Physics Flashcards
Critical temperature
Temperature above which, no matter how much pressure apply cannot liquefy a gas
Pseudocritical temperature
what is it
what does it normally describe
whats the temp of that gas
Crit temp mix gas, 50:50 mix O2 & Nitrous seperates
-7-5.5 depending on pressure
Clark / Poloragaphic electrode
Platinum anode silver cathode & external power source
Galvanic
Gold & lead - own power
Current generate is proport to PP O2
Pouiselles
Q = ΔPπr4/8Lη
Frequency wavelength velocity formula
λ = v/f
frequency (f), wavelength (λ) and velocity (v) is as follows:
gauge pressure
Amount by which the pressure measured in a fluid exceeds that of the atmosphere
Dir releate to SVP & temp
(not Volume, weight or pressure)
Radioactivity unit & define
Becquerel Disintegration of 1 nucleus every second
Force =
Mass x acceleration
Capacitance =
Charge / voltage
Kinetic energy=
1/2 mass x velocity^2
Charge =
Potential x capicatance
7 Fundamental SI units
Second Metre Mole Ampere Candela Kelvin Kg
Second is
Frequency of radiation Caesium 133
Metre is
Length light travel in vacuum during specified fraction second
Mole is
Amt of substance contain elementary many particle as atoms 0.012kg C 12
Ampere is
Current prod force 2 x10-7 n/m between 2 conductor 1m apart in vacuum
Candela is
Luminous intensity - perfect black body @ spec high temp
Kelvin is
Fraction 1/273.16 thermodynamic temp of triple point of h2o
Kilogram is
Defined international prototype at Sevres
4 derived electricity units
Volt
Ohm
Coulomb
Farad
7 derived Non electrical unit
Hertz Pascal Acceleration Newton Joule Electron volt Watt Celsius
Volt is
Electric potential
1v = diff electrical potential between 2 points of conduct, carrying current 1 ampere power dissipated 1 watt
Ohm is
Electrical resistance
Potential 1 volt apply across conductor & produces 1 ampere resistance = 1 ohm
Coulomb is
Unit charge / quantity electricity
1 coulomb quantity electricity transported in 1s by 1 ampere
Farad is
Capacitance
1 farad capacitor potent difference 1 volt present across plates - charge 1 coulomb held
Hertz is
Frequncy
1 cycle per second
Newton
Force
1 newton give mass 1 kg & accel 1 metere per second per seocnd
Pascal
Pressure
Pressure of 1 newton per square metere
Joule
Unit energy / work
expended point of application of force 1n move 1 metre - direction force
Electronvolt
Unit energy typer electromagnetic radiation
Energy - move 1 electron through ptoetnial difference 1 volt in vacuum = 1.6 x 10-19 joule
Watt
Power
Rate energy expenditure 1 watt = 1 joule/sec
Celsius
Temperature
1 degree identical 1 kelvin
1 Celsius = 1kelvin -273.15
What is STP
101.325 Kpa & 273.15 K
Avogadro’s Hypothesis
Equal volumes of gas at STP contain equal numbers of moles
Mol wt may differ - but no molecules same
Oxygen
Crit temp, cylinder, % o2 at altitude
Crit temp - cannot be liquefied no matter how much pressure
-118.6 (cannot be liquefy at room temp)
Black cylinder white shoulder
Same % O2 at altitude, PP reudced
OHMs law
Pot diff = Flow x Resistance
V = IxR
R = V/I
PVR =
MPAP − PCWP / CO × 80
Seebeck effect
Potential difference (V) @ 2 conductor - proport to temp
Thermistor
Resistance falls exponentially as temp rises
Platinum resistance wire
resistance increases linear w/ temperate
Coanda Effect
Development reduced pressure between fluid jet from nozzle & adjacent surface
Jet adhering to surface
Control mech in vent
Fick principle
calc blood flow / unit time to any organ
Measure CO
Turbulent Flow calculation
Q =r2. √ΔP/L.density
Therefore turbulent flow is proportional to:
The radius ^2
The square root pressure gradient and
Is inversely proportional to length and the density of the fluid
Reynolds number
Flow becomes turbulent, inverse to viscosity
Re >2000 - turbulence likel
Re -2000-4000 transitional flow
PAC Est w/ CO
Thermodilution
inject cold solution smoothyl over 4s
AUC temp change @ dist end of thermistor
PAC Est w/ CO
Thermodilution
inject cold solution smoothyl over 4s
AUC temp change @ dist end of thermistor
Damping
Factors
Progressive decrease in amplitude of oscillation d/t dissipation energy
Undamped = 0 Crit damp = 1 Optimally damp 0.64
Resonant
Driving force frequency coincides w/ resonant freq system
tubing too long / stiff
Diaphragm may also be too stiff
Impedence
When resistance depends on frequency
Capacitor
Stores energy in electrical field.
Resist instant change volatge
doesnt conduct DC
Beers law
Absorption of radiation - given thickness solution - given conc - same twice thickness of a solution of half the concentration
Bougner’s or Lambert’s Law
Each layer of equal thickness absorbs an equal fraction of radiation which passes through it
Boyles law
Constant temp volume gas inverse proport to abs pressure
Grahams Law
Rate diffusion gas Inverse proport to square root molar weight
Raoult
Depression / Reduction vapour pressure of solvent proportional to molar conc solute
Art line frequency
0.5 - 40Hz
Nautral frequency
frequency at which the monitoring system itself resonates amplifies signal should be at least x10 fundamental frequency.
The natural frequency is directly related to the catheter diameter (not indirectly).
It is inversely related to the square root of the: system compliance, length of tubing and the density of the fluid in the system.
Doppler effect
Apparent change in frequency
cause by movement of object in `relation to source
Bernoulli principle
utilised
Increase in the flow velocity of an ideal fluid will be accompanied simultaneous reduction in its pressure Fluid logic ventilators Gas driven nebulisers Jet ventilation devices Venturi oxygen mask
How does a thermocouple work
bimetallic strip has a junction potential proportional to temperature
