Sunday, 8 June 2008

Geography notes on second term

Geography notes – earthquake and volcanic eruptions

1) Structure of earth: Crust: outer layer made up by solid rock,60-120km thick and its’ continents and oceans floor. Mantle is the inner layer that made up of molten rock as magma. Core is the innermost layer made up of iron and nickel, it’s very hot and high pressure.

2) The crust broken into plates. They move slowly by the convection of magma caused by thermal expansion, the boundary between plates are called plate boundary. Earthquakes and volcanic eruptions are mainly found along plate boundaries and they are result of boundary movement.

3) When the plates move oppositely, pressure builds up gradually, earthquake is result from releasing pressure suddenlyearth shake violently.

4) Cracks formed from moving of plates, gases, solid rocks and magma may forced out violently though out cracks, this is volcanic eruptions.

5) Earthquakes and ranked according to magnitude and we use Richter Scale to indicate earthquake.

6) Six effect of earthquake: (1)Collapse of buildingsmain cause of death and injuries. (2)Earthquake cause breakdown of gas and oil pipelineswidespread firelots of death and widespread destruction. (3)Breaking of rock, road and bridgedelaying rescue work. (4)It cause subsidence of land, landslides, dams collapseflooding. (5)Earthquake occurring under the sea may cause giant tidal wave(tsunami) and cause coastal flooding. (6)There are still aftershocks after the main earthquake, also victims may suffer from hunger and spread of diseases.

7) Four effects of volcanic eruption: (1)It release gases and most of them are poisonous and harmful to the health (e.g.). (2) Large rock fragments are thrown out as volcanic bombs and volcanic ash is released also, they buries building and farmland. (3)Hot magma flow known as lava flow destroy and burn everything up the way. (4)Volcanic ash or volcanic bombs may mix with rain water or melting snow and form mudflow and buries house and farmland.

8) Immediate measures: earthquake: send armies and rescues teams to search in rubble, settle them in temporary shelters, give them food, water and blankets, restoring communication, putting out fires and providing medical services.

9) Volcanic eruptions: divert flows away from human settlement.

10) Long-term measures: (1) Use sensitive instruments to give prediction and warning. (2) Use modern technology to make earthquake-proof design. (3)Reducing the pressure of cracks. (4)Land use zoning reduce loss from fire in high-risk areas. (4)Teaching.

Geography notes – farming

1) System of farming: (Input-> process -> output)

2) Types of farming: Types of output: livestock onlypastoral, crops onlyarable, bothmixed. Use of output: feed themselvessubsistence and sold for profitcommercial.

3) South China: small farm, labour input, machinery input, yield per unit of land, yield per farmer intensive farming, output: rice.

4) Australia outback: big farm, labour input, machinery input, yield per unit of land, yield per farmer extensive farming, output: cattle.

Problems of farming:

1) Extremes in rainfall: Australia get less than 500 mm rainfall per year, it’s hard to support growth of crops and large populations of cattle. South China always have typhoonsheavy rain, flooding.

2) Poor soil: In Australia half of land is infertile and in China soil erosion make soil thin and infertile.

3) Pests and diseases may result in crop failure or deaths of livestock

4) In mountainous areas, terrace are common and the land is steep and soil is thin. It’s hard to use machines and output is limited.

5) Australia is short of labour.

6) In China, urbanization happens and good farmland is taken away by houses and factories.

7) In China, farmers other don’t have money to buy machines, good seeds, fertilizers and pesticides. This limited their profit of output.

Ways to solve the problem:

1) Use machines to productivity and instead of labour. Machines can ploughing, sowing, harvesting and even milking.

2) Chemical fertilizers puts back some nutrients back to the soil, Pesticides kills and deter pests, weedicides kills unwanted plant.

3) Development of generically modified crops improve the quality.

4) Irrigation technology supplies water for a large area of farmland and it’s reliable.

The problem of scientific farming methods:

1) Those methods are too expensive that some farmers can’t pay for it.

2) Some of the farmers are poor educated so that they don’t know how to use the methods in correct way.

3) Using machines efficientlycut down tree and bushes to enlarge farm sizethe lost of windbreaks may lead to crop destroying by strong wind.

4) Machine may harden the soil that water may just flow over it.

5) Chemical fertilizers lack of organic matter that used to bind soil togetherafter several time, the soil is loosened and can easily be eroded, also, chemicals made rapid growth of algae in surrounding streams, the fish passing there may lack of oxygen and die.

6) Pesticides are poisonous and people may be poisoned if they eat it, also, pesticides may passed to other living organism through food chain.

7) Poor country can’t afford to research new seed and breeds, GM food are produced by changing/ removing some genes from crops, some people think that it can solve food problem but some think that this may change the neutral environment and hurt their health.

Science note unit 9 - force

IS note unit 9 – force

Three effect of force

- Change the speed (accelerate for same direction and slow down when opposes)

- Change the direction of motion

- Change the shape (when the force is larger than the force that hold the shape)

We Use Newton balance to measure the force and the unit is Newton (N).

A contract force opposing your force is called friction. They happens when two surfaces are in contact, it always opposes the motion of object. They come from the tiny bumps that the bumps on two surfaces catch each other. So that the rougher surface cause bigger friction. Also, when the object move through water or air, there’s friction too, the friction of air is called air friction or air resistance. Moving against friction can produce heat.

Three ways to reduce friction:

- Changing from sliding motion to rolling motion

- Moving object on a layer of air

- Streamlined object towards air friction

- Smoothen the surface (e.g. use lubricants)

Friction sometimes is useful too, e.g. pick up something.

Force of gravity is a non- contract force. It pulls thing direct downwards to the core of earth (or other object which known as universal gravitation, they attracts other objects toward it by their mass, but the force is too small that we can’t feel, force of gravity is only about the planet). The force on an object is known as weight, a weight of 1kg cause 10N force on gravity on Earth, force of gravity on Moon is 1/6 of Earth.

Action and Reaction

- They occurs in pairs

- The magnitude of force is exactly equal

- The force react in opposite direction

Rocket use that reaction by burning fuels to fly, the fuels are liquid oxygen and liquid hydrogen. They give a clean flame, burning reaction of this fuel (2H2+O2=>2H2O) and a high temperature, so that this is a big propulsion for rocket. There solid grain fuel also. In the middle of journey, the astronauts is weightless because the friction between the planets are offset.

Function of space suit:

maintain living environment of astronaut (e.g. body temperature, pressure, resistance radiation, treat body waste, supply oxygen and remove carbon dioxide, etc.

When the rocket backs to the atmosphere, it’s rise in temperature by heating effect. It can be reduces by insulating tiles and parachutes.

EPA note 6,7

EPA note unit 6, 7

Law is a set of binding rules by which every person and organization and society has to abide.

Three meaning of “rule of law”

The government must act and rule according to the law which serves as the basis for its legality.

Equality before the law is upheld.

The judiciary is independent of the executive and legislative branches.

Three importances of law and the rule of law:

Maintain order and security, prevent abuses of power and protect people’s freedoms and legal rights

Source of law:

The Basic Law of the HKSAR is the constitutional document of HKSAR.

Annex III of National Law are applied in HKSAR.

Laws in force in HK before handover including: Ordinances and subsidiary legislation, Common law and Chinese customary law (e.g. relation to land in NT)

The laws enacted by LegCo after handover is the major source.

Some international laws and conventions have been applied to HKSAR.

Law is effective only when it’s strictly enforced, law enforcement body is to maintain order. They are also restricted by the law so as to prevent power abuses.


They receives and investigates allegations of corruption that the complaint from public.

Examines the practices and procedures of gov. departments and public organizations.

Provide corruption prevention advices on request from private organizations.

Promote anti-corruption messages and regular corruption prevention training for stuff of public organizations and maintains regular contract with public organizations to promote good corporate governance and ethical practice.

Wednesday, 4 June 2008

IS notes unit 10,11 form 2

1) Acids (acidic substances) taste sour, fruits contain citric acid and soft drinks contain carbonic acid. Alkalis (Alkaline substances) are slippery. 2) Some natural materials contain pigments that changes colour in acid / alkalis, they are natural indicators. 3) Common acids in Lab.: hydrochloric acid, sulphuric acid and nitric acid. 4) Common alkalis in Lab.: sodium hydroxide and ammonia. 5) Litmus: Acids turn blue litmus blue and alkalis turn red litmus blue, if no change for both colour, it’s neutral. (Litmus solution or litmus paper which soaked in the litmus solution.) 6) Universal indicator: they show a wide range of colours depending on the degree of acidity or alkalinity of substances, pH paper is soaked in the universal indicator. pH scale shows the different colour to show their acidity or alkalinity from 0 to 14. Lower value is more acidic and higher value is more alkaline, 7 is neutral. 7) pH meter is as electronic appliance that measure the value accurately. 8) The pH value in daily: blood: 7.4; stomach juice:2; intestinal juice: 8.5, skin: 5.5 and soil: 6-8. 9) Test for hydrogen: burning splint, burn with a pop sound (explosion). 10) Corrosive effect of metal + acid => Hydrogen + salt , (energy release) Acids corrode metals but aluminium resistance from this because aluminium react with oxygen and form aluminium oxide which resistance from corroding. 11) Corrosive effect :acid +marble (-> Calcium carbonate)=> Carbon dioxide+ water (+ salt) 12) Rain water is slightly acidic because in air dissolves in rain water and form carbonic acid, when the pH value of rain water lower than 5.6, it’s acid rain. They formed because air pollutants such as sulphur dioxide and nitrogen oxides. 13) The acid rain will corroding stone(marble) structures, metal structures, damage forests and make the water be acidic where most aquatic life can’t live. It’s a regional problem that HKSARgov. and Guangdong Provincial gov. joined to control acid rain. They reduce the release pollutants form vehicles and power stations. We can use energy efficiently to reduce also. 14) Acids help to preserve food, they slow down their activities or even kill them. Vinegar is non-toxic solution that contains acetic(ethanoic) acid so they use vinegar as food preservative. 15) *higher pH value can slow down the browning effect. 16) Oven, drain cleanser contains sodium hydroxide, glass cleanser contains ammonia and toilet cleanser contains hydrochloric acid. 17) Neutralization: Acids + Alkalis => Salt + water 18) Daily use of neutralization: Antacid (alkaline) is used for excess acid in stomach, Baking soda for bee, ant and mosquito stings and vinegar for wasp stings, lime is alkali that neutralize the acidic soil. All chemical waste should be neutralize before dispose it. Also, lye is added to neutralize the acidity of glutinous rice and vinegar is used to neutralize the lye in noodles. 19) Strong acids or alkalis cause a burn, they are highly corrosive. When diluting a concentrated solution, we add it to water but not add water to solutions, adding them slowly and mix them when diluting. 20) We detect different stimuli (stimulus) with different sense organs, they sense with their own sensory cells. Eye→sight, ear→hearing, tongue→taste, nose→smell, skin→touch. 21) The parts of eye: Eyebrow, eyelash on the eye lid; Cornea is a clear layer in front of eye, help focusing light, Iris, changes the size to fit the amount of light going in, they have different colours refer to pigments; Pupil allows light go in the eye; focusing muscles help control the thickness of lens to focus image; Lens can change in thickness to focus light in retina; Retina contains light-sensitive cell and sends stimuli to brain by Optic nerve; Blind spot is in front of the optic nerve and we can’t sense light there, yellow spot is that most of the light-sensitive cell are there, protective coat (sclera) protects eyeball and maintain its’ shape. Aqueous Humor(watery fluid) is water in front of lens and Vitreous Humor is jelly-like fluid that behind lens. The light goes with an inverted image in the eye. 22) Cones cells sense colours in bright light, three types sensing for red, blue and green. They used to form colour images (no. 6M), rod cell form B&W images in dim light, 1 types only (no. 1.2 B) 23) Three reason for short sight: the lens stable to be thick, eyeball too long or focusing muscles too weak, three reason for long sight just the opposite.