scholarly journals Materials for Future Quantum Dot-Based Memories

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
T. Nowozin ◽  
D. Bimberg ◽  
K. Daqrouq ◽  
M. N. Ajour ◽  
M. Awedh
Keyword(s):  
Cross Sections ◽  
Room Temperature ◽  
Storage Time ◽  
Thermal Emission ◽  
Current Status ◽  
Strong Electron ◽  
Self Organized ◽  
Hole Confinement ◽  
Storage Times ◽  
Capture Cross Sections

The present paper investigates the current status of the storage times in self-organized QDs, surveying a variety of heterostructures advantageous for strong electron and/or hole confinement. Experimental data for the electronic properties, such as localization energies and capture cross-sections, are listed. Based on the theory of thermal emission of carriers from QDs, we extrapolate the values for materials that would increase the storage time at room temperature to more than millions of years. For electron storage, GaSb/AlSb, GaN/AlN, and InAs/AlSb are proposed. For hole storage, GaSb/Al0.9Ga0.1As, GaSb/GaP, and GaSb/AlP are promising candidates.

scholarly journals Defective States in Micro-Crystalline CsPbBr3 and Their Role on Photoconductivity

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 177 ◽  
Author(s):  
Mara Bruzzi ◽  
Fabio Gabelloni ◽  
Nicola Calisi ◽  
Stefano Caporali ◽  
Anna Vinattieri
Keyword(s):  
Cross Sections ◽  
Dark Current ◽  
Room Temperature ◽  
Energy Levels ◽  
Constant Density ◽  
Capture Cross ◽  
Defect Tolerance ◽  
Thermally Stimulated Current ◽  
Temperature Range ◽  
Capture Cross Sections

Intrinsic defects in CsPbBr3 microcrystalline films have been studied using thermally stimulated current (TSC) technique in a wide temperature range (100–400 K). Below room temperature, TSC emission is composed by a set of several energy levels, in the range 0.11–0.27 eV, suggesting a quasi-continuum distribution of states with almost constant density. Above room temperature, up to 400 K, the temperature range of interest for solar cells, both dark current and photocurrent, are mainly dominated by energy levels in the range 0.40–0.45 eV. Even if measured trap densities are high, in the range 1013–1016 cm−3, the very small capture cross-sections, about 10−26 m2, agree with the high defect tolerance characterizing this material.

Effects of storage time and temperature on urinary enzymes

1991 ◽  
Vol 37 (8) ◽  
pp. 1436-1441 ◽  
Author(s):  
E Matteucci ◽  
G Gregori ◽  
L Pellegrini ◽  
R Navalesi ◽  
O Giampietro
Keyword(s):  
Low Temperatures ◽  
Healthy Subjects ◽  
Room Temperature ◽  
Storage Time ◽  
Short Term ◽  
Brush Border Enzymes ◽  
Urinary Enzymes ◽  
Gamma Glutamyltransferase ◽  
Renal Tubular ◽  
Storage Times

Abstract We measured three renal tubular brush-border enzymes (lactate dehydrogenase, LDH, EC 1.1.1.27; gamma-glutamyltransferase, GGT, EC 2.3.2.2; and alkaline phosphatase, AP, EC 3.1.3.1) in morning urine samples from 48 healthy subjects to check whether different storage times and temperatures could modify enzyme concentrations. Short-term (24 h) storage time at room temperature or 4 degree C does not affect urinary enzyme activity. A few days of freezing, at -20 or -70 degrees C, dramatically lowers LDH and AP values; GGT is partially preserved only at -70 degrees C, if the sample has been previously centrifuged. Urinary enzymes investigated in this study are extremely labile at low temperatures.

Carrier storage time of milliseconds at room temperature in self-organized quantum dots

2006 ◽  
Vol 89 (7) ◽  
pp. 072103 ◽  
Author(s):  
A. Marent ◽  
M. Geller ◽  
D. Bimberg ◽  
A. P. Vasi’ev ◽  
E. S. Semenova ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Storage Time ◽  
Self Organized

scholarly journals Temperature-Dependent Stimulated Emission Cross-Section in Nd3+:YLF Crystal

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 431
Author(s):  
Giorgio Turri ◽  
Scott Webster ◽  
Michael Bass ◽  
Alessandra Toncelli
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Room Temperature ◽  
Radiative Decay ◽  
Emission Cross Section ◽  
Spectroscopic Properties ◽  
Stimulated Emission ◽  
Different Temperatures ◽  
Stimulated Emission Cross Section ◽  
Semi Empirical

Spectroscopic properties of neodymium-doped yttrium lithium fluoride were measured at different temperatures from 35 K to 350 K in specimens with 1 at% Nd3+ concentration. The absorption spectrum was measured at room temperature from 400 to 900 nm. The decay dynamics of the 4F3/2 multiplet was investigated by measuring the fluorescence lifetime as a function of the sample temperature, and the radiative decay time was derived by extrapolation to 0 K. The stimulated-emission cross-sections of the transitions from the 4F3/2 to the 4I9/2, 4I11/2, and 4I13/2 levels were obtained from the fluorescence spectrum measured at different temperatures, using the Aull–Jenssen technique. The results show consistency with most results previously published at room temperature, extending them over a broader range of temperatures. A semi-empirical formula for the magnitude of the stimulated-emission cross-section as a function of temperature in the 250 K to 350 K temperature range, is presented for the most intense transitions to the 4I11/2 and 4I13/2 levels.

scholarly journals The accuracy of gypsum casts obtained from the disinfected extended-pour alginate impressions through prolonged storage times

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rania A. Sharif ◽  
Khalid M. Abdelaziz ◽  
Najla M. Alshahrani ◽  
Fatimah S. Almutairi ◽  
Mohrah A. Alaseri ◽  
...  
Keyword(s):  
Dimensional Stability ◽  
Storage Time ◽  
Prolonged Storage ◽  
Time Intervals ◽  
Superior Surface ◽  
Stability Data ◽  
Surface Detail ◽  
Storage Times ◽  
One Way Anova ◽  
Chemical Disinfection

Abstract Background Manufacturers of the extended-pour alginates claimed their dimensional stability through prolonged storage. No data confirmed the ability of these materials to maintain their dimensions and the reproduced oral details following their chemical disinfection. Therefore, this study evaluated the dimensional stability and surface detail reproduction of gypsum casts obtained from disinfected extended-pour alginate impressions through different storage time intervals. Methods Two hundred and forty three hydrocolloid impressions were made from one conventional (Tropicalgin) and two extended-pour (Hydrogum 5 and Chromaprint premium) alginates. These impressions were subjected to none, spray and immersion disinfection before their storage in 100% humidity for 0, 72 and 120 h. The dimensional stability and the surface detail reproduction were indirectly evaluated under low angle illumination on the resulted gypsum casts. At α = 0.05, the parametric dimensional stability data were analyzed using One-Way ANOVA and Tukey’s comparisons, while the nonparametric detail reproduction data were analyzed using KrusKal Wallis and Mann–Whitney's tests. Results All gypsum casts exhibited a degree of expansion; however, the recorded expansion values did not differ between test categories (P > 0.05). Generally, casts obtained from spray-disinfected impressions showed lower detail accuracy (P < 0.05). Immersion-disinfected extended-pour alginates produced casts with better detail accuracy following 120 h of storage (P < 0.05). Conclusion All alginates materials offer comparable cast dimensions under different testing circumstances. Extended-pour alginates offer casts with superior surface details following their immersion disinfection and 120 h of storage. Spray-disinfection using 5.25% sodium hypochlorite affects the surface details of casts obtained from conventional and extended-pour alginates adversely.

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