IPG Photonics

About: IPG Photonics is a based out in . It is known for research contribution in the topics: Laser & Fiber laser. The organization has 903 authors who have published 1241 publications receiving 63339 citations.

Determination of interatomic distances and coordination numbers by K-XANES in crystalline minerals with distorted local structure

Abstract: The method for quantitative determination of interatomic distances and coordination numbers (CN) from experimental K-XANES of light metallic atoms in crystalline compounds with distorted local structure is proposed, based on the extraction of the first shell term and the multiple-scattering term. In crystalline minerals the extraction of these terms can be obtained under uncertainties of ~0.3 - 0.4 A in the values of the second and more distant shell radii, using the unambiguous diffraction data on cell unit parameters and the type of point symmetry. The fitting of the extracted first shell term by theoretical terms, generated within alternative models for the split of this shell under the local structure distortions in the environment of the absorbing metallic atom, permits one to obtain the interatomic distances and CN in reasonable quantitative agreement with the diffraction data for the reference compounds studied.

Recent Breakthroughs in Solid-State Mid-IR Laser Technology

Abstract: Availability of compact and cost-efficient mid-infrared (MIR) laser sources with a broad range of parameters is of great interest for a number of current and emerging applications. For instance, femtosecond (fs) MIR sources with high average power and broad spectral span enable high dynamic range spectroscopy, sensing, and imaging in the molecular fingerprint region. On the other hand, few-optical-cycle MIR pulses with high energy are of particular importance for the development of EUV and X-ray sources based on strong field nonlinear optics, e.g. high harmonic generation. Furthermore, high-power mid-IR lasers are of interest for processing polymers, glasses and composites, surgical, dental and cosmetology procedures, as well as numerous defense-related applications.

Biogeochemical insights into microbe-mineral-fluid interactions in hydrothermal chimneys using enrichment culture.

Abstract: Active hydrothermal chimneys host diverse microbial communities exhibiting various metabolisms including those involved in various biogeochemical cycles. To investigate microbe-mineral-fluid interactions in hydrothermal chimney and the driver of microbial diversity, a cultural approach using a gas-lift bioreactor was chosen. An enrichment culture was performed using crushed active chimney sample as inoculum and diluted hydrothermal fluid from the same vent as culture medium. Daily sampling provided time-series access to active microbial diversity and medium composition. Active archaeal and bacterial communities consisted mainly of sulfur, sulfate and iron reducers and hydrogen oxidizers with the detection of Thermococcus, Archaeoglobus, Geoglobus, Sulfurimonas and Thermotoga sequences. The simultaneous presence of active Geoglobus sp. and Archaeoglobus sp. argues against competition for available carbon sources and electron donors between sulfate and iron reducers at high temperature. This approach allowed the cultivation of microbial populations that were under-represented in the initial environmental sample. The microbial communities are heterogeneously distributed within the gas-lift bioreactor; it is unlikely that bulk mineralogy or fluid chemistry is the drivers of microbial community structure. Instead, we propose that micro-environmental niche characteristics, created by the interaction between the mineral grains and the fluid chemistry, are the main drivers of microbial diversity in natural systems.

First report of ultrahigh-temperature sapphirine + spinel + quartz and orthopyroxene + spinel + quartz parageneses discovered in Al–Mg granulites from the Khanfous area (In Ouzzal metacraton, Hoggar, Algeria)

Abstract: Abstract The Archaean to Palaeoproterozoic Khanfous area from the Archaean In Ouzzal granulite terrane (Western Hoggar, Algeria) preserves exceptional thermal-peak (1150

Structure of Pd–Te precipitates in a simulated high-level nuclear waste glass

Abstract: Structural and bonding characteristics of simplified (Pd, Te) precipitates have been determined in a simulated nuclear French glass using extended x-ray absorption fine structure (EXAFS) and x-ray diffraction. In this sample, these precipitates have a homogeneous composition, with about 10 wt.% Te. They retain a face-centered cubic structure as in pure Pd with a cell parameter which obeys Vegard’s law. Pd K-edge EXAFS shows the presence of Te in the Pd coordination shell, with (Pd–Te) distances of 2.80 A. These distances, higher by 0.05 A than the (Pd–Pd) distances, may result in a lower packing efficiency of the CFC lattice. The comparison with the average distances derived from x-ray diffraction shows the nonmetallic character of the Pd–Te bond in these precipitates. These bonding modifications may cause the limited solubility of Te in metallic Pd.