimal control problem in a class of smooth boundary controls with pointwise restrictions and perform numerical tests.
A. V. Arguchintsev, V. P. Poplevko
openaire   +1 more source

Chemical and physico-chemical characterization of vermicomposts and their humic acid fractions

Science of The Total Environment, 1989
Peer ...
Hervás, L., Mazuelos Vela, Carmen, Senesi, N., Sáiz-Jiménez, Cesáreo   +3 more
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Chemical Fractionation at Environmental Interfaces

2010
Chemical processes at the interfaces often differ kinetically and mechanistically from the bulk counterparts, partly due to the concentration inhomogeneity of different chemicals at the interfaces. The fractionation of chemicals at the interfaces not only determines their interfacial concentrations, but also affects the physicochemical properties of ...
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Chemical Fractionation of Antiviral Plants

Medicina et Pharmacologia Experimentalis, 2008
S C, Chou, S, Ramanathan, W, Cutting
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