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Standards for cryogenic valves
Do you know where I can get some documents of testing specification or US standards for cryogenic valves (DN 250)? Or could you give me some suggestion for that?
Recent material and fabrication developments in low-temperature regeneration
In the area of low-temperature regeneration, what are some recent material and fabrication developments?
Vendors for cryopreserved rat arteries
My department is starting up a microsurgery training lab as an adjunct to our resident curriculum. Instead of using live rats, we want to pursue the option of using cryopreserved rat arteries. I have been unsuccessful in finding animal/rodent vendors who deal in this. I basically found a lot of...
Source for pressure switch
Where can I find a pressure switch operating in the range 0.2 to 0.4 psi which is not affected by magnetic fields up to about 1000 Gauss?
Cryostat for storing fish samples at -20 degrees C
We are a small Food Chemistry Laboratory functioning within the Seychelles Bureau of Standards. We wish to purchase a cryostat for the purpose of storing fish samples at *-20ºC* prior to the analysis of Histamine in the tissue of Tuna by HPLC.
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Mixed Refrigerant Cycles
Most cryogenic refrigeration systems, both large scale systems and cryocoolers, use helium as a working fluid. There are a number of advantages to helium, not the least of which is that helium remains a fluid down to the lowest achievable temperatures. In order to freeze helium, pressures of over 20...
Fountain Pumps and He II Phase Separators
Helium II (He II), the second liquid phase of the 4He isotope described in this column in Cold Facts Spring 2010 (http://2csa.us/he2), can be modeled as consisting of two interpenetrating fluids. One, the superfluid component, has zero viscosity and entropy and the other, the normal fluid component, has nonzero viscosity...
Turboexpanders
A vital technology in the refrigerators and liquefiers described in Cold Facts Volume 31 Number 3 is that of turboexpanders. These devices are rotating machines in which the process fluid (e.g., helium) does work against the turboexpander while moving from high pressure to a lower pressure and thus is cooled....
Cryogenic Electronics
Randall Kirschman, consulting physicist, Mountain View, California ExtElect@gmail.com Cryogenic electronics—the operation of electronic devices, circuits, and systems at cryogenic temperatures—has been a valuable technology for decades. Cryogenic electronics (also referred to as low-temperature electronics, or cold electronics) can be based on semiconductive devices, on superconductive devices, or on a combination...
Particle Physics: High Energy Physics
Cryogenics and High-Energy Physics 1. From symmetry magazine: http://www.symmetrymagazine.org/cms/?pid=1000627: Cryogenics is the study of how materials behave at temperatures near absolute zero. In high-energy particle accelerators, such frigid temperatures reduce the electrical resistance of wires in superconducting magnets, increasing the magnet strength and allowing faster particle acceleration. The same holds...
HTS Degaussing Systems
From the Spring 2009 issue of Cold Facts (Volume 25, Number 2): Thanks to a joint project by the US Navy and a number of industry partners, high temperature superconducting (HTS) technology is now at the heart of an advanced degaussing system aboard the USS Higgins at the naval station...
Magnetic Resonance Imaging
From http://www.superconductors.org: An area where superconductors can perform a life-saving function is in the field of biomagnetism. Doctors need a non-invasive means of determining what’s going on inside the human body. By impinging a strong superconductor-derived magnetic field into the body, hydrogen atoms that exist in the body’s water and...
An Issue of Pressure and Flow Rate in a Supply Tank
Please help solve this problem: A supply tank requires a vaporizer to generate sufficient pressure to pump stored fluid up into a vehicle or tank. The available head is limited as the tank level falls and it is important to minimize the system pressure drop to maintain the desired flow...
Using MLI on VJ Line Joints or Cryo Storage Tanks
When installing Multi Layer Insulation (MLI) blankets on VJ line joints or cryo storage tanks should they be wrapped and tied down tight or loose? These are usually pre-cut to size. Also should they have an access hole at the point of where the molecular sieve is installed to help...
Separated layers of ice over a pipe
I want to know that why there are different layers of ice over a pipe carrying a cryogenic fluid, each layer separated with clear marks / lines? What do these layers signify?