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Record W8835558

Helium Purification by Gas Adsorption method

2011· dissertation· en· W8835558 on OpenAlexvenueno aff
Jitendra Bhushan

Bibliographic record

VenueThe Journal of Rheumatology · 2011
Typedissertation
Languageen
FieldEngineering
TopicSpacecraft and Cryogenic Technologies
Canadian institutionsnot available
Fundersnot available
KeywordsHeliumMaterials scienceLambda point refrigeratorAir separationHeat exchangerNuclear engineeringWaste managementChemistryLiquid heliumThermodynamicsOxygenPhysics
DOInot available

Abstract

fetched live from OpenAlex

In a cryogenic establishment, helium gas is an expensive consumable. Conservation of helium is important not only for saving on cost, but also for ensuring supply at the time of need. During laboratory experiment, helium gas is often contaminated with air impurities (nitrogen, oxygen, argon, moisture etc.) which must be removed before the spent gas is reused for liquefaction. Therefore, a helium purifier is an integral part of any cryogenic establishment to conserve helium gas by providing grade 4.5 helium or 99.995% pure helium to liquefier after separating air contaminants from impure helium. The helium purification is based on two principles, one is cryocondensation of moisture and air impurities, on heat exchangers at appropriate temperature and other one is cryosorption on activated charcoal to yield grade 4.5 helium from 60% pure helium at LN¬2 temperature and at high pressure of about 150 bar. The purifier has been designed for purifying impure helium upto 40% of impurity by running 6 hours non-stop operation with the mass flow rate of 20 nm3/hr and delivery of impure helium to purifier at a pressure of 150 bar(a) ,which is ensured by a 3-stage reciprocating compressor. In the helium purifier for cryocondensation and cryosorption process the components are moisture collector vessel, three heat exchangers, liquid air separator vessel and adsorber columns. Other major components are gas bag, compressor, LN2 vessel and cylinder manifold. Where, all cryogenic components are housed in Superinsulated LN2 vessel. Purification of helium involved two phase, one is regeneration phase and second is purification phase. For complete removal of moisture from charcoal beds regeneration should be done before purification, by heating and evacuation with purging of pure helium to whole system. And in purification phase we have taken 95% of pure helium and 5% of impurity i.e. dry nitrogen contaminants. Experiment was carried out for one session and four samples are taken in sample cylinder at different interval of time. Sample analysis by Linde Multi Component Detector reveals that the total impurity, consisting of nitrogen, oxygen and moisture is less than 5 ppm be volume, thus making the purified gas much better than grade 4.5 helium.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.001
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.021
Threshold uncertainty score0.071

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.001
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0020.001
Science and technology studies0.0010.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0210.013

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.010
GPT teacher head0.242
Teacher spread0.231 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designBench or experimental
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations1
Published2011
Admission routes1
Has abstractyes

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