Search results for "Length"
showing 10 items of 2188 documents
Direct observation of coherent magnons with suboptical wavelengths in a single crystalline ferrimagnetic insulator
2019
In the field of magnetism, spin waves are a subject of great interest for fundamental and application-oriented research. Time-resolved scanning transmission x-ray microscopy, a technique that allows for direct spin-wave imaging below the optical resolution limit, is usually limited to thin layers deposited on x-ray transparent membranes. Here, the authors report on a preparation routine that makes single-crystalline materials accessible to this powerful technique. The latter is subsequently implemented on the ferrimagnetic insulator yttrium iron garnet, where spin waves down to 100-nm wavelength are observed.
Study of the mutual influence of ligands in cobalt(II) complexes containing thiocyanate and imidazole derivatives
1997
Abstract The cobalt(II) complexes of formula [Co(NCS)2L2] and [Co(NCS)2L′4] (L = imidazole (iz) derivatives, I-Meiz (1), Z-Meiz (2), 2-Etiz (3), 2-Isopropiz (4), 2-Pheniz (5), 1,2-Me2iz (6), Biz (7), 2-Mebiz (8), 2-Etbiz (9); L′ = iz (10), 1-Meiz (11)) have been synthesized and characterized by spectroscopic methods and magnetic measurements. The crystal and molecular structures of complexes 6 and 11 have been determined by X-ray diffraction methods. Complex 6 crystallizes inthe orthorhombic space group Pnma with cell constants a=9.209 (3), b = 12.462 (5), c = 14.851(3) A ; V = 1704.3(9) A 3 , D ( calc ., Z = 4) = 1.43 g cm −3 , M r =367.35, F(000)=640 , λ( Mo K α)=0.71079 A , μ=11.2 cm−1 a…
Ferromagnetic Coupling Through the End-to-End Thiocyanate Bridge in Cobalt(II) and Nickel(II) Chains
2015
The preparation, spectroscopic characterization, and X-ray crystal structure of two novel one-dimensional compounds of formula [MII(tppz)(NCS)(μ-1,3-NCS)]n [tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine and M = Co(1) and Ni (2)] are reported. 1 and 2 are isomorphous compounds, and they crystallize in the P21/n space group. Their structures are made up of zigzag chains of cobalt(II) (1) and nickel(II) ions (2) bridged by single end-to-end thiocyanate groups with a tridentate tppz molecule and a terminally bound thiocyanate-N ligand achieving distorted MN5S octahedral surroundings around each metal center. The main source of the distortion of the ideal octahedron is due to the geometrical constr…
Intracavity Frequency Doubling and Difference Frequency Mixing for Pulsed ns Ti:Sapphire Laser Systems at On-Line Radioactive Ion Beam Facilities
2015
Intra-cavity second harmonic generation of a Titanium:sapphire (Ti:sa) laser system has been used to improve the conversion efficiency to the second harmonic. Over the course of several experiments performance data spanning the whole wavelength range of a Ti:sa has been collected, which may be used as a guideline for future experiments. An average output power of up to 3.7 W was achieved, resulting in a conversion efficiency of >75 % to the second harmonic. A wavelength coverage from 340-525 nm has been demonstrated. To extend the wavelength range of the solid state laser system, difference frequency mixing has been applied to the intra-cavity doubled light and the fundamental output of a s…
In vivo 3D muscle architecture quantification based on 3D freehand ultrasound and magnetic resonance imaging
2023
Muscle architecture parameters, such as the fascicle length, pennation angle, and volume, are important muscle morphology characteristics. Accurate in vivo quantification of these parameters allows to detect changes due to pathologies, interventions, and rehabilitation trainings, which ultimately impact on muscles’ force-producing capacity. In this study, we compared three-dimensional (3D) muscle architecture parameters of the tibialis anterior and gastrocnemius medialis, which were quantified by 3D freehand ultrasound (3DfUS) and a magnetic resonance imaging (MRI) technique, diffusion tensor imaging (DTI), respectively. Sixteen able-bodied subjects were recruited where seven of them receiv…
REM near-IR and optical multiband observations of PKS 2155-304 in 2005
2007
Spectral variability is the main tool for constraining emission models of BL Lac objects. By means of systematic observations of the BL Lac prototype PKS 2155-304 in the infrared-optical band, we explore variability on the scales of months, days and hours. We made our observations with the robotic 60 cm telescope REM located at La Silla, Chile. VRIJHK filters were used. PKS 2155-304 was observed from May to December 2005. The wavelength interval explored, the total number of photometric points and the short integration time render our photometry substantially superior to previous ones for this source. On the basis of the intensity and colour we distinguish three different states of the sour…
Estimation of annual energy output of a wind turbine using wind speed probability distribution
2016
In this work, annual energy output of a variable speed wind turbine is analyzed using annual Weibull wind speed probability distribution function. The power coefficient variation with tip speed ratio in torque control region as well as pitch angle variation for maximum power output from wind turbine are analyzed for identifying control system parameters. The wind turbine power output and variation of power coefficient with tip speed ratio as well as pitch angle are examined / reported using annual Weibull distribution function. Finally the variation of the estimated annual energy output of the given wind turbine with the mean wind speed is presented.
Morphological and Biometric Features of Male BluethroatsLuscinia svecicain Central Iberia
2011
Summary. In order to test biometrics and plumage variability in bluethroats Luscinia svecica in central Iberia, 185 birds were captured in four areas (Sierra-Bejar, Sierra-Piedrahita, Sierra-Gredos and Sierra-Paramera). Older bluethroats were significantly larger than second calendar year birds in wing, tail, and total body lengths, but not in tarsus and bill lengths. A multivariate analysis of variance (MANOVA) and a principal component analysis (PCA) were used. Total body length only varied significantly between sampling areas: the birds from Sierra-Bejar were larger than those from Sierra-Gredos and Sierra-Paramera, but were similar to those of Sierra-Piedrahita. Birds with a white spot,…
Achromatic linear retarder with tunable retardance
2018
We present a universal design and proof-of-concept of a tunable linear retarder of uniform wavelength response in a broad spectral range. It consists of two half-wave retarders (HWR) between two quarter-wave retarders (QWRs), where the uniform retardance can be tuned continuously by simply rotating one of the HWRs. A proof-of-concept of this design is built by using commercially available Fresnel rhomb retarders that provide retardation with almost wavelength uniformity in the visible and near infrared from 450 to 1550 nm. The design is universal, since other achromatic QWRs and HWRs could also be employed. The system is experimentally demonstrated to control the state of polarization of a …
Efficient thermo-optically controlled Mach-Zhender interferometers using dielectric-loaded plasmonic waveguides
2012
Compact fiber-coupled dielectric-loaded plasmonic Mach-Zehnder interferometers operating at telecom wavelengths and controlled via the thermo-optic effect are reported. Two fabricated structures with Cytop substrate and a ridge made of PMMA or a cycloaliphatic acrylate polymer (CAP) were considered showing low switching power of 2.35 mW and switching time in the range of microseconds for a CAP ridge and milliseconds switching time for a PMMA ridge. Full output modulation is demonstrated for the structure with a CAP ridge and 40% modulation with a PMMA ridge. (C) 2012 Optical Society of America Compact fiber-coupled dielectric-loaded plasmonic Mach-Zehnder interferometers operating at teleco…