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 does skewness and kurtosis in construction management refer to and what are permissible limits of these in civil engineering with references?

The question is about assessment of skewness and kurtosis to carryout a research in construction management through SPSS software. The purpose behind the question is to know the permissible values...

12 November 2020 7,114 3 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

what is the simplest definition of ion exchange capacity

What this unit identifies for the ion exchange capacity ca. 0.92 meq. g-1. I am a newcomer in the membrane area. I just started. I highly appreciate your help

08 May 2021 0 0 View

what is the simplest definition of ion exchange capacity

What this unit identifies for the ion exchange capacity ca. 0.92 meq. g-1. I am a newcomer in the membrane area. I just started. I highly appreciate your help

08 May 2021 0 0 View

Dapi fluorescence protocol for colon cell lines ?

28 February 2021 2,534 2 View

Cloudy/high background western blot - can anyone help me?

Hi everyone! I try to detect VDR protein (~48 kDa) using Western Blot. After SDS-PAGE using 10% MP TGX Stain-Free Gel from BioRad I transferred the protein onto an metOH activated PVDF membrane...

23 February 2021 6,266 3 View

Protocol for membrane extraction E. coli?

Hello! I am interested in determining whether a poly-unsaturated fatty acid I have engineered E. coli to produce is being incorporated into the membrane of the cells or if it is simply a free...

21 February 2021 7,447 2 View

How do you prepare a porous crosslinked Polyvinyl alcohol and Glutaraldehyde membrane or film?

I am trying to prepare a Polyvinyl alcohol membrane for carbondioxide adsorption

08 February 2021 7,493 3 View

Background and spots in Western Blot membrane?

Do you know why my membrane looks like this? I did this western for Anti-hnRNP D/AUF1 antibody ab50692, as primary antibody in 1:1000 overnight at 4c and Anti-rabbit IgG HRP linked antibody...

07 February 2021 5,591 4 View

Acoustic simulation of Membrane?

I have 1 mm thick membrane. This membrane is perforated. I want to simulate this in Acoustic module of comsol. For this ,which type of module I can use in comsol.?

02 February 2021 2,505 6 View

Can i re-incubate a WB membrane with a higher solution of the previously used 1ry ab?

I've incubated my western-blot membrane with both primary and secondary antibodies and i just realized at the end that i've used a lower concentration of my primary antibody for my loading control...

27 January 2021 1,034 3 View

Difficulties purifying Outer Membrane Vesicles using a Sucrose Density Gradient: Unable to detect any protein after this process?

I'm currently trying to purify Outer Membrane Vesicles (OMVs) following their extraction from the bacteria I'm working with. After the initial extraction the concentration of protein seems good...

27 January 2021 6,852 3 View