Category: Ask the Experts

I would like to know how to calculate the equivalent refrigeration capacity at 4.5 K of a cryogenic system operating at higher temperature.

I have to maintain a certain mass (some tons) at 100 K by circulating in it GHe (through apposite channels). How can I calculate the flow rate needed? I suppose that the delta T (T inlet and T outlet) and the heat load on the mass are necessary. Knowing the …

What do cryogenics companies do about liability insurance? Is there a special type for cryogenics?

Are you aware of permitting or license requirements (other than local city or town) needed for the storage or transportation of cryogenic materials?

I want to expand my knowledge of cryogenics in general and tool steels in particular. Specifically, I am keenly interested in learning about the presence of alloying elements in tool steels and how their presence in various combinations affects the performance of tool steels after cryogenic treatment.

I was wondering if I could ask for input on pros and cons of barcoding. We are in the process of trying to decide if we should start barcoding our samples and I'm just not sure if this is feasible for our organization. We have numerous sites all over the …

I would like to know what the principal methods and the relative instrumentation to check the purity level of helium gas stream in the purification system of a common helium cryogenic plant are. What principles are these instruments based on? And what are their principal characteristics?

I am the cryogenic specialist for a stem cell bank in Greece. I am trying to find the minimum requirements (purity, humidity, etc.) of liquid nitrogen for cryopreservation through controlled rate freezing of biological samples.

Currently we use in our Biobank an upright -80 freezer to store all our samples. We are planning to buy a fully automated bio-repository storage that will do the picking of samples under restricted conditions. But in the meantime I foresee that we have to pick the samples manually. The …

I am looking into standardizing our range of bio storage tubes (cryogenic vials). These will be for both blood and tissue samples and their derivatives. Any recommendations, comments on Micronics, Nalgene, Nunc and or others that are suitable for long term -80 C and -196 C storage, DNA/RNA suitable, would …

We are an ice making company and have started a new project, which is related to flash freezing of water. It is based on cryogenics technology and we need a custom made machine. I would kindly ask you to pass me a few companies who would be interested in such …

I would like to construct a small cooling circuit (appr. 50 x 50 cm) pumping liquid at a temperature down to -120°C from a cold reservoir to the specimen to be cooled. The tubes and connections are not a problem, but does somebody know a pump (suction/compression for circulation) suitable …

I was wondering if anyone could provide feedback/data on whether it is best in terms of preserving tissue quality to freeze tissue in OCT using dry ice versus liquid nitrogen?

We are a relatively new Biorepository that was developed as part of a large breast cancer epidemiology study, and thus far we have accumulated DNA on over 8000 women along with extensive questionnaire, mammography, and case status data. I was wondering, are there lists of existing Biorepositories with their contents? …

To size a relief valve for a LN2 cryostat I have to know “worse case” boil-off rate when vacuum insulation failed and inner vessel with LN2 is in direct contact with room temperature air at 300K. So, I am looking for a heat flux value (watt/m2) to LN2 inner vessel …

I am working on a project where we are trying to design a system to store ammonia at -33°C. In order to size the compressors to maintain the ammonia in the liquid state, I need to estimate the heat gained from the environment including the radiation from the sun and …

I am looking for a metal (alloy) that supports high temperatures (at least 1600K) and keeps its elastic property at low temperatures down to 10K. Rhenium is a good one because it does not become brittle. But it is quite expensive. Pure tungsten and molybdenum enter in the brittle regime …

I'm student of University of Barcelona. We do technical cryogenic research and we are searching for a cryogenic portable freezer that does not need electricity. We can't find any company that offers something like this. The product we are looking for is the typical portable freezer for food or drinks …

Can you please advise if FEP Encapsulated O rings are used within the cryogenic process and what materials? I have been asked by my company to write about FEP Encapsulated O rings for a training seminar.

I am a ME grad student currently working on the design of a detector array / focal plate of a scientific space instrument operating at a temperature of about -80...-100°C. Although this is not in the cryogenic temperature range, I would like to address two questions to you as the …