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

Final Pressure of an isochoric gas-evolving reaction ?

Hello, I got stuck in the thermodynamic problem. You place e.g. Zinc and HCl in an autoclave. Then the H2 evolvement starts.At which pressure will this isochoric reaction stop (pressure dependence...

01 February 2017 5,262 0 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

error in running a model in Abaqus

Excessive rotation of nodes in node set ErrNodeExcessRotation-Step1

17 August 2021 0 0 View

error in modelling model in Abaqus

Excessive rotation of nodes in node set ErrNodeExcessRotation-Step1

17 August 2021 0 0 View

MGL tools

20 June 2021 0 0 View

what is the simplest definition of ion exchange capacity

What this unit identifies for the ion exchange capacity ca. 0.92 meq. g-1. I am a newcomer in the membrane area. I just started. I highly appreciate your help

08 May 2021 0 0 View

what is the simplest definition of ion exchange capacity

What this unit identifies for the ion exchange capacity ca. 0.92 meq. g-1. I am a newcomer in the membrane area. I just started. I highly appreciate your help

08 May 2021 0 0 View

i have some problem with chtMultiRegionSimpleFoam

--> FOAM FATAL ERROR: Maximum number of iterations exceeded From function Foam::scalar Foam::species::thermo::T(Foam::scalar, Foam::scalar, Foam::scalar, Foam::scalar (Foam::species::thermo::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo::*)(Foam::scalar) const) const [with Thermo = Foam::hConstThermo >; Type = Foam::sensibleEnthalpy; Foam::scalar = double; Foam::species::thermo = Foam::species::thermo >, Foam::sensibleEnthalpy>] in file /home/ubuntu/OpenFOAM/OpenFOAM-4.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 66. FOAM aborting #0 Foam::error::printStack(Foam::Ostream&) at ??:? #1 Foam::error::abort() at ??:? #2 Foam::heRhoThermo >, Foam::sensibleEnthalpy> > > >::calculate() at ??:? #3 Foam::heRhoThermo >, Foam::sensibleEnthalpy> > > >::correct() at ??:? #4 ? at ??:? #5 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #6 ? at ??:?

24 March 2021 0 0 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's the best way to measure growth rates in House sparrow chicks from day 2 to day 10?

What's the best way to measure growth rates in House sparrow chicks from day 2 to day 10? Since, the growth curve from day 2 to 10 won't be like the "Logistic curve" it might not follow logistic...

03 March 2021 1,401 3 View

What is the production process of CaFe ferroalloys?

I looking for ferro calcium production process

03 March 2021 1,755 4 View

Resistor definition in Piezoelectric bimorph with ANSYS workbench

Hello, good day! I am trying to simulate similar bimorph piezoelectric harvester with below commands. However, the output power doesn't change with resistor value. Please help to find the reason. ET,10,CIRCU94,0 !SET UP RESISTOR R,1,100000 !RESISTANCE VALUE TYPE,10 !SET ELEMENT TYPE E,1,2 !CREATE RESISTOR BETWEEN NODES 1 AND 2 Thanks in advance Regards,

02 March 2021 0 0 View