Migration of Extender Oil in Natural and Synthetic Rubber

1967 ◽  
Vol 40 (5) ◽  
pp. 1570-1584 ◽  
Author(s):  
James E. Lewis ◽  
Marvin L. Deviney
Keyword(s):  
Radioactive Isotopes ◽  
Sufficient Information ◽  
Oil Migration ◽  
Migration Rates ◽  
Carbon 14 ◽  
Modern Computer ◽  
Synthetic Rubber ◽  
Wide Range ◽  
Basic Differential Equation ◽  
Diffusion Rates

Abstract The migration of oil, and in particular, the migration of extender oils in rubber is being studied through the use of radioactive isotopes. Techniques have been developed for uniform carbon-14 labelling of the aromatic-polar fractions of extender oils by Friedel-Crafts reaction and for the uniform labelling of the paraffinic fraction by methylene diradicals generated during photolysis of diazomethane-C14. These techniques formed the basis for a comparative study of the diffusion rates of aromatic and polar, and paraffinic, fractions of a highly aromatic and a paraffinic extender oil in several rubbers which represent a wide range in type of polymeric structure. Faster diffusion rates of both aromatic and polar, and paraffinic fractions, were observed in polybutadiene and natural rubber than in SBR, EPT, and polychloroprene. In most rubbers, paraffinic materials migrated appreciably faster than aromatic and polar fractions. Experiments using Firestone flex blocks indicated that oil migration rates are higher under simulated working conditions than when the sample is subjected to heat treatment alone. Diffusion coefficients for the migrating fractions were calculated from an appropriate solution of the basic differential equation of diffusion using modern computer techniques. The methods which have been developed are suitable for fundamental studies to gain more insight into the mechanisms of diffusion. These experimental methods are also suitable for use in practical studies of oil migration under actual or simulated working and environmental conditions. Ultimately sufficient information should be obtained to permit an accurate prediction of the performance of an extender oil in selected rubbers on the basis of the physical properties of the oil and a quantitative knowledge of the major molecular types present in the oil.

Migration of Antioxidants and Accelerators in Natural and Synthetic Rubber II. Sulfenamide System Studies and Comparison of Age Resister Migration under Inert and Practical Conditions

1969 ◽  
Vol 42 (3) ◽  
pp. 892-902 ◽  
Author(s):  
James E. Lewis ◽  
Marvin L. Deviney ◽  
Lawrence E. Whittington
Keyword(s):  
Diffusion Coefficient ◽  
Carbon Black ◽  
Natural Rubber ◽  
Count Data ◽  
Diffusion Coefficients ◽  
Oil Migration ◽  
Carbon 14 ◽  
Synthetic Rubber ◽  
End Use ◽  
In Cis

Abstract Radiochemical techniques developed for studying extender oil migration in various elastomers have been adapted for use in investigating the migration of age resisters and curatives. This paper contains basic diffusion coefficient data for nine compounds including both staining and nonstaining antioxidants and members of the sulfenamide, thiazole and thiuram accelerator series. Techniques for synthesizing these age resisters and curatives in the carbon-14 and sulfur-35 labelled form are described. Migration was studied in natural rubber, SBR, cis-polybutadiene and EPT vulcanizates. Computer techniques were used to calculate diffusion coefficients from radiochemical count data. Results from preliminary migration studies under practical curing and end-use conditions are also presented. In the case of phenyl-2-naphthylamine migration in cis-polybutadiene, a pronounced decrease in diffusivity with increasing surface area of the carbon black filler was observed.

The Migration of Extender Oil in Natural and Synthetic Rubber. V. Dependence of Diffusion Rates on Oil Concentration and Elastomer Blend Ratios. The Locus of Oil in a Simulated Tire during Service

1971 ◽  
Vol 44 (1) ◽  
pp. 87-105 ◽  
Author(s):  
M. L. Deviney ◽  
L. E. Whittington ◽  
B. G. Corman
Keyword(s):  
Weighted Average ◽  
Fold Increase ◽  
Polymer Composition ◽  
Carbon 14 ◽  
Synthetic Rubber ◽  
Oil Concentration ◽  
Diffusion Rates ◽  
Blend Ratios ◽  
Rubber Product ◽  
Diene Rubber

Abstract Using carbon-14 labelled aromatic extender oil as a penetrant species, diffusion rates were measured in practical elastomeric compounds of high oil concentration, and in elastomer compounds based on blended polymers. These results, combined with earlier data, allow the calculation of the locus of oil during the service life of the rubber product. Increasing the concentration of oil increases the rate of diffusion of oil. Butyl rubber was the most sensitive to this effect, albeit the slowest in rate of migration, with a 2-fold increase in migration rate over the range of oil concentration of 2–27%, followed by polybutadiene, 1.53; natural rubber, 1.27; and ethylene-propylene-diene rubber, 1.26, and SBR, 1.00. Polymer blends display no synergism in their effect on diffusion; the diffusivity of oil in the blends was predicted exactly by the weighted average of polymer composition. Further studies of the effect of dynamic flexing indicated that, at constant temperature, static and dynamic conditions gave equal diffusivities. Calculations were made of the locus of the oil in a simulated tire section at 3000, 6000, 9000, and 24,000 miles. These agree very closely with experi mental results on a vulcanized, aged simulated tire segment.

scholarly journals A survey of methods for evaluating mini-publics

2021 ◽  
Author(s):  
Takeuchi Ayano
Keyword(s):  
Decision Making ◽  
Academic Research ◽  
Future Research ◽  
The Political ◽  
Decision Making Process ◽  
Sufficient Information ◽  
Practical Case ◽  
Political Decision ◽  
Wide Range ◽  
Political Decision Making

AbstractPublic participation has become increasingly necessary to connect a wide range of knowledge and various values to agenda setting, decision-making and policymaking. In this context, deliberative democratic concepts, especially “mini-publics,” are gaining attention. Generally, mini-publics are conducted with randomly selected lay citizens who provide sufficient information to deliberate on issues and form final recommendations. Evaluations are conducted by practitioner researchers and independent researchers, but the results are not standardized. In this study, a systematic review of existing research regarding practices and outcomes of mini-publics was conducted. To analyze 29 papers, the evaluation methodologies were divided into 4 categories of a matrix between the evaluator and evaluated data. The evaluated cases mainly focused on the following two points: (1) how to maintain deliberation quality, and (2) the feasibility of mini-publics. To create a new path to the political decision-making process through mini-publics, it must be demonstrated that mini-publics can contribute to the decision-making process and good-quality deliberations are of concern to policy-makers and experts. Mini-publics are feasible if they can contribute to the political decision-making process and practitioners can evaluate and understand the advantages of mini-publics for each case. For future research, it is important to combine practical case studies and academic research, because few studies have been evaluated by independent researchers.

scholarly journals In-Situ Cosmogenic 14C: Production and Examples of its Unique Applications in Studies of Terrestrial and Extraterrestrial Processes

Radiocarbon ◽  
2001 ◽  
Vol 43 (2B) ◽  
pp. 731-742 ◽  
Author(s):  
D Lal ◽  
A J T Jull
Keyword(s):  
Half Life ◽  
Earth Science ◽  
Chemical Properties ◽  
Radioactive Isotopes ◽  
Earth’S Atmosphere ◽  
The Earth ◽  
Wide Range ◽  
History Of ◽  
Earth's Atmosphere

Nuclear interactions of cosmic rays produce a number of stable and radioactive isotopes on the earth (Lai and Peters 1967). Two of these, 14C and 10Be, find applications as tracers in a wide variety of earth science problems by virtue of their special combination of attributes: 1) their source functions, 2) their half-lives, and 3) their chemical properties. The radioisotope, 14C (half-life = 5730 yr) produced in the earth's atmosphere was the first to be discovered (Anderson et al. 1947; Libby 1952). The next longer-lived isotope, also produced in the earth's atmosphere, 10Be (half-life = 1.5 myr) was discovered independently by two groups within a decade (Arnold 1956; Goel et al. 1957; Lal 1991a). Both the isotopes are produced efficiently in the earth's atmosphere, and also in solids on the earth's surface. Independently and jointly they serve as useful tracers for characterizing the evolutionary history of a wide range of materials and artifacts. Here, we specifically focus on the production of 14C in terrestrial solids, designated as in-situ-produced 14C (to differentiate it from atmospheric 14C, initially produced in the atmosphere). We also illustrate the application to several earth science problems. This is a relatively new area of investigations, using 14C as a tracer, which was made possible by the development of accelerator mass spectrometry (AMS). The availability of the in-situ 14C variety has enormously enhanced the overall scope of 14C as a tracer (singly or together with in-situ-produced 10Be), which eminently qualifies it as a unique tracer for studying earth sciences.

Epigenetics and Applied Anthropology

2021 ◽  
Author(s):  
Charles H. Klein
Keyword(s):  
Social Inequalities ◽  
Homo Sapiens ◽  
Single Gene ◽  
Molecular Genetic ◽  
Healthcare Providers ◽  
Basic Research ◽  
Sufficient Information ◽  
Theoretical Frameworks ◽  
Noncoding Dna ◽  
Wide Range

Since Francis Crick and James D. Watson’s discovery of DNA in 1953, researchers, policymakers, and the general public have sought to understand the ways in which genetics shapes human lives. A milestone in these efforts was the completion of the Human Genome Project’s (HGP) sequencing of Homo sapiens’ nearly three million base pairs in 2003. Yet, despite the excitement surrounding the HGP and the discovery of the structural genetic underpinnings of several debilitating diseases, the vast majority of human health outcomes have not been linked to a single gene. Moreover, even when genes have been associated with particular diseases (e.g., breast and colon cancer), it is not well understood why certain genetically predisposed individuals become ill and others do not. Nor has the HGP’s map provided sufficient information to understand the actual functioning of the human genetic code, including the role of noncoding DNA (“junk DNA”) in regulating molecular genetic processes. In response, a growing number of scientists have shifted their attention from structural genetics to epigenetics, the study of how genes express themselves in particular situations and environments. Anthropologists play roles in these applications of epigenetics to real-world settings. Their new theoretical frameworks unsettle the nature-versus-nurture binary and support biocultural anthropological research demonstrating how race becomes biology and embodies social inequalities and health disparities across generations. Ethnographically grounded case studies further highlight the diverse epigenetic logics held by healthcare providers, researchers, and patient communities and how these translations of scientific knowledge shape medical practice and basic research. The growing field of environmental epigenetics also offers a wide range of options for students and practitioners interested in applying the anthropological toolkit in epigenetics-related work.

Chlorophyll-a Concentration Assessment Using Remotely Sensed Data over Multiple Years along the Coasts of the United Arab Emirates

2020 ◽  
pp. 345
Author(s):  
Eihab M. Fathelrahman ◽  
Khalid A. Hussein ◽  
Safwan Paramban ◽  
Timothy R. Green ◽  
Bruce C. Vandenberg
Keyword(s):  
Chlorophyll A ◽  
United Arab Emirates ◽  
Algal Blooms ◽  
Water Desalination ◽  
Least Square ◽  
Sufficient Information ◽  
Chlorophyll A Concentration ◽  
Explanatory Variables ◽  
Wide Range ◽  
Best Fit

The United Arab Emirates (UAE) recently witnessed algal/phytoplankton blooms attributed to the high concentrations of Chlorophyll-a associated with the spread and accumulation of a wide range of organisms with toxic effects that influence ecological and fishing economic activities and water desalination along coastal areas.  This research explores the UAE coasts as a case study for the framework presented here. In this research, we argue that advances in satellite remote sensing and imaging of spatial and temporal data offer sufficient information to find the best-fit regression method and relationship between Chlorophyll-a concentration and a set of climatic and biological explanatory variables over time. Three functional forms of regression models were tested and analysed to reveal that the Log-Linear Model found to be the best fit providing the most statistically robust model compared to the Linear and the Generalised Least Square models.  Besides, it is useful to identify the factors Sea Surface temperature, Calcite Concentration, Instantaneous Photosynthetically Available Radiation, Normalized Fluorescence Line Height, and Wind Speed that significantly influence Chlorophyll-a concentration. Research results can be beneficial to aid decision-makers in building a best-fit statistical system and models of algal blooms in the study area. The study found results to be sensitive to the study’s temporal time-period length and the explanatory variables selected for the analysis.

An Integrated Approach to Design Mechatronic Systems: Cross-Disciplinary Constraint Modeling

2008 ◽  
Author(s):  
Kenway Chen ◽  
Jitesh Panchal ◽  
Dirk Schaefer
Keyword(s):  
Integrated Design ◽  
Integrated Approach ◽  
Sufficient Information ◽  
Robot Arm ◽  
Mechatronic Systems ◽  
Wide Range ◽  
Constraint Modeling ◽  
Automated Feedback ◽  
To Receive

Mechatronic systems encompass a wide range of disciplines and hence are collaborative in nature. Currently the collaborative development of mechatronic systems is inefficient and error-prone because contemporary design environments do not allow sufficient information flow of design and manufacturing data across the electrical and mechanical domains. Mechatronic systems need to be designed in an integrated fashion allowing designers from both electrical and mechanical engineering domains to receive automated feedback regarding design modifications throughout the design process. Integrated design of mechatronic products can be realized through the integration of mechanical and electrical CAD systems. One approach to achieve this type of integration is through the propagation of constraints. Cross-disciplinary constraints between mechanical and electrical design domains can be classified, represented, modeled, and bi-directionally propagated in order to provide automated feedback to designers of both engineering domains. In this paper, the authors focus on constraint classification and constraint modeling and provide a case study example using a robot arm. The constraint modeling approach presented in this paper represents a blueprint for the actual implementation.

scholarly journals Using <sup>226</sup>Ra and <sup>228</sup>Ra isotopes to distinguish water mass distribution in the Canadian Arctic Archipelago

2020 ◽  
Author(s):  
Chantal Mears ◽  
Helmuth Thomas ◽  
Paul B. Henderson ◽  
Matthew A. Charette ◽  
Hugh MacIntyre ◽  
...  
Keyword(s):  
Water Exchange ◽  
Water Mass ◽  
Dissolved Inorganic Carbon ◽  
Canadian Arctic ◽  
Atlantic Water ◽  
Radioactive Isotopes ◽  
Total Alkalinity ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
Wide Range

Abstract. As a shelf dominated basin, the Arctic Ocean and its biogeochemistry are heavily influenced by continental and riverine sources. Radium isotopes (226Ra, 228Ra, 224Ra, 223Ra), are transferred from the sediments to seawater, making them ideal tracers of sediment-water exchange processes and ocean mixing. 226Ra and 228Ra are the two longer-lived isotopes of the Radium Quartet (226Ra, t1/2 = 1600 y and 228Ra, t1/2 = 5.8 y). Because of their long half-lives they can provide insight into the water mass compositions, distribution patterns, as well as mixing processes and the associated timescales throughout the Canadian Arctic Archipelago (CAA). The wide range of 226Ra, 228Ra, and of the 228Ra / 226Ra ratio, measured in water samples collected during the 2015 GEOTRACES cruise, complemented by additional chemical tracers (dissolved inorganic carbon (DIC), total alkalinity (AT), barium (Ba), and the stable oxygen isotope composition of water (δ18O)) highlight the dominant biogeochemical, hydrographic and bathymetric features of the CAA. Bathymetric features, such as the continental shelf and shallow coastal sills, are critical in modulating circulation patterns within the CAA, including the bulk flow of Pacific waters and the inhibited eastward flow of denser Atlantic waters through the CAA. Using a Principal Component Analysis, we unravel the dominant mechanisms and the apparent water mass end-members that shape the tracer distributions. We identify two distinct water masses located above and below the upper halocline layer throughout the CAA, as well as distinctly differentiate surface waters in the eastern and western CAA. Furthermore, we identify water exchange across 80° W, inferring a draw of Atlantic water, originating from Baffin Bay, into the CAA. In other words, this implies the presence of an Atlantic water U-turn located at Barrow Strait, where the same water mass is seen along the northernmost edge at 80° W as well as along south-easternmost confines of Lancaster Sound. Overall, this study provides a stepping stone for future research initiatives within the Canadian Arctic Archipelago, revealing how quantifying disparities in radioactive isotopes can provide valuable information on the potential effects of climate change within vulnerable areas such as the CAA.

scholarly journals Creation of musical pieces At GUITAR PRO 6 (Part 2)

2021 ◽  
pp. 88-96
Author(s):  
Valery Kozlin ◽  
Valentina Grishenko
Keyword(s):  
Computer Program ◽  
Systematic Approach ◽  
Musical Notation ◽  
Modern Computer ◽  
Innovative Methods ◽  
Wide Range ◽  
Musical Scores ◽  
Software Product ◽  
Sound Engineer ◽  
First Time

The purpose of the article is to find out the specifics and methods of creating music in the sequencer GUITAR PRO 6. Methodology. The article uses a systematic approach, and also applies methods of comparison and generalization. Scientific novelty. For the first time in domestic musicology, innovative methods of working in the modern computer program sequencer GUITAR PRO 6 were discovered and proposed. The application of the methods and rules presented in the study provides the opportunity to transfer the work of a composer, arranger, sound engineer, musician, with a computer to a completely new stage in the development of musical creativity, which significantly improves the result of the study of musical texture, expanding the ways of existence of the work and the like. Conclusions. This software product is a powerful editor that allows you to create original scores at a professional level for subsequent editing. The program presents many useful tools with which the user can work with a different set of symbols of musical notation, as well as with a wide range of regulation of sound dynamics and tempo, which allows you to create samples of musical scores that sound and their phonograms. It has a powerful built-in MIDI editor, chord builder, player, metronome, and many other useful instruments for musicians. Ability to run Guitar Pro 6 on Windows, Linux, Mac OS platforms. Widely used by composers, arrangers, and sound engineers. Also, the methods of work in Guitar Pro 6 can be used for study by students who master the relevant specialties.

scholarly journals DEVELOPMENT OF A METHOD FOR DETERMINING THE MAXIMUM ACHIEVABLE GAIN (TRANSMISSION) KmS

2020 ◽  
pp. 25-31
Author(s):  
Andriy Vydmysh ◽  
Oleksandr Voznyak ◽  
Mykhailo Zamrii
Keyword(s):  
Short Circuit ◽  
Microwave Range ◽  
Clock Frequency ◽  
Standard Equipment ◽  
Modern Computer ◽  
Urgent Task ◽  
Wide Range ◽  
S Parameters ◽  
Accuracy Of Measurement ◽  
Ultrahigh Frequencies

Increasing the level of semiconductor devices, improving their characteristics significantly affects the potential stability in a wide range of frequencies. Classical methods and standard measuring equipment are not designed to measure the parameters of potentially unstable transistors. Measuring systems are excited uncontrollably, which increases the measurement error. Therefore, today there is an urgent task of measuring the parameters of both transistors in particular and quadrupoles in general, in the frequency range of potential instability. The clock frequency at which modern computer equipment works is close to the microwave range (ultrahigh frequencies), which makes the problem of measuring and calculating the various functional units of the computer quite relevant. The development of new methods and means of measuring the parameters of potentially unstable quadrupoles in the microwave range is an important scientific field that can significantly improve the accuracy of their measurement on standard equipment. The conducted researches and the developed technique allow to increase accuracy of measurement of parameters of four-poles and to provide stability of experimental installation at measurement of parameters of any four-pole. The proposed methods are more efficient and solve the problem of measuring the S-parameters of potentially unstable quadrupoles in the microwave range. The parameters of the quadrupole have the dimensions of the elements of standard W-parameters, their measurements are performed in the microwave range with an error of less than 5%, and to a lesser extent depends on the coefficient of stability of the measuring path than when measuring S-parameters. When measuring the parameters of the quadrupole, there is no need to use the modes of short circuit and XX or make measurements with a coordinated measuring path, which allows to increase the measurement accuracy and ensure stability when measuring potentially unstable quadrupoles with Ks> 0.

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