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

Energy Sources

Energy is the ability of a system to do work. Chemical: stored energy contained in chemical compounds. Released during chemical reactions, electrical: produced by the flow of electric charge, thermal: released as heat, electromagnetic: stored in electromagnetic waves or radiation, mechanical: combination of two energies (kinetic: things in motion, potential: stored within an object), nuclear: stored in the nuclei of atoms (fission: nucleus splits, fusion: nucleus joins).

Non-Renewable Energy Sources

Non-renewable energy sources are limited energy resources obtained from beneath the Earth. They are being used faster than they can be replenished. Fossil fuels are formed from the remains of microorganisms, plants and animals buried... Continue reading "Understanding Energy Sources: Renewable vs Non-Renewable" »

Hydropower

Hydropower utilizes the energy of water in rivers, which can be dammed to create reservoirs. These reservoirs have exit gates that lead to a turbine. The rotation of the turbine is converted into electricity. Reservoirs also serve to store water for irrigation and human consumption, and they help prevent dangerous floods.

However, hydropower has drawbacks. It can:

1. Inundate large areas of the banks.
2. Destabilize deltas (sediment that nourished these is now trapped at the bottom of the reservoir, and the sea erodes the delta).
3. Alter aquatic life.

Consequently, new hydropower plants are no longer built in many countries, and some older ones are being dismantled in more advanced nations.

Nuclear Energy

Globally, there are 442 nuclear power plants... Continue reading "Sustainable Energy Sources: Hydropower, Nuclear, Wind, and Solar" »

(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" »