A centered heptagonal number is a type of figurate number that represents a heptagon (a polygon with seven sides) with a center point. These numbers can be generated using a specific formula.

"Portrait" is the debut studio album by British singer Rick Astley, released on November 16, 1987. The album features Astley's distinctive baritone voice and his blend of pop and dance music. It includes his iconic hit single "Never Gonna Give You Up," which topped charts around the world and became an enduring pop culture phenomenon.

The Central Security Service (CSS) is a U.S. government organization that plays a crucial role in the collection and analysis of signals intelligence (SIGINT). It was created in 1972 and operates as part of the National Security Agency (NSA). The CSS primarily focuses on providing support to the Department of Defense (DoD) by assisting military cryptologic operations and ensuring the effective use of signals intelligence in military contexts.

K-mirror optics is a specific configuration used in optical systems, primarily in the design of telescopes and other imaging instruments. The term "K-mirror" typically refers to a type of optical scheme that employs multiple mirrors to achieve specific imaging or focusing properties. A K-mirror system generally consists of two mirrors arranged in a way that allows light to be reflected and focused in a desired manner.

"Songs by Others" typically refers to a collection of songs that are not originally by the main artist but are performed or covered by them. This term is often used in the context of albums, playlists, or performances where an artist pays tribute to other musicians by interpreting their work. It can include cover versions of songs from various genres and eras, showcasing the artist's influences and the songs that have inspired them.

"The Finally LP" is the debut studio album by the American hip-hop duo, The Healing Component, which consists of artists Saba and daedaePIVOT. Released on October 24, 2020, the album explores themes of personal growth, mental health, and the complexities of relationships, featuring a blend of introspective lyrics and a diverse musical style. The project has received positive reviews for its lyrical depth and production quality.

A Certificate Signing Request (CSR) is a block of encoded text that is generated on the server where the certificate will be installed. It is used to request a digital certificate from a Certificate Authority (CA). A CSR contains important information about the entity requesting the certificate, including: 1. **Public Key**: The public key that will be included in the certificate.

A Certification Practice Statement (CPS) is a formal document that outlines the practices and policies that a Certification Authority (CA) follows to issue digital certificates. It serves as a crucial part of a Public Key Infrastructure (PKI) and contains detailed information about the processes related to the management of digital certificates. Key components that are typically included in a CPS include: 1. **Certificate Lifecycle Management**: Details the processes regarding the issuance, renewal, revocation, and expiration of certificates.

Cetyl alcohol is a fatty alcohol derived from natural sources such as coconut oil or palm oil. Chemically, it is known as hexadecan-1-ol, with the molecular formula C16H34O. This compound appears as a white, waxy solid at room temperature and is often used in various cosmetic and personal care products due to its emollient properties.

Chagai-II refers to a series of nuclear tests conducted by Pakistan on May 30, 1998. These tests were carried out shortly after India conducted its own nuclear tests earlier that month, known as Pokhran-II. Chagai-II consisted of several underground nuclear detonations in the Chagai District of Balochistan province. The tests solidified Pakistan's status as a nuclear-armed country and were met with international condemnation and sanctions.

A chain drive is a mechanical system used to transmit power and motion between two rotating shafts. It consists of a chain that runs over a series of sprockets (toothed wheels) attached to the shafts. Chain drives are commonly found in various applications, including bicycles, motorcycles, industrial machinery, and automotive systems. ### Key Features of Chain Drives: 1. **Components**: - **Chain**: A series of interconnected links that transfer power between sprockets.

Chained volume series is an economic measurement technique used to assess changes in real output or volumes of goods and services over time, accounting for inflation or deflation. This method is particularly useful for analyzing economic data where traditional measures, such as the simple percentage change, may not accurately reflect the underlying trends due to the effects of varying inflation rates or changes in relative prices over time.

Charles-Augustin de Coulomb (1736–1806) was a French physicist and civil engineer best known for his work in electrostatics and magnetism. He is most famous for formulating Coulomb's Law, which describes the force between two charged objects. This law states that the electric force between two point charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them.

In computer science, the term "channel system" can refer to a variety of concepts depending on the context, but it is often associated with communication mechanisms or data transfer methods. 1. **Channels in Concurrency**: In the context of concurrent programming, channels are used as a way to facilitate communication between different threads or processes. They allow for the safe exchange of data by providing a way to send and receive messages.

Charbel Farhat is a prominent figure in the field of aeronautics and engineering, particularly known for his contributions to computational mechanics and aerospace engineering. He is a professor at Stanford University, where he has conducted extensive research and published numerous papers on topics such as structural analysis, fluid dynamics, and simulation methods. Farhat's work often involves the development and application of advanced numerical methods, including finite element methods and implicit time integration techniques, which are used in the analysis and design of complex engineering systems.

Pulvermacher's chain, also known as Pulvermacher's catholicon or Pulvermacher's electro-galvanic chain, is a type of medical device that was developed in the 19th century. It consists of a series of connected galvanic cells made from galvanic metals—typically zinc and copper—arranged in a chain. The purpose of this device was to deliver low-level electrical currents to the body for therapeutic purposes.

The Probability of Default (PD) is a financial term used to quantify the likelihood that a borrower will fail to meet their debt obligations within a specified time frame, such as one year. It is a critical metric in credit risk management, used by lenders, investors, and financial institutions to assess the creditworthiness of borrowers, including individuals, corporations, and governments.

The Charlie-Gibbs Fracture Zone is a significant transform fault located in the North Atlantic Ocean. It serves as a boundary between the North American Plate and the Eurasian Plate. This geological feature is characterized by its linear extent and the distinctive horizontal motion of tectonic plates on either side. The fracture zone is named after two nearby shipping routes: the Charlie and Gibbs routes.

The Georgi–Jarlskog mass relation is a theoretical expression in particle physics that relates the masses of different quarks and leptons based on certain symmetries of the Standard Model, particularly in the context of grand unified theories (GUTs) and higher-dimensional theories.

"Punk Goes Pop Volume Two" is a compilation album in the "Punk Goes Pop" series, which features various punk, rock, and alternative bands covering popular pop songs. Released on November 22, 2006, this album includes a variety of artists and showcases their unique interpretations of chart-topping hits, blending punk and rock styles with mainstream pop music.