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

How to calculate the crystallinity of cellulose film?

27 February 2021 2,753 4 View

No title

23 February 2021 4,014 3 View

What is the optimal method to prepare a controlled porosity osmotic pump (CPOP) tablet for scanning electron microscopy?

In order to assess the shape and size of pores formed by dissolving the pore former in the semipermeable membrane structure, SEM images are needed. Cellulose acetate was used in the coating...

15 February 2021 6,135 3 View

Peptide precipitation as pre-step for acid hydrolysis for amino acid analysis?

I'm currently experiencing problems during acid hydrolysis for total amino acid analysis as my first samples contain high amounts of sugar (I get too low results back). I therefore had the idea to...

14 February 2021 6,049 3 View

What is best technique to quantify necrotic cell death of specific cell populations?

I currently using FACS (Aurora Cytek) to quantify necrotic Gr1+ cell death from the spleens of immune competent mice. I target Gr1+ cells in the spleens of tumor-bearing mice using a photodynamic...

08 February 2021 733 6 View

Does viral RNA extraction from nasopharyngeal swabs require pre-centrifugation with supernatant collection?

06 February 2021 323 3 View

How to Remove DNA From a Sample Without Rupturing Yeast?

I transformed a plasmid into yeast and selected for transformants by growing them in a selective media (liquid, not agar plate). My experiment requires that I continually grow/ split these...

01 February 2021 9,936 2 View

What is the minimum centrifugation RPM and minimum time for TiO2 nanoparticle synthesis from plant extract?

In my laboratory, I have an analog centrifuge (does not show real RPM value). Its' brochure indicates the range is 300-3000 RPM. The regulator is marked from 1 to 10. Is there any way to determine...

01 February 2021 2,061 4 View

Is carboxymethyl cellulose a better electrolyte host polymer than methyl cellulose and cellulose acetate?

I want to prepare a cellulose-based biopolymer solid electrolyte by solution casting technique. However, choosing the right cellulose derivative has been my major challenge. Among the many factors...

30 January 2021 5,355 3 View

Does anyone have experience with NCI H716 cell line?

Hello! I am working with NCI H716 cells and I am struggling a bit trying to "wash" the cells since they are producing significant debris. I have centrifugated and resuspended them in their media...

28 January 2021 6,421 1 View