éric 🚲 🇪🇺 Jul 30, 2025

New blog post on the inspiration for a new Julia package I am writing.

The package will address the optimization based design of heat exchanger networks for process integration (energy use reduction). The optimization will be based on decision variables defined on the basis of visualisation of hot and cold streams in a process.

The blog post illustrates the concepts using gnuplot src blocks in org mode in Emacs and highlights a nice feature of code reuse in org mode. There is also a small example of the use of Emacs Calc to do some algebra.

The plan is to have a series of blog posts as the code is developed. This is the first in the series.

#HeatExchangerNetworkDesign #HeatExchangerNetworkSynthesis #HENS #Optimization #ProcessOptimization #ProcessIntegration #visualization #Emacs #Calc #EmacsCalc #orgmode #gnuplot #JuliaLang #blog

https://www.homepages.ucl.ac.uk/~ucecesf/blog/20250730.html

QTHEN: 1. Inspiration from visualization for heat exchanger network design

Alejandro GalloMay 17, 2023

Small yet neat thing to convert #Hartree energy units into #ElectronVolt in my #emacs #calc workflow for #MaterialsScience users.

https://alejandrogallo.github.io/blog/posts/converting-energy-into-hartree-in-emacs/

#QuantumChemistry #Hartree #EmacsLisp #EmacsCalc

Convert energy into Hartree energy in emacs

There is a neat program in emacs which is called (GNU Emacs Calc Manual). Up to now in order to do energy conversion I always wrote small scripts in whatever language to do this. Now I discovered that you do these conversions also in emacs, you can do M-x calc, insert an algebraic form typing ' followed by 1.5 ev, which inputs 1.5 electron volt into the stack of the calculator.

Ale's Ecke
c_alphaDec 5, 2022
@ericsfraga @tacosandlinux HP-41C - brings back memories. I had one in the late 1980s when I started studying engineering. The programming part always felt a bit clumsy though (tiny display). So I sold it and shelled out a couple of bucks on top, and spent a fortune (for my standards at the time anyway) on a 48SX in the early 1990s. The greatness of #HpCalculators lives on in #EmacsCalc !
c_alphaNov 28, 2022
@tacosandlinux #EmacsCalc is great indeed. Thanks for the video! If you’re a former HP 48 SX/GX (The best handheld calculator mankind ever made™ btw.) like me, you will feel at home right away and you won’t be missing a thing.