How can I analyze variables with several zeros?

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What is the density for pva electrospining?

I'm Juan Carlos, a high school student who is working with electropinning, I made an electropinning machine with a 21g needle and a 30kv high voltage source and the distance between my needle is...

28 February 2021 298 3 View

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I am trying to find how to know the density needed for a pva electrospinning in a 0.6mm neddle, the electrospinning will be from top to bottom and the problem I really have is the solution because...

25 February 2021 2,615 3 View

HPLC baseline failure (ACN/Water)?

My baseline increases without any explanation, it is only fixed by changing the solution B, will it be the column? Reagents? Bomb? Detector? Solution A: H3PO4 0.01% IN WATER Solution B: H3PO4...

21 February 2021 5,656 3 View

Algorithms to filter corrective max and min from a set of data?

I've got this 5 year Direct Normal Irradiance data I downloaded from https://re.jrc.ec.europa.eu/. I ordered this by year and by every 24 hours because I need the DNI curve by max in summer, min...

17 February 2021 2,777 5 View

How to improve the buffer capacity of sea water?

Hello everyone I would like to improve the buffer capacity of seawater (pH ~8) in order to dissolve as much CO2 as possible without dropping the pH below 7.5 (a range between 7 - 7.5 is...

17 February 2021 2,797 2 View

Resume Book UEP2013 Asian Edition, dis somebodey has it?

I am looking for a copy of the resume book of UEP2013 Asian Edition (Urban Environmental Pollution 2013 Asian Edition) held in Beijing. If somebody has it, please I would like to obtain an...

11 February 2021 2,247 2 View

How do they fill/replace metal hydrides in vessels?

Surely they will want to avoid contact with air/moisture, so what is the procedure for this?

23 January 2021 428 2 View

What type of spectral radiation has greater penetration on materials, UV or IR? What book or source do you recommend for information on this?

I need information concerning the penetration and reflection capacity of ultraviolet and infrared radiation wavelengths on different most common materials. Edit. Can somebody recommend a book to...

16 January 2021 8,051 6 View

What is the easiest and cheapest molecular magnet to synthesize at home and how can it be done?

im looking for a diy at home (home lab) molecular magnet in a chemical suspension that is stable at room temperatures and cheap

30 December 2020 626 1 View

What defines the time it takes to disconnect a molecular switch?

I have been thinking about a material that was made 6 months ago, which is a tetramethylsiloxane linked to a thiazolidinedione and finally to a naphthalene, but I can't find the original paper (if...

30 December 2020 5,347 1 View

Energy minimization in LAMMPS using NVT ?

How do I do energy minimization in lammps with NVT ensemble ? I am using the following command and it does not seem to work. It stops at extremely high energy and gives me the error zero search...

01 March 2021 2,294 3 View

Why is the sum of the elements in a row in a Q matrix equal to zero?

When explaining substitution models, the substitutions are expressed as Q matrix. Why is the sum of the elements in a row zero?

28 February 2021 3,864 3 View

Why the CHi^2 is close to zero with a bad fitting but the Rp and Rwp are still high?

I am refining my XRD data using in FullProf program. The intensity of the modulated X-ray peaks is almost flat. I tried to adjust the peak intensities but unsuccessful. What is the reason? I guess...

23 February 2021 2,304 4 View

Can we use a compensation matrix with single staining that the negative population for each single staining is below zero?

Recently we used single staining to make a compensation matrix. But, for each single staining we saw that 13 to 25 percent of our negative population had been shown below Zero. In this situation...

21 February 2021 9,982 2 View

How to compare means of continuous data with zero-inflation and skew?

I have two groups (unpaired) of plant biomass measurements and want to know whether there is a test that can be used to determine statistical significance where assumptions are not violated. The...

18 February 2021 1,258 4 View

What does it mean if in mediation analysis the indirect effect is significant but is a larger b value than that of the direct effect?

I understand that for partial mediation to have occured the CI for the indirect effect must not cross zero and the b value for the indirect effect should be smaller than the b value for the direct...

14 February 2021 3,273 7 View

T-test and Mann-Whitney U test on groups with different sample sizes and variances?

Hello I have 2 groups with different sample sizes of (experts: 5 to 8) and (Users: 28 to 35) answering 21 questions on a 7 points Likert scale about the importance of some dimensions for...

31 January 2021 3,885 7 View

How nessesary is working point zero charges for any adesorbent?

How nessesary is working point zero charges for any adesorbent? I want to know how suitable the surface of the material is good for adsorption. I got SEM and FTIR results and thought those are...

30 January 2021 5,120 2 View

How to rotate an anisotropic stiffness matrix to an orthotropic matrix of cancellous bone?

Hi everyone, recently i have a question about how to calculate the orthotropic elastic matrix of cancellous bone cube. I really need the help!!!! I applied six stress states to the cancellous...

21 January 2021 9,143 2 View

Does anyone know how to code a size distribution function in a dynamic model under gProms ?

More specifically, how to integrate the distribution function from zero to infinity at any time to solve a dynamic equation.

20 January 2021 6,994 3 View