Scorching of Rubber Mixes. I. Structural Changes in Unfilled and Filled Stocks

1962 ◽  
Vol 35 (2) ◽  
pp. 509-516
Author(s):  
B. A. Dogadkin ◽  
A. V. Dobromyslova ◽  
O. N. Belyatskaya ◽  
T. A. Gyul'-Nazarova
Keyword(s):  
Carbon Black ◽  
Functional Groups ◽  
Significant Influence ◽  
Fine Particle ◽  
Structural Changes ◽  
Ph Value ◽  
Important Influence ◽  
The Other ◽  
Flow State ◽  
Carbon Blacks

Abstract 1. In the process of scorching there takes place a combination of the sulfur with the rubber. The flow of unfilled stocks heated at 120° ceases at the instant of combination of ∼0.5% sulfur reckoned on the stock. 2. In carbon black filled stocks there is an increase in the rate of combination of sulfur with rubber and a decrease in the time for which the stock is in the flow state, as the pH value of the carbon black added to the stock increases. 3. In processing a stock on the mill in the presence of fine-particle carbon black there is formed a rubber-carbon black gel, the amount of which hardly changes in the process of heating the stock in the plastimeter at 120°; only at the instant of cessation of the flow of the stock does its solubility decrease perceptibly. 4. In filled stocks in which a rubber-carbon black gel is formed in the course of treatment on the mill, the limiting amount of bound sulfur combined at the instant of cessation of the flow of the stock is less than in stocks in which no rubber-carbon black gel is formed. 5. Alteration in the amount of oxygen-containing functional groups upon the surface of the carbon black does not cause any important influence upon the amount of rubber-carbon black gel, but significantly alters the rate of combination of sulfur with rubber and the tendency of the stock to premature vulcanization. 6. Thus the phenomenon of premature vulcanization is governed for the most part by the reaction of the rubber with the sulfur and the other vulcanizing agents. In stocks with fine-particle carbon blacks there is also a significant influence from the formation of the rubber-carbon black gel in the processing of the stock on the mill.

The Organic Nature of Carbon Black Surfaces

1958 ◽  
Vol 31 (4) ◽  
pp. 941-952
Author(s):  
Jules V. Hallum ◽  
Harry V. Drushel
Keyword(s):  
Carbon Black ◽  
Functional Groups ◽  
Chemical Interaction ◽  
Hydroxyl Groups ◽  
Carbon Blacks

Abstract Evidence is presented for the existence of quinone groups and aromatic hydroxyl groups on the surface of carbon black particles. This evidence is based largely upon polarographic analyses of slurries of carbon blacks. A mechanism for the chemical interaction of carbon blacks with elastomers is proposed on the basis of these functional groups.

A Method for Evaluation of Carbon Blacks and Correlation with Road Wear Ratings

1974 ◽  
Vol 2 (3) ◽  
pp. 211-228 ◽  
Author(s):  
G. R. Cotten ◽  
E. M. Dannenberg
Keyword(s):  
Carbon Black ◽  
Abrasion Resistance ◽  
Laboratory Tests ◽  
The Other ◽  
Rubber Content ◽  
Carbon Blacks ◽  
Heat Treated ◽  
Bound Rubber ◽  
Normal Production

Abstract Prediction of tread wear from laboratory tests can be a valuable guide in the development of improved carbon blacks and controlling the quality of normal production. We have developed two tests which give good correlation with actual road wear data on over 100 experimental blacks. One test involves running Akron angle abrasion on a compound with only 30 phr of carbon black where differences in abrasion resistance are magnified. The other test measures surface activity towards the polymer by determining bound rubber content of a heat-treated nonproductive mix. By using both tests together, tread wear ratings of blacks used in this study could be predicted almost as well as by a single, controlled, multisectional road test with five tires run for 8000–10,000 miles.

Preparation of ZrSiO4/C Inclusion Pigments by Nonhydrolytic Sol-Gel Methed Combined with the Process of Carbon Black Modification

2013 ◽  
Vol 745-746 ◽  
pp. 545-550 ◽  
Author(s):  
Wei Hui Jiang ◽  
Yong Feng ◽  
Jian Min Liu ◽  
Qing Xia Zhu ◽  
Xia Yi Xu
Keyword(s):  
Nitric Acid ◽  
Carbon Black ◽  
Functional Groups ◽  
Process Parameters ◽  
Structural Changes ◽  
Sol Gel ◽  
B Value ◽  
Crystalline Phases ◽  
Binding Force ◽  
Inclusion Pigment

nclusion pigments of ZrSiO4/C were prepared by nonhydrolytic sol-gel (NHSG) method combined with the process of carbon black modification. The crystalline phases, microstructure, functional groups on the surface of carbon black and chromatic value of the pigments were characterized by XRD, TEM, FTIR and Colorimeter, respectively. The surface structural changes of the carbon black modified by nitric acid and the influences of process parameters on the chromatic value of the pigments were also investigated. The results show that the process of carbon black modification enhances the affinity and binding force between carbon black and ZrCl4 sol, which contributes to improve the effect of carbon black wrapped by ZrSiO4. The ZrSiO4/C inclusion pigment were obtained after calcining at 1000 °C for 8 h, and the L*, a* and b* value is 53.88, 0.74, and 1.88, respectively.

Effect of Elongation on the Electrical Anisotropy of Natural Rubber and SBR Vulcanizates Containing ISAF Carbon Black

1962 ◽  
Vol 35 (2) ◽  
pp. 317-325 ◽  
Author(s):  
R. Chasset ◽  
P. Thirion
Keyword(s):  
Mechanical Properties ◽  
Electrical Resistivity ◽  
Carbon Black ◽  
Natural Rubber ◽  
The Other ◽  
Electrical Anisotropy ◽  
Ohm’S Law ◽  
Carbon Blacks ◽  
Ohm's Law ◽  
Current Flows

Abstract The electrical resistivity of testpieces under different elongations, both parallel and at right-angles to the axis of elongation, was measured for two vulcanizates, i.e. one of natural rubber and the other of SBR, compounded with 20 volume per cent of ISAF black (Vulcan 6). Within the range of validity of Ohm's law, the main results of this study are as follows: a) the resistivities of both vulcanizates increase considerably with elongation, in both directions. b) on the whole, both vulcanizates are electrically anisotropic, since current flows more easily longitudinally than it does transversely. The anisotropy increases at the start with elongation, then becomes practically constant. However, the latter level is much higher with natural rubber, for which it corresponds to an anisotropy of about 1,000 and an elongation of around 150%. For SBR this level is only 20 to 30 and is reached at only 50% elongation. Owing to the complexity of the problem, no interpretation can yet be given for these differences. It will first be necessary to examine other elastomers and carbon blacks. For the time being, it may merely be stated that the electrical anisotropy of natural rubber and SBR reinforced vulcanizates differs as much as their mechanical properties, especially their tearing behavior.

Comparative Labelling and Biokinetic Studies of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn)

1977 ◽  
Vol 16 (01) ◽  
pp. 30-35 ◽  
Author(s):  
N. Agha ◽  
R. B. R. Persson
Keyword(s):  
Complex Formation ◽  
Significant Influence ◽  
Room Temperature ◽  
Ph Value ◽  
Maximum Activity ◽  
Reduction Step ◽  
Labelling Yield ◽  
Different Temperatures ◽  
Kinetics Of

SummaryGelchromatography column scanning has been used to study the fractions of 99mTc-pertechnetate, 99mTcchelate and reduced hydrolyzed 99mTc in preparations of 99mTc-EDTA(Sn) and 99mTc-DTPA(Sn). The labelling yield of 99mTc-EDTA(Sn) chelate was as high as 90—95% when 100 μmol EDTA · H4 and 0.5 (Amol SnCl2 was incubated with 10 ml 99mTceluate for 30—60 min at room temperature. The study of the influence of the pH-value on the fraction of 99mTc-EDTA shows that pH 2.8—2.9 gave the best labelling yield. In a comparative study of the labelling kinetics of 99mTc-EDTA(Sn) and 99mTc- DTPA(Sn) at different temperatures (7, 22 and 37°C), no significant influence on the reduction step was found. The rate constant for complex formation, however, increased more rapidly with increased temperature for 99mTc-DTPA(Sn). At room temperature only a few minutes was required to achieve a high labelling yield with 99mTc-DTPA(Sn) whereas about 60 min was required for 99mTc-EDTA(Sn). Comparative biokinetic studies in rabbits showed that the maximum activity in kidneys is achieved after 12 min with 99mTc-EDTA(Sn) but already after 6 min with 99mTc-DTPA(Sn). The long-term disappearance of 99mTc-DTPA(Sn) from the kidneys is about five times faster than that for 99mTc-EDTA(Sn).

THE EFFECT OF EVENT AND PUBLICITY TOWARDS BRAND AWARENESS ON FINANCIAL SERVICE AUTHORITY (OJK)

2017 ◽  
Vol 2 ◽  
pp. 281-292
Author(s):  
Donant Alananto Iskandar ◽  
Siti Dewi Sri Ratna Sari
Keyword(s):  
Public Relations ◽  
Significant Influence ◽  
Quantitative Method ◽  
Statistical Approach ◽  
Financial Service ◽  
The Other ◽  
Brand Awareness ◽  
Financial Service Authority ◽  
Other Hand ◽  
The People

This study aims to find out the effect of event and publicity towards brand awareness on Indonesia Financial Service Authority, usually called with its abbreviation OJK. The research background is because OJK was newly established as a financial service authority, replacing Bank Indonesia. Therefore, exploring the awareness of the people about the function of OJK is interesting to be a research subject.This method used in this study is the quantitative method with 82 samples as the questionnaire respondents. The population chosen was an OJK’s event held at LPPI and Indonesia Banking School with 122 participants. Validity, reliability, normality, multicollinearity, heteroskedasticity, correlation, determination, regression, hypothesis and ANOVA tests are used as a statistical approach in order to define the outcome of the survey. The results of this study are both event and publicity have a positive and a significant influence towards brand awareness partially and simultaneously. As the conclusion, OJK should continue its programs. On the other hand, OJK should find another public relations strategy to accelerate people awareness about the duties of OJK. Keywords: Event, Publicity, Brand Awareness

scholarly journals Identifying key processes and sectors in the interaction between climate and socio-economic systems: a review toward integrating Earth–human systems

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Kaoru Tachiiri ◽  
Xuanming Su ◽  
Ken’ichi Matsumoto
Keyword(s):  
Ecosystem Services ◽  
Gross Domestic Product ◽  
Significant Influence ◽  
Ghg Emissions ◽  
Climate Impacts ◽  
Ecological Impacts ◽  
The Other ◽  
Economic Damage ◽  
Economic Systems ◽  
The Impact

AbstractFor the purpose of identifying the key processes and sectors involved in the interaction between Earth and socio-economic systems, we review existing studies on those processes/sectors through which the climate impacts socio-economic systems, which then in turn affect the climate. For each process/sector, we review the direct physical and ecological impacts and, if available, the impact on the economy and greenhouse gas (GHG) emissions. Based on this review, land sector is identified as the process with the most significant impact on GHG emissions, while labor productivity has the largest impact on the gross domestic product (GDP). On the other hand, the energy sector, due to the increase in the demand for cooling, will have increased GHG emissions. Water resources, sea level rise, natural disasters, ecosystem services, and diseases also show the potential to have a significant influence on GHG emissions and GDP, although for most of these, a large effect was reported only by a limited number of studies. As a result, more studies are required to verify their influence in terms of feedbacks to the climate. In addition, although the economic damage arising from migration and conflict is uncertain, they should be treated as potentially damaging processes.

scholarly journals Changes in Value Orientations in Serbia, 2003–2018 . Patriarchy, Authoritarianism and Nationalism

Südosteuropa ◽  
2020 ◽  
Vol 68 (3) ◽  
pp. 408-431
Author(s):  
Irena Petrović ◽  
Marija Radoman
Keyword(s):  
Structural Changes ◽  
Empirical Studies ◽  
Value Orientations ◽  
The Other ◽  
Social Changes ◽  
Ethnic Nationalism ◽  
Political Situation ◽  
Other Hand ◽  
The Social ◽  
Private And Public

AbstractThe authors analyze the changes in value patterns—patriarchy, authoritarianism and nationalism—in Serbia in the context of the social changes that have marked the postsocialist transformation period. They focus on the extent and intensity of two sub-patterns within each of these three basic value patterns: private and public patriarchy, general and specific authoritarianism, organic (natural) and ethnic nationalism. The conclusions about changes in these value patterns are drawn on the basis of three empirical studies conducted in 2003, 2012, and 2018. They show the prevalence of private patriarchy, general authoritarianism, and organic (natural) nationalism over their counterparts. Private patriarchy has weakened, which is largely to be explained by the significant structural changes in Serbia. On the other hand, support of general authoritarianism and organic (natural) nationalism has been on the rise, which clearly mirrors the unfavorable economic and political situation in the country.

scholarly journals Influence of Ceramic Particles Character on Resulted Properties of Zinc-Hydroxyapatite/Monetite Composites

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 499
Author(s):  
Klára Hosová ◽  
Jan Pinc ◽  
Andrea Školáková ◽  
Vilém Bartůněk ◽  
Petr Veřtát ◽  
...  
Keyword(s):  
Significant Influence ◽  
Degradation Rate ◽  
Point Of View ◽  
The Other ◽  
Ceramic Particles ◽  
Biological Aspects ◽  
Strength And Ductility

Zinc and its alloys seem to be promising candidates for biodegradable applications. Those materials are often modified by other elements or compounds in order to enhance their properties. The combination of zinc and apatites is challenging for several reasons. However, the advantages connected with the biological aspects suggest the need for further research into such materials. In this study, three zinc-based composites with 4 and 8 wt. % of nanohydroxyapatite or nanomonetite (Zn-4MO, Zn-4HA, Zn-8HA) were prepared by sintering and subsequent extrusion. Materials prepared in this way were characterized from the microstructural, mechanical and corrosion point of view. The obtained results showed a significant influence of particle character (amount and morphology) on the strength and ductility of the prepared materials. In case of Zn-4MO, the presence of monetite significantly increased the ductility compared with the other materials. In addition, the increment of the degradation rate caused by the presence of monetite was observed as well. All obtained results pointed out to significant advantages of monetite for the preparation of Zn-apatite composites compared with hydroxyapatite.

scholarly journals Involvement of loop 5 lysine residues and the N-terminal β-hairpin of the ribotoxin hirsutellin A on its insecticidal activity

2016 ◽  
Vol 397 (2) ◽  
pp. 135-145 ◽  
Author(s):  
Miriam Olombrada ◽  
Lucía García-Ortega ◽  
Javier Lacadena ◽  
Mercedes Oñaderra ◽  
José G. Gavilanes ◽  
...  
Keyword(s):  
Active Sites ◽  
Structural Changes ◽  
The Other ◽  
Spatial Proximity ◽  
Ribonucleolytic Activity ◽  
The Family ◽  
Lysine Residues ◽  
Hirsutella Thompsonii ◽  
Close Spatial Proximity ◽  
High Degree

Abstract Ribotoxins are cytotoxic members of the family of fungal extracellular ribonucleases best represented by RNase T1. They share a high degree of sequence identity and a common structural fold, including the geometric arrangement of their active sites. However, ribotoxins are larger, with a well-defined N-terminal β-hairpin, and display longer and positively charged unstructured loops. These structural differences account for their cytotoxic properties. Unexpectedly, the discovery of hirsutellin A (HtA), a ribotoxin produced by the invertebrate pathogen Hirsutella thompsonii, showed how it was possible to accommodate these features into a shorter amino acid sequence. Examination of HtA N-terminal β-hairpin reveals differences in terms of length, charge, and spatial distribution. Consequently, four different HtA mutants were prepared and characterized. One of them was the result of deleting this hairpin [Δ(8-15)] while the other three affected single Lys residues in its close spatial proximity (K115E, K118E, and K123E). The results obtained support the general conclusion that HtA active site would show a high degree of plasticity, being able to accommodate electrostatic and structural changes not suitable for the other previously known larger ribotoxins, as the variants described here only presented small differences in terms of ribonucleolytic activity and cytotoxicity against cultured insect cells.

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