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

Khondalite: Petrographic Notes and Indian Occurrence

Khondalite is a high-grade metamorphic rock belonging to the gneiss-schist group, composed mainly of a quartzo-feldspathic-garnet-sillimanite assemblage with graphite. The term was coined by T. L. Walker (1902) after the Khond tribe of Odisha.

Megascopic Characters

• Colour: Brown to greyish brown
• Grain size: Medium to coarse-grained
• Texture: Porphyroblastic (garnet as porphyroblasts)
• Structure: Schistose to gneissose, well-developed foliation

Microscopic (Petrographic) Characters

• Texture: Granoblastic to lepidoblastic
• Quartz: Colourless, anhedral, shows undulose extinction
• Feldspar (K-feldspar ± plagioclase): Subhedral, shows twinning
• Garnet: Euhedral to subhedral porphyroblasts, isotropic
• Sillimanite:

Understanding Earth's Atmosphere

Atmospheric Composition Evolution

Primitive Atmosphere: Composed of water vapor, carbon dioxide, nitrogen, hydrogen, ammonia, methane, and other oxides, but notably *no oxygen*.

Present Atmosphere: Consists of approximately 78% nitrogen, 21% oxygen, 1% carbon dioxide, water vapor, and trace gases like argon. The ozone layer later formed from oxygen.

Atmospheric Layers (In Order)

• Ionosphere: Temperature around 1,000 ºC.
• Mesosphere: Approximately 40 km thick.
• Stratosphere: Approximately 30 km thick. Temperature increases from 0 ºC at its upper limit to 70 ºC at its lower limit (Note: The original text stated an increase *to* 0ºC, which is inconsistent with standard models; this reflects the general structure).
• Troposphere:

Volcanic Eruptions

Molten rock and gases are ejected through the Earth's crust.

Continental Drift

A slow horizontal movement of the continents.

Earthquakes

A violent trembling of the Earth's crust which lasts a short time and varies in intensity.

Isostasy

Slow vertical movement of the Earth's crust.

Our atmosphere was formed about 4,000 million years ago.

The Magnetic Field

Around the Earth originates in the outer core.

Hot Rocks

Allow the installation of geothermal plants that take advantage of the heat to vaporize water and produce electricity.

Hydrothermal Phenomena

Occur when water seeps into the crust through cracks, it gets into contact with rocks at high temperatures.

The Earth's crust is a rigid and cold layer. Magma is a mixture of gases and molten... Continue reading "Earth's Geology and Natural Phenomena" »

Diphthongs

Described as vowel glides, since in their production the tongue begins in one place and moves to another. This movement of the tongue, however smooth, results in a change of vowel quality, which is why diphthongs are sometimes looked upon as 'combinations of 2 vowels'.

Diphthongs are usually classified according to whether they are:

• Falling or rising
• Wide or narrow
• Front or back
• Closing or centering

The diphthongs of RP are all stressed on the first element, described as falling. Those stressed on the finishing point (rising), can also be wide or narrow, according to the movement of the tongue from the first to the second target. Those in which the position of the tongue body changes quite noticeably are described as 'wide diphthongs'.... Continue reading "English Phonetics: Diphthongs and Consonants" »

What is an Environmentally Sustainable Society?

One that meets the current and future basic resource needs of its people in

a just and equitable manner without compromising the ability of the future

generations to meet their basic resource needs

Environmental Scientists

John Muir (1892) - created Yosemite National Parks

Created Sierra club

Eugene and Howard (1953) - wrote the first ecology textbook

Rachel Carson (1962) - wrote Silent Spring

Effects of DDT

Lois Gibbs (1980) - formed the Citizens Clearinghouse for hazardous

 waste, petition to Jimmy Carter

The town was called Love Canal

Theodore Roosevelt (1900) - created the United States Forest Service

 for Wildlife

Established 5 national parks

Antiquities Act

James Lovelock (1960s) - created the Gaia

Why in soft clays should be done undrained cond? Clays soils present a very low permeability, so water pres disipation takes a lot of time, so failure will be reached in undrain conditions. It contracts when shear stresses are apllyed. Undrain resist is much smaller than draine, and can be aprox: Cu=0,25+sicma'v and for triax cu=q/2 b)How the second consol coef can be estimated?Settlement can be reduced  by preloading the soil with a load equal or higher to the one it will withstand after construc. 2) Which parameters or fundamental control the seismic ... Shear modulus G and damping (la de compu rara), which are turned relationed with porosity, relatv densi y wave speed 's'. Shear modu is the ratio of shear stres and deformation . Damping... Continue reading "Geotechnical Engineering Principles: Soil Mechanics Insights" »

The Devastating Impact of Plastic Pollution

Ubiquitous Waste: A Global Problem

Plastic waste has become ubiquitous, contaminating every corner of our planet, including our oceans. Its persistence and improper disposal lead to its widespread distribution, harming ecosystems and wildlife.

Biodegradable vs. Non-Biodegradable: A Misconception

While plastic may break down into smaller pieces, it does not biodegrade. These fragments can be ingested by animals, entering the food chain and causing contamination and health issues.

The Lasting Legacy of Plastic: A Threat to Humanity

Most plastics are virtually indestructible, outlasting even the harshest conditions. This poses a significant threat to our planet and future generations, as it will continue to... Continue reading "The Devastating Impact of Plastic Pollution: A Call to Action" »

What is Climate Change?

Climate change refers to the long-term variations in global climate patterns. These changes can be driven by natural processes, external forces, or human activities. However, the term "global warming" specifically highlights the impact of human activities on the planet's temperature.

The Human Impact

Over the past few decades, human activities have significantly contributed to global warming. The Earth's average temperature has risen by approximately two degrees Celsius, and projections indicate continued warming unless we take action. While thousands share responsibility for this change, several key factors contribute to the problem:

• The Greenhouse Effect: The burning of fossil fuels releases greenhouse gases into the atmosphere,

The Electric Scooter Accumulates 3,000 Fines in Barcelona in 2018

The City Council and the Urban Guard warn that these vehicles are not toys, so their drivers must respect the regulations.

The increase in sanctions to electric scooter drivers, about 3,000 in 2018, has led the Barcelona City Council to redouble the information about the traffic regulations of these vehicles, which has been in force since 2017, informed this Friday Ricardo Salas, mayor of the Urban Guard. Manuel Valdés, Manager of Mobility and Infrastructure of the consistory, stressed that these vehicles are not toys and emphasized that it is important to remember the regulations to all those who have thought of buying or giving them away.

Electric scooters are prohibited from

TERZA PARTE

1. Fed-batch biological reactor: material balances with Monod kinetics and operating methods:

• it maintains some operational characteristics of the batch, while ensuring constant biomass production such as a CSTR
• Therefore, there is an inlet supply with V˙e and [substrate] Cse and negligible Cxe
• since it is not a continuous reactor, it will never reach the steady state condition, there will always be an accumulation
• at zero time there will be: a certain initial V_R with an initial [substrate], initial [biomass] and subsequently the volume will increase over time.
• Total biomass balance:
• dmtot / dt = me, with me = ρe V ,e,
• from this relationship we obtain that
  1. dVr / dt = V˙e.
• At this point two feeding strategies can be considered,
  1. 1. one with