mercoledì 29 dicembre 2010

Happy new Year from Italian Physics Society

Happy New Year!

Wishing all a joyful new year, All members of the Physic Nerd team propose the picture sent to all members of Italian Physic Society.

martedì 14 dicembre 2010

Snow at Physic Dep.

New experience at the Physics Department of Bari ... " Jingle Bell jingle Bell Jingle è tropp beelll! "

lunedì 8 febbraio 2010

STS-130 Last Space Shuttle Launch

Launch of NASA's Shuttle Endeavour Sparks Early Monday Sunrise
CAPE CANAVERAL, Fla. -- Space shuttle Endeavour lit up the predawn sky above Florida's Space Coast on Monday with a 4:14 a.m. EST launch from NASA's Kennedy Space Center. The shuttle's last scheduled night launch began a 13-day flight to the International Space Station and the final year of shuttle operations.

Endeavour's STS-130 mission will include three spacewalks and the delivery of the Tranquility node, the final major U.S. portion of the station. Tranquility will provide additional room for crew members and many of the space station's life support and environmental control systems.

Attached to Tranquility is a cupola with seven windows, which houses a robotic control station. The windows will provide a panoramic view of Earth, celestial objects and visiting spacecraft. After the node and cupola are added, the orbiting laboratory will be approximately 90 percent complete.

Shortly before liftoff, Commander George Zamka said, "Thanks to the great team that got Tranquility, cupola and Endeavour to this point. And thanks also to the team that got us ready to bring Node 3 and cupola to life. We'll see you in a couple of weeks. It's time to go fly."

lunedì 25 gennaio 2010

La potenza del Telerilevamento !

Recentemente sono stati effettuati dall' A.S.I. ( Agenzia Spaziale Italiana ) studi approfonditi sulla reale potenza del telerilevamento da satellite. I primi test sono stati effettuati su sensori ottici come GEO EYE, l'intento era quello di cercare con moderni sensori ottici di aumentare la risoluzione a 10m dal suolo .

Pochi giorni fa sono stati pubblicati i primi risultati, agli occhi degli esperti a dir poco impressionanti.
Ecco cosa è stato in grado di rilevare il satellite :

Ecco i commenti dei piu illustri esperti nel campo del terelivamento , che per ragioni di Privacy hanno preferito non essere citati .

Per fortuna che c’è ancora gente che ricorda ( e fa ricordare) quali sono le cose importanti della vita.

F.(Ingegnere aereospaziale)
qualcosa di strano?

no vivaddio, piuttosto un singulto di simpatia per chi, alla faccia del celodurismo, riconosce spontaneamente vocazioni e riconoscenza …………… che dio la benedoca…………..

L. (Ingegnere capodipartimento)
tu hai cancellato la “S” prima della parola?

venerdì 22 gennaio 2010

Non newtonian fluid

A non-Newtonian fluid is a fluid whose flow properties are not described by a single constant value of viscosity. Many polymer solutions and molten polymers are non-Newtonian fluids, as are many commonly found substances such as ketchup, starch suspensions, paint, blood and shampoo. In a Newtonian fluid, the relation between the shear stress and the strain rate is linear (and if one were to plot this relationship, it would pass through the origin), the constant of proportionality being the coefficient of viscosity. In a non-Newtonian fluid, the relation between the shear stress and the strain rate is nonlinear, and can even be time-dependent. Therefore a constant coefficient of viscosity cannot be defined. A ratio between shear stress and rate of strain (or shear-dependent viscosity) can be defined, this concept being more useful for fluids without time-dependent behavior.

Although the concept of viscosity is commonly used to characterize a material, it can be inadequate to describe the mechanical behavior of a substance, particularly non-Newtonian fluids. They are best studied through several other rheological properties which relate the relations between the stress and strain rate tensors under many different flow conditions, such as oscillatory shear, or extensional flow which are measured using different devices or rheometers. The properties are better studied using tensor-valued constitutive equations, which are common in the field of continuum mechanics.