Laser-induced incandescence
Laser-Induced Incandescence (LII) is a diagnostic technique used primarily in the study of combustion and particulate matter in various environments. It involves the use of a laser to excite particles, such as soot or other nanoparticles, to a high energy state. When these particles absorb the laser energy, they become incandescent, emitting light as they return to their lower energy states.
Laser diffraction analysis
Laser diffraction analysis is a widely used technique for measuring the size distribution of particles in a sample. This method is based on the principle of diffraction, which occurs when a beam of light interacts with particles. Here’s how it works and its key aspects: ### Principles of Laser Diffraction 1. **Laser Beam**: A coherent light source, typically a laser, emits a beam of light that is directed towards a sample containing particles.
Light Scattering Spectroscopy
Light Scattering Spectroscopy (LSS) is an analytical technique that involves studying the scattering of light by particles or molecules in a sample. It is primarily used to characterize the size, shape, and distribution of small particles, as well as to analyze the properties of macromolecules, such as proteins and polymers, in solution.
Linear dichroism
Linear dichroism (LD) is a spectroscopic technique used to study the orientation of molecules in a sample by measuring the difference in absorbance of light polarized in different directions. It is particularly useful for analyzing macromolecules like proteins, nucleic acids, and some types of polymers. In a typical LD experiment, a sample is illuminated with linearly polarized light, and the absorbance is measured for two orthogonal polarization directions (usually parallel and perpendicular to a particular molecular axis).
List of spectroscopists
A list of spectroscopists typically includes notable scientists and researchers who have made significant contributions to the field of spectroscopy. Spectroscopy is the study of the interaction between matter and electromagnetic radiation, and it has applications in various fields such as chemistry, physics, astronomy, and materials science.
Littrow expansion
Littrow expansion, named after the Austrian physicist Heinrich Littrow, is a method used in optics and diffraction-grating theory. It specifically pertains to the analysis of light diffraction by a grating at a specific angle, known as the Littrow angle. In the context of a diffraction grating, the Littrow expansion occurs when the incoming light is focused so that the angle of incidence equals the angle of diffraction for one of the diffracted orders.
Magic angle (EELS)
The term "magic angle" in the context of Electron Energy Loss Spectroscopy (EELS) relates to the angle at which a sample is tilted to optimize the resolution and signal quality in the measurement of energy losses in electrons transmitted through a thin material. In EELS, the "magic angle" typically refers to an angle of approximately 54.
Magnetic circular dichroism
Magnetic circular dichroism (MCD) is a spectroscopic technique that measures the difference in absorption of left-handed and right-handed circularly polarized light in the presence of a magnetic field. This phenomenon is commonly observed in materials that have unpaired electrons and is particularly relevant in the study of transition metal complexes, rare earth elements, and paramagnetic species.
Mass-analyzed ion-kinetic-energy spectrometry (MIKES) is an analytical technique used in mass spectrometry to provide detailed information about the kinetic energy distribution of ions. The method involves measuring the kinetic energy of ions after they are generated and manipulated in a mass spectrometer. MIKES can be particularly useful for studying the dynamics of chemical reactions, fragmentation processes, and the conformational states of molecules in the gas phase.
Matrix isolation
Matrix isolation is a powerful experimental technique used in chemistry and physics to study reactive species, such as free radicals, small molecules, and unstable compounds, in a controlled environment. The fundamental idea behind matrix isolation is to trap these species at very low temperatures (typically in the range of 10 to 20 K) within an inert solid matrix, such as rare gas (like argon or neon) or other inert solids.
Maxwell–Wagner–Sillars (MWS) polarization is a phenomenon that occurs in heterogeneous materials, particularly in dielectric materials, where different phases or components have distinct electrical properties. This type of polarization arises due to the accumulation of charges at interfaces between different materials, leading to the creation of polarization charges. The MWS effect is characterized by two main aspects: 1. **Heterogeneous Media**: The materials involved have different dielectric constants and conductivities.
McCumber relation
The McCumber relation, named after Eric McCumber, is an important concept in the field of quantum optics and quantum information. It describes the relationship between the noise and the signal in quantum systems, particularly in the context of the measurement process. The relation is often used in discussions of quantum measurements and the trade-offs between the information gained and the disturbance caused by the measurement.
Micro-spectrophotometry
Micro-spectrophotometry is an analytical technique used to measure the absorbance, transmittance, or reflectance of very small samples, often at the microscopic scale. This method utilizes the principles of UV-Vis (ultraviolet-visible) spectroscopy, allowing scientists to study the optical properties of materials or biological samples with minimal sample consumption.
Microprobe
A microprobe is a scientific instrument used to analyze the composition of small samples of material at a microscale. It employs various techniques to determine the chemical and physical properties of materials, often down to the level of individual grains or particles. Microprobes can be used in a wide range of fields, including materials science, geology, biology, and electronics.
Microwave spectroscopy
Microwave spectroscopy is a technique used to study the interactions of molecules with microwave radiation. It is primarily concerned with the rotational energy levels of molecules, which correspond to transitions between different rotational states. Microwave spectroscopy involves exposing a sample to microwave radiation and measuring the absorption or emission of this radiation as the molecules transition between their rotational states. The technique takes advantage of the fact that different molecules have unique rotational spectra, allowing researchers to identify and characterize them based on their rotational transitions.
Miro Analytical
Miro Analytical is a company that specializes in providing analytical solutions and services, particularly in the field of process analytics and monitoring. They focus on developing advanced technologies and instruments that enable real-time analysis of chemical processes, which can be crucial for industries such as pharmaceuticals, petrochemicals, and specialty chemicals. Their products and services often aim to enhance process efficiency, product quality, and safety by providing accurate and timely data about ongoing production processes.
Molecular Hamiltonian
The Molecular Hamiltonian is a mathematical operator used in quantum mechanics that describes the total energy of a molecular system. It is a fundamental part of quantum chemistry, as it helps in understanding the electronic structure of molecules. The Hamiltonian incorporates various contributions to the energy of a molecule, including kinetic and potential energy terms.
Molecular electronic transition
Molecular electronic transition refers to a process in which a molecule absorbs or emits energy, resulting in a change in its electronic energy state. This typically occurs when electrons in certain molecular orbitals move from a lower energy state (such as a ground state) to a higher energy state (an excited state) or vice versa. These transitions are fundamental to understanding various phenomena in chemistry and physics, including spectroscopy, photochemistry, and the behavior of materials when exposed to light.
Molecular term symbol
Molecular term symbols are a notation used in molecular spectroscopy and quantum chemistry to describe the electronic states of molecules. These symbols provide important information about the energy levels and symmetries of molecular states which are pivotal in understanding electronic transitions, bonding characteristics, and other physical properties of molecules. A molecular term symbol generally follows the notation of: \[ ^{2S+1}L_J \] where: - **S** is the total spin angular momentum quantum number.
Molecular vibration
Molecular vibration refers to the oscillatory motion of atoms within a molecule around their equilibrium positions. This phenomenon occurs because molecular bonds can be thought of as springs that can stretch and compress, allowing the atoms to move closer together or further apart. During vibration, different types of motions can occur, including: 1. **Stretching**: This can be further divided into: - **Symmetric stretching**: Both bonds are elongated or shortened simultaneously.