Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Atomic Nuclei: Nuclear Spin State Population Distribution01:14

Atomic Nuclei: Nuclear Spin State Population Distribution

Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
Carrier Generation and Recombination01:22

Carrier Generation and Recombination

Carrier generation is the process by which electron-hole pairs (EHPs) are created within the semiconductor. In direct-bandgap semiconductors, such as gallium arsenide (GaAs), this occurs efficiently when energy absorption prompts valence electrons to leap into the conduction band, leaving behind holes.
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
Atomic Nuclei: Nuclear Relaxation Processes01:23

Atomic Nuclei: Nuclear Relaxation Processes

In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis,  the precessing magnetic moments are randomly oriented around the z-axis. This...
Speciation Rates01:07

Speciation Rates

Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.
Composition of Blood Plasma01:24

Composition of Blood Plasma

Blood plasma is a fluid that contains approximately 92% water and 8% solutes. The solutes include various types of proteins, which constitute about 7% of the total solutes in the plasma. The high-molecular-weight proteins—albumins, globulins, and fibrinogen—are essential to plasma function. Albumins, making up about 60% of the plasma proteins, maintain the osmotic balance within blood vessels by preventing excessive water leakage. Additionally, albumins serve as carrier proteins, binding to...
Conservative Site-specific Recombination and Phase Variation02:53

Conservative Site-specific Recombination and Phase Variation

Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Peri- and postoperative kinetics of endothelin-1/big endothelin-1 and effects of endothelin antagonist in porcine liver transplantation from non-heart-beating donors.

Transplantation proceedings·2000
Same author

Long-term graft survival of living-related kidneys after donor-specific transfusion.

Transplantation proceedings·2000
Same author

Ionotropic glutamate receptors expressed in human retinoblastoma Y79 cells.

Neuroscience letters·2000
Same author

Pharmacologic graft protection without donor pretreatment in liver transplantation from non-heart-beating donors.

Transplantation·2000
Same author

No evidence for an association between the Glu298Asp polymorphism of the NOS3 gene and Alzheimer's disease.

Journal of neural transmission (Vienna, Austria : 1996)·2000
Same author

Calcium level-responsive in-vitro zinc release from zinc containing tricalcium phosphate (ZnTCP).

Journal of biomedical materials research·2000

Related Experiment Video

Updated: Jun 15, 2026

Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity
11:30

Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity

Published on: March 6, 2017

Population inversion in a stationary recombining plasma.

M Otsuka

    Applied Optics
    |March 18, 2010
    PubMed
    Summary

    Researchers observed population inversion in a recombining helium plasma using hydrogen as a contact gas. This method achieved a significantly higher overpopulation density of 10^8 cm^-3 compared to previous studies.

    Area of Science:

    • Plasma Physics
    • Atomic and Molecular Physics

    Background:

    • Population inversion is crucial for laser operation.
    • Recombining plasmas offer a potential pathway to achieve population inversion.
    • Previous studies with helium contact gas showed limited inversion densities.

    Purpose of the Study:

    • To investigate population inversion in a recombining helium plasma.
    • To explore the effect of using hydrogen as a contact gas.
    • To compare inversion densities achieved with different contact gases.

    Main Methods:

    • Generating a stationary helium plasma.
    • Introducing a neutral hydrogen gas for plasma contact.
    • Measuring population inversion between low-lying hydrogen levels.
    • Analyzing results using the collisional-radiative (CR) model.

    More Related Videos

    Total Internal Reflection Absorption Spectroscopy (TIRAS) for the Detection of Solvated Electrons at a Plasma-liquid Interface
    08:50

    Total Internal Reflection Absorption Spectroscopy (TIRAS) for the Detection of Solvated Electrons at a Plasma-liquid Interface

    Published on: January 24, 2018

    Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator
    07:31

    Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator

    Published on: May 9, 2014

    Related Experiment Videos

    Last Updated: Jun 15, 2026

    Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity
    11:30

    Recombination Dynamics in Thin-film Photovoltaic Materials via Time-resolved Microwave Conductivity

    Published on: March 6, 2017

    Total Internal Reflection Absorption Spectroscopy (TIRAS) for the Detection of Solvated Electrons at a Plasma-liquid Interface
    08:50

    Total Internal Reflection Absorption Spectroscopy (TIRAS) for the Detection of Solvated Electrons at a Plasma-liquid Interface

    Published on: January 24, 2018

    Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator
    07:31

    Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator

    Published on: May 9, 2014

    Main Results:

    • Achieved noticeable population inversion between low-lying hydrogen levels.
    • Observed a significantly higher overpopulation density (approx. 10^8 cm^-3) with hydrogen.
    • This density is orders of magnitude greater than that obtained with helium (approx. 10^5 cm^-3).

    Conclusions:

    • Hydrogen is a more effective contact gas than helium for achieving population inversion in this plasma system.
    • The experimental findings align with predictions and conditions discussed within the CR model.
    • This research provides insights into optimizing conditions for population inversion in recombining plasmas.