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

After a reference from Int J Body Compos Res, can any body help?

Hi, I am after the reference below, my library says it cannot obtain a copy either locally or internationally, any help appreciated! Chris Wang ZM, Heshka S, Wielopolski L, Pi-Sunyer FX, Pierson...

03 March 2021 6,193 1 View

Irradiation data for JAPAN?

Hi, Could you help me to get the latest (2019, 2020) solar resource data for a particular site in JAPAN? PV GIS and NSRDB data are not in reach to JAPAN, I'm looking for some other database for...

03 March 2021 961 3 View

How to calculate Ligand-active site distance in a ligand-protein complex from MD simulation?

I have run a MD simulation of a ligand-protein complex in GROMACS using CHARMM forcefield. Reviewer has asked me to calculate Ligand-activesite distance and binding free energy of ligand with...

27 February 2021 4,703 1 View

LEDs on Vis Light photo degradation of MB water sol via N doped TiO2 in a mini flume?

Good day to all, I have no experience with light emitting diodes. I am building a glass mini flume to demonstrate the photo degradation of Methylene Blue in water running over self cleaning...

26 February 2021 4,026 5 View

Why do the air flow results vary totally when adding scalar in CFD ?

Dear All, We are using Autodesk cfd to calculate the air flow in a single sided naturally ventilated room, where air flow depends only on buoyancy due to temperature difference between inside and...

25 February 2021 9,602 4 View

How to model Supercritical water gasification (SCWG) process in Homer software?

Hi everyone How to model Supercritical water gasification (SCWG) process in Homer software?

25 February 2021 4,075 1 View

Steps to calculate activation energy by coats & redfern method?

I'm a chemistry student and I'm researching the kinetic degradation of mixed plastic waste. I'm having trouble calculating the activation energy by the coats & Redfern method. The data that...

24 February 2021 974 1 View

Is it possible to define biogas as a fuel in the reformer process(scwg) in Homer software?

Hi every one Is it possible to define biogas as a fuel in the reformer process(scwg) in Homer software? Biogas fuel is not available in the options thanks

23 February 2021 6,518 3 View

Are there any candidates for an Einstein's bare cosmological constant?

It is commonly accepted that General Relativity has its own 'bare' cosmological constant that contributes together with the cosmological constant resulting from vacuum energy density for an...

23 February 2021 5,448 8 View

Helix antenna coupling problem?

Dealing with a helix antenna, made with flexible material and not rigid like using a PCB board or wire. At the beginning of the helix is too close to the ground plane, causing coupling. How can I...

21 February 2021 4,453 3 View