Material Properties: Metals, Polymers, Ceramics, and Composites
Metals and Metal Alloys
Metallic bonds
Features:
- Ordered crystalline structure
- High electrical conductivity
- High thermal conductivity
- Ductility
- Reflect light (shine)
- Large alloy
- Plastic deformation
- They are tenacious
- Medium elasticity
- Medium voltage
Covalent Bonds: Polymers
Features:
- Material formed by long chains from the union called monomers (basic chain)
- Are not crystal
- Polymer mechanical properties vary
- Bad electrical conductors
- Thermal bad drivers
- Used as an insulator
- Low density
- Low-temperature decomposition
Ionic
Read MoreUnderstanding Soil Types and Foundation Engineering
Types of Land
Classification by RQD (%), one considers the following types of terrain in its initial state, in excavations:
- Excellent or Hard: Attackable with machinery and/or scaler, but not billed as a land of transit, broken rocks, soil, very compact, and so on.
- Good Quality: Attackable with a machine.
- Medium Quality: Attackable with beaks, but not with the shovel, as semicompact clays with or without gravel or gravel.
- Poor Quality: Attack with the shovel, and loose soils, topsoil, sand, etc.
- Very
Earth’s Dynamics, Natural Hazards, and Resource Management
Earth: A Dynamic Planet
Earth is a dynamic planet where changes occur, some cyclically, i.e., repeated periodically.
- Heat from the sun falling on the air makes it rise. Its place is occupied by colder air, and this produces atmospheric currents. By heating the water, the hydrologic cycle starts (evaporation, condensation, and precipitation) and, similar to the atmospheric currents, produces ocean currents (oceanic conveyor belt).
- The core of the Earth warms the planet’s interior, and convection produces
Water Properties, Circulation, and Resources Management
Importance of Water for People, Industry, Agriculture, Ecosystems, Recreation, and Landscape
- The human body is comprised of approximately 80% water.
- A loss of 12% of body water can result in death.
- The minimum amount of water required, depending on climate, is 2-7 liters per day.
- Average water consumption for domestic purposes is 135-150 liters per day.
- In developed countries, it is 500 liters per day per person.
Functions of Water:
- Domestic and municipal purposes
- Navigation of rivers and channels
- Industrial
Mineral Flotation: Process, Reagents, and Variables
Flotation in mining is a physicochemical process widely used for the separation of sulfide minerals from their concentration or the separation of different mineralized species, exploiting the properties of hydrophobicity. It is induced by chemical reagents: collector, foaming agents, and modifiers.
Objective of Flotation
The flotation process is based on the hydrophilic and hydrophobic properties of minerals. This is essentially a behavioral phenomenon of solids in water. Flotation is performed using
Read MoreMethods and Effects of Food Preservation Techniques
Food Preservation by Moisture Control
Dehydration, Drying, and Concentration of Food: Water is removed under natural conditions in the field, in cooking and baking food, and controlled processes of dehydration. Aimed to increase the shelf life of foods, reduce the weight and volume, reduce costs of transport, packaging, and storage, and to produce products with convenience of use.
Physical Principles Involved: Transmission of heat and removal of water are facilitated by increasing the surface of food,
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