The Grunwald-Winstein equation is a notable relationship in organic chemistry that relates the solvent effects on the rates of nucleophilic substitution reactions, particularly those involving substrates that undergo unimolecular nucleophilic substitution (S_N1) and bimolecular nucleophilic substitution (S_N2) mechanisms.
The Hammett equation is a mathematical expression used in physical organic chemistry to relate reaction rates and equilibrium constants of reactions involving substituted aromatic compounds to the electronic effects of the substituents. It provides a quantitative measure of how substituents (such as -NO2, -Cl, -CH3, etc.) influence the reactivity of the aromatic compound in electrophilic or nucleophilic reactions.
Negative hyperconjugation refers to a phenomenon in organic chemistry where electron donation occurs from a filled p orbital or lone pair on a substituent to a π* (pi anti-bonding) orbital of a neighboring bond, such as a carbon-carbon double bond or a carbon-heteroatom bond. This process leads to a stabilization of the system by delocalizing the electrons across the molecule.
The Woodward–Hoffmann rules are a set of principles used in organic chemistry to predict the outcome of pericyclic reactions, which are reactions that involve cyclic transition states and occur via a concerted mechanism (simultaneous bond-breaking and bond-forming processes). Named after chemists Robert Burns Woodward and Donald Albert Hoffmann, these rules provide a framework to determine whether a pericyclic reaction is thermally allowed or forbidden based on molecular orbital (MO) theory.
"Gravitation" is a comprehensive textbook on gravitational physics, co-authored by Charles W. Misner, Kip S. Thorne, and John Archibald Wheeler. First published in 1973, it is often regarded as a classic in the field of general relativity and gravitational physics. The book provides an in-depth exploration of the concepts and mathematical formulations of Einstein's theory of general relativity, as well as its applications to various physical phenomena.
Georges-Louis Le Sage was an 18th-century Swiss physicist and philosopher, born on June 16, 1724, and he passed away on August 2, 1803. He is best known for his work in the fields of gravity and atomic theory. Le Sage is particularly noted for proposing a mechanical explanation of gravity, often referred to as the "Le Sage theory of gravitation.
Milü, often referred to as "Milu" or "Milü deer," is a species of deer known scientifically as *Elaphurus davidianus*. It is native to eastern Asia, particularly China, and is known for its distinctive appearance, which includes large antlers and a striking coat. The Milü is notable for its long, slender legs and adaptations to wetland habitats.
Lead zirconate titanate (PZT) is a ceramic compound composed of lead, zirconium, and titanium. It has the chemical formula \( \text{Pb(Zr}_{x}\text{Ti}_{1-x})\text{O}_3 \), where \( x \) can vary to create different compositions of the material. PZT is well-known for its piezoelectric properties, which means it can generate an electrical charge in response to applied mechanical stress and vice versa.
Cured-in-place pipe (CIPP) is a trenchless rehabilitation method used to repair existing pipelines, particularly those made of materials like clay, concrete, or PVC. This technique is commonly employed for sewer, water, and drain systems. ### Key Features of CIPP: 1. **Process**: - **Preparation**: The existing pipe is inspected, usually using video cameras, to assess its condition. Any obstructions are cleared.
Pipe marking refers to the labeling of pipes in industrial and commercial settings to indicate the contents, direction of flow, hazards, and other important information. This practice is essential for safety, maintenance, and operational efficiency. Properly marked pipes help workers quickly identify the substances flowing through them, enabling safer handling and preventing accidents. Key elements of pipe marking include: 1. **Color Coding**: Different colors are used to represent various types of contents.
In plumbing, a "nipple" is a short piece of pipe that has threaded ends, allowing it to connect two other fittings or pieces of pipe. Nipples are typically used to extend the reach of existing pipes, to connect various components in a plumbing system, or to serve as a transition between different types of pipes or fittings. They are often made from materials such as steel, brass, copper, or plastic, depending on the application and the fluid being transported.
The tubular pinch effect is a phenomenon observed in plasmas, particularly in the context of magnetic confinement fusion. It refers to the compression of plasma into a cylindrical or tubular shape under certain conditions, which can enhance the confinement of the charged particles within the plasma. This effect can be achieved with the use of magnetic fields, where the magnetic forces act to squeeze the plasma into a tighter configuration.
Pipeline video inspection is a method used to visually assess the condition of pipelines using specialized video equipment. This technique involves inserting a camera into the pipeline to capture real-time footage or recordings of the interior surfaces. It is widely used for various types of pipelines, including sewer, stormwater, gas, oil, and water lines. ### Key Benefits and Features 1.
A Process Flow Diagram (PFD) is a type of flowchart that illustrates the flow of materials and information through various processes within a system. It is commonly used in engineering, manufacturing, and business contexts to provide a visual representation of the steps involved in a process, showing how inputs are transformed into outputs.
The "list of exoplanet firsts" refers to notable milestones and achievements in the discovery and study of exoplanets (planets located outside our solar system). Here are some significant firsts in the field: 1. **First Confirmed Exoplanet**: 51 Pegasi b (1995) - Discovered by Michel Mayor and Didier Queloz, this was the first exoplanet found orbiting a sun-like star.
The Plasma Acoustic Shield System (PASS) is a technology developed to reduce the impact of sound and noise pollution. Although specific technical details can vary depending on the application and the context in which it's used, the basic principle behind a plasma acoustic shield involves using plasma – ionized gas made up of particles that can conduct electricity – to manipulate sound waves. Here's a general overview of how such a system might work: 1. **Plasma Generation**: The system generates plasma using electrical energy.
Cartonplast refers to a brand of reusable, durable plastic pallets and containers designed primarily for the transport and storage of goods. The Cartonplast products are made from high-quality materials, typically polypropylene, and offer a sustainable alternative to traditional wooden pallets or cardboard boxes. These products are used in various industries such as food and beverage, agriculture, logistics, and manufacturing, providing benefits like improved hygiene, reduced waste, and enhanced shelf life for products.
Commodity plastics are a category of plastics that are produced in large quantities and are typically used for a wide range of everyday applications. These plastics are characterized by their relatively low cost, ease of processing, and general availability. They are often used to manufacture a variety of consumer products, packaging materials, automotive parts, household goods, and more.
Ionomers are a type of polymer that contain ionizable groups, which can be either cationic or anionic. These groups give the material unique properties that differ significantly from typical polymers. Here are some key points about ionomers: 1. **Structure**: Ionomers are typically derived from standard polymers, such as polyethylene or polypropylene, to which small amounts of ionic or ionizable groups are incorporated.
Polyvinyl nitrate (PVN) is a synthetic polymer formed from the polymerization of vinyl nitrate monomers. It is a type of nitrated polymer that contains nitrate functional groups within its structure. Like other nitrated polymers, PVN can exhibit properties that make it suitable for specific applications, particularly in the areas of energetic materials, explosives, or propellants.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 2.
    You can publish local OurBigBook lightweight markup files to either https://OurBigBook.com or as a static website
    .
    Figure 3.
    Visual Studio Code extension installation
    .
    Figure 4.
    Visual Studio Code extension tree navigation
    .
    Figure 5.
    Web editor
    . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
    Video 4.
    OurBigBook Visual Studio Code extension editing and navigation demo
    . Source.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact