Laboratories for Performing He4 Analysis Work
We are hoping to produce helium-4 with very low helium-3 contamination. Can you identify any laboratories that could assist in performing analysis work?
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Grinding HNBR slab into 32-mesh powder
We have a small quantity to prove the feasibility of using HNBR slab ground into a small powder about 32 mesh or finer. Can you suggest an organization that can do this small quantity (about 1 or 2 lbs) and production quantities of a few hundred pounds?
Domestic companies that could cryogenically treat a tube?
Please identify some domestic companies that could cryogenically treat a tube.
Company to supply metallic recoated FBG sensor
I am studying FBG sensors for cryogenic temperature measurements. I am looking for a company that can supply me a metallic recoated FBG sensor. Please let me know if anybody has a contact.
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?
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Cold Compressors
A common way to provide cooling below the normal boiling point of helium (4.2K) is to reduce the pressure above the bath of liquid helium, thus also reducing the bath’s equilibrium saturation temperature. For example, to produce a 1.8K bath of liquid helium, the saturation pressure has to be reduced...
Kapitza Conductance
Kapitza conductance refers to the heat transfer between a solid surface and a fluid that covers that surface. Fundamentally, it describes the inherent difficulty in transferring energy from a solid to the fluid covering the solid surface. This phenomenon was first observed by P. L. Kapitza in 1941 while studying...
Thermosyphons
A thermosyphon (or thermosiphon) is a device that transfers heat via natural convection in a fluid. The natural convection is driven by gravity with the colder, denser fluid flowing downhill and the warmer, less dense fluid flowing back up. Thus, thermosyphons connect an object to be cooled with a reservoir...
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?