Search results for "atomic and molecular physics"
showing 10 items of 4501 documents
Application of 3D printed scavengers for improving the accuracy of single-particle inductively coupled plasma mass spectrometry analyses of silver na…
2023
The determination of silver nanoparticles (Ag NPs) with single-particle inductively coupled plasma mass spectrometry can be severely interfered with coexisting dissolved silver causing high background signals, which can lead to inaccurate quantification of NP size and particle concentration. In this paper, chemically active and reusable 3D printed scavengers are applied for highly efficient dissolved silver removal in Ag NP dispersions, allowing more accurate determination of particle concentration and size. Selective laser sintering was used for constructing the porous 3D scavengers constituting of polystyrene used as a supporting material and ion-exchange material SiliaBond Tosic acid (TA…
PQ and Harmonic Assessment Issues on Low-Cost Smart Metering Platforms: A Case Study
2020
This paper presents a feasibility study on how to implement power quality (PQ) metrics in a low-cost smart metering platform. The study is aimed at verifying the possibility of implementing PQ monitoring in distribution networks without replacing existing smart metering devices or adding new modules for PQ measurements, thus zeroing the installation costs. To this aim, an electronic board, currently used for remote energy metering, was chosen as a case study, specifically the STCOMET platform. Starting from the specifications of this device, the possibility of implementing power quality metrics is investigated in order to verify if compliance with standard requirements for PQ instruments ca…
Multispectral filter arrays: Recent advances and practical implementation
2014
Thanks to some technical progress in interferencefilter design based on different technologies, we can finally successfully implement the concept of multispectral filter array-based sensors. This article provides the relevant state-of-the-art for multispectral imaging systems and presents the characteristics of the elements of our multispectral sensor as a case study. The spectral characteristics are based on two different spatial arrangements that distribute eight different bandpass filters in the visible and near-infrared area of the spectrum. We demonstrate that the system is viable and evaluate its performance through sensor spectral simulation. Multispectral filter arrays: Recent advan…
Trapped Ion Oscillation Frequencies as Sensors for Spectroscopy
2010
The oscillation frequencies of charged particles in a Penning trap can serve as sensors for spectroscopy when additional field components are introduced to the magnetic and electric fields used for confinement. The presence of so-called "magnetic bottles" and specific electric anharmonicities creates calculable energy-dependences of the oscillation frequencies in the radiofrequency domain which may be used to detect the absorption or emission of photons both in the microwave and optical frequency domains. The precise electronic measurement of these oscillation frequencies therefore represents an optical sensor for spectroscopy. We discuss possible applications for precision laser and microw…
Realization of time-resolved two-vacuum-ultraviolet-photon ionization
2009
International audience; Ultrafast dynamics of excited molecules is studied through time-resolved two-vacuum-ultraviolet (vuv)- photon ionization using a nonlinear volume autocorrelator unit. The two-vuv-photon process is induced by the intense fifth harmonic radiation of a femtosecond Ti:sapphire laser. In a proof-of-principle experiment, ultrafast dynamics of excited ethylene and oxygen molecules are investigated. Molecular decay times are deduced by comparing the experimental data with the results of a numerical model that accounts for the spatial and temporal characteristics of the harmonic field. The present experiments pave a convenient way for time domain investigations in the vuv-xuv s…
Surrogate Modelling for Oxygen Uptake Prediction Using LSTM Neural Network
2023
Oxygen uptake (V˙O2) is an important metric in any exercise test including walking and running. It can be measured using portable spirometers or metabolic analyzers. Those devices are, however, not suitable for constant use by consumers due to their costs, difficulty of operation and their intervening in the physical integrity of their users. Therefore, it is important to develop approaches for the indirect estimation of V˙O2-based measurements of motion parameters, heart rate data and application-specific measurements from consumer-grade sensors. Typically, these approaches are based on linear regression models or neural networks. This study investigates how motion data contribute to V˙O2 …
Copper-hydride nanoclusters with enhanced stability by N-heterocyclic carbenes
2021
AbstractCopper-hydrides have been intensively studied for a long time due to their utilization in a variety of technologically important chemical transformations. Nevertheless, poor stability of the species severely hinders its isolation, storage and operation, which is worse for nano-sized ones. We report here an unprecedented strategy to access to ultrastable copper-hydride nanoclusters (NCs), namely, using bidentate N-heterocyclic carbenes as stabilizing ligands in addition to thiolates. In this work, a simple synthetic protocol was developed to synthesize the first large copper-hydride nanoclusters (NCs) stabilized by N-heterocyclic carbenes (NHCs). The NC, with the formula of Cu31(RS)2…
CO(2)-water supercritical mixtures: Test of a potential model against neutron diffraction data
2007
Abstract A neutron diffraction experiment on supercritical mixtures of water and CO 2 at two concentrations is presented. Data are analyzed within the EPSR framework and the water–water and water–CO 2 radial distribution functions are compared with those calculated by a Molecular Dynamics simulation performed by using the TIPS2 and EPM-M potential models for water and CO 2 respectively. It is found that the Molecular Dynamics simulation reproduces the overall shape of the site–site radial distribution functions, although missing a few subtle changes brought along when the CO 2 concentration is increased.
Engineered surface waves in hyperbolic metamaterials
2013
We analyzed surface-wave propagation that takes place at the boundary between a semi-infinite dielectric and a multilayered metamaterial, the latter with indefinite permittivity and cut normally to the layers. Known hyperbolization of the dispersion curve is discussed within distinct spectral regimes, including the role of the surrounding material. Hybridization of surface waves enable tighter confinement near the interface in comparison with pure-TM surface-plasmon polaritons. We demonstrate that the effective-medium approach deviates severely in practical implementations. By using the finite-element method, we predict the existence of long-range oblique surface waves. This research was fu…