The Olami-Feder-Christensen (OFC) model is a theoretical framework used to study the dynamics of earthquakes and the mechanics of fault systems. Developed by the physicists Daniel Olami, Sergio Feder, and Hyman Christensen in 1992, the OFC model is a type of self-organized criticality (SOC) model that simulates how stress accumulates in a system and leads to seismic events.

"Promoting adversaries" can refer to various contexts depending on the situation. Generally, it may describe the practice of elevating or enhancing the status, visibility, or capabilities of opponents or rival entities. This can occur in political, social, or competitive environments. Here are a few possible interpretations: 1. **Political Context**: In politics, promoting adversaries might involve giving attention or credibility to opposing viewpoints, which can sometimes strengthen their position or influence.

The Hille–Yosida theorem is a fundamental result in functional analysis that characterizes the generators of strongly continuous semigroups of linear operators on Banach spaces. It provides a set of conditions under which a certain type of linear operator can be considered the generator of a strongly continuous semigroup. This theorem is particularly important in the study of evolution equations and the analysis of time-dependent systems.

A **null semigroup** is a concept from algebra, specifically in the context of semigroup theory. A semigroup is a set equipped with an associative binary operation. In the case of a null semigroup, this structure is characterized by the presence of a zero element (often denoted as 0), such that the operation involving this zero element yields 0 when combined with any other element of the semigroup.

A quasicontraction semigroup is a concept from functional analysis and the theory of semigroups of operators, particularly in the context of Banach spaces. It generalizes the notion of a strongly continuous semigroup, commonly referred to as a \(C_0\)-semigroup, to situations where the mappings may not preserve all the properties of contractions.

A **refinement monoid** is a concept from algebra and theoretical computer science, specifically in the context of algebraic structures and formal language theory. It is a special type of monoid that is used to model certain types of relationships and transformations on sets or structures. In general, a **monoid** is an algebraic structure consisting of a set equipped with an associative binary operation and an identity element.

"Union Harmony" could refer to different concepts depending on the context in which it's used. It may relate to principles in music, philosophy, social movements, or other areas. Without a specific context, it's challenging to provide a precise definition. 1. **In Music**: Union Harmony may refer to the blending or combination of different musical elements or styles to create a cohesive sound.

The Semigroup Forum is a scholarly journal dedicated to the study of semigroups and their applications in various fields of mathematics. Semigroups are algebraic structures that generalize groups, and they have important applications in areas such as automata theory, digital communications, and mathematical biology. The journal publishes research articles, survey papers, and other contributions that advance the theory and applications of semigroups.

"Sequences in time" generally refers to a series of events, actions, or phenomena that occur in a specific chronological order. This concept can apply to various fields and contexts, including: 1. **History**: Sequences of historical events can outline the progression of significant occurrences over time, helping us understand causality and the development of societies.

A tuple is a data structure used in programming to store a collection of items. It is similar to a list but has some key differences: 1. **Immutability**: Once a tuple is created, its elements cannot be changed, added, or removed. This makes tuples suitable for fixed collections of items where immutability is required. 2. **Syntax**: In Python, for example, tuples are created by placing a comma-separated sequence of items inside parentheses.

The Champernowne constant is a decimal number that is constructed by concatenating the positive integers in sequence. It is defined as follows: \[ C_{10} = 0.123456789101112131415161718192021...

The "New Harp of Columbia" is a collection of songs and music compiled primarily for use in American revival meetings and religious gatherings during the 19th century. It was published in 1884 and is associated with the use of hymns and spiritual music in Christian worship, particularly in the context of the evangelistic movements of that era. The compilation often includes a mix of traditional hymns, newly composed songs, and various arrangements aimed at fostering congregational singing.

William Burton Walbert is not a widely recognized public figure, historical person, or notable entity up until my last knowledge update in October 2021. If you have a specific context in mind, such as a field of study, profession, or a certain event related to this name, please provide more details, and I would be happy to help! It's also possible that new developments have occurred after my last update, so checking current sources may yield more information.

Picoplankton refers to a size class of plankton that includes tiny, microscopic organisms typically ranging from 0.2 to 2 micrometers in size. This group primarily consists of photosynthetic and heterotrophic microorganisms, including certain types of bacteria, cyanobacteria, and small phytoplankton. Picoplankton plays a crucial role in marine and freshwater ecosystems as they are primary producers and contribute significantly to the aquatic food web.

Aldine Silliman Kieffer is a name that does not appear to be widely recognized in historical, cultural, or scientific literature as of my last knowledge update in October 2021. It's possible that this individual may be a private person, or could be a name that has gained significance in a specific field or community after that date.

Low-background steel refers to a type of steel that has been specifically processed to minimize its radioactive background, particularly the levels of natural radioactivity. It is commonly used in applications where low levels of radiation are crucial for the integrity of experiments or measurements, such as in nuclear physics, radiation detection, or in the construction of sensitive scientific instruments. The steel is typically sourced from areas or processes known to have low natural radioactive content, or it might be manufactured using methods that reduce the concentration of radioactive isotopes.

Jacob Kimball Jr. was an American businessman and politician from Massachusetts in the 19th century. He was notably involved in the textile industry and served as a member of the Massachusetts House of Representatives. Jacob Kimball Jr. is often recognized for his contributions to local commerce and governance during his time. If you meant something else by "Jacob Kimball Jr.

As of my last knowledge update in October 2023, "Supply Belcher" does not appear to be a widely recognized term or concept in any mainstream context. It's possible that it could refer to a specific term in a niche industry, a local business, or perhaps a concept that has emerged more recently.

"The Christian Harmony" refers to a shape-note hymn book created by William Walker, first published in 1835. It is significant in the American sacred music tradition, particularly in the Southern United States. Walker's book features a simpler music notation system designed to aid congregations and choirs in singing hymns. Shape-note music uses different shapes to represent different musical notes, making it easier for singers—especially those who may not have formal music training—to learn and perform hymns.

Fractional approval voting is a voting method that extends the concept of approval voting, where voters can express approval for multiple candidates. In fractional approval voting, voters can not only approve of a candidate but also indicate varying degrees of approval, effectively allowing voters to allocate fractional values (e.g., from 0 to 1) to each candidate based on their preferences.