Relationship between phase changes and engineering properties of materials based on the ZrO2-CeO2 system

Refractories ◽  
1968 ◽  
Vol 9 (5-6) ◽  
pp. 301-305
Author(s):  
Ya. V. Klyucharov ◽  
V. I. Strakhov
Keyword(s):  
Phase Changes ◽  
Engineering Properties ◽  
Properties Of Materials

scholarly journals FRICTION COEFFICIENT OF MUNICIPAL SOLID WASTE COMPONENTS

2020 ◽  
Vol 7 (7) ◽  
pp. 1-7
Author(s):  
Yesuenyeagbe A.K. Fiagbe ◽  
Emmanuel W. Ramde
Keyword(s):  
Friction Coefficient ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Coefficient Of Friction ◽  
Engineering Properties ◽  
Engineering Systems ◽  
Critical Property ◽  
Properties Of Materials ◽  
Wooden Surface ◽  
Wood Surfaces

Engineering properties of materials includes coefficient of friction (COF) which are basic in design performance of engineering systems. The COF can be considered as very important in design of handling tools. Various types of handling tools and equipment are used at various stages of disposal and treatment of MSW and COF is one critical property. This paper presents estimate of COF of municipal solid waste components. The components of the municipal solid waste are paper, plastic, organic and others. The estimation of the COF was done using an inclino-tribometer. Waste from 16 sample locations were used with 6 surfaces which are considered to be of relevant. It was estimated that Formica surface has the least COF values and range from 0.269 and 0.312 with ‘others’ – formica surface tribosystem being the least. It was also found that paint application on wooden surface with oil paint would increase COF as compared to applying emulsion on same wooden surface. The study pointed out that polishing with vanish is the best way to reduce COF in wood surfaces. It was also observed that painting metal surfaces with oil paint will increase the COF than when the same metal was left unpolished or unpainted.

Waste utilization to enhance performance of road subbase fill

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kurban Onturk ◽  
Seyhan Firat ◽  
Gulgun Yilmaz ◽  
Jamal Khatib
Keyword(s):  
Circular Economy ◽  
Control Sample ◽  
Value Added ◽  
Waste Utilization ◽  
Phase Changes ◽  
Engineering Properties ◽  
Waste Materials ◽  
Unit Weight ◽  
Content Type ◽  
Fill Materials

Purpose The purpose of this study is to use waste materials in construction to create sustainable practices. This will contribute towards circular economy which has gained momentum in recent years throughout the world. Design/methodology/approach Waste materials cause enormous environmental problems that can have an adverse effect on the environment. Recycling of waste consists an important part of the circular economy. Therefore, researchers have been investigating the economic use of a variety of waste materials for reducing their environmental impact. One potential usage is in road subbase fill materials where wastes can be incorporated in large quantities. In this study, the engineering properties of road subbase fill materials (i.e. kaolinite) mixed with Granite Waste (GW), coal Fly Ash (FA) and lime are investigated. Kaolinite was replaced with 15% lime and FA, whereas the GW replacement varied from 10% to 20%. Testing included strength of the various soil compositions subjected to different curing times. Also the microstructural analyses and phase changes of samples were conducted using scanning electron microscopy and x-ray diffraction techniques, respectively. The results obtained indicate that GW can be incorporated in road base materials to improve its bearing capacity. The mixture consisting of 15% lime, 15% FA, 20% GW and 50% kaolinite resulted in maximum dry unit weight and optimum moisture content. Using GW exhibited a noticeable increase in the California Bearing Ratio of more than eight times at 1 day and 28 days curing regime compared with the control sample. Findings This study shows that GW and FA can be used for road subbase materials and can contribute toward a better and cleaner environment. Originality/value In this study, the engineering properties of road subbase fill materials (i.e. kaolinite) mixed with GW, coal FA and lime are investigated. This are value added in circular economy.

Metallurgical Effects of Grain Boundary Ledges

1977 ◽  
Vol 35 ◽  
pp. 126-129
Author(s):  
L.E. Murr
Keyword(s):  
Grain Boundary ◽  
Quantitative Data ◽  
Mechanical Treatment ◽  
Unit Length ◽  
Physical And Mechanical Properties ◽  
Direct Observations ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Thermo Mechanical Treatment ◽  
Ledge Density

Ledges in grain boundaries can be identified by their characteristic contrast features (straight, black-white lines) distinct from those of lattice dislocations, for example1,2 [see Fig. 1(a) and (b)]. Simple contrast rules as pointed out by Murr and Venkatesh2, can be established so that ledges may be recognized with come confidence, and the number of ledges per unit length of grain boundary (referred to as the ledge density, m) measured by direct observations in the transmission electron microscope. Such measurements can then give rise to quantitative data which can be used to provide evidence for the influence of ledges on the physical and mechanical properties of materials.It has been shown that ledge density can be systematically altered in some metals by thermo-mechanical treatment3,4.

A Stable Field Emission Electron Source

1977 ◽  
Vol 35 ◽  
pp. 58-59
Author(s):  
W.R. Bottoms ◽  
G.B. Haydon
Keyword(s):  
Field Emission ◽  
Signal To Noise Ratio ◽  
High Brightness ◽  
Electron Sources ◽  
Brightness Field ◽  
Current Densities ◽  
Properties Of Materials ◽  
Stable Field ◽  
Stable Current ◽  
Careful Design

There is great interest in improving the brightness of electron sources and therefore the ability of electron optical instrumentation to probe the properties of materials. Extensive work by Dr. Crew and others has provided extremely high brightness sources for certain kinds of analytical problems but which pose serious difficulties in other problems. These sources cannot survive in conventional system vacuums. If one wishes to gather information from the other signal channels activated by electron beam bombardment it is necessary to provide sufficient current to allow an acceptable signal-to-noise ratio. It is possible through careful design to provide a high brightness field emission source which has the capability of providing high currents as well as high current densities to a specimen. In this paper we describe an electrode to provide long-lived stable current in field emission sources.The source geometry was based upon the results of extensive computer modeling. The design attempted to maximize the total current available at a specimen.

The Interpretation of Crystal Lattice Images

1972 ◽  
Vol 30 ◽  
pp. 550-551
Author(s):  
J. M. Cowley ◽  
Sumio Iijima
Keyword(s):  
Crystal Orientation ◽  
Diffraction Theory ◽  
Phase Changes ◽  
Electron Wave ◽  
Crystal Lattices ◽  
Heavy Atoms ◽  
Lattice Images ◽  
The Right ◽  
Intuitive Interpretation ◽  
Suitable Approximation

The imaging of detailed structures of crystal lattices with 3 to 4Å resolution, given the correct conditions of microscope defocus and crystal orientation and thickness, has been used by Iijima (this conference) for the study of new types of crystal structures and the defects in known structures associated with fluctuations of stoichiometry. The image intensities may be computed using n-beam dynamical diffraction theory involving several hundred beams (Fejes, this conference). However it is still important to have a suitable approximation to provide an immediate rough estimate of contrast and an evaluation of the intuitive interpretation in terms of an amplitude object.For crystals 100 to 150Å thick containing moderately heavy atoms the phase changes of the electron wave vary by about 10 radians suggesting that the “optimum defocus” theory of amplitude contrast for thin phase objects due to Scherzer and others can not apply, although it does predict the right defocus for optimum imaging.

Remote diagnostics of vibrations of dynamic objects by Doppler microwave sensors

Metrologiya ◽  
2020 ◽  
pp. 25-42
Author(s):  
Dmitrii V. Khablov
Keyword(s):  
Intelligent Systems ◽  
Electromagnetic Waves ◽  
Continuous Monitoring ◽  
Phase Changes ◽  
Vibration Diagnostics ◽  
Remote Diagnostics ◽  
Active Vibration ◽  
Dynamic Objects ◽  
Microwave Sensors ◽  
Non Destructive

This paper describes a promising method for non-contact vibration diagnostics based on the use of Doppler microwave sensors. In this case, active irradiation of the object with electromagnetic waves and the allocation of phase changes using two-channel quadrature processing of the received reflected signal are used. The modes of further fine analysis of the resulting signal using spectral or wavelet transformations depending on the nature of the active vibration are considered. The advantages of this non-contact and remote vibration analysis method for the study of complex dynamic objects are described. The convenience of the method for machine learning and use in intelligent systems of non-destructive continuous monitoring of the state of these objects by vibration is noted.

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