Selecting particular columns from large datasets (csv) using R Studio?

So I have large number of csv files (100+) in a directory with same structure and column names. The data is in time series and there are approx 30 columns/file. However i only want to aggregate...

08 February 2021 245 5 View

How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for Metabarcoding?

I'm working on pollen DNA metabarcoding to identify the floral composition of honey. How much pre-PCR dilution of mixed-template DNA extracted from pollen (honey) is appropriate for the...

28 December 2020 9,132 1 View

How to add two vertical and parallel Fresnel reflection coefficients to retrieve overall reflection coefficient for a right hand circular wave?

I have a problem in which a right hand circular polarized wave (GPS wave) encounters an ideal smooth plane obliquely, and then is reflected off that. To solve this kind of problems, the wave is...

28 December 2020 2,271 3 View

Which is better to focus on teaching or research for a good academic life and Why?

Which is better to focus on teaching or research for For a good academic life and Why?

26 December 2020 5,737 9 View

Is ag paste suitable for back contact on silicon wafer? or i should deposit al on the back surface using pvd or plasma sputtering?

Fabricating silicon solar cell

22 December 2020 4,906 7 View

Which renewable source is the best ?

wind hydro solar etc.

21 December 2020 6,360 16 View

Why is light pure energy?

light is pure because the light is the simplest electromagnetic construct but the energy of any object is also of the same kind.

20 December 2020 207 4 View

How to handle Missing Values for Skipped Questions (Systematic Missing) in R ?

10 December 2020 435 4 View

What is the best industrial emulsifier to make silicon oil in water emulsion?

I need to make long-lasting stable emulsions of 6 wt. % percent silicon oil in DI water. The previousely made emulsions using Tween and Span Emulsifiers did not remain stable after a week.

31 October 2020 3,568 3 View

Carbon Emission calculation factors ?

I am thinking about writing a paper on carbon emissions based on electricity consumption data from some buildings. From a research perspective, which factors should i specially focus while...

09 October 2020 4,142 3 View

Resistor definition in Piezoelectric bimorph with ANSYS workbench

Hello, good day! I am trying to simulate similar bimorph piezoelectric harvester with below commands. However, the output power doesn't change with resistor value. Please help to find the reason. ET,10,CIRCU94,0 !SET UP RESISTOR R,1,100000 !RESISTANCE VALUE TYPE,10 !SET ELEMENT TYPE E,1,2 !CREATE RESISTOR BETWEEN NODES 1 AND 2 Thanks in advance Regards,

02 March 2021 0 0 View

Is there any tutorial for comsol general projections?

Hi, im trying to make a projection in a 3d comsol model. I have a non uniforme chanel and my intention is to get the average tempreture in the y-z cross section and se the average tempreture...

02 March 2021 4,624 4 View

Why are the velocities so high in my Boussinesq approximation Fluent simulation?

Hello, I have a mechanism where air rises due to convective flows. In this simulation, nothing is driving the air except this. I understand that the Boussinesq approximation only works for small...

02 March 2021 4,910 3 View

Is it possible to do piezoelectric coupling in ANSYS-APDL or COMSOL between tapered substrate and rectangular piezoelectric patch?

How to do Piezoelectric coupling in ANSYS-APDL or COMSOL between tapered substrate and rectangular piezoelectric patch? Piezoelectric coupling between the rectangular substrate and rectangular...

02 March 2021 9,833 3 View

LOAD DISPLACEMENT CURVES Stiffness increasing in ANSYS non linear analysis. HOW CAN I CORRECT IT?

Hi. I am doing non linear FE analysis using a new material beam under flexural 2 point loading using ANSYS. I have defined a bilinear material model. The solution has converged. In results I am...

01 March 2021 9,911 3 View

How to show arrows over the streamlines in CFD-post?

I follow this to make streamlines like the photos attached below: (software- CFD post-processing) First I plot the 2D streamline over a surface "streamline 1". them I plot a vector by the...

01 March 2021 8,668 3 View

Which one is easier and better at modeling slender masonry structures? ANSYS or ABAQUS?

I need to model masonry and reinforced concrete minarets for my MSc thesis. Which one is easier and better at modeling slender masonry structures? ANSYS or ABAQUS? (Or any other program for just...

01 March 2021 736 3 View

Can Virtual Servers (remote dekstop manager) run heavy ANSYS Fluent CFD simulation ?

I have a virtual machine. My host Pc specs are not that good thats why i went for virtual servers. so basically my host pc has 8gb of ram with nvidia quadro k2200 4Gb DDR5 GPU ,processor intel...

01 March 2021 8,415 1 View

How can i resolve the "final solutuin is not converged" error in Comsol for my heat transfer simulation??

I have been trying to simulate heat transfer problem in Comsol 5.5 for long time but it always throw an error stating: "Failed to find a solution. Maximum number of Newton iterations...

28 February 2021 8,626 3 View

How to increase mesh quality of a cfd model in ansys fluent?

How can one improve mesh skewness, orthogonality, aspect ratio?

28 February 2021 7,730 3 View