Results 341 to 350 of about 3,443,174 (389)

Chemistry of peat bitumen: Fractionation and infra‐red studies

Journal of Applied Chemistry, 1962
AbstractBitumen extracted from high‐moor peat has an ultra‐violet absorption maximum at 285 mμ. This has been used to follow the fractionation of a methanol‐soluble extract of the bitumen on an anion‐exchange column in the acetate form, with methanol, methanol acetic acid (3:1) and glacial acetic acid as eluants.The infra‐red spectra from 900 to 4000cm.
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Wastewater Chemistry and Fractionation of Bioactive Phosphorus in Dairy Manure

Communications in Soil Science and Plant Analysis, 2006
Abstract Because manure organic phosphorus (P) is environmentally bioactive, a novel in situ enzyme hydrolysis assay was developed to identify water soluble‐ and labile complexed P and mechanisms controlling P solubilization in dairy manure. Water‐extractable P averaged 16% (±14.8%) of total P of 107 manures collected across five northeastern states of
Thanh H. Dao, A. Lugo‐Ospina, J. B. Reeves, Hailin Zhang   +3 more
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Fractionation and chemistry of ethyl acetate-soluble thearubigins from black tea

Phytochemistry, 1976
Abstract Sephadex LH-20 chromatography was used to fractionate purified ethyl acetate-soluble thearubigins, prepared from an aqueous ethanolic extract of black tea. Three subfractions were so produced, each having a MW of about 1500 and each being degradable into cyanidin, delphinidin, gallic acid, the same two flavan-3-ols, and the same two flavan-3-
D.J. Cattell, H.E. Nursten
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K isotopic fractionation in K-feldspar: Effects of mineral chemistry

American Mineralogist
Abstract Controlling factors of potassium (K) isotopic fractionation in K-feldspar remain poorly constrained. In this study, we analyzed the K isotopic compositions of 11 K-feldspar samples from diverse lithological compositions. The degree of Al/Si order ranged from 0.22 to 0.94 (1.0 = completely ordered).
Shanke Liu, Wenjun Li, Benxun Su, Qiqi Pan, Meng Yuan, Patrick Asamoah Sakyi   +5 more
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Biomass Fractionation and its Effects on Pyrolysis Chemistry

SSRN Electronic Journal, 2022
Zhongya Guo, Ke Zhang, Qi Zhang, Lili Fu, Ze Liu, Zhen Kong, Le Wang, Bin Li, Lei Hua, Chuan Liu   +9 more
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Fractionating column efficiency: Quantitative experiment in elementary organic chemistry laboratory

Journal of Chemical Education, 1964
This experiment estimates the efficiency of a fractionating column by slowly distilling a three-to-one mixture of toluene and benzene.
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Bubble fractionation. A physical chemistry experiment

Journal of Chemical Education, 1973
Angel A. Garmendia, Daniel L. Perez, Miguel Katz   +2 more
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Comparison of wet chemistry and near infrared reflectance measurements of carbon-fraction chemistry and nitrogen concentration of forest foliage

, 1991
T. M. McLellan, Mary E. Martin, J. Aber, J. Melillo, K. Nadelhoffer, B. Dewey   +5 more
semanticscholar   +1 more source

Factors and geochemical barriers controlling clay fraction chemistry in nile delta sediments, Egypt

, 1988
F. R. Siegel, C. Gerber, N. Gupta, D. Stanley   +3 more
semanticscholar   +1 more source

Molecular imaging in oncology: Current impact and future directions

Ca-A Cancer Journal for Clinicians, 2022
Steven P Rowe, Martin G Pomper
exaly