The preservation of the nuclear polarization of hydrogen atoms during the recombination to molecules was observed on different surface materials in the temperature range from 45 to 100 K and for magnetic fields up to 1 T. On a gold and a fused quartz surface, the expected molecular polarization of about 50% or lower of the atomic polarization was measured, while a surface layer of perfluoropoly...

Homologous recombination functions universally in the maintenance of genome stability through the repair of DNA breaks and in ensuring the completion of replication. In some organisms, homologous recombination can perform more specific functions. One example of this is in antigenic variation, a widely conserved mechanism for the evasion of host immunity. Trypanosoma brucei, the causative agent ...

Transient photoconductance decay (PCD) in ingots or wafers has been numerically simulated by a finite-element method (FEM). We examined two types of light sources for carrier injection in transient PCD measurements. Large discrepancies between the widely used asymptotic approximation and the FEM simulations of wafers were seen, and an empirical fitting of the FEM results suggests that the effec...

Carrier lifetime degradation of reactive ion etch-processed silicon samples are investigated. Two types of carrier recombination: reversible and irreversible degradations induced by reactive ion etching (RIE) are identified. Irreversible carrier recombination is due to surface damage created by the RIE process that propagates a few microns deep into the silicon substrate. Reversible carrier rec...

Chemical and crystallographic defects are a reality of solar grade silicon wafers and industrial production processes. Long overlooked, phosphorus as a dopant in silicon wafers is an excellent way to mitigate recombination associated with these defects. This paper details the connection between defect recombination and solar cell terminal characteristics, for one specific case of high hole life...

Electron-hole generation and recombination rates for plasmon emission and absorption in graphene are presented. The recombination times of carriers due to plasmon emission are found to be in the tens of femtoseconds to hundreds of picoseconds range. The recombination times depend sensitively on the carrier energy, carrier density, temperature, and plasmon dispersion. Carriers near the Dirac poi...

Macronuclear development in ciliates is characterized by extensive rearrangement of genetic material, including sequence elimination, chromosome fragmentation and telomere addition. Intragenic recombination is a relatively rare, but evolutionarily important phenomenon occurring in mitosis and meiosis in a wide variety of organisms. Here, we show that high frequency intragenic recombination, on ...

Using interdisciplinary fields relevant to a highly excited semiconductor — nonequilibrium phenomena in high density plasma, light-induced changes of optical properties, and dynamic holography, we developed time-resolved four-wave mixing technique for monitoring the spatial and temporal carrier dynamics in wide band-gap semiconductors. This opened a new possibility to analyse fast electronic pr...

Electroluminescence allows rapid characterization of an entire photovoltaic solar cell and visualization defects at the micrometer scale. Here we focus on optoelectronic properties silicon interdigitated back contact cells characterized by electroluminescence. The spatially resolved electroluminescence helps us control quality structures used in bottom subcells a three-terminal tandem perovskit...

We present high signal-to-noise echelle spectra of the compact high surface brightness, low ionization planetary nebula IC 418. These reveal 807 emission lines down to intensities less than 10 that of Hβ for which we determine widths and relative intensities. We show that line profiles are a valuable parameter for making line identifications and in constraining the excitation mechanism of the l...