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Related papers: Molecular Tagging Velocimetry in Superfluid Helium…

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We perform fully coupled two--dimensional numerical simulations of plane channel helium II counterflows with vortex--line density typical of experiments. The main features of our approach are the inclusion of the back reaction of the…

Other Condensed Matter · Physics 2015-12-09 Luca Galantucci , Michele Sciacca , Carlo F. Barenghi

We introduce the first comprehensive approach to determine the uncertainty in volumetric Particle Tracking Velocimetry (PTV) measurements. Volumetric PTV is a state-of-the-art non-invasive flow measurement technique, which measures the…

Fluid Dynamics · Physics 2022-10-19 Sayantan Bhattacharya , Pavlos P. Vlachos

Aims: Hydrogen and helium line spectra are crucial diagnostic features for the quantitative analysis of OB stars. We compute synthetic spectra based on a hybrid non-LTE approach in order to test the ability of these models to reproduce…

Astrophysics · Physics 2009-11-11 M. F. Nieva , N. Przybilla

An experiment is proposed to excite the 'forbidden' 1s2s 3S1 - 1s2s 1S0 magnetic dipole (M1) transition at 1557 nm in a collimated and slow atomic beam of metastable helium atoms. It is demonstrated that an excitation rate of 5000 /s can be…

Atomic Physics · Physics 2009-11-13 K. A. H. van Leeuwen , W. Vassen

The hydrodynamic Drude model (HDM) has been successful in describing the optical properties of metallic nanostructures, but for semiconductors where several different kinds of charge carriers are present, an extended theory is required. We…

Mesoscale and Nanoscale Physics · Physics 2018-03-14 Johan R. Maack , N. Asger Mortensen , Martijn Wubs

The next generation of proton decay and neutrino experiments, the post-SuperKamiokande detectors as those that will take place in megaton size water tanks, will require very large surfaces of photodetection and a large volume of data. Even…

Flow velocity is an important characteristic of the fluidic mediums. In this paper, we introduce a molecular based flow velocity meter consisting of a molecule releasing node and a receiver that counts these molecules. We consider both flow…

Information Theory · Computer Science 2021-01-12 Maryam Farahnak-Ghazani , Mahtab Mirmohseni , Masoumeh Nasiri-Kenari

We introduce X-ray Particle Tracking Velocimetry (XPTV) as a promising method to quantitatively resolve the velocity field and associated rheological information of polymer melt flow within the nozzle of a fused filament fabrication (FFF)…

The most essential characteristic of any fluid is the velocity field v(r) and this is particularly true for macroscopic quantum fluids. Although rapid advances have occurred in quantum fluid v(r) imaging, the velocity field of a charged…

Superconductivity · Physics 2021-10-12 Xiaolong Liu , Yi Xue Chong , Rahul Sharma , J. C. Séamus Davis

The differential affine velocity estimator (DAVE) developed in Schuck (2006) for estimating velocities from line-of-sight magnetograms is modified to directly incorporate horizontal magnetic fields to produce a differential affine velocity…

Astrophysics · Physics 2009-11-13 P. W. Schuck

Far Ultraviolet Spectroscopic Explorer (FUSE) data is used to investigate the molecular hydrogen (H_2) content of intermediate-velocity clouds (IVCs) in the lower halo of the Milky Way. We analyze interstellar absorption towards 56 (mostly…

Astrophysics · Physics 2009-11-07 P. Richter , B. P. Wakker , B. D. Savage , K. R. Sembach

In microdosimetry, lineal energies y are calculated from energy depositions $\epsilon$ inside the microdosimeter divided by the mean chord length, whose value is based on geometrical assumptions on both the detector and the radiation field.…

Tracer particles designed specifically for X-ray particle tracking and imaging velocimetry (XPTV and XPIV) are necessary to widen the range of flows that can be studied with these techniques. In this study, we demonstrate in-lab XPTV using…

Fluid Dynamics · Physics 2022-11-30 Jason T. Parker , Jessica DeBerardinis , Simo A. Mäkiharju

We combine X-ray-specific tracer particles, a photon counting detector, and a liquid metal jet anode X-ray source to achieve $O$(1 kHz) X-ray imaging speeds in the laboratory, 15$\times$ faster than previous comparable studies with $O$(50…

Fluid Dynamics · Physics 2023-10-17 Jason T. Parker , Till Dreier , Daniel Nilsson , Simo A. Mäkiharju

Superionic conductors, or solid-state ion-conductors surpassing 0.01 S/cm in conductivity, can enable more energy dense batteries, robust artificial ion pumps, and optimized fuel cells. However, tailoring superionic conductors require…

Instrumentation and Detectors · Physics 2024-07-23 Kim H. Pham , Scott K. Cushing

A beam tagging hodoscope prototype made of squared 1 mm$^2$ fibers arranged in two perpendicular planes and coupled to multi-anode photomultipliers has been studied using 65 MeV proton as well as 95 MeV/u $^{12}$C beams at various…

Temporal Action Detection(TAD) is a crucial but challenging task in video understanding.It is aimed at detecting both the type and start-end frame for each action instance in a long, untrimmed video.Most current models adopt both RGB and…

Computer Vision and Pattern Recognition · Computer Science 2024-02-05 Bowen Deng , Dongchang Liu

Photon statistics is a powerful tool for characterizing the emission dynamics of nanoscopic systems and their photophysics. Recent advances that combine correlation spectroscopy with scanning tunneling microscopy-induced luminescence (STML)…

Mesoscale and Nanoscale Physics · Physics 2018-12-20 Pablo Merino , Anna Rosławska , Christopher C. Leon , Abhishek Grewal , Christoph Große , Cesar González , Klaus Kuhnke , Klaus Kern

The experimental investigation of superfluid turbulence in 3He-B is generally not possible with the techniques which have been developed for 4He-II. We describe a new method by which a transient burst of turbulent vortex expansion can be…

Soft Condensed Matter · Physics 2009-11-10 A. P. Finne , S. Boldarev , V. B. Eltsov , M. Krusius

We explore the strengths and limitations of using a standard Michelson interferometer to sample line-of-sight-averaged temperature in water via two experimental setups: slow-varying temperature in static fluid and fast temperature…

Fluid Dynamics · Physics 2023-11-01 Xinyang Ge , Joanna A. Zielińska , Sergio Maldonado