Bonding of Rubber to Metal by Means of New Chemical Derivatives of Rubber

1950 ◽  
Vol 23 (1) ◽  
pp. 281-291 ◽  
Author(s):  
Jacques Gossot
Keyword(s):  
Ph Value ◽  
Chemical Reactivity ◽  
Point Of View ◽  
Physical Point ◽  
General Application ◽  
Chemical Derivatives ◽  
Special Cases ◽  
Practical Standpoint ◽  
In Virtue Of ◽  
Derivatives Of

Abstract The bonding process which has been described is of general application to all types of rubber mixtures, to metals, and to various other materials, without any change in composition of the bonding agent for the different materials. Although the problem of adhesion has been approached in this work only from the purely practical standpoint, it should be realized how little progress has been made in the theoretical knowledge of the problem. As a matter of fact, only a few authors have attempted to explain, on a basis of general concepts, certain special cases of adhesion, and there is still no real insight into the problem as a whole which might open the way to material progress. If one turns to the works of MacBain, Delmonte, and Buchan among the most important contributions to the phenomena of adhesion, the ultimate conclusion must be drawn that little has been accomplished in orienting investigations in this field toward more productive ends. From the physical point of view, particular attention must be paid to the condition of the state of the surface of the material to be bonded, to the surface tension, to the viscosity, and to the pH value of the adhesive. The chemical structure of the latter is that of a long-chain compound and, as has been proved conclusively in the present investigation, certain groups play a fundamental role, both in virtue of their chemical reactivity, and in virtue of the polar moment which they confer upon the molecule.

The Chlorination of Disaggregated Rubber

1935 ◽  
Vol 8 (3) ◽  
pp. 371-374
Author(s):  
B. V. Buizov ◽  
V. S. Molodenskii ◽  
N. I. Mikhailov
Keyword(s):  
Point Of View ◽  
Raw Material ◽  
Elastic Structure ◽  
Chemical Derivatives ◽  
Copper Compounds ◽  
Rubber Compounds ◽  
Cyclic Compounds ◽  
Derivatives Of

Abstract 1. Methods of production of chemical derivatives of rubber must be based upon the use of old, disaggregated raw material. The application of this principle to the production of chlorinated rubber has been firmly established, and thus offers the possibility, upon the basis of our first experiments, of developing methods for the production of chlorinated rubber. 2. The investigation of the process of chlorination of rubber disaggregated by means of copper compounds completely supports the authors' point of view concerning the character of the action of copper compounds on the rubber. The authors view this action as a disaggregation of the rubber, which destroys its elastic structure and transforms the rubber compounds into forms which are chemically reactive. 3. The process of chlorination of disaggregated rubber by the means of copper compounds proves the authors' hypothesis about the mechanism of this disaggregation, which leads to the formation of cyclic compounds of rubber.

GROUNDWATER TIME SERIES

1970 ◽  
Vol 1 (3) ◽  
pp. 181-205 ◽  
Author(s):  
ERIK ERIKSSON
Keyword(s):  
Time Series ◽  
Point Of View ◽  
Hydrologic Models ◽  
Physical Point ◽  
Run Off ◽  
Fort Collins ◽  
Statistical Sense ◽  
Full Benefit ◽  
Future Work ◽  
Prediction Problems

The term “stochastic hydrology” implies a statistical approach to hydrologic problems as opposed to classic hydrology which can be considered deterministic in its approach. During the International Hydrology Symposium, held 6-8 September 1967 at Fort Collins, a number of hydrology papers were presented consisting to a large extent of studies on long records of hydrological elements such as river run-off, these being treated as time series in the statistical sense. This approach is, no doubt, of importance for future work especially in relation to prediction problems, and there seems to be no fundamental difficulty for introducing the stochastic concepts into various hydrologic models. There is, however, some developmental work required – not to speak of educational in respect to hydrologists – before the full benefit of the technique is obtained. The present paper is to some extent an exercise in the statistical study of hydrological time series – far from complete – and to some extent an effort to interpret certain features of such time series from a physical point of view. The material used is 30 years of groundwater level observations in an esker south of Uppsala, the observations being discussed recently by Hallgren & Sands-borg (1968).

Some 2-substituted derivatives of 5-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acid

1981 ◽  
Vol 46 (6) ◽  
pp. 1397-1404 ◽  
Author(s):  
Rudolf Kotva ◽  
Jiří Křepelka ◽  
Antonín Černý ◽  
Vojtěch Pujman ◽  
Miroslav Semonský
Keyword(s):  
Point Of View ◽  
Pentanoic Acid ◽  
Antineoplastic Effect ◽  
Derivatives Of

On condensation of 6-substituted trialkyl esters of 2-carboxy-1,7-heptanedioic acids XIII-XXIII with guanidineand subsequent saponification 2-substituted 5-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acids II-XII were prepared. From the pharmacological point of view some of the substances prepared had a potentiating effect on the antileukemia effect of 5-fluorouracil in mice and the antineoplastic effect manifested by a diminution of the tumours in animals with experimental tumours.

scholarly journals Chemical Derivatives of α-Chymotrypsinogen

1960 ◽  
Vol 235 (2) ◽  
pp. 396-404
Author(s):  
Djahanguir M. Abadi ◽  
Philip E. Wilcox
Keyword(s):  
Chemical Derivatives ◽  
Derivatives Of

scholarly journals Chemical Derivatives of α-Chymotrypsinogen

1961 ◽  
Vol 236 (5) ◽  
pp. 1328-1337
Author(s):  
Marilynn S. Doscher ◽  
Philip E. Wilcox
Keyword(s):  
Chemical Derivatives ◽  
Derivatives Of

scholarly journals Percolation and tortuosity in heart-like cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Rabinovitch ◽  
Y. Biton ◽  
D. Braunstein ◽  
I. Aviram ◽  
R. Thieberger ◽  
...  
Keyword(s):  
Action Potential ◽  
Forest Fire ◽  
Sinus Node ◽  
Heart Tissue ◽  
Point Of View ◽  
Physical Point ◽  
Electrical Currents ◽  
Single Wave ◽  
Heart Arrhythmia ◽  
The One

AbstractIn the last several years, quite a few papers on the joint question of transport, tortuosity and percolation have appeared in the literature, dealing with passage of miscellaneous liquids or electrical currents in different media. However, these methods have not been applied to the passage of action potential in heart fibrosis (HF), which is crucial for problems of heart arrhythmia, especially of atrial tachycardia and fibrillation. In this work we address the HF problem from these aspects. A cellular automaton model is used to analyze percolation and transport of a distributed-fibrosis inflicted heart-like tissue. Although based on a rather simple mathematical model, it leads to several important outcomes: (1) It is shown that, for a single wave front (as the one emanated by the heart's sinus node), the percolation of heart-like matrices is exactly similar to the forest fire case. (2) It is shown that, on the average, the shape of the transport (a question not dealt with in relation to forest fire, and deals with the delay of action potential when passing a fibrotic tissue) behaves like a Gaussian. (3) Moreover, it is shown that close to the percolation threshold the parameters of this Gaussian behave in a critical way. From the physical point of view, these three results are an important contribution to the general percolation investigation. The relevance of our results to cardiological issues, specifically to the question of reentry initiation, are discussed and it is shown that: (A) Without an ectopic source and under a mere sinus node operation, no arrhythmia is generated, and (B) A sufficiently high refractory period could prevent some reentry mechanisms, even in partially fibrotic heart tissue.

scholarly journals Rate of Convergence for Ibragimov-Gadjiev-Durrmeyer Operators

2017 ◽  
Vol 50 (1) ◽  
pp. 119-129 ◽  
Author(s):  
Tuncer Acar
Keyword(s):  
Rate Of Convergence ◽  
Bounded Variation ◽  
General Class ◽  
Durrmeyer Operators ◽  
Special Cases ◽  
Derivatives Of

Abstract The present paper deals with the rate of convergence of the general class of Durrmeyer operators, which are generalization of Ibragimov-Gadjiev operators. The special cases of the operators include somewell known operators as particular cases viz. Szász-Mirakyan-Durrmeyer operators, Baskakov-Durrmeyer operators. Herewe estimate the rate of convergence of Ibragimov-Gadjiev-Durrmeyer operators for functions having derivatives of bounded variation.

scholarly journals Focal transformation, an imaging concept for signal restoration and noise removal

Geophysics ◽  
2006 ◽  
Vol 71 (6) ◽  
pp. A55-A59 ◽  
Author(s):  
A. J. Berkhout ◽  
D. J. Verschuur
Keyword(s):  
Input Data ◽  
Noise Removal ◽  
Point Of View ◽  
Data Interpolation ◽  
Signal Restoration ◽  
Physical Point ◽  
Seismic Processing ◽  
Promising Tool ◽  
Focal Area ◽  
Forward Operator

Interpolation of data beyond aliasing limits and removal of noise that occurs within the seismic bandwidth are still important problems in seismic processing. The focal transform is introduced as a promising tool in data interpolation and noise removal, allowing the incorporation of macroinformation about the involved wavefields. From a physical point of view, the principal action of the forward focal operator is removing the spatial phase of the signal content from the input data, and the inverse focal operator restores what the forward operator has removed. The strength of the method is that in the transformed domain, the focused signals at the focal area can be separated from the dispersed noise away from the focal area. Applications of particular interest in preprocessing are interpolation of missing offsets and reconstruction of signal beyond aliasing. The latter can be seen as the removal of aliasing noise.

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