Breakage of Carbon-Rubber Networks by Applied Stress

1952 ◽  
Vol 25 (4) ◽  
pp. 808-842 ◽  
Author(s):  
A. F. Blanchard ◽  
D. Parkinson
Keyword(s):  
Chemical Nature ◽  
Weak Type ◽  
Chain Structure ◽  
Strength Distribution ◽  
Particle Sizes ◽  
Carbon Particles ◽  
Different Types ◽  
Filler Particles ◽  
Mode Of Attachment ◽  
Rubber Filler

Abstract The results of this investigation strongly support previous conclusions by the authors that the softening of reinforced rubber when it is stressed to moderate extensions owes little to breakdown of filler chain structure and is due primarily to rupture of attachments between the filler and the rubber molecules. This means that the stiffness of reinforced rubber is influenced greatly by the mode of attachment of filler to rubber, and the conclusion reached is that such stiffening by finely divided fillers is largely a consequence of linkages between rubber molecules formed through the filler particles by rubber-filler bonds and assisted by the presence of coherent chain structure of the filler particles themselves. The work further suggests that the linkages formed through carbon particles are of two kinds : one a relatively weak type linkage due to physical (van der Waals) attachments, the other a strong type linkage due to chemisorptive attachments which remain unbroken by stressing. The strong linkages are relatively few and have not been found with fillers other than carbon black, but the strength distribution of the weaker type does not depend on the chemical nature or type of filler, although differences are found in the total number of such relatively weak attachments. The weak linkages are substantially all broken in the course of stressing to high elongations and the stiffening at the highest elongations is a consequence of the relatively small number of strong linkages. It is to be expected that among the fully reinforcing carbon blacks, where the particle sizes of the different types are roughly equivalent, those providing the greatest number of strong linkages will have the greatest reinforcing ability, and it may be significant in this connection that HAF black vulcanizates are recognized to have better abrasion resistance than MPC vulcanizates, in keeping with a larger number of strong linkages.

Characterisation of Drawing Papers for Borko Lazeski’s Cartoons (1951–56)

2018 ◽  
Vol 39 (3) ◽  
pp. 157-183
Author(s):  
Maja Kostadinovska
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Nature ◽  
Lignin Content ◽  
Mural Painting ◽  
Micro Raman Spectroscopy ◽  
Different Types ◽  
Informed Treatment ◽  
Acidic Conditions ◽  
Spot Tests ◽  
High Lignin Content

Abstract This paper presents a study of the drawing papers from Borko Lazeski’s cartoons for a mural painting. The collection is comprised of more than 20 single pieces (170×500 cm) executed in charcoal, pencil, pastel, tempera and ink. The cartoons exhibit different types of damages, such as grease stains, moisture stains, cracks, flaking paint, areas of loss caused by insects and mould stains. The study included spot tests, ATR-FTIR and micro-Raman spectroscopy to characterise the artist’s papers. They were found to be a type of paper composed of partly bleached, neutral sulphite semi-chemical (NSSC) wood pulp originating from coniferous trees (softwood) with the occasional use of abaca fibres. The laboratory tests revealed slightly acidic conditions (pH=5.01–6.52), high lignin content (>5 %) and alum-rosin sizing. Infrared spectroscopy confirmed all findings of the spot tests. Micro-Raman spectroscopy showed the presence of gypsum in the papers. The study addresses conservation issues arising from the chemical nature of the paper support and highlights the need for an extended study in order to be able to make informed treatment choices.

scholarly journals Зміни в вітамінній ланці антиоксидантної системи корів різних типів вищої нервової діяльності

2017 ◽  
Vol 19 (78) ◽  
pp. 81-85
Author(s):  
Yu.O. Sysyuk ◽  
V.I. Karpovskiy ◽  
O.V. Zhurenko ◽  
O.V. Danchuk ◽  
R.V. Postoy
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Blood Serum ◽  
Significant Influence ◽  
Weak Type ◽  
Nervous Activity ◽  
Winter Season ◽  
Tocopherol Content ◽  
Higher Nervous Activity ◽  
Different Types

The article presents the results of the studying the content of some vitamins in blood serum of cows with different types of higher nervous activity depending on the season. The purpose of the study was to determine the influence of the typological features of the nervous system on the content of separate vitamins in blood serum of cows depending on the season. The experiment was carried out on the basis of the farm «Kolos» village Borodianka, Kyiv region on clinically healthy cows of Ukrainian black-and-white dairy breed of 2–3rd lactation. On the basis of the investigation the conditioned reflex activity, 4 experimental groups of animals were formed with 4 most typical representatives of the identified types of higher nervous activity in each: 1st group – strong balanced mobile type, 2nd group – strong balanced inert type, 3rd group – strong unbalanced type, 4th group – weak type. The research material was blood serum, in which the content of vitamins A, E and C was determined by express method via liquid chromatography. The conducted investigation of ascorbic acid, retinol and tocopherol content in blood serum of cows with different types of higher nervous activity in winter and summer periods shown that its content is significantly dependent on the season. In particular, the content of ascorbic acid in blood serum of cows with different types of higher nervous activity in the winter season was lower by 22–27% in compare with its meaning in the summer season. It should be noted that the largest difference in content of vitamin C in blood serum depending on the season was found in animals of strong balanced inert and weak types of higher nervous activity (by 27.4%, P < 0.001 and 24.0%, P < 0.001 respectively). While in animals of strong balanced mobile and strong unbalanced types of higher nervous activity the content of vitamin C in blood serum was lower by 23.2% (P < 0.001) and 21.7% (P < 0.001), respectively. The content of fat-soluble vitamins in blood serum of cows with different types of higher nervous activity is also largely dependent on the season. Thus, the content of tocopherol was lower in the winter season by 35.8–41.6% (P < 0.001) depending on the type of higher nervous activity. And the retinol content was lower by 49.2–55.3% (P FU=3.0; P FU = 3.0; P < 0.05. However, the main properties of cortical processes did not have a significant influence on the content of retinol in blood serum – F = 2.8 < FU = 3.0; P = 0.06. The season has a significant influence on the content of the above mentioned vitamins – F = 126–348 > FU = 4.3; P < 0.001, which is obviously due to the level of supply the animal’s body with vitamins during different seasons. It should be noted that there is no relationship between the sources of variation (type of higher nervous activity and season), which obviously testifies to the absence of influence of the seasons on the main features of cortical processes (F = 0.37–1.64 < FU = 3.0; P = 0.208–0.775). Thus, the influence of the main features of cortical processes on the content of ascorbic acid, retinol and tocopherol in blood serum of cows is found. In animals of weak type of higher nervous activity the vitamin content in blood serum is lower than in animals of strong types. The lower content of ascorbic acid, retinol and tocopherol in blood serum of cows in the winter season, regardless the type of higher nervous activity, has been established.

scholarly journals A general database of hydrometeor single scattering properties at microwave and sub-millimetre wavelengths

2018 ◽  
Author(s):  
Patrick Eriksson ◽  
Robin Ekelund ◽  
Jana Mendrok ◽  
Manfred Brath ◽  
Oliver Lemke ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Single Scattering ◽  
Particle Orientation ◽  
Maximum Diameter ◽  
Particle Sizes ◽  
Orientation Data ◽  
Different Types ◽  
Rain Drops ◽  
Cloud Ice ◽  
Random Particle

Abstract. A main limitation today in simulations and inversions of microwave observations of ice hydrometeors (cloud ice, snow, hail ...) is the lack of data describing the interaction between electromagnetic waves and the particles. To improve the situation, the development of a comprehensive dataset of such "scattering properties" has been started. The database aims at giving a broad coverage in both frequency (1 to 886 GHz) and temperature (190 to 270 K), to support both passive and active current and planned measurements, and to provide data corresponding to the full Stokes vector. This first version of the database is restricted to totally random particle orientation. Data for 34 particle sets, i.e. habits, have been generated. About 17 of the habits can be classified as single crystals, three habits can be seen as heavily rimed particles, and remaining habits are aggregates of different types, representing e.g. snow and hail. The particle sizes considered vary between the habits, but a maximum diameter of 10 and 20 mm are typical values for the largest single crystal and aggregate particles, respectively, and the number of sizes per habit is at least 30. Particles containing liquid water are also inside the scope of the database, but this phase of water is so far only represented by a liquid sphere habit. The database is built upon the netCDF4 file format. Interfaces to browse, extract and convert data for selected radiative transfer models are provided in Matlab and Python. The database and associated tools are publically available from Zenedo (https://doi.org/10.5281/zenodo.1175572 and https://doi.org/10.5281/zenodo.1175588, respectively). Planned extensions include non-spherical rain drops, melting particles and a second orientation case that can be denoted as azimuthally random.

Proteins Induced Formation of Hydrothermal Nitrogen Doped Carbons

2009 ◽  
Vol 1219 ◽  
Author(s):  
Niki Baccile ◽  
Maria-Magdalena Titirici
Keyword(s):  
Particle Size ◽  
Carbon Source ◽  
Nitrogen Sources ◽  
Model Compounds ◽  
Nitrogen Doped ◽  
Carbon Particles ◽  
Structural Order ◽  
Different Types

AbstractThis contribution illustrates the synthesis of nitrogen-containing hydrothermal carbon particles from a mixture of glucose, as carbon source, and different types of proteins, as nitrogen sources. Casein, ovalbumin, hemoglobin and gelatin were chosen here as model compounds. The particle size and the level of structural order could be tuned according to the protein type and the amount utilized.

scholarly journals Size-segregated characteristics of organic carbon (OC), elemental carbon (EC) and organic matter in particulate matter (PM) emitted from different types of ships in China

2020 ◽  
Vol 20 (3) ◽  
pp. 1549-1564 ◽  
Author(s):  
Fan Zhang ◽  
Hai Guo ◽  
Yingjun Chen ◽  
Volker Matthias ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Particle Size ◽  
Elemental Carbon ◽  
Fine Particles ◽  
Particle Mass ◽  
Fuel Oil ◽  
Chemical Compositions ◽  
Particle Sizes ◽  
Heavy Fuel Oil ◽  
Different Types ◽  
Marine Diesel

Abstract. Studies of detailed chemical compositions in particles with different size ranges emitted from ships are in serious shortage. In this study, size-segregated distributions and characteristics of particle mass, organic carbon (OC), elemental carbon (EC), 16 EPA polycyclic aromatic hydrocarbons (PAHs) and 25 n-alkanes measured aboard 12 different vessels in China are presented. The results showed the following. (1) More than half of the total particle mass, OC, EC, PAHs and n-alkanes were concentrated in fine particles with aerodynamic diameter (Dp) < 1.1 µm for most of the tested ships. The relative contributions of OC, EC, PAH and alkanes to the size-segregated particle mass are decreasing with the increase in particle size. However, different types of ships showed quite different particle-size-dependent chemical compositions. (2) In fine particles, the OC and EC were the dominant components, while in coarse particles, OC and EC only accounted for very small proportions. With the increase in particle size, the OC / EC ratios first decreased and then increased, having the lowest values for particle sizes between 0.43 and 1.1 µm. (3) Out of the four OC fragments and three EC fragments obtained in thermal–optical analysis, OC1, OC2 and OC3 were the dominant OC fragments for all the tested ships, while EC1 and EC2 were the main EC fragments for ships running on heavy fuel oil (HFO) and marine-diesel fuel, respectively; different OC and EC fragments presented different distributions in different particle sizes. (4) The four-stroke low-power diesel fishing boat (4-LDF) had much higher PAH emission ratios than the four-stroke high-power marine-diesel vessel (4-HMV) and two-stroke high-power heavy-fuel-oil vessel (2-HHV) in fine particles, and 2-HHV had the lowest values. (5) PAHs and n-alkanes showed different profile patterns for different types of ships and also between different particle-size bins, which meant that the particle size should be considered when source apportionment is conducted. It is also noteworthy from the results in this study that the smaller the particle size, the more toxic the particle was, especially for the fishing boats in China.

Imogolite: a unique aluminosilicate

Clay Minerals ◽  
1969 ◽  
Vol 8 (1) ◽  
pp. 87-99 ◽  
Author(s):  
J. D. Russell ◽  
W. J. McHardy ◽  
A. R. Fraser
Keyword(s):  
Electron Diffraction ◽  
Infrared Absorption ◽  
Chain Structure ◽  
Absorption Bands ◽  
Repeat Units ◽  
Sample Orientation ◽  
Different Types ◽  
Stretching Vibrations ◽  
Diffraction Patterns ◽  
Silicate Chain

The fibrous aluminosilicate imogolite has been studied by electronoptical and infrared absorption methods. Electron diffraction patterns are interpreted in terms of repeat units of 8·4 Å parallel and 23 Å perpendicular to the fibre axis. These spacings can not be reconciled with a continuous silicate chain structure and this conclusion is supported by an Si-O vibration near 930 cm−1. A structure is postulated in which distorted chains of Al-O octahedra are cross-linked through isolated Si2O7 groups.Multiple OH stretching vibrations indicate different types of OH group in the imogolite structure. Absorption bands near 1000, 700 and 600 cm−1 are sensitive to sample orientation. This is attributed to the morphology and dimensions of the imogolite fibres.

Reactions of Polymers in Bulk. I. Influence of Fillers on the Degree of Crosslinking of Natural Rubber

1962 ◽  
Vol 35 (3) ◽  
pp. 563-571 ◽  
Author(s):  
J. Janacek
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Specific Surface ◽  
Contact Surface ◽  
Chemical Nature ◽  
Chain Structure ◽  
Filler Concentration ◽  
Carbon Blacks

Abstract The relation between the degree of crosslinking determined by means of swelling and the theoretical total contact surface of rubber to carbon black was investigated with vulcanizates of two elastomers which were cured by various vulcanization methods and using various concentrations—even extremely high ones—of carbon blacks with different specific surface, degrees of chain structure and chemical activities. A constant, α, the magnitude of which generally depends upon the degree of agglomeration of the carbon blacks and on the chemical nature of their surface as well as on the polymers used and the vulcanization method, but which is practically unrelated to the filler concentration, has been proposed to express the relative crosslinking activity of carbon blacks.

Practical Evaluation of Commercial Rubber Carbon Blacks by X-Ray Diffraction

1940 ◽  
Vol 13 (3) ◽  
pp. 655-666
Author(s):  
George L. Clark ◽  
Herbert D. Rhodes
Keyword(s):  
Point Of View ◽  
Resolving Power ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Carbon Blacks ◽  
Carbon Particles ◽  
Near Ultraviolet ◽  
Practical Evaluation ◽  
Individual Particles ◽  
Satisfactory Theory

Abstract Of the dozen or more reinforcing agents used in the commercial compounding of rubber, carbon blacks are outstanding in their excellence. Though no completely satisfactory theory has yet been forthcoming to explain the action of this material, the literature indicates that, among other factors, the size and shape of the ultimate carbon particles profoundly affect the characteristics of the rubber products obtained. Particle sizes of fillers and pigments are commonly determined by microscopic methods. Of those that have been suggested, the method of Gehman and Morris is perhaps most widely accepted as reliable. All microscopic methods, however, are subject to the limitation of resolving power imposed by the relatively narrow range of wave lengths in the visible and near ultraviolet which can be used for viewing and photographic purposes. Further, no distinction can be drawn between ultimate particles and compact secondary aggregates from the microscopic point of view. Thus, there always exista the possibility that microscopic particle sizes represent groups of individual particles rather than the individuals themselves.

Factors Affecting Strength of Agglomerates Formed During Spray Drying of Nanophase Powders

1994 ◽  
Vol 346 ◽  
Author(s):  
A. Maskara ◽  
D.M. Smith
Keyword(s):  
Surface Tension ◽  
Particle Size ◽  
Spray Drying ◽  
Particle Surface ◽  
Strength Distribution ◽  
Particle Sizes ◽  
Factors Affecting ◽  
Surface Hydroxyl ◽  
Alcohol Water ◽  
Nanosized Silica

ABSTRACTNanosized silica particles dispersed in various solvents were spray dried and the change in size distribution, agglomerate strength, and strength distribution was determined. The effect of solvent surface tension, pH, and particle surface chemistry on strength of agglomerates formed during spray drying was studied for particle sizes between 15 and 500 nm. Alcohol/water mixtures having different surface tension, and water at different pH levels, were employed to separate the effects of capillary pressure and surface hydroxyl condensation reactions. The agglomerate strength was determined using an ultrasonic measurement technique. The particle size was determined using sedimentation. The strength and strength distribution of agglomerates was found to depend on the solvent surface tension, solubility (pH), and primary particle size.

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