Posts about sciblog

2016-11-04 homebrew cask : creating a new cask

A new version of https://nteract.io/ is out, I will try today to push that new infomation to http://caskroom.io/ by creating a new cask for this application. I will base things on this previous contribution where I was simply editing an existing cask.

  • getting the token
    "$(brew --repository)/Library/Taps/caskroom/homebrew-cask/developer/bin/generate_cask_token" '/Applications/nteract.app'
  • set-up variables
    cd "$(brew --prefix)"/Homebrew/Library/Taps/caskroom/homebrew-cask
    github_user='laurentperrinet'
    project='nteract'
    git remote -v

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2014-12-04 paramétrer l'e-mail à l'INT

  • paramétrer un nouveau compte avec son adresse lolo.toto@univ-amu.fr
  • indiquer les parametres:
    1. en entrant, serveur IMAP imap.univ-amu.fr avec SSL (port 993) et l'authentification est par mot de passe
    2. en sortant, serveur SMTP smtp.univ-amu.fr en STARTTLS, port 587 et l'authentification est par mot de passe
    3. attention, en entrant et en sortant, comme identifiant, l'identifiant univ-amu (de la forme toto.l)

2014-01-01 How Airplanes Fly: A Physical Description of Lift

  • http://www.allstar.fiu.edu/aero/airflylvl3.htm
  • quote
     - The amount of air diverted by the wing is proportional to the speed of the wing and the air density.
     - The vertical velocity of the diverted air is proportional to the speed of the wing and the angle of attack.
     - The lift is proportional to the amount of air diverted times the vertical velocity of the air.
     - The power needed for lift is proportional to the lift times the vertical velocity of the air.
    
    Now let us look at some situations from the physical point of view and from the perspective of the popular explanation.
    
     - The plane’s speed is reduced. The physical view says that the amount of air diverted is reduced so the angle of attack is increased to compensate. The power needed for lift is also increased. The popular explanation cannot address this.
     - The load of the plane is increased. The physical view says that the amount of air diverted is the same but the angle of attack must be increased to give additional lift. The power needed for lift has also increased. Again, the popular explanation cannot address this.
     - A plane flies upside down. The physical view has no problem with this. The plane adjusts the angle of attack of the inverted wing to give the desired lift. The popular explanation implies that inverted flight is impossible.