Wear-Life Models for Angular Contact Spherical Plain Bearing under Different Load Types

2013 ◽  
Vol 344 ◽  
pp. 3-7
Author(s):  
Xiang Po Zhang ◽  
Jian Zhong Shang ◽  
Xun Chen ◽  
Chun Hua Zhang ◽  
Ya Shun Wang

To meet the demand of wear-life calculation of spherical plain bearing (SPB), the wear-life models for angular contact spherical plain bearing (ACSPB) under different types of load were created based on the joint wear calculation method (JWCM). By integrating the friction wear laws of materials, specific configuration & mating characteristics of the SPB, and function requirement, the new models were more theoretical and had a good applicability and pertinence compared to the empirical models used at present.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Volker Abetz ◽  
Torsten Brinkmann ◽  
Mustafa Sözbilir

Abstract The paper gives an introduction to membrane science and technology, an area of research of high significance for the development of a sustainable life for human beings. It is therefore intended to be a guide for teachers in the areas of chemistry, physics, or biology, who can incorporate the presented materials in their respective courses. The paper gives some insights into the different types of membranes, their functions, production and use in some selected areas.


2021 ◽  
Author(s):  
Fang Zhou ◽  
Chang Su ◽  
Shuqi Xu ◽  
Linyuan Lü

Abstract In real-world networks, there usually exist a small set of nodes that play an important role in the structure and function of networks. Those vital nodes can influence most other nodes in the network via a spreading process. While most of the existing works focused on vital nodes that can maximize the spreading size in the final stage, which we call final influencers, recent work proposed the idea of fast influencers, which emphasizes nodes’ spreading capacity at the early stage. Despite the recent surge of efforts in identifying these two types of influencers in networks, there remained limited research on untangling the differences between fast influencers and final influencers. In this paper, we first distinguish the two types of influencers: fast-only influencers and final-only influencers. The former is defined as individuals who can achieve a high spreading effect at the early stage but lose their superiority in the final stage, and the latter are those individuals that fail to exhibit a prominent spreading performance at the early stage but influence a large fraction of nodes at the final stage. Further experiments based on eight empirical datasets, we reveal the key differences between the two types of influencers concerning their spreading capacity and the local structures. We also analyze how network degree assortativity influences the fraction of the proposed two types of influencers. The results demonstrate that with the increase of degree assortativity, the fraction of the fast-only influencers decreases, which indicates that more fast influencers tend to keep their superiority at the final stage. Our study provides insights into the differences and evolution of different types of influencers and has important implications for various empirical applications, such as advertisement marketing, and epidemic suppressing.


1995 ◽  
Vol 7 (4) ◽  
pp. 847 ◽  
Author(s):  
C Gagnon

With very few exceptions, the basic structure of the 9+2 axoneme has been well preserved over a very long period of evolution from protozoa to mammais. This stability indicates that the basic structural components of the axoneme visible by electron microscopy, as well as most of the other unidentified components, have withstood the passage of time. It also means that components of the 9+2 axoneme have sufficient diversity in function to accommodate the various types of motility patterns encountered in different species of flagella. Several of the 200 polypeptides that constitute the axoneme have been identified as components of the dynein arms, radial spokes etc. but many more remain to be identified and their function(s) remain to be determined. Because this review deals with the regulation of flagellar movement at the axonemal level, it does not include regulation of flagella by extracellular factors unless these factors have a direct action on axonemal components. In this context, it is very important firstly to understand the structural components of the axoneme and how they influence and regulate axonemal movement. Different primitive organisms are mentioned in this review since major breakthroughs in our understanding of how an axoneme generates different types of movement have been made through their study. Despite some variations in structure and function of axonemal components, the basic mechanisms involved in the regulation of flagella from Chlamydomonas or sea urchin spermatozoa should also apply to the more evolved mammalian species, including human spermatozoa.


2021 ◽  
pp. 1-49
Author(s):  
Li Xiao ◽  
Yingqiang Xu ◽  
Zhiyong Chen

Abstract In this paper, a multi-layer body model in which material properties and wear coefficient change with node coordinates is proposed, so that the wear profile is not restricted by the singularity of the interface of the coated contact pairs. The conversion rate of the adhered particles was obtained to describe the growth and expansion of the debris at the fretting interface based on experiments, and the wear model of coated contact pair considering the dynamic evolution of the debris layer was established. By comparing the previous experimental and computational results, the wear calculation method proposed in this paper is more reasonable to predict the wear profile of the coated contact pair. In addition, the influence of the debris layer on the wear depth, friction width, and contact pressure in the fretting process is analyzed, indicating that the existence of the debris layer can delay the wear process. Finally, the fretting wear life of the SCMV steel contact pair deposited with the W-DLC coating is estimated.


2020 ◽  
Vol 3 (2) ◽  
pp. 84
Author(s):  
Melat Cherim ◽  
Rodica Sîrbu

Collagen is the core protein of connective tissues: skin, bone, tendon, base membrane, etc. Collagen is actually a family of several different genetic types. Currently they are known, in vertebrates, at least 27 different types of collagens, which shows a remarkable diversity in molecular and supramolecular organization of the tissue distribution and function, discovered and developed over 45 years. They were studied, in detail, 12 main types. Collagen-based bioproducts can be produced in a variety of molecular structures (micro and nano structures) in powder form, hydrogels and injectable solutions, films, membranes and matrices, etc. This paper presents the drying processes that are selected depending on the nature of the extract (undenatured or denatured) and morphological structure bioproduct or sponge, fibers or membranes. The most frequently used procedures for drying are freeze-drying and free drying at a temperature of approx. 25 ° C. Both processes produce no distorts to the extracts They are presented bioproducts derived from collagen which are used in medicine.


2020 ◽  
pp. 188-203
Author(s):  
Jean-Pierre Llored

This paper aims to analyze the two aspects of elements, material and conceptual, in order to further understand the functional role played by elements in chemistry. First, we will refer to how Mendeleev gradually built his periodic table. Second, we will both highlight and reflect upon the functional role of elements in chemistry. In doing so, we will refer in particular to Cassirer’s philosophy of science. In conclusion, we propose that a functional approach is important for understanding current chemical practice, especially in nanochemistry and quantum chemistry. This approach also contributes to the analysis of different types of mereology that coexist in chemistry today.


2020 ◽  
pp. 1-28
Author(s):  
Jack Beatson ◽  
Andrew Burrows ◽  
John Cartwright

This introductory chapter first considers the nature and function of contract. It then discusses the contractual obligations in English law; the content of the contract law as set out in this book, which is concerned with the ‘general principles’ of contract rather than the detailed rules applicable to different types of contracts; the location of contract as part of the law of obligations and its relation to other parts of the law of obligations, tort and restitution of an unjust enrichment, and property law.


2018 ◽  
Vol 49 (2) ◽  
pp. 109-116
Author(s):  
Gonca Akcaer ◽  
Asena Soyluk

In this study, on airport terminal building design, passing long span beams and the concept of biomimesis have been the design criteria; the use of a steel structure has been examined for supporting the design form. In the airport terminal building, steel roof types in smooth surfaced, single curved-arciform, and double-curved wave forms have been designed. The three different types of steel frame roof model have been designed with the forms frequently used within the scope of the biomimesis concept and provide a covering shaped like a bird's nest, bird wing and bubble. Dynamic analysis of the three different roof forms is according to the first-degree seismic zone and Z4 local ground class. As a result, in the long-span design criterion, the aesthetics and function influence each other and change the building's behaviour.


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