Notes, summaries, assignments, exams, and problems for Geology

(Metal) Cutting - Controlled separation of a material – to make something! Creates two new surfaces. – Not splitting like wood or slate – can't put the surfaces back together. What about floppy slices? Cucumber? Lots of plastic deformation. Relatively low forces, but very high stresses (force applied over tiny areas)

Positive = Could be independent of the wedge and clearance angle
Negative = Not independent of the wedge and clearance angle

Cutting edge: to separate a chip from the parent work material
Rake face: direct the flow of newly formed chips.
Rake angle: it is measured relative to a plane perpendicular to the work surface.
Relief angle: the flank of the tool provides a clearance between the tool and the newly generated work surface.... Continue reading "Metal Cutting: Controlled Separation and Chip Formation" »

Matter and Energy

Matter

• Atoms and molecules
• Everything that has mass and volume
• Law of Conservation of Matter: Matter is neither created nor destroyed, it only transforms.

Energy

• Light, chemical, and heat
• Ability to perform work
• Law of Conservation of Energy: Energy is neither created nor destroyed, it only transforms.
• Second Law of Thermodynamics: Entropy tends to increase in the universe.

Cycles of Matter

We can study matter by the path of the atoms and molecules that constitute it. We consider that each trophic level is a compartment, through which the atoms pass.

Energy Flows

• Energy passes from one level or compartment to another, through trophic networks.
• In each step, a significant part of energy is lost as heat or entropy.
• Energy cycles are not closed

Geological Processes and Clay Formation

Clay is formed through two geological processes: weathering and erosion.

Source Material for Clay

The material broken down into clay by these processes is primarily granite rock.

Classifications of Clay

Clay is classified into two categories based on its location:

• Primary clay: Found at the source of its formation, it is considered"pure" and includes only kaolin.
• Secondary clay: Found far from its source, it has traveled through erosion, picking up contaminants and undergoing particle size changes.

Types of Clay

There are six unique types of clay:

• Kaolin: Pure, white, low plasticity, used in porcelain production.
• Fire clay: Coarse, contains metallic oxides, fires to various colors, highly refractory, used in industrial

Natural Environment

Europe

The natural environment encompasses all living and non-living elements found on the Earth's crust. Weathering, driven by natural phenomena, continuously shapes and reshapes our planet.

Location and Geography

Europe, situated on the Eurasian tectonic plate, is separated from Asia by the Ural Mountains, Caspian Sea, and other geographical features. The Mediterranean Sea forms a natural boundary between Europe and Africa. Europe's landscape is characterized by numerous gulfs, bays, and peninsulas, including the Iberian, Scandinavian, Italian, and Balkan peninsulas. The continent boasts a diverse topography, with significant variations in elevation and landforms within relatively small areas.

Climate and Biogeography

Several... Continue reading "Natural Environments of Europe and North America" »

Thermal Energy

Thermal energy is the energy a body has due to the movement of its particles. Temperature is a physical magnitude which measures the thermal energy, that is, the movement of a body's particles - SI: KELVIN. The CELSIUS is more generally used. Heat is the thermal energy in transit. This process is carried out naturally between two material systems which are at different temperatures - SI: JOULES-Calories. 1 cal = 4.18 J 1 J = 0.24 Cal. Two bodies A and B have thermal equilibrium when both are at the same temperature.

Physical Changes

Temperature variation: normally the temperature of a body increases when it gains heat and decreases when it loses heat. Changes of state: when a change of state occurs, the temperature of a material... Continue reading "Understanding Thermal Energy and Heat Transfer" »

Week 4 and 5: Zoonotics and Climate Change

What is a vector-borne disease?

Vector-borne diseases are human illnesses caused by parasites, viruses, and bacteria that are transmitted by mosquitoes, sandflies, triatomine bugs, blackflies, ticks, tsetse flies, mites, snails, and lice. Know some examples of common vector-borne diseases such as cholera, dengue, and malaria. Be able to name a few common vectors (mosquitos, ticks, fleas) and a disease they carry.

Difference between direct and indirect modes of transmission

Indirect has a vector.

Role of Climate Change on Vector-Borne Diseases

Week 6: Toxic Metals: CERCLA and Superfund Sites

Clean up of waste sites. Toxic and hazardous and radioactive. Superfund is a United States federal government program... Continue reading "Vector-Borne Diseases, Toxic Metals, Pesticides, and Air Pollution" »

Limit equilibrium methods are used for soil analysis, particularly for determining the material factor of safety. These methods analyze a finite number of potential sliding surfaces.

For each surface, equilibrium is formulated using the maximum stresses available along the sliding surface, with soil strength reduced by an unknown factor F. The value of F is obtained from the solution of the resulting equations.

In soils, commonly selected surfaces are straight lines, circles, or log spirals. In rocks, sliding is governed by weakness planes, and hence blocks or wedges with planar faces are considered.

Corrective Measures for Soil Instability

Corrective measures typically involve either reducing unfavorable actions (weight and/or water flow) or increasing... Continue reading "Soil Stability Analysis: Limit Equilibrium Methods" »

Sedimentary Rocks and Their Formation

Sedimentary rocks are created from the aggregation of particles of sediments. They form layers called "Beds".

1. Weathering:

   Disintegration and decomposition of rocks or dead animals and plants.

2. Erosion:

   Natural forces (water, wind, ice...) break rocks into fragments (sediments) and transport them.

3. Deposition:

   Sediments are layered on top of one another. The old sediments are in the lower layers and the new sediments create the upper layers.

4. Lithification or Diagenesis:

   Compaction: Sediments pile up and the space between grains reduces.

   Cementation: Liquids put the aggregates together like a natural glue or cement.

Metamorphic Rocks

1. Regional Metamorphism:

   Heat and pressure increase in large areas due to tectonic movement.

the atmosphere is the gaseous layer around the earth. Wihthout this layer there is life in the earth.

Internal Forces in the Formation of Relief

• VOLCANOES: Cracks in the Earth's crust can be deep enough to reach areas where there is magma. The magma rises and passes through the volcano's crater to the surface in a volcanic eruption. Volcanic eruptions expel gases, ash, rocks, and lava. When these materials come into contact with the air, they cool down and form a volcanic cone.
• EARTHQUAKES: are the result of the movement of the Earth's tectonic plates. This movement travels in all directions in the form of seismic waves. Earthquakes usually last for only a few seconds, but they cause the ground to shake and can have devastating effects. Earthquakes can be of different magnitudes.

External Forces in the Formation of Relief

• THE ACTION OF WATER: Water