The introns late theory supposes that spliceosomal introns arose in remotely antiquated eukaryotes from self-splicing introns. These group II introns were present in the mitochondrial organelles of endosymbionts, and invaded previously undivided genes and intron-less genomes, and the spliceosome evolved as a way to remove them (Cavalier-Smith, 1991). The argument for self-splicing introns giving rise to spliceosomal introns and the spliceosomes is based on functional and structural similarities between self-splicing group II introns and spliceosomal introns. In both types of introns, the 5? end becomes bound to an adenine near the 3? end, forming a lasso structure that is excised (Newman, 1997). Furthermore, the group II introns appear to be phylogenetically limited to eubacteria (Bonen
Venturi Meter Coefficient Discharge Experiment
Aims and Objectives: In this experiment the flow (k) and discharge (Cd) coefficients of a venturi meter will be assessed by comparing the real discharge measured in the experiment with the theoretical discharge calculated by deriving venturi discharge formula from Bernoulli and continuity equations.
The apparatus used in this experiment are:
Stopwatch – It is used to calculate the time required for a specific volume of water to be supplied, to measure the rate (actual) of flow (Qa).
Venturi apparatus – The venturi apparatus is connected at six different points to the manometer
Thermometer – Thermometer is used to measure the temperature of the water, the Reynolds number will be calculated by the resulting kinematic viscosity.
Hydraulic bench – The hydraulic bench contains water pump and tracks the volume of water collected. The jet apparatus rests on it.
Place the meter horizontally, in such a way that at point 1 and 2 the z values are the same.
Open the inlet valve and leave at it maximum flow.
Release the air from the manometer and venturi tube.
Tightly close the air purge valve on the upper manifold.
Allow the water to flow by switching on the bench supply valve.
Make sure to close apparatus control valve.
Allow some air to enter by slowly opening the spindle once more
With the stop match measure the discharge by recording the time required for a specific volume of water to be collected.
To measure the discharge use the stop watch to record the time required for a specific volume of water to be collected. (Volume of the water is measured by a meter beside the supply valve.)
Repeat this 16 times and measure the flow rate. Along with it, measure h1, h2 and h3.
h1 = Height of water in manometer tube A (inlet)
h2 = Height of water in manometer tube D (throat)