Results 31 to 40 of about 494,691 (265)
Surfaces of colloidal PbSe nanocrystals probed by thin-film positron annihilation spectroscopy
Positron annihilation lifetime spectroscopy and positron-electron momentum density (PEMD) studies on multilayers of PbSe nanocrystals (NCs), supported by transmission electron microscopy, show that positrons are strongly trapped at NC surfaces, where ...
L. Chai +13 more
doaj +1 more source
A 3D‐printable breast phantom is developed using patient‐derived MRI data and hydrogels that replicate the dielectric properties of healthy and cancerous tissues. Mechanical and dielectric characterization confirm its suitability for microwave imaging.
Carlos M. Andreu +5 more
wiley +1 more source
Hydrophilic PEO‐copolymers and hydrophobic PDMS are physically integrated via a compatibilizing solvent into an amphipathic dual‐polymer network with versatile interfacial affinity and completely amorphized PEO segments for hyper‐permeable CO2 transport.
Ji Wu +9 more
wiley +1 more source
Characterization of vacancy defects in Cu(In,Ga)Se2 by positron annihilation spectroscopy
The photovoltaic performance of Cu(In1-x,Gax)Se2 (CIGS) materials is commonly assumed to be degraded by the presence of vacancy-related defects. However, experimental identification of specific vacancy defects remains challenging.
M. R. M. Elsharkawy +4 more
doaj +1 more source
Genetic Algorithms for Positron Lifetime Data
Recently, genetic algorithms have been applied for ultrafast optical spectrometry in systems with several convoluted lifetimes. We apply these algorithms and compare the results with POSFIT (by Kirkegaard and Eldrup) and LT programme (by Kansy). The analysis was applied to three types of samples: molybdenum monocrystals, Czochralski-grown silicon with ...
A. Karbowski +4 more
openaire +4 more sources
The mechanical performance of nanocellular polyetherimide cannot be explained by nanoporosity alone. It is shown that CO2 saturation and desorption leave a distinct mechanical signature in the glassy matrix before foaming. This matrix contribution provides a new route to understand and optimize the brittle to ductile transition in nanocellular polymers.
Félix Lizalde‐Arroyo +7 more
wiley +1 more source
Ion Concentration and Voltage Imaging With Fluorescent Nanodiamonds
We demonstrate reversible switching between the fluorescent NV0 and the dark NV+ state, in sub‐30 nm FNDs via surface oxidation and hydrogenation, respectively. In an electrochemical cell, we show that the fluorescence from hydrogenated particles enables all‐optical imaging of voltages and ion concentrations at the micrometer scale.
Patrick Voorhoeve +8 more
wiley +1 more source
Advanced Materials for Biologics Delivery to Brain Tumors
Material innovation is central to unlocking the therapeutic potential of biologics against many central nervous system diseases, including brain cancer. By engineering carriers with controlled transport, targeting, and release properties, advanced materials can overcome the blood–brain barrier and tumor microenvironment, improving the delivery of ...
Yuran Feng +4 more
wiley +1 more source
Positron annihilation spectroscopy in polymers
S.219-223During the last decades positron annihilation has become a very powerful tool for the investigation of polymers. In particular, positron annihilation lifetime spectroscopy (PALS) yields valuable information on free volume and other properties ...
Günther-Schade, K. +5 more
core +1 more source
Methodology and Algorithm of Multicomponent Analysis of Positron Annihilation Spectra for Nanostructured Functional Materials [PDF]
Methodology for treatment of positron annihilation lifetime spectra by LT computer program in the nanostructured ceramic materials was proposed. Features of mathematical description of annihilation spectra was demonstrated. The algorithm for selection of
H.I. Klym +6 more
doaj +1 more source

