Refractory Metal Facings for Protection of Metal Surfaces Subjected to Repeated High-Temperature Pulses

1959 ◽  
Vol 81 (2) ◽  
pp. 197-202
Author(s):  
Aaron Cohen ◽  
Edward Homer

Because the operating frequency of a magnetron has a direct relationship to the size of the resonant structure, the power at a given frequency that can be obtained from a magnetron may be limited by the temperature which the resonating structure can withstand. A rise in the temperature of the resonant structure is caused by the impact of high-energy electrons emitted from the cathode at high peak-power levels for short durations. This paper deals with the analytical determination of the temperature of the resonant structure, a solution to the heat problem in which a thin coating of refractory metal is used to prevent the vulnerable components from melting, and some experimental results to verify the analysis.

2019 ◽  
Vol 40 (4) ◽  
pp. 393-400
Author(s):  
Ali Nassiri ◽  
Hafida Idrissi-Saba ◽  
Abdelkader Boulezhar

Abstract In this work, we have developed an analytical model of an actively Q-switched Ytterbium-doped fiber laser by using two coupled cavities with amplifying fibers in Mach–Zehnder interferometer configuration. This oscillator system provides high peak power and high energy nanosecond pulse. The pulse energy is almost twice the energy of an individual fiber laser with a combining efficiency goes up 99%. This concept brings some novel perspectives for scaling the high energy and high peak power of nanosecond pulse fiber laser.


Author(s):  
John Minelly ◽  
Fabio Teodoro ◽  
Matthias Savage-Leuchs ◽  
Deborah Alterman ◽  
Christopher Brooks ◽  
...  

2013 ◽  
Vol 38 (22) ◽  
pp. 4686 ◽  
Author(s):  
A. Malinowski ◽  
P. Gorman ◽  
C. A. Codemard ◽  
F. Ghiringhelli ◽  
A. J. Boyland ◽  
...  

1996 ◽  
Author(s):  
Sheldon B. Hutchison ◽  
Alexandra M. Berezinskaya ◽  
Alan B. Petersen ◽  
Jan-Willem J. Pieterse ◽  
William L. Nighan, Jr. ◽  
...  

2021 ◽  
Vol 9 (4) ◽  
pp. 1366-1379
Author(s):  
Kevser Arman ◽  
Arzu Organ

In today's world where the importance of digitalization is increasing day by day, companies to increase their competitiveness have focused on digital supply chain instead of traditional supply chain. In a world where resources are constantly decreasing, the concept of sustainability has become very crucial in every part of life. Digital technologies, on the other hand, have a direct relationship with sustainability. Sustainability has three main dimensions: economic, environmental, and social. Therefore, the aim of this study is to evaluate digital supply chain on 3 basic dimensions of sustainability. For this purpose, Fuzzy Best Worst Method (F-BWM) was used to define the importance level of criteria. Findings reveal that the concept of sustainability in textile firms in Turkey is generally perceived within an economic and environmental area, rather than within a social dimension. This study is very important in putting forward digital technologies which utilizing in supply chain and the impact of the digital supply chain on sustainability.


Author(s):  
Sheldon B. Hutchison ◽  
Alexandria M. Berezinskaya ◽  
Alan B. Petersen ◽  
Jan-Willem Pieterse ◽  
William L. Nighan ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
M. F. Ritter ◽  
A. Fuhrer ◽  
D. Z. Haxell ◽  
S. Hart ◽  
P. Gumann ◽  
...  

AbstractRecent experiments with metallic nanowires devices seem to indicate that superconductivity can be controlled by the application of electric fields. In such experiments, critical currents are tuned and eventually suppressed by relatively small voltages applied to nearby gate electrodes, at odds with current understanding of electrostatic screening in metals. We investigate the impact of gate voltages on superconductivity in similar metal nanowires. Varying materials and device geometries, we study the physical mechanism behind the quench of superconductivity. We demonstrate that the transition from superconducting to resistive state can be understood in detail by tunneling of high-energy electrons from the gate contact to the nanowire, resulting in quasiparticle generation and, at sufficiently large currents, heating. Onset of critical current suppression occurs below gate currents of 100fA, which are challenging to detect in typical experiments.


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