The behaviour of additives in explosions and the mechanism of antiknock. I

1960 ◽  
Vol 259 (1298) ◽  
pp. 304-324 ◽  
Keyword(s):  
The Other ◽  
Manganese Compound ◽  
Tin Compounds ◽  
Induction Periods ◽  
Auto Ignition ◽  
Metal Additives ◽  
Manganese Tricarbonyl ◽  
Absorption And Emission Spectroscopy ◽  
Manganese Compounds ◽  
Iron And Manganese

The behaviour of Te Me 2 , I 2 , Si Me 4 , Sn Et 4 , methyl cyclo pentadienyl manganese tricarbonyl ( AK -33X), Fe(CO) 5 , ferrocene, Hg vapour and Hg ( iso -propyl) 2 was observed during explosions of amyl nitrite (sensitizer), n -heptane and oxygen. After flash initiation, the reactions were followed by kinetic absorption and emission spectroscopy. The effect of these substances with respect to antiknock action, smoke formation, effect on induction period (preflame reaction) and the emission of light, has been recorded. With the tin and transition metal additives, smokes formed during the induction periods, characterized by a continuous scattering over the entire continuum. A K -33X increased or decreased the induction periods, according to the conditions. TeMe2 and I 2 increased the induction periods by homogeneous reactions. None of the other compounds changed the duration of the induction periods, including the iron compounds which are known to be antiknocks. With the iron and tin compounds included in the charges, smokes formed early in the induction periods and it was therefore concluded that the colloidal solids formed during the combustion of these compounds do not delay auto-ignition by preflame end gas reactions. It follows that there are two mechanisms of antiknock. It is suggested that the occurrence of heterogeneous inhibition is contrary to experience: (a) because there is insufficient surface exposed, (b) because the efficiency of reaction of chain centres at surfaces is low, (c) because the other antiknocks, Te Me 2 I 2 and Pb Et 4 act homogeneously. It is proposed that the second mechanism of antiknock, into which category the iron and manganese compounds fall, is a result of the reaction of the additive on the burnt or burning gases, rather than on the unburned gases. An intense emission of infra-red and visible light from explosions containing iron and manganese may be related to their mechanism as antiknocks; it is suggested that the increase in radiative cooling, caused by excitation and fluorescence of gaseous metal oxides and/or specific deactivation of propagating centres by metal or metal oxide species, plays an important role in this effect. The manganese compound also exhibits antiknock properties of the first type.

Synthesis of 1-(2-oxopropyl)adamantane from 1-bromo(chloro)adamantanes and isopropenyl acetate in the presence of iron and manganese compounds

2014 ◽  
Vol 50 (9) ◽  
pp. 1272-1275
Author(s):  
R. I. Khusnutdinov ◽  
N. A. Shchadneva ◽  
K. S. Kislitsina ◽  
V. A. Veklov ◽  
B. I. Kutepov
Keyword(s):  
Manganese Compounds ◽  
Iron And Manganese ◽  
Isopropenyl Acetate

scholarly journals Magnetic Field Usage Supported Filtration Through Different Filter Materials

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1584 ◽  
Author(s):  
Ewa Szatyłowicz ◽  
Iwona Skoczko
Keyword(s):  
Magnetic Field ◽  
Aqueous Solutions ◽  
Water Purification ◽  
Activated Alumina ◽  
Filtration Process ◽  
Manganese Removal ◽  
Filter Materials ◽  
The Subject ◽  
Manganese Compounds ◽  
Iron And Manganese

Currently, methods of water purification and aqueous solutions leading to effective reduction of introduced chemical compounds into water purification systems have become the subject of research. Physical methods have become an alternative, because by subjecting water and aqueous solutions to UV (ultraviolet) radiation or magnetic fields (MF), either ultrasonic or electric, it is possible to influence the change of structure, which results in changes in the properties of water and aqueous solutions. This paper attempts to verify the influence of a weak magnetic field on the removal of iron and manganese compounds in the filtration process on gravel of 1–2 mm granulation, sand of 0.4–0.8 mm granulation, activated alumina and activated carbon. The conducted research proved that MF has a significant influence on the effectiveness of iron and manganese removal from water in the case of alumina, while in the filtration process through other filter materials the effect of MF was small.

scholarly journals On iron flagellates

1946 ◽  
Vol 232 (588) ◽  
pp. 311-342 ◽  
Keyword(s):  
Organic Substances ◽  
Habitat Conditions ◽  
Liquid Media ◽  
Brown Colour ◽  
Fe And Mn ◽  
Iron Deposits ◽  
Manganese Compounds ◽  
Small Content ◽  
Iron And Manganese

The physiology and morphology of iron- and manganese-depositing flagellates are investigated by means of cultural experiments, with special reference to Anthophysa vegetans Stein, Siderodendron manganiferum n.gen., n.sp., Siphomonas Fritschii n.gen., n.sp. and Bikosoeca ( Poteriodendron ) petiolata (Stein) n.comb. Anthophysa multiplies in various liquid media containing small amounts of organic substances, hay decoction being specially favourable. Still better results are achieved with soil-water cultures, which afford the only successful cultures of Siderodendron and Siphomonas , while Bikosoeca also grows well in hay infusions. Addition of Fe" and Mn" is essential. The brown colour of biological iron deposits is shown to be due to admixture of manganese compounds, while mere ferric precipitates are in microscopical amounts almost colourless. Anthophysa and Siderodendron deposit more manganese than iron, so that their stalks appear brown, while those of Siphomonas are generally light brown. The envelopes of Bikosoeca are almost entirely composed of ferric compounds and appear colourless or faintly yellowish. All four organisms exhibit various modifications according to the habitat conditions. The formation of stalks and envelopes respectively depends on the availability of the relevant metals in the form of lower oxides, but the organisms here described can also exist without producing these structures. The oxidation of ferrous and manganese compounds is catalysed by the cells of these flagellates, although the role of this process in the cellular metabolism is not known. Nutrition is holozoic, chiefly by ingestion of bacteria. Like other holozoic flagellates these organisms cannot exist in the presence of an abundant bacterial vegetation owing to the resulting lack of oxygen. They thrive in quiet, well-aerated waters, with a small content of organic substances, above zones in which Fe and Mn compounds are reduced and from which ferrous and manganous compounds diffuse to the overlying oxidation zone, where these flagellates deposit Fe"' and Mn'" in a morphologically defined form. ‘Iron’ flagellates generally live in association and competition with iron bacteria of the Leptothrix group, the removal of which produces much better growth. A description of the relevant flagellates and of their appearance under various conditions, as well as diagnoses of Siderodendron and Siphomonas , are given.

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.

Influence of Ammonia Nitrogen on Treatment of Groundwater Containing iron and Manganese in Aeration-Contact Oxidation Filtration Process

2012 ◽  
Vol 170-173 ◽  
pp. 2414-2418
Author(s):  
Yu Hua Zhao ◽  
Yan Feng Li ◽  
Wen Bo Zhang ◽  
Chun Na Zhang ◽  
Jin Xiang Fu ◽  
...  
Keyword(s):  
Water Treatment ◽  
Nitrogen Concentration ◽  
Great Influence ◽  
Ammonia Nitrogen ◽  
The Other ◽  
Iron Removal ◽  
Manganese Concentration ◽  
Filtration Process ◽  
Contact Oxidation ◽  
Iron And Manganese

Two different kinds of water were treated with aeration-contact oxidation filtration process. One was groundwater containing iron and manganese (GIM), the other was GIM polluted by ammonia (GAIM). The results showed that ammonia has almost no influence on iron removal, but has great influence on manganese. Under the condition of 1m/h filter velocity and 10 mg/L average ammonia nitrogen concentration of inlet，the outlet manganese concentration for GAIM was less than 0.1 mg/L after 315 days. When temperature dropped to 18°C below, the manganese concentration of effluent exceeded 0.1 mg/L. When average ammonia nitrogen concentration of inlet for GAIM dropped to 3.27 mg/L, the manganese concentration of outlet for GAIM was less than 0.1 mg/L in winter. And for GIM, the manganese concentration of outlet was less than 0.1 mg/L only after 52 days. Although the filter velocity increased gradually from 1 to 7 m/h, the manganese concentration of effluent was always less than 0.1 mg/L. Therefore, ammonia pollution in the groundwater greatly increases the difficulty of water treatment.

A mathematical model for hydrocarbon autoignition at high pressures

1975 ◽  
Vol 346 (1647) ◽  
pp. 515-538 ◽  
Keyword(s):  
Mathematical Model ◽  
High Pressures ◽  
The Other ◽  
Chain Mechanism ◽  
Rapid Compression Machine ◽  
High Pressure And Temperature ◽  
Cool Flame ◽  
Induction Periods ◽  
Branched Chain ◽  
Low Pressures

We have developed a generalized mathematical model for the autoignition of hydrocarbons under the conditions of high pressure and temperature achieved in a rapid-compression machine. The model is able to simulate the essential phenomena of the two-stage autoignition of alkanes under these conditions; these are a well-defined cool flame that is often quenched rapidly and completely before the onset of a sharp ignition. It also pre­dicts correctly the transition to single-stage autoignition at even higher temperatures and the variation with temperature of the characteristic induction periods. The model is based on a degenerate-branched-chain mechanism. We show that it must contain as necessary features two termination processes, one linear and the other quadratic in radial concen­tration, and two routes for the formation of branching agent, one of which involves intermediate products of oxidation. The model also predicts, without any adjustment of the kinetic parameters, the essential pheno­mena of cool-flame and ignition behaviour that are observed at low pressures.

Excess heats of tri-n-alkylamines and tetraalkyl tin compounds in linear and branched alkanes: correlations of molecular orientations and steric hindrance effect

1979 ◽  
Vol 57 (5) ◽  
pp. 517-525 ◽  
Author(s):  
R. Philippe ◽  
G. Delmas ◽  
Phuong Nguyen Hong
Keyword(s):  
Steric Hindrance ◽  
Solution Structure ◽  
The Other ◽  
Short Chain ◽  
Flory Theory ◽  
Tin Compounds ◽  
Branched Alkanes ◽  
Linear Alkanes ◽  
Chain Compounds ◽  
Long Chain

Excess heats of the following mixtures of trialkylamines and tetraalkyl tin compounds with branched and linear alkanes have been measured at 25 °C: five trialkylamines NR3 (R = C2H5, C3H7, C4H9, C10H21, C12H25) with six linear alkanes, n-C5, n-C6, n-C8, n-C10, n-C12, n-C16, and three highly branched alkanes, 2,2,4-trimethylpentane, 2,2,4,6,6-pentamethylheptane, and 2,2,4,4,6,8,8-heptamethylnonane (br-C16). Further measurements were carried out on tetrapropyl tin (SnPr4) with n-C8, n-C16, and br-C16.Measurements were made to obtain more information on the heats of disordering of long chain compounds and on an exothermic contribution to the heats coming possibly from the sterically hindered character of one of the components of the mixture. The three short-chain trialkylamines have large heats with the linear long alkanes and small heats with the branched alkanes. On the other hand, the two long-chain trialkylamines have very small heats with linear alkanes and large heats with the branched alkanes. These results are interpreted as indicating no change of liquid or solution 'structure' when two ordered compounds (long alkanes and long-chain amines) are mixed but a change of 'structure' when an ordered compound (long alkane or long-chain amine) is mixed with a non-ordered one (branched alkane or short-chain amine). The heat of disordering of n-hexadecane is obtained with many order breakers and found to depend to some extent on the expansion coefficient of the order breaker. HE values for the series of the shorter NR3 do not vary regularly with molecular weight but are smaller for the propyl (and possibly the ethyl) derivative. Similarly, HE of SnPr4 in n-C16, br-C16, and n-C8 are much lower than the corresponding heats with SnEt4 and SnBut4. This is attributed to the presence of the exothermic contribution to the heats, HE(steric hindrance). The X12 parameter of the Flory theory has been calculated and is interpreted in terms of the disorder and steric hindrance contributions to the heats.

STUDIES IN PLANT MINERAL NUTRITION: III. THE EFFECTS OF CALCIUM CONCENTRATION IN CULTURE SOLUTIONS UPON THE ABSORPTION OF IRON AND MANGANESE BY DWARF KIDNEY BEAN

1957 ◽  
Vol 35 (5) ◽  
pp. 773-777 ◽  
Author(s):  
C. D. Taper ◽  
W. Leach
Keyword(s):  
Calcium Level ◽  
The Other ◽  
Manganese Concentration ◽  
Culture Solution ◽  
Optimum Range ◽  
Deficiency Symptoms ◽  
Leaf Tissues ◽  
Iron Manganese ◽  
Nutrient Solutions ◽  
Iron And Manganese

Definite relationships between the absorption of iron, manganese, and calcium were revealed in experiments with dwarf kidney beans grown in complete nutrient solutions containing various concentrations of iron and manganese, and two concentrations of calcium. The effects of these treatments upon the leaf contents of iron and manganese were determined by spectrophotometric analysis.It was found that increase in the concentration of either one of the metals, iron or manganese, relative to the concentration of the other, in the culture solution, appeared to depress the concentration of the other in the leaves, regardless of calcium level in the solution. Further, increase in the calcium level appeared to depress the accumulation by the leaves of both iron and manganese, regardless of their concentrations in the culture solution and the ratio between them.The iron to manganese concentration ratio in the culture solution was a factor in determining the presence or absence of deficiency symptoms. With 42 p.p.m. of calcium in the culture solution, healthy plants resulted within an optimum iron: manganese ratio range of approximately 0.5 to 5.0, whereas, in the case of 143 p.p.m. of calcium, healthy plants resulted only when the ratio was 2, indicating a narrower optimum range for the higher calcium level. Iron: manganese ratios below the optimum range resulted in iron deficiency symptoms, and above this range, in manganese deficiency symptoms.The data suggest that a minimum content of each of the metals, iron and manganese, must be present in the leaf tissues in order that healthy plants may result.

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