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 can solve the second order linear homogeneous partial differential equation with variable coefficients?

can someone help me with reduced the partial differential equation du/dt = - f(x) d^2 u/ dx^2 - g(x) du/dx --- (1) to become: du/dt = - p(x) d^2 u/ dx^2...

21 January 2021 3,296 1 View

IHC-paraffin experiment: how do you approach shopping for an antibody?

Hello everyone! I am shopping for an arginase 1 antibody to use for IHC-paraffin experiments with rat tissue. So far what I have understood is that if an antibody says it is reactive with rat,...

16 January 2021 794 3 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 explain insignificant independent variable which is significant with interacting (Moderation) variable?

10 December 2020 3,037 1 View

What is the most Operating System (OS) which can be INSTALL on Tiny hard devices like Raspberry Pi (RPi) hardware ?

I'm targeting to deploy a mesh network and manually configure MANET routing protocols. I'm preparing scenarios, architectures, and hard devices needed to do that. Are there some step-by-step...

03 March 2021 1,931 5 View

Can we classify HV and LV lines based on line length?

I have dataset which shows the length of power lines. I need to classify the lines based on the line length. Is there a rule to classify the High voltage (HV) and low voltage (LV) lines based on...

03 March 2021 4,116 4 View

What is your perception on using visual analysis or quantitative approaches to evaluate data from single-case research designs (n of 1 trials)?

Results of single-case research designs (i.e., n-of-1 trials) are often evaluated by visually inspecting the time-series graph and computing quantitative indices. A question our research team is...

03 March 2021 687 1 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

I need to image mesoporous silica nanoparticles that are in ~100 nm size and do high resolution TEM to look at mesopores. what grids should I use?

Need to image mesoporous silica nanoparticles using the TEM. Also, need high resolution TEM images to see the mesoporous structure. Kindly suggest what kind of grids to use. Thanks, Shatadru

02 March 2021 1,787 2 View

Is there a classification scheme for rock cavities or caverns with respect to their size and shape?

The range of forms and sizes of cavities in rock is very big. Is there a classification scheme for rock cavities regarding their size and shape?

02 March 2021 4,511 3 View

How the parameters (such as Mw, Chemical bonds, polymer bland and so on) affect the mechanic property of polymer (such as storage, loss modulus) ?

Anyone can recommend any books on such topics? Thanks in advance.

02 March 2021 8,457 2 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 there a powerful system for the security of the systems distributed on IoT systems?

Is there a powerful system for the security of the systems distributed on IoT systems?

02 March 2021 3,858 10 View