Sorption properties of novel-fashioned low-cost hydrogen getters in a high-vacuum-multilayer insulation structure

Vacuum ◽  
2021 ◽  
pp. 110452
Author(s):  
Yang Yu ◽  
Ming Zhu ◽  
Qianghua Huang ◽  
Liang Huang ◽  
Chao Dong ◽  
...  
2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Sarita Boolchandani ◽  
Subodh Srivastava ◽  
Y. K. Vijay

The indium selenium (InSe) bilayer thin films of various thickness ratios, InxSe(1-x) (x = 0.25, 0.50, 0.75), were deposited on a glass substrate keeping overall the same thickness of 2500 Ǻ using thermal evaporation method under high vacuum atmosphere. Electrical, optical, and structural properties of these bilayer thin films have been compared before and after thermal annealing at different temperatures. The structural and morphological characterization was done using XRD and SEM, respectively. The optical bandgap of these thin films has been calculated by Tauc’s relation that varies within the range of 1.99 to 2.05 eV. A simple low-cost thermoelectrical power measurement setup is designed which can measure the Seebeck coefficient “S” in the vacuum with temperature variation. The setup temperature variation is up to 70°C. This setup contains a Peltier device TEC1-12715 which is kept between two copper plates that act as a reference metal. Also, in the present work, the thermoelectric power of indium selenide (InSe) and aluminum selenide (AlSe) bilayer thin films prepared and annealed in the same way is calculated. The thermoelectric power has been measured by estimating the Seebeck coefficient for InSe and AlSe bilayer thin films. It was observed that the Seebeck coefficient is negative for InSe and AlSe thin films.


2018 ◽  
Vol 930 ◽  
pp. 609-612
Author(s):  
Quezia Cardoso ◽  
Franks Martins Silva ◽  
Ligia Silverio Vieira ◽  
Julio Cesar Serafim Casini ◽  
Solange Kazume Sakata ◽  
...  

Graphene has attracted significant interest because of its excellent electrical properties. However, a practical method for producing graphene on a large scale is yet to be developed. Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups and recovering the conjugated structure. GO can be produced using inexpensive graphite as the raw material via cost-effective chemical methods. High vacuum and temperature (10−7 mbar and 1100°C, respectively) conditions are well-known to enable the preparation of reduced powder at the laboratory scale. However, a large-scale high vacuum reduction system that can be routinely operated at 10−7 mbar requires considerable initial capital as well as substantial operational and maintenance costs. The current study aims at developing an inexpensive method for the large-scale reduction of graphene oxide. A stainless steel vessel was evacuated to backing-pump pressure (10−2 mbar) and used to process GO at a range of temperatures. The reduction of GO powder at low vacuum pressures was attempted and investigated by X-ray diffraction and Fourier transform infrared spectroscopy. The experimental results of processing GO powder at various temperatures (200–1000°C) at relatively low pressures are reported. The microstructures of the processed materials were investigated using scanning electron microscopy and chemical microanalyses via energy dispersive X-ray analysis.


2010 ◽  
Vol 436 ◽  
pp. 131-140 ◽  
Author(s):  
Ralph W. Bruce ◽  
Arne W. Fliflet ◽  
Hugo E. Huey ◽  
Chad Stephenson ◽  
M. Ashraf Imam

The emerging reduction technologies for titanium from ore produce powder instead of sponge. Conventional methods for sintering and melting of titanium powder are costly, as they are energy intensive and require high vacuum, 10-6 Torr or better, since titanium acts as a getter for oxygen at high temperature, adversely affecting mechanical properties. Other melting processes such as plasma arcs have the additional problem of electrode consumption, and direct induction heating of the titanium powder is problematic. Microwave sintering or melting in an atmospheric pressure argon gas environment is potentially cost effective and energy efficient due to the possibility of direct microwave heating of the titanium powder augmented by hybrid heating in a ceramic casket. We are investigating this approach at the Naval Research Laboratory using an S–Band microwave system. The experimental setup and the results of melting and sintering experiments will be described including a rough estimate of energy usage.


2011 ◽  
Vol 19 (3) ◽  
pp. 16-20
Author(s):  
Niels de Jonge ◽  
Elisabeth A. Ring ◽  
Wilbur C. Bigelow ◽  
Gabriel M. Veith

Solid materials in subambient gaseous environments have been imaged using in situ transmission electron microscopy (TEM), for example to study dynamic effects: carbon nanotube growth, nanoparticle changes during redox reactions, and phase transitions in nanoscale systems. In these studies the vacuum level in the specimen region of the electron microscope was increased to pressures of up to 10 mbar using pump-limiting apertures that separated the specimen region from the rest of the high-vacuum electron column, but it has not been possible to achieve the higher pressures that are desirable for catalysis research. TEM imaging at atmospheric pressure and at elevated temperature was achieved with 0.2-nm resolution by enclosing a gaseous environment several micrometers thick between ultra-thin, electron transparent silicon nitride windows. Although Ångström-level resolution in situ TEM has been demonstrated with aberration-corrected systems, the key difficulty with TEM imaging is its dependence on phase contrast, which requires ultra-thin specimens, limiting the choice of experiments.


2015 ◽  
Vol 2015 (1) ◽  
pp. 000375-000378 ◽  
Author(s):  
Roupen Keusseyan ◽  
Tim Mobley

Significant advances have been accomplished in the field of Through Glass Via (TGV) technology; enabling a new generation of electronic designs that achieve higher performance, while leveraging low cost system solutions. Through-hole creation methods in glass have been optimized for mass production with consistent via diameter, shape and wall chemistry/morphology. This has enabled the development of unique copper via metallization materials that exhibit very high conductivity, thermal expansion matching (with borosilicate glass) and hermeticity in the 10E-10 Atm.cc/sec range (Ultra-High Vacuum Hermeticity). Further developments in Chemical Mechanical Polishing (CMP) for glass wafers with copper vias, surface sensitization and metal deposition techniques, have enabled thin film metallization on both sides of the glass wafer for fine line redistribution layers (RDL). The thin film RDL is compatible with the TGV with excellent continuity in conductivity. The RDL metallization is plated to allow flip chip, land grid array, wire-bond, solder, or other interconnection methods. The paper will discuss the technical, material and process challenges in each of the areas mentioned above which enable a hermetically sealed glass package. Detailed data and experimental results will be discussed.


1988 ◽  
Vol 31 (6) ◽  
pp. 30-38
Author(s):  
Elhanan Dgany ◽  
Eytan Kochavi ◽  
Shimon Gruntman ◽  
Asher Kinan

A thermal vacuum testing facility for electronic units has been specified, designed, and built. It is fully operational and performs its tasks—thermal vacuum qualification and acceptance testing of electronic units. All performance requirements and design details have been carefully evaluated on a cost-effective basis, resulting in achieving the design goal of low price (purchase, operation, and maintenance) together with ease of operation, maintenance simplicity, and upgrading options. The major cost saving originated from a detailed analysis of thermal vacuum requirements that resulted in low cost substitutes to the common thermal shroud, together with a thermal plate. The plate is actively thermally controlled by a circulating fluid that is temperature regulated by a commercial heating and cooling unit. The high vacuum pumping system includes a diffusion pump with backstreaming holders.


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