How to seperate a stearic acid PCA from powders after ball milling?

More David Hopkinson's questions See All

Is it possible to conjugate an NHS ester to the N-terminus of a peptide ON RESIN?

So i have a few peptides (synthesized by SPPS and not cleaved from resin) and I want to add a maleimide label. We have NHS-PEG-Maleimide and from literature it is evident that the free amine group...

18 July 2024 4,075 3 View

Hot to do MTT assay data analysis?

I have repeated an MTT assay three times using different batches of the same cell line. Each time, I tested the same treatment (different medium) and seeded the same number of cells. Additionally,...

08 July 2024 1,900 1 View

What is wrong with Site-Directed Mutagenesis?

I am following the NEB protocol to perform SDM with Q5 and NEB HiFi Assembly. I am making a two base pair change. First picture is my Primers designed with NEBaseChanger. Second Picture is my...

24 June 2024 6,079 4 View

Does anyone have suggestions for this esterification?

I have a very polar alcohol (soluble in MeOH, H2O, partially in heated DMSO). And a long chain fatty acid that I would like to couple. I can't find a common solvent for them. I can form the...

24 June 2024 9,319 0 View

How do you add multiple nodes or cutting planes in Abaqus?

Hi, In a previous question I asked how to effectively model springs in Abaqus. However, I figured out the feature under Assembly -> springs/dashspots -> node to node Springs. I have a cylinder...

20 June 2024 892 3 View

How do you add radial spring elements in Abaqus?

Hi, I am trying to complete a buckling analysis on a tube with an external pressure. This solves itself easily by adding radial constraint on the internal edge of the tube, one axial constraint...

17 June 2024 8,165 7 View

Given that Mesozoic placentals were largely arboreal (with fingers), do you know of any studies that illustrate the finger-to-hoof transition?

I'm interested in the earliest days of placental terrestrial locomotion in large herbivorous taxa. Phenacodus seems to be transitional in this regard. Any others?

06 June 2024 5,182 2 View

How reliable is ninhydrin test in solid-phase peptide synthesis?

Hey everyone! I'm doing peptide synthesis on Rink amide resin and sometimes I need to add amino acids with secondary amines or beta amino acids. Normally I synthesize 35 to 40 mer peptides. As a...

21 May 2024 9,035 0 View

How does one generate a normalized TCSPC curve from actual photon counts versus time?

Sometimes TCSPC curves are analyzed using the actual photon counts, and sometimes they are normalized with the signal running from 0 to 1, or even from 0 to some value less than 1. What quantity...

20 May 2024 4,277 0 View

Problem when running Spin-Orbit Coupling using CASTEP. What is nlpot_prepare_precon_ks?

I am currently using CASTEP version 22.11, and I encounter the following error when running calculations with spin-orbit coupling: Error with dsytrf in nlpot_prepare_precon_ks Current trace...

19 May 2024 4,236 5 View

Separation of organic acids-HPLC?

Hello What should be done to separate and identify organic acids in HPC when their RetTime is the same?Like oxalic acid with Propanoic Acid.or acids that have a very close RetTime.

07 August 2024 8,782 3 View

Are there any good simple systems or platforms to recommend?

In order to show people the beauty of control and enhance enthusiasm for learning control theories, are there any good simple systems or platforms to recommend?

05 August 2024 10,034 1 View

Determining the worth of a point improvement in Hamilton Depression Scale?

Dear readers, Thanks for your attention. I am wondering about the health economic problem of quantifying the value of interventions which a) prevent, b) improve symptom profile and c) ultimately...

05 August 2024 3,246 1 View

Senescence-associated beta galactosidase staining is False Positive in control group?

Hi guys If anyone is currently working on aging cells, you guys would like to give me some advice. I'm testing against biomarker (SA-beta-Gal), I encountered a false positive in the control group...

02 August 2024 6,735 1 View

Are current regulations effective in preventing cancer caused by toxins?

I am currently researching the impact of environmental toxins on children's health and would greatly appreciate insights from experts in the field. If you are an expert or researcher working on...

02 August 2024 4,474 2 View

Some new emerging problems on application of RL for scheduling in IoT networks?

I have seen plenty of existing works on applied Reinforcement Learning (RL) policies for optimized scheduling in IoT networks including Q-learning, DQNs, and the newer ones including PPO for...

01 August 2024 8,754 2 View

How to make a Lateral flow control line more uniform?

We have a lateral flow test on Sartorius 140 NC. The conjugate is gold-monoclonal antibody. Using different control lines (GAM, protein A, protein G) we get a very strong leading edge with reduced...

31 July 2024 4,510 3 View

Conjugation of PEG-Amine to an Amino Acid Using EDC?

I am attempting to conjugate PEG to an amino acid at the C-terminus, for the purposes of producing nanoparticles. I have been told that PEG modified with amine groups can be used for this purpose,...

31 July 2024 2,033 1 View

Can we patent a process flow diagram developed using a process simulator but no actual cases is carried out?

Can we patent a process flow diagram developed using a process simulator but no actual cases is carried out? For example consider a process for certain product manufacture where a new process flow...

31 July 2024 781 1 View

Is it possible to use a safer acid instead of monochloroacetic acid to convert bacterial cellulose to carboxymethyl cellulose?

Hi, researchers, Is it possible to use a safer acid instead of monochloroacetic acid to convert bacterial cellulose to carboxymethyl cellulose?

29 July 2024 4,570 0 View

Abbas Ramezani

Dear David,

The acid stearic usage in milling process is very low (under 1%). If it is necessary to remove it:

Stearic acid has a C18H36O2 formulation and boiling point of 3610C.

Therefore, if your powder and its size not sensible to temperature up to 3610C, you can easily remove stearic acid by thermal treatment.

Raghd Muhi Al-Deen Jassim

what is the material you enter the ball mill? if it metal, please, specified it