The Direct Determination of Oxygen in Rubber. The Adaptation of the Ter Meulen Method to Rubber and Its Application to the Study of Aging

1939 ◽  
Vol 12 (2) ◽  
pp. 269-282 ◽  
Author(s):  
H. I. Cramer ◽  
I. J. Sjothun ◽  
L. E. Oneacre
Keyword(s):  
Tensile Strength ◽  
Physical Properties ◽  
Direct Determination ◽  
Sulfur Poisoning ◽  
Oxidation Products ◽  
Oxygen Bomb ◽  
Vulcanized Rubber ◽  
Relationship Of ◽  
The Relationship

Abstract The ter Meulen method for the direct determination of oxygen has been adapted, with modifications, to the analysis of raw and vulcanized rubbers. Raney nickel has been found to be quite effective as the reducing catalyst and to be satisfactorily resistant to sulfur poisoning. The method has been applied to the study of the aging of vulcanized rubber in the Geer oven and oxygen bomb. From this study the following conclusions may be drawn: (1) The increase in combined oxygen is greater in the oxygen bomb than in the Geer oven. (2) Deterioration of rubber in the oxygen bomb involves oxidation primarily, whereas that occurring in the Geer oven involves not only oxidation but also thermal decomposition followed by volatilization of oxidation products. (3) The effectiveness of an antioxidant in retarding the absorption of oxygen in oxygen-bomb aging agrees well with its ability to maintain the physical properties of the stock in which it is present. (4) The deterioration in physical properties of a rubber stock in the oxygen bomb during the early stages of aging is a linear function of the increase in combined oxygen. For stocks containing antioxidants and diphenylguanidine as the accelerator, an increase in combined oxygen of approximately 1.2% corresponds to a decrease in tensile strength of 50%. (5) The relationship of increase in combined oxygen to decrease in tensile strength seems to be affected not only by antioxidants, but also by accelerators of vulcanization.

The Oxidation Products of Rubber

1939 ◽  
Vol 12 (2) ◽  
pp. 225-234
Author(s):  
A. van Rossem ◽  
P. Dekker
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Tensile Properties ◽  
High Speed ◽  
Accelerated Aging ◽  
Direct Determination ◽  
Oxidation Products ◽  
Vulcanized Rubber

Abstract In their summary of the aging of vulcanized rubber, Porritt and Scott state that three factors are responsible for the changes in mechanical properties of vulcanized rubber during aging, viz.: (a) oxidation of the rubber; (b) after-vulcanization; (c) some colloidal change of the rubber, sometimes termed aggregation. Of these factors, oxidation is by far the most important because it is responsible for the decrease in mechanical properties, which leads to the general deterioration of rubber from a technical standpoint. It was Marzetti who proved that the decrease of mechanical properties in accelerated aging is due to oxidation. Later, Kohman confirmed this in a more concise way and showed that even such small amounts as 0.5% of oxygen absorbed by vulcanized rubber are sufficient to decrease tensile properties to 50% of their original value. When studying aging, three ways of tackling this problem are possible, viz.: (1) Investigations of the mechanical properties, either under normal conditions, or under special conditions such as elevated temperature or high speed. (2) Determination of oxidation products, which are formed during oxidation of the rubber. (3) Direct determination of the amount of oxygen which is absorbed by the rubber. It is clear that any of these methods may be combined with accelerated aging tests.

Dependence of Tensile Strength of Vulcanized Rubber on the Degree of Cross-Linking

1950 ◽  
Vol 23 (1) ◽  
pp. 27-43
Author(s):  
Paul J. Flory ◽  
Norman Rabjohn ◽  
Marcia C. Shaffer
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Chain Scission ◽  
General Character ◽  
Cross Linking ◽  
Vulcanized Rubber ◽  
Relationship Of ◽  
The Relationship ◽  
Considerable Detail ◽  
Proportionality Relationship

Abstract The suitability of disazodicarboxylates as quantitative cross-linking agents for the preparation of rubber vulcanizates of known degrees of cross-linking has been emphasized previously. In a recent paper we have presented the results of an investigation on the dependence of the equilibrium force of retraction on the elongation and degree of cross-linking of rubber and GR-S vulcanized with these compounds. The present paper reports an extension of these investigations of the relationship of physical properties of rubberlike materials to their network structure. Specifically, the tensile strength of azo vulcanized natural rubber has been explored as a function of the degree of cross-linking and of the extent of modification of the chain units. The tensile strengths of natural rubber specimens vulcanized to various extents using sulfur alone or sulfur in conjunction with various accelerators have been investigated in considerable detail recently by Gee, who has emphasized the critical dependence of the tensile strength on the degree of cross-linking. Values for the latter quantity, however, were deduced indirectly from the equilibrium force of retraction using the simple proportionality relationship between force of retraction and degree of cross-linking afforded by the theory of rubber elasticity. This relationship is known to be only approximately valid. Furthermore, the effects on the force of retraction of chain scission, which doubtless accompanied some of the vulcanizations to a considerable degree, were disregarded. For these reasons, Gee's values for the degrees of cross-linking occurring in his vulcanizates are only approximate estimates, and in a few cases they may be seriously in error. Nevertheless, the general character of the relationship between tensile strength and degree of cross-linking which he obtained is confirmed by our results on rubber samples quantitatively cross-linked with measured proportions of decamethylene-dismethyl azodicarboxylate.

Calculating the aerodynamics of vertical axis wind turbines

2012 ◽  
Vol 34 (3) ◽  
pp. 169-184 ◽  
Author(s):  
Hoang Thi Bich Ngoc
Keyword(s):  
Wind Turbine ◽  
Incidence Angle ◽  
Vertical Axis ◽  
Rotor Blades ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Velocity Triangle ◽  
Relationship Of ◽  
The Relationship

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.

Tire Treadwear — A Comprehensive Evaluation of the Factors: Generic Type, Aspect Ratio, Tread Pattern, and Tread Composition Part I: Introduction and Details on the Organization of the Program

1986 ◽  
Vol 14 (4) ◽  
pp. 201-218 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Aspect Ratio ◽  
Comprehensive Evaluation ◽  
Test Method ◽  
Interactive Effects ◽  
Data Analyses ◽  
Main Effect ◽  
Systematic Determination ◽  
Relationship Of ◽  
The Relationship

Abstract This four-part series of papers addresses the problem of systematic determination of the influence of several tire factors on tire treadwear. Both the main effect of each factor and some of their interactive effects are included. The program was also structured to evaluate the influence of some external-to-tire conditions on the relationship of tire factors to treadwear. Part I describes the experimental design used to evaluate the effects on treadwear of generic tire type, aspect ratio, tread pattern (groove or void level), type of pattern (straight rib or block), and tread compound. Construction procedures and precautions used to obtain a valid and functional test method are included. Two guiding principles to be used in the data analyses of Parts II and III are discussed. These are the fractional groove and void concept, to characterize tread pattern geometry, and a demonstration of the equivalence of wear rate for identical compounds on whole tread or multi-section tread tires.

Optimize Mixing Process Parameters of Synchronous Rotor Mixer Based on Orthogonal Method

2012 ◽  
Vol 501 ◽  
pp. 442-447
Author(s):  
Ping Fu ◽  
Feng Bao Bai ◽  
Chuan Sheng Wang ◽  
Shan Hu Li
Keyword(s):  
Physical Properties ◽  
Process Parameters ◽  
Fill Factor ◽  
Cooling Water ◽  
Mixing Process ◽  
Rotor Speed ◽  
Orthogonal Method ◽  
Cooling Water Temperature ◽  
Vulcanized Rubber ◽  
The Relationship

In this paper adopting the orthogonal method, self-developed compound formulation had tested, and the relationship between the physical properties of vulcanized rubber and rectangular synchronous rotor mixer parameters had researched. The results showed that when the fill factor was 0.6, the rotor speed was 70r/min, cooling water temperature was 45 °C, pressure on the top bolt was 0.8Mpa, the physical properties of the vulcanized rubber was best.

Knowledge management implementation in Indian automobile ancillary industries

2016 ◽  
Vol 11 (3) ◽  
pp. 802-810 ◽  
Author(s):  
Nitin Yashwant Patil ◽  
Ravi M. Warkhedkar
Keyword(s):  
Knowledge Management ◽  
Industrial Area ◽  
Total Quality ◽  
Limited Data ◽  
Interpretive Structural Modeling ◽  
Content Type ◽  
Relationship Of ◽  
Power And Dependence ◽  
The Relationship

Purpose In the past decade, much has been written about knowledge management (KM) in the manufacturing; however, less attention has been paid to the Indian automobile ancillary industries located in Chinchwad, Pune. It is suitable to find out the relationship of the factors of the study. It helps in identifying the hierarchy of factors to be taken, and interlinking of production department with KM improves the productivity of the industries. Categorization of these principles based on their driving power (principles which hold other principles) and dependence (principles which are dependent on other principles) has also been examined for KM implementation to study the driving power and dependence power of these principles. This paper aims to determine the roadmap of KM implementation and categorize KM principles based on their driving power for manufacturing industries with the use of the interpretive structural modeling (ISM)-based model. The results indicate that the principles possessing higher driving power, such as KM, inventory control, quality control, productivity and scheduling and their interlinking. The major contribution of this research lies in the development of contextual relationship among various identified factors of KM and determination of their driving and dependence power through a single systemic framework. Design/methodology/approach In this paper, author find out the suitability ISM for Indian Automobile industries to find the relation among the variables. Findings ISM model has been developed for the hierarchy of the identified KM. As ISM model results a hypothetical hierarchy which needs a proper quantitative analysis to evaluate their percentage effectiveness in the hierarchy. Research limitations/implications It is applied to automobile industries with limited number of variables that will show the dependence variable and driving variables and their interrelations. It can be applied other fields to fine the relationship of variables. Practical implications The ISM may be used in supply chain management and total quality management to find interlinking between the variables. Originality/value The limited data collected from Pimpri Chinchwad industrial area of Pune from Maharashtra state (India).

Carbon Black. I—A Study of Its Volatile Constituents

1928 ◽  
Vol 1 (3) ◽  
pp. 485-497 ◽  
Author(s):  
C. R. Johnson
Keyword(s):  
Carbon Black ◽  
Volatile Matter ◽  
Original Sample ◽  
Missing Information ◽  
Volatile Constituents ◽  
Vulcanized Rubber ◽  
Rates Of Evolution ◽  
Temperature And Pressure ◽  
The Relationship

Abstract The rates of evolution of gas from carbon black with variation of time, temperature, and pressure have been determined. Complete analyses have been made of five types of carbon black, which involve an organic combustion of the original sample, an organic combustion of the sample after the gases have been removed, a determination of the loss in weight represented by the gases removed, analyses of the gases removed, and finally a complete accounting, or balance, of the carbon in the steps considered. In an attempt to supply some missing information not revealed by the foregoing, some special gas analyses under varying conditions were made. The relationship between the amount and composition of volatile matter evolved from carbon blacks and the properties imparted to vulcanized rubber when compounded with these blacks has been studied.

Еarly diagnosis of multiple sclerosis: experience with the use of class G oligoclonal immunoglobulin

2021 ◽  
Vol 26 (3) ◽  
pp. 34-39
Author(s):  
Z. A. Goncharova ◽  
Y. Y. Pogrebnova ◽  
N. M. Yarosh ◽  
S. M.M. Sehweil
Keyword(s):  
Multiple Sclerosis ◽  
Early Diagnosis ◽  
Literature Review ◽  
Demyelinating Disease ◽  
Mcdonald Criteria ◽  
Mri Features ◽  
Oligoclonal Igg ◽  
Relationship Of ◽  
The Relationship

The article presents the literature review and our experience in early diagnosis of multiple sclerosis based on the updated McDonald criteria of 2017. The study included 256 patients with clinic symptoms of probable idiopathic infl ammatory demyelinating disease, including rare and atypical forms of demyelination. As a result of the study the sensitivity and specifi city of the determination of oligoclonal immunoglobulin G in the population of Rostov-on-Don was described for the fi rst time, including dependence of the duration of the disease. The relationship of clinical and MRI features of the fi rst attack of the disease with the probability of determining oligoclonal IgG in the cerebrospinal fl uid is refl ected

The impact of the ESA 2010 on statistics of the general government sector

2015 ◽  
Vol 60 (11) ◽  
pp. 1-15
Author(s):  
Olga Leszczyńska-Luberek
Keyword(s):  
The European Union ◽  
Government Sector ◽  
General Government ◽  
European System ◽  
Relationship Of ◽  
The Impact ◽  
Methodological Guidelines ◽  
The Relationship ◽  
Excessive Deficit Procedure

The author presents the importance of the new European System of National and Regional Accounts (ESA 2010) for statistics of the general government sector. She pays particular attention to the development of data for the excessive deficit procedure. The article explains the methodological changes made to the studies in this field parallel to the ESA 2010. It discusses, among others, issues related to defining the deficit and debt of the general government, as well as the determination of a new way registering transfer of liabilities of pension schemes. It also presents the impact of new methodological guidelines for the relationship of deficit and debt to GDP in the Member States of the European Union.

scholarly journals Autonomy and Attachment in Relationships with Parents in the Context of Students’ Real Self-Determination

2021 ◽  
Vol 12 (1) ◽  
pp. 113-125
Author(s):  
D.A. Krasilo ◽  
T.A. Krassilo ◽  
A.N. Zalipaeva
Keyword(s):  
Inverse Relationship ◽  
Self Determination ◽  
Education Environment ◽  
Cognitive Autonomy ◽  
Positive Correlations ◽  
Almost All ◽  
Relationship Of ◽  
Real Self ◽  
The Relationship

Objectives. Studying the relationship of autonomy and attachment in relationships with parents with real self-determination in students. Background. The growing world globalization, intercultural contradictions, confrontation within society seriously complicate the path of self-determination of modern youth. At the same time, due to technical progress and digitalization of the communication and education environment, there are significant transformations in the interaction of people in almost all spheres, including in the family. Therefore, the question of studying the most important aspects in the relationship of young people with their parents for real self-determination is especially acute. Study design. The work studied the indicators of real self-determination, attachment to parents and autonomy among students. The presence of a relationship between these parameters was established by calculating the Spearman correlation coefficient. Participants. 60 college students aged 18 to 21. Measurements. Methodology “Scale of adult attachment for close relationships”; autonomy questionnaire (authors O.A. Karabanova and N.N. Poskrebysheva); questionnaire “ORS” (author D.A. Krasilo). Results. An inverse relationship of indicators of real self-determination of students with the level of intimacy and the level of anxiety (scales of attachment to parents) was established. A direct relationship was revealed between the indicators of real self-determination and the level of autonomy. Conclusions. Proximity and anxiety (components of attachment) have a significant inverse relationship with the level of real self-determination in students. There are no significant connections between reliability (a component of attachment) and real self-determination in the sample under study. Emotional autonomy, cognitive autonomy, behavioral autonomy, and value autonomy have significant positive correlations with the level of real self-determination in students.

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