Physical and Chemical Properties of Hydroxyflavones. I. Infrared Absorption Spectra of Monohydroxyflavones and Their O-Methyl and O-Acetyl Derivatives1,2

The author having been engaged since the year 1877 in investigating and correlating the physical and chemical properties of aromatic substances in relation to their chemical structure or constitution, he has latterly found it desirable that several very definite compounds should be examined in a state of vapour, as well as in solution. The work of E. Pauer, W. Friederichs, and of L. Grebe is referred to in detail. The vapours of benzene and several of its derivatives have been examined (1) at different temperatures and constant pressure; and (2) at different pressures, the temperature being constant. The previous measurements of Pauer, Friederichs, and Grebe have been confirmed, and reconciled where they do not show complete agreement with each other. The records of temperature and pressure, and the shortening of the exposure of the photographic plates, constitute important differences between the work of the former investigators and that of the author.

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Application of Infrared Absorption Spectra to Studies of the Oxidation of Sodium-Butadiene Rubber

Rubber Chemistry and Technology ◽

10.5254/1.3543088 ◽

1951 ◽

Vol 24 (3) ◽

pp. 591-596

Author(s):

B. Dogadkin ◽

B. Kasatochkin ◽

N. Klauzen ◽

A. Smirnova

Keyword(s):

Quantitative Analysis ◽

Molecular Oxygen ◽

Structural Changes ◽

Chemical Properties ◽

Butadiene Rubber ◽

Physical And Chemical Properties ◽

Reaction Products ◽

Infrared Absorption Spectra ◽

Physical And Chemical ◽

And Chemical Properties

Abstract The reaction of rubber with molecular oxygen explains well the structural changes which take place in rubber during aging and during a number of important technological processes, such as plasticization and vulcanization. Furthermore, during vulcanization, in addition to its reaction with the vulcanizing agent, rubber also reacts with oxygen contained in the mixture. This may be one of the reasons for an optimum point of vulcanization. However, it is difficult to explain the changes of physical properties of rubber by simple union of oxygen, with formation of oxygen-bearing groups. To account for the changes observed, addition of a large quantity of oxygen would be necessary, whereas actually notable changes are brought about by the absorption of only 2–3 per cent of oxygen. To explain this, it must be assumed that oxygen causes structural changes in rubber and that these changes become evident when the percentage of oxygen in the reaction products is still negligible. In the case of sodium-butadiene rubber, as was shown by one of the authors, this reaction at any particular temperature causes an increase of strength and of elasticity, and a loss of solubility. The object of the present investigation was a qualitative and limited quantitative analysis of those groups which originate during oxidation and also an examination of the structures which determine the changes of the physical and chemical properties in the reaction of rubber with molecular oxygen.

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Statistical criteria of stellar population types

Symposium - International Astronomical Union ◽

10.1017/s0074180900053304 ◽

1966 ◽

Vol 24 ◽

pp. 101-110

Author(s):

W. Iwanowska

Keyword(s):

Stellar Population ◽

Chemical Properties ◽

Spectrophotometric Study ◽

Physical And Chemical Properties ◽

Population Type ◽

The Galaxy ◽

Distribution Parameters ◽

Physical And Chemical ◽

Statistical Criteria ◽

And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

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Only one sugar offers you such a variety of important physical and chemical properties

Chemical & Engineering News ◽

10.1021/cen-v037n007.p004 ◽

1959 ◽

Vol 37 (7) ◽

pp. 4

Keyword(s):

Chemical Properties ◽

Physical And Chemical Properties ◽

Physical And Chemical ◽

And Chemical Properties

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Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

Annals of Tropical Research ◽

10.32945/atr39sa3.2017 ◽

2017 ◽

pp. 31-43

Author(s):

Berta Ratilla ◽

Loreme Cagande ◽

Othello Capuno

Keyword(s):

Block Design ◽

Management Strategies ◽

Chemical Properties ◽

Organic Fertilizers ◽

Growth And Yield ◽

Physical And Chemical Properties ◽

Total N ◽

Randomized Complete Block Design ◽

Physical And Chemical ◽

And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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