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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 Treatment of Materials
F.J. Diekman Controlled Thermal Processing, Inc. info@metal-wear.com Cryogenic Processing (also called cryogenic treatment, and incorrectly “cryogenic tempering”) is a process that uses cryogenic temperatures to modify materials to enhance their performance. Cryogenic Processing involves the slow reduction in temperature of the material to at least -300°F (-185°C) and holding the...
Cryogenics in Space
Peter Kittel University of California-Berkeley pkittel@cal.berkeley.edu Space Cryogenics is the application of cryogenics to space missions. These applications fall into two broad areas, supporting space science missions and supporting the space transportation infrastructure. Science applications: The atmosphere is opaque to much of the electro-magnetic spectrum. In space, the absence of...
Cryosurgery
Review of Cryosurgery Boris Rubinsky, PhD Hebrew University School of Science and Engineering Research Center for Biomedical Engineering 78b Ross Building Givat Ram, Jerusalem 91904 Israel rubinsky@cs.huji.ac.il as published in Annual Review of Biomedical Engineering, August 2000, Vol. 2, pp. 157-187. Abstract: Cryosurgery is a surgical technique that employs freezing...
Liquefied Natural Gas
Liquefied Natural Gas as it relates to the Field of Cryogenics John W. Bonn VJ Systems, LLC johnbonn@vjsystems-lic.com Today the world is looking for a cleaner fuel and Liquefied Natural Gas (LNG) plays a large part in achieving this goal. LNG in a liquid form is at -162°C (-259°F) 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?