Notes, summaries, assignments, exams, and problems

The Spanish Civil War (1936–1939)

The Spanish Civil War took place between 1936 and 1939. On July 17, 1936, the conflict began at the headquarters in Melilla. By July 18, the military rebellion—the name chosen by the Spanish Armed Forces after the dissolution of the volunteer militias formed in 1936 to counter the coup—extended across Spain. However, in most cities, the coup failed, and what was intended as a swift takeover became a protracted civil war.

The Republican government received support from the Soviet Union, which mobilized the International Brigades. Mexico also provided assistance, having recently emerged from the Mexican Revolution. Western democracies, including France, the United Kingdom, and the United States, decided to... Continue reading "The Spanish Civil War: Key Figures and Historical Terms" »

What is the penalty for the disposal of inherited real estate when the registrations required by Article 688 are omitted?

Thesis 1: Absolute Nullity for All Sales

The penalty is absolute nullity because it violates the mandatory rules of the Conservador de Bienes Raíces (CBR). This applies to both voluntary and forced sales.

Thesis 2: Absolute Nullity Limited to Voluntary Sales

The penalty would be absolute nullity, but only for voluntary sales and not forced ones. This is based on two reasons:

• Article 688 specifically refers to "the heirs," a limitation that cannot be extended to the justice system.
• If absolute invalidity were applied to forced sales, the heirs of a debtor could refuse to register the property to paralyze all execution against

Electric Field Flux and Gaussian Surfaces

The flow of an electric field through a Gaussian surface, also known as electric flux (symbol Φ), is a property of any vector field referring to a hypothetical surface that can be closed or open. For an electric field, the flow (Φe) is measured by the number of lines of force crossing the surface.

To define Φe precisely, consider an arbitrary closed surface within an electric field. The surface is divided into elementary squares (ΔS), each of which is small enough so it can be considered flat. These area elements can be represented as vectors ΔS, whose magnitude is the area itself, the direction is normal to the surface, and the orientation is towards the outside. For each elementary square, it is... Continue reading "Electric Field Flux and Lines of Force Principles" »

Saint Augustine: Faith and Reason

For Saint Augustine, both faith and reason are necessary to reach Christian truth. This collaboration is expressed in the phrase: "I believe so that I may understand; I understand so that I may believe." Faith helps us understand reason, and reason must be based on rational discourse. Faith paves the way for reason, ultimately leading to wisdom.

Thomas Aquinas: Harmony of Faith and Reason

Thomas Aquinas argues that faith does not remove reason but complements it; they are two distinct paths that do not conflict. While he does not grant total autonomy to reason—as it remains linked to faith—he distinguishes between them:

• Reason: The power of the human mind to understand and accept propositions.
• Faith: The truths

Minerals and Alloy Fundamentals

Minerals: A usable part is formed by the metal and rich-looking material, named the ore, and another not usable part because it is very poor in metal, called the gangue (bargain).

Alloys: A product obtained from the union of two or more chemical elements which presents the characteristics of a metal. An alloy modifies its crystalline structure, increasing its hardness and mechanical resistance but lowering its conductivity.

Solidification of Alloys

• Area liquid phase: Liquidus line for liquid (it will always be liquid).
• Area solid + liquid phase: Contains a mass of solid and another of liquid.
• Solid-phase area: Below the solidus line (always a solid phase).

Classification of Metal Products

Shop-metal products:

• Ferrous

Introduction to Chemical Reactions

Chemical reactions are chemical phenomena that cause a modification of the internal molecular structure. Examples include the oxidation of iron and the degradation of food.

Energy in Chemical Processes

Synthesis reactions (manufacture) or anabolic processes are endothermic reactions; for example, photosynthesis and lipid synthesis. Conversely, exothermic reactions involve catabolism (not synthesis), such as cellular respiration and fermentation.

Chemical Equation for Cellular Respiration

The chemical equation for cellular respiration with oxygen is: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O.

Factors Affecting the Rate of a Reaction

• Temperature: With increasing temperature, chemical reactions occur with more numerous shocks (

1989 Constitutional Amendments and Institutional Changes

• Institutionalization of Power: Following the death of the Ayatollah, the informal practices he established were institutionalized.
• The Expediency Council: This body was institutionalized to resolve conflicts between liberals and conservatives. While it existed previously, its role was expanded and formalized.
• Assembly of Religious Experts: The amendments also expanded the number of members in the Assembly of Religious Experts.

Impact of Oil Dependence on the Iranian State

• The Rentier State: Iran receives sufficient revenue from oil to disregard its internal tax base. This causes the Iranian state to become independent of society; since there is little taxation, there is little public representation

Vacation and Leave Entitlements

• Vacation Days: A staff member with a 25-year career is entitled to 25 vacation days.
• Birth of a Child: Officials are entitled to 15 days off from the date of birth.
• Parental Leave: Officials with a newborn child may benefit from both paternity and maternity leave.

Remuneration and Pensions

• Extra Pay: Defined as basic remuneration.
• Basic Pay Determination: In the Central Government, this is determined by the Law of State Budget.
• Pension Rights: Pension rights are unalienable and cannot be seized.
• Retirement Accrual: Retirement pensions begin to accrue from the first day of the month of retirement.
• Pension Classes: Pensions are classified as ordinary or extraordinary.

Disciplinary and Legal Procedures

• Serious Offenses: Dismissal

Chemical Kinetics and Reaction Rates

Factors Influencing Reaction Velocity

• Rate Equation: V = k · [A]^a · [B]^b
• Temperature: The Arrhenius Law: k = k₀ · e^{-E_a / (R · T)}
• Concentration and Pressure: P · V = n · R · T
  P = (n · R · T) / V → n / V = concentration
  P = [X] · R · T
• Standard State and Physical State:
  • Solid: Few collisions result in slow reactions. The level of division is key; more particles mean a greater impact surface.
  • Liquid: Average collision frequency results in average reaction speeds.
  • Gas: Many collisions result in faster reactions.
• Catalysts: Positive catalysts increase speed. Negative catalysts (inhibitors) slow it down. Catalysts do not change thermochemical quantities (ΔH, ΔG, ΔS...), the quantity of product, or

English Grammar Practice Exercises

Improve your language skills with these exercises covering conditionals, passive voice, and complex verb tenses.

Conditionals and Sentence Matching

Match the columns:

• He'll call us as soon as...
• Answers: 1b, 2f, 3c, 4a, 5d, 6e

Verb Tense Completion

Complete the sentences using the verbs in parentheses:

• I would return the book...
• Answers: Would return / knew; Had offered / would have accepted; Doesn't train / won't win

Sentence Transformation and Meaning

Complete the sentences so that the meaning remains the same:

• I don't think you should buy that car. → I wouldn't buy that car.
• I would have been exhausted if I hadn't stayed up all night.
• If I hadn't reminded him, Sam would have forgotten about the meeting.
• If I were old