The Vicat softening point is a measure of the temperature at which a material, typically a thermoplastic polymer, begins to soften and deform under a specified load. This point is determined using a standardized test, often the Vicat test, where a needle or other specified indenter is pressed into a material sample at a controlled rate while being heated.
Zeolite is a naturally occurring or synthetic mineral that belongs to a group of hydrated aluminosilicate minerals. They have a crystalline structure and are characterized by an open framework that contains cavities or pores, which can hold water and various cations like sodium, potassium, calcium, and magnesium. This unique structure allows zeolites to have the ability to exchange ions and to absorb and release water, making them useful in a wide range of applications.
The YORP effect, which stands for Yarkovsky-O'Keefe-Radikowski-Paddack effect, refers to a phenomenon that affects the rotation of small celestial bodies, such as asteroids and comets, in space. It results from the way these bodies absorb solar energy and then re-radiate that energy as thermal radiation. Here's how it works: 1. **Absorption and Re-radiation**: When an asteroid absorbs sunlight, it heats up.
Prestressed concrete is a type of concrete that is specially designed to withstand tensile stresses that occur in structures. This is achieved by introducing internal stresses to the concrete before it is subjected to external loads. The main objective of prestressing is to improve the performance of the concrete, allowing it to resist cracking and increasing its load-bearing capacity.
Brian D. Ripley is a prominent statistician known for his contributions to the fields of statistical computing, spatial statistics, and the development of the R programming language. He has played a significant role in advancing statistical methods and tools, particularly in the context of geostatistics and spatial analysis. Ripley is also recognized for his work on statistical models and for authoring influential books and papers. One of his notable works includes "Spatial Statistics," which is widely referenced in the field.
William Sealy Gosset (1876–1937) was an influential Irish statistician known primarily for developing the concept of the t-distribution, which is widely used in statistical inference. He worked at the Guinness Brewery in Dublin, where he applied statistical methods to improve the quality control of brewing processes. Gosset published under the pseudonym "Student," which is how the t-distribution is often referred to as the "Student's t-distribution.
A CCTV drain camera, often referred to as a plumbing camera or sewer camera, is a specialized device used in plumbing to inspect the interior of drainage systems, pipes, and sewers. This technology employs a small, high-resolution camera attached to a flexible cable that can be navigated through the plumbing system. Here’s a breakdown of how it works and its benefits: ### How It Works 1.
A pipe wrench is a type of adjustable wrench used primarily for gripping and turning cylindrical objects, particularly pipes. It features two jaws, one of which is fixed and the other is movable and can be adjusted to accommodate various pipe diameters. The design includes serrated teeth on the jaws, which provide a strong grip on the pipe, allowing the user to apply significant torque without slipping.
Repiping is the process of replacing old or damaged plumbing pipes in a building with new piping. This can be necessary for several reasons, including: 1. **Corrosion:** Over time, pipes can corrode, leading to leaks and water quality issues. Materials like galvanized steel or copper can deteriorate. 2. **Leaking Pipes:** Frequent leaks can indicate that the pipes are no longer functioning properly. Repiping can resolve these issues permanently.
Trace heating is a method used to maintain or raise the temperature of pipes, tanks, vessels, and other equipment in various industries. It involves heating cables or tapes that are applied along the surface of the material being heated to prevent freezing, maintain process temperatures, or ensure the proper functioning of the system. Trace heating can be applied in various forms, including: 1. **Electrical Trace Heating**: This involves using electrical heating cables that can be self-regulating or constant wattage.
Electric power systems are complex networks that generate, transmit, and distribute electrical energy to consumers. The main components of electric power systems can be categorized into several key parts: 1. **Generation**: - **Power Plants**: Facilities where electrical power is generated. These can be based on various sources such as: - Fossil Fuels (coal, natural gas, oil) - Nuclear Energy - Renewable Sources (solar, wind, hydroelectric, geothermal, biomass) 2.
Load balancing in the context of electrical power refers to the practice of distributing electrical loads across multiple power sources or components to ensure the efficient, stable, and reliable operation of an electrical power system. This process is crucial for maintaining the overall stability of power grids and preventing overloads that can lead to outages or equipment damage.
A spinor condensate is a state of matter characterized by the condensation of particles with intrinsic spin, specifically in systems where the particles have spin degrees of freedom that can be coupled to the system's order parameter. This concept primarily arises in the context of Bose-Einstein condensates (BECs) and quantum gases. In a typical spinor condensate, the particles exhibit a multicomponent wavefunction, where each component corresponds to a different spin state (e.g.
An electrophile is a species that is electron-deficient and can accept an electron pair from a nucleophile during a chemical reaction. Electrophiles are typically positively charged or neutral molecules with polar bonds that make them susceptible to nucleophilic attack. In organic chemistry, common examples of electrophiles include carbocations, carbonyl compounds, and halogenated compounds. In general, electrophiles play a crucial role in various reactions, including addition reactions, substitution reactions, and more.
Clar's Rule is a principle used in the field of organic chemistry, particularly in the study of polycyclic aromatic hydrocarbons (PAHs). It relates to the structure and stability of these compounds by focusing on the concept of resonance. Specifically, Clar's Rule states that the most stable resonance structures of PAHs can be determined by identifying the maximum number of completely benzenoid (aromatic) systems within the molecule.
Homoaromaticity is a concept in organic chemistry that describes a type of stability and electronic arrangement in certain cyclic compounds. Specifically, it refers to compounds where the stability typically associated with aromatic systems is present, but the compound lacks the traditional aromatic features such as a completely conjugated ring of p-orbitals.
LFER, or Linear Free Energy Relationship, is a concept used in chemistry to establish a correlation between the free energy of a reaction or process and various thermodynamic parameters, such as solvent properties. LFER solvent coefficients are numerical values that represent the sensitivity of a chemical reaction or property to changes in the solvent environment.
The "polar effect" can refer to various contexts depending on the field of study. Here are a few interpretations: 1. **Geographical Context**: In geography or environmental science, the polar effect might relate to how climate change impacts polar regions, leading to phenomena such as ice melting, ocean circulation changes, and shifts in ecosystems in the Arctic and Antarctic.
The Taft equation is a mathematical relation used in physical chemistry and molecular modeling to describe the relationship between the electronic properties of organic molecules and their chemical reactivity. More specifically, it is often employed to correlate various substituent effects in terms of their electronic nature on reaction rates or equilibrium constants.

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