The Wood–Armer method is a technique used in soil mechanics, particularly for the determination of the moisture content and density of a soil sample. This method is often utilized for characterizing granular soils, allowing engineers and geologists to assess the compaction and stability of soil in various construction and civil engineering applications. In the Wood–Armer method, a specific volume of the soil sample is taken, and its weight is measured.
Gene targeting is a molecular biology technique used to create specific modifications in the genome of an organism. It allows researchers to alter, delete, or insert genes at precise locations in the DNA sequence. This method is particularly valuable in functional genomics and gene therapy, as it enables the study of gene function and the modeling of genetic diseases.
Ballistic foam is a type of material that is designed to provide protection against impacts, specifically from projectiles such as bullets or shrapnel. It is often used in various applications related to military and law enforcement, as well as in personal protective equipment and vehicle armor. Ballistic foam is typically lightweight and capable of absorbing and dissipating energy from incoming projectiles. It can be made from various materials, such as polyurethane or polyethylene foams, which are engineered to achieve specific performance characteristics.
Carbon nanofoam is a type of nanostructured carbon material characterized by its unique properties, including a high surface area, low density, and exceptional mechanical strength. It is composed of a network of interconnected carbon atoms, often arranged in a porous structure that resembles a foam. This material can be produced through various methods, such as laser ablation or chemical vapor deposition.
Polyimide foam is a type of polymer foam that is derived from polyimide, a high-performance thermosetting polymer known for its excellent thermal stability, mechanical properties, and resistance to chemicals and radiation. Polyimide foams are lightweight, have low thermal conductivity, and are often used in applications where high-temperature resistance and insulation are critical.
Agar is a gelatinous substance derived from red algae, specifically from the cell walls of certain species of seaweed. It is primarily composed of agarose and agaropectin, which are polysaccharides. Agar is commonly used in various applications, including: 1. **Culture Medium**: In microbiology, agar serves as a solid medium for growing bacteria and fungi in laboratory settings. Different types of agar, such as nutrient agar and agar plates, provide nutrients needed for microbial growth.
Polyacrylamide is a synthetic polymer derived from the acrylamide monomer. It is commonly used in various applications due to its hydrophilic properties and ability to form gels. Here are some key points about polyacrylamide: 1. **Chemical Structure**: Polyacrylamide is formed through the polymerization of acrylamide, and its structure consists of repeating units of the acrylamide monomer, which gives it its high molecular weight.
A thickening agent is a substance added to a liquid to increase its viscosity, which helps to create a thicker or more gelatinous consistency. Thickening agents are commonly used in various industries, including food production, cosmetics, pharmaceuticals, and oil drilling. In cooking, thickening agents can include: 1. **Starches**: Such as cornstarch, wheat flour, and tapioca. These are often used to thicken sauces, soups, and gravies.
Homogeneous alignment is a concept often used in the study of materials, especially in the fields of physics, materials science, and engineering. It refers to a uniform arrangement of structural features, properties, or characteristics throughout a material or system. In the context of materials, homogeneous alignment might pertain to the uniform distribution of grains in metals, the consistent orientation of polymer chains, or the organization of molecules in a liquid or crystalline solid.
Water is a chemical substance composed of two hydrogen atoms covalently bonded to one oxygen atom, represented by the chemical formula H₂O. It is a transparent, odorless, tasteless liquid at room temperature and is essential for all known forms of life. Here are some key characteristics and aspects of water: 1. **States of Matter**: Water naturally occurs in three states—liquid (water), solid (ice), and gas (water vapor or steam), depending on temperature and pressure.
CRC Industries is a company that specializes in the development and manufacturing of a wide range of products focused on maintenance, repair, and operations (MRO) for various industries. Founded in 1958 and headquartered in Warminster, Pennsylvania, CRC offers products such as lubricants, rust inhibitors, cleaning agents, sealants, and other specialty chemicals. The company serves diverse markets, including automotive, industrial, marine, and consumer applications.
Nye Lubricants, Inc. is a company that specializes in the development and manufacturing of high-performance lubricants and specialty fluids. Established in 1844, Nye Lubricants provides a wide range of products designed for various applications, including automotive, aerospace, electronics, industrial, and medical devices. The company's product offerings include both lubricants for standard applications and specialized formulations tailored to specific customer needs.
Spindle oil is a type of lubricant specifically designed for use in high-speed machinery, such as spindles in textile and sewing equipment, as well as in certain types of bearings and other precision instruments. It is typically characterized by its low viscosity and excellent lubricating properties, which help reduce friction and wear between moving parts. Key features of spindle oil include: 1. **Low Viscosity**: This allows it to flow easily and provide lubrication to areas that may have tight clearances.
Iron-56 (Fe-56) is a stable isotope of iron, which is one of the most abundant elements in the universe and a key component of many materials found on Earth. Isotopes of an element have the same number of protons but different numbers of neutrons. For Iron-56, it has 26 protons and 30 neutrons, giving it a total atomic mass of approximately 56 atomic mass units (amu).
Δ¹⁸O (Delta oxygen-18) is a measure of the ratio of stable isotopes of oxygen, specifically the ratio of oxygen-18 (¹⁸O) to oxygen-16 (¹⁶O). It is expressed as a difference in parts per thousand (‰) compared to a standard reference material, typically Vienna Standard Mean Ocean Water (VSMOW).
Isotopically pure diamond refers to a diamond that is composed entirely of one stable isotope of carbon, typically carbon-12 (C-12). Natural diamonds contain a mixture of carbon isotopes, mainly carbon-12 and carbon-13, with trace amounts of carbon-14 present due to cosmic radiation.
Iodine-129 (\(^{129}\text{I}\)) is a radioactive isotope of iodine. It has a half-life of approximately 15.7 million years, making it a long-lived isotope.
Nitrogen-13 (\(^{13}\text{N}\)) is a radioactive isotope of nitrogen. It has 7 protons and 6 neutrons in its nucleus, which gives it an atomic mass of approximately 13 atomic mass units (amu). This isotope is notable for its role in nuclear medicine, particularly in positron emission tomography (PET) imaging.
Plutonium-242 is an isotope of plutonium, which is a radioactive metallic element with the atomic number 94. It is one of the several isotopes of plutonium, and it has a relatively long half-life of about 376,000 years. This makes it one of the more stable isotopes of plutonium, though it is still radioactive.
Potassium-40 (K-40 or ^40K) is a naturally occurring isotope of potassium, which is a vital nutrient for various biological and geological processes. It is one of the three stable isotopes of potassium, alongside Potassium-39 (^39K) and Potassium-41 (^41K). K-40 is notable because it is radioactive and has a long half-life of about 1.248 billion years, which means it decays very slowly.

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