scholarly journals Testing and Applications of Non-Linear Wave Shaping Circuits Based on Zener Diodes at Cryogenic Temperatures

2017 ◽  
Vol 13 (4) ◽  
pp. 4910-4918
Author(s):  
A. M. Abd El-Maksood
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
The Other ◽  
Electronic Systems ◽  
Linear Wave ◽  
Cryogenic Temperatures ◽  
Temperature Variations ◽  
Wide Range ◽  
Non Linear ◽  
The Stability

            Applications of wave-shaping clipping circuits based on Zener diodes are of great interest in a wide range of modern electronic systems. As well, given the strong interest in space research and trips to distant planets, where the journey takes long periods. Therefore, the matter requires reliance on electronic systems with special specifications commensurate with the nature of the extremely low-temperature environments, down to cryogenic level (around 90 K). So, the present paper was concerned with studying the stability of the performance of different non-linear wave-shaping systems, based on silicon Zener diodes, whenever operates at very low temperatures down to cryogenic levels. From which, it is clear that for BZX79-C4V7 and BZX79-C5V6 Zeners, such electronic systems were shown to be insensitive to temperature variations. On the other hand, low breakdown voltage Zeners (BZV86-1V4 and BZX83-C3V6), the clipping edges were shown to be increased with lowering temperatures from 300 K down to 93 K. Finally, for Zener diodes with VZ greater than 6.0 V (BZX83-C6V8 and BZX55C9V1), the temperature coefficient is positive, so the clipping edges decrease with lowering temperatures, for the same range of temperatures.

scholarly journals The Stability of Icosahedral Cd-Yb

2003 ◽  
Vol 805 ◽  
Author(s):  
Günter Krauss ◽  
Sofia Deloudi ◽  
Andrea Steiner ◽  
Walter Steurer ◽  
Amy R. Ross ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Mechanical Stress ◽  
Single Crystals ◽  
High Temperatures ◽  
Low Temperatures ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability

ABSTRACTThe stability of single-crystalline icosahedral Cd-Yb was investigated using X-ray diffraction methods in the temperature range 20 K ≤ T ≤ 900 K at ambient pressure and from ambient temperature to 873 K at about 9 GPa. Single-crystals remain stable at low temperatures and in the investigated HP-HT-regime. At high temperatures and ambient pressure, the quasicrystal decomposes. The application of mechanical stress at low temperatures yields to the same decomposition, the formation of Cd. A reaction of icosahedral Cd-Yb with traces of oxygen or water causing the decomposition seems reasonable, but a low-temperature instability of this binary quasi-crystal cannot be ruled out totally.

scholarly journals A method for identification of non-linear multi-degree-of-freedom systems

1998 ◽  
Vol 212 (4) ◽  
pp. 287-298 ◽  
Author(s):  
G Dimitriadis ◽  
J E Cooper
Keyword(s):  
System Identification ◽  
Degree Of Freedom ◽  
Accurate Identification ◽  
Wide Range ◽  
Non Linear ◽  
Linear System Identification ◽  
The Stability ◽  
Non Linear System ◽  
Identification Techniques ◽  
Flutter Testing

System identification methods for non-linear aeroelastic systems could find uses in many aeroelastic applications such as validating finite element models and tracking the stability of aircraft during flight flutter testing. The effectiveness of existing non-linear system identification techniques is limited by various factors such as the complexity of the system under investigation and the type of non-linearities present. In this work, a new approach is introduced which can identify multi-degree-of-freedom systems featuring any type of non-linear function, including discontinuous functions. The method is shown to yield accurate identification of three mathematical models of aeroelastic systems containing a wide range of structural non-linearities.

scholarly journals Thermodynamics for the interaction of ε-dinitrophenyl-l-lysine and bovine colostral anti-dinitrophenyl immunoglobulin G2

1978 ◽  
Vol 173 (1) ◽  
pp. 39-44 ◽  
Author(s):  
T K S Mukkur
Keyword(s):  
Low Temperatures ◽  
Heat Capacity Change ◽  
Compensation Mechanism ◽  
Linear Least Squares ◽  
Capacity Change ◽  
Wide Range ◽  
Non Linear ◽  
Entropy Factor ◽  
Hoff Plot ◽  
Computer Procedure

The effect of varying the temperature over a wide range (4–60 degrees C) on the binding of epsilon-dinitrophenyl-L-lysine to bovine colostral anti-dinitrophenyl immunoglobulin G2 yielded a non-linear van′t Hoff plot. The extent of curvature was indicative of a large positive heat-capacity change, and the thermodynamic parameters, calculated by using a non-linear least squares computer procedure, revealed an enthalpy–entropy-compensation mechanism for hapten-antibody binding. The enthalpy factor was found to be the primary contributor for the complex-formation at low temperatures, but at increasing temperatures the entropy factor assumed greater importance. At physiological temperature (39 degrees C), the entropy factor was the major contributor to the free energy of reaction.

Improved Stability Against Light-Exposure in Deuterated Amorphous Silicon Alloy Solar Cells

1997 ◽  
Vol 467 ◽  
Author(s):  
S. Sugiyama ◽  
J. Yang ◽  
S. Guha
Keyword(s):  
Solar Cells ◽  
Low Temperature ◽  
Amorphous Silicon ◽  
Light Exposure ◽  
The Other ◽  
Silicon Alloy ◽  
Improved Stability ◽  
The Stability ◽  
Microstructure Of The Material ◽  
Hydrogen Effusion

ABSTRACTWe have studied light-induced degradation in hydrogenated and deuterated amorphous silicon alloy solar cells in which intrinsic layers were deposited by using SiH4+H2 and SiD4+D2 gas mixtures respectively. Replacing hydrogen with deuterium in the intrinsic layer of the cell improves stability against light exposure. On the other hand, cells in which intrinsic layers were deposited from SiD4+H2 and SiH4+D2 do not show any improvement in stability. This result shows that improved stability in deuterated cell does not originate from simple replacement of hydrogen with deuterium. From deuterium/hydrogen effusion measurements, we found similar effusion at low temperature (400 °C) in both deuterated film and hydrogenated film prepared with heavy dilution. The latter film was shown to have oriented microstructure which was correlated with higher stability. This correlation strongly indicates that microstructure of the material plays a key role in improving the stability.

scholarly journals EFFECT OF WAVE-CURRENT INTERACTION ON THE WAVE PARAMETER

1982 ◽  
Vol 1 (18) ◽  
pp. 28
Author(s):  
Yu-Cheng Li ◽  
John B. Herbich
Keyword(s):  
Wave Height ◽  
Wave Length ◽  
Wave Theory ◽  
Length Change ◽  
Numerical Calculations ◽  
Wave Parameter ◽  
Linear Wave ◽  
Linear Wave Theory ◽  
Wide Range ◽  
Non Linear

The interaction of a gravity wave with a steady uniform current is described in this paper. Numerical calculations of the wave length change by different non-linear wave theories show that errors in the results computed by the linear wave theory are less than 10 percent within the range of 0.15 < d/Ls s 0.40, 0.01 < Hs/Ls < 0.07 and -0.15 < U/Cs i 0.30. Numerical calculations of wave height change employing different wave theories show that errors in the results obtained by the linear wave theory in comparison with the non-linear theories are greater when the opposing relative current and wave steepness become larger. However, within range of the following currents such errors will not be significant. These results were verified by model tests. Nomograms for the modification of wave length and wave height by the linear wave theory and Stokes1 third order theory are presented for a wide range of d/Ls, Hs/Ls and U/C. These nomograms provide the design engineer with a practical guide for estimating wave lengths and heights affected by currents.

Jojoba: Temperature Adaptation as Expressed in Growth and Leaf Function

1983 ◽  
Vol 10 (3) ◽  
pp. 299 ◽  
Author(s):  
IF Wardlaw ◽  
JE Begg ◽  
D Bagnall ◽  
RL Dunstone
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Vascular System ◽  
Starch Content ◽  
Dry Weight ◽  
Co2 Exchange ◽  
Temperature Adaptation ◽  
Pulse Labelling ◽  
Wide Range ◽  
Young Leaves

The adaptation of jojoba [Simmondsia chinensis (Link) Schneider] to temperature was studied under controlled conditions. Shoot extension and leaf area development reflected the very low rate of growth of this species, even under favourable conditions, and were stable with an increase in temperature from 20 to 30°C. However growth was markedly reduced at temperatures below 20°C and at 6°C there was no net gain in dry weight over a 42 day period. Root: shoot ratios were near unity and showed a small drop in response to increasing temperature. Leaves adapted to low temperature by an increase in thickness, specific leaf weight and starch content. Chlorophyll formation was retarded in young leaves developing at 15/10°C, but there was no sign of photodestruction of previously formed chlorophyll in mature leaves. Young leaves developing at 30/25°C had a very high chlorophyll a/b ratio of 9.5, but otherwise leaf chlorophyll was apparently normal (2.3-3.4) over a wide range of temperatures. Light saturation of net CO2 exchange (NCE) occurred at about 1000 �E m-2 s-1 for leaves grown over a wide range of temperatures and the maximum NCE of approximately 16 mg CO2 dm-2 h-1 (0.45 mg m-2 s-1) occurred between 19 and 25°C. Pulse labelling with 14CO2 indicated that low temperature (18°C) reduced the rate of transfer of 14C from the primary products of fixation to sucrose. The rate of movement of 14C-labelled photosynthate out of the leaf was negligible at 18°C, and reached only about 3% h-1 at 30°C. In the stems, shortly after 14CO2 uptake by the leaf, 86% of the 14C activity was in sucrose, indicating that this was the preferred form of translocate in the vascular system. However glucose was more abundant in the leaves than sucrose, particularly at low temperatures. Starch accumulated in the leaves at low temperatures, reaching nearly 30% of the dry weight at 18/13°C. Photosynthetic stability rather than active adaptation appears to form the basis of resistance to temperature stress in jojoba. With low rates even under optimal conditions this is essentially one of adaptation for survival rather than adaptation for production.

scholarly journals Low-temperature dynamics in a dye-doped polymer: correspondence between the data obtained by photon echo and single molecule spectroscopy

2018 ◽  
Vol 190 ◽  
pp. 04008
Author(s):  
Kamil Karimullin ◽  
Andrei Naumov
Keyword(s):  
Low Temperature ◽  
Single Molecule ◽  
Vibrational Relaxation ◽  
Low Temperatures ◽  
Photon Echo ◽  
Single Molecule Spectroscopy ◽  
Dye Molecules ◽  
Wide Range ◽  
Temperature Dynamics ◽  
Doped Polymer

Low temperature dynamics (tunneling and vibrational relaxation) in doped polyisobutylene film has been reinvestigated using 2-pulse incoherent photon echo (2IPE) and compared with single-molecule spectroscopy (SMS) data. It has been shown that in a very wide range of low temperatures the 2IPE gives optical dephasing times which correspond to the narrowest zero-phonon lines of single dye molecules.

A Method of Full Digital Clock Generation with Adjustable Frequency and Phase

2014 ◽  
Vol 599-601 ◽  
pp. 703-706
Author(s):  
Yan Nian Lou ◽  
Zhong He Jin ◽  
Chao Jie Zhang
Keyword(s):  
High Frequency ◽  
The Other ◽  
Electronic Systems ◽  
Clock Generation ◽  
Digital Clock ◽  
On Line ◽  
The Stability ◽  
Fundamental Requirement ◽  
Better Than

In modern electronic systems, a reliable clock with precise frequency is a fundamental requirement. Moreover, the frequency and phase of the clock needs to be adjustable in some situations. So a method of full digital clock generation is proposed in this paper. Compared with other methods, it has two advantages: one is the capability of adjusting the frequency and phase on-line; the other is the high frequency precision. Experiment results show that this method can generate clock at 19.0484MHz, 19.0485MHz, 19.0486MHz with controlled phases, and the stability within 90 seconds is better than 0.05Hz.

Dust formation at cryogenic temperatures

2017 ◽  
Vol 13 (S332) ◽  
pp. 312-319
Author(s):  
Thomas Henning ◽  
Cornelia Jäger ◽  
Gaël Rouillé ◽  
Daniele Fulvio ◽  
Serge A. Krasnokutski
Keyword(s):  
Low Temperature ◽  
Interstellar Medium ◽  
Striking Similarity ◽  
Rare Gas ◽  
Dust Formation ◽  
Cryogenic Temperatures ◽  
Numerical Studies ◽  
Wide Range ◽  
Hydrogenated Amorphous ◽  
Shock Fronts

AbstractThe efficiency of dust formation in a variety of environments is an ongoing topic for discussions, especially if it comes to dust formation in the interstellar medium. Although this possibility is discussed in a wide range of numerical studies, experiments on the formation of dust at low densities and temperatures are mostly lacking. This contribution summarizes the main findings of our low-temperature condensation experiments including the formation of silica, complex silicates with pyroxene and olivine stoichiometry, and of carbonaceous refractory materials. Atomic and molecular species to be expected as products of supernovae shock fronts were produced by laser ablation of silicates and graphite. These species were deposited together with a rare gas on cold substrates representing the surfaces of surviving dust grains in the interstellar medium. After characterizing the precursor species, the rare gas matrix was annealed to induce diffusion and reactions between the initial components. We found the production of amorphous and homogeneous silica and magnesium iron silicates at temperatures of about 12 K in a barrierless reaction as monitored by infrared spectroscopy. The 10 μm band of the low-temperature siliceous condensates shows a striking similarity to the 10 μm band of interstellar silicates. Carbonaceous atoms and molecules can also react without a barrier and form an amorphous or hydrogenated amorphous carbon material. The refractory condensate has properties comparable to fullerene-like carbon grains formed at high temperatures.

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