Kirlian photography is a technique that captures the phenomenon of electrical discharges, often referred to as "electrography." This method was developed in the late 1930s by the Russian photographer Semyon Kirlian and his wife Valentina, who accidentally discovered that objects placed on a photographic plate connected to a high-voltage source would produce unique images characterized by glowing, colorful halos or auras around them.

Lightning refers to a natural electrical discharge that occurs during thunderstorms. It is characterized by a bright flash of light, a rapid release of energy, and can occur between clouds, between a cloud and the ground, or within a single cloud. The phenomenon is a result of the buildup of electrical charge within a storm cloud, which occurs due to the movement of water droplets and ice particles. When the difference in electrical charge becomes too great, it results in a sudden discharge of electricity, creating the lightning bolt.

Jerry Tersoff is a prominent American physicist recognized for his significant contributions to the field of condensed matter physics, particularly in the area of surface science, nanotechnology, and the development of theoretical models for the behavior of materials at the atomic scale. He is known for his work related to the theory of scanning tunneling microscopy (STM), which has played a crucial role in shaping our understanding of electronic and structural properties of surfaces and materials at the nanoscale.

Lightning activity levels are classifications or scales used to describe the frequency and intensity of lightning strikes in a particular area over a specific period. These activity levels can help meteorologists and researchers understand and predict thunderstorms and severe weather. Lightning activity levels can vary based on different factors, including: 1. **Frequency**: The number of lightning strikes within a given area over a defined time frame. 2. **Intensity**: The strength or energy of the lightning, which can affect the damage it may cause.

The list of electrical phenomena encompasses various behaviors and effects that occur due to the presence and movement of electric charges. Here are some key electrical phenomena: 1. **Electric Charge**: The fundamental property of matter, which can be positive or negative, leading to the attraction or repulsion between particles. 2. **Electric Current**: The flow of electric charge, typically measured in amperes (A). This can occur in materials that conduct electricity (like metals) or in electrolytes.

Mains hum, often referred to as "60 Hz hum" in the United States or "50 Hz hum" in many other countries, is an audible electrical noise that is typically associated with alternating current (AC) power supply systems. **Causes of Mains Hum:** 1. **Power Frequency:** The hum arises because of the frequency of the AC power supply. In the U.S.

Advanced Functional Materials is a multidisciplinary scientific journal that focuses on research in the field of materials science. It publishes high-quality articles covering a wide range of topics related to functional materials, which are materials designed to have specific properties and functionalities for various applications. These can include, but are not limited to, materials used in electronics, photonics, energy storage, nanotechnology, biomaterials, and environmental applications.

The multipactor effect is a phenomenon that occurs in vacuum environments, typically in high-frequency electronic devices, such as satellites, microwave systems, and spacecraft. It involves the emission and multiplication of electrons within a gaseous or vacuum medium, leading to a cascade of continuous electron emission and potentially causing device failure.

The piezoelectric coefficient is a measure of the efficiency with which a material converts mechanical energy into electrical energy (and vice versa) through the piezoelectric effect. It quantifies the relationship between the mechanical stress applied to a piezoelectric material and the resulting electric charge (or voltage) generated.

Piezoelectric microelectromechanical systems (PiezoMEMS) refer to systems that integrate piezoelectric materials with microelectromechanical systems technology. These systems leverage the piezoelectric effect, which is the ability of certain materials to generate an electric charge in response to applied mechanical stress, and vice versa.

A piezoelectric speaker is a type of speaker that utilizes the piezoelectric effect to convert electrical energy into mechanical vibrations, producing sound. The piezoelectric effect refers to the ability of certain materials (typically specific ceramics or crystals) to produce an electrical charge in response to applied mechanical stress and vice versa. ### Key Features of Piezoelectric Speakers: 1. **Construction**: Piezoelectric speakers typically consist of a piezoelectric ceramic or crystal element that is bonded to a diaphragm.

Piezoelectricity is the electrical charge that accumulates in certain materials (known as piezoelectric materials) in response to applied mechanical stress. When these materials are deformed—either by compression, tension, or shear—they generate an electrical voltage. Conversely, applying an electrical voltage to these materials can induce a mechanical deformation. The term "piezoelectric" comes from the Greek word "piezein," which means "to press.

An active circulator is a type of radio frequency (RF) component used in microwave and antenna systems to direct the flow of signals. Unlike passive circulators, which rely solely on passive components and ferrite materials to route RF signals, active circulators incorporate active components, like amplifiers, to enhance signal transmission and improve overall performance.

Natalia Komarova is a mathematician and professor known for her work in the fields of mathematical biology, dynamical systems, and applied mathematics. She has made significant contributions to understanding complex systems, particularly in areas such as cancer modeling, evolutionary biology, and the dynamics of infectious diseases. Komarova is also recognized for her interdisciplinary approach, combining mathematics with biological problems to provide insights into various phenomena in life sciences.

Relativistic runaway electron avalanche (RREA) is a phenomenon that occurs in strong electric fields, typically in the context of thunderstorm electrification, atmospheric electricity, or other high-energy physics systems. It involves the generation of high-energy electrons that can lead to an exponential increase in the number of secondary electrons through a process of ionization and acceleration.

Relaxor ferroelectrics are a class of materials that exhibit a complex dielectric response due to their unique structural and electronic properties. These materials are characterized by their diffuse phase transition, meaning they do not have a sharp transition from a non-polar (cubic or high-temperature phase) to a polar (tetragonal or low-temperature phase) state, as seen in conventional ferroelectric materials.

The Sauerbrey equation is a fundamental principle used in the field of quartz crystal microbalance (QCM) sensing. It relates the change in frequency of a quartz crystal oscillator to the mass of material that has been deposited on its surface. The equation is particularly useful for measuring thin films and mass changes at the nanogram level.

Stoletov's law refers to a principle in the field of photoconductivity and describes the relationship between the intensity of light and the electrical conductivity of certain materials, particularly semiconductors. Formulated by the Russian physicist Alexander Stoletov in the late 19th century, the law states that the photoelectric effect leads to an increase in the electrical conductivity of a material when it is exposed to light.

The triboelectric effect is a phenomenon in which certain materials become electrically charged after they come into frictional contact with each other. When two different materials rub against each other, electrons may transfer from one material to the other, resulting in one material becoming positively charged and the other negatively charged. The degree of charge exchange depends on the properties of the materials involved and their position in the triboelectric series, which is a list that ranks materials based on their tendency to gain or lose electrons.

The two-photon photovoltaic (TPPV) effect refers to a process in which two photons are simultaneously absorbed by a semiconductor material, leading to the generation of an electrical current. Unlike the traditional photovoltaic effect, where a single photon creates an electron-hole pair (exciton) that can contribute to electrical conduction, the TPPV effect specifically involves the absorption of two photons such that their combined energy exceeds the bandgap energy of the semiconductor.