Stark Effect
Stark Effect - Related Videos
05:57
Dean-Stark Trap
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2023
Source: Vy M. Dong and Jan Riedel, Department of Chemistry, University of California, Irvine, CA A Dean-Stark trap is a special piece of glassware, which allows the collection of water during a reaction through an azeotropic distillation. The desire to collect water from a reaction can have various reasons. It can drive the equilibria in reactions, where water is formed as a byproduct. According to Le Chatelier's principle, a change in temperature, pressure, concentration, or volume will cause...
15:53
Isolation and Biophysical Study of Fruit Cuticles
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Cited by 16 •
2012
Aerial plant organs are protected by the cuticle, a supramolecular biopolyester-wax assembly. We present protocols to monitor selective removal of epi- and intracuticular waxes from tomato fruit cuticles on molecular and micro scales by solid-state NMR and atomic force microscopy, respectively, and to assess the cross-linking capacity of engineered cuticular biopolyesters.
10:21
Characterization and Isolation of Mouse Primary Microglia by Density Gradient Centrifugation
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Cited by 8 •
2018
A protocol for the isolation of primary microglia from murine brains is presented. This technique aids in furthering the current understanding of neurological conditions. Density gradient centrifugation and magnetic separation are combined to produce sufficient yield of a highly pure sample. Furthermore, we outline the steps for characterization of microglia.
09:12
Surface Functionalization of Hepatitis E Virus Nanoparticles Using Chemical Conjugation Methods
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Cited by 15 •
2018
We have engineered the capsid protein of hepatitis E virus as a theranostic nanoparticle (HEVNP). HEVNP self-assembles into a stable icosahedral cage in mucosal delivery. Here, we describe the modification of HEVNPs for tumor targeting by mutating surface-exposed residues to cysteines, which conjugate synthetic ligands that specifically bind tumor cells.
06:47
3D Organotypic Co-culture Model Supporting Medullary Thymic Epithelial Cell Proliferation, Differentiation and Promiscuous Gene Expression
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Cited by 15 •
2015
Studying medullary thymic epithelial cells in vitro has been largely unsuccessful, as current 2D culture systems do not mimic the in vivo scenario. The 3D culture system described herein - a modified skin organotypic culture model - has proven superior in recapitulating mTEC proliferation, differentiation and maintenance of promiscuous gene expression.
FAQs
An external electric field couples to permanent or induced electric dipole moments, altering the energies of quantum states. Because spectral transitions depend on differences between those state energies, the observed line can move, or a single line can separate into multiple components. This state-specific response lets spectroscopy reveal how matter interacts with its electromagnetic surroundings.
The distinction between linear and quadratic responses indicates how transition frequencies depend on field strength. A linear change means the frequency varies in direct proportion to the field, while a quadratic change reflects dependence on the field squared. Identifying this behavior helps researchers interpret measured spectra and determine how strongly the field perturbs the system.
Permanent and induced dipoles contribute differently to the field interaction: a permanent dipole is already present, while an induced dipole develops in response to the applied field. Considering which contribution is relevant helps explain why different atoms, molecules, or quantum states show different spectral responses under comparable electric-field conditions.
To use Stark-effect spectroscopy, researchers expose the material or system to an external electric field and examine its spectral lines. They track whether lines shift or split and relate the transition-frequency change to the applied perturbation. The resulting pattern can characterize the electric-field environment and provide information about the perturbed quantum states.
Stark-effect measurements serve as a route to electric-field sensing because field-induced changes in transition frequencies provide a spectroscopic signal. The same measurements support plasma diagnostics and precision spectroscopy, where the spectral response can reveal electromagnetic conditions or enable precise observation of matter. Thus, the effect connects quantum-level changes with engineering measurements.
Stark-effect measurements inform the design of quantum and optoelectronic devices by showing how electric fields modify energy levels and optical transitions. They also support material characterization and control of light-matter interactions. These capabilities are relevant to tunable components for communications and photonics, where adjusting or monitoring spectral behavior can connect device operation to an applied field.