memories of hong wen
Pen down your memories of Hong Wen in your preferred form of presentation (songs, poems, powerpoint presentations, website, etc).
Some ideas to include:
- favourite moments (through the 6 yrs), e.g. excursions, lessons etc
- favourite teachers (what they have done for you)
- worst/embarassing moments
- favourite places/corners
- best friends made
- which part of hws you would like to preserve or have it brought to new school
- your wishes for the future of hws
expectations of your work:
- genuine, heartfelt, moving, funny, touching
i may be sharing your work with other teachers :)
deadline for submission: Wednesday 15 October
Monday, October 13, 2008
Tuesday, June 24, 2008
Wednesday, June 18, 2008
Genetically Modified (GM) food
here are some useful links to articles on gm food:
Harvest of Fear
GM food: Monster or Saviour
some links to videos on gm food:
GM: a solution for Africa
GM needed to fight banana wilt
Harvest of Fear
GM food: Monster or Saviour
some links to videos on gm food:
GM: a solution for Africa
GM needed to fight banana wilt
Tuesday, June 17, 2008
What are biofuels?
the following article is taken from http://news.bbc.co.uk/1/hi/sci/tech/6294133.stm
Biofuels are any kind of fuel made from living things, or from the waste they produce.
This is a very long and diverse list, including:
wood, wood chippings and straw
pellets or liquids made from wood
biogas (methane) from animals' excrement
ethanol, diesel or other liquid fuels made from processing plant material or waste oil
In recent years, the term "biofuel" has come to mean the last category - ethanol and diesel, made from crops including corn, sugarcane and rapeseed.
Bio-ethanol, an alcohol, is usually mixed with petrol, while biodiesel is either used on its own or in a mixture.
Pioneers such as Henry Ford and Rudolph Diesel designed cars and engines to run on biofuels. Before World War II, the UK and Germany both sold biofuels mixed with petrol or diesel made from crude oil; the availability of cheap oil later ensured market dominance.
Ethanol for fuel is made through fermentation, the same process which produces it in wine and beer. Biodiesel is made through a variety of chemical processes.
There is interest in trying biobutanol, another alcohol, in aviation fuel.
Are biofuels climate-friendly?
In principle, biofuels are a way of reducing greenhouse gas emissions compared to conventional transport fuels.
Burning the fuels releases carbon dioxide; but growing the plants absorbs a comparable amount of the gas from the atmosphere.
However, energy is used in farming and processing the crops, and this can make biofuels as polluting as petroleum-based fuels, depending on what is grown and how it is treated.
A recent UK government publication declared that biofuels reduced emissions "by 50-60% compared to fossil fuels".
Where are biofuels used?
Production of ethanol doubled globally between 2000 and 2005, with biodiesel output quadrupling.
Brazil leads the world in production and use, making about 16 billion litres per year of ethanol from its sugarcane industry.
Sixty percent of new cars can run on a fuel mix which includes 85% ethanol.
The European Union has a target for 2010 that 5.75% of transport fuels should come from biological sources, but the target is unlikely to be met.
The British government's Renewable Transport Fuel Obligation requires 5% of the fuel sold at the pump by 2010 to be biofuel.
In the US, the Renewable Fuels Standard aims to double the use of biofuels in transport by 2012.
What are the downsides?
From the environmental point of the view, the big issue is biodiversity.
With much of the western world's farmland already consisting of identikit fields of monocultured crops, the fear is that a major adoption of biofuels will reduce habitat for animals and wild plants still further.
Asian countries may be tempted to replace rainforest with more palm oil plantations, critics say.
If increased proportions of food crops such as corn or soy are used for fuel, that may push prices up, affecting food supplies for less prosperous citizens.
The mixed picture regarding the climate benefit of biofuels leads some observers to say that the priority should be reducing energy use; initiatives on biofuels detract attention from this, they say, and are more of a financial help to politically important farming lobbies than a serious attempt to cut greenhouse gas emissions.
There are few problems technically; engines can generally cope with the new fuels.
But current technologies limit production, because only certain parts of specific plants can be used.
The big hope is the so-called second-generation of biofuels, which will process the cellulose found in many plants. This should lead to far more efficient production using a much greater range of plants and plant waste.
Biofuels are any kind of fuel made from living things, or from the waste they produce.
This is a very long and diverse list, including:
wood, wood chippings and straw
pellets or liquids made from wood
biogas (methane) from animals' excrement
ethanol, diesel or other liquid fuels made from processing plant material or waste oil
In recent years, the term "biofuel" has come to mean the last category - ethanol and diesel, made from crops including corn, sugarcane and rapeseed.
Bio-ethanol, an alcohol, is usually mixed with petrol, while biodiesel is either used on its own or in a mixture.
Pioneers such as Henry Ford and Rudolph Diesel designed cars and engines to run on biofuels. Before World War II, the UK and Germany both sold biofuels mixed with petrol or diesel made from crude oil; the availability of cheap oil later ensured market dominance.
Ethanol for fuel is made through fermentation, the same process which produces it in wine and beer. Biodiesel is made through a variety of chemical processes.
There is interest in trying biobutanol, another alcohol, in aviation fuel.
Are biofuels climate-friendly?
In principle, biofuels are a way of reducing greenhouse gas emissions compared to conventional transport fuels.
Burning the fuels releases carbon dioxide; but growing the plants absorbs a comparable amount of the gas from the atmosphere.
However, energy is used in farming and processing the crops, and this can make biofuels as polluting as petroleum-based fuels, depending on what is grown and how it is treated.
A recent UK government publication declared that biofuels reduced emissions "by 50-60% compared to fossil fuels".
Where are biofuels used?
Production of ethanol doubled globally between 2000 and 2005, with biodiesel output quadrupling.
Brazil leads the world in production and use, making about 16 billion litres per year of ethanol from its sugarcane industry.
Sixty percent of new cars can run on a fuel mix which includes 85% ethanol.
The European Union has a target for 2010 that 5.75% of transport fuels should come from biological sources, but the target is unlikely to be met.
The British government's Renewable Transport Fuel Obligation requires 5% of the fuel sold at the pump by 2010 to be biofuel.
In the US, the Renewable Fuels Standard aims to double the use of biofuels in transport by 2012.
What are the downsides?
From the environmental point of the view, the big issue is biodiversity.
With much of the western world's farmland already consisting of identikit fields of monocultured crops, the fear is that a major adoption of biofuels will reduce habitat for animals and wild plants still further.
Asian countries may be tempted to replace rainforest with more palm oil plantations, critics say.
If increased proportions of food crops such as corn or soy are used for fuel, that may push prices up, affecting food supplies for less prosperous citizens.
The mixed picture regarding the climate benefit of biofuels leads some observers to say that the priority should be reducing energy use; initiatives on biofuels detract attention from this, they say, and are more of a financial help to politically important farming lobbies than a serious attempt to cut greenhouse gas emissions.
There are few problems technically; engines can generally cope with the new fuels.
But current technologies limit production, because only certain parts of specific plants can be used.
The big hope is the so-called second-generation of biofuels, which will process the cellulose found in many plants. This should lead to far more efficient production using a much greater range of plants and plant waste.
Honda makes first hydrogen cars
the following article taken from http://news.bbc.co.uk/1/hi/business/7456141.stm
Japanese car manufacturer Honda has begun the first commercial production of a zero-emission, hydrogen fuel-cell powered vehicle.
The four-seater, called FCX Clarity, runs on electricity produced by combining hydrogen with oxygen, and emits water vapour.
Honda claims the vehicle offers three times better fuel efficiency than a traditional, petrol-powered car.
Honda plans to produce 200 of the cars over the next three years.
One of the biggest obstacles standing in the way of wider adoption of fuel-cell vehicles is the lack of hydrogen fuelling stations.
This is an important day in the history of fuel-cell vehicle technology
John Mendel, executive vice president of American Honda
Critics also point out that hydrogen is costly to produce and the most common way to produce hydrogen is still from fossil fuels.
Analysis of the environmental impact of different fuel technologies has shown that the overall carbon dioxide emissions from hydrogen powered cars can be higher than that from petrol or diesel-powered vehicles.
'Monumental step'
The first five customers are all based in southern California because of the proximity of hydrogen fuelling stations, Honda said.
US actress Jamie Lee Curtis will be among the first to take delivery of the vehicle, the firm added.
The car will initially be available for lease rather than purchase in California, starting in July, and then in Japan later this year.
It is being built on the world's first dedicated production line for fuel-cell vehicles in Japan.
"This is an important day in the history of fuel-cell vehicle technology and a monumental step closer to the day when fuel-cell cars will be part of the mainstream," said John Mendel, executive vice president of American Honda.
How the technology works
Honda says it expects to lease a few dozen units in the US and Japan in 2008, and about 200 units within three years.
It said the cost of the car, on a three-year lease, would be $600 (£300) a month.
The FCX Clarity is based on Honda's first-generation hydrogen fuel-cell vehicle, the FCX concept car. Honda delivered around 34 of these cars, mainly in the US, of which 10 remain in use.
Booming demand
Many car makers are developing cleaner, more economical vehicles because of high fuel prices and as consumers become more concerned with the environment.
Toyota said it was struggling to keep up with booming demand for its hybrid vehicles because it was unable to make enough batteries.
Hybrid vehicles, such as Toyota's top-selling Prius, switch between a petrol engine and electric motor.
Toyota Motor Corp's executive vice president, Takeshi Uchiyamada, told the Associated Press that new battery production lines could not be added until next year.
"Hybrids are selling so well we are doing all we can to increase production," he said. "We need new lines."
Volkswagen, Europe's biggest car maker said on Monday it wanted to produce a Golf which consumed three to four litres of petrol per 100 kilometres compared with 4.3 litres currently for the most fuel-efficient model.
"In the next few years, we are not going to do without petrol and diesel motors, but the future belongs to the electric car," VW chairman Martin Winterkorn told German newspaper Bild-Zeitung.
Japanese car manufacturer Honda has begun the first commercial production of a zero-emission, hydrogen fuel-cell powered vehicle.
The four-seater, called FCX Clarity, runs on electricity produced by combining hydrogen with oxygen, and emits water vapour.
Honda claims the vehicle offers three times better fuel efficiency than a traditional, petrol-powered car.
Honda plans to produce 200 of the cars over the next three years.
One of the biggest obstacles standing in the way of wider adoption of fuel-cell vehicles is the lack of hydrogen fuelling stations.
This is an important day in the history of fuel-cell vehicle technology
John Mendel, executive vice president of American Honda
Critics also point out that hydrogen is costly to produce and the most common way to produce hydrogen is still from fossil fuels.
Analysis of the environmental impact of different fuel technologies has shown that the overall carbon dioxide emissions from hydrogen powered cars can be higher than that from petrol or diesel-powered vehicles.
'Monumental step'
The first five customers are all based in southern California because of the proximity of hydrogen fuelling stations, Honda said.
US actress Jamie Lee Curtis will be among the first to take delivery of the vehicle, the firm added.
The car will initially be available for lease rather than purchase in California, starting in July, and then in Japan later this year.
It is being built on the world's first dedicated production line for fuel-cell vehicles in Japan.
"This is an important day in the history of fuel-cell vehicle technology and a monumental step closer to the day when fuel-cell cars will be part of the mainstream," said John Mendel, executive vice president of American Honda.
How the technology works
Honda says it expects to lease a few dozen units in the US and Japan in 2008, and about 200 units within three years.
It said the cost of the car, on a three-year lease, would be $600 (£300) a month.
The FCX Clarity is based on Honda's first-generation hydrogen fuel-cell vehicle, the FCX concept car. Honda delivered around 34 of these cars, mainly in the US, of which 10 remain in use.
Booming demand
Many car makers are developing cleaner, more economical vehicles because of high fuel prices and as consumers become more concerned with the environment.
Toyota said it was struggling to keep up with booming demand for its hybrid vehicles because it was unable to make enough batteries.
Hybrid vehicles, such as Toyota's top-selling Prius, switch between a petrol engine and electric motor.
Toyota Motor Corp's executive vice president, Takeshi Uchiyamada, told the Associated Press that new battery production lines could not be added until next year.
"Hybrids are selling so well we are doing all we can to increase production," he said. "We need new lines."
Volkswagen, Europe's biggest car maker said on Monday it wanted to produce a Golf which consumed three to four litres of petrol per 100 kilometres compared with 4.3 litres currently for the most fuel-efficient model.
"In the next few years, we are not going to do without petrol and diesel motors, but the future belongs to the electric car," VW chairman Martin Winterkorn told German newspaper Bild-Zeitung.
Wednesday, May 28, 2008
Thursday, May 22, 2008
Tuesday, May 20, 2008
Microsoft WorldWide Telescope
Click Microsoft WorldWide Telescope to download
Microsoft WorldWide Telescope is a FREE virtual telescope software that enables you to explore the universe with the help of interactive star charts and high resolution imagery from some of the best land and sky based telescopes. You can manually explore the night sky for your geographical location or enjoy one of the many interactive tours that will take you on an educational journey across the universe, to visit the solar system, black holes, star clusters, nebula, cosmic events and more. WorldWide Telescope also supports the ASCOM platform which allows you to connect and control a compatible telescope directly to the software. Other features include real-time tracking of the night sky in your location, a finder scope to reveal details for any object, multiple sources for imagery, object search and filtering, and morel. WorldWide Telescope provides a user friendly interface, and is well suited for casual night sky explorers as well as more advanced star gazers and hobby astronomers...
Microsoft WorldWide Telescope is a FREE virtual telescope software that enables you to explore the universe with the help of interactive star charts and high resolution imagery from some of the best land and sky based telescopes. You can manually explore the night sky for your geographical location or enjoy one of the many interactive tours that will take you on an educational journey across the universe, to visit the solar system, black holes, star clusters, nebula, cosmic events and more. WorldWide Telescope also supports the ASCOM platform which allows you to connect and control a compatible telescope directly to the software. Other features include real-time tracking of the night sky in your location, a finder scope to reveal details for any object, multiple sources for imagery, object search and filtering, and morel. WorldWide Telescope provides a user friendly interface, and is well suited for casual night sky explorers as well as more advanced star gazers and hobby astronomers...
Sunday, May 04, 2008
China turns to algae-gobbling carp to clear fetid lakes
Remember what you have learnt about factors affecting the environment and food webs? Here is a news article taken from the straits times to show how it is relevant to our lives.
CHAOHU LAKE - THIS sprawling, jade-hued lake in eastern China is pleasant enough on a cool spring day. But when spring warms into sultry summer, Chaohu turns slimy and stinky as algae fed by sewage, farm and factory runoff bloom, leaving it toxic and undrinkable.
China's pollution busters, banking on a rather unorthodox approach, are hoping this summer might be different.
Across the country, officials desperate to meet a national goal of restoring China's severely polluted lakes by 2030 are dumping tonnes of voracious fish into lakes in hopes they will gobble up the algae infestations.
Other countries have tried this in sewage treatment pools or drinking water reservoirs - with mixed success - but nowhere else has it been attempted on such a large scale.
Workers dumped 1.6 million silver carp fry into Chaohu Lake in February in the largest such project in China. They expect each fish to eat about 45kg of algae as they grow, helping to ensure clean drinking water for more than a million people.
'We're trying to restore the ecological balance. That's the main principle,' Mr Che Jiahu, a local fisheries official, said in his chilly office in Zhongmiao, a small temple town on Chaohu's north shore. The village is a tourist attraction - when the algae is not in full bloom.
Officials also hope the carp will revive a local fishing industry nearly wiped out by pollution. They shrug off questions about the wisdom of consuming fish that feed on pollutant-laden algae.
'We've never heard of anyone getting sick from eating Chaohu's fish or aquatic products,' Mr Che said. The fish are not as tasty as when he was a child, he concedes, but 'still, I believe fish that eat the algae are safe.'
About 200km east of Chaohu, fisheries workers released 100 million whitebait fry in Taihu Lake in March, hoping they will eat up the nitrogen and phosphorous that feed algae blooms that forced the cutoff of water to millions of residents last summer.
Another 50 tonnes of whitebait and carp fry were dumped into Taihu last week to counter an unusually early algae bloom, said Mr Fan Xiao, an official with the Taihu Fishery Administration.
'We didn't really expect the first attempt to work right away,' he explained. 'This algae bloom makes us even more determined to carry on.'
It's not the first time China has resorted to novel strategies to combat stubborn problems.
In the 1950s leader Mao Zedong ordered farmers to bang pots and pans to scare sparrows away from grain fields. The experiment backfired. All sorts of birds too frightened to alight dropped dead from exhaustion, allowing an explosion of crop-devouring pests that they might otherwise have eaten.
In America, the use of carp to control algae in sewage treatment pools created problems when the nonnative fish escaped into waterways.
In China, that's less of a problem, because carp are an indigenous species that have been fished for centuries.
The tricky part is figuring out how many carp to put in a lake.
Too few, and the algae will still prevail. Too many, and the waste from the fish themselves may simply feed more algae blooms, experts warn.
The silver carp thrive on blue-green algae, which lurk in microscopic form until rising temperatures trigger a foul-smelling, often toxic bloom that saps the water of oxygen, killing fish and making it unhealthy to drink.
From the United States to Australia, such blooms are flourishing across the globe, fueled by warming temperatures and pollution.
In Israel, the use of silver carp and other filter-feeding fish in drinking water reservoirs has worked in some cases, and failed in others, says Ms Ana Milstein, an aquaculture expert there.
Others are more sceptical.
'Big, artificial fix'
China's undertaking 'sounds like a big, artificial fix, which from my experience doesn't often work and often leads to more unplanned problems,' says Mr Paul Csagoly, an expert who worked on a project to clear fish that had been introduced to eat grass in the Danube River.
History is replete with examples of the dangers of messing with Mother Nature.
Toxic cane toads imported for beetle eradication on sugar cane plantations are a threat to Australia's indigenous wildlife.
Mongooses introduced to the Hawaiian islands in the 19th century ended up doing more harm to native birds than to the rats they were meant to kill.
Still, the folks in Chaohu seem to figure they have little to lose.
A decade ago, the lake was already rated dangerously polluted.
Loans from the Asian Development Bank helped pay for upgrading some heavily polluting factories and building sewage treatment plants.
All to little avail. Two industrial cities of 5 million - Chaohu to the northeast and Hefei to the northwest - flank the lake, providing a steady diet of nitrogen, phosphorous and other nutrients to algae that last summer turned wide swaths of the lake a brilliant algae green, and then putrid black.
'Economic development has had a negative impact on the lake. We're just finding ways to counteract that,' Mr Che says.
The cleanup involves more than just stocking the lake with carp fry, says Mr Ding Zhisong, deputy director of Chaohu's environmental bureau. He shows off a grove of trees planted in contaminated silt dredged from the lake.
Dozens of fishing boats are moored nearby, their occupants busy mending nets and painting, since the lake is closed to fishing until mid-June.
The water's edge is a soapy froth mixed with trash; the only sign of aquatic life, a tiny freshwater shrimp meandering through thick green fronds of algae.
Most environmental experts warn against consuming carp and other bottom feeders from lakes such as Chaohu that are contaminated not just with algae but also with toxins such as lead, cadmium, mercury and arsenic.
Though the official government line is that the fish are fine, Prof Yvonne Sadovy, a Hong Kong University professor who sometimes meets with fisheries experts in China, said some of them have expressed concern.
While silver carp sometimes can consume toxic algae without becoming poisonous themselves, they also may absorb other contaminants, says Prof Celia Chen, a Dartmouth College professor who has researched how pollution affects the food chain.
'I would ask myself as a scientist and as a consumer, 'What would make me comfortable eating the fish?' and that would be knowing the fish tissue did not have contaminants in it,' she said in an e-mailed response to an inquiry.
She noted that most fish in China are never tested because of the expense involved.
'I wouldn't eat them on a regular basis,' she said. -- AP
CHAOHU LAKE - THIS sprawling, jade-hued lake in eastern China is pleasant enough on a cool spring day. But when spring warms into sultry summer, Chaohu turns slimy and stinky as algae fed by sewage, farm and factory runoff bloom, leaving it toxic and undrinkable.
China's pollution busters, banking on a rather unorthodox approach, are hoping this summer might be different.
Across the country, officials desperate to meet a national goal of restoring China's severely polluted lakes by 2030 are dumping tonnes of voracious fish into lakes in hopes they will gobble up the algae infestations.
Other countries have tried this in sewage treatment pools or drinking water reservoirs - with mixed success - but nowhere else has it been attempted on such a large scale.
Workers dumped 1.6 million silver carp fry into Chaohu Lake in February in the largest such project in China. They expect each fish to eat about 45kg of algae as they grow, helping to ensure clean drinking water for more than a million people.
'We're trying to restore the ecological balance. That's the main principle,' Mr Che Jiahu, a local fisheries official, said in his chilly office in Zhongmiao, a small temple town on Chaohu's north shore. The village is a tourist attraction - when the algae is not in full bloom.
Officials also hope the carp will revive a local fishing industry nearly wiped out by pollution. They shrug off questions about the wisdom of consuming fish that feed on pollutant-laden algae.
'We've never heard of anyone getting sick from eating Chaohu's fish or aquatic products,' Mr Che said. The fish are not as tasty as when he was a child, he concedes, but 'still, I believe fish that eat the algae are safe.'
About 200km east of Chaohu, fisheries workers released 100 million whitebait fry in Taihu Lake in March, hoping they will eat up the nitrogen and phosphorous that feed algae blooms that forced the cutoff of water to millions of residents last summer.
Another 50 tonnes of whitebait and carp fry were dumped into Taihu last week to counter an unusually early algae bloom, said Mr Fan Xiao, an official with the Taihu Fishery Administration.
'We didn't really expect the first attempt to work right away,' he explained. 'This algae bloom makes us even more determined to carry on.'
It's not the first time China has resorted to novel strategies to combat stubborn problems.
In the 1950s leader Mao Zedong ordered farmers to bang pots and pans to scare sparrows away from grain fields. The experiment backfired. All sorts of birds too frightened to alight dropped dead from exhaustion, allowing an explosion of crop-devouring pests that they might otherwise have eaten.
In America, the use of carp to control algae in sewage treatment pools created problems when the nonnative fish escaped into waterways.
In China, that's less of a problem, because carp are an indigenous species that have been fished for centuries.
The tricky part is figuring out how many carp to put in a lake.
Too few, and the algae will still prevail. Too many, and the waste from the fish themselves may simply feed more algae blooms, experts warn.
The silver carp thrive on blue-green algae, which lurk in microscopic form until rising temperatures trigger a foul-smelling, often toxic bloom that saps the water of oxygen, killing fish and making it unhealthy to drink.
From the United States to Australia, such blooms are flourishing across the globe, fueled by warming temperatures and pollution.
In Israel, the use of silver carp and other filter-feeding fish in drinking water reservoirs has worked in some cases, and failed in others, says Ms Ana Milstein, an aquaculture expert there.
Others are more sceptical.
'Big, artificial fix'
China's undertaking 'sounds like a big, artificial fix, which from my experience doesn't often work and often leads to more unplanned problems,' says Mr Paul Csagoly, an expert who worked on a project to clear fish that had been introduced to eat grass in the Danube River.
History is replete with examples of the dangers of messing with Mother Nature.
Toxic cane toads imported for beetle eradication on sugar cane plantations are a threat to Australia's indigenous wildlife.
Mongooses introduced to the Hawaiian islands in the 19th century ended up doing more harm to native birds than to the rats they were meant to kill.
Still, the folks in Chaohu seem to figure they have little to lose.
A decade ago, the lake was already rated dangerously polluted.
Loans from the Asian Development Bank helped pay for upgrading some heavily polluting factories and building sewage treatment plants.
All to little avail. Two industrial cities of 5 million - Chaohu to the northeast and Hefei to the northwest - flank the lake, providing a steady diet of nitrogen, phosphorous and other nutrients to algae that last summer turned wide swaths of the lake a brilliant algae green, and then putrid black.
'Economic development has had a negative impact on the lake. We're just finding ways to counteract that,' Mr Che says.
The cleanup involves more than just stocking the lake with carp fry, says Mr Ding Zhisong, deputy director of Chaohu's environmental bureau. He shows off a grove of trees planted in contaminated silt dredged from the lake.
Dozens of fishing boats are moored nearby, their occupants busy mending nets and painting, since the lake is closed to fishing until mid-June.
The water's edge is a soapy froth mixed with trash; the only sign of aquatic life, a tiny freshwater shrimp meandering through thick green fronds of algae.
Most environmental experts warn against consuming carp and other bottom feeders from lakes such as Chaohu that are contaminated not just with algae but also with toxins such as lead, cadmium, mercury and arsenic.
Though the official government line is that the fish are fine, Prof Yvonne Sadovy, a Hong Kong University professor who sometimes meets with fisheries experts in China, said some of them have expressed concern.
While silver carp sometimes can consume toxic algae without becoming poisonous themselves, they also may absorb other contaminants, says Prof Celia Chen, a Dartmouth College professor who has researched how pollution affects the food chain.
'I would ask myself as a scientist and as a consumer, 'What would make me comfortable eating the fish?' and that would be knowing the fish tissue did not have contaminants in it,' she said in an e-mailed response to an inquiry.
She noted that most fish in China are never tested because of the expense involved.
'I wouldn't eat them on a regular basis,' she said. -- AP
Colossal squid's big eye revealed
Read this online article about the colossal squid and how it is adapted to living in the depths of the ocean.
http://news.bbc.co.uk/1/hi/sci/tech/7374297.stm
http://news.bbc.co.uk/1/hi/sci/tech/7374297.stm
Monday, April 28, 2008
ICAS Science Competition
click here to access past year sample papers.
Primary 3 - Paper B
Primary 4 - Paper C
Primary 5 - Paper D
Primary 6 - Paper E
Primary 3 - Paper B
Primary 4 - Paper C
Primary 5 - Paper D
Primary 6 - Paper E
Tuesday, April 22, 2008
Revision for P4 pupils on Diversity and Cycles
P4 Science Topics
Living things (Diversity/Cycles)
1. Plants and animals in the local environment
http://www.bbc.co.uk/schools/scienceclips/ages/6_7/plants_animals_env.shtml
2. Variation
http://www.bbc.co.uk/schools/scienceclips/ages/6_7/variation.shtml
3. Growing plants
http://www.bbc.co.uk/schools/scienceclips/ages/5_6/growing_plants.shtml
4. Helping plants grow well
http://www.bbc.co.uk/schools/scienceclips/ages/7_8/plants_grow.shtml
Materials (Diversity)
1. Sorting and using materials
http://www.bbc.co.uk/schools/scienceclips/ages/5_6/sorting_using_mate.shtml
2. Grouping and changing materials
http://www.bbc.co.uk/schools/scienceclips/ages/6_7/grouping_materials.shtml
3. Characteristics of materials
http://www.bbc.co.uk/schools/scienceclips/ages/7_8/characteristics_materials.shtml
Magnets (Interactions)
1. Magnets and Springs
http://www.bbc.co.uk/schools/scienceclips/ages/7_8/magnets_springs.shtml
Matter (Cycle)
1. Gases, liquids and solids
http://www.bbc.co.uk/schools/ks2bitesize/science/activities/gases.shtml
2. Solids and liquids
http://www.bbc.co.uk/schools/ks2bitesize/science/activities/solids_liquids.shtml
3. Changing state
http://www.bbc.co.uk/schools/ks2bitesize/science/activities/changing_state.shtml
Living things (Diversity/Cycles)
1. Plants and animals in the local environment
http://www.bbc.co.uk/schools/scienceclips/ages/6_7/plants_animals_env.shtml
2. Variation
http://www.bbc.co.uk/schools/scienceclips/ages/6_7/variation.shtml
3. Growing plants
http://www.bbc.co.uk/schools/scienceclips/ages/5_6/growing_plants.shtml
4. Helping plants grow well
http://www.bbc.co.uk/schools/scienceclips/ages/7_8/plants_grow.shtml
Materials (Diversity)
1. Sorting and using materials
http://www.bbc.co.uk/schools/scienceclips/ages/5_6/sorting_using_mate.shtml
2. Grouping and changing materials
http://www.bbc.co.uk/schools/scienceclips/ages/6_7/grouping_materials.shtml
3. Characteristics of materials
http://www.bbc.co.uk/schools/scienceclips/ages/7_8/characteristics_materials.shtml
Magnets (Interactions)
1. Magnets and Springs
http://www.bbc.co.uk/schools/scienceclips/ages/7_8/magnets_springs.shtml
Matter (Cycle)
1. Gases, liquids and solids
http://www.bbc.co.uk/schools/ks2bitesize/science/activities/gases.shtml
2. Solids and liquids
http://www.bbc.co.uk/schools/ks2bitesize/science/activities/solids_liquids.shtml
3. Changing state
http://www.bbc.co.uk/schools/ks2bitesize/science/activities/changing_state.shtml
Friday, April 18, 2008
WebQuest on Animal Adaptations
Adaptations Adventure WebQuest
Some useful links to replace those that are not working in the webquest:
How animals have adapted to their environment
Animal Adaptations powerpoint
This is the same powerpoint presentation that is stored in the 6R folder in the projects area.
Amazing Animals
This website is good for those looking for adaptations of a particular animal.
Camouflage field book
Thursday, March 20, 2008
Environment
here is the website which we have used for our lesson on Environment:
ActiveScience - GSK
if you can find websites that are similar or even better, do drop me a note and i'll put up the links after looking through them.
one of best websites on our local environment is none other than habitatnews. i've never failed to be amazed by the variety of flora and fauna that could be found right here in singapore. do check it out!
ActiveScience - GSK
if you can find websites that are similar or even better, do drop me a note and i'll put up the links after looking through them.
one of best websites on our local environment is none other than habitatnews. i've never failed to be amazed by the variety of flora and fauna that could be found right here in singapore. do check it out!
Thursday, March 06, 2008
Pen spinning
something caught my eye the other day while i was invigilating the P6 classes during CA1 exams... a handful of kids were trying to spin their pens and making quite a din with their pens dropping all over the place...
even though pen spinning is not a required skill but still it makes for a neat trick to impress your friends :)
take a look at this video where 'cool' kids spin their pens like magic!
now while pen spinning looks fun and meaningless, there's science behind it as well! you need to find a pen that is somewhat longer than average and has its centre of gravity in the middle to make it easier to twirl around your thumb. if you are keen to learn how to spin your pen, watch the following video.
even though pen spinning is not a required skill but still it makes for a neat trick to impress your friends :)
take a look at this video where 'cool' kids spin their pens like magic!
now while pen spinning looks fun and meaningless, there's science behind it as well! you need to find a pen that is somewhat longer than average and has its centre of gravity in the middle to make it easier to twirl around your thumb. if you are keen to learn how to spin your pen, watch the following video.
Monday, February 18, 2008
Build a roller coaster!!
Hi kids, i found these websites where you can build your own roller-coaster.
*Warning: you might suffer from giddiness :p
- http://www.learner.org/interactives/parkphysics/coaster/
- http://www.abc.net.au/spark/games/rollercoaster.htm
- http://www.sci-quest.org/home/just_for_kids/coaster.phtml
- http://www.mhhe.com/physsci/physical/giambattista/roller/roller_coaster.html
14 challenges for next 50 years
Experts believe solving these problems will make life better for mankind:
1. Make solar energy affordable.
2. Provide energy from nuclear fusion.
3. Develop methods to capture carbon dioxide produced by burning fossil fuels and tackle global warming.
4. Manage the rate at which human activity removes nitrogen from the air, worsening global warming.
5. Provide access to clean water.
6. Restore and improve urban infrastructure while preserving the environment.
7. Advance health informatics so that doctors can track carefully patients' biological information.
8. Engineer better medicines.
9. Reverse engineer the brain and determine how it works.
10. Prevent nuclear terror by finding ways to protect energy sources.
11. Secure cyberspace from identity thefts and viruses.
12. Enhance virtual reality so that it can be used for training experts and treating patients.
13. Advance personalised learning by using Internet courses or virtual reality.
14. Engineer the tools for scientific discovery.
Which do you think is the most important?
1. Make solar energy affordable.
2. Provide energy from nuclear fusion.
3. Develop methods to capture carbon dioxide produced by burning fossil fuels and tackle global warming.
4. Manage the rate at which human activity removes nitrogen from the air, worsening global warming.
5. Provide access to clean water.
6. Restore and improve urban infrastructure while preserving the environment.
7. Advance health informatics so that doctors can track carefully patients' biological information.
8. Engineer better medicines.
9. Reverse engineer the brain and determine how it works.
10. Prevent nuclear terror by finding ways to protect energy sources.
11. Secure cyberspace from identity thefts and viruses.
12. Enhance virtual reality so that it can be used for training experts and treating patients.
13. Advance personalised learning by using Internet courses or virtual reality.
14. Engineer the tools for scientific discovery.
Which do you think is the most important?
Materials and Manufacturing
Challenges in the aviation industry
GLOBAL CHALLENGES:
Materials and manufacturing
- Titanium
Titanium is used in the aerospace industry because of its lightness, but cutting it to shape is challenging.
The tool bits of machines used to cut and shape the metal wear out easily.
Shards of titanium - the waste from the cutting process - have been known to stick to the piece of titanium being cut and become obstacles to manipulating the material.
Titanium has to be cut slowly, which does not augur well for an industry already plagued by delays in delivery of planes.
- Magnesium
This could be used as aircraft material, but it oxidises easily and is not easy to manipulate.
- Self-healing material
Aerospace researchers want to develop a material which, when cracked, can release an adhesive to seal the crack by itself.
- Composite material
This is getting popular in the industry for the external body of the plane.
But not much is known about how electricity is conducted by composite material, unlike metal whose properties are established. Information on its conductivity will have implications for flights amid lightning storms.
- The process
Research is being done on how components, damaged as they are delivered from the manufacturing plant, can be repaired.
- In operation
Titanium and nickel are valued in aerospace for their ability to withstand the high temperatures and pressures of combustion in aircraft engines, but technology in advanced cooling systems is also needed to prevent overheating.
- Inspection and testing
Composite materials are also becoming popular in the making of the external body of the plane, but engineers need to find a way of detecting cracks in a material which is made up of a mesh of different materials.
- Repair and maintenance
Every hour an aircraft is not in the air is money not coming in for airlines. The challenge, therefore, is to develop new techniques of maintaining and repairing aircraft parts without having to take them to a hangar elsewhere for disassembly.
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