The Shrinkage of Mold Cured Elastomer Compositions

1955 ◽  
Vol 28 (4) ◽  
pp. 1141-1156 ◽  
Author(s):  
A. E. Juve ◽  
J. R. Beatty
Keyword(s):  
Major Part ◽  
Room Temperature ◽  
Curing Temperature ◽  
Mold Material ◽  
Thermal Coefficient ◽  
Thermal Contraction ◽  
Specific Effects ◽  
Minor Part ◽  
A Minor ◽  
Soft Rubber

Abstract The coefficient of expansion of elastomer compositions depends on the kind of polymer employed, the volume per cent of polymer plus all other organic materials, and the kind and the amount of pigment present. The specific effects of pigments in retarding the shrinkage are shown. A procedure is given by which the shrinkage of most soft rubber compositions of the principal rubbers may be calculated from the recipe. The major part of the shrinkage of elastomer compositions is due to the much greater thermal contraction of the composition than of the material from which the mold is made. This portion of the shrinkage depends on the thermal coefficient of expansion of the composition and the mold material and the temperature difference between the curing temperature and room temperature. A minor part of the shrinkage is due to a contraction of volume resulting form vulcanization. For normal soft rubber stocks with sulfur ratios of three parts or less and for normal Neoprene stocks, this factor may be neglected. For stocks having higher sulfur ratios, an allowance needs to be made for this factor.

Effect of Composition on Shrinkage of Mold Cured Elastomeric Compounds

1978 ◽  
Vol 51 (5) ◽  
pp. 1044-1059 ◽  
Author(s):  
J. R. Beatty
Keyword(s):  
Major Part ◽  
Thermal Coefficient ◽  
Thermal Contraction ◽  
Volume Percent ◽  
Specific Effects ◽  
Degree Of Orientation ◽  
Minor Part ◽  
The Common ◽  
A Minor ◽  
Soft Rubber

Abstract The mold shrinkage of elastomer compositions depends upon the elastomer employed, the volume percent of elastomer plus all other organic materials, and the kind and amount of pigment present. The specific effects of pigments in inhibiting the shrinkage are shown. A procedure is given by which the shrinkage of most soft rubber compositions of the common elastomers may be calculated from the recipe. The major part of the shrinkage of elastomer compositions is due to the much greater thermal contraction of the composition than that of the mold. This portion of the shrinkage depends upon the thermal coefficient of expansion of the composition and mold and the temperature difference between the curing and room temperatures. A minor part of the shrinkage is due to a contraction in volume resulting from vulcanization. For normal soft rubber stocks with sulfur concentrations of three phr or less and for normal neoprene stocks, this factor may be neglected. For stocks having higher sulfur ratios an allowance needs to be made for this factor. Shrinkage of fiber loaded stocks should be determined carefully depending on the quantity, and particularly on the degree of orientation of the processed stock.

STUDY OF SITE GEOMETRY OF THE Sn CATIONS IN THE Sn-ADDED Tl-Pb(1223) SUPERCONDUCTING SYSTEM USING MÖSSBAUER AND AUGER EMISSION TECHNIQUES

1999 ◽  
Vol 13 (23) ◽  
pp. 2887-2893
Author(s):  
KAMLESH KUMARI ◽  
R. K. SINGHAL ◽  
K. B. GARG ◽  
E. M. BAGGIO-SAITOVICH ◽  
SOUZA AZAVEDO ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Major Part ◽  
Mössbauer Spectra ◽  
Mossbauer Spectra ◽  
Doublet Line ◽  
Minor Part ◽  
A Minor ◽  
Tetravalent State ◽  
Weak Doublet

The addition of Sn in Tl,Pb(1223) ( Tl 0.5 Pb 0.5 Sn x Sr 1.6 Ca 2.4 Cu 3 O y) has been investigated using AES and Mössbauer Emission techniques to probe the valence and site geometry of Sn cations. It was found that Sn is present in tetravalent state in the compound at two sites with differing weights. The major part of the tin resides inside the grain and a minor part (weak doublet line in Mossbauer spectra) represents the contribution from the tin at the grain boundary.

New Method for Quantitative Preparation of Lignin- Carbohydrate Complex from Unbleached Softwood Kraft Pulp: Lignin-Polysaccharide Networks I

Holzforschung ◽  
2003 ◽  
Vol 57 (1) ◽  
pp. 69-74 ◽  
Author(s):  
M. Lawoko ◽  
G. Henriksson ◽  
G. Gellerstedt
Keyword(s):  
Major Part ◽  
Kraft Pulp ◽  
The Other ◽  
Quantitative Yield ◽  
New Method ◽  
Residual Lignin ◽  
Carbohydrate Complex ◽  
Softwood Kraft Pulp ◽  
Minor Part ◽  
A Minor

Summary A new method for the quantitative preparation of pulp representative lignin-carbohydrate complexes (LCC) has been developed, in which LCC has been systematically prepared at quantitative yield, fractionated and qualitatively determined. At least 90% of residual lignin in softwood kraft pulp is proposed to be chemically bonded to carbohydrates. A major part of LCC (92%) in softwood kraft pulp was observed between lignin, xylan and glucomannan, whereas a minor part (8%) was linked to cellulose. Half of the hemicelullosic LCC is a lignin-glucomannan complex. The other half is lignin-xylan complex and xylan-lignin-glucomannan complex. Thus, part of the residual lignin in softwood kraft pulp crosslinks xylan and glucomannan. The proposed linkages are of covalent type. At most 10% of the residual lignin is not bonded covalently to carbohydrates.

FREE AND PROTEIN-BOUND TRI-IODOTHYRONINE IN THE SERUM OF VITAMIN A-DEFICIENT RATS

1980 ◽  
Vol 84 (1) ◽  
pp. 135-140 ◽  
Author(s):  
H. GARCIN ◽  
P. HIGUERET
Keyword(s):  
Vitamin A ◽  
Negative Correlation ◽  
Major Part ◽  
Serum Vitamin ◽  
Serum Samples ◽  
Deficient Diet ◽  
Serum Free ◽  
Positive Correlation ◽  
Minor Part ◽  
A Minor

Tri-iodothyronine (T3) transport in the serum of rats on a vitamin A-deficient diet was studied by electrophoresis after the incubation of serum samples with radioactive T3. The level of serum free tri-iodothyronine (fT3) was measured by radioimmunoassay after serum chromatography on Sephadex LH-20 gel. In the serum of control rats a major part of the radioactivity was bound to the albumin zone (61%) and a minor part to the prealbumin zone (32%). In the serum of vitamin A-deficient rats a larger amount of radioactivity was bound to the postalbumin zone; the lower the level of vitamin A in serum, the greater was the radioactivity in this zone of the electrophoretogram. In these animals there was also a negative correlation between the serum vitamin A and the fT3. There was also a positive correlation between the radioactivity bound to the postalbumin zone and the fT3. The possible causes and effects of these modifications in vitamin A-deficient rats are discussed.

THE ROLE OF ANTHROPONYMS IN THE SEMANTIC FIELD OF ARTISTIC WORKS

2019 ◽  
Vol 2019 (29) ◽  
pp. 66-77
Author(s):  
Lidiya Derbenyova
Keyword(s):  
Literary Work ◽  
Main Theme ◽  
Semantic Field ◽  
New Meanings ◽  
Minor Part ◽  
The One ◽  
A Minor ◽  
And Storage ◽  
Horizon Of Expectations

The article explores the role of antropoetonyms in the reader’s “horizon of expectation” formation. As a kind of “text in the text”, antropoetonyms are concentrating a large amount of information on a minor part of the text, reflecting the main theme of the work. As a “text” this class of poetonyms performs a number of functions: transmission and storage of information, generation of new meanings, the function of “cultural memory”, which explains the readers’ “horizon of expectations”. In analyzing the context of the literary work we should consider the function of antropoetonyms in vertical context (the link between artistic and other texts, and the groundwork system of culture), as well as in the context of the horizontal one (times’ connection realized in the communication chain from the word to the text; the author’s intention). In this aspect, the role of antropoetonyms in the structure of the literary text is extremely significant because antropoetonyms convey an associative nature, generating a complex mechanism of allusions. It’s an open fact that they always transmit information about the preceding text and suggest a double decoding. On the one hand, the recipient decodes this information, on the other – accepts this as a sort of hidden, “secret” sense.

Electrostatic effects on ionization equilibria: An MNDO study of proton and hydrogen transfer reactions of 4-fluorobutylamine

1990 ◽  
Vol 55 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Zdeněk Friedl ◽  
Stanislav Böhm
Keyword(s):  
Hydrogen Transfer ◽  
Substituent Effects ◽  
Radical Cations ◽  
Transfer Reactions ◽  
Protonated Forms ◽  
Minor Part ◽  
Bond Strengths ◽  
Ionization Equilibria ◽  
A Minor ◽  
Gas Phase Basicities

The relative enthalpies of proton transfer δ ΔH0and homolytic bond strengths δDH0(B-H+) were calculated by the MNDO method for the sp and ap conformers of 4-flurobutylamine. The data obtained, along with the experimental gas phase basicities, are compared with the values predicted by the electrostatic theory. It is shown that the substituent polar effects FD on the basicities of amines are predominantly due to interactions in their protonated forms (X-B-H+) and/or radical-cations (X-B+.), those in the neutral species (X-B) playing a minor part. A contribution, which is considerably more significant in the sp conformer than in the ap conformer, arises probably also from substituent effects on the homolytic bond strength DH0(B-H+.

scholarly journals Phase Transformation of Kaolin-Ground Granulated Blast Furnace Slag from Geopolymerization to Sintering Process

2021 ◽  
Vol 7 (3) ◽  
pp. 32
Author(s):  
Noorina Hidayu Jamil ◽  
Mohd. Mustafa Al Bakri Abdullah ◽  
Faizul Che Pa ◽  
Mohamad Hasmaliza ◽  
Wan Mohd Arif W. Ibrahim ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Room Temperature ◽  
Curing Temperature ◽  
Curing Process ◽  
Sintering Process ◽  
Granulated Blast Furnace Slag ◽  
Fluxing Agent ◽  
Furnace Slag

The main objective of this research was to investigate the influence of curing temperature on the phase transformation, mechanical properties, and microstructure of the as-cured and sintered kaolin-ground granulated blast furnace slag (GGBS) geopolymer. The curing temperature was varied, giving four different conditions; namely: Room temperature, 40, 60, and 80 °C. The kaolin-GGBS geopolymer was prepared, with a mixture of NaOH (8 M) and sodium silicate. The samples were cured for 14 days and sintered afterwards using the same sintering profile for all of the samples. The sintered kaolin-GGBS geopolymer that underwent the curing process at the temperature of 60 °C featured the highest strength value: 8.90 MPa, and a densified microstructure, compared with the other samples. The contribution of the Na2O in the geopolymerization process was as a self-fluxing agent for the production of the geopolymer ceramic at low temperatures.

Formation and dynamics of Saturn and its disk simulated by using a new N-body model

Open Physics ◽  
2003 ◽  
Vol 1 (4) ◽  
Author(s):  
A. Pavlov ◽  
Y. Pavlova
Keyword(s):  
Surface Density ◽  
Electromagnetic Interaction ◽  
The Core ◽  
Body Model ◽  
Magnetic Forces ◽  
Axis Of Rotation ◽  
Gravitational Model ◽  
Minor Part ◽  
Body Self ◽  
A Minor

AbstractThe formation of Saturn and its disk is simulated using a new N-body self-gravitational model. It is demonstrated that the formation of the disk and the planet is the result of gravitational contraction of a slowly rotated particle cloud that have a shape of slightly deformed sphere. The sphere was flattened by a coefficient of 0.8 along the axis of rotation. During the gravitational contraction, the major part of the cloud transformed into a planet and a minor part transformed into a disk. The thin structured disk is a result of the electromagnetic interaction in which the magnetic forces acting on charged particles of the cloud originate in the core of the planet. The simulation program gives such parameters of Saturn as the escape velocity of about 35 km/s at the surface, density, rotational velocities of the rings and temperature distribution.

CLAY-INORGANIC STUDIES. II. HYDROXY ALUMINUM PHOSPHATE–MONTMORILLONITE COMPLEX

1975 ◽  
Vol 55 (2) ◽  
pp. 225-233 ◽  
Author(s):  
H. KODAMA ◽  
M. D. WEBBER
Keyword(s):  
Relative Humidity ◽  
Room Temperature ◽  
Aluminum Phosphate ◽  
Silicate Layer ◽  
Basal Spacing ◽  
Minor Amount ◽  
Chemical Compositions ◽  
A Minor ◽  
Positively Charged ◽  
Water Contents

Two specimens of hydroxy aluminum phosphate interlayer materials in montmorillonite clay were prepared with 7.20 meq Al and 11.29 meq H3PO4/g clay and with 14.40 meq Al and 22.58 meq H3PO4/g clay, and the resulting complexes studied by chemical and mineralogical methods. Both interlayer materials were slightly positively charged and except for different water contents their chemical compositions were almost identical. They contained Al, PO4 and H2O and a minor amount of Ca and approximated hydrous AlPO4∙nH2O. The mole ratios of Al:Ca:PO4:OH were 1.00:0.08:0.92:0.24 and 1.00:0.05:0.91:0.24, respectively. The interlayer materials appeared to be loosely packed and distributed sparsely in interspaces of the montmorillonite. The degree of packing was greater for the preparation with the larger amount of interlayer material. The materials increased the montmorillonite basal spacing to 23.3 Å under air-dry condition (30–40% relative humidity) but did not affect the lateral dimensions. The basal spacing varied somewhat with relative humidity at room temperature and decreased markedly as water was driven off by heating. Heat treatments between room temperature and 300 C sharply reduced the d001 spacings to 16.7 Å which persisted up to 700 C. It is postulated that the large basal spacings occur because the hydrated interlayer materials have a framework structure with tunnels along the c-axis. This being so, changes in the spacings with different humidities might result from the movement of water molecules among interstitial spaces existing around and between the loosely distributed molecules of interlayer material. The 16.7 Å spacing for the dehydrated phase corresponds to the sum of 7.0 Å, the edge dimension of an orthorhombic anhydrous AlPO4 and 9.7 Å, the silicate layer thickness.

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