Why is Enthalpy a state variable and Heat is not?

10 November 2018 4,444 0 View

1st years physics students book about: dependent / independent variable, inextensive/intensive variable, internal/external state variables?

Hello, I need a low level educational book explaining the PRACTICAL use (and interrelationship) of dependent / independent variables, inextensive/intensive variables, internal/external variables...

06 July 2018 1,517 0 View

State variables and process variables?

Hello, pressure p (intensive) and volume V (extensive) are thermodynamic state variables - independent on the way how a state was achieved. pdV =W is work and NOT a state variable, but a...

05 June 2018 3,662 24 View

Why can the photoeffect not be explained by wave-energy knocking out electrons?

Hello, the de Broglie relation says: wavelength= h/p (h=Planck const, p=momentum)....means: Lightwaves with a certain wavelength have a momentum. Then waves should set free an electron...

31 December 2017 8,756 4 View

Why can Heat not be Transformed completely into work?

04 May 2017 3,076 6 View

How evaporates a thin liquid film?

Hello, breathing on a cold window pane results in a thin film. The observation is: the diameter gets smaller with time and the edge is very dynamic! The center seems unchanged until the "shrinking...

01 February 2017 3,696 3 View

How do CO2 bubbles in water grow?

Hello, have a look at a glass of sparkling water or beer. When you observe it over a period of time and the initial heavy sparkling ceased you see a few stationary points, from which very tiny...

10 November 2016 1,331 3 View

Temperature dependence of citric acid solubility in water?

08 September 2016 9,717 0 View

Why is there no Citric acid "self-esterification"?

08 September 2016 8,558 3 View

Commercial Biotech Downstream Separation: Which Substances (Antibiotics, Insulin...) are intracellular (cell disruption) and which are extracellular?

06 July 2016 4,886 2 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

How Can I bring as much common elements in steel as possible to calculate stable phase(s) in OpenCalphad?

As I was tweaking step-by-step OpenCalphad6 Macros step1.ocm involving phase and thermal property calculation of a High-speed steel, I could not incorporate more than 6 elements in the steel...

01 March 2021 8,840 1 View

For gelatin coating for culturing HUVEC.Should the gelatin be made in sterile water or PBS? Do I need to autoclave the gelatin soln after making it ?

I want to use 0.1% gelatin. Should that be made in PBS or sterile water? Should I autoclave the gelatin soln after making it in water/PBS?

28 February 2021 274 2 View

The reason that the culture of white fungi Contamination with green mold(Trichoderma), the culture autoclave at121 for 15 min. What is it?

Is the period to autoclave not enough? The inoculation in a hood and flame and UV and alcohol.

27 February 2021 9,356 3 View

What is the error of the Txy diagram?

Hi, I know the attached Txy diagram has an error but can't figure it out. Could you please look at the diagrams and explain it to me?

23 February 2021 4,239 1 View

How the values of errors can be calculated for thermodynamic data?

I have calculated thermodynamic parameters for surfactant solutions in aqueous and mixed alcoholic solvents. I want to calculate the value of errors in the data and represent it in the table along...

22 February 2021 239 2 View

Charmm/GROMACS Residue 'ZN' not found in residue topology database?

I am trying to do some MD simulations of a protein with zinc ions. I am trying to use a charmm forcefield (I have tried 2017 and 2021) and Gromacs. I get an error when doing pdb2gmx Residue 'ZN'...

12 February 2021 9,367 2 View

Does any one have experience with Autoclavable cell culture media (RPMI 1640/DMEM)? Does it work well?

12 February 2021 2,958 1 View

What recipe of homemade lenti-virus concentrator do you use?

My lab is using a lenti-X concentrator. And we are looking for a homemade recipe. I have tried this recipe....

08 February 2021 5,965 1 View

Does anyone knows about a comercial software to record pressure and temperature during reaction in an Autoclave?

Dear all: Currently I am working with polymerization reaction in a reactor. For this, I need to control temperature, pressure, agitation speed etc. For calculation of rate of polymerization, I...

07 February 2021 355 2 View