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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?

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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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...

Air Separation and Liquefaction

by Nils Tellier, PE, President, EPSIM Corporation (CSA CSM) nils@epsim.us All illustrations courtesy EPSIM Corporation Background History of Air Separation and Liquefaction This section builds on a rich history of methods to develop deep refrigeration and cryogenic liquefaction during the 19th Century. You are encouraged to read Cryo Central’s History...

Bose-Einstein Condensate

A Bose-Einstein condensate, first proposed in 1925 by Albert Einstein based on work done by Satyendra Nath Bose (the same Bose from whom the term boson is derived), is a super-cold state of matter in which almost all of the individual atoms have “condensed” down to the lowest possible quantum...

Cold Technology for Pest Control

While it does not reach temperatures cold enough to be called cryogenic, carbon dioxide snow is at the heart of a new way of dealing with unwanted pests. It utilizes a quick freezing process that takes advantage of the properties of carbon dioxide snow and has a number of benefits...

Cryogenic Finishing

The following 3 articles discuss the uses and procedures of various type of cryogenic finishing. 1) By Robin A. Rhodes, Cryogenic Institute of New England, Inc. rrhodes@nitrofreeze.com Cryogenic Deflashing is employed to remove undesired residual mold flash that remains on molded parts after they are removed or ejected from the...

Power usage: cryogenic systems vs. regular refrigerators

A recent project highlighted to me that closed cycle cryogenic cooling systems use far more electrical power to reduce temperatures by a few watts than regular refrigerators. I am sure it must be something to do with the extra difficulty of removing the heat from the liquid nitrogen or similar...

Redundancy strategies for mechanical -80C freezers

I was wondering what kind of redundancy strategies are people using for their mechanical -80C freezers? I am aware of the following. Please add if you are doing something different. 1) 1 Backup freezer for every 10 freezers – Empty and maintained at -80C at all times 2) Backup C02...

Method to move components in a cryogenic environment

Does anyone know of a method with which to reliably move components in a cryogenic environment? We are interested in moving detectors in a cryogenically cooled (2K) vacuum chamber, which is contained within a larger cryostat/isolation vacuum with thermal shields. As the desired horizontal or vertical displacement is between 10...