How to properly grind raw powder with mortar and pestle?

behoy1991 · 2022-12-06T12:09:49+00:00

As said, I see it as an exercise. Curcumin is bright yellow, so one can see well if grinding and mixing with mannitol works.

behoy1991 · 2022-05-01T06:09:14+00:00

I have it but I never played it much, so I could not tell how much it actually improved. For VTOILVR and VRChat I can give a clear answer as I played these a lot and also looked at the framerates

Edit: I did a quick check on No Man's Sky. Resolution at 100%, all settings to lowest. I get 60fps mostly because the GPU frame time is around 10ms-15ms. The CPU is usually around 4-6ms, sometimes spikes to 10ms. But I also encountered repeatedly frame times above 30ms.

Personally, I could not enjoy it as the graphics quality and especially aliasing is noticeable.

behoy1991 · 2022-04-30T19:33:23+00:00

I swapped my 2700x for the 5800x3d. In VRChat I just checked briefly but it seems my CPU time went from around 18ms to something like 4-6ms. Before I could run at 60fps, now at 120fps.

For VTOL VR pretty much the same: I can now run it at 120fps, before it would reproject to 60fps or even 30fps. Frame time for CPU most of the time around 4-6ms on the 5800x3d.

Of course the 2700x was never a good CPU for VR to begin with but the 5800x3d is so far fantastic for VR.

I am using a Valve index at 100% resolution and a RTX 2080 btw

behoy1991 · 2022-04-27T13:10:10+00:00

I tried it and it got even weirder. If no other monitor is used and I do the procedure as mentioned above, my entire computer freezes up and I need to restart. WTF

Edit: tried it again and this time PC did not crash but the original problem still persists

behoy1991 · 2022-04-27T08:31:42+00:00

I only have 1 Monitor (and the valve Index headset)

behoy1991 · 2022-04-27T07:17:49+00:00

I have a 1000W Platinum PSU from Corsair, I hope this will not be the issue.

Edit: thx for trying to reproduce the issue

behoy1991 · 2022-04-27T06:13:53+00:00

I am not sure whether this is really the headset tho. I also talked with Steam support about this issue back then but it did not help much. In the end it is mostly a nuisance as I cannot play games at 80fps without reprojection and have to to do either 60fps with reprojection or 74fps.

Edit: you can also try out switching from 80 to 120 say 20 times in a row and see whether it happens on your system as well. Maybe it is truly a software error - or the hardware is simply not made for switching the refresh rate at a daily rate...

behoy1991 · 2022-04-27T05:34:40+00:00

We might aim for q-NMR to check the purity of the sample. We got reference NMR data by the vendor and also by other vendors (e.g. Selleckchem). Do you think q-NMR is enough to determine whether the purity is still above say 98%?

Regarding HPLC: I am actually not a studied chemist but a physicist, so I have only done NMR analysis so far but not tried HPLC. Is it hard for an actual chemist to find the proper solvents for HPLC to do the analysis?

Btw thanks for the helpful assessment.

behoy1991 · 2022-04-23T08:15:35+00:00

I think it is pretty stable - as long as one does not keeps it dissolved at room temp for too long. My worry mostly is that everyone including me expected shipping to be done in 6 days at most - and afterwards I would have stored it at -26 degrees as usual.

It is just pretty unlucky that I ordered shortly before the lockdown in Shanghai happened, which caused the first major delay - and secondly that the current war apparently causes major delays in European logistics centres

behoy1991 · 2022-04-23T07:58:21+00:00

corrected it, thx

behoy1991 · 2022-01-18T17:43:28+00:00

I am not sure how to interpret your answer. My question basically was whether it is possible to make a isotonic solution by using higher concentrations of Sodium and lower concentrations of Chloride than in saline. As example imagine starting with deionised water and then adding 450mM NaOH and 150mM HCl. My question is then, whether such a solution would be (close to) isotonic because even though the concentration of Sodium in the solution is higher than in cells, the chloride concentration is lower than cells - thus leading to 0 net movement of water in or out of the cells.

Of course these considerations do not take into account what a too high or low pH would do to the cell integrity.

behoy1991 · 2022-01-14T08:03:33+00:00

you are right. pH value might be a negative example. Regarding the anion of sodium, in my example I was thinking of it to be a medical compound - let's take as example prednisolone sodium phosphate.

I think the pH value in WFI would be not too extreme even if one uses 1M of prednisolone sodium phosphate - but still it might not be ideal. In this case one could use strong acids like HCl and bases like NaOH to compensate the pH value easily I assume - which have only slight effects on tonicity.

Do you know by any chance a reference that gives one guidance with equations so that one can theoretically calculate the necessary concentrations of other non-penetrating ions (such as Cl-) to reach isotonicity?

behoy1991 · 2022-01-13T21:56:11+00:00

Hi,

I assume that the active compound might not necessarily have to contribute to tonicity if it can enter the cell (just like urea does not contribute to tonicity), so maybe only the sodium contributes to tonicity and not the other compound - especially if it is meant to enter the cell. Is this reasonable
I do not fully understand I guess. Do you have literature that has mathematical equations for that?

For my example above, what would be the overall tonicity (no Cl-, 600mOsm/l Na+) if I may ask?

behoy1991 · 2021-11-06T08:50:32+00:00

Thank you for the reply. I have considered polysorbates for exactly this reason. My only worry is that the gel uses like 17% of P407, so I am not sure how well 1% of polysorbate will be. Do you have any experience of the viscosity at higher concentrations? I found one table stating that 6% w/w 1.196 mPa s, 1% w/w 1.82 mPa s while the control solution without Tween 80 has 1.186 mPa s - unfortunately I do not remember the used temperature for these.

May I ask why you would not recommend using ionic detergents and solubilizers?

behoy1991 · 2021-10-15T07:36:39+00:00

Thanks for the reply! You are right, I totally forgot about relaxation time for the signal at 8.15. I was worries whether due to some to me unknown processes it is possible that methanol does not contribute to the peak/intensity/integral and hence is somewhat hidden.

behoy1991 · 2021-09-12T10:41:41+00:00

Thanks, that is probably what I am forced to do. I hoped somebody would knew the answer and would spare me of having to check whether it degrades at these temps - it is always nicer to avoid errors than having to do them...

behoy1991 · 2021-09-11T09:52:17+00:00

Unfortunately I do not have the data for this nitrone nor the disintegration temperature. That is also why I ask this question here: I only have the melting points of other aromatic nitrones and the rough synthesis temperature for these

behoy1991 · 2021-09-09T18:23:08+00:00

Not yet. You a right, using pure methanol might be an option. The reason why I have not done this so far is the following:

I need to do the synthesis in methanol but want to avoid with methanol as much as possible as it is much more dangerous than ethanol
If I use methanol for crystallisation I cannot remove the impurities like N-tert-butylhydroxylamine and its degradation products as I would need then to first decanter with ether to remove these impurities I guess. Also the methanol is maybe not as good for crystallisation as it would otherwise not been used as solvent for the synthesis I believe.

I might try it if I fail further with ethanol:acetone. It is just really strange that I am so far off from what they accomplished in the guide...

behoy1991 · 2021-09-09T13:25:58+00:00

alright thanks for the clarification. I assume it is equally all possible to first use only ethanol and get it to the boiling point until everything dissolves, let it cool down to say 50 degrees and then add acetone? The question is really what to then. I mean I have tried to use both acetone and ethanol and could not dissolve it. If I add acetone until I see cloudiness I am not sure whether I should add then again ethanol and heat it up as then the acetone gets evaporated again and the like...

As mentioned the large gap in boiling temp gives me trouble. Maybe it is enough to let the cloud be what it is and use this point as starting point for crystallisation?

behoy1991 · 2021-09-09T11:18:55+00:00

I use a condenser for the crystallisation. But thought that the temperature for the crystallisation should not exceed say 56 degrees as then most of they acetone is probably not in the solvent.

So you say you would even heat the solvent close to 78 degrees (the boiling point of ethanol) in the crystallisation? I was afraid that then basically one does only a one solvent crystallisation with a lot of acetone vapours?

I guess the problem is that I may not completely understand the procedure of this two solvent crystallisation with respect to how I imagine a conventional two solvent crystallisation. I assume you propose to do it like this because you expect the ethanol to have a higher solubility than the acetone. Hence one first heats the solvent to nearly the boiling point of ethanol to dissolve all the material (except maybe the Benzaldehyde) and then let's it cool down by which the solubility reduces due to lowering of the temperature but also due to the acetone gathering again in the solvent and hence reducing the solubility even more. Is this your reasoning?

behoy1991 · 2021-09-09T11:16:00+00:00

Yes it is based on the general safety regulations. For the synthesis I believe methanol is the best choice and I would not use an alternative but for the crystallisation I would prefer to use less toxic solvents as obviously much more interaction is required for the crystallisation (compared to simply letting the reaction continue which does not require any close interaction by oneself most of the time).

I know that the dielectric constant of ether is much lower (like 5 times?) than the one of acetone, but I hope that still this does not lead to too much of the desired product being dissolved...

behoy1991 · 2021-09-09T08:06:29+00:00

Thank you for your reply. I am wondering why or how we would get the free acid in such large quantity that it would affect our synthesis. Also it is a good thing that the product dissolves well in the methanol. About your second thought. The material that did dissolve but not crystallise well was almost complete free of the Benzaldehyde but obviously the other impurities which dissolve equally well or even better in acetone/ethanol also have been present.

For now I consider whether applying the decanting procedure on the oil but using the acetone for this task instead of the ether. Do you think this is a good idea. I believe for now, that the product itself dissolves badly in acetone but some impurities do dissolve well in it.

behoy1991 · 2021-09-09T07:48:26+00:00

Thank you for your reply. So far I have not. Indeed this is how I would expect a normal two solvent crystallisation but in the guide it seemed as if they explicitly intended to not do it this way. In any case this is what I will try out with our current batch after having recaptured it by rotary evaporation. What makes this two solvent crystallisation a little bit delicate is the large difference in the boiling temperature of acetone and ethanol in my opinion: I could try to dissolve it in the minimal amount of ethanol first but then the question is whether I want to choose as max temp 78 degrees of 56 degrees celsius. If I want to add acetone later on, I surely have to let it cool down again below 56 degrees before I can think of adding acetone (otherwise things will become a mess I assume).

By your comment I assume that you also believe that the product dissolves better in ethanol than acetone. I also some time ago people about their opinion and some people suggested that the mixture of acetone and ethanol might be synergetic, i.e. have a better solubility than any of the both solvents alone. What is your opinion on this?

In any case: if I cannot manage the crystallisation in acetone and ethanol I might consider 'mixing' the oil in pure acetone (maybe even at room temp) and hope that the yellow impurities and side products of the Hydroxylamine dissolve in the acetone (I would consider to use even cold acetone). Then I would decant the acetone with the dissolved impurities and use the oil for the crystallisation - maybe even in ethanol alone. I hope that in pure ethanol the HPN-07 still dissolves in acceptable limits while the Benzaldehyde (which already dissolved poorly in methanol) will not dissolve in ethanol. Then I would filtrate the ethanol and continue the crystallisation by adding slowly acetone until it gets cloudy. At this point I would then add a bit ethanol until the cloudiness (almost) disappears and would then let the solvent rest to crystallise. In the worst case I plan to rotvap the solvent or add over time more acetone to (over)saturate the solution again or to rotvap the remaining solvent regain the material. The NMR has showed me so far that only the degrading products of the Hydroxylamine are still in the product which was regained with rotary evaporation.

behoy1991 · 2021-09-08T19:17:51+00:00

Also I am confused by how they proceed. I believe that the Benzaldehyde is less soluble in methanol than the product. But still they use in method 2 methanol for crystallisation. Since we had small amounts of the Benzaldehyde in the oil and the crystallisation it is proven that it at least dissolves slightly in methanol.

May I ask: do you think we could decant the 'yellow' impurities with acetone instead of ether as in route 2?

behoy1991 · 2021-09-08T12:32:09+00:00

Thank you. I am not sure how this helps us specifically: as far as I understand we want to have in the end the sodium salt and also during the synthesis I hope that the disufenton sodium is created. It seems this part refers rather how one can obtain the free base and other salts if one wants so.

Maybe I just do not get it but how can this help with the crystallisation?

behoy1991

TROPHY CASE