Some Possible Alternatives for Longer-Life Locomotive Wheels

2002 ◽  
Author(s):  
Cameron Lonsdale ◽  
Daniel Stone
Keyword(s):  
Service Life ◽  
Service Time ◽  
Wheel Rim ◽  
Repair Costs ◽  
Martensitic Microstructure ◽  
Wear Life ◽  
Wide Range ◽  
Alternative Materials ◽  
Points Of View ◽  
Locomotive Wheels

An increase in the wear life of locomotive wheels is considered desirable from the locomotive builder and railroad user points of view. If a wheel has a longer service life, economics are improved due to less locomotive out-of-service time, reduced maintenance repair costs and reduced wheel renewal costs. This paper discusses possible alternative materials and microstructures that could be used for longer-life locomotive wheels, and also tires. If locomotive builders and users consider wheel rim hoop compression essential, then microalloying and increased carbon content are perhaps the most likely courses of action to improve wheel life. If rim hoop compression is not considered essential, a wide range of alternatives become possible including bainitic and martensitic microstructure monobloc wheels and tires.

Interfaces in Structural Ceramics

MRS Bulletin ◽  
1990 ◽  
Vol 15 (10) ◽  
pp. 51-59 ◽  
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Structural Ceramics ◽  
Interface Engineering ◽  
Micro Structure ◽  
Complete Understanding ◽  
Intimate Contact ◽  
Transmission Electron ◽  
Processed Material ◽  
Wide Range ◽  
Alternative Materials ◽  
The Relationship

Structural ceramics are necessarily polycrystalline and their usefulness is largely determined by the interfaces between the grains. The relationship between the structure and chemistry of different interfaces and the micro-structure can be illustrated by reviewing studies of interfaces in a wide range of materials including such classical ceramics as Al2O3, the current “hightech” polyphase ceramics exemplified by ZrO2-toughened Al2O3, and the composite materials of the future. Using transmission electron microscopy is essential for a complete understanding, but limitations to its use must be recognized. Only by understanding the factors that control the behavior of these interfaces will it become possible to further extend the application of interface engineering.Structural ceramics are a group of materials that can be used for applications requiring their strength to persist at high temperatures or in conditions that would be particularly corrosive to alternative materials, which are usually metallic. Strength and strength-related properties such as toughness depend largely on the microstructural features of the processed material.The microstructure is defined by the morphology and size of the grains and the interfaces between these grains. If the grains are in intimate contact, then the interface is a grain boundary of the type familiar from studies of metals.

Estimation of Service Life of Mechanical Engineering Components

2019 ◽  
Vol 799 ◽  
pp. 71-76
Author(s):  
Oskars Linins ◽  
Ernests Jansons ◽  
Armands Leitans ◽  
Irina Boiko ◽  
Janis Lungevics
Keyword(s):  
Service Life ◽  
Service Time ◽  
Surface Texture ◽  
Mechanical Engineering ◽  
Friction Pair ◽  
Theory Of Elasticity ◽  
New Approach ◽  
Material Fatigue ◽  
Texture Parameters ◽  
3D Surface Texture

The paper is aimed to the methodology for estimation of service life of mechanical engineering components in the case of elastic-plastic contact of surfaces. Well-known calculation methods depending on physics, theory of probability, the analysis of friction pair’ shape and fit include a number of parameters that are difficult or even impossible to be technologically controlled in the manufacturing of mechanical engineering components. The new approach for wear rate estimation using surface texture parameters as well as physical-mechanical properties and geometric parameters of components is proposed. The theoretical part of the calculations is based on the 3D surface texture principles, the basics of material fatigue theory, the theory of elasticity and the contact mechanics of surfaces. It is possible to calculate the service time of the machine, but the process of running-in of the components is relatively short (less than 5%), therefore, the service time is mainly determined by a normal operating period, which also was used to evaluate this period. The calculated input parameters are technologically and metrologically available and new method for calculating the service time can be used in the design process of the equipment. The results of approbation of the method for estimation service time of mechanical engineering, which prove the applicability of mentioned method, are offered as well.

Effect of Alternative Materials Added to the Plaster Composition

2014 ◽  
Vol 92 ◽  
pp. 127-132
Author(s):  
Nurcan Seyhan ◽  
Aslı Tayçu ◽  
Mehmet Gula ◽  
Arzu Eker ◽  
Kagan Kayaci ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Service Life ◽  
Scanning Electron Microscope ◽  
Water Absorption ◽  
Bending Strength ◽  
Setting Time ◽  
Glass Beads ◽  
Noticeable Effect ◽  
Alternative Materials ◽  
Scanning Electron

In this study, the effect of alternative additives on the properties spred diameter, setting time, bending strength and water absorption of sanitaryware plaster moulds was investigated. The plaster was partially replaced by the alternative additives such as perlite, diatomite and glass beads. Microstructural features of the resultant compositions were determined by scanning electron microscope (SEM). Finally, represantative moulds were produced and their performance was investigated under industrial conditions. It was observed that perlite and diatomite addition deteriorated the strength of plaster moulds and there was no noticeable effect of these additives on casting performance of the plaster moulds. Morever, the presence of glass beads in plaster decreased weight of the moulds without deterioration of moulds service life.

Modern Downsizing

2021 ◽  
pp. 1970-1983
Author(s):  
Grzegorz Wojtkowiak
Keyword(s):  
Financial Analysis ◽  
Management Tool ◽  
Future Research ◽  
Research Directions ◽  
Good Practices ◽  
Strategic Option ◽  
Wide Range ◽  
Future Research Directions ◽  
Points Of View

The aim of the chapter is to present the concept of downsizing from different points of view: as a strategic option, as a management tool and as a phenomenon. It describes the evolution of the term, its definitions, and different directions of development. A scale and possible outcomes are described on the basis of financial analysis; however it also discusses the role of non-financial aspects. The chapter points out reasons, aims and a wide range of tools that may be used during implementation of downsizing. One of the conclusions of the chapter is to present future research directions aiming at increasing knowledge of managers and providing them with detailed good practices.

scholarly journals A Comprehensive Review on Corn Starch-Based Nanomaterials: Properties, Simulations, and Applications

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2161
Author(s):  
Chella Perumal Palanisamy ◽  
Bo Cui ◽  
Hongxia Zhang ◽  
Selvaraj Jayaraman ◽  
Gothandam Kodiveri Muthukaliannan
Keyword(s):  
Zea Mays ◽  
Food Industry ◽  
Zea Mays L ◽  
Corn Starch ◽  
Food Crops ◽  
Natural Polymer ◽  
Comprehensive Review ◽  
Commercial Scale ◽  
Wide Range ◽  
Alternative Materials

Corn (Zea mays L.) is one of the major food crops, and it is considered to be a very distinctive plant, since it is able to produce a large amount of the natural polymer of starch through its capacity to utilize large amounts of sunlight. Corn starch is used in a wide range of products and applications. In recent years, the use of nanotechnology for applications in the food industry has become more apparent; it has been used for protecting against biological and chemical deterioration, increasing bioavailability, and enhancing physical properties, among other functions. However, the high cost of nanotechnology can make it difficult for its application on a commercial scale. As a biodegradable natural polymer, corn starch is a great alternative for the production of nanomaterials. Therefore, the search for alternative materials to be used in nanotechnology has been studied. This review has discussed in detail the properties, simulations, and wide range of applications of corn starch-based nanomaterials.

Plastic bans will rise but recycling faces constraints

2018 ◽  
Keyword(s):  
Consumer Preferences ◽  
Content Type ◽  
Demand Growth ◽  
Wide Range ◽  
Alternative Materials ◽  
Substitute Materials ◽  
Plastic Products

Subject Plastics sector dynamics. Significance Rising concern about plastics pollution is leading to tighter regulation. This is affecting a wide range of industries. Impacts Some plastic products will vanish, others will see less usage as producers will substitute materials and consumer preferences will change. Plastics demand, and demand growth for oil from petrochemicals, will slow, but not sharply unless legislation tightens more than planned. Markets for alternative materials including paper and glass are likely to be boosted.

Carbonation of Surface Protected Concrete with Silicone Material

2014 ◽  
Vol 584-586 ◽  
pp. 883-886
Author(s):  
Hong Song Wang ◽  
Wei Wang ◽  
Rui Wang ◽  
Wen Bin Wang ◽  
Lei Li ◽  
...  
Keyword(s):  
Service Life ◽  
Surface Treatment ◽  
Steel Reinforcement ◽  
Rapid Decay ◽  
Carbonation Depth ◽  
Surface Protection ◽  
Maintenance And Repair ◽  
Repair Costs ◽  
Harmful Substances ◽  
Concrete Service

Concrete structures are exposed to carbonation that may cause rapid decay, shortening their service life and raising maintenance and repair costs. Carbonation lowers the alkalinity of the concrete depassivating the steel reinforcement. The prescriptive methodology is not a guarantee to obtain the desired service lives of 50 or 100 years. Surface treatment is commonly used to improve the resistance of concrete to carbonation. Using the silicone materials to an immersion treatment can effectively block the invasion of harmful substances,the carbonation of concretes with surface protection with silicone materials was evaluated. The results showed silicone can lower carbonation depth than the non-protected concretes. The carbonation depth will not increase significantly in the latter part of the concrete service.

scholarly journals INCREASED VIBRATION ON REFRIGERATOR SHIPS OF B437/11 PROJECT AND TECHNICAL PROPOSALS ON ITS REDUCTION

2018 ◽  
pp. 58-69
Author(s):  
Minas Armenakovich Minasyan ◽  
Aung Myo Thant ◽  
Armen Minasovich Minasyan
Keyword(s):  
Service Life ◽  
Vibration Isolation ◽  
Steel Wire ◽  
Modern Technology ◽  
Wire Rope ◽  
Diesel Generator ◽  
Vibration Isolators ◽  
Wide Range ◽  
Isolation Systems ◽  
The Impact

The paper considers the causes of increased vibration of four auxiliary diesel-generator sets of "Sulzer" 5АL25 type on board nine refrigerated vessels of B437 / 11 project after 15 years of operation. The proposed wide range of possible applications to address the problem of high vibration of diesel generators and motor vessels there were generally implemented upgraded turbocharger brackets, engine sub-frame and supporting spiral-rope vibration isolators in the shock absorption system of the diesel-generator. Four original patented technical solutions have been presented, among which one solution is implemented in 5AL25 diesel generator and 2H 8.5/11 diesel damping systems. There has been offered wide application both wire rope vibration isolators and combined isolators, in which elastic elements are made of nonflammable materials. Wire rope vibration isolators combine high bearing capacity (static loads within 1 N - 50 kN) with high elasticity under dynamic effects; their natural frequencies can drop to 2.5 Hz. Under the worst conditions 75% of the free moving weakens the impact to values that ensure the necessary safety of the object. Experience in designing vibration isolation systems allows to set the maximum range of loads within 15 - 25 g. The vibration isolators made of steel wire rope are practically not affected by the environment, they are made of stainless steel. They effectively operate at temperatures -200°C - +370°C in the presence of oil, dirt, sand, salt fog, etc. They usually have a service life comparable with the service life of the insulated object. Wire rope vibration isolators and combined vibration isolators can be used in all fields of modern technology: shipbuilding, power engineering, automotive, aviation and space industries, etc.

scholarly journals DELAY MODELS BASED ON SYSTEMS WITH USUAL AND SHIFTED HYPEREXPONENTIAL AND HYPERERLANGIAN INPUT DISTRIBUTIONS

2021 ◽  
pp. 56-64
Author(s):  
V. N. Tarasov ◽  
N. F. Bakhareva
Keyword(s):  
Integral Equation ◽  
Closed Form ◽  
Waiting Time ◽  
Service Time ◽  
Spectral Decomposition ◽  
Flow Distribution ◽  
Input Flow ◽  
Average Delay ◽  
Spectral Expansions ◽  
Wide Range

Context. In the queueing theory, the study of systems with arbitrary laws of the input flow distribution and service time is relevant because it is impossible to obtain solutions for the waiting time in the final form for the general case. Therefore, the study of such systems for particular cases of input distributions is important. Objective. Getting a solution for the average delay in the queue in a closed form for queuing systems with ordinary and with shifted to the right from the zero point hyperexponential and hypererlangian distributions in stationary mode. Method. To solve this problem, we used the classical method of spectral decomposition of the solution of the Lindley integral equation. This method allows to obtaining a solution for the average delay for two systems under consideration in a closed form. The method of spectral decomposition of the solution of the Lindley integral equation plays an important role in the theory of systems G/G/1. For the practical application of the results obtained, the well-known method of moments of probability theory is used. Results. For the first time, a spectral decomposition of the solution of the Lindley integral equation for systems with ordinary and with shifted hyperexponential and hyperelangian distributions is obtained, which is used to derive a formula for the average delay in a queue in closed form. Conclusions. It is proved that the spectral expansions of the solution of the Lindley integral equation for the systems under consideration coincide; therefore, the formulas for the mean delay will also coincide. It is shown that in systems with a delay, the average delay is less than in conventional systems. The obtained expression for the waiting time expands and complements the wellknown incomplete formula of queuing theory for the average delay for systems with arbitrary laws of the input flow distribution and service time. This approach allows us to calculate the average delay for these systems in mathematical packages for a wide range of traffic parameters. In addition to the average waiting time, such an approach makes it possible to determine also moments of higher orders of waiting time. Given the fact that the packet delay variation (jitter) in telecommunications is defined as the spread of the waiting time from its average value, the jitter can be determined through the variance of the waiting time.

Sign in / Sign up

Export Citation Format

Share Document