Notes, summaries, assignments, exams, and problems for Other courses

The Nitrogen Cycle: Essential Biogeochemical Process

Question: Briefly explain the nitrogen cycle with a diagram.

Answer: The nitrogen cycle is a biogeochemical process where nitrogen is converted between different chemical forms as it moves through living and non-living components. It plays a crucial role in maintaining the nitrogen balance in ecosystems.

Stages of the Nitrogen Cycle

The nitrogen cycle consists of several important steps:

1. Nitrogen Fixation
2. Nitrification
3. Assimilation
4. Ammonification (Decay)
5. Denitrification

1. Nitrogen Fixation

Atmospheric nitrogen ($ ext{N}_2$) is inert, meaning plants and animals cannot directly use it.

• Certain bacteria, such as Rhizobium & Azotobacter, known as nitrogen-fixing bacteria, convert $ ext{N}_2$ gas into

Work and Career Vocabulary

• apply for a place (v) – solicitar una plaza
• appoint (v) – nombrar
• become an apprentice (v) – convertirse en aprendiz
• commission someone to do something (v) – encargar a alguien que haga algo
• full-time job (n) – trabajo a tiempo completo
• graduate from (v) – graduarse de
• homeless shelter (n) – refugio para personas sin hogar
• internship (n) – prácticas
• low paid (adj) – mal pagado
• mentor an intern (v) – guiar a un becario
• part-time job (n) – trabajo a tiempo parcial
• permanent position (n) – puesto fijo
• placement (n) – práctica laboral
• supervise someone (v) – supervisar a alguien
• take on (a job) (phr v) – aceptar (un trabajo)
• temporary job (n) – trabajo temporal
• turn down (a job) (phr v) – rechazar (

The Daily Life of an Electrician

I start my work at 7:30 a.m. I bring my essential tools, including:

• Pliers
• Screwdriver
• Voltage tester
• Wire cutters

My job involves installing electrical wiring, repairing faulty circuits, and reading blueprints to plan electrical systems. Sometimes, I also install outlets and lighting fixtures.

Safety Protocols in Electrical Work

Safety is very important in my work. I wear protective gear to ensure my safety:

• Safety gloves
• Goggles
• Hard hat

I always turn off the power before working on any electrical system. I also use insulated tools to prevent shocks.

End of Shift Routine

I finish work around 4:30 p.m. Before leaving, I clean my tools and put them back in my toolbox. I also check my schedule for the next day and make sure... Continue reading "Electrician's Daily Work, Safety, Tools, and Vocabulary" »

Spine Structure and Biomechanics

Primary Functions of the Spine

• Support and movement of the trunk.
• Protection of the spinal cord.
• Absorption of shock between the ground and the brain.

Vertebral Column Composition

The vertebral column consists of 33 vertebrae:

• 7 Cervical vertebrae
• 12 Thoracic vertebrae
• 5 Lumbar vertebrae
• 5 Fused Sacral vertebrae
• 4 Fused Coccygeal vertebrae

The Motion Segment

A motion segment consists of two adjacent vertebrae and the intervening soft tissue. Each segment contains three articulations:

• The Intervertebral Disc (a symphysis joint).
• The right and left Facet Joints (gliding synovial joints).

Intervertebral Discs

These are fibrocartilage structures connecting adjacent vertebrae, accounting for 20–25% of the spine's total height.

Annulus

I start my work at 7:30 a.M. I bring my tools, including pliers, a screwdriver, wire cutters, and a voltage tester. I also carry a tool belt to keep everything organized. During the day, I install new electrical wiring, repair faulty circuits, and read blueprints to understand wiring plans. Sometimes, I troubleshoot electrical problems in homes or offices. Safety is very important in my job. I always wear safety gloves, goggles, and a helmet to protect myself. I also use a multimeter to check for live wires before touching them. I make sure to follow all safety rules to prevent accidents. I finish work at 4:30 p.M. Before leaving, I clean my tools, put everything back in my toolbox, and check my schedule for the next day. This helps me stay... Continue reading "I choose to live" »

English Grammar Points

Passive Voice

Structure: Subject + conjugated 'be' + past participle

Causative Verbs

Structure: Conjugated 'have'/'get' + object + past participle

Using So and Such

• So: so + adjective/adverb
• So: so + many/much/few/little + noun

Using Enough

• Enough: adjective/adverb + enough (+ to + verb)
• Enough: enough + noun (+ to + verb)

Reported Speech

• Present Simple → Past Simple
• Present Perfect Simple → Past Perfect Simple
• Future Simple → would + infinitive
• Can → Could
• May → Might
• Have to → Had to
• Should → Should
• Yes/No Question → if/whether + subject + verb (past tense)
• Wh-Question → wh-word + subject + verb (past tense)

Conditional Sentences

• Type 1 (Real Conditional): If + Present Simple, Future Simple
• Type 2 (Unreal Present Conditional)

What is PHP?

PHP (Hypertext Preprocessor) is a widely-used open-source scripting language primarily designed for web development. It runs on the server-side, meaning the code is executed on the web server before the output is sent to the user's browser. PHP is embedded within HTML and supports various databases, making it a powerful tool for creating dynamic and interactive web applications.

Key Features of PHP

PHP has several features that make it a popular choice for web development:

• Open-Source – PHP is free to use, with a large community of developers providing support and updates.
• Cross-Platform Compatibility – PHP works on multiple operating systems like Windows, Linux, and macOS.
• Easy to Learn and Use – Its syntax is simple and similar

Arithmetic Mean

The following C++ code calculates the arithmetic mean of numbers from 1 to n:

int main() {
    int n;
    double suma = 0;
    cout << "Vnesi broj: ";
    cin >> n;
    if (n <= 0) {
        cout << "Brojot na elementi mora da bide pogolem od 0!" << endl;
        return 1;  
    }
    for (int i = 1; i <= n; i++) {
        suma += i;  
    }
    double sredina = suma / n;
    cout << "Aritmetichkata sredina na broevite od 1 do " << n << " e: " << sredina << endl;
    return 0;
}

Sum

The following C++ code calculates the sum of numbers from 1 to n:

int main() {
    int n, sum = 0;
    cout << "Vnesi broj n: ";
    cin >> n;
    for (int i = 1; i <= n; i++)

Table Styles

/* 1. Agregar borde a todas las celdas */
table, th, td {
    border: 1px solid black;
    border-collapse: collapse;
    padding: 10px;
    text-align: left;
}

/* 2. Alternar colores de fondo en las filas */
tr:nth-child(odd) {
    background-color: white;
}

tr:nth-child(even) {
    background-color: lightgray;
}

/* 3. Aplicar fondo amarillo a la primera fila */
tr:first-child {
    background-color: yellow;
}

/* 4. Cambiar color de fondo al pasar el mouse */
tr:hover {
    background-color: lightblue;
}

Card Styles

/* 1. Estilos generales para las tarjetas */
.tarjeta {
    background-color: #f5f5f5;
    padding: 20px;
    margin: 15px;
    border-radius: 10px;
    text-align: center;
    transition: transform 0.3s, background-color... Continue reading "CSS Styling Techniques and Responsive Design" »

Residual claim: shareholders get only what is left-over after everyone has been paid. Discount rate: the rate at which present and future values are traded off. Future value of cash flow: C x (1+ r)^n. R= (FV/PV)^1/n - 1. Present value= C/(1+ r)^n. Compound interest: exponential growth in wealth, initial amount of money + the interest that has been added the previous years. Perpetuity, Growing Perpetuity, Annuity: multiple payments overtime, same amount, regular interest. NPV: the difference between and investment's value and its cost. Positive NPV=investment yes; NPV=0 project earns the required rate. . IRR measures the average return on the investment: accept project if IRR is greater than the discount rate(minimum return you want). Payback