In DFT or HF, is it more expensive to calculate the H matrix or to diagonalize it?

I was wondering: in common DFT (or Hartree-Fock) algorithms/codes, and in particular in solving the Roothan equation, what is the most computationally expensive part: 1- evaluate all the terms of...

01 February 2021 396 2 View

Warning in Lavaan, variance-covariance not positive definite!, model is not identified?

Dear colleagues, I am new to R, I have been using Amos for conducting CFA but came to learn that when dealing with Likert scale, Lavaan in R is a better tool to do such analysis. I started using...

30 December 2020 5,608 3 View

How can i figure out whether nanoparticles in my synthesis crosslinked or not?

i prepare protein nanoparticles. in one of my synthesis i use trifle amount of crosslinker and the nanoparticles stick in the bottom of plate. how can i understand that nanoparticles become...

03 December 2020 559 8 View

What is the best solver in OpenFOAM to study melt-water interaction?

During a severe accident in a nuclear reactor an energetic molten fuel/coolant interaction could happen, where a multiphase flow of a steam-water mixture in a region which contain drops of a...

29 November 2020 8,376 2 View

How can we define columns in 3D PLAXIS model for buildings existing near the excavation?

I started by a model using 3D PLAXIS to study the effect of deep excavations on existing buildings. The building was simulated as a surface plate with a surface load. Now I'm trying to do it as a...

29 November 2020 3,198 4 View

How to read forces from a file and apply them to a specified nodes in ANSYS APDL?

I want to apply different forces for every node. These force values are saved in .txt or .csv file. Can anybody help me to do that using APDL command. I attached Ansys input file for my model and...

15 November 2020 2,883 1 View

Where can I find off targets for Apis mellifera?

I would like to find off target sites for my sgRNA, however the more commonly used off target finders do not include apis meliifera, is there an application or website that would allow me to do...

09 November 2020 3,463 1 View

What is the best method to sterilize hydroxyapatite nanoparticles?

Powder insoluble

08 November 2020 509 3 View

Wrong cell dimension (cosAB)?

All input files with bravais lattice that contains an angle doesnt run in my Quantum espresso. i even tried running them in my friends laptop but the crash file displays the same problem. i hope...

03 November 2020 2,722 1 View

How Abaqus can generate lumped mass matrix with non zero values only at the diagonal ?

Hi everybody I generated mass matrix by Abaqus, but it has nonzero off diagonal values. I need to get lumped mass matrix with nonzero values only at the diagonal. In Ansys I can turn Lump on...

28 October 2020 5,960 4 View

Is it possible for two human neuronal cell lines to have different gene sequence for the same protein?

I am looking at the ATP1A2 (Sodium/Potassium ATPase alpha subunit 2) in two human neuronal cell lines. Expression levels of this protein seems to be almost equal when detected by one antibody....

01 March 2021 3,607 3 View

Why is there cloudy white solution in flavonoid test tube?

I do flavonoid test for biscuit incorporated with muntingia fruit powder. Sample extracted with metanol (1:10 ,w/v), macerated 24h, sentrifuged and filtered. Supernatan used for analysis. I have...

08 February 2021 6,779 4 View

What is the maximum storage time for samples used in soil enzyme assays?

01 February 2021 4,616 3 View

Difference between assessing EC50 in presence of physiological levels of human serum albumin and alpha1 acid glycoprotein vs. % human serum?

01 February 2021 1,825 1 View

Does the UV radiation affect on fruits ?

I want to examine a kind of fruit's extract's antimicrobial effects. At first I want to put it under the UV radiation to prevent the mold or any kind of fungi's and bacteria's growth. The...

24 January 2021 8,350 20 View

Does anyone grow Mycobacteria in TECAN Spark machine to get growth curves? What setting is necessary? Any tips (use Tween20 or tyloxapol?)?

I would like to grow Mycobact. Smegmatis in 24well plate in TECAN Spark machine. So far, I was using 100ml erlenmeyer flasks with 20 ml bacterial culture w/ shaking 180 rpm in 37C . Tecan would...

10 January 2021 6,624 2 View

Should I normalise data when measuring fluorescence intensity ?

I'm measuring fluorescence intensity of the product in an enzyme reaction in 37 celsius degree. I set a kinetic measurement in 1 hour. The fluorescence intensity of the BLANK ( contains only...

03 January 2021 5,554 5 View

.In my results the slope of curves got from Microplate reader is seems less (less than 1) and negetive some times. What is the reason for that?

In my research I'm enumeraring the florescence intensity (FI) Vs E-coli concentration in river water. I measure FI by Tecan I control 200 pro and E-coli by Membrane filtration.

03 January 2021 2,991 3 View

You can mention a contribution that science will achieve in this year 2021?

It is known that scientific knowledge is replicated each time at more unusual speeds, however, humanity expects more from our scientific work, that is, solutions to problems that have accumulated...

02 January 2021 8,300 16 View

Why nitrocefin is preferred over CENTA?

The chromogenic beta-lactamase substrate CENTA is at least five times cheaper than the other famous substrate nitrocefin and can be used with most enzymes, still, nitrocefin is preferred. Any...

17 December 2020 3,735 2 View