1. Pump에서의 Cavitation (공동현상) 에 대하여 기술하고 이로 생길 수 있는 문제점과 그 방지책에 대해 논하시오
- Cavitation이란
유체가 넓은 유로에서 좁을 곳으로 고속 유입하거나 벽면의 요철, 만곡부 등으로 흐름이 직선적이지 못할 때 유체는 저압이 되고 포화증기압보다 낮아지면 기화되어 기포가
Resistance... John
Conner. My son. *
The first terminator was programmed to strike * at me, in the year
1984... before John was born. * It failed. *
TERMINATOR 2 - Rev. 9/10/90 3
6 VOICE (SARA CONNER) 6* The second was set to strike at John himself,
* when he was still a child. As before, the * Resistance was able
to send a lone warrior. A * protector for John. It was just a
question of * which o
DR. BURTON, the Chief Psychiatrist moves down the old hallway, face tense. He steps through a doorway into...
INT. MAXIMUM SECURITY - NIGHT
Security cells. Criminal maniacs sealed behind protective casings.
A GUARD stands before a heavy door.
GUARD
Hell of a night, huh Doc?
BURTON
Hells in here.
Hydraulics HISS. The cell door unseals.
INT. SECURE ISOLATION CELL
Hydraulic failure.
Planes are not responding, sir!
Power returns in time for the sonarman to get a glimpse at the side-scan
display... AS THE SHEER CLIFF WALL LOOM BEFORE THEM.
HELMSMAN
Hydraulics restored, sir.
EXT. U.S.S. MONTANA 7
The cliff wall materializes out of the blue limbo off the port bow with
nightmarish slow-motion. The sub slams into it with horrific force, scraping
along and bounci
PFCs(Perfluorinated Chemicals)
Manmade chemicals, synthetic
Resistant to heat, water, oil, grease & stains
Stable, extremely resistant to breakdown
Widely used in diverse applications
Economically useful
Electronegativity of Fluorine
Partial charges in the polarized C-F bond
C-F bond
: strongest bond in
organic chemistry
: high energy bond
Two most studied compounds