ag (0617) - SFP: water management

water quality is an issue, things to look out for are sediment runoff, excessive nutrients eg. from animal waste or fertilizers, salinity problems and pesticide runoff.

water quantity is an issue especially during times of drougt. irrigation has to be carefully planned, since if done irresponsibly, a majority of the water can be lost through evaporation.

government legislations are put into place to help manage the use of water. water licenses are required to extract water from catchments, but it's allocations that matter. allocations dictate how much water a farmer can use during a year based on their license. sometimes they might not be allocated any at all, but have to pay license fees anyway

phys (0617) - ItI: thomson's experiment

the aim of thomson's experiment was to determine the ratio of charge to mass in cathode rays.

his apparatus was a cathode ray tube with a screen, and he had both an electric field and a magnetic field to focus the cathode rays. with this he found the velocity of the rays, knowing that:

for electric fields:
F = qE

for magnetic fields:
F = qvB

therefore
qE = qvB
v = E/B

when these weren't there, however, he noticed that the rays produced a circular pattern, and he concluded that this was due to a centripetal force.

knowing
F = (mv^2)/r = qE = qvB

he could determine the ratio, ie. m/q

after testing this with different metals in the cathode, he discovered that the ratio was always the same, which proved that the negative particles within the cathode ray were the same for all metals, and later it was concluded that it was the same for all materials.

this was the introduction of the term, electron

ag (0616) - SFP: land capability system

the land capability system is a method of classification for land for agricultural use.

it ranges from class I to class VIII,
with class I to III suitable for cultivation
IV to VI suitable for grazing
and VII and VIII not suitable at all.

check table on sheet for details on each class.

the land is classified based on factors such as climate, soil, fertility, slope and drainage

knowledge of the land capability helps in making decisions about the practices done on the land, for example methods of cultivation (minimum till etc)

math (0616) - E&LF: differentiation of expontentials

the important thing to remember, is that the derivative of e, is e. basically.

y = e^f(x)
y' = e^f(x) * f'(x)

notes are proably not the best way of studying maths

bio (0616) - SfBH: pasteur & koch

no teacher today, so we had to read things on our own.

louis pasteur was a french chemist who studied the shape of organic crystals. he discovered that diseases were caused by micro-organisms, and this was known as GERM THEORY OF DISEASE. pasteur was the guy who eliminated the theory of spontaneous generation, which was previously believed that maggots and things appeared out of nowhere. he also created the process of pasteurisation, which in ag we have learned that is the method of heating liquid to high temperatures to kill microbes.

robert koch created a set of postulates known as KOCH's POSTULATES to identify which micro-organisms caused diseases
- the organism needed to always be present when the disease occurred
- it needed to be isolated and grown in pure culture
- organisms from the culture when given to healthy hosts produced diseasse
- this is repeated and compared to the first host

090610 - Physics

Finally Started the Ideas and Implementations topic.

Mainly stuff on CRTs (Cathode Ray Tubes) today.

Cathode = Negative
Anode = Positive

Electrons accelerate from the cathode to the anode (i think) and any ions produced accelerate towards the cathode.

TVs, electron microscopes, and photocopiers use CRTS.

Electric and magnetic fields are used to deflect cathode rays (the electrons).

The right hand palm rule works for CONVENTIONAL current only - opposite the direction of the electrons.

Thats pretty much it.

There seems to be a serious lack of DEDICATION affecting this blog.

We'll see if this becomes the final post.