Monitor environment
This learning object addresses the competency required to monitor the environment as part of a tailings dam management process. You will learn about the function of tailings dams, and how to inspect and maintain the dams and associated ponds. Topics include legislation, environmental impact assessments, site plans, emergency procedures and reporting.
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Fe, C 0.2 (wt%), explosively deformed - mechanical twins
This sample was explosively deformed so that there was insufficient time for dislocation motion to occur. Hence, mechanical twins are produced despite the b.c.c. structure of mild steel.
Author(s): Prof T W Clyne, Department of Materials Science an

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3.091 Introduction to Solid State Chemistry (MIT)
This course explores the basic principles of chemistry and their application to engineering systems. It deals with the relationship between electronic structure, chemical bonding, and atomic order. It also investigates the characterization of atomic arrangements in crystalline and amorphous solids: metals, ceramics, semiconductors, and polymers (including proteins). Topics covered include organic chemistry, solution chemistry, acid-base equilibria, electrochemistry, biochemistry, chemi
Author(s): Sadoway, Donald

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Content within individual OCW courses is (c) by the individual authors unless otherwise noted. MIT OpenCourseWare materials are licensed by the Massachusetts Institute of Technology under a Creative C

A three-point bend test: deflection and failure load of a greenheart wood sample
A three-point bend test to measure the deflection and failure load of a greenheart wood sample. From TLP: The Structure and Mechanical Behaviour of Wood, http://www.msm.cam.ac.uk/doitpoms/tlplib/wood/wood_strength.php
Author(s): DoITPoMS, University of Cambridge

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The NHS - its organisation and structure
26 PowerPoint slides from Richard Smith of the London School of Hygiene and Tropical Medicine on The NHS - its organisation and structure, covering: History, Organisation, Finance and Staff.
Author(s): Richard Smith

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TALAT Lecture 2110.02: Product information structure, business concept and LCA
This lecture gives a brief introduction to the product information structure, a sustainable business concept and Life Cycle; it presents the product and process "Generic Code" - the chromosomes; it generates interest about the concept of "Know Your Product", "Life Cycle Logistics", "Universal Virtues" and "Material/Component Hierarchical Structure" and their use creating a sustainable business concept; it imparts knowledge about Life Cycle Assessment. Some familiarity with QFD (Quality Functions
Author(s): Tor Bakkelund, The Norwegian Institute of Technolo

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TALAT Lecture 2711: Design of a Helicopter Deck
This lecture presents design of the main structural parts of an aluminium alloy helicopter deck. The design of a bolted connection on the supporting structure is also presented.
Author(s): Federico M Mazzolani, University Federico II, Napo

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TALAT Lecture 3203: The Filling of Castings
This lecture describes the function and design of all parts of the running and gating systems used in the production of castings. The students will be able to tackle the design of a simple running system in a systematic manner. Basic knowledge of foundry processes and basic mathematics is assumed.
Author(s): John Campbell, Interdisciplinary Research Centre i

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Thin section of ZnO varistor
The micrograph shows structure of ZnO, containing small amounts of oxides such as Sb2O3 and Bi2O3. Thin section was produced using liquid phase sintering: gives rise to a structure consisting of conductive ZnO grains with the additional oxides being preferentially located at grain boundaries. A varistor is used to short-circuit transient high voltage spikes in electronic devices. Incorporated into circuits, in parallel with the device to be protected. Acts as an insulator below a certain breakdo
Author(s): Dr K M Knowles, Department of Materials Science an

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Low magnification SEM image of open cell polyurethane foam
If a gas is injected into a liquid it forms a cellular foam structure. When a thermoset prepolymer of low viscosity is foamed, the polymer can drain from the cell walls (driven by surface tension) before it sets at the cell edges, leaving an open-celled foam. The cell edges have three concave sides, giving rise to the tri-cuspid cross section visible at the bottom of this image. The average co-ordination number for the nodes (where struts meet) is four, giving tetrahedral junctions.
Author(s): Dr J A Elliott, Department of Materials Science an

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Cu 70, Ni 30 (wt%), cored dendrites
This alloy is typical of many copper based alloy systems. The dendrite structure shows coring (variation in solute concentration). The light areas are rich in nickel and the darker areas are low in nickel. Chill casting extracts heat quickly enough to prevent significant solid state diffusion, resulting in cored dendrites. The centres of the dendrites that cool near the liquidus temperature, are nickel rich compared to the outer layers that solidify at progressively lower temperatures. Because t
Author(s): Prof T W Clyne, Department of Materials Science an

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X-ray tomography image of open cell polyurethane foam
If a gas is injected into a liquid it forms a cellular foam structure. When a thermoset prepolymer of low viscosity is foamed, the polymer can drain from the cell walls (driven by surface tension) before it sets at the cell edges, leaving an open-celled foam. The cell edges have three concave sides. The average co-ordination number for the nodes (where struts meet) is four, giving tetrahedral junctions. The deformation behaviour of the foam was observed by X-ray microtomography at the ESRF in Gr
Author(s): Dr J A Elliott, Department of Materials Science an

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Rapid solidification in an atomised droplet
Because of the fine scale of the droplet, heat extraction is very rapid, and large undercoolings are achieved before crystal nucleation can begin. Thus, in this droplet, the solidification front has advanced very rapidly through the droplet from the nucleation point (on the surface at the left of the image). Its velocity is initially so great that no interfacial breakdown is possible. As the front advances, however, latent heat is evolved and this 'recalescence' reduces the rate of solidificatio
Author(s): Prof T W Clyne, Department of Materials Science an

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Fe, Ni 30, C 0.3 (wt%), quenched - martensite plates
This sample was quenched to -80 °C to give a metastable martensitic microstructure. The martensite plates show a lenticular morphology as the material attempts to shear as it transforms but is unable to open up voids at the grain boundaries. The plates form in a similar way to mechanical twins but the shear processes lead to changes in crystal structure as well as crystallographic orientation.
Author(s): Prof T W Clyne, Department of Materials Science an

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Silal
This sample shows the typical structure of silal, irons with high Si content (5.5-7.9 wt%). It is a grey cast iron alloyed with 4-6wt% Si to provide good oxidation resistance. The high Si content forms a dense, adherent iron silicate surface film, which is resistant to oxygen penetration. The flake graphite iron Silal was one of the first heat resisting cast irons developed. Spheroidal graphite Si irons have higher strength and improved ductility. The structure shows cored dendrites of ferrite w
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Fe, C 0.9 (wt%), martensite
Martensite is a metastable supersaturated solid solution of C in steel. The excess carbon atoms sufficiently strain the matrix to produce a b.c.t (body centred tetragonal) structure. In order to minimise interfacial strain between the parent austenite and the transforming martensite the martensites assume a lath or needle shape.
Author(s): Prof T W Clyne, Department of Materials Science an

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Silal
This sample shows the typical structure of silal, irons with high Si content (5.5-7.9 wt%). It is a grey cast iron alloyed with 4-6wt% Si to provide good oxidation resistance. The high Si content forms a dense, adherent iron silicate surface film, which is resistant to oxygen penetration. The flake graphite iron Silal was one of the first heat resisting cast irons developed. Spheroidal graphite Si irons have higher strength and improved ductility. The structure shows cored dendrites of ferrite w
Author(s): Dr R F Cochrane, Department of Materials, Universi

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Ni-hard iron
This is a Ni-hard iron, one of the first cast irons to be developed. These white irons contain Ni to ensure that the austenite transforms to martensite following heating and chromium to increase the hardness of the eutectic carbide.Ni-hard irons are normally stress relieved at 200-300 °C for approximately four hours to relieve the martensitic transformation stresses and to promote the transformation of retained austenite. The structure consists of proeutectic austenite dendrites containing mart
Author(s): Prof T W Clyne, Department of Materials Science an

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Cu 60, Zn 40 (wt%), quenched and held at 300°C - Widmanstätten microstructure
This sample was quenched and held at 300 °C for one hour. It has a Widmanstätten microstructure with the α phase precipitating out of the single β phase during cooling to give α plates in a β matrix. The low temperature at which the transformation takes place leads to less diffusion and results in a finer structure.
Author(s): Prof T W Clyne, Department of Materials Science an

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Wrought-grade aluminium alloy
The micrograph shows Al-Mg-Fe-Si containing < 1wt.% of each solute; refined with TiB2 particles. Deformation of grain structure is due to cutting of sample with scissors. This micrograph illustrates the effect of deformation on a previously equiaxed structure. Strain causes the elongation of grains and the subsequent anodising produces 'mottled' grain colours; the oxide layer is not of constant orientation or thickness across a grain.The Barker's etch and applied electrical field produce a thick
Author(s): T Quested, Department of Materials Science and Met

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