The International Meridian Conference was a meeting held in Washington, D.C., in 1884, which aimed to establish a standard for the Prime Meridian and coordinate global timekeeping. The conference was attended by representatives from 25 nations and resulted in the adoption of the Greenwich Meridian as the prime reference point for international timekeeping and geography.
Fast Automatic Restoration (FAR) typically refers to a system or process designed to quickly restore data, systems, or applications to a normative state following an incident such as a failure, outage, or data corruption. The goal of FAR is to minimize downtime and ensure business continuity by providing a rapid recovery mechanism. Key elements of Fast Automatic Restoration may include: 1. **Automated Backups**: Regularly scheduled backups that can be automatically restored when needed.
Allotropes are different forms of the same element, where the atoms are arranged in different ways. Iron has several allotropes, mainly distinguished by their crystal structures and physical properties. The primary allotropes of iron are: 1. **Alpha Iron (α-iron)**: Also known as ferrite, it is the most stable form of iron at room temperature. It has a body-centered cubic (BCC) crystal structure and is magnetic (ferromagnetic).
Dynamic recrystallization (DRX) is a process that occurs in materials, particularly in metals, during deformation processes such as hot working or high-temperature straining. It involves the formation of new, strain-free grains within a deformed microstructure while the material is being subjected to mechanical stress. This process is essential for understanding the mechanical behavior of materials, especially under conditions where they reach temperatures that facilitate recrystallization.
Hexaferrum is a type of material that is primarily composed of iron and exhibits ferrimagnetic properties. It consists of an arrangement of iron ions in a hexagonal crystal structure, which contributes to its magnetic characteristics. Hexaferrum is often studied for its potential applications in magnetic materials, including magnetic recording and data storage technologies, as well as in various electronic devices.
An Isothermal Transformation Diagram (often referred to as an IT diagram or TTT diagram for Time-Temperature-Transformation) is a graphical representation used in materials science and metallurgy to illustrate the phase changes of a material, typically steel, as it is cooled or heated under isothermal (constant temperature) conditions. ### Key Aspects of Isothermal Transformation Diagrams: 1. **Axes**: The diagram typically features temperature on the vertical axis and time on the horizontal axis.
Alloyant is a technology company that focuses on developing software solutions for various industries. It is known for utilizing emerging technologies, such as artificial intelligence and machine learning, to enhance its products and services. Alloyant may offer solutions in areas like data analytics, automation, or other innovative software applications, often catering to specific business needs. To provide the most accurate and detailed information, please verify the context or specific area of interest regarding Alloyant, as companies can evolve and change their offerings over time.
Prepainted metal, often referred to as pre-coated metal or prefinished metal, is a type of metal substrate, usually steel or aluminum, that has been coated with a layer of paint or other protective finish before it is formed into final products. This process generally involves two main steps: 1. **Surface Preparation**: The metal is thoroughly cleaned and treated to ensure good adhesion and to prevent corrosion. This may include processes such as washing, phosphating, and applying a primer.
Continuous Cooling Transformation (CCT) refers to a metallurgical process that describes the changes in the microstructure of a material, usually steel, as it cools at a continuous, rather than an instantaneous or isothermal, rate. This process is significant in understanding how cooling rates affect the phase transformation and mechanical properties of steel.
Metallic objects are items made primarily of metal, a material characterized by its conductivity, malleability, ductility, and luster. Metals possess specific physical properties that make them unique, such as high density, shiny appearance, and ability to conduct heat and electricity. Common examples of metallic objects include: 1. **Utensils**: Spoons, forks, knives made of stainless steel or silver.
The Global Powder Metallurgy Property Database (GPMPD) is a comprehensive online resource that provides standardized data on the properties of materials used in powder metallurgy (PM). Powder metallurgy is a manufacturing process that involves the production of metal parts from powdered materials, typically involving pressing and sintering techniques. The GPMPD collects and compiles data on various materials, including metals, alloys, and other compounds used in PM applications.
Martensite is a microstructure that forms in steel and other alloys during rapid cooling or quenching from a high temperature. It is characterized by its unique arrangement of atoms, which creates a distinct, hard, and brittle phase. The formation of martensite occurs when austenite, a face-centered cubic phase of iron, is rapidly cooled to below a certain temperature, known as the martensite start temperature (Ms).
Metal casting is a manufacturing process in which liquid metal is poured into a mold to create a specific shape or form upon solidification. This technique is one of the oldest known methods of shaping metal and is widely used in various industries, including automotive, aerospace, and construction, due to its ability to produce complex shapes with high precision.
Nanocrystalline materials are materials that have a crystalline structure with grain sizes typically in the nanometer range, usually defined as being smaller than 100 nanometers (1 nanometer = 1 billionth of a meter). These materials can be composed of metals, ceramics, semiconductors, or other substances, and their unique properties stem from their small grain size, which significantly influences their mechanical, electrical, thermal, and optical characteristics.
In slang, "stringer" typically refers to a freelance journalist or writer who contributes articles or news stories to various media outlets on a temporary or irregular basis. These individuals often work independently rather than being employed full-time by a single publication. The term can also imply a certain level of expertise or niche focus, as stringers are usually expected to find and report on stories that may not be covered by larger media organizations.
Permeability in the context of foundry sand refers to the ability of the sand to allow gases and liquids to pass through it. This property is crucial in the foundry industry, especially in sand casting processes, where the sand mixture is used to create molds for metal casting. Here are some key points about permeability in foundry sand: 1. **Importance in Casting**: During the casting process, molten metal is poured into a mold made of sand.
Silver overlay is a decorative technique often used in jewelry, tableware, and other decorative items. The process typically involves applying a thin layer of silver over a base material, which can be made of metals such as brass or copper. This method provides the appearance of solid silver while being more cost-effective and lightweight. There are a few key points about silver overlay: 1. **Appearance**: The silver layer gives the item a shiny, attractive finish that closely resembles that of solid silver.
Solid-state physics is a branch of physics that deals with the study of solid materials, particularly their properties and behaviors at the atomic and molecular level. This field encompasses a wide range of topics, including the structure, dynamics, and interactions of solid materials, with the goal of understanding how these properties arise from the arrangement and behavior of their constituent atoms and molecules.
Superalloys, also known as high-performance alloys, are a class of materials that are designed to withstand extreme conditions, such as high temperatures, high mechanical stress, and corrosive environments. These alloys are primarily used in applications where durability and reliability are crucial, such as in the aerospace, power generation, and automotive industries.
Centerless grinding is a manufacturing process used to grind cylindrical parts without the need for a central axis. Unlike traditional cylindrical grinding, where the part is held between centers, centerless grinding allows for continuous production of cylindrical components by utilizing a system of rollers and grinding wheels. ### Key Components: 1. **Grinding Wheel**: The primary abrasive wheel that removes material from the workpiece. 2. **Regulating Wheel**: A second wheel that controls the rotation and axial movement of the workpiece.

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