Thursday, 29 October 2009
ROLLY POLLY IN KULACHI
WE HAVE BEEN USING A ROLLY POLLY DEVICE IN OUR SCHOOL TO MANAGE WASTE IN THE SCHOOL FOR MAKING BIO-MANURE FOR USING IN THE SCHOOL GARDEN.
Thursday, 30 July 2009
Thursday, 28 May 2009
ECO-DRIVING
Being a good driver is no more the sole criterion for getting a driving license… at least not in Britain. One has to show that he or she can be environment-friendly too by simply using fuel effectively. The British government has declared that from now fuel efficiency of teh vehicle would be made part of the driving test to help reduce polluting emissions, and to save money on energy bills.
Agropedia
Indian scientists have created an ‘agricultural Wikipedia’ to act as an online repository of agricultural information in the country. It would disseminate crop and region-specific information to researchers, students, farmers and agricultural extension workers, who share the knowledge with farmers. The site also has blogs and other platforms. The website currently contains information on nine crops — rice, wheat, chickpea, pigeon pea, vegetable pea, lychee, sugarcane, groundnut and sorghum. More topics will be added soon, after being validated through review and analysis by invited agricultural researchers. “It is hoped that even where farmers have no access to the Internet, the Agropedia information can be used as a basis for radio plays, for example,” says V. Balaji, head of knowledge management and sharing with the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), a partner in the project.
Ghg satellite
Japan has launched the world’s first greenhouse gas monitoring satellite into space. It is called Ibuki, which means ‘breath’. It will circle the planet every 100 minutes, gathering data to be shared with space and scientific organisations. It has three major mission objectives – to monitor the density of greenhouse gases precisely and frequently; to study the absorption and emission levels of greenhouse gases per continent or large country over a certain period of time; to establish advanced technologies essential for precise greenhouse gas observations. “The satellite is expected to play an important role in monitoring global environmental changes and look out for any small warning signs that could affect our future,” says a statement released by Japan Aerospace Exploration Agency (JAXA).
Medicines Made Of Cow Dung
Cow has been a part and parcel of our life since the time immemorial. In Gurukul Cow Shed, cows of high yielding breed are reared and their urine and dung are used for the preparation of so many medicines. All kinds of stomach related disorders are cured through the excreta of cow. Here soaps are also made by using cow urine which are very beneficial in skin related infections
cow-dung is also used to wax the floors in making Kolam ----a form of sandpainting of South India.
Kolam is a form of sandpainting that is drawn using rice powder by female members of the family in front of their home. It is widely practised by Hindus in South India. A Kolam is a sort of painted prayer — a line drawing composed of curved loops, drawn around a grid pattern of dots.
Kolams are thought to bestow prosperity to homes. Every morning in southern India, millions of women draw kolams on the ground with white rice powder. Through the day, the drawings get walked on, rained out, or blown around in the wind; new ones are made the next day. Every morning before sunrise, the floor is cleaned with water, the universal purifier, and the muddy floor is swept well for an even surface. The kolams are generally drawn while the surface is still damp so that it is held better. Occasionally, cow-dung is also used to wax the floors. Cow dung has antiseptic properties and hence provides a literal threshold of protection for the home. It also provides contrast with the white powder.
Decoration was not the sole purpose of a Kolam. In olden days, kolams used to be drawn in coarse rice flour, so that the ants don't have to work so hard for a meal. The rice powder is said to invite birds and other small critters to eat it, thus inviting other beings into one's home and everyday life: a daily tribute to harmonious co-existence. It is a sign of invitation to welcome all into the home, not the least of whom is Goddess Lakshmi, the Goddess of prosperity. The patterns range between geometric and mathematical line drawings around a matrix of dots to free form art work and closed shapes. Folklore has evolved to mandate that the lines must be completed so as to symbolically prevent evil spirits from entering the inside of the shapes, and thus are they prevented from entering the inside of the home.
3x3 dot all and only symmetry 9 Goddesses Swastika Kolam with a single cycle by Nagata S, each of which is corresponded to one of the nine Davi of the Hindu or the nine Muses in GreekIt used to be a matter of pride to be able to draw large complicated patterns without lifting the hand off the floor standing up in between. The month of Margazhi was eagerly awaited by young women, who would then showcase their skills by covering the entire width of the road with one big kolam.
The ritual kolam patterns created for occasions such as weddings can stretch all the way down streets. Patterns are often passed on generation to generation, from mother to daughter.
(from wikipedia)
COWDUNG CAKES
Indian women dry cow dung cakes for use as cooking fuel in Phoolpur village, about 45 kilometers (28 miles) east of Allahabad, India, Sunday, June 8, 2008.
Tuesday, 26 May 2009
Improvement of methanogenesis from cow dung and poultry litter waste digesters by addition of iron
Improvement of methanogenesis from cow dung and poultry litter waste digesters by addition of iron
Journal World Journal of Microbiology and Biotechnology
Publisher Springer Netherlands
When 50mM FeSO4 was added to cow dung and poultry litter waste which had been processed in daily-fed batch digesters, digesters subsequently unfed showed a faster conversion of substrate and overloaded digesters stabilized within 48 h. Early stabilization of digesters was achieved by adding 20 or 50mM FeSO4 though the latter concentration was faster. When 20mM FeSO4 was added to the daily-fed cow dung and poultry litter waste digesters, it increased methanogenesis by 40% and 42%, respectively, and increased the turnover rate of total solids, volatile solids and volatile fatty acids and the number of methanogens.
AUTHORS:-P. Preeti Rao and G. Seenayya
The authors are with the Department of Microbiology, Osmania University, Hyderabad-500007, India
Journal World Journal of Microbiology and Biotechnology
Publisher Springer Netherlands
When 50mM FeSO4 was added to cow dung and poultry litter waste which had been processed in daily-fed batch digesters, digesters subsequently unfed showed a faster conversion of substrate and overloaded digesters stabilized within 48 h. Early stabilization of digesters was achieved by adding 20 or 50mM FeSO4 though the latter concentration was faster. When 20mM FeSO4 was added to the daily-fed cow dung and poultry litter waste digesters, it increased methanogenesis by 40% and 42%, respectively, and increased the turnover rate of total solids, volatile solids and volatile fatty acids and the number of methanogens.
AUTHORS:-P. Preeti Rao and G. Seenayya
The authors are with the Department of Microbiology, Osmania University, Hyderabad-500007, India
Increased production of biogas from cowdung by adding other agricultural waste materials
Increased production of biogas from cowdung by adding other agricultural waste materials
R. D. Laura, M. A. Idnani
Division of Soil Science and Agricultural Chemistry, Indian Agricultural Research Institute, New Delhi, India
Abstract
It was found that the addition of nitrogenous materials, such as casein, urea or urine, increased the extem of decomposition of cowdung, resulting in higher gas production. The effect appears to be due to the maintenance of pH > 7 during fermentation. With the addition of urea or CaCO3, materials such as. dry leaves and cane sugar have yielded high proportions of methane in the gas mixtures and these additions also increased the rate of gas production by promoting anaerobic conditions in the medium. Addition of cellulose also increased the rate but the gas mixture obtained had a lower methane content.
--------------------------------------------------------------------------------
R. D. Laura, M. A. Idnani
Division of Soil Science and Agricultural Chemistry, Indian Agricultural Research Institute, New Delhi, India
Abstract
It was found that the addition of nitrogenous materials, such as casein, urea or urine, increased the extem of decomposition of cowdung, resulting in higher gas production. The effect appears to be due to the maintenance of pH > 7 during fermentation. With the addition of urea or CaCO3, materials such as. dry leaves and cane sugar have yielded high proportions of methane in the gas mixtures and these additions also increased the rate of gas production by promoting anaerobic conditions in the medium. Addition of cellulose also increased the rate but the gas mixture obtained had a lower methane content.
--------------------------------------------------------------------------------
GREEN BRICKS
We’ve covered the value of worm poop, and now it’s time for the merits of cow dung to come to the fore. EcoFaeBrick turns cattle waste into bricks that are greener, stronger and 20% lighter than regular clay bricks.
The Indonesian organization was set up earlier this year to tackle the problem of excessive waste in farming areas. From this, the ecological and economical solution of the Cow Dung Brick was born. There's no visible difference between a traditional brick and the dung brick—and before you ask, there's no smell either. Instead of using wood fire the dung bricks are fired using biogas, helping to further reduce carbon emissions. The new product also lets land be retained for farming, rather than being excavated for clay for conventional bricks, or becoming a health risk due to ‘too much dung’.
A green product that boosts the wealth of rural Indonesians, it's not hard to see why EcoFaeBrick came first in the 2009 Global Social Venture competition. The company has identified 22 areas around Indonesia that they want to expand the project to, plus 22 more in other parts of the world. One to support, or otherwise get involved with!
The Indonesian organization was set up earlier this year to tackle the problem of excessive waste in farming areas. From this, the ecological and economical solution of the Cow Dung Brick was born. There's no visible difference between a traditional brick and the dung brick—and before you ask, there's no smell either. Instead of using wood fire the dung bricks are fired using biogas, helping to further reduce carbon emissions. The new product also lets land be retained for farming, rather than being excavated for clay for conventional bricks, or becoming a health risk due to ‘too much dung’.
A green product that boosts the wealth of rural Indonesians, it's not hard to see why EcoFaeBrick came first in the 2009 Global Social Venture competition. The company has identified 22 areas around Indonesia that they want to expand the project to, plus 22 more in other parts of the world. One to support, or otherwise get involved with!
Sunday, 10 May 2009
Wednesday, 6 May 2009
The power of cow dung
A NEWSLETTER FOR YOUR REFERENCE
Siba Mohanty First Published : 08 Nov 2008 01:59:00 AM ISTLast Updated : 11 Nov 2008 01:17:53 AM IST
A silent revolution is taking place in Orissa to reduce greenhouse gas emissions. While policymakers and energy strategists are harping on the need to tap wind, solar, biomass and hydel power to meet the energy needs of India, this eastern state is going back to the good old days when cows provided most of the fuel. Cow power, if one may so describe it, is a demonstration of how traditional technology can be used to generate carbon credits and bring in the euros for end users living in far-flung villages.
Very recently, Orissa entered into a tie-up with a German bank to sell carbon reductions generated through biogas plants in the state. The pact between Orissa Renewable Development Agency (OREDA), the state government’s nodal agency for renewable and non-conventional energy sources, and KfW Bankengruppe will mean that around 11,000 biogas plants stand to gain from certified emission reductions (CER) — carbon credits issued under the clean development mechanism (CDM) — they trade with this foreign bank. Each plant would make about Rs 6,000 worth of CER a year.
This may sound modest when nuclear energy is the flavour of the season across the country. Nonetheless, it makes sense considering that the Union government is struggling to meet the energy needs of rural India. After all, electricity tariffs are slated to rise in the years to come, making power more of a mirage for the average user. Demand for power is so huge that even the 123 Agreement won’t mean much in the long run. Even by government estimates, civil nuclear energy will only produce about 20,000 MW by 2020, which is about 10 per cent of the total power generated in India. Renewable energy is, probably, a more convincing option.
For instance, biogas would not only meet the household energy requirements and enhance livelihood options for villagers; it would also reduce pressure on local forests, as people are so dependent on wood for fuel.
Biogas plants have many benefits. As OREDA chief executive Ajit Bharthuar explains, “The one-time cost of setting up a plant is Rs 9,000. While government gives a subsidy to the tune of Rs 3,000, the rest is borne by the individual. Once the benefits of CDM reach the end user, he/she is likely to get back his investment within a year-and-a-half even after some deduction for maintenance.” As per the OREDA-KfW Bankengruppe pact, the users will enter into an agreement with the state nodal agency to monitor the plants. Users have to pay the maintenance cost of Rs 1,500 a year while OREDA will provide the technical expertise.
But it is not all that easy. Biogas plants have, over the time, witnessed a slow growth — or even a collapsing trend — thanks to prevailing socio-economic conditions in the villages, a drastic change in lifestyle (call it penetration of LPG), technical problems and absence of adequate finances.
A recent survey showed a massive phasing out of the units that are either in operation or degraded due to ineffective use. Of the 64,144 units installed during 2000-2005, only 32,072 plants are in use. About 11,000 plants set up during 2006-08 are in operation. As per the Kyoto Protocol, units installed after 2006 will be eligible for CDM.
“The reason why we incorporated carbon credit scheme for biogas was to modify the gas transmission system and promote continuous use of plants to develop a good environmental integrity in a sustainable manner,” says Bharthuar. About 7,000 plants that add up every year too may come under CDM.
What OREDA is looking at in terms of greenhouse gases reduction — ultimately fetching the users CERs — is pretty impressive. An estimate says it aims at 75,435 tonnes of carbon dioxide in 2009 which will rise to 1,03,497 tonnes of the gas in 2010. In 2018, the amount of reduction would have stood at 1,31,559 tonnes of CO2. Cumulatively, the plants would have reduced a whopping 12,31,403 tonnes of dangerous carbon dioxide from the atmosphere. That’s something to cheer about, for sure.
Carbon trading can be either done through the regulated mode or in the voluntary market. Since the regulated market calls for stringent guidelines that the plant users are unlikely to meet, OREDA has decided to go the voluntary way even though the earnings are less. If a tonne of CER in regulated market fetches about 17 euros, the same in a voluntary market can range between 13 and 4 euros.
OREDA is taking the chance and even hopes to strike the best price available. It is also planning to bring under CDM units that have remained out of operation during 2000-05 through a bundling project. Over 2.2 lakh biogas plants have been set up across Orissa under National Biogas and Manure Management Programme since 1981-82, while the capacity is well over 4 lakh.
A New and Renewable Energy Ministry report says India has generated 12.6 GW of power from renewable resources and plans to generate 20 per cent of its total energy from renewable sources in 12 years. With climate change slated to determine global energy policies in the years to come, renewable sour- ces could just be the order of the day.
Siba Mohanty First Published : 08 Nov 2008 01:59:00 AM ISTLast Updated : 11 Nov 2008 01:17:53 AM IST
A silent revolution is taking place in Orissa to reduce greenhouse gas emissions. While policymakers and energy strategists are harping on the need to tap wind, solar, biomass and hydel power to meet the energy needs of India, this eastern state is going back to the good old days when cows provided most of the fuel. Cow power, if one may so describe it, is a demonstration of how traditional technology can be used to generate carbon credits and bring in the euros for end users living in far-flung villages.
Very recently, Orissa entered into a tie-up with a German bank to sell carbon reductions generated through biogas plants in the state. The pact between Orissa Renewable Development Agency (OREDA), the state government’s nodal agency for renewable and non-conventional energy sources, and KfW Bankengruppe will mean that around 11,000 biogas plants stand to gain from certified emission reductions (CER) — carbon credits issued under the clean development mechanism (CDM) — they trade with this foreign bank. Each plant would make about Rs 6,000 worth of CER a year.
This may sound modest when nuclear energy is the flavour of the season across the country. Nonetheless, it makes sense considering that the Union government is struggling to meet the energy needs of rural India. After all, electricity tariffs are slated to rise in the years to come, making power more of a mirage for the average user. Demand for power is so huge that even the 123 Agreement won’t mean much in the long run. Even by government estimates, civil nuclear energy will only produce about 20,000 MW by 2020, which is about 10 per cent of the total power generated in India. Renewable energy is, probably, a more convincing option.
For instance, biogas would not only meet the household energy requirements and enhance livelihood options for villagers; it would also reduce pressure on local forests, as people are so dependent on wood for fuel.
Biogas plants have many benefits. As OREDA chief executive Ajit Bharthuar explains, “The one-time cost of setting up a plant is Rs 9,000. While government gives a subsidy to the tune of Rs 3,000, the rest is borne by the individual. Once the benefits of CDM reach the end user, he/she is likely to get back his investment within a year-and-a-half even after some deduction for maintenance.” As per the OREDA-KfW Bankengruppe pact, the users will enter into an agreement with the state nodal agency to monitor the plants. Users have to pay the maintenance cost of Rs 1,500 a year while OREDA will provide the technical expertise.
But it is not all that easy. Biogas plants have, over the time, witnessed a slow growth — or even a collapsing trend — thanks to prevailing socio-economic conditions in the villages, a drastic change in lifestyle (call it penetration of LPG), technical problems and absence of adequate finances.
A recent survey showed a massive phasing out of the units that are either in operation or degraded due to ineffective use. Of the 64,144 units installed during 2000-2005, only 32,072 plants are in use. About 11,000 plants set up during 2006-08 are in operation. As per the Kyoto Protocol, units installed after 2006 will be eligible for CDM.
“The reason why we incorporated carbon credit scheme for biogas was to modify the gas transmission system and promote continuous use of plants to develop a good environmental integrity in a sustainable manner,” says Bharthuar. About 7,000 plants that add up every year too may come under CDM.
What OREDA is looking at in terms of greenhouse gases reduction — ultimately fetching the users CERs — is pretty impressive. An estimate says it aims at 75,435 tonnes of carbon dioxide in 2009 which will rise to 1,03,497 tonnes of the gas in 2010. In 2018, the amount of reduction would have stood at 1,31,559 tonnes of CO2. Cumulatively, the plants would have reduced a whopping 12,31,403 tonnes of dangerous carbon dioxide from the atmosphere. That’s something to cheer about, for sure.
Carbon trading can be either done through the regulated mode or in the voluntary market. Since the regulated market calls for stringent guidelines that the plant users are unlikely to meet, OREDA has decided to go the voluntary way even though the earnings are less. If a tonne of CER in regulated market fetches about 17 euros, the same in a voluntary market can range between 13 and 4 euros.
OREDA is taking the chance and even hopes to strike the best price available. It is also planning to bring under CDM units that have remained out of operation during 2000-05 through a bundling project. Over 2.2 lakh biogas plants have been set up across Orissa under National Biogas and Manure Management Programme since 1981-82, while the capacity is well over 4 lakh.
A New and Renewable Energy Ministry report says India has generated 12.6 GW of power from renewable resources and plans to generate 20 per cent of its total energy from renewable sources in 12 years. With climate change slated to determine global energy policies in the years to come, renewable sour- ces could just be the order of the day.
What about BIO GAS ???? from cowdung !!!
Enclose a volume of cow patties and urine add enough water to cover, Stir and stir till you make a creamy mixture. Put on a tight lid with a pipe screwed to the lid some where, attach a hose to the pipe, add a valve, and the other end of the hose going to an inner tube, add warmth and Presto three to fourteen days later the cow pies are magically transformed to BIO GAS. Suitable for cooking, or running a generator (its only half as hot as propane so you need twice as much). Fortunately cows are free with their organic
uses of cow dung
1. Fuel - cow dung patties (gootte) for cooking
2. Fertilizer - composting makes it even more powerful
3. Heat source - cow dung is naturally hot -compost makes hotter put in glass house to heat glass house or run pipes thru it to get hot water.
3. Purifier - natural antiseptic qualities
4. Floor coating - used mixed with mud and water on floors in mud houses. Improves water absorption of mud. Prevents muddy puddles resulting from spilt water.
5. Mud brick additive - improves resistance to disintegration
6. Skin tonic - mixed with crushed neem leaves smeared on skin - good for boils and heat rash (SP used it for heat rash in Mayapur.)
7. Smoke producer - smoldering cow patties keep away mosquitoes. Can also make smoked paneer over such smoke. Tastes great in pasta! :)
Ash - from patties used in cooking. -
8. Pot cleaner - used dry absorbs oil and fat wet as a general cleaner
9. Brass polisher - tamarind removes oxidation - wet ashes polishes
10. Fertilizer - alkaline - cow dung ash is basically lime with a few other mineral mixed in
11. Mud additive - dries up slippery mud puddles
12. Mud brick additive - mud and lime (cow dung ashes) becomes like cement
13. Pond PH balancer - thrown into pond neutralizes acid.
14. Tooth polish -
15. Sun-dried organic recreational-aerodynamic-device -cow patty Frisbees ;)
16. Fan for fire - large cow patties can be used as make shift fans.
17. Deity worship - ingredient in panca gavya
2. Fertilizer - composting makes it even more powerful
3. Heat source - cow dung is naturally hot -compost makes hotter put in glass house to heat glass house or run pipes thru it to get hot water.
3. Purifier - natural antiseptic qualities
4. Floor coating - used mixed with mud and water on floors in mud houses. Improves water absorption of mud. Prevents muddy puddles resulting from spilt water.
5. Mud brick additive - improves resistance to disintegration
6. Skin tonic - mixed with crushed neem leaves smeared on skin - good for boils and heat rash (SP used it for heat rash in Mayapur.)
7. Smoke producer - smoldering cow patties keep away mosquitoes. Can also make smoked paneer over such smoke. Tastes great in pasta! :)
Ash - from patties used in cooking. -
8. Pot cleaner - used dry absorbs oil and fat wet as a general cleaner
9. Brass polisher - tamarind removes oxidation - wet ashes polishes
10. Fertilizer - alkaline - cow dung ash is basically lime with a few other mineral mixed in
11. Mud additive - dries up slippery mud puddles
12. Mud brick additive - mud and lime (cow dung ashes) becomes like cement
13. Pond PH balancer - thrown into pond neutralizes acid.
14. Tooth polish -
15. Sun-dried organic recreational-aerodynamic-device -cow patty Frisbees ;)
16. Fan for fire - large cow patties can be used as make shift fans.
17. Deity worship - ingredient in panca gavya
uses of cow dung
Uses
In many parts of the developing world, cow dung is used as a fertilizer and fuel. Caked and dried cow dung is used as a fuel to cook food in many parts of Asia and Africa.
In recent times, the dung is collected and used to produce biogas to generate electricity and heat. The gas is a rich source of methane and is used in rural areas of India and elsewhere to provide a renewable and stable source of electricity.
Cow dung is also used to line the floor and walls of buildings owing to its insect repellent properties. In cold places, cow dung is used to line the walls of rustic houses as a cheap thermal insulator.
It was also used extensively on Indian Railways to seal smokeboxes on steam locomotives.[citation needed]
Cow dung is also an optional ingredient in the manufacture of adobe mud brick housing depending on the availability of materials at hand.[1]
In many parts of the developing world, cow dung is used as a fertilizer and fuel. Caked and dried cow dung is used as a fuel to cook food in many parts of Asia and Africa.
In recent times, the dung is collected and used to produce biogas to generate electricity and heat. The gas is a rich source of methane and is used in rural areas of India and elsewhere to provide a renewable and stable source of electricity.
Cow dung is also used to line the floor and walls of buildings owing to its insect repellent properties. In cold places, cow dung is used to line the walls of rustic houses as a cheap thermal insulator.
It was also used extensively on Indian Railways to seal smokeboxes on steam locomotives.[citation needed]
Cow dung is also an optional ingredient in the manufacture of adobe mud brick housing depending on the availability of materials at hand.[1]
cow dung
Cow dung is the waste of bovine animal species. These species include domestic cattle ("cows"), bison ("buffalo"), yak and water buffalo. Cow dung is the undigested residue of herbivorous matter which has passed through the animal's gut. The resultant faecal matter is rich in minerals. Colour ranges from greenish to blackish, often darkening in colour soon after exposure to air.
Thursday, 16 April 2009
WHAT IS MATTER?
ANYTHING THAT OCCUPIIES
SPACE AND HAS MASS
IS MATTER.
MATTER ----- THE FIRST WORD IN THE LANGUAGE OF CHEMISTRY.
ANYTHING THAT WE SEE, TOUCH OR FEEL IS CALLED MATTER.
THE BONES AND FLESH OF YOUR BODY IS CALLED MATTER.
THE FABRIC OF YOUR CLOTHES IS MATTER.
THE FOOD YOU EAT IS MATTER.
THE WATER YOU DRINK IS MATTER.
THE AIR YOU BREATHE IS MATTER.
WHAT IS NOT MATTER?
THINGS WHICH DON’T HAVE WEIGHT AND DON’T OCCUPY SPACE ARE CALLED NON MATTER.
RADIO AND TELEVISION SIGNALS ARE NOT MATTER.
OUR FEELINGS OF LOVE AND HAPPINESS ARE ALSO NON MATTER.
INTELLIGENCE AND VIRTUES ARE ALSO NON MATTER.
SPACE AND HAS MASS
IS MATTER.
MATTER ----- THE FIRST WORD IN THE LANGUAGE OF CHEMISTRY.
ANYTHING THAT WE SEE, TOUCH OR FEEL IS CALLED MATTER.
THE BONES AND FLESH OF YOUR BODY IS CALLED MATTER.
THE FABRIC OF YOUR CLOTHES IS MATTER.
THE FOOD YOU EAT IS MATTER.
THE WATER YOU DRINK IS MATTER.
THE AIR YOU BREATHE IS MATTER.
WHAT IS NOT MATTER?
THINGS WHICH DON’T HAVE WEIGHT AND DON’T OCCUPY SPACE ARE CALLED NON MATTER.
RADIO AND TELEVISION SIGNALS ARE NOT MATTER.
OUR FEELINGS OF LOVE AND HAPPINESS ARE ALSO NON MATTER.
INTELLIGENCE AND VIRTUES ARE ALSO NON MATTER.
Sunday, 29 March 2009
Wednesday, 25 March 2009
food chart making activity
All class VI students are to do the food chart making activity!
RECORD YOUR STATE OF HEALTH IN YOUR NOTEBOOK.
PREPARE A FOOD CHART FOR YOURSELF ACCORDING TO THE CLASSROOM DISCUSSION AND STICK TO THE SAME FOR AT LEAST ONE WEEK.
RECORD YOUR STATE OF HEALTH AFTER ONE WEEK AGAIN IN YOUR NOTEBOOK.
COMPARE THE 2 STATES OF YOUR HEALTH.
WHAT DO YOU INFER FROM THIS?
BALANCED DIET IS THE KEY TO A WONDERFUL STATE OF HEALTH FOR ALL.
PROMISE TO YOURSELF TO CONTINUE EATING A BALANCED DIET FOREVER.
RECORD YOUR STATE OF HEALTH IN YOUR NOTEBOOK.
PREPARE A FOOD CHART FOR YOURSELF ACCORDING TO THE CLASSROOM DISCUSSION AND STICK TO THE SAME FOR AT LEAST ONE WEEK.
RECORD YOUR STATE OF HEALTH AFTER ONE WEEK AGAIN IN YOUR NOTEBOOK.
COMPARE THE 2 STATES OF YOUR HEALTH.
WHAT DO YOU INFER FROM THIS?
BALANCED DIET IS THE KEY TO A WONDERFUL STATE OF HEALTH FOR ALL.
PROMISE TO YOURSELF TO CONTINUE EATING A BALANCED DIET FOREVER.
Wednesday, 11 February 2009
Just a thought
Listen to the Exhortation of the Dawn!
Look to this Day!
For it is Life, the very Life of Life.
In its brief course lie all the
Verities and Realities of our Existence.
The Bliss of Growth,
The Glory of Action,
The Splendor of Beauty;
For Yesterday is but a Dream,
And To-morrow is only a Vision;
But To-day well lived makes
Every Yesterday a Dream of Happiness,
And every Tomorrow a Vision of Hope.
Look well therefore to this Day!
Such is the Salutation of the Dawn!
Keep doing good! Keep feeling good!
Look to this Day!
For it is Life, the very Life of Life.
In its brief course lie all the
Verities and Realities of our Existence.
The Bliss of Growth,
The Glory of Action,
The Splendor of Beauty;
For Yesterday is but a Dream,
And To-morrow is only a Vision;
But To-day well lived makes
Every Yesterday a Dream of Happiness,
And every Tomorrow a Vision of Hope.
Look well therefore to this Day!
Such is the Salutation of the Dawn!
Keep doing good! Keep feeling good!
Sunday, 8 February 2009
solar eclipse
The Moon's Two Shadows
An eclipse of the Sun (or solar eclipse) can only occur at New Moon when the Moon passes between Earth and Sun. If the Moon's shadow happens to fall upon Earth's surface at that time, we see some portion of the Sun's disk covered or 'eclipsed' by the Moon. Since New Moon occurs every 29 1/2 days, you might think that we should have a solar eclipse about once a month. Unfortunately, this doesn't happen because the Moon's orbit around Earth is tilted 5 degrees to Earth's orbit around the Sun. As a result, the Moon's shadow usually misses Earth as it passes above or below our planet at New Moon. At least twice a year, the geometry lines up just right so that some part of the Moon's shadow falls on Earth's surface and an eclipse of the Sun is seen from that region.
The Moon's shadow actually has two parts:
1. Penumbra
The Moon's faint outer shadow.
Partial solar eclipses are visible from within the penumbral shadow.
2. Umbra
The Moon's dark inner shadow.
Total solar eclipses are visible from within the umbral shadow.
When the Moon's penumbral shadow strikes Earth, we see a partial eclipse of the Sun from that region. Partial eclipses are dangerous to look at because the un-eclipsed part of the Sun is still very bright. You must use special filters or a home-made pinhole projector to safely watch a partial eclipse of the Sun (see: Observing Solar Eclipses Safely).
What is the difference between a solar eclipse and a lunar eclipse? A lunar eclipse is an eclipse of the Moon rather than the Sun. It happens when the Moon passes through Earth's shadow. This is only possible when the Moon is in the Full Moon phase.
An eclipse of the Sun (or solar eclipse) can only occur at New Moon when the Moon passes between Earth and Sun. If the Moon's shadow happens to fall upon Earth's surface at that time, we see some portion of the Sun's disk covered or 'eclipsed' by the Moon. Since New Moon occurs every 29 1/2 days, you might think that we should have a solar eclipse about once a month. Unfortunately, this doesn't happen because the Moon's orbit around Earth is tilted 5 degrees to Earth's orbit around the Sun. As a result, the Moon's shadow usually misses Earth as it passes above or below our planet at New Moon. At least twice a year, the geometry lines up just right so that some part of the Moon's shadow falls on Earth's surface and an eclipse of the Sun is seen from that region.
The Moon's shadow actually has two parts:
1. Penumbra
The Moon's faint outer shadow.
Partial solar eclipses are visible from within the penumbral shadow.
2. Umbra
The Moon's dark inner shadow.
Total solar eclipses are visible from within the umbral shadow.
When the Moon's penumbral shadow strikes Earth, we see a partial eclipse of the Sun from that region. Partial eclipses are dangerous to look at because the un-eclipsed part of the Sun is still very bright. You must use special filters or a home-made pinhole projector to safely watch a partial eclipse of the Sun (see: Observing Solar Eclipses Safely).
What is the difference between a solar eclipse and a lunar eclipse? A lunar eclipse is an eclipse of the Moon rather than the Sun. It happens when the Moon passes through Earth's shadow. This is only possible when the Moon is in the Full Moon phase.
The Moon's Two Shadows
An eclipse of the Sun (or solar eclipse) can only occur at New Moon when the Moon passes between Earth and Sun. If the Moon's shadow happens to fall upon Earth's surface at that time, we see some portion of the Sun's disk covered or 'eclipsed' by the Moon. Since New Moon occurs every 29 1/2 days, you might think that we should have a solar eclipse about once a month. Unfortunately, this doesn't happen because the Moon's orbit around Earth is tilted 5 degrees to Earth's orbit around the Sun. As a result, the Moon's shadow usually misses Earth as it passes above or below our planet at New Moon. At least twice a year, the geometry lines up just right so that some part of the Moon's shadow falls on Earth's surface and an eclipse of the Sun is seen from that region.
The Moon's shadow actually has two parts:
1. Penumbra
The Moon's faint outer shadow.
Partial solar eclipses are visible from within the penumbral shadow.
2. Umbra
The Moon's dark inner shadow.
Total solar eclipses are visible from within the umbral shadow.
When the Moon's penumbral shadow strikes Earth, we see a partial eclipse of the Sun from that region. Partial eclipses are dangerous to look at because the un-eclipsed part of the Sun is still very bright. You must use special filters or a home-made pinhole projector to safely watch a partial eclipse of the Sun (see: Observing Solar Eclipses Safely).
What is the difference between a solar eclipse and a lunar eclipse? A lunar eclipse is an eclipse of the Moon rather than the Sun. It happens when the Moon passes through Earth's shadow. This is only possible when the Moon is in the Full Moon phase.
An eclipse of the Sun (or solar eclipse) can only occur at New Moon when the Moon passes between Earth and Sun. If the Moon's shadow happens to fall upon Earth's surface at that time, we see some portion of the Sun's disk covered or 'eclipsed' by the Moon. Since New Moon occurs every 29 1/2 days, you might think that we should have a solar eclipse about once a month. Unfortunately, this doesn't happen because the Moon's orbit around Earth is tilted 5 degrees to Earth's orbit around the Sun. As a result, the Moon's shadow usually misses Earth as it passes above or below our planet at New Moon. At least twice a year, the geometry lines up just right so that some part of the Moon's shadow falls on Earth's surface and an eclipse of the Sun is seen from that region.
The Moon's shadow actually has two parts:
1. Penumbra
The Moon's faint outer shadow.
Partial solar eclipses are visible from within the penumbral shadow.
2. Umbra
The Moon's dark inner shadow.
Total solar eclipses are visible from within the umbral shadow.
When the Moon's penumbral shadow strikes Earth, we see a partial eclipse of the Sun from that region. Partial eclipses are dangerous to look at because the un-eclipsed part of the Sun is still very bright. You must use special filters or a home-made pinhole projector to safely watch a partial eclipse of the Sun (see: Observing Solar Eclipses Safely).
What is the difference between a solar eclipse and a lunar eclipse? A lunar eclipse is an eclipse of the Moon rather than the Sun. It happens when the Moon passes through Earth's shadow. This is only possible when the Moon is in the Full Moon phase.
Tuesday, 20 January 2009
Saturday, 27 December 2008
Force Definition:
The product of mass (m) and acceleration (a). Newton's law of acceleration is used to derive the units of force. With the formula F = Ma in the SI system, one newton is the force needed to accelerate one kilogram of mass by one metre per square second.
Sunday, 14 December 2008
How energy is measured
One of the basic measuring blocks for energy is called a Btu or British thermal unit. Btu is defined as the amount of heat energy it takes to raise the temperature of 1 pound of water by 1 degree Fahrenheit, at sea level. One Btu equals about one black-tip kitchen match. It takes about 2000 Btu to make a pot of coffee.
Energy can also be measured in joules (pronounced the same way as ‘ jewels’). One joule is the amount of energy needed to lift 1 pound about 9 inches. It takes 1000 joules to equal a Btu. It would take 2 million joules to make a pot of coffee.
Joule is named after an English physicist named James Prescott Joule who lived from 1818 to 1889. He discovered that heat is a type of energy.
Around the world, scientists measure energy in joules rather than Btu. It is much like people around the world using the metric system, metres and kilograms. Like in the metric system, you can have kilojoules: ‘kilo’ means 1000, therefore, 1000 joules = 1 kilojoule = 1 Btu.
Energy can also be measured in joules (pronounced the same way as ‘ jewels’). One joule is the amount of energy needed to lift 1 pound about 9 inches. It takes 1000 joules to equal a Btu. It would take 2 million joules to make a pot of coffee.
Joule is named after an English physicist named James Prescott Joule who lived from 1818 to 1889. He discovered that heat is a type of energy.
Around the world, scientists measure energy in joules rather than Btu. It is much like people around the world using the metric system, metres and kilograms. Like in the metric system, you can have kilojoules: ‘kilo’ means 1000, therefore, 1000 joules = 1 kilojoule = 1 Btu.
Due to the problems associated with the use of fossil fuels, alternative sources of energy have become important and relevant in today’s world. These sources, such as the sun and wind, can never be exhausted and are therefore called renewable. Also known as non-conventional sources of energy, they cause less emission and are available locally. Their use can significantly reduce chemical, radioactive, and thermal pollution. They are viable sources of clean and limitless energy. Most of the renewable sources of energy are fairly non-polluting and considered clean. However, biomass is a major polluter indoors.
Renewable energy sources include the sun, wind, water, agricultural residue, fuelwood, and animal dung. Fossil fuels are non-renewable sources. Energy generated from the sun is known as solar energy. Hydel is the energy derived from water. Biomass – firewood, animal dung, and biodegradable waste from cities and crop residues – is a source of energy when it is burnt. Geothermal energy is derived from hot dry rocks, magma, hot water springs, natural geysers, etc. Ocean thermal is energy derived from waves and also from tidal waves.
Through the method of co-generation a cleaner and less polluting form of energy is being generated. Fuel cells are also being used as cleaner energy source. In India a number of initiatives have been taken. A good example is the model village of Ralegaon Siddhi.
Ralegaon Siddhi, a success story –
In 1975, when Anna Hazare, a retired army man, went back to his village in Ahmednagar district, Maharashtra, he found the village reeling under drought, poverty, debt, and unemployment. He decided to mobilize the people and, with the collective support of all the villagers, he began to introduce changes.
Today Ralegaon Siddhi is being taken as a role model for other villages by the Maharashtra government and by other states too. Massive tree plantation has been undertaken, and hills have been terraced to check erosion. Large canals with ridges on either side have been dug to retain rainwater. As a result, the water table in this area is now considerably higher and the wells and tube wells are never dry, making it possible to raise three crops a year where only one was possible before.
The village's biggest achievement is undoubtedly in the area of non-conventional energy. All the streets in the village are lit by solar lights, each with a separate panel. There are four large community biogas plants and one of them is fitted to the community toilet. There is a large windmill used for pumping water. A number of households have their own biogas plants. The village is self sufficient .
types of energy
The discovery of fire by man led to the possibility of burning wood for cooking and heating thereby using energy. For several thousand years human energy demands were met only by renewable energy sources—sun, biomass (wood, leaves, twigs), hydel (water) and wind power.
As early as 4000–3500 BC, the first sailing ships and windmills were developed harnessing wind energy. With the use of hydropower through water mills or irrigation systems, things began to move faster. Fuelwood and dung cakes are even today a major source of energy in rural India. Solar energy is used for drying and heating.
With the advent of the Industrial Revolution, the use of energy in the form of fossil fuels began growing as more and more industries were set up. This occurred in stages, from the exploitation of coal deposits to the exploitation of oil and natural gas fields. It has been only half a century since nuclear power began being used as an energy source. In the past century, it became evident that the consumption of non-renewable sources of energy had caused more environmental damage than any other human activity. Electricity generated from fossil fuels such as coal and crude oil has led to high concentrations of harmful gases in the atmosphere. This has in turn led to problems such as ozone depletion and global warming. Vehicular pollution is also a grave problem.
There has been an enormous increase in the demand for energy since the middle of the last century as a result of industrial development and population growth. World population grew 3.2 times between 1850 and 1970, per capita use of industrial energy increased about twentyfold, and total world use of industrial and traditional energy forms combined increased more than twelvefold.
ENERGY
Can you imagine life without lights, fans, cars, computers and television, or of fetching water from the well and river? This is what life would have been like had man not discovered the uses of energy – both renewable and nonrenewable sources.
What is energy ?
Energy lights our cities, powers our vehicles, and runs machinery in factories. It warms and cools our homes, cooks our food, plays our music, and gives us pictures on television.
Energy is defined as the ability or the capacity to do work.
We use energy to do work and make all movements. When we eat, our bodies transform the food into energy to do work. When we run or walk or do some work, we ‘burn’ energy in our bodies. Cars, planes, trolleys, boats, and machinery also transform energy into work. Work means moving or lifting something, warming or lighting something. There are many sources of energy that help to run the various machines invented by man.
What is energy ?
Energy lights our cities, powers our vehicles, and runs machinery in factories. It warms and cools our homes, cooks our food, plays our music, and gives us pictures on television.
Energy is defined as the ability or the capacity to do work.
We use energy to do work and make all movements. When we eat, our bodies transform the food into energy to do work. When we run or walk or do some work, we ‘burn’ energy in our bodies. Cars, planes, trolleys, boats, and machinery also transform energy into work. Work means moving or lifting something, warming or lighting something. There are many sources of energy that help to run the various machines invented by man.
Quiz time
Statement
A book falls off a table and free falls to the ground.
Answer with Explanation
Yes.
This is an example of work. There is a force (gravity) which acts on the book which causes it to be displaced in a downward direction (i.e., "fall").
A book falls off a table and free falls to the ground.
Answer with Explanation
Yes.
This is an example of work. There is a force (gravity) which acts on the book which causes it to be displaced in a downward direction (i.e., "fall").
Statement
A teacher applies a force to a wall and becomes exhausted.
Answer with Explanation
This is not an example of work. The wall is not displaced. A force must cause a displacement in order for work to be done.
A teacher applies a force to a wall and becomes exhausted.
Answer with Explanation
This is not an example of work. The wall is not displaced. A force must cause a displacement in order for work to be done.
work ......concept
When a force acts upon an object to cause a displacement of the object, it is said that work was done upon the object. There are three key ingredients to work - force, displacement, and cause. In order for a force to qualify as having done work on an object, there must be a displacement and the force must cause the displacement. There are several good examples of work which can be observed in everyday life - a horse pulling a plow through the field, a father pushing a grocery cart down the aisle of a grocery store, a freshman lifting a backpack full of books upon her shoulder, a weightlifter lifting a barbell above his head, an Olympian launching the shot-put, etc. In each case described here there is a force exerted upon an object to cause that object to be displaced.
Wednesday, 3 December 2008
Saturday, 29 November 2008
electricity
The three fundamental particles comprising most atoms are called protons, neutrons and electrons. Whilst the majority of atoms have a combination of protons, neutrons, and electrons, not all atoms have neutrons; an example is the protium isotope (1H1) of hydrogen (Hydrogen-1) which is the lightest and most common form of hydrogen which only has one proton and one electron. Atoms are far too small to be seen, but if we could look at one, it might appear something like this:
Even though each atom in a piece of material tends to hold together as a unit, there's actually a lot of empty space between the electrons and the cluster of protons and neutrons residing in the middle.
This crude model is that of the element carbon, with six protons, six neutrons, and six electrons. In any atom, the protons and neutrons are very tightly bound together, which is an important quality. The tightly-bound clump of protons and neutrons in the center of the atom is called the nucleus, and the number of protons in an atom's nucleus determines its elemental identity: change the number of protons in an atom's nucleus, and you change the type of atom that it is. In fact, if you could remove three protons from the nucleus of an atom of lead, you will have achieved the old alchemists' dream of producing an atom of gold! The tight binding of protons in the nucleus is responsible for the stable identity of chemical elements, and the failure of alchemists to achieve their dream.
Neutrons are much less influential on the chemical character and identity of an atom than protons, although they are just as hard to add to or remove from the nucleus, being so tightly bound. If neutrons are added or gained, the atom will still retain the same chemical identity, but its mass will change slightly and it may acquire strange nuclear properties such as radioactivity.
However, electrons have significantly more freedom to move around in an atom than either protons or neutrons. In fact, they can be knocked out of their respective positions (even leaving the atom entirely!) by far less energy than what it takes to dislodge particles in the nucleus. If this happens, the atom still retains its chemical identity, but an important imbalance occurs. Electrons and protons are unique in the fact that they are attracted to one another over a distance. It is this attraction over distance which causes the attraction between rubbed objects, where electrons are moved away from their original atoms to reside around atoms of another object.
Electrons tend to repel other electrons over a distance, as do protons with other protons. The only reason protons bind together in the nucleus of an atom is because of a much stronger force called the strong nuclear force which has effect only under very short distances. Because of this attraction/repulsion behavior between individual particles, electrons and protons are said to have opposite electric charges. That is, each electron has a negative charge, and each proton a positive charge. In equal numbers within an atom, they counteract each other's presence so that the net charge within the atom is zero. This is why the picture of a carbon atom had six electrons: to balance out the electric charge of the six protons in the nucleus. If electrons leave or extra electrons arrive, the atom's net electric charge will be imbalanced, leaving the atom "charged" as a whole, causing it to interact with charged particles and other charged atoms nearby. Neutrons are neither attracted to or repelled by electrons, protons, or even other neutrons, and are consequently categorized as having no charge at all.
The process of electrons arriving or leaving is exactly what happens when certain combinations of materials are rubbed together: electrons from the atoms of one material are forced by the rubbing to leave their respective atoms and transfer over to the atoms of the other material. In other words, electrons comprise the "fluid" hypothesized by Benjamin Franklin. The operational definition of a coulomb as the unit of electrical charge (in terms of force generated between point charges) was found to be equal to an excess or deficiency of about 6,250,000,000,000,000,000 electrons. Or, stated in reverse terms, one electron has a charge of about 0.00000000000000000016 coulombs. Being that one electron is the smallest known carrier of electric charge, this last figure of charge for the electron is defined as the elementary charge.
The result of an imbalance of this "fluid" (electrons) between objects is called static electricity. It is called "static" because the displaced electrons tend to remain stationary after being moved from one insulating material to another. In the case of wax and wool, it was determined through further experimentation that electrons in the wool actually transferred to the atoms in the wax, which is exactly opposite of Franklin's conjecture! In honor of Franklin's designation of the wax's charge being "negative" and the wool's charge being "positive," electrons are said to have a "negative" charging influence. Thus, an object whose atoms have received a surplus of electrons is said to be negatively charged, while an object whose atoms are lacking electrons is said to be positively charged, as confusing as these designations may seem. By the time the true nature of electric "fluid" was discovered, Franklin's nomenclature of electric charge was too well established to be easily changed, and so it remains to this day.
Michael Faraday proved (1832) that static electricity was the same as that produced by a battery or a generator. Static electricity is, for the most part, a nusiance. Black powder and smokeless powder have graphite added to prevent ignition due to static electricity. It causes damage to sensitive semiconductor circuitry. While is is possible to produce motors powered by high voltage and low current characteristic of static electricity, this is not economic. The few practical applications of static electricity include xerographic printing, the electrostatic air filter, and the high voltage Van de Graaff generator.
Even though each atom in a piece of material tends to hold together as a unit, there's actually a lot of empty space between the electrons and the cluster of protons and neutrons residing in the middle.
This crude model is that of the element carbon, with six protons, six neutrons, and six electrons. In any atom, the protons and neutrons are very tightly bound together, which is an important quality. The tightly-bound clump of protons and neutrons in the center of the atom is called the nucleus, and the number of protons in an atom's nucleus determines its elemental identity: change the number of protons in an atom's nucleus, and you change the type of atom that it is. In fact, if you could remove three protons from the nucleus of an atom of lead, you will have achieved the old alchemists' dream of producing an atom of gold! The tight binding of protons in the nucleus is responsible for the stable identity of chemical elements, and the failure of alchemists to achieve their dream.
Neutrons are much less influential on the chemical character and identity of an atom than protons, although they are just as hard to add to or remove from the nucleus, being so tightly bound. If neutrons are added or gained, the atom will still retain the same chemical identity, but its mass will change slightly and it may acquire strange nuclear properties such as radioactivity.
However, electrons have significantly more freedom to move around in an atom than either protons or neutrons. In fact, they can be knocked out of their respective positions (even leaving the atom entirely!) by far less energy than what it takes to dislodge particles in the nucleus. If this happens, the atom still retains its chemical identity, but an important imbalance occurs. Electrons and protons are unique in the fact that they are attracted to one another over a distance. It is this attraction over distance which causes the attraction between rubbed objects, where electrons are moved away from their original atoms to reside around atoms of another object.
Electrons tend to repel other electrons over a distance, as do protons with other protons. The only reason protons bind together in the nucleus of an atom is because of a much stronger force called the strong nuclear force which has effect only under very short distances. Because of this attraction/repulsion behavior between individual particles, electrons and protons are said to have opposite electric charges. That is, each electron has a negative charge, and each proton a positive charge. In equal numbers within an atom, they counteract each other's presence so that the net charge within the atom is zero. This is why the picture of a carbon atom had six electrons: to balance out the electric charge of the six protons in the nucleus. If electrons leave or extra electrons arrive, the atom's net electric charge will be imbalanced, leaving the atom "charged" as a whole, causing it to interact with charged particles and other charged atoms nearby. Neutrons are neither attracted to or repelled by electrons, protons, or even other neutrons, and are consequently categorized as having no charge at all.
The process of electrons arriving or leaving is exactly what happens when certain combinations of materials are rubbed together: electrons from the atoms of one material are forced by the rubbing to leave their respective atoms and transfer over to the atoms of the other material. In other words, electrons comprise the "fluid" hypothesized by Benjamin Franklin. The operational definition of a coulomb as the unit of electrical charge (in terms of force generated between point charges) was found to be equal to an excess or deficiency of about 6,250,000,000,000,000,000 electrons. Or, stated in reverse terms, one electron has a charge of about 0.00000000000000000016 coulombs. Being that one electron is the smallest known carrier of electric charge, this last figure of charge for the electron is defined as the elementary charge.
The result of an imbalance of this "fluid" (electrons) between objects is called static electricity. It is called "static" because the displaced electrons tend to remain stationary after being moved from one insulating material to another. In the case of wax and wool, it was determined through further experimentation that electrons in the wool actually transferred to the atoms in the wax, which is exactly opposite of Franklin's conjecture! In honor of Franklin's designation of the wax's charge being "negative" and the wool's charge being "positive," electrons are said to have a "negative" charging influence. Thus, an object whose atoms have received a surplus of electrons is said to be negatively charged, while an object whose atoms are lacking electrons is said to be positively charged, as confusing as these designations may seem. By the time the true nature of electric "fluid" was discovered, Franklin's nomenclature of electric charge was too well established to be easily changed, and so it remains to this day.
Michael Faraday proved (1832) that static electricity was the same as that produced by a battery or a generator. Static electricity is, for the most part, a nusiance. Black powder and smokeless powder have graphite added to prevent ignition due to static electricity. It causes damage to sensitive semiconductor circuitry. While is is possible to produce motors powered by high voltage and low current characteristic of static electricity, this is not economic. The few practical applications of static electricity include xerographic printing, the electrostatic air filter, and the high voltage Van de Graaff generator.
Static electricity
Glass and silk aren't the only materials known to behave like this. Anyone who has ever brushed up against a latex balloon only to find that it tries to stick to them has experienced this same phenomenon. Paraffin wax and wool cloth are another pair of materials early experimenters recognized as manifesting attractive forces after being rubbed together:
This phenomenon became even more interesting when it was discovered that identical materials, after having been rubbed with their respective cloths, always repelled each other:
It was also noted that when a piece of glass rubbed with silk was exposed to a piece of wax rubbed with wool, the two materials would attract one another:
Furthermore, it was found that any material demonstrating properties of attraction or repulsion after being rubbed could be classed into one of two distinct categories: attracted to glass and repelled by wax, or repelled by glass and attracted to wax. It was either one or the other: there were no materials found that would be attracted to or repelled by both glass and wax, or that reacted to one without reacting to the other.
More attention was directed toward the pieces of cloth used to do the rubbing. It was discovered that after rubbing two pieces of glass with two pieces of silk cloth, not only did the glass pieces repel each other, but so did the cloths. The same phenomenon held for the pieces of wool used to rub the wax:
Now, this was really strange to witness. After all, none of these objects were visibly altered by the rubbing, yet they definitely behaved differently than before they were rubbed. Whatever change took place to make these materials attract or repel one another was invisible.
Some experimenters speculated that invisible "fluids" were being transferred from one object to another during the process of rubbing, and that these "fluids" were able to effect a physical force over a distance. Charles Dufay was one the early experimenters who demonstrated that there were definitely two different types of changes wrought by rubbing certain pairs of objects together. The fact that there was more than one type of change manifested in these materials was evident by the fact that there were two types of forces produced: attraction and repulsion. The hypothetical fluid transfer became known as a charge.
One pioneering researcher, Benjamin Franklin, came to the conclusion that there was only one fluid exchanged between rubbed objects, and that the two different "charges" were nothing more than either an excess or a deficiency of that one fluid. After experimenting with wax and wool, Franklin suggested that the coarse wool removed some of this invisible fluid from the smooth wax, causing an excess of fluid on the wool and a deficiency of fluid on the wax. The resulting disparity in fluid content between the wool and wax would then cause an attractive force, as the fluid tried to regain its former balance between the two materials.
Postulating the existence of a single "fluid" that was either gained or lost through rubbing accounted best for the observed behavior: that all these materials fell neatly into one of two categories when rubbed, and most importantly, that the two active materials rubbed against each other always fell into opposing categories as evidenced by their invariable attraction to one another. In other words, there was never a time where two materials rubbed against each other both became either positive or negative.
Following Franklin's speculation of the wool rubbing something off of the wax, the type of charge that was associated with rubbed wax became known as "negative" (because it was supposed to have a deficiency of fluid) while the type of charge associated with the rubbing wool became known as "positive" (because it was supposed to have an excess of fluid). Little did he know that his innocent conjecture would cause much confusion for students of electricity in the future!
Precise measurements of electrical charge were carried out by the French physicist Charles Coulomb in the 1780's using a device called a torsional balance measuring the force generated between two electrically charged objects. The results of Coulomb's work led to the development of a unit of electrical charge named in his honor, the coulomb. If two "point" objects (hypothetical objects having no appreciable surface area) were equally charged to a measure of 1 coulomb, and placed 1 meter (approximately 1 yard) apart, they would generate a force of about 9 billion newtons (approximately 2 billion pounds), either attracting or repelling depending on the types of charges involved.
It was discovered much later that this "fluid" was actually composed of extremely small bits of matter called electrons, so named in honor of the ancient Greek word for amber: another material exhibiting charged properties when rubbed with cloth. Experimentation has since revealed that all objects are composed of extremely small "building-blocks" known as atoms, and that these atoms are in turn composed of smaller components known as particles. The three fundamental particles comprising most atoms are called protons, neutrons and electrons.
Now, this was really strange to witness. After all, none of these objects were visibly altered by the rubbing, yet they definitely behaved differently than before they were rubbed. Whatever change took place to make these materials attract or repel one another was invisible.
Some experimenters speculated that invisible "fluids" were being transferred from one object to another during the process of rubbing, and that these "fluids" were able to effect a physical force over a distance. Charles Dufay was one the early experimenters who demonstrated that there were definitely two different types of changes wrought by rubbing certain pairs of objects together. The fact that there was more than one type of change manifested in these materials was evident by the fact that there were two types of forces produced: attraction and repulsion. The hypothetical fluid transfer became known as a charge.
One pioneering researcher, Benjamin Franklin, came to the conclusion that there was only one fluid exchanged between rubbed objects, and that the two different "charges" were nothing more than either an excess or a deficiency of that one fluid. After experimenting with wax and wool, Franklin suggested that the coarse wool removed some of this invisible fluid from the smooth wax, causing an excess of fluid on the wool and a deficiency of fluid on the wax. The resulting disparity in fluid content between the wool and wax would then cause an attractive force, as the fluid tried to regain its former balance between the two materials.
Postulating the existence of a single "fluid" that was either gained or lost through rubbing accounted best for the observed behavior: that all these materials fell neatly into one of two categories when rubbed, and most importantly, that the two active materials rubbed against each other always fell into opposing categories as evidenced by their invariable attraction to one another. In other words, there was never a time where two materials rubbed against each other both became either positive or negative.
Following Franklin's speculation of the wool rubbing something off of the wax, the type of charge that was associated with rubbed wax became known as "negative" (because it was supposed to have a deficiency of fluid) while the type of charge associated with the rubbing wool became known as "positive" (because it was supposed to have an excess of fluid). Little did he know that his innocent conjecture would cause much confusion for students of electricity in the future!
Precise measurements of electrical charge were carried out by the French physicist Charles Coulomb in the 1780's using a device called a torsional balance measuring the force generated between two electrically charged objects. The results of Coulomb's work led to the development of a unit of electrical charge named in his honor, the coulomb. If two "point" objects (hypothetical objects having no appreciable surface area) were equally charged to a measure of 1 coulomb, and placed 1 meter (approximately 1 yard) apart, they would generate a force of about 9 billion newtons (approximately 2 billion pounds), either attracting or repelling depending on the types of charges involved.
It was discovered much later that this "fluid" was actually composed of extremely small bits of matter called electrons, so named in honor of the ancient Greek word for amber: another material exhibiting charged properties when rubbed with cloth. Experimentation has since revealed that all objects are composed of extremely small "building-blocks" known as atoms, and that these atoms are in turn composed of smaller components known as particles. The three fundamental particles comprising most atoms are called protons, neutrons and electrons.
Now, this was really strange to witness. After all, none of these objects were visibly altered by the rubbing, yet they definitely behaved differently than before they were rubbed. Whatever change took place to make these materials attract or repel one another was invisible.
Some experimenters speculated that invisible "fluids" were being transferred from one object to another during the process of rubbing, and that these "fluids" were able to effect a physical force over a distance. Charles Dufay was one the early experimenters who demonstrated that there were definitely two different types of changes wrought by rubbing certain pairs of objects together. The fact that there was more than one type of change manifested in these materials was evident by the fact that there were two types of forces produced: attraction and repulsion. The hypothetical fluid transfer became known as a charge.
One pioneering researcher, Benjamin Franklin, came to the conclusion that there was only one fluid exchanged between rubbed objects, and that the two different "charges" were nothing more than either an excess or a deficiency of that one fluid. After experimenting with wax and wool, Franklin suggested that the coarse wool removed some of this invisible fluid from the smooth wax, causing an excess of fluid on the wool and a deficiency of fluid on the wax. The resulting disparity in fluid content between the wool and wax would then cause an attractive force, as the fluid tried to regain its former balance between the two materials.
Postulating the existence of a single "fluid" that was either gained or lost through rubbing accounted best for the observed behavior: that all these materials fell neatly into one of two categories when rubbed, and most importantly, that the two active materials rubbed against each other always fell into opposing categories as evidenced by their invariable attraction to one another. In other words, there was never a time where two materials rubbed against each other both became either positive or negative.
Following Franklin's speculation of the wool rubbing something off of the wax, the type of charge that was associated with rubbed wax became known as "negative" (because it was supposed to have a deficiency of fluid) while the type of charge associated with the rubbing wool became known as "positive" (because it was supposed to have an excess of fluid). Little did he know that his innocent conjecture would cause much confusion for students of electricity in the future!
Precise measurements of electrical charge were carried out by the French physicist Charles Coulomb in the 1780's using a device called a torsional balance measuring the force generated between two electrically charged objects. The results of Coulomb's work led to the development of a unit of electrical charge named in his honor, the coulomb. If two "point" objects (hypothetical objects having no appreciable surface area) were equally charged to a measure of 1 coulomb, and placed 1 meter (approximately 1 yard) apart, they would generate a force of about 9 billion newtons (approximately 2 billion pounds), either attracting or repelling depending on the types of charges involved.
It was discovered much later that this "fluid" was actually composed of extremely small bits of matter called electrons, so named in honor of the ancient Greek word for amber: another material exhibiting charged properties when rubbed with cloth. Experimentation has since revealed that all objects are composed of extremely small "building-blocks" known as atoms, and that these atoms are in turn composed of smaller components known as particles. The three fundamental particles comprising most atoms are called protons, neutrons and electrons.
This phenomenon became even more interesting when it was discovered that identical materials, after having been rubbed with their respective cloths, always repelled each other:
It was also noted that when a piece of glass rubbed with silk was exposed to a piece of wax rubbed with wool, the two materials would attract one another:
Furthermore, it was found that any material demonstrating properties of attraction or repulsion after being rubbed could be classed into one of two distinct categories: attracted to glass and repelled by wax, or repelled by glass and attracted to wax. It was either one or the other: there were no materials found that would be attracted to or repelled by both glass and wax, or that reacted to one without reacting to the other.
More attention was directed toward the pieces of cloth used to do the rubbing. It was discovered that after rubbing two pieces of glass with two pieces of silk cloth, not only did the glass pieces repel each other, but so did the cloths. The same phenomenon held for the pieces of wool used to rub the wax:
Now, this was really strange to witness. After all, none of these objects were visibly altered by the rubbing, yet they definitely behaved differently than before they were rubbed. Whatever change took place to make these materials attract or repel one another was invisible.
Some experimenters speculated that invisible "fluids" were being transferred from one object to another during the process of rubbing, and that these "fluids" were able to effect a physical force over a distance. Charles Dufay was one the early experimenters who demonstrated that there were definitely two different types of changes wrought by rubbing certain pairs of objects together. The fact that there was more than one type of change manifested in these materials was evident by the fact that there were two types of forces produced: attraction and repulsion. The hypothetical fluid transfer became known as a charge.
One pioneering researcher, Benjamin Franklin, came to the conclusion that there was only one fluid exchanged between rubbed objects, and that the two different "charges" were nothing more than either an excess or a deficiency of that one fluid. After experimenting with wax and wool, Franklin suggested that the coarse wool removed some of this invisible fluid from the smooth wax, causing an excess of fluid on the wool and a deficiency of fluid on the wax. The resulting disparity in fluid content between the wool and wax would then cause an attractive force, as the fluid tried to regain its former balance between the two materials.
Postulating the existence of a single "fluid" that was either gained or lost through rubbing accounted best for the observed behavior: that all these materials fell neatly into one of two categories when rubbed, and most importantly, that the two active materials rubbed against each other always fell into opposing categories as evidenced by their invariable attraction to one another. In other words, there was never a time where two materials rubbed against each other both became either positive or negative.
Following Franklin's speculation of the wool rubbing something off of the wax, the type of charge that was associated with rubbed wax became known as "negative" (because it was supposed to have a deficiency of fluid) while the type of charge associated with the rubbing wool became known as "positive" (because it was supposed to have an excess of fluid). Little did he know that his innocent conjecture would cause much confusion for students of electricity in the future!
Precise measurements of electrical charge were carried out by the French physicist Charles Coulomb in the 1780's using a device called a torsional balance measuring the force generated between two electrically charged objects. The results of Coulomb's work led to the development of a unit of electrical charge named in his honor, the coulomb. If two "point" objects (hypothetical objects having no appreciable surface area) were equally charged to a measure of 1 coulomb, and placed 1 meter (approximately 1 yard) apart, they would generate a force of about 9 billion newtons (approximately 2 billion pounds), either attracting or repelling depending on the types of charges involved.
It was discovered much later that this "fluid" was actually composed of extremely small bits of matter called electrons, so named in honor of the ancient Greek word for amber: another material exhibiting charged properties when rubbed with cloth. Experimentation has since revealed that all objects are composed of extremely small "building-blocks" known as atoms, and that these atoms are in turn composed of smaller components known as particles. The three fundamental particles comprising most atoms are called protons, neutrons and electrons.
Now, this was really strange to witness. After all, none of these objects were visibly altered by the rubbing, yet they definitely behaved differently than before they were rubbed. Whatever change took place to make these materials attract or repel one another was invisible.
Some experimenters speculated that invisible "fluids" were being transferred from one object to another during the process of rubbing, and that these "fluids" were able to effect a physical force over a distance. Charles Dufay was one the early experimenters who demonstrated that there were definitely two different types of changes wrought by rubbing certain pairs of objects together. The fact that there was more than one type of change manifested in these materials was evident by the fact that there were two types of forces produced: attraction and repulsion. The hypothetical fluid transfer became known as a charge.
One pioneering researcher, Benjamin Franklin, came to the conclusion that there was only one fluid exchanged between rubbed objects, and that the two different "charges" were nothing more than either an excess or a deficiency of that one fluid. After experimenting with wax and wool, Franklin suggested that the coarse wool removed some of this invisible fluid from the smooth wax, causing an excess of fluid on the wool and a deficiency of fluid on the wax. The resulting disparity in fluid content between the wool and wax would then cause an attractive force, as the fluid tried to regain its former balance between the two materials.
Postulating the existence of a single "fluid" that was either gained or lost through rubbing accounted best for the observed behavior: that all these materials fell neatly into one of two categories when rubbed, and most importantly, that the two active materials rubbed against each other always fell into opposing categories as evidenced by their invariable attraction to one another. In other words, there was never a time where two materials rubbed against each other both became either positive or negative.
Following Franklin's speculation of the wool rubbing something off of the wax, the type of charge that was associated with rubbed wax became known as "negative" (because it was supposed to have a deficiency of fluid) while the type of charge associated with the rubbing wool became known as "positive" (because it was supposed to have an excess of fluid). Little did he know that his innocent conjecture would cause much confusion for students of electricity in the future!
Precise measurements of electrical charge were carried out by the French physicist Charles Coulomb in the 1780's using a device called a torsional balance measuring the force generated between two electrically charged objects. The results of Coulomb's work led to the development of a unit of electrical charge named in his honor, the coulomb. If two "point" objects (hypothetical objects having no appreciable surface area) were equally charged to a measure of 1 coulomb, and placed 1 meter (approximately 1 yard) apart, they would generate a force of about 9 billion newtons (approximately 2 billion pounds), either attracting or repelling depending on the types of charges involved.
It was discovered much later that this "fluid" was actually composed of extremely small bits of matter called electrons, so named in honor of the ancient Greek word for amber: another material exhibiting charged properties when rubbed with cloth. Experimentation has since revealed that all objects are composed of extremely small "building-blocks" known as atoms, and that these atoms are in turn composed of smaller components known as particles. The three fundamental particles comprising most atoms are called protons, neutrons and electrons.
Now, this was really strange to witness. After all, none of these objects were visibly altered by the rubbing, yet they definitely behaved differently than before they were rubbed. Whatever change took place to make these materials attract or repel one another was invisible.
Some experimenters speculated that invisible "fluids" were being transferred from one object to another during the process of rubbing, and that these "fluids" were able to effect a physical force over a distance. Charles Dufay was one the early experimenters who demonstrated that there were definitely two different types of changes wrought by rubbing certain pairs of objects together. The fact that there was more than one type of change manifested in these materials was evident by the fact that there were two types of forces produced: attraction and repulsion. The hypothetical fluid transfer became known as a charge.
One pioneering researcher, Benjamin Franklin, came to the conclusion that there was only one fluid exchanged between rubbed objects, and that the two different "charges" were nothing more than either an excess or a deficiency of that one fluid. After experimenting with wax and wool, Franklin suggested that the coarse wool removed some of this invisible fluid from the smooth wax, causing an excess of fluid on the wool and a deficiency of fluid on the wax. The resulting disparity in fluid content between the wool and wax would then cause an attractive force, as the fluid tried to regain its former balance between the two materials.
Postulating the existence of a single "fluid" that was either gained or lost through rubbing accounted best for the observed behavior: that all these materials fell neatly into one of two categories when rubbed, and most importantly, that the two active materials rubbed against each other always fell into opposing categories as evidenced by their invariable attraction to one another. In other words, there was never a time where two materials rubbed against each other both became either positive or negative.
Following Franklin's speculation of the wool rubbing something off of the wax, the type of charge that was associated with rubbed wax became known as "negative" (because it was supposed to have a deficiency of fluid) while the type of charge associated with the rubbing wool became known as "positive" (because it was supposed to have an excess of fluid). Little did he know that his innocent conjecture would cause much confusion for students of electricity in the future!
Precise measurements of electrical charge were carried out by the French physicist Charles Coulomb in the 1780's using a device called a torsional balance measuring the force generated between two electrically charged objects. The results of Coulomb's work led to the development of a unit of electrical charge named in his honor, the coulomb. If two "point" objects (hypothetical objects having no appreciable surface area) were equally charged to a measure of 1 coulomb, and placed 1 meter (approximately 1 yard) apart, they would generate a force of about 9 billion newtons (approximately 2 billion pounds), either attracting or repelling depending on the types of charges involved.
It was discovered much later that this "fluid" was actually composed of extremely small bits of matter called electrons, so named in honor of the ancient Greek word for amber: another material exhibiting charged properties when rubbed with cloth. Experimentation has since revealed that all objects are composed of extremely small "building-blocks" known as atoms, and that these atoms are in turn composed of smaller components known as particles. The three fundamental particles comprising most atoms are called protons, neutrons and electrons.
Static electricity
It was discovered centuries ago that certain types of materials would mysteriously attract one another after being rubbed together. For example: after rubbing a piece of silk against a piece of glass, the silk and glass would tend to stick together. Indeed, there was an attractive force that could be demonstrated even when the two materials were separated:
Electric circuits
You might have been wondering how electrons can continuously flow in a uniform direction through wires without the benefit of these hypothetical electron Sources and Destinations. In order for the Source-and-Destination scheme to work, both would have to have an infinite capacity for electrons in order to sustain a continuous flow! Using the marble-and-tube analogy, the marble source and marble destination buckets would have to be infinitely large to contain enough marble capacity for a "flow" of marbles to be sustained.
The answer to this paradox is found in the concept of a circuit: a never-ending looped pathway for electrons. If we take a wire, or many wires joined end-to-end, and loop it around so that it forms a continuous pathway, we have the means to support a uniform flow of electrons without having to resort to infinite Sources and Destinations:
Each electron advancing clockwise in this circuit pushes on the one in front of it, which pushes on the one in front of it, and so on, and so on, just like a hula-hoop filled with marbles. Now, we have the capability of supporting a continuous flow of electrons indefinitely without the need for infinite electron supplies and dumps. All we need to maintain this flow is a continuous means of motivation for those electrons, which we'll address in the next section of this chapter.
It must be realized that continuity is just as important in a circuit as it is in a straight piece of wire. Just as in the example with the straight piece of wire between the electron Source and Destination, any break in this circuit will prevent electrons from flowing through it:
An important principle to realize here is that it doesn't matter where the break occurs. Any discontinuity in the circuit will prevent electron flow throughout the entire circuit. Unless there is a continuous, unbroken loop of conductive material for electrons to flow through, a sustained flow simply cannot be maintained.
The answer to this paradox is found in the concept of a circuit: a never-ending looped pathway for electrons. If we take a wire, or many wires joined end-to-end, and loop it around so that it forms a continuous pathway, we have the means to support a uniform flow of electrons without having to resort to infinite Sources and Destinations:
Each electron advancing clockwise in this circuit pushes on the one in front of it, which pushes on the one in front of it, and so on, and so on, just like a hula-hoop filled with marbles. Now, we have the capability of supporting a continuous flow of electrons indefinitely without the need for infinite electron supplies and dumps. All we need to maintain this flow is a continuous means of motivation for those electrons, which we'll address in the next section of this chapter.
It must be realized that continuity is just as important in a circuit as it is in a straight piece of wire. Just as in the example with the straight piece of wire between the electron Source and Destination, any break in this circuit will prevent electrons from flowing through it:
An important principle to realize here is that it doesn't matter where the break occurs. Any discontinuity in the circuit will prevent electron flow throughout the entire circuit. Unless there is a continuous, unbroken loop of conductive material for electrons to flow through, a sustained flow simply cannot be maintained.
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Wednesday, 26 November 2008
Structure of an electric torch
Why did the designer choose this particular combination of materials? The metal parts of the torch must conduct electric current if the torch is to function, but they must also be able to stand up to physical forces. The spring holding the cells in place should stay springy, while the parts of the switch must make good electrical contact and be undamaged by repeated use.
The lamp and reflector make up an optical system, often intended to focus the light into a narrow beam. The plastic casing is an electrical insulator. Its shape and colour are important in making the torch attractive and easy to handle and use.
A torch is a simple product, but a lot of thought is needed to make sure that it will work well. Can you think of other things which the designer should consider?
A different way of describing the torch is by using a circuit diagram in which the parts of the torch are represented by symbols:
There are two electric cells ('batteries'), a switch and a lamp (the torch bulb). The lines in the diagram represent the metal conductors which connect the system together.
A circuit is a closed conducting path. In the torch, closing the switch completes the circuit and allows current to flow. Torches sometimes fail when the metal parts of the switch do no make proper contact, or when the lamp filament is 'blown'. In either case, the circuit is incomplete.
Current
An electric current is a flow of charged particles. Inside a copper wire, current is carried by small negatively-charged particles, called electrons. The electrons drift in random directions until a current starts to flow. When this happens, electrons start to move in the same direction. The size of the current depends on the number of electrons passing per second.
Current is represented by the symbol I, and is measured in amperes, or 'amps', A. One ampere is a flow of 6.24 x 1018 electrons per second past any point in a wire. That's more than six million million million electrons passing per second. This is a lot of electrons, but electrons are very small and each carries a very tiny charge.
In electronic circuits, currents are most often measured in milliamps, mA, that is, thousandths of an amp.
how batteries work
A battery is essentially a can full of chemicals that produce electrons. Chemical reactions that produce electrons are called electrochemical reactions. In this article, you'll learn all about batteries -- the basic concept at work, the actual chemistry going on inside a battery, rechargeable versions, what the future holds for batteries and possible power sources that could replace them.
If you look at any battery, you'll notice that it has two terminals. One terminal is marked (+), or positive, while the other is marked (-), or negative. In an AA, C or D cell (normal flashlight batteries), the ends of the battery are the terminals. In a large car battery, there are two heavy lead posts that act as the terminals.
Electrons collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal as fast as they can (and wear out the battery very quickly -- this also tends to be dangerous, especially with large batteries, so it is not something you want to be doing). Normally, you connect some type of load to the battery using the wire.
If you look at any battery, you'll notice that it has two terminals. One terminal is marked (+), or positive, while the other is marked (-), or negative. In an AA, C or D cell (normal flashlight batteries), the ends of the battery are the terminals. In a large car battery, there are two heavy lead posts that act as the terminals.
Electrons collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal as fast as they can (and wear out the battery very quickly -- this also tends to be dangerous, especially with large batteries, so it is not something you want to be doing). Normally, you connect some type of load to the battery using the wire.
Saturday, 4 October 2008
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Thursday, 2 October 2008
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Wednesday, 24 September 2008
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