Search results for "laser"
showing 10 items of 3161 documents
A Portable Dynamic Laser Speckle System for Sensing Long-Term Changes Caused by Treatments in Painting Conservation
2018
[EN] Dynamic laser speckle (DLS) is used as a reliable sensor of activity for all types of materials. Traditional applications are based on high-rate captures (usually greater than 10 frames-per-second, fps). Even for drying processes in conservation treatments, where there is a high level of activity in the first moments after the application and slower activity after some minutes or hours, the process is based on the acquisition of images at a time rate that is the same in moments of high and low activity. In this work, we present an alternative approach to track the drying process of protective layers and other painting conservation processes that take a long time to reduce their levels …
Gas cell studies of thorium using filament dispensers at IGISOL
2020
Abstract Filament-based dispensers of thorium have been investigated at the IGISOL facility, Jyvaskyla, for potential use as a thorium ion source for future collinear laser spectroscopy experiments. Several different filaments were manufactured in the Institute of Atomic and Subatomic Physics of TU Wien, with 232Th and 229Th prepared on tantalum substrates either by drying thorium nitrate solution or via molecular plating, while adding a layer of zirconium for oxide reduction. The filaments were characterized in a helium-filled gas cell by performing selective and efficient in-gas-cell resonance laser ionization and by analyzing the resulting ion beams by mass spectrometry. Additionally, th…
Vibrio gallaecicus sp. nov. isolated from cultured clams in north-western Spain.
2009
Abstract A group of three motile facultative anaerobic marine bacteria were isolated from cultured Manila clams (Ruditapes philippinarum) in Galicia, north-western Spain. The strains were characterized phenotypically and genotypically. Phylogenetic analysis of the 16S rRNA gene and four housekeeping genes, RNA polymerase α-chain (rpoA), RecA protein (recA), the α-subunit of bacterial ATP synthase (atpA) and the uridine monophosphate (UMP) kinase (pyrH), indicated that these strains were closely related to the Vibrio splendidus clade. The amplified fragment length polymorphism (AFLP) fingerprints, DNA–DNA hybridizations and phylogenies of the housekeeping and 16S rRNA gene sequences showed t…
Description of Tropicibacter mediterraneus sp. nov. and Tropicibacter litoreus sp. nov.
2013
Four strains (M15∅_3, M17(T), M49 and R37(T)) were isolated from Mediterranean seawater at Malvarrosa beach, Valencia, Spain. Together with an older preserved isolate (strain 2OM6) from cultured oysters at Vinaroz, Castellón, Spain, the strains were thoroughly characterized in a polyphasic study and were placed phylogenetically within the Roseobacter clade in the family Rhodobacteraceae. Highest 16S rRNA sequence similarities of the five strains to the types of any established species corresponded to Tropicibacter multivorans (95.8-96.4%), Phaeobacter inhibens (95.9-96.3%) and Phaeobacter gallaeciensis (95.9-96.2%). On the other hand, whole genome (ANI) and protein fingerprinting (MALDI-TOF…
Genetic diversity and phenotypic characterization of Iodobacter limnosediminis associated with skin lesions in freshwater fish
2021
The relatively unknown genus Iodobacter sp. has been repeatedly isolated from skin ulcers and saprolegniosis on freshwater fish in Finland, especially farmed salmonids. Genetic characterization verified that all 23 bacterial isolates studied here belonged to the species Iodobacter limnosediminis, previously undescribed from the fish microbiota. Whole-genome pulsed-field gel electrophoresis revealed variability between the I. limnosediminis strains, suggesting that they were most likely of environmental origin. Two I. limnosediminis strains caused lesions in 27%–53% of brown trout (Salmo trutta) injected intramuscularly (p ≤ .05). The lesions represented moderate to severe tissue damage, but…
Analysis of Infrared and Raman-Spectra of 116SnH4 in the 1900 cm-1 Region - Study of the 1000, 0010 Interacting States
1991
0022-2852
Collisional Broadening, Line Shifting, and Line Mixing in the Stimulated Raman 2-v2 Q-Branch of CH4
1991
0021-9606; Self-, argon-, and helium-broadening coefficients have been measured for 13 lines in the 2v2 Raman Q branch of CH4 using stimulated inverse Raman spectroscopy. The linewidths clearly show the symmetry-state dependence characteristic of pressure broadening, and inelastic processes in general, involving spherical-top molecules. Pressure-induced line shifts have also been measured for these features in pure methane. The pressure-shift coefficients do not display the symmetry-state dependence found for the linewidths. By applying the Rosenkranz perturbation treatment to a pair of collisionally mixed lines, we have been able to obtain an estimate of individual state-to-state contribut…
Ultrafast Optical Demagnetization manipulates Nanoscale Spin Structure in Domain Walls
2012
During ultrafast demagnetization of a magnetically ordered solid, angular momentum has to be transferred between the spins, electrons, and phonons in the system on femto- and picosecond timescales. Although the intrinsic spin-transfer mechanisms are intensely debated, additional extrinsic mechanisms arising due to nanoscale heterogeneity have only recently entered the discussion. Here we use femtosecond X-ray pulses from a free-electron laser to study thin film samples with magnetic domain patterns. We observe an infrared-pump-induced change of the spin structure within the domain walls on the sub-picosecond timescale. This domain-topography-dependent contribution connects the intrinsic dem…
Size dependent carrier thermal escape and transfer in bimodally distributed self assembled InAs/GaAs quantum dots
2012
We have investigated the temperature dependent recombination dynamics in two bimodally distributed InAs self assembled quantum dots samples. A rate equations model has been implemented to investigate the thermally activated carrier escape mechanism which changes from exciton-like to uncorrelated electron and hole pairs as the quantum dot size varies. For the smaller dots, we find a hot exciton thermal escape process. We evaluated the thermal transfer process between quantum dots by the quantum dot density and carrier escape properties of both samples. © 2012 American Institute of Physics.
Polarization-domain-wall complexes in fiber lasers
2013
To study the possible build-up of polarization-domain-walls (PDWs) in fiber laser cavities, an erbium-doped fiber ring laser was used and a wide range of vector polarization dynamics that can be selected at a given pump power, by using the degrees of freedom of two intracavity polarization controllers (PC) was investigated. A simple theoretical model that explains polarization switching in fiber ring lasers featuring a normally dispersive cavity with a typical, moderate, level of birefringence is presented. Such polarization dynamics, based on a special class of polarization-domain-wall structures, agrees qualitatively well with experimental observations. The paper stresses on the complex a…