Notes, summaries, assignments, exams, and problems

Principle of Chromatography - Chromatography is a separation method where the analyte is combined within a liquid or gaseous mobile phase, which is pumped through a stationary phase. Usually, one phase is hydrophilic and one is lipophilic. The components of the analyte interact differently with these two phases. Depending on their polarity, they spend more or less time interacting with the stationary phase. This leads to the separation of different components present in the sample. Each sample component elutes from the stationary phase at a specific time called retention time.

Types of Chromatography

1. Liquid Chromatography - This type of chromatography is used to separate and analyze non-volatile compounds. In this technique, the sample is dissolved

1. Client Initiation and DNS Lookup

• The user enters a URL or clicks a link in the browser. The browser parses the URL and extracts the domain (e.g., www.example.com).

• A **DNS lookup** translates this domain into an IP address—acting like a digital phonebook entry.

2. Establishing the TCP Connection

The browser’s operating system (OS) creates a socket and initiates the **TCP three-way handshake** with the server:

1. SYN: Client sends a synchronization request to the server.
2. SYN-ACK: Server acknowledges the request and sends its own synchronization.
3. ACK: Client acknowledges the server's response.

Once this handshake is complete, a full-duplex TCP connection is open and ready for reliable data exchange.

3. Sending the HTTP Request Message

The client constructs... Continue reading "The Complete HTTP Request Lifecycle Explained Step-by-Step" »

JavaScript Regular Expressions: An Introduction

This concise and clear introduction to Regular Expressions (RegExp) in JavaScript covers their usage, modifiers, patterns, methods, and string integration.

Regular Expressions are powerful patterns used to match, search, and manipulate strings. In JavaScript, regular expressions are objects used with string methods to perform pattern matching.

RegExp Syntax Fundamentals

You can define a regular expression using literal notation:

const pattern = /expression/modifiers;

Or by using the RegExp constructor:

const pattern = new RegExp("expression", "modifiers");

RegExp Modifiers (Flags) Explained

Modifiers change how a Regular Expression behaves:

Understanding Political Economy

Political economy applies economic principles to the analysis of political decision-making.

Public Goods & Direct Democracy

Economists have studied several methods for choosing levels of public goods in a direct democracy.

Lindahl Pricing & Preference Revelation

Lindahl pricing results in a unanimous decision to provide an efficient quantity of public goods, but relies on honest revelation of preferences.

Majority Voting Challenges

Majority voting may lead to inconsistent decisions regarding public goods if some people's preferences are not single-peaked.

Logrolling: Trading Votes

Logrolling allows voters to express the intensity of their preferences by trading votes. However, minority gains may come at the expense... Continue reading "Political Economy: Government Decisions & Public Policy" »

Qualification and Disqualification of Candidates

This document outlines the qualifications and disqualifications for becoming a member of Parliament and State Legislatures, drawing from the Constitution of India (Articles 84, 101, 102, 103, 104 for Parliament, and 173, 190, 191, 192 for State Legislatures) and Sections 3 to 11A of the Representation of the People (R.P.) Act, 1951.

Constitutional Disqualifications for Legislators

• Holding any office of profit under the Government of India or the government of any state.
• Being of unsound mind as declared by a competent court.
• Being an undischarged insolvent.
• Not being a citizen of India.
• Disqualification by or under any law made by Parliament (including the 10th Schedule).

Relevant Sections of the R.P.

Yellow Fever Vaccination: Requirements and Procedure

Vaccination Fees

The total cost for the Yellow Fever vaccination service is $120, broken down as follows:

• Travel Consultation Fee: $50
• Yellow Fever (YF) Assessment Fee: $50
• Injection Fee: $20

Country Requirements for Yellow Fever Vaccine

The following countries often require proof of Yellow Fever vaccination for entry:

Pharmacy Workflow Steps

1. Patient checks in.
2. Fees are explained (Total: $120).
3. Consent is obtained.
4. Check Travax: Ensure the administration date is at least 10 days before the

Chapter 12: Chemical Kinetics

1. Reaction Rate & Stoichiometry

For aA+bB→cC+dD:

Rate = −(1/a)∗Δ[A]/Δt = −(1/b)∗Δ[B]/Δt = (1/c)∗Δ[C]/Δt = (1/d)∗Δ[D]/Δt

• Rate is always positive. Reactants are negative, products positive.
• Ex: 2NO2​→2O2​. If Rate of disappearance of NO2​=0.010: Rate = −(1/2)∗(0.005 M/s. Rate of formation of O2​=0.005. Rate of formation of NO=20.005 M/s=0.010.

2. Rate Laws & Reaction Order

Rate = k[A]m[B]n

• k: Rate constant (temp-dependent)
• m,n: Reaction orders (exp. Determined)
• Overall Order = m+n
• Method of Initial Rates: Compare two experiments where only one reactant's conc. Changes. (Rate/Rate) = ([A]2​/[A]1​)
  • If Rate x2 when [A] x2 ⟹m=1 (1st order)
  • If Rate x4 when [A] x2 ⟹m=2 (2nd order)

Understanding English Clause Structures

Relative Clauses

• Adnominal Relative Clauses

  These clauses depend on and refer back to a noun. They can be restrictive (e.g., 'The house that I bought is small,' where 'that' functions as a direct object) or non-restrictive (e.g., 'John, who is my brother, is tall'). Their syntactic function is to modify the noun, acting as the antecedent.

• Nominal Relative Clauses

  These clauses have no explicit antecedent; the relative pronoun acts like a noun (e.g., 'What I bought was a house').

• Sentential Relative Clauses

  In these clauses, the antecedent is a whole clause, with the relative pronoun referring back to the entire preceding clause.

Complement Clauses

Complement clauses function as complements of larger constructions.... Continue reading "English Clause Types and Relativizer Dynamics in Singapore English" »

Understanding Macronutrients and DRIs

Macronutrients

Macronutrients, which include protein, carbohydrates, and fat, are required by the body in relatively large amounts (hence "macro"). All three provide energy. Fiber is a type of carbohydrate.

Dietary Reference Intakes (DRIs)

The Acceptable Macronutrient Distribution Ranges (AMDRs) are part of the DRIs. They recommend a balance of macronutrients, expressed as a percentage of total dietary energy, that is associated with:

• Maintenance of a healthy weight
• The lowest risk for chronic disease
• The lowest risk for nutrient deficiencies

Consuming macronutrients below or above these ranges increases the risk of chronic disease. Notably, the age group with the highest AMDR for fat is children aged 1-3 years.... Continue reading "Macronutrient Breakdown: Carbohydrates, Sugars, and Fats" »