Sabbaticals

Term 1: Aviation Science

In term 1, I attended a sabbatical regarding aviation science and plane fighting. This sabbatical was something totally new to me as I  have never really paid attention to how planes fly and what is required for a successful take off. For the first 3 days, we learnt to take off and land a plane. We were given a flight simulator to try this out and I successfully managed to take off almost 70% of the time. It became easy after a few tries and we could then fly the plane anywhere in the virtual world. Here is a picture of the flight simulator:

Through this flight simulator, I found out that angling the nose of the plane downwards increases the speed of the plane while angling the nose of the plane skywards decreases the speed of the plane until the engines of the plane stall. When in a stall, the plane is unable to move and drops down towards the ground. If nothing is done to recover from the stall, the plane will crash. I also learnt how to plot a flight course for an aeroplane and found out that many of the annual aerial accidents happen because of a mistake in flight path planning and engine failure.

On the third day, we had a lesson on meteorites. We learnt about the different types of meteorites, the most common being the stony meteorite and the iron meteorite. 

Stony meteorite

Iron meteorite

Meteorites are lumps of rock which either used to be part of a planet or was discharged by a dying planet. These lumps of rock shoot across space at breakneck speeds and some of them end up on earth due to its gravitational pull. Many of the meteorites burn and melt away during their flight.

On the fourth and fifth day, we went into an advanced module on fighter planes. We were taught on the        types of missiles there are, the maneuvers we could perform to escape or destroy an enemy plane and how to use the radar tracking system in a plane. 

There are 3 main types of missiles:

~heat tracking missile

~radar tracking missile

~semi radar tracking missile

Here is a picture for reference:

Some Maneuvers we learnt are too difficult to describe but most of them include complicated twists and turns and it would be easier to view them through the diagrams below:

My reflections: This sabbatical was really engaging and fun as we got a lot of time to play around with the simulator and even had a mock battle within the sabbatical on the fifth day using planes from World War 1. The simulator was a realistic impression of the real aeroplane flight. I took a few tries to get used to the simulator but I knew from experience that failing at the first try is not unnatural. :)

Term 2: Environmental Science Studies

Day 1: Lecture on the effects of climate change

Watched video: The Day After Tomorrow

Lecture on Ecology

Day 2: Watched Movie: 1) Coral Reefs 

                                       2) Amazing Caves

At Omni Theatre

Day 3: Introduction to waste management and recycling

Visit to Marina Barrage with Guided tour

Day 4: Solar Power Course

Day 5: Visit to Incineration Plant

My reflections: This sabbatical was mostly boring lectures but they were informative at the same time. The field trips were enjoyable and helped increase my knowledge of what Singapore is doing for the environment. 

Growing Mushrooms

Growing Mushrooms


In term 2, 16th of April 2012, we were tasked with the growing of Pleurotus Ostreatus --- Grey Oyster Mushrooms from a commercial mushroom grow bag. The mushroom bag was a cylindrical looking object filled with sawdust and had a black ring at the top of the bag with a black cap. The bag was already implanted with spores from the oyster mushroom and their growth depended on how well we could take care of them. Here are some of the questions I had before starting out:
~What conditions do the mushrooms need for growth?
~What is actually inside the bag?
~How many mushrooms will there be?
~How long will it take for the mushrooms to grow?
These questions will be answered throughout my task.
Here is an accurate schedule of what I did exactly when I got home over a period of time where the mushrooms grew.
*To note: Misting of mushroom refers to the spraying of water on the sawdust using a spray can. As the mushroom grows up, the number of misting sessions increased from once a day all the way to about 6 times a day.

Growing of  Oyster Mushrooms from a commercial mushroom grow bag

16-4-12, 3.13pm:  opened the cap and misted the mushrooms. Saw some white cotton wool with sawdust. Placed the sawdust about 1 meter away from the window behind a flower vase.

17-4-12, 3.13pm: misted the mushroom again. No visible change to the sawdust.

18-4-12, 3.13pm: misted the mushroom again. No visible change to the sawdust.

19-4-12, 3.13pm: misted the mushroom again. No visible change to the sawdust.

20-4-12, 3.13pm: misted the mushroom again. No visible change to the sawdust.

21-4-12, 3.13pm: misted the mushroom again. No visible change to the sawdust.

22-4-12, 3.13pm: misted the mushroom again. Transparent gelatinous substance observed on sawdust. Yellow growth observed at the sides of the black ring.

23-4-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

24-4-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

25-4-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

26-4-12, 3.13pm: misted the mushroom again. Surface of sawdust turns white.

27-4-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

28-4-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

29-4-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

30-4-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

1-5-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

2-5-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

3-5-12, 3.13pm: misted the mushroom again. No further visible change to the sawdust.

4-5-12, 3.13pm: forgot to mist mushroom. No further visible change to the sawdust.

5-5-12, 3.13pm: forgot to mist mushroom. No further visible change to the sawdust.

6-5-12, 3.13pm: forgot to mist mushroom. No further visible change to the sawdust.

7-5-12, 3.13pm: forgot to mist mushroom. No further visible change to the sawdust.

8-5-12, 3.13pm: misted the mushroom again. Six small white coloured stumps appeared below the black ring.

9-5-12, 3.13pm: misted the mushroom again. The white stumps have grown above the black ring. Traces of cap observed.

9-5-12, 9.13pm: misted the mushroom again. Cap appears to be bigger.

10-5-12, 6.13am: misted the mushroom again. No further visible change to the mushroom

10-5-12, 3.13pm: misted the mushroom again. Cap is substantially bigger.

10-5-12, 9.13pm: misted the mushroom again. No further visible change to the mushroom

11-5-12, 6.13am: misted the mushroom again. Cap is much bigger for the five  mushrooms.  One mushroom remains small.

11-5-12, 3.13pm: misted the mushroom again. Mushrooms continue to grow bigger.

11-5-12, 5.13pm: misted the mushroom again. Mushrooms continue to grow bigger.

11-5-12, 7.13pm: misted the mushroom again. Mushrooms continue to grow bigger.

11-5-12, 9.13pm: misted the mushroom again. Mushrooms continue to grow bigger.

11-5-12, 11.13pm: misted the mushroom again. Mushrooms continue to grow bigger. Edges of mushroom cap curl upwards.

12-5-12, 1.13pm: misted the mushroom again. Mushrooms are ready for harvesting. Five big mushrooms are grey in colour. The weaker mushroom turns yellow.

12-5-12, 1.36pm: misted the mushroom again. Time to harvest the mushrooms!

Procedures:

First, the black ring was twisted.
Second, the mushrooms were gently pulled out.

Third, the mushrooms were stir-fried with oyster sauce. Fresh and Yummy!

12-5-12, 2.13pm: scrapped the white sawdust off. Misted the sawdust. Capped the sawdust. Will continue to monitor its growth.

My Reflections: Throughout this project, I learnt many of the common values such as perseverance, patience and persistance. However, there is another thing I learnt which is more obscure and less heard of. I learnt that often, too much of something can inhibit growth of its supposedly beneficial effects. For example, the mushrooms did not grow when I misted them daily but after I left them alone for 4 days, they finally grew. This shows that too much water and care can end up doing harm instead of good.

Science Ace Project

I embarked on 3 projects for my science ACE in Term 2.
1) Field Trip + Report
2) Research article + comments
3) Make something related to science


Here are my projects:

1) Science ACE Term 2

Name : Teo Xue Shen (26)
Class: 2P3
Field Trip Report: Trip To Pasir Ris Fishing Pond

Date: 29-4-12

Place: Pasir Ris Fishing Pond

Brief Description of Trip:

My family and I set out in the afternoon to Pasir Ris Fishing Pond to try to catch some
snapper fish. Pasir Ris Fishing Pond is a salt water pond with two main types of fish, the
snapper and the white pomfret. As we were aiming to catch the snappers, we bought small
life fish as bait. We brought portable battery operated air pump to generate air for the small
fish. Upon arrival, we paid $50 per rod to start fishing. After about half an hour, I caught
my first snapper. it was the strongest fish I ever fought with on the fishing rod. Weighing
about 2kg, the fish was literally ripping the line out of the reel. the strength of the fish was
unbelievable. Every time I got it within 10 meters from shore, it would get a sudden burst of
speed and drag some line out again. After fighting it for about 5-10 minutes, the fish grew
weary and gave up. It was the biggest fish I ever hooked. A special tool was used to clamp
down on the jaw of the fish to hold it in place while I took a picture. Then it was placed into
a netted black basket which was tied to the side of the pond and immersed in the water to
keep it alive. A grand total of 6 snappers were caught that day.

Fishing Gear: 1x1.5m fishing rod, 8-15lb, medium action
1 x fishing reel, line cap 122 yards, 3 ball bearings, gear ratio 5.2:1
Nylon line
Live Small Fish as bait

Some Major Takeaways:
-snapper fish prey on small fish
-snapper fish and pomfrets can co-exist together in a confined space
-pomfrets feed on prawn and not fish
-more energy is used when fighting a fish on a line than grabbing it with your hands
-snappers and pomfrets can survive in murky environments
-it is possible to get dragged into the water by a powerful fish
-fish can have great strength
- to reel up a very heavy fish require a lot of strength, skills and experiences

I feel that fishing is a very fun outdoor activity and it can help to strengthen family bonds.
It is also a way to relax. Fishing helps develop patience as the fish normally takes time to
get hooked. There is a great deal of excitement when the fish is being reeled up. Family
members tend to help each other to take care of the rods when the other member is taking a
break or resting. Fishing does inculcate a sense of helpfulness. Therefore, fishing is not only
a very fun activity but also has many benefits.

Attached are some photos of my fishing trip. One of the photos shows one of the big
snappers that I caught on that day. My parents, my brother and I were all smiles. We
enjoyed fishing together. We had a yummy curry fish for dinner that night.

Fishing Trip At Pasir Ris Fishing Pond

2) Science ACE term 2

Class: 2P3

Research article review on growth and survival of larval Snakehead
(Channa striatus), fed different life feed organisms

Authors: Mehrajuddin War, Kareem Altaff, Mohammed Abdulkhader Haniffa

As the snakehead larvae grows, naturally, it will develop teeth and prefer
larger foods such as other snakeheads rather than tiny cladocerans. A mixed
cladoceran diet will reduce the chances of cannibalism while brine shrimp
larvae will increases the chances of snakehead survival. Fish fed with brine
shrimp larvae showed the greatest weight and height gain over the period
of one week. The results showed in this research article is most likely very
reliable as their procedure is completely standardized with the only variable
being the type of food. Even the slightest bit of disturbance of fish larvae or
cladoceran larvae was taken into consideration. Everything was transported
with ‘the least disturbance’, which proves the reliability of the source.

How has the research improved lives?

This research is linked directly to the farming of snakeheads for worldwide
consumption. Thus, it affects the productivity rate of all fish farms farming
snakeheads. If the feeding of brine shrimp larvae can reduce the rate of
cannibalism and increase the rate of survival of these fish, more fish can be
sold for consumption for less cost in rearing the fish. This will result in an
improvement in the aquacultural economy.

The experiment could be repeated thrice over four weeks instead of once over
four weeks. This will make the results much more reliable. Perhaps change
of the substance used to cultivate the food can be considered as certain
larvae may thrive in different conditions which will allow them to have different
nutritional values.

Source:
http://www.trjfas.org/pdf/issue_11_04/0405.pdf


3) I used lobster exoskeleton which I collected from my lobsters over the years to make some sort of a specimen case. I used thread to sew the blue lobster exoskeletons to a board. Each exoskeleton depicts the size of the lobster at different stages of growth. Here is the end product:

Lesson 6,7,8

Lesson 6,7,8
Light





In this lesson, we learnt about LIGHT:
1) Reflection and Refraction
2) Lenses
3) Colours of light

Reflection & Refraction
Light travels in a straight line and thus, it cannot turn away or bend off course to avoid any object in its path. As light strikes the surface of different mediums, there will be reflection. Not all the light is absorbed by the object and some light is reflected off the object and into the surroundings. The key rule of reflection is that the angle of reflection is equal to the angle of incidence. Here is a diagram showing the law.

The dotted line in the middle of the figure is called the normal and is perpendicular to the surface. The properties of reflection is used in mirrors. So, why is it that we can see our reflection on a mirror but not on a piece of paper? This is because there are two different types of reflection: specular reflection and diffused reflection.

Specular reflection occurs when a light ray or a beam of light hits a smooth surface. Diffused reflection occurs when a light ray or a beam of light hits a rough surface and is reflected at different angles. A piece of paper has a seemingly smooth surface but it actually has millions of microscopic bumps and holes on it. This causes diffused reflection and thus, we cannot see our image on a piece of paper. 

However, not all the light is reflected off the surface. What happens to the light which is absorbed?

Refraction is the process where light bends away from or towards the normal when it passes from a medium of higher density to a medium of lower density or vice versa. When light passes from an optically denser medium into an optically less dense medium, it refracts and bends away from the normal. When light passes from an optically less dense medium into an optically denser medium, it refracts and bends towards the normal. Here is what actually happens when a ray/beam of light strikes a surface:

The angle of refraction, as seen in the diagram, is the angle formed by the refracted ray and the normal. The greater the optical density of the medium, the greater/smaller the angle of refraction depending on the direction of light. In order to remember which way the light will bend, just imagine the light ray as a trolley which is being pushed across the floor at high speeds. The floor is the optically less dense medium. This trolley is being pushed at an angle. Now, imagine a carpet right in front of you. That is the optically denser medium, As one wheel of the trolley hits the carpet, it slows down. However, the other wheels of the trolley are still moving at high speeds. thus, the trolley begins to turn towards an imaginary line on the carpet, which is the normal.

Some rules to follow:

The angle of incidence is NOT equal to the angle of refraction

There is no angle of refraction if the angle of incidence is 90 degrees.

Lenses:

There are 2 types of lenses which we are studying. They are the concave lens and the convex lens. Before starting on the topic of lenses, we did an experiment to determine if the distance of an object infront of a mirror is equal to the distance of the image in the mirror. Here is our set-up as shown below:

The distance between L and the mirror was measured. Here is the image in the mirror:

As you can see, the image is upright, laterally inverted and same size as the object.

This topic on lenses is a very confusing topic and requires memorizing whole chunks of information. Here is a brief summary of what we learnt:

Optical center of a lens: point at centre of lens

Principal Axis: line passing symmetrically through the optical centre of the lens

Focal Point: Point where all rays close to and parallel to the principal axis converge after refraction by lens

Focal Length: Distance between optical centre and focal point

Focal Plane: Plane passing through the focal point and perpendicular to the principal axis

Here are all the cases in which light strikes a convex lens:

There are 6 cases in total.

Case                                            Image                                            Uses

1                                                  ~real                                             ~ telescope

                                                    ~inverted                                                                                                   

                                                    ~laterally inverted

                                                    ~diminished            

2                                                  -real                                             -camera

                                                    -inverted    

                                                    -laterally inverted

                                                    -diminished

3                                                  *real                                             *photocopier (equal sized copy)

                                                    *inverted    

                                                    *laterally inverted

                                                    *same size as object       

4                                                 >real                                               >projector

                                                   >inverted    

                                                   >laterally inverted

                                                   >magnified              

5                                                ! virtual                                           ! spot light

                                                  ! upright    

                                                  ! magnified              

6                                              ~ virtual                                           ~ magnifying glass

                                                ~ upright    

                                                ~ magnified        

Here is the case for a concave lens:

A concave lens is also known as a diverging lens because it diverges light rays that passes through the lens. The focal point, F, is the point where the diverging rays meet when extended backwards.

Here are some photographs of concave and convex mirrors:

Concave Mirror

Convex Mirror

Here is an experiment we did in the science laboratory on whether the angle of reflection is equal to the angle of incidence using a plane mirror and a concave mirror. the light ray came from a light box as shown below:

Here is the results of our experiment both with the plane mirror and with the concave mirror:

 Plane mirror

Concave mirror

Colours:

In 1665, Issac Newton discovered that by placing a triangular prism in the path of a beam of white light, the light was split into seven bands of different colours, red, orange, yellow, green, blue, indigo, violet. This is called the visible spectrum. The process of separating white light into its constituent coloured lights is known as the dispersion of light.

This splitting of light can be attributed to the wavelength of each different colour. Red light has the longest wavelength and thus, it bends the least while violet light has the shortest wavelength and bends the most.

In order to recombine white light, another identical prism can be placed and inverted in front of the first prism. All the seven bands of coloured light will recombine into white light once again.

The 3 primary colours of light are: red, green and blue. Here are a few combinations of the primary colours of light to form other colours.

Green + Red = Yellow

Blue + Green = Cyan

Red + Blue = Magenta

When white light is shone at light filters, the filter absorbs one or more colours of light and the rest is transmitted. However, when a beam of single coloured light is shone at a filter that is made to transmit light of another colour, the resulting colour of light transmitted is black.

Example: when red light is shone on a green filter, black light is transmitted

On the other hand, when coloured light is shone on an opaque object, the opaque object reflects certain colours of light only. The rest is absorbed by the object. For example, a blue chair absorbs red and green light and reflects the blue light into our eyes such that the chair appears blue. Similar to light filters, when light is shone on a coloured object that does not reflect any colour of light found in the beam of light, the object appears black.   

My Reflections: Reflection, refraction and the colours of light are pretty basic topics. Once I had the foundations covered, it became easier and easier. Lenses, on the other hand, was a totally different topic. It required massive amounts of brain power to memorize all 6 cases and 1 case for the convex and concave lenses. This was another of the killer topics for me as I had limited interest in this field, found it hard to memorize stuff just using raw brain power and I had to memorize many other things at the same time. As a result, I ended up spending more and more time on lenses and less time on other topics. However, to this date, I am still unable to memorize all of the conditions, images and many others for the two different types of lenses. Will keep trying! :D                                                                                                                 

                                                                                      

Lesson 5

Lesson 5:
Plant reproduction and Human reproduction

Sexual reproduction allows the offspring of the plant to inherit beneficial qualities from both parents and increases the chances of the species's survival. The flower is the reproductive organ of the plant. A flower can be found individually or in inflorescences. We went to the science lab to dissect a hibiscus flower and view the different parts of the plants reproductive system. We found out that a complete flower should have a pedicel, a receptacle, sepals, petals, stamens and carpels.

Pollination: 

Self pollination: pollen transferred within the same flower or the same plant. It is faster, easier and does not rely on external factors such as wind or animals. However, the young plant will be exactly the same as the parent plant and will have a lack of genes, which means that a single spread of disease could wipeout the entire species. The flowers of self pollinated plants do not bloom fully and often have their stigmas below their anthers.

Cross pollination: pollen transferred from one flower to another on different plants of the same species. Plants bear either only male or female flowers and their anthers and stigmas mature at different times to prevent self pollination. Cross pollination requires pollinators which can be wind or animals. Wind pollinated flowers have feathery stigmas, small, light pollen grains and are small and dull coloured. Animal pollinated flowers are usually brightly coloured, big, sweet smelling and have rough pollen grains.

Human Reproduction:

Sexual reproduction in humans occur during sexual intercourse between a male and female. The sperms from the male are released from the epididymis where they have been stored after being produced by the testes. The sperm passes through the prostate gland, which produces the seminal fluid in order to assist the sperm in their journey to the ovum. As for the female, menstruation occurs ever 28 days or so when the uterine lining breaks down and is discharged as waste. After that, the uterine lining thickens again as levels of progesterone rises. The fertile period of a woman is usually between day 14 and day 16 of her menstrual cycle. This is when the uterine lining, or endometrium, is the thickest and is prepared for the implantation of a fertilised egg. The sperm consists of a head, a mid-piece and a flagellum. The sperm uses its flagellum it swim up the fallopian tubes to fuse with the egg. Out of 5 million sperms, only one will fertilise the egg. The rest will die off within the span of 1 to 3 days. The mid-piece contains mitochondria, which provides energy for the sperm to be able to lash its flagellum to swim up the fallopian tube. When the sperm reaches the ovum, acrosomes will start digesting the walls of the ovum to enable the nucleus of the sperm to fuse with the egg. The head attaches to the egg and the rest of the sperm falls away. After fertilisation, The egg is implanted in the endometrium to protect the egg and prevent it from moving about to ensure successful development of the foetus. Here are some diagrams to help understanding of this topic:

The Anatomy of a Sperm Cell

Diagram of a Male Reproductive System

Female Reproductive System

However, sexual intercourse has risks of passing on Sexually Transmitted Diseases (STDs). STDs include Gonorrhea, Acquired ImmunoDeficiency Syndrome (AIDS), Syphilis and many others. Currently, there is no cure for AIDS and only cure for gonorrhea and syphilis if detected in its early stages. Both AIDS and syphilis can lead to horrible deaths. (pictures will not be shown as there may be  viewers who are unable to stomach those sights)
There are a few ways to prevent contraction of STDs. 

1) Contraceptions such as condoms and diaphragm caps prevent the sperm from entering the vagina

99% effective only as microscopic tears may be present in the device

A rolled up condom

2) Spermicide: a chemical which is sprayed inside the vagina to kill sperms upon entry

99.9% effective only as some sperms may develop a resistance to spermicide

Tube of Spermicide

3) Tracking of Menstrual cycle and not having sexual intercourse during the fertile period

Unreliable as it may not be accurate and is subjected to changes in hormone levels

4) Vasectomy or Ligation: 100% effective

Vasectomy refers to the cutting and tying of the sperm ducts to prevent sperms from entering the penis

Ligation refers to the cutting and tying of the oviducts to prevent the ovum from moving through the oviducts

Ligation

5) Abstinence: 100% effective.

My Reflections: (Plant) This topic is the simplest topic I have learnt so far. Firstly, this topic was taught in Primary school and I had quite a firm grounding in it. Secondly, due to my prolonged interest in biology and the constant spamming of chemistry in term 1, I was able to launch myself into this topic with greater enthusiasm than for other topics. Although I had to memorize parts of the flower, they are definitely more appealing to the eye and more recognizable than coloured balls floating around in rings (atom models). However, I had to spend less time on this topic as I was weaker in other topics. Unfortunately, the only topic which appealed to me so far was not covered in great detail and we did not spend as much time on it as we did on other more boring topics. I also realized that enjoying a topic makes memorizing information about the topic easier and less boring.

(Human) This topic was also taught in primary school and I do have some basic foundation in it. This topic is much more difficult than Plant reproduction as there are much more things to be memorized and much more things to take into consideration. Biology may be my interest, but I am more interested in marine biology than studies on the human reproductive system. However, I still managed to spark a little more interest in this topic and make things easier for myself. :D