Free carriers's effective mass and relaxation-time analysis by high-pulsed-field Faraday oscillations in III-V compounds

1976 ◽  
Vol 13 (6) ◽  
pp. 2576-2582 ◽  
Author(s):  
D. Julienne ◽  
F. Le Saos ◽  
A. Fortini ◽  
Ph. Bauduin
Keyword(s):  
Relaxation Time ◽  
Effective Mass ◽  
Time Analysis ◽  
Pulsed Field

scholarly journals In Vivo MRI Tracking of Mesenchymal Stromal Cells Labeled with Ultrasmall Paramagnetic Iron Oxide Particles after Intramyocardial Transplantation in Patients with Chronic Ischemic Heart Disease

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Anders Bruun Mathiasen ◽  
Abbas Ali Qayyum ◽  
Erik Jørgensen ◽  
Steffen Helqvist ◽  
Annette Ekblond ◽  
...  
Keyword(s):  
Heart Disease ◽  
Relaxation Time ◽  
Iron Oxide ◽  
Ischemic Heart Disease ◽  
Mesenchymal Stromal Cells ◽  
Stromal Cells ◽  
Human Studies ◽  
Ischemic Heart ◽  
Time Analysis ◽  
Intramyocardial Injection

Background. While regenerative stem cell therapy for ischemic heart disease has moved into phase 3 studies, little is still known about retention and migration of cell posttransplantation. In human studies, the ability to track transplanted cells has been limited to labeling with radioisotopes and tracking using nuclear imaging. This method is limited by low resolution and short half-lives of available radioisotopes. Longitudinal tracking using magnetic resonance imaging (MRI) of myocardial injected cells labeled with iron oxide nanoparticles has shown promising results in numerous preclinical studies but has yet to be evaluated in human studies. We aimed to evaluate MRI tracking of mesenchymal stromal cells (MSCs) labeled with ultrasmall paramagnetic iron oxide (USPIO) nanoparticles after intramyocardial transplantation in patients with ischemic heart disease (IHD). Methods. Five no-option patients with chronic symptomatic IHD underwent NOGA-guided intramyocardial transplantation of USPIO-labeled MSCs. Serial MRI scans were performed to track labeled cells both visually and using semiautomated T2∗ relaxation time analysis. For safety, we followed symptoms, quality of life, and myocardial function for 6 months. Results. USPIO-labeled MSCs were tracked for up to 14 days after transplantation at injection sites both visually and using semiautomated regional T2∗ relaxation time analysis. Labeling of MSCs did not impair long-term safety of treatment. Conclusion. This was a first-in-man clinical experience aimed at evaluating the utility of MRI tracking of USPIO-labeled bone marrow-derived autologous MSCs after intramyocardial injection in patients with chronic IHD. The treatment was safe, and cells were detectable at injection sites up to 14 days after transplantation. Further studies are needed to clarify if MSCs migrate out of the injection area into other areas of the myocardium or if injected cells are washed out into the peripheral circulation. The trial is registered with ClinicalTrials.gov NCT03651791.

Relaxation Time Analysis of a Simulated Binary Alloy

1991 ◽  
Vol 02 (01) ◽  
pp. 491-496
Author(s):  
JACEK SOŁTYS ◽  
TOMASZ A. KOCHAN
Keyword(s):  
Relaxation Time ◽  
Binary Alloy ◽  
Time Analysis

Measurement of the Effective Mass of Transparent Conducting films of Cadmium Tin Oxide

1997 ◽  
Vol 471 ◽  
Author(s):  
W. P. Mulligan ◽  
T. J. Coutts
Keyword(s):  
Relaxation Time ◽  
Effective Mass ◽  
Transparent Conducting Oxides ◽  
High Mobility ◽  
Carrier Relaxation ◽  
Conducting Oxides ◽  
Transparent Conducting Films ◽  
Transparent Conducting ◽  
Carrier Effective Mass ◽  
Cadmium Stannate

ABSTRACTWe have prepared transparent conducting films of cadmium stannate (Cd2SnO4 with resistivity as low as 1.5×10-4 Ω cm. The resistivity of these films is low because of their surprisingly high mobility (60 cm2 V-1 sec-1) at high carrier concentration (7×1020cm-3). We conducted an investigation to determine whether the high mobility is due to unusually low carrier effective mass or to a long carrier relaxation time. The conductivity effective mass and relaxation time were estimated by Drude free-electron modeling of reflectance and transmittance spectroscopie measurements. The Drude model appears to represent the behavior of cadmium tin oxide very well. The optical effective mass of the electrons in cadmium stannate is about 0.35 mo, which is similar to that of other transparent conducting oxides. By varying the doping level, we were able to fabricate films with various levels of degeneracy, but these showed no significant difference in effective mass.We were also able to determine the carrier effective mass and the relaxation time by measuring four separate electron transport coefficients: conductivity, Hall, Seebeck, and transverse Nernst-Ettingshausen (Nernst). The Fermi level was found to vary from 0.31 to 0.83 eV above the conduction band minimum, and the conduction band was very close to parabolic in this range, with m* ∼ 0.33 mo, in good agreement with the optical result. We conclude that the effective mass of electrons in cadmium stannate is similar to electrons in other transparent conducting oxides and that high mobility results from a relatively long carrier relaxation time.

Distribution of Relaxation Time Analysis of Cathode Micro-Patterned PEFC

2020 ◽  
Vol MA2020-02 (33) ◽  
pp. 2158-2158
Author(s):  
Morio Tomizawa ◽  
Keisuke Nagato ◽  
Kohei Nagai ◽  
Masayuki Nakao
Keyword(s):  
Relaxation Time ◽  
Time Analysis
Sign in / Sign up

Export Citation Format

Share Document