Rotary Power Loss Machine

1959 ◽  
Vol 32 (3) ◽  
pp. 915-939
Author(s):  
D. Bulgin ◽  
G. D. Hubbard
Keyword(s):  
Energy Loss ◽  
Rolling Resistance ◽  
Polymeric Materials ◽  
Complete Information ◽  
High Energy ◽  
Practical Significance ◽  
Sufficient Information ◽  
Fixed Temperature ◽  
Wide Range ◽  
Materials Used

Abstract Rubberlike polymeric materials, particularly in the technical form when compounded with carbon black, are imperfectly elastic and the associated energy loss is of considerable practical significance. In some applications a high energy loss is of value to provide high damping, but in many cases and particularly in tires, the temperature rise due to the losses may be a limiting operational factor. The losses cause the tire to exhibit rolling resistance which, in the case of solid tires, can be related accurately to the modulus and resilience of the rubber. An analysis of this system has been carried out by Evans, while Tabor has considered the case of rigid cylinders and spheres rolling on flexible rubber surfaces. In the case of pneumatic tires the composite nature of the construction of fabric and rubber and the complex system of strain distribution make the calculation of rolling resistance from polymer properties extremely complicated. In order to approach this problem it is necessary to know the modulus and resilience of the materials used over a very wide range of temperature and a range of amplitude of deformation and of frequency. The required temperature range may be from −60° C to above 200° C, but the frequency range over which appreciable amplitudes are involved does not extend beyond approximately a thousand cycles per second while the amplitude of deformation does not exceed 50 per cent. In order to investigate adequately the many possible combinations of polymers and compounding systems, the values of resilience and modulus are required over the above range of conditions, and various instruments have been described which measure some or all of these properties. The rebound pendulum was one of the earliest instruments and is widely used for the measurement of resilience because of its inherent simplicity of operation and high accuracy, but as normally operated at a fixed temperature does not provide sufficient information for evaluation of materials for use in tires. This type of instrument also is not well suited for determination of modulus owing to its single cycle method of operation. The vibrator type instruments give more complete information but normally demand a high degree of skill in their operation and in the interpretation of results and are more suited to research than routine work.

Polymer Surface Modification

1992 ◽  
Vol 65 (3) ◽  
pp. 687-696 ◽  
Author(s):  
Walter H. Waddell ◽  
Larry R. Evans ◽  
James G. Gillick ◽  
Derek Shuttleworth
Keyword(s):  
Surface Modification ◽  
Scientific Literature ◽  
Ion Beam ◽  
Polymer Surface ◽  
Polymeric Materials ◽  
High Energy ◽  
Polymer Materials ◽  
Diverse Range ◽  
Rubber Industry ◽  
Wide Range

Abstract Surface modification as a technology has been employed in various ways for many years, however, the breadth and magnitude of its applications have grown significantly during the last decade. Much of this growth has been facilitated by the development and spread of rapid and reliable surface characterization techniques. And, as would be expected of a maturing field, the bulk of investigations are now turning to applications rather than a pure understanding. Publications in both the scientific literature and patents describe research on a diverse range of polymeric substrates and potential applications using a wide range of modification techniques. Methods include chemical, photochemical, and high-energy physical techniques to modify polymer surfaces. Searches were made of these methods as applied to the surface modification of polymeric materials of particular interest to the rubber industry. Chemical methods include reactions such as halogenation, addition, etching, and oxidation. Photochemical techniques include surface reactions such as oxidative and nonoxidative degradation, halogenation, and photografting. Physical methods include corona discharge, plasma, electron and ion beam treatments. The 1980's literature on these subjects is published in a variety of languages, including a number of informative review articles and books printed in English on various aspects of this subject. The subject of this review concentrates on the surface modification of polymeric materials of particular interest to the rubber industry by focussing largely on scientific literature published in English and patent literature published during this time period that describe interesting and useful surface chemistry on elastomer substrates and rubber articles containing polymers such as natural rubber, cis-polyisoprene, styrene-butadiene copolymer, nitrile rubber, silicone, etc, and fibers and fabric made from fiber-forming polymer materials such as aramid, nylon, polyester, and carbon fiber, and those techniques reported successful in altering their surfaces. For organizational simplicity, three basic categories are used: elastomers, fibers and others. The latter category refers to those substrates without specific, current application in the rubber industry, but which have interesting or novel scientific features. Restriction of interest to rubber-relevant materials greatly reduced the scope of this work, and the interested reader should be aware that a great deal of activity is to be found in the rigid plastic and, to a lesser extent, biopolymer industries.

scholarly journals Science-Based Strategies of Antiviral Coatings with Viricidal Properties for the COVID-19 Like Pandemics

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4041
Author(s):  
Rakesh Pemmada ◽  
Xiaoxian Zhu ◽  
Madhusmita Dash ◽  
Yubin Zhou ◽  
Seeram Ramakrishna ◽  
...  
Keyword(s):  
Antiviral Agents ◽  
Polymeric Materials ◽  
Protective Equipment ◽  
Risk Of Infection ◽  
Functional Nanomaterials ◽  
Enveloped Viruses ◽  
Action Mode ◽  
Wide Range ◽  
Materials Used ◽  
Antiviral Mechanism

The worldwide, extraordinary outbreak of coronavirus pandemic (i.e., COVID-19) and other emerging viral expansions have drawn particular interest to the design and development of novel antiviral, and viricidal, agents, with a broad-spectrum of antiviral activity. The current indispensable challenge lies in the development of universal virus repudiation systems that are reusable, and capable of inactivating pathogens, thus reducing risk of infection and transmission. In this review, science-based methods, mechanisms, and procedures, which are implemented in obtaining resultant antiviral coated substrates, used in the destruction of the strains of the different viruses, are reviewed. The constituent antiviral members are classified into a few broad groups, such as polymeric materials, metal ions/metal oxides, and functional nanomaterials, based on the type of materials used at the virus contamination sites. The action mode against enveloped viruses was depicted to vindicate the antiviral mechanism. We also disclose hypothesized strategies for development of a universal and reusable virus deactivation system against the emerging COVID-19. In the surge of the current, alarming scenario of SARS-CoV-2 infections, there is a great necessity for developing highly-innovative antiviral agents to work against the viruses. We hypothesize that some of the antiviral coatings discussed here could exert an inhibitive effect on COVID-19, indicated by the results that the coatings succeeded in obtaining against other enveloped viruses. Consequently, the coatings need to be tested and authenticated, to fabricate a wide range of coated antiviral products such as masks, gowns, surgical drapes, textiles, high-touch surfaces, and other personal protective equipment, aimed at extrication from the COVID-19 pandemic.

Nano-emulgel: Emerging as a Smarter Topical Lipidic Emulsion-based Nanocarrier for Skin Healthcare Applications

2019 ◽  
Vol 14 (1) ◽  
pp. 16-35 ◽  
Author(s):  
Kumar Anand ◽  
Subhabrata Ray ◽  
Mahfoozur Rahman ◽  
Adil Shaharyar ◽  
Rudranil Bhowmik ◽  
...  
Keyword(s):  
Health Care ◽  
Polymeric Materials ◽  
High Energy ◽  
Gelling Agent ◽  
Healthcare Applications ◽  
Topical Gel ◽  
Drug Molecules ◽  
Toxicological Studies ◽  
Materials Used ◽  
Approved Drugs

Background: In recent decades, enormous efforts for different drug discovery processes have led to a number of drug molecules available today to overcome different challenges of the health care system. Unfortunately, more than half of these drugs are listed in either BCS (biopharmaceutical classification system) class II/ IV or both are eliminated from the development pipeline due to their limited clinical use. A nanotechnological approach bears much hope and lipoidal fabrication is found to be suitable for the delivery of such drugs. Nanoemulsion based gel i.e. nanoemulgel out of different nanolipoidal formulations has been found to be a suitable approach to successful drug delivery through topical routes. In past few years many herbal and synthetic active pharmaceutical ingredients (APIs) has been patented as nano sized emulsified gel for various therapeutic activities. Methods: Nanoemulgel is basically an emulsion-based topical gel formulation, where nanosized emulsion globules can be prepared with the help of high energy or low energy methods and further converted into nanoemulgel by adding a suitable gelling agent. Nanoemulgel fabrication enlists various kinds of polymeric materials, surfactants and fatty substances of natural, synthetic and semi-synthetic nature with a globule size range from 5 to 500 nm. Results: Nanoemulgel can be applicable to various acute and chronic diseases through topical routes. Conclusion: Nanoemulgel preparations of many recently approved drugs are being used successfully in different areas of health care and have re-defined the significance of topical route of delivery as compared to other routes. However, along with various improvements in the current state of the delivery system, the safety factor needs to be taken into account by toxicological studies of the materials used in such formulations.

Insulation Materials for Wire and Cable Applications

2002 ◽  
Vol 75 (4) ◽  
pp. 701-712 ◽  
Author(s):  
J. L. Mead ◽  
Z. Tao ◽  
H. S. Liu
Keyword(s):  
Material Selection ◽  
Polymeric Materials ◽  
Dielectric Strength ◽  
Thermoplastic Elastomers ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Flame Resistance ◽  
Wide Range ◽  
Materials Used ◽  
Styrene Butadiene

Abstract A wide range of polymers has been used for wire and cable insulation. Older materials include natural, butyl, and styrene-butadiene rubber. Newer materials include crosslinked polyethylene, silicone rubber, ethylene-propylene elastomers, and thermoplastic elastomers. Properties of importance to electrical insulation ability include dielectric constant, resistivity, dielectric loss, and dielectric strength. Flame resistance is also important in certain applications. This paper reviews the different polymeric materials used in cable constructions and the important electrical properties for material selection.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Compact back-scattered electrons' energy analyzer for standard SEM

1994 ◽  
Vol 52 ◽  
pp. 488-489
Author(s):  
S. Likharev ◽  
A. Kramarenko ◽  
V. Vybornov
Keyword(s):  
Depth Resolution ◽  
High Energy ◽  
Primary Beam ◽  
Layer By Layer ◽  
Energy Analyzer ◽  
High Energy Part ◽  
Small Window ◽  
Energy Part ◽  
Wide Range ◽  
High Voltage Supply

At present time the interest is growing considerably for theoretical and experimental analysis of back-scattered electrons (BSE) energy spectra. It was discovered that a special angle and energy nitration of BSE flow could be used for increasing a spatial resolution of BSE mode, sample topography investigations and for layer-by layer visualizing of a depth structure. In the last case it was shown theoretically that in order to obtain suitable depth resolution it is necessary to select a part of BSE flow with the directions of velocities close to inverse to the primary beam and energies within a small window in the high-energy part of the whole spectrum.A wide range of such devices has been developed earlier, but all of them have considerable demerit: they can hardly be used with a standard SEM due to the necessity of sufficient SEM modifications like installation of large accessories in or out SEM chamber, mounting of specialized detector systems, input wires for high voltage supply, screening a primary beam from additional electromagnetic field, etc. In this report we present a new scheme of a compact BSE energy analyzer that is free of imperfections mentioned above.

Monte Carlo Modelling of Secondary Electron Yield from Rough Surfaces

1990 ◽  
Vol 48 (1) ◽  
pp. 422-423
Author(s):  
John C. Russ
Keyword(s):  
Monte Carlo ◽  
Energy Loss ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Analytical Calculation ◽  
Mean Free Path ◽  
Single Scattering ◽  
High Energy ◽  
Secondary Electron Yield ◽  
Electron Yield

Monte-Carlo programs are well recognized for their ability to model electron beam interactions with samples, and to incorporate boundary conditions such as compositional or surface variations which are difficult to handle analytically. This success has been especially powerful for modelling X-ray emission and the backscattering of high energy electrons. Secondary electron emission has proven to be somewhat more difficult, since the diffusion of the generated secondaries to the surface is strongly geometry dependent, and requires analytical calculations as well as material parameters. Modelling of secondary electron yield within a Monte-Carlo framework has been done using multiple scattering programs, but is not readily adapted to the moderately complex geometries associated with samples such as microelectronic devices, etc.This paper reports results using a different approach in which simplifying assumptions are made to permit direct and easy estimation of the secondary electron signal from samples of arbitrary complexity. The single-scattering program which performs the basic Monte-Carlo simulation (and is also used for backscattered electron and EBIC simulation) allows multiple regions to be defined within the sample, each with boundaries formed by a polygon of any number of sides. Each region may be given any elemental composition in atomic percent. In addition to the regions comprising the primary structure of the sample, a series of thin regions are defined along the surface(s) in which the total energy loss of the primary electrons is summed. This energy loss is assumed to be proportional to the generated secondary electron signal which would be emitted from the sample. The only adjustable variable is the thickness of the region, which plays the same role as the mean free path of the secondary electrons in an analytical calculation. This is treated as an empirical factor, similar in many respects to the λ and ε parameters in the Joy model.

Parameters Of Technological Processes Reengineering

2020 ◽  
pp. 28-33
Keyword(s):  
Spatial Organization ◽  
Parametric Model ◽  
Practical Significance ◽  
Machine Time ◽  
Time Machine ◽  
Technological Processes ◽  
Technical Capability ◽  
Materials Used ◽  
The Cost ◽  
Qualitative Characteristics

The article is devoted to reengineering of technological processes - a method of their qualitative transformation on an innovative basis, which in turn assumes the availability of tools that make it possible to establish the economic efficiency and technical capability of such transformations of construction production, to identify the effect of their implementation. In this regard, the problem of forming a parametric model of reengineering of construction technological processes, which involves four enlarged groups of indicators that reflect the quantitative and qualitative characteristics of the processes: materials used, working time, machine time, spatial organization, is considered. It is established that parameters can have either an absolute (physical, cost) or relative (point, percentage) expression and also make their own decomposition. The practical significance of the provisions given in the article is determined by the development of methods of technical rationing, which leads to a reduction in the cost and duration of construction.

Rolling Resistance Calculation Procedure Using the Finite Element Method

2019 ◽  
Vol 48 (3) ◽  
pp. 224-248
Author(s):  
Pablo N. Zitelli ◽  
Gabriel N. Curtosi ◽  
Jorge Kuster
Keyword(s):  
Finite Element ◽  
Energy Dissipation ◽  
Rolling Resistance ◽  
Element Model ◽  
The Finite Element Method ◽  
Temperature Changes ◽  
Rubber Compounds ◽  
Different Temperatures ◽  
Materials Used ◽  
Account Temperature

ABSTRACT Tire engineers are interested in predicting rolling resistance using tools such as numerical simulation and tests. When a car is driven along, its tires are subjected to repeated deformation, leading to energy dissipation as heat. Each point of a loaded tire is deformed as the tire completes a revolution. Most energy dissipation comes from the cyclic loading of the tire, which causes the rolling resistance in addition to the friction force in the contact patch between the tire and road. Rolling resistance mainly depends on the dissipation of viscoelastic energy of the rubber materials used to manufacture the tires. To obtain a good rolling resistance, the calculation method of the tire finite element model must take into account temperature changes. It is mandatory to calibrate all of the rubber compounds of the tire at different temperatures and strain frequencies. Linear viscoelasticity is used to model the materials properties and is found to be a suitable approach to tackle energy dissipation due to hysteresis for rolling resistance calculation.

Total Tire Energy Loss Comparison by the Whole Tire Hysteresis and the Rolling Resistance Methods

1995 ◽  
Vol 23 (4) ◽  
pp. 256-265 ◽  
Author(s):  
P. S. Pillai
Keyword(s):  
Energy Loss ◽  
Rolling Resistance ◽  
Hysteresis Loss ◽  
Basic Premise ◽  
Resistance Method

Abstract Energy loss per hour in a tire traveling at 80 km/h was obtained for a number of tires of different sizes and makes from the respective whole tire hysteresis loss of each tire. This loss value was then compared to the corresponding rolling loss obtained from the 1.7 m dynamometer rolling resistance method. The two methods agreed, indicating that the basic premise of the rolling resistance hysteresis ratio relation is valid.

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