LWIR telescope design considerations for high-temperature operation

1995 ◽  
Author(s):  
R. Lawrence Sinclair ◽  
Martin High
Keyword(s):  
High Temperature ◽  
Design Considerations ◽  
High Temperature Operation

Design Considerations for Reliable High Temperature Operation of Wet Electrolytic Tantalum Capacitors

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000103-000111 ◽  
Author(s):  
Jeremy Ladd
Keyword(s):  
High Temperature ◽  
Internal Pressure ◽  
Current Flow ◽  
Hydrogen Gas ◽  
Ambient Conditions ◽  
Design Considerations ◽  
Electrical Stress ◽  
Temperature Performance ◽  
Reliable Performance ◽  
High Temperature Operation

Wet electrolytic tantalum (Ta) capacitors have historically been utilized in a variety of applications which endure harsh ambient conditions. Thermal, electrical and mechanical stresses, though, pose significant challenges to reliable performance of these capacitors in such environments. Thermal stress can increase the internal pressure of the capacitors, as well as mechanically compromise some of the components of which the capacitors are comprised. Electrical stress, in the form of current flow due to applied voltage, can elicit hydrogen gas evolution, which further exacerbates the internal pressure issue, potentially embrittles Ta components, and degrades AC performance of the capacitors. Mechanical stress, resulting from shock and vibration for example, can jeopardize the internal mechanical integrity of the capacitors. This paper elaborates on these obstacles, and offers design approaches to reliably overcome them. Also presented are results of high temperature performance, predominantly up to 230°C, but also a mention of limited 245°C results, of wet Ta capacitors manufactured with proper attention paid to these concerns.

Design Optimization of a High Temperature 1.2 kV 4H-SiC Buried Grid JBS Rectifier

2017 ◽  
Vol 897 ◽  
pp. 455-458 ◽  
Author(s):  
Hossein Elahipanah ◽  
Nicolas Thierry-Jebali ◽  
Sergey A. Reshanov ◽  
Wlodek Kaplan ◽  
A. Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Leakage Current ◽  
Voltage Drop ◽  
Shielding Effect ◽  
Wafer Level ◽  
Reverse Voltage ◽  
Forward Voltage ◽  
Design Considerations ◽  
Forward Voltage Drop ◽  
High Temperature Operation

1.2 kV SiC buried grid junction barrier Schottky (BG-JBS) diodes are demonstrated. The design considerations for high temperature applications are investigated. The design is optimized in terms of doping concentration and thickness of the epilayers, as well as grid size and spacing dimensions, in order to obtain low on-resistance and reasonable leakage current even at high temperatures. The device behavior at temperatures ranging from 25 to 225ºC is analyzed and measured on wafer level. At 100 A/cm2 a forward voltage drop of 2 V at 25ºC and 3 V at 225ºC is achieved. At reverse voltage of 1 kV, a leakage current density below 0.1 µA/cm2 and below 0.1 mA/cm2 is measured at 25 and 225ºC, respectively. This proves the effective shielding effect of the BG-JBS design and provides benefits in high voltage applications, particularly for high temperature operation.

High-Temperature Operation of Photonic-Crystal Lasers for On-Chip Optical Interconnection

2012 ◽  
Vol E95.C (7) ◽  
pp. 1244-1251 ◽  
Author(s):  
Koji TAKEDA ◽  
Tomonari SATO ◽  
Takaaki KAKITSUKA ◽  
Akihiko SHINYA ◽  
Kengo NOZAKI ◽  
...  
Keyword(s):  
High Temperature ◽  
Photonic Crystal ◽  
Optical Interconnection ◽  
On Chip ◽  
High Temperature Operation

KUBOTA UCX

Alloy Digest ◽  
2008 ◽  
Vol 57 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Temperature Performance ◽  
High Temperature Operation ◽  
Oxidation And Corrosion ◽  
Very High

Abstract Kubota UCX was developed for very high temperature operation for ethylene pyrolysis service. The alloy also has excellent oxidation and corrosion resistance. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting and joining. Filing Code: Ni-663. Producer or source: Kubota Metal Corporation, Fahramet Division.

scholarly journals Identification of Existing Challenges and Future Trends for the Utilization of Ammonia-Water Absorption–Compression Heat Pumps at High Temperature Operation

2021 ◽  
Vol 11 (10) ◽  
pp. 4635
Author(s):  
Marcel Ulrich Ahrens ◽  
Maximilian Loth ◽  
Ignat Tolstorebrov ◽  
Armin Hafner ◽  
Stephan Kabelac ◽  
...  
Keyword(s):  
High Temperature ◽  
Water Absorption ◽  
Industrial Sector ◽  
Heat Pumps ◽  
Working Fluid ◽  
Large Temperature ◽  
Future Trends ◽  
Ammonia Water ◽  
Starting Point ◽  
High Temperature Operation

Decarbonization of the industrial sector is one of the most important keys to reducing global warming. Energy demands and associated emissions in the industrial sector are continuously increasing. The utilization of high temperature heat pumps (HTHPs) operating with natural fluids presents an environmentally friendly solution with great potential to increase energy efficiency and reduce emissions in industrial processes. Ammonia-water absorption–compression heat pumps (ACHPs) combine the technologies of an absorption and vapor compression heat pump using a zeotropic mixture of ammonia and water as working fluid. The given characteristics, such as the ability to achieve high sink temperatures with comparably large temperature lifts and high coefficient of performance (COP) make the ACHP interesting for utilization in various industrial high temperature applications. This work reviews the state of technology and identifies existing challenges based on conducted experimental investigations. In this context, 23 references with capacities ranging from 1.4 kW to 4500 kW are evaluated, achieving sink outlet temperatures from 45 °C to 115 °C and COPs from 1.4 to 11.3. Existing challenges are identified for the compressor concerning discharge temperature and lubrication, for the absorber and desorber design for operation and liquid–vapor mixing and distribution and the choice of solution pump. Recent developments and promising solutions are then highlighted and presented in a comprehensive overview. Finally, future trends for further studies are discussed. The purpose of this study is to serve as a starting point for further research by connecting theoretical approaches, possible solutions and experimental results as a resource for further developments of ammonia-water ACHP systems at high temperature operation.

High-Temperature Operation Method for Image Pickup Tube

2021 ◽  
pp. 1-1
Author(s):  
Yoichiro Neo ◽  
Masato Nakata ◽  
Yukino Kameda ◽  
Yoshinori Hatanaka ◽  
Hidenori Mimura
Keyword(s):  
High Temperature ◽  
Operation Method ◽  
High Temperature Operation

High-temperature operation of GaN-based OPAMP on silicon substrate

2010 ◽  
Vol 7 (7-8) ◽  
pp. 1952-1954 ◽  
Author(s):  
Kazuki Nomoto ◽  
Kazuya Hasegawa ◽  
Tohru Nakamura
Keyword(s):  
High Temperature ◽  
Silicon Substrate ◽  
High Temperature Operation
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