Bidirectional current refers to an electrical current that can flow in two opposite directions. This characteristic is essential in various applications, including: 1. **Electric Vehicles (EVs)**: In electric vehicles, bidirectional current allows for the flow of electricity from the battery to the electric motor and vice versa, enabling functions like regenerative braking, where the motor acts as a generator to recharge the battery.
Galvanic shock, often referred to in the context of dentistry and medical devices, typically describes a sensation or discomfort caused by electrical currents created by certain metal dental restorations (like crowns or fillings) coming into contact with each other or with different materials in the mouth. This phenomenon can occur when a person's dental materials create a slight electric current due to their different electrical potentials when saliva acts as an electrolyte.
The Journal of Applied Electrochemistry is a scholarly peer-reviewed journal that publishes research articles, reviews, and technical notes focusing on the field of electrochemistry and its applications.
The Koutecký–Levich equation is an important equation in the field of electrochemistry that describes the relationship between the current density in an electrochemical reaction and the concentration of a reactant species, particularly in the context of finite-diffusion transport in an electrochemical system. It is often used to analyze mass transport in electrochemical systems, particularly in the study of electrodes.
Micro pitting is a surface degradation phenomenon that occurs in rolling element bearings, gears, and other mechanical components subject to high contact stresses and alternating loads. It is characterized by the formation of small, localized wear spots or pits on the surface of the material, usually at a microscopic level. These pits can significantly affect the performance and lifespan of mechanical components by leading to increased friction, noise, and ultimately premature failure.
Microwave enhanced electrochemistry refers to a method in electrochemical processes where microwave radiation is used to enhance the efficiency and effectiveness of electrochemical reactions. This approach leverages the unique properties of microwaves, such as rapid heating and the ability to selectively energize specific molecules or ions in a solution.
The Pitting Resistance Equivalent Number (PREN) is a numerical value used to assess the resistance of stainless steel and other alloys to pitting corrosion, particularly in environments that are chloride-rich, such as marine settings. Pitting corrosion is localized corrosion that leads to the formation of small holes or pits in the metal. PREN is calculated using the formula: \[ \text{PREN} = %Cr + 3.
Jefimenko's equations are a set of equations in electrodynamics that describe the electric and magnetic fields produced by time-varying charge and current distributions. They are noteworthy because they provide an explicit expression for electromagnetic fields resulting from arbitrary distributions of charges and currents, without requiring the use of the more complex concepts of potentials. These equations are derived from Maxwell's equations and are especially important in the theory of electromagnetic radiation.
Materials with memory, often referred to as "shape memory materials," are a class of advanced materials that can undergo significant changes in shape or properties in response to external stimuli, such as temperature, stress, or electric/magnetic fields. The most well-known examples of shape memory materials include shape memory alloys (SMAs) and shape memory polymers (SMPs).
Band bending is a phenomenon that occurs in semiconductor physics and materials science, particularly at the interface between two different materials, such as a semiconductor and a metal or between two different semiconductors. It describes the change in energy band structure, specifically the bending of the energy bands (valence band and conduction band) in response to an electric field, charge distribution, or the presence of interfaces.
Algebraic operations refer to mathematical processes that manipulate algebraic expressions and equations using rules of algebra. The primary algebraic operations include: 1. **Addition**: Combining two or more algebraic expressions. For example, \(a + b\) or \(2x + 3x = 5x\). 2. **Subtraction**: Removing one algebraic expression from another.
A linear equation is a mathematical equation that represents a straight line when graphed on a coordinate plane. It typically takes the form: \[ ax + by + c = 0 \] or in slope-intercept form: \[ y = mx + b \] where: - \( x \) and \( y \) are the variables. - \( a \), \( b \), and \( c \) are constants (with \( a \) and \( b \) not both zero).
A relation \( R \) on a set is called a transitive relation if, for all elements \( a, b, c \) in that set, whenever \( a \) is related to \( b \) (denoted \( aRb \)) and \( b \) is related to \( c \) (denoted \( bRc \)), then \( a \) must also be related to \( c \) (denoted \( aRc \)).
Two-element Boolean algebra, also known as Boolean algebra of two values, is a mathematical structure that deals with binary variables that can take on one of two values: typically represented as 0 and 1. This framework is foundational to digital logic and computer science.
Maxwell's theorem in geometry concerns the properties of convex polyhedra. It states that the number of vertices \( V \), edges \( E \), and faces \( F \) of a convex polyhedron are related by the formula: \[ V - E + F = 2 \] This relationship is a specific case of Euler's characteristic formula for polyhedra. The theorem is named after James Clerk Maxwell, who contributed to its formalization in the context of geometric topology.
The entropy of entanglement is a measure of the quantum entanglement between two parts of a quantum system. It quantifies how much information about one part of a system is missing when only the other part is observed. The concept is most commonly associated with bipartite quantum systems, which can be divided into two subsystems, often denoted as \(A\) and \(B\).
Pierre Sikivie is a physicist known for his work in theoretical physics, particularly in the fields of astrophysics and particle physics. He is best known for his research on axions, hypothetical particles proposed as a solution to the strong CP problem in quantum chromodynamics and as candidates for dark matter. Sikivie's work has contributed to the understanding of axions and their potential implications for both fundamental physics and cosmology.
The Möbius inversion formula is a result in number theory and combinatorics that provides a way to invert certain types of relationships expressed in terms of sums over divisors. It is named after the German mathematician August Ferdinand Möbius.
Chandrasekhar's white dwarf equation is derived from the principles of quantum mechanics and stellar physics to describe the maximum mass of a white dwarf star. The result, known as the Chandrasekhar limit, is approximately 1.4 times the mass of the Sun (about \(1.4 M_{\odot}\)). The equation is based on the balance between the gravitational forces trying to compress the star and the electron degeneracy pressure that arises due to the Pauli exclusion principle.
The Roche limit is the minimum distance to which a celestial body, such as a moon or a satellite, can approach a planet without being torn apart by the planet's tidal forces. This concept is named after the French astronomer Édouard Roche, who formulated it in the 19th century. The Roche limit depends on the densities of both the planet and the satellite.

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