scholarly journals Fluorescence quantum efficiency of Ti3+:Al2O3 at cryogenic temperatures and excitation by laser diodes

2021 ◽  
Vol 2067 (1) ◽  
pp. 012010
Author(s):  
A Gribanov ◽  
G Nikolaev ◽  
M Mosin ◽  
D Yakovin ◽  
M Yakovin
Keyword(s):  
Quantum Efficiency ◽  
Cryogenic Temperature ◽  
Laser Diodes ◽  
Czochralski Method ◽  
Sapphire Crystal ◽  
Cryogenic Temperatures ◽  
Temperature Range ◽  
Temperature Dependences ◽  
First Time

Abstract In this work the temperature dependences of the fluorescence of a titanium-sapphire crystal excited by radiation with λ=507 nm, λ=454 nm and λ=405 nm are measured. The quantum efficiency of fluorescence is determined. It was found for the first time that the quantum efficiency of fluorescence exceeds 100% in the cryogenic temperature range when the crystal is excited by radiation with λ = 454 nm. It is equal to (117 ± 5) % and (114 ± 5) % at T = 77 K for crystals grown by the Czochralski method and by gradient of temperature one, respectively.

Dynamic Viscosity of Compressed Water to 10 Kilobar and Steam to 1500°C

1969 ◽  
Vol 11 (2) ◽  
pp. 189-205 ◽  
Author(s):  
E. A. Bruges ◽  
M. R. Gibson
Keyword(s):  
Gaseous Phase ◽  
Dynamic Viscosity ◽  
Low Temperatures ◽  
Pressure Range ◽  
Low Pressure ◽  
Temperature Range ◽  
Inversion Temperature ◽  
Pressure Steam ◽  
Correlating Equations ◽  
First Time

Equations specifying the dynamic viscosity of compressed water and steam are presented. In the temperature range 0-100cC the location of the inversion locus (mu) is defined for the first time with some precision. The low pressure steam results are re-correlated and a higher inversion temperature is indicated than that previously accepted. From 100 to 600°C values of viscosity are derived up to 3·5 kilobar and between 600 and 1500°C up to 1 kilobar. All the original observations in the gaseous phase have been corrected to a consistent set of densities and deviation plots for all the new correlations are given. Although the equations give values within the tolerances of the International Skeleton Table it is clear that the range and tolerances of the latter could with some advantage be revised to give twice the existing temperature range and over 10 times the existing pressure range at low temperatures. A list of the observations used and their deviations from the correlating equations is available as a separate publication.

scholarly journals Joining of Electrodes to Ultra-Thin Metallic Layers on Ceramic Substrates in Cryogenic Sensors

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4919
Author(s):  
Marcin Lebioda ◽  
Ryszard Pawlak ◽  
Jacek Rymaszewski
Keyword(s):  
Cryogenic Temperatures ◽  
Thermal And Mechanical Properties ◽  
Reflow Soldering ◽  
Ceramic Substrates ◽  
Temperature Range ◽  
Wave Soldering ◽  
Materials Used ◽  
Standard Designs ◽  
Electrical Connections ◽  
Method Show

Microjoining technologies are crucial for producing reliable electrical connections in modern microelectronic and optoelectronic devices, as well as for the assembly of electronic circuits, sensors, and batteries. However, the production of miniature sensors presents particular difficulties, due to their non-standard designs, unique functionality and applications in various environments. One of the main challenges relates to the fact that common methods such as reflow soldering or wave soldering cannot be applied to making joints to the materials used for the sensing layers (oxides, polymers, graphene, metallic layers) or to the thin metallic layers that act as contact pads. This problem applies especially to sensors designed to work at cryogenic temperatures. In this paper, we demonstrate a new method for the dynamic soldering of outer leads in the form of metallic strips made from thin metallic layers on ceramic substrates. These leads can be used as contact pads in sensors working in a wide temperature range. The joints produced using our method show excellent electrical, thermal, and mechanical properties in the temperature range of 15–300 K.

scholarly journals Isolation and characterization of a new cold-active protease from psychrotrophic bacteria of Western Himalayan glacial soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saleem Farooq ◽  
Ruqeya Nazir ◽  
Shabir Ahmad Ganai ◽  
Bashir Ahmad Ganai
Keyword(s):  
Specific Activity ◽  
Temperature Range ◽  
Psychrotrophic Bacteria ◽  
Isolation And Characterization ◽  
Cold Active ◽  
Active Protease ◽  
Quantitative Screening ◽  
First Time ◽  
Low K

AbstractAs an approach to the exploration of cold-active enzymes, in this study, we isolated a cold-active protease produced by psychrotrophic bacteria from glacial soils of Thajwas Glacier, Himalayas. The isolated strain BO1, identified as Bacillus pumilus, grew well within a temperature range of 4–30 °C. After its qualitative and quantitative screening, the cold-active protease (Apr-BO1) was purified. The Apr-BO1 had a molecular mass of 38 kDa and showed maximum (37.02 U/mg) specific activity at 20 °C, with casein as substrate. It was stable and active between the temperature range of 5–35 °C and pH 6.0–12.0, with an optimum temperature of 20 °C at pH 9.0. The Apr-BO1 had low Km value of 1.0 mg/ml and Vmax 10.0 µmol/ml/min. Moreover, it displayed better tolerance to organic solvents, surfactants, metal ions and reducing agents than most alkaline proteases. The results exhibited that it effectively removed the stains even in a cold wash and could be considered a decent detergent additive. Furthermore, through protein modelling, the structure of this protease was generated from template, subtilisin E of Bacillus subtilis (PDB ID: 3WHI), and different methods checked its quality. For the first time, this study reported the protein sequence for psychrotrophic Apr-BO1 and brought forth its novelty among other cold-active proteases.

An NMR solid-echo Study of Guanidinium Cation Reorientation in [C(NH2)3]3Sb2Cl9

2004 ◽  
Vol 59 (11) ◽  
pp. 787-790
Author(s):  
P. Bilski ◽  
M. Olszewskia ◽  
N. A. Sergeev ◽  
J. Wa̻sicki
Keyword(s):  
Wide Temperature Range ◽  
Temperature Range ◽  
Temperature Dependences ◽  
Time Position ◽  
Nmr Solid ◽  
Guanidinium Cation

The NMR solid-echo polycrystalline tris-guanidinium nonachlorodiantimonate (III) has been studied in a wide temperature range. The temperature dependences of a time position and an amplitude of solid-echo are characterized by minima at ca. 143 K and 273 K, which are assigned to the reorientation of two dynamically inequivalent guanidinium cations [C(NH2)3]+. The motional parameters of the two types of guanidinium cations have been determined. -PACS: 64.70K; 76.60.E

Highly reliable spot-size converter integrated laser diodes over a wide temperature range for access network systems

2001 ◽  
Vol 41 (1) ◽  
pp. 111-118 ◽  
Author(s):  
H Oohashi ◽  
M Fukuda ◽  
Y Kondo ◽  
M Yamamoto ◽  
Y Kadota ◽  
...  
Keyword(s):  
Wide Temperature Range ◽  
Laser Diodes ◽  
Access Network ◽  
Spot Size ◽  
Network Systems ◽  
Temperature Range

scholarly journals Operando and in situ in a TEM imaging in a cryogenic temperature range

2021 ◽  
Vol 27 (S1) ◽  
pp. 386-387
Author(s):  
Martial Duchamp ◽  
Joseph Vas ◽  
Reinis Ignatans ◽  
Aaron David Mueller ◽  
Rohit Medwal ◽  
...  
Keyword(s):  
Cryogenic Temperature ◽  
Temperature Range

Cracking Response of a Concrete Wall to Cryogenic Temperature

2015 ◽  
Vol 365 ◽  
pp. 71-76
Author(s):  
Lahlou Dahmani ◽  
Rabah Hammar ◽  
Mohamed Oussalem Mechiche
Keyword(s):  
Cryogenic Temperature ◽  
Heat Conduction Problem ◽  
Outer Wall ◽  
Distribution Data ◽  
Cryogenic Temperatures ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Concrete Wall ◽  
Steel Tank ◽  
Concrete Tank

Liquefied natural gas (LNG) has the cryogenic temperature of –160°C to ensure the minimum storage volume when stored in LNG containers. Among various types of LNG storage containers, the full containment above-ground type with a double safety system (outer concrete tank and inner steel tank) is very common. Normally, the inner tank contains LNG, but when the LNG leaks from the inner tank, the outer concrete tank comes into contact with LNG. Under this accidental case, it is indispensable for the outer wall to keep the liquid tightness in order to safely contain the LNG before taking any countermeasure. It is, therefore, proposed to take up a heat conduction problem using the finite element method with the ANSYS software to obtain temperature distribution data of a concrete wall at cryogenic temperatures.

Growth, thermal, and spectroscopic properties of a 2.911 μm Yb,Ho:GdYTaO4 laser crystal

CrystEngComm ◽  
2014 ◽  
Vol 16 (48) ◽  
pp. 11007-11012 ◽  
Author(s):  
Renqin Dou ◽  
Qingli Zhang ◽  
Dunlu Sun ◽  
Jianqiao Luo ◽  
Huajun Yang ◽  
...  
Keyword(s):  
Laser Crystal ◽  
Czochralski Method ◽  
Spectroscopic Properties ◽  
First Time

A promising 2.911 μm Yb,Ho:GdYTaO4 laser crystal was grown successfully by the Czochralski method for the first time.

Can molten carbonate be a non-metal catalyst for CO oxidation?

2018 ◽  
Vol 42 (19) ◽  
pp. 16372-16377
Author(s):  
Jingjing Tong ◽  
Xueling Lei ◽  
Peng Zhang ◽  
Kevin Huang ◽  
Godwin Mbamalu ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Metal Catalyst ◽  
Molten Carbonate ◽  
Temperature Range ◽  
First Time

For the first time, we have examined molten carbonate as a non-metal catalyst for CO oxidation in the temperature range of 300–600 °C.

scholarly journals Room Temperature CW Operation of GaN-based Blue Laser Diodes by GaInN/GaN optical guiding layers

2000 ◽  
Vol 5 (S1) ◽  
pp. 1-7 ◽  
Author(s):  
Masayoshi Koike ◽  
Shiro Yamasaki ◽  
Yuta Tezen ◽  
Seiji Nagai ◽  
Sho Iwayama ◽  
...  
Keyword(s):  
Room Temperature ◽  
Continuous Wave ◽  
Laser Diodes ◽  
Threshold Current ◽  
Crystal Defects ◽  
Blue Laser ◽  
Buffer Layers ◽  
Continuous Wave Laser ◽  
Cw Operation ◽  
First Time

GaN-based short wavelength laser diodes are the most promising key device for a digital versatile disk. We have been improving the important points of the laser diodes in terms of optical guiding layers, mirror facets. The continuous wave laser irradiation at room temperature could be achieved successfully by reducing the threshold current to 60 mA (4 kA/cm2). We have tried to apply the multi low temperature buffer layers to the laser diodes for the first time to reduce the crystal defects.

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