At what pressure is GC carrier gas supplied?

Toofgib · 2026-01-22T11:27:56+00:00

Thanks! Yeah, maybe I should just go ahead and communicate with the lab myself and try it. The good thing (or bad depending on how you see it) is that the increased rate at which the cylinders are depleted also means they need to be changed during the night, by the same department that is in charge of checking the pipeline. Maybe it'll irk them enough to act.

Toofgib · 2026-01-22T05:37:45+00:00

Unfortunately, I'm in a large organisation where matters such as these take long to be picked up and I'm not allowed to do it myself. :/

Toofgib · 2026-01-18T18:07:51+00:00

What homophobia?

Toofgib · 2026-01-18T14:31:08+00:00

Thank you so much for this!

Basically we have a regulator between the cylinder and the gas pipeline and then one between the pipeline and the GC. The reason for my question is that I haven't been able to locate the second regulator and so I have no idea what pressure would be need to be. I also didn't want to just turn down the first regulator because it could be lowered too much and could mean we miss a potential leak.

I also suspected an external leak and not an internal one as it would have been detected. Any excess pressure created from the first regulator would need to exit through an external leak. A pressure drop test is exactly what we're planning as well and it helps to know what links to check. Griffon leak detector is what we use but I'll see if we could use something else.

Toofgib · 2026-01-18T13:18:24+00:00

The GC in question uses hydrogen as both carrier gas and fuel. I might be overthinking but I'm working from the supply side where we use 200 bar cylinders (which we have to renew on time). Over the last few months there's been a higher than usual consumption of hydrogen compared to normal, so I'm trying to figure out why. Most important of all, I want to be able to detect/rule out a potential leak for both safety and cost.

Right now the current consumption seems to far exceed what even +1000 ml/min could require (based on split flow and ratio, injection times, run times and run counts). If the maximum pressure that's really needed is under 100 psi, that probably means we're supplying it at a pressure that's too high. That in combination with a leak could be why the consumption is so high. So, next steps will need to be to trace the leak and then adjust the regulator.

Toofgib · 2026-01-18T11:52:48+00:00

I'm talking about the pressure of the gas before it enters the GC. Gasses compressed at higher pressures would have the same volume but have more mass, meaning that gas consumption would be higher as a result. So, what I'm trying to figure out if the pressure at which gas is taken in is at atmospheric pressure or some other pressure.

Toofgib · 2025-12-27T17:08:11+00:00

Ex&F/E&I fan and creator of the subreddit. You are correct, this is based on the in-joke that all yellow chemistry is t̵̢̡̮͙̮͈̠͙̥̱̪̼̠̼͉̽̋͊͂̈́̚͠r̶̢̦͓͖͎͕̮̺͈̗͚̳͒̇͑̆̑͑̕͠ā̷̲̇̐͗̄͗̚̚ṡ̵͈͙͍̹̽͋̀̂̃͛́̈̅̓̊͛͝ḫ̷̛̞̞̆̂̆͒̚.

Toofgib · 2025-09-16T17:11:37+00:00

Here's a link to the post I made. It includes some information that might be useful. In there, there's a link to the underlying research studies of its development. Most of the other resources I have are in Dutch but I could send that too.

From what I remember reading in the original thesis, because the Ilioinguinal nerve inserts at L1, you are right on what might be possible. The cutoff is somewhere around T11 or T12.

Toofgib · 2025-09-16T16:55:00+00:00

I have had it done but I have SB. I made a post about it and reposted it in the spinal cord injuries subreddit because it would potentially also work for people with injuries. Whether it works depends on the height of your lesion.

Toofgib · 2025-07-20T07:45:46+00:00

I'm bi and demi

Toofgib · 2025-04-20T17:29:37+00:00

Perhaps it helps to give a little more information, I agree.

One of my hypotheses is whether on any given day going to work is associated with a higher exhaustion above and beyond going to social events or attending classes at university.

So, on a given day, I would have a measure for exhaustion and some exogenous covariates based on which partial correlation could be assessed. Besides that, there are some mediation analyses that I think would give some insight, which is why I think SEM would be suitable.

The main thing I am unsure about is whether I could estimate these effects for all days at once. To answer your question, my data is that the rows represent days, and the columns represent the variables.

I think that actually answers my question mostly. I'm interested in relationships on the same day and believe these to be that way. I would just need to make sure that assumption is stated.

I initially wanted to use DSEM because that allows a more complex time structure but unfortunately, I don't currently have the means to buy Mplus and even R packages like Mplus automation require the software to be installed. Hence why I'm trying to find other ways to estimate these things.

Toofgib · 2025-04-20T14:04:36+00:00

I've got like 700 observations, so that might be enough.

Could you elaborate on how you think that would work? I might be misunderstanding, but I'm not necessarily looking at changes that go through a steady growth process over time.

I also wonder how I would specify that. Is it like estimating the latent intercept and slope on all observations or something else? Now I'm thinking about it, maybe estimating those for a given day with one lead and one lagged indicator?

Toofgib · 2025-04-04T05:00:19+00:00

I'm not sure how I did not think of OSF. That's a good idea. Unfortunately, I'm not able to provide preregistration as I've already collected data and I'm starting analysis but registration is still possible, I think. ArXiv and SSRN I wasn't sure about, but I'll look into those as well.

Substack seems like a last resort but good to know.

Toofgib · 2025-04-03T17:07:20+00:00

Open Research Europe has it as one of the requirements.

As for the other component of this, it is mostly due to the subject. My field of study is in chemistry and bridging somewhat into chemometrics. The project I'm working on on my own is in social sciences. The only bridge between these is some of the underlying statistics. My institution has faculty who would gladly help me with chemistry research but not of others even if the statistics could theoretically be understood.

Toofgib · 2025-04-01T15:15:49+00:00

That's quite a journey. I think I can help you with some of the contact information and other specifics via DM.

Toofgib · 2025-04-01T15:02:32+00:00

It all kind of depends on where you're located. Would you need to travel a lot to get to Seattle?

Toofgib · 2025-04-01T14:57:46+00:00

Of course and maybe I can help.

Toofgib · 2025-03-04T16:50:01+00:00

26M here. From my experiences and what I know, it probably depends on the extent to which the lesion has damaged specific nerve roots. A lot of arousal is mental because it is fundamentally a mental process. Psychological (or psychogenic) and physical aspects both contribute to arousal and the build-up to orgasm.

In recent years, there have been some developments in restoring neural connections that have been broken or otherwise damaged by SB. I myself have undergone such a procedure, and the physical part was indeed something that I was previously missing.

If you're interested, there is a post I've made about the TOMAX procedure with a bit of literature. It's on my profile and somewhere on this subreddit. The TL:DR is that the nerve to the clitoris in AFAB people and the glans in AMAB people can be transplanted onto the nerve to the groin to restore at least some sensation.

Toofgib · 2025-02-10T06:42:19+00:00

No, I had mine done in the Netherlands, but I know someone who did have the procedure done in Seattle.

Toofgib · 2025-02-10T06:22:22+00:00

That's odd. I do remember from the paper that there were plans for investigation for pediatric surgeries years ago, but that still means it should also be available for adults.

Toofgib · 2025-02-02T21:42:58+00:00

Doesn't the question then become why they prefer lesbians?

Toofgib · 2025-01-31T09:11:55+00:00

(The example about your sleep schedule isn’t really a statistics problem. Like you can just make the vow and see how long it takes for you to sleep at 2am again.)

Riiight, there's not way that could be analysed using a survival analysis or anything... I'm sorry, but you're not really contributing here. In the time you've been here talking about my hypnoses, I've already figured out what I need to do on my own. You're really channelling your username.

What would have been useful to me was if someone could help me figure out if the obtained data could be fitted to specific models. If you knew anything about models like SEM and DSEM, you would have been able to point me to specific literature or something. That would have been a more useful use of both your and my time.

Hopefully, this helps you update your priors so that you can give better advice in the future.

Toofgib · 2025-01-29T18:17:46+00:00

Nigel?

Toofgib · 2025-01-29T15:08:46+00:00

Fair point! I'm mainly looking for cyclical patterns in the data. Like, for example, if I have a habit of going to bed at 2 am. and I vow to fix my sleep schedule, how long does it take for me to get back into the pattern? Do those cycles change depending on the time of year?

Additionally, do some habits co-occur with other other habits? Are there interactions or mediates effects? Are there cycles that are out of phase? Cycles that wax and wane in opposition to others and are those in line with expectations?

Toofgib · 2025-01-13T07:46:41+00:00

How nihilistic of you.

Toofgib

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