What is the role of the restrictors in gas chromatograph?

Hello, As you can see in the figure, restrictors are on the way of carrier gas or some time sample gas. Why do we use the restrictors in gas chromatograph systems? what is the role of this part?

08 September 2018 9,996 3 View

How do I add time dependence variable in COMSOL?

Hello I want to add a time dependence external force such as a pulse into my model in comsol. How do I add this? in general, How can I add a time dependence variable or dipole(for example) in a...

07 August 2016 637 2 View

How to use previous solution as initial value of pressure in second study in COMSOL?

Hello I am use two "Pressure Acoustics, Transient" physics (actd & actd2) and two "Time Dependent" study (sol1(for actd) & sol2(for actd2)) and in 3D I have two regions with different...

07 August 2016 7,271 6 View

What is the vibrational level n probability in thermodynamics equilibrium condition?

Hello for a diatomic gas in thermodynamics equilibrium, what is the vibrational level n probability? is below equation correct? P(vibration level n probability)=(1/Total Partition...

06 July 2016 7,187 2 View

What are the energy values of the electronic levels in Methane molecule?

06 July 2016 9,469 2 View

Why don't we consider electronic level of molecule as degree of freedom such as vibration and rotation?

06 July 2016 7,618 5 View

What is the physical reason for anode potential drop in low-pressure glow discharges?

Hello In low-pressure glow discharges, two regions which are close to electrodes have relatively stronge electrical field and potential drops occur in this two regions. What is the physical reason...

04 May 2016 2,542 7 View

What happened to photons energy?

03 April 2016 2,899 3 View

Are there some of quantum measurements based on weak interaction?

06 July 2015 2,600 10 View

Physics: Why do we describe light by referring to its wavelength, but microwaves and radar pulses by referring to their frequency?

In physics, the description of the properties of light generally refers to its wavelength (nm), while in the range of microwaves and radio waves we refer to the frequency of a signal (e.g. kHz or...

03 March 2021 1,682 3 View

Does the pressure(-600 mmHg) affects pH?

When I conducted the degassing experiment using decompression under anaerobic condition(and I used ferrous based chelating agent), the oxidized ferric were observerd. So, could you tell me the...

03 March 2021 4,892 5 View

Why can't make aluminum nitride film successfully by use sputter?

We use reactive sputtering process to make aluminum nitride film, and want to make c-axis aluminum nitride film on a silicon substrate, but the crystal orientation cannot be seen with...

03 March 2021 7,975 3 View

How to access MSCI KLD Stats and Sustainalytics?

Hello all, I'm currently working on my undergraduate thesis and I'm having difficulties trying to access KLD Stats and Sustainalytics because my campus Airlangga University and apparently other...

02 March 2021 8,525 1 View

Is there any test to determine the cardiovascular risk of patients with obesity? from the perspective of obesity?

We found tests to determine cardiovascular risk taking into account lipid profile, blood pressure, age, history of diabetes, other laboratories. But when weight is involved, there is a paradox. I...

02 March 2021 6,036 1 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

Sample dilution for quantitative analysis using ELISA?

If the detection range is in ng/ml but the reference range is in ug/ml for a molecule or protein in serum or plasma .how to dilute and what is the initial volume to be taken for quantitative analysis

02 March 2021 7,670 3 View

What analysis to choose with a large neste dataset and clearly skewed or kurtotic distributions?

Hello! I have a dataset of n=3000 nested within 8 countries with approximately 200 or 400 responses in each country. I originally planned to perform multilevel modelling with 4 dependent variables...

02 March 2021 6,865 1 View

Why almost every element would be metallized in sufficiently high pressure and low temperature?

(This statement is from wikipedia, BTW). What is so special about metallic bond that is limiting high-P low-T state of a matter (as long as individual atoms exist, not white dwarf of neutron star...

02 March 2021 3,309 2 View

Sutter electrode holder leaking after applying positive pressure. How to fix?

I am using a Sutter electrode holder for my patch clamp experiments, but I'm having trouble keeping positive pressure inside my electrode due to a leak out of the back of the holder. I have added...

02 March 2021 5,829 1 View