Since the gas is less dense at higher altitudes, the density of a gas influences flows when passing through the orifice. Due to this reason, for a given flow rate, the bobbin will not be forced as far up the rotameter tube.

At higher altitudes, the volume of a fixed mass of gas increases, and therefore the molecules of gas are widely spaced resulting in a decrease in density with an increase in altitude.

Viscosity is simply termed as friction of gas. The viscosity of a gas is important only at low flow rates when the flow characteristic of the gas is laminar.

Charle’s law stated that the volume occupied by a fixed amount of gas is directly proportional to its absolute temperature (T) provided the pressure remains constant.

Boyle’s law for a fixed amount of gas at constant temperature, the pressure (P) and volume (V) are inversely proportional.

The Tare weight of a cylinder is the weight when it is empty. So,

Weight of cylinder – tare weight = weight of remaining N2O (g).
4.44 kg – 4 kg = 0.44 kg
Here,
0.44 kg of nitrous oxide remains in the cylinder

Since the molecular weight of nitrous oxide is 44 g and one mole of an ideal gas will occupy a volume of 22.4 litres at STP
Therefore amount left in the cylinder is several (gN2O/44) x 22.4 litres of N2O.

(440/44) x 22.4 = 224 litres.

pH is the negative log to the base 10 of hydrogen ion concentration:

So, what power produces the answer?

pH = – log10 [H+]

Making [H+] the subject:

[H+] = 10-pH

Substituting, [H+] = 10-7

One nanomole = 1 x 10-9 or 0.000000001

10-7 = 1x 0.0000001 or 10 x 0.00000001 or 100 x 0.000000001

100 nanomole

In the Child-Pugh classification system, the following 5 components are determined or calculated in order:

Ascites

Grade of encephalopathy

Serum bilirubin (?mol/L)

Serum Albumin (g/L)

Prothrombin time or INR

Raised liver enzymes are not the component of the classification system.

Oxygen is formed by a molecule of oxygen and two molecules of hydrogen with a molecular formula of H2O

The critical temperature is defined as a temperature above which the substance cannot be liquefied, no matter how much pressure is applied.
Water has a critical temperature of -118.6oC. So, it cannot be liquified at room temperature.

Medical oxygen cylinder is stored in a cylinder with a white shoulder and black body. Meanwhile, medial air is stored in cylinders with a white and black shoulder and a French grey body.

The partial pressure of air at a high altitude is less but the relative concentration remains constant.

The following units are derived SI units of measurement.

Energy or work: kg.m2.s-2
The Joule (J) is the energy transferred to an object when a force of one newton acts on that object in the direction of its motion through a distance of one meter or N.m.

Power: kg.m2.s-3
The Watt (W) = rate of transfer of energy or Joule per second J/s.

Force: kg.m.s-2
One Newton (N) which is the international unit of measure for force = 1 kilogram meter per second squared. 1 Newton of force is the force required to accelerate an object with a mass of 1 kilogram 1 meter per second per second.

Volt: kg.m2.s-3.A-1
The volt (V) is defined as the potential difference across a conductor when a current of one ampere dissipates one watt of power or W/A.

Pressure: kg.m-1.s-2
A pascal (Pa) is force per unit area or N/m2.

Bernoulli’s principle states that as the speed of a moving fluid increases, there is a simultaneously decrease in static pressure or a decrease in the fluid’s potential energy.
This is seen in the simultaneous increase in speed and kinetic energy and fall in pressure that causes entrainment of large volumes of air into a flow of 100% oxygen in the nozzle of HAFOE masks.

The reduction in fluid pressure that happens when a fluid flows through a constriction in a tube is the Venturi effect.

When a flow of gas or liquid attaches itself to a nearby surface and remains attached even when the surface curves away from the initial direction of flow, this is the Coanda effect.

The branch of engineering and technology that is concerned with the building of devices that use the flow and pressure of a fluid for functions usually performed by electronic devices is Fluidics . Fluidic logic is used to power some ventilators.

The branch of engineering that utilises pressurised gases is Pneumatics.

The total body water content of a 70kg man is (70 × 0.6) = 42 litres. For a woman, the calculation is (70 × 0.55) = 38.5 litres.

For a man, it is subdivided into:

Extracellular fluid (ECF) = 14L (1/3)
Intracellular fluid (ICF) = 28L (2/3).

The ECF volume is further divided into:

Interstitial fluid = 10.5 litres
Plasma = 3 litres
Transcellular fluid (CSF/synovial fluid) = 0.5 litres.

Directly measured fluid compartments:

Heavy water (deuterium) can be used to measure total body water content, which is freely distributed.
Albumin labelled with a radioactive isotope or using a dye called Evans blue can be used to measure Plasma volume . They do not diffuse into red blood cells.
Radiolabelled (Cr-51) red blood cells can be used to measure total erythrocyte volume.
Inulin as the tracer can be used to measure ECF volume as it circulate freely in the interstitial and plasma volumes.

Indirectly measured fluid compartments:

Total blood volume can be calculated with the level of haematocrit and the volume of total circulating red blood cells.
ICF volume can be calculated by subtracting ECF volume from total blood volume.

The starling forces operate to maintain a homeostatic flow across the pulmonary capillary bed.

The outward driving force comprises of the capillary hydrostatic pressure (13 mmHg), negative interstitial fluid pressure (zero to slightly negative), and interstitial colloid osmotic pressure (17 mmHg). The inward driving force is controlled by the plasma colloid osmotic pressure (25 mmHg).