Effects of surface-active materials on the oscillations of a liquid jet

1972 ◽  
Author(s):  
G Quinn ◽  
D Saville
1975 ◽  
Vol 29 (5) ◽  
pp. 1408-1410 ◽  
Author(s):  
I. L. Povkh ◽  
A. B. Stupin ◽  
S. N. Maksyutenko ◽  
P. V. Aslanov ◽  
E. A. Roshchin ◽  
...  

1960 ◽  
Vol s3-101 (55) ◽  
pp. 313-332
Author(s):  
H. E. HINTON

In flies of the subfamily Muscinae the egg-shell has both an outer and an inner meshwork layer, each of which holds a continuous film of air. Between these two meshwork layers there is a more or less thick middle layer to which the shell chiefly owes its mechanical strength. Holes or aeropyles through the middle layer effect the continuity of the outer and inner films of air. Both meshwork layers consist of struts that arise perpendicularly from the middle layer. In both layers the struts are branched at their apices in a plane normal to their long axes. These horizontal branches form a fine and open hydrofuge network that provides a large water-air interface when the egg is immersed. When it rains or when the egg is otherwise immersed in water, the film of air held in the outer meshwork layer of the shell funtions as a plastron. To be an efficient respiratory structure a plastron must resist wetting by both the hydrostatic pressures and the surface active materials to which it is normally exposed. The plastrons of all the Muscinae tested resist wetting in clean water by pressures far in excess of any they are likely to encounter in nature. The resistance of a plastron to hydrostatic pressures varies directly as the surface tension of the water, and the surface tension of water in contact with the decomposing materials in which the Muscinae lay their eggs is much lowered by surface active materials. These considerations seem to provide an explanation for the great resistance of the plastron of the Muscinae to wetting by excess pressures and for the paradox that the plastrons of these terrestrial eggs are more resistant to high pressures than are the plastrons of some aquatic insects that live in clean water.


Author(s):  
Mahmood Alizadeh Sani ◽  
Mohammad Maleki ◽  
Hadi Eghbaljoo-Gharehgheshlaghi ◽  
Arezou Khezerlou ◽  
Esmaeil Mohammadian ◽  
...  

2019 ◽  
Vol 806 ◽  
pp. 39-44 ◽  
Author(s):  
Pavel L. Titov ◽  
Svetlana A. Shchegoleva ◽  
Nikolai B. Kondrikov

In this paper, the ordering of the arrays of TiO2 nanotubes obtained by the method of anodic oxidation in the fluoro-containing aqueous-nonaqueous electrolytes containing glycerine and surface-active materials is investigated. For analysis of ordering, the two-dimensional Fourier spectrum, do-it-yourself configurational geometrical entropy and section of the two-dimensional autocorrelation function were used. These characteristics allow us to identify a nature of ordering in sufficient detail and to obtain the preliminary quantitative assessments of this order. It is found that, in the systems of titanium-oxide nanotubes, the stable, almost correct short-range order is established within the first coordination sphere. Such order is similar to the amorphous ordering. At the same time, the ordering of nanotubes arrays differs in detail from the amorphous one in the greater expressiveness of the typical scale the sizes of which can be estimated using the Fourier spectra as well as autocorrelation function.


1943 ◽  
Vol 16 (2) ◽  
pp. 365-380
Author(s):  
H. C. Baker

Abstract In a previous paper by the present author, a general method for determining the distribution of the nonrubber substances between the rubber-and-water phases in latex was described and results were given of its application to the study of the distribution of nitrogen and materials extractable with acetone. It was shown that the nitrogen associated with the rubber phase is of two different types, a small amount (about 0.02 per cent) being independent of particle size and consequently distributed throughout the mass of the rubber, whereas the remainder is a function of particle size, replaceable by surface-active materials, such as soaps, and is, consequently, situated at the surface of the particles. The surface nitrogen in ammoniated latex was variable, decreased with age of latex, could be partially desorbed at an alkaline pH by washing the latex, for instance, by dilution or repeated creaming, and is considered to represent the protective protein covering of the latex globules. The total variation experienced in unconcentrated ammoniated latices of varying ages was from 0.11 to 0.18 per cent, but in latex of good quality about six months old, surface nitrogen was 0.15 per cent, corresponding to about 1 per cent protein. Distribution experiments on the acetone extract showed that there is from 2 to 3 per cent of acetone-soluble substances associated with the rubber, of which less than one-half represents ammonium soaps at the surface of the particles. The surface of the rubber particles is, therefore, composed largely of protein and fat acids, and it was thought probable that the ratio between them might change, both during the life of a single latex and from one latex to another.


1998 ◽  
Vol 4 (1) ◽  
pp. 49-55
Author(s):  
Antanas Laukaitis

The aim of this work was to investigate 300 kg/m3 density foam-gaseous silicate concrete production parameters and properties. The optimal mentioned density product formation parameter determination was conducted in a wide density interval. The raw material chemical composition is given in Table 1. Sand slime and porous silicate concrete mixture formation was performed in a laboratory mixer at 750 RPM. Surface active agents sulphanol and OP-10 (ethylphenyl ethylene glycol ether) was used for this purpose. An additional blowing agent-aluminium powder hydrophilizated with sulfanol (20 g/kg) was used. Formation mixture plasticity strength was calculated according to equation 1. Low-density porous silicate concrete sample compression strength depends not only on raw material fineness, binder amount, but also on its structure. Cast silicate concrete samples (without aluminium powder) were formed to determine the milled sand fineness needed for the optimal mixture activity. Their compression strength at 1100 kg/m3 density was calculated using equation 2. The sample compression strength dependency on mixture activity and sand fineness is given in Fig 1. The cast silicate concrete mixture technological parameters are given in Table 2. The mixtures activity is 20%, when the sand fineness approaches 130 m2/kg and 27%—340, 31%—500. Surface active materials amount (0,1—0,2%) lowers the silicate concrete samples compression strength insignificantly (Fig 2). The formation mixture envolves the surrounding air during sand slime and surface active agent mixing and partly swells. The amount of entrained air depends on the mixing time (Fig 3). However the main result is reached in 5 min. The slime density decreases from 1.7 to 0.8 kg/1, ie by 2.1 times. The mixing of surface active materials with all the mixture components is more effective, then whipping the slime separately with surface active agent and then adding lime and mixing again with the blown sand slime (Fig 4). This is explained by the fact, that when lime is added to the blown sand slime, its structure is partly destroyed. The surface active additives lower the foam silicate concrete formation mixture fluidity (Fig 5), due to the absorbed air during mixing. Sulphanol is a more effective surface active agent, than OP—10 (Fig 5). It is impossible to reach a sample density lower than 400 kg/m3, when surface active agents are mixed with silicate concrete mixture. That is why experiments were conducted where aluminium powder was added, ie a foam-gaseous silicate concrete was produced. Its density depends an V/S ratio and aluminium powder amount (Fig 6). The investigation of 300 kg/m3 density porous silicate concrete mass plasticity strength showed that it is the highest for gaseous silicate concrete and the lowest for foam silicate concrete. Foam-gaseous silicate concrete mass plasticity strength occupies an intermediate position (Fig 7). The porous silicate concrete mixtures highest temperature also depends on the porous silicate type. A gaseous silicate concrete mixture reaches 88 °C already in 30 min. Foam silicate concrete temperature increases more slowly and reaches 60 °C in 60 min. Foam-gaseous silicate concrete mixture temperature occupies an intermediate position and reaches 69 °C after 36 min (Fig 8). The sample compression strength is the highest for foam silicate concrete and the lowest for gaseous silicate concrete. Foam-gaseous silicate concrete sample compression strength occupies an intermediate position and depends directly on pores produced by whipping sand slime with surface active materials and mixture mixing with Al powder, ratio (Fig 9). This is predetermined by the different pore origin and pore structure formed during different degrees of mass warm-up. The latter was discussed in our earlier publications [8,13,15].


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