Indirect estimation of helium pressure at cryogenic temperatures

2020 ◽  
Vol 45 (1) ◽  
pp. 166-171
Author(s):  
Rajendra Dutt ◽  
Vijay Soni ◽  
Navneet Suman ◽  
Shankar Ram ◽  
Soumen Kar ◽  
...  
2011 ◽  
Vol 19 (13) ◽  
pp. 12766 ◽  
Author(s):  
Antonio Lucianetti ◽  
Daniel Albach ◽  
Jean-Christophe Chanteloup

Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).


Alloy Digest ◽  
2012 ◽  
Vol 61 (2) ◽  

Abstract SSC Invar 36 was developed for use in applications where dimensional stability is essential. It is a nickel-iron alloy with a very low coefficient of thermal expansion from cryogenic temperatures to 200 deg C (390 deg F). It is utilized in aerospace composite tooling and die applications, as well as laser components, and cryogenic components and piping: liquefied natural gas production, storage, and transportation. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as forming. Filing Code: Fe-158. Producer or source: Sandmeyer Steel Company. Originally published December 2011, revised February 2012.


Alloy Digest ◽  
1966 ◽  
Vol 15 (7) ◽  

Abstract INCONEL alloy X-750 is an age-hardenable, nickel-chromium alloy used for its corrosion and oxidation resistance and high creep rupture strength at temperature up to 1500 F. It also has excellent properties at cryogenic temperatures. It was originally developed for use in gas turbines, but because of its low cost, high strength and weldability it has become the standards choice for a wide variety of applications. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep and fatigue. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-115. Producer or source: Huntington Alloy Products Division, An INCO Company.


Alloy Digest ◽  
1975 ◽  
Vol 24 (2) ◽  

Abstract USS 18-8S (AISI Type 304) and USS 18-8I (AISI Type 304L) are austenitic chromium-nickel steels that are easy to fabricate and weld. They combine high strength with excellent stability and shock resistance, even at cryogenic temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on low temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-305. Producer or source: United States Steel Corporation.


2020 ◽  
Vol 96 (3s) ◽  
pp. 347-352
Author(s):  
Д.Г. Алипа ◽  
В.В. Краснов ◽  
В.М. Минненбаев ◽  
А.В. Редька ◽  
Ю.В. Федоров

В статье представлены результаты исследования возможности применения при криогенных температурах водородного уровня дискретных приборов и монолитных схем на основе нитрида галлия в составе малошумящих усилителей сантиметрового и миллиметрового диапазона длин волн для приемных устройств систем дистанционного зондирования Земли из космоса и в составе криогенных комплексов наблюдения космического пространства. The article presents the results of the research on the possibility of using discrete devices and gallium nitride monolithic circuits at the cryogenic temperatures of hydrogen level as part of low-noise amplifiers of centimeter and millimeter-wave bands used in receivers of Earth remote sensing space systems and in cryogenic systems for space observation.


Author(s):  
Dilesh Maharjan ◽  
Mustafa Hadj-Nacer ◽  
Miles Greiner ◽  
Stefan K. Stefanov

During vacuum drying of used nuclear fuel (UNF) canisters, helium pressure is reduced to as low as 67 Pa to promote evaporation and removal of remaining water after draining process. At such low pressure, and considering the dimensions of the system, helium is mildly rarefied, which induces a thermal-resistance temperature-jump at gas–solid interfaces that contributes to the increase of cladding temperature. It is important to maintain the temperature of the cladding below roughly 400 °C to avoid radial hydride formation, which may cause cladding embrittlement during transportation and long-term storage. Direct Simulation Monte Carlo (DSMC) method is an accurate method to predict heat transfer and temperature under rarefied condition. However, it is not convenient for complex geometry like a UNF canister. Computational Fluid Dynamics (CFD) simulations are more convenient to apply but their accuracy for rarefied condition are not well established. This work seeks to validate the use of CFD simulations to model heat transfer through rarefied gas in simple two-dimensional geometry by comparing the results to the more accurate DSMC method. The geometry consists of a circular fuel rod centered inside a square cross-section enclosure filled with rarefied helium. The validated CFD model will be used later to accurately estimate the temperature of an UNF canister subjected to vacuum drying condition.


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