Effect of Certain Metallic Salts on the Aging of a Tread Compound

1928 ◽  
Vol 1 (1) ◽  
pp. 97-100
Author(s):  
Bert S. Taylor ◽  
Webster N. Jones
Keyword(s):  
Organic Acids ◽  
Copper Chloride ◽  
Natural Aging ◽  
Test Strips ◽  
Low Concentrations ◽  
Metallic Salts ◽  
Salts Of Organic Acids ◽  
Mercury Salts ◽  
Effects Of Aging ◽  
Manganese Salts

Abstract The effect on aging produced by the addition of low concentrations of iron, copper, manganese, and mercury salts of higher aliphatic organic acids to a tread compound was investigated. The data obtained from aging in the bomb show that the presence of copper and manganese salts of organic acids in very small concentrations is harmful to the aging of rubber. As little as 0.1 per cent of either cupric stearate or manganic oleate is detrimental. Iron stearate has a less deleterious effect, but 0.5 per cent iron stearate produced much poorer aging than the blank. The mercury salts in the concentrations used—0.1 to 1.0 per cent—did not affect the aging so noticeably as the other salts. The effects of aging in the Bierer-Davis bomb and in the Geer oven are markedly different, both as to tensile strength and the hardening of the test strips. The bomb test at 70° C. was much more severe than the oven test at the same temperature. Further investigation will be made to determine which type of artificial aging test most nearly corresponds to the natural aging of these stocks. The presence of copper chloride on the surface of the test strips exerts a deteriorating influence on the stock in the aging bomb. The effect is similar to that obtained when copper stearate is compounded into the stock.

ABOUT SOME PECULIARITIES OF THE PHYSIOLOGICAL HETEROGENEITY OF THE POPULATION OF SCENEDESMUS QUADRICAUDA (TURP.) BREB. IN THE PRESENCE OF LOW CONCENTRATIONS OF METALS

2018 ◽  
pp. 34-43
Author(s):  
V. I. Ipatova ◽  
A. G. Dmitrieva ◽  
О. F. Filenko ◽  
T. V. Drozdenko
Keyword(s):  
Cell Division ◽  
Toxic Effect ◽  
Copper Chloride ◽  
Single Cells ◽  
Physiological State ◽  
Scenedesmus Quadricauda ◽  
Physiological Status ◽  
Lag Phase ◽  
Protective Mechanism ◽  
Low Concentrations

The structure of the laboratory population of green microalgae Scenedesmus quadricauda (Turp.) Breb (=Desmodesmus communis E. Hegew.) was studied at different stages of its growth (lag-phase, log-phase and stationary phase) at low concentrations of copper chloride and silver nitrate by the method microculture, allowing to monitor the state and development of single cells having different physiological status. The response of the culture of S. quadricauda - the change in the number of cells and the fractional composition (the fraction of dividing, «dormant» and dying cells) depended not only on the concentration of the toxicant in the medium, but also on the physiological state of the culture: the level of synchronization and the growth phase. Silver ions at low concentrations had a more pronounced toxic effect on the culture than copper ions at different phases of its development, especially at a concentration of 0.001 mg/l (10-9 M). The main mechanism of the toxic effect of metals is to inhibit the process of cell division. At low concentrations of toxicants, especially at a concentration of 0.001 mg/l, a «paradoxical» effect expressed in the predominance of the fraction of «dormant» cells was revealed. The temporary inhibition of the process of cell division can be regarded as a protective mechanism that allows preserving the integrity of the population and its ability to survive in a changing environment. The obtained data explain the effect of action of low concentrations of substances due to their inclusion in the cell, the subsequent accumulation in the cell and their low excretion.

Rice acclimation to soil flooding: Low concentrations of organic acids can trigger a barrier to radial oxygen loss in roots

2019 ◽  
Vol 42 (7) ◽  
pp. 2183-2197 ◽  
Author(s):  
Timothy David Colmer ◽  
Lukasz Kotula ◽  
Al Imran Malik ◽  
Hirokazu Takahashi ◽  
Dennis Konnerup ◽  
...  
Keyword(s):  
Organic Acids ◽  
Radial Oxygen Loss ◽  
Oxygen Loss ◽  
Soil Flooding ◽  
Low Concentrations

Proflavine binding and release by sensitive and resistant Bacillus subtilis

1970 ◽  
Vol 16 (10) ◽  
pp. 973-981
Author(s):  
Gy. Barabas ◽  
B. M. Mehta ◽  
D. J. Kushner
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Organic Acids ◽  
Resistant Strain ◽  
Binding Capacity ◽  
Sensitive Strain ◽  
Growth Media ◽  
Sodium Salts ◽  
Salts Of Organic Acids ◽  
Resistant Cells

Proflavine binding of a sensitive strain of Bacillus subtilis and of a resistant strain derived from it was compared. Proflavine was bound very rapidly and more was bound at 0 °C than at 37 °C. Boiling increased the proflavine-binding capacity at 37 °C of sensitive but not of resistant cells. The binding capacity of sensitive and resistant cells suspended in buffer was the same; this was also true in various growth media. If cells were able to grow in the presence of proflavine their proflavine content decreased.Bound proflavine was released when cells were treated with growth media or with the salts of growth media. Sodium salts of organic acids also caused a release. This effect seemed due to their Na+ content, and was somewhat higher for resistant than for sensitive cells. The mechanism of proflavine resistance in B. subtilis is probably different from that of Escherichia coli, which is thought to depend on an energy-driven release of bound proflavine.

Effect of Metallic Poisons. Especially Manganese, on Aging of Vulcanized Natural Rubber

1947 ◽  
Vol 20 (3) ◽  
pp. 821-826
Keyword(s):  
Organic Acids ◽  
Natural Rubber ◽  
Harmful Effect ◽  
Manganese Compound ◽  
Naturally Occurring ◽  
Different Types ◽  
Salts Of Organic Acids ◽  
General Experience ◽  
Manganese Compounds ◽  
Harmful Effects

Abstract 1. Information received from rubber manufacturers on their experience of the effects of manganese and copper on aging is summarized. Although there is evidence that the amounts of these impurities in fillers tended to increase during the early war years (1939–42), it seems to be the general experience that little trouble arose from their effects on the properties of the rubber. Fillers containing as much as 0.05–0.10 per cent of manganese, or 0.005 per cent of copper, have not shown any obvious harmful effects. 2. Experiments with a large number of manganese compounds, including naturally occurring (mineral) forms and salts of organic acids, used in amounts equivalent to 0.01 per cent manganese on the raw rubber, have failed to show any pronounced harmful effect on the aging (oven or oxygen bomb) of a vulcanized natural rubber containing mercaptobenzothiazole, although deterioration was noticeably accelerated in some cases. Probably on account of the smallness of the effects observed, it is not possible as yet to draw any conclusion as to the relative activities of different types of manganese compound. 3. According to results of previous workers, manganese in the amount used in the present experiments can produce a more serious effect than these experiments indicate. The effect of manganese is known to depend on the type of mix used, and this aspect of the problem would thus appear to merit further investigation, as does also the influence of the method and degree of dispersion of the manganese compound in the rubber mix.

A Quinonoid Structure for Hydroquinone Pyridinium Salts of Organic Acids

Nature ◽  
1949 ◽  
Vol 163 (4145) ◽  
pp. 565-566 ◽  
Author(s):  
ABDEL FATTAH ALY ISMAIL
Keyword(s):  
Organic Acids ◽  
Pyridinium Salts ◽  
Salts Of Organic Acids
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